JP2000314667A - Method and device for evaluating sitting posture compatibility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate the compatibility of sitting person with an sitting object after long time work with high reliability and in a short time by evaluating compatibility based on the back shape of the sitting person on the object and body pressure distribution on the sitting object during sitting. SOLUTION: A back shape-measuring device 11 consists of a measuring part where many linear potentiometers are arranged in vertical direction to a sensor frame with specific intervals and measures the back shape of the sitting person. On the other hand, a body pressure sensor mat 13 is composed of a measuring part where load cells are arranged with specific intervals on the sitting mat of sitting plane of a chair and back of the chair and measures the body pressure distribution during sitting. Then, a scanner 15 scans in turn the measuring part of the back shape-measuring device 11 and the body sensor mat 13 by the control of a scanner controller 17 and takes in data from the sensors corresponding to each part of the person. A personal computer 19 evaluates compatibility of the chair with the sitting person based on the taken-in back shape data and body pressure sensor data and indicates on the screen of a monitor 19a.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sitting posture suitability evaluation method and a sitting posture suitability evaluation apparatus for evaluating the comfort of sitting on a chair or the like.

2. Description of the Related Art When a person sits on a chair and performs work such as office work or driving, a feeling such as "comfortable" and "easy to get tired" is generated. This is because the body sensation determined by the compatibility between the chair and the body is determined and recognized. Designing and selecting a chair with a high degree of compatibility between the chair and the body also provides an accurate work space for humans. As a conventional evaluation method and evaluation apparatus, for example, Japanese Patent Application Laid-Open No. 10-27457
There is one shown in FIG. In this evaluation method and evaluation apparatus, a pressure sensor array 5 is provided on a chair seat surface 3 of a chair 1, and the pressure sensor array 5 is connected to an input / output sort of a computer 9 via a driver 7. A signal representing the contact pressure output from each pressure sensor of the pressure sensor array 5 is converted into digital data by the driver 7 and output to the computer 9. Therefore, a predetermined evaluation can be performed based on the contact pressure on the chair seat surface 3.

By the way, humans have individual differences such as the back shape, and it is considered that the morphological characteristics of the human side have a great influence on the suitability of the sitting posture. But,
In the conventional evaluation method and evaluation apparatus, since the evaluation is based solely on the contact pressure of the chair seat surface 3, the morphological characteristics of a human cannot be taken into consideration, and there is a certain limit in the reliability of the evaluation. Was. In addition, the compatibility between the target chair and the body can be evaluated by using a subjective evaluation. Particularly, in the case of a work chair or the like, a long-term evaluation is required. However, it is difficult for a subject to sit in a work chair for a long time each time and take data, and the evaluation work is complicated. An object of the present invention is to provide a sitting posture suitability evaluation method and a sitting posture suitability evaluation device capable of performing more reliable evaluation and performing suitability evaluation after a long working time in a short time. And

According to a first aspect of the present invention, a shape of a back of a seated person on a seated object and at least a body pressure distribution on the seated object at the time of sitting are measured, and based on the back shape and at least the body pressure distribution. The suitability between the seated object and the seated person is evaluated. The invention of claim 2 is
The sitting posture suitability evaluation method according to claim 1, wherein the evaluation is a sensory evaluation index obtained by multiplying a fatigue sensory evaluation of each part of the body of the seated person by a weight coefficient indicating a degree of importance of each part of the body for sitting comfort. Is used. The invention of claim 3 is the sitting posture suitability evaluation method according to claim 2, wherein the evaluation is a relationship between a load supporting ratio of a skeleton feature point position of a body based on the body pressure distribution and the sensory evaluation index. It is characterized by performing in. The invention according to claim 4 is the sitting posture suitability evaluation method according to any one of claims 1 to 3, wherein the evaluation is performed for each class by classifying the back shape into at least three classes. I do. Claim 5
The present invention is the sitting posture suitability evaluation method according to claim 3, wherein the evaluation is based on a sensory evaluation index based on long-term data of the fatigue sensory evaluation and a load supporting ratio of the skeleton feature point position. The relationship is preliminarily analyzed and prepared, and the sensory evaluation index after a long sitting time is predicted using the body pressure distribution measured at least in the early stage of sitting on the seating target for the relationship. According to a sixth aspect of the present invention, there is provided the sitting posture suitability evaluation method according to the fifth aspect, wherein the predicted sensory evaluation index is different for each part of each body part. The invention according to claim 7 is the sitting posture suitability evaluation method according to claim 5, wherein the predicted sensory evaluation index is obtained by summing up the index for each body part. The invention according to claim 8 is a back shape measuring means for measuring a back shape of a seated person on a seated object, a body pressure distribution measuring means for measuring a body pressure distribution at the time of sitting on the seated object, and the measured back It is characterized by comprising evaluation means for evaluating the suitability between the seated object and the occupant based on the shape and body pressure distribution, and evaluation output means for outputting the evaluation of the evaluation means. According to a ninth aspect of the present invention, in the sitting posture suitability evaluation apparatus according to the eighth aspect, the evaluation means indicates a degree of importance of each part of the body with respect to sitting comfort in a sensory evaluation of each part of the body of the seated person. It is characterized by using a sensory evaluation index multiplied by a weight coefficient. According to a tenth aspect of the present invention, in the sitting posture suitability evaluating apparatus according to the ninth aspect, the evaluation unit is configured to determine a load support ratio of a body skeleton feature point position based on the body pressure distribution and the sensory evaluation index. It is characterized in that evaluation is performed in relations. The invention of claim 11 is the sitting posture suitability evaluation apparatus according to any one of claims 8 to 10, wherein the evaluation means performs at least three classifications of the back shape and performs evaluation for each class. It is characterized by. A twelfth aspect of the present invention is the sitting posture suitability evaluation apparatus according to the tenth aspect, wherein the evaluation means includes a sensory evaluation index based on long-term data of the fatigue sensory evaluation and a load at the skeleton feature point position. It is characterized in that the relationship with the support ratio is analyzed and created in advance, and the sensory evaluation index after a long sitting time is predicted using the body pressure distribution measured at least in the early stage of sitting on the seating object. According to a thirteenth aspect of the present invention, there is provided the sitting posture suitability evaluating apparatus according to the twelfth aspect, wherein the predicted sensory evaluation index is for each part of each body part.
A fourteenth aspect of the present invention is the sitting posture suitability evaluation apparatus according to the twelfth aspect, wherein the predicted sensory evaluation index is obtained by integrating the sensory evaluation index for each body part. The invention according to claim 15 is the sitting posture suitability evaluation apparatus according to any one of claims 8 to 14, wherein the back shape measuring means includes a linear potentiometer group arranged vertically at predetermined intervals as a measuring unit. It is characterized by doing. The invention according to claim 16 is the sitting posture suitability evaluation apparatus according to any one of claims 8 to 15, wherein the body pressure distribution measuring means includes:
A load cell group arranged at predetermined intervals on a seating surface of the seating target is used as a measuring unit. The invention of claim 17 is the sitting posture suitability evaluation apparatus according to any one of claims 8 to 16, wherein the evaluation output means displays the evaluation on a screen. The invention according to claim 18 is the sitting posture suitability evaluation apparatus according to claim 17, wherein the evaluation output means simultaneously outputs the evaluation as a sensory evaluation index indicating a contour line of body pressure distribution, a back shape, and fatigue. It is characterized by displaying.

According to the first aspect of the present invention, the shape of the back of the seated person and the body pressure distribution on the seated object at the time of sitting are measured, and the suitability between the seated object and the seated person is determined based on the back shape and the body pressure distribution. Evaluation can be performed, and more reliable evaluation can be performed by considering not only the body pressure distribution but also the back shape. According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, by using a sensory evaluation index obtained by multiplying the fatigue sensory evaluation of each part of the body by a weighting coefficient, a sensory evaluation index of a portion having a high degree of importance for sitting comfort is obtained. Can be used, and a more reliable evaluation can be performed. According to the third aspect of the present invention, the evaluation is performed based on the relationship between the load supporting ratio at the skeleton feature point position and the sensory evaluation index, so that the support pressure balance and the degree of concentration in the region considered to be related to the degree of physical fatigue are considered. And a more reliable evaluation can be performed. In the invention of claim 4, in addition to the effect of any of the inventions of claims 1 to 3, at least three types of the back shape are classified and evaluated for each classification, so that the morphological characteristics of the human are accurately considered, A more reliable evaluation can be performed. In the invention of claim 5, in addition to the effect of the invention of claim 3, the sensory evaluation index after a long sitting time is predicted in a short time by using the relationship between the sensory evaluation index and the load support ratio which are preliminarily analyzed and created. , Quick evaluation can be performed. According to the invention of claim 6, claim 5
In addition to the effects of the invention, evaluation can be obtained for each part of the body. According to the invention of claim 7, in addition to the effect of the invention of claim 5, it is possible to easily obtain the fitness evaluation of the whole body. According to the invention of claim 8, the back shape of the seated person and the body pressure distribution with respect to the seated object at the time of sitting can be measured, and the suitability between the seated object and the seated person can be evaluated based on the back shape and the body pressure distribution. By considering not only the body pressure distribution but also the shape of the back, a more reliable evaluation can be performed. According to the ninth aspect of the present invention, in addition to the effects of the eighth aspect of the present invention, by using a sensory evaluation index obtained by multiplying a weighting coefficient by a fatigue sensory evaluation of each part of the body, a sensory evaluation index of a portion having a high degree of importance for sitting comfort is obtained. , A more reliable evaluation can be performed. According to the tenth aspect of the present invention, in addition to the effect of the ninth aspect of the present invention, the evaluation of the relationship between the load supporting ratio at the skeleton feature point position and the sensory evaluation index is performed to support a region considered to be related to the degree of physical fatigue. The pressure balance and the degree of concentration can be considered, and a more reliable evaluation can be performed. According to the invention of claim 11, in addition to the effects of any of the inventions of claims 8 to 10, at least three types of the back shape are classified and evaluated for each classification, so that the morphological characteristics of the human are accurately considered, A more reliable evaluation can be performed. According to the twelfth aspect of the invention, in addition to the effects of the tenth aspect, the sensory evaluation index after a long sitting time is predicted in a short time by using the relationship between the sensory evaluation index and the load support ratio that are preliminarily analyzed and created. , Quick evaluation can be performed. According to the thirteenth aspect, in addition to the effects of the twelfth aspect, an evaluation can be obtained for each part of the body. According to the fourteenth aspect, in addition to the effects of the twelfth aspect, it is possible to easily obtain the fitness evaluation of the entire body. According to the invention of claim 15, in addition to the effects of the invention of any of claims 8 to 14,
When measuring the back shape of the subject, the back shape can be measured simply by pressing the back against the linear potentiometer group of the measuring unit. Therefore, when compared with a laser displacement meter or the like, the subject does not need to be naked for each measurement, the measurement can be performed from the top of clothing, and a quick suitability evaluation can be performed. According to the sixteenth aspect, claims 8 to
In addition to the effects of the invention of any one of the fifteenth aspects, by measuring the body pressure distribution with the load cell group, the measurement sensitivity can be maintained even at a low pressure, and the pressure ratio of the lumbar spine having a high correlation with the feeling of fatigue, etc. The measurement of the quantitative evaluation index can be reliably performed, and more accurate suitability evaluation can be performed. According to the seventeenth aspect, in addition to the effects of any one of the eighth to sixteenth aspects, the evaluation can be viewed on a screen display, and the evaluation can be reliably and easily recognized. In the invention of claim 18,
In addition to the effects of the seventeenth aspect, it is possible to simultaneously recognize the isobar of the body pressure distribution, the shape of the back, and the sensory evaluation index indicating fatigue as an evaluation, and more easily and reliably recognize the suitability evaluation. .

FIG. 1 is a block diagram of a sitting posture suitability evaluation apparatus according to an embodiment of the present invention. This apparatus comprises a back shape measuring device 11 as a back shape measuring means, a body pressure sensor mat 13 as a body pressure distribution measuring means, a scanner 15, a scanner controller 17, and a personal computer 19. The back shape measuring device 1
1 measures the back shape of the seated person. The body pressure sensor mat 13 measures the body pressure distribution at the time of sitting. Scanner 1
5 is a back shape measuring device 11 and a body pressure sensor mat 13
In, the measuring unit is sequentially scanned so as to take in data from sensors corresponding to various parts of the human. The scanner controller 17 controls the scanner 15 and takes in data. The personal computer 1
Reference numeral 9 evaluates and outputs the suitability between the chair and the occupant based on the data on the back shape and the data from the body pressure sensor. The output is output from the personal computer 19.
Is displayed on the screen by the monitor 19a provided in the monitor. Therefore, the personal computer 19 constitutes an evaluation means for evaluating the suitability between the seated object and the occupant based on the measured back shape and body pressure distribution, and the monitor 19a outputs an evaluation output means for outputting the evaluation of the evaluation means. Is composed. The specific structure of the back shape measuring device 11 is as shown in FIG. That is, in the back shape measurement device 11, the measurement unit 21 is attached to the base 23. The measuring section 21 is configured by arranging a large number of linear potentiometers 27 at predetermined intervals in the vertical direction with respect to the sensor frame 25, and is constituted by a group of linear potentiometers. Linear potentiometer 27
Can be measured as shown in the back shape 29 in FIG. The scanner 15 scans each of the linear potentiometers 27. The measurement unit 21 can be driven by a motor in the up, down, left, and right directions, and can measure a height difference, a sitting position, and a standing position in the up and down direction. In the left-right direction, it is possible to measure and analyze only the center of the back, but it is also possible to perform the push-in measurement several times while moving in the lateral direction, and also perform the three-dimensional shape measurement of the entire back. By using the back shape measuring device 11 using the linear potentiometer 27, compared with the case of using a laser displacement meter or the like, it is less susceptible to clothes, hair, etc., and the subject can be pushed into the sensor from above the clothes. And the measurement can be easily performed. The body pressure sensor mat 13 is arranged as shown in FIG. That is, the seat 31 includes a seat mat 35 attached to the chair seating surface 33 of the chair 31 and a backrest mat 39 attached to the chair backrest surface 37. The body pressure sensor mat 13 includes a main part having a cross-sectional shape as shown in FIG. That is, the thin load cell 41 is fixed on the substrate 43, and the sensor cap 45 is mounted on the substrate 43 and the load cell 41. The sensor substrate 43 and the sensor cap 45 are
They are engaged so as not to be separated by a. The upper portion of the sensor cap 45 is covered with a stocking material 47 and entirely covered with a lower skin 49 and an upper skin 51. 5
3 is a lead wire. In the seat mat 35, the main parts including the load cells 41 are arranged at a pitch P as shown in FIG. 2B, and a dummy sensor is arranged at the center of each pitch to form a dense arrangement. Also, the backrest mat 3
In FIG. 9, they are arranged at a pitch P as shown in FIG. Therefore, with such an arrangement, the load cell groups are arranged at predetermined intervals on the seat mat 35 and the backrest mat 39, and the measuring units 55 and 57 are formed. Therefore, in the present embodiment, by arranging the body pressure sensor mat 13 as shown in FIG. 3, the body pressure distribution measuring means uses the load cell groups arranged at predetermined intervals on the seating surface of the seating target as the measuring units 55 and 57. . Therefore, the chair 3 to which the body pressure sensor mat 13 is attached
When the subject is seated at 1, a load is input to the sensor cap from the upper skin, the load is detected by the load cell 41, and data is output via the lead wire 53. The scanner 15 scans each of the load cell 41 groups. The body pressure sensor mat 1
3, the detection result is, for example, as shown in FIG.
(A) shows the body pressure distribution at the backrest 37, and (b) shows the body pressure distribution at the seat 33. In (a), the left side in the figure is above the backrest 37 and the right side is below. In (b), the left side in the figure is the rear of the seat 33, and the right side is the front. 6 to 8 show flowcharts according to an embodiment of the present invention. FIG. 6 is a flowchart of back shape measurement, FIG. 7 is a flowchart of body pressure distribution measurement, and FIG. 8 is a flowchart of sitting posture suitability evaluation. First, in the back shape measurement, as shown in FIG. 6, in step S61, the height of the sitting height is set according to the sitting height of the subject. In step S62, the subject is allowed to take a sitting position by calculating the sitting height. In step S63, the measurement unit 21 of the back shape measurement device 11 is pressed against the subject in a sitting position.
By this pressing, the linear potentiometers 27 are pushed in as shown in FIG.
Is output. In step S64, after confirming that the shape is properly removed, the subject is released. In step S65, the measurement data from the linear potentiometer 27 is captured as a back shape in the personal computer 19, and recorded in a file together with the output value of the sitting height meter. In the body pressure distribution measurement, as shown in FIG. 7, in step S71, the body pressure sensor mat 13 is set on the chair to be seated as shown in FIG. In step S72, the subject is caused to take a working posture using the backrest 37.
The output from each load cell 41 of the seat mat 35 and the backrest mat 39 at this time is taken into the personal computer 19 as a body pressure distribution and recorded in a file. In the sitting posture suitability evaluation, subject characteristics are entered in step S81 as shown in FIG. This entry is
For example, this is performed by inputting the height of the subject into the personal computer 19. In step S82, the data of the back shape measurement obtained in the flow of FIG. 6 is read. In step S83, the classification of the back shape is entered. In this entry, the classification of the back shape is determined and stored based on the data of the back shape measurement.
The classification of the back shape will be described later. In step S84, the body pressure distribution measurement data stored in the flow of FIG. 7 is read. In step S85, the position of the spine feature point on the body pressure sensor mat 13 is estimated from the sitting height of the subject. The spine feature points and their position estimation will be described later. In step S86, the feature amount of the body pressure distribution according to the position of the spine feature point is calculated. The body pressure distribution feature amount will be described later. In step S87, a formula for estimating a sensory evaluation index for each site is selected for each back shape. The estimation formula will be described later. In step S88, a sensory evaluation index for each part of each part of the projectile is calculated from the height and the body pressure distribution feature amount. The calculation will be described later. In step S89, the sensory evaluation indices for each part are integrated,
That is, calculation of the added general sensory evaluation index is performed.
In step S810, the body pressure distribution, the back shape, and the comprehensive sensory evaluation index are displayed on the monitor 1 of the personal computer 19.
9a is displayed on the screen. FIG.
5 shows an example of a screen display by a. In the present embodiment, the monitor 19a simultaneously displays on the screen the isobar 59 of the backrest body pressure distribution, the isobar 61 of the seat body pressure distribution, the back shape 63, and the sensory evaluation index 65 indicating fatigue as an evaluation of the sitting posture suitability. ing. Therefore, the evaluator can reliably and easily recognize the sitting posture suitability evaluation by looking at the monitor 19a. FIG. 10 shows an example of the back shape classification entry in step S83 of FIG. 8, and in this embodiment, at least three classifications are entered. There are S-shaped, cat-backed, and linear types, and (a), (c), and (e) show S in the natural standing position.
It shows the shape of a letter, a cat, and a straight back, (b),
(D) and (f) show the S-shaped, cat-back, and linear back shapes in the normal sitting position. As a criterion for classification, the sigmoid type has both the kyphosis of the thorax and the lordosis of the lumbar vertebrae. In the straight type, both the thorax and the lumbar spine have a small curvature and are flat from shoulder to hip. In this way, the back shape is classified into at least three categories, and each class is evaluated. This is various chairs,
Preliminary experiments by various subjects confirmed that the difference in the support condition of the occupant's spine posture affected the back and lower back pain, and that the type of spine shape of the subject affected the evaluation of posture support. . As shown in FIG. 11, the vertebral column feature point positions in step S85 are
The thoracic vertebra 69, the third lumbar vertebra 71, the fifth lumbar vertebra 73, and the height of the first sacral vertebra (not shown) indicate that the smaller the sensory evaluation index is, the less fatigue, that is, the higher the fitness. In addition, although evaluation can be performed for each site, a comprehensive sensory evaluation index obtained by integrating the results for each site can be used as a simple index. Here, the derivation of the estimation formula will be described. The sensory evaluation was performed using a sensory evaluation sheet as shown in FIG. The work experiment was performed on 10 adult male subjects, using a total of 6 legs including 4 chairs with different support of the backrest and 2 chairs with different support of the seat as evaluation conditions.
Time tasks were performed. In the experiment, sensory evaluation on support and fatigue and measurement of body pressure distribution were recorded in a time series at each specific time. Measurement time is 0, 5, 15, 30, 4
5, 60, 90, 120 and 150 minutes. In addition, in order to analyze the body pressure distribution data in association with the body position, the setting of the chair was recorded at the time of work, and the characteristic point positions on the spine during the work posture were measured by reproducing the work posture separately reproduced. . In the data analysis, the fatigue of each part was examined for each feature of the back shape, and a primary regression equation was created using the objective variables as sensory evaluation indices and the explanatory variables as body pressure features or body dimensions for each part. In addition, the sensory evaluation index was an average of 90 to 150 minutes at which the subjective evaluation of long-term fatigue was stabilized. Further, the back shape was qualitatively classified into three classifications of S-shape, straight type, and cat-back type, classified according to the degree of curvature for each part as shown in Table 1, and an estimation formula was created for each curvature feature.

[Table 1] [Neck sensory evaluation index] As shown in FIG. 13 (a), a correlation (R = 0.525) with a risk factor of 1% or less was observed for subjects with a curved chest. Although not significant at a risk factor of 10% or less, the opposite tendency (R = −0.52) was observed for subjects with a flat chest as shown in FIG. 13 (b). Therefore, the estimation formula is as follows. Neck sensory evaluation index = 2.622 x (thoracic spine support ratio)-
0.063: Chest curve type neck sensory evaluation index = -1.952 x (thoracic spine support ratio) +
0.957 ... Chest flat type [Shoulder sensory evaluation index] As shown in FIG. 14 (a), the correlation between the thoracic vertebra support rate and the risk factor of 5% or less (R = 0.428) was obtained for subjects with a curved chest type. Admitted. On the other hand, in a subject with a flat chest type, the opposite tendency (R = −0.436) with a risk factor of 5% or less was observed as shown in FIG. Therefore, the estimation formula is as follows. Shoulder sensory evaluation index = 1.851 x (ratio of thoracic spine support) +
0.099: Chest curve type shoulder sensory evaluation index = -4.216 x (thoracic spine support ratio) +
0.871 ... Chest flat type [Back sensory evaluation index] The sensory evaluation index of the back does not show any unique tendency for each morphological characteristic of the subject, and a correlation is found between the thoracic spine support ratio and the lumbar spine support ratio as common trends. Was. Therefore, a multiple regression analysis was performed using the thoracic spine support ratio and the lumbar spine support ratio as explanatory variables, and as shown in FIG. 15, an index formula (R =
0.459). Back sensory evaluation index = 1.466 x (thoracic spine support ratio) +
3.179 × (lumbar spine support ratio) −0.299 [Chest sensory evaluation index] For subjects with a curved chest,
As shown in FIG. 16 (a), the thoracic spine support ratio and the risk factor 1%
The following strong correlation (R = 0.641) was observed. or,
Although the significance level is not significant at 10% or less, the opposite tendency (R = −
0.102) was found. Therefore, the estimation formula is as follows. Chest sensory evaluation index = 1.947 x (thoracic spine support ratio)-
0.1058 ... Chest curve type Chest sensory evaluation index = -0.415 x (Thoracovertebra support ratio) +
0.210 ... Chest flat type [lumbar sensory evaluation index] For subjects with a curved waist,
As shown in FIG. 17A, a lumbar support ratio and a negative tendency (R = −0.551) of 5% or less were recognized. On the other hand, in the lumbar spine flat type subjects, a positive correlation (R = 0.478) with a risk factor of 1% or less was observed as shown in FIG. 17 (b). Therefore, the estimation formula is as follows. Lumbar sensory evaluation index = -5.581 x (lumbar spine support ratio) +
1.518 ... waist curve type waist sensory evaluation index = 6.692 x (lumbar spine support ratio)-
0.094 ... waist flat type Fatigue of the parts related to the lower limbs shown below is considered to be unrelated to the shape of the back. Therefore, the subjects were not particularly classified and the whole data was examined. [But buttocks sensory evaluation index]
As shown in Fig. 8, a high correlation (R = 0.491) with the ischial support rate and the risk factor of 0.1% or less was observed. From this, the following estimation formula was obtained. Buttocks sensory evaluation index = 4.700 x (sciatic support rate)-
1.983 [Thigh sensory evaluation index] As shown in Fig. 19, the thigh sensory evaluation index has a weak correlation (R = 0.009) with a thigh support ratio and a risk factor of 10% or less. Was. Therefore,
The estimation formula is as follows. Thigh sensory evaluation index = 0.265 x (thigh support ratio)
+0.131 [Thigh sensory evaluation index] Regarding the fatigue of the lower leg, it is not related to the body pressure distribution because it is not basically in contact with the chair, but it is relative to the position where the foot is placed depending on the leg length. Will change. Therefore, as shown in FIG. 20, an estimation formula was created based on the height having a high correlation with the leg length. Lower leg sensory evaluation index = -0.013 x (height) + 2.3
55. In FIGS. 13 to 20, the vertical axis is a sensory evaluation index for each part in which the sensory evaluation result of the sensory evaluation experiment is weighted to a certain degree, and the horizontal axis is the support of the feature point position based on the body pressure distribution detected at that time. It is a percentage. The experimental values are plotted at points, and from this point a straight line representing the estimation formula was obtained by regression analysis. In FIG. 13, only the thoracic spine support ratio is shown on the horizontal axis. However, in the experiment, the relationship between the neck sensory evaluation index and other body pressure distribution features is also taken as data. As a result of narrowing down the number of variables as much as possible and examining the causal relationship as a result,
Thorax support ratio is selected. This relationship is shown in FIG.
The same applies to all other items in FIG. In step S88, by adapting the body pressure distribution feature amount or height in the linear regression equation obtained as described above, a sensory evaluation index for each part of the body can be obtained. That is, in the estimation formulas represented by the straight lines in FIGS. 13 to 20, the body pressure distribution feature amount is applied to the support ratio on the horizontal axis, and the sensory evaluation index on the vertical axis is obtained. With the sensory evaluation index for each part, the fatigue state of each part of the body can be known, and the suitability between the chair to be seated and the seated person can be accurately evaluated. In addition, since the back shape is classified into at least three categories and the evaluation is performed for each class, a more reliable and accurate evaluation of the suitability can be performed in consideration of the morphological individual difference of the human. Further, by calculating the comprehensive sensory evaluation index as in step S89, fatigue of the entire body can be easily recognized, and simple sitting posture suitability evaluation can be performed. Further, as described above, since the output is performed by the monitor 19a as shown in FIG. 9, it is possible to quickly and accurately recognize the suitability evaluation of the sitting posture. In this way, the relationship between the sensory evaluation index based on long-term data of the fatigue sensory evaluation and the load bearing ratio of the skeleton feature point position is analyzed and created in advance, and the relationship is measured in the early stage of sitting on the chair to be seated. By using the obtained body pressure distribution, the load supporting ratio is determined, and by adapting the load supporting ratio to the previously determined relationship, the sensory evaluation index after a long sitting time can be predicted in a short time, which is extremely simple. It is possible to obtain a simple sitting posture suitability evaluation method and a sitting posture suitability evaluation device. In the above-described embodiment, the back shape is classified into three classes. However, by performing more classes, it is possible to perform a fine evaluation for each class and to perform a more accurate sitting posture suitability evaluation.

[Brief description of the drawings]

FIG. 1 is an overall block diagram of a sitting posture suitability evaluation apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a back shape measuring device according to one embodiment.

FIG. 3 is a perspective view showing a relationship between a body pressure sensor mat and a chair.

4A and 4B show a main part of the same body pressure sensor mat, wherein FIG. 4A is a cross-sectional view of the main part, FIG. 4B is a plan view showing a part of an upper skin of the seat mat, and FIG. It is the top view which opened the skin partly.

FIG. 5 is a diagram showing a backrest portion,
(B) is an explanatory view of a seat.

FIG. 6 is a flowchart of the back shape measurement.

FIG. 7 is a flowchart of a body pressure distribution measurement.

FIG. 8 is a flowchart of a sitting posture suitability evaluation.

FIG. 9 is an explanatory diagram of a screen display on a monitor.

FIG. 10 shows the classification of the back shape, (a) is an S-shaped natural standing position, (b) is a normal sitting position, (c) is a cat standing natural standing position,
(D) is a normal sitting position, (e) is a linear natural standing position, (f)
Is an explanatory diagram of the normal sitting position.

FIG. 11 is an explanatory diagram showing positions of body feature points.

FIG. 12 is an explanatory diagram showing the same sensory evaluation sheet.

FIG. 13 is a graph showing a relationship between a neck curvature sensory evaluation index of a curved chest type and a thoracic spine support ratio,
(B) is a graph showing a relationship between a flat chest type neck sensory evaluation index and a thoracic spine support ratio.

14A and 14B are graphs showing a relationship between a chest flexion-type shoulder sensory evaluation index and a thoracic spine support ratio, and FIG. 14B is a graph showing a relationship between a flat chest type shoulder sensory evaluation index and a thoracic vertebra support ratio. It is a graph of the relationship of.

FIG. 15 is a graph showing a relationship between a back sensory evaluation index and a body pressure support ratio in the estimation formula.

16A and 16B are graphs showing a relationship between a chest curved arm sensory evaluation index and a thoracic spine support ratio, and FIG. 16B is a graph showing a relationship between a chest flat type arm sensory evaluation index and a thoracic vertebra support ratio. It is a graph of the relationship of.

17A and 17B are graphs showing a relationship between a waist curve type lumbar sensory evaluation index and a lumbar support ratio, and FIG. 17B is a graph showing a relationship between a lumbar flat type lumbar sensory evaluation index and a lumbar support ratio. It is a graph of.

FIG. 18 is a graph showing the relationship between the buttocks sensory evaluation index and the ischial support rate in the estimation formula.

FIG. 19 is a graph showing a relationship between a thigh sensory evaluation index and a thigh support ratio according to the estimation formula.

FIG. 20 is a graph showing the relationship between the lower leg sensory evaluation index and the height in the estimation formula.

FIG. 21 is an overall block diagram of a device according to a conventional example.

[Explanation of symbols]

It is estimated from the measurement, and the corresponding position on the body pressure sensor mat 13 is estimated. Further, the peak value of the body pressure distribution measurement value by the seat mat 35 is set as the ischium position 75, and the characteristic point position is estimated. The calculation of the body pressure distribution feature amount in step S86 is performed by taking the sum of the body pressure distribution measurement values in the vicinity of each body feature point and defining the ratio with the sum of the measurement values of the backrest 37 or the seat 33 as a support ratio. Thoracic vertebra support ratio = sum of body pressure measurement values from the 10th thoracic vertebra to twelfth thoracic vertebra / total body pressure of the backrest Lumbar vertebra support ratio = sum of body pressure measurement values in the range of 35 mm above and below the third lumbar vertebra / backrest Total body pressure Pelvic support ratio = Total measured body pressure from the 5th lumbar vertebra to the lowermost end of the mat / Total body pressure of the backrest Sciatic support ratio = Total measured body pressure in the 35 mm center of the ischial position / Total measured seat value Thigh support ratio = Sum of measured body pressure from the position of the ischial bone to the front end of the mat / Summed value of the seat part. That is, regarding the seat pressure distribution, the support pressure balance and concentration in the region related to the human skeleton load are considered to have a high correlation with the sitting posture suitability, and are used as explanatory variables. The estimation formula in step S87 is as follows: (neck sensory evaluation index) = 2.622 × (thoracic vertebra support ratio) −0.063… chest curved type = −1.952 × (thoracic vertebra support ratio) +0.957… chest flat type (Shoulder sensory evaluation index) = 1.861 x (thoracic vertebra support ratio) + 0.099 ... Chest curved type = -4.216 x (thoracic vertebra support ratio) + 0.871 ... Chest flat type (back sensory evaluation index) = 1.466 x (thoracic vertebra support ratio) + 3.179 x (thoracic vertebra support ratio)-0.299 (arm sensory evaluation index) = 1.947 x (thoracic vertebra support ratio)-0.108 ... Chest curved type = -0 .415 x (ratio of thoracic spine support) + 0.210 ... flat chest type (lumbar sensory evaluation index) = -5.581 x (ratio of lumbar support) + 1.518 ... waist curve type = 6.692 x (lumbar support ratio)- 0.094 ... waist flat type ) = 4.700 x (sciatic support rate)-1.983 (femoral support index) = 0.265 x (femoral support rate) + 0.131 (femoral support index) = -0 0.013 × (height) +2.355 (overall) = Σ (sensory evaluation index for each site). That is, the compatibility between the chair and the subject can be evaluated by using a subjective evaluation. In particular, in the case of a work chair or the like, a long-term evaluation is required. Therefore, based on the definition of the suitability of the chair as "a chair with high suitability is a chair that does not tire for a long time", the site-specific subjective evaluation by the site after a long working time is multiplied by a certain weighting factor. The sensory evaluation index was used as an evaluation index. For this sensory evaluation index for each part, an estimation formula (index formula) using body pressure distribution features for each body part at the time of sitting is used as the state quantity of compatibility between the chair and the body, It is possible to predict the sensory evaluation index after a long working time from the sitting state quantity of the user. The weighting factors are determined based on the importance of the questionnaire survey, and indicate the importance of each part of the body with respect to sitting comfort. By using such a weight coefficient, a more accurate sensory evaluation index can be obtained. 11 back shape measuring device (back shape measuring means) 13 body pressure sensor mat (body pressure distribution measuring means) 19 personal computer (evaluation means) 19a monitor (evaluation output means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoichi Kishi Nissan Motor Co., Ltd. (2) Nissan Motor Co., Ltd. (2) Inventor Toshimichi Hanai 2 Takaracho, Kanagawa Ward, Yokohama City, Kanagawa Prefecture F Terms (reference) 2F051 AA01 AB06 AC09 BA07 BA08 2F063 AA50 BA29 CA13 DA02 DA05 DA21 DD06 DD08 FA01 KA02 MA05 ZA01 ZA02 3B087 DE08 DE10 3B088 QA06 4C038 VA03 VB29 VC11 VC20

Claims (18)

[Claims] 1. A back shape of a seated person on a seated object and at least a body pressure distribution on the seated object at the time of sitting are measured, and the suitability between the seated object and the seated person based on the back shape and at least the body pressure distribution. A sitting posture suitability evaluation method for evaluating the posture. 2. The sitting posture suitability evaluation method according to claim 1, wherein the evaluation includes a weighting factor indicating a degree of importance to the suitability of each body part in the sensory evaluation of fatigue of each body part of the seated person. A sitting posture suitability evaluation method characterized by using a sensory evaluation index representing fatigue on riding. 3. The sitting posture suitability evaluation method according to claim 2, wherein the evaluation is performed based on a relationship between a load supporting ratio of a body skeleton feature point position based on the body pressure distribution and the sensory evaluation index. A sitting posture suitability evaluation method characterized by the following. 4. The sitting posture suitability evaluation method according to claim 1, wherein the evaluation is performed for each class by classifying the back shape into at least three categories. Posture suitability evaluation method. 5. The sitting posture suitability evaluation method according to claim 3, wherein the evaluation includes a sensory evaluation index based on long-term data of the fatigue sensory evaluation and a load supporting ratio of the skeleton feature point position. A relationship between the body posture and the body posture distribution measured at least in the early stage of sitting on the object, and predicting a sensory evaluation index after a long sitting time. . 6. The sitting posture suitability evaluation method according to claim 5, wherein the predicted sensory evaluation index is for each body part. 7. The sitting posture suitability evaluation method according to claim 5, wherein the predicted sensory evaluation index is obtained by summing up the values for each part of each body part. Sex evaluation method. 8. A back shape measuring means for measuring a back shape of a seated person on the seated object; a body pressure distribution measuring means for measuring a body pressure distribution when the seated object is seated; A seating posture suitability evaluation device, comprising: evaluation means for evaluating suitability between the seated object and the seated person based on body pressure distribution; and evaluation output means for outputting the evaluation of the evaluation means. 9. The sitting posture suitability evaluation apparatus according to claim 8, wherein the evaluation means includes a weighting coefficient indicating a degree of importance of each part of the body with respect to sitting comfort in a sensory evaluation of fatigue of each part of the body of the seated person. A sitting posture suitability evaluation device characterized by using a sensory evaluation index raised to a power. 10. The sitting posture suitability evaluation apparatus according to claim 9, wherein the evaluation means is configured to determine a relationship between a load support ratio of a body skeleton feature point position based on the body pressure distribution and the sensory evaluation index. A sitting posture suitability evaluation device characterized by performing an evaluation. 11. The sitting posture suitability evaluation device according to claim 8, wherein the evaluation unit performs at least three classifications of the back shape and performs evaluation for each class. Sitting posture suitability evaluation device. 12. The sitting posture suitability evaluation apparatus according to claim 10, wherein the evaluation means includes a sensory evaluation index based on long-term data of the fatigue sensory evaluation and a load supporting ratio of the skeleton feature point position. And a sensory evaluation index after a long sitting time is predicted by using a body pressure distribution measured at least in the initial stage of sitting on the seating object for the relationship. apparatus. 13. The sitting posture suitability evaluation apparatus according to claim 12, wherein the predicted sensory evaluation index is for each part of each body part. 14. The sitting posture suitability evaluation apparatus according to claim 12, wherein the predicted sensory evaluation index is obtained by integrating values for each part of each body part. Sex evaluation device. 15. The sitting posture suitability evaluation device according to claim 8, wherein the back shape measuring means is a group of linear potentiometers arranged vertically at predetermined intervals. A sitting posture suitability evaluation device characterized by the following. 16. The sitting posture suitability evaluation apparatus according to claim 8, wherein the body pressure distribution measuring unit measures a group of load cells arranged at predetermined intervals on a seating surface of the seating target. A sitting posture suitability evaluation apparatus characterized by comprising a section. 17. The sitting posture suitability evaluation device according to claim 8, wherein the evaluation output means displays the evaluation on a screen. 18. The sitting posture suitability evaluation device according to claim 17, wherein the evaluation output means simultaneously displays the evaluation as a sensory evaluation index indicating a contour line of body pressure distribution, a back shape, and fatigue. A sitting posture suitability evaluation device characterized by the above-mentioned.