Methods and devices are provided comprising an implantable lead having electrodes configured to be located proximate to a heart, the electrodes defining a sensing vector through a region of interest in the heart. The method and system collect an intra-cardiac electrogram (EGM) signal associated with an event of interest and determining an global amplitude characteristic (GAC) and a global slope characteristic (GSC) from the EGM signal under control of one or more processors within an implantable medical device (IMD). A QRS start time is defined, within the EGM signal, based on the GSC and determining a local amplitude characteristic (LAC) for a segment of the EGM signal within a search window of the GAC under control of one or more processors within an implantable medical device (IMD) A QRS end time is defined, within the EGM signal, based on the LAC; and calculating a QRS duration based on the QRS start time and QRS end time under control of one or more processors within an implantable medical device (IMD).

According to at least one example, an ambulatory medical device is provided. The device includes a plurality of electrodes disposed at spaced apart positions about a patient's body and a control unit. The control unit includes a sensor interface, a memory and a processor. The sensor interface is coupled to the plurality of electrodes and configured to receive a first ECG signal from a first pairing of the plurality of electrodes and to receive a second ECG signal from a second pairing of the plurality of electrodes. The memory stores information indicating a preferred pairing, the preferred pairing being either the first pairing or the second pairing. The processor is coupled to the sensor interface and the memory and is configured to resolve conflicts between interpretations of first ECG signal and the second ECG signal in favor of the preferred pairing.

VfA cardiac therapy uses an implantable medical device or system. The implantable medical device includes a tissue-piercing electrode implanted in the left ventricular myocardium of the patient's heart from the right atrium through the right atrial endocardium and central fibrous body. The device may include a right atrial electrode, a right atrial motion detector, or both. The device may be implanted completely within the patient's heart or may use one or more leads to implant electrodes in the patient's heart. A separate medical device may be used to provide some functionality for cardiac therapy. The implantable medical device or separate medical device may be used to measure physiological response information, such as cardiac electrical heterogeneity information. The physiological response information may be used to calibrate and deliver adaptive pacing therapy.

An example method includes analyzing morphology and/or amplitude of each of a plurality of electrophysiological signals across a surface of a patient's body to identify candidate segments of each signal satisfying predetermined conduction pattern criteria. The method also includes determining a conduction timing parameter for each candidate segment in each of the electrophysiological signals.

Electrocardiogram (ECG) data is compressible at high compression ratios using suitable compressive sensing techniques. Methods of detecting QRS complexes in an ECG signal may comprise receiving compressively-sensed measurements of an ECG signal; constructing an estimate of the ECG signal from the received compressively-sensed measurements, and detecting QRS complexes in the estimate of the ECG signal. QRS complexes may be detected by computing the first-order difference of the estimate of the ECG signal and processing the first-order difference of the estimate of the ECG signal to locate one or more significant natural blocks, each indicating a QRS complex in the ECG signal. QRS complexes may also be detected by using a conventional QRS detection algorithm on the estimate of the ECG signal. Also disclosed are related systems for detecting QRS complexes and for compressively sensing ECG signals.

Disclosed are a method and a system for comprehensive evaluation of organic compound and heavy metal pollution in water based on fish electro-cardio, and fish electro-cardio signals are acquired by a real-time and miniaturized fish electro-cardio acquisition system which includes a real-time and miniaturized fish electro-cardio acquisition device, then a change of the electro-cardio index in a QT interval is obtained for assessing the corresponding organic compound in water to be tested, and a change of the electro-cardio index in a QRS interval is obtained for assessing the corresponding heavy metal in water to be tested. Based on fish electro-cardio acquired continuously on-line in real-time while keeping fish swims in a normal state and the water quality parameters acquired by various water quality sensors, water quality is online analyzed and water sudden pollution is online monitored and assessed.

An analyzing method is to be implemented in an analyzing device, and includes: (A) dividing respective cycle lengths of a plurality of cardiac cycles of a user during sleep into a plurality of groups based on an order of occurrence of the cardiac cycles; (B) for each group, performing Fourier transform on the cycle lengths of the group to generate a respective spectrum; (C) for each group, calculating total power of the respective spectrum; and (D) determining, for each group, whether sleep quality of the user in a time period during which the corresponding cardiac cycles occurred is poor based on the total power of the respective spectrum and a predetermined threshold.

An acute ischemia detection device comprises a 12-lead electrocardiograph (ECG) device (12), an electronic data processing device (12), and a display component (22). The electronic data processing device applies 12-lead ECG to vessel-specific lead (VSL) transforms (50) to 12-lead ECG data acquired by the 12-lead ECG device to generate VSL lead data (e.g., LAD, LCX, and RCA vessel-specific lead data), determines ST values for the VSL lead data, and decides whether the 12-lead ECG data acquired by the 12-lead ECG device indicates acute ischemia by comparing the ST values for the VSL lead data with VSL lead ST thresholds (60). The display component may display an acute ischemia alarm or warning if the decision is the 12-lead ECG data acquired by the 12-lead ECG device indicates acute ischemia, and/or may display the generated VSL lead ECG traces.

Cardiac activity (e.g., a cardiac electrogram) is analyzed for local abnormal ventricular activity (LAVA), such as by using a LAVA detection and analysis module incorporated into an electroanatomical mapping system. The module transforms the electrogram signal into the wavelet domain to compute as scalogram; computes a one-dimensional LAVA function of the scalogram; detects one or more peaks in the LAVA function; and computes a peak-to-peak amplitude of the electrogram signal. If the peak-to-peak amplitude does not exceed a preset amplitude threshold, then the module can compute one or more of a LAVA lateness parameter for the electrogram signal using one of the one or more peaks detected in the LAVA function and a LAVA probability parameter for the electrogram signal.

The present invention relates to a method to provide a mean temporal spatial isochrone (TSI) path relating to an ECG feature (wave form) of interest, such as the activation of the heart from a single point (QRS), relative to the heart in a torso while using an ECG measurement from an ECG recording device. The method includes: receiving ECG measuring data from the ECG recording device; determining vector cardiogram (VCG) data; receiving a model of the heart, preferably with torso, as an input, preferably based on a request including request parameters; determining mean TSI data values representing the TSI path relating to an electrophysiological phase representing the ECG feature, the mean TSI providing a location within the heart representing the mean location of the ECG feature at the corresponding time; positioning the mean TSI path and preferably the vector cardiogram data points in the model of the heart and/or torso at an initial position; and rendering the model of the heart, preferably with torso, with the mean TSI path, preferably with VCG data related to the TSI, for displaying on a display screen for interpretation of the displayed rendering.