Abstract: The disclosure is directed to a capacitive pressure sensor, and the assembly of a capacitive pressure sensor, that may be used within an implantable medical pump. In one example, a housing ferrule that encloses one capacitive plate and includes at least one protrusion for attaching a support structure of the capacitive plate. The at least one protrusion defines a smaller inner diameter as a reference point for securing the support structure while the ferrule provides a larger inner diameter to allow the support structure to tilt inside the ferrule to orient the capacitive plate into a desired plane. Despite manufacturing irregularities, the capacitive plate can be mounted in the desired plane parallel to another capacitive plate, a diaphragm, mounted to an edge of the ferrule. In another example, an assembly tool provides a stage to orient the capacitive plate and support structure within the ferrule at a desired depth.

Abstract: Various embodiments concern identifying a biomarker in the presence of electrical stimulation. Various embodiments concern delivering electrical stimulation to a patient and sensing one or more signals while the electrical stimulation is being delivered, the one or more signals including data indicative of physiological activity. Various embodiments further include determining an intensity of the electrical stimulation and determining whether the data indicates the presence of a biomarker based on a variable threshold, the variable threshold being variable based on the intensity of the electrical stimulation. Various embodiments concern determining a relationship between stimulation intensity and a biomarker parameter to determine the variability of the variable threshold.

Abstract: A patient controls the delivery of therapy through volitional inputs that are detected by a biosignal within the brain. The volitional patient input may be directed towards performing a specific physical or mental activity, such as moving a muscle or performing a mathematical calculation. In one embodiment, a biosignal detection module monitors an electroencephalogram (EEG) signal from within the brain of the patient and determines whether the EEG signal includes the biosignal. In one embodiment, the biosignal detection module analyzes one or more frequency components of the EEG signal. In this manner, the patient may adjust therapy delivery by providing a volitional input that is detected by brain signals, wherein the volitional input may not require the interaction with another device, thereby eliminating the need for an external programmer to adjust therapy delivery. Example therapies include electrical stimulation, drug delivery, and delivery of sensory cues.

Abstract: This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device, to provide a stable, low-noise output signal.

Abstract: A capacitive interface circuit for a low power system is described. The capacitive interface circuit is configured to achieve very low noise sensing of capacitance-based transducers, such as a micro-electro-mechanical system (MEMS)-based sensor, with high resolution and low power. The capacitive interface circuit uses a differential amplifier and correlated triple sampling (CTS) to substantially eliminate, or at least reduce, kT/C noise, as well as amplifier offset and flicker (1/f) noise, from the output of the amplifier. The capacitive interface circuit may further include an output stage that reduces glitching, i.e., clock transients, in the output signal by allowing transients in the amplifier output to settle. In this manner, the circuit can be used in a low power system to produce a stable, low-noise output.

Abstract: Posture-responsive therapy is delivered by the medical system based on posture state input from only one of multiple posture sensors at any given time. An example implantable medical system includes a first posture sensor and a second sensor. A processor controls therapy delivery to the patient based on at least one of a patient posture state or a patient activity level determined based on input from only one of the first or second posture sensors. In some examples, one of multiple posture sensors of an implantable posture-responsive medical system is used to automatically reorient another posture sensor (of the system), which has become disoriented. The disoriented posture sensor may be automatically reoriented for one or more posture states at a time.

Abstract: A therapy program is selected based on a patient state, where the patient state comprises at least one of a movement state, sleep state or speech state. In this way, therapy delivery is tailored to the patient state, which may include specific patient symptoms. The therapy program is selected from a plurality of stored therapy programs that comprise therapy programs associated with a respective one at least two of the movement, sleep, and speech states. Techniques for determining a patient state include receiving volitional patient input or detecting biosignals generated within the patient's brain. The biosignals are nonsymptomatic and may be incidental to the movement, sleep, and speech states or generated in response to volitional patient input.

Abstract: A charging system is disclosed. In one embodiment, the system includes a charging unit having a primary coil, and an implantable medical device comprising a secondary coil to receive charge from the primary coil. The implantable medical device further includes a half-wave voltage-doubling rectifier coupled to the secondary coil, a full-wave rectifier coupled to the secondary coil, and a rechargeable power source. Control logic is provided to periodically configure the rechargeable power source to receive charge from a selected one of the voltage-doubling circuit and the full-wave rectifier in a manner that increases rate at which charge is transferred from the secondary coil to the rechargeable power source. The control logic may configure the rechargeable power source to receive charge based on one or more monitored conditions which may include, for example, an indication of a current, a voltage, a coupling coefficient, back-scatter, and temperature.

Abstract: This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device. The amplifier may be used for physiological signal sensing, impedance sensing, telemetry or other test and measurement applications.

Abstract: A charging system for an implantable medical device having a secondary coil. The charging system includes an external power source having at least one primary coil, a modulation, circuit operatively coupled to the primary coil and capable of driving it in a manner characterized by a charging parameter, and a sensor in communication with the modulation circuit and capable of sensing a condition indicating a need to adjust the charging parameter during a charging process. The parameter may be varied so that data sensed by the sensor meets a threshold requirement, which may be based on a patient preference, a government regulation, a recommendation promulgated by a health authority and/or a requirement associated with another device carried by the patient. In one embodiment, the regulation dictates maximum magnetic field exposure, and a field limiting circuit is employed to adjust the charging process.

Abstract: Posture-responsive therapy is delivered by the medical system based on posture state input from only one of multiple posture sensors at any given time. An example implantable medical system includes a first posture sensor and a second sensor. A processor controls therapy delivery to the patient based on at least one of a patient posture state or a patient activity level determined based on input from only one of the first or second posture sensors. In some examples, one of multiple posture sensors of an implantable posture-responsive medical system is used to automatically reorient another posture sensor (of the system), which has become disoriented. The disoriented posture sensor may be automatically reoriented for one or more posture states at a time.

Abstract: Systems and methods for orienting a medical instrument relative to at least a portion of a medical device include a first tilt detector associated with the medical instrument and a second tilt detector associated with the medical device. The first tilt detector may be within an orientation device that is coupled to or separate from the medical instrument. The tilt detectors generate signals that may be used to determine the relative orientation between at least a portion of the medical device and medical instrument. For example, in some embodiments, the signals may be used to determine whether the orientations of the portion of the medical device and the medical instrument substantially match.

Abstract: The invention relates to systems and methods for stabilizing therapeutic formulations used in medical devices. In particular, the invention relates to systems designed to inhibit the aggregation of therapeutic molecules such as polypeptides stored within a medication delivery device, for example polypeptide aggregation that can result from jostling the medication within a fluid medication reservoir. In embodiments of the invention, a damping system is operably connected to a fluid medication reservoir that is disposed within the housing of a device so as to inhibit the agitation of a fluid medication. Typically the damping system comprises one or more energy absorbing materials.

Abstract: A movement state of a patient is detected based on brain signals, such as an electroencephalogram (EEG) signal. In some examples, a brain signal within a dorsal-lateral prefrontal cortex of a brain of the patient indicative of prospective movement of the patient may be sensed in order to detect the movement state. The movement state may include the brain state that indicates the patient is intending on initiating movement, initiating movement, attempting to initiate movement or is actually moving. In some examples, upon detecting the movement state, a movement disorder therapy is delivered to the patient. In some examples, the therapy delivery is deactivated upon detecting the patient is no longer in a movement state or that the patient has successfully initiated movement. In addition, in some examples, the movement state detected based on the brain signals may be confirmed based on a signal from a motion sensor.

Abstract: Aspects of this disclosure relate to coupling and decoupling a power source of a device with circuitry within the device. For example, in aspects of this disclosure, when a short develops within the device, a switch circuit may decouple the power source from the some of the circuitry within the device. Decoupling the power source when a short develops may extent the operational time of the power source, and may reduce thermal excursion.

Abstract: A movement state of a patient is detected based on brain signals, such as an electroencephalogram (EEG) signal. In some examples, a brain signal within a dorsal-lateral prefrontal cortex of a brain of the patient indicative of prospective movement of the patient may be sensed in order to detect the movement state. The movement state may include the brain state that indicates the patient is intending on initiating movement, initiating movement, attempting to initiate movement or is actually moving. In some examples, upon detecting the movement state, a movement disorder therapy is delivered to the patient. In some examples, the therapy delivery is deactivated upon detecting the patient is no longer in a movement state or that the patient has successfully initiated movement. In addition, in some examples, the movement state detected based on the brain signals may be confirmed based on a signal from a motion sensor.

Abstract: This disclosure provides techniques for bladder sensing. In accordance with the techniques described in this disclosure, a device may measure the impedance of a bladder, determine the posture of a patient, and determine a status of the bladder based on the impedance and posture.

Abstract: The disclosure is directed to a capacitive pressure sensor, and the assembly of a capacitive pressure sensor, that may be used within an implantable medical pump. In one example, a housing ferrule that encloses one capacitive plate and includes at least one protrusion for attaching a support structure of the capacitive plate. The at least one protrusion defines a smaller inner diameter as a reference point for securing the support structure while the ferrule provides a larger inner diameter to allow the support structure to tilt inside the ferrule to orient the capacitive plate into a desired plane. Despite manufacturing irregularities, the capacitive plate can be mounted in the desired plane parallel to another capacitive plate, a diaphragm, mounted to an edge of the ferrule. In another example, an assembly tool provides a stage to orient the capacitive plate and support structure within the ferrule at a desired depth.

Abstract: The disclosure is directed to a pressure sensor of an implantable medical device. The pressure sensor may utilize detect fluid pressure based on a changing capacitance between two capacitive elements. The pressure sensor may define at least a portion of a fluid enclosure of the IMD. In one example, the pressure sensor has a self-aligning housing shape that occludes an opening in the pump bulkhead of the IMD. An operative surface of the pressure and the portion of the fluid enclosure may be formed of a corrosion resistant and/or biocompatible material. A first capacitive element of the pressure sensor may be a metal alloy diaphragm that deflects in response to external fluid pressure. A second capacitive element of the pressure sensor may be a metal coating on a rigid insulator sealed from the fluid by the diaphragm and a housing of the sensor.

Abstract: This disclosure describes a capacitive interface circuit for a low power system. The capacitive interface circuit is configured to achieve very low noise sensing of capacitance-based transducers, such as a micro-electro-mechanical system (MEMS)-based sensor, with high resolution and low power. The capacitive interface circuit uses a differential amplifier and correlated triple sampling (CTS) to substantially eliminate, or at least reduce, kT/C noise, as well as amplifier offset and flicker (1/f) noise, from the output of the amplifier. The capacitive interface circuit may further include an output stage that reduces glitching, i.e., clock transients, in the output signal by allowing transients in the amplifier output to settle. In this manner, the circuit can be used in a low power system to produce a stable, low-noise output.