Mobile three-lead cardiac monitoring device and method for automated diagnostics
Methods and apparatuses, including devices and systems, for remote and detection and/or diagnosis of acute myocardial infarction (AMI). In particular, described herein are handheld devices having an electrode configuration capable of recording three orthogonal ECG lead signals in an orientation-specific manner, and transmitting these signals to a processor. The processor may be remote or local, and it may automatically or semi-automatically detect AMI, atrial fibrillation or other heart disorders based on the analyses of the deviation of the recorded 3 cardiac signals with respect to previously stored baseline recordings.
1. A method for automated cardiac diagnostics, the method comprising:
acquiring a first set of at least three orthogonal leads from a patient's chest and hands at a first time;
acquiring a second set of at least three orthogonal leads from the patient's chest and hands a second time;
determining if the second set of at least three orthogonal leads is rotated relative to the first set of at least three orthogonal leads in a three-dimensional (3D) vector space and compensating for any rotation;
performing a beat alignment in a processor on the first and second sets of at least three orthogonal leads to synchronize representative beats from the first and second sets of at least three orthogonal leads;
calculating a difference signal representing the change between the first and second at least three orthogonal leads in the 3D vector space;
detecting cardiac changes suggestive of a cardiac condition by comparing parameters of the first and second at least three orthogonal leads or by comparing parameters of the difference signal to a predefined threshold; and
communicating cardiac changes to the patient.
2. A method for automated cardiac diagnostics, the method comprising:
positioning a device configured to detect at least three orthogonal leads from a patient's chest and hands against the subject's chest in a first recording position;
acquiring a first set of at least three orthogonal leads from the device at a first time;
communicating the first set of at least three orthogonal leads to a processor;
positioning the device against the subject's chest in a second recording position;
acquiring a second set of at least three orthogonal leads from the patient using the device at a second time;
communicating the second set of at least three orthogonal leads to the processor;
determining if the second set of at least three orthogonal leads is rotated relative to the first set of at least three orthogonal leads in a vector space and compensating for any rotation;
performing a beat alignment in the processor to synchronize representative beats from the first and second sets of at least three orthogonal leads;
calculating a difference signal representing the change between the first and second sets of at least three orthogonal leads in the vector space;
detecting cardiac changes suggestive of a cardiac condition by comparing one or more parameters of the difference signal to a predefined threshold;
communicating cardiac changes from the device to the patient.
3. The method of claim 2 , wherein positioning the device comprises placing a housing of the device having four integrated electrodes against the patient's chest.
4. The method of claim 2 , wherein communicating the first and second sets of at least three orthogonal leads to the processor comprises communicating the first and second sets of at least three orthogonal leads to a local processor within the housing.
5. The method of claim 2 , wherein detecting cardiac changes comprises detecting one or more of: acute ischemia, atrial fibrillation, atrial flutter, premature ventricular contractions (PVCs), and premature atrial contractions (PACs).
6. The method of claim 2 , wherein the first and second recording positions are the same position.
7. The method of claim 2 , wherein the first and second recording positions are different.
8. The method of claim 2 , wherein communicating the first and second sets of at least three orthogonal leads to the processor comprises wirelessly transmitting the first and second sets of at least three orthogonal leads to a remote processor.
9. The method of claim 2 , further comprising pre-processing the first and second sets of at least three orthogonal leads in the processor to achieve one or more of:
eliminate power line interference, baseline wandering and/or muscle noise; obtain a representative beat using fiducial points and median beat procedure; and check for switching of the left and right finger.
10. The method of claim 2 , wherein detecting cardiac changes suggestive of the cardiac condition comprises determining the Clew of a P wave and processing said Clew in order to detect atrial fibrillation.
11. The method of claim 2 , further comprising transmitting any ECG changes suggestive of a cardiac condition from the processor to the device.
12. The method of claim 2 , wherein communicating any ECG changes suggestive of a cardiac condition from the device to the patient comprises presenting a visual and/or audible alert to the patient.
13. 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.