Abstract: Systems, devices, and techniques are described for calibrating a medical device that senses ECAP signals from a patient's nerve tissue. For example a method includes instructing, with processing circuitry, stimulation circuitry of a medical device to deliver, on stimulation electrodes of the medical device, an electrical stimulation signal having an amplitude substantially equal to zero to a patient, entering, with the processing circuitry subsequent to instructing the stimulation circuitry to deliver the electrical stimulation signal, a passive recharge state on stimulation electrode circuitry, and auto-zeroing, with the processing circuitry, inputs to an operational amplifier of sensing circuitry electrically coupled to sensing electrodes of the medical device while the stimulation electrode circuitry is in the passive recharge state.

Abstract: Systems, devices, and techniques are described for analyzing evoked compound action potentials (ECAP) signals to assess the effect of a delivered electrical stimulation signal. In one example, a system includes a stimulation generator configured to deliver a stimulation pulse to a patient, sensing circuitry configured to sense an evoked compound action potential (ECAP) signal evoked from the stimulation pulse, and processing circuitry. The processing circuitry may be configured to determine a maximum value of a derivative of the ECAP signal, determine a minimum value of the derivative of the ECAP signal, determine, based on the maximum value of the derivative and the minimum value of the derivative, a characteristic value of the ECAP signal, and determine, based on the characteristic value of the ECAP signal, at least one parameter value at least partially defining electrical stimulation therapy to be delivered to the patient.

Abstract: Systems, devices, and techniques are described for calibrating a medical device that senses ECAP signals from a patient's nerve tissue. For example a method includes: instructing, with processing circuitry, stimulation circuitry of a medical device to deliver, on stimulation electrodes of the medical device, an electrical stimulation signal having an amplitude substantially equal to zero to a patient; entering, with the processing circuitry subsequent to instructing the stimulation circuitry to deliver the electrical stimulation signal, a passive recharge state on stimulation electrode circuitry; and auto-zeroing, with the processing circuitry, inputs to an operational amplifier of sensing circuitry electrically coupled to sensing electrodes of the medical device while the stimulation electrode circuitry is in the passive recharge state.

Abstract: A system for providing therapy to a patient includes stimulation generation circuitry, sensing circuitry, and processing circuitry. The processing circuitry is configured to cause storage of a first voltage at a first terminal at a first calibration capacitor and storage of a second voltage at a second terminal at a second calibration capacitor. The processing circuitry is configured to switch out a first calibration switch to prevent the first voltage stored at the first calibration capacitor from changing and switch out a second calibration switch to prevent the second voltage stored at the second calibration capacitor from changing and determine, with the sensing circuitry, a sensing signal based on the first voltage offset by a first calibration voltage stored by the first capacitor and based on the second voltage offset by a second calibration voltage stored by the second capacitor.

Abstract: An example medical device includes a battery configured to provide power to the medical device and stimulation circuitry configured to generate an electrical stimulation signal. The medical device includes hibernation control circuitry configured to cause the medical device to enter a hibernation mode in response to a hibernation trigger and exit the hibernation mode in response to a wake-up trigger. The medical device includes a switch configured to open in response to the hibernation control circuitry causing the medical device to enter a hibernation mode and close in response to the hibernation control circuitry causing the medical device to exit the hibernation mode and isolation interface circuitry configured to prevent power leakage from the hibernation control circuitry to the stimulation circuitry when the medical device is in hibernation mode. The stimulation circuitry is not powered by the battery when the medical device is in the hibernation mode.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: Systems, devices, and techniques are described for analyzing evoked compound action potentials (ECAP) signals to assess the effect of a delivered electrical stimulation signal. In one example, a system includes a stimulation generator configured to deliver a stimulation pulse to a patient, sensing circuitry configured to sense an evoked compound action potential (ECAP) signal evoked from the stimulation pulse, and processing circuitry. The processing circuitry may be configured to determine a maximum value of a derivative of the ECAP signal, determine a minimum value of the derivative of the ECAP signal, determine, based on the maximum value of the derivative and the minimum value of the derivative, a characteristic value of the ECAP signal, and determine, based on the characteristic value of the ECAP signal, at least one parameter value at least partially defining electrical stimulation therapy to be delivered to the patient.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: Techniques are described for real-time phase detection. For the phase detection, a signal is correlated with a frequency component of a frequency band whose phase is being detected, and the correlation includes predominantly decreasing weighting of past portions of the signals.

Abstract: The accuracy of data processing operations in an electronic device is improved through reductions in errors associated with data acquisition, reading, and transmission. In one embodiment, two or more modules of an integrated circuit are operated at different clock speeds and a voting scheme is utilized to obtain a valid data value from one of the modules. The disclosure describes methods, devices and systems that utilize the voting schemes to eliminate errors induced by race conditions in obtaining valid data values during data transfer by obtaining a plurality of data samples while the communicating modules are operating at the different clock speeds and selecting from among the data samples the valid data value.

Abstract: The accuracy of data processing operations in implantable medical devices is improved through reductions in errors associated with data acquisition, reading, and transmission. In one embodiment, two or more circuit modules of the device are operated at different clock speeds and a voting scheme is utilized to obtain a valid data value from one of the modules. The disclosure describes methods, devices and systems that utilize the voting schemes to eliminate errors induced by race conditions in obtaining the valid data values by obtaining a plurality of data samples during operation of the circuit modules at the different clock speeds and selecting from among the data samples the valid data value.

Abstract: The accuracy of data processing operations in an electronic device is improved through reductions in errors associated with data acquisition, reading, and transmission. In one embodiment, two or more modules of an integrated circuit are operated at different clock speeds and a voting scheme is utilized to obtain a valid data value from one of the modules. The disclosure describes methods, devices and systems that utilize the voting schemes to eliminate errors induced by race conditions in obtaining valid data values during data transfer by obtaining a plurality of data samples while the communicating modules are operating at the different clock speeds and selecting from among the data samples the valid data value.

Abstract: The accuracy of data processing operations in implantable medical devices is improved through reductions in errors associated with data acquisition, reading, and transmission. In one embodiment, two or more circuit modules of the device are operated at different clock speeds and a voting scheme is utilized to obtain a valid data value from one of the modules. The disclosure describes methods, devices and systems that utilize the voting schemes to eliminate errors induced by race conditions in obtaining the valid data values by obtaining a plurality of data samples during operation of the circuit modules at the different clock speeds and selecting from among the data samples the valid data value.

Abstract: This disclosure is directed to the synchronization of clocks of a secondary implantable medical device (IMD) to a clock of a primary IMD. The secondary IMD includes a communications clock. The communications clock may be synchronized based on at least one received communications pulse. The secondary IMD further includes a general purpose clock different than the communications clock. The general purpose clock may be synchronized based on at least one received power pulse. The communications clock may also be synchronized based on the at least one received power pulse.

Abstract: This disclosure is directed to the synchronization of clocks of a secondary implantable medical device (IMD) to a clock of a primary IMD. The secondary IMD includes a communications clock. The communications clock may be synchronized based on at least one received communications pulse. The secondary IMD further includes a general purpose clock different than the communications clock. The general purpose clock may be synchronized based on at least one received power pulse. The communications clock may also be synchronized based on the at least one received power pulse.

Abstract: A medical device for determining a respiratory effort having a pressure sensor to sense pressure signals, a housing having system components positioned therein, and a microprocessor positioned within the housing, wherein the microprocessor detects an inspiration and an expiration in response to the pressure signals, detects a breath in response to the detected inspiration and the detected expiration, and determines the respiratory effort in response to the detected breath.

Abstract: A method of determining respiratory effort in a medical device in which pressure signals are sensed to generate corresponding sample points, an inspiration and an expiration are detected in response to the sensed pressure signals, a breath is detected in response to the detected inspiration and the detected expiration, and the respiratory effort is determined in response to the detected breath.