JP7553098B2 - Method and device for measuring contact pressure of body support equipment - Google Patents

Description

The present invention is primarily used to evaluate the contact pressure with the body when using body support equipment such as general mattresses, mattresses for preventing bedsores, cushions for supporting sitting position, sofas, or seats, and relates to a measurement method and device for measuring the contact pressure when protruding parts of the body, such as the sacrum, coccyx, and calcaneus, which are particularly susceptible to the development of bedsores, come into contact with the body support equipment.

Body support equipment, such as mattresses, cushions for supporting the sitting position, sofas, and seats, that come into contact with the body to support the body's posture and position are used daily in all aspects of life. When evaluating or designing the comfort and functionality of such products, it is important to quantitatively analyze the contact pressure at the point where the body and the body support equipment come into contact. For example, in medical institutions, nursing/welfare facilities, home care, etc., in order to prevent the development of bedsores in people who are in the same position for long periods of time and are continuously subjected to pressure on their bodies, it is necessary to select a body pressure dispersion mattress product that suits the user's condition. In order to evaluate the body pressure reduction performance of this type of mattress product, the contact pressure (body pressure) at protruding parts such as the sacrum is known as an effective indicator. Thus, it is important to know how to measure and evaluate the contact pressure of the body against the body support equipment.

As a method for evaluating the contact pressure of such body support devices, there is a method for evaluating the body pressure reduction performance of bedsore prevention devices such as body pressure dispersion mattresses, that is, a method for measuring contact pressure according to the JIS standard (JIS T9256) (Non-Patent Document 1). In this method, a pressure sensor (see Figure 14) with a convex spherical surface (height 28 mm, R200 mm) protruding from a disk-shaped base plate with a diameter of 300 mm and a thickness of 14 mm is used to measure the contact pressure. More specifically, in JIS T 9256, an air bag type pressure sensor is attached to the center of the convex spherical surface of this pressure sensor, which is placed on the mattress to be measured, and then a weight is placed on the base plate of the pressure sensor so that the weight including the pressure sensor is 23 kg, and the pressure value is measured.

As another method, Patent Document 1 describes a contact pressure measurement sensor for measuring the contact pressure when a subject lies on a mattress to be measured, and a contact pressure measurement device equipped with the same. This contact pressure measurement sensor is constructed by sandwiching a foamed plastic, which returns to its original shape when pressure is released, between two air-impermeable sheets in an uncompressed state, and arranging a tube that extends from near the foamed plastic to the outside of the air-impermeable sheet, and bonding the foamed plastic and the air-impermeable sheet around the tube to each other. In this device, the contact pressure measurement sensor itself has a self-suction function, so there is no need to inject a certain amount of air into the sensor, and the contact pressure between the subject and the mattress can be easily measured.

JP 2000-111420 A

Japan Industrial Standards, JIS T9256 "Home use bedsore prevention equipment"

However, the measurement method shown in Non-Patent Document 1 has problems in that the pressure receiving area of the pressure element is large because the shape of the pressure element is a predetermined convex spherical surface, which means that the contact pressure is different from that of protruding pressure-concentrating areas of the body such as the sacrum, coccyx, and calcaneus, and that it is difficult to detect differences due to mattresses.

In addition, the measuring device described in Patent Document 1 measures contact pressure by placing a contact pressure sensor between the subject's body and the mattress, which means that it is difficult to reliably measure contact pressure and obtain reproducible data, particularly in protruding areas of the body where pressure is concentrated, such as the sacrum, or when the shape of the contact area is complex.

The present invention has been made in consideration of the above-mentioned points, and its purpose is to provide a measurement method and device that can obtain the contact pressure of localized areas when the body is in contact with a body support device with good reproducibility and accuracy under conditions close to the actual contact conditions without using a subject, and that is particularly useful for measuring the contact pressure of protruding areas of the body such as the sacrum, coccyx, calcaneus, and pelvis, which are prone to developing bedsores.

The inventor found that the pressure received by a protruding part of the body, such as the sacrum, from a body support tool varies depending on the load "around" the protruding part of the body, such as the buttocks, and the "protruding state" of the protruding part of the body, such as the sacrum, and completed the present invention based on this finding. In order to solve the above problem, the contact pressure measurement method of the present invention is a method for measuring contact pressure of a local part model of the body, in which a body support tool is used as a measurement object, and includes a first compressive deformation step in which a first pressure stick having a contact part that imitates the shape of the area around the local part of the body and a guide hole part in a part of the contact part that corresponds to the local part of the body is pressed against the surface of the measurement object with a preset load to compress and deform the measurement object, and a first pressure stick holding member that holds the first pressure stick at the first pressing position, in which the position of the first pressure stick in the pressing direction when the measurement object is compressed and deformed in the first compressive deformation step is set as a first pressing position, and a first pressure stick holding member is used to hold the first pressure stick at the first pressing position. a second compression deformation step in which a second pressure tool having an abutment portion simulating the shape of a local part of the body and formed to be freely inserted into the guide hole of the first pressure tool is moved through the guide hole of the first pressure tool to a second pressing position where the tip of the abutment portion of the second pressure tool is at least flush with or protrudes from the tip of the abutment portion of the first pressure tool at the first pressing position, and the surface of the object to be measured is pressed with the second pressure tool to compress and deform the object to be measured; and a measurement step in which the force that the second pressure tool receives from the object to be measured in the second compression deformation step is measured by a load measuring device.

In the contact pressure measurement method according to the present invention, the contact pressure of the local body part model is measured by controlling the load of the first pressure element corresponding to the periphery of the local body part and the contact state between the second pressure element corresponding to the local body part and the body support tool, respectively. The first pressure element in the present invention corresponds to the periphery of the local body part, such as the buttocks, and has a contact part that imitates the shape of the periphery of the local body part. In the first compressive deformation step, the contact part of the first pressure element presses the surface of the body support tool with a preset load, i.e., a load corresponding to the periphery of the local body part, to compressively deform the body support tool. Next, in the first pressure element holding step, the first pressure element is held at the position (first pressing position) of the pressing direction of the first pressure element when the body support tool is compressed and deformed in the first compressive deformation step described above. The reason for holding the position of the first pressure element here is to adjust the "contact state" between the second pressure element corresponding to the local body part, such as the sacrum, and the body support tool in a step described later. Therefore, the second pressure element in the present invention corresponds to a local part of the body such as the sacrum, and has an abutment part that imitates the shape of the local part of the body. In the second compressive deformation step, the abutment part of the second pressure element presses the surface of the body support tool that has already been pressed by the first pressure element. Here, the surface of the body support tool has already been pressed by the first pressure element, and the first pressure element has a guide hole part at a part corresponding to the local part of the body of the abutment part of the first pressure element, and this guide hole part is configured to guide the second pressure element to the surface of the body support tool. On the other hand, the second pressure element is formed so as to be freely inserted into the guide hole part of the first pressure element. Therefore, the second pressure element can press the surface of the body support tool with its abutment part through the guide hole part of the first pressure element. When pressing the surface of the body support tool with the second pressure tool, the contact state between the second pressure tool corresponding to the local part of the body and the body support tool is important, and the second pressure tool is moved to a second pressing position where the tip of the contact part of the second pressure tool is located at least on the same plane as the tip of the contact part of the first pressure tool at the first pressing position, or where the tip of the contact part of the second pressure tool protrudes from the tip of the contact part of the first pressure tool at the first pressing position. This second pressing position can be determined by the part selected as the local part of the body and the shape and unevenness around that part, the body shape and physique of the model assumed to be measured, the risk level, etc. In this second pressing deformation step, the force received by the second pressure tool from the body support tool is measured by a load measuring device, and the contact pressure of the local part model of the body is measured. In this way, when the first pressure element is pressed with a set load against the body support equipment, compressing and deforming it, the second pressure element can measure only the force it receives from the body support equipment, making it possible to obtain contact pressure data for local body part models with good reproducibility and accuracy.

In addition, in the contact pressure measurement method of the present invention, it is also preferable that in the first pressure holder holding step, the first pressure holder is held at the first pressing position and then left for a predetermined time. By leaving it for a predetermined time in the first pressure holder holding step, the changes related to the compressive deformation of the object to be measured pressed by the first pressure holder can be completed and the compressive deformation state can be stabilized, thereby improving the reproducibility and accuracy of the measurement data.

In addition, in the contact pressure measurement method of the present invention, it is also preferable that, in the second compressive deformation step, after the second pressure element is moved to the second pressing position, the second pressure element is left at the second pressing position for a predetermined time. By leaving the second pressure element for a predetermined time in the second compressive deformation step, the change related to the compressive deformation of the measured object pressed by the second pressure element is completed, and the compressive deformation state of the measured object and the force that the second pressure element receives from the compressed and deformed measured object can be stabilized, thereby improving the reproducibility and accuracy of the contact pressure data related to pressing by the second pressure element.

In addition, in the contact pressure measurement method of the present invention, it is also preferable that the temperature of the contact part of the first pressure bar or the contact part of the second pressure bar that presses against the surface of the object to be measured is 30 to 40°C. This allows the surface of the object to be pressed at a temperature close to body temperature, resulting in conditions close to the actual contact state when the body support equipment is used, and thus improving the accuracy of the measurement data.

In addition, in the contact pressure measurement method of the present invention, the local body part model is a protruding body part model, the first pressure element has an abutment part that mimics the shape of the periphery of the protruding body part and has a guide hole part at the part of the abutment part that corresponds to the protruding body part, and the second pressure element has an abutment part that mimics the shape of the protruding body part, and it is also preferable that in the second compressive deformation step, the second pressing position is a position where the tip of the abutment part of the second pressure element protrudes from the tip of the abutment part of the first pressure element at the first pressing position. This makes it possible to objectively, reproducibly, and highly accurately measure the contact pressure at a desired part of a protruding body part where the contact pressure with the body support tool is particularly high and the shape of the contact part is often complex, regardless of the subject.

In addition, in the contact pressure measurement method of the present invention, it is also preferable that the contact portion of the first pressure element has a shape simulating the buttocks, and the contact portion of the second pressure element has a shape simulating the sacrum or a part of the sacrum. This makes it possible to objectively, reproducibly, and highly accurately measure the contact pressure at a desired site on the "sacrum," which is one of the sites most susceptible to the development of bedsores, regardless of the subject.

The contact pressure measuring device of the present invention is a contact pressure measuring device for a model of a local part of the body, with a body support tool as the object to be measured, and includes a first pressure element having a first contact part that imitates the shape of the area around the local part of the body, with the first contact part being arranged in a direction to press the surface of the object to be measured, a load application means for supporting the first pressure element and pressing the surface of the object to be measured with a preset load, and a second pressure element having a second contact part that imitates the shape of the local part of the body, with the second contact part being arranged in a direction to press the surface of the object to be measured. The device includes an indenter, a load measuring means connected to the second indenter for measuring the force received by the second indenter, a second indenter moving means for freely moving the second indenter in the pressing direction, and a position setting means connected to the second indenter moving means for setting the pressing position of the second indenter. The first indenter has a guide hole through which the second indenter can be freely inserted at a portion of the first contact portion that corresponds to a localized area of the body, and the second indenter is configured to press the surface of the object to be measured through the guide hole of the first indenter.

In the contact pressure measuring device according to the present invention, the load of the first pressure element corresponding to the periphery of the local part of the body and the contact state between the second pressure element corresponding to the local part of the body and the body support tool are controlled, respectively, to measure the contact pressure of the local part model of the body. The first pressure element in the present invention corresponds to the periphery of the local part of the body, such as the buttocks, and has a first abutment part that imitates the shape of the periphery of the local part of the body. The first abutment part of the first pressure element is arranged in a direction that presses the surface of the body support tool, which is the object to be measured, and the first pressure element supports it and presses the body support tool by a load loading means for pressing the surface of the body support tool with a preset load, i.e., a load corresponding to the periphery of the local part of the body, to compress and deform the body support tool. On the other hand, the second pressure element in the present invention corresponds to the local part of the body, such as the sacrum, and has a second abutment part that imitates the shape of the local part of the body. The second contact part of the second pressure bar is arranged in a direction to press the surface of the body support tool, which is the object to be measured, but the surface of the body support tool is also pressed by the first pressure bar, and the first pressure bar is provided with a guide hole part at a part corresponding to the local part of the body of the first contact part of the first pressure bar, and this guide hole part is configured to guide the second pressure bar to the surface of the body support tool. On the other hand, the second pressure bar is formed so as to be freely inserted into the guide hole part of the first pressure bar. Therefore, the second pressure bar can be inserted into the guide hole part of the first pressure bar, and the surface of the body support tool can be pressed by the second contact part of the second pressure bar. When the second pressure tool is used to press the surface of the body support tool, the contact state between the second pressure tool corresponding to the local part of the body and the body support tool is important. The second pressure tool is moved to a position where the tip of the second contact part of the second pressure tool is located at least on the same plane as the tip of the first contact part of the first pressure tool, or to a position where the tip of the second contact part of the second pressure tool protrudes from the first contact part of the first pressure tool, by using the second pressure tool moving means for freely moving the second pressure tool in the pressing direction and the position setting means for setting the pressing position of the second pressure tool, to press the surface of the body support tool. The pressing position by the second pressure tool can be determined by the part selected as the local part of the body and the shape and unevenness around the part, the body shape and physique of the model assumed to be measured, the risk level, etc. The force received by the second pressure tool from the body support tool by the pressing of the second pressure tool is measured by the load measuring means connected to the second pressure tool, and the contact pressure of the local part model of the body is obtained. In this way, the force received by the body support tool by the second pressure tool can be measured while the first pressure tool is pressing and compressing the body support tool with a load corresponding to the area around the local body part, resulting in a measurement device that can obtain contact pressure data for the local body part model with good reproducibility and accuracy.

In addition, in the contact pressure measuring device of the present invention, it is also preferable that the first contact portion of the first pressure element or the second contact portion of the second pressure element is covered with rubber or a material having viscoelasticity. This allows the surface of the object to be measured to be pressed with a contact portion having a structure closer to that of the human body, resulting in a device that is closer to the actual contact state when the body support tool is used, and capable of obtaining measurement data with higher accuracy.

The contact pressure measuring device of the present invention is also preferably such that a temperature control means that provides a temperature of 30 to 40°C is connected to the first contact portion of the first pressure element or the second contact portion of the second pressure element. This allows the surface of the object to be pressed at a temperature close to body temperature, resulting in a device that is close to the actual contact state when the body support tool is used, and capable of obtaining measurement data with higher accuracy.

In addition, it is also preferable that the contact pressure measuring device of the present invention has a local body part model that is a protruding body part model, the first pressure element has a first contact part that mimics the shape of the periphery of the protruding body part and has a guide hole part at the part of the first contact part that corresponds to the protruding body part, and the second pressure element has a second contact part that mimics the shape of the protruding body part. This makes it possible to obtain a device that can objectively, reproducibly, and highly accurately measure the contact pressure at a desired part of a protruding body part, which has a particularly high contact pressure with the body support tool and in which the shape of the contact part is often complex, regardless of the subject.

In addition, it is also preferable that the contact pressure measuring device of the present invention has a first contact portion of the first pressure element that has a shape simulating the buttocks, and a second contact portion of the second pressure element that has a shape simulating the sacrum or a part of the sacrum. This makes it possible to obtain a device that can objectively, reproducibly, and highly accurately measure contact pressure at a desired site on the "sacrum," which is one of the sites that is considered to be most susceptible to the development of bedsores, regardless of the subject.

In addition, in the contact pressure measuring device of the present invention, it is also preferable that the guide hole portion of the first pressure bar is composed of a through hole penetrating the first pressure bar, a through groove provided on the outer periphery of the first pressure bar, or a frame portion provided on the outer periphery of the first pressure bar. This allows a configuration for the guide hole portion of the first pressure bar to be selected that is suited to a local area of the body.

According to the present invention, it is possible to provide a measurement method and a measurement device having the following excellent effects.
(1) The contact pressure when a model of a localized area, such as a protruding area of the body or an area with a complex shape of the contact area, such as the sacrum, coccyx, or calcaneus, which are prone to developing bedsores, comes into contact with a body support device can be obtained with good reproducibility and accuracy under conditions close to the actual contact conditions.
(2) Measurement can be performed without relying on subjects, so objective data can be obtained. In addition, by appropriately setting the load applied by the first pressure element and the second pressure position when applying pressure with the second pressure element, data can be obtained that assumes the user's body shape (physique) and posture on the body support tool.
(3) Furthermore, since no subject is used for the measurement, there is no need to prepare a body support tool such as a mattress for the measurement, and valid measurements can be performed on a part of the body support tool, such as a partial sample.
(4) The measurement operations are simple, and measurement values can be obtained in a short time.

1 is a schematic configuration diagram of a contact pressure measuring device according to a first embodiment. 2 is a partially enlarged view showing a first pressure element and a second pressure element in the contact pressure measuring device shown in FIG. 1 . 3A is a plan view of the first pressure tool shown in FIG. 1, FIG. 3B is a cross-sectional view taken along line AA' in FIG. 3A, and FIG. 3C is a bottom view. 4A is a plan view of the second pressure tool shown in FIG. 1, FIG. 4B is a cross-sectional view taken along line BB' in FIG. 4A, and FIG. 13A and 13B are a plan view and a side view showing another example of the configuration of the guide hole of the first pressing tool. 1A shows another example of the combination of the first pressure tool and the second pressure tool, (a) a bottom view, a front view and a side view of the first pressure tool 200, (b) a bottom view, a front view and a side view of the second pressure tool 300, (c) an oblique view of the first pressure tool 200 and the second pressure tool 300, and (d) an explanatory diagram showing the second pressure tool 300 inserted into the guide hole 240 of the first pressure tool 200. 1A and 1B show other examples of the combination of the first and second pressure elements, in which (a) is a bottom view, a front view and a side view of the first pressure element 201, (b) is a bottom view and a front view of the second pressure element 301, (c) is an oblique view of the first pressure element 201 and the second pressure element 301, and (d) is an explanatory diagram showing the second pressure element 301 inserted into the guide hole 241 of the first pressure element 201. 1A shows another example of the combination of the first and second pressure elements, in which (a) is a bottom view, a front view and both side views of the first pressure element 202, (b) is a bottom view, a front view and a side view of the second pressure element 302, (c) is an oblique view of the first pressure element 202 and the second pressure element 302, and (d) is an explanatory diagram showing the second pressure element 302 inserted into the guide hole 242 of the first pressure element 202. 1A shows another example of the combination of the first and second pressure elements, in which (a) is a bottom view, a front view and a side view of the first pressure element 203, (b) is a bottom view, a front view and a side view of the second pressure element 303, (c) is an oblique view of the first pressure element 203 and the second pressure element 303, and (d) is an explanatory diagram showing the second pressure element 303 inserted into the guide hole 243 of the first pressure element 203. 1 is an explanatory diagram of a contact pressure measuring method according to the present invention. FIG. 11 is a schematic configuration diagram of a contact pressure measuring device according to a second embodiment. 1 is a graph showing (a) the contact pressure measurement results in Example 1 and Comparative Example 1, (b) the contact pressure measurement results in Example 2 and Comparative Example 2, and (c) the contact pressure measurement results in Example 3 and Comparative Example 3. 13A is a diagram showing a simulation model in Example 4, and FIG. 13B is a graph showing contact pressure measurements and simulated values according to the present invention. 1A and 1B are a plan view and a side view showing a pressing tool used in JIS T9256.

The following describes the contact pressure measuring device 1 according to the first embodiment of the present invention, as shown in Figures 1 to 9.

As shown in FIG. 1, the contact pressure measuring device 1 according to this embodiment is roughly composed of a first pressure piece 2 that presses the surface of the body support tool, a load applying means 4 that supports the first pressure piece 2 and applies a predetermined load to the body support tool, a second pressure piece 3 that presses the surface of the body support tool, a load measuring means 5 that measures the force that the second pressure piece 3 receives from the body support tool, a second pressure piece moving means 6 that allows the second pressure piece 3 to move freely in the pressing direction, and a position setting means 7 that sets the pressing position of the second pressure piece 3. A stage 9 for placing the body support tool is provided in the pressing direction of the first pressure piece 2 and the second pressure piece 3. In this specification, up and down refers to the up and down direction in the direction in which the body support tool is pressed, i.e., the up and down direction in FIG. 1.

First, the first pressure piece 2 constituting the contact pressure measuring device 1 according to this embodiment will be described with reference to Figures 1 to 3. The first pressure piece 2 has a first contact portion 23 that mimics the shape of the periphery of a protruding part of the body, and the first contact portion 23 is arranged in the direction of pressing the surface of the object to be measured, that is, downward in Figures 1 and 2. As shown in Figure 3, the first pressure piece 2 according to this embodiment is composed of a disk-shaped base portion 21 and a convex portion 22 that is approximately truncated cone-shaped and protrudes in the pressing direction, and is formed by combining both. A through hole is provided at the axial center of the base portion 21 and the convex portion 22 to allow the second pressure piece 3 described later to be inserted, and therefore a guide hole portion 24 is formed in the axial center portion of the first pressure piece 2. In addition, the base portion 21 has four mounting holes 25 for connecting the shaft 42 of the load application means 4 described later.

In this embodiment, the sacrum, which is a protruding part in the supine position, is selected as the local part of the body where the contact pressure is measured, and the first pressure piece 2 is formed in a shape that imitates the area around the sacrum, i.e., the buttocks, and the first contact part 23 is formed in a shape that imitates the protruding state around the sacrum in a body type that is prone to developing bedsores. Specifically, the shape of the base part 21 of this first pressure piece 2 is a disk shape with a diameter of 300 mm and a thickness of 15 mm, with the corners in the pressing direction rounded and chamfered, and is designed based on the shape of the disk-shaped substrate (diameter 300 mm, thickness 14 mm) of the pressure piece used in JIS T0256 of the above-mentioned non-patent document 1. The shape of the convex portion 22 of the first pressure element 2 is a generally truncated cone with a protruding height of 20 mm, a circular shape with a diameter of 160 mm on the upper side, and an elliptical shape with a major axis diameter of 32 mm and a minor axis diameter of 22 mm on the lower side, and is designed based on the judgment criteria and bone protrusion judger of pathological bone protrusion of the sacrum in the OH scale, which judges the risk factors of bedsore development. Note that the "pathological bone protrusion" of the OH scale is judged by how much the buttocks are lower than the sacrum at a distance 80 mm outside the center of the sacrum, and if the buttocks are lower than the sacrum by 0 to less than 20 mm, the risk factor is judged to be mild/moderate, and if the buttocks are lower than the sacrum by 20 mm or more, the risk factor is judged to be high. In this embodiment, the protruding height of the convex portion 22 of the first pressure tool is set to 20 mm, which is the boundary value between mild/moderate and severe on the OH scale, but it can be set according to the desired protruding body part model, and can also be set based on other risk assessment scales, etc.

As shown in Figs. 1 to 3, the first pressure tool 2 has a guide hole 24 formed as a through hole for inserting the second pressure tool 3 described below. The guide hole 24 is formed to a size that allows the second pressure tool 3 to be inserted, and it is preferable that the guide hole 24 is formed to a size that allows the second pressure tool 3 to slide along the inner wall of the guide hole 24 of the first pressure tool 2 so that the central axis of the second pressure tool 3 does not shift when moving and pressing.

In addition, the guide hole 24 of the first pressure bar 2 in this embodiment is shown as a hole provided vertically at approximately the center of the first pressure bar 2, but it can also be configured as shown in Figures 5(a) to (c) depending on the contact state between the protruding part of the body to be measured and the body support tool A. Specifically, Figure 5(a) shows an example in which the guide hole 24 is formed as a hole provided obliquely in the thickness direction of the first pressure bar 2, Figure 5(b) shows an example in which the guide hole 24 is formed as a through groove provided on the outer periphery of the first pressure bar 2, and Figure 5(c) shows an example in which the guide hole 24 is formed from a frame portion provided on the outer periphery of the first pressure bar 2. When the second pressure bar 3 presses the body support tool A, the configuration of the guide hole 24 as described above is selected to approximate the contact state of the protruding part of the body with the body support tool A in various postures such as supine position and sitting position.

In this embodiment, the first pressure element 2 is composed of a base portion 21 and a protruding portion 22, and is formed so that the protruding portion 22 can be replaced according to the desired protruding part model of the body, but the first pressure element 2 may be formed by integrating the base portion 21 and the protruding portion 22.

Next, the second pressure element 3 according to this embodiment will be described with reference to Figures 1, 2 and 4. The second pressure element 3 has a second contact portion 31 that mimics the shape of a protruding part of the body, and the second contact portion 31 is arranged in the direction in which it presses against the surface of the object to be measured, that is, facing downward in Figures 1 and 2. As shown in Figure 4, the second pressure element 3 according to this embodiment is formed in a generally cylindrical shape with an oval axial cross section, and has a mounting hole 32 on the upper side for connecting the shaft portion 53 of the load measuring means 5.

In this embodiment, the sacrum, which is a protruding part in the supine position, is selected as the local part of the body to be measured for contact pressure, and the second contact part 31 of the second pressure bar 3 is formed to mimic the most protruding part of the sacrum in the body. Specifically, the second pressure bar 3 is approximately cylindrical with rounded corners in the pressing direction to form a hemispherical shape, and the axial cross-sectional shape is an ellipse with a major axis diameter of 30 mm and a minor axis diameter of 20 mm. As shown in Figures 1 and 2, the second pressure bar 3 is formed so that it can be inserted into the guide hole 24 provided in the first pressure bar 2, and it is preferable that the second pressure bar 3 is formed so that it can slide along the inner wall of the guide hole 24 of the first pressure bar 2 so that the central axis of the second pressure bar 3 does not shift when moving and pressing.

In this embodiment, the sacrum, which is a protruding part in the supine position, is selected as the local part of the body to measure contact pressure, but this is not limited thereto, and any local part of the body in contact can be selected, and when the local part is a protruding part, various protruding parts of the body can be selected, such as those shown in Table 1 below and Figures 6 to 9.

Figures 6 to 9 show specific examples of the configuration of the first and second pressure elements in which various parts are selected as the protruding parts of the body to be measured for contact pressure. In Figure 6, the ischium in a seated position is selected as the protruding part of the body, and the second contact part 310 of the second pressure element 300 is formed to imitate the shape of the ischium in a seated position. On the other hand, the first pressure element 200 that is combined with this has a first contact part 230 that imitates the area around the ischium in a seated position, i.e., the shape of the buttocks in a seated position. In Figures 6(a) to (c), both contact parts are shown facing upward in order to illustrate the shapes of the first contact part 230 and the second contact part 310, but in Figure 6(d), the first contact part 230 and the second contact part 310 are arranged to face downward, and the state in which both pressure elements are combined when the pressing direction is in the direction of the arrow is shown. As an example, the first pressure member 200 is formed to have a width of 372 mm, a length of 493 mm, and a maximum height of 83 mm, and the second pressure member 300 is formed to have an oval cross-sectional shape with a major axis of 51 mm and a minor axis of 25 mm, but the size can be appropriately changed depending on the body shape and physique of the model assumed to be measured. In addition, in FIG. 7, the occipital protrusion in the supine position is selected as the protruding part of the body, and the second contact part 311 of the second pressure member 301 is formed to imitate the shape of the occipital protrusion in the supine position. On the other hand, the first pressure member 201 combined with this has a first contact part 231 that imitates the shape of the occipital region around the occipital protrusion in the supine position. This shape is designed based on the data published in the database information on the head dimensions of Japanese people (Japanese Head Dimension Database 2001: https://www.airc.aist.go.jp/dhrt/head/index.html, website of the Artificial Intelligence Research Center). In Fig. 7(a) to (c), the first contact portion 231 and the second contact portion 311 are shown facing upwards in order to illustrate the shapes of the first contact portion 231 and the second contact portion 311, but Fig. 7(d) shows a state in which the first contact portion 231 and the second contact portion 311 are arranged facing downwards and the pressing direction is the direction of the arrow, and the two pressure elements are combined. In Fig. 8, the femoral trochanter in the lateral position is selected as the protruding part of the body, and the second contact portion 312 of the second pressure element 302 is formed to imitate the shape of the femoral trochanter in the lateral position. On the other hand, the first pressure element 202 to be combined with this has a first contact portion 232 that imitates the area around the femoral trochanter in the lateral position, that is, the shape of the buttocks to thighs in the sideways position. In Fig. 8(a) to (c), in order to illustrate the shapes of the first contact portion 232 and the second contact portion 312, both contact portions are shown facing upward, and the thin lines drawn on the surface of the first contact portion 232 of the first pressure member 202 in Fig. 8(c) are lines drawn to specify the three-dimensional shape. Fig. 8(d) shows the state in which the first contact portion 232 and the second contact portion 312 are arranged facing downward, and the pressing direction is the direction of the arrow, and both pressure members are combined. Furthermore, in Fig. 9, the scapular prominence in the supine position is selected as the protruding part of the body, and the second contact portion 313 of the second pressure member 303 is formed to imitate the shape of the scapular prominence in the supine position. On the other hand, the first pressure member 203 combined with it has a first contact portion 233 that imitates the shape of the periphery of the scapular prominence in the supine position, i.e., the upper back. In Fig. 9(a) to (c), the first contact portion 233 and the second contact portion 313 are shown facing upwards in order to illustrate the shapes of the first contact portion 233 and the second contact portion 313 of the first pressure element 203 in Fig. 9(c) are thin lines drawn on the surface of the first contact portion 233 of the first pressure element 203 to identify the three-dimensional shape. Fig. 9(d) shows the state in which the first contact portion 233 and the second contact portion 313 are arranged facing downwards and the two pressure elements are combined when the pressing direction is in the direction of the arrow. In this way, the contact pressure measuring device for the selected protruding portion model is composed of the second pressure element 3 having the second contact portion 31 that imitates the shape of the selected protruding portion and the first pressure element 2 having the first contact portion 23 that imitates the shape around the protruding portion.

In this embodiment, the first pressure element 2 and the second pressure element 3 are formed of a rigid material such as metal or hard resin so as to reliably press against the body support tool A, but in order to obtain contact pressure data with a structure closer to that of the human body, it is also possible to configure the first contact portion 23 of the first pressure element 2 and/or the second contact portion 31 of the second pressure element 3 to be covered with rubber or a material having viscoelasticity. This results in each contact portion having a structure that mimics the human body, so that the conditions are closer to the actual contact state when the body support tool is used, and measurement data can be obtained with higher accuracy.

In addition, in order to obtain contact pressure data with a structure closer to that of the human body, a temperature control means that provides a temperature of 30 to 40°C can be connected to the first contact portion 23 of the first pressure element 2 and/or the second contact portion 31 of the second pressure element 3, and these contact portions 23, 31 can be made to a temperature close to body temperature. This allows the surface of the body support tool A to be pressed at a temperature close to body temperature, resulting in conditions close to the actual contact state when the body support tool is in use, and measurement data with higher accuracy can be obtained.

Next, the load application means 4 according to this embodiment will be described with reference to FIG. 1. The load application means 4 supports the first pressure bar 2 and is configured to be able to press the surface of the body support tool A, which is the object to be measured, with the first pressure bar 2 at a preset load. The load application means 4 according to this embodiment is roughly composed of a shaft 42 connected to the first pressure bar 2, a pressure plate 41 connected to the other end of the shaft 42, a load setting means 43 connected to the pressure plate 41 for measuring and setting the load applied by the pressure plate 41, a lifting platform 44 supporting the load setting means 43, a lifting unit 45 for moving the lifting platform 44 in the pressing direction and its handle 46, and a position measuring device 47 connected to the handle 46 for measuring the amount of movement of the lifting unit 45.

In this embodiment, four shafts 42 are provided and are supported on the support 8 via bearing members so as to be movable in the pressing direction. In addition, one end of each of the shafts 42 is fixed near each corner of the pressing plate 41 made of a substantially square metal plate, and the other end of each is fixed to the base member 21 of the first pressure element 2. As a result, by pressing the pressing plate 41 downward, the first pressure element 2 is pressed downward via the shaft 42, and the body support tool A is pressed. Here, in this embodiment, a load setting means 43 is connected to the pressing plate 41. This load setting means 43 is composed of a load meter 43a that measures the load, its pressure probe 43b, and an axis portion 43c that connects the pressure probe 43b and the pressing plate 41, which are connected in series in the same direction as the pressing direction. In this embodiment, a force gauge is selected as the load meter 43a, and the load when the first pressure element 2 presses the body support tool A through the pressing plate 41, etc. is measured by the load meter 43a. In this embodiment, the load meter 43a of the load setting means 43 is attached to and supported by a lifting platform 44, which is attached to a lifting unit 45 fixed to the support 8. The lifting platform 44 is configured to move up and down by operating a handle 46 of the lifting unit 45, and the amount of movement is measured by a position measuring device 47.

By turning the handle 46 to move the lifting platform 44 of the lifting unit 45 in the pressing direction, the press plate 41 moves in the pressing direction via the load setting means 43 attached to the lifting platform 44, and the first pressure element 2 connected to the shaft 42 presses the surface of the body support device A. The load related to the pressing by the first pressure element 2 is measured by the load setting means 43 connected to the press plate 41, so by moving the lifting platform 44 in the pressing direction with the lifting unit 45 until it reaches the set load, the surface of the body support device A can be pressed by the first pressure element 2 with a predetermined load.

In this embodiment, the push plate 41 moves in the pressing direction via the load setting means 43 attached to the lifting platform 44, but it is also possible to attach the push plate 41 directly or indirectly to the lifting platform 44 so that the push plate 41 moves in the pressing direction without the load setting means 43. The lifting unit 45 can be a manual type operated by a handle 46, or an electric type lifting unit.

Next, the load measuring means 5 according to this embodiment will be described with reference to Figs. 1 and 2. The load measuring means 5 is connected to the upper side of the second pressure bar 3 and is configured to measure the contact pressure when the second pressure bar 3 presses the surface of the body support tool A through the guide hole 24 of the first pressure bar 2. This load measuring means 5 is composed of a load meter 51 that measures the force received by the second contact part 31 of the second pressure bar 3, its pressure probe 52, and a shaft part 53 that connects the pressure probe 52 and the second pressure bar 3, which are connected in series in the same direction as the pressing direction. The shaft part 53 is attached with one end embedded in the mounting hole 32 provided on the upper side of the second pressure bar 3. In this embodiment, a force gauge is selected as the load meter 51, and the load meter 51 of this load measuring means 5 is attached to and supported by the lifting platform 62 of the second pressure bar moving means 6 described later.

Next, the second pressure element moving means 6 and the position setting means 7 according to this embodiment will be described with reference to FIG. 1. The second pressure element moving means 6, which allows the second pressure element 3 to move in the pressing direction, is composed of a lifting platform 62 that supports the load measuring means 5 connected to the second pressure element 3, and a lifting unit 61 and its handle 63 for moving the lifting platform 62 in the pressing direction. The lifting unit 61 is fixed to a support 8, and the lifting platform 62 attached to the lifting unit 61 is configured to move up and down by operating the handle 63. The handle 63 of the second pressure element moving means 6 is connected to a position setting means 7 that measures the amount of movement of the lifting unit 61, and a position measuring device that displays the position of the lifting unit 61 according to the amount of rotation of the handle 63 is selected as the position setting means 7.

By turning the handle 63 to move the lift platform 62 of the lift unit 61 in the pressing direction, the second pressure element 3 moves in the pressing direction via the load measuring means 5 attached to the lift platform 62, and presses against the surface of the body support tool A via the guide hole 24 of the first pressure element 2. By setting the position of the second contact tip 31a of the second pressure element 3 using the position setting means 7, the force that the second pressure element 3 receives from the body support tool A at the specified pressing position is measured by the load measuring means 5.

In the present embodiment, the second pressure bar moving means 6 is configured so that the second pressure bar 3 moves in the pressing direction via the load measuring means 5 attached to the lifting platform 62, but it is also possible to configure the second pressure bar 3 to be directly or indirectly attached to the lifting platform 62 so that the second pressure bar 3 moves in the pressing direction without the load measuring means 5. The lifting unit 61 can be a manual type operated by a handle 63, or an electric type lifting unit.

Next, a method for measuring contact pressure of a local body part model according to the present invention will be described. The contact pressure measuring method according to the present embodiment is roughly composed of a first compressive deformation step S1 in which the surface of the body support tool is compressed and deformed by pressing the first pressure tool with a preset load, a first pressure tool holding step S2 in which the pressing position of the first pressure tool is held when the body support tool is compressed and deformed in step S1, a second compressive deformation step S3 in which the second pressure tool is moved to a position where the abutment tip of the first pressure tool and the abutment tip of the second pressure tool are flush with each other or to a position where the abutment tip of the second pressure tool protrudes from the abutment tip of the first pressure tool, and the second pressure tool is pressed against the surface of the body support tool to compress and deform it, and a measurement step S4 in which the force that the second pressure tool receives from the body support tool in step S3 is measured by a load measuring device. Hereinafter, a method for measuring contact pressure using the contact pressure measuring device 1 described above will be described with reference to FIG. 10.

The first compression deformation step S1 will be described. First, the body support tool A, which is the object to be measured, is placed on the stage 9 (not shown) of the contact pressure measuring device 1. Next, the handle 46 of the load application means 4 of the measuring device 1 is turned to move the lifting platform 44 of the lifting unit 45 in the pressing direction. When the lifting platform 44 is moved in the pressing direction, the pressing plate 41 moves in the pressing direction via the load setting means 43 attached to the lifting platform 44, and as shown in Figures 10(a) and 10(b), the first pressure piece 2 connected to the shaft 42 presses the surface of the body support tool A. At this time, the load related to the pressing by the first pressure piece 2 is measured by the load setting means 43 consisting of a force gauge 43a connected to the pressing plate 41. Therefore, by turning the handle 46 and moving the lifting platform 44 in the pressing direction until the load measured by the force gauge 43a becomes equal to the set load, the surface of the body support device A is pressed by the first pressure element 2 with a predetermined set load, and the body support device is compressed and deformed.

In this step S1, the set load for the pressure by the first pressure element 2 is a load corresponding to the periphery of the local part of the body whose shape the first pressure element 2 mimics. For example, in this embodiment, the sacrum, which is a protruding part, is selected as the local part of the body, and the buttocks are selected as the periphery of this protruding part, so the weight of the body corresponding to the buttocks is the set load. Since the ratio of the weight of the buttocks to the total body weight is 40 to 45%, for example, when measuring the contact pressure of a person weighing 40 kg, the set load is 16 to 18 kg, and when measuring the contact of a person weighing 70 kg, the set load is 28 to 31.5 kg. In this way, the set load is determined by the total weight of the model assumed to be the measurement target and the ratio of each part of the body to the total weight.

Next, the first pressure stick holding step S2 will be described. In this step S2, the first pressure stick 2 is held at the position in the pressing direction of the first pressure stick 2 when the body support tool A is compressed and deformed with a predetermined set load in the previous step S1 (first pressing position). In FIG. 10(b), the position P1 of the first contact tip 23a of the first pressure stick 2 is shown as the first pressing position. Here, the reason for holding the first pressure stick 2 at the first pressing position P1 is to adjust the "contact state" between the second pressure stick 3 corresponding to a local part of the body such as the sacrum and the body support tool A in step S3 described later. In the measuring device 1, the first pressure stick 2 is supported by the load application means 4, so that the first pressure stick 2 is held at the first pressing position P1 by holding the load application means 4 in the state of the previous step S1.

In addition, in the above-mentioned first pressure tool holding step S2, after holding the first pressure tool 2 at the first pressing position P1, step S3 described below may be performed immediately, or a step of leaving the first pressure tool 2 at the first pressing position P1 for a predetermined time may be provided. The time to leave it depends on the material and configuration of the body support tool A, but for example, if the body support tool A is made of foamed plastic, it is preferably set to about 5 seconds to 1 minute, and more preferably about 10 seconds to 30 seconds. By leaving the first pressure tool 2 at the first pressing position P1 for a predetermined time, the change related to the compressive deformation of the body support tool A pressed by the first pressure tool 2 is completed, and the compressive deformation state of the body support tool A can be stabilized, thereby improving the reproducibility and accuracy of the measurement data.

Next, the second compressive deformation step S3 will be described. In this step S3, the second pressurizer 3 presses the surface of the body support tool A through the guide hole 24 of the first pressurizer 2, compressing and deforming the body support tool A. Specifically, the handle 63 of the second pressurizer moving means 6 of the measuring device 1 is turned to move the lifting platform 62 of the lifting unit 61 in the pressing direction. When the lifting platform 62 is moved in the pressing direction, the second pressurizer 3 connected to the load measuring means 5 attached to the lifting platform 62 moves in the pressing direction, and as shown in FIG. 10 (c), the second pressurizer 3 presses the surface of the body support tool A through the guide hole 24 of the first pressurizer 2. When the second pressurizer 3 presses the surface of the body support tool A, it is important at what position the second pressurizer 3 corresponding to the local part of the body comes into contact with and presses the surface of the body support tool A. In this embodiment, the sacrum is selected as a protruding part of the body as a local part, so the protruding level of the second pressure element 3 that imitates the sacrum is important, and the second pressure element 3 is moved from the first contact tip 23a of the first pressure element 2 at the first pressing position P1 to the second pressing position P2 where the second contact tip 31a of the second pressure element 3 protrudes. The second pressing position P2 can be adjusted by the position setting means 7 connected to the second pressure element moving means 6 of the measurement device 1.

In this step S3, the position P2 of the second contact tip 31a at the second pressing position of the second pressure element 3 is determined by the part selected as the local part of the body and the body shape, physique, risk level, etc. of the model assumed to be measured. For example, in this embodiment, the sacrum, which is a protruding part, is selected as the local part of the body, and a position protruding 2.5 mm from the position P1 of the first contact tip 23a of the first pressure element 2 is set as the reference position for the position P2 of the second contact tip 31a at the second pressing position. This position P2 can be set to a position with a protruding length smaller or larger than this reference position depending on the body shape, pressure ulcer risk level, etc. of the model assumed to be measured.

Depending on the shape of the part selected as the local part of the body, the body shape and build of the model assumed to be measured, the risk level, etc., in this step S3, the second pressure element 3 may be moved so that the second contact tip 31a of the second pressure element 3 is positioned on the same plane as the first contact tip 23a of the first pressure element 2 at the first pressing position P1, and the surface of the body support tool A may be pressed (position P1 of the first contact tip 23a at the first pressing position = position P2 of the second contact tip 31a at the second pressing position). In this way, the contact state of the second pressure element 3 simulating the local part of the body with the body support tool A is controlled by the position P2 of the second contact tip 31a of the second pressure element 3, so that contact pressure data corresponding to the selected local part model can be obtained.

In FIG. 10, in this step S3, the second pressure element 3 is inserted from above into the guide hole 24 of the first pressure element 2 and moves in the pressing direction within the guide hole 24. However, in order to smoothly and quickly move the second pressure element 3 in the pressing direction, in the first compression deformation step S1, the second pressure element 3 may be set in a state in which it is somewhat inserted into the guide hole 24 of the first pressure element 2 beforehand.

Furthermore, the second pressure element 3 may be inserted in advance into the guide hole 24 of the first pressure element 2, and adjusted so that the second contact tip 31a of the second pressure element 3 protrudes a predetermined amount from the first contact tip 23a of the first pressure element 2 or the first contact tip 23a and the second contact tip 31a are flush with each other, and in this state, the first pressure element 2 and the second pressure element 3 may be moved together in the pressing direction, and steps S1 to S3 may be performed substantially simultaneously.

In the second compressive deformation step S3 described above, the second pressure element 3 may be moved to the second pressing position P2, and then the measurement may be performed immediately in step S4 described later. Alternatively, a step of leaving the second pressure element 3 at the second pressing position P2 for a predetermined time may be provided. The time to leave the second pressure element 3 at the second pressing position P2 depends on the material and configuration of the body support tool A, but for example, when the body support tool A is made of foamed plastic, the time is preferably set to about 5 seconds to 1 minute, and more preferably to about 10 seconds to 30 seconds. By leaving the second pressure element 3 at the second pressing position P2 for a predetermined time, the change related to the compressive deformation of the body support tool A pressed by the second pressure element 3 is completed, and the compressive deformation state of the body support tool A can be stabilized, so that the reproducibility and accuracy of the contact pressure data related to the pressing by the second pressure element 3 can be improved.

Next, the measurement step S4 will be described. In this step S4, the force received from the body support tool A by the second pressure tool 3 pressing and deforming the body support tool A in the previous step S3 is measured by the load measuring device. As a result, the contact pressure of the local body part model is measured. Specifically, when the second pressure tool 3 is moved to the second pressing position P2, the measurement device 1 performs measurement using the load measuring means 5 consisting of the force gauge 51 connected to the upper side of the second pressure tool 3 via the shaft part 53. As a result, it is possible to measure only the force received by the second pressure tool 3 from the body support tool A in a state in which the body support tool A is pressed and compressed by the first pressure tool 2 with a predetermined load, and therefore it is possible to obtain data on the contact pressure of the local body part model with good reproducibility and accuracy.

Next, a contact pressure measuring device 10 according to a second embodiment of the present invention shown in FIG. 11 will be described. As shown in FIG. 11, the contact pressure measuring device 10 according to this embodiment is roughly composed of a first pressure piece 2 that presses the surface of the body support tool, a load applying means 40 that supports the first pressure piece 2 and applies a predetermined load to the body support tool, a second pressure piece 3 that presses the surface of the body support tool, a load measuring means 5 that measures the force that the second pressure piece 3 receives from the body support tool, a second pressure piece moving means 6 that allows the second pressure piece 3 to move freely in the pressing direction, and a position setting means 7 that sets the pressing position of the second pressure piece 3. A stage 9 for placing the body support tool is provided in the pressing direction of the first pressure piece 2 and the second pressure piece 3.

In this embodiment, the configuration of the load applying means 40 is different from that of the first embodiment described above. Specifically, the load applying means 40 in this embodiment is roughly composed of a shaft 420 connected to the first pressure element 2, a pressure plate 410 connected to the other end of the shaft 420, and a support means 48 connected to the pressure plate 410 to set the load applied by the pressure plate 410 and to support them.

In this embodiment, the pressure plate 410 is composed of two elongated metal plates and is arranged above the first pressure plate 2. The pressure plate 410 and the first pressure plate 2 are connected via a shaft attached to the mounting hole 25 of the first pressure plate 2. The two pressure plates 410 are arranged on the same plane at a position that does not interfere with the movement of the second pressure plate 3, and as shown in FIG. 11, two shafts 420 are connected to each pressure plate 410. As a result, by moving the pressure plate 410 downward, the first pressure plate 2 moves downward via the shaft 420, and the body support tool A is pressed. Here, in this embodiment, a support means 48 is provided for setting the load by the pressure plate 410 and supporting them. The support means 48 is composed of four cut bolts 48a and four wing nuts 48b screwed thereto. One end of each cut bolt 48a is fixed below the stage 9, and the other end is inserted into a through hole provided near the end of the press plate 410, and each wing nut 48b is screwed onto the bolt 48a from the upper side of the press plate 410. As a result, by tightening each wing nut 48b a predetermined distance, the press plate 410 moves downward a predetermined distance, so that the first pressure piece 2 is pressed downward via the shaft 420 and the body support tool A is pressed. The pressing load by the first pressure piece 2 is not shown in FIG. 11, but is measured, for example, by connecting a load meter to the first pressure piece 2. Therefore, by tightening each wing nut 48b until the set load is reached and moving the press plate 410 in the pressing direction, the surface of the body support tool A can be pressed by the first pressure piece 2 with a predetermined load.

The explanation regarding the configuration of the first pressure element 2, the second pressure element 3, the load measuring means 5, the second pressure element moving means 6, and the position setting means 7 that constitute the contact pressure measuring device 10 in this embodiment is the same as that of the measuring device 1 according to the first embodiment described above, and the action and effect thereof and the method of measuring contact pressure using the measuring device 10 are also the same.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[Example 1]
1. Contact pressure measurement of a local body part model according to the present invention (1)
Using the contact pressure measuring device 1 according to the first embodiment shown in FIG. 1, the contact pressure of the sacrum model, which is a protruding part in the supine position as a local part, was measured. Digital force gauges (manufactured by Imada Co., Ltd.) were used as the load meters 51 and 43a. A body pressure dispersion type mattress product (product name: Alphapla F, manufactured by Taica Co., Ltd.) for moderate to high risk individuals with an OH scale score of 3 to 8 was selected as the body support tool A to be measured. The cover attached to the product was removed before use. The set load for the pressure applied by the first pressure element 2 was calculated with the ratio of the weight of the buttocks to the total body weight being 44%. Since the average weight M of people aged 60 or older is 53.4 kg, the base set load was set to 23 kg (the same as the pressing load in JIS T9256). In addition, the weight corresponding to the 2σ interval (standard deviation σ = 8.24) of the data related to this average weight M was also measured. For M-2σ=36.9 kg, the set load was 16 kg, and for M+2σ=69.9 kg, the set load was 30 kg.

The body support tool A was placed on the stage 9, and the handle 46 of the load application means 4 of the measuring device 1 was turned to move the lifting platform 44 of the lifting unit 45 in the pressing direction until the pressing load by the first pressure tool 2 reached 23 kg, and the body support tool A was compressed and deformed by the first pressure tool 2. After leaving it in this state for 10 seconds, the handle 63 of the second pressure tool moving means 6 was turned to move the lifting platform 62 of the lifting unit 61 in the pressing direction, and the body support tool A was compressed and deformed by the second pressure tool 3 through the guide hole 24 of the first pressure tool 2. At this time, the pressing position of the second pressure tool 3 was adjusted so that the second contact tip 31a of the second pressure tool 3 protruded 2.5 mm from the first contact tip 23a of the first pressure tool 2. After leaving it in this state for 10 seconds, the contact pressure received by the second pressure tool 3 from the body support tool A was measured by the force gauge 51 connected to the upper side of the second pressure tool 3. The contact pressure was also measured in the same manner when the pressing load applied by the first pressure element 2 was changed to 16 kg or 30 kg.

[Comparative Example 1]
1. Measurement of contact pressure of local body part models in JIS T9256 method (1)
For the body support equipment measured in Example 1 (a pressure dispersion mattress product for moderate to high risk individuals with an OH scale score of 3 to 8 [product name: Alphapla F, product of Taica Corporation]), the contact pressure of the sacrum model, which is a protruding part in the supine position as a local part, was measured as a pressure value at a load of 23 kg using the pressure element shown in FIG. 14 in accordance with the measurement method of the pressure value of the sample in the performance test of the body pressure reduction of a static mattress in JIS T9256-2 "Home use bedsore prevention equipment". Note that, as in Example 1, the cover attached to the mattress product was removed and the measurement was performed. In addition, the pressure value was measured in the same manner when the load by the pressure element shown in FIG. 14 was changed to 16 kg or 30 kg. A simplified body pressure measuring device (product name Cero, model CR-270, product of Cape Corporation) was used as the pressure measuring device.

[Example 2]
2. Contact pressure measurement of a local body part model according to the present invention (2)
A pressure dispersion type mattress product (product name: Alphapla L, manufactured by Taica Corporation) for mild to moderate risk individuals with an OH scale score of 1 to 4 was used as the body support equipment A, and the contact pressure received by the second pressure element 3 from the body support equipment A was measured in the same manner as in Example 1. Note that, as in Example 1, the cover attached to the mattress product was removed before the measurement.

[Comparative Example 2]
2. Measurement of contact pressure of local body part models in JIS T9256 method (2)
The pressure value was measured in the same manner as in Comparative Example 1, except that a pressure dispersion mattress product (product name: Alphapla L, manufactured by Taica Corporation) for people with mild to moderate risk, with an OH scale score of 1 to 4, was used as the body support equipment A. The cover attached to the mattress product was removed before the measurement.

[Example 3]
3. Contact pressure measurement of a local body part model according to the present invention (3)
A body pressure dispersion type mattress product (product name: Alphapla Suktto Re, manufactured by Taica Corporation) with an OH scale score of 0 to 3 and intended for people with no or mild risk was used as the body support equipment A, and the contact pressure received by the second pressure element 3 from the body support equipment A was measured in the same manner as in Example 1. Note that, as in Example 1, the cover attached to the mattress product was removed before the measurement was performed.

[Comparative Example 3]
3. Measurement of contact pressure of local body part models in JIS T9256 method (3)
As body support equipment A, a pressure dispersion mattress product for people with no or mild risk of injury (OH scale score of 0 to 3) (product name: Alphapla Suktto Re, product of Taica Corporation)
The pressure value was measured in the same manner as in Comparative Example 1, except that the cover attached to the mattress product was removed before the measurement.

The results of Example 1 and Comparative Example 1 are shown in Table 2 below and FIG. 12(a). The results of Example 2 and Comparative Example 2 are shown in Table 3 below and FIG. 12(b). The results of Example 3 and Comparative Example 3 are shown in Table 4 below and FIG. 12(c).

According to the results of Examples 1 to 3 and Comparative Examples 1 to 3, the measured values according to the present invention were greater than those according to the JIS method at a load of 23 kg, which assumes an average body weight, and at a load of 30 kg, which assumes a high body weight (approximately 70 kg). On the other hand, at a load of 16 kg, which assumes a low body weight (approximately 37 kg), the measured values according to the present invention were smaller than those according to the JIS method. This supports the issue that the JIS method is less likely to produce differences in pressure values due to differences in mattresses, and it became clear that the JIS method is less likely to produce differences in pressure values even when the load is increased or decreased, making it difficult to reflect the actual contact state. In contrast, with the measurement method of the present invention, the contact pressure increased according to the pressing load on the mattress, and the slope of the approximation curve was also greater than that of the JIS method. From these findings, it was shown that the present invention can easily and accurately obtain contact pressure data of a local body part model with good reproducibility under conditions close to the actual contact state.

[Example 4]
4. Measurement of contact pressure of a local body part model according to the present invention and its measurement by a simulation model In this example, the contact pressure was measured when the second pressing position P2 of the second pressure element 3 was changed using the contact pressure measuring device 10 according to the second embodiment shown in FIG. 11. Note that digital force gauges (manufactured by Imada Co., Ltd.) were used as the load meters 51 and 43a. In addition, for the contact pressure measuring device according to this example, a simulation model of a two-layer structure in which different urethane foams are laminated as shown in FIG. 13(a) was created using simulation software (product name: MARC, product of MSC Software Co., Ltd.), and the contact pressure was simulated when the second pressing position P2 of the second pressure element 3 was changed. Here, the contact pressure was calculated using the finite element method based on the compressed hyperelastic body model shown in Equation 1, which is set as a calculation model of the urethane foam material in the simulation software. In the strain energy density function W shown in Equation 1 below, μ, α, and β are material constants, μ is the elastic modulus of the urethane foam constituting the object to be measured, α is the deviation index, and β is the volume index. J corresponds to the volume ratio before and after deformation, and is the product of λ ₁ , λ _2, and λ ₃ related to the main elongation.

A 100 mm thick mattress part formed by stacking two 50 mm thick urethane foam sheets was prepared as the subject of measurement, body support equipment A. The upper layer was a 50 mm thick urethane foam (product name: TB-SKL, product of Achilles Corporation, hardness at 40% compression according to JIS K 6400-2 A method is 120 ± 27 N), and the lower layer was a 50 mm thick urethane foam (product name: TB-QKQ, product of Achilles Corporation, hardness at 40% compression according to JIS K 6400-2 A method is 200 ± 35 N).

The body support tool A was placed on the stage 9, and the wing nut 48b was tightened to move the press plate 410 downward, and the first pressure tool 2 was moved in the pressing direction. At this time, the first pressure tool 2 was pressed into the body support tool A until the first pressing position P1 related to the first contact part tip 23a of the first pressure tool 2 was 37.5 mm from the surface of the body support tool A in the pressing direction. The load by the first pressure tool 2 at this time was 33.5 kg. Next, the handle 63 of the second pressure tool moving means 6 was turned to move the lifting platform 62 of the lifting unit 61 in the pressing direction, and the second pressure tool 3 was moved in the pressing direction through the guide hole 24 of the first pressure tool 2, and the body support tool A was compressed and deformed. At this time, the contact pressure that the second pressure tool 3 received from the body support tool A was measured by the force gauge 51 connected to the upper side of the second pressure tool 3 for each position of the second contact part tip 31a of the second pressure tool 3. The results are shown in Figure 13(b).

On the other hand, to simulate the contact pressure of body support device A, the measured data of the load-displacement curves during compression deformation for the upper and lower urethane foam layers were input into the simulation software as energy density functions W, and the λ, α, and β that fit the measured W based on the model of Equation 1 were determined in the simulation software, and the deformation amount and load during compression for the structure in Figure 13(a) were calculated using the obtained λ, α, and β for each urethane foam. The contact pressure data calculated using the simulation software is also shown in Figure 13(b).

13(b), the position of the tip of the second pressure element 3 is shown on the horizontal axis, which means the position from the surface of the body support tool A. Since the first pressing position P1 of the first contact tip 23a of the first pressure element 2 is 37.5 mm, when the position of the tip of the second pressure element becomes 37.5 mm, the first pressing position P1 of the first contact tip 23a of the first pressure element 2 and the second pressing position P2 of the second contact tip 31a of the second pressure element 3 become the same position. Therefore, the position of the tip of the second pressure element that exceeds 37.5 mm becomes the position where the contact tip 31a of the second pressure element 3 protrudes from the contact tip 23a of the first pressure element 2. Comparing the simulation data with the actual measurement data, it was found that there is a difference in the values until the position of the second contact tip 31a of the second pressure element 3 reaches 37.5 mm, but after 37.5 mm, that is, from the position where the second contact tip 31a of the second pressure element 3 protrudes from the contact tip 23a of the first pressure element 2, the difference becomes slight, and when the protruding height of the second contact tip 31a of the second pressure element 3 is 2.5 mm (the position of the tip of the second pressure element is 40 mm), the values are almost the same (actual measurement value according to the present invention: 4.6 N, simulation value: 4.5 N). From these findings, it was found that the present invention can easily and accurately obtain contact pressure data of a local body part model as data similar to that of a simulation model.

The present invention is not limited to the above-mentioned embodiment, and the technical scope of the invention includes various modified designs within the scope of the claims.

REFERENCE SIGNS LIST 1, 10 Contact pressure measuring device 2, 200, 201, 202, 203 First pressure element 21 Base portion 22 Convex portion 23, 230, 231, 232, 233 First contact portion 23a First contact portion tip 24, 240, 241, 242, 243 Guide hole portion 25 Mounting hole 3, 300, 301, 302, 303 Second pressure element 31, 310, 311, 312, 313 Second contact portion 31a Second contact portion tip 32 Mounting hole 4, 40 Load applying means 41, 410 Press plate 42, 420 Shaft 43 Load setting means 43a Load meter (force gauge)
43b Pressure tester 43c Shaft 44 Lifting platform 45 Lifting unit 46 Handle 47 Position measuring device 48 Support means 48a Bolt 48b Wing nut 5 Load measuring means 51 Load gauge
52 Pressure tester 53 Shaft portion 6 Second pressure tester moving means 61 Lifting unit 62 Lifting platform 63 Handle 7 Position setting means (position measuring device)
8 Support 9 Stage A Body holding device (object to be measured)
P1: Position of the tip of the first contact portion at the first pressing position P2: Position of the tip of the second contact portion at the second pressing position

Claims (12)

A method for measuring contact pressure of a local body part model, the method comprising the steps of:
a first compressive deformation step of compressing and deforming the object by pressing a surface of the object with a preset load using a first pressure tool having a contact part that imitates the shape of the periphery of a local part of the body and a guide hole part at a part of the contact part that corresponds to the local part of the body;
a first pressure tool holding step of holding the first pressure tool at a first pressing position, the first pressure tool being positioned in a pressing direction when the object is compressed and deformed in the first compressive deformation step;
a second compressive deformation step of moving a second pressure tool having a contact portion simulating the shape of a local part of a body and formed so as to be freely inserted into the guide hole portion of the first pressure tool through the guide hole portion of the first pressure tool to a second pressing position where a tip end of the contact portion of the second pressure tool is located at least on the same plane as the tip end of the contact portion of the first pressure tool at the first pressing position or is located at a position protruding therefrom, and pressing a surface of the object to be measured with the second pressure tool to compressively deform the object to be measured;
a measuring step of measuring the force received by the second pressure element from the object to be measured in the second compressive deformation step by a load measuring device. The contact pressure measurement method according to claim 1, characterized in that in the first pressure probe holding step, after the first pressure probe is held at the first pressing position, it is left for a predetermined period of time. The contact pressure measurement method according to claim 1 or 2, characterized in that, in the second compressive deformation step, after the second pressure element is moved to the second pressing position, the second pressure element is left at the second pressing position for a predetermined time. The contact pressure measurement method according to any one of claims 1 to 3, characterized in that the temperature of the contact part of the first pressure tool or the contact part of the second pressure tool that presses against the surface of the object to be measured is 30 to 40°C. The local body part model is a protruding body part model,
the first pressure member has a contact portion that imitates a shape of a protruding part of the body and has the guide hole portion at a portion of the contact portion that corresponds to the protruding part of the body;
The second pressure member has a contact portion that resembles a protruding part of a body,
The contact pressure measuring method according to any one of claims 1 to 4, characterized in that in the second compressive deformation step, the second pressing position is a position where a tip of the contact portion of the second pressing member protrudes from a tip of the contact portion of the first pressing member at the first pressing position. The contact pressure measuring device according to any one of claims 1 to 5, characterized in that the contact portion of the first pressure element has a shape that imitates the buttocks, and the contact portion of the second pressure element has a shape that imitates the sacrum or a part of the sacrum. A contact pressure measuring device for a local body part model, the contact pressure measuring device being a body support tool as a measurement object,
a first pressure element having a first contact portion that imitates the shape of a localized area of a body, the first contact portion being disposed in a direction in which the first contact portion presses against a surface of the object to be measured;
a load applying means for supporting the first pressure bar and for pressing the surface of the object to be measured with a preset load;
a second pressure element having a second contact portion that imitates the shape of a local part of a body, the second contact portion being disposed in a direction in which the second contact portion presses against the surface of the object to be measured;
A load measuring means connected to the second pressure piece for measuring a force applied to the second pressure piece;
A second pressure piece moving means for moving the second pressure piece in a pressing direction;
a position setting means connected to the second pressure tool moving means for setting a pressing position of the second pressure tool,
the first pressure member has a guide hole portion through which the second pressure member can be freely inserted at a portion of the first contact portion corresponding to a localized part of the body;
A contact pressure measuring device, characterized in that the second pressure element is configured to press the surface of the object to be measured through the guide hole portion of the first pressure element. The contact pressure measuring device according to claim 7, characterized in that the first contact portion of the first pressure element or the second contact portion of the second pressure element is covered with rubber or a material having viscoelasticity. The contact pressure measuring device according to claim 7 or 8, characterized in that a temperature adjusting means that provides a temperature of 30 to 40°C is connected to the first contact part of the first pressure element or the second contact part of the second pressure element. The local body part model is a protruding body part model,
the first pressure member has a first contact portion that imitates a shape of a protruding part of the body and has the guide hole portion at a portion of the first contact portion that corresponds to the protruding part of the body;
10. The contact pressure measuring device according to claim 7, wherein the second pressure element has a second contact portion that mimics the shape of a protruding part of the body. The contact pressure measuring device according to any one of claims 7 to 10, characterized in that the first contact portion of the first pressure element has a shape simulating the buttocks, and the second contact portion of the second pressure element has a shape simulating the sacrum or a part of the sacrum. The contact pressure measuring device according to any one of claims 7 to 11, characterized in that the guide hole portion of the first pressure bar is composed of a through hole penetrating the first pressure bar, a through groove provided on the outer periphery of the first pressure bar, or a frame portion provided on the outer periphery of the first pressure bar.

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