Nonlinear method and apparatus for electrocardiogram pacemaker signal filtering
First Claim
1. A method to at least one of detecting, removing and estimating a pacemaker signal from an electrocardiogram (“
- ECG”
) signal of a human or animal to diagnose a physiological condition, said method comprising the steps of;
digitizing a plurality of ECG potentials (M channels of ECG lead data) with an analog to digital converter (“
ADC”
) to create a discrete signal representation of each potential in time;
filtering the plurality of ECG potentials using a digital filter to create a plurality of filtered ECG potentials;
operating on the plurality of filtered ECG potentials using a non-linear mathematical morphology function to detect and remove the pacer maker signal from the ECG signal to create a plurality of processed ECG potentials; and
diagnosing a physiological condition of the human or animal based on the processed ECG potentials.
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Accused Products
Abstract
Signal “peak” and “valley” removal properties of mathematical morphology operators are exploited in a method and apparatus for detecting, removing, or improving fidelity of pacemaker signal components of the Electrocardiogram (ECG) at sampling rates well below the pacemaker signal Nyquist rate. The method works for the wide variability in pacemaker signal amplitude, width, firing frequency, and other characteristics encountered in practice, and it works for malfunctioning pacemakers that may fire at any point relative to the QRS complex of the ECG signal. Filtering operations require minimal digital storage and are computationally inexpensive (no multiplications), mainly involving “maximum” and “minimum” type signal detections over a finite time history of the input signal. This implies that the method can be inexpensively implemented on small instruments in either hardware or software. The method may also be used to estimate the height and polarity of the pacemaker voltage spike, even though the base sampling period may be longer than the width of the spike.
40 Citations
26 Claims
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1. A method to at least one of detecting, removing and estimating a pacemaker signal from an electrocardiogram (“
- ECG”
) signal of a human or animal to diagnose a physiological condition, said method comprising the steps of;
digitizing a plurality of ECG potentials (M channels of ECG lead data) with an analog to digital converter (“
ADC”
) to create a discrete signal representation of each potential in time;
filtering the plurality of ECG potentials using a digital filter to create a plurality of filtered ECG potentials;
operating on the plurality of filtered ECG potentials using a non-linear mathematical morphology function to detect and remove the pacer maker signal from the ECG signal to create a plurality of processed ECG potentials; and
diagnosing a physiological condition of the human or animal based on the processed ECG potentials. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- ECG”
-
14. An electrocardiogram (“
- ECG”
) apparatus to at least one of detecting, removing and estimating pacemaker pacer signals from an ECG waveform to diagnose a physiological condition of a human or animal, said apparatus comprising;
ECG electrodes to pickup a plurality of ECG potentials (M channels of ECG lead data) from the body of the human or animal being diagnosed, the electrodes electrically coupled to the body and connected to an ECG input;
an analog to digital converter (“
ADC”
) electrically connected to the ECG input, the ADC to digitize the ECG potentials and to create a discrete signal representation of each potential in time;
a filter block electrically coupled to the ADC to transfer the discrete signal representation of each potential in time to the filter block, the filter block to perform digital filtering on the discrete signal representation of each potential and to create a plurality of filtered ECG potentials;
a non-linear pacer filter electrically coupled to the filter block to receive the plurality of filtered ECG potentials, the non-linear pacer filter to perform at least one non-linear mathematical morphology function on the filtered ECG potentials to detect an(I remove the pacer signal from the ECG waveform and to create at least one processed ECG waveform; and
a display to allow viewing of the processed ECG waveform to diagnose a physiological condition of a human or animal based at least in part on the viewing of the processed ECG waveform. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- ECG”
Specification