Abstract: A micro electromechanical (MEMS) switch suitable for use in medical devices is provided, along with methods of producing and using MEMS switches. In one aspect, a micro electromechanical switch including a moveable member configured to electrically cooperate with a receiving terminal is formed on a substrate. The moveable member and the receiving terminal each include an insulating layer proximate to the substrate and a conducting layer proximate to the insulating layer opposite the substrate. In various embodiments, the conducting layers of the moveable member and/or receiving terminal include a protruding region that extends outward from the substrate to switchably couple the conducting layers of the moveable member and the receiving terminal to thereby form a switch. The switch may be actuated using, for example, electrostatic energy.

Abstract: A method and apparatus for adjusting a sensing parameter in a medical device that includes a sensing electrode sensing cardiac signals, a processor to determine an adjusting characteristic associated with the cardiac signals sensed over a predetermined sensing window, and a control unit to update the sensing parameter in response to the determined adjusting characteristic.

Abstract: A lead of an implantable medical device system having an elongated lead body, a sensor coupled to the lead body and extending from a proximal end to a distal end, and a distal lead adaptor having a first arm extending distally from the distal end of the sensor to a first arm end, a second arm extending distally from the distal end of the sensor to a second arm end, and a third arm extending between the first arm end and the second arm end, wherein the first arm, the second arm, and the third arm form an open portion.

Abstract: A method and apparatus for verifying a determined cardiac event in a medical device based on detected variation in hemodynamic status that includes a plurality of sensors sensing cardiac signals, and a physiologic sensor sensing physiologic signals to generate a plurality of variation index samples corresponding to the sensed signals. A microprocessor detects a cardiac event in response to the sensed cardiac signals, computes a variation index trend associated with a predetermined number of variation index samples of the plurality of variation index samples, determines whether the sensed cardiac signals are associated with noise in response to the computed variation index, and confirms the determined cardiac event in response to the sensed cardiac signals not being associated with noise.

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, an isobestic blood volume index in response to determined light measurements of the plurality of light measurements from a first light source of the plurality of light sources emitting light at an isobestic wavelength, determines an oxygen index associated with light measurements of the plurality of light measurements from a light source of the plurality of light sources other than the first light source, and verifies the identifying of the cardiac event in response to the determined isobestic blood volume index and the determined oxygen index.

Abstract: An optical perfusion sensor may monitor blood oxygen saturation of blood-perfused tissue, which may be referred to as tissue perfusion, until a tissue perfusion value is within a threshold range of a reference value, and, in some examples, for at least a minimum period of time. The tissue perfusion value may indicate an absolute blood oxygen saturation level or a relative change in blood oxygen saturation level. The reference value may be, for example, determined by an optical oxygenation (O2) variation index that indicates a change in blood oxygen saturation of tissue. In some examples, an operation of a cardiac signal sensing module may be controlled based upon detecting a threshold change in tissue perfusion. For example, the cardiac signal sensing module may be activated upon detecting a threshold change in tissue perfusion.

Abstract: This disclosure is directed to techniques for treating tachyarrhythmias, such as atrial or ventricular fibrillation, in which a number of electrodes are employed to deliver electrical stimulation to a patient's heart in a manner designed to terminate the tachyarrhythmia episode.

Abstract: In general, the disclosure is directed to techniques for identification and remediation of oversensed cardiac events using far-field electrograms (FFEGMs). Identification of oversensed cardiac events can be used in an ICD to prevent ventricular fibrillation (VF) detection, and thereby avoid delivery of an unnecessary defibrillation shock. Alternatively, or additionally, identification of oversensed cardiac events can be used in an ICD to support delivery of bradycardia pacing during an oversensing condition. In some cases, bradycardia pacing delivered in response to detection of oversensed cardiac events may include pacing pulses from multiple vectors to provide redundancy in the event the oversensing may be due to a lead-related condition.

Abstract: An implantable medical device having an acoustic element includes a control module coupled to the acoustic element, an acoustic sensing module coupled to the control module, and a patient alert driver module coupled to the control circuit. The patient alert driver module generates a patient alert drive signal for activating the acoustic element to emit a patient alert signal. The control module includes an isolation circuit for isolating the acoustic sensing module from the acoustic element in response to the patient alert drive signal.

Abstract: A method and system for determining undersensing during post-processing of sensing data generated by a medical device that includes transmitting a plurality of stored sensing data generated by the medical device to an access device, the stored sensing data including sensed atrial events and sensed ventricular events. The access device determines, in response to the transmitted data, instances where the medical device identified a cardiac event being detected in response to the sensing data, and determines whether one of a predetermined number of undersensing criteria have been met in response to the transmitted data.

Abstract: A system and method for determining oversensing during post-processing of sensing data generated by a medical device that includes transmitting a plurality of stored sensing data generated by the medical device to an access device, the stored sensing data including sensed atrial events and sensed ventricular events. The access device determines, in response to the transmitted data, instances where the medical device identified a cardiac event being detected in response to the sensing data, identifies and removes suspected far-field R-waves, and determines whether a signal including the removed suspected far-field R-waves is regular.

Abstract: A method and apparatus of updating a sensing parameter in a medical device that includes sensing cardiac signals, determining intervals in response to the sensed cardiac signals, determining interval patterns associated with the determined intervals, and updating the sensing parameter in response to the determined interval patterns.

Abstract: A method and apparatus for determining a T-wave shock interval sense a cardiac electrogram (EGM) signal comprising a T-wave signal. A T-wave center is determined from the EGM signal, and a T-wave shock interval is determined in response to determining the T-wave center. A T-wave shock is delivered at the T-wave shock interval computed based on the T-wave center.

Abstract: A medical device and associated method classify a tachycardia according to a site of origin of the tachycardia. Cardiac signals are sensed and a tachycardia event is detected in response to the sensed cardiac signals. Pacing pulses are delivered and a time interval corresponding to a distance traversed by a depolarization associated with the last one of the pacing pulses from a site of delivery of the plurality of pacing pulses is determined. The tachycardia event is classified according to a site of origin in response to the determined time interval.

Abstract: An implantable medical device that includes a housing having a first shield having an outwardly extending first flange and a second shield having an outwardly extending second flange. The first flange is fixedly engaged with the second flange along a seal to form a housing flange extending outward from the housing, and a surround shroud, having first recessed portions for receiving the housing flange when the shroud is positioned about the housing.

Abstract: Heart failure decompensation is detected by sensing at least one physiological signal. Values of at least two different heart failure variables are derived using one or more physiological signals and a threshold for the first heart failure variable is adjusted in response to the value of the second heart failure variable. The value of the first heart failure variable is compared to first threshold for detecting a heart failure condition.

Abstract: A method and device are described to form a sensor using a cardiomyocyte by advancing a catheter into the tissue of interest, cardiac in the preferred embodiment, and using the catheter to ablate a cone- or a dome-shaped region to form an electrically isolated section of tissue. An electrode is later fixed to the region encompassed by the dome-shaped area of tissue and used to detect the electrophysiological activity of this electrically independent cluster of cells. These cells combined with the electrode and a detection circuitry will form a cell-based sensor to monitor the effects of the anti-arrhythmic drugs in the circulation. The inventive device includes an ablation catheter and a sensing lead. Catheter is a hollow conductor which used to carry RF power from the external generator to the myocardium and to form a cone-shaped ablation zone to electrically isolate a part of myocardium from the rest.

Abstract: A cardiac rhythm sensor positioned on or close to the heart senses electrical or mechanical activity and transmits a cardiac rhythm signal wirelessly to a subcutaneous ICD. Arrhythmia detection and delivery of therapy are performed by the SubQ ICD based upon the cardiac rhythm signal received from the sensor.

Abstract: A medical device and associated method discriminate near-field and far-field events by sensing a bipolar signal and a unipolar signal at a tissue site, detecting an event in response to one of the bipolar and unipolar signals, and comparing an event feature determined from the bipolar signal to an event feature determined from the unipolar signal.

Abstract: A system and method for filtering a pressure signal in a medical device in which a sensor terminal senses the pressure signal, an electrode terminal receives cardiac electrical signals, a signal filtering system filters the sensed pressure signal in response to a determined heart rate to generate a heart-rate dependent frequency response, and a microprocessor derives a respiration signal in response to the heart rate dependent frequency response, and determines metrics of hemodynamic function in response to the derived respiration signal.