Abstract: A tine portion of an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from a distal end of the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, for example, defined by a single radius, preferably tapers from a first width thereof, in proximity to a proximal end thereof, to a smaller, second width thereof, in proximity to the distal end thereof, wherein the tip has a width that is greater than the second width of the hook segment. Alternately, the tine portion may include a hook segment that is defined by two radii and a straight section extending therebetween.

Abstract: In some examples, determining a heart failure status includes using an implantable medical device configured for subcutaneous implantation and comprising a plurality of electrodes and an optical sensor. Processing circuitry of a system comprising the device may determine, for a patient, a current tissue oxygen saturation value based on a signal received from the at least one optical sensor, a current tissue impedance value based on a subcutaneous tissue impedance signal received from the electrodes, and a current pulse transit time value based on a cardiac electrogram signal received from the electrodes and at least one of the signal received from the optical sensor and the subcutaneous tissue impedance signal. The processing circuitry may further compare the current tissue oxygen saturation value, current tissue impedance value, and current pulse transit time value to corresponding baseline values, and determine the heart failure status of the patient based on the comparison.

Abstract: In some examples, determining a health status includes using an implantable medical device configured for subcutaneous implantation and comprising at least one optical sensor. Processing circuitry of a system comprising the device may determine, for a patient, a current tissue oxygen saturation value based on a first signal received from the at least one optical sensor and a current pulsatile oxygen saturation value based on a second signal received from the at least one optical sensor. The processing circuitry may further compare the current tissue oxygen saturation and current pulsatile oxygen saturation values to corresponding baseline values, determine corresponding heart failure and pulmonary statuses of the patient based on the comparisons, and determine the health status of the patient based on the statuses.

Abstract: Various embodiments of a sealed package and a method of forming such package are disclosed. The package includes a housing, a substrate hermetically sealed to the housing, and a light source disposed on a first major surface of the substrate. The package further includes a detector disposed on the first major surface of the substrate and having a detecting surface. The package also includes a masking layer disposed on at least one of the first major surface and a second major surface of the substrate, where the masking layer includes a first aperture aligned with an emission axis of the light source in a direction orthogonal to the first major surface of the substrate. The masking layer further includes a second aperture aligned with a detection axis of the detector in a direction orthogonal to the first major surface of the substrate.

Abstract: A fixation member component, for example, employed by a relatively compact implantable medical device, includes a plurality of fingers; each finger includes a first segment extending from a fixed end of the corresponding finger, and a second segment extending from the corresponding first segment to a free end of the corresponding finger. Each first segment is elastically deformable from a relaxed to an extended condition, and from the relaxed to a compressed condition, and includes a peripheral portion and a central cut-out portion, framed by the peripheral portion. In the compressed condition, a free tip of the cut-out portion of some or all of the fingers may lodge against opposing tissue surfaces, via a spring force of the compressed fingers. Each second segment and cut-out portion is preferably configured to prevent penetration thereof within tissue at the implant site.

Abstract: In some examples, a medical system includes a medical device. The medical device may include a housing configured to be implanted in a target site of a patient, a light emitter configured to emit a signal configured to cause a fluorescent marker to emit a fluoresced signal into the target site, and a light detector that may be configured to detect the fluoresced signal. The medical system may include processing circuitry configured to determine a characteristic of the fluorescent marker based on the emitted signal and the fluoresced signal. The characteristic of the fluorescent marker may be indicative of a presence of a compound in the patient, and the processing circuitry may be configured to track the presence of the compound of the patient based on the characteristic of the fluorescent marker.

Abstract: The exemplary systems and methods may monitor one or more signals to be used to assess the hemodynamic status of a patient. The one or more signals may be used to calculate, or determine, a plurality of pulse transit times. The plurality of pulse transit times may be used to determine hemodynamic status values that may be indicative of a patient's aggregate hemodynamic status.

Abstract: A medical device for monitoring delivery of a therapy that includes a therapy delivery module to deliver a therapy, a controller to set a therapy delivery control parameter, an optical sensor to produce a signal corresponding to tissue light attenuation, and a processor configured to compute a tissue oxygenation measurement from the optical sensor signal, wherein the controller, the optical sensor, and the processor operate cooperatively to determine a setting of the therapy delivery control parameter corresponding to a maximum tissue oxygenation.

Abstract: A tine portion of an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from a distal end of the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, for example, defined by a single radius, preferably tapers from a first width thereof, in proximity to a proximal end thereof, to a smaller, second width thereof, in proximity to the distal end thereof, wherein the tip has a width that is greater than the second width of the hook segment. Alternately, the tine portion may include a hook segment that is defined by two radii and a straight section extending therebetween.

Abstract: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

Abstract: Various embodiments of a hermetically-sealed package and a method of forming such package are disclosed. The package can include a housing having an inner surface and an outer surface, and a non-conductive substrate hermetically sealed to the housing. The package can also include a light source disposed on a first major surface of the substrate and adapted to emit light through the first and second major surfaces of the substrate, and a detector disposed on the first major surface of the substrate and adapted to detect the light emitted by the light source.

Abstract: Various embodiments of a sealed package and a method of forming such package are disclosed. The package includes a housing, a substrate hermetically sealed to the housing, and a light source disposed on a first major surface of the substrate. The package further includes a detector disposed on the first major surface of the substrate and having a detecting surface. The package also includes a masking layer disposed on at least one of the first major surface and a second major surface of the substrate, where the masking layer includes a first aperture aligned with an emission axis of the light source in a direction orthogonal to the first major surface of the substrate. The masking layer further includes a second aperture aligned with a detection axis of the detector in a direction orthogonal to the first major surface of the substrate.

Abstract: A medical system includes at least two sensing modules that each generate an optical signal that changes as a function of a physiological parameter of a patient. The sensing modules may be coupled to a common light source and a common receiver via an optically transmissive member. At least a first sensing module that is closest to the light source along a length of the optically transmissive member may include a waveguide to split the light emitted by the light source. A first portion of the light may be directed toward the first sensing module and a second portion of the light may be directed toward a second sensing module that is placed downstream of the first sensing module in a direction substantially along the direction of light flow through the optically transmissive member and away from the light source.

Abstract: A tine portion of an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from a distal end of the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, for example, defined by a single radius, preferably tapers from a first width thereof, in proximity to a proximal end thereof, to a smaller, second width thereof, in proximity to the distal end thereof, wherein the tip has a width that is greater than the second width of the hook segment. Alternately, the tine portion may include a hook segment that is defined by two radii and a straight section extending therebetween.

Abstract: A medical device system is configured to sense a physiological signal by a first device and generate a control signal by the first device in response to the physiological signal. An optical transducer is controlled by the first device to emit an optical trigger signal in response to the control signal. A second device receives the optical trigger signal and delivers an automatic therapy to a patient in response to detecting the optical trigger signal.

Abstract: A tine portion for an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, has one of: a round cross-section and an elliptical cross-section, while the distal segment has a flattened, or approximately rectangular cross-section. One or a pair of the tine portions may be integrally formed, with a base portion, from a superelastic wire, wherein the base portion is configured to fixedly attach to the device, for example, being captured between insulative members of a fixation subassembly.

Abstract: A pressure sensing system provides signals representative of a magnitude of pressure at a selected site. A sensor module includes a first transducer producing a first signal having an associated first response to pressure and strain applied to the sensor module and a second transducer producing a second signal having an associated second response to pressure and strain applied to the sensor module. A calculated pressure, a bending pressure error and a bend-compensated pressure are computed in response to the first signal and the second signal.

Abstract: The exemplary systems and methods may monitor one or more signals to be used to assess the hemodynamic status of a patient. The one or more signals may be used to calculate, or determine, a plurality of pulse transit times. The plurality of pulse transit times may be used to determine hemodynamic status values that may be indicative of a patient's aggregate hemodynamic status.

Abstract: A fixation member component, for example, employed by a relatively compact implantable medical device, includes a plurality of fingers; each finger includes a first segment extending from a fixed end of the corresponding finger, and a second segment extending from the corresponding first segment to a free end of the corresponding finger. Each first segment is elastically deformable from a relaxed to an extended condition, and from the relaxed to a compressed condition, and includes a peripheral portion and a central cut-out portion, framed by the peripheral portion. In the compressed condition, a free tip of the cut-out portion of some or all of the fingers may lodge against opposing tissue surfaces, via a spring force of the compressed fingers. Each second segment and cut-out portion is preferably configured to prevent penetration thereof within tissue at the implant site.

Abstract: A tine portion for an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, has one of: a round cross-section and an elliptical cross-section, while the distal segment has a flattened, or approximately rectangular cross-section. One or a pair of the tine portions may be integrally formed, with a base portion, from a superelastic wire, wherein the base portion is configured to fixedly attach to the device, for example, being captured between insulative members of a fixation subassembly.