A system for acquiring electrocardiograph (ECG) and bioimpedance (BI) data is disclosed. The system (an ECG/BI measurement system) can use as few as one or two pairs of electrodes, permitting wearable devices employing the ECG/BI measurement system to be made into smaller, more comfortable, and more inconspicuous formats, as well as decreasing potential failure points in the measurement of electrical signals conducted between the system and the user. The system can measure both ECG and BI data using at least one shared pair of electrodes. In some cases, ECG and BI data are separately extracted from a measured signal across a shared pair of electrodes, while another pair of electrodes is being driven with a supply current. In other cases, internal switching can automatically switch a pair of electrodes between ECG-measuring circuitry and BI-measuring circuitry, such as based on a clock signal or other trigger.

A method and a wireless cardiac monitoring device to measure and transmit cardiac physiological signals of a subject. The device comprises a patch configured to be in contact with a skin surface of the subject. The patch comprises a plurality of electrodes and at least one wire-free module, embedded in the patch. The wire-free module comprises a patch orientation detection module to detect an orientation of the patch on the subject using a plurality of sensors. The wire-free module also comprises a processing module to select at least two pair of electrodes from the plurality of electrodes based on the detected orientation of the patch and process one or more bio-potential signals corresponding to the at least two pair of electrodes selected, as the physiological signals. The wire-free module further comprises a transmission module to transmit the physiological signals to an external device for further processing.

A method and a wireless cardiac monitoring device to measure and transmit cardiac physiological signals of a subject. The device comprises a patch configured to be in contact with a skin surface of the subject. The patch comprises a plurality of electrodes and at least one wire-free module, embedded in the patch. The wire-free module comprises a patch orientation detection module to detect an orientation of the patch on the subject using a plurality of sensors. The wire-free module also comprises a processing module to select at least two pair of electrodes from the plurality of electrodes based on the detected orientation of the patch and process one or more bio-potential signals corresponding to the at least two pair of electrodes selected, as the physiological signals. The wire-free module further comprises a transmission module to transmit the physiological signals to an external device for further processing.

Systems and methods for evaluating patients for ischemic heart disease are provided. An example system includes a flow sensor to sense a respiratory flow, an analyzer to determine a respiratory gas composition of at least a portion of the respiratory flow, an ECG device configured to determine ST segment values, and a computing device. The computing device may be configured to: receive gas exchange measurements that are based on breath-by-breath data captured by the flow sensor and the analyzer during a cardiopulmonary exercise test that includes an exercise phase; receive ST segment values captured by the ECG device during the cardiopulmonary exercise test; determine an ischemic index value based on the received gas exchange measurements and ST segment values; and output the ischemic index. The ST segment values may include ST segment depression or elevation values and the ischemic index value may be determined from the ST segment depression/elevation values.

Systems and methods for evaluating patients for ischemic heart disease are provided. An example system includes a flow sensor to sense a respiratory flow, an analyzer to determine a respiratory gas composition of at least a portion of the respiratory flow, an ECG device configured to determine ST segment values, and a computing device. The computing device may be configured to: receive gas exchange measurements that are based on breath-by-breath data captured by the flow sensor and the analyzer during a cardiopulmonary exercise test that includes an exercise phase; receive ST segment values captured by the ECG device during the cardiopulmonary exercise test; determine an ischemic index value based on the received gas exchange measurements and ST segment values; and output the ischemic index. The ST segment values may include ST segment depression or elevation values and the ischemic index value may be determined from the ST segment depression/elevation values.

An electronic device and method are disclosed herein. The electronic device includes a housing, a first, second, third and fourth electrode coupled to the housing, a communication module, and a processor. The processor implements the method, including: detect a first signal using the first electrode and the fourth electrode, detect a second signal using the second electrode and the fourth electrode, detect a third signal using the third electrode and the fourth electrode, transmit the first signal, the second signal, and the third signal to an external electronic device via the communication module, and receive, from the external electronic device, via the communication module, data for generating guidance information to correct an attachment position of the electronic device, wherein the guidance information is generated based on: a first biological signal generated based on the first signal and the second signal, a second biological signal generated based on the second signal and the third signal, and a third biological signal generated based on the third signal and the first signal.

An electronic device and method are disclosed herein. The electronic device includes a housing, a first, second, third and fourth electrode coupled to the housing, a communication module, and a processor. The processor implements the method, including: detect a first signal using the first electrode and the fourth electrode, detect a second signal using the second electrode and the fourth electrode, detect a third signal using the third electrode and the fourth electrode, transmit the first signal, the second signal, and the third signal to an external electronic device via the communication module, and receive, from the external electronic device, via the communication module, data for generating guidance information to correct an attachment position of the electronic device, wherein the guidance information is generated based on: a first biological signal generated based on the first signal and the second signal, a second biological signal generated based on the second signal and the third signal, and a third biological signal generated based on the third signal and the first signal.

A method of detection of a recurrent feature of interest within a signal including: obtaining evidence, based on a signal, the evidence including a probability density function for each of a plurality of parameters for parameterizing the signal, including at least one probability density function for a parameter, of the plurality of parameters, that positions a feature of interest within signal data of the signal; parameterizing a portion of the signal data from the signal based upon a hypothesis that a point of interest in the signal data is a position of the feature of interest; determining a posterior probability of the hypothesis being true given the portion of the signal data by combining a prior probability of the hypothesis and a conditional probability of observing the portion of the signal data given the hypothesis.

A method of detection of a recurrent feature of interest within a signal including: obtaining evidence, based on a signal, the evidence including a probability density function for each of a plurality of parameters for parameterizing the signal, including at least one probability density function for a parameter, of the plurality of parameters, that positions a feature of interest within signal data of the signal; parameterizing a portion of the signal data from the signal based upon a hypothesis that a point of interest in the signal data is a position of the feature of interest; determining a posterior probability of the hypothesis being true given the portion of the signal data by combining a prior probability of the hypothesis and a conditional probability of observing the portion of the signal data given the hypothesis.

Closed-loop stimulation of the Vagus nerve in response to a detected myocardial ischemia state within a therapeutic window can mitigate or reverse effects of the ischemia. This window is between 0 and 50 seconds of the onset of ischemia, before the myocardial ischemia reaches a statistically significant evolution level. A properly trained machine learning system such as a long short-term memory system can be used to analyze cardiovascular features and detect myocardial ischemia within the therapeutic window.