Abstract: A leadless implantable medical device (LIMD) includes a housing formed from a battery and an end cap. A proximal end of the end cap forms an LIMD proximal end and a distal end of the battery case forms an LIMD distal end. A non-conductive coupler mechanically secures a terminal end of the battery case to a mating end of the end cap, while maintaining the battery case and end cap electrically separated. A first electrode projects from the proximal end of the end cap. An intra-cardiac (IC) device extension projects from the distal end of the battery case. The extension includes a second electrode that is electrically connected to the battery case. The second electrode is located remote from the LIMD distal end. An electronics module is located within an internal cavity of the end cap and communicates with the first and second electrodes.

Abstract: The device includes radio frequency (RF) communication components installed within a case of the device and an antenna with an inverted E shape mounted within a header of the device. The antenna has three branches extending from a main horizontal arm: a capacitive branch connecting one end of the main arm to the case via a capacitive load; an RF signal feed branch connecting a middle portion of the main arm to the internal RF components of the device via a feedthrough; and an inductive branch connecting the opposing (far) end of the main arm to the case to provide a shunt to ground. The E-shaped configuration and the provision of capacitive loading allows for cancellation of inductance to bring the antenna into resonance and to provide optimal radiation efficiency as well as to provide for impedance with no reactive component.

Abstract: A method is provided for establishing a communication session with an implantable medical device (“IMD”). The method includes configuring an IMD and an external device to communicate with one another through a protocol that utilizes a dedicated advertisement channel. The IMD periodically transmitting advertisement notices over the dedicated advertisement channel according to the protocol. The advertisement notices being transmitted periodically at an advertisement period over multiple cycles. The method further includes repeatedly scanning the advertisement channel, by the external device, for select scanning intervals in search of the advertisement notices, the scanning operation being repeated periodically at a scan period over the multiple cycles. The advertisement period and the scan period are independent of one another such that the advertisement and scan periods at least partially overlap intermittently after a number of cycles.

Abstract: A leadless implantable medical device (LIMD) includes a housing formed from a battery and an end cap. A proximal end of the end cap forms an LIMD proximal end and a distal end of the battery case forms an LIMD distal end. A non-conductive coupler mechanically secures a terminal end of the battery case to a mating end of the end cap, while maintaining the battery case and end cap electrically separated. A first electrode projects from the proximal end of the end cap. An intra-cardiac (IC) device extension projects from the distal end of the battery case. The extension includes a second electrode that is electrically connected to the battery case. The second electrode is located remote from the LIMD distal end. An electronics module is located within an internal cavity of the end cap and communicates with the first and second electrodes.

Abstract: A method for determining the cause of an irregularity in physiologic data collected by a medical device may include monitoring a collected physiologic characteristic of a patient through the physiologic data, detecting an irregularity in the physiologic data, monitoring position data of the patient, correlating the physiologic data with the position data, and determining the cause of the irregularity in the physiologic data based on correlation of the physiologic data with the position data.

Abstract: Methods, systems, and apparatus for signal detection are described. In one example, a detection assembly includes a signal detector. The signal detector is configured to receive a sensor signal having a peak magnitude and a first frequency and generate an output signal having a magnitude proportional to the peak magnitude of the sensor signal and having a second frequency less than the first frequency of the sensor signal.

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: Methods, systems, and apparatus for signal detection are described. In one example, a detection assembly includes a signal detector. The signal detector is configured to receive a sensor signal having a peak magnitude and a first frequency and generate an output signal having a magnitude proportional to the peak magnitude of the sensor signal and having a second frequency less than the first frequency of the sensor signal.

Abstract: Methods, systems, and apparatus for signal detection are described. In one example, a detection assembly includes a signal detector. The signal detector is configured to receive a sensor signal having a peak magnitude and a first frequency and generate an output signal having a magnitude proportional to the peak magnitude of the sensor signal and having a second frequency less than the first frequency of the sensor signal.

Abstract: Leadless neurostimulation (NS) device including a device body and electrodes positioned along an active side of the device body. The electrodes form a multi-electrode array that is configured to interface with nervous tissue of a patient and supply electrical pulses to the nervous tissue. The NS device also includes an electronic sub-system that is coupled to the device body. The electronic sub-system includes switching circuitry, a power source, and an inductive coil that is operably coupled to the power source. The inductive coil is configured to receive electrical power through inductive coupling with an external coil. The device body, including the inductive coil coupled thereto, is sized and shaped to be disposed within an epidural space of a patient.

Abstract: Techniques are provided for estimating defibrillation impedance of an implantable cardioverter/defibrillator (ICD). Briefly, at least two low-voltage resistance values are measured at different voltages using a pair of stimulation electrodes connected to the ICD. High-voltage defibrillation impedance is then estimated by the ICD based on a weighted combination of the measured resistance values. In one example, a set of weight coefficients, calculated during an initial calibration procedure, are applied to the measured resistance values to produce the estimate of the high-voltage defibrillation impedance. The weight coefficients are updated whenever a defibrillation shock is delivered, based on actual defibrillation impedance values measured during the shock.

Abstract: A leadless intra-cardiac medical device includes a housing that is configured to be implanted entirely within a single local chamber of the heart. A first electrode is provided on the housing at a first position such that when the housing is implanted in the local chamber, the first electrode engages the local wall tissue at a local activation site within the conduction network of the local chamber. An intra-cardiac extension is coupled to the housing and configured to extend from the local chamber into an adjacent chamber of the heart. A stabilization arm of the intra-cardiac extension engages the adjacent chamber. A second electrode on the intra-cardiac extension engages distal wall tissue at a distal activation site within the conduction network of the adjacent chamber.

Abstract: A method for detecting potential failures by a lead of an implantable medical device is provided. The method includes sensing a first signal over a first channel between a first combination of electrodes on the lead and sensing a second signal from a second channel between a second combination of electrodes on the lead. The method determines whether at least one of the first and second signals is representative of a potential failure in the lead and identifies a failure and the electrode associated with the failure based on which of the first and second sensed signals is representative of the potential failure. Optionally, when the first and second sensed signals are both representative of the potential failure, the method further includes determining whether the first and second sensed signals are correlated with one another. When the first and second sensed signals are correlated, the method declares an electrode common to both of the first and second combinations to be associated with the failure.

Abstract: The device includes radio frequency (RF) communication components installed within a case of the device and an antenna with an inverted E shape mounted within a header of the device. The antenna has three branches extending from a main horizontal arm: a capacitive branch connecting one end of the main arm to the case via a capacitive load; an RF signal feed branch connecting a middle portion of the main arm to the internal RF components of the device via a feedthrough; and an inductive branch connecting the opposing (far) end of the main arm to the case to provide a shunt to ground. The E-shaped configuration and the provision of capacitive loading allows for cancellation of inductance to bring the antenna into resonance and to provide optimal radiation efficiency as well as to provide for impedance with no reactive component.

Abstract: A method for determining the cause of an irregularity in physiologic data collected by a medical device may include monitoring a collected physiologic characteristic of a patient through the physiologic data, detecting an irregularity in the physiologic data, monitoring position data of the patient, correlating the physiologic data with the position data, and determining the cause of the irregularity in the physiologic data based on correlation of the physiologic data with the position data.

Abstract: Systems and methods are provided for allowing an implantable medical device, such as pacemaker, to properly sense electrophysiological signals and hemodynamic signals within a patient during a magnetic resonance imaging (MRI) procedure. Systems and methods are also provided for allowing the implantable medical device to transmit the sensed data to an external monitoring system during the MRI procedure so that attending medical personnel can closely monitor the health of the patient and the operation of the implantable device during the MRI. These improvements provide the attending personnel with information needed to determine whether the MRI should be suspended in response to induced tachyarrhythmias or other adverse conditions within the patient.

Abstract: A leadless implantable medical device (LIMD) includes a housing formed from a battery and an end cap. A proximal end of the end cap forms an LIMD proximal end and a distal end of the battery case forms an LIMD distal end. A non-conductive coupler mechanically secures a terminal end of the battery case to a mating end of the end cap, while maintaining the battery case and end cap electrically separated. A first electrode projects from the proximal end of the end cap. An intra-cardiac (IC) device extension projects from the distal end of the battery case. The extension includes a second electrode that is electrically connected to the battery case. The second electrode is located remote from the LIMD distal end. An electronics module is located within an internal cavity of the end cap and communicates with the first and second electrodes.

Abstract: A leadless intra-cardiac medical device includes a housing that is configured to be implanted entirely within a single local chamber of the heart. A first electrode is provided on the housing at a first position such that when the housing is implanted in the local chamber, the first electrode engages the local wall tissue at a local activation site within the conduction network of the local chamber. An intra-cardiac extension is coupled to the housing and configured to extend from the local chamber into an adjacent chamber of the heart. A stabilization arm of the intra-cardiac extension engages the adjacent chamber. A second electrode on the intra-cardiac extension engages distal wall tissue at a distal activation site within the conduction network of the adjacent chamber.

Abstract: A high voltage switching and control circuit is provided for an implantable medical device (IMD). The circuit includes a high voltage positive (HVP) node, configured to receive a positive high voltage signal from a high energy storage source, and a high voltage negative (HVN) node, configured to receive a negative high voltage signal from a high energy storage source. Additionally, the circuit includes first, second and third output terminals that are configured to be connected to electrodes for delivering high voltage energy. First and second SCR switches are connected to the first and second output terminals, respectively. The first and second SCR switches are connected in series with one another and are connected to one of the HVP and HVN nodes. The first and second SCR switches have gating terminals. A control circuit is connected to the gating terminals and delivers first and second gating signals to turn ON the first and second SCR switches, respectively.

Abstract: A filter circuit embedded into a header of an implantable medical device attenuates energy that may otherwise enter the implantable medical device. At MRI frequencies, the impedance of the filter circuit is much higher than the impedance of the feedthrough capacitor of the implantable medical device. Thus, MRI-induced current that would otherwise enter the implantable medical device is limited by the filter circuit. Consequently, localized device heating that may otherwise occur during MRI scanning is significantly reduced by operation of the filter circuit. In some implementations, the header embedded filter circuit is electrically isolated from the header housing. In this way, localized heating of the header housing also may be avoided.