Portable electronic cardiac stimulator

• US 3,866,615 A
• Filed: 01/15/1973
• Issued: 02/18/1975
• Est. Priority Date: 01/15/1973
• Status: Expired due to Term

• Current Assignee: John R. Hewson
• Original Assignee: John R. Hewson
• Inventors: Hewson, John R.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/323,972
• Time in Patent Office: 764 Days
• Field of Search: 128/404,418,419C,419D,419E,419P,421,422,423
• US Class Current: 607/4
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39

Abstract

A light weight portable electronic cardiac emergency stimulator which includes separate defibrillation and pacemaking electronic circuits and a self-contained battery pack. The defibrillation and pacing circuits are selectively connectable, through a switch, to a pair of electrodes of special design which may be introduced rapidly into the patient'"'"''"'"'s heart by a needle through his chest wall. The electrodes are self-spreading within the heart to establish firm electrical contact with opposite sides of its inner surface. After the electrodes have been introduced to the heart, as into the left ventricle, the circuits can be selectively connected to the electrodes through a switch to controllably apply either defibrillation or pacemaking electric pulses to the heart without delay.

Claims

1. A portable emergency cardiac stimulator comprising:

defibrillation circuit means for generating a high voltage electrical pulse for defibrillating a fibrillating ventricle of a heart when applied directly to the wall of said ventricle;

pacing circuit means for generating repetitive low voltage electrical pulses at a predetermined rate;

transthoracically insertable bipolar cardiac electrode means for directly contacting substantially diametrically opposite portions the ventricle, said electrode means having leads trailing therefrom, such that when said electrode means are disposed interiorly of said ventricle the trailing ends of said leads may extend transthoracically and be disposed exteriorly of the patient;

switch means, having an input, said switch means further including a common output lead, for selectively connecting the output of either of said defibrillation circuit means or said pacing circuit means to said common output lead;

means for detachably connecting, in electrically conductive relation, the trailing leads of said electrode means to said common output lead to enable said electrode leads to be connected to said common output lead after transthoracic insertion of said electrode means into said ventricle; and

battery means connected to the input of said switch means for powering said defibrillation circuit means and said pacing circuit means.

2. A device defined in claim 1 further comprising:

said battery means including pair of identical storage batteries and second switch means for selectively connecting either of said storage batteries to the input of said first mentioned switch means.

3. A bipolar cardiac electrode comprising:

a pair of flexible, electrically conductive wires, each of said wires having a leading end and a trailing end, said leading ends of said wires extending generally transversely and away from each other when relaxed to assume a generally T-shaped configuration whereby when disposed within said cardiac lumen, the most laterally disposed regions of the leading ends of said wires may contact substantially diametrically opposite portions of the inner surface of said cardiac lumen;

said leading ends of said wires being resilient and flexible to enable said leading ends to be constrained into a substantially parallel configuration thereby to enable said leading ends to be retained within and passed through a cardiac needle and to spread and return toward said T-shaped configuration when said leading ends pass through the end of said needle into said cardiac lumen;

insulation means surrounding said wires fully along the length of said wires;

the outer extremities of the leading ends of said wires being curved inwardly toward each other, when relaxed, thereby defining curved convex cOnfigurations at the lateral extremities of said relaxed leading ends so that the lateral extremities of said wires are defined by regions between the longitudinal extremities of said leading ends thereof;

means defining a window in said insulation means surrounding each of said leading ends, each of said windows being disposed at the curved convex lateral extremity of its associated wire, each of said windows exposing its associated conductive wire outwardly and transversely;

means for exposing each of said wires at their trailing ends to enable said wires to be connected to a source of electricity.

4. A bipolar cardiac electrode as defined in claim 3 further comprising:

said windows are defined by generally laterally outwardly facing openings in said insulation and circumscribing approximately 180* of the cross section of said wire.

5. An electrode arrangement as defined in claim 4 wherein said window is approximately 3/16 of an inch in length.

6. A bipolar cardiac electrode as defined in claim 3 further comprising:

each of said leading ends being of substantially S-shaped configuration when relaxed, said S-shaped configuration including said convex curved outer extremity of said leading end in a reverse curved segment, the reverse curved segments of said leading ends merging into a common insulative sheath at the trailing lead of said electrode.

7. A bipolar cardiac electrode as defined in claim 4 wherein the leading ends further comprise:

said wire being biologically nonreactive and being of a diameter of approximately 0.012 inches; and

said insulative sheath being biologically non-reactive and having an outer diameter of approximately 0.017 inches.