JP2006000200A - Chair cushion and wheelchair with the cushion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chair cushion capable of suppressing the occurrence of high pressure or extreme pressure concentration despite individual differences in sitting postures and buttocks shapes, providing superior sitting comfort and suppressing the development of the decubitus even if being used for a long period of time and to provide a wheelchair having the cushion. <P>SOLUTION: This chair cushion is provided with a buffer part 2 composed of a material having a small repulsive property and supporting the buttocks; a support part 3 having a buttock support part 3a supporting at least the sacrum, the coccyx and the both gluteus maximus muscles excluding the ischial tuberosity part in the rear part of the buttocks, and a thigh support part 3b, and composed of a material having the largest repulsive property compared with other materials; and a seat pressure dispersing/following part 4 having a hole or a groove 4a fitted with the buffer part 2 in the central part, composed of a material having a repulsive property smaller than or similar to the support part 3, having at least one part positioned in the lower part of the support part and substantially disposed across the whole area of the seat part, and dispersing the seat pressure to the whole area of the seat part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cushion used for a seat portion such as a chair or a wheelchair, and more particularly to a body pressure distribution structure in the cushion, and a wheelchair including the cushion.

  If you sit on a chair such as a general chair, seat chair, or wheelchair for a long time, the buttocks will hurt, floor slippage, and wounds may occur. The structure is devised to disperse the body pressure when sitting there (see, for example, Patent Documents 1 to 7).

  For example, the functions and required items required for a sitting environment and chair cushions for a wheelchair are summarized as follows. Regardless of the wheelchair, the living body is subjected to mechanical stress (pressure) to the action of sitting, and the influence is generated. FIG. 10A, which will be described later, shows a body pressure distribution in a state where a person is sitting on a wheelchair. The body pressure distribution exhibits a plurality of isobaric distributions centered on the two left and right ischial nodules. In general, a portion having a high pressure in the central portion has a problem in that it greatly deforms the living body, mechanically damages skin, fat, muscle, and the like, and at the same time compresses blood vessels to inhibit blood flow. In particular, in a portion where the bone is close to the surface of the living body, there arises a problem that stress on the living body due to pressure increases.

  FIG. 15 is an explanatory view of bones and muscles of the limbs related to the description of the present invention to be described later, (a) is a rear view, (b) and (c) are side views, and (b) is only a bone. Indicates. In FIG. 15, a, b, c, d, e, f, and g are the sciatic nodule, the tailbone, the sacrum, the iliac crest, the hipbone, the greater trochanter, and the spinal column (illustrated by the alternate long and short dash line). A, B, C and D are the gluteal muscle, the biceps femoris, the semi-tendon-like muscle and the semi-membranous muscle, respectively. The three muscle groups of the biceps femoris, semi-tendon-like muscle, and semi-membranous muscle are collectively called hamstring muscles. In the above-mentioned hipbone, the three bones of the iliac bone, the sciatic bone, and the pubic bone are distinguished until the adolescence and are in a cartilage-coupled state. In adults, however, the cartilage is ossified and the three bones are fused together. Become an individual hipbone. Furthermore, the skeleton composed of the left and right hipbone, sacrum, and tailbone is called the pelvis. FIG. 16 shows a rear view of the pelvis. The pelvis is the most gender-related part of the skeleton.

By the way, bones close to the surface of the living body related to the occurrence of the problem in the sitting are sciatic nodules, coccyx, and sacrum, and occurrence of pressure ulcer is also recognized in the site.
In addition, the pressure environment changes greatly depending on the posture of the body when sitting. FIG. 17 is a diagram illustrating a typical example of how to sit in a poor posture. FIG. 17 (a) shows a so-called sitting state of a front sitting, which is a sitting method in which the pelvis is tilted backward. The front sitting is a sitting method often seen especially in the elderly. In this case, in addition to the sciatic nodule, a high pressure portion appears in the coccyx and sacrum, and the sciatic nodule portion also moves forward. FIG. 17B shows a sitting method in which the pelvis is inclined. In this case, pressure is concentrated on one side of the left and right. Further, FIG. 17C shows a sitting method in which the pelvis rotates, and in this case, pressure concentration also occurs. Even when the pressure environment changes due to the above-mentioned collapse of the sitting posture, the cushion is required to stabilize the posture (pelvis), minimize the deformation of the buttocks shape, and reduce the rise in pressure. The The three-dimensional curved surface shape of the buttocks in the seated state is determined by the pelvic state and the accompanying muscles and fats such as the gluteal and hamstring muscles.

  Also, considering the pressure ulcers in particular, the following points need to be considered for the cushion. The cause of pressure ulcers is not only the pressure on the skin, but also other factors. The points generally considered as factors that cause pressure ulcers (bed sores) are pressure, displacement, wetting, bone protrusion, and nutrition. Among them, there are three external effects: pressure, displacement, and wetting. The displacement force is related to friction with the living body, and the wetness is related to an increase in temperature and humidity. The wet state causes skin damage due to a decrease in skin strength, an increase in bacteria, and the like. It becomes a factor. Further, the bone protrusion is considered to be a factor that increases the above-described pressure / displacement force, and the bone protrusion parts are four parts of the sciatic nodule a, the tail bone b, the sacrum c, and the greater trochanter f in FIG. It is.

  As a configuration of the chair cushion, various configurations have been proposed from the viewpoint of meeting the above demands (see Patent Documents 1 to 7). Firstly, Patent Document 1 quotes the description of the publication as follows: "In the portion of the chair that supports the buttocks or the like with the seat or mattress, the body pressure is dispersed without abruptly changing the repulsive force of the cushion depending on the position. Disclosure of cushion structures aimed at providing a cushion structure that does not hurt the body even when used for a long time, and a wheelchair or mattress equipped with the cushion structure, and wheelchairs and mattresses using the cushion structure Yes.

  FIG. 25 is a side view of the wheelchair disclosed in Patent Document 1 as FIG. 1, and the cushion is shown as the seat portion 11. According to the description of Patent Document 1, the wheelchair of FIG. 25 is “a seat portion 11 configured substantially horizontally, an armrest 13 standing on both sides thereof, and a backrest that stands obliquely upward from the rear end portion of the seat portion 11. The vehicle body 10 having the portion 12 and a large-diameter rear wheel 51 located on the side of the armrest 13 are roughly configured.The rim of the large-diameter rear wheel 51 is not shown. " The other part numbers and the entire description in FIG. 1 are omitted (refer to Patent Document 1 for details).

  Next, the cushion structure described in Patent Document 1 will be described based on FIGS. 23 and 24 disclosed in the publication. 23 is a perspective view of a seat cushion used for the seat portion of the wheelchair shown in FIG. 25, and FIG. 24 is an exploded view of the left half of the seat cushion shown in FIG. The seat cushion has the following configuration. That is, “the first cushion material 74 that supports the buttocks with a small repulsive force, the second cushion material 75 that supports the thigh side with a larger repulsive force than the cushion material, and a large repulsive force around the first cushion material 74. The third and fourth cushion materials 76 and 77 are joined obliquely so that both cushion materials overlap each other at their joint portions, and the first and second cushion materials 74 and 75 are the upper layers thereof. A thin upper layer side cushion 73 having a larger repulsive force than the first cushion material 74 is provided on the side, and a lower layer side cushion 71 having a larger repulsive force than the first cushion material 74 is provided on the lower layer side. . "

  According to the configuration of the seat cushion described above, “the cushion materials having different repulsive forces are joined obliquely so as to overlap each other, so that a sudden change in the repulsive force of the cushion can be reduced in this portion. Therefore, the body pressure does not concentrate at the joint part or locally, so the body does not hurt even if it is used for a long time, and the repulsive force is continuously changed to the optimum state in the surface direction of the cushion. In the seat part provided with the cushion structure, since the entire collar part is supported by the cushioning material, the upper body can be stably held.

  Next, Patent Document 2 will be described. FIG. 20 is a perspective view of a main part of the sitting position holding cushion disclosed in Patent Document 2. According to the description of the publication, the cushion shown in FIG. 20 is “the bottom surface 51 is a flat plate having cushioning properties, and is a crotch wall that is raised like a bank in the middle of the front portion with ischial holes 52 and 53 at the center of the bottom surface. 54. Then, a horseshoe-shaped staircase ridge 55 is provided from the rear to both sides. ”With the above configuration,“ the seated bone can be stabilized in the sitting position, and the femoral head inversion "By reducing the posterior tilt of the pelvis and suppressing the R-shaped spine, the burden on the upper body and the lumbar spine and the compression of the internal organs can be reduced."

  Patent Document 2 also includes the following description. That is, “the seat-holding cushion is formed by integrally molding a resin-based foam material such as synthetic rubber, urethane rubber, polyethylene, etc.” and “a staircase-shaped ridge wall embankment”. No. 55 is a horseshoe shape with reference to the shape of the periphery of the buttocks and the body pressure distribution of the seat surface, and the bank is stepped for the purpose of increasing the repulsive force of the cushion.

  Next, Patent Document 3 will be described. According to the description of the publication, the cushion material disclosed in Patent Document 3 is “in a cushion material partially including a seat portion that receives the weight of a user in a concentrated manner, the seat portion being a first cushion body. The second cushion body and the third cushion body are laminated in order in the thickness direction, and the first cushion body is lower in hardness than the second cushion body and the thickness is the second in the seating portion. The thickness of the third cushion body is greater than that of the second cushion body, and the thickness of the third cushion body is smaller than the thickness of the second cushion body in the seating portion. Cushion material. " With this configuration, "providing a comfortable feeling without raising the bottom and feeling of bottoming even if the user's weight increases or decreases under the condition that the overall thickness of the cushion material is kept within a certain range. In addition, if the concave portion for detachably holding the first cushion is formed in the width direction of the second cushion body, it is easy to replace the first cushion body according to the body shape and preference of the user. "I can do it."

  Next, Patent Document 4 will be described. FIG. 21 shows a cushion seat provided on a seat chair disclosed in Patent Document 4. In FIG. 21, 81 is a seating surface, 82 is a backrest surface, 83 is a cushion sheet, 84 is a space for pressure ulcer, 85 is a space for spine, and 87 is a seat chair. According to the description of the publication, the cushion sheet of FIG. 21 is “a cushion sheet comprising a seating surface and a backrest surface following the rear end of the seating surface, and a seated person in the center of the rear end of the seating surface. The space around the caudal bone and the pressure ulcer part is provided so that it does not hit, and the space part that prevents the spine part from hitting the central part of the back surface is provided. According to the above configuration, “there is a space for preventing pressure sores and bent or protruding spines from hitting, The effect of being able to spend comfortably for a long time without causing pain in the sitting position or raising the body in a bed and moving with a wheelchair or a vehicle is produced.

  Next, Patent Document 5 will be described. 22A and 22B show the seat cushion disclosed in Patent Document 5, wherein FIG. 22A is a perspective view thereof, and FIG. 22B is a diagram showing a relationship between the seat cushion and the skeleton. In FIG. 22, 56 is a sheet plate, 57 is a recess, and 58 is a film. According to the description of the publication, the seat cushion of FIG. 22 is provided with “a recess 57 for accommodating the sciatic bone in the seated state at the rear edge portion of the seat plate 56 formed of the elastic material, The concentration of pressure is suppressed, and the body pressure is dispersed in the flat buttocks and thighs, so that the buttocks are less likely to hurt. "

  Next, Patent Document 6 will be described. FIG. 18 is a wound prevention mat disclosed in Patent Document 6. In FIG. 18, 1a is a rectangular parallelepiped gel body, 2a is a cover material covering the entire surface, and a part thereof is cut out in the figure, and 3a is a seal portion of the cover material. According to the description of the publication, the wound prevention mat shown in FIG. 18 is “the flexibility of the entire gel body is increased by the air bubbles enclosed in the gel body. The cross-linking density of the gel body can be increased. As a result, separation of the gel body does not occur and it does not lose its shape, a good body pressure dispersion effect can be obtained, and the specific gravity of the gel body having a specific gravity of approximately 1 or more. By substituting a part with bubbles, the weight of the gel body is reduced and the operability of the mat is improved. ”

  Next, Patent Document 7 will be described. FIG. 19 shows a seat system disclosed in Patent Document 7. According to the description of the publication, “the seat system (2b) in FIG. 19 includes a base member (6b) having an upper surface (8b) and a fluid pad (7b) placed on the upper surface (8b). The upper surface (8b) is contoured and dimensioned to have areas (12b, 14b, 16b) corresponding to the rough surface and coccyx of the user's ischia with the user's femur including the trochanter. The fluid pad (7b) in the preferred embodiment is a single item and has at least three separate pouches (1b, 3b, 5b) filled with fluid, each pouch being in it. Each of the pouches of the pad (7b) is connected to the upper surface (8b) of the base member (6b) to contain fluid and to prevent and isolate communication with the fluid in the other two pouches. ) On the rough surface of the user's sciatus and below the tailbone, respectively. The face and tailbone are supported by their own separate fluid pouches, "and" with such an arrangement, the user's sciatic bone can be roughened by appropriately adjusting the amount of fluid in each pouch. " The surface and coccygeal support pressures can be made substantially equal or different as desired. "

Japanese Patent Laid-Open No. 9-51918 JP-A-8-140784 JP 2002-165676 A Utility Model Registration No. 3092029 JP 2003-394 A Japanese Utility Model Publication No. 6-10980 Special Table 2000-513591

  By the way, in the case of the conventional cushion disclosed by the said patent documents 1-7, although the structure which can respond to a part of subject requested | required of the cushion for chairs and a wheelchair is provided, the following problems are included. there were. In describing individual problems, the main points of the above-mentioned problems of chair cushions are summarized as follows.

Problem (1): Suppressing high pressure and extreme pressure concentration. In particular, it suppresses pressure concentration on the sciatic nodule, sacrum, coccyx, and greater trochanter of the femur.
Problem (2): Regardless of the sitting posture such as the front sitting, the pressure concentration can be suppressed in any sitting posture. More preferably, it has a function of preventing an unsatisfactory posture such as a front seat or a tilted seat.
Problem (3): The improvement of the problems (1) and (2) can be realized by adapting regardless of a wide variety of buttocks shapes based on individual differences.
Problem (4): Furthermore, in addition to realizing the above functions, in order to prevent the occurrence of pressure ulcers, it is possible to improve air permeability and suppress an increase in temperature and humidity.

  In light of the above problems, the cushions of Patent Documents 1 to 7 are considered, and although the configurations that individually solve or partially solve each problem are recognized, the problems (1) to (3) are comprehensive. There is nothing that has a configuration that solves this problem. First, in the case of Patent Document 1, since the cushion materials having different repulsive forces are joined obliquely so as to overlap vertically, the various patents mentioned above are effective in suppressing high pressure and extreme pressure concentration. It can be said that it has the most preferable configuration in the literature. However, in the case of the configuration of Patent Document 1, as described above, “the second cushion material 75 supporting the thigh side, and the third and fourth cushion materials 76 and 77 having a large repulsive force around the second cushion material 75. However, the above-mentioned problems (2) and (3) cannot be achieved because there is no “component that supports the back surface of the collar”. Details of this reason and the problems of the prior art described later will be described in detail in comparison with the prior art in the description of embodiments of the present invention described later.

  By the way, when the prior art is limited to the above-mentioned “constituent member that supports the back portion of the collar portion”, the constituent member is disclosed in Patent Document 2. That is, in Patent Document 2, as described above, “the staircase-like dam part embankment 55 is molded into a horseshoe shape with reference to the shape around the buttock and the body pressure distribution of the seat surface, and the repulsive force of the cushion For the purpose of increasing the height of the bank, the bank is staircase-shaped. " However, the horseshoe-shaped buttocks ridge 55 of Patent Document 2 has a structure that promotes compression of the sacrum and coccyx, which are sites where the pressure ulcer is frequently generated. Further, in Patent Document 2, there is no configuration related to the combination of cushion materials having different repulsive forces as described in Patent Document 1, so that the problem of pressure concentration cannot be avoided as a whole.

  In addition, it is related with the structure which supports the back part of a buttocks, and the patent document 4 is "the structure which provided the space part which avoided the pressure-cushion part around the tail bone of a seated person" in patent document 5, Discloses a “configuration provided with a recess 57 in which a sciatic bone is accommodated in a sitting state”, but in these cases as well, there is a problem with local pressure concentration due to a poor sitting posture or the like.

  The remaining inventions of Patent Documents 3, 6 and 7 are also aimed at suppressing pressure concentration and aiming at a body pressure dispersion effect and a pleasant feeling of use, but all support the back part of the buttocks. There is no disclosure of the configuration, and it does not have a configuration in which a sufficient solution has been taken regarding the suppression of pressure concentration as a whole.

  This invention has been made in view of the above problems, and the problem of the present invention is that it is possible to suppress the occurrence of high pressure and extreme pressure concentration regardless of individual differences in sitting posture and buttocks shape, An object of the present invention is to provide a cushion for a chair that is comfortable to sit on and that can suppress the occurrence of pressure sores even when used for a long time, and a wheelchair including the cushion.

  In order to solve the above-described problems, the present invention provides a cushion for a chair used in a seat such as a chair or a wheelchair, a cushioning portion made of a material having a low resilience, and supporting the buttocks, and at least the sacrum, coccyx, and sciatic nodules behind the buttocks A support portion made of a material having the greatest resilience compared to other materials, and a buffer portion at the center portion. Having a hole or groove to be inserted, made of a material having a smaller resilience or equivalent to the support portion, at least a part of which is disposed below the support portion and substantially over the entire seat portion; And a seat pressure dispersion follower that disperses the seat pressure over the entire area of the seat (claim 1). In the above, a material having a small resilience means a material having a large strain (deformation amount) with respect to the same stress (body pressure). In general, a material used as a cushioning material is preferably a material having a large initial elasticity (hardness) and a small increase in stress in the middle of deformation (low rebound). In view of the rebound of the generated stress, a material having a small difference in energy consumption (hysteresis loss) between loading and dewetting and a small rebound resilience (resilience or rebound) is preferable.

  According to the first aspect of the present invention, since the buffer portion, the support portion, and the seat pressure dispersion follow-up portion are made of materials having different resilience, the generation of high pressure and extreme pressure concentration can be suppressed as a whole. . In addition, “a material that has at least a buttocks support part that supports both the great gluteal muscle parts excluding the sacrum, coccyx, and sciatic nodule part, and a thigh support part at the back of the buttocks, and has the greatest resilience compared to other materials. The structure with the `` supporting part '' makes it possible to support the posterior part of the buttocks while avoiding the site where many pressure ulcers occur, so it is possible to suppress pressure ulcer generation and pressure concentration due to accurate pelvic support. A correct sitting posture is inevitably corrected. In addition, by designing the shape of the buttock support portion so as to appropriately support the pelvis obliquely from behind, it is possible to further suppress the occurrence of high pressure and extreme pressure concentration regardless of individual differences in sitting posture and buttock shape. In addition, in the said support part, although it is preferable that the collar part support part is a material with large resilience compared with another support part, equivalent resilience may be sufficient. In particular, in the case of integral molding, it is preferable from the viewpoint of facilitating manufacturing that the same resilience is achieved. Further, the resilience of the seat pressure dispersion follow-up part and the support part may be the same.

  The embodiments of the invention of claim 1 are preferably the inventions of claims 2 to 5 below, but are not limited to the configurations of these embodiments. The effects of the invention of claim 1 and the embodiments of claims 2 to 5 and other embodiments (other variations) different from the embodiments will be described in detail later.

  First, the chair cushion according to claim 1, wherein the support portion is provided at an upper portion of an outer peripheral portion of the seat pressure dispersion follow-up portion, and has a hole through which at least the buffer portion can be penetrated at a central portion thereof. (Claim 2). Further, in the chair cushion according to claim 2, the support portion is provided in a frame shape on the outer peripheral portion of the seat pressure dispersion follow-up portion, and the buttocks support portion abuts against the lower rear portion of the buttocks. It is provided on both sides of one side of the frame (claim 3). By the said embodiment, generation | occurrence | production of a high pressure and extreme pressure concentration can be suppressed as a whole, and generation | occurrence | production of pressure sores can also be suppressed. In addition, you may make it provide the hole of the same shape as a buffer part only in the part which fits the said buffer part, without making the said support part into a frame shape.

  Further, in the chair cushion according to claim 3, the frame-shaped support portion is provided for preventing the greater trochanter contact in the femur on two sides orthogonal to one side of the frame contacting the back of the buttocks. A notch is provided (claim 4). Thereby, the pressure concentration of the greater trochanter part can be avoided. Furthermore, the cushion for chairs of any one of the said Claim 1 thru | or 4 WHEREIN: As for the said buffer part, the outline of the seat surface has predetermined | prescribed centering on the three sides of the triangle which connects a coccyx and both sciatic nodules. It is characterized by having a wavy trajectory line along the constant pressure line and having a polygonal star shape as a whole (Claim 5). As will be described in detail later, the body pressure acting on the buffer portion can be gradually dispersed (gradation) in the support portion in the polygonal star-shaped portion, and the body pressure dispersion effect can be improved.

  Although not provided with the function of the support portion as described above, the invention of claim 6 below is preferable when the main purpose is to improve the body pressure dispersion effect. That is, in a cushion for a chair used for a seat such as a chair or a wheelchair, a cushioning portion made of a material having a low resilience and supporting a heel portion and a material having a resilience larger than the cushioning portion, and the cushioning portion is inserted in a central portion. And a seat pressure dispersion follow-up portion that is disposed substantially over the entire seat portion and distributes the seat pressure over the entire seat portion, and the buffer portion has a contour of the seat surface. Has a wavy trajectory line along a predetermined isobaric line centering on three sides of a triangle connecting the coccyx and both ischial nodules, and has a polygonal star shape as a whole (Claim 6). .

  The cushion for a chair according to any one of claims 1 to 6, wherein the cushion portion is disposed over the entire seat portion above the buffer portion and the support portion, or the buffer portion and the seat pressure dispersion follow-up portion. It is characterized by comprising a seating part made of a material having a higher resilience or an equivalent material (Claim 7). Thereby, sitting comfort can be improved. Furthermore, the cushion for chairs of any one of the said Claim 1 thru | or 5 or 7 WHEREIN: As for the said support part, the buttock support part and the thigh support part are divided and arrange | positioned mutually independently. It is characterized (claim 8). Thereby, although the number of parts increases, functions, such as a support function and a body pressure dispersion | distribution function, become clear, and it can improve sitting comfort.

  Further, in the chair cushion according to any one of claims 1 to 8, the mutual contact surfaces of the buffer portion, the support portion, the seat pressure dispersion follow-up portion, or the seating portion are different from each other with respect to the seat pressure. It is an adhesive state in which can move freely, or a non-adhesive state or a loose fit state. Thereby, since the deformation of each member accompanying the body pressure does not inhibit the body pressure dispersion function of the adjacent members, the body pressure dispersion function can be improved as compared with the case where the members are bonded.

  Furthermore, the cushion for chairs of any one of the said Claim 1 thru | or 9 WHEREIN: The material of the said buffer part, a support part, a seat pressure dispersion | distribution follow-up part, or a seating part shall be urethane foam which has air permeability. It is characterized (claim 10). Thereby, the pressure sore generation environment is improved, and the effect of suppressing pressure sore generation is improved.

  Furthermore, the cushion for chairs of any one of the said Claim 1 thru | or 10 WHEREIN: The said buffer part, a support part, a seat pressure dispersion | distribution follow-up part, or a seating part is an outer package in which these members are included comprehensively. The material of at least the seating surface of the outer wrapping is formed by antibacterial and water repellent treatment (claim 11). Thereby, safe use and easy handling of the cushion can be achieved.

  Finally, as a wheelchair, the chair cushion according to any one of claims 1 to 11 is provided (claim 12).

  According to the present invention, it is possible to suppress the occurrence of high pressure and extreme pressure concentration regardless of the individual posture of the seating posture and the shape of the buttocks, it is comfortable to sit down, and the occurrence of pressure ulcers can be suppressed even after prolonged use. A chair cushion and a wheelchair including the cushion can be provided.

  Embodiments of the present invention will be described with reference to the drawings. First, a basic embodiment and its modification will be described with reference to FIGS. FIG. 1: shows the chair cushion of this invention, (a) is the perspective view, (b)-(f) saw the left half which divided | segmented the cushion for chairs shown to (a) by AA '. In the figure, (b) is a rear view thereof, (c) is a left side view thereof, (d) is a plan view thereof, (e) is a right side sectional view thereof, and (f) is a front view thereof. FIG. 2 shows an exploded view of a basic embodiment of the chair cushion of the present invention and its modification, wherein (C), (D), and (E) are exploded views of different embodiments, respectively (A ), (B) are exploded partial views for convenience explaining the function of the embodiment of (C).

  1 and 2, 1 is a cushion for a chair, 2 is a buffer portion, 3 is a support portion, 4 is a seat pressure dispersion follow-up portion, and 5 is a seating portion. Reference numeral 3a denotes a buttocks support part, 3b a thigh support part, 3c a hole in the support part, 3d a notch part in the support part, and 4a a hole or groove in the seat pressure dispersion follow-up part.

  As shown in the embodiment of FIG. 1 and FIG. 2 (C), a cushion 1 for a chair according to the present invention includes a buffer portion 2 made of a material with low resilience and supporting a hip portion, and at least the sacrum, coccyx, and ischial tuberosity at the rear of the hip portion. The support part 3 which has the buttocks support part 3a and the thigh support part 3b which support both the great gluteal muscle parts except the part, and is made of the material having the greatest resilience compared with other materials, and cushions in the center part A hole or groove 4a into which the portion 2 is fitted, made of a material having a smaller resilience or equivalent to the support portion 3, and at least part of which is below the support portion 3 and substantially over the entire seat portion And a seat pressure dispersion follow-up section 4 that disperses the seat pressure over the entire seat section.

  Moreover, the support part 3 is provided with the hole 3c which can penetrate the buffer part 2 at least in the center part. The hole 3c may be a hole having the same shape as the buffer portion. However, in the example shown in FIG. 2, the support portion 3 has a frame shape, and the flange support portion 3a is provided on both sides of one side of the frame. It is comprised so that it may contact | abut to a collar part lower back part. Furthermore, notches 3d are provided on two sides orthogonal to one side of the frame to prevent contact of the greater trochanter in the femur. Moreover, the buffer part 2 is made into the polygonal star shape as a whole, and has aimed at the gradation of the seating pressure so that it may explain in full detail later. 2A and 2B respectively show a combination of the support portion 3 and the seat pressure dispersion follow-up portion 4 and a combination of the buffer portion 2 and the seat pressure dispersion follow-up portion 4 related to the sixth aspect. Functionally, it is shown that FIG. 2C is configured by a combination of (A) and (B).

  Next, the embodiment of FIGS. 2D and 2E will be described. FIG. 2D is an embodiment in which a seating portion 5 is added to the embodiment of FIG. Sitting comfort can be improved by providing the seat part 5 which has a resilience larger than a buffer part, or consists of an equivalent material. FIG. 2E shows an embodiment in which the buttocks support part 3a and the thigh support part 3b of the support part 3 are divided and arranged independently of each other. 2 (C) to 2 (E), the buffer portion 2, the support portion 3, the seat pressure dispersion follow-up portion 4 or the seating portion 5 are not bonded to each other, and each of the body pressure is associated with each other. The deformation of the member does not hinder the body pressure dispersion function of the adjacent member. In this case, in order to facilitate the handling of the cushion, an outer packaging (not shown) that comprehensively encloses each member is provided, and from the viewpoint of safety, at least the seating surface material of the outer packaging is antibacterial. And water repellent finish. From the viewpoint of preventing pressure ulcers from occurring, the material of the buffer portion 2, the support portion 3, the seat pressure dispersion follow-up portion 4 or the seat portion 5 is preferably a urethane foam having air permeability.

  In addition, regarding the material of each part, the detail of the material which can be used including materials other than the said urethane foam is described collectively in the term of the Example mentioned later. 2 (C) to 2 (E), only the example of projecting toward the seating portion 5 side is shown as the heel support portion 3a, but the configuration of projecting toward the seat pressure dispersion following portion 4 side is also shown. It is good. In this case, the seat pressure dispersion follower 4 is not disposed over the entire seat portion, and the overhanging portion of the flange support portion 3a may be cut.

  According to the present invention, it is possible to suppress the occurrence of high pressure and extreme pressure concentration, regardless of individual differences in the sitting posture and the shape of the buttocks, it is comfortable to sit on, and the occurrence of pressure ulcers is suppressed even when used for a long time. A possible chair cushion and a wheelchair comprising the cushion are obtained. These functions and effects will be described below in relation to the problems (1) to (4) of the present invention.

  First, the suppression of pressure concentration in the problem (1) will be described. FIG. 3 is a diagram for explaining the principle of pressure concentration suppression by a combination of materials having different rebound resilience. FIG. 3 shows three diagrams of the upper, middle, and lower stages. In the case of a flat plate as shown in the upper chart, it shows that pressure concentration occurs according to the displacement. Moreover, although the figure of a middle stage shows the case where the board along a collar part shape is formed, for example with a mold, it shows that pressure concentration may generate | occur | produce based on the individual difference of a collar part shape in this case. The lower figure shows that by combining materials with different resilience and using a material with relatively low resilience for the buttocks, the seat pressure can be dispersed and pressure concentration can be suppressed. The configuration shown in FIG. 2B, that is, the combined configuration of the buffer portion 2 made of a material having a low resilience and the seat pressure dispersion follow-up portion 4 in FIG. Yes, the embodiment of the present application shown in FIGS. 2C to 2E has the above-described seat pressure dispersion function. Note that a technique for combining materials having different resilience is disclosed in, for example, Patent Documents 1 and 3.

  Next, the function and effect of the buttocks support portion 3a of the present invention which is related to the problem (2) and which is not disclosed in the prior art will be described. FIGS. 4A and 4B are diagrams showing a state in which the seat pressure is generated when there is no flange support portion. FIG. 4A shows a case where the seating surface is not inclined, and FIG. 4B shows a case where the seating surface is inclined. In the sitting posture, the center of gravity moves backward due to the weight of the trunk, and the support pressure on the seating surface increases toward the rear. Further, since the seating surface of a wheelchair or the like has a slope that becomes lower toward the rear, the center of gravity moves further rearward. (B) In the figure, a portion G indicated by a black circle indicates a region where pressure is concentrated, and is a region that applies stress to the living body.

  Therefore, in order to solve the above problem, in the present invention, as shown in FIG. 2, a buttock support portion 3a for supporting at least the both gluteal muscle portions excluding the sacrum, the tailbone and the sciatic nodule portion is provided behind the buttock. FIG. 5 is a diagram for explaining the state of change in the support force and the center of gravity when the heel support 3a is provided. FIG. 6 is an explanatory diagram of a state in which the pelvis is supported by the buttock support portion 3a, (a) is a diagram for explaining a state of supporting the posterior inclination of the pelvis, and (b) is a pelvic back surface portion. It is a figure explaining the state which is provided in both right-and-left both sides and supports a pelvis from diagonally backward.

  By providing the above-mentioned buttocks support part 3a, it becomes possible to support the back part of the buttocks avoiding the site where many pressure sores occur, and it is possible to suppress pressure concentration and suppress the occurrence of pressure sores regardless of individual differences in the buttocks shape It becomes. Furthermore, the buttocks support portion 3a has an effect of correcting a poor sitting posture, and has an effect of suppressing pressure concentration regardless of the sitting posture. By the way, FIG. 7 is a comparison diagram of body pressure distribution in a state where a person is sitting on a chair, (a) without a cushion, (b) with a flat cushion, (c) according to the present invention. The case where the cushion which has the said collar part support part 3a is provided is shown. In the case of (c), it can be seen that the pressure concentration is dispersed.

  Next, the effect of providing the support part 3 on the seat pressure dispersion | distribution follower 4 in connection with the subject (3) is described based on FIG. FIG. 8 is a diagram for explaining the principle of pressure concentration suppression by the above-described configuration. In FIG. 8, four cases (a) to (d) are compared and described. In the case of (a) seating on a single flat plate material, (b) is a case where the support is placed in a middle frame shape. (C) is a single mold material, (d) is the case where the support is located on the tracking layer (corresponding to FIG. 2C). Show.

  Each case is described in detail in the right column of each figure in FIG. 8, but in short, in the case of the flat single material (a), the resilience at a small deformed portion is low, Although supportability against shaking is inferior, when a support portion (black portion in the figure) is provided in a portion with little deformation as in the configuration of (b), the repulsive force is high and the supportability is improved. It shows that pressure dispersion can be achieved. In addition, in the case of FIG. 8C, in the case of a flange shape different from the mold shape, the portion that does not match the shape becomes one-sided and bottomed and pressure concentration occurs, but as in the configuration of (d) When a material with low rebound resilience is combined with the lower part of the support (blacked portion in the figure), the shape of the buttock can be followed, and the body pressure can be dispersed.

  In FIG. 2C, the support portion 3 and the seat pressure dispersion follow-up portion 4 are combined as in the configuration of FIG. In addition, the support part 3 shall connect the front and back of a collar part by the part with comparatively little seating pressure, and it will form in a frame shape, and shall equip the collar part back with the collar part support part 3a. Further, in FIG. 2D, as shown in FIG. 8B, the support portion 3 is combined with the support portion 3 between the seat portion 5 and the seat pressure dispersion follow-up portion 4, so that the support portion 3 has a frame shape. And it shall be provided with the collar part support part 3a. The same applies to FIG. 2 (E). In any case, the above-described configuration enables suitable buttock support and body pressure dispersion.

  Moreover, the support part 3 in the structure of FIG.2 (C)-(E) is provided with the notch part 3d for a greater trochanter contact prevention. This eliminates local pressure on the greater trochanter. FIG. 9 is a comparative view of seating body pressure distribution related to the effect of the notch portion for preventing the greater trochanter contact, where (a) shows the case without the notch portion and (b) shows the case with the notch portion. It is. According to FIG. 9, it can be seen that the pressure dispersion is achieved by providing the notches.

  Next, the problem (4) can be achieved by making each part material have good air permeability. This point will be described in detail in the embodiment section.

  Finally, according to claim 5 and claim 6, “the contour of the seating surface of the buffer portion 2 has a wavy trajectory line along a predetermined isobaric line centering on three sides of a triangle connecting the coccyx and both ischial nodules. Then, the effect of having a polygonal star shape as a whole "will be described.

  As shown in FIG. 10A, the body pressure distribution of the buttocks when seated is a body pressure distribution having a plurality of isobaric lines centered on the sciatic nodule. On the other hand, body pressure dispersion can be achieved by combining materials having different resilience as described above, but at that time, resilience changes abruptly at the boundary of the material. As a result, a sudden change in mechanical characteristics occurs, so that local stress is generated and the seating comfort is affected.

  FIG. 10B is a distribution diagram in which the isobars are formed in a smooth shape based on FIG. The width, distribution area, pressure value, etc. of the isobaric lines vary depending on the ridge shape. In order to alleviate the sudden change in the mechanical characteristics, it is desirable that the number of annual rings in FIG. 10 (b) is larger, and in accordance with this, it is desirable to sequentially arrange materials having different rebound resilience. Manufacturing cost increases and is not practical. Moreover, in the cushion described in Patent Document 1, a configuration in which an inclination is provided on a boundary surface of materials having different rebound resilience is disclosed, but in this configuration, the area of the boundary surface of the material increases. There is an effect to relieve stress. However, when the boundary surface is not linear, there is a limit to the increase of the inclined surface in consideration of manufacturing problems.

  Therefore, in the embodiment of FIG. 2, the contour of the seating surface of the buffer portion 2 is provided with the polygonal star shape. This polygonal star shape will be described in detail with reference to FIG. FIG. 11 (b) is a diagram showing body pressure distribution at the time of sitting and a triangle T connecting the coccyx and both ischial nodules, and FIG. 11 (a) shows the triangle T and a relatively high pressure portion of the buttocks. It is a figure which shows the relationship between the predetermined isobaric line P to include and a polygon star shape. As shown in FIG. 11 (b), a plurality of isobaric lines are formed with the triangle T connecting the tailbone and both ischial nodules as the central axis. The predetermined isobaric line P shown in FIG. 11 (a) is set in consideration of the case where the seating posture is shifted forward, and the contour of the seating surface of the buffer portion 2 has a wavy locus line along the isobaric line P. And determined as having a polygonal star shape as a whole. As the number of waves increases, the relaxation area increases. However, if the number of waves is too large, manufacture becomes difficult. Considering the effect and manufacturing, the number of waves is preferably about 5 to 20. The polygonal star shape of the buffer portion 2 may be designed according to needs in consideration of the above viewpoints in a comprehensive manner, and is not limited to the shape and dimensions shown in the drawings. There can be variations.

  Also, the sudden change in the mechanical characteristics can be mitigated by providing a buffer means having the following configuration without forming the boundary surface of the material having different rebound resilience as the polygonal star shape as described above. . That is, it is a buffering means in which a soft material gel body or fluid that does not undergo volume deformation is combined with a different type foam boundary surface. The gel body is a gel body described in Patent Document 6, and, for example, the gel body is provided in a semicircular cross section across a butt surface between a high elastic body foam and a low elastic body foam. According to this configuration, the gel and the fluid are not easily deformed in volume, so that the gel and the fluid are greatly deformed in a direction where the repulsive force due to deformation transmitted from the foam is weak. As a result, the repulsive force in the vicinity of the boundary surface can be dispersed, and a sudden change in elastic properties at the boundary can be mitigated.

  Further, the buffer part 2 in FIG. 2D is changed to a gel body having extremely low elasticity, and the buffer part 2 of the gel body is configured to be fitted into the seat part 5, and the seat pressure dispersion follow-up part 4. A gap for releasing deformation of the gel body may be provided between the buffer portion 2 and the buffer portion 2. According to this structure, a gel body deform | transforms flexibly with respect to the said clearance gap, and can relieve | moderate the change of the elastic characteristic of the boundary rapidly.

  Next, examples and performance evaluation results of the present invention will be described below together with various comparative examples (commercial products 1 to 3 and no cushion). FIG. 12 shows an introduction regarding configurations including shapes, dimensions, and weights of examples and various comparative examples, measurement results of pressure distribution, maximum pressure, average pressure, and sensory evaluation (sitting comfort evaluation) results to be described later. . In the product column of FIG. 12, “None” indicates that there is no cushion. Moreover, an Example shows the Example regarding embodiment of FIG.2 (D), and the commercial item 1,2,3 shows the product corresponded to patent documents 7,1,6, respectively. Introductory information about the composition, etc. shows only main introductory information.

  By the way, the material of each part and its physical properties and characteristics in the embodiment of FIG. 12 are shown in the column of the embodiment on the right side of FIG. The left column of FIG. 13 widely shows materials that can be used for each part (sitting part, buffer part, support part, seat pressure dispersion follower part, and envelope not shown in FIG. 2). Etc.

  Indexes for evaluating the performance of wheelchair cushions include evaluation items such as pressure reduction, pressure concentration dispersibility, sitting comfort (sense), and temperature and humidity rise reduction. The pressure reduction can be determined by measuring the maximum pressure (around the sciatic tuberosity) and the average pressure, and the dispersibility of the pressure concentration can be determined by measuring the maximum pressure, the pressure distribution chart, and the like. The pressure measurement is performed by a pressure distribution measuring device. Moreover, sitting comfort (sensation) was judged by sensory evaluation based on the subject questionnaire. Furthermore, the temperature and humidity increase can be judged by measuring the time course of the temperature and humidity at the subject's sciatic tuberosity and rupture. In addition, regarding the temperature, since the heat capacities of the respective products are different, the influence of factors other than the air permeability is large, so here, the determination was made based on the measurement result of the time course of humidity described later.

  According to FIG. 12, it can be seen that the example has the lowest average pressure and the maximum pressure value as compared with the comparative example, and the body pressure dispersibility is excellent also from the pressure distribution measurement result. Furthermore, the numerical value of the sensory evaluation (maximum 5 points) based on the questionnaire was the largest, and it was found that the sitting comfort (sense) was the best. The sensory evaluation will be described in detail below.

  The feeling of sitting (likes and dislikes) varies depending on the individual, purpose of use, and environment. Therefore, as a wheelchair cushion, based on the normal sitting position of an individual on the wheelchair and the feeling of depression at the buttocks when sitting in the ideal sitting position, the sense of stability when sitting, 18 Evaluation was conducted by a questionnaire targeting healthy individuals.

  The sensory test (questionnaire) was given a maximum of 5 points, and in the case of the examples, the highest score was 4.7. In the case of the commercially available product 1, the evaluation was low because it felt one-sided from the posture and the body shape of the subject, and the evaluation score was 3.1. In the case of the commercial product 2, although the evaluation is high due to the same foam system configuration as in the example, it is pointed out that a feeling of deep sinking is felt, and the evaluation score is 3.7, which is the next evaluation. It was. The cushion using the gel of the commercial product 3 became the minimum evaluation score of 1.5 because of load dispersibility and coldness.

  Next, the humidity measurement results will be described. The time transition of humidity after the start of seating is related to the residual moisture released from the living body between the buttocks and the cushion and the cushion during seating. If the moisture release is poor, the humidity increases with time. . In order to measure the effect of humidity perceived by the living body, it is effective to measure at the sciatic nodule (the higher the pressure, the higher the divergence from the living body) and the rupture (the effect of humidity changes due to urinary organs, etc.) Therefore, the measurement was carried out with a small sensor without changing the seating pressure environment.

  FIG. 14 shows an example of a change in humidity after sitting. In FIG. 14, the vertical axis represents humidity (% RH), and the horizontal axis represents time (minutes) after the start of seating. Of the three humidity change curves, A is an example, B is a commercial product 1, and C is a commercial product 2. According to FIG. 14, the increase in humidity of Example A was the lowest, and Example A was found to be most suitable for suppressing the occurrence of pressure ulcers.

The block diagram in connection with embodiment of the cushion for chairs of this invention. The exploded view regarding embodiment of the cushion for chairs of this invention, and its modification. The figure explaining the action principle of pressure concentration suppression by the combination of the material from which resilience differs. The figure which shows the generation | occurrence | production state of the seat pressure in case there is no buttock support part. The figure explaining the state of the change of the supporting force at the time of providing a collar part support part, and a gravity center. Explanatory drawing of the state which supports a pelvis with a buttocks support part. The comparison figure of the body pressure distribution in the state where the person sat on the chair. The figure explaining the effect of providing a support part on a seat pressure dispersion | distribution follow-up part. The comparison figure of the seating body pressure distribution in connection with the effect of the notch part for greater trochanter contact prevention. Body pressure distribution diagram of the buttocks when seated. Explanatory drawing regarding making the outline of the bearing surface of a buffer part into a polygonal star shape. The figure which shows the result of having performed performance evaluation regarding the Example and comparative example of this invention. The figure which shows the material of each part of embodiment containing an Example, its physical property, and a characteristic. The figure which shows an example of the change of the humidity after seating with a comparative example. Explanatory drawing of the bone and muscle of a limb. The rear view explaining a pelvis. The figure which shows the typical example of how to sit down in a posture. The perspective view which shows the structure of the wound prevention mat | matte disclosed by patent document 6. FIG. The perspective view of the seat part system disclosed by patent document 7. FIG. The principal part perspective view of the sitting position holding cushion disclosed by patent document 2. FIG. The perspective view of the cushion sheet provided on the seat chair disclosed by patent document 4. FIG. Explanatory drawing of the seat cushion disclosed by patent document 5. FIG. The perspective view of the seat cushion used for the seat part of the wheelchair disclosed by patent document 1. FIG. The exploded view of the left half of the seat cushion shown in FIG. The side view of the wheelchair disclosed by patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cushion for chairs 2 Buffer part 3 Support part 3a Hip part support part 3b Thigh support part 3c Hole in support part 3d Notch part in support part 4 Seat pressure dispersion follow-up part 4a Hole or groove in seat pressure dispersion follow-up part 5 Seat part

Claims (12)

In chair cushions used for seats such as chairs and wheelchairs,
A cushioning part made of a material with low resilience and supporting the buttocks, a buttocks support part that supports at least the major gluteal muscle parts excluding the sacrum, coccyx and ischial nodule part at the back of the buttocks; a thigh support part; A support portion made of a material having the largest resilience compared to the material, and a hole or groove for fitting the buffer portion in the central portion, made of a material having a smaller resilience or equivalent to the support portion, at least A cushion for a chair comprising: a seat pressure dispersion follower part of which is partly below the support part and disposed substantially over the entire seat part, and disperses seat pressure over the entire seat part. .   The cushion for a chair according to claim 1, wherein the support portion is provided at an upper portion of an outer peripheral portion of the seat pressure dispersion follow-up portion, and has a hole that can penetrate at least the buffer portion at a central portion thereof. .   The support portion is provided in a frame shape at the upper part of the outer periphery of the seat pressure dispersion follow-up portion, and the flange support portion is provided on both sides of one side of the frame contacting the lower rear portion of the flange. The chair cushion according to claim 2, wherein the chair cushion is a chair cushion.   The frame-shaped support portion is provided with notches for preventing greater trochanter abutment in the femur on two sides orthogonal to one side of the frame abutting on the back surface of the buttocks. The chair cushion according to claim 3.   The buffer portion has a wavy trajectory line along a predetermined isobaric line centering on three sides of a triangle connecting the coccyx and both ischial nodules, and has a polygonal star shape as a whole. The chair cushion according to any one of claims 1 to 4, wherein the chair cushion is provided. In chair cushions used for seats such as chairs and wheelchairs,
A buffer part made of a material having a small resilience and supporting a collar part, a material having a greater resilience than the buffer part, having a hole or a groove into which the buffer part is fitted in the central part, and substantially over the entire seat part A seating pressure dispersion follower that disperses seating pressure throughout the seating part, and the buffer part has a contour of the seating surface centered on three sides of a triangle connecting the coccyx and both ischial nodules. A chair cushion characterized by having a wavy locus line along a predetermined isobaric line and having a polygonal star shape as a whole.   The cushioning portion and the support portion, or the cushioning portion and the seating pressure dispersion follower are disposed over the entire seating portion, and the seating portion is made of a material having a resilience greater than or equal to that of the cushioning portion. The chair cushion according to any one of claims 1 to 6.   The cushion for a chair according to any one of claims 1 to 5, wherein the support portion is formed by dividing a hip support portion and a thigh support portion independently of each other.   The mutual contact surfaces of the buffer portion, the support portion, the seat pressure dispersion follow-up portion, or the seat portion are in an adhesive state where each portion can freely move with respect to the seat pressure, or in an unadhered state or a loosely fitted state. The chair cushion according to any one of claims 1 to 8.   The cushion for a chair according to any one of claims 1 to 9, wherein a material of the buffer portion, the support portion, the seat pressure dispersion follow-up portion, or the seat portion is urethane foam having air permeability.   The buffer section, the support section, the seat pressure dispersion follow-up section or the seat section includes an outer package in which these members are comprehensively included, and at least the material of the seat surface of the outer package is antibacterial and water repellent processed The cushion for a chair according to any one of claims 1 to 10, wherein the cushion is for a chair. A wheelchair comprising the chair cushion according to any one of claims 1 to 11.

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