Method and apparatus for switching cardiac stimulation signals

• US 5,044,367 A
• Filed: 06/26/1989
• Issued: 09/03/1991
• Est. Priority Date: 06/26/1989
• Status: Expired due to Fees

• Current Assignee: Oregon State University (Oregon University System)
• Original Assignee: Oregon State University (Oregon University System)
• Inventors: Endres, William P., Stephens, Betty
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Schaetzle, Kennedy J.
• Application Number:
  US07/371,495
• Time in Patent Office: 799 Days
• Field of Search: 128/419 P, 128/419 PG, 128/419 D, 128/419 R, 128/419 S, 128/709
• US Class Current: 607/4
• CPC Class Codes: A61N 1/37 Monitoring; Protecting

Abstract

Cardiac stimulation signals are routed through a switching network to select only one cardiac stimulation signal as an output signal. The selected output signal may be routed to one of two patient electrode pairs for application to specific stimulation sites on the heart.

Claims

1. An apparatus for selectively applying first and second cardiac stimulation signals to a human or other animal subject via an electrode pair, the apparatus comprising:

first means for receiving a first cardiac stimulation signal;

second means for receiving a second cardiac stimulation signal;

switching means, coupled to said first and second means, for selectively providing only one of the first and second cardiac stimulation signals as a selected output signal;

output means coupled to said switching means for applying the selected output signal to an electrode pair, said output means including first and second electrode connector pairs; and

said switching means comprising a first switch coupled to said means for receiving the first cardiac stimulation signal and to said means for receiving the second cardiac stimulation signal, said first switch selecting one of the first cardiac stimulation signal and the second cardiac stimulation signal or a null signal as the selected output signal, and a second switch receiving the selected output signal and operative to route the selected output signal to one of said first and second electrode connector pairs.

2. An apparatus according to claim 1 wherein said apparatus further comprises means for generating the first cardiac stimulation signal, said means for generating the first cardiac stimulation signal being coupled to said means for receiving the first cardiac stimulation signal.

3. An apparatus according to claim 1 wherein said means for receiving the first cardiac stimulation signal comprises a connector adapted for coupling to a first cardiac stimulation signal generator.

4. An apparatus according to claim 1 further comprising a plurality of connector means each adapted for coupling to separate patient electrode pairs, and wherein said switching means comprises means for routing the selected output signal to one of said plurality of connector means.

5. An apparatus according to claim 1 wherein said first cardiac stimulation signal is a fibrillation signal and said second cardiac stimulation signal is a pacing signal.

6. In combination,

means for receiving a pacing signal,

a fibrillation signal generator providing a fibrillation signal as output,

a switching network coupled to said means for receiving the pacing signal and to said fibrillation signal generator for selecting one of said pacing signal and said fibrillation signal as a selected output signal;

connector means coupled to said switching network to receive the selected output signal, said connector means being adapted for coupling to a patient electrode pair, and including a plurality of separate connector jack pairs, each connector jack pair being adapted for connection to separate patient electrode pairs, and wherein said switching network comprises means for routing the selected output signal to one of said connector jack pairs.

7. A combination according to claim 6 wherein the combination further comprises a pacing signal generator coupled to said means for receiving the pacing signal.

8. A combination according to claim 6 wherein said switching network comprises a first switch for selecting one of the pacing signal and the fibrillation signal as the selected output signal, and a second switch coupled to said first switch for delivering the selected output signal to one of said connector jack pairs.

9. Apparatus for selectively applying one of a pacing signal and a fibrillation signal to one of a first patient electrode pair and a second patient electrode pair, the apparatus comprising:

a transformer adapted for connecting to a source of AC power and providing a stepped-down AC signal;

amplitude adjustment means for receiving said stepped-down AC signal, adjustably attenuating the amplitude of the stepped-down AC signal, and providing the attenuated stepped-down AC signal as the fibrillation signal;

means for receiving the pacing signal;

a first switch having a first pole set coupled to said amplitude adjustment means to receive the fibrillation signal, a second pole set connected to said receiving means to receive the pacing signal, and a center pole set providing a selected output signal whereby a first position of said first switch connects the first pole set to the center pole set to provide the fibrillation signal as the selected output signal, a second position of said first switch connects the second pole set to the center pole set to provide the pacing signal as the selected output signal, and a third position of said first switch isolates the center pole set from the first and second pole sets and provides a null signal as the selected output signal;

a second switch having a first pole set, a second pole set, and a center pole set, the center pole set of said first switch being connected to the center pole set of said second switch whereby a first position of said second switch connects the center pole set of said second switch to the first pole set of said second of said second switch, a second position of said second switch connects the center pole set of said second switch to the second pole set of said second switch, and a third position of said second switch isolates the center pole set of said second switch from the first and second pole sets of said second switch;

first output connector means connected to the first pole set of said second switch and adapted for coupling to said first patient electrode pair; and

second output connector means connected to the second pole set of said second switch and adapted for coupling to said second patient electrode pair.

10. An apparatus according to claim 9 wherein said means for receiving the pacing signal comprises a connector adapted for coupling to a pacing signal generator.

11. An apparatus according to claim 9 wherein said amplitude adjustment means comprises an adjustable voltage divider connected to a secondary winding of said transformer.

12. A method of stimulating hear tissue by electric signal, the method comprising the steps:

providing first and second cardiac stimulation signals;

routing said first and second cardiac stimulation signals through a switching network for selecting one of said first and second cardiac stimulation signals as a selected output signal; and

applying the selected output signal to a connector pair adapted for coupling to a patient electrode pair by routing the selected output signal through a second switching network for routing the selected output signal to one of two connector pairs each adapted for coupling to separate patient electrode pairs.

13. A method according to claim 12 wherein said step of providing first and second cardiac stimulation signals includes the steps of generating one of said first and second cardiac stimulation signals and receiving the other one of said first and second cardiac stimulation signals by connector means.

14. A method according to claim 12 wherein said first cardiac stimulation signal causes said heart tissue to substantially stop pumping blood and said second cardiac stimulation signal causes said heart tissue to pump blood at a regulated pace.

15. A method according to claim 12 wherein the first cardiac stimulation signal is a fibrillation signal and the second cardiac stimulation signal is a pacing signal.