JP2017176223A - Heartbeat detection accuracy estimation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate detection accuracy of a heartbeat extracted from an electrocardiogram waveform.SOLUTION: A heartbeat detection accuracy estimation device includes a detection accuracy determination part 3 for causing the heartbeat detection accuracy to be of a value lower than the maximum value when an absolute value of sampling data of an electrocardiogram waveform measured by an electrocardiograph 1 is larger than a predetermined potential threshold, and a detection accuracy restoration part 4 for restoring the detection accuracy to a higher level at a fixed rate in accordance with the lapse of time when the absolute value of sampling data of the electrocardiogram waveform becomes higher than the potential threshold and subsequently becomes the potential threshold or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for estimating the detection accuracy of heartbeat data such as an RR interval obtained from an electrocardiogram waveform.

  Recently, there is an active movement to measure heartbeat data in daily life by using an electrocardiographic measurement device that can be worn on the body and to use it for health care and the like. A device that has electrodes in clothes such as shirts is suitable for long-term measurements because it puts less on the psychological and physical burden on the user. However, there is a problem that the ECG (Electrocardiogram) waveform is easily disturbed with body movement because of less tightening to the body. When the ECG waveform is disturbed, the obtained heart rate data necessarily includes an error.

  Patent Document 1 discloses a configuration for recognizing and calibrating an extremely small T wave peak value when observing an ECG waveform T wave. However, there is no mention of a case where large noise is superimposed on the ECG waveform or an index of data reliability.

Japanese Patent No. 5632570

  In the conventional electrocardiogram / heart rate measurement device, when a large noise is superimposed on the ECG waveform or the amplitude of the ECG waveform is very small, it becomes difficult to detect the heartbeat, and the heart rate output from the electrocardiogram / heart rate measurement device Although the data contains false information, there is a problem that the user who sees the heart rate data does not know how reliable the data is.

  The present invention has been made in view of the above points, and estimates the detection accuracy of the heart rate and RR interval extracted from the sampling data of the ECG waveform, and verifies the data of the heart rate and RR interval data. An object of the present invention is to provide a heartbeat detection accuracy estimation method that indexes gender.

According to the heartbeat detection accuracy estimation method of the present invention, when the absolute value of sampling data of an electrocardiogram waveform of a living body is larger than a predetermined first potential threshold, or from a predetermined second potential threshold smaller than the first potential threshold. The method further includes a detection accuracy determination step of evaluating the detection accuracy of the heartbeat or the RR interval lower than the maximum value when the absolute value of the sampling data is small.
Further, in one configuration example of the heartbeat detection accuracy estimation method of the present invention, the detection accuracy determination step immediately includes the detection accuracy when the absolute value of the sampling data of the electrocardiogram waveform is larger than the first potential threshold. Including a step of setting a value lower than the maximum value.
In addition, one configuration example of the heartbeat detection accuracy estimation method of the present invention further includes a time difference value calculation step of calculating a time difference value of sampling data of the electrocardiogram waveform for each sampling time, and the detection accuracy determination step includes: When the absolute value of the sampling data of the electrocardiogram waveform is larger than the first potential threshold and the absolute value of the time difference value is larger than a predetermined time difference threshold, the detection accuracy is lower than the maximum value. The method includes a step of setting a value.
In addition, in one configuration example of the heartbeat detection accuracy estimation method of the present invention, when the absolute value of the sampling data of the electrocardiogram waveform exceeds the first potential threshold and becomes equal to or lower than the first potential threshold. The method includes a detection accuracy return step for returning the detection accuracy to a higher one at a constant first rate as time elapses.
In one configuration example of the heartbeat detection accuracy estimation method of the present invention, the detection accuracy value lower than the maximum value depends on the absolute value of the sampling data of the electrocardiogram waveform when the first potential threshold is exceeded. It is a value determined by

Further, in one configuration example of the heartbeat detection accuracy estimation method of the present invention, the detection accuracy determination step is performed when a state where the absolute value of the sampling data of the electrocardiogram waveform is smaller than the second potential threshold continues for a certain time or more. The method further includes a step of setting the detection accuracy to a value lower than the maximum value.
In addition, in one configuration example of the heartbeat detection accuracy estimation method of the present invention, the second potential is further detected after a state in which the absolute value of the sampling data of the electrocardiogram waveform is smaller than the second potential threshold continues for a certain time or more. The method includes a detection accuracy return step of returning the detection accuracy to a higher one at a constant second rate as time elapses when the threshold value is exceeded.
In one configuration example of the heartbeat detection accuracy estimation method of the present invention, the detection accuracy value lower than the maximum value is a predetermined constant value.

  According to the present invention, when the absolute value of the sampling data of the electrocardiogram waveform of the living body is larger than the predetermined first potential threshold or the absolute value of the sampling data is smaller than the predetermined second potential threshold smaller than the first potential threshold. When the value is small, by evaluating the detection accuracy of the heartbeat or the RR interval lower than the maximum value, the credibility of the data of the heartbeat or the RR interval can be appropriately indexed. It is possible to inform how reliable the heart rate and RR interval data are.

It is a block diagram which shows the structure of the heart rate detection accuracy estimation apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart explaining the heart rate detection accuracy estimation method which concerns on the 1st Embodiment of this invention. It is a figure which shows the detection accuracy determined by the example of the electrocardiogram waveform, the RR interval extracted from the electrocardiogram waveform, and the heartbeat detection accuracy estimation method according to the first embodiment of the present invention. It is a figure which shows the detection accuracy determined with the other example of the electrocardiogram waveform, the RR interval extracted from the electrocardiogram waveform, and the heartbeat detection accuracy estimation method according to the first embodiment of the present invention. It is a figure which shows the detection accuracy determined with the other example of the electrocardiogram waveform, the RR interval extracted from the electrocardiogram waveform, and the heartbeat detection accuracy estimation method according to the first embodiment of the present invention. It is a block diagram which shows the structure of the heart rate detection accuracy estimation apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart explaining the heart rate detection accuracy estimation method which concerns on the 2nd Embodiment of this invention. It is a figure which shows one example of an electrocardiogram waveform, and the RR space | interval extracted from the electrocardiogram waveform. It is a figure which shows one example of an electrocardiogram waveform, the detection accuracy determined with the heart rate detection accuracy estimation method which concerns on the 1st Embodiment of this invention, and the time difference value of an electrocardiogram waveform. It is a block diagram which shows the structure of the heart rate detection accuracy estimation apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart explaining the heart rate detection accuracy estimation method which concerns on the 3rd Embodiment of this invention. It is a figure which shows the detection accuracy determined by the example of the electrocardiogram waveform, the RR interval extracted from the electrocardiogram waveform, and the heartbeat detection accuracy estimation method according to the third embodiment of the present invention.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the heartbeat detection accuracy estimation apparatus according to the first embodiment of the present invention. The heartbeat detection accuracy estimation device includes a storage unit 2 that stores a sampling data string of an ECG waveform measured by the electrocardiograph 1 and sampling time information, and a first potential threshold value in which the absolute value of the sampling data of the ECG waveform is a predetermined value. Is greater than the first potential threshold after the absolute value of the sampling data of the ECG waveform exceeds the first potential threshold. The detection accuracy return unit 4 for returning the detection accuracy to a higher one at a certain rate as time elapses, and heart rate time calculation for calculating the heart rate time from the sampling data of the ECG waveform and the sampling time Part 5.

  FIG. 2 is a flowchart for explaining the heartbeat detection accuracy estimation method according to the present embodiment. In the following embodiment, a data string obtained by sampling an ECG waveform is assumed to be X (i). i (i = 1, 2,...) is a number assigned to one sampling data. Needless to say, the larger the number i, the later the sampling time.

The electrocardiograph 1 measures an ECG waveform of a living body (human body) (not shown) and outputs a sampling data string X (i) of the ECG waveform. At this time, the electrocardiograph 1 adds the sampling time information to each sampling data and outputs it. Since a specific method for measuring an ECG waveform is a well-known technique, detailed description thereof is omitted.
The storage unit 2 stores the sampling data string X (i) of the ECG waveform output from the electrocardiograph 1 and information on the sampling time.

  The heartbeat time calculation unit 5 calculates at least one of the heartbeat time and the RR interval from the sampling data X (i) of the ECG waveform and the sampling time. As a method for obtaining the heartbeat time, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 2015-217060. The RR interval is an interval between the R wave and the next R wave in the ECG waveform. If the heartbeat time can be obtained, the RR interval can be obtained as the heartbeat time interval. As another method for obtaining the RR interval, for example, the document “ECG Implementation on the TMS320C5515 DSP Medical Development Kit (MDK) with the ADS1298 ECG-FE”, Texas Instruments Incorporated, <http: //www.ti. com / lit / an / sprabj1 / sprabj1.pdf>, 2011 ”. Note that the present invention can be applied regardless of the method for obtaining the heartbeat time and the RR interval.

  Next, the detection accuracy determination unit 3 determines the detection accuracy of the heartbeat time and the RR interval for each sampling data according to the absolute value of the sampling data X (i) of the ECG waveform. Specifically, the detection accuracy determination unit 3 detects the detection accuracy when the absolute value of the sampling data X (i) of the ECG waveform is larger than a predetermined first potential threshold (eg, 5000 μV) (YES in step S1 in FIG. 2). Is already the minimum value (YES in step S2 in FIG. 2), the process proceeds to step S1 of the next sampling data as it is, and if the detection accuracy is not the minimum value (NO in step S2 in FIG. 2), the detection accuracy is set to the current value. Is lowered by a preset value in accordance with the absolute value of the sampling data (step S3 in FIG. 2). If the absolute value of the sampling data X (i) is less than or equal to the first potential threshold (NO in step S1), if the detection accuracy is the highest value (YES in step S4), the process proceeds to step S1 of the next sampling data as it is. If the detection accuracy is not the highest value (NO in step S4), the detection accuracy return unit 4 returns the detection accuracy to the higher accuracy at a constant first rate (for example, 20% per second). (FIG. 2, step S5).

  For example, as in the technique disclosed in Japanese Patent Application Laid-Open No. 2015-217060, when the threshold for detecting the heartbeat time and the RR interval is constantly updated according to the sampling data of the ECG waveform, large noise is generated in the ECG waveform. If the absolute value of the sampling data is superposed and exceeds the first potential threshold, not only the heartbeat time and the RR interval become inappropriate, but also the threshold becomes an inappropriate value. In particular, when the threshold value is determined based on the time average of specific values calculated from the sampling data, the threshold value increases greatly by taking in the peak value derived from noise, and the influence of noise continues for a certain period of time. Therefore, by slowly returning the detection accuracy, the user is informed that the state of low credibility of heartbeat time and RR interval data continues.

  In this way, the processing of steps S1 to S5 is repeatedly executed at every sampling time (each sampling data).

  If a large noise due to the floating of the electrode of the electrocardiograph 1 due to body movement is mixed in the ECG waveform, it becomes difficult to detect the heartbeat. Therefore, in this embodiment, when the absolute value of the sampling data of the ECG waveform is much larger than the normal fluctuation range, the heartbeat detection accuracy is lowered. Thus, in the present embodiment, the credibility of heartbeat data can be appropriately indexed, and the user can be informed of how reliable the heartbeat data is.

  The heartbeat detection accuracy estimation apparatus according to this embodiment and the following embodiments may be provided with a display unit to display the detection accuracy, or a communication unit may be provided to transmit the detection accuracy to the outside. May be. Needless to say, the utilization form of the detection accuracy may be appropriately determined according to the purpose.

  3A shows an example of an ECG waveform, FIG. 3B shows an RR interval extracted from the ECG waveform of FIG. 3A, and FIG. 3C shows the present embodiment. It is a figure which shows the detection accuracy determined about the ECG waveform of FIG. In the example of FIG. 3A, the ECG waveform is also stable, and the RR interval is accurately obtained.

  In the example of FIG. 3A, the ECG waveform has a cardiac potential in the range of −500 to 1500 μV, and the absolute value of the cardiac potential is equal to or less than the first potential threshold (for example, 5000 μV). The accuracy is evaluated as 100%.

  4A shows another example of an ECG waveform, FIG. 4B shows a RR interval extracted from the ECG waveform of FIG. 4A, and FIG. 4C shows heart rate detection. It is a figure which shows the detection accuracy which the accuracy estimation apparatus determined about the ECG waveform of FIG. 4 (A). In the example of FIG. 4A, some spike noises indicated by N1, N2 and N3 are mixed in the ECG waveform.

  Since the absolute value of the potential of these noises exceeds 5000 μV, the detection accuracy determination unit 3 lowers the detection accuracy when the absolute value of the potential exceeds 5000 μV as shown in FIG. At this time, in order to inform the user that the credibility of the heartbeat time and RR interval data continues, how much the detection accuracy is reduced depends on the absolute value of the electrocardiogram as described above. The detection accuracy is set to be lower as the absolute value of the electrocardiogram is larger. When the absolute value of the electrocardiogram returns to 5000 μV or less, the detection accuracy return unit 4 increases the accuracy of the detection accuracy at a constant first rate (for example, a rate of 20% per second) over time. Return to the higher one.

  In the example of FIGS. 4A to 4C, the detection accuracy is gradually recovered every time spike noise enters the ECG waveform, and after the detection accuracy reaches 100%, the RR interval is recovered. It can be seen that the extraction has been resumed.

  5A shows another example of the ECG waveform, FIG. 5B shows the RR interval extracted from the ECG waveform of FIG. 5A, and FIG. 5C shows heart rate detection. It is a figure which shows the detection accuracy which the accuracy estimation apparatus determined about the ECG waveform of FIG. 5 (A).

  In the example of FIG. 5B, the RR interval seems to be extracted, but the ECG waveform of FIG. 5A has periodic large-amplitude spike-like noise that is not related to the heartbeat. This noise is mistakenly detected as a heartbeat. Since the absolute value of noise exceeds 20000 μV, the heartbeat detection accuracy estimation apparatus of the present embodiment keeps the detection accuracy as a low number as shown in FIG. That is, the RR interval extracted from the ECG waveform of FIG. 5A indicates that the credibility is low.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 6 is a block diagram showing the configuration of the heartbeat detection accuracy estimation apparatus according to the second embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals. In the heartbeat detection accuracy estimation device according to the present embodiment, the absolute value of the sampling data of the ECG waveform is larger than the first potential threshold, and the absolute value of the time difference value of the sampling data is a predetermined time difference. When the value is larger than the threshold value, the detection accuracy determination unit 3a that makes the heartbeat detection accuracy lower than the maximum value, the detection accuracy return unit 4, the heartbeat time calculation unit 5, and the sampling data from the sampling data string of the ECG waveform And a time difference value calculation unit 6 for calculating the time difference value for each sampling time.

FIG. 7 is a flowchart for explaining the heartbeat detection accuracy estimation method according to the present embodiment. First, since the time difference value calculation unit 6 calculates the time difference value Y (i) of the sampling data X (i) of the ECG waveform, the data X (i + 1) and 1 after 1 sampling of the sampling data X (i). Data X (i-1) before sampling is acquired from the storage unit 2, and a time difference value Y (i) of the sampling data X (i) is calculated as follows (step S10 in FIG. 7).
Y (i) = X (i + 1) −X (i−1) (1)

  The detection accuracy determination unit 3a has an absolute value of sampling data X (i) of the ECG waveform larger than a predetermined first potential threshold (eg, 5000 μV) (YES in step S11 in FIG. 7), and a time difference value calculation unit 6 Is larger than a predetermined time difference threshold value (for example, 1000 μV) (YES in step S12 in FIG. 7) and the detection accuracy is not the lowest value (NO in step 13 in FIG. 7). ) The detection accuracy of the heartbeat time and the RR interval is lowered by a value set in advance according to the absolute value of the sampling data so as to be lower than the maximum value (step S14 in FIG. 7). The process in step S14 is the same as step S3 in the first embodiment.

  In addition, the detection accuracy determining unit 3a determines that the absolute value of the sampling data X (i) of the ECG waveform is equal to or lower than the first potential threshold (NO in step S11), or the absolute value of the sampling data X (i) is the first. If the absolute value of the time difference value Y (i) is equal to or smaller than the time difference threshold value (NO in step S12) even if the detection accuracy is the highest value (YES in step S15 in FIG. 7). If the detection accuracy is not the highest value (NO in step S15 in FIG. 7), the detection accuracy return unit 4 sets the detection accuracy to a certain first rate (for example, 1 second). It is returned to the one with higher accuracy at a rate of 20% (step S16 in FIG. 7).

  In this way, the processing of steps S10 to S16 is executed for each sampling time (for each sampling data).

  The ECG waveform usually takes a value in the range of about ± 3 mV. When the value greatly exceeds this range, there is a high possibility that intense noise that is not a signal derived from heart activity is superimposed. In such a case, it can be determined that the heartbeat detection accuracy is low immediately. However, when the influence of the perturbation of the baseline of the ECG waveform is large, it is possible to cancel the baseline perturbation and extract the peak derived from the heartbeat by obtaining the time difference value. Can be properly evaluated.

  8A shows an example of an ECG waveform, FIG. 8B shows a RR interval extracted from the ECG waveform of FIG. 8A, and FIG. 9A shows FIG. 9B is a diagram showing the same ECG waveform, and FIG. 9B is a diagram showing the detection accuracy determined by the heartbeat detection accuracy estimation device of the first embodiment for the ECG waveform of FIG. 8A and FIG. 9A. FIG. 9C is a diagram showing time difference values of the ECG waveforms of FIGS. 8A and 9A.

  In the examples of FIGS. 8A and 9A, noise is superimposed on the ECG waveform, and the baseline is perturbed. According to the first embodiment, as shown in FIG. 9B, the detection accuracy determination unit 3 detects the detection accuracy when the absolute value of the cardiac potential exceeds a first potential threshold (for example, 5000 μV). Lower. On the other hand, referring to FIG. 8B, the RR interval is appropriately extracted. As shown in FIG. 9C, when the time difference value of the ECG waveform is obtained, the absolute value of the time difference value is within a time difference threshold (for example, 1000 μV), and the value of the ECG waveform when there is no peristalsis of the baseline. The value is the same level as the fluctuation range.

  Therefore, in the first embodiment, the detection accuracy is lowered as shown in FIG. 9B, but the detection accuracy determination unit 3a of the present embodiment has an absolute value of the time difference value of 1000 μV or less. Even when the absolute value of the cardiac potential exceeds 5000 μV, the maximum value of 100% is maintained without lowering the detection accuracy. Thereby, in this Embodiment, the reliability of the data of heartbeat time and RR interval can be appropriately evaluated, without being influenced by the fluctuation | variation of the base line of ECG waveform by mixing of noise.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. FIG. 10 is a block diagram showing the configuration of the heartbeat detection accuracy estimation apparatus according to the third embodiment of the present invention. The same components as those in FIGS. 1 and 6 are denoted by the same reference numerals. The heartbeat detection accuracy estimation apparatus according to the present embodiment has a heartbeat detection accuracy when the storage unit 2 and the state where the absolute value of the sampling data of the ECG waveform is smaller than a predetermined second potential threshold continues for a predetermined time or longer. And the detection accuracy determination unit 3b that makes the value lower than the maximum value, and the absolute value of the sampling data of the ECG waveform is smaller than the second potential threshold, and then becomes equal to or higher than the second potential threshold after a certain time or longer In some cases, a detection accuracy return unit 4b for returning the detection accuracy to a higher one at a constant rate as time passes and a heartbeat time calculation unit 5 are provided.

  FIG. 11 is a flowchart for explaining the heartbeat detection accuracy estimation method according to the present embodiment. When the absolute value of the ECG waveform sampling data X (i) is greater than or equal to a predetermined second potential threshold (for example, 100 μV) (NO in step S21 in FIG. 11), the detection accuracy determination unit 3b of the present embodiment detects the detection accuracy. Is the highest value (YES in step S25 in FIG. 11), the process proceeds to step S21 of the next sampling data as it is, and if the detection accuracy is not the highest value (NO in step S25 in FIG. 11), the detection accuracy return unit 4b detects. The accuracy is returned to a higher accuracy at a constant second rate (for example, a rate of 50% in 0.5 seconds) (step S26 in FIG. 11).

  Further, the detection accuracy determination unit 3b determines that the duration of the state in which the absolute value of the sampling data X (i) of the ECG waveform is continuously less than the second potential threshold is equal to or longer than a certain time (YES in step S22). If the detection accuracy is the lowest value (YES in step S23 in FIG. 11), the process proceeds to step S21 of the next sampling data as it is. If the detection accuracy is the lowest value (NO in step S23 in FIG. 11), the detection accuracy is set. A predetermined value (for example, 0%) preset so as to be lower than the maximum value is set (step S24 in FIG. 11).

  In this way, the processing of steps S21 to S26 is repeatedly executed at every sampling time (each sampling data). Other configurations are the same as those described in the first embodiment.

  Even when the absolute value of the sampling data of the ECG waveform becomes very small due to the position of the electrode of the electrocardiograph 1 and the contact state with the body surface, it becomes difficult to detect the heartbeat. Therefore, in this embodiment, when the absolute value of the sampling data of the ECG waveform is much smaller than the normal fluctuation range, the heartbeat detection accuracy is lowered. However, the ECG waveform fluctuates across the base line (= 0), and it is not abnormal to instantaneously take 0 or a small value. To distinguish between cases where the absolute value of sampling data of the ECG waveform is extremely small and it is difficult to detect a heartbeat, or when the ECG waveform becomes flat due to electrode detachment, the absolute value of the ECG waveform is extremely small. You need to make sure that the condition is sustained. Further, when such a state is resolved and the absolute value of the sampling data of the ECG waveform returns to the normal range, the subsequent heartbeat detection is hardly affected.

  Therefore, in the present embodiment, the second ratio is set to a value larger than the first ratio described in the first embodiment. As a result, when the absolute value of the sampling data of the ECG waveform returns to the second potential threshold or more, the detection accuracy is quickly returned to the higher one.

  12A shows an example of an ECG waveform, FIG. 12B shows an RR interval extracted from the ECG waveform of FIG. 12A, and FIG. 12C shows this embodiment. It is a figure which shows the detection accuracy determined about the ECG waveform of FIG. In the example of FIGS. 12A to 12C, when the absolute value of the cardiac potential is smaller than a second potential threshold (for example, 100 μV) for a predetermined time or longer (120 in FIG. 12A). , 121), as shown in FIG. 12C, when the detection accuracy is lowered to a certain value (for example, 0%) and the absolute value of the electrocardiogram becomes 100 μV or more, for example, it becomes 100 μV or more. The detection accuracy is recovered in proportion to the period. Further, while the ECG waveform passes through a region lower than 100 μV in the course of recovery of the detection accuracy, the detection accuracy is in a level state in which neither the detection accuracy decreases nor recovers.

  The detection accuracy is evaluated as 0% while the absolute value of the electrocardiogram is smaller than 100 μV. However, when the electrocardiogram is observed again, the detection accuracy quickly returns to 100%, and R It can be seen that the -R interval is starting to be extracted.

  Needless to say, the first embodiment and the third embodiment may be combined, or the second embodiment and the third embodiment may be combined.

  The heartbeat detection accuracy estimation device described in the first to third embodiments can be realized by a computer having a CPU (Central Processing Unit), a storage device, and an interface, and a program for controlling these hardware resources. it can. The CPU executes the processes described in the first to third embodiments in accordance with a program stored in the storage device.

  The present invention can be applied to a technique for detecting a heartbeat or RR interval of a living body.

  DESCRIPTION OF SYMBOLS 1 ... Electrocardiograph, 2 ... Memory | storage part, 3, 3a, 3b ... Detection accuracy determination part, 4, 4b ... Detection accuracy return part, 5 ... Heartbeat time calculation part, 6 ... Time difference value calculation part.

Claims (8)

  When the absolute value of the sampling data of the electrocardiogram waveform of the living body is larger than the predetermined first potential threshold, or when the absolute value of the sampling data is smaller than the predetermined second potential threshold smaller than the first potential threshold The method further comprises a detection accuracy determination step for evaluating the detection accuracy of the heartbeat or the RR interval to be lower than the maximum value. The heartbeat detection accuracy estimation method according to claim 1,
The detection accuracy determining step includes a step of immediately setting the detection accuracy to a value lower than the maximum value when an absolute value of sampling data of the electrocardiogram waveform is larger than the first potential threshold value. Heart rate detection accuracy estimation method. The heartbeat detection accuracy estimation method according to claim 1,
Furthermore, a time difference value calculating step for calculating a time difference value of sampling data of the ECG waveform for each sampling time,
The detection accuracy determination step includes the detection accuracy when the absolute value of the sampling data of the electrocardiogram waveform is larger than the first potential threshold value and the absolute value of the time difference value is larger than a predetermined time difference threshold value. A method for estimating a heartbeat detection accuracy, comprising: setting a value lower than the maximum value. The heartbeat detection accuracy estimation method according to claim 2 or 3,
Further, when the absolute value of the sampling data of the electrocardiogram waveform exceeds the first potential threshold and becomes equal to or lower than the first potential threshold, the detection accuracy is set to a constant first value as time passes. A heartbeat detection accuracy estimation method comprising a detection accuracy return step for returning to a higher one at a rate of. The heartbeat detection accuracy estimation method according to any one of claims 2 to 4,
The detection accuracy value lower than the maximum value is a value determined in accordance with an absolute value of sampling data of the electrocardiogram waveform when the first potential threshold is exceeded, heart rate detection accuracy estimation Method. The heartbeat detection accuracy estimation method according to claim 1,
The detection accuracy determination step is a step of setting the detection accuracy to a value lower than the maximum value when a state where the absolute value of the sampling data of the electrocardiogram waveform is smaller than the second potential threshold continues for a certain time or more. Including a heartbeat detection accuracy estimation method. The heartbeat detection accuracy estimation method according to claim 6,
Further, when the absolute value of the sampling data of the electrocardiogram waveform is smaller than the second potential threshold value after the predetermined time or more and then becomes the second potential threshold value or more, the detection accuracy is determined as the passage of time. A heartbeat detection accuracy estimation method comprising a detection accuracy return step for returning to a higher one at a constant second rate. The heartbeat detection accuracy estimation method according to claim 6 or 7,
The heart rate detection accuracy estimation method, wherein the detection accuracy value lower than the maximum value is a predetermined constant value.