Abstract: Techniques are disclosed for defining a homeostatic window for controlling delivery of electrical stimulation therapy to a patient. In one example, a method includes generating and delivering electrical stimulation therapy to tissue of a patient via electrodes. Further, the method includes adjusting a level of a parameter of the electrical stimulation therapy such that a signal of the patient is not less than a lower bound and not greater than an upper bound. The lower bound is determined to be the magnitude of the signal while receiving electrical stimulation therapy sufficient to reduce one or more symptoms of a disease while the patient was receiving medication for reduction of the one or more symptoms. Further, the upper bound is determined to be the magnitude of the signal while receiving electrical stimulation therapy sufficient to reduce the one or more symptoms when the patient was not receiving the medication.

Abstract: The disclosure describes a method and system or controlling symptoms of patients suffering from Parkinson's Disease. In some examples, one or more biomarkers indicative of a patient's present symptoms are determined. The biomarkers may be used to control therapy delivered to the patient in a closed-loop manner. In addition, biomarkers may be used as an indication of therapy effectiveness.

Abstract: Techniques are described determining electrodes that are proximate or distal to location of an oscillatory signal source in a patient based on current source densities (CSDs). Processing circuitry may determine, for one or more electrodes of a plurality of electrodes, respective time-varying measurements of CSDs, aggregate, for the one or more electrodes of the plurality electrodes, the respective time-varying measurements of the CSDs to generate respective average level values for the one or more electrodes of the plurality of electrodes, determine, for one or more electrodes of the plurality of electrodes, respective phase-magnitude representations of the time-varying measurements of the CSDs. The respective phase-magnitude representations are indicative of respective magnitudes and phases of a particular frequency component of respective time-varying measurements of the CSDs.

Abstract: A medical device may receive sensor data from sensing sources, and determine confidence levels for sensor data received from each of the plurality of sensing sources. Each of the confidence levels of the sensor data from each of the sensing sources is a measure of accuracy of the sensor data received from respective sensing sources. The medical device may also determine one or more therapy parameter values based on the determined confidence levels, and cause delivery of therapy based on the determined one or more therapy parameter values.

Abstract: Various embodiments concern delivering electrical stimulation to the brain at a plurality of different levels of a stimulation parameter and sensing a bioelectrical response of the brain to delivery of the electrical stimulation for each of the plurality of different levels of the stimulation parameter. A suppression window of the stimulation parameter can be identified as having a suppression threshold as a lower boundary and an after-discharge threshold as an upper boundary based on the sensed bioelectrical responses. A therapy level of the stimulation parameter can be set for therapy delivery based on the suppression window. The therapy level of the stimulation parameter may be set closer to the suppression threshold than the after-discharge threshold within the suppression window. Data for hippocampal stimulation demonstrating a suppression window is presented.

Abstract: A method includes monitoring a sensor signal and classifying a physiological marker of a patient based upon the sensor signal. The method also includes generating a control signal based on the classified physiological marker, the control signal controlling an implantable stimulation device to provide the electrical stimulation at a target site within the patient. The method further includes adapting one or more of a manner in which processor circuitry classifies the physiological markers, generates the control signal, or one or more stimulation parameters of a stimulation program based on the classified physiological markers or patient input so as to automatically adjust one or more of timing or the stimulation parameters of the electrical stimulation.

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 disclosed to automate determination of therapy parameter values for adaptive deep brain stimulation (aDBS). A medical device may determine differences in power values between a present and a previous power value. Based on the difference being greater than or equal to a threshold value, the medical device may iteratively adjust a present therapy parameter value until the difference in the power values between a present and a previous power value is less than the threshold value.

Abstract: Various embodiments concern delivering electrical stimulation to the brain at a plurality of different levels of a stimulation parameter and sensing a bioelectrical response of the brain to delivery of the electrical stimulation for each of the plurality of different levels of the stimulation parameter. A suppression window of the stimulation parameter can be identified as having a suppression threshold as a lower boundary and an after-discharge threshold as an upper boundary based on the sensed bioelectrical responses. A therapy level of the stimulation parameter can be set for therapy delivery based on the suppression window. The therapy level of the stimulation parameter may be set closer to the suppression threshold than the after-discharge threshold within the suppression window. Data for hippocampal stimulation demonstrating a suppression window is presented.

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: Devices, systems, and techniques for controlling electrical stimulation therapy are described. In one example, a system may be configured to deliver electrical stimulation therapy to a patient, the electrical stimulation therapy comprising a plurality of therapy pulses at a predetermined pulse frequency over a period of time and deliver, over the period of time, a plurality of control pulses interleaved with at least some therapy pulses of the plurality of therapy pulses. The system may also be configured to sense, after one or more control pulses and prior to an immediately subsequent therapy pulse of the plurality of therapy pulses, a respective evoked compound action potential (ECAP), adjust, based on at least one respective ECAP, one or more parameter values that at least partially defines the plurality of therapy pulses, and deliver the electrical stimulation therapy to the patient according to the adjusted one or more parameter values.

Abstract: Systems and method may be used for interfacing with a patient. Systems may include a plurality of electrodes in electrical communication with a processor. The processor may determine a relative impedance difference between a first electrode and a second electrode, and apply a sub-therapeutic stimulation pulse to one of the first and second electrodes to adjust the relative impedance difference therebetween. Systems may include a processor capable of one or both of providing therapeutic stimulation to a patient via at least one electrode, and receiving electrical signals indicative of the patient's physiological activity. In some examples, the processor may simultaneously provide therapeutic stimulation to a patient and receive electrical signals from the patient indicative of the patient's physiological activity.

Abstract: Techniques, systems, and devices are disclosed for delivering stimulation therapy to a patient. In one example, a medical device senses, via one or more electrodes, one or more oscillations of a bioelectrical signal of a brain of a patient. In response to sensing the one or more oscillations, the medical device generates a plurality of bursts of stimulation therapy pulses, the plurality of bursts comprising an inter-burst frequency selected based on a frequency of the one or more oscillations of the bioelectrical signal. Further, the medical device delivers the plurality of bursts of stimulation therapy pulses to the patient to modulate a state of the patient associated with the one or more oscillations of the bioelectrical signal.

Abstract: Techniques, devices, and systems for isolating, by isolation circuitry connected to a power source, a voltage from the power source, receiving, by sensing circuitry, the isolated voltage, receiving, by the sensing circuitry, a reference voltage from an implantable reference electrode via a reference node, and sensing, by the sensing circuitry, the biomedical signal with two or more implantable sensing electrodes using the isolated voltage with respect to the reference voltage.

Abstract: Techniques, devices, and systems for isolating, by isolation circuitry connected to a power source, a voltage from the power source, receiving, by sensing circuitry, the isolated voltage, receiving, by the sensing circuitry, a reference voltage from an implantable reference electrode via a reference node, and sensing, by the sensing circuitry, the biomedical signal with two or more implantable sensing electrodes using the isolated voltage with respect to the reference voltage.

Abstract: Leakage of signal between conduction paths of an implantable medical lead or lead and lead extension combination is detected. A stimulation signal is provided via one electrode. Two other electrodes sense the stimulation signal. A difference in amplitude of the two sensed signals is determined and based on this difference, leakage is detected. A sensing circuit may use differential amplification of the two signals and compare a resulting output signal to a leakage threshold. When the amplitude of the output signal exceeds the leakage threshold, then leakage is occurring between the conduction path providing the stimulation and one of the conduction paths used for sensing. Other techniques for determining leakage from the difference may also be used such as comparing the amplitudes of the two sensed signals and providing a value that is based on the comparison to indicate whether leakage is present.

Abstract: A medical device may receive sensor data from sensing sources, and determine confidence levels for sensor data received from each of the plurality of sensing sources. Each of the confidence levels of the sensor data from each of the sensing sources is a measure of accuracy of the sensor data received from respective sensing sources. The medical device may also determine one or more therapy parameter values based on the determined confidence levels, and cause delivery of therapy based on the determined one or more therapy parameter values.

Abstract: An implantable medical device (IMD) is described capable of determining whether a patient is susceptible to freezing of gait events during ambulatory movement without the patient demonstrating an episode of freezing of gait. In one example, the IMD senses, via one or more electrodes, a bioelectrical signal of a brain of the patient while the patient performs movement associated with freezing of gait. The IMD determines, based on the bioelectrical signal, whether the patient is susceptible to freezing of gait while the patient is not experiencing an episode of freezing of gait. Further, upon detecting the movement associated with freezing of gait, the IMD delivers electrical stimulation therapy to the patient configured to suppress freezing of gait.

Abstract: Leakage of signal between conduction paths of an implantable medical lead or lead and lead extension combination is detected. A stimulation signal is provided via one electrode. Two other electrodes sense the stimulation signal. A difference in amplitude of the two sensed signals is determined and based on this difference, leakage is detected. A sensing circuit may use differential amplification of the two signals and compare a resulting output signal to a leakage threshold. When the amplitude of the output signal exceeds the leakage threshold, then leakage is occurring between the conduction path providing the stimulation and one of the conduction paths used for sensing. Other techniques for determining leakage from the difference may also be used such as comparing the amplitudes of the two sensed signals and providing a value that is based on the comparison to indicate whether leakage is present.

Abstract: Systems and method may be used for interfacing with a patient. Systems may include a plurality of electrodes in electrical communication with a processor. The processor may be configured to receive sense signals from electrodes and to determine the reliability of the received signal. A test tone signal comprising a test tone frequency may be applied, and the magnitude of the test tone frequency may be analyzed in the received signal. If it is determined that the magnitude of the test tone frequency is below a threshold, the system may take action, such as lowering the gain on an amplifier. Stimulation signals may be applied to the patient at a stimulation frequency simultaneously with one or both of receiving sense signals and providing the test tone signal.