초록 ▼

An improved system and method for performing automatic capture/threshold detection in an implantable cardiac stimulation device or any device capable of stimulating some organ or tissue in the body. In existing systems a threshold stimulation energy level is periodically determined and a working sti

An improved system and method for performing automatic capture/threshold detection in an implantable cardiac stimulation device or any device capable of stimulating some organ or tissue in the body. In existing systems a threshold stimulation energy level is periodically determined and a working stimulation energy level is then set by increasing the threshold stimulation energy level by a fixed or preprogrammed safety margin, e.g., a fixed voltage level or a percentage safety margin. However, in certain circumstances this safety margin may not be sufficient, resulting in either frequent threshold level determinations or losses-of-capture. To avoid these situations which may be wasteful of battery energy or dangerous for the patient, embodiments of the present invention periodically increase and/or decrease the safety margin according to the performance of the stimulation device, i.e., based upon the frequency of capture.

대표청구항 ▼

1. An implantable cardiac stimulation device for stimulating a patient's heart during a cardiac cycle through at least one electrode implanted in electrical contact with selected cardiac tissue, the stimulation device comprising:a pulse generator configured for electrical coupling to the electrode a

1. An implantable cardiac stimulation device for stimulating a patient's heart during a cardiac cycle through at least one electrode implanted in electrical contact with selected cardiac tissue, the stimulation device comprising:a pulse generator configured for electrical coupling to the electrode and configured to generate stimulation pulses at a controlled energy level to thereby stimulate the patient's heart, wherein the controlled energy level has an amplitude component and a duration component; a detection circuit configured for electrical coupling to the electrode and configured to receive cardiac signals for determining the presence or absence of an evoked response to each of the stimulation pulses; a controller coupled to the pulse generator and the detection circuit for determining the controlled energy level by adding a safety margin value to a threshold controlled energy level at which capture is detected; and wherein the safety margin value varies according to a safety margin adjustment criteria related to the absence of evoked responses.