EP-4736768-A1 - BIOSIGNAL PROCESSING DEVICE, BIOSIGNAL MEASURING DEVICE, AND BIOSIGNAL PROCESSING METHOD

EP4736768A1EP 4736768 A1EP4736768 A1EP 4736768A1EP-4736768-A1

Abstract

A plurality of heartbeat waveforms extracted from time-series data of an ECG signal are divided into a plurality of heartbeat waveform groups including at least a first heartbeat waveform group and a second heartbeat waveform group, a first representative P wave interval waveform and a second representative P wave interval waveform, which are typical P wave interval waveforms, are acquired from the first heartbeat waveform group and the second heartbeat waveform group, respectively, and when a similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is higher than a threshold value, it is determined that a P wave is included in the time-series data of the ECG signal.

Inventors

KUBO, MITSUAKI
KOIZUMI, MASAYUKI
WANG, Danni
KIMURA ISHIDA, Yui
FUJII, KENJI
KAWABATA, YASUHIRO

Assignees

OMRON Corporation
Omron Healthcare Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240806

Claims (18)

A biosignal processing device comprising: an acquisition unit that acquires time-series data of an ECG signal measured from a user; and a P wave determination unit that extracts a first P wave interval waveform from a first P wave interval set with reference to a time point of a first R wave in the time-series data of the ECG signal and extracts a second P wave interval waveform from a second P wave interval set with reference to a time point of a second R wave different from the first R wave, and when a similarity between the first P wave interval waveform and the second P wave interval waveform is higher than a threshold value, determines that a P wave is included in the first P wave interval and the second P wave interval.
A biosignal processing device comprising: an acquisition unit that acquires time-series data of an ECG signal measured from a user; and a P wave determination unit that extracts at least a first heartbeat waveform group and a second heartbeat waveform group from the time-series data of the ECG signal, extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the first heartbeat waveform group and extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the second heartbeat waveform group, generates a first representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the first heartbeat waveform group and generates a second representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the second heartbeat waveform group, and when a similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is higher than a threshold value, determines that a P wave is included in the first heartbeat waveform group and the second heartbeat waveform group.
A biosignal processing device comprising: an acquisition unit that acquires time-series data of an ECG signal measured from a user; a candidate detection unit that detects a P wave candidate from the time-series data of the ECG signal; and a P wave determination unit that, in a case where the P wave candidate is detected by the candidate detection unit, divides a plurality of heartbeat waveforms extracted from the time-series data of the ECG signal into a plurality of heartbeat waveform groups including at least a first heartbeat waveform group and a second heartbeat waveform group, acquires a first representative P wave interval waveform and a second representative P wave interval waveform, which are typical P wave interval waveforms, from the first heartbeat waveform group and the second heartbeat waveform group, respectively, and when a similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is higher than a threshold value, determines that a P wave is included in the time-series data of the ECG signal.
The biosignal processing device according to claim 3, wherein when the similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is equal to or less than the threshold value, the P wave determination unit determines that whether the P wave is included in the time-series data of the ECG signal is indeterminable.
The biosignal processing device according to claim 3, wherein the P wave determination unit allocates, among the plurality of heartbeat waveforms extracted from the time-series data of the ECG signal, a heartbeat waveform extracted in a first half into the first heartbeat waveform group and a heartbeat waveform extracted in a second half into the second heartbeat waveform group.
The biosignal processing device according to claim 3, wherein the P wave determination unit alternately or randomly selects, from among the plurality of heartbeat waveforms extracted from the time-series data of the ECG signal, a heartbeat waveform to be allocated to the first heartbeat waveform group and a heartbeat waveform to be allocated to the second heartbeat waveform group.
The biosignal processing device according to claim 3, wherein the P wave determination unit divides the plurality of heartbeat waveforms extracted from the time-series data of the ECG signal into the first heartbeat waveform group and the second heartbeat waveform group such that the number of heartbeat waveforms of the first heartbeat waveform group and the number of heartbeat waveforms of the second heartbeat waveform group are equal to each other.
The biosignal processing device according to claim 3, wherein the P wave determination unit extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the first heartbeat waveform group, and acquires, as the first representative P wave interval waveform, an average, a median value, or a mode value of waveforms of a plurality of P wave intervals extracted from the first heartbeat waveform group, and extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the second heartbeat waveform group, and acquires, as the second representative P wave interval waveform, an average, a median value, or a mode value of waveforms of a plurality of P wave intervals extracted from the second heartbeat waveform group.
The biosignal processing device according to claim 3, wherein the P wave determination unit evaluates the similarity between the first representative P wave interval waveform and the second representative P wave interval waveform by cross-correlation between the first representative P wave interval waveform and the second representative P wave interval waveform.
The biosignal processing device according to claim 3, wherein the candidate detection unit generates a representative heartbeat waveform, which is a typical heartbeat waveform, from a plurality of heartbeat waveforms extracted from the time-series data of the ECG signal, and detects a P wave candidate from the representative heartbeat waveform.
The biosignal processing device according to claim 10, wherein the candidate detection unit extracts a feature amount from a P wave interval set with reference to a time point of an R wave in the representative heartbeat waveform, and when the feature amount satisfies a predetermined condition, determines that the P wave candidate is present.
The biosignal processing device according to claim 10, wherein the candidate detection unit selects, from the time-series data of the ECG signal, data of a low-noise interval in which a degree of noise is lower than a predetermined level, and generates the representative heartbeat waveform by using a plurality of heartbeat waveforms extracted from the data of the low-noise interval.
The biosignal processing device according to claim 12, wherein when the number of heartbeat waveforms extracted from the data of the low-noise interval is less than a predetermined number, the P wave determination unit determines that whether the P wave is included in the time-series data of the ECG signal is indeterminable.
The biosignal processing device according to claim 10, wherein when the P wave candidate is not detected by the candidate detection unit, the P wave determination unit evaluates a degree of smoothness of a P wave interval set with reference to a time point of an R wave in the representative heartbeat waveform, determines, in a case where the degree of smoothness is equal to or greater than a predetermined value, that the P wave is not included in the time-series data of the ECG signal, and determines, in other cases, that whether the P wave is included in the time-series data of the ECG signal is indeterminable.
A biosignal measuring device comprising: an ECG sensor that is configured to be worn on a limb of a user; and the biosignal processing device according to any one of claims 1 to 14, which processes an ECG signal measured by the ECG sensor.
A biosignal processing method performed by a biosignal processing device, the biosignal processing method comprising: acquiring time-series data of an ECG signal measured from a user; and extracting a first P wave interval waveform from a first P wave interval set with reference to a time point of a first R wave in the time-series data of the ECG signal and extracting a second P wave interval waveform from a second P wave interval set with reference to a time point of a second R wave different from the first R wave, and when a similarity between the first P wave interval waveform and the second P wave interval waveform is higher than a threshold value, determining that a P wave is included in the first P wave interval and the second P wave interval.
A biosignal processing method performed by a biosignal processing device, the biosignal processing method comprising: acquiring time-series data of an ECG signal measured from a user; and extracting at least a first heartbeat waveform group and a second heartbeat waveform group from the time-series data of the ECG signal, extracting waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the first heartbeat waveform group and extracting waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the second heartbeat waveform group, generating a first representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the first heartbeat waveform group and generating a second representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the second heartbeat waveform group, and when a similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is higher than a threshold value, determining that a P wave is included in the first heartbeat waveform group and the second heartbeat waveform group.
A biosignal processing method performed by a biosignal processing device, the biosignal processing method comprising: acquiring time-series data of an ECG signal measured from a user; detecting a P wave candidate from the time-series data of the ECG signal; and in a case where the P wave candidate is detected, dividing a plurality of heartbeat waveforms extracted from the time-series data of the ECG signal into a plurality of heartbeat waveform groups including at least a first heartbeat waveform group and a second heartbeat waveform group, acquiring a first representative P wave interval waveform and a second representative P wave interval waveform, which are typical P wave interval waveforms, from the first heartbeat waveform group and the second heartbeat waveform group, respectively, and when a similarity between the first representative P wave interval waveform and the second representative P wave interval waveform is higher than a threshold value, determining that a P wave is included in the time-series data of the ECG signal.

Description

TECHNICAL FIELD The present invention relates to a biosignal processing device, a biosignal measuring device, and a biosignal processing method. BACKGROUND OF INVENTION Atrial fibrillation (AF) is a type of arrhythmia, and is a disease in which the atria fibrillate rapidly due to abnormal electrical signals generated from sites other than the sinoatrial node, and the pulse (heartbeat interval) becomes irregular. Atrial fibrillation not only causes palpitations and shortness of breath, which can interfere with daily life, but also has the potential to cause serious diseases such as stroke and heart failure. Therefore, early detection and appropriate treatment of atrial fibrillation are desired. It is known that two characteristics, "the irregularity of the heartbeat interval" and "P wave disappearance", appear in an electrocardiogram (ECG) during a seizure of atrial fibrillation. Therefore, in order to realize automatic detection of atrial fibrillation by signal processing, it is necessary to accurately evaluate the irregularity of the heartbeat interval and detect a P wave (determine P wave presence/absence) from the time-series data of the ECG signal. Here, since the irregularity of the heartbeat interval is captured as the variation of an RRI (RR interval; a time from the peak of an R wave to the peak of a next R wave) in the ECG signal, the irregularity can be evaluated relatively easily and accurately. However, it is quite difficult to accurately determine the P wave presence/absence. This is because the amplitude of the P wave is much smaller than that of the R wave and is easily contaminated by noise (it is difficult to distinguish the P wave from the noise). In addition, the fact that there are individual differences in the waveform (amplitude, shape, orientation (polarity), and the like) of the P wave also increases the difficulty of detecting the P wave. PTL 1 discloses an idea of generating a template of P waves based on an ECG signal, extracting only waveforms having a high cross-correlation with the template from heartbeat waveforms of the ECG signal, and averaging the waveforms, thereby detecting P waves with high accuracy. CITATION LIST PATENT LITERATURE PTL 1: US 5840038 NON-PATENT LITERATURE NPL 1: Saclova, L., Nemcova, A., Smisek, R. et al., "Reliable P wave detection in pathological ECG signals", Sci Rep 12, 6589 (2022). SUMMARY TECHNICAL PROBLEM In a known detection algorithm, there are cases where an erroneous detection of "P wave present" occurs even though the P wave is not present, or conversely, an erroneous determination of "P wave absent" occurs even though the P wave is present. When such erroneous detection or erroneous determination occurs, the subsequent determination of atrial fibrillation is affected, and the detection accuracy or reliability of atrial fibrillation is significantly reduced. The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel technique for determining presence of a P wave with high reliability from time-series data of an EGG signal by signal processing. SOLUTION TO PROBLEM The present disclosure includes a biosignal processing device including: an acquisition unit that acquires time-series data of an ECG signal measured from a user; and a P wave determination unit that extracts a first P wave interval waveform from a first P wave interval set with reference to a time point of a first R wave in the time-series data of the ECG signal and extracts a second P wave interval waveform from a second P wave interval set with reference to a time point of a second R wave different from the first R wave, and when a similarity between the first P wave interval waveform and the second P wave interval waveform is higher than a threshold value, determines that a P wave is included in the first P wave interval and the second P wave interval. The present disclosure includes a biosignal processing device including: an acquisition unit that acquires time-series data of an ECG signal measured from a user; and a P wave determination unit that extracts at least a first heartbeat waveform group and a second heartbeat waveform group from the time-series data of the ECG signal, extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the first heartbeat waveform group and extracts waveforms of P wave intervals each set with reference to a time point of an R wave from respective heartbeat waveforms of the second heartbeat waveform group, generates a first representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the first heartbeat waveform group and generates a second representative P wave interval waveform, based on a waveform group of a plurality of P wave intervals extracted from the second heartbeat waveform group, and when a similarity between the first representative P wave interval wav