Abstract: This disclosure is directed to devices, systems, and techniques for determining an efficacy of a treatment program. For example, a medical device system includes a medical device including one or more sensors configured to generate a signal that indicates a parameter of a patient. Additionally, the medical device system includes processing circuitry configured to receive data indicative of a user selection of a reference time; determine a plurality of parameter values of the parameter based on a portion of the signal corresponding to a period of time including the reference time. Additionally, the processing circuitry is configured to identify, based on a first set of parameter values, a reference parameter value, calculate a parameter change value, and determine, based on the parameter change value, whether an improvement or a worsening of the patient has occurred responsive to a treatment administered beginning at the reference time.

Abstract: An implantable medical device is configured to determine a first atrial arrhythmia score from ventricular events sensed by a sensing circuit of an implantable medical device and determine a second atrial arrhythmia score from an intraventricular signal comprising atrial mechanical event signals attendant to atrial systole and produced by a sensor of the implantable medical device. An atrial arrhythmia is detected based on the first atrial arrhythmia score and the second atrial arrhythmia score.

Abstract: Techniques for using multiple physiological parameters to provide an early warning for worsening heart failure are described. A medical device monitors a primary diagnostic parameter that is indicative of worsening heart failure, such as intrathoracic impedance or pressure, and one or more secondary diagnostic parameters. The medical device detects worsening heart failure in the patient based on the primary diagnostic parameter when an index that is changed over time based on the primary diagnostic parameter value is outside a range of values, termed the threshold zone. When the index is within the threshold zone, the medical device detects worsening heart failure in the patient based on the one or more secondary diagnostic parameters. Upon detecting worsening heart failure, the medical device may, for example, provide an alert that enables the patient to seek medical attention before experiencing a heart failure event.

Abstract: A system and method for detecting and verifying bradycardia/asystole episodes includes sensing an electrogram (EGM) signal. The EGM signal is compared to a primary threshold to sense events in the EGM signal, and at least one of a bradycardia or an asystole is detected based on the comparison. In response to detecting at least one of a bradycardia or an asystole, the EGM signal is compared to a secondary threshold to sense events under-sensed by the primary threshold. The validity of the bradycardia or the asystole is determined based on the detected under-sensed events.

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: An example device for detecting one or more parameters of a cardiac signal is disclosed herein. The device includes one or more electrodes and sensing circuitry configured to sense a cardiac signal via the one or more electrodes. The device further includes processing circuitry configured to determine an R-wave of the cardiac signal and determine whether the R-wave is noisy. Based on the R-wave being noisy, the processing circuitry is configured to determine whether the cardiac signal around a determined T-wave is noisy. Based on the cardiac signal around the determined T-wave not being noisy, the processing circuitry is configured to determine a QT interval or a corrected QT interval based on the determined T-wave and the determined R-wave.

Abstract: An example device for detecting one or more parameters of a cardiac signal is disclosed herein. The device includes one or more electrodes and sensing circuitry configured to sense a cardiac signal via the one or more electrodes. The device further includes processing circuitry configured to determine an R-wave of the cardiac signal and determine a previous RR interval of the cardiac signal and a current RR interval of the cardiac signal based on the determined R-wave. The processing circuitry is further configured to determine a search window based on one or more of the current RR interval or the previous RR interval, determine a T-wave of the cardiac signal in the search window, and determine a QT interval based on the determined T-wave and the determined R-wave.

Abstract: An implantable medical device is configured to determine a first atrial arrhythmia score from ventricular events sensed by a sensing circuit of an implantable medical device and determine a second atrial arrhythmia score from an intraventricular signal comprising atrial mechanical event signals attendant to atrial systole and produced by a sensor of the implantable medical device. An atrial arrhythmia is detected based on the first atrial arrhythmia score and the second atrial arrhythmia score.

Abstract: In some examples, determining a heart failure status of a patient using a medical device comprising a plurality of electrodes includes determining an estimated arterial pressure waveform of the patient based on an arterial impedance signal received from at least two of the plurality of electrodes. The estimated arterial pressure waveform may comprise a plurality of arterial pressure cycles. Each of the plurality of arterial pressure cycles may correspond to a different cardiac cycle of a plurality of cardiac cycles of the patient. At least one value of an intrinsic frequency of the corresponding arterial pressure cycle may be determined for at least some of the plurality of cardiac cycles and the heart failure status of the patient may be determined based on the at least one value of the intrinsic frequency.

Abstract: A system and method for detecting and verifying bradycardia/asystole episodes includes sensing an electrogram (EGM) signal. The EGM signal is compared to a primary threshold to sense events in the EGM signal, and at least one of a bradycardia or an asystole is detected based on the comparison. In response to detecting at least one of a bradycardia or an asystole, the EGM signal is compared to a secondary threshold to sense events under-sensed by the primary threshold. The validity of the bradycardia or the asystole is determined based on the detected under-sensed events.

Abstract: A method for differentiating heart failure risk scores that includes receiving a current data transmission and acquiring patient metrics from a remote device, determining a daily heart failure risk score for each day occurring during a time period from a previous received data transmission to the current received data transmission based on the acquired patient metrics, determining a maximum daily heart failure risk score of the determined daily heart failure risk scores during a lookback window prior to the current received data transmission, determining a heart failure risk status alert for the received data transmission based on the temporal proximity of the determined maximum heart failure risk score and receipt of the current data transmission, selecting a type of notification based on the heart failure risk status differentiation, and indicating the transmission heart failure risk status and the heart failure risk status differentiation via the selected type of notification.

Abstract: Techniques for triggering the storage or transmission of cardiac electrogram (EGM) signals associated with a premature ventricular contractions (PVC) include sensing a cardiac EGM signal of a patient via a plurality of electrodes, detecting a premature ventricular contraction (PVC) within the cardiac EGM signal, determining whether PVC storage criteria is met, in response to a determination that the PVC storage criteria is met, storing a portion of the cardiac EGM signal associated with the PVC, and in response to a determination that the PVC storage criteria is not met, eschewing storing the portion of the cardiac EGM signal associated with the PVC.

Abstract: A method for secure call endpoint pairing is disclosed. The method includes starting, at a call endpoint, a pairing procedure with a wireless headset. Also, the method includes receiving a headset identifier from the wireless headset. Further, the method includes sending the headset identifier in a request to a headset registry server, and receiving, from the headset registry server, a response to the request. Additionally, the method includes terminating the pairing procedure based on the response from the headset registry server.

Abstract: Techniques for determining a likeliness that a patient may incur an adverse health event are described. An example technique may include utilizing a probability model that uses as evidence nodes various diagnostic states of physiological parameters, which may include one or more subcutaneous impedance parameters. The probability model may include a Bayesian Network that determines a posterior probability of the adverse health event occurring within a predetermined period of time.

Abstract: Techniques for obtaining impedance data to provide an early warning for heart failure decompensation are described. An example device may be configured to measure subcutaneous impedance values, and increment an impedance score. In some examples, the device may use an adaptive threshold and fluid index in incrementing the impedance score. In some examples, the impedance score is compared to a threshold to determine a heart failure status of a patient. In some examples, may cause resets in fluid index values and/or determine positions or orientations of the device when determining the impedance score.

Abstract: Techniques for obtaining impedance data to provide an early warning for heart failure decompensation are described. An example device may be configured to measure subcutaneous impedance values, and increment an impedance score. In some examples, the device may use an adaptive threshold and fluid index in incrementing the impedance score. In some examples, the impedance score is compared to a threshold to determine a heart failure status of a patient.

Abstract: Some aspects relate to systems, devices, and methods of assessing heart rate recovery. A heart rate of a patient may be measured during a plurality of heart rate recovery events. Each of the plurality of heart rate recovery events comprises a duration of time after an activity resulting in an elevated heart rate. Heart rate recovery information may be determined based on the measured heart rate during each of the plurality of heart rate recovery events and a cardiac status of the patient may be generated from the determined heart rate recovery information over the plurality of heart rate recovery events.

Abstract: In some examples, determining a heart failure status of a patient using a medical device comprising a plurality of electrodes includes determining an estimated arterial pressure waveform of the patient based on an arterial impedance signal received from at least two of the plurality of electrodes. The estimated arterial pressure waveform may comprise a plurality of arterial pressure cycles. Each of the plurality of arterial pressure cycles may correspond to a different cardiac cycle of a plurality of cardiac cycles of the patient. At least one value of an intrinsic frequency of the corresponding arterial pressure cycle may be determined for at least some of the plurality of cardiac cycles and the heart failure status of the patient may be determined based on the at least one value of the intrinsic frequency.

Abstract: A method for secure call endpoint pairing is disclosed. The method includes starting, at a call endpoint, a pairing procedure with a wireless headset. Also, the method includes receiving a headset identifier from the wireless headset. Further, the method includes sending the headset identifier in a request to a headset registry server, and receiving, from the headset registry server, a response to the request. Additionally, the method includes terminating the pairing procedure based on the response from the headset registry server.

Abstract: This disclosure is directed to devices, systems, and techniques for identifying a respiration rate based on an impedance signal. In some examples, a medical device system includes a medical device including a plurality of electrodes. The medical device is configured to perform, using the plurality of electrodes, an impedance measurement to collect a set of impedance values, where the set of impedance values is indicative of a respiration pattern of a patient. Additionally, the medical device system includes processing circuitry configured to identify a set of positive zero crossings based on the set of impedance values, identify a set of negative zero crossings based on the set of impedance values, and determine, for the impedance measurement, a value of a respiration metric using both the set of negative zero crossings and the set of positive zero crossings.