Abstract: An implantable medical device is manufactured with a hermetically sealed housing and a modular assembly enclosed within the housing. The modular assembly includes a circuit board, an electronic component mounted on a top surface of the circuit board, and a wall formed having an outer surface and an inner surface separated by a top edge and a bottom edge, the wall bottom edge positioned against the circuit board such that the wall encircles the electronic component coupled to the circuit board. The wall top edge is coupled to the housing a ferrule in one embodiment.

Abstract: An implantable medical device and associated method provide atrial pacing and measure intervals between atrial pacing pulses and subsequently sensed ventricular events. A decreasing trend in the intervals indicative of a pre-junctional rhythm is detected. The atrial pacing pulse is delivered at a shortened atrial pacing pulse interval in response to detecting the decreasing trend to reduce the likelihood of a junctional rhythm.

Abstract: A method of determining respiratory effort in a medical device in which pressure signals are sensed to generate corresponding sample points, an inspiration and an expiration are detected in response to the sensed pressure signals, a breath is detected in response to the detected inspiration and the detected expiration, and the respiratory effort is determined in response to the detected breath.

Abstract: A medical device and associated method for detecting arrhythmias that includes electrodes for sensing cardiac electrical signals and a hemodynamic sensor for sensing a hemodynamic signal. An episode of cardiac electrical event intervals meeting cardiac arrhythmia detection criteria is detected from the sensed electrical signals. Cardiac mechanical events and/or cardiac mechanical event intervals are measured from the hemodynamic signal and used to withhold or confirm a cardiac arrhythmia detection of the episode.

Abstract: Techniques for storing electrograms (EGMS) that are associated with sensed episodes or events that may be non-physiological and, instead, associated with a sensing integrity condition are described. In some examples, a device or system identifies suspected non-physiological NSTs, and stores an EGM for the suspected non-physiological NSTs within an episode log. In some examples, a device or system determines whether to store an EGM for a suspected non-physiological episode or event based on whether an impedance integrity criterion has been satisfied. For example, a device or system may store an EGM for a detected short interval if the impedance integrity criterion has been met. In some examples, a device or system determines whether to buffer EGM data based on whether an impedance integrity criterion or other sensing integrity criterion has been met.

Abstract: A medical device for sensing cardiac events that includes a plurality of light sources capable of emitting light at a plurality of wavelengths, and a detector to detect the emitted light. A processor generates an ambient light measurement in response to ambient light detected by the detector, generates a plurality of light measurements in response to the emitted light detected by the detector, and adjusts the plurality of light measurements in response to the ambient light measurement.

Abstract: A system and method for use in a medical device for discriminating cardiac events establishes population-based thresholds corresponding to cardiac signal morphology metrics for discriminating between a first cardiac event and a second cardiac event. A population-based threshold criterion for discriminating cardiac events is established. The population-based threshold criterion is applied to a cardiac signal segment and the segment is classified if the criterion is satisfied. A patient-specific threshold is established in response to the sensed cardiac signal segment not being classified after applying the population-based threshold criterion. The sensed signal segment is classified in response to the patient-specific threshold comparison.

Abstract: A system and method for delivering both anti-tachy pacing (ATP) therapy and high-voltage shock therapy in response to detection of abnormal cardiac rhythms is disclosed. The system controls the time between delivering ATP therapy and the charging of high-voltage capacitors in preparation for shock delivery based on a predetermined set of criteria. In one embodiment, the inventive system operates in an ATP During Capacitor Charging (ATP-DCC) mode wherein all, or substantially all, of the ATP therapy is delivered during charging of the high-voltage capacitors. Based on evaluation of the predetermined set of criteria, the system may switch to an additional ATP Before Capacitor Charging (ATP-BCC) mode, wherein substantially all of the ATP therapy is delivered prior to charging of the high-voltage capacitor. According to one aspect of the invention, the predetermined set of criteria is based, at least in part, on the effectiveness of previously-delivered ATP therapy.

Abstract: A medical device and associated method deliver cardiac pacing in a dual chamber pacing mode and schedule an atrial-ventricular (AV) conduction check during the dual chamber pacing mode to detect the presence of AV conduction. If AV conduction is detected during the scheduled AV conduction check, the medical device switches to an atrial pacing mode and switches back to the dual chamber pacing mode in response to an absence of AV conduction during the atrial pacing mode. The detected AV conduction is identified as a false positive detection in response to the pacing mode switch to the dual chamber pacing mode occurring within a predetermined interval of time from detecting the AV conduction.

Abstract: An implantable medical device system including an optical sensor monitors for the presence of overgrowth on the sensor by sensing light scattered by a measurement volume, the sensed light corresponding to a first wavelength, and deriving an overgrowth metric in response to the sensed light. The overgrowth metric is correlated to the presence of overgrowth on the sensor and is compared to a predetermined threshold. The presence of overgrowth on or near the sensor is detected in response to the overgrowth metric crossing the threshold.

Abstract: A medical device for sensing cardiac events that includes a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event, a plurality of light sources capable of emitting light at a plurality of wavelengths, and a detector to detect the emitted light. A processor determines a plurality of light measurements in response to the emitted light detected by the detector, and generates a blood volume index in response to a light source of the plurality of light sources emitting light at an isobestic wavelength. The blood volume index is then utilized to verify the identifying of the cardiac event.

Abstract: An implantable medical device for monitoring tissue perfusion that includes a light source emitting light having a light wavelength corresponding to a blue to ultraviolet light spectrum and a light detector receiving light emitted by the light source and scattered by a volume of body tissue. The light detector emits a signal correlated to the received light wavelength, and a processor receives the signal from the light detector and determines a patient condition in response to the signal.

Abstract: A medical device that includes a lead having a lead body extending from a proximal end to a distal end, and a housing having a connector block for receiving the proximal end of the lead body. A fixation mechanism is positioned proximal to an electrode coil located at the distal end of the lead body, and a fixation member or a plurality of fixation members extend from the fixation mechanism from a fixation member proximal end to a fixation member distal end. The fixation members are advanceable from a first position corresponding to the fixation member distal end being positioned along the lead during subcutaneous placement of the lead, to a second position corresponding to the fixation member distal end being positioned away from the lead to fixedly engage the lead at a target site.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, and determining whether the sensing of cardiac signals along the first sensing vector and along the second sensing vector is corrupted by noise. If the cardiac signals sensed along both the first sensing vector and the second sensing vector are not corrupted by noise, a determination is made as to whether the cardiac signals sensed along the first sensing vector and along the second sensing vector are one of a first cardiac event and a second cardiac event. The determination of whether the cardiac signals sensed along the first sensing vector and along the second sensing vector are one of a first cardiac event and a second cardiac event is then confirmed.

Abstract: A method and apparatus for detecting a cardiac event in a medical device determine an activity level count from an activity sensor signal for each of a number of time segments, store an activity level count for each of the time segments in a histogram, and accumulate the stored activity level counts to determine a percentage of time segments having an activity level count above a given activity level count.

Abstract: A subcutaneous implantable device is provided that includes a defibrillation electrode disposed along a portion of a lead, and a lead tip connected to the lead. The lead tip includes a trailing end coupled to a distal end of the lead, and first and second non-parallel sides extending from the trailing end that converge to a leading end that is configured to wedge between tissue layers as the lead is advanced subcutaneously.

Abstract: Techniques for detecting heart sounds to reduce inappropriate tachyarrhythmia therapy are described. In some examples, a medical device determines that a cardiac rhythm of the patient is treatable with a therapy, such as a defibrillation pulse, based on a cardiac electrogram (EGM). The medical device analyzes detected heart sounds, and withholds or allows the therapy based on the analysis of the heart sounds.

Abstract: An implantable medical device and associated method assess T-wave alternans by sensing a cardiac electrogram (EGM) signal and selecting a pair of consecutive T-wave signals from the EGM signal. A first amplitude and a second amplitude from each of the consecutive T-wave signals are determined. The differences between the first amplitudes and the second amplitudes of the consecutive T-wave signal pairs are used to compute a T-wave alternans metric.

Abstract: A medical device and associated method for detecting arrhythmias that includes sensing cardiac electrical signals and cardiac hemodynamic signals, determining a long-term baseline hemodynamic measurement in response to a plurality of the sensed cardiac hemodynaic signals, detecting a period of increased metabolic demand in response to the sensed cardiac electrical signals, determining a sinus tachycardia baseline hemodynamic measurement in response sensing of cardiac hemododynamic signals during the detected period of increased metabolic demand, and detecting the arrhythmia and delivering therapy in response to one of only the sensed cardiac electrical signals and the sensed cardiac electrical signals in combination with one or both of the determined long-term baseline hemodynamic measurement and the sinus tachycardia baseline hemodynamic measurement.

Abstract: Embodiments of the invention provide systems and methods for an implantable capacitive pressure sensor. Some embodiments of the invention include a capacitive pressure sensor capsule comprising a substrate, a conductive plate functionally coupled to the substrate, a conductive diaphragm spaced from the conductive plate and functionally coupled to the substrate, a lid hermetically sealed against the substrate, and pressure sensing circuitry disposed within a volume generally defined by the lid and the substrate. Embodiments of the invention also include a lead provided with an implantable pressure sensor capsule and a method of manufacturing a capacitive pressure sensor capsule.