Abstract: In general, this disclosure is directed to a mixer amplifier that can be utilized within a chopper stabilized instrumentation amplifier. The chopper stabilized instrumentation amplifier may be used for physiological signal sensing, impedance sensing, telemetry or other test and measurement applications. In some examples, the mixer amplifier may include a current source configured to generate a modulated current at a modulation frequency for application to a load to produce an input signal, an amplifier configured to amplify the input signal to produce an amplified signal, and a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load.

Abstract: A glucose sensor product maintains the sterility of the glucose sensor while allowing gaseous manufacturing by-products to be vented from the inside of the glucose sensor package. An exemplary glucose sensor product includes a plastic package tray and a glucose sensor assembly in the plastic package tray. The glucose sensor assembly includes an electrochemical sensor with glucose oxidase enzyme, a sensor base formed at least in part from plastic, a sensor mounting pedestal formed at least in part from plastic, and a sensor introducer formed at least in part from plastic. The glucose sensor product also includes a microbial barrier material coupled to the plastic package tray to seal the glucose sensor assembly in the plastic package tray. The microbial barrier material maintains sterility of the glucose sensor assembly while venting substances outgassed from the plastic package tray, the sensor base, the sensor mounting pedestal, and the sensor introducer.

Abstract: The invention features modular implantable ventricular assist devices configured to be, at least in part, assembled within a patient. The devices generally include a pump assembly and an expandable frame. The frame is configured to engage tissue of a patient when implanted. The pump assembly is configured to be operably coupled to the frame when the frame is implanted and in the expanded configuration.

Abstract: Methods and apparatus to determine the presence of and track functional chronotropic incompetence (hereinafter “CI”) in an in-home setting under conditions of daily living. The functional CI of the patient may be determined with one or more of a profile of measured patient heart rates, a measured maximum patient heart rate, or a peak of the heart rate profile. The functional CI of the patient may be determined with the measured heart rate profile, in which the measured heart rate profile may correspond to heart rates substantially less than the maximum heart rate of the patient, such that the heart rate can be safely measured when the patient is remote from a health care provider. The functional CI of the patient may be determined based a peak of the remotely measured heart rate profile, for example a peak corresponding to the mode of the heart rate distribution profile.

Abstract: The drug eluting folded stent and a stent delivery system, which includes a stent having a plurality of struts interconnected to form a tubular body. At least one of the struts includes a U-shaped strut having in cross-section a first leg, a second leg, and a closed end connecting the first leg and the second leg, wherein the first leg, the second leg, and the closed end define a recess having a drug release opening opposite the closed end; and a drug coating disposed on the first leg, the second leg, and the closed end within the recess. The drug release opening is sized to release a drug from the drug coating at a predetermined drug elution rate.

Abstract: A delivery catheter, including a catheter body, a side port, a first electrode, and a second electrode, is described. The catheter body may comprise a proximal end, a distal end, and a perimeter surface. The catheter body defines a delivery lumen extending longitudinally within the catheter body. The side port is defined in the perimeter surface of the catheter body proximate the distal end and in communication with the delivery lumen. The electrodes may be adjacent to and spaced from the side port. Techniques for using the delivery catheter to identify a desired lead implantation location, e.g., via the electrodes, and implant a medical lead or other implantable element at the desired location through the delivery lumen and side port are also described.

Abstract: A system and associated method is disclosed for determining whether signal is valid. The system comprises an electrode apparatus comprising a plurality of electrodes configured to be located proximate tissue of a patient. A display apparatus comprising a graphical user interface, wherein the graphical user interface is configured to present information to a user. A computing apparatus coupled to the electrode apparatus and display apparatus, wherein the computing apparatus is configured to determine whether a signal acquired from a channel associated with an electrode from the plurality of electrodes is valid and sufficiently strong by i) calculating a first derivative of the signal; ii) determining a minimum and maximum derivative from the first derivative; iii) determining whether signs of the minimum and maximum derivative are different; and in response to determining whether the signs of the minimum and maximum derivative are different, displaying on a display apparatus whether the signal is valid.

Abstract: A method and medical device for detecting a cardiac event that includes sensing cardiac signals from a plurality of electrodes, sensing a plurality of beats in response to the sensed cardiac signals, identifying each beat of the plurality of beats as one of a normal beat and a not normal beat, determining at least one of whether a number of beats identified as a normal beat is greater than a normal beat threshold, whether an RR interval associated with the beats identified as being a normal beat is less than a threshold interval, and whether RR intervals associated with the beats identified as being normal beats are within an RR interval range, and identifying the cardiac event as being one of shockable and not shockable in response to the determining.

Abstract: A characteristic of a washout period following the delivery of therapy to a patient according to a therapy program may be determined based on a physiological parameter of the patient. A washout period includes the period of time during which a carryover effect from the therapy dissipates. The washout period characteristic may include, for example, a duration of the washout period, an amplitude or a trend in a physiological signal during the washout period or a power level or a ratio of power levels in frequency bands of the physiological signal. In some embodiments, washout period characteristics associated with a plurality of therapy programs may be used to compare the programs. In other embodiments, a washout period characteristic may be used to determine a mood state of the patient and, in some cases, modify a therapy program. Monitoring a washout period may also be useful for timing therapy program trials.

Abstract: A catheter body includes an exit port over which a pressure responsive sleeve is formed that allows material to exit a lumen of the catheter body at a given pressure. In one embodiment, a surface of the sleeve is approximately flush with a surface of the catheter body.

Abstract: An antenna structure, for use in an implantable medical device, may include an inner portion that is magnetically coupled to an outer portion. In one example, the inner and outer portions include conductive loops. In accordance with the techniques of this disclosure, a capacitive sensor is electrically coupled to one of the conductive loops of the antenna of the implantable medical device. As the capacitance of the capacitive sensor changes as a function of the sensed parameter, an impedance of the antenna varies with the output of the capacitive sensor. This variation in impedance of the antenna modulates a carrier signal with the measured parameter. In other words, the measured parameter is modulated onto the carrier signal as a change in amplitude caused by variation in impedance of antenna during radiation/transmission.

Abstract: A fluid infusion device and an insertion mechanism are disclosed. The insertion mechanism actuates an assembly having a fluid conduit and a needle. An embodiment of the insertion mechanism includes a first sliding block, a second sliding block, a torsion spring, and a living hinge. The first block is coupled to the conduit to move the conduit in an insertion direction. The second block is coupled to the needle to move the needle in the insertion direction and in a retraction direction, wherein movement of the second block in the insertion direction pushes the first block in the insertion direction. The living hinge is coupled between the torsion spring and the second block. Rotation of the torsion spring during an insertion action actuates the living hinge to move the second block in the insertion direction and, thereafter, in the retraction direction.

Abstract: Disclosed herein is a fluid infusion device of the type that delivers medication fluid to the body of a patient. The device includes or cooperates with a fluid reservoir, and the device has a sealing assembly to receive and form a fluid seal with the fluid reservoir. A retractable sealing element surrounding a hollow fluid delivery needle may be used to seal a port of the fluid reservoir. The port may include a pressure vent that is sealed by the retractable sealing element. In one variation, the reservoir includes a moving valve sleeve that holds a septum. The septum moves to allow the reservoir to vent, and to form a seal with the port when the needle pierces the septum. In another variation, the device includes a needleless sealing assembly. In yet other variations, the device uses a needled fluid reservoir.

Abstract: A device includes an elongated cannula with an opening positioned at its distal end. A tissue engagement structure is affixed proximate the distal end of the cannula and surrounds the opening. The tissue engagement structure includes a tissue engaging portion to engage and control tissue. An adhesive is dispensed through the cannula opening to repair tissue.

Abstract: Implant tools and techniques for implantation of a medical lead, catheter or other implantable component are provided. The implant tools and techniques are particularly useful in implanting medical electrical leads in extravascular locations, including subcutaneous locations. An example implant tool for implanting a medical lead includes a rod and a sheath configured to be placed on the rod. The rod includes a handle, a shaft having a proximal end adjacent to the handle and a distal end, and an attachment feature toward the distal end of the shaft, the attachment feature configured to couple to the medical lead. The sheath is configured to be placed in multiple positions along the rod including a first position in which the sheath does not interact with the attachment feature and second position in which the sheath does interact with the attachment feature.

Abstract: Connector enclosure assemblies for medical devices provide an angled lead passageway. The lead passageway which is defined by electrical connectors and intervening seals within the connector enclosure assembly establishes the angle relative to a base plane of the connector enclosure assembly. Various other aspects may be included in conjunction with the angled lead passageway, including an angled housing of the connector enclosure assembly, feedthrough pins that extend to the electrical connectors where the feedthrough pins may include angled sections, and a set screw passageway set at an angle relative to the lead passageway to provide fixation of a lead within the lead passageway.

Abstract: Connector enclosure assemblies for medical devices provide an angled lead passageway. The lead passageway which is defined by electrical connectors and intervening seals within the connector enclosure assembly establishes the angle relative to a base plane of the connector enclosure assembly. Various other aspects may be included in conjunction with the angled lead passageway, including an angled housing of the connector enclosure assembly, feedthrough pins that extend to the electrical connectors where the feedthrough pins may include angled sections, and a set screw passageway set at an angle relative to the lead passageway to provide fixation of a lead within the lead passageway.

Abstract: The invention relates to devices, systems, and methods for recharging zirconium phosphate in a reusable zirconium phosphate sorbent module. The devices, systems, and methods provide for customization of the zirconium phosphate effluent pH based on the needs of the user and system. The devices systems and methods also provide for calculation of the volumes of recharge solution needed for fully recharging the zirconium phosphate modules.

Abstract: A method and implantable medical device for determining an atrial arrhythmia event that includes sensing a cardiac signal, determining an atrial arrhythmia score for identifying the arrhythmia event in response to the sensed cardiac signal, determining a sensing window in response to the sensed cardiac signal, the sensing window having a first portion and a second portion, determining signal characteristics of the sensed cardiac signal within the first portion and within the second portion, determining whether the sensed cardiac signal within the first portion and within the second portion corresponds to a P-wave in response to the determined signal characteristics, determining whether a signal to noise ratio of the sensed cardiac signal within the first portion and the second portion of the sensing window is satisfied, determining whether to update the arrhythmia score in response to the determined P-wave and the determined signal to noise ratio, and determining whether to delivery an arrhythmia therapy in r

Abstract: An implantable medical device includes a low-power circuit and a multi-cell power source. The cells of the power source are coupled in a parallel configuration. The implantable medical device includes both a low power circuit that is selectively coupled between the first and second cells and a high power output circuit that is directly coupled to the first and second cells in a parallel configuration. An isolation circuit is coupled to the first cell, the second cell and the low power circuit to maintain a current isolation between the first cell and the second cell at least during delivery currents having a large magnitude that are delivered to the high power output circuit.