MULTIMODE CARDIAC PACES WITH P-WAVE AND R-WAVE SENSING MEANS

• US 3,648,707 A
• Filed: 07/16/1969
• Issued: 03/14/1972
• Est. Priority Date: 07/16/1969
• Status: Expired due to Term

• Current Assignee: Wilson Greatbatch
• Original Assignee: Wilson Greatbatch
• Inventors: Greatbatch, Wilson
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/842,290
• Time in Patent Office: 972 Days
• Field of Search: 128/419P,421,422
• US Class Current: 607/9
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence

Abstract

A cardiac pacer including a pulse generator having an R-C circuit for controlling the generation of stimulating pulses. An electrode surgically placed on or in the ventricle of the heart is coupled to the output of the pulse generator. A reference or indifferent electrode is subcutaneously implanted and coupled to the pacer circuits. When no cardiac electrical activity exists stimulating pulses are provided at a preset rate. The ventricular electrode is coupled to the input of a first signal responsive circuit and to the pulse generator. In response to ventricular electrical signals of either polarity, for example R-waves, the first signal responsive circuit resets the R-C circuit in the pulse generator to a predetermined level inhibiting the subsequent generation of impulses for a suitable time such as one second. Another electrode surgically placed on or in the atrium of the heart is coupled to the input of a second signal responsive circuit which includes timing means and which is connected in controlling relation to the pulse generator. In response to atrial electrical signals, known as P-waves, and in the absence of ventricular electrical signals, the second signal responsive circuit causes the pulse generator to provide timedelayed stimulating pulses synchronized with the atrial beats.

Claims

1. A cardiac pacer comprising:

a. pulse generating means including timing means controlling the generation of pulses;

b. first and second electrodes coupled to said pulse generating means, at least one of said electrodes adapted to be operatively connected to a patient'"'"''"'"'s heart on or in the ventricle thereof;

c. a third electrode adapted to be operatively connected to a patient'"'"''"'"'s heart on or in the atrium thereof;

d. first signal responsive means coupled to at least the ventricular one of said first and second electrodes and responsive to electrical signals in the ventricle of the heart, said signal responsive means being operatively connected to said pulse generating means so that a ventricular electrical signal causes said signal responsive means to reset said timing means to a predetermined level;

e. second signal responsive means coupled to said third electrode and responsive to electrical signals in the atrium of the heart, said second signal responsive means including timing means and being operatively connected to said pulse generating means so that each natural atrial beat causes said second signal responsive means to activate said pulse generating means a predetermined time after the atrial beat and coordinated with the natural beat;

f. said first signal rEsponsive means including means for inhibiting activation of said pulse generating means by said second signal responsive means for a predetermined time following the accurrence of a natural ventricular beat; and

g. electrical power supply means connected to said pulse generating means and to said first and second signal responsive means.

2. A totally implantable cardiac pacemaker according to claim 1 which further includes moistureproof, human body reaction-free enclosure means enveloping said pulse generating means, said first and second signal responsive means, and said power supply means.

3. The cardiac pacer according to claim 1 wherein said pulse generating means including timing means comprises:

a. a semiconductor pulse generator;

b. an R-C timing circuit connected to said power supply and to said pulse generator for controlling the generation of pulses; and

c. a semiconductor switch connected to and controlled by said first signal responsive means and operatively connected to said R-C timing circuit for preventing said R-C circuit from reaching a predetermined voltage level in response to electrical signals in the ventricle of the heart.

4. The cardiac pacer according to claim 3 wherein the output of said second signal responsive means is connected to said R-C timing circuit for controlling the generation of pulses.

5. The cardiac pacer according to claim 1 wherein said first signal responsive means includes means responsive to cardiac electrical signals of either polarity.

6. The cardiac pacer according to claim 5 wherein said first signal responsive means comprises:

a. a plurality of semiconductor amplifier stages;

b. signal transmission means connected to the input of the first of said semiconductor amplifier stages;

c. means connected to the output of the last of said semiconductor amplifier stages for converting a monopolar input signal of either polarity into a bipolar output signal; and

d. semiconductor switching mean having a control terminal coupled to the output of said signal converting means and connected between said power supply and said pulse generating means.

7. The cardiac pacer according to claim 6 wherein said signal transmission means comprises a filter network adapted to reject signals having a frequency of around 60 cycles per second.

8. The cardiac pacer according to claim 6 wherein said signal converting means comprises an R-C differentiating circuit.

9. The cardiac pacer according to claim 7 wherein the first of said semiconductor amplifier stages includes a field-effect transistor, the gate terminal of which is connected to the output of said filter network.

10. The cardiac pacer according to claim 1 wherein said second signal responsive means comprises:

a. a plurality of semiconductor amplifier stages;

b. signal transmission means connected to the input of the first of said semiconductor amplifier stages;

c. means connected to the output of the last of said semiconductor stages for converting a monopolar input signal of either polarity into a bipolar output signal;

d. trigger pulse producing means connected to the output of said signal converting means;

e. a circuit connected to said trigger pulse producing means and operative in response to the occurrence of a trigger pulse for providing an output pulse having a predetermined width after a predetermined time delay; and

f. pulse amplitude limiting means connected to the output of said circuit.

11. The cardiac pacer according to claim 10 wherein said signal transmission means comprises a filter network adapted to reject signals having a frequency of around 60 cycles per second.

12. The cardiac pacer according to claim 10 wherein said signal converting means comprises an R-C differentiating circuit.

13. The cardiac pacer according to claim 10 wherein said circuit responsive to a trigger pulse comprises:

a. a first semiconductor switch connected to the output tHereof. b. an R-C timing circuit connected to the input thereof and to the control terminal of said first semiconductor switch; and

c. a second semiconductor switch connected to and controlled by said first semiconductor switch and providing a conduction path for said R-C circuit.

14. The cardiac pacer according to claim 11 wherein the first of said semiconductor amplifier stages includes a field effect transistor, the gate terminal of which is connected to the output of said filter network.

15. The cardiac pacer according to claim 1 further including independently operable switching means for selectively connecting said electrical power supply means to said pulse generating means and to said first and second signal responsive means.

16. The cardiac pacer according to claim 6 further including a frequency responsive R-C network connected to the output of said semiconductor switching means for rendering said switching means unresponsive to signals above a predetermined rate.

17. The cardiac pacer according to claim 10 further including a frequency responsive R-C network connected between said converting means and said trigger pulse producing means for rendering said trigger pulse producing means unresponsive to signal above a predetermined rate.