摘要:
Heart stimulator that stimulates at least a heart's right atrium and ventricle in an atrium asynchronous stimulation mode with an overdrive stimulation rate. Interposes one resynchronization cycle after a sensed atrial event to regain AV synchrony during otherwise asynchronous stimulation mode. Allows for pacing mode that can pace the atrium with an overdrive stimulation rate in dual-chamber asynchronous mode while maintaining the AV synchrony and is called DDI(R)+. In DDI(R)+, pacemaker performs an atrial asynchronous (V synchronous) pacing mode such as DDI or DDI(R). The overdrive stimulation rate (OSR) is either a fixed rate (programmed by the external device) that is thought to be above the underlying intrinsic atrial rate, or is dynamically adjusted according to the measured atrial cycle length to be slightly above intrinsic atrial rate. The overdrive stimulation rate may be based on an intrinsic atrial rate or on hemodynamic need. DDI(R)+ timing may be ventricle-based.
摘要:
Heart stimulator that stimulates at least a heart's right atrium and ventricle in an atrium asynchronous stimulation mode with an overdrive stimulation rate. Interposes one resynchronization cycle after a sensed atrial event to regain AV synchrony during otherwise asynchronous stimulation mode. Allows for pacing mode that can pace the atrium with an overdrive stimulation rate in dual-chamber asynchronous mode while maintaining the AV synchrony and is called DDI(R)+. In DDI(R)+, pacemaker performs an atrial asynchronous (V synchronous) pacing mode such as DDI or DDI(R). The overdrive stimulation rate (OSR) is either a fixed rate (programmed by the external device) that is thought to be above the underlying intrinsic atrial rate, or is dynamically adjusted according to the measured atrial cycle length to be slightly above intrinsic atrial rate. The overdrive stimulation rate may be based on an intrinsic atrial rate or on hemodynamic need. DDI(R)+ timing may be ventricle-based.
摘要:
Uses dual-chamber (RA-RV), three-chamber (BiA-RV, or RA-BiV), or four-chamber (BiA-BiV) implantable cardiac device including pacemakers, defibrillators and cardioverters, which stimulate cardiac tissue electrically to control the patient's heart rhythm to create a far-field intra-atrial electrogram (AEGM) and a far-field intra-ventricular electrogram (VEGM) that are independently filtered, scaled, and then summed to form a composite far-field electrogram.
摘要:
Implantable medical device with an impedance determination unit with constant current/voltage source having current feed terminals connected to electrodes for intracorporal placement which generates measuring current pulses having constant current/voltage, for causing a current through a body via intracorporally placed electrodes, a measuring unit for measuring voltage/current strength of voltage/current fed through body, an impedance value determination unit connected to the current/voltage source and adapted to determine an impedance value for each measuring current pulse, and an impedance measuring control and evaluation unit connected to the impedance determination unit which controls the unit and evaluates a sequence of consecutive impedance values, the impedance determination unit further adapted to determine at least intrathoracic and intracardiac impedance values for same period of time, the intrathoracic values sampled with a lower sampling rate than the intracardiac values.
摘要:
Implantable medical device with an impedance determination unit with constant current/voltage source having current feed terminals connected to electrodes for intracorporal placement which generates measuring current pulses having constant current/voltage, for causing a current through a body via intracorporally placed electrodes, a measuring unit for measuring voltage/current strength of voltage/current fed through body, an impedance value determination unit connected to the current/voltage source and adapted to determine an impedance value for each measuring current pulse, and an impedance measuring control and evaluation unit connected to the impedance determination unit which controls the unit and evaluates a sequence of consecutive impedance values, the impedance determination unit further adapted to determine at least intrathoracic and intracardiac impedance values for same period of time, the intrathoracic values sampled with a lower sampling rate than the intracardiac values.
摘要:
The invention relates to heart stimulators and implantable atrial pacemakers which utilize a rhythm based atrial capture threshold test wherein in a ventricle based DDI mode a predetermined number of ventricle started atrial and ventricular escape intervals are triggered with an overdrive rate about 20% higher than an intrinsic heart rate. The number of atrial sense events during atrial capture threshold test is counted. Too high of a number of atrial sense events indicates loss of capture due to too small of a pulse strength of the atrial stimulation pulses.
摘要:
The invention relates to heart stimulators and implantable atrial pacemakers which utilize a rhythm based atrial capture threshold test wherein in a ventricle based DDI mode a predetermined number of ventricle started atrial and ventricular escape intervals are triggered with an overdrive rate about 20% higher than an intrinsic heart rate. The number of atrial sense events during atrial capture threshold test is counted. Too high of a number of atrial sense events indicates loss of capture due to too small of a pulse strength of the atrial stimulation pulses.
摘要:
Method and apparatus that uses dual-chamber (RA-RV), three-chamber (BiA-RV, or RA-BiV), or four-chamber (BiA-BiV) implantable cardiac devices including pacemakers, defibrillators and cardioverters, which stimulate cardiac tissue electrically to control the patient's heart rhythm. The method and apparatus are further configured to create a far-field intra-atrial electrogram (AEGM) and a far-field intra-ventricular electrogram (VEGM) that are independently filtered, scaled, and then summed to form a composite far-field electrogram.
摘要:
The present disclosure refers to a heart stimulator comprising a stimulation control unit, a stimulation unit, an impedance measurement unit and an impedance evaluation unit. The stimulation control unit is operatively connected to the stimulation unit to control timing of stimulation pulses by said stimulation unit. The impedance measurement unit is configured to determine an impedance signal reflecting intracardiac impedance. The impedance evaluation unit is operatively connected to the impedance measurement unit and to the stimulation control unit and is configured to evaluate the impedance signal so as to determine an isovolumic contraction time, an isovolumic relaxation time, an ejection time and a filling time from said impedance signal. The stimulation control unit is further configured to control timing of stimulation pulses depending on a performance index.
摘要:
A heart stimulator provides a reliable automatic capture threshold search feature. A stimulation pulse generator is connected to at least a ventricular stimulation electrode for delivering electric stimulation pulses to at least the ventricle of the heart. The stimulation pulses generated have a strength depending on a control signal. A sensing stage is connected to an electrode for picking up electric potentials inside at least said ventricle of a heart and a control unit connected to the sensing stage and to the stimulation pulse generator determines points of time for scheduling stimulation pulses, to trigger the stimulation pulse generator so as to deliver a stimulation pulse when scheduled and to put out control signals for controlling the strength of the stimulation pulse. The control unit is further adapted to perform a capture analysis which may take into account extraordinary events.