ECG analysis of signals with offsets
An electrocardiogram (ECG) acquisition system comprises a processor configured to process an ECG signal from a patient, a plurality of ECG electrodes configured to be coupled to the patient to obtain the ECG signal from the patient, and an analog-to-digital (A/D) converter configured to acquire the ECG signal from the plurality of ECG electrodes, and to provide the ECG signal to the processor as ECG data representative of the ECG signal. The A/D converter is configured to acquire the ECG signal at a first resolution and the processor is configured to process the ECG data at a second resolution, and the first resolution is higher than the second resolution.
1 . An electrocardiogram (ECG) acquisition system, comprising:
a plurality of ECG electrodes configured to be coupled to a patient to obtain an ECG signal from the patient, the ECG signal including a plurality of signal offsets;
an analog-to-digital (A/D) converter configured to acquire the ECG signal from the plurality of ECG electrodes, and to convert the ECG signal into ECG data representative of the ECG signal at a first resolution;
a high-pass filter configured to receive the ECG data from the A/D converter and to high-pass filter the ECG data at the first resolution to remove the plurality of signal offsets; and
a processor configured to receive and process the filtered ECG data at a second resolution,
wherein the first resolution is higher than the second resolution.
2 . The ECG acquisition system of claim 1 , wherein:
the high-pass filter is configured to high-pass filter the ECG data at the first resolution prior to processing by the processor at the second resolution.
3 . The ECG acquisition system of claim 2 , further comprising:
a data limiter configured to receive the ECG data from the high-pass filter after being high-pass filtered and prior to being processed by the processor,
wherein the data limiter is further configured to limit the ECG data received from the high-pass filter at the first resolution to a maximum value or a minimum value of the second resolution.
4 . The ECG acquisition system of claim 1 , wherein:
the high-pass filter has a corner frequency of 0.05 Hz or lower.
5 . The ECG acquisition system of claim 1 , wherein:
the high-pass filter has a corner frequency greater than 0.05 Hz.
6 . The ECG acquisition system of claim 1 , wherein:
the high-pass filter has a corner frequency selected to trade off a reduction in signal distortion of the ECG data with a reduction in baseline wander in the ECG data.
7 . The ECG acquisition system of claim 1 , wherein:
the first resolution comprises a 24-bit resolution, and
the second resolution comprises a 16-bit resolution.
8 . The ECG acquisition system of claim 1 , further comprising:
a preamplifier coupled between the plurality of ECG electrodes and the A/D converter,
wherein the plurality of ECG electrodes are direct-current (DC) coupled between the patient and the preamplifier.
9 . The ECG acquisition system of claim 1 , wherein the ECG acquisition system is incorporated into a wearable system configured to be worn by the patient.
10 . The ECG acquisition system of claim 9 , wherein the ECG data from the wearable system is remotely monitored and communicated to emergency medical services or a remote caregiver to provide assistance to the patient.
11 . The ECG acquisition system of claim 1 , wherein the processor is configured to process the ECG signal to detect ventricular fibrillation (VF) or ventricular tachycardia (VT).
12 . The ECG acquisition system of claim 1 , wherein the ECG data from the ECG acquisition system is transmitted to a communication device.
13 . The ECG acquisition system of claim 1 , wherein the plurality of ECG electrodes are dry electrodes.
14 . The ECG acquisition system of claim 1 , wherein the processor is further configured to perform rhythm analysis based on QRS width and heart rate data derived from the ECG data.
15 . An electrocardiogram (ECG) acquisition system, comprising:
a plurality of ECG electrodes configured to be coupled to a patient to obtain an ECG signal from the patient, the ECG signal including a plurality of signal offsets;
an analog-to-digital (A/D) converter configured to acquire the ECG signal from the plurality of ECG electrodes, and to convert the ECG signal into ECG data representative of the ECG signal at a first resolution;
a high-pass filter configured to receive the ECG data from the A/D converter and to high-pass filter the ECG data at the first resolution to remove the plurality of signal offsets;
a data limiter configured to receive the ECG data from the high-pass filter, wherein the data limiter is further configured to limit the high-pass filtered ECG data to a maximum value or a minimum value of a second resolution; and
a processor configured to receive and process the limited ECG data at the second resolution,
wherein the first resolution is higher than the second resolution.
16 . The ECG acquisition system of claim 15 , wherein:
the high-pass filter has a corner frequency of 0.05 Hz or lower.
17 . The ECG acquisition system of claim 15 , wherein:
the high-pass filter has a corner frequency greater than 0.05 Hz.
18 . The ECG acquisition system of claim 15 , wherein:
the high-pass filter has a corner frequency selected to trade off a reduction in signal distortion of the ECG data with a reduction in baseline wander in the ECG data.
19 . The ECG acquisition system of claim 15 , wherein:
the first resolution comprises a 24-bit resolution, and
the second resolution comprises a 16-bit resolution.
20 . The ECG acquisition system of claim 15 , further comprising:
a preamplifier coupled between the plurality of ECG electrodes and the A/D converter,
wherein the plurality of ECG electrodes are direct-current (DC) coupled between the patient and the preamplifier.