Abstract: An exemplary includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Embodiments include electrical leads and methods of using electrical leads that may be used for delivering both cardioversion/defibrillation signals and pacing signals and sensing to target tissue. Some of these embodiments may also be used to sense and transmit electrical signals from target tissue. Some electrical lead embodiments are configured to be delivered into a patient's intrapericardial space by non-invasive methods.

Abstract: An exemplary method includes selecting a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector; acquiring position information during one or more cardiac cycles for the first and second pairs of electrodes wherein the acquiring comprises using each of the electrodes for measuring one or more electrical potentials in an electrical localization field established in the patient; and determining a dyssynchrony index by applying a cross-covariance technique to the position information for the first and the second vectors. Another method includes determining a phase shift based on the acquired position information for the first and the second vectors; and determining an interventricular delay based at least in part on the phase shift.

Abstract: A surface electrocardiogram (EKG) is emulated using signals detected by internal leads of an implanted device. In one example, emulation is performed using a technique that concatenates portions of signals sensed using different electrodes, such as by combining far-field ventricular signals sensed in the atria with far-field atrial signals sensed in the ventricles. In another example, emulation is performed using a technique that selectively amplifies or attenuates portions of a single signal, such as by attenuating near-field portions of an atrial unipolar signal relative to far-field portions of the same signal. The surface EKG emulation may be performed by the implanted device itself or by an external programmer based on cardiac signals transmitted thereto. A transtelephonic monitoring network is also described, wherein the emulated surface EKG (or raw data used to emulate the EKG) is relayed from an implanted device to a remote monitor, typically installed in a physician's office.

Abstract: A method for use in an implantable medical device comprises the steps of monitoring respiration with an amplifier having a gain, generating a moving apneic threshold based on recent respiration cycles, accumulating differences between amplitudes of respiration cycles and the moving apnea detection threshold and comparing the accumulated differences against an apnea detection threshold to detect the onset of an episode of apnea. The method further comprises measuring respiration levels upon detecting the onset of apnea, confirming the episode of apnea based upon the respiration levels measured upon detecting the onset of apnea; and adjusting one of the gain of the amplifier and the apnea detection threshold so that the time from the detection of onset of apnea to the time of confirmation of the episode of apnea is within a predetermined time range following the detection of the onset of apnea.

Abstract: An implantable system acquires intracardiac impedance with an implantable lead system. In one implementation, the system generates frequency-rich, low energy, multi-phasic waveforms that provide a net-zero charge and a net-zero voltage. When applied to bodily tissues, current pulses or voltage pulses having the multi-phasic waveform provide increased specificity and sensitivity in probing tissue. The effects of the applied pulses are sensed as a corresponding waveform. The waveforms of the applied and sensed pulses can be integrated to obtain corresponding area values that represent the current and voltage across a spectrum of frequencies. These areas can be compared to obtain a reliable impedance value for the tissue. Frequency response, phase delay, and response to modulated pulse width can also be measured to determine a relative capacitance of the tissue, indicative of infarcted tissue, blood to tissue ratio, degree of edema, and other physiological parameters.

Abstract: Techniques are provided for use by implantable medical devices such as pacemakers or by external systems in communication with such devices. An intracardiac electrogram (IEGM) is sensed within a patient in which the device is implanted using a cardiac signal sensing system. Cardiac events of interest such as arrhythmias, premature atrial contractions (PACs), premature ventricular contractions (PVCs) and pacemaker mediated tachycardias (PMTs) are detected within the patient using event detection systems and then portions of the IEGM representative of the events of interest are recorded in device memory. Subsequently, during an off-line or background analysis, the recorded IEGM data is retrieved and analyzed to identify false detections. In response to false detections, the cardiac signal sensing systems and/or the event detection systems of the implantable device are selectively adjusted or reprogrammed to reduce or eliminate any further false detections, including false-positives or false-negatives.

Abstract: A filtering scheme for an implantable medical device mitigates potentially adverse effects that may be caused by MRI-induced signals. In some aspects filtering is provided to attenuate MRI-induced signals on an implanted cardiac lead that is coupled to an implanted device. In some aspects the filter may be configured to complement a capacitor circuit (e.g., a feedthrough capacitor) that reduces the amount of EMI that enters the implanted device via the cardiac lead. In some implementations the filter consists of a LC tank circuit and a series LC circuit, where the LC tank circuit is in series with the cardiac lead and a cardiac stimulation circuit and the series LC circuit is in a shunt configuration across the cardiac stimulation circuit.

Abstract: An exemplary method includes providing an optimal interventricular interval, determining an atrio-ventricular conduction delay for the ventricle having faster atrio-ventricular conduction, determining an interventricular conduction delay and determining an advance atrio-ventricular pacing interval, for use in pacing the ventricle having slower atrio-ventricular conduction, based at least in part on the optimal interventricular interval and the interventricular conduction delay. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: The intrapericardial lead includes a lead body having a proximal portion and a flexible, pre-curved distal end portion. The distal end portion carries at least one electrode assembly containing an electrode adapted to engage pericardial tissue. The distal end portion further carries a pre-curved flexible wire member having ends attached to spaced apart points along the distal end portion of the lead body, the flexible wire member having a normally expanded state wherein an intermediate portion of the wire member is spaced apart from the distal end portion, and a generally straightened state wherein the wire member and the distal end portion are disposed in a more parallel, adjacent relationship so as to present a small frontal area to facilitate delivery into the pericardial space. The wire member re-expands to its normal state after delivery into the pericardial space to anchor the distal end portion of the lead body relative to the pericardial tissue.

Abstract: Techniques are described for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT) using an implantable medical device capable of multi-site ventricular sensing. In one example, ventricular depolarization events are detected within a patient by the implantable device during a tachyarrhythmia, at both a left ventricular sensing site and a right ventricular sensing site. Ventricular event timing differences are then ascertained. The device compares the ventricular event timing differences detected during the tachyarrhythmia with predetermined supraventricular event timing differences for the patient, such as event timing differences previously detected within the patient during sinus rhythm or extrapolated from sinus rhythm values. The device then distinguishes VT from SVT based on the comparison of the event timing differences detected during the tachyarrhythmia with the predetermined supraventricular event timing differences.

Abstract: An implantable lead is provided that comprises a lead body and a header assembly. The lead body has a distal end and a proximal end. The lead body is configured to be implanted in a patient. The header assembly is provided at the distal end of the lead body and includes an internal chamber and a tissue engaging end. An electrode is provided on the header assembly. The electrode is configured to deliver a stimulating pulse. A resonant inductor is located within the chamber in the header assembly. An electrically floating heat spreader is provided on the header assembly. The heat spreader is located proximate to the resonant inductor and is positioned on the header assembly to cover at least a portion of the resonant inductor. The heat spreader is thermally coupled to the resonant inductor to convey thermal energy away from the header assembly.

Abstract: Techniques are provided for use with an implantable cardiac stimulation device equipped for multi-site left ventricular (MSLV) pacing using a multi-pole LV lead. In one example, MSLV interelectrode conduction delays are determined among the electrodes of the multi-pole LV lead. MSLV interelectrode pacing delays are then set based on the MSLV interelectrode conduction delays for use in delivering MSLV pacing. To this end, various criteria are exploited for determining optimal values for the pacing delays based on the interelectrode conduction delays. MSLV pacing is then controlled using the specified MSLV interelectrode pacing delays. In some examples, the optimization procedure is performed by the implantable device itself. In other examples, the procedure is performed by an external programmer device. In such an embodiment, the external device determines optimal MSLV interelectrode pacing delays and then transmits programming commands to the implantable device to program the device to use the pacing delays.

Abstract: Techniques are provided for use by implantable medical devices for determining a preferred or optimal pair of electrodes for delivering biventricular pacing therapy. In one example, the implantable device is equipped with a right ventricular (RV) lead and a multi-pole left ventricular (LV) lead. Briefly, for each of a selected set of RV/LV electrode pairs, electrocardiac parameters are detected within a patient in which the device is implanted, including parameters representative of an intrinsic biventricular electrical separation between LV and RV and parameters representative of a mechanical contraction delay in the LV. An optimal RV/LV electrode pair is then determined for delivering biventricular pacing based on an analysis of the intrinsic biventricular electrical separation and the mechanical contraction delay. Pacing latency, pacing delay from LV to RV, and the maximum slope of an LV evoked response may be used as proxies or surrogates for mechanical contraction delay.

Abstract: Detection of T wave oversensing in an ICD is accomplished in order to prevent improper application of treatment to a patient. The ICD device senses for electrical impulses representing the R waves of a beating heart. In some instances the ICD device will sense T waves that it will assume to be R waves, because the ICD device expects or assumes that such sensed signals are R waves. Time intervals between each detected, assumed R waves are measured and a list of intervals is generated. The list is transformed into its frequency domain equivalent and analyzed for peaks and randomness criteria to determine whether T wave oversensing has occurred.

Abstract: Disclosed herein is an implantable pulse generator. The implantable pulse generator includes a header, a can, a feedthru, a feedthru substrate and a conductor. The header includes a lead connector block. The can is coupled to the header and includes a wall and an electronic substrate housed within the wall. The feedthru is mounted in the wall and includes a header side, a can side and a feedthru wire extending through the feedthru and having a first end and a second end opposite the first end. The first end is electrically coupled to the lead connector block. The feedthru substrate is adjacent the can side and includes capacitance layers, an electrically conductive input layer, and an electrically conductive input surface defined on a surface of the feedthru substrate and electrically coupled to the input layer. The input layer is electrically coupled to the second end. The conductor electrically couples the input surface and the electronic substrate. The conductor may be in the form of a wire bond.

Abstract: A surface electrocardiogram (EKG) is emulated using signals detected by the internal leads of an implanted device. In one example, the emulation is performed using a technique that concatenates portions of signals sensed using different electrodes. In another example, the emulation is performed using a technique that selectively amplifies or attenuates portions of a single cardiac signal sensed using a single pair of electrodes. The surface EKG emulation may be performed by the implanted device itself or by an external device, such as a programmer, based on cardiac signals transmitted thereto. The external device then displays the emulated surface EKG along with an intracardiac electrogram (IEGM) and set of event markers. Alternatively, the external device displays an entire set of emulated EKGs that had been generated based on the same patient input data but using different emulation techniques.

Abstract: An implantable cardiac stimulation device provides measurement of intrinsic heart activity metrics while sustaining pacing of the heart. The device includes a pulse generator that delivers pacing pulses to a first chamber of corresponding chambers of a heart, and a sensing circuit that senses a conducted evoked response of a second chamber of the corresponding chambers of the heart in response to the pacing pulse to provide an electrical signal representing the conducted evoked response. The device further includes a measuring circuit that measures a metric of the electrical signal to approximate a corresponding metric of an intrinsic electrical feature of the second chamber.

Abstract: An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a venous network of a heart of a patient wherein the cardiac information comprises position information with respect to time for one or more electrodes of the catheter; performing a principal component analysis on at least some of the position information; and selecting at least one component of the principal component analysis to represent an axis of a cardiac coordinate system. Various other methods, devices, systems, etc., are also disclosed.