초록 ▼

A pacemaker and physiological sensor for use therewith that allows the rate at which the pacemaker delivers electrical stimulation pulses to the heart, or the escape interval during which a natural heart event must occur before an electrical stimulation pulse is delivered, to be adjusted as needed i

A pacemaker and physiological sensor for use therewith that allows the rate at which the pacemaker delivers electrical stimulation pulses to the heart, or the escape interval during which a natural heart event must occur before an electrical stimulation pulse is delivered, to be adjusted as needed in order to satisfy the body\s physiological needs. The sensor measures the depolarization time interval between an atrial stimulation pulse, A, and the responsive atrial or ventricle depolarization, P or R respectively, as an indication of the physiological demands placed on the heart. The time interval between a ventricular stimulation pulse, V, and the responsive ventricular depolarization, R, may also be measured and used as an indication of physiological need, and hence as an alternative criteria for rate control. Atrial depolarization is sensed by detecting a P-wave, and ventricular depolarization is preferably sensed by detecting an R-wave. A method of measuring A-P, A-R, or V-R intervals is used to ascertain if these intervals are increasing or decreasing. If, over several heart cycles or beats, an increase or decrease in these measurements is detected, the pacing interval set by the pacemaker is adjusted in an appropriate direction in order to adjust the heart stimulation rate accordingly.

대표청구항 ▼

A cardiac pacemaker for controlling the rate at which a heart beats as a function of physiological need, said heart beat rate defining a cardiac cycle during which atrial and ventricular events occur, said pacemaker comprising: means for generating an atrial stimulation pulse (A); means for deliveri

A cardiac pacemaker for controlling the rate at which a heart beats as a function of physiological need, said heart beat rate defining a cardiac cycle during which atrial and ventricular events occur, said pacemaker comprising: means for generating an atrial stimulation pulse (A); means for delivering said atrial stimulation pulse to an atrium of the heart in order to trigger atrial depolarization (P); means for sensing the occurrence of said triggered atrial depolarization; means for measuring the time interval between the generation of said atrial stimulation pulse and said triggered atrial depolarization, said atrial depolarization time interval being referred to as an A-P interval, said A-P interval varying as a function of physiological need; and means for adjusting the pacemaker-controlled rate as a function of the measured A-P interval; whereby the pacemaker-controlled rate is adjusted as a function of physiological need as sensed by measuring said depolarization time interval.