JP5800357B2 - Biological signal detection mechanism - Google Patents

Description

  The present invention relates to a biological signal detection mechanism that supports a human body and is suitable for collecting a biological signal used for human state estimation from the upper body of the person.

  In recent years, monitoring the biological state of a driver during driving has attracted attention as an accident prevention measure or the like. In Patent Documents 1 to 3, the present applicant discloses a method of determining a sleep onset symptom by arranging a pressure sensor in a seat cushion portion, collecting and analyzing a heel pulse wave.

  Specifically, the maximum value and the minimum value of the time series waveform of the pulse wave are obtained by the smoothing differential method using Savitzky and Golay, respectively. Then, the maximum value and the minimum value are divided every 5 seconds, and the average value of each is obtained. The square of the difference between the average values of the obtained local maximum and local minimum is used as a power value, and this power value is plotted every 5 seconds to create a time series waveform of the power value. In order to read the global change of the power value from this time series waveform, the gradient of the power value is obtained by the least square method for a certain time window Tw (180 seconds). Next, the next time window Tw is similarly calculated at the overlap time Tl (162 seconds), and the result is plotted. This calculation (movement calculation) is sequentially repeated to obtain a time series waveform of the gradient of the power value. On the other hand, the maximum Lyapunov exponent is obtained by chaos analysis of the time series waveform of the pulse wave, the maximum value is obtained by smoothing differentiation, and the time series waveform of the gradient of the maximum Lyapunov exponent is obtained by moving calculation.

  The time series waveform of the power value slope and the time series waveform of the maximum Lyapunov exponent slope are in opposite phase, and furthermore, the time series waveform of the power value slope has a low frequency and large amplitude waveform. The waveform is determined as a characteristic signal indicating a sleep onset sign, and the point at which the amplitude subsequently decreases is determined as the sleep onset point.

  Further, as Patent Document 4, an air bag (air pack) in which a three-dimensional solid knitted fabric is inserted is provided, and the air pack is disposed at a portion corresponding to a person's back to measure air pressure fluctuations of the air pack. A system for detecting a human biological signal from the obtained time-series data of air pressure fluctuation and analyzing the state of the human biological body is disclosed. Non-Patent Documents 1 and 2 also report attempts to detect a human biological signal by arranging an air pack sensor along the lumbar gluteal muscle. This air pressure fluctuation of the air pack is due to shaking of the descending aorta accompanying the movement of the heart, and it is possible to capture a state change closer to the movement of the heart than when using the buttocks pulse wave of Patent Documents 1 and 2. .

JP 2004-344612 A JP 2004-344613 A WO2005 / 092193A1 publication JP 2007-90032 A

“Original, Development of a method for measuring the symptoms of falling asleep using fingertip plethysmogram information” Yasunori Fujita (8 others), Ergonomics Vol 41, No. 1 4 (’05) "Application of biological fluctuation signals measured by non-invasive sensors to fatigue and sleep prediction", Naoki Ochiai (6 others), 39th Annual Meeting of the Japan Ergonomics Society, Chugoku-Shikoku Branch, 2006 Issued on May 25, Publisher: Japan Ergonomics Society Chugoku-Shikoku Branch Office "Prototype of vehicle seat with non-invasive biological signal sensing function", Shinichiro Maeda (4 others), 39th Japan Ergonomics Society China-Shikoku Branch Conference, Proceedings, November 25, 2006 Place: Japan Ergonomics Society Chugoku / Shikoku Branch Office

  As described above, in the techniques of Patent Documents 1 to 4 and Non-Patent Documents 1 to 3, the time-series waveform of the power value gradient and the time-series waveform of the gradient of the maximum Lyapunov exponent are in opposite phases, and the power value gradient When the low-frequency and large-amplitude waveforms occur in the time-series waveform, it is regarded as a sleep onset symptom phenomenon.

  The present applicant has also proposed the following technique as Japanese Patent Application No. 2009-237802. In other words, it is a technique that obtains a time series waveform of a frequency from a time series waveform of a biological signal obtained by a biological signal measuring means, and uses a frequency gradient time series waveform and a frequency variation time series waveform obtained from the time series waveform of this frequency. , Positive / negative of frequency slope time series waveform, positive / negative of integral waveform of frequency slope time series waveform, appearance of reverse phase when frequency slope time series waveform and frequency fluctuation time series waveform are output overlaid (appearance of reverse phase falling asleep) This is a technique for determining a person's condition by combining the signs).

  Although the present applicant has proposed a technique for grasping a person's state using a biological signal as described above, a proposal for a technique for grasping a person's state more accurately is always desired. For that purpose, it is desirable not only to devise a biosignal analysis algorithm but also to collect biosignals as accurately as possible. Further, the above-described technique is manufactured as an air pack or the like incorporated in a seat back portion of a seat structure when collecting a biological signal. That is, it is a dedicated seat structure type for the purpose of collecting biological signals, and is not versatile. Therefore, in a general seat structure or other human body support mechanism that does not incorporate a biological signal collection function, there is a new proposal of a biological signal detection mechanism that enables detection of a biological signal simply by setting the existing human body support mechanism. It was desired. The present invention has been made in view of these problems.

In order to solve the above problems, a biological signal detection mechanism of the present invention covers a back support cushion member, a base cushion member disposed on the back side of the back support cushion member, and an outer surface of the base cushion member. , A side edge portion joined to a side edge portion of the back support cushion member, and a bag-like member that supports the base cushion member therein, and an intermediate layer between the back support cushion member and the base cushion member A sensing mechanism for collecting a biological signal from the back of the seated person and a back side of the back support cushion member, and spaced apart below the sensing mechanism, and the back support cushion member And the sensing mechanism is disposed between the back support cushion member and the base cushion member. A pelvis / lumbar support member that forms a clearance, reduces a load input to the back support cushion member, and absorbs movement of the pelvis due to breathing and body movement, and supports the back of the human body support mechanism It is characterized in that it is stretched around the part.
A belt member extending outward from the back support cushion member may be stretched around the back support portion of the human body support mechanism. It is preferable that the load sharing ratio by the pelvis / lumbar support member is 50% or more with respect to the total load of the seated person applied to the back support cushion member. The load sharing ratio with respect to the total load of the seated person on the back support cushion member is set to 20% or less in the intermediate region where the sensing mechanism portion is arranged, and the pelvis / lumbar portion where the pelvis / lumbar support member is arranged In the support area and the scapula support area, it is preferable that both are set to 80% or more. The pelvis / lumbar support member is separated from the outline line of the back of the person to be supported as the line along the front faces toward the upper edge, and the line along the front and the back of the person to be supported It is preferable that the angle formed by the outer shape line is set in a range of 5 to 45 degrees. The base cushion member and the back support cushion member are preferably formed of a three-dimensional solid knitted fabric.
The sensing mechanism unit has a predetermined thickness, a core pad having a through-hole of a predetermined area penetrating in the thickness direction, a spacer pad disposed in the through-hole formed in the core pad, and the spacer pad A sensor disposed in the through hole; and a front film and a rear film that cover the spacer pad and the sensor disposed in the through hole and are laminated in close contact with the front surface and the back surface of the core pad, respectively. It is preferable to become. It is preferable that the core pad is formed from a bead foam and the spacer pad is formed from a three-dimensional solid knitted fabric.
It is preferable that the human body support mechanism has a seat structure, and is configured to be a seat cushion type that is stretched on the back support portion and used by being placed on the seat structure. Further, the base cushion member and the back cushion member are supported on the back frame of the back support portion of the seat structure, the sensing mechanism portion is disposed therebetween, and the seat structure integrated type integrally incorporated in the seat structure; You can also

In the present invention, a back support cushion member and a base cushion member, which are provided as a tension structure on a back support portion of a human body support mechanism, are integrated by a bag-like member, and further, the back support cushion member and the base cushion member Is a three-layer structure including a sensing mechanism portion disposed between the pelvis and the lumbar support member for urging the pelvis and lumbar support region of the back support cushion member below the sensing mechanism portion It is. Since the sensing mechanism is disposed between the back support cushion member and the base cushion member, tension is generated in the surface direction of each cushion member. In addition, it is further provided on the back support portion of the human body support mechanism. Since the pelvis / lumbar support member presses the back support cushion member, the pelvis / lumbar support member becomes the starting point of the movement, and it is necessary to support and maintain the posture. While absorbing movement, a large amount of support pressure due to sitting is received by the back support cushion member, and the influence of the support pressure is reduced by the base cushion member on the back side. On the other hand, the anti-gravity muscle is in a relaxed state because the load sharing ratio is small in the intermediate region where the sensing mechanism unit is arranged. Therefore, the sensing mechanism portion arranged on the back side of the back support cushion member can detect the biological signal with high sensitivity. In addition, since the pelvis / lumbar region support member absorbs movements of breathing and body movements, a biological signal that does not contain much frequency components due to breathing and body movements, especially body pulse waves (Aortic Pulse Wave ( APW): It is possible to suitably collect a biological signal (heart fluctuation wave) generated by fluctuations of the atrium, ventricle and aorta.
In addition, the sensing mechanism is sandwiched between the back support cushion member and the base cushion member, and the base cushion member and the sensing mechanism are not fixed to the back support cushion member but supported in the bag-like member. Therefore, it can move in the vertical direction (shear direction) with respect to the back support portion of the human body support mechanism. Therefore, in the human body support mechanism (for example, a seat structure of an automobile), the base cushion member can absorb vibrations input from the seat support part and vibrations transmitted from the back support part. That is, since the present invention has a structure that can also reduce the influence of external vibration, the body surface pulse wave of the back part can be detected with high sensitivity in the sensing mechanism part.
In addition, by adopting a seat cushion type that is used by placing the biological signal detection mechanism of the present invention on the seat structure, it is possible to accurately detect the biological signal simply by placing it on the seat structure regardless of the type of the seat structure. it can. Moreover, it can be manufactured at a lower cost than when a dedicated seat structure is manufactured, and the cost advantage is great.

FIG. 1 is a view showing a seat cushion according to the biological signal detection mechanism of the first embodiment of the present invention. FIG. 2 is a view showing a state in which the seat cushion is mounted on the seat structure. 3 is a cross-sectional view of the center of FIG. FIG. 4A is a partially cutaway view showing the structure of the seat cushion mounted on the seat structure, and FIG. 4B is a cross-sectional view taken along the line AA in FIG. FIG. 5 is an exploded perspective view of the seat cushion. 6 is an exploded perspective view of FIG. 5 as viewed from the opposite side. FIG. 7 is a view showing an arrangement relationship of the pelvis / lumbar support member, the sensing mechanism portion, and the base cushion member. FIG. 8 is an exploded perspective view of the sensing mechanism unit. FIG. 9 is a front view showing a seat structure according to the biological signal detection mechanism of the second embodiment of the present invention. FIG. 10 is a view showing a sensing mechanism portion and a pelvis / lumbar support member provided in the seat structure of FIG. FIG. 11 is a diagram showing a body pressure distribution in Test Example 1. 12A and 12B are diagrams showing body pressure distribution at the time of maximum pressure in Test Example 2. FIG. FIGS. 13A and 13B are diagrams showing body pressure distributions when pressure is normal in Test Example 2. FIG. 14A and 14B are diagrams showing body pressure distributions when the pressure is minimum in Test Example 2. FIG. FIGS. 15A and 15B are diagrams showing body pressure distribution at the time of maximum pressure in Test Example 3. FIG. 16 (a) and 16 (b) are diagrams showing body pressure distribution at normal pressure in Test Example 3. FIG. FIG. 17 is a view showing a body pressure distribution of Test Example 4. FIG. 18 is a diagram showing the vibration transmissibility of the subject A in Test Example 5. FIG. 19 is a diagram showing the vibration transmissibility of the subject C in Test Example 5. FIG. 20 is a diagram showing the frequency analysis result of the vibration transmissibility of the subject C in FIG. FIG. 21A is a diagram showing a comparison between the conventional seat and the developed sensing seat of the vertical acceleration power spectrum of the seat in Test Example 6, and FIGS. 21B and 21C are the conventional seats. It is the figure which showed the acceleration power spectrum of the up-down direction in the chest in the developed sensing sheet, and the front-back direction. FIG. 22 is a diagram showing a comparison of the APW signal power spectrum, the acceleration power spectrum generated on the floor when the vehicle is running, and the vibration transmission characteristic of the bottom with respect to the vertical vibration input of the conventional seat in Test Example 6. is there. FIGS. 23A and 23B are diagrams showing the activity level of the autonomic nervous system by wavelet analysis of the fingertip plethysmogram in the test example 7. FIG. FIGS. 24A and 24B are diagrams showing the activity levels of the autonomic nervous system by analyzing the APW of the subject collected from the sensing mechanism unit in Test Example 7. FIG. FIG. 25A shows the quantification evaluation result of the ride quality of the sensory evaluation using the four-quadrant map, and FIG. 25B shows the evaluation result of the quantification of the vibration ride quality by the sensory response map using the APW. FIG.

  Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings. FIGS. 1-8 is a figure for demonstrating the 1st Embodiment of this invention, As shown in these figures, the biological signal detection mechanism of this embodiment is a seat structure which is a human body support mechanism. The seat cushion 200 is placed so as to overlap with the seat 100. The seat cushion 200 of the present embodiment is configured to include a back support cushion member 201 and a seat support cushion member 202, and at the boundary between the back support cushion member 201 and the seat support cushion member 202, A protruding piece 203 protruding rearward is formed. The projecting piece 203 is inserted into the gap between the seat back portion 101 and the seat cushion portion 102 of the seat structure 100, and the back support cushion member 201 is stretched on the back support portion (seat back portion 101) of the seat structure, which will be described later. It is pulled and stretched by means (see FIGS. 1 to 3).

  As shown in FIGS. 3 to 6, the sensing mechanism 230 and the base cushion member 220 are disposed on the back side of the back support cushion member 201. Specifically, both sides of a bag-like member 210 made of a cloth material are joined to the peripheral edge of the back-supporting cushion member 201, and the base cushion member 220 and the sensing mechanism 230 are inside the bag-like member 210. Is inserted and arranged. Accordingly, the base cushion member 220 and the sensing mechanism portion 230 are not fixed to the back support cushion member 201 but can be displaced in the vertical direction within the bag-like member 210.

  As the back support cushion member 210 and the base cushion member 220, it is preferable to use a three-dimensional solid knitted fabric having high rigidity in the tension direction. Note that the three-dimensional solid knitted fabric includes, for example, a pair of ground knitted fabrics arranged apart from each other as disclosed in JP 2002-331603 A, JP 2003-182427 A, and the like. It is a knitted fabric having a three-dimensional three-dimensional structure having a large number of connecting yarns that reciprocate between the ground knitted fabrics and couple them. Three-dimensional solid knitted fabric is stretched at a stretch rate of 0% and is pressed approximately perpendicularly to the surface direction. The load is determined by pressing with a compression plate having a diameter of 30 mm as the spring constant determined from the deflection characteristics. The spring constant obtained from the load-deflection characteristic when pressurized with a compression plate having a diameter of 98 mm is higher than the spring constant obtained from the deflection characteristic. With this configuration, it has characteristics similar to the load characteristics of human muscles, and it is possible to increase fit and improve posture support.

  As shown in FIG. 8, the sensing mechanism unit 230 includes a core pad 231, a spacer pad 232, a sensor 233, a front film 234, and a rear film 235.

  The core pad 231 is formed in a plate shape, and two vertically long through holes 231a and 231a are formed at symmetrical positions across a portion corresponding to the spinal column. The core pad 231 is preferably composed of a bead foam formed in a plate shape. When the core pad 231 is made of a bead foam, the foaming ratio is preferably in the range of 25 to 50 times, and the thickness is preferably less than the average diameter of the beads. For example, when the average diameter of 30 times expanded beads is about 4 to 6 mm, the thickness of the core pad 231 is sliced to about 3 to 5 mm. Thereby, soft elasticity is given to the core pad 231 and it becomes easy to produce the solid vibration which resonated to the vibration with a small amplitude.

  The spacer pad 232 is loaded in the through holes 231a and 231a of the core pad 231. The spacer pad 232 is preferably formed from a three-dimensional solid knitted fabric. When the three-dimensional solid knitted fabric is pressed by the person's back, a tension is generated in the connecting thread of the three-dimensional solid knitted fabric, and the vibration of the body surface through the human muscle accompanying the biological signal is propagated. In addition, it is preferable to use a spacer pad 232 made of a three-dimensional solid knitted fabric that is thicker than the core pad 231. As a result, when the peripheral portions of the front film 234 and the rear film 235 are attached to the peripheral portions of the through holes 231a and 231a, the spacer pad 232 made of a three-dimensional solid knitted fabric is pressed in the thickness direction. Tension due to the reaction force of the film 235 is generated, and solid vibration (membrane vibration) is likely to occur in the front film 234 and the rear film 235. On the other hand, preliminary compression also occurs in the spacer pad 232 made of the three-dimensional solid knitted fabric, and tension due to reaction force also occurs in the connecting yarn that holds the shape in the thickness direction of the three-dimensional solid knitted fabric. The surface fastener 234 a is attached to the upper portion of the front film 234 and joined to the surface fastener 220 a attached to the upper portion of the base cushion member 220, whereby the sensing mechanism portion 230 is held by the base cushion member 220. The four corners of the sensing mechanism 230 are also held by the base cushion member 220 via the tape member 230a.

  The sensor 233 is fixedly disposed on one of the spacer pads 232 before the above-described front film 234 and rear film 235 are laminated. The three-dimensional solid knitted fabric constituting the spacer pad 232 is composed of a pair of ground knitted fabrics and connecting yarns. The string vibration of each connecting yarn is applied to the front film 234 and the rear film 235 via the nodes with the ground knitted fabric. In order to be transmitted, the sensor 233 is preferably fixed to the surface of the spacer pad 232 (the surface of the ground knitted fabric). As the sensor 233, it is preferable to use a microphone sensor, in particular, a condenser microphone sensor.

  A pelvis / lumbar support member 240 is disposed on the back side of the back support cushion member 201 and below the sensing mechanism 230. As shown in FIG. 7, the pelvis / waist support member 240 swells upward and downward by bending the upper and lower edges of the three-dimensional solid knitted fabric inward and sewing the vicinity of the center. The urging member 241 in which 241a and 241b are generated and the urging member 241 are disposed on the front surface of the urging member 241. The urging member 241 is formed in a substantially rectangular shape having an area covering the front surface of the upper and lower bulges 241a and 241b. It has a flexible plate-like member 242 made of a synthetic resin that functions. The urging member 241 is folded and sewed to generate bulges 241a and 241b on both sides, whereby the elasticity is increased and the support pressure can be increased, and a feeling of stroke is generated. The flexible plate-like member 242 covers the front surface of the urging member 241 to reduce the feeling of hitting the urging member 241. Therefore, the pelvis / lumbar support member 240 of the present embodiment can function a high support pressure in the pelvis / lumbar support region while having a simple configuration.

  In the present embodiment, the urethane foam 241c is inserted and disposed in the internal space of the lower bulge 241b. The lower end edge of the base cushion member 220 has a size up to a position that covers the upper bulge 241a, and the lower bulge 241b and the urethane foam 241c are not covered by the base cushion member 220. Therefore, when a load is applied, the lower bulge 241b and the urethane foam 241c serve as starting points when the flexible plate-like member 242 bends, and obliquely below the waist from the human pelvis. A force to support diagonally upward is applied.

  Here, the pelvis / lumbar region support region is a region in which a predetermined support pressure is applied from the human pelvis to the vicinity of the lumbar region by the elasticity of the pelvis / lumbar region support member 240 and the tension of the back support cushion member 201. In Test Example 1 to be described later, the position of the pelvis / lumbar support region is set as an area up to 350 mm from the seating surface of the seat support cushion member 202, and the range further 100 mm above is set as an intermediate area. Further, the upper region was used as a shoulder rib support region (see FIG. 11). In this embodiment, when the seat cushion 200 is set on the seat structure 100, a person is seated in a static state on the seat cushion 200, and the body pressure distribution in the back support cushion member 201 is measured. It is preferable that the load sharing ratio with respect to the total load of the seated person on the back support cushion member 201 is 50% or more in the pelvis / lumbar support region. More preferably, the load sharing ratio in the intermediate region with respect to the total load of the seated person on the back support cushion member 200 is set to be 20% or less, and the both are combined in the pelvis / lumbar support region and the shoulder rib support region. The load sharing ratio is set to be 80% or more. More preferably, the load sharing rate in the intermediate region is 10% or less, and the combined load sharing rate is 90% or more in the pelvis / lumbar support region and the scapula support region. Since these ratios are relative, they are almost in this range regardless of the pressure applied to the back support cushion member 201 as in the test examples described later (see Test Examples 2 and 3). The same is true even if the reclining angle changes. For example, the seat back portion 101 of the seat structure 100 is tilted with respect to the seat cushion portion 102 until it becomes flat (substantially the same as a state in which the user lies on the bedclothes on his / her back. The same applies to (state) (see Test Example 4). It should be noted that by adjusting the thickness and material of the flexible plate-like member 242 such as the thickness of the three-dimensional solid knitted fabric constituting the urging member 241 of the pelvis / lumbar support member 240 and the size of the bulges 241a and 241b, The elasticity of the waist support member 240 can be adjusted, and the load sharing ratio can be set within the above range.

  In addition, the position setting of the pelvis / lumbar support region, the intermediate region, and the shoulder rib support region is not fixed within the above-described range. The above range is set according to the region corresponding to the pelvis and the waist and the region corresponding to the shoulder ribs when a person near the average height of a Japanese male adult sits down. Of course, since there are individual differences in body shape, the position of each region (arrangement position of the pelvis / waist support member 240, arrangement position of the sensing mechanism 230, etc.) can be individually set according to each user. .

  In the above-described sensing mechanism unit 230, the position of the sensor 233 is set to a position in the middle region, and the sensing mechanism unit 230 is predetermined from the upper edge of the pelvis / lumbar support member 240 when viewed from the front. It arrange | positions so that it may become a position spaced apart. This is to prevent the movement of the pelvis / lumbar support member 240 from affecting the sensing mechanism 230, and the separation distance is set to 10 mm or more, preferably 30 mm or more, more preferably 50 mm or more.

  The pelvis / waist support member 240 supports the vicinity of the human pelvis / waist, but preferably acts so as to press obliquely from below to above as described above. The line along the front surface of the plate-like member 242 moves away from the outline line of the back of the person that is the support object as it goes toward the upper edge, and the line along the front face and the outline line of the back of the person that is the support object It is preferable that the angle is set so that it is set within a range of 5 to 45 degrees. More preferably, the angle formed by the line along the front surface and the outline line of the back of the person to be supported is set in the range of 5 to 20 degrees.

  The seat cushion 200, which is the biological signal detection mechanism of the present embodiment, is provided with tensioning means, and this tensioning means is attached to the seat back portion 101 of the seat structure 100 and tensioned. As a stretching means for stretching the back support cushion member 201 to the seat back portion 101, the first belt member 251 that can be pulled out from the peripheral portion and provided on both sides of the shoulder rib support region, It can be set as the structure which has the 2nd belt member 252 provided in the both sides of a waist | hip | lumbar part support area | region. The first and second belt members 251 and 252 are hung around the seat back portion 101, and the length is adjusted and fixed, whereby the back portion supporting cushion member 201 is stretched as a tension structure. Further, the protruding piece 203 at the boundary between the back portion supporting cushion member 201 and the seat portion supporting cushion member 202 is inserted and sandwiched between the seat back portion 101 and the seat cushion portion 102.

  By arranging in this manner, the load received in the pelvis / lumbar support region where the pelvis / lumbar support member 240 is disposed is relatively high, and the load received in the intermediate region is relatively low. That is, according to the present embodiment, for example, even in a general seat structure 100 using a urethane material as a cushioning material, the pelvis and waist of the back support cushion member 201 can be provided by disposing the seat cushion 200. A structure in which the support load in the support region is relatively high and the support load in the intermediate region is relatively low can be easily created. Therefore, the biological signal can be detected with high sensitivity by disposing the sensor 233 in the intermediate region of the back support cushion member 201. In the present embodiment, the sensing mechanism unit 230 is provided between the back support cushion member 201 and the base cushion member 220, and includes three layers of the back support cushion member 201, the sensing mechanism unit 230, and the base cushion member 220. Since it has a structure and is disposed in the bag-like member 210, the sensing mechanism 230 and the base cushion member 220 can be displaced in the vertical direction. Therefore, the vibration transmitted from the seat structure 100 is isolated by the base cushion member 220 and its displacement. Further, since the sensing mechanism unit 230 is disposed at a predetermined distance from the pelvis / lumbar region support member 240, the sensing mechanism unit 230 is not easily affected by external vibration. In particular, in the present embodiment, a body surface pulse wave (Aortic Pulse Wave (APW): a biological signal generated by the shaking of the atrium, ventricle, and aorta) is collected from the back of the person. With this configuration, the influence of other vibrations (external vibrations, body motion components, etc.) close to the frequency component of the APW can be suppressed, which contributes to accurate detection of the APW.

  The seat cushion 200 according to the above embodiment realizes more accurate detection of a biological signal (particularly APW) regardless of the type of the seat structure 100 to be attached, that is, even when a urethane material is used as a cushioning material. However, the seat structure itself may be a biological signal detection mechanism suitable for collecting biological signals. FIG. 9 and FIG. 10 show the embodiment (second embodiment).

  That is, in the second embodiment, the seat structure 500 includes a pair of side frames 511 and 512, and upper frames 513 and 514 arranged between the upper portions of the side frames 511 and 512, as the seat structure 500, It has a frame-like back frame 510 provided with a lower frame 515 disposed between lower portions of the side frames 511 and 512. Within the range surrounded by the back frame 510, no other skeletal member is arranged and is a space.

  A pelvis / lumbar support member 520 is provided at a position slightly above the lower frame 515, that is, at a position corresponding to the vicinity of the lumbar region from the upper part of the pelvis of the seated person (pelvis / lumbar region support region). The pelvis / waist support member 520 is formed of a synthetic resin plate-like member or bead foam formed in a substantially rectangular shape having a predetermined area when viewed from the front, and an S spring that is spanned between the side frames 511 and 512. 521 is energized. The elastic force of the S spring 521 causes the pelvis / waist support member 520 to press the vicinity of the waist from the seated person's pelvis, creating a back-and-forth stroke feeling and creating a restoring force against the rotational and reciprocating motion generated in the pelvis. When the upper edge side of the pelvis / waist support member 520 is pressed, the pelvis is rotated rearward around the lower edge side, and the pelvis can be supported by a reaction force by a spring from diagonally downward to diagonally upward.

  A back base net 530 is supported by the side frames 511 and 512 and the first and second upper frames 513 and 514 of the back frame 510. By stretching the back base net 530 in this manner, the portions near the side frames 511 and 512 corresponding to the body side of the seated person become parts with small bending back and forth, and the center line of the back base net 530 The portion corresponding to the spinal column along the axis is easily bent back and forth. As a result, if an inertial force acts in the left-right direction during cornering, a rotational motion about the spinal column is likely to occur. When the rotational movement occurs, if the portion along the center line bends back and forth, the support pressure of the pelvis / lumbar support member 520 acts strongly. This prevents the body from shifting in the left-right direction. The back base net 530 can be formed from a three-dimensional solid knitted fabric, a two-dimensional net material, a laminate of a thin urethane material on a two-dimensional net material, or the like, but a three-dimensional solid knitted fabric excellent in rigidity in the tension direction is used. It is preferable.

  The front side covering member 540 is covered with a predetermined tension so as to cover the back base net 530 and the back frame 510. The front side covering member 540 is also preferably a thin three-dimensional solid knitted fabric with excellent rigidity in the tension direction. In addition, it is arbitrary to arrange | position skins, such as leather, further on the outer side of the front side covering member 540.

  The seat structure 500 includes a pelvis / lumbar support member 520, a back base net 530 and a front cover member 540 that are stretched with a predetermined tension to form a tension structure, and support the posture as described above. It has a high ability to reduce external vibration. Therefore, the back base net 530 and the front side covering member 540 correspond to the base cushion member and the back support cushion member of the above embodiment, and the sensing mechanism portion 550 similar to the above embodiment is disposed between them. . At this time, in the same manner as in the above embodiment, the sensing mechanism 550 is disposed at a predetermined distance from the pelvis / lumbar support member 520. As a result, the sensing mechanism 550 is not supported by a rigid body such as a skeleton member, but is supported in a semi-floating manner by using the tension of the back base net 530 and the front side covering member 540 which are tension structures. It will be.

  Since the back frame 510 is formed in a frame shape as described above, there is no skeletal member in the intermediate region above the pelvis / lumbar support region where the pelvis / lumbar support member 520 is disposed. Therefore, also in this embodiment, the load sharing rate of the pelvis / lumbar support region is relatively high, and the load sharing rate is relatively small in the intermediate region, so that the anti-gravity muscle can be supported in a relaxed state. Therefore, providing the sensor of the sensing mechanism unit 550 in the intermediate region contributes to accurate detection of the APW.

  In other words, the present embodiment is a structure in which a rigidity difference is generated between the skeleton and the tension structure, and the longitudinal vibration caused by the seat skeleton of the seat back portion 501 and the vertical vibration generated from the seat cushion portion 502 due to the rigidity difference. A buffer zone that relaxes in the shear direction (referred to as “shear stress zone”) is made. In other words, in the present embodiment, there is no high-rigidity posture support member such as an S spring or a hard steel wire coming from the skeleton of the seat back portion 501 in the intermediate region that is the sensing portion, and the skeleton of the seat back portion 501 is generated. It is a posture support structure that uses a tension structure that has a shock absorber that relieves longitudinal vibrations and left and right vibrations, and supports the majority of the trunk's body weight with the pelvis and lumbar support areas (the pelvis and iliac bone) It is a body-side support structure supported near the ridge. In addition, it has a shear stress structure band that can control the phase of the vertical vibration input from the bottom in a low frequency band, and the sensing mechanism moves with the trunk while the sensor and the shear stress structure band Since these are connected with a soft spring characteristic, the structure contributes to accurate detection of a biological signal.

(Test Example 1)
The male subject A (height 167 cm, weight 70 kg) is seated on the seat structure 100 having a cushion material made of urethane as the seat cushion 200 which is the biological signal detection mechanism of the first embodiment shown in FIGS. The body pressure distribution of the back support cushion member 210 in the static sitting state was measured, and the load value in each region was examined. The results are shown in FIG.

  The pelvis / waist support area is an area up to 350 mm above the seating support cushion member 202, and the upper area of the pelvis / waist support area is 100 mm above the intermediate area, and the area above that. Was used as the shoulder rib support area. As a result, with respect to the total load, the load value of the pelvis / lumbar support region: 14062.28 g, the load sharing rate: 62.36%, the load value of the intermediate region: 2085.34 g, and the load sharing rate: 9.25% The load value of the shoulder and rib support region was 6403.69 g, and the load sharing ratio was 28.40%.

  Accordingly, the configuration shown in FIGS. 1 to 8 can set the load sharing rate in the intermediate region to 10% or less, and can set the load sharing rate including the pelvis / lumbar region support region and the shoulder and rib support region to 90% or more. Recognize.

(Test Example 2)
As in Test Example 1, the seat cushion 200 of the first embodiment is set on the seat structure 100 having a urethane cushion material, and a male subject B (height 179 cm, weight 96 kg) is seated, and the body pressure distribution is determined. It was measured. At this time, when the subject B strongly presses the back against the back support cushion member 201 (maximum pressure), when the subject B leans against the back support cushion member 201 in a normal static seating state (normal pressure), Was measured with respect to the back support cushion member 201 lighter than usual (minimum pressure).

  12 (a), 13 (a), and 14 (a) show body pressure distribution on the surface of the back support cushion member 201 in a bag shape. As shown in these drawings, according to the seat cushion 200 of the above embodiment, even if the force pressed against the back support cushion member 201 is changed, the load value in the intermediate region can be relatively lowest, It can be seen that the above load is applied to the cushion member 201 for supporting the back of the surface, the pelvis / lumbar support region, and the shoulder rib support region.

  FIGS. 12B, 12 </ b> B, and 12 </ b> B show body pressure distribution on the inner surface of the base cushion member 220 disposed in the bag-like member 210. As shown in these figures, since the base cushion member 220 and the back support cushion member 201 are formed in a bag shape by the bag-like member 210, the back support cushion member 201 has a predetermined tension in the surface direction. In addition, since it is stretched around the seat back portion, it can be seen that almost no load is applied to the intermediate region of the base cushion member 220 even when a pressing force acts on the surface.

  Therefore, according to the seat cushion 200 of the above embodiment, it can be seen that the support pressure of the human body in the intermediate region is extremely small, and this range does not function as a transmission path for external vibration. Therefore, it can be seen that by setting the sensor 233 of the sensing mechanism unit 230 in this range, detection of a biological signal can be performed more accurately than in the past.

(Test Example 3)
When a male subject C having a height of 169 cm and a weight of 61 kg is seated on the seat structure 1 and his back is strongly pressed against the back support cushion member 201 (maximum pressure), the back support cushion member 201 is in a normal static seating state. The test similar to Test Example 2 was carried out when leaning (normal pressure).

  As a result, as shown in FIGS. 15 (a) and 16 (a), on the surface of the back support cushion member 201, in any case, the load values in the intermediate region are the pelvis / lumbar support region and the scapula support region. It was relatively lower than the combined load value. Further, as shown in FIGS. 15B and 16B, on the inner surface of the base cushion member 220, in any case, almost no load is applied to the intermediate region, and the physique difference of the seated person Regardless of this, it can be seen that the support pressure of the human body in the intermediate region can be lowered, and the structure is suitable as a biological signal detection mechanism.

(Test Example 4)
The seat cushion 200 of the above embodiment is set on the urethane seat structure 100, and the seat back part of the seat structure 100 is reclined until it becomes flat with the seat cushion part, and the male subject D having a height of 171 cm and a weight of 67 kg is supine. It was. The pressure distribution at that time is shown in FIG. As is apparent from this figure, the load value of the back support cushion member 201 is relatively the lowest in the intermediate region even in such a supine posture, and a large amount of load is applied to the pelvis / lumbar support region and the shoulder ribs. It turns out that it is provided to the support area. Therefore, it can be seen that even in such a supine posture, the configuration of the seat cushion 200 of the present invention can detect a biological signal more accurately.

(Test Example 5)
The seat cushion 200 of the above embodiment is set on the seat structure 100 having a urethane cushion material and installed on a vibration exciter, and the male subject A of Test Example 1 and the male subject C of Test Example 3 are respectively set. Sitting in a sitting posture, the input vibration was changed from 0.5 Hz to 15 Hz, and vibration was applied by vibration in a vertical direction with a sine wave log sweep having an amplitude on one side of 1 mm (amplitude between peaks 2 mm). FIG. 18 shows the test results of subject A, and FIG. 19 shows the test results of subject C.

  From these figures, the vibration transmissibility of the surface layer of the intermediate region in the frequency band of the biological signal is 0.2 to 0.3 near 10 Hz, and external vibration is difficult to be transmitted in the intermediate region. It can be seen that the detection accuracy of the biological signal can be improved by arranging the portion.

  20 shows the vibration transmissibility of the intermediate region on the surface of the back support cushion member 201 of the subject C in FIG. 19 (indicated as “normal pressure / front side” in FIG. 20) and the inner surface of the base cushion member 220 (in FIG. It is the figure which showed the frequency analysis result of the vibration transmissibility of the pressure normal / inside the bag. As is clear from this figure, it can be seen that the base cushion member 220 (inside the bag) has a very small transmission of external vibrations and can block external vibrations.

(Test Example 6)
The seat structure 500 (development sensing seat) according to the second embodiment, and a conventional type in which a urethane material having an average thickness of 50 to 70 mm is laminated as a cushion material on the S spring and the cushion pan in the seat back portion and the seat cushion portion. Comparison was made with a urethane sheet (conventional sheet). In the test, each seat was placed on a shaker, a male subject A was seated, the input vibration was changed from 0.5 Hz to 15 Hz, and up and down by a sine wave log sweep with one side amplitude of 1 mm (peak-to-peak amplitude of 2 mm). Vibration was transmitted by directional vibration and the vibration transmissibility was measured.

FIG. 21 (a) shows a comparison of the vertical acceleration power spectrum of the seat using the conventional seat and the developed sensing seat. It can be seen that the acceleration response in the vertical direction of the seat has no significant difference up to around 5 Hz, and that the developed sensing sheet has higher vibration absorption after 5 Hz. FIGS. 21B and 21C show acceleration power spectra in the vertical direction and the front-rear direction in the chest (corresponding to the intermediate region) which is a so-called sensing space in the conventional seat and the developed sensing seat. The developed sensing sheet shows high vibration absorption from the band of 5Hz or more in the vertical and longitudinal vibrations, tends to be lower than the acceleration value of 0.1m / s ² , and is well controlled in terms of vibration sensitivity. It can be said. This is considered to be an effect of the above-described shear stress structure in the seat back portion, and is due to phase control in a band of 5 Hz or more. On the other hand, the case of the conventional sheet exceeds 0.1 m / s ² even in a band of 5 Hz or more. This is easy to feel vibration from the viewpoint of vibration sensitivity, and is not phase-controlled, and the vibration absorption effect by the S spring arranged at the upper back is small. On the contrary, it can be seen that it is a vibration transmission path.

  FIG. 22 shows a comparison of the APW signal power spectrum, the acceleration power spectrum generated on the floor when the vehicle is running, and the vibration transmission characteristics of the bottom of the seat with respect to the vertical vibration input of the conventional seat. From this figure, it can be said that the natural frequency of the back skeleton is preferably between 40 and 50 Hz indicated by the arrow a, avoiding the frequency band input from the vehicle. In addition, the natural frequency of the tension structure that becomes the shear stress structure band and the cushion material provided in the seat back part is 8 Hz that is the visceral resonance frequency of the trunk and 10 Hz that feels a sensitive joint shock by vertical vibration. It is preferable to set it in the vicinity of 4 to 5 Hz indicated by the arrow b.

(Test Example 7)
A biological signal sampling experiment was performed on the seat cushion 200 according to the biological signal detection mechanism according to the first embodiment and the seat structure 500 according to the biological signal detection mechanism according to the second embodiment. Specifically, the seat structure 500 of the second embodiment is directly attached to a vertical electrodynamic single-axis vibrator, and the seat cushion 200 of the first embodiment is a conventional one using a urethane material as a cushion material. The mold sheet was set and attached to the same uniaxial vibrator as described above, and each was subjected to vibration for 1 hour to conduct a physiological index measurement experiment under dynamic conditions. The subjects were healthy adult men in their 30s. The excitation waveform is a random waveform with an average acceleration amplitude of the vertical component of 0.98 m / s ² and a maximum acceleration of 4.9 m / s ² . This random waveform is a waveform taken from the floor when traveling on a highway in Michigan, USA at about 100 km / h by SUV. The subject measured the APW by sitting on both seats and capturing the detection signals of the sensors of the sensing mechanism units 230 and 550. The state of the subject was evaluated by quantifying the vibration ride comfort using a sensory response map using APW, and the ride comfort quantification evaluation using a four-quadrant map as a comparative index was also performed.

  FIGS. 23A and 23B show the activity level of the autonomic nervous system by wavelet analysis of the fingertip volume pulse wave of the subject. 24A and 24B similarly show the activity level of the autonomic nervous system by analyzing the APW of the subject collected from the sensing mechanisms 230 and 550. FIG. Both are the results of the seat structure 500 according to the second embodiment, and (b) are the results of the seat cushion 200 according to the first embodiment mounted on the conventional seat. 23 and 24, it can be seen that the increasing / decreasing trends of HF and LF / HF are relatively consistent. In the case of the seat cushion 200 according to the first embodiment attached to the conventional seat, it can be said that the correlation is recognized, but the relative tendency is captured in 3300 to 3600 seconds.

  FIG. 25A shows the quantification evaluation result of the ride quality of the sensory evaluation using the four-quadrant map, and FIG. 25B shows the evaluation result of the quantification of the vibration ride quality by the sensory response map using the APW. Indicates. This is a graph in which a tilt time-series waveform is created from an APW original waveform, frequency-analyzed, and a waveform of a frequency analysis result is scored and plotted based on a certain standard.

  Both the seat structure 500 according to the second embodiment and the seat cushion 200 according to the first embodiment mounted on the conventional seat shift in the depressing direction over time, and the sensory evaluation and the sense by the APW The relative comparison of response maps is considered to have been made. From this result, it can be seen that the seat structure 500 of the second embodiment and the seat cushion 200 of the first embodiment mounted on the conventional seat capture the APW well, and the sensing performance is almost equivalent. You can see that

200 Seat Cushion 201 Back Support Cushion Member 210 Bag-shaped Member 220 Base Cushion Member 230 Sensing Mechanism 233 Sensor 240 Pelvis / Lumbar Support Member 241 Energizing Member 242 Flexible Plate Member 500 Seat Structure 510 Back Frame 520 Pelvis / Lumbar support member 530 Back base net 540 Front cover member 550 Sensing mechanism

Claims (10)

A back support cushion member;
A base cushion member disposed on the back side of the back support cushion member;
A bag-like member that covers an outer surface of the base cushion member, a side edge portion is joined to a side edge portion of the back support cushion member, and supports the base cushion member inside;
A sensing mechanism that is disposed as an intermediate layer between the back support cushion member and the base cushion member and collects a biological signal from the back of the seated person;
The back support cushion member is disposed on the back side of the back side of the sensing mechanism portion so as to be spaced apart from the sensing mechanism portion. The back support cushion member is urged forward, and the back support cushion member and the base cushion member A pelvis / lumbar support member that forms a clearance for disposing the sensing mechanism portion on the back, reduces a load input to the back support cushion member, and absorbs movement of the pelvis due to breathing and body movement; And a biological signal detection mechanism that is stretched and used on the back support portion of the human body support mechanism.   The biological signal detection mechanism according to claim 1, wherein the biological signal detection mechanism is stretched on a back support portion of the human body support mechanism by a belt member extending outward of the back support cushion member.   The biological signal detection mechanism according to claim 1, wherein a load sharing ratio by the pelvis / waist support member is 50% or more with respect to a total load of a seated person applied to the back support cushion member.   The load sharing ratio with respect to the total load of the seated person on the back support cushion member is set to 20% or less in the intermediate region where the sensing mechanism portion is arranged, and the pelvis / lumbar portion where the pelvis / lumbar support member is arranged 4. The biological signal detection mechanism according to claim 3, wherein the support area and the scapula support area are set to 80% or more in total.   The pelvis / lumbar support member is separated from the outline line of the back of the person to be supported as the line along the front faces toward the upper edge, and the line along the front and the back of the person to be supported The biological signal detection mechanism according to any one of claims 1 to 4, wherein an angle formed with the outer shape line is set in a range of 5 to 45 degrees.   The biological signal detection mechanism according to claim 1, wherein the base cushion member and the back support cushion member are formed of a three-dimensional solid knitted fabric. The sensing mechanism part has a predetermined thickness, a core pad having a through-hole of a predetermined area penetrating in the thickness direction;
A spacer pad disposed in a through hole formed in the core pad;
A sensor disposed in the through hole together with the spacer pad;
The front and rear films according to any one of claims 1 to 6, further comprising a front film and a rear film that cover the spacer pad and the sensor disposed in the through-hole and are laminated in close contact with the front and back surfaces of the core pad, respectively. The biological signal detection mechanism according to 1.   The biological signal detection mechanism according to claim 7, wherein the core pad is formed from a bead foam, and the spacer pad is formed from a three-dimensional solid knitted fabric.   The biological signal detection according to any one of claims 1 to 8, wherein the human body support mechanism is a seat structure, and is a seat cushion type that is stretched on a back support portion and used by being placed on the seat structure. mechanism.   A seat structure integrated type in which the base cushion member and the back cushion member are supported by a back frame of a back support portion of the seat structure, the sensing mechanism portion is disposed therebetween, and is integrated into the seat structure. Item 9. The biological signal detection mechanism according to any one of Items 1 to 8.