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.

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.

Abstract: In some examples, a device includes at least three electrodes a first pair of electrodes and a second pair of electrodes. The device also includes circuitry configured to generate a first cardiac signal based on a first differential signal received across the first pair, generate a first brain signal based on the first differential signal received across the first pair, generate a second cardiac signal based on a second differential signal received across the second pair, and generate a second brain signal based on the second differential signal received across the second pair. The circuitry is also configured to output a composite cardiac signal based on the first cardiac signal and the second cardiac signal and to output a composite brain signal based on the first brain signal and the second brain signal.

Abstract: Devices, systems, and techniques are described for detecting stroke or seizure with a compact system. For example, a system includes a memory, a plurality of electrodes, and sensing circuitry configured to sense, via at least two electrodes of the plurality of electrodes, electrical signals from a patient, and generate, based on the electrical signals, physiological information. The system may also include processing circuitry configured to receive, from the sensing circuitry, the physiological information, determine, based on the physiological information, a seizure metric indicative of a seizure status of the patient and a stroke metric indicative of a stroke status of the patient, and store the seizure metric and the stroke metric in the memory. A housing may carry the plurality of electrodes and contain both of the sensing circuitry and the processing circuitry.

Abstract: A system for detecting strokes includes a sensor device configured to obtain physiological data from a patient, for example brain activity data. The sensor device can include electrodes configured to be disposed at the back of the patient's neck or base of the skull. The electrodes can detect electrical signals corresponding to brain activity in the P3, Pz, and/or P4 brain regions or other brain regions. A computing device communicatively coupled to the sensor device is configured to receive the physiological data and analyze it to indicate whether the patient has suffered a stroke.

Abstract: A system for detecting strokes includes a sensor device configured to obtain physiological data from a patient, for example brain activity data. The sensor device can include electrodes configured to be disposed at the back of the patient's neck or base of the skull. The electrodes can detect electrical signals corresponding to brain activity in the P3, Pz, and/or P4 brain regions or other brain regions. A computing device communicatively coupled to the sensor device is configured to receive the physiological data and analyze it to indicate whether the patient has suffered a stroke.

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.

Abstract: A medical device system and associated method determine an implantable medical device state prior to implantation. An impedance monitoring module monitors for a change in impedance between a pair of electrodes coupled to the impedance monitoring circuit. The system includes an enclosure for carrying the implantable medical device. The enclosure has a surface having an electrical impedance. A control module is configured to detect one of a first pre-implant state and a second pre-implant state of the implantable medical device in response to the impedance monitoring module detecting a change in impedance between the electrodes and adjust operation of the implantable medical device in response to detecting the impedance change.

Abstract: A medical device system and associated method determine an implantable medical device state prior to implantation. An impedance monitoring module monitors for a change in impedance between a pair of electrodes coupled to the impedance monitoring circuit. The system includes an enclosure for carrying the implantable medical device. The enclosure has a surface having an electrical impedance. A control module is configured to detect one of a first pre-implant state and a second pre-implant state of the implantable medical device in response to the impedance monitoring module detecting a change in impedance between the electrodes and adjust operation of the implantable medical device in response to detecting the impedance change.