JP2023003530A - Electrode position determination method - Google Patents

Abstract

A method for determining suitable electrode positions and a biosignal acquisition garment capable of acquiring biometric information with high accuracy are provided. Kind Code: A1 The present disclosure is an electrode position determining method for determining the positions of electrodes provided on clothing for acquiring biological information of a wearer, and includes an index representing the degree of curvature of the human body surface, a clothing deformation rate, and a body weight. a step of acquiring evaluation values for one or more elements selected from the surface potential for each of a plurality of positions; and determining the positions of at least two electrodes based on a group of overall evaluation values obtained by combining the evaluation values of the elements for each of the positions. [Selection drawing] Fig. 14

Description

TECHNICAL FIELD The present invention relates to a method for determining electrode positions of a biosignal acquisition garment, and a biosignal acquisition garment.

In recent years, clothes equipped with a system capable of detecting biological signals (electrical signals from living bodies) from living bodies have been proposed. has been introduced in In order to acquire the wearer's biological information with high accuracy, it is necessary to bring the electrodes into close contact with the wearer's body. Therefore, in the case of a clothing-type biological information measuring device, a garment such as compression wear that strongly tightens the upper body is used as the clothing main body, and this tightening effect brings the electrodes into close contact with the body.

On the other hand, if the posture of the human body changes, the electrodes and the human body may become separated from each other. Therefore, a bioelectrical signal acquisition system configured to select a bioelectrical signal to be acquired from the electrodes according to the change in posture is disclosed. ing. For example, Patent Document 1 discloses an acquisition unit that acquires a bioelectric signal using a first electrode and a plurality of second electrodes different from the first electrode, and an acceleration sensor that detects a change in the posture of a living body. and a switch that selects a bioelectrical signal having the highest R-wave peak-to-peak among the bioelectrical signals acquired using one of the first electrode and the plurality of second electrodes when the A bioelectrical signal acquisition system is disclosed. In one example of this bioelectrical signal acquisition system, for example, a first electrode is placed on the left chest, and second electrodes are placed at five locations: left upper back, right upper back, right chest, right abdomen, and left abdomen. are doing.

JP 2018-183635 A

However, until now, the preferred electrode positions have not been examined in detail.

The present disclosure provides a method for determining suitable electrode positions, and biosignal acquisition clothing capable of accurately acquiring biometric information.

In one aspect, the present disclosure provides:
An electrode position determination method for determining the positions of electrodes provided on clothing for acquiring biological information of a wearer, comprising:
a step of acquiring, at each of a plurality of positions, an evaluation value relating to one or more elements selected from an index representing the curvature of the human body surface, the clothing deformation rate, and the body surface potential;
Positions of at least two electrodes based on a group of obtained evaluation values for one type of element, or based on a group of overall evaluation values obtained by combining the obtained evaluation values for two or more types of elements for each position. and determining.

In another aspect, the present disclosure is a biosignal acquisition garment comprising electrodes arranged on a garment body for acquiring a wearer's biosignal,
The electrodes are
a first electrode disposed on one of the left abdomen and the lower left dorsal surface;
and a second electrode disposed on either one of the left chest region and the right upper back region.

In still another aspect, the present disclosure is a biosignal acquisition garment comprising electrodes arranged on a garment body for acquiring a wearer's biosignal,
Regarding the area facing the body surface between the horizontal line that connects the left and right acromion and the horizontal line that passes through the iliac tia, among the front and back bodies of the main body of the garment, each body is divided into a plurality of vertical imaginary parts that equally divide the width of the body. Divided into 117 virtual areas by lines and multiple horizontal virtual lines that divide the length into equal parts,
The 117 virtual regions of the front body are given region numbers F1 to F117 in this order from the top row to the bottom row and from the right to the left on the same row,
For the 117 virtual regions of the back body, when region numbers B1 to B117 are assigned in this order from the top row to the bottom row and from left to right on the same row,
The electrodes are
a first electrode arranged so as to partially or wholly overlap with either one of the following region group a and the following region group b;
The present invention relates to a biological signal acquisition garment including a second electrode arranged so as to partially or wholly overlap with either one of region group c and region group d described below.
Area group a: F98, F99, F107, F108, F116, F117
Area group b: B91, B92, B100, B101, B109, B110
Area group c: F34, F35, F42, F43, F51, F52
Area group d: B44, B45, B53, B54, B62, B63

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a method for determining suitable electrode positions, and biosignal acquisition clothing capable of accurately acquiring biometric information.

FIG. 1 is an explanatory diagram illustrating an example of the definition of curvature in the present disclosure. FIG. 2 is a color map obtained by converting the curvature of the torso of the simulated human body into colors according to each stage specified in the evaluation scale. FIG. 3A is a front view of clothing used for measuring the dimensional change rate, and FIG. 3B is a diagram for explaining the attachment positions of reflective markers attached to the front body of the clothing. FIG. 4A is a rear view of clothing used for measuring the dimensional change rate, and FIG. 4B is a diagram for explaining the positions of reflective markers attached to the back body of the clothing. FIG. 5 is a color bar representation of the clothing behavior analysis with both arms raised to 180° abduction. FIG. 6 is a color map obtained by converting the clothes deformation rate at each measurement point when both arms are raised to abduction 180° into colors according to each stage specified in the color scale. FIG. 7 is a color map after linear interpolation in which the clothes deformation rate at each measurement point when both arms are raised to abduction of 180° is converted into colors according to each step specified in the color scale. FIG. 8 is a color map obtained by converting the average value of the evaluation values regarding the clothes deformation rate for each of the five actions into colors according to each stage specified in the evaluation scale. FIG. 9 is an explanatory diagram for explaining the arrangement positions (measurement points) of electrodes used for electrocardiogram measurement. FIG. 10 is a color map obtained by converting the peak potentials at all measurement points obtained from the electrocardiogram measurement into colors according to each step specified in a color scale with the maximum value being +1 and the minimum value being -1. In FIG. 11, the peak potentials at all measurement points obtained from electrocardiogram measurement are converted into colors according to each step specified in a color scale with the maximum value being +1 and the minimum value being -1, and color interpolation is performed by weighted averaging. is a color map. Fig. 12 shows the arrangement of the positive electrode (+ electrode) in which the peak potential at each measurement point obtained by measuring the surface potential is converted into a color according to each stage of the evaluation scale in which the higher the potential, the larger the numerical value. A color map for position evaluation and a color map for evaluating the placement position of the negative electrode (- electrode) converted into colors according to each stage of the evaluation scale in which the lower the potential, the larger the numerical value. FIG. 13 is a color map obtained by converting the product of the evaluation values (comprehensive evaluation value) of the three elements into colors according to each stage defined in the evaluation scale. FIG. 14 is a diagram in which the color map of FIG. 13 is projected onto opposing portions of the clothing body of the clothing for biosignal acquisition, and the clothing body is divided into a plurality of regions. FIG. 15A is an explanatory diagram in which the front body is divided into 117 virtual regions (plural regions) and a region number is assigned to each region, and FIG. 15B shows the back body in 117 virtual regions (plural regions). 2 is an explanatory diagram in which each region is divided into regions and a region number is assigned to each region. FIG. FIG. 16A is a schematic front view of a biological signal acquisition garment according to one aspect of the present disclosure, and FIG. 16B is a schematic rear view thereof. FIG. 17A is a schematic front view of a biological signal acquisition garment according to another aspect of the present disclosure, and FIG. 17B is a schematic rear view thereof. FIG. 18A is a schematic front view of a biological signal acquisition garment according to yet another aspect of the present disclosure, and FIG. 18B is a schematic rear view thereof. 19A is a schematic front view of the biological signal acquisition garment of Comparative Example 1, and FIG. 19B is a schematic rear view thereof. FIG. 20 is a graph comparing heart rate detection rates obtained by having subjects wear the biological signal acquisition clothes of Examples 1 to 3 and Comparative Example 1. FIG.

As a result of intensive studies, it was found that the accuracy of acquisition of biometric information is affected by the floating of the electrode from the human body surface, the displacement of the electrode, and the magnitude of the R-wave potential value, and these each represent the curvature of the human body surface. We found that it can be evaluated by the elements (parameters) of index, clothing deformation rate, and body surface potential. Then, evaluation values for one or more elements selected from the three elements are obtained for each of a plurality of positions, and the obtained evaluation values for the plurality of positions for the one element (evaluation value group ) or based on a comprehensive evaluation value group obtained by combining the obtained evaluation values regarding two or more elements for each of the positions, selecting the positions where the two or more electrodes are arranged allows the clothes for acquiring biosignals to be It was found that the acquisition accuracy of biometric information can be improved.

Hereinafter, embodiments of the present disclosure will be described in more detail based on the drawings. However, the invention is not limited to what is shown in the following drawings.

In one aspect, the present disclosure is an electrode position determination method for determining the positions of electrodes provided on clothing that acquires biological information of a wearer, comprising:
a step of acquiring, at each of a plurality of positions, an evaluation value relating to one or more elements selected from an index representing the curvature of the human body surface, the clothing deformation rate, and the body surface potential;
Based on the obtained evaluation values (evaluation value group) at the plurality of positions for one element, or based on a comprehensive evaluation value group obtained by combining the obtained evaluation values for two or more elements for each position, and determining the positions of the at least two electrodes.
In the step of determining the positions of the electrodes, preferably, at least two positions of the electrodes are determined based on the group of comprehensive evaluation values, from the viewpoint of improving the accuracy of obtaining biometric information. In the step of acquiring the evaluation values of the two or more elements for each of a plurality of positions, if necessary, the evaluation values of the elements are subjected to interpolation processing such as linear interpolation (interpolation processing), Acquire evaluation values of the plurality of positions common to two or more elements. Specifically, an element may be interpolated with a spatial resolution that matches or is higher than the spatial resolution of another element. Alternatively, interpolation or decimation processing may be performed according to elements with low spatial resolution.

[Acquisition of each element and its evaluation value]
(1) Index Representing Curvature of Human Body Surface Acquisition accuracy of biometric information increases as the electrodes are less likely to float from the human body surface. The floating of the electrode occurs when the clothing pressure is insufficient, and the clothing pressure increases as the curvature of the human body increases. Therefore, from the viewpoint of improving the accuracy of acquiring biometric information, positions with relatively large curvature on the human body surface are superior and thus are evaluated highly, and positions with relatively small curvature are evaluated low. Therefore, the evaluation value for the curvature is selected from, for example, an evaluation scale defined such that the larger the curvature, the larger the numerical value. The evaluation scale can be represented by, for example, 11 levels, and the evaluation value is an integer from 0 to 10.

The curvature of the human body can be calculated, for example, based on point group coordinate data measured using a three-dimensional human body measuring device BLS (Body Line Scanner). The test subject may be a human body of standard body shape or a mannequin that simulates the human body. Using the three-dimensional human body measuring device, for example, a mannequin is irradiated with laser light from top to bottom at intervals of, for example, 2 mm, and point cloud coordinate data is acquired from the reflected light. The interval between coordinate points in the horizontal direction is also set to 2 mm, for example. However, the intervals between coordinate points in the vertical direction and the horizontal direction are not limited to this.

For example, from three continuous coordinate points among a plurality of coordinate points existing in the same horizontal plane in the obtained point group coordinate data, the curvature at a position including these three coordinate points is calculated. Specifically, as shown in FIG. 1, there are two straight lines passing through two adjacent coordinate points out of three continuous coordinate points, and from the intersection of the perpendicular bisectors L _vb of each straight line, the continuous The distance to the coordinate point located in the middle of the three coordinate points is obtained as the radius of curvature R, and its reciprocal is obtained as the curvature.

If such local curvature calculation is performed using all of the point group coordinate data, the curvature distribution of the entire test subject can be obtained. When the evaluation value of the evaluation scale is an integer from 0 to 10, for example, when the curvature value is 0 (zero), the evaluation value is set to 0 (zero), and all the obtained curvature values are evaluated from the larger one An evaluation value of less than 10% curvature is set to 10, and an evaluation value of 10% or more and less than 20% curvature is set to 9, and the evaluation values are divided to the curvature distribution in the same ratio.

A curvature radius may be used instead of the curvature as an index representing the degree of curvature of the human body surface. In this case, an evaluation scale is used that is defined such that the smaller the radius of curvature, the larger the numerical value.

The multiple curvature values obtained may be visualized by a color map that is pseudo-color-converted, as shown in FIG. The continuity of curvature values between adjacent positions (coordinate points) can be intuitively understood by visualizing with a color map converted into colors corresponding to each step specified in the evaluation scale. As shown in FIG. 2, the positions in the vicinity of both side surfaces of the front surface and the vicinity of both side surfaces of the back surface are superior in improving the acquisition accuracy of biometric information as judged from the curvature distribution.

(2) Clothing Deformation Rate The biometric information acquisition accuracy decreases when the electrodes are displaced from desired positions. Displacement of electrodes is also displacement of clothes, and displacement of clothes occurs because deformation of clothes cannot follow deformation of skin caused by movements of the human body or the like. If no clothing deformation has occurred, no clothing deviation has occurred. Therefore, by evaluating the clothes deformation rate described below, it is possible to evaluate the degree of easiness or difficulty of electrode displacement. The clothing deformation rate, which will be described in detail below, is the average value of the absolute values of the radial dimensional change rate caused by the motion of the human body.

If the motion of the human body is different, the deformation of the clothes will also be different. Therefore, from the viewpoint of determining the electrode positions of the highly versatile biosignal acquisition clothes, the evaluation of the clothes deformation rate is preferably the average value of the evaluation values obtained when performing a plurality of types of actions. Symmetry is preferred. The clothing deformation rate can be calculated from the result of clothing behavior analysis using a three-dimensional motion analysis device, and can be calculated using the dimensional change rate measured using the three-dimensional motion analysis technique. Specifically, for example, as shown in FIGS. 3 and 4, a total of 70 reflective markers 11 are attached to the front body (excluding sleeves) and the back body (excluding sleeves) of clothing. 3 and 4, the first reference line 7 is a sewing line between the front body and the back body, and the second reference line 8 is a line that divides the body width between the pair of first reference lines 7 into four. be. The third reference line 9 is a horizontal line that divides a line extending from the lowermost collar portion of the front body and the hem into seven equal parts. A fourth reference line 10 is a sewing line on the armhole. However, although the position where the reflective markers 11 are attached is not limited to this example, the distance between adjacent reflective markers is preferably 5 to 10 cm from the viewpoint of improving the accuracy of obtaining biometric information.
Deformation at each measurement point (position where the reflective marker 11 is attached) when the subject wearing the clothing with the reflective marker performs, for example, one of the following three types of trials (movements) Display the direction and the dimensional change rate for each deformation direction with a color bar.

[Attempt 1: Shoulder abduction]
Stand still (starting posture) and raise both arms to abduction 180° over 2 seconds (final posture).
[Attempt 2: Side bending]
Stand still (starting posture) and laterally bend to the right or left while raising one arm to 180° abduction over 2 seconds (final posture).
[Attempt 3: Rotation]
Standing still (starting position) and rotating the trunk to the right or left (final position) for 2 seconds.

The example shown in FIG. 5 is a color bar display of clothing behavior analysis in the state of the final posture of Trial 1 (state in which both arms are raised to 180° abduction). The deformation directions are, for example, 8 directions centered on the measurement point X. For example, the dimensional change rate in the XA direction is −60% and the dimensional change rate in the XC direction is +30%. If the dimensional change rate is negative, it means that compression strain has occurred and the clothing has shrunk. If the dimensional change rate is positive, it means that the clothing has elongated due to elongation strain. The larger the absolute value of the dimensional change rate, the more likely the clothes are to be deformed. It is possible to evaluate the likelihood of clothes deformation at the measurement point. As shown in the following formula, for example, the sum of the absolute values of the dimensional change rates in all directions from the measurement point X is divided by the number of deformation directions n, in this embodiment, the number of color bars. ^- You can quantify the deformation of clothes by (clothing deformation rate).

If the clothes deformation rate X ⁻ is calculated at all measurement points, the clothes deformation rate distribution for the entire test subject can be obtained. The clothes deformation rate at each measurement point may be visualized by a color map converted into pseudo colors, as shown in FIG. 6, for example. Alternatively, the clothing deformation rate between measurement points may be linearly interpolated. Interpolation processing may be performed so as to acquire evaluation values relating to clothes deformation rate at a plurality of positions common to elements other than clothes deformation rate among the two or more types of elements used for determining electrode positions. Specifically, for example, interpolation may be performed with a spatial resolution that matches or is higher than the spatial resolution of elements other than the clothing deformation rate. As shown in FIG. 7, if the interpolated data is color-mapped, the continuity of the clothing deformation rate between adjacent measurement points can be intuitively understood. 6 and 7, the upper two are color maps of the front surface of the body viewed obliquely from left to right, and the lower two are color maps of the back of the body viewed obliquely from left to right. As shown in FIGS. 6 and 7, in the final posture of Trial 1 (both arms raised to 180° abduction), the clothing deformation rate was small in the abdomen and lower back, and Large at the top.

Similarly, for Trial 2 (right side flexion, left side flexion) and Trial 3 (right rotation, left rotation), the clothing deformation rate X ⁻ in the final posture was obtained, and 3 trials, a total of 5 types of movements The average value of the clothing deformation rate when the body lifts the body, bends the trunk to the right, bends the trunk to the left, rotates the trunk to the right, and rotates the trunk to the left is calculated for each measurement point. In this way, by performing a plurality of types of motions and using the average value of the clothing deformation rates of the plurality of types of motions, it is possible to obtain a distribution of clothing deformation useful for determining the electrode positions of highly versatile biosignal acquisition clothing. can be done.

As shown in FIG. 8, the average values of clothes deformation ratios X ⁻ for a plurality of, for example, five motions may be visualized using a color map converted into colors according to each stage specified in the evaluation scale. Visualization with a color map makes it possible to intuitively understand the continuity of clothing deformation rates between adjacent measurement points.

From the viewpoint of improving the acquisition accuracy of biometric information, it is advantageous that clothing deformation is less likely to occur, that is, the clothing deformation rate is relatively small. Therefore, as the evaluation scale for the clothes deformation rate, for example, an evaluation scale defined such that the smaller the clothes deformation rate, the larger the numerical value is used. The evaluation scale can be represented by, for example, 11 levels, and the evaluation value is an integer from 0 to 10. For example, if the clothing deformation rate X ⁻ is 0 (zero), the evaluation value is set to 10, and among all the obtained clothing deformation rates X ⁻ (excluding 0 (zero)), the smallest 10% The evaluation value for clothing deformation rate X ⁻ less than X is 9, and the evaluation value for curvature of 10% or more and less than 20% from the smallest is 8, and the evaluation value is divided to the clothing deformation rate distribution in the same ratio. . As shown in FIG. 8 , measurement points with high evaluation values for the average clothes deformation rate obtained by performing 3 trials and a total of 5 motions are concentrated in the abdomen and lower back. Areas with low evaluation values (areas where many deviations occur and are not superior as electrode positions) are the vicinity of the left and right armholes and the left and right flanks of the front body.

(3) Body Surface Potential The magnitude of the R-wave potential value affects the acquisition accuracy of biological information. The waveform of the R wave differs depending on the measurement point. The distribution of R-wave potential values on the body surface of the torso can be used to evaluate the placement positions of the electrodes. In addition, one of the pair of electrodes constituting the biosignal acquisition clothes is a positive electrode (+ electrode) and the other is a negative electrode (- electrode). acquisition accuracy is improved.

The potential distribution of R-wave potential values can be obtained, for example, by the following method. For example, as shown in FIG. 9, a total of 120 medical electrodes are attached to the front of the body, the left side of the body, the back of the body, and the right side of the body, and an electrocardiogram is measured. The electrodes in the same column are arranged at equal intervals in the height direction, and the centers of the electrodes arranged in the same row are arranged at equal intervals on the same horizontal line along the trunk. The measurement posture is standing still. The induction method is monopolar induction, and the measurement time is, for example, 30 seconds for each point.
[Body front]
Electrode number: 1-54
Electrode center placement area: intersection of horizontal line through left and right acromion and midclavicular line (line through center of clavicle), anterior edge of right axilla, right iliac tract, left iliac tract, and left axillary anterior The area where the edge is connected [Left side of the torso part]
Electrode number: 55-60
Electrode center placement area: the area between the left anterior axillary line (vertical line passing through the anterior edge of the left axilla) and the left posterior axillary line (vertical line passing through the posterior edge of the left axilla) [back of the torso]
Electrode number: 61-114
Electrode center placement area: area connecting left and right acromion, posterior margin of right axilla, right iliac tract, left iliac tract, and posterior margin of left axilla [right side of trunk]
Electrode number: 115-120
Electrode center placement area: the area between the right anterior axillary line (vertical line passing through the anterior edge of the right axilla) and the right posterior axillary line (vertical line passing through the posterior edge of the right axilla)

From the electrocardiogram data obtained at all 120 measurement points, the average R-wave waveform at each measurement point is calculated. Specifically, from the electrocardiogram at each measurement point, extra peaks such as myoelectricity are removed by filtering using a band-pass filter (5-100 Hz), and the timing of the peak of the true value (second lead) is determined. A waveform at each measurement point is cut out from the original, and an average waveform of, for example, 8 beats is calculated. Each of the 120 average waveforms includes one with a positive peak and one with a negative peak. As described above, the greater the potential difference between the positive electrode and the negative electrode in the biosignal acquisition clothing, the higher the accuracy of biometric information acquisition. is superior as the placement position of the positive electrode, and the measurement points with relatively high peaks on the negative side, ie, relatively low potentials, are superior as the placement position of the negative electrode.

From the above, the distribution of the R wave potential value on the body surface of the body part is converted to a scale in which the maximum value of the peak potentials of the 120 average waveforms is +1 and the minimum value is -1, and is shown in FIG. Thus, by making a color map, it is possible to instantly understand the advantageous arrangement positions of each of the plus electrodes and the minus electrodes. Further, as shown in FIG. 11, if color interpolation is performed by weighted averaging between measurement points, the continuity of the potential can be understood intuitively. In FIG. 10, only three dots surrounded by broken lines among the 120 dots have negative values, and the three dots correspond to electrode numbers (measurement points) 30, 31, and 39. A region surrounded by a dashed line in FIG. 11 is a region including measurement points 30 , 31 , and 39 .

As shown in FIG. 12, the acquisition of evaluation values regarding the body surface potential may be performed for each of the positive electrode and the negative electrode. In this case, for the positive electrode, an evaluation scale is defined in which the higher the potential, the larger the numerical value, and the evaluation value is selected from the evaluation scale. For the negative electrode, an evaluation scale is defined in which the lower the potential, the larger the numerical value, and the evaluation value is selected from the evaluation scale. Both evaluation scales, for example, may be evaluated in 11 stages, with evaluation values being integers from 0 to 10. Interpolation processing such as linear interpolation is performed on the peak value of the R wave at each measurement point, and a plurality of positions common to elements other than the body surface potential among the two or more elements used for determining the electrode position. , the body surface potential may be obtained and an evaluation value may be selected from the evaluation scale. Specifically, interpolation may be performed with a spatial resolution that matches or is higher than the spatial resolution of elements other than the body surface potential. As shown in FIG. 12, the superior positions for placing the positive electrode are from the lower left breast to the left abdomen and the lower left back, and the superior position for placing the negative electrode is the left chest.

[Acquisition of comprehensive evaluation values and determination of electrode positions]
At least two electrode installation positions are determined based on the group of evaluation values for one of the elements obtained as described above. Alternatively, two or more of the elements obtained as described above can be combined to obtain a comprehensive evaluation value group, and based on the comprehensive evaluation value group, the installation positions of at least two electrodes are determined. do. An evaluation value group is a set of evaluation values (data) at a plurality of positions regarding one type of element. A comprehensive evaluation value group is a collection of comprehensive evaluation values (data) at each position, and the comprehensive evaluation value is a combination of evaluation values relating to two types of elements, for example, a product. In one aspect of the present disclosure, the product of the evaluation value for curvature (see FIG. 2), the evaluation value for clothing deformation rate (see FIG. 8), and the evaluation value for body surface potential (see FIG. 12) is the total evaluation value group. to create Each of the above three elements has an evaluation scale of 11 levels, and evaluation values are integers from 0 to 10.

FIG. 13 is a distribution diagram of the product of the evaluation values for the three elements, that is, the distribution of the overall evaluation values in the trunk (the trunk portion located between the horizontal line connecting the left and right acromions and the horizontal line passing through the iliac tract). 14 is a diagram in which the distribution map of FIG. 13 is projected onto the body of the clothes for biosignal acquisition, and the body of the clothes is divided into a plurality of regions. In FIG. 14, in order to facilitate the determination of the electrode positions, for each of the front body and the back body, a plurality of vertical virtual lines dividing the body width into equal parts and a plurality of horizontal lines dividing the body length into equal parts. 117 virtual regions are divided by virtual lines, and a comprehensive evaluation is performed for each region. In this embodiment, the number of regions in each body is 117. FIG. 15A is an explanatory diagram in which the 117 virtual areas of the front body are assigned area numbers, and FIG. 15B is an explanatory diagram in which the 117 virtual areas of the back body are assigned area numbers. be.

In this embodiment, in order to specify the position where the overall evaluation value is superior, as shown in FIGS. From the left to the left, the area numbers F1 to F117 are attached in this order, and for the 117 areas of the back body, from the upper row to the lower row and from left to right in the same row, the area numbers B1 to B117 in this order shall be attached. Here, "upper" refers to the side closer to the neck, and "lower" refers to the side farther from the neck. there is

As shown in FIGS. 14 and 15, the superior positions for placement of the positive electrode (+ electrode) are the left abdomen and the lower left back, or regions F98, F99, F107, F108, F116, F117 (hereinafter referred to as , and these are collectively referred to as "region group a") and regions B91, B92, B100, B101, B109, and B110 (hereinafter collectively referred to as "region group b"). 14 and 15, the region group a is denoted by R1, and the region group b is denoted by R2. Advantageous positions for placing the negative electrode (− electrode) are the left chest and upper left back, or areas F34, F35, F42, F43, F51, and F52 (hereinafter collectively referred to as "area group c"). ) and regions B44, B45, B53, B54, B62, and B63 (hereinafter collectively referred to as “region group d”). In FIGS. 14 and 15, the region group c is denoted by R3, and the region group d is denoted by R4.

Therefore, from the viewpoint of improving the accuracy of obtaining biometric information, it is preferable to determine one of the left abdomen and the lower left back surface of the clothing body as the placement position of the positive electrode (first electrode). . From a similar point of view, it is preferable to determine either one of the left chest region and the upper right back surface of the clothing body as the placement position of the negative electrode (second electrode). In addition, from the viewpoint of improving the acquisition accuracy of biometric information, a position where one of the region group a (R1) and the region group b (R2) partially or wholly overlaps is set to a positive electrode (first It is preferable to determine the arrangement position of the electrode). From a similar point of view, a position partially or entirely overlapping with either one of the region group c (R3) and the region group d (R4) is determined as the arrangement position of the negative electrode (second electrode). preferably. Here, "partially or entirely overlapping" means that part or all of the area group is covered with the electrode.

In the above aspect of the present disclosure, a combination of evaluation values relating to three types of elements is obtained as a comprehensive evaluation value, but a combination of evaluation values of two or more types of elements may be used. In the above aspect of the present disclosure, the product of the evaluation values of two or more elements is obtained as the overall evaluation value in order to give sharpness to the overall evaluation result. or at least one of the two or more evaluation values may be weighted.

In the above aspect of the present disclosure, as the evaluation scale for the three elements, the evaluation value is an integer of 0 to 10 and the evaluation is performed in 11 stages, but the evaluation scale is limited to this. For example, the number of steps may be more, less, or different from element to element. In addition, in the above aspect of the present disclosure, the lowest evaluation value on the evaluation scale is set to 0 (zero) in order to give sharpness to the overall evaluation result, but it may be a real number exceeding 0, for example.

[Clothes for biosignal acquisition]
Next, an example of a biological signal acquisition garment in which electrode positions are determined using the electrode position determination method of one aspect of the present disclosure will be described with reference to FIGS. 16 to 18. FIG. In this specification, the term "rear side or back side" refers to the side closer to the living body, and the term "front side or front side" refers to the side farther from the living body. "Upper" refers to the side closer to the neck, and "lower" refers to the side farther from the neck.

As shown in FIGS. 16 to 18, the biosignal acquisition garment 1 of this embodiment includes a garment body 2, electrodes 3a and 3b, biosignal transmitters 4a and 4b, and connectors 5a and 5b. there is The electrodes 3a and 3b are arranged on the back side of the garment main body fabric 201 forming the garment main body 2, and are in contact with the living body (wearer's skin) to acquire biosignals from the living body. 16 to 18 have the same configuration except that the electrode positions and the lengths of the biosignal transmission parts 4a and 4b are different. Since the electrode positions of the biosignal acquisition garment 1 are determined using the electrode position determination method of the present disclosure, biometric information acquisition accuracy is excellent. In addition, since the number of electrodes is two, both a simple structure and high biometric information acquisition accuracy are achieved. Since it has a simple structure, it is possible to provide clothes for biosignal acquisition at low cost and with good biometric information acquisition accuracy. However, in the present disclosure, the number of electrodes is not limited to two, and may be three or more. Depending on the number of electrodes, the numbers of biosignal transmission units 4a and 4b and connectors 5a and 5b may be adjusted as appropriate.

In the biological signal acquisition garment 1 of FIG. 16, the positive electrode 3a is arranged on the lower left back surface, or is arranged so as to partially or wholly overlap with the region group b (R2), and the negative electrode 3b is arranged on the left side. It is arranged on the chest, or arranged so as to partially or wholly overlap with the region group c (R3). In this way, if multiple electrodes are all on the left side of the torso, in occupations where special equipment (harnesses) must be worn on the right side, the swinging of the equipment will adversely affect the contact between the electrodes and the skin. This is preferable from the viewpoint of obtaining biometric information with high accuracy.

In the biosignal acquisition garment 1 of FIG. 17, the positive electrode 3a is arranged on the left abdomen or arranged so as to partially or wholly overlap with the region group a (R1), and the negative electrode 3b is arranged on the left chest. , or is arranged so as to partially or wholly overlap with the region group c (R3). In this manner, both electrodes are arranged on the front body, and both electrodes are located on the left side of the torso, so that biological information can be obtained with high accuracy, and it is suitable for occupations that require equipment on the back body side. It is preferable because it can be used for

In the biological signal acquisition garment 1 of FIG. 18, the positive electrode 3a is arranged on the lower left back surface, or is arranged so as to partially or wholly overlap with the region group b (R2), and the negative electrode 3b is arranged on the right side. It is arranged on the upper part of the back surface, or arranged so that part or all of it overlaps with the region group d (R4). Such a mode in which both electrodes are arranged on the back body can be suitably used in occupations that require equipment on the front body side.

The material of the electrodes 3a and 3b is not particularly limited as long as it can acquire biosignals. For example, it can be made of conductive fibers. As the conductive fiber, for example, a conductive metal-plated fiber obtained by plating a conductive metal on the fiber, a fiber impregnated with a conductive polymer, or the like can be used. Examples of conductive metals include silver, alumina, gold, and copper, and silver is preferable from the viewpoint of high conductivity. Although the fiber is not particularly limited, polyester fiber, nylon fiber, or the like can be used from the viewpoint of excellent durability. Conductive fibers can be used as an electrode by forming a fiber aggregate such as non-woven fabric, knitted fabric, and woven fabric. The fiber assembly constituting the electrodes 3a and 3b is not particularly limited, but may have a basis weight of 100 to 500 g/m ² , for example. The size and shape of the electrodes 3a and 3b are not particularly limited as long as the biosignals can be acquired. For example, the vertical and horizontal lengths of the electrodes 3a and 3b may both be 1 to 10 cm. The electrodes 3a and 3b are not particularly limited, but may have a thickness of 0.01 to 5 mm, for example.

The biosignal transmitters 4a and 4b are arranged on the back side of the garment body fabric 201, are electrically connected to the electrodes 3a and 3b, and transmit biosignals acquired by the electrodes 3a and 3b. The biosignal transmitters 4a and 4b are not particularly limited as long as they can transmit the biosignals acquired by the electrodes 3a and 3b. For example, like the electrodes 3a and 3b, they can be made of conductive fibers. In this embodiment, the electrodes 3a, 3b and the biosignal transmitters 4a, 4b are integrated (one structure), that is, the biosignal transmitters 4a, 4b are configured by extending a part of the electrodes 3a, 3b. It is Specifically, peripheral portions and projecting portions extending from the electrodes 3a and 3b constitute biosignal transmission portions 4a and 4b. The electrodes 3a, 3b and the biosignal transmission parts 4a, 4b may be separate structures instead of being integrated. When the electrodes 3a, 3b and the biosignal transmission parts 4a, 4b are separate structures, the electrodes 3a, 3b and the biosignal transmission parts 4a, 4b may be joined by sewing with a conductive fiber thread. , the electrodes 3a and 3b and the biosignal transmission portions 4a and 4b may be adhered. The adhesive is not particularly limited, and for example, a hot melt adhesive or the like can be used.

Each of the connectors 5a and 5b has a connecting portion arranged on the surface side of the cloth body of the garment and a fixing portion for fixing the connecting portion to the cloth body. They may be arranged so as to sandwich the portions 4a and 4b. As the connectors 5a and 5b, for example, conductive metal snap buttons, magnet hooks, or the like can be used.

On the back side of the biosignal acquisition garment 1, the biosignal transmitters 4a and 4b and the fixed portions of the connectors 5a and 5b are preferably covered with an insulating sheet (not shown). Thereby, noise other than the biosignal to be detected can be reduced. The insulating sheet is not particularly limited as long as it has electrical insulation. Examples thereof include polyethylene terephthalate sheet, polyethylene naphthalate sheet, polyurethane sheet and the like.

The biomedical signal acquisition garment 1 may have a receiver 6 for receiving biomedical signals. The biosignal receiving device 6 receives the biosignals acquired by the electrodes 3a and 3b and transmitted by the biosignal transmission units 4a and 4b, converts the biosignals into electric signals, and transmits them, for example, wirelessly. It is a small portable terminal device that transmits. In this embodiment, the biosignal receiving device 6 has a connecting portion (not shown), and by detachably engaging the connecting portion with the connecting portions of the connectors 5a and 5b, the biosignal receiving device can be operated. 6 and connectors 5a and 5b can be detachably connected. The biological signal receiving device 6 can be removed when the clothes are not in use, especially when they are washed.

The garment body fabric 201 forming the garment body 2 may be a knitted fabric or a woven fabric. From the viewpoint of facilitating adhesion of the electrodes 3a and 3b to the living body, it is preferable that the garment main body fabric 201 is a stretchable fabric. For example, the garment main body fabric 201 preferably has a lateral and/or longitudinal elongation rate of 50% or more and 400% or less, more preferably 100% or more and 300% or less. In this specification, elongation is measured under a load of 15 N based on JISL1096 8.16.1 (B method). Such elastic fabrics can be composed of elastic fibers (threads) and non-elastic fibers (threads). Examples of elastic fibers include, but are not limited to, polyurethane elastic fibers, polyether-ester elastic fibers, polyamide elastic fibers, and polyolefin elastic fibers. Polyurethane elastic fibers are preferred from the viewpoint of excellent extensibility. The inelastic fibers are not particularly limited, but polyester synthetic fibers such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, and polyamide synthetic fibers such as nylon can be used.

16 to 18 exemplify the case where the biosignal acquisition garment 1 is a short-sleeved shirt, but the biosignal acquisition garment 1 may be worn as long as it comes into contact with the living body. A sleeveless shirt, a long-sleeved shirt, a girdle, etc. are mentioned. By wearing the biological signal acquisition clothes 1, an electrocardiogram or the like can be continuously measured for a long period of time while carrying out daily life.

Note that the biomedical signal acquisition garment 1 of the present disclosure is not limited to including the above configuration, and may include configurations that conventionally known biomedical signal acquisition garments have, except for the arrangement of the electrodes. For example, as described in Japanese Patent Application Laid-Open No. 2019-58346, a cushion layer disposed between the connectors 5a and 5b and the insulating sheet to reduce the feeling of a foreign object caused by the connectors 5a and 5b, or to increase the adhesion between the electrodes and the living body A cushion layer or the like may be further provided between the electrodes and the garment body fabric.

EXAMPLES The present invention will be specifically described below using examples. In addition, the present invention is not limited to the following examples.

(electrode)
Electrodes used for fabricating biosignal acquisition clothes of Examples 1 to 3 and Comparative Example 1 were prepared as follows. A woven fabric was produced using a conductive fiber (manufactured by Mitsufuji Co., Ltd.: "AGposs") obtained by plating nylon fiber with silver. Next, the fabric was cut into a predetermined size to produce an electrode 3 (50 mm long and 70 mm wide).

(Example 1)
The biosignal acquisition garment of Example 1 is the biosignal acquisition garment shown in FIG. 16 . As the clothing body, the same clothing as the biological signal acquisition clothing of Comparative Example 1 below was used (short-sleeved shirt, length L1: 63.0 cm, width (length of line connecting from right side to left side) L2: 40.0 cm. 8 cm, chest circumference 81.6 cm) were prepared. In FIG. 16, L3 is 23 cm, L4 is 10 cm, L5 is 10 cm, and L6 is 12 cm. Electrodes 3a and 3b and biosignal transmission units 4a and 4b are fixed to garment body fabric 201 using a hot melt adhesive. went. The back surfaces of the biological signal transmission parts 4a and 4b and the fixed parts of the connectors 5a and 5b are covered with an insulating sheet (manufactured by Poly Tape Co., Ltd.: "Poly Flex") so as not to come into contact with the living body when worn. The insulating sheet was fixed to the garment body fabric 201 by heat sealing.

(Example 2)
The biosignal acquisition garment of Example 2 is the biosignal acquisition garment shown in FIG. 17 . In FIG. 17, L7 is 23 cm, L8 is 10 cm, L9 is 10 cm, and L10 is 12 cm. A biological signal acquisition garment having the same configuration as that of Example 1 except for the above was produced.

(Example 3)
The biosignal acquisition garment of Example 3 is the biosignal acquisition garment shown in FIG. 18 . In FIG. 18, L11 is 28 cm, L12 is 13 cm, L13 is 10 cm, and L14 is 12 cm. A biological signal acquisition garment having the same configuration as that of Example 1 except for the above was produced.

(Comparative example 1)
The biosignal acquisition garment of Comparative Example 1 is the biosignal acquisition garment shown in FIG. 19 . As the biosignal acquisition garment of Comparative Example 1, a commercially available biosignal acquisition garment (trade name Smart Fit (registered trademark), manufactured by Kurashiki Boseki Co., Ltd., short-sleeved shirt, chest circumference 81.6 cm, waist width passing through the center of the electrode 72 cm) were prepared. In FIG. 19, L15 is 23 cm and L16 is 10 cm.

Subjects (2 males in their twenties) wear the biological signal acquisition clothes of Examples 1 to 3 and Comparative Example 1, and perform the following trials I to IV under an environment of 23 ± 1 ° C. and 50 ± 5%. An electrocardiogram was taken to measure heart rate. Specifically, after wearing the clothes for biosignal acquisition, the left and right electrodes were wetted with about 0.1 mL of water, respectively, and after resting sufficiently, an electrocardiogram was measured while performing the following trials I to IV. In addition, an electrocardiogram was measured in the second lead (potential difference between left leg and right hand) using medical electrodes while performing similar trials. A BIOPAC MP160 electrocardiogram amplifier ECG100C was used as a measuring instrument.

[Attempt I: Shoulder abduction]
After standing still for 2 seconds, raise both arms to 180° abduction, hold still for 2 seconds, and then return to standing still for 8 seconds each time. Repeat this 5 times.
[Attempt II: Side bend]
After standing still for 2 seconds, the subject bends sideways while raising one arm to abduction 180°, holds still for 2 seconds, and then returns to standing still for 8 seconds each time, and repeats 5 times.
[Attempt III: Forward bending]
After standing still for 2 seconds, bend forward, stay still for 2 seconds, and then return to standing still for 8 seconds each time. Repeat this 5 times.
[Attempt IV: Rotation]
After standing still for 2 seconds, rotate the trunk to the left, hold still for 2 seconds, and then return to standing still for 8 seconds each time. Repeat this 5 times.

The heart rate was counted from the obtained electrocardiogram, the heart rate detection rate was calculated from the following formula, and the average value of the heart rate detection rates for the two subjects was obtained. FIG. 20 shows the average values of the heart rate detection rate when trials I to IV were performed.
Heart rate detection rate (%) = heart rate (beats) measured by the power of clothes for biosignal acquisition/heart rate (beats) measured by medical electrodes × 100

As shown in FIG. 20, all of the biosignal acquisition clothes of Examples 1 to 3 have a higher heart rate detection rate and biometric information acquisition accuracy than the biosignal acquisition clothes of Comparative Example 1. FIG.

The biological signal acquisition garment of the present invention can acquire biological information with high accuracy even during operation. Therefore, it is suitable for workers' health care.

1 clothes for biosignal acquisition 2 clothes main body 3a, 3b electrodes 3a positive electrode (first electrode)
3b negative electrode (second electrode)
4 biosignal transmitter 5 connector 6 biosignal receiver 7 first reference line 8 second reference line 9 third reference line 10 fourth reference line 11 reflective marker 201 clothing body fabric R1 area group a
R2 region group b
R3 region group c
R4 region group d

Claims (11)

An electrode position determination method for determining the positions of electrodes provided on clothing for acquiring biological information of a wearer, comprising:
a step of acquiring, at each of a plurality of positions, an evaluation value relating to one or more elements selected from an index representing the curvature of the human body surface, the clothing deformation rate, and the body surface potential;
Positions of at least two electrodes based on a group of obtained evaluation values for one type of element, or based on a group of overall evaluation values obtained by combining the obtained evaluation values for two or more types of elements for each position. and determining. 2. The electrode position determination method according to claim 1, wherein said comprehensive evaluation value group is a set of products of obtained evaluation values relating to two or more elements for each of said positions. 3. The electrode position determination method according to claim 1, wherein said clothes deformation rate is calculated based on a radial dimension change rate caused by a human body motion. 4. The electrode position determination method according to claim 1, wherein the evaluation value regarding the clothing deformation rate is an evaluation value regarding the clothing deformation rate associated with a plurality of types of motions. 5. The electrode position determination method according to claim 1, wherein the evaluation value for the clothes deformation rate is selected from an evaluation scale in which the smaller the clothes deformation rate, the larger the numerical value. The index representing the curvature of the human body surface is the curvature of the human body,
The electrode position determination method according to any one of claims 1 to 5, wherein the evaluation value for said curvature is selected from an evaluation scale in which the larger the curvature, the larger the numerical value. the electrodes include a positive electrode and a negative electrode;
Acquisition of evaluation values regarding the body surface potential is performed for the positive electrode and the negative electrode,
The evaluation value for the body surface potential of the positive electrode is selected from an evaluation scale in which the higher the potential, the larger the value,
The electrode position determination method according to any one of claims 1 to 6, wherein the evaluation value for the body surface potential of the negative electrode is selected from an evaluation scale in which the lower the potential, the larger the numerical value. The electrode position determination method according to any one of claims 5 to 7, wherein the lowest evaluation value on said evaluation scale is 0 (zero). In the step of obtaining evaluation values for the two or more elements at each of a plurality of positions, the values of the elements are linearly interpolated as necessary to obtain the plurality of positions common to the two or more elements The electrode position determination method according to any one of claims 1 to 8, wherein the evaluation value of is obtained. A biosignal acquisition garment comprising an electrode arranged on a garment body for acquiring a wearer's biosignal,
The electrodes are
a first electrode disposed on one of the left abdomen and the lower left dorsal surface;
and a second electrode positioned on either one of the left chest and the right upper back. A biosignal acquisition garment comprising an electrode arranged on a garment body for acquiring a wearer's biosignal,
Regarding the area facing the body surface between the horizontal line connecting the left and right acromions and the horizontal line passing through the iliac tia when worn, of the front and back bodies of the garment body,
Each body is divided into 117 virtual areas by a plurality of vertical virtual lines that divide the body width into equal parts and a plurality of horizontal virtual lines that divide the body length into equal parts,
The 117 virtual regions of the front body are given region numbers F1 to F117 in this order from the top row to the bottom row and from the right to the left on the same row,
For the 117 virtual regions of the back body, when region numbers B1 to B117 are assigned in this order from the top row to the bottom row and from left to right on the same row,
The electrodes are
a first electrode arranged so as to partially or wholly overlap with either one of the following region group a and the following region group b;
A biological signal acquisition garment including a second electrode arranged so as to partially or wholly overlap with either one of region group c and region group d described below.
Area group a: F98, F99, F107, F108, F116, F117
Area group b: B91, B92, B100, B101, B109, B110
Area group c: F34, F35, F42, F43, F51, F52
Area group d: B44, B45, B53, B54, B62, B63

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