×

Dual chamber rate responsive pacemaker with automatic mode switching

  • US 5,144,949 A
  • Filed: 03/15/1991
  • Issued: 09/08/1992
  • Est. Priority Date: 03/15/1991
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of operating a programmable dual chamber, rate-responsive pacemaker capable of operating in more than one pacing mode and provided with atrial and ventricular sensing input and stimulation output circuitry and control logic means for operating said pacemaker in an atrial synchronous mode providing ventricular stimulation output pulses synchronously with sensed atrial depolarizations, and in at least one further rate responsive pacing mode providing atrial and/or ventricular stimulation output pulses on demand at a rate dependent upon a sensor related pacing rate control signal, comprising the steps of:

  • monitoring atrial heart beats;

    developing an average atrial heart rate/interval from successive atrial heart beats;

    providing at least one physiologic sensor for sensing a patient'"'"'s physiologic requirements of cardiac output and providing a sensor output signal in response thereto;

    developing a sensor related pacing rate/interval from said sensor output signal;

    establishing a sensor driven upper pacing rate limit for pacing said further pacing mode;

    establishing an atrial synchronous upper pacing rate limit for pacing in said atrial synchronous pacing mode;

    establishing a lower pacing rate limit;

    establishing a first mode switching boundary function defining a first set of correlated sensor related and average atrial pacing rate/interval values, wherein the sensor related rate/interval values set a pacing rate greater than the average atrial rate, through the range of possible rate/interval values between said lower pacing rate limit and said atrial synchronous upper pacing rate limit;

    establishing a second mode switching boundary function defining a second set of correlated sensor related and average atrial pacing rate/interval values, wherein the average atrial rate/interval values set a pacing rate greater than the sensor related rate, through the range of possible rate/interval values between said lower pacing rate limit and said sensor driven upper pacing rate limit;

    periodically comparing the average atrial and sensor related rate/interval values to the first and second mode switching boundary function values; and

    operating said pacemaker in said atrial synchronous mode as long as the correlated sensor related and average atrial rate/interval values do not match a value falling outside the first and second mode switching boundary functions.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×