Mobile three-lead cardiac monitoring device and method for automated diagnostics

A mobile, hand-held apparatus for automated cardiac electrical signal analysis, the apparatus comprising:

• a housing having a back, a first side, and a front;
• a first electrode and a second electrode integrated on the back of the housing configured to measure bioelectric signals from a patient's chest, wherein the first and second electrode are positioned a distance of at least 5 cm apart;
• a third electrode configured to measure bioelectric signals from the patient's right hand;
• a fourth electrode configured to measure bioelectric signals from the patient's left hand;
• a resistive network connecting at least two of the first, second, third and fourth electrodes, wherein the resistive network forms a central point, wherein at least one lead is formed between one of the said electrodes and the central point formed by mutually connecting at least two electrodes by the resistive network;
• and
• a processor configured to record at least 3 orthogonal cardiac leads from the first, second, third and fourth electrodes, wherein the processor comprises a register configured to store a first set of three orthogonal cardiac leads taken at a first time, and a comparator configured to determine a difference signal between the first set of three orthogonal cardiac leads and a second set of three orthogonal cardiac leads taken at a second time.

A method for automated ECG diagnostics, the method comprising:

• placing a device comprising a housing having four integrated electrodes arranged to measure three orthogonal leads from a patient's chest and hands against the subject's chest in a first recording position;
• acquiring a first 3 lead ECG recording from the device at a first time;
• communicating the first 3 lead ECG recording to a processor;
• storing the first 3 lead ECG recording as baseline recording;
• placing the device against the subject's chest in a second recording position;
• acquiring a second 3 lead ECG recording from the device at a second time;
• communicating the second 3 lead ECG recording to the processor;
• pre-processing the first and second 3 lead ECG recordings in the processor to eliminate power line interference, baseline wandering and muscle noise, obtain a representative beat using fiducial points and median beat procedure, and to check for switching of the left and right finger;
• performing beat alignment in the processor to bring representative beats from the first and second 3 lead ECG recordings in a same time frame so that corresponding points are synchronized;
• compensating for chest electrode miss-positioning between the first and second recording positions in the processor by compensating a heart electrical axis deviation in a 3 ECG leads vector space;
• calculating a difference signal representing the change between the first and second 3 ECG leads recordings;
• detecting ECG changes suggesting ischemia by comparing parameters of the first and second 3 lead ECG recording or by comparing parameters of the difference signal to a predefined threshold;
• communicating any ECG changes suggesting ischemia from the device to the patient.