External Cardiac Resuscitation Aid

This invention relates to a small inflatable "pillow" provided with a pressure gauge for enabling a rescuer to accurately control the force or pressure applied to the victim's chest when administering external cardiac resuscitation.

When the heart is stopped as a result of injury, poisoning, electric shock, heart attack or other causes, circulation sufficient to maintain life may be maintained by the rythmic application of the correct amount of pressure to the chest. This technique is known as manual, external, cardiac compression, and when combined with artifical respiration it is called cardiopulmonary resuscitation (CPR).

In adult males, for example, the correct pressure or force that should be applied to the chest is approximately 90 pounds. If too little pressure is applied the circulation created, if any, will not be sufficient to prevent brain damage or even death. On the other hand, if the pressure applied is too great, broken ribs, punctured lungs and other damage may result. Further, application of pressure on too small an area of the chest can more readily result in broken ribs and other damage, for example, if the knuckles of the rescuer's hand are pressing on the victim's ribs. Also, if the pressure is not applied evenly but applied in quick jabs, the likelihood of injury is increased, and if the pressure is not applied rythmically and with proper timing, satisfactory results may not be obtained.

Therefore, it is an object of this invention to provide a method and apparatus whereby the pressure applied during external cardiac resuscitation may be observed by the person administering such aid.

It is a further object of this invention to provide an inexpensive and compact device which will indicate the amount of pressure or force applied during external cardiac resuscitation.

It is also an object of this invention to provide an inexpensive and compact pressure distribution device which optionally may not have the pressure measuring and indicating means.

It is another object of this invention to provide one or more of the above described devices with a timing indication means to insure that the rescuer will use the appropriate rythmn in the application of external cardiac resuscitation.

It is a further object of the invention to provide the above-mentioned devices with an adhesive backing so that the device is secured and located in the proper position on the victim.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. The objects and advantages are realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

To achieve these and other objects the present invention provides for an inflatable structure of heavy vinyl or other suitable material approximately three inches square and two inches high (when inflated) having a pressure indicating device such as a pressure gauge associated therewith. The structure is inflated by mouth through a suitable inflation valve such as are found on air mattresses. The gauge may be calibrated to indicate the pressure or force applied to a victim by placing the inflatable structure on a spring weight scale and applying various pressures, (especially in the range required for external cardiac resuscitation) on the structure and recording these pressures from the spring weight scale onto the face of the pressure gauge indicator face. In experiments it has been found that a pressure of eight pounds per square inch on the gauge is representative of a downward force on the inflatable structure of ninety pounds.

In use, the above described external cardiac resuscitation aid is inflated by mouth and placed on a victim's chest over the lower sternum, and pressure or force is applied to the victim's chest directly through the device. The user will observe the gauge to obtain a substantially instantaneous reading each time he applies pressure (about once per second) to be sure that the proper pressure is attained.

In another embodiment a timing device such as an easily readable stop watch may be attached to the device to enable the rescuer to maintain the proper rythmn. Any other suitable adjustable timing device can be used using audible and/or visual signals, as an example. Electronic or other timing means and even a compact metronome device could be used. For example, with two rescuers the rythmm should be one compression and relaxation per second (compression comprising one half second relaxation one half second).

In another embodiment, the timing means may be an integral part of the pressure gauge, for example, the pressure gauge may be designed so that an appropriate time interval, e.g., one half second, is required for the pressure indicator pointer to relax to zero. Ideally, this timing feature is adjustable to suit different circumstances.

The resiliency of the inflatable "pillow" or other pressure applying means is a valuable feature of the invention. This resiliency tends to reduce the chances of damage or injury to the patient when administering cardiopulmonary resuscitation (CPR) by virtue of the fact that it provides for an even distribution of pressure. Further, it tends to absorb the harmful effects of improperly applied (CPR), such as sharp jabs rather than even, regular compressions. The "pillow"acts as a resilient, force equalizing and transmitting member and as a force receiving and transmitting means by evenly distributing the force applied directly thereto by the rescuer and by transmitting that force to the patient's chest. Accordingly, one embodiment of the invention would consist simply in an inflatable "pillow" or other similarly shaped structure of suitable material such as foam rubber for the application of CPR. Such a device would be of value even though it did not have the pressure sensing and pressure indicating means and other features described above. However, it could include these additional features or any combination thereof, including the use of the timing means.

Further improvement to the above-described embodiments is the provision of a pressure sensitive adhesive surface, such as medical adhesive tape, on the bottom of the "pillow" or resilient cushion. This adhesive would have a peel-off cover. Thus, the rescuer need only locate the proper position for the device, peel off the cover and apply it to the victim's chest. Then, should the rescuer have to stop the CPR for an interval because of moving or transporting the victim or to apply mouth- to-mouth resuscitation (one man rescue) the rescuer will not lose time in reapplying CPR because the device will have remainded in the proper position on the victim's chest. Further, the chance of causing damage by inadvertently applying pressure in the wrong place will be greatly reduced.

Any type of suitable pressure-sensing device coupled with a suitable pressure indicating means may be employed in the practice of this invention. For example, an electrical transducer might be used to sense pressure in the inflatable "pillow" or might be used to sense the direct pressure applied through the resilient cushion to the victim. Pressure indicating means may be a visual and/or an audible signal.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the invention, and together, with the description serve to explain the principles of the invention.

FIG. 1 is a perspective view of one embodiment of the invention;

FIG. 2 shows a section of another embodiment of the invention;

FIG. 3 is a cross-section of a further embodiment of the invention;

FIG. 4 is a cross-section of still another embodiment of the invention; and

FIG. 5 is a view illustrating the application of CPR using the cushion or pillow of this invention.

With reference now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 an inflatable "pillow" of vinyl or other suitable material 1 with an inflation valve 2, such as found in air mattresses and children's inflatable toys. The inflatable structure 1 is also provided with a pressure gauge 3 axially aligned with the "pillow" and which measures the pressure inside the inflatable structure 1. The pressure gauge 3 senses and indicates the downward force exerted on the structure 1, which force is related to but not necessarily equal to the pressure inside the structure 1. Optional instructions 4 may be printed on the top of the inflatable portion of the external cardiac resuscitation aid. In addition a timing means (not shown) may be used in conjuction with pressure gauge 3 to enable proper rythmical application of CPR.

FIG. 2 is a cross-sectional view of a similar embodiment with optional improvements. Inflatable vinyl pillow 11 is provided with one way inflation valve and tube 13. Inflation valve 13 is optional if the device is provided with its own sealed-in supply of air or other fluid. An optional, resilient, porous, foam rubber or porous foam plastic pad 12 may be located inside the inflatable or inflated vinyl pillow 11 to permit continued use of the pillow even if it becomes punctured and unable to hold air. Optional adhesive layer 14 may be located on the bottom surface of the pillow covered by removable sheet 15. A flexible instruction sheet 16 showing detailed instructions for CPR is attached both to the pillow and to pressure gauge 17. Instructions 16 and the face of pressure gauge 17 may be provided with luminous lettering or other indicia for use when no light is available. Pressure gauge 17 may be optionally designed so that the pressure indicator needle requires one half second or some other predetermined time interval to relax back to zero to provide for a timing reference for the rescuer. Another optional feature may provide for this relaxation time interval to be adjustable. This timing feature is illustrated in FIG. 2 by 17' and other timing means not specifically described herein may also be used. Hollow tube 18 conducts fluid pressure from the interior 11' of pillow 11 to pressure gauge 17 so that the force and pressure exerted by the rescuer on the pillow is registered on gauge 17.

With reference now to FIG. 3, cushion or pillow 19 is constructed of suitably resilient foam rubber or foam plastic or other suitable material 12 to provide even pressure distribution in the application of CPR and to lessen harmful effects of improperly applied CPR. Optionally, instruction sheet 16 may also be provided attached to cushion 19. Though not shown, adhesive layer and removable sheet 14, 15 of FIG. 2 may be attached to the bottom of cushion 19.

FIG. 4 shows an inflatable pillow 20 which has an inflation tube and valve 13. Instruction sheet 16 is also attached to inflatable pillow 20. The pillow may be constructed of vinyl or other suitable material. This embodiment has the advantage, that it may be deflated and easily carried on the person or stored in a small space. Though not shown, the adhesive features 14 and 15 of FIG. 2 may also be provided with this unit.

The present invention provides for an inexpensive, portable, and compact device and method for assisting a rescuer in applying CPR by indicating the amount of pressure applied. The device may also provide for a predetermined time interval for relaxation to zero of the pressure gauge whereby a timing reference is also provided for the rescuer and whereby the correct rhythm can be followed in applying CPR. Studies have shown that up to 40% of persons trained in CPR forget the proper CPR techniques three months after having been trained. This invention enables anyone to properly administer CPR, even those who are untrained or those who have forgotten their training.

The invention in its broader aspects is not limited to the specific details shown and described, and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.