×

Cardiac pacemaker with selective unipolar/bipolar pacing

  • US 4,741,342 A
  • Filed: 03/11/1986
  • Issued: 05/03/1988
  • Est. Priority Date: 03/11/1986
  • Status: Expired due to Term
First Claim
Patent Images

1. A dual chamber cardiac pacemaker for pacing the atrial and ventricular chambers of the heart in any combination of unipolar and bipolar pacing modes, comprising:

  • atrial and ventricular leads each including a stimulating cathodic electrode and an anodic electrode to be positioned within the respective chamber of the heart.a dc power source for delivering a voltage of predetermined polarity and magnitude between a power terminal and a ground reference terminal thereof,circuit means coupled across the power and reference terminals of said power source for sequentially applying said voltage as an electrical stimulus to first one and then the other of said stimulating electrodes,a case housing said circuit means, said case including a third anodic electrode,said circuit means includingswitch means for selectively conductively connecting at least one among the three anodic electrodes to the reference terminal of the power source at all times, andcontrol means for completing a conductive path between the power terminal of the power source and the stimulating electrode for the respective chamber undergoing pacing while simultaneously actuating said switch means to maintain a conductive connection between the reference terminal of the power source and one of said anodic electrodes selected according to the desired pacing mode for said respective heart chamber undergoing pacing, said control means includingmeans for selectively applying control voltages of the same polarity as the voltage at said power terminal to said switch means for actuation thereof to provide the respective conductive connections, andmeans for maintaining each of said control voltages at a magnitude greater than the magnitude of the voltage at said power terminal to maintain said switch means in the desired actuated state and to avoid undesired switching of said reference terminal among said anodic electrodes.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×