CARDIAC RESUSCITATOR

• US 3,716,059 A
• Filed: 08/24/1970
• Issued: 02/13/1973
• Est. Priority Date: 08/24/1970
• Status: Expired due to Term

• Current Assignee: Melvin A. Holznagel, Warren S. Welborn
• Original Assignee: Melvin A. Holznagel, Warren S. Welborn
• Inventors: Holznagel, Melvin A., Welborn, Warren S.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/066,189
• Time in Patent Office: 904 Days
• Field of Search: 128/2.6A,2.6E,2.6F,2.6R,2.1E,2.1R,2.1Z,419D,419P,2.5P,2.5R
• US Class Current: 607/4
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3904 External heart defibrillators [EHD]
• CPC Class Codes: A61N 1/39046 User protection from shock
• 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 electrical and mechanical output of the heart of a suspected heart attack victim, and means for substantially immediately applying a pacing pulse or a defibrilating pulse, as required. Thus, if both electrical and mechanical outputs have low rates, or are nonexistent, a pacing pulse is automatically applied for stimulating a heart beat in time with such pulse. However, if electrical activity is present while mechanical output is absent, indicative of ventricular fibrillation, a defibrillating pulse is applied to the patient. If both electrical and mechanical activity are present, indicative of substantially normal operation, 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:

means for detecting electrical activity of a patient'"'"''"'"'s heart, means for detecting mechanical activity of a patient'"'"''"'"'s heart, and means for applying a defibrillating pulse to said patient in the presence of electrical activity accompanied by the absence of mechanical activity as compared with predetermined activity levels.

2. The apparatus according to claim 1 including means for rendering said means for detecting mechanical activity effective only immediately following detected electrical activity.

3. The apparatus according to claim 1 wherein said means for detecting mechanical activity comprises means for detecting impedance changes in a patient'"'"''"'"'s body.

4. Cardiac resuscitator apparatus comprising:

first means for detecting an electrocardiac signal generated by a patient'"'"''"'"'s heart including the QRS wave of the electrocardiac complex, second means responsive to mechanical movement in the patient'"'"''"'"'s body indicative of a patient'"'"''"'"'s heart beat, means for applying a pacing pulse at a predetermined rate to the patient in response to the absence of both electrical and mechanical activity of the patient'"'"''"'"'s heart as indicated by failure of both said first and second means to produce outputs above predetermined limits, and means for applying a defibrillating pulse to the patient in response to the presence of an electrical activity indicating output above a predetermined lImit from said first means and the absence of a mechanical activity indicating output above a predetermined limit from said second means.

5. The apparatus according to claim 4 wherein said means for detecting mechanical activity comprises means for applying a signal to the patient, and means for detecting a change in voltage drop produced by said signal for detecting changes in body impedance caused by mechanical heart activity.

6. The apparatus according to claim 5 wherein said means for applying a signal to a patient includes a first electrode connected to the means for applying a signal, a second electrode for application to the patient, and means connecting the second electrode to the means for detecting a change in voltage drop.

7. The apparatus according to claim 6 wherein at least one of said electrodes is also coupled to said first means for detecting the electrocardiac signal.

8. A cardiac resuscitator comprising:

electrode means for application to a patient suffering from possible heart attack, first 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, if present, second means coupled to said electrode means for detecting impedance changes in the patient'"'"''"'"'s body, logical means coupled to receive outputs from said first and second means and for determining when said first and second means produce output rates respectively indicative of acceptable electrical and mechanical activity of the patient'"'"''"'"'s heart, as the pulse rate detected by each of said first and second means exceeds predetermined levels, pacer means coupled to said logical means and responsive to the absence of both electrical and mechanical activity, as indicated by failure of the outputs of either said first and second means to exceed predetermined levels, for providing an output comprising periodic pacing pulses at a predetermined rate, means coupling the last mentioned output to said electrode means, and defibrillator means coupled to said electrode means and responsive to said logical means, as the output of said first means above a predetermined level indicates electrical activity of the patient'"'"''"'"'s heart, while the output of the second means fails to exceed a predetermined level indicating absence of acceptable mechanical activity of the patient'"'"''"'"'s heart, for applying a defibrillating pulse to said electrode means.

9. The apparatus according to claim 8 including indicating means responsive to said logical means when both said first and second means produce outputs above predetermined limits for indicating normal heart activity.

10. The apparatus according to claim 8 including a coincidence detector for receiving the outputs of both said first and second means and providing the output of said second means to said logical means only in the event that the output of said second means occurs within predetermined time limits of the output of said first means such that mechanical activity will only be detected in each instance substantially immediately following a detection of electrical activity of a patient'"'"''"'"'s heart.

11. The apparatus according to claim 8 wherein said logical means comprises means for counting the outputs of said first means and said second means within predetermined time periods and producing logical outputs in accordance with the count of said outputs as they exceed predetermined lower activity levels.

12. The apparatus according to claim 8 wherein said means for detecting impedance changes of the patient'"'"''"'"'s body comprises means for generating a high frequency alternating current for application to said patient'"'"''"'"'s body via said electrode means, and means responsive to the signal received at other electrode means for detecting changes in said signal.

13. The apparatus according to claim 8 including means for decoupling said detecting means from said electrode means during an output from said pacemaker Means or said defibrillator means.

14. The apparatus according to claim 8 including means for determining the continuity of connection of said electrode means with the patient'"'"''"'"'s body, and means for inhibiting the pacing pulse and defibrillating pulse application of said resuscitator apparatus, in response to a lack of such continuity.

15. The apparatus according to claim 8 wherein said first detecting means includes a variable sensitivity signal channel, having means for receiving and coupling the electrocardiac signal and means for storing previous peak values detected, the signal channel being coupled to the means for storing for changing the sensitivity of said signal channel in response to the previous level of peak values stored for causing said first detecting means to be responsive to signals exceeding at least a predetermined proportion of said peak values.

16. The apparatus according to claim 15 further including means for limiting the level stored by said storing means to a predetermined multiple of said peak values stored theretofore.