Cardiac Pacemakers, Inc.

Scot C Boon

Imad Libbus

Qingsheng Zhu

Michael J Lyden

Ramprasad Vijayagopal

Keith R Maile

William J Linder

Paul J Huelskamp

Mark Gryzwa

David J Ternes

Sunipa Saha

Paul Allan Haefner

Kristofer J James

Scott R Vanderlinde

David B Krig

Eric Keith Enrooth

Rajesh Krishan Gandhi

Kenneth Tobacman

Embodiments of the invention are related to managing noise in sensed signals in implantable medical devices, amongst other things. In an embodiment the invention includes a method for processing electrical signals obtained from a patient including gathering a first set of electrical signals using an implantable medical device, filtering to provide a second set of electrical signals, the second set including frequencies above a threshold frequency, and estimating the amount of noise present in the first set of electrical signals based on the magnitude of the second set. In an embodiment, the invention includes a medical device configured to gather a first set of electrical signals, filter the first set to provide a second set of electrical signals including frequencies above a threshold frequency, and estimate the amount of noise present in the first set based on the magnitude of the second set. Other embodiments are also included herein.

Systems and methods for managing noise in implantable medical devices

An apparatus comprises a therapy circuit that provides a neural stimulation current, an impedance measurement circuit that measures a value of impedance at the output of the therapy circuit, a supply voltage generating circuit that provides an adjustable supply voltage value to the therapy circuit including a first supply voltage value when in a first mode, and a control circuit communicatively coupled to the therapy circuit, the impedance measuring circuit, and the supply voltage generating circuit. The control circuit, upon receiving an indication to exit the first mode, initiates an impedance measurement by the impedance measurement circuit, determines the second supply voltage value using the impedance measurement, and initiates a change from the first supply voltage value to the second supply voltage value. The second supply voltage value is sufficient to operate the therapy circuit and to provide a specified load current value to the measured impedance.

Power supply management for implantable neurostimulation devices

An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

Method and apparatus for intra-body ultrasound communication

Various aspects of the present subject matter provide a filter module. In various embodiments, the filter module comprises an input, an output, a signal path from the input to the output, a filter and a switch. The filter has a transfer response to attenuate a frequency of a neural stimulation signal. The switch is adapted to place the filter in the signal path when the neural stimulation signal is applied and to remove the filter from the signal path when the neural stimulation signal is not applied. Other aspects are provided herein.

System and method for filtering neural stimulation

A system and method monitors or reports the battery status of an implantable medical device to a user. The battery terminal voltage and charge delivered are measured. Before the battery terminal voltage falls below an Elective Replacement Indicator (ERI) threshold voltage, a charge-delivered indication of battery status is provided to a user. Thereafter, a battery terminal voltage indication of battery status is provided to a user. The Elective Replacement Indicator (ERI) and End of Life (EOL) threshold voltages are each functions of delivered battery current. A fault current detection is also provided to a user. A device temperature sensor discounts the battery voltage reading when the device is too cold.

System and method for monitoring or reporting battery status of implantable medical device

A cardiac rhythm management device having a capture verification sensing circuit for use in either a normal beat to beat pacing mode or an autothreshold mode. The cardiac rhythm management device is coupled to one or more pacing leads having pacing/sensing electrodes coupled thereto, and includes a sensing circuit for sensing electrical activity of the patient's heart, wherein the sensing circuit includes a dedicated evoked response sense amplifier and at least one high pass coupling capacitor electrically connected as a portion of a high pass network and between a pacing/sensing electrode and a blanking switch. A plurality of high pass coupling capacitors are coupled in parallel each having a separate blanking switch, thereby creating a differential network to offset imbalance sensed from the electrode due to extraneous factors.

Cardiac sense amplifier for capture verification

A cardiac rhythm management device having a capture verification sensing circuit for use in either a normal beat to beat pacing mode or an autothreshold mode. The cardiac rhythm management device is coupled to one or more pacing leads having pacing/sensing electrodes coupled thereto, and includes a sensing circuit for sensing electrical activity of the patient's heart. The sensing circuit includes a sense amplifier electrically connected in a manner, wherein a polarity of an amplitude of the sensed signal corresponding to an evoked response is opposite a polarity of an amplitude of the sensed signal corresponding to afterpotential. The sensing circuit further includes a band pass filter having a single high pass pole.

Wide-band evoked response sensing for capture verification

A method and apparatus for attenuating polarization voltages or 'afterpotentials' which develop at the heart tissue/electrode interface following the delivery of a pacing stimulus to the heart tissue such that the evoked response of the heart may be accurately detected to determine whether each pacing stimulus resulted in heart capture or contraction, thereby facilitating improved tracking of the capture threshold for minimizing power consumption while assuring therapeutic efficacy. The conventional large capacitance coupling capacitor used to suppress DC components of the pacing pulse is reduced to effectively lower the equivalent capacitance of the pacing and coupling capacitors following delivery of the pacing pulse, allowing shorter recharge and blanking intervals. As a result, the evoked response is more easily detected.

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Lino Lakes, MN, United States of America

Scot C Boon