Patient Care System

The present invention relates to a system and method for patient identification and clinical care verification. More particularly, the present invention relates to a patient identification system and method providing for accurate identification of a patient and for relating items to a patient and ensuring that patient specific items do properly correspond to a patient, thereby providing for accurate medical treatment, billing and inventory and cost control.

Medical institutions are faced with a competitive environment which they must improve profitability and yet simultaneously improve patient care. There are several factors which contribute to the ever increasing costs of hospital care. For example, there is an ever increasing amount of paperwork required by nurses, pharmacists and laboratory personnel. In addition, inaccurate recording of drugs, supplies and tests involved in patient care results in decreasing revenues by a failure to fully capture billing opportunities of these actual costs. Inadequate management also results in a failure to provide an accurate report of all costs involved in treating a particular illness.

In most hospitals and clinical laboratories, a bracelet device containing the patient's name is permanently affixed around the arm of an incoming patient in order to identify the patient during his or her entire stay. Despite this, numerous situations arise which results in errors in patient identification.

For example, when a blood sample is taken from a patient, the blood sample must be identified by the name on the patient's bracelet. In transferring the patient's name a nurse or technician may miscopy the name or may rely on memory or a different data source, rather than actually reading the patient's bracelet.

Moreover, the lack of accurate and rapid transfer of patient information often reduces the accuracy and/or effectiveness of drug administration and patient care, thereby increasing the duration of hospital stay.

In addition, hospitals and other institutions must continuously strive to provide quality patient care. Medical errors, where the wrong patient receives the wrong drug at the wrong time, in the wrong dosage or even the wrong surgery, are a significant problem for all health care facilities. Many prescription drugs and injections are identified merely by slips of paper on which the patient's name and identification number have been handwritten by a nurse or technician who is to administer the treatment. For a variety of reasons, such as the transfer of patients to different beds and errors in marking the slips of paper, a patient may be given an incorrect treatment.

Further, as health care facilities continue to decrease the number of staff personnel as a cost cutting measure, the possibility of personnel errors will most likely increase.

The present invention offers a system which solves or at least reduces the impact of the above-identified problems and other problems associated with health care facilities.

The present invention relates to a system for patient identification comprising a programmed general purpose computer means for processing and storing patient data. Input devices are operatively interconnected with the computer means for input of patient data into the computer. A first identification device is adapted for attachment to a patient for identification of the patient and includes a patient-unique code. A plurality of second identification devices are provided for relating various items to a particular patient, the second identification devices including a patient-unique code different from that of the first identification device so as to differentiate first and second identification devices from each other. The input means includes a portable terminal having a bar code reader for scanning the code of the first identification device to identify the patient and for scanning the code of the second identification devices. The portable terminal further includes an RF transceiver for transmitting bar code data representative of the codes scanned by the bar code reader and for receiving data. Modem means interconnected to the computer by, in part, a telephone line is adapted for receipt of the RF signal and for transmitting data to the computer via the telephone line. A plurality of terminals are located remotely from the computer at various locations and are interconnected to the computer at least in part by telephone lines for input and output of patient data to and from the computer.

One object of the present invention is to provide a patient identification system for identifying patients.

Yet another object of the present invention is to provide a patient identification system for relating items to a patient.

Another object of the present invention is to provide for identification of certain items which are patient specific, such as drugs, blood test samples, IV's, surgical procedures, etc. and to provide a cross-check to ensure that the identified item properly corresponds to an identified patient. The present invention not only provides this verification function, but provides a full audit trail of all transactions concerning patient therapy, the audit trail including staff ID, date, time flagging or marking, etc.

Still another object of the present invention is to provide for recall and review of patient information in various presentation formats at display terminals and at printer devices.

Yet another object of one embodiment of the present invention is to provide for limited access to the system and provide for identification of the person and/or department entering data respecting a patient and/or items.

An object of one embodiment of the present invention is to provide automatic billing and/or inventory control. Cost capture is provided at consumption point which is not possible with current systems.

Yet another object of one embodiment of the present invention is to provide improved communications using existing transmission paths. In particular, one embodiment uses existing telephone wiring. This eliminates the substantial cost of wiring installation required by other conventional means.

It is an object of the present invention to provide more reliable and safe treatment of patients.

It is an object of one embodiment of the present invention to provide an alert if a particular drug administration is overdue and/or improper. In one embodiment, the overdue drug alert occurs both at a nurses'terminal and at a portable bar code reading device when the nurse scans her identification bar code.

It is yet another object of the present invention to provide for the coordination and collection of data.

It is an object of one embodiment of the present invention to provide a bed-side electronic patient file for recording and recall/review of previous vital signs, drugs administered, etc.

It is an object of one embodiment of the present invention to provide for electronic generation of a medical administration record (MAR), nurses'assignment sheets, graphic presentations of vital signs versus drugs, etc. In addition, the present invention provides for an automatic source of administrative reports required by industry, thus saving staff time for clinical therapy instead of paperwork.

It is an object of one embodiment of the present invention to utilize a radio frequency bar code reader device with liquid crystal display and key pad for input to a computer system of patient identification information and item identification information so as to enable a correlation thereof. Moreover, the bar code reader device includes memory files for maintaining a record for recall and review of patient vital signs and the times PRN or other controlled drugs were administered for pain or the like.

It is an object of yet another embodiment of the present invention to provide an apparatus in each patient's room for automatically providing the bar code reader device with a unique address whenever interconnected thereto, whereby bar code reader devices can be interchanged between rooms.

It is an object of one embodiment of the present invention to provide a relatively inexpensive system which makes substantial use of existing wiring and existing technology. In particular, one embodiment of the present invention uses data over voice (DOV) transmission on existing telephone lines.

Additional objects of yet other embodiments of the present invention are to provide a system which is very easy to use; will reduce the amount of administrative paperwork such as charting and will decrease the amount of time hospital staff spend charting their activities.

Still another object of one embodiment of the present invention is to monitor a nurse's time with the patient and maintain a chronology of patient events such as when a patient is moved to another room, drugs are administered, a patient has lab tests conducted, a patient checks out of the hospital, etc. whereby a time audit can be performed on the hospital's patient activities.

It is an object of yet another embodiment to provide for narcotics inventory control.

Yet another objective of one embodiment of the present invention is to provide a data base management function.

Still another objective of one embodiment of the present invention is to provide a system and method for determining the identification and location of personnel including patients and staff members, and miscellaneous items. For example, in the case of a patient, radio frequency (RF) transmitter means is worn on the body of the patient for transmitting an RF signal including unique patient identifier information. A plurality of spaced apart RF receiver means is provided for receiving the RF signal transmitted from the RF transmitter means. The RF receiver means includes fixed position RF receiver means and portable RF receiver means, contained in portable handheld patient terminals, the portable handheld patient terminals including RF transmitter means for transmitting an RF signal. The RF receiver means includes interface means for retransmitting the unique patient identifier information over electrical wiring interconnecting the RF receiver means to central computer means. The central computer means receiver the unique patient identifier information transmitted by the RF receiver means and including program means for determining patient location based on the unique patient identifier information received. A plurality of terminal means are interconnected to the central computer means for displaying the patient location upon inquiry by a user. This embodiment is particularly suited for health care institutions and more particularly nursing homes and mental institutions wherein the patients are very ambulatory and are not always cognizant of their actions.

It is an objective of yet another embodiment of the invention to provide a programmable, addressable RF transmitter to be fitted on to a disposable bracelet being worn by a patient. The RF transmitter, if its supporting electronics, and power supply are encapsulated within a media allowing for sterilization and cleaning so the RF transmitter can be used. The RF transmitter is reprogrammable such that it can be reused and programmed to transmit unique patient identifier information. The power supply is a battery with a substantially long life thereby enabling the RF transmitter to be used a number of times.

In yet another embodiment of the present invention, fixed position and portable RF receiver units are utilized. The fixed position RF receiver units are located at predetermined locations throughout the health care facility. The portable RF receiver units are mounted in portable handheld patient terminals which also include an RF transmitter for retransmission of the RF signal received from the patient worn transmitter to a fixed position RF receiver unit.

Another objective of one embodiment of the present invention is to provide fixed position RF receiver units which are hardwired to a central computer system by existing telephone wiring or twisted pair wiring and includes data over voice (DOV) modems for transmission of the unique patient identifier information over the telephone wire or RS232 interface means for transmission on the twisted pair wiring. A central computer system will be programmed to determine a patient's location based on the information received, and will display the information when so requested by a user at a terminal interconnected to the computer system.

Yet another object of the present invention is the provision of a portable handheld terminal providing wireless communication by use of an electromagnetic transceiver to a base station transceiver unit. The base station being interconnected to a host central computer system so as to provide real time or near real time communication system so as to provide real time or near real time communication between the portable handheld terminal and the host central computer system.

Still another object of the present invention is to provide a portable handheld patient terminal including optical bar code reader which is easy to hold during use. The portable handheld patient terminal includes a housing having first and second spaced apart, opposing major surfaces extending generally along a longitudinal axis of the housing between first and second end portions of the housing. Keyboard means is disposed on the first opposing surface for entering data. Display means is disposed on the first opposing surface for displaying data. Optical sensor means is disposed approximate the first end portion of the housing for sensing bar code indicia. Control means as contained in the housing and operatively interconnected to the keyboard means, display means, and optical sensor means for controlling the operation of the keyboard means, the display means, and the optical sensor means. Elongated handle means is interconnected to the housing and extends longitudinally along the second surface, the elongated handle means being spaced from the second surface along a portion thereof, whereby the handle means can be grasped by a user of the portable handheld patient terminal.

Yet another objective of the present invention is to provide a portable handheld patient terminal with a bar code reader which is self-scanning. A binary imaging sensor is provided which enables the bar code reader to self-scan the bar code indicia in both the X and Y directions. The bar code reader does not have to be moved relative to the bar code in order to read the bar code indicia. The user simply positions the binary imaging sensor over the bar code to be read and activates the sensor which takes a digital "picture" of the bar code. The digital "picture" is then processed by appropriate digital processing techniques. In addition, contact between the bar code reader and the bar code is not required. The present invention is particularly useful for reading bar codes on curved surfaces as well as flat surfaces. In addition, a bar code reader of the portable handheld patient terminal of the present invention can be used to read characters as well as bar codes.

One object of the present invention is to provide a portable handheld patient terminal providing the main data collection component of the patient identification system. In a hospital setting, it is ideally located in every patient room along with a base unit. In long term health care facilities such as nursing homes and mental health care facilities, the portable handheld patient terminal is kept at a nursing station and then carried with the nurse or other staff member as they make their rounds administering medications, taking vital signs, etc. In this particular application, the portable handheld patient terminal will have additional memory to allow storage of data relating to several patients. The data is then subsequently transmitted via an RF data communication link provided by a conveniently located base station having a transceiver function and thence from the base station over telephone wires by data over voice (DOV) techniques to a central computer system. The portable handheld patient terminal provides a means of data entry by means of a bar code reader, keypad, and a port for connection to an external vital signs measurement system. Communications is a radio frequency (RF) linked to the base unit or a direct link to a nurses terminal via a communications port. Interaction with the user is provided by liquid crystal display (LCD), a keypad, an audio alarm, and light emitting diode (LED) indicators. The portable handheld patient terminal is preferably operated by a rechargeable battery. The base unit will provide communications between the portable handheld patient terminal via the RF link and the central computer system via a telephone link using data over voice (DOV) technology or a twisted pair wire link using existing pairs of wires or newly installed wire. In addition, the base unit might also utilize the existing AC wiring for power line carrier (PLC) communication. The base unit will include a means of communications through a port to the portable handheld patient terminal when the terminal is inserted into the base. Also included is a battery charger circuit for the portable hand-held patient terminal when it is not in use, such that the rechargeable battery supply can be recharged. The base unit is ideally stationary such as being mounted on a wall and holds the portable handheld patient terminal when not in use.

The present invention, in addition to the above features and others, provides the following advantages over existing system, (1) patient identification, (2) cost capture, (3) reduction in nursing and administrative time, and (4) immediate data capture and positive identification and verification of all therapy provided to the patient.

Another advantage of the present invention is the provision of a communications protocol which assures a quick response to user entries and requests at the patient terminal. In one embodiment, the base unit provides an acknowledgement to the patient terminal upon successful receipt of a message from the patient terminal before transmitting the message on to the central computer system. Moreover, the present invention provides for accurate transmission of information which is critical in the hospital care setting.

Another advantage of one embodiment of the present invention is the provision of a flat panel display monitor which can be adjustably positioned relative to its housing in any one of a number of positions so as to allow viewing of the monitor from varying locations within a room.

Yet another embodiment of the present invention includes a bar code holder apparatus for retaining a bar code label on the wrist of a patient so as to facilitate accurate scanning of the bar code indicia.

Still another embodiment of the present invention includes a terminal support unit (TSU) which enables a plurality of printers and other devices to share a common telephone line in communicating with the central computer system.

These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects attained by its use, reference should be had to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.

Continuation-in-part application, Ser. No. 862,278, filed May 12, 1986 adds FIGS. 21-35 to FIGS. 1-20 of the parent application, while the present continuation-in-part application adds FIGS. 36-51.

In the drawings, in which like reference numerals and letters indicate corresponding parts throughout the several views,

FIG. 1 is a block diagram of an embodiment of a patient identification system in accordance with the principles of the present invention;

FIG. 2 is a diagrammatic view of a drug vial with an item bar code identifier thereon;

FIG. 3 is a diagrammatic view of a patient identification bracelet with a patient identifier bar code thereon;

FIG. 4 is a diagrammatic view of a sheet of labels with patient identification bar code identifiers thereon;

FIG. 5 is a block diagram of an embodiment of the RF/DOV modem illustrated in FIG. 1;

FIG. 6 is a block diagram of an alternate embodiment of a patient identification system in accordance with the principles of the present invention;

FIG. 7 is a block diagram of an embodiment of the twisted pair multiplexer illustrated in FIG. 5;

FIG. 8 is a block diagram of an embodiment of the RF/PLC modem illustrated in FIG. 5;

FIG. 9 is a block diagram of an embodiment of the PLC modem illustrated in FIG. 5;

FIG. 10 is a block diagram of an embodiment of a portable bar code reader device in accordance with the principles of the present invention;

FIG. 11 is a perspective view of an embodiment of a portable bar code reading device in accordance with the principles of the present invention;

FIG. 12 is a perspective view of the embodiment of the bar code reading device illustrated in FIG. 10 with the bar code reading device mounted in a wall-mounted rechargable housing unit;

FIG. 13 is a block diagram of an embodiment of microcomputer architecture which might be utilized in accordance with the principles of the present invention;

FIG. 14 is a block diagram of an embodiment of a multi-user software operating system which might be utilized in accordance with the principles of the present invention;

FIG. 15 is a block diagram illustrating a possible arrangement of computer system input/output devices in accordance with the principles of the present invention;

FIG. 16 is a diagrammatic illustration of an embodiment of a patient information data file;

FIG. 17 is a diagrammatic illustration of an embodiment of a patient/drug data file;

FIG. 18 is a diagrammatic illustration of an embodiment of an inventory data file;

FIG. 19 is a diagrammatic illustration of an embodiment of a patient/item data file;

FIG. 20 is a diagrammatic illustration of an embodiment of a patient/lab test data file;

FIG. 21 is a block diagram of an alternate embodiment of the present invention including a patient identification and location system;

FIG. 22 is a block diagram of an embodiment of an RF transmitter unit including RF transmitter, control circuitry, and power supply sealed in a protective media;

FIG. 23 is a block diagram of an embodiment of an RF receiver unit;

FIG. 24 is a functional flow diagram of an embodiment of a patient identification and location method in accordance with the principles of the present invention;

FIG. 25 is a block diagram of an embodiment of a portable handheld patient terminal in accordance with the principles of the present invention;

FIG. 26 is a perspective view of an alternate embodiment of a portable handheld patient terminal including optical bar code reader;

FIG. 27 is a side elevational view of the portable handheld patient terminal shown in FIG. 26;

FIG. 28 is a back end elevational view of the portable handheld patient terminal shown in FIG. 26;

FIG. 29 is a block diagram of an embodiment of a portable handheld patient terminal shown in FIG. 26;

FIG. 30 is a perspective view of the portable handheld patient terminal shown in FIG. 26 mounted in a base station;

FIG. 31 is a side view of the base station and its respective portable handheld patient terminal mounted thereon;

FIG. 32 is a block diagram of one embodiment of the base station;

FIG. 33 is a block diagram of one embodiment illustrating use by the recharging circuitry of a power supply temperature sensor;

FIG. 34 is a block diagram of one embodiment of the recharging procedure;

FIG. 35 is an embodiment of a keyboard arrangement of the portable handheld patient terminal;

FIG. 36 is a perspective view of an embodiment of a bar code holder apparatus attached to a patient's identification bracelet, a bar code label being contained therein;

FIG. 37 is an enlarged perspective view of the bar code holder apparatus shown in FIG. 36 prior to attachment to a patient's identification bracelet and prior to insertion of a bar label into a pocket of the bar code holder apparatus;

FIG. 38 is an enlarged sectional view of the bar code holder apparatus shown in FIG. 36;

FIG. 39 is a block diagram of an embodiment of a terminal support unit (TSU);

FIG. 40 is a block diagram of the TSU shown in FIG. 39 illustrating the TSU character and block/buffer transmission features of the TSU;

FIG. 41 is a block diagram of an embodiment of a bus structure of the TSU shown in FIG. 39;

FIG. 42 is a perspective view of a flat panel display monitor in accordance with the principles of the present invention:

FIG. 43 is a perspective view illustrating the extension and rotation of the video screen of the flat panel display monitor of the preferred embodiment in accordance with the principles of the present invention;

FIG. 44 is a perspective view illustrating the video screen of the preferred embodiment pivoting in a first direction in accordance with the principles of the present invention;

FIG. 45 is a perspective view illustrating the video screen of the preferred embodiment pivoting in a second direction in accordance with the principles of the present invention;

FIG. 46 is a diagrammatical view of the video screen pivoting as shown in FIG. 44 in accordance with the principles of the present invention;

FIG. 47 is a diagrammatical view of the video screen pivoting as shown .in FIG. 45 in accordance with the principles of the present invention.

FIG. 48 is a perspective view illustrating connection of the flat panel display monitor to the base unit in accordance with the principles of the present invention;

FIG. 49 is a perspective view illustrating the permanent connection of the flat panel display monitor to the base unit in accordance with the principles of the present invention;

FIG. 50 is a schematic view of an alternate embodiment of the present invention wherein the video screen is removable from the housing; and

FIG. 51 is a planar view of an embodiment of a continuous bar code label.

While the detailed description is provided in terms of a hospital environment, it will be appreciated that the present invention has application and utility to a variety of patient care facilities wherein patient identification and relating items including such disposable items as drugs, supplies, etc. to a particular patient is desirable and important for proper care, administration, inventory control and billing.

Referring now to the drawings, there is illustrated in FIG. 1 an embodiment of a patient identification system generally referred to by the reference numeral 40 in accordance with the principles of the present invention. As illustrated, the patient identification system 40 includes a programmed general purpose computer system 42; for example, a super microcomputer with 2 Mbytes of random access memory. The computer system 42 includes appropriate memory devices 44 such as floppy diskette drives, hard disk drives, streaming tape backup, etc; for example, a 145 Mbyte 8" disk drive might be used. In addition, the computer system 42 includes appropriate printer devices 46 for printout of information such as patient identification bracelets; patient identification labels, item identification labels for drugs, blood test samples, surgical supplies, IV solutions, etc.; generation of medical records (MAR); billing statements, etc. Certain ones of the printer devices are preferably portable, hand-held printers capable of printing alpha/numerics and bar codes. In addition, the computer system 42 will include terminals 45 including a keyboard and a display for input of data to and output of data from the computer system 42. The terminals 45 and the printer devices 46 might be located locally and at remote locations, as required; for example, in the pharmacy, in the laboratory, in the supply room, in X-ray, in radiology, in the billing department, at the nurses'stations, etc.

In a typical hospital application, hospital items including drugs, general supplies, etc. will include a label 47 with an item identification bar code 49 attached thereto. Diagrammatically illustrated in FIG. 2 is a drug vial 43 with such a label and bar code. Custom made items such as special medications, tests, IV's, etc. made for a specific patient will preferably have a label with a custom made item identification bar code attached at the time those items are made. Patients will have a patient identification bar code 50 appearing on their identification bracelet 52, as diagrammatically illustrated in FIG. 3, along with the patient's name. In addition, a patient identification bar code 51 will appear on the patient's medical chart and will preferably also appear on a supply of labels 53 in the patient's file. Illustrated in FIG. 4 is a sheet of such adhesive labels 53 which might be placed in a patient's medical file and then peeled off and applied to various items so as to relate those items to the patient, as required. The bar code format comprises a series of printed bars of various widths and spacing, preferably in accordance with a standard bar code system, such as the National Drug Code (NDC), Health Industry Bar Code (HIBC), Universal Product Code (UPC), Health Care Provider Application (HCPA), etc.

Typically, each patient room will be provided with a portable bar code reading device 48 which will be used to read the patient and item identification bar codes. However, it will be appreciated that there might be many other ones of the bar code reading devices 48 located throughout the hospital, and indeed, each nurse and/or patient's bed might have one of the bar code reading devices 48. Moreover, nonportable bar code reading devices might be used in some areas of the hospital where portability is not necessary or desirable. The patient identification bar codes 50 on the patient's identification bracelet 52 will specifically identify the patient, while the patient identification bar codes 51 on the labels 53 will be used to relate the various items to which they are attached to a particular patient. Preferably, the bar codes 50 on the patient's identification bracelet 52 will not be the same as the bar code 51 on the labels 53, such that the source of a bar code can be identified as being a patient or as being an item relating to that patient.

In the embodiment illustrated in FIG. 1, data representative of the bar code identifier scanned by the bar code reader device 48 is transmitted as a radio frequency (RF) signal to an RF/data over voice (DOV) modem transceiver 55 located in the patient's room where the bar code reader device 48 is located. As diagrammatically illustrated in FIG. 5, the RF/DOV modem transceiver 55 includes an RF modem 56 interconnected to a DOV modem 57 by a microprocessor 58 which serves as a protocol handler enabling communication between the modems 56, 57. The RF modem 56 provides for transmission and reception of RF signals to and from the bar code reading device 48 and the DOV modem 57 provides for transmission and reception of signals via in place, existing telephone wiring such as twisted pair or 4-wire to and from the computer system 42 using DOV technology. The RF/DOV modem transceivers 55 in the various hospital rooms are interconnected by separate telephone wires 60 such as twisted pair or 4-wire to a DOV modem/multiplexer (MUX) 62 located in the hospital's telephone switching room 64. The DOV/MUX 62 is interconnected to a single port of the computer system 42, which is preferably a network port such as an ETHERNET port, by a hardwired connection 66. Conventional DOV technology enables transmission of data at rates of up to 19.2 kilobits per second. In yet other embodiments of the present invention, limited distance modems might be used in conjunction with dedicated telephone wiring such as twisted pair or 4-wire and appropriate devices such as RS-422 drivers. The DOV/MUX 62 might transmit data to and from the computer system 42 at the rate of 9600 baud or higher.

The terminals 45 located remotely of the computer system 42 are interconnected to a DOV modem 68 which transmits data to and from the computer system 42 over existing twisted pair telephone wires 70 to DOV modem 72 located in the telephone switching room 64. The DOV modems 72 are interconnected by separate hardwired interconnects 74 to serial RS 232 ports of the computer system 42.

The embodiment of the invention illustrated in FIG. 1 enables communication from the remotely located terminals 45 and the portable bar code reader devices 48 to occur over conventional twisted pair telephone wires, thereby reducing costs and facilitating installation. It will be appreciated that various embodiments of the patient identification system might be utilized in keeping with the principles of the present invention. For example, the portable bar code reading device 48 might utilize infrared (IR) transmission/reception in place of RF transmission. In yet another embodiment, the RF/DOV modem transceiver 55 might be replaced by an RF/Power Line Carrier (PLC) modem transceiver which enables communication via AC power lines to an intermediate location, such as a nurses' station, where a PLC/DOV modem might transmit the signal to the computer system 42 by telephone wires.

Illustrated in FIGS. 6 through 9 is an alternate embodiment of the present invention wherein communications occur mostly over existing AC power lines and twisted pair wire. The bar code reader device 48 in this embodiment communicates with an RF/power line carrier (RF/PLC) modem 90, an embodiment of which is illustrated in FIG. 8. The RF/PLC modem 90 transmits data on existing AC power lines 92 to a power line carrier (PLC) modem 94, an embodiment of which is illustrated in FIG. 9. As illustrated in FIG. 6, the nurses'terminals 45a are interconnected by twisted pair wiring 96 to a twisted pair multiplexer 98, an embodiment of which is illustrated in FIG. 7. The twisted pair wiring 96 provides for faster communication than the AC power lines. The twisted pair multiplexer 98 provides communication with the computer system 42 and/or with an existing hospital mainframe computer 100. The power line carrier (PLC) is a somewhat noisy medium which will necessitate a robust protocol. Data bit errors encountered are usually burst errors where more than one bit is affected. This embodiment will preferably use a protocol involving the first three layers of the international standard organization standard. The PLC protocol will include individual addressing of devices, data field length and data similar to high level data link control (HDLC), but unlike HDLC, the protocol will be asynchronous. Error detection will be via a sixteen bit CRC with the message being retransmitted when an error is detected. Since multiple devices can be on the power lines at the same time, a collision detect multiple access (CSMA/CD) scheme with random backoff will be used. Non-coherent frequency shift keying (FSK) is preferably the modulation used, with 160 KHz being the operating frequency. The protocol to the computer system will be standard ASCII with one bit parity error detection. The PLC modem 94 will include a microprocessor such as the Z80 with a two Kbyte memory for handling the communications protocol between the AC power lines and the computer system. The LM1893 IC from National Semiconductor is used in the interface to the AC power lines and the RS232 driver is used in the interface to the computer system. The RF/PLC modem 90 will be located near the nurses' station and will relay information between the bar code reading device 48 and the PLC modem 94 near the computer system.

A frequent error in UHF transmission is multipathing. This is caused by the RF signal bouncing off objects and arriving at the receiver as two out of phase signals. Multipathing could occur in the present invention because of a nurse moving a medication cart around the room, etc. Accordingly, the same protocol selected for the PLC medium will be used to detect errors and retransmit data. The twisted pair multiplexer 98 enables the mainframe computer 100 and the computer system 42 to communicate with terminals at various locations. Preferably, in the event of a failure at the twisted pair multiplexer 98 or the computer system 42, normal communications are automatically set up between the mainframe 100 and the nurses' terminal 45a. The twisted pair multiplexer 98 will preferably not affect protocols of the mainframe 100 or the computer system 42. Data passed will be time division multiplexed and will reside in the twisted pair multiplexer's buffering memory during simultaneous transmissions.

It will be appreciated that the computer system 42 of the preferred embodiment, although not illustrated in FIG. 1, might also be interconnected to an existing hospital mainframe computer with proper protocol conversion. If there is no direct interconnection, or if communication to the hospital mainframe computer is not otherwise provided, data can be downloaded into the mainframe computer by manually transferring data storage media, such as diskettes, magnetic tape, etc. from the computer system 42 to the mainframe system 100.

As illustrated in FIGS. 10 through 12, an embodiment of the bar code reading device 48 might include a programmed microprocessor 110, such as a Z80 and its associated memory and real time clock mounted in a hand held housing 112. The bar code reading device will preferably use low voltage battery power for portability and to prevent shocks to a patient. In addition, a key pad 114 is provided for entry of data and commands. An LCD display 116 will be provided for displaying information and status. Input/output channels 118 might be present for input of data directly into the microprocessor 110 from such items as a temperature sensor, pulse sensor, blood pressure sensor, respiration rate sensor, etc. and output of data to such items as a portable alpha/numeric bar code label printer 115 for printing bar code labels in the patient's room at bedside. The bar code reading device 48 includes a wand device 120 interconnected by a cord 121, the wand device 120 including a light emitting source for illuminating a bar code and an optical detector for reading the resulting reflections from the bars of the bar code. The wand device 120 preferably uses a light emitting diode (LED) as a light emitting source, although an infrared (IR) or laser light source can also be used. In an alternate embodiment, the wand device 120 might include an optical imaging capability utilizing charge coupled devices (CCD's) or optic random access memory (RAM). The remote terminals 45 might also be interconnected to a similar wand device 123 for reading bar codes at the terminals. The bar code reading device 48 is preferably provided with status lights 122 for providing a visual confirmation of proper correlation between an item, such as an IV solution, and the patient. In FIGS. 11 and 12, three such status lights 122a,b,c are shown, the status lights being red, amber and green. The bar code reading device 48 will preferably include an RF modem transceiver 124 and associated antenna 126 for transmission/reception of an RF signal. In yet other embodiments, the bar code reading device 48 might include an infrared transmitter/receiver arrangement to enable transmission/reception of data as an infrared signal. The bar code reading device 48 might be mounted in a wall mounted recharging unit 128 when not in use to enable recharging of batteries which might be used to power the bar code reading device 48. The recharging unit 128 is interconnected to the AC power supply by an electrical cord 130. The RF/DOV modem 55 might be a part of the recharging unit 128. As illustrated, the bar code reading device 48 is preferably a hand held unit to facilitate portability and ease of use. Moreover, although not shown, the bar code reading device 48 might include a clip or other suitable device enabling attachment to a patient's chart.

Each of the recharging units 128 will preferably have a unique address which can be manually set by a dip switch 129 or the like mounted inside the housing of the recharging unit 128 so that data transmitted to and from the portable bar code reader 48 will be addressed for a particular recharging unit 128. Moreover, the recharging unit 128 will preferably only communicate with a bar code reading device 48 having a corresponding address and will preferably include circuitry for automatically coding the portable bar code reading device 48 with the corresponding address when the portable bar code reading device 48 is mounted in the recharging unit 128 whereby portable bar code reading devices 48 can be moved from one room to another without interfering with the other portable bar code reading devices, since a bar code reading device will only communicate with a recharging unit with a corresponding address.

In the embodiment shown, the key pad 114 includes a ten key arrangement for entry of numerals and the following special function keys:

It will be appreciated that numerous combinations and arrangements of special function keys might be utilized in keeping with the principles of the present invention.

As illustrated in FIGS. 13 and 14, the computer system 42 might be an off-the-shelf item such as a 16/32 bit microcomputer designed for the multi-user UNIX operating system. A typical computer system hardware configuration is illustrated in FIG. 13. Multiple communication processors might be utilized to provide sufficient throughput during the communication periods. Communication inputs and outputs might be via RS232 ports. Direct communication with the hospital's main-frame computer might be through a synchronous remote job entry facility with interactive emulation of a mainframe terminal.

The computer system 42 will collect and coordinate the data received from the various terminals 45 and bar code reading devices 48 and store the data in various patient/item data files for later reference and use.

As illustrated in FIG. 14, a network operating system will preferably be utilized which will allow users to interactively access files through a distributed file system. The network operating system will preferably use high level communication protocols which will be independent of the physical network medium utilized, thereby providing ease in networking to other parts of the hospital system which might have different protocols.

Use of the system and method of the present invention will now be described in terms of a sample scenario and a block diagram which is illustrated in FIG. 15.

At the time of patient admittance, patient information will be entered into the computer system 42 via a terminal 45b at the admitting office. One of the tasks of the admitting staff member will be to print out at a bar code printer 46b a sheet of the bar code labels 53 containing both the patient specific bar code identifiers 51 and the patient's name in human readable form. The bar code labels are placed inside the patient's chart for future use. One of the labels 53 is attached to the patient's medical chart. The patient-unique bar code 50 identifier label will be affixed to the patient's identification bracelet 52 or will be printed on a special patient bracelet by the bar code printer 46b. The bar code identifier 50 on the patient's identification bracelet 52 will be different from that on the labels 53 to enable determination of whether a patient identifying bar code is being read from a patient's identification bracelet 52 or from a label. The bar code 50 for the patient's identification bracelet 52 will be unique from the bar code 51 placed on the labels 53 in the patient's chart to ensure, for example, that it is actually the patient and not the patient's bar code that is receiving drug treatment. Additional patient billing information and other pertinent patient information such as blood type and drugs to which the patient might have an allergic reaction can be entered into the computer system 42 at this time or at some other time when the information becomes available. For example, allergies might be entered at the nurses' terminal 45a after allergy tests have been performed. The patient information will be stored in memory as a suitable patient data file, an embodiment of which is diagrammatically illustrated in FIG. 16. It will be appreciated that any number and configurations of patient data files might be utilized with various types of information. Preferably, duplication of the patient identification bracelet 52 can occur only at the admitting desk.

After a physician writes a prescription prescribing a drug treatment for the patient, a secretary or other staff person will access from a terminal 45a a drug data file stored in the computer system 42 to display at the terminal 45a the list of drugs after scanning the patient identifier bar code 51 on the patient's chart. The staff person will then enter each scanned drug's dosage and frequency of administration via the terminal 45b. Many drugs have a standard dosage and quantity. These standard values can be stored in the appropriate drug data file of the computer system 42 along with the drug such that the dosages, etc. need not be separately entered if the prescription calls for a standard dosage. This enters into the computer system 42 the patient's name, drugs, dosage and times of day they are to be administered. This information is stored in the computer system's memory as a data file correlating the patient and drug information. An example of an embodiment of such a data file layout is diagrammatically illustrated in FIG. 17. It will be appreciated that this data file and/or other data files might include additional drug-related information, such as allergies, etc. The staff person then places a preprinted patient identification bar code label 53 on each of the prescriptions and sends them to the pharmacy for filling.

At the time the pharmacist checks and fills the prescriptions, the pharmacist will scan the patient's identification bar code 51 on the patient's prescription using a bar code reader and will bring up the patient's file at a pharmacy terminal 45c. The pharmacist will check the computer data against the prescription. If the pharmacist does not approve, he will change the prescription or take other appropriate action, such as talking to the responsible doctor. If approved, the pharmacist will then fill the prescription by scanning the drug's identification bar code. He will then scan a bar code in his identification badge indicating his approval. If a bar code identifying the drug is not already on the drug package, the pharmacist will take a pre-coded label and affix it to the drug. This might occur in the case of unit dosages not bar coded by the manufacturer, in which case a sheet of bar codes might be provided which are perforated to the same package size specifications as the package of unit dosages. In the case of unique drugs, such as IV solutions where a pharmacist may combine two or more drugs to form a custom patient IV, a custom bar code might be generated in the pharmacy on its bar code printer 46c and the resulting bar code label affixed to the IV solution. Preferably, the bar code label will list all standard IV information and will also list the names of the ingredient drugs and other pertinent data such as patient's name and rate of delivery (drip rate). If not previously entered, the pharmacist might also manually enter any drug administration guidelines noted by the physician, such as time of day if the drug has no standard times or if the prescription varies from the standard times normally given, although this might be done by the nurse at the nurses' station.

Scanning the drug identifier bar code on the drug package after scanning the patient's bar code will automatically enter and record the drug prescription as being approved for that particular patient and the MAR is updated. Dosage and times per day will be automatically displayed and subsequently printed. However, it will be appreciated that if the times per day for each drug are not stored in the computer system 42, this information can be manually entered at a terminal. Preferably, such things as known allergies for each patient have been previously entered into the patient's computer record such that any drug allergies for a particular patient will be flagged by the computer system and the pharmacist will be informed at the terminal 45c. Moreover, the computer system 42 might be programmed so as to flag any major drug inconsistencies or contradictions at the pharmacy terminal for pharmacy disposition.

In addition, the computer system 42 might also check for significant drug incompatibility problems. If such a problem is detected, a message or alert will appear at the pharmacy terminal 45c.

Moreover, as the prescriptions are filled by the pharmacist or any other item is used or disposed of, the computer system 42 will automatically record such an occurrence in an inventory file identifying all items which have been disposed of, thereby providing for accurate inventory control. An embodiment of such a data file is diagrammatically illustrated in FIG. 18.

Upon approving the prescriptions, a medical administration record (MAR) for that patient is printed at the pharmacy and placed in the patient's drug cart drawer. After all drugs for the period, i.e., eight or twenty-four hours, have been entered and placed in the cart, a patient/drug schedule or assignment sheet might be printed for each nurse, giving names of patients, room numbers and drugs to be dispensed by time of day and dosage for each nurse's shift. Additionally, these records and schedule sheets can be printed at any time at the nurses' stations.

If the pharmacist changes any of the drugs prescribed, such as when filling a prescription with a generic drug, the computer system 42 will mark the new drug. When giving a drug so marked, an alert will be received at the bar code reading device 48 unless the nurses and the pharmacist have both previously entered their personal identifier bar codes to approve the new drug on the MAR. A special flag will be placed on the unapproved MAR to identify a larger than recommended normal dosage. Additionally, a similar alert will be received at the bar code reading device 48 if the dosage prescribed exceeds the maximum dosage specified in the computer system's data files and if the pharmacist and the nurse have not previously entered their personal identifier bar codes.

When ready to administer treatment, a nurse will take the portable RF bar code reading device 48 and read her own identifying bar code badge to access the system and to identify herself. Next, the nurse will read the patient identifier bar code on the patient's identification bracelet and the item identifier bar code on the items to be administered and press a "SEND" key on the bar code reading device 48 while in the patient's room. This activates the transmission of data via the telephone wiring to the computer system 42. While checking a drug against the patient's computer stored data files to verify it properly corresponds to the patient, the bar code reading device 48 will preferably light the amber status light 122b to indicate "in progress" or the words "IN PROGRESS" will be displayed on the liquid crystal display 116 of the bar code reading device 48. In certain instances, it may be necessary for the nurse to use the key pad 114 to enter dosages by use of the "DOS" key, such as in the case of custom made IV solutions or when the dose is other than a unit dose. The bar code reading device 48 might include an optional temperature, pulse and blood pressure cuff module, enabling temperature, pulse and blood pressure data to be directly obtained; however, the nurse can also enter the patient's vital signs via the key pad 114 on the bar code reading device 48. Preferably, the bar code reading device 48 will store and will display upon request six to ten previously entered vital statistics by use of the recall key "REC". This enables a new nurse coming on duty or a physician to access the system when in the patient's room and review on the liquid crystal display 116 the more recent vital signs. Additionally, the bar code reading device will preferably store a record of the most recently administered PRN or other controlled drug administered to control pain or the like and the times they were administered. This eliminates the need to track down the patient's records, which is an important benefit in times of emergency. In addition, scrolling keys might be provided to enable scrolling of the data.

The bar code reading device 48 will preferably include a printer module enabling labels to be printed bedside at a label printer 46e interconnected to the portable bar code reading device 48 such that a nurse can print bar code identifier labels as necessary; for example, a nurse might print a label for attachment to a test tube containing a patient's blood sample by scanning the patient's identification bar code and pressing a print key on the portable bar code reader 48.

If the drug bar code scanned matches the patient identification bar code and the pharmacy-entered drug code, the green status light 122c or other appropriate readout on the LCD 116 will prompt the nurse to proceed. If there is a discrepancy, the red status light 122a might flash and/or some other appropriate readout might appear at the LCD display 116 indicating why the red status light 122a is on. The nurse may elect to override the warning at that time if she believes it is appropriate to administer the drug or take whatever actions she deems necessary. In such cases, a computer record of such events will be stored and will be available for review at a future time.

Preferably, administration of the drug will be automatically recorded when the green status light 122c or other appropriate indication appears on the LCD display 116, or unless the nurse pushes a button on the bar code reading device 48 to indicate that treatment did not occur. If for some reason the nurse cannot proceed with administration of the drug, for example, the patient refusing to take the drug, the nurse will press a "HOLD" key and scan the bar code label on the drug. The patient/drug data files will be updated to reflect that the drug was not taken. The bar code reading device 48 might include several special function buttons on the key pad 114 for explaining why the drug is being held. Although a specific embodiment of the portable bar code reader 48 is illustrated, it will be appreciated that other embodiments might be utilized and that any number and arrangement of special function keys, indicators, input ports, etc. might be present.

Whenever a drug or any other item is dispensed to a patient, the computer system 42 will automatically record such an occurrence in a patient billing file, identifying all items which are to be billed to the patient. An embodiment of such a file is diagrammatically illustrated in FIG. 19. The billing data file is preferably accessible from a terminal 45f in the billing department.

The nurses' terminal 45a will be alerted by the computer system 42 if a drug has not yet been given and is overdue, reminding the station staff to check with the appropriate nurse. Preferably, the computer system 42 will cause a printout of the nurses' drugs and patient's names for the drugs overdue at the terminals associated with printer 46a. Preferably, this will be a buffered output transparent to the printer's normal activity, such that if the printer 46a is in the middle of a printout, the printer will not be interrupted until it is finished. Accordingly, normal printer operation is not interfered with. The computer system data files will include an adjustable time window adjusted and entered by the pharmacist in which the drug can be administered. If drug administration does not occur in this time window, the alert occurs. Moreover, whenever a nurse administers drugs to a particular patient by transmitting via the portable bar code reading device 48 her ID, the patient's ID and the drug's ID, the computer system 42 will check to see if a drug is overdue for any of that nurse's patients. If a drug is overdue, the nurse will be alerted at the portable bar code reading device 48 by the red status light 122a and a message on the display 116.

Preferably a new MAR for each patient and a new assignment sheet for each nurse will be printed at the beginning of each new shift at a printer 46a at the nurses' station. These hard copy reports will provide the nurse coming onto the shift with a record of what has been completed on the previous shift, what has not been completed and what treatment, the time for each treatment and which patient should be treated on the new shift. Additional terminals 46 might be utilized by the nurses to chart additional information before going off their shift.

A permanent MAR may be generated or demanded and placed in the patient's record. The physician can then review this hard copy or go to the nurses' station terminal and review the patient's current MAR on the screen.

The control of controlled drugs such as narcotics is important and regulated in all medical institutions. The present invention performs the following narcotics inventory control functions: (a) reports inventory of all narcotics located or distributed at nursing or pharmacy locations; (b) reports and controls accessibility to such narcotics; and (c) automatically records when supply reaches "reorder" level from main pharmacy. When any narcotics are removed from their locked drawer or drug cart, the nurse scans, in sequence, her badge to identify herself, the cart's own bar code (identifies the stock location) and the narcotic(s) to be administered. The system now has checked the drug out from the cart and has put it into the nurse's inventory, where it will remain until she administers the drug to the patient, via standard procedure as described earlier. If the narcotic(s) are on the patient's electronic MAR, the green status light 122c will be lit. At such time, the narcotics can be administered to the patient in the normal manner. At that time, the narcotic is removed from the nurses' inventory. Dispensing the narcotic to the patient is handled in the same manner as all drugs, except that once the drug is administered to the patient, the narcotic is removed from the "nurse inventory" and automatically billed to the patient. At the end of the shift, a narcotic inventory is printed out, along with who dispensed narcotics, who received narcotics, the nurse(s) leaving the shift, the nurse(s) starting the new shift (who will undertake a physical narcotics count). If any deviations occur, they will have to be corrected via one of the terminals 45. When the inventory level drops to the "automatic order" point, the computer system 42 alerts the pharmacy to fill the drawer. When the drugs are placed in the narcotics cart drawer, the inventory level is again upgraded.

In ordering a laboratory test, a nurse or other staff person will scan the patient's identification bar code on the patient's chart, and scan or scroll for the bar code for the test required, which might be provided on a preprinted sheet available at the nurses' station. At the lab, a draw list will be printed out at a printer 46d instructing the lab staff which samples to draw from which patients. On each label will be the test's corresponding bar code identifier and name. This label will then be affixed to the test tube or other container required for the test. Before taking the test sample, the lab technician will scan a bar code identifier on his or her badge, scan the patient's identification bar code on the patient's identification bracelet and scan the test bar code on the sample container. The computer system 42 will then indicate if this is the correct patient and the correct test by access to the lab test data file which correlates patients to specific lab tests to be performed. A diagrammatic illustration of such a file is illustrated in FIG. 20. This process will take place in the patient's room. Back in the lab, the technician will scan the patient's identifier bar code on the test sample, perform the test and enter the results into a lab test computer via the terminal 45d or automatically via the test instrument if applicable. The lab test results will be entered into an existing and separate lab test computer system which will perform the usual analysis, although the lab test computer will preferably be interconnected to the computer system 42 for exchange of data and recording of the test results. The lab will be assured that the sample being tested belongs to the correct patient and the results are recorded against the correct patient's data files. In addition, the system will automatically update the billing data file so the patient is billed for the test and will store the dates and times when the test(s) were undertaken for future reference.

The present invention will provide for keeping track of the time a nurse spends with a patient, as well as time audit record of patient events, such as when a patient is checked in and out, moved to a different area, has tests performed and/or drugs administered, etc. This serves a very useful audit function and drug control function; for example, when a patient is checked out, drugs can be put on hold.

It will be appreciated that the computer system might be programmed in any number of ways to utilize any number and arrangement of data files in providing for identification of patients, relating items to patients and verifying proper correlation between patients and various items.

The present invention will preferably include a data base management capability so that the staff can generate report forms as they wish, in accordance with their procedures.

FIGS. 21-35 illustrate alternate embodiments of the present invention. Referring now to FIGS. 21-25, there is illustrated an alternate embodiment of a patient identification and location system and methodology in accordance with the principles of the present invention. An RF transmitter unit 220, reprogrammable to transmit unique patient identifier information, is worn on the body of a patient, preferably mounted in a disposable standard plastic identification bracelet 222 typically worn by a patient in a health care institution and/or badges worn by personnel in the health care institution. In addition, the RF transmitter unit 220 might be mounted on suitable equipment and other moveable items within the health care institution so as to identify and track the items. It will be appreciated that although the present invention has particular application in health care settings, nevertheless, the present invention has application wherever identification and location of personnel and items is required.

In the embodiment shown, RF signals transmitted by the patient-worn RF transmitter units 220 are received by a plurality of RF receiver units including stationary, known position RF receiver units 226 capable of receiving RF signals strategically located in hallways, dining areas, lounge areas, etc., as well as base stations 228, somewhat similar to the transceiver units 55 of the previous embodiment, which in addition to being capable of receiving RF signals from the transmitter units 220, include a transceiver capability for communication with portable RF transceiver units mounted in portable handheld patient terminals (PHPT) 224, somewhat similar to the bar code reader devices 48 of the previous embodiment, carried by the health care staff and used when administering drugs, taking vital signs, etc. In the embodiment shown, the RF receiver units 226 are not capable of transmitting RF signals, although they too might include a transceiver function. As illustrated in FIG. 25, the portable handheld patient terminals 224 include an RF modem 270 and associated antenna 271, which functions as a transceiver transmitting and receiving RF signals, for retransmittal of the RF signals to the base stations 228 which might be located in the patient's room or other areas wherein patients are frequently present. The base stations 228 include an RF modem and antenna similar to that of the portable handheld patient terminal 224 for receiving and transmitting RF signals to and from the portable handheld patient terminal 224. The base station 228 also receives RF signals directly from the transmitter unit 220. In the preferred embodiment, the portable handheld patient terminal 224 will only communicate with a base station 228 having a corresponding address, the portable handheld terminal 224 and base station 228 being uniquely addressable by storage of an address in memory. The base station 228 will only communicate with a portable handheld terminal 224 having a cooperating address.

The embodiment of the RF transmitter unit 220 shown in FIG. 22 includes RF transmitter 230, a power supply 232, and reprogrammable control 234 preferably encapsulated in a media 236 so a to be able to withstand sterilization by ethylene oxide or the like; and not be affected by water, body fluids, or common organic solvents and cleaners. The encapsulated RF transmitter unit 220 is suitably removeably mounted on the standard plastic identification bracelet 222 by any number of methods.

The preferred embodiment of the RF transmitter unit 220 can be made to change duty cycles or periodicity of RF transmission by use of proper handshaking signals with the reprogrammable control 234. For example, the RF transmitter unit 220 might typically transmit in a low duty cycle mode of once every two seconds. This transmittal rate is more than adequate for locating a patient. However, when administering drugs, taking vital signs, etc. it is desirable to have a greater frequency of transmission so as to enable more rapid patient identification and better system response time. Thus the portable handheld patient terminal 224 in the preferred embodiment has the ability to change the duty cycle of the RF transmitter unit 220 to a high duty cycle such as twice every second. This might occur when the portable handheld terminal 224 is brought into close proximity with the RF transmitter 220. The RF transmitter unit 220 might have a different range of detection when in the high duty cycle mode. For example, in the low duty cycle, the detection range might be seven meters; while in the high duty cycle, the detection range might be eight to fifteen centimeters. It will be appreciated that the above operating parameters are given by way of example and should not be construed to limit the invention to those specific parameters.

The RF transmitter unit 220 is reprogrammable so as to enable the patient identifier code transmitted by the RF transmitter unit 220 to be changed. The RF transmitter unit 220 is preferably reprogrammable several times throughout its lifetime. For example, if the RF transmitter unit 220 utilizes a microprocessor with a fifteen bit data structure, each RF transmitter unit 220 could be reprogrammed sixty-four times per year and support five hundred beds for a total of 32,768 unique patient identifiers. It will be appreciated that more data bits could be added if needed; but the more bits used the more power consumed, and consequently the shorter the battery life. The power supply 232 will preferably be a battery having a life of one year or more. Examples of such batteries which might be used are lithium, silver oxide, and alkaline. Although not shown, the RF transmitter will preferably include circuitry to shut off the power supply when the RF transmitter unit 220 is not in use.

It is important that the RF signals transmitted by the RF transmitter unit 220 not be affected by static, X-rays, and other electromagnetic fields present in hospital environments.

The RF modem 270 of the portable handheld patient terminal 224 will preferably have a lesser detection range than the fixed position RF receiver units 226, for example, eight to fifteen centimeters, and include a device such as a signal generator to switch the RF transmitter unit duty cycle. Detection might be accomplished by use of a "crystal set" which has a reduced detection range. This eliminates the possibility of the portable handheld patient terminal 224 from being interfered with by other RF transmitter units 220 in the health care facility.

The RF transmitter unit 220 might be built around a three hundred megahertz frequency, although other frequencies might be utilized in order to comply with appropriate governmental regulation. Various types of modulation such as pulse-position modulation (PPM) and frequency-shift keying (FSK) might be used.

As illustrated in FIG. 21, the fixed position RF receiver units 226,228 are interconnected to a programmed computer system 240 by telephone wiring 241 in a fashion similar to that of the previous embodiment. Upon receipt of a transmission from the transmitter unit 220, the RF receiver units 226,228 will transmit to the computer system 240 by data over voice (DOV) techniques using the telephone wiring 241. In the embodiment illustrated in FIG. 23, the RF receiver units 226,228 include an RF modem 242 for RF reception and a DOV modem 244 for DOV transmission and a microprocessor controlled communication interface 246 which will provide the interface function between the RF modem 242 and the DOV modem 244.

The embodiment of the system illustrated in FIG. 21 includes a DOV modem rack 250 housing a plurality of DOV modems in relatively close proximity to the computer system 240 and includes a corresponding DOV modem 250a for every RF receiver unit DOV modem transmitting to the computer system 240 over the telephone wiring 241. The DOV modems of the modem rack 250 are interconnected to a data switch/multiplexer arrangement 251 for multiplexing the numerous RF receiver DOV modem inputs into the few input/output channels 252 of the computer system 240. The computer system is illustrated as including memory devices 254, printer devices 256, and terminals 258.

The computer system 240 is interconnected to remote dumb terminals 260 distributed throughout the health care facility. The terminals 260 are shown interconnected to the computer system 240 by terminal support unit (TSU) devices 262 via the telephone wiring 241. The TSU 262 includes a DOV modem for communication with the modems of the DOV modem rack 250 so as to enable data over voice (DOV) transmission. The TSUs 262 include ports for interconnection to printers 270 such as bar code printers and dot matrix printers and a bar code reader 272 for reading bar codes. Accordingly, the terminal support unit (TSU) 262 serves as a "data traffic cop" or I/O controller enabling the central computer system 240 to communicate via a single telephone line to the terminal 260, bar code printer, dot matrix printer, bar code reader, etc. The terminal support unit (TSU) 262 provides an interface between the present invention and existing computer systems which might be present in the healthcare facility. In a preferred embodiment, the terminal support unit (TSU) will include four serial ports and one parallel port controlled by a programmed microprocessor and associated memory including read-only memory (ROM).

In some embodiments, the RF receiver units 226,228 might use twisted pair wiring for communication to the computer system 240. In this embodiment, driver and receiver circuitry might be used to provide RS-232 interface signals. Although not shown, a time division multiplexer might be used to interconnect multiple ones of the RF receiver units 226,228 to the computer system 240. A limited distance modem is another alternative for transmitting on the twisted pair wiring. Yet another method of communication to the central computer is using power line carrier (PLC) techniques for transmission over the AC wiring.

A user wishing to locate an object, e.g., a patient, can use the terminals 258,260 to enter the patient's name or unique identifier. This will activate the computer system program which will then display at the terminal the location of the RF receiver unit 226,228 wherein the patient was last detected. An example display on the terminal, might display patient name/identifier, location, e.g., dining room, and time at location. In addition, the terminal might display or a hard copy printout be made of the patient's movements over a user selected period of time and at a user selected time interval.

Illustrated in FIG. 24 is an embodiment of a method in accordance with the principles of the present invention. The RF transmitter units 220 will periodically transmit unique object identifier information identifying the object wearing the transmitter. The RF transmissions will be detected by one or more of the RF receiver units 226,228. The RF receiver units 226,228 transmit the unique object identifier information to the computer system 240 as well as identifier information identifying the RF receiver unit 226,228 sending the object information. The object and RF identifier information will be stored in appropriate data files contained in computer system memory. Also, the time and date of the RF transmitter unit 220 transmission to the RF receiver unit 226,228 will be stored in an appropriate data file. The time might be determined by the computer system noting when an input from the RF receiver units 226,228 is received although other methods can be used. Upon request by a user at one of the terminals, the computer system program will transmit the location of the object to the user terminal. In the preferred embodiment, the object's location will be determined by the location of the RF receiver unit 226,228 to last detect the object's transmitter, the location of the RF receiver units 226,228 being known and stored in the memory of the computer system. In addition, the preferred embodiment of the invention can be used to maintain a time record of staff and patient activity. This is particularly helpful in determining how long a particular activity takes. Moreover, an historical record of staff and patient movements over a specified period of time, e.g., days, at selected intervals can be requested.

Illustrated in FIG. 25 is an embodiment of a portable handheld patient terminal 224. As illustrated, the portable handheld patient terminal 224 is controlled by a microprocessor and memory 272. The portable handheld patient terminal 224 might include a liquid crystal display 273, various status lights 274 indicating different conditions of operation, a communications port 275 for input and output of data, a keypad 276 for entry of data, and a rechargeable power supply 278. In addition, as illustrated, the portable handheld patient terminal might include a binary imaging sensor with associated decoder device 280 for reading bar codes and other alphanumeric indicia. A switch 281 is illustrated as controlling operation of the binary imaging sensor.

In addition to locating objects, the present invention can be used to identify patients, staff, drugs, supplies, etc. when administering drugs, taking vital signs, etc. The RF transmitter units 220 might be the primary means of identification or a secondary means for providing a second means of patient identification verification or backup.

Although wireless electromagnetic transmissions in the radio frequency (RF) range have been discussed in the preferred embodiment, alternate types of wireless electromagnetic transmissions might be utilized, e.g., infrared.

Referring now to FIGS. 26-35, there is illustrated an alternate embodiment of the bar code reader devices 48 and the portable handheld patient terminals 224, herein referred to as a portable handheld terminal 320. As illustrated in FIG. 26, the portable handheld terminal 320 is packaged in a portable handheld housing 322 having first and second spaced apart, opposing major surfaces 324,326, respectively, extending generally along the longitudinal axis of the portable handheld terminal 320 between first and second end portions 328 and 330, respectively. The first major surface 324 might also be referred to as the bottom surface, and the second major surface 326 might also be referred to as the top surface. The first end portion 328 might also be referred to as the front end portion, and the second end portion 330 might also be referred to as the back end portion. As illustrated, interconnected to the housing 322 proximate the first end portion 328 is an elongated handle portion 340 which extends upwardly away from the second major surface 326 and backwardly generally along the longitudinal axis of the housing 322 toward the second end portion 330. As illustrated, in the embodiment shown, the handle portion 340 includes an arcuate portion 342 and a substantially straight portion 344 which is spaced sufficiently far from the second surface 326 of the portable handheld terminal 320 so as to enable a user's hand 350 to grasp around the handle portion 340 with the user's fingers extending into the space between the handle portion 340 and the second major surface 326 as illustrated in FIG. 26. The handle portion 340 enables the terminal to be held in either hand during use. In an alternate embodiment, the handle portion 340 might be interconnected to the housing at both ends. The portable handheld terminal will preferably be made by conventional molded plastic processes.

As illustrated in FIG. 28, when seen from the back end portion 330, the portable handheld terminal 320 has a generally truncated pyramid shape, generally becoming narrower toward the top.

As illustrated in phantom line in the embodiment shown in FIG. 27, located proximate the first end portion 328 of the portable handheld terminal 320 is an optical sensor device 352 of a bar code reader. As illustrated in FIG. 30, positioned on the handle 340 is a push button, contact switch 341 for activating the sensor device 352 via an appropriate electrical interconnection. The switch 341 will normally be in an off position and will return to the off position upon being released by the user. Disposed on the first major surface 324 is a liquid crystal display (LCD) 354 which in the embodiment shown is capable of displaying four lines of text, each line containing up to twenty characters. Also disposed on the first major surface 324 is a keyboard 356. In the preferred embodiment, a membrane keypad is used. An embodiment of the keyboard is illustrated in FIG. 35. In the embodiment shown, the keyboard 356 includes status lights 358, special function keys 360, and a numeric keypad 362.

As illustrated in the block diagram shown in FIG. 29, the portable handheld terminal 320 includes a microprocessor and associated memory 364. An example of one such microprocessor is an INTEL 3031. In addition, the portable handheld terminal includes an RF transceiver arrangement including an RF modem 366 and antenna 367 for real time data transmission and reception of RF signals. Moreover, a communications port 368 including a multipin connector is present for input of data to and output of data from the portable handheld terminal 320. The portable handheld terminal 320 is provided with additional memory so as to enable storage of data and downloading at a later time via the communications port 368. For example, the portable handheld terminal 320 might store vital signs, drugs administered, etc. for a plurality of patients. In addition, external vital signs measurement equipment might be interconnected to the communications port 368 for input of data. The communications port 368 includes a multipin connector. In addition to input and output of data, the communications port 368 will also be used in the preferred embodiment for charging a rechargeable, removable power supply 375 of the portable handheld terminal 320. In the preferred embodiment, the portable handheld terminal 320 will operate for over one hour between recharging.

The optical sensor device 352 is preferably a binary imaging device such as a charged coupled device or optic RAM device; e.g., Hitachi Model No. HE97l34. The optical sensor device 352 includes an optical lens and a low-powered, high sensitivity light source 355 for illumination of the bar code indicia. The optical sensor device 352 includes an image capture device including an X-Y array of light sensitive elements; e.g., a 2048 pixel array of light sensitive elements, which will provide a digital image of the bar code indicia being read. Accordingly, the present invention will simply require the user to point the optical sensor device 352 of the portable handheld patient terminal 320 at the bar code indicia and press the switch 341 on the handle portion 340 to take an electronic digital "picture" of the bar code indicia. The electronic digital "picture" is then electronically interpreted by a microprocessor controlled decoder device 353. It will be appreciated that charged coupled devices and optic RAM devices are commercially available.

As illustrated in FIGS. 30-34, the portable handheld terminal 320 is used in conjunction with a wall mounted base station 376 for wireless communication with the portable handheld terminal and for storage of the portable handheld terminal 320 during non-use. The base station in the embodiment shown, includes an RF transceiver arrangement including an RF modem 379 and antenna 380 for communicating with the RF transceiver arrangement of the portable handheld terminal 320. The base station 376 further includes a data over voice (DOV) modem 377 for data over voice communications over telephone wire to a computer system. In addition, the base station 376 will include a central processor and memory 373 for controlling operation of the base station 376 and in particular handling the communication interface between the DOV modem 377 and the RF modem 379, as well as communication with the computer system. The base station 376 preferably derives its power from a transformer 381 interconnected to an AC power supply. In addition, the base station 376 includes a communications port 382 adapted for interconnection to the communications port 368 of the portable handheld terminal 320.

The base station 376 includes non-volatile memory 386 which can be programmed to uniquely address the base station 376. When the portable handheld terminal 320 is stored at the base station 376, the base station 376 will download its unique address or identifier via the communications ports 382,368 into the memory of the portable handheld terminal. When transmitting to the base station 376, the portable handheld terminal 320 will include this address or identifier with its transmissions. If the identifier is not recognized by the base station 376, the base station will ignore the transmission and not respond. This prevents interference with the base station 376 by other portable handheld terminals 320 located throughout the facility. In a preferred embodiment, the portable handheld terminal is capable of programming the address or identifier of the base station 376. This is accomplished by the operator entering an appropriate command at the keyboard of the portable handheld terminal which is recognized by the base station and indicates to the base station that its address is to be modified by the portable handheld terminal 320. When the portable handheld terminal 320 is stored in the base station 376, the unique address or identifier will be downloaded from the portable handheld terminal to the non-volatile memory 386 of the base station.

As illustrated, the base station 376 includes recharging circuitry 378 for charging the rechargeable power supply 375 of the portable handheld terminal 320. As illustrated in FIG. 33, the recharging circuitry 378 is interconnected by a temperature sensor, a rad relay 371, mounted to a battery cell in the rechargeable power supply 375 of the portable handheld terminal 320. The read relay 371 is mounted so as to provide sensing of the highest temperature in the battery pack. The relay 371 will have one lead connected to the positive terminal of the battery pack and the other lead provided to the recharging circuitry 378 through the communication ports 368,382. In operation, as illustrated in FIG. 34, when the portable handheld terminal is placed in the base station as illustrated at block 390, the base station 376 will check to see if the power supply 375 is at full charge as illustrated at decision block 391. If the power supply is at full charge, the recharging circuitry 378 will switch to a trickle charge mode as illustrated at block 392. In the trickle charge mode, the recharging circuitry 378 will provide power to the logic control of the portable handheld unit. As illustrated at block 393, if the power supply 375 is not fully charged, the recharging circuitry 378 will provide a rapid charge. In the preferred embodiment, rapid charge current is at 2C=900 mA while trickle charge is at C/3=150 mA. The recharging circuitry 378 will check to see if the power supply 375 has reached a critical temperature (Temp1) as illustrated at block 394. If the critical temperature has been reached, then, as illustrated at block 395, the recharging circuitry 378 will switch into trickle charge mode. The recharging circuitry 378 will monitor the temperature such that if the temperature falls below a specified temperature (Temp2) as illustrated at block 396, the recharging circuitry 378 will go back to rapid charge mode if the power supply is not fully charged.

Mounted on the outside of the base station 376 is a status light 383 which varies in intensity between trickle charge and rapid charge so as to indicate the charging mode. The status light 383 will come on as soon as the portable handheld terminal 320 is properly inserted in the base station 376.

The power supply 381 will preferably provide the following power outputs:

400 mA at +5.0V

80 mA at +7.2V

100 mA at +12V

100 mA at -12V

In addition, as illustrated in FIG. 32, the base station 376 might include a communications port 369 for interconnection to a printer.

The power supply 375 in the portable handheld terminal might include removable batteries or a removable battery pack stored in the handle portion 340 or between the surfaces 324,326 proximate the end portion 330.

As previously indicated, electrical interconnection between the portable handheld terminal 320 and the base station 376 will be provided by the communications ports 368,382 which might comprise a standard multipin type of interface connector. In addition to use for recharging and addressing of the portable handheld terminal 320, the communication ports might be utilized for diagnostic testing of the portable handheld terminal 320.

Although not shown, the base station 376 might include a biasing mechanism for forcing the portable handheld terminal 320 in a generally upward direction such that an edge 384 of the base station 376 cooperates with an inside wall 334 of the portable handheld terminal housing portion defining a window or opening 335 for an optical sensor 352. As illustrated in FIG. 31, a wall 385 of the base station 376 might cooperate with a back wall 387 to define a cavity for receipt and retention of the back end portion 330 of the portable handheld terminal 320. The wall 385 slants at a slight angle away from the wall 387 so that the portable handheld terminal 320 can be inserted downwardly with low insertion force into proper connection with the multiple pin connector of the communications port 382 and tilted outwardly to enable easy mounting and removal thereof from the base station 376. The mating connector arrangements of the communication ports 368,382 are capable of being connected numerous times.

The base station 376, in addition to communicating over existing telephone wiring, might communicate via twisted pair wiring in a serial interface fashion, as part of a local area network, or over the existing AC wiring using power line carrier (PLC) techniques, etc.

In typical use, the user will enter data at the handheld portable terminal 320 via the keyboard 356 and the optical bar code reader 352 and transmit the same as RF signals to the base station 376. The base station 376 will then communicate with the central computer system wherein master data files might be kept. The central computer system will, upon receiving the data, respond and provide output data to the base station 376 which will, in turn, communicate by RF signals to the portable handheld terminal 320.

It will be appreciated that other forms of electromagnetic transmissions might be utilized other than radio frequency (RF) transmissions, e.g., infrared.

The keypad of the portable handheld patient terminal 320 will allow the operator to select the function desired, allow manual entry of information, and control the operation of the handheld terminal. An audible alarm sounds if an invalid key is pressed. Also, an indication will be displayed at the LCD indicating that an invalid key was pressed. This screen will be shown for a period of time and then the portable handheld patient terminal will display the screen that was shown before the invalid key was pressed. During communications with the base station 376, the keys on the portable handheld patient terminal 320 will not function.

Access to any function via the keyboard can only be accomplished by reading of a hospital staff ID badge after the portable handheld patient terminal 320 is removed from the base station 376 or after the "new patient" key is depressed. The liquid crystal display will display to the user an indication to scan their ID badge. After a valid scan of their ID badge, the portable handheld patient terminal will be in the main menu for function selection. Access to the system has now been gained. Once access is gained, the ID number of the staff person is retained until access to functions is cancelled. When a function requiring patient ID or drug cart ID is requested, the portable handheld patient terminal 320 will prompt the user to scan the appropriate bar code, if it has not already been entered. The patient ID or drug cart ID can be entered before the function selection is made. Once entered, all IDs are retained until access to functions is cancelled. Access to functions is done whenever the functions for a particular patient or drug cart are complete. This is accomplished by depressing the "end/new patient" key or placing the portable handheld patient terminal into the base station 376. In a preferred embodiment, the access to functions is cancelled thirty seconds after the portable handheld patient terminal is placed into the base station. Once this is done, the portable handheld patient terminal goes into an inoperative mode except for diagnostics which might be initiated by the computer system. Even though the portable handheld patient terminal has not been placed back in the base station, if there have been no valid functions performed for a period of five minutes, access to the system functions via the portable handheld patient terminal is cancelled. This is to avoid unauthorized personnel access if the staff personnel forget to press the "end/new patient" key. The staff ID, drug cart ID, and patient ID will be removed from the memory of the portable handheld patient terminal when access to functions is cancelled. If a function is in process when the "end/new patient" key is pressed, an audible alarm will sound. The portable handheld patient terminal can only be turned off by pressing the "end/new patient" key when in the main menu. Data design to be entered via bar codes, e.g., staff ID numbers, patient ID numbers, supplies identification, drug identification, drug cart identification, etc. cannot be entered via the keypad 356. Patient data such as vital signs, patient assessments, etc. can be entered via the keypad, as well as quantity items.

The following is a brief description of the various keys of the keypad 356:

There are four LED indicators on the portable handheld patient terminal 320. The liquid crystal display (LCD) 354 will also provide information relating to the LEDs. The yellow LED 358a will be lit when the SEND key is pressed and will remain lit until communications with the base unit is complete. During this time, the user cannot make any entries at the keyboard. A red LED 358b is lit when information entered for a function desired does not match what is the correct information for that function, or when an invalid key is pressed. The red LED 358b is a warning not to proceed without first checking for a potential problem. The red LED will remain lit continuously under the first condition until some action is taken to remedy the problem. Under the second condition, the red LED will remain lit while the LCD displays the invalid key pressed message. A green LED 358c is lit when a function is valid to proceed. The green LED is lit momentarily under this condition. The green LED is also lit when the central computer system acknowledges receipt of proper information. The green LED is lit continuously under this condition until some other action is taken. A yellow LED 358d will indicate the early warning of a low battery in the portable handheld patient terminal. This is an early warning level and the portable handheld patient terminal will still function. However, operation of the portable handheld patient terminal will be locked out when the batteries reach a level where the data in the patient history is corrupted. Before lock out occurs, the LCD display 354 will display a warning.

Preferably, the LCD display 354 will be capable of displaying four lines of text each containing twenty characters. The LCD will have a lighting source which will provide illumination under low light conditions. This lighting will be controlled by a key on the keypad switching the lighting source from the on to off or off to on condition. If the light source is on when the portable handheld patient terminal is returned to the base unit, it will automatically be turned off.

The preferred embodiment of the portable handheld patient terminal 320 will make use of audible tones to a limited extent and include means to disable the audible tones. It will be appreciated that there are a number of situations wherein an audible tone or alert could be utilized. For example, (1) a single beep when a valid bar code read occurs, (2) three beeps when the red LED is lit, (3) three beeps when invalid key pressed, (4) three beeps when a bar code is successfully read but the data contained in the bar code does not meet the requirements for the field being displayed on the LCD display 354, etc.

Illustrated in FIGS. 36 through 38 is an embodiment of a bar code holder apparatus 400 which is used to hold a bar code label 402 and is attached to a patient's identification bracelet 404. The bar code holder 400 comprises flexible plastic, translucent first and second flaps 408,410 suitably attached to one another along a first edge 412. Intermediate the first and second flaps 408,410 and attached to the first edge 412 is a flexible, plastic third flap 414. The second flap 410 has first and second layers 416,418 attached along their edges so as to form a space 420 for receipt of the bar code label 402. An opening 422 in the second layer 418 providing access into the space 420 proximate the first edge 412 intermediate the second flap 410 and the third flap 414. The third flap 414 preferably includes an opaque releasable backing 424 covering an adhesive layer 426 on the third flap 414 such that upon removal of the backing 424, the third flap 414 can be adhesively attached to the second layer 418 so as to seal off the opening 422 thereby providing a fluid tight seal protecting the bar code label 402 from any spillage of fluids which might occur. The first layer 416 is substantially transparent to allow accurate reading of the bar code indicia on the bar code label 402.

A third layer 428 is attached to the second layer 418 along a second edge 426 facing oppositely from that of the first edge 412 and is disposed intermediate the second layer 418 and the first flap 408. The third layer 428 has attached thereto on a side facing the first flap 408 a male member 430 of a non-releasable snap arrangement. The first flap 408 has attached to it on a facing surface, a cooperating female member 432 for receiving the male member 430 whereby the first flap 408 can be non-releasably snapped to the third layer 428 of the second flap 410. It will be appreciated that a variety of snap arrangements might be utilized.

In use, a bar code label 402 having a patient's bar code identifier thereon is inserted into the space 420 with the bar code identifier facing the first substantially transparent layer 416 and being readable in a direction extending along the length of the first and second flaps 408,410. A fluid tight seal is formed by removing the backing 424 of the third flap 414 and pressing its adhesive layer 426 against the second layer 418 of the second flap 410. The patient's conventional wrist identification bracelet 404 is then disposed transversely between the first and second flaps 408,410 and the first and second flaps 408,410 are snapped together thereby securing the bar code holder 400 to the patient's identification bracelet. The bar code holder 400, since it is oriented at right angles to the identification bracelet 404, enables reading of the bar code identifier along the length of the patient's wrist as opposed to reading about the girth of the wrist. This provides for a much flatter bar code surface, since the bar code does not wrap about the patient's wrist. Moreover, the bar code holder 400 may be readily positioned for scanning. Accordingly, more accurate readings are attainable with less accurate scanners.

Illustrated in FIGS. 39 through 41 is a embodiment of the terminal support unit (TSU) 262 shown in FIG. 21, the terminal support unit (TSU) being referred to by reference numeral 440. The TSU 440 allows data-over-voice (DOV) communication between the computer system 240 and various peripherals such as a non-intelligent terminal 442 used for entry of patient related data, a bar code reader device 444, a serial printer device 446, and a parallel printer device 448. The TSU enables central computer system to communicate over a single telephone line with these devices via the TSU 440 using DOV transmission. As illustrated in FIG. 40, the TSU 440 includes control circuitry 450 for two types of interfaces; i.e., character transmission and block, also referred to as buffered transmission. In the embodiment shown, two DOV modems 451 and 452 are present for communication with the computer system 240. A bus structure 453 for the embodiment of the TSU shown is illustrated in FIG. 41. The bus structure includes parallel printer interface controller logic 454 for interfacing with a printer 455 via a parallel port, read only memory (ROM) 456, random access memory (RAM) 458, serial I/O interface logic such as dual asynchronous receiver/transmitters (DART) 460,462,464 providing a serial interface capability, a counter timer 466, seven segment display 468, and a microprocessor 470 such as a Z-80 electrically interconnected to a clock 472. A power supply 474 such as 110 volt AC provides the needed power supply for the TSU 440. The bar code reader device 444 is stored on a cradle structure on the side of the TSU housing, an electrical switch being provided to electrically switch off the bar code reader when the bar code reader is placed in the cradle so as to minimize energy usage.

The TSU functions as a master control and directs information from the main computer system to the appropriate peripheral device. Data input from the main computer system which is intended for one of the printers includes an identifier identifying which printer is to print the data. The TSU will strip this identifier off before sending the remaining data to the identified printer. The TSU includes logic for notifying the main computer system if a printer fills the TSU buffer due to running out of paper or some other problem. The TSU further includes logic for monitoring the status of the printers and notifying the main computer system there is a change of status; i.e., operational or nonoperational. The main computer system will cease data transmission upon being notified by the TSU of printer nonoperation and will resume transmission upon being informed of printer operation. The TSU further includes logic for informing the main computer system if block data to the printers is lost due to transmission errors such as framing, over-run, parity errors, etc. The main computer system then retransmits the block of data to the TSU for which an error was detected.

Referring now to FIGS. 42 through 50, there is illustrated a flat panel display monitor 451. The flat panel display monitor 451 has a housing 450 which is rectangularly shaped with a top 452, bottom 454, side 456, and side 458, which is opposite side 456. The housing 450 has a back side 460 which is substantially flat so that the monitor 451 can be mounted on a wall. Reference numeral 470 in FIG. 42 refers to the back side of support member 464 which is housed in housing 450. A lower section 462 of housing 450 houses the electrical circuitry necessary to electrically interconnect monitor 451 to a suitable data input device.

FIG. 43 shows a video screen 466 and support member 464 in an extended position. Video screen 466 is substantially flat and rectangular in shape. Video screen 466 is connected to support member 464 and support member 464 is, in turn, connected to housing 450 by arm assemblies 472. Only one arm assembly 472 is shown in the drawings; the other arm assembly 472 is identical to the one shown and is located directly across from the one shown proximate side 458 of housing 450. The description of the arm assembly 472 shown should suffice. The arm assembly 472 consists of a large rectangular hollow section 474 and a smaller rectangular section 476. Hollow section 474 is connected to a front edge 478 of housing 450. Section 476 of arm assembly 472 is connected to end 508 of support member 464 by pin 482. Section 476 is housed in hollow section 474 so that section 476 can slide in and out of hollow section 474. Thus, support member 464 and video screen 466 which is attached to support member 464 can be housed in cavity 484 on the front side of housing 450 when section 476 is telescoped into hollow section 474 and can be extended from housing 450 by telescoping section 476 out of hollow section 474.

FIG. 43 also illustrates the capability of support member 464 and attached video screen 466 to rotate about a horizontal axis running through pins 482 on arm assemblies 472. Support member 464 rotates about pins 482 which connect support member 464 to arm assembly 472. Thus, back side 470 of support member 464 can face outward with respect to housing 450 or a front side 486 of video screen 466 can face outward with respect to housing 450. It will be appreciated that support member 464 and video screen 466 can be in any position intermediate these two positions by rotating support member 464 about pins 482 to a position where backside 470 of support member 464 and frontside 486 of video screen 466 are not parallel to the front side of housing 450.

FIGS. 44 and 45 illustrate video screen 466 tilting to one side and to the other. Video screen 466 is rectangularly shaped and has a front side 486 with a screen 490, a backside 494, an end 496 and an end 496 opposite end 496. In the preferred embodiment, video screen 466 is a gas plasma display. Video screen 466 can have 256.times.512 pixels or up to 400.times.640 pixels. Video screen 466 has a 150.degree. viewing angle, a 10:1 contrast ratio and a 40-foot Lamberts peak brightness. These features make the video screen easier to read than the traditional cathode ray tube displays and provide significantly better resolution. In the preferred embodiment, video screen 466 is very thin, for instance, as thin as 1.25 inches. Screen 490 is a truly flat screen and the memory capability and special circuitry of video screen 466 enables screen 490 to be free from flicker, jitter and edge distortion, all of which are typical problems of a cathode ray tube type display. Another advantage of video screen 466 of the preferred embodiment is that it does not subject users to radiation, implosion danger, or toxic chemicals if it is accidentally damaged. Screen 490 in the preferred embodiment, is capable of displaying 25 lines of 80 characters each. Video screen 466 is interconnected to electrical circuitry housed in section 462 of housing 450 by way of a ribbon cable or the like.

Video screen 466 is connected to support member 464 by arm 500 shown in FIG. 44 and by arms 502 and 504 shown in FIG. 45. The connections of arms 500,502 and 504 to video screen 466 and support member 464 will be explained with reference to FIGS. 46 and 47. End 510 of arm 500 is hinged to front side 492 of support member 464 very close to end 508 of support member 464. End 512 of arm 500 is hinged to back side 494 of video screen 466 very close to end 498 of video screen 466. Arm 500 is not attached to support member 464 or video screen 466 anywhere other than that at end 510 and 512. End 514 of arm 502 is hinged to front side 492 of support member 464 very close to end 506 of support member 464. End 516 of arm 502 is hinged to back side 494 of video screen 466 very close to end 496 of video screen 466. End 518 of arm 504 is hinged to front side 492 of support member 464 very close to end 506 of support 464. End 520 of arm 504 is hinged to back side 494 of video screen 466 very close to end 496 of video screen 466. Arms 502 and 504 are not connected to support member 464 and video screen 466 other than at ends 514, 516, 518, 520, respectively. It is important to note that end 508 of support member 464 is not connected to end 496 of video screen 466 and that end 506 of support member 464 is not connected to end 498 of video screen 466. The hinges connecting arms 500, 502, and 504 to support member 464 and video screen 466 can be of one piece with arms 500, 502 and 504 or separate.

The movement of arms 500, 502 and 504 can be seen with reference to FIGS. 46 and 47. In FIG. 46, video screen 466 is pivoting on hinges at end 512 of arm 500, end 514 of arm 502 and end 518 of arm 504. In FIG. 47, video screen 466 is pivoting on hinges at end 510 of arm 500, end 516 of arm 502 and end 520 of arm 504. In FIG. 46, arm 500 is adjacent front side 492 of support member 464 and arms 502, 504 are adjacent back side 494 of video screen 466. In FIG. 47, arm 500 is now adjacent back side 494 of video screen 466 and arms 502, 504 are adjacent front side 492 of support member 464.

FIG. 48 shows the compatibility of monitor 451 with data input devices. The data input device shown in FIG. 48 is an embodiment of a portable handheld terminal 524 as discussed above and referred to by reference numerals 224 and 320. Monitor 451 has a communication port 522 for electrically interconnecting monitor 451 to a base unit (also referred to as a base station) 528 as discussed above and referred to by reference numerals 228 and 376 which house the portable handheld terminal 524 when the terminal 524 is not in use. Communication port 522 on monitor 451 connects to communication port 526 on base unit 528. As discussed previously, the terminal 524 has integrated keypad, display and optical bar code read functions, a handle design which facilitates ease of use and also includes electromagnetic transceiver means for wireless transmission of data to and from base unit 528. Terminal 524 has its own rechargeable power supply which can be recharged at base unit 528. Terminal 524 transmits information to base unit 528 via radio frequency signals. Base unit 528 in turn communicates this information to monitor 451 via communication ports 526 and 522. The hospital staff member can then readily read monitor 451 from any location in the room to see results of tests; such as from the hospital laboratory, determine what the medical type and dosage is and whether it matches what was prescribed.

A hospital staff member can also use portable terminal 524 and monitor 451 to input data to the computer system 240 which is hardwired to a plurality of base units. The staff member can use the keyboard on terminal 524 to input the data to base unit 528. This data would be displayed on monitor 451 and could be transferred to the central computer. It should also be noted that information received at base unit 528 from the central computer can be displayed on monitor 451 via the communication ports 526 and 522.

Monitor 451 can be removably attached to a wall and a data input device as shown in FIG. 48. Thus, a hospital staff member could disconnect ports 52 and 526 and remove monitor 451 from the wall in one hospital room and move monitor 451 to another hospital room where it could be reconnected to the wall and a data input device via port 522.

Furthermore, monitor 451 can also be configured to be portable within a hospital room. Portable monitor 451 would have its own power source and would communicate with a data input device via radio frequency signals. Thus, a hospital staff member could place monitor 451 any place within the room and still communicate with a data input device.

The monitor 451 and the base unit of the data input device can also be one unit. FIG. 49 shows monitor 451' and base unit 528', which houses a portable handheld terminal 524, as one integral unit. The circuitry of monitor 451' and base unit 528' would then be internally electrically interconnected.

Flat panel display monitor 451 provides a display for a bedside computer system that can be wall-mounted and therefore does not take up any valuable space in a hospital room. Monitor 451 provides the hospital staff with the capability of displaying relevant data about the patient such as patient care plans, assessments, lab results, vital sign plots and medication profiles, as well as other patient data.

The flat panel monitor 451 provides a full screen display for display of larger amounts of data than is possible with the portable handheld terminal 524. Real time patient data can be brought up on the flat panel monitor 451 from any location in a patient's room using the portable handheld terminal 524. In one embodiment, in addition to the circuitry required to operate the monitor, the flat panel monitor 451 will include a microprocessor and associated memory with the flat panel monitor 451 being interconnected to the base unit 528 by an RS-232 interface. The microprocessor has the ability to upload customized screen formats from the computer system 240 (see FIG. 21) into its associated memory for subsequent display on the monitor 451 upon request by the user at the portable handheld terminal 524. A forms development program is provided for generating and maintaining customized screen formats from a microcomputer terminal such as an IBM PC,XT,AT or compatible interconnected to the computer system 240 for downloading the screen format data onto the computer system 240 for subsequent transfer to the flat panel monitor 451 as requested by a user. In one embodiment, the microprocessor of the monitor 451 will maintain customized screen formats in its available associated memory based on their frequency of use. The less frequently used screen formats will be deleted from memory to make room for those more frequently used. When a user requests a particular screen format, the monitor's processor will check if that screen format is stored in its memory, and if not, will request the same from the computer system 240. With the forms development program, the hospital can define menu screens for building menu paths, selection screens for specifying data to be selected, input/output screens for defining data entry fields and output fields for displaying data generated by the computer system 240 of the present invention, dynamic screens which can be scrolled, graph parameter screens to define graphs, re-display menus to allow access to uploaded data saved in local memory of the monitor 251, and error screens for displaying transaction error messages. In addition, the forms development program allows the user to define and modify field parameters. A test program is provided in one embodiment of the present invention which uses the microprocessor to emulate the computer system 240 for purposes of testing new forms. A library utility it provided for storing the screen formats on a storage device for later use with the test program.

Flat panel display monitor 451 also provides a display that while wall-mounted, is capable of tilting so that a hospital staff member can view the display from any location within a patient's room. The capability of tilting the display allows for the privacy of patient data when there is more than one patient in the hospital room and it also allows a hospital staff member to view the display without allowing the patient to view it.

The present invention also provides a display that is compact and portable so that it can easily be moved from one patient's room to another and mounted on the wall in the new location.

In yet another embodiment of the present invention, the video screen 466" is removable from the housing 450" and includes a support structure 530 for supporting the video screen in an upright position on a flat surface such as a table top. The video screen 466" suitably interconnected to the housing 450" by an electrical cord 532. This embodiment of the invention allows the video screen 466" to be used at various locations removed from the housing 450".

In yet alternate embodiments of the display monitor 451 of the present invention, wireless communication such as via an RF transceiver may be utilized to communication with input devices such as the portable handheld terminal 524.

Illustrated in FIG. 51 is a bar code label 540 which might be used in accordance with the principles of the present invention. In particular, the bar code label 540 shown has particular application for use with unit dosage packages of medication, although it will be appreciated that the bar code label 540 might be used in conjunction with any number of different items and/or with the patient's identification bracelet and/or bar code holder apparatus as previously discussed. The bar code label 540 shown is a continuous strip having a longitudinally extending continuous bar code indicia 541 printed on a top surface thereof. Also included is a drug identifying name 542, a drug identifying number 543, a dosage identifier 544, and an identifier 545 identifying the form of the medication, that is, tablet, capsule, etc. The longitudinally extending bar code indicia 541 extends along a bottom edge 546 while the additional human recognizable information lies along top edge 547. The bar code label is made of a synthetic material having substantial tensile strength in the longitudinal direction, and further is toothed and/or slitted with slits 548 so as to enable the bar code label 540 to be readily torn in the transverse direction. A back surface of the bar code label 540 preferably includes an adhesive along the top edge 547 for attachment to unit medication dosage packages or other items. In addition, the adhesive is preferably covered by a releasable backing material. The bar code label 540 is preferably dispensed from a suitable bar code dispenser apparatus as disclosed in applicant's co-pending application, Ser. No. 072102, filed July 10, 1987.

One embodiment of a computer system, base station, and portable handheld terminal in accordance with the principles of the present invention will include logic for generating predetermined system responses including predetermined screen formats at the portable handheld terminal 320. Following is a description of but one embodiment incorporating a predetermined set of presentation screens at the portable handheld terminal 320. It will be appreciated that various presentation screens at the portable handheld terminal, in keeping with the principles of the present invention, may be utilized. There are seven basic login screen presentations, and roughly sixteen system screen presentations, as well as additional screen presentations for control, administration, functions, patients, review, and vitals. The following are the seven login screen displays and sixteen system screen displays:

Entries by the user at the portable handheld terminal 242 while one of the six login screens is displayed, can result in a login or system screen as indicated below:

Initially, the user is directed to enter his/her staff ID via the keyboard. The number keys and the decimal point key are valid keys for entry. Due to the necessity for keeping the staff IDs secret, the data entered is not displayed. An asterisk is displayed for each valid character entered so that the user can tell when a key entry has been received by the handheld unit. The user is also requested to enter his/her barcode ID. The computer system will compare the barcode ID and the staff ID. This provides a double verification of the user's authority to access the system. Even though the user may have entered the proper ID via the keyboard, if their bar code identifier is invalid, the system will deny the user access. If a non-staff barcode is read, the handheld unit will beep twice and change displays to the System #4 screen. Return from the System #4 screen will be to the Login #2 screen. If a staff barcode is read and the staff ID is invalid, the portable handheld terminal 320 will change displays to the System #7 screen. If a staff barcode is read and the staff member does not have any overdue medications, the portable handheld terminal 320 will change displays to the System #1 screen, otherwise, the Login #4 screen will be displayed. If a staff barcode is read, the portable handheld terminal 320 will change displays to the Login #3 screen. If overdue medications are not reviewed by selecting option #2 in the Login #4 screen, all subsequent changes to the System #1 screen will instead go to the Login #3 screen. The NEXT key will cause the display of the next overdue medication. The PREV key will cause the display of the previous overdue medication. On the last overdue medication screen, the NEXT key will change screens to the Login #5 screen. On the first overdue medication, the PREV key is inoperative. Overdue medications are listed in chronological order, longest overdue being listed first. The Login #5 screen displays the user name, the room number and bed number, the time, and the patient.

System screens 3, 4 and 6-16 indicate various system errors, invalid IDs, entry errors, and patient care errors. The System #5 screen lists the overdue medications. The System #2 screen indicates that communications to/from the portable handheld terminal are in progress. The System #1 screen indicates that the portable handheld terminal is ready to receive user input.

When the System #1 screen display is displayed and the user requests to administer medications, enter patient data, review patient history or select a new patient for data entry or end a patient data entry session, the request is sent to the computer system and a check is made to see if a patient has been identified and, if not, a patient #1 screen is displayed requesting the user to read the patient ID on the wrist band. The patient ID is sent back to the computer system and a check is made to determine if this is a proper patient ID by checking it against a master list of the patient IDs. If not, a patient #2 screen is displayed indicating that the patient ID is invalid and the user is requested to press the MAIN MENU key so as to return to the previous screen.

As illustrated in FIG. 21, data transfer in the present invention occurs generally between three locations in the overall patient care system of the present invention. Data transfer occurs between the portable handheld terminal 224, the base station 228, and the computer system 240. As discussed, the portable handheld terminal communicates via a radio frequency (RF) link with the base station 228, the base station 228, in turn, communicating to the computer system 240 via the switch 251 by use of data-over-voice (DOV) transmission which enables the use of conventional telephone wiring. Although DOV transmission is much preferred, it will be appreciated that other types of transmission might be utilized between the base station 228 and the computer system 240. The present invention utilizes a unique protocol which provides for accurate data transmission while providing the user of the portable handheld terminal with quick response to any user input and/or request at the portable handheld terminal 224.

Referring now to Table 1, upon transmission of a message (MSG) to the base station 228 from the portable handheld terminal, the base station 224 responds with an acknowledgement (ACK) if there are no detectable transmission errors and a non-acknowledgement (NAK) if transmission errors are detected before transmitting the message on to the computer system 240. After sending the ACK or NAK, the base station 228 listens to the RF carrier to see if the carrier is quiet. If the carrier is quiet after sending an ACK, the base station assumes the ACK was received. If the carrier is not quiet after sending an ACK, the base station assumes the portable handheld terminal interpreted the ACK as a NAK. If after sending a NAK, no response is received or a meaningless response is received, this is interpreted as a NAK. A similar type of ACK/NAK procedure occurs between the base station 228 and the computer system 240. Accordingly, the intermediate data transmission verification at the base station 228 assures a quick response time to the user. After sending the ACK signal to the portable handheld terminal 224, the base station sends a switch on command (SWON) to the data switch 251 and the data switch 251 provides an ACK signal to the base station 228 that it is switched on before the base station proceeds with transmission of data (MSG) to the computer system 240. Once the data (MSG) is transmitted to the computer system 240 and received by the computer system 240, the computer system 240 transmits an ACK followed by data (RSP) in response to base station 228. Upon receipt of the RSP from the computer system 240, the base station 228 transmits the RSP to the portable handheld terminal 224 before transmitting an ACK back to the computer system 240, thereby assuring that user at the portable handheld terminal 224 gets the data even though the base station 228 and the computer system 240 have not completed transfer of their control signals. The base station 228 then transmits a switch off command (SWOFF) to the data switch 251 and an ACK to the portable handheld terminal 224. In those embodiments which use the flat panel display 451, the above described interfacing protocol also applies to data transmission between the portable handheld terminal 224, the base station 228, and the computer system 240.

As illustrated in Table 2, when communication occurs between the portable handheld terminal and the flat panel display 451, such as when using the flat panel display as the presentation screen, transmission occurs on a character by character basis with the base station 228 sending an ACK to the portable handheld terminal 224 only after the base station 228 has sent the character on to the flat panel display 451 and has received an ACK back from the flat panel display 451.

As illustrated in Table 3, the present invention also provides for the portable handheld terminal 224 to send a command (ENQ) to the base station 228 soliciting an acknowledgement from the base station 228 to ascertain that the base station 228 is on line and in communication with the portable handheld terminal 224. The base station 228 will respond with either an ACK or a NAK. In addition, as illustrated in Table 4, the present invention also provides for diagnostic messages (BAS) to be sent to the base station 228. As illustrated, the base station 228 will respond with an ACK and an appropriate response (RSP).

As illustrated in Tables 1-4, the base station 228 sends the final ACK in the interface protocol after having received an ACK from the portable handheld terminal 224 (or the flat panel display 451 where used) or from the computer system 240. If the portable handheld terminal 224 does not receive the final ACK from the base station 228, the portable handheld terminal can query the base station 228 to see if data transferred properly to the computer system 240. Thus, if an error in transmission should occur between the base station 228 and the portable handheld terminal 224 at the very end of the data transfer process, the portable handheld terminal 224 can automatically verify with the base station 228 that transfer occurred properly without having to retransmit the data. Should an error occur in data transmission between any two of the locations (portable handheld terminal 224, base station 228, or computer system 240), automatic retransmission of the data will be allowed a predetermined number of times before communications are terminated and an error in communication is indicated to the user. Predetermined timeouts will be used to determine an apparent loss of communication. In those situations where communication timeouts are reached or the maximum number of attempted retransmissions has been reached, a suitable message is displayed at the portable handheld terminal 224 to inform the user of the communication problem. Responsibility for displaying the suitable message will rest with either the portable handheld terminal 224, the base station 228, or the computer system 240, depending on where the communication error occurs.

In the event where communication fails between the computer system 240 and the base station 228, the data previously transmitted to the computer system 240 is not recorded at the computer system 240. Moreover, should communication failure occur from the base station 228 to the portable handheld terminal 224, the base station 228 notifies the computer system 240 that the data previously stored at the computer system 240 during the current data transmission session must be removed from the computer system 240. The base station 228 will transmit a modified message to the computer system 240 informing the computer system 240 of the communication failure. Upon receipt of the message, the computer system 240 will delete the newly stored data from its memory. The base station 228 ignores any timeouts and does not timeout during the process of sending the modified message since the modified message must be delivered to the computer system 240.

Examples of messages which might be displayed are as follows:

COMM ERROR, NO RESPONSE, BASE TO HANDHELD, WIRED CONNECTION

COMM ERROR, NO RESPONSE, HANDHELD TO BASE, RF CONNECTION

COMM ERROR, NO RESPONSE, BASE TO HOST

COMM ERROR, NO RESPONSE, HOST TO BASE

COMM ERROR, NO ACCESS THROUGH STATISTICAL SWITCH

COMM ERROR, NO DOV MODEM DATA SET READY (DSR) SIGNAL

COMM ERROR, NO CLEAR TO SEND (CTS) SIGNAL

COMM ERROR, PATIENT TERMINAL NOT IN BASE STATION

COMM ERROR, HOST SYSTEM FAILURE

It will be appreciated that the above messages are meant to be but examples of some of the types of communication messages which might be displayed.

The interface protocol of the present invention provides reliability of communications from and to the portable handheld terminal 224. Moreover, this is accomplished without the user having to get involved or even be aware of temporary breakdowns in data transmission which the protocol is able to correct. However, if breakdowns in communication do occur, the user is notified by an appropriate message at the portable handheld terminal 224 (messages may also be displayed on the flat panel display 451).

The RF transceiver modem 270 of the portable handheld terminal 224 is equipped with a control line in each direction, a transmit enable line and a carrier detect line. Activation of the transmit enable line will allow the RF carrier to be transmitted and the carrier detect line will be activated whenever the transceiver senses the presence of a carrier. Before activating the transmit enable line, the carrier detect line is sensed to see if it is active; i.e., has the carrier detect line sensed the presence of a carrier. If the carrier detect line is active, the transmit enable line is not activated so as to prevent interference due to multiple transmissions occurring at the same time which might otherwise result in interference.

A cyclic redundancy check (CRC) is generated from incoming bytes of data, and a one (1) byte number is generated in a suitable register or memory location. This number will be initialized to zero (0) before transmissions occur. Each byte received is exclusively ordered (XOR) with the byte in the register or memory location containing the CRC number. The result is then rotated right one (1) bit. The high order bit is set to the value shifted out of the low order bit position on the shift operation. This new result is, in turn, stored in the CRC register or memory location.

The present invention includes numerous logic checks and verification procedures for alerting the user of erroneous conditions. Below are some examples of the types of messages which might appear at the portable handheld terminal.

STAFF ID INVALID; MEMBER NOT IN DATA BASE

PATIENT ID INVALID

DRUG BAR CODE INVALID

SAMPLE ID INVALID

FORM/DOCUMENT ID INVALID

SUPPLY ID INVALID

CAR ID INVALID

STAFF ID INVALID, MEMBER NOT ALLOWED TO PERFORM REQUESTED ACTION

DATA INVALID, OUT OF RANGE, MEANINGLESS

INCORRECT TIME FOR PROCEDURE

SAMPLE DRAW NOT ORDERED

TEST NOT ORDERED

FREQUENCY OF ADMINISTRATION EXCEEDED

INCORRECT DOSAGE

INCORRECT ROUTE OF ADMINISTRATION

SAMPLE AND PATIENT ID MISMATCH

SURGERY NOT PRESCRIBED

NOT APPROVED BY PHARMACIST

NOT APPROVED BY NURSE

INCORRECT SITE OF ADMINISTRATION

TOO LATE TO REVERSE FUNCTION

SAMPLE ALREADY COLLECTED

CANCELLED

TOO LATE

INCORRECT TIME FOR SAMPLE DRAW BECAUSE OF DRUG ADMINISTRATION

REVERSE FUNCTION IMPOSSIBLE

The above are meant to be but a brief sample of the types of message displayed and are by no mean exhaustive of the types of messages which might be displayed in keeping with the principles of the present invention.

It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.