Heart stimulator with an evoked response detector
First Claim
1. A heart stimulator comprising:
- a pulse generator which emits stimulation pulses of various amplitudes, said stimulation pulses including one of said stimulation pulses having an amplitude U1stim which is sufficiently high for obtaining safe capture and another of said stimulation pulses having an amplitude U2stim which is less than U1stim ;
a lead connected to said pulse generator and adapted for implantation in a subject to deliver said stimulation pulses to cardiac tissue in said subject and to pick up successive electrode signals respective produced by cardiac tissue in response to said stimulation pulses, said electrode signals thus being respectively associated with said stimulation pulses, and each of said electrode signals comprising a signal component which is substantially proportional to the amplitude of the associated stimulation pulse and an evoked response component which is independent of the amplitude of the associated stimulation pulse;
measuring and memory means for measuring and storing a measured amplitude U1meas for the electrode signal associated with said one of said stimulation pulses having the amplitude U1stim and a measured amplitude U2meas for the electrode signal associated with the other of said stimulation pulses having the amplitude U2stim ; and
analyzer means supplied with U1stim, U2stim, U1meas and U2meas for detecting an evoked response signal from a predetermined relation among U1stim, U2stim, U1meas and U2meas.
1 Assignment
0 Petitions
Accused Products
Abstract
An evoked response detector for a heart stimulator determines evoked response in the presence of polarization. The heart stimulator has a pulse generator which produces stimulation pulses of varying amplitudes, and a lead adapted for introduction into the heart of a patient is connected to the pulse generator for delivering stimulation pulses to the heart. The evoked response detector includes measuring and memory circuitry for measuring and storing the electrode signals picked up by the lead in response to the delivered stimulation pulses, at least one of these stimulation pulses having a sufficiently high amplitude for obtaining capture. Each measured electrode signal contains two signal components, one of these signal components being proportional to the amplitude of the associated stimulation pulse and the other signal component being substantially constant, independent of the associated stimulation pulse amplitude. An analyzing unit determines the evoked response signal from a predetermined relation between the amplitudes of at least two stimulation pulses of different amplitudes and the resulting measured electrode signals.
-
Citations
18 Claims
-
1. A heart stimulator comprising:
-
a pulse generator which emits stimulation pulses of various amplitudes, said stimulation pulses including one of said stimulation pulses having an amplitude U1stim which is sufficiently high for obtaining safe capture and another of said stimulation pulses having an amplitude U2stim which is less than U1stim ; a lead connected to said pulse generator and adapted for implantation in a subject to deliver said stimulation pulses to cardiac tissue in said subject and to pick up successive electrode signals respective produced by cardiac tissue in response to said stimulation pulses, said electrode signals thus being respectively associated with said stimulation pulses, and each of said electrode signals comprising a signal component which is substantially proportional to the amplitude of the associated stimulation pulse and an evoked response component which is independent of the amplitude of the associated stimulation pulse; measuring and memory means for measuring and storing a measured amplitude U1meas for the electrode signal associated with said one of said stimulation pulses having the amplitude U1stim and a measured amplitude U2meas for the electrode signal associated with the other of said stimulation pulses having the amplitude U2stim ; and analyzer means supplied with U1stim, U2stim, U1meas and U2meas for detecting an evoked response signal from a predetermined relation among U1stim, U2stim, U1meas and U2meas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
Specification