Techniques that enable medical devices to quickly recover from loss of sensory functions are provided. In some examples, a medical device is configured to advantageously leverage differences between a first type of sensing electrode and a second type of sensing electrode that has a shorter recovery time than the first type of sensing electrode. In some examples, a medical device is configured to reference data generated by a first conditioning circuit that is configured to process signals acquired under a first set of environmental conditions and to reference data generated by a second conditioning circuit that is configured to process signal acquired under a second set of environmental conditions. In some examples, a medical device is configured to arrange electrodes used by the medical device to acquire signals in at specific locations to reduce the amount of disruptive power the electrodes encounter.

Techniques are disclosed for modulating the generation of charge current by operational circuitry included in an implantable medical device (IMD) for delivery of an induction stimulation pulse waveform by the IMD. The modulation may include modulating a charging circuit of the operational circuitry to facilitate the regulation of the induction stimulation pulse waveform. The techniques include monitoring an electrical parameter of a charging path during the delivery of the induction stimulation pulse and modulating the charging circuit based on the monitored electrical parameter.

Apparatus is disclosed for providing access to a functioning vascular system of a patient, the apparatus comprising: a main body having sidewalls defining an interior region and an exterior region, a bottom end and a top end; a base being formed at the bottom end of the main body, securing means being configured on the base so as to allow attachment and formation of a seal between the base and the functioning vascular system of the patient, and the base being configurable to provide a passageway from the interior region of the main body to the functioning vascular system of the patient; and a cover being formed at the top end of the main body, wherein the cover provides a barrier between the interior region and the exterior region at the top end of the main body.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) is configured to induce a tachyarrhythmia by charging a high voltage capacitor to a voltage amplitude and delivering a series of pulses to a patient's heart by discharging the capacitor via an extra-cardiovascular electrode vector. Delivering the series of pulses includes recharging the high-voltage capacitor during an inter-pulse interval between consecutive pulses of the series of pulses.

Techniques that enable medical devices to quickly recover from loss of sensory functions are provided. In some examples, a medical device is configured to advantageously leverage differences between a first type of sensing electrode and a second type of sensing electrode that has a shorter recovery time than the first type of sensing electrode. In some examples, a medical device is configured to reference data generated by a first conditioning circuit that is configured to process signals acquired under a first set of environmental conditions and to reference data generated by a second conditioning circuit that is configured to process signal acquired under a second set of environmental conditions. In some examples, a medical device is configured to arrange electrodes used by the medical device to acquire signals in at specific locations to reduce the amount of disruptive power the electrodes encounter.

In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

A method of pacing a His bundle of a patient heart using a stimulation system including a memory, a pulse generator, a stimulating electrode and at least one sensing electrode includes applying a plurality of impulses through the stimulating electrode to induce a plurality of responses from the patient heart. Each impulse of the plurality of impulses is delivered at a different impulse energy corresponding to a respective output setting of the stimulation system. The response characteristics for each of the plurality of responses are measured and each impulse is assigned a classification based on whether the respective response characteristics indicate capture of one or both of the His bundle and a ventricle of the patient heart. The output setting and classification for each impulse is then stored in the memory.

An external defibrillator system is disclosed that generates and applies a diagnostic signal to the patient in conjunction with defibrillation therapy. The diagnostic signal is designed to elicit a physiologic response from the patient's heart, namely, mechanical cardiac response and electrical cardiac response, electrical cardiac response only, or no cardiac response. Depending upon the type of cardiac response detected, the system selects an appropriate resuscitation protocol that considers the likely responsiveness of the patient to defibrillation therapy. In one practical embodiment, a stimulus signal is applied to patients that show mechanical and electrical capture in response to the diagnostic signal. The stimulus signal maintains the mechanical capture (and, therefore, perfusion) for a period of time prior to the delivery of a defibrillation pulse.

A method of pacing a His bundle of a patient heart using a stimulation system including a memory, a pulse generator, a stimulating electrode and at least one sensing electrode includes applying a plurality of impulses through the stimulating electrode to induce a plurality of responses from the patient heart. Each impulse of the plurality of impulses is delivered at a different impulse energy corresponding to a respective output setting of the stimulation system. The response characteristics for each of the plurality of responses are measured and each impulse is assigned a classification based on whether the respective response characteristics indicate capture of one or both of the His bundle and a ventricle of the patient heart. The output setting and classification for each impulse is then stored in the memory.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) is configured to induce a tachyarrhythmia by charging a high voltage capacitor to a voltage amplitude and delivering a series of pulses to a patient's heart by discharging the capacitor via an extra-cardiovascular electrode vector. Delivering the series of pulses includes recharging the high-voltage capacitor during an inter-pulse interval between consecutive pulses of the series of pulses.