CARDIAC RESUSCITATOR

• US 3,703,900 A
• Filed: 12/02/1969
• Issued: 11/28/1972
• Est. Priority Date: 12/02/1969
• Status: Expired due to Term

• Current Assignee: Melvin A. Holznagel
• Original Assignee: Melvin A. Holznagel
• Inventors: Holznagel, Melvin A.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/881,470
• Time in Patent Office: 1,092 Days
• Field of Search: 128/2.5T,2.6A,2.6B,2.6E,2.6F,2.6G,2.6R,2.6V,2.1E,419D,419P
• US Class Current: 607/4
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/3904 External heart defibrillators [EHD]
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock

Abstract

A resuscitator apparatus includes means for detecting and counting the heart beat of a suspected heart attack victim, and means for substantially immediately applying a pacing pulse or a defibrillating pulse, as required. Thus, if the patient'"'"''"'"'s pulse rate is extremely low or nonexistent, a pacing pulse is automatically applied for stimulating a heart beat in time with such pulse. However, if the electrocardiac signal from the patient indicates an extremely high rate indicative of ventricular fibrillation, a defibrillating pulse is applied to the patient. If a normal beat occurs, appropriate indication is given, and no corrective action is taken. The apparatus attaches to the patient for administering the correct electrical stimulation to the patient as soon as possible after the occurrence of the suspected attack.

Claims

1. A cardiac resuscitator comprising:

electrode means for application to a patient suffering from possible heart attack, means coupled to said electrode means for detecting the electrocardiac signal generated by the patient'"'"''"'"'s heart including the QRS wave of the electrocardiac complex for indicating the patient'"'"''"'"'s heart beat, means responsive to the detecting means for determining the patient'"'"''"'"'s heart rate and for producing a first output for a heart rate below predetermined normal limits, and a second output for a heart rate above said predetermined normal limits, pacer means coupled to said electrode means and automatically responsive to said first output for applying a periodic pacing pulse at a predetermined rate in the range of a normal heart rate to said electrode means, and defibrillator means coupled to said electrode means and automatically responsive to a said second output for applying only a single substantially higher voltage defibrillating pulse to said electrode means within a period on the order of at least several seconds and in response to a given determination of heart rate above said predetermined normal limits.

2. The apparatus according to claim 1 wherein said means responsive to said detecting means includes means operative for initiating said second output only in response to occurrence of a heart rate above said predetermined normal limits for at least two successive periods of several seconds each.

3. The apparatus according to claim 1 including diode means for decoupling said detecting means from said electrode means during an output from said pacer means or said defibrillator means in response to an electrical output therefrom.

4. The apparatus according to claim 1 wherein said detecting means includes a variable sensitivity signal channel and means for storing previous peak values detected, the sensitivity of said signal channel being responsive to the previous level of said peak values as stored by said storing means for causing said detecting means to be responsive to signals exceeding at least a predetermined proportion of stored peak values.

5. The apparatus according to claim 4 further including means for limiting the level stored by said storing means to a predetermined multiple of said peak values stored theretofore, a said predetermined proportion of said multiple being less than unity.

6. The apparatus according to claim 1 including switching diode means between said defibrillator means and said patient electrode means as well as between said pacer means and said electrode means for substantually automatically disconnecting said pacer means and said defibrillator means from said electrode means and from each other except during operation of one of the respective pacer means or defibrillator means, at which time said one of said respective pacer or defibrillator means is connected to said electrode means.

7. The apparatus according to claim 1 further provided with a normal heart indicator, said means responsive to the detecting means providing a third output for operating said normal heart indicator when said heart rate is within said predetermined normal limits.

8. A cardiac resuscitator comprising:

electrode means for application to a patient suffering from possible heart attack, means coupled to said electrode means for detecting the electrocardiac signal generated by the patient'"'"''"'"'s heart including the QRS wave of the electrocardiac complex for indicating the patient'"'"''"'"'s heart beat, means responsive to the detecting means for determining the patient'"'"''"'"'s heart rate and for producing a first output for a heart rate below predetermined normal limits, and a second output for a heart rate above said predetermined normal limits, pacer means coupled to said electrode means and automaTically responsive to said first output for applying a periodic pacing pulse at a predetermined rate to said electrode means, and defibrillator means coupled to said electrode means and automatically responsive to said second output for applying a higher voltage defibrillating pulse to said electrode means, said apparatus including a U-shaped applicator wherein said electrode means are carried by said U-shaped applicator, said U-shaped applicator being positionable for yieldably urging said electrode means into firm contact with the patient'"'"''"'"'s body, one of said electrode means being mounted from an upper leg of said applicator for location against the patient'"'"''"'"'s chest over the heart area, and a second separately connected electrode means being mounted upon a lower leg of said applicator for positioning against the patient'"'"''"'"'s back opposite the first mentioned electrode means.

9. The apparatus according to claim 8 wherein said applicator further carries an indifferent electrode for application to the patient'"'"''"'"'s body at a separate location, and means for connecting the indifferent electrode to a neutral or grounded point in the apparatus.

10. A cardiac resuscitatoe comprising:

electrode means for attachment to a patient suffering from possible heart attack, means coupled to said electrode means for detecting an electrocardiac signal generated by the patent'"'"''"'"'s heart including successive pulses derived from the electrocardiac complex for indicating the patient'"'"''"'"'s heart beat, means responsive to the detecting means for counting said successive pulses during a predetermined period of time for producing a first output for a heart rate below predetermined normal limits, and a second output for a heart rate above said predetermined normal limits, pacer means coupled to said electrode means and responsive to said first output of said counting means for applying a periodic pacing pulse at a predetermined rate in the range of a normal heart rate to said electrode means, and defibrillator means coupled to said electrode means and responsive to a said second output of said counting means for applying only one substantially higher voltage defibrillating pulse to said electrode means within a period on the order of at least several seconds.

11. The apparatus according to claim 10 further including a clock means operatively connected to said counting means for predetermining a period of time during which said counting means counts said pulses, wherein said clock means resets and recycles said counting means.

12. The apparatus according to claim 11 including means for determining the continuity between said electrode means and the patient'"'"''"'"'s body, and means for inhibiting said clock means as well as inhibiting said pacer means and defibrillator means in response to the lack of such continuity.

13. The apparatus according to claim 11 wherein said counting means includes means for remembering a given count during a given cycle of said clock means, and output means responsive to said means for remembering for producing said first and second outputs at the end of a given cycle of said clock means.

14. The apparatus according to claim 13 wherein said defibrillator means is provided with connection means coupled for resetting said clock means and said counting means, and connection means for clearing said means for remembering, upon the occurrence of a defibrillating pulse.

15. The apparatus according to claim 10 including means for inhibiting operation of said pacer means until time has elapsed for occurrence of an output from said counting means.

16. The apparatus according to claim 10 wherein said counting means comprises:

a first counter operable to produce an output after a predetermined number of said pulses, first storing means for temporarily storing an output of said first counter, a second counter responsive to the output of the first counter, and a second storing means for temporarily storing an ouTput of the second counter, a first output means for receiving and remembering an output from said first storing means indicative of a heart rate below a predetermined minimum rate, and a second output means for receiving and remembering an output from said second storing means indicative of a heart rate above a predetermined maximum rate.

17. The apparatus according to claim 16 wherein said first output is provided by said first output means, and further including means for recycling said first and second counters and for recycling said first and second storage means, and gate means providing said second output in response to a level of said second output means and said second storing means at a given time to produce said second output after two successive counting cycles for indicating a heart rate above said predetermined normal limits.

18. A cardiac resuscitator comprising:

electrode means for attachment to a patient suffering from possible heart attack, means coupled to said electrode means for detecting an electrocardiac signal generated by the patient'"'"''"'"'s heart including successive pulses derived from the electrocardiac complex for indicating the patient'"'"''"'"'s heart beat, means responsive to the detecting means for counting said successive pulses during a predetermined period of time for producing a first output for a heart rate below predetermined normal limits, and a second output for a heart rate above said predetermined normal limits, said counting means comprising a first counter operable to produce an indication after a predetermined number of pulses and a second counter for producing a second indication after a higher count of pulses, said first output being responsive to the indication of said first counter, and said second output being responsive to said second indication, pacer means coupled to said electrode means and responsive to said first output of said counting means for applying a periodic pacing pulse at a predetermined rate to said electrode means, and defibrillator means coupled to said electrode means and responsive to said second output of said counting means for applying a defibrillating pulse to said electrode means.

19. The apparatus according to claim 18 wherein said second counter receives as its input the said indication of said first counter.

20. The apparatus according to claim 18 including means responsive to said indication of said first counter and the absence of an indication from said second counter for producing a third output indicative of a heart rate within said predetermined normal limits.

21. The apparatus according to claim 1 wherein said detecting means includes means for detecting positive excursions of said electrocardiac signal, means for detecting negative excursions of said electrocardiac signal, means for determining the predominant polarity of said electrocardiac signal, and gating means responsive to the last mentioned means for coupling an output from the detecting means the polarity of which predominates.

22. A cardiac resuscitator comprising:

electrode means for application to a patient suffering from possible heart attack, means coupled to said electrode means for detecting the electrocardiac signal generated by the patient'"'"''"'"'s heart including the QRS wave of the electrocardiac complex for indicating the patient'"'"''"'"'s heart beat, means responsive to the detecting means for determining the patient'"'"''"'"'s heart rate and for producing a first output for a heart rate below predetermined normal limits, and a second output for a heart rate above said predetermined normal limits, pacer means coupled to said electrode means and automatically responsive to said first output for applying a periodic pacing pulse at a predetermined rate to said electrode means, defibrillator means coupled to said electrode means and automatically responsive to said second output for applying a higher voltage defibrillating pulse to said electrode means, means for deTermining the continuity of connection of said electrode means with a patient'"'"''"'"'s body, said means for determining the continuity including means for applying a DC current to ones of said electrodes and means for measuring a resulting DC voltage at the same electrodes, and means for inhibiting operation of said resuscitator apparatus in response to a lack of such continuity.