Abstract: A method and apparatus determines the presence of a cardiac pulse in a patient by evaluating a physiological signal in the patient, preferably for the presence of characteristic heart sounds. The presence of a heart sound in a patient is determined by analyzing phonocardiogram (PCG) data obtained from the patient. Analyzing the PCG data may include evaluating temporal energy in the PCG data or evaluating spectral energy in the PCG data. Evaluating temporal energy in the PCG data may include estimating a first and second energy in the PCG data and comparing the first and second energy to determine a relative change in energy between them. Evaluating spectral energy in the PCG data may include calculating an energy spectrum of the PCG data and evaluating either the energy value or the frequency of a peak energy in the energy spectrum. The presence of a heart sound may also be determined by combining an evaluation of temporal energy with an evaluation of spectral energy in the PCG data.

Abstract: A reduced lead set device (10) that detects and reports the presence of an acute cardiac ischemic condition in a patient includes a reduced set of sensing electrodes (12, 14, 16, 18, and 20) placed on a patient for acquiring ECG data from the patient. The reduced lead set device evaluates the ECG data on a reduced set of leads by analyzing local features and/or global features of the ECG data. Local features may include local morphological measures such as ST elevation and clinical information on the patient such as age and sex. Global features include projection coefficients calculated from projecting a concatenated vector of heartbeat data onto separate sets of basis vectors that define signal subspaces of ischemic and non-ischemic ECGs. One or more classifiers evaluate the local features and/or global features to determine whether an acute cardiac ischemic condition is detected. The operating point, i.e., sensitivity and specificity, of the reduced lead set device is adjustable.

Abstract: A device (10) that detects and reports the presence of an acute cardiac ischemic condition in a patient includes sensing electrodes (12, 14, 16, 18, 20, 22, 24, 26, 28, and 30) placed on a patient for acquiring multiple (e.g., twelve) lead ECG data from the patient. The device evaluates the acquired ECG data by analyzing global features derived from the ECG data. Global features include projection coefficients calculated from projecting a concatenated vector of representative heartbeat data onto sets of basis vectors that define an acute cardiac ischemic ECG subspace and a non-ischemic ECG subspace. A classifier evaluates the global features to determine whether an acute cardiac ischemic condition is detected. In a further embodiment of the invention, one or more classifiers evaluate local features, such as local morphological features and patient clinical information, in addition to the global features to determine whether an acute cardiac ischemic condition is detected.