Physiological status monitor

[0001] The present application claims priority benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/775,568 filed Mar. 9, 2013, titled Physiological Status Monitor. The above-cited provisional patent application is hereby incorporated in its entirety by reference herein.

[0002] Pulse oximetry is a widely accepted noninvasive procedure for measuring the oxygen saturation level of arterial blood, an indicator of a person's oxygen supply. A typical pulse oximetry system utilizes an optical sensor attached to a fingertip to measure the relative volume of oxygenated hemoglobin in pulsatile arterial blood flowing within the fingertip. Oxygen saturation (SpO₂), pulse rate and a plethysmograph waveform, which is a visualization of pulsatile blood flow over time, are displayed on a monitor accordingly.

[0003] Conventional pulse oximetry assumes that arterial blood is the only pulsatile blood flow in the measurement site. During patient motion, venous blood also moves, which causes errors in conventional pulse oximetry. Advanced pulse oximetry processes the venous blood signal so as to report true arterial oxygen saturation and pulse rate under conditions of patient movement. Advanced pulse oximetry also functions under conditions of low perfusion (small signal amplitude), intense ambient light (artificial or sunlight) and electrosurgical instrument interference, which are scenarios where conventional pulse oximetry tends to fail.

[0004] Advanced pulse oximetry is described in at least U.S. Pat. Nos. 6,770,028; 6,658,276; 6,157,850; 6,002,952; 5,769,785 and 5,758,644, which are assigned to Masimo Corporation (“Masimo”) of Irvine, Calif. and are incorporated in their entirety by reference herein. Corresponding low noise optical sensors are disclosed in at least U.S. Pat. Nos. 6,985,764; 6,813,511; 6,792,300; 6,256,523; 6,088,607; 5,782,757 and 5,638,818, which are also assigned to Masimo and are also incorporated in their entirety by reference herein. Advanced pulse oximetry systems including Masimo SET® low noise optical sensors and read through motion pulse oximetry monitors for measuring SpO₂, pulse rate (PR) and perfusion index (PI) are available from Masimo. Optical sensors include any of Masimo LNOP®, LNCS®, SofTouch™ and Blue™ adhesive or reusable sensors. Pulse oximetry monitors include any of Masimo Rad-8®, Rad-5®, Rad®-5v or SatShare® monitors.

[0005] Advanced blood parameter measurement systems are described in at least U.S. Pat. No. 7,647,083, filed Mar. 1, 2006, titled Multiple Wavelength Sensor Equalization; U.S. Pat. No. 7,729,733, filed Mar. 1, 2006, titled Configurable Physiological Measurement System; U.S. Pat. Pub. No. 2006/0211925, filed Mar. 1, 2006, titled Physiological Parameter Confidence Measure and U.S. Pat. Pub. No. 2006/0238358, filed Mar. 1, 2006, titled Noninvasive Multi-Parameter Patient Monitor, all assigned to Cercacor Laboratories, Inc., Irvine, Calif. (Cercacor) and all incorporated in their entirety by reference herein. Advanced blood parameter measurement systems include Masimo Rainbow® SET, which provides measurements in addition to SpO₂, such as total hemoglobin (SpHb™), oxygen content (SpOC™), methemoglobin (SpMet®), carboxyhemoglobin (SpCO®) and PVI®. Advanced blood parameter sensors include Masimo Rainbow® adhesive, ReSposable™ and reusable sensors. Advanced blood parameter monitors include Masimo Radical-7™, Rad-87™ and Rad-57™, Pronto-7® and Pronto® monitors, all available from Masimo. Such advanced pulse oximeters, low noise sensors and advanced blood parameter systems have gained rapid acceptance in a wide variety of medical applications, including surgical wards, intensive care and neonatal units, general wards, home care, physical training, and virtually all types of monitoring scenarios.

[0006] Advantageously, a physiological status monitor provides information that allows a medical practitioner to visually discern patient condition at a glance. In an embodiment, a colored historical pie chart for a critical parameter, such as oxygen saturation, can be displayed for multiple patients. In another embodiment, multiple historical pie charts are displayed, depicting various parameters for a single patient so as to allow assessment of real time data and duration of time spent in various ranges. In particular, colored historical pie charts reflect visual representations of parameter histograms. Furthermore, colored pie charts may also represent alarm histories or medical personnel shifts.

[0007] One aspect of a physiological status monitor displays historical physical information of patients side by side, visually compares the information and identifies patients in need of immediate medical attention. In various embodiments, the display divides the information into medical conditions including a normal condition and a serious condition and distinguishes the conditions with indicators. Comparing may comprise viewing the indicators and discerning a serious condition with an indicator representing a particular serious condition. Identifying may comprise determining a patient having a high percentage of a serious condition indicator as the one in need of immediate medical attention. A particular condition may be oxygen saturation status. Distinguishing may comprise assigning colors to the conditions or assigning objects to the conditions.

[0008] Another aspect of a physiological status monitor is a monitor having an interconnected sensor. The sensor transmits optical radiation into a tissue site and generates a sensor signal responsive to the optical radiation after attenuation by pulsatile blood flow within the tissue site. The monitor computes a physiological parameter responsive to the sensor signal and utilizes a display to show the physiological parameter on screen. In an embodiment, the physiological status monitor comprises a monitor that determines a physiological parameter in response to an optical sensor signal derived from patients, a display incorporated with the monitor so as to present the physiological parameter, objects representing historical information regarding the physiological parameter over patients and a preferred screen presenting the objects side by side on the display for viewing by a caregiver so that the caregiver can visually discern and readily identify patients in need of immediate medical attention.

[0009] In various embodiments, the objects are colored pie charts. Each of the pie charts have zones representing different medical conditions, wherein the zones are assigned colors to make a visual distinction. The physiological parameter is oxygen saturation. The colors comprise a green color indicating a normal condition, an orange color indicating an abnormal condition and a red color indicating a serious condition, wherein a patient corresponding to one of the pie charts having the most percentage of the red color is in need of a immediate medical attention. The objects are different shapes, wherein the shapes are filled in lines, dots, circle and square patterns to make a distinction for a color blind user.

[0010] As used herein the term “display” is used to denote how a monitor screen appears on a physical monitor device. The term “monitor” is used as shorthand for a monitor screen and its associated appearance to someone viewing a physical monitor.

[0019] FIG. 1 illustrates a physiological status monitor 100 having a multiple-patient display 110 and a selected-patient display 120 of a critical parameter, such as oxygen saturation, over time. Historical information of a critical parameter over a duration of time is advantageously displayed for multiple patients simultaneously so as to allow a caregiver to visually discern and readily identify one or more patients in need of immediate medical attention. Advantageously, multiple colored historical pie charts 110 are advantageously utilized to represent the historical information. In an embodiment, each pie chart 110 has zones 112, 114, 116 representing the percentage of time a parameter has been measured in a particular range of values. Each zone 112, 114, 116 is assigned a different color indicating a different medical condition so that a relative comparison is made by simply viewing the size of a particular slice. For example, a pie chart 110 having a large red slice may indicate the corresponding patient has been experiencing difficulties and is in need of immediate medical attention.

[0020] As shown in FIG. 1, the exemplar parameter depicted in the pie charts 110 is oxygen saturation (SpO₂). In other embodiments, the display 100 may depict any of various alternative parameters, such as those described above and with respect to FIG. 2, below. In an embodiment, each pie chart 110 has a first zone 112 assigned to a safe green color indicating a normal oxygen saturation condition, a second zone 114 assigned to an orange color indicating an abnormal oxygen saturation condition and a third zone 116 assigned to a warning red color indicating a serious oxygen saturation condition. A normal patient condition is advantageously identified when the first zone 112 (green) is the largest slice of a pie chart, with the second zone 114 (orange) and the third zone 116 (red) being significantly smaller slices, such as shown with respect to pie charts 101 and 103. That is, patients represented by the pie charts 101, 103 are in a normal condition over most of a specified time period, such as 12 hours.

[0021] Also shown in FIG. 1, an abnormal, but not serious, patient condition is advantageously identified when the third zone 116 (red) occupies a significant portion, but less than half, of a pie chart and the other zones 112, 114 combined occupy more than half of the pie chart. An example is pie chart 105, which a caregiver can readily identify at a glance as a patient needing an immediate medical assessment and further care.

[0022] Further shown in FIG. 1, a serious patient condition is advantageously identified when the third zone 116 (red) occupies most of the pie chart, and the other two zones 112, 114 combined occupy less of the pie chart than the third zone 116. As example is pie chart 107, which a caregiver can readily identify at a glance as a patient in distress and in need of emergency medical attention.

[0023] Additionally shown in FIG. 1, a selected-patient display 120 has a pie chart 130 mini screen and a graph 150 mini screen that provide more details regarding a selected patient than are available from the multiple patient display 110. In particular, the pie chart 130 mini screen shows details of a particular pie chart 131 including the critical parameter 132, a duration of time 134, a histogram 136 and range categories 138. The range categories 138 have predetermined value ranges and corresponding percentages of time that the selected parameter 132 spent in each range. Each range 138 is assigned to a color corresponding to that in the pie chart 130. The percentages of time spent in each range 138 over the specified time duration 134 is automatically tracked and displayed. In this manner, the details of one pie chart 131 can be viewed with respect to parameter ranges 138 that each color represents. For example, a green color in the pie chart 131 represents an SpO₂ range of 93-85, and the patient spent 86% of time spent in this range. An orange color represents an SpO₂ range of 96-94 and 84-80 and the patient spent 10% and 0% of the time in those ranges, respectively. A red color represents an SpO₂ range of 100-97 and 79-0 and the patient spent 4% and 0% of the time in those ranges, respectively.

[0024] Also shown in FIG. 1, the selected-patient display 120 has a graph mini-screen 150 showing further details of the pie chart 131. The graph mini-screen 150 has a graph 152 showing parameter values versus time over a period, an upper alarm limit 153 and a lower alarm limit 155. Thus, the specific times in an alarm state are illustrated.

[0025] FIG. 2 illustrates a single-patient physiological status monitor 200 displaying multiple parameters, such as oxygen saturation, pulse rate, blood pressure, perfusion index, respiration rate and temperature over time. Advantageously, the display 200 allows a caregiver to view multiple parameter histories side-by side in a visually-rich format. In this manner, a caregiver can readily identify a patient having a serious medical condition or one incapable of adapting to a constantly changing medical environment. In particular, multiple-colored historical pie charts 210 are advantageously utilized to represent multiple parameters over time. Each colored pie chart 210 corresponds to a parameter and is a visual representation of the percentage of time spent in predetermined parameter ranges. Each range is assigned to a different color so that a serious medical condition can be rapidly discerned by simply comparing the multiplicity of the colors across the pie charts 210. Specifically, pie charts 210 that have a rainbow of colors indicate physiological variability, which is a normal condition depending on the parameter. Pie charts 210 having only a single color, or just a few colors, indicate a patient that may not be adapting to their environment, which may indicate an abnormal condition depending on the parameter.

[0026] As shown in FIG. 2, the display 200 has multiple-colored pie charts 210 representing parameters over time. In this embodiment, a SpO₂ pie chart 201, a pulse rate (PR) pie chart 202, a blood pressure (BP) pie chart 203, a perfusion index (PI) pie chart 204, a respiration rate (RR) pie chart 205 and a temperature (T) pie chart 206 are shown. The PR pie chart 202 has a rainbow of colors showing that the patient's pulse rate is constantly varying over time and indicating the patient is adapting to a varying environment in this respect. The T pie chart 206 has only a single color showing the patient's temperature is constant. The pie charts SpO₂ 201, BP 203, PI 204 and RR 205 each has moderate color changes in between a rainbow style and a single color showing the measured parameters SpO₂, BP, PI and RR are varying somewhat, but are not constantly varying over the monitored time duration. By viewing the color variety in pie charts 201-206, the patient's condition may be determined as moderately good. Advantageously, the display of multiple parameters over time as colored pie charts may allow a ready determination of a patient's condition based upon color variability. If all or most of the pie charts 210 have a single color, the patient may have a serious condition in need of immediate medical attention.

[0027] FIGS. 3-4 illustrate a single-patient, single-parameter physiological status monitor 300, 301 displaying a parameter over time, where the pie chart colors correspond to assigned ranges for the parameter. The displays 300, 301 track a single parameter 320 for a single patient over a period of time and includes a pie chart 310, a parameter indicator 320 and time duration 330. The pie chart 310 has different zones 312, 314, 316 representing ranges of parameter values 340. Each zone 312, 314, 316 is assigned a different color so as to be easily viewed by a user. The parameter indicator 320 indicates the particular parameter depicted in the charts, such as SpO₂, HbCO, HbMet, Hbt, Hct, PI or PVI, to name a few.

[0028] As shown in FIG. 3, the single-patient, single parameter monitor 300, 301 has parameter value ranges 340 (FIG. 3) and the associated percentage of time 350 (FIG. 3) the parameter 320 spends in each range 340. Each of the ranges 340 is assigned a corresponding color in the pie chart 310. In this manner, the details of each zone (color) can be viewed. For example, a green zone 312 indicates a normal condition, i.e. SpO₂ in the range of 85-100%, an orange zone 314 indicates an abnormal condition, i.e. SpO₂ in the range of 84-80%, and a red zone 316 indicates a serious condition, i.e. SpO₂ below 79%.

[0029] As shown in FIG. 4, an alternative display 301 shows sequential time intervals 360 in the two unsafe zones 314, 316 of the pie chart 310. These unsafe intervals 360 are shown sequentially. When scrolled down, the display 360 shows all of the intervals in the two unsafe zones 314, 316 until reaching the total duration of time. The intervals 360 have colors corresponding to the colors in the two unsafe zones 314, 316 so as to provide the details of specific times spent in the unsafe zones. In another embodiment, the display 301 shows the longest intervals in the dangerous zone 316 of the pie chart 310. By repeatedly clicking on the intervals, smaller intervals in the dangerous zone 316 are shown. In yet another embodiment, the display 301 shows intervals sequentially in all zones 312, 314, 316 of the pie chart 301. The totality of intervals are shown by scrolling down the display 360 until the time duration 370 is displayed.

[0030] FIG. 5 illustrates a single-patient, multiple-parameter physiological monitor 500 displaying parameter alarm limits. The display 500 has a pie chart 510, an indicator of duration of time 520, a parameter value 540 and alarm limits 550. The pie chart 510 has a zone 512 assigned in a distinct color, red, for example, representing a percentage of time in alarm during the duration of time. The alarm limits 550 are displayed next to the actual parameter value 540 having a lower limit 552 and an upper limit 554. An alarm is activated when the limits 552, 554 are exceeded.

[0031] Also shown in FIG. 5, the display 500 has a graph 570 showing the parameter values versus time during the duration of time and thus the specific times in alarm are shown. By repeatedly clicking the graph 570, the rest of the times can be shown until the end of the recorded time duration is reached. For example, FIG. 5 shows the lower limit 552 is 83 and no upper limit 554. Because the graph 570 does not exceed the lower limit 83 between 8:00 to 9:00, no alarm is activated during this period of time. By clicking the graph 570, other values and times in alarm will be shown until reaching the duration of 12 hours.

[0032] FIG. 6 illustrates a single-patient, single-parameter physiological status monitor 600 displaying parameter trends having integrated pie-chart summaries at specific time intervals. The display 600 has a trend line 610 with integrated pie-chart summaries 612 at specific time intervals. The display 600 also has a parameter indicator 620, a duration of time 630 and a shift timeline 640. The parameter indicator 620 corresponds to the trend line 610 and pie chart summaries 612. The duration of time 630 is the duration of the trend line 610. The trend line 610 has a plurality of pie charts 612 indicating a patient's parameter levels for each of the shifts over the shift duration. This trend line 610 advantageously provides an overview of each staff shift with respect to difficulty or success in patient management. In particular, the trend line 610 indicates acceptable levels of patient condition during each staff shift. This provides hospital or a medical institution feedback of medical care efficacy. For example, the monitor 600 advantageously provides information regarding which shift is maintaining the better patient management and which staff members are maintaining better patient management.

[0033] As shown in FIG. 6 as an example, six shifts and associated pie charts are displayed 600. Shift 3 had difficulty with this patient. However, the patient improved over his three day stay across the different shifts.

[0034] FIG. 7 illustrates a single-patient, single-parameter physiological status monitor 700 has a pie chart 710, a parameter indicator 720 and a duration of time indicator 730. The pie-chart 710 has a height 705 that represents the total monitored time interval and pie slices 712, 714, 716 that each represent the percentage of time 750 a parameter is within the specified value range 740. The pie chart 710 is a histogram over a duration of time 730, such as 24 hours. The pie chart 710 has different zones 712, 714, 716 indicating percentage of time 750 spent in each of the different value ranges 740. Each zone 712, 714, 716 is assigned to a different color so as to be easily viewed by a user to determine, at a glance, an overview of a patient's condition over a time interval.

[0035] For example, in the pie chart 710, a safe green color 712 indicates a normal condition occurring 75% of the time. An orange color 714 indicates an abnormal condition occurring 17% of the time. A red color 716 indicates a dangerous condition occurring 8% of the time. Accordingly, the details of the pie chart 710 are viewed in the range chart 740, 750 showing 9% of time spent in a SpO₂ range of 100-97, 66% of time spent in a range of 96-94, 9% in a range of 93-95, 8% in a range 84-80 and 8% in a range of 79-0.

[0036] FIG. 8 illustrates a single-patient, single-parameter physiological status monitor 800 displaying iconic patterns utilized in lieu of colors, such as for a color blind user, a monochromatic display or a high contrast display. The display 800 has different shapes 810 representing percentages of time in each condition instead of a pie chart. Further, each shape 810 has lines, dots, circle patterns to distinguish each other rather than different colors assigned in a pie chart. Accordingly, value ranges 820 and percentages of time 830 have corresponding lines, dots, circle and square patterns, instead of different colors, assigned to each range.

[0037] A physiological status monitor has been disclosed in detail in connection with various embodiments. These embodiments are disclosed by way of examples only and are not to limit the scope of the claims that follow. One of ordinary skill in art will appreciate many variations and modifications.