Evaluation method for gait impact of absorbent articles

Abstract

The present invention provides a method for evaluating the gait influence of an absorbent article, which evaluates the degree of influence of wearing the absorbent article on gait, comprising the following steps (A) to (C). (A) a step of causing a person to walk at least three walking cycles without wearing the absorbent article to be evaluated, and monitoring the normal gait; (B) a step of causing a person to walk at least three walking cycles while wearing the absorbent article to be evaluated, and monitoring the gait while wearing the article; and (C) a step of comparing the normal gait with the gait while wearing the article.

Description

Technical Field

[0001] The present invention relates to a method for evaluating the gait influence of an absorbent article. Background Art

[0002] One of the various performances required of absorbent articles such as disposable diapers is the ease of movement of the lower limbs when worn, and a method for evaluating the ease of movement has been proposed.

[0003] For example, the present applicant has proposed a method for evaluating the ease of movement of the wearer's lower limbs while wearing a pants-type diaper, based on the degree of muscle burden on the wearer's lower limbs when walking while wearing the diaper (see Patent Document 1).

[0004] According to the method of patent document 1, the ease of movement of the wearer's lower limbs while wearing a shorts-type diaper can be objectively evaluated. For example, regarding the ease of movement of the lower limbs, even if the wearer is an infant who is difficult to directly listen to opinions, an objective evaluation of the ease of movement of the lower limbs can be achieved.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-15747 Summary of the invention

[0008] The present invention provides a method for evaluating the degree of influence of an absorbent article on gait, which evaluates the degree of influence of wearing of the absorbent article on gait.

[0009] The evaluation method of the present invention preferably includes the following steps (A) to (C).

[0010] (A) a step of causing a person to walk at least three walking cycles without wearing the absorbent article to be evaluated, and photographing a normal gait for monitoring;

[0011] (B) a step of walking at least three walking cycles while wearing the absorbent article to be evaluated, and photographing and monitoring the gait while wearing the article; and

[0012] (C) A comparison step of comparing the normal gait and the gait when wearing the device.

[0013] In the step (C), preferably, based on the information on gait and the parameters indicating gait (gait parameters) obtained by analyzing or processing the data obtained as a result of monitoring in the steps (A) and (B), a comparison is made between the normal gait and the gait when wearing the wearable device. The term "analyze or process" also includes analysis and processing.

[0014] In addition, the gait comparison in the above step (C) does not need to utilize all the data of the three walking cycles monitored in the above steps (A) and (B), but only the data of one walking cycle can be extracted and compared with the data of the one walking cycle.

[0015] The present invention provides a method for evaluating the degree of influence of absorbent articles on gait, which compares and evaluates the degree of influence of wearing of absorbent articles on gait for at least two different absorbent articles.

[0016] The evaluation method of the present invention preferably includes the following steps (D) to (F).

[0017] (D) a step of walking at least three walking cycles while wearing an absorbent article and monitoring the gait by photographing the gait while wearing the article;

[0018] (E) the step of walking for at least three walking cycles while wearing another absorbent article and monitoring the gait by photographing the gait while wearing the article; and

[0019] (F) A comparing step of comparing the gait when the one absorbent article is worn with the gait when the other absorbent article is worn.

[0020] In the step (F), the gaits of the plurality of absorbent articles are preferably compared based on information on gait or parameters indicating gait (gait parameters) obtained by analyzing or processing the data obtained as a result of monitoring in the steps (D) and (E). The term "analyze or process" also includes analysis and processing.

[0021] In addition, the gait comparison in the above step (F) does not need to utilize all the data of the three walking cycles monitored in the above steps (D) and (E), but only the data of one walking cycle can be extracted and compared with the data of the one walking cycle.

[0022] Other features of the present invention will become apparent from the description of the claims and the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a bird's-eye view of a walkway showing a preferred example of a walkway for monitoring gait.

[0024] Figure 2 It is the state of wearing a sensor for obtaining a three-dimensional image in a method of analyzing a monitored gait.

[0025] Figure 3 (a) and Figure 3(b) is an illustration of the coronal plane hip joint angle and the change of the coronal plane hip joint angle. Figure 3 (c) is a graph showing the measurement results of changes in the frontal plane hip joint angle during walking of infants wearing diapers and infants not wearing diapers.

[0026] Figure 4 (a) and Figure 4 (b) is an illustration of the pelvic angle and the change of the pelvic angle. Figure 4 (c) is a graph showing the measurement results of changes in the pelvic angle of infants wearing diapers and infants not wearing diapers during walking.

[0027] Figure 5 (a) and Figure 5 (b) is an illustration of the sagittal plane hip joint angle and the change of the sagittal plane hip joint angle. Figure 5 (c) is a graph showing the measurement results of changes in the sagittal plane hip joint angle during walking of infants wearing diapers and infants not wearing diapers.

[0028] Figure 6 (a) and Figure 6 (b) is a diagram illustrating the body's center of gravity and the left-right changes in the body's center of gravity. Figure 6 (c) is a graph showing the measurement results of the total movement distance of the body center of gravity in the left-right direction of the infants wearing diapers and the infants not wearing diapers while walking.

[0029] Figure 7 (a) is a diagram illustrating the change in the vertical direction of the body's center of gravity. Figure 7 (b) is the vertical movement distance of the center of gravity of the body of the infant wearing a diaper and the infant not wearing a diaper while walking.

[0030] Figure 8 (a) is an illustration of the step length. Figure 8 (b) is a graph showing the measurement results of the stride lengths of infants wearing diapers and infants not wearing diapers during walking.

[0031] Fig. 9 (a) is the block diagram of the gait impact evaluation system. Fig. 9 (b) is a flow chart of the evaluation based on the gait impact evaluation system.

[0032] Fig.10 This is a cross-sectional view of the absorbent body used in the diaper of Test Example 1, taken along the diaper width direction.

[0033] Fig.11 This is a graph showing the relationship between the frontal plane hip joint angle and the ratio of the pressure applied to the inner side of the leg.

[0034] Fig.12 This is a graph showing the measurement results of the frontal plane hip joint angle in the evaluation I of the gait influence degree.

[0035] Fig.13 This is a graph showing the measurement results of the total moving distance of the body center of gravity in the left-right direction in the evaluation I of the gait influence degree.

[0036] Fig.14 This is a graph showing the measurement results of the stride length based on the skeleton information in the evaluation II of the gait influence degree.

[0037] Fig.15 This is a graph showing the measurement results of the distance between both knees in the evaluation II of the gait influence degree. DETAILED DESCRIPTION

[0038] The performance of absorbent articles is expected to be improved year by year. For example, diapers with better lower limb mobility when worn are developed, or when evaluating the ease of movement of multiple diapers while wearing them, it is hoped that small differences in gait between multiple diapers can be detected. However, existing evaluation methods still have room for improvement in detecting small differences between multiple diapers.

[0039] Furthermore, Patent Document 1 does not describe attaching electrodes to the legs to measure changes in myoelectric potential during walking and monitor gait.

[0040] The present invention relates to a method for evaluating the degree of influence of an absorbent article on a person's gait, and is capable of evaluating the influence of an absorbent article on a person's gait with high accuracy.

[0041] Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.

[0042] In addition, the term "measurement" in this specification is not limited to obtaining data values, but also includes obtaining data and obtaining a predetermined parameter by calculation using the obtained value.

[0043] The absorbent article evaluation method of the present invention is a method for evaluating the influence of absorbent articles such as diapers on the gait of a wearer wearing the absorbent article. Gait refers to dynamic characteristics such as posture, movement, joint movement, etc. during walking, or characteristics when touching the ground such as stride or step length, which are all visually captured states of the walker. Gait is visually monitored by photographing the walker. Only one of the dynamic characteristics and the characteristics when touching the ground may be monitored, or both may be monitored.

[0044] The absorbent articles to be evaluated broadly include articles for absorbing liquid discharged from the human body. Absorbent articles generally have a liquid-permeable front sheet, a liquid-impermeable or water-repellent leakproof sheet, and a liquid-retaining absorbent body interposed between the two sheets. Examples of absorbent articles include disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., but are not limited thereto.

[0045] The absorbent article to be evaluated is preferably a disposable diaper. Disposable diapers include shorts-type diapers and unfolded diapers. Shorts-type diapers usually have an absorbent body, which includes a liquid-permeable front sheet, a liquid-impermeable or water-repellent leakproof sheet, and a liquid-retaining absorbent body arranged between the two sheets, and the two side edges of the end of one side in the length direction of the absorbent body and the two side edges of the end of the other side are joined to each other to form a shorts type. The unfolded diaper usually has an absorbent body, which includes a liquid-permeable front sheet, a liquid-impermeable or water-repellent leakproof sheet, and a liquid-retaining absorbent body arranged between the two sheets, and a fixing belt is provided on the two side edges of the end of one side in the length direction of the absorbent body, and a fixed area fixed to the fixing belt is provided on the outer surface of the other end.

[0046] The diapers to be evaluated may be diapers for adults or diapers for infants.

[0047] The evaluation method of the preferred first embodiment of the present invention is a method for evaluating the degree of influence of wearing an absorbent article on gait, and an evaluation method for the gait influence of an absorbent article. The evaluation method of the first embodiment includes the following steps (A) to (C). The order in which steps (A) and (B) are performed is not distinguished. For example, step (B) can be performed after step (A), or step (A) can be performed after step (B).

[0048] [Step (A)]

[0049] Step (A) is a step of causing a person to walk at least three walking cycles without wearing an absorbent article to be evaluated, and monitoring the gait. The gait in the state of not wearing an absorbent article is referred to as a normal gait. The gait in the state of wearing an absorbent article is referred to as a wearing gait. Here, the so-called "state of not wearing an absorbent article" is a naked state where the body is not wearing anything, or a state of wearing only underwear made of cloth or non-woven fabric without an absorbent body.

[0050] Hereinafter, a description will be given of an example in which the absorbent article to be evaluated is a disposable diaper (hereinafter also referred to as a diaper).

[0051] In step (A), the person is made to walk without wearing the absorbent article of the evaluation object, and the walking state is monitored. The monitoring is preferably performed by photographing the walking person with a known camera device. It is sufficient for the monitoring to obtain the data required for the walking information for comparative evaluation, such as the change in the hip joint angle, the rotation of the pelvis, or the movement of the center of gravity, which will be described later. As described in the present embodiment, when a camera device is used, the camera device may be a device for taking dynamic images, or a device for taking static images multiple times at appropriate intervals. In addition, a three-dimensional motion capture device (three-dimensional motion analysis device) can also be used, which can take in the positions of the respective marks set on multiple parts of the wearer's body at a specified time. As a marker of the three-dimensional motion capture device (three-dimensional motion analysis device), an appropriate marker can be selected according to the type of the device, for example, a sheet-like or spherical component that reflects various light rays such as infrared rays can be used.

[0052] A particularly preferred camera device is a Vicon camera system, for example, Vicon's Vantage / Vero camera system can be used. The Vicon camera system can measure the position information and movement information of the marker in real time with high accuracy, and process the information using motion capture software such as Nexus, Shogun, Tracker, Polygon, and Pegasus, thereby making it possible not only to perform the shooting in step (B), but also to easily implement the measurement of the wearer's changes over time in step (C).

[0053] In step (A), the gait of the walking person is monitored, and data of changes in the positions of the markers occurring in at least three gait cycles are acquired. By monitoring the gait for three or more gait cycles, a more accurate evaluation can be achieved.

[0054] In step (A), specific positions of the body can also be extracted based on the dynamic image data obtained by shooting a person walking without markings, using well-known skeleton information acquisition technologies, such as OpenPose (URL = https: / / gthub.com / CMU-Perceptual-Computing-Lab / openpose) and VisionPose (URL = https: / / www.next-system.com / visionpose). In the skeleton information acquisition technology, for example, the neck, shoulders, elbows, wrists, waist, knees, ankles, etc. are extracted, and the extracted parts are represented by points and lines to infer the posture. In addition, the joint position can also be determined using the skeleton information acquisition technology. Using the dynamic image data of the gait and the skeleton information acquisition technology, it becomes easy to measure the gait parameters and their changes for gait comparison.

[0055] [Step (B)]

[0056] Step (B) is a step of causing a person to walk at least three walking cycles while wearing the absorbent article to be evaluated, and monitoring the gait while wearing the article. The monitoring is preferably performed by photographing the walking person with a known imaging device.

[0057] From the perspective of eliminating the influence of individual differences, it is preferred that the person walking in step (A) and the person walking in step (B) are basically the same person, but this is not limited to this. It is also possible to compare groups of multiple people with similar attributes, not necessarily limited to the same person.

[0058] In step (B), the diaper to be evaluated is preferably worn by a person of the age assumed to wear the diaper. For example, the wearer in the case of an adult diaper is an adult, and the wearer in the case of an infant diaper is an infant. However, in order to evaluate the influence on the wearer's walking, the wearer in the case of a pants-type diaper for infants is limited to an infant of an age that can walk. The age mentioned in this specification includes the age in months.

[0059] The walking ability of infants and young children changes greatly from the time when they can stand by holding their hands to the time when they can walk back and forth freely. Considering that the influence of diapers on walking changes during this period of rapid development of walking ability, it is useful to investigate the influence of diapers on the walking of infants and young children in this period for the development of diapers suitable for each stage of development. From this point of view, the wearer is preferably 12 to 30 months old.

[0060] The diaper worn by the wearer as the evaluation object may be a dry diaper that has not absorbed the assumed liquid such as urine, or a wet diaper that has absorbed the assumed liquid such as urine. As the assumed liquid such as urine, water or physiological saline is preferably used.

[0061] By comparing the wearing of a dry diaper with the wearing of a wet diaper, it is possible to investigate whether there is a difference between the effects of the dry diaper and the wet diaper on the wearer's gait.

[0062] [Step C]

[0063] Step (C) is a step of comparing the normal gait with the gait when wearing the device.

[0064] In step (C), based on the data obtained from the monitoring results in step (A) and step (B), walking information is obtained for normal gait and gait when wearing the device by analyzing the gait. The data obtained from the monitoring results is, for example, the position information or movement information of the marker obtained by the Vicon camera system.

[0065] The method for analyzing gait is preferably three-dimensional image analysis. By using three-dimensional image analysis, position information about the walking body shape, bones, joints, etc. is obtained, and by analyzing dynamic images or multiple still images taken continuously, their time series motion information is obtained. As a method of three-dimensional image analysis, examples include: using multiple cameras to construct a shooting space and track the position of a reflective marker, that is, an optical method; an inertial sensor method that calculates the position and posture based on the inertial sensor composed of a gyro sensor (angular velocity meter) and an accelerometer to reverse the motion information; a mechanical method using a sensor that measures the rotation angle and displacement such as a locator and an encoder; a magnetic method that uses a magnetic field generating device to send a magnetic field to the shooting range and is received by a wearable magnetic sensor, etc. Among these, from the perspective of high absolute position accuracy, it is preferred to use an optical motion capture system such as Vicon's Vantage / Vero camera system. It is also possible to use a method of extracting three-dimensional coordinates (kinect) of feature points from a dynamic image without annotated markers.

[0066] The method of analyzing gait is preferably a method of calculating three-dimensional image coordinates based on two-dimensional dynamic image coordinates, from the perspective of having fewer restrictions on equipment and being able to monitor more daily gait. As a method of obtaining three-dimensional image coordinates based on two-dimensional dynamic images, there are technologies that use deep learning and neural networks to infer three-dimensional coordinates based on two-dimensional images. In either case, three-dimensional coordinates are constructed by inferring the coordinates of two-dimensional skeleton points such as OpenPose. Among these methods, there are supervised learning and unsupervised learning, but in terms of accuracy, a gait analysis method based on the construction of three-dimensional coordinates from two-dimensional skeleton point coordinates based on supervised learning is preferred.

[0067] The comparison of gait in step (C) is preferably performed using information representing gait or gait parameters representing gait. As gait parameters, preferably, at least one of (1) coronal plane hip joint angle, (2) pelvic angle, (3) sagittal plane hip joint angle, (4) amount of movement of the body's center of gravity, (5) step length, or (6) distance between the two knees is included. In step (C), as the wearer's change over time, preferably the change in coronal plane hip joint angle, the change in pelvic angle, the change in sagittal plane hip joint angle, or the amount of movement of the body's center of gravity is used as a reference to compare the normal gait and the gait when wearing the wearer.

[0068] (1) Changes in the coronal plane hip angle

[0069] The measurement of changes in the coronal plane hip joint angle and the evaluation based on the measurement results are described.

[0070] The coronal plane hip angle is Figure 3(a) and Figure 3 (b) is an index mainly indicating the amount of movement of the femoral segment to the side of the pelvis. For example, in the XYZ coordinate system of the pelvis (refer to Figure 4 (a), hereinafter also referred to as the pelvic coordinate system], and the XYZ coordinate system of the thigh segment [refer to Figure 3 (a), hereinafter also referred to as the femoral coordinate system), the inclination angle of the X-axis or Z-axis of the femoral coordinate system rotated around the Y-axis of the pelvic coordinate system relative to the YZ plane or XY plane of the pelvic coordinate system is measured as the coronal plane hip joint angle. The Z-axis of the femoral coordinate system is assumed to be on the straight line connecting the hip joint center P1 and the knee joint center P2. Regarding the hip joint center P1 and the knee joint center P2, for example, the hip joint center P1 can be calculated based on the positions of the greater trochanter M1 and the pelvis, and the position of the knee joint center P2 can be calculated as the midpoint of the outer knee M2 and the inner knee M3. The position of the pelvis is composed of the sacrum P5 and the left and right anterior superior iliac spines P3 and P4 [refer to Figure 4 (a)〕. The Y axis of the femoral coordinate system is assumed to be a straight line passing through the hip joint center P1 and perpendicular to the plane passing through the hip joint center P1, the knee joint center P2 and the greater trochanter M1. The X axis of the femoral coordinate system is assumed to be a straight line passing through the hip joint center P1 and perpendicular to the Y axis and Z axis of the femoral coordinate system. The various parts of the hip joint center P1, the knee joint center P2, etc. are obtained based on the parts detected by a motion capture device, etc., using well-known analysis software such as Visual3D.

[0071] In the step of monitoring gait, by monitoring the gait of the wearer for more than three walking cycles, for example, data on changes in the positions of the markers generated in the three walking cycles can be obtained, and thus using these data, it is possible to measure, for example, Figure 3 (c) shows the changes in hip joint angle during a walking cycle.

[0072] As shown in this embodiment, with respect to the hip joint angle (coronal plane hip joint angle, sagittal plane hip joint angle), from the perspective of more accurately comparing gaits, it is preferred to measure or analyze the displacement of the hip joint, femoral joint, etc. in relation to a coordinate system set in the pelvis. The method for measuring the coronal plane hip joint angle is not limited to the above method. The same is true for the sagittal plane hip joint angle described later.

[0073] Figure 3 (c) is to make 26 infants aged 18 to 20 months who can walk independently and wear only 1 to 3 pants-type diapers, without teaching them speed and stride length. Figure 1The graph shows the change in the hip joint angle for one walking cycle when walking on the walking path 3 shown, together with the result when the person walks in the nude state without wearing a diaper.

[0074] Diapers 1 and 2 have the same structure, while diaper 3 has a different structure from diapers 1 and 2. Diapers 1 and 3 are in a wet state after absorbing 160 g of saline solution, while diaper 2 is in a dry state. The dry state is the state before absorbing saline solution. Figure 1 A plurality of Vicons 31 are arranged around the walkway 3 shown in FIG. 3 as three-dimensional motion capture devices. Reference numeral 32 denotes a device for measuring the force received from the ground, and a force plate (AMTI, 2000 Hz) is used.

[0075] The following Table 1 shows the structures of diapers 1, 2, and 3. In Table 1, the meanings of the absorbent core, the central region, the side regions, the pair of bending guides, and the other bending guides are the same as those of the diaper 4 described in the test example described later (see Fig.10 ). In Table 1 and Table 3, the dimensions of each part of the absorbent core are values ​​in a dry state.

[0076] [Table 1]

[0077]

[0078] [Measurement of pressure applied to the inner side of the leg]

[0079] The values ​​of pressure applied from both sides of the crotch of the diaper to the inner side of the legs were measured by the following method for the dry diaper 2 and the wet diapers 1 and 3. Table 2 shows, for each diaper, the ratio of the pressure applied to the inner side of the legs (kPa) and the pressure (kPa) of the dry diaper 2 to the reference value 1 as a reference value.

[0080] [Method for measuring pressure applied to the inner side of the leg]

[0081] A baby mannequin with movable lower limbs was put on a diaper, and the pressure applied by the diaper to the inner sides of the left and right legs when the left and right legs were crossed at the position where the left and right intervals between the legs were the narrowest during walking was measured using a contact pressure measuring device ("AMI3037" manufactured by AMI TECHNO CO., LTD.).

[0082] [Table 2]

[0083]

[0084] like Figure 3As shown in (b), when the hip joint is abducted (abduction) when the knee joint center P2 moves to the outside of the wearer's left-right direction, the value of the coronal plane hip joint angle (°) decreases, and when the hip joint is adducted (adduction) when the knee joint center P2 moves to the inside of the wearer's left-right direction, the value of the coronal plane hip joint angle (°) increases. Figure 3 In (c), the difference in walking distance per walking cycle due to the difference in diapers is ignored, and the walking distance in the X-axis direction corresponding to one walking cycle is expressed as the same. Figure 3 The graph (c) shows the average value of the coronal plane hip joint angle of the right foot and the average value of the coronal plane hip joint angle of the left foot, which is 1 / 2 of the sum of the values ​​at the positions with the same ratio from the starting end of the one gait cycle in one gait cycle. Regarding the change in the amount of one gait cycle of each right foot and left foot, at least three gait cycle amounts are measured for each foot, and the average value of the values ​​at the positions with the same ratio from the starting end of the one gait cycle is averaged as the change in the amount of one cycle of each foot.

[0085] like Figure 3 As shown in (c), the walking state of wearing diapers 1 to 3 is a walking state with the hip joint abducted compared to the walking state of the naked body. Since the naked body is the state where the diaper has the least influence on the walking of the wearer, by comparing the changes in the hip joint angles of the walking state of wearing diapers 1 to 3 and the walking state of the naked body, the influence of diapers 1 to 3 on the walking of the wearer can be evaluated.

[0086] In order to reduce the influence of the absorbent article on walking, it is preferred that there is no difference or a small difference in the change of the hip joint angle between the normal gait and the gait when wearing the absorbent article.

[0087] For example, the integral value of the whole or a part of a walking cycle in the graph of the change of the coronal plane hip joint angle in a walking cycle is calculated, and when the integral value is compared between the normal gait and the gait when wearing the device, the integral value in the normal gait is larger than the integral value in the gait when wearing the device, but the smaller the difference is, the better. The integral value is, for example, Figure 3 In (c), the area of ​​the region enclosed by the straight line with an angle of zero and the curve of the entire gait cycle is expressed numerically, and from the viewpoint of obtaining an absorbent article with a small gait influence, preferably the difference between the integral value in the normal gait and the integral value in the gait when worn, i.e., (integral value in the normal gait) - (integral value in the gait when worn) is 0 or more and 5 or less, and more preferably 0 or more and 4 or less. In this case, the area below the straight line with an angle of zero, i.e., the negative area, is calculated as a negative value.

[0088] In addition, it is preferred to compare the maximum or minimum value of the coronal plane hip joint angle in a walking cycle between the normal gait and the gait when wearing the device. Figure 3 (c) shows the angle when the adduction side angle is positive and the abduction side angle is negative. When the coronal plane hip joint angle is at its maximum value, the value during gait is usually larger than the value during gait when wearing, but the difference is preferably smaller. When the hip joint angle is at its minimum value, the value during gait is usually larger than the value during gait when wearing, but the difference is preferably smaller.

[0089] From the perspective of forming an absorbent article with little influence on gait, the difference between the maximum value of the coronal plane hip joint angle during normal gait and the maximum value of the coronal plane hip joint angle during gait when worn, that is, (maximum value during normal gait) - (maximum value during gait when worn) is greater than 0 and less than 2, and more preferably greater than 0 and less than 1.6.

[0090] The difference between the minimum value of the coronal plane hip joint angle during normal gait and the minimum value of the coronal plane hip joint angle during gait when wearing, i.e. (minimum value during normal gait) - (minimum value during gait when wearing), is preferably greater than 0 and less than 2, and more preferably greater than 0 and less than 1.6.

[0091] In addition, it is preferred to compare the value of the coronal plane hip joint angle at a predetermined point in the step phase of a walking cycle between the normal gait and the gait when wearing the device. Figure 3 (c) shows the angle when the adduction side angle is positive and the external rotation side angle is negative. For example, the value of the coronal plane hip joint angle at a position of 80% of the walking distance in a walking cycle in a predetermined point of the stride period of the coronal plane hip joint angle can be used as a parameter related to gait.

[0092] Fig.11 In the figure, the relationship between the value of the coronal plane hip joint angle at a specified point of the stride period of 80% of the walking distance in one walking cycle and the ratio of the pressure applied to the inner side of the leg in the non-worn state (naked) and the worn state of diapers 1 to 3 is represented graphically.

[0093] like Fig.11 As shown in the graph, when the coronal plane hip joint angle at 80% is used as a parameter about gait, there is a correlation between the evaluation result based on the evaluation method of gait influence and the magnitude of the pressure applied by the diaper to the inner side of the leg. Therefore, based on the information of such correlation, the gait influence of the gait influence can also be quantified. The evaluation result of the evaluation method of the gait influence of the present invention changes correspondingly with the performance of the diaper such as the ease of walking, so the degree of influence on gait can also be quantified.

[0094] As described above, when the value of the frontal plane hip joint angle at a predetermined point in the swing phase is compared between the normal gait and the gait when wearing the device, the value in the normal gait is larger than the value in the gait when wearing the device, but the difference is preferably smaller.

[0095] From the perspective of forming an absorbent article with little influence on gait, the difference in the coronal plane hip joint angle at a specified point in the stride period, for example, at a position of 80% of the walking distance in a walking cycle, i.e., (the coronal plane hip joint angle at a position of 80% of the walking distance during normal gait) - (the coronal plane hip joint angle at a position of 80% of the walking distance during gait when worn) is preferably greater than 0 and less than 3, and more preferably greater than 0 and less than 2.5.

[0096] The evaluation method according to a preferred second embodiment of the present invention is a method for evaluating the gait influence of absorbent articles by comparatively evaluating at least two different absorbent articles, and includes the following steps (D) to (F).

[0097] (D) the step of walking for at least three walking cycles while wearing an absorbent article and monitoring the gait by photographing the gait while wearing the article;

[0098] (E) a step of walking for at least three walking cycles while wearing another absorbent article and monitoring the gait by photographing the gait while wearing the article;

[0099] (F) A step of comparing a gait when the one absorbent article is worn with a gait when the other absorbent article is worn.

[0100] Steps (D) and (E) of the second embodiment can be implemented in the same manner as step (B) of the first embodiment. Step (F) of the second embodiment can be implemented in the same manner as step (C) of the first embodiment. In the second embodiment, the order in which steps (D) and (E) are performed is not differentiated. For example, step (E) can be performed after step (D), or step (D) can be performed after step (E). From the viewpoint of eliminating the influence of individual differences, it is preferred that the person walking in step (D) and the person walking in step (E) are basically the same person, but this is not limited to this, and groups of multiple people with similar attributes can also be compared with each other, so they are not necessarily limited to the same person. In addition, in addition to having different structures, two different absorbent articles may also be absorbent articles that differ in state, such as one being in a wet state and the other being in a dry state.

[0101] By wearing different absorbent articles in step (D) and step (E) and comparing walking information obtained by monitoring the gait while wearing each absorbent article, it is possible to compare the effects of wearing two different absorbent articles on a person's gait.

[0102] For example, Figure 3 The diapers 1 and 2 shown in (c) have the same structure, but because one is in a wet state and the other is in a dry state, the wet diaper 1 has a higher tendency to stretch out than the dry diaper 2, so it can be evaluated that the wet diaper 1 has a greater impact on the wearer's walking than the dry diaper 2. In addition, even if they are both in a wet state, because the diaper 3 has a higher tendency to stretch out than the diaper 1, it can be evaluated that even if they are both in a wet state, the wet diaper 3 has a greater impact on the wearer's walking than the diaper 1.

[0103] In the above steps (B), (D) and (E), when monitoring the gait during wearing, it is preferred to perform an acclimation step after the person wears the absorbent article and before the person walks to monitor the gait. The acclimation step is a step of acclimation treatment to adapt the absorbent article to the body shape of the person. As the acclimation treatment, for example, after the person wears a certain absorbent article, the person walks for more than 3 minutes. It is preferred that the acclimation treatment be performed every time the absorbent article is changed.

[0104] The comparison between a normal gait and a gait when worn, or the comparison between gaits when worn between different absorbent articles, based on walking information or gait parameters will be further described.

[0105] (2) Changes in pelvic angle

[0106] The measurement based on the change of the pelvic angle and the evaluation of the measurement results are described.

[0107] Pelvic angle Figure 4 (a) and Figure 4 As shown in (b), for example, when the plane passing through the three points of the left and right anterior superior iliac spines P3, P4 and the sacrum P5 is set as the pelvic plane P, the angle that changes due to the rotation of the X-axis or Y-axis of the coordinate system of the pelvic plane P around the Z-axis is defined as the relative angle with the laboratory coordinate system (XY plane).

[0108] The changes in the pelvic angle can be exemplified by: a rotation about the X-axis in which the sacrum P5 side in the pelvic plane P is displaced in the up-down direction relative to the X-axis passing through the left and right anterior superior iliac spines P3 and P4; a rotation about the Z-axis in which the left and right anterior superior iliac spines P3 and P4 of the wearer move one direction to the front of the wearer and the other direction to the back of the wearer relative to the Z-axis passing through the center position between the left and right anterior superior iliac spines P3 and P4 and perpendicular to the pelvic plane P; a rotation about the Y-axis in which one of the left and right anterior superior iliac spines P3 and P4 is displaced upward in the vertical direction and the other downward in the vertical direction relative to the Y-axis orthogonal to the X-axis and the Z-axis; and a composite rotation of two or more of these rotations.

[0109] The positions of the anterior superior iliac spines P3 and P4 and the position of the sacrum P5 can be calculated based on the position information of the markers respectively set correspondingly. The changes in the pelvic angle generated in a walking cycle, such as the rotation of the pelvic plane around the X-axis, Y-axis or Z-axis mentioned above, can also be obtained by measuring the position information of the markers respectively set corresponding to the positions of the anterior superior iliac spines P3 and P4 and the position of the sacrum P5 and their movement.

[0110] Figure 4 (c) is for 26 infants aged 18 to 20 months who are able to walk independently and wear pants-type diapers for 1 to 3 months, and make them walk without teaching them speed and stride. Figure 1 The graph shows the change in pelvic angle for one walking cycle when walking on the walking path 3, more specifically, the rotation about the Z axis (rotation of the pelvis), together with the result of walking in the same manner in a naked state without wearing a diaper. Diapers 1 to 3 include a wet state or a dry state in which 160 g of physiological saline solution is absorbed, and are the same as the above-mentioned diapers 1 to 3. Figure 4 The graph shown in (c) shows that, for one walking cycle of the right foot, the rotation around the Z-axis of the wearer's right anterior superior iliac spine P3 moving backward is regarded as external rotation, and for one walking cycle of the left foot, the rotation around the Z-axis of the wearer's left anterior superior iliac spine P4 moving backward is regarded as external rotation, indicating the average value of the rotation angle about the right foot and the rotation angle about the left foot.

[0111] like Figure 4As shown in (c), the rotation angle in the external rotation direction of the walking state wearing diapers 1 to 3 is larger than that of the walking state in the naked state. Since the naked state is the state where the diaper has the least influence on the walking of the wearer, the influence of diapers 1 to 3 on the walking of the wearer can be evaluated by comparing the size of the rotation angle of the pelvis in the external rotation direction of the walking state wearing diapers 1 to 3 and the walking state in the naked state. Compared with the naked state, the degree of rotation in the external rotation direction of the walking state wearing diapers 1 to 3 is larger. It is speculated that in order to avoid the bulge of the diaper, the difficulty of swinging the feet forward is coped with, so the pelvis is rotated more than when naked.

[0112] In addition, although diaper 1 and diaper 2 have the same structure, one is in a wet state and the other is in a dry state. The wet diaper 1 rotates more in the outward direction than the dry diaper 2, so it can be evaluated that the wet diaper 1 has a greater impact on the wearer's walking than the dry diaper 2. In addition, even if both are in a wet state, since diaper 3 has a higher tendency to rotate outward than diaper 1, it can be evaluated that diaper 3 has a greater impact on the wearer's walking than diaper 1.

[0113] In order to form an absorbent article that has no influence on walking, it is preferred that there is no difference or a small difference in the change of the pelvic angle between a normal gait and a gait when wearing the absorbent article.

[0114] For example, the integral value of the whole or a part of a walking cycle in a graph of the change of the pelvic angle in a walking cycle is calculated, and when the integral value is compared between a normal gait and a gait when wearing the wearer, the integral value in the normal gait is smaller than the integral value in the gait when wearing the wearer, but the smaller the difference, the better. The integral value is, for example, Figure 4 In (c), the area of ​​the region surrounded by the straight line with an angle of zero and the curve for one walking cycle is expressed numerically, from the viewpoint of forming an absorbent article with a small gait influence, preferably the difference between the integral value in the normal gait and the integral value in the gait when worn, i.e., (integral value in the normal gait) - (integral value in the gait when worn) is -450 or more and 0 or less, and more preferably -400 or more and 0 or less. In this case, the area below the straight line with an angle of zero, i.e., the negative area is calculated as a negative value.

[0115] In addition, it is preferred that the differential value in a predetermined area of ​​the graph of the change in the pelvic angle in one walking cycle be compared between the normal gait and the gait when worn. From the viewpoint of forming an absorbent article with a small gait influence, in the first half 0-50% of one walking cycle, the value in the normal gait is smaller than the value in the gait when worn, but the difference is preferably small, and in the second half 050-100% of one walking cycle, the value in the normal gait is larger than the value in the gait when worn, but the difference is preferably small. In numerical terms, from the viewpoint of forming an absorbent article with a small gait influence, the ratio of the maximum value of the differential value in the normal gait in the first half 0-50% of one walking cycle to the maximum value of the differential value in the gait when worn, or the ratio of the minimum value of the differential value in the normal gait in the second half 050-100% of one walking cycle to the minimum value of the differential value in the gait when worn, that is, (differential value in the gait when worn) / (differential value in the normal gait) is preferably 1 or more and 1.5 or less, and more preferably 1 or more and 1.3 or less. The differential value normalizes one walking cycle to 101 points, and calculates the ratio of the change per point.

[0116] In addition, it is preferred to compare the value of the pelvic angle at a predetermined point in a walking cycle between the normal gait and the gait when wearing the wearer. Figure 4 (c) shows the angle when the angle on the external rotation side is set to positive and the angle on the internal rotation side is set to negative. When the value of the pelvic angle at a predetermined point in a walking cycle is compared between a normal gait and a gait when wearing the device, the value in the normal gait is smaller than the value in the gait when wearing the device, but the difference is preferably smaller.

[0117] From the perspective of forming an absorbent article with little influence on gait, the difference in the value of the pelvic angle at a specified point in a walking cycle, for example, a position of 50% of the walking distance in a walking cycle, that is, (pelvic angle at a position of 50% of the walking distance during normal gait) - (pelvic angle at a position of 50% of the walking distance during gait when worn) is preferably greater than -10 and less than 0, and more preferably greater than -7 and less than 0.

[0118] (3) Changes in sagittal hip angle

[0119] The measurement of changes in the sagittal plane hip joint angle and the evaluation based on the measurement results are described.

[0120] Sagittal plane hip angle Figure 5 (a) and Figure 5 (b) is the coordinate system of the thigh segment around the pelvis (refer to Figure 4 The angle changes with the rotation of the X-axis of (a). For example, the inclination angle of the Z-axis of the femoral segment relative to the X-Z plane of the pelvis is measured, and the angle increases when bending and decreases when extending.

[0121] like Figure 5 As shown in (c), the sagittal plane hip joint angle tends to be lower when walking while wearing diapers 1 to 3 than when walking while naked. Since the naked state is the state where the diaper has the least effect on the wearer's walking, by comparing the sagittal plane hip joint angle between the walking while wearing diapers 1 to 3 and the walking while naked, the effect of diapers 1 to 3 on the wearer's walking can be evaluated. Compared with the naked state, the sagittal plane hip joint angle of walking while wearing diapers 1 to 3 is smaller, indicating that diapers 1 to 3 have an effect on gait.

[0122] In order to form an absorbent article with little influence on walking, it is preferred that there is no difference or a small difference in the sagittal plane hip joint angle between a normal gait and a gait when the absorbent article is worn.

[0123] For example, the integral value of the whole or a part of a walking cycle in the graph of the sagittal plane hip joint angle of a walking cycle is calculated, and when the integral value is compared between the normal gait and the gait when wearing the clothes, the integral value in the normal gait is smaller than the integral value in the gait when wearing the clothes, and the smaller the difference is, the better. The integral value is, for example Figure 5 In (c), the area of ​​the region surrounded by the straight line having an angle of minus 10 degrees and the curve in the second half of one walking cycle is expressed numerically as the difference between the integral value in the normal gait and the integral value in the gait when worn, i.e., (integral value in the normal gait) - (integral value in the gait when worn), preferably from the viewpoint of constituting an absorbent article with a small gait influence, of 0 to 700, more preferably from 0 to 650. In this case, the area below the straight line having an angle of zero, i.e., the negative area is calculated as a negative value.

[0124] In addition, it is preferred to compare the change in the sagittal plane hip joint angle in one walking cycle, that is, the difference between the maximum value and the minimum value, between the normal gait and the gait when the wearer is worn. When comparing the difference between the maximum value and the minimum value in the normal gait and the gait when the wearer is worn, it is assumed that the difference in the normal gait is greater than the difference in the gait when the wearer is worn, and the smaller the difference is, the better. From the perspective of constituting an absorbent article with a small gait influence, the change in the sagittal plane hip joint angle in one walking cycle, the difference between the change in the normal gait and the change in the gait when the wearer is worn, that is, (the change in the normal gait) - (the change in the gait when the wearer is worn) is preferably greater than -300 and less than 5, and more preferably greater than -200 and less than 0.

[0125] (4) Movement of the body’s center of gravity

[0126] The measurement of the amount of movement of the body's center of gravity and the evaluation based on the measurement results will be described.

[0127] The body center of gravity is the center of gravity P6 of the wearer's body. When the wearer is in an upright position, Figure 6 As shown in (a), the center of the body is located near the center of the width direction at approximately the same position as the pelvis, but its position swings left and right during walking. In a preferred method for measuring the amount of movement of the center of gravity of the body, as shown in Figure 6 As shown in (a), the center of gravity of the whole body is obtained by taking into account the center of gravity of the head obtained from the marker position set at the head, the center of gravity of the upper limbs obtained from the marker position set at the upper limbs, the center of gravity of the pelvis obtained from the marker position set at the pelvis, and the center of gravity of the lower limbs obtained from the marker position set at the lower limbs. The method for calculating the center of gravity of the body is well known, for example, it can be obtained using the function of Visual3D of motion capture software.

[0128] As the amount of movement of the body center of gravity, it is preferable to measure the integral value of the body center of gravity in the left-right direction (X direction) in one walking cycle, that is, the total movement distance in the left-right direction. The left-right direction (X direction) is a direction that intersects with the wearer's traveling direction (Y direction) in a top view of the walking path. The total movement distance when the body center of gravity does not shake at all in the left-right direction is zero.

[0129] Figure 6 (c) is for 26 infants aged 18 to 20 months who are able to walk independently and wear pants-type diapers for 1 to 3 months, and make them walk without teaching them speed and stride. Figure 1 The total distance of movement of the center of gravity in the left-right direction for one walking cycle when walking on the walking path 3 shown is shown together with the result of walking in the naked state without wearing a diaper. Diapers 1 to 3 are the same as the above-mentioned diapers 1 to 3 in a wet state or a dry state including 160g of physiological saline absorbed. Figure 6 The graph shown in (c) shows the average value of the total moving distance of the right foot per walking cycle and the total moving distance of the left foot per walking cycle.

[0130] exist Figure 6 (c) shows the average and standard deviation of the total movement distance of 26 infants. Figure 6 In (c), "**" indicates a significant difference between diapers or between diaper and naked state with a p value < 0.01, and "*" indicates a significant difference between diapers or between diaper and naked state with a p value < 0.05.

[0131] like Figure 6As shown in (c), the total distance of movement of the center of gravity in the left-right direction is larger when walking while wearing diapers 1 to 3 than when walking while naked. Since the naked state is the state where the diaper has the least influence on the wearer's walking, by comparing the length of the total distance of movement of the center of gravity in the left-right direction between the walking while wearing diapers 1 to 3 and the walking while naked, the influence of diapers 1 to 3 on the wearer's walking can be evaluated. Compared with the naked state, the total distance of movement of the center of gravity in the left-right direction is longer when walking while wearing diapers 1 to 3, which means that the state of wearing diapers 1 to 3 has a greater influence on walking than the naked state, and it is not easy to walk. In addition, although diaper 1 and diaper 2 have the same structure, one is in a wet state and the other is in a dry state. Compared with diaper 2 in a dry state, the total distance of movement of the center of gravity in the left-right direction of diaper 1 in a wet state is longer. Therefore, compared with diaper 2 in a dry state, diaper 1 in a wet state has a greater influence on the wearer's walking, and it can be evaluated that it is difficult to walk. Furthermore, even in a wet state, the total distance of movement of the center of gravity in the left-right direction of the diaper 3 is longer than that of the diaper 1. Therefore, the diaper 3 has a greater influence on the wearer's walking than the diaper 1, and it can be evaluated that the wearer has difficulty walking.

[0132] In order to form an absorbent article with little influence on walking, it is preferable that there is no difference or the difference is small in the amount of movement of the center of gravity of the body between a normal gait and a gait when wearing the absorbent article.

[0133] For example, when comparing the total distance of movement of the body center of gravity in the left-right direction in one walking cycle between the normal gait and the gait when wearing, the value in the normal gait is smaller than the value in the gait when wearing, but the smaller the difference is, the better. From the viewpoint of forming an absorbent article with a small gait influence, regarding the total distance of movement of the body center of gravity in the left-right direction in one walking cycle, the difference between the total distance of movement of the body center of gravity in the left-right direction in the normal gait and the total distance of movement of the body center of gravity in the left-right direction in the gait when wearing, i.e., (the total distance of movement of the body center of gravity in the left-right direction in the normal gait) - (the total distance of movement of the body center of gravity in the left-right direction in the gait when wearing) is preferably -0.020 or more and 0 or less, and more preferably -0.012 or more and 0 or less.

[0134] In addition, if Figure 7 As shown in (b), the vertical movement distance of the body center of gravity, that is, the difference between the maximum value and the minimum value, can be used as walking information. In order to form an absorbent article with little influence on gait, it is preferred that there is no difference or a small difference in the vertical movement distance of the body center of gravity between the normal gait and the gait when wearing.

[0135] For example, when comparing the maximum or minimum value of the vertical movement distance of the center of gravity of the body in a walking cycle or 1 / 2 walking cycle in a normal gait with that in a wearing gait, the value in the normal gait is larger than the value in the wearing gait, and the difference is preferably smaller.

[0136] From the perspective of constituting an absorbent article with little influence on gait, regarding the movement distance of the body center of gravity in the vertical direction, the difference between the total movement distance of the body center of gravity in the vertical direction during normal gait and the total movement distance of the body center of gravity in the vertical direction during gait when worn, that is, (the total movement distance of the body center of gravity in the vertical direction during normal gait) - (the total movement distance of the body center of gravity in the vertical direction during gait when worn) is preferably greater than 0 and less than 0.015, and more preferably greater than 0 and less than 0.010.

[0137] In addition, it is also preferred to compare the maximum or minimum value of the vertical movement distance of the body center of gravity in one walking cycle between the normal gait and the gait when wearing. When comparing the maximum value between the normal gait and the gait when wearing, it is preferred that the difference is as small as possible, provided that the maximum value in the normal gait is greater than the maximum value in the gait when wearing. From the viewpoint of forming an absorbent article with a small gait influence, the difference between the maximum value in the normal gait and the maximum value in the gait when wearing, i.e., (the maximum value in the normal gait) - (the maximum value in the gait when wearing) of the difference between the maximum value and the minimum value of the vertical movement distance of the body center of gravity in one walking cycle or 1 / 2 walking cycle, is preferably 0 or more and 0.003 or less, and more preferably 0 or more and 0.002 or less.

[0138] In addition, when comparing the minimum value of the vertical movement distance of the body center of gravity in one walking cycle between the normal gait and the gait when wearing, the smaller the difference is, the better, provided that the minimum value in the normal gait is smaller than the minimum value in the gait when wearing. From the viewpoint of forming an absorbent article with a small gait influence, the difference between the maximum value and the minimum value of the vertical movement distance of the body center of gravity in one walking cycle or 1 / 2 walking cycle, the difference between the minimum value in the normal gait and the minimum value in the gait when wearing, i.e., (the minimum value in the normal gait) - (the minimum value in the gait when wearing) is preferably -0.001 or more and 0 or less, and more preferably -0.0005 or more and 0 or less.

[0139] According to the evaluation method of the absorbent article of the first and second embodiments, as the change of the wearer, the change of the hip angle (coronal plane hip angle, sagittal plane hip angle), the change of the pelvic angle, or the amount of movement of the center of gravity of the body is measured, and based on the measurement results, the influence of the absorbent article on the walking of the wearer is evaluated. Therefore, as described above, by comparing with walking naked, the influence of the diaper on walking can be evaluated, and in addition, the influence of the diaper on walking can be evaluated with high precision, for example, the difference in walking ease that cannot be clearly shown by the method of the prior art can be objectively expressed. In addition, since the evaluation can be performed objectively without directly asking the wearer, the subjective cognition of the wearer can be eliminated, and the evaluation of walking ease or walking difficulty can be performed with high precision and in an objective process for both infant diapers and adult diapers.

[0140] As mentioned above, although this invention was demonstrated based on the preferred embodiment, this invention is not limited to the said embodiment, It can change suitably.

[0141] For example, in the evaluation step (step (C)), as changes in the wearer over time, two or more of (1) changes in the frontal plane hip joint angle, (2) changes in the pelvic angle, (3) sagittal plane hip joint angle, and (4) the amount of movement of the body's center of gravity may be measured, and the effect of the diaper on the wearer's walking may be evaluated based on the measurement results of multiple indicators.

[0142] Alternatively or in addition to these, the walking of the wearer wearing the diaper may be photographed to measure the stride length of the walking wearer. The stride length is the distance along the X direction between a straight line connecting the heel contact positions of one foot arranged in series in the direction of travel (Y direction) during walking and a straight line connecting the heel contact positions of the other foot arranged in series in the direction of travel (Y direction) during walking.

[0143] Figure 7 It means that 26 infants aged 18 to 20 months who were able to walk independently and wore pants-type diapers, i.e., diapers 1 to 3, were allowed to walk without being taught speed and stride. Figure 1 The graph is a graph of values ​​of stride lengths calculated by taking a picture of the person walking on the walking path 3 shown.

[0144] Regarding the stride length, the stride length of the wearer wearing diapers 1 to 3 is larger than that of the wearer in the naked state. Since the naked state is the state where the diaper has the least influence on the wearer's walking, by comparing the stride length of the wearer wearing diapers 1 to 3 and the wearer in the naked state, the influence of diapers 1 to 3 on the wearer's walking can be evaluated. Compared with the naked state, the stride length of the wearer wearing diapers 1 to 3 is longer, which means that the wearer wearing diapers 1 to 3 has a greater influence on walking than the naked state, and it is difficult to walk. In addition, although diaper 1 and diaper 2 have the same structure, when one is in a wet state and the other is in a dry state, the stride length of diaper 1 in the wet state is longer than that of diaper 2 in the dry state, so the diaper 1 in the wet state has a greater influence on the wearer's walking than the diaper 2 in the dry state, and it can be evaluated that it is difficult to walk. In addition, even if both are in a wet state, diaper 3 has a longer stride length than diaper 1, so diaper 3 has a greater influence on the wearer's walking than diaper 1, and it can be evaluated that it is difficult to walk.

[0145] Together with one or more measurement results of changes in hip angle, changes in pelvic angle, and movement of the body's center of gravity, plus the measurement results of stride length, the effect of the diaper on the wearer's walking can be evaluated, thereby enabling more accurate diaper evaluation.

[0146] A specific example of a method of evaluating the gait influence using the step length and the distance between both knees as information representing the gait (gait parameters) will be described in Test Example 2 described later.

[0147] The gait influence evaluation system of the present invention is described based on a preferred embodiment.

[0148] The gait influence evaluation system 200 of the present embodiment acquires moving image data captured of a walking person via a network or using a predetermined medium.

[0149] Gait impact evaluation system 200 Fig. 9As shown in (a), it includes an acquisition unit 110, an extraction unit 120, a calculation unit 130 and a comparison and evaluation unit 140. The acquisition unit 110 takes the dynamic image data acquired via the network or using a predetermined medium into the information processing terminal 100. The extraction unit 120 extracts specific parts of a person in the acquired dynamic image data. As the extraction unit, the well-known bone information acquisition technology from the human body image, the motion capture technology by attaching marks to specific parts, etc. can be cited. The calculation unit 130 calculates the gait parameters representing the gait using the time change of the position of the extracted specific part. The comparison evaluation unit 140 compares the gait parameters of the normal gait calculated based on the dynamic image data obtained by photographing the gait of the person walking without wearing the absorbent article, and the gait parameters of the gait when wearing the absorbent article calculated based on the dynamic image data obtained by photographing the gait of the person walking with the absorbent article, or compares the gait parameters of a plurality of gaits when wearing the absorbent article calculated based on the dynamic image data obtained by photographing the gait of the person walking with different absorbent articles, and outputs the comparison result. The comparison result is preferably output in a form that is easy to understand visually, for example, the gait parameters to be compared are preferably summarized in a graph (see FIG. 1 ). Figure 3 (c) Figure 4 (c)), or the gait parameters to be compared are arranged in one or more graphs (see Figure 8 (b)). In addition, it is preferable to perform a comparison display with other gait parameters, a comparison display with past data, etc. The gait influence evaluation system 200 has an information processing terminal 100 capable of performing various processes, and the information processing terminal 100 has an extraction unit 120, a calculation unit 130, and a comparison evaluation unit 140. The information processing terminal 100 has an input device such as a keyboard and a pointing device, an operation processing device, a storage unit, etc.

[0150] The dynamic image data is the dynamic image data captured by a camera device, which may be a common RGB camera, a black and white camera, or a spectral camera, and the performance and specifications of the camera device are not limited. The camera device includes a video recorder, a camera built into a smartphone, a camera built into a tablet terminal, a web camera that can be installed with a personal computer or the like by a connection method such as a cable, etc.

[0151] The person who photographs the gait using a camera device may be the developer of the absorbent article, or may be the walker's parents, grandparents, etc., and preferably, the camera built into a smartphone is used to photograph the gait.

[0152] The captured dynamic image data is preferably transmitted (delivered) to the development stage calculation system 200 via a network or using a predetermined medium. The comparison result by the evaluation unit 140 can be output to a display unit or a printing device etc. of the development stage calculation system 200, or the inspected object can be sent to a smartphone.

[0153] For a preferred example of the evaluation process using the gait influence evaluation system 200, refer to Fig. 9 (b) is described below.

[0154] Step S10 acquires a plurality of dynamic image data obtained by photographing a person's gait. The dynamic image data may be directly acquired from a camera device included in the gait impact assessment system 200, or acquired from a camera device independent of the gait impact assessment system 200 via a network or a predetermined medium.

[0155] Step S11 is a step of extracting a specific part from the acquired dynamic image data. The specific part mentioned here may be a part with a marker installed, or a part of the body of a person moving by walking and calculated without a marker installed. As specific parts, examples include the top of the head, the brow, the neck, the upper end of the sternum on the back side, the left and right acromion, the left and right elbows, the left and right wrists, the left and right anterior superior iliac spines, the left and right greater trochanters, the left and right knees, the left and right lateral epicondyles of the femur (knee joints), the left and right lateral malleolus (foot joints), the left and right ankles, etc., but are not limited to these.

[0156] Step S12 is a step of calculating gait parameters for a plurality of walks based on a plurality of dynamic image data. Step S13 is a step of outputting the comparison result directly to a display unit of the gait impact assessment system 200, or to another device such as a smartphone independent of the gait impact assessment system 200 via a network or using a predetermined medium.

[0157] In step S12, the gait parameters of the normal gait calculated from the dynamic image data obtained by photographing the gait when walking without wearing the absorbent article are compared with the gait parameters of the wearing gait calculated from the dynamic image data obtained by photographing the gait when walking with the absorbent article worn, or the gait parameters of the wearing gait calculated from the dynamic image data obtained by photographing the gait when walking with different absorbent articles worn are compared with each other. Specifically, the method described above or the method shown in the test example described later can be used.

[0158] The gait impact assessment program of the present invention is, for example, software that enables a computer to function as a gait impact assessment system. As a computer, a well-known general-purpose computer, a smart phone or a tablet terminal, etc. can be used. A general-purpose computer is composed of a CPU, ROM, RAM, SDD or HDD, etc. The processing of the above-mentioned steps S11 to S13 is implemented by the CPU expanding the program stored in the ROM or optical disk in the RAM and executing it. The above-mentioned processing can also be implemented by a GPU (Graphics processing Unit) or an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of an ASIC and an FPGA.

[0159] [Test example]

[0160] Hereinafter, the present invention will be described in more detail using test examples, but the scope of the present invention is not limited to these test examples.

[0161] As the underpants-type diapers used in the test examples, the following two types of diapers 4 and 5 were produced.

[0162] 〔Diaper 4〕

[0163] First, a nonwoven fabric front sheet and a resin film back sheet are placed between them. Fig.10The absorbent body 4 of the cross-sectional structure shown in the figure is used as an absorbent body, and leak-proof cuffs are set on both sides of the absorbent body, which are formed by fixing the leak-proof cuff forming elastic member in an extended state on the leak-proof cuff forming sheet. The outer body is joined to the non-skin-opposite side of the absorbent body, and the two side edges of the ventral part and the back part of the outer body are joined to each other to form a pair of side sealing parts. The absorbent body 4 of the diaper 4 obtained in this way is composed of an absorbent core 40 containing a fiber material and a water-absorbent polymer 46, and a core packing 48 covering the surface of the absorbent core 40, and has a central absorbent body 4C and a pair of side absorbent bodies 4S, 4S in the crotch part C, and a pair of bending guides 45, 45 between these central absorbent body 4C and the side absorbent body 4S. Such an absorbent core 40 has a central area 41 in the central absorbent body 4C and a side area 43 in the side absorbent body 4S, and the central area 41 and the side area 43 are divided by a pair of bending guides 45, 45. A pair of curved guides 45, 45 extend along the longitudinal direction of the diaper at the crotch portion of the diaper. The curved guide 45 is formed by a slit that penetrates the absorbent core 40 in the thickness direction Z. The absorbent body 4 of the diaper 4 is formed such that the core packing 48 located on the skin-facing side and the non-skin-facing side of the absorbent core 40 are joined to each other in the slit.

[0164] In Table 3 below, the structures of diapers 4 and 5 are shown. Fig.10 , W1 is the width of the central region 41, W2 is the width of the side region, W3 is the width of the curved guide portion, and Wa is 1 / 2 of the width W1 of the central region.

[0165] 〔Diaper 5〕

[0166] A diaper 5 having the same structure as the diaper 4 was produced except that a thin low-weight portion was provided in a part of the absorbent core as the bending guide portion instead of providing a slit in the absorbent core.

[0167] [Table 3]

[0168]

[0169] The 30 mm compression load was measured for Diapers 1, 3, 4 and 5 described above.

[0170] 160 g of artificial urine is injected into an injection point 7 cm away from the center of the diaper toward the ventral side in the longitudinal direction. After standing for 5 minutes in a standard swollen state, the compression load when the crotch of the diaper bent so as to divide the width of the diaper into two equal parts is compressed to 30 mm (hereinafter referred to as 30 mm compression load) is less than 7 N, more preferably less than 6.5 N.

[0171] The 30 mm compression load is measured by the following method.

[0172] The diaper is unfolded and stretched, and after it becomes a standard swollen state, the diaper is bent along the longitudinal center line CL so as to divide the width of the diaper into two equal parts, and the test body 1a is set. The test body 1a is placed in a horizontal place without wrinkles or bends so that the longitudinal direction (the direction orthogonal to the width direction Y, hereinafter also referred to as "longitudinal direction X") of the bent diaper is aligned with the horizontal direction. With respect to the test body 1a, a rectangular acrylic plate of 5 cm in width × 15 cm in length and weighing 28.7 g is placed at the central position in the longitudinal direction X (hereinafter referred to as "first measurement position") and at a position 2.5 cm away from the central position toward the abdominal part A (hereinafter referred to as "second measurement position"). At this time, the acrylic plate is placed so that the width of the acrylic plate is aligned with the longitudinal direction X of the diaper, and the center of the width is aligned with the first measurement position or the second measurement position. The acrylic plate is moved downward at a compression speed of 100 mm / min and compressed until the thickness of the test body 1a becomes 30 mm. The compression is performed using a material testing machine (e.g. Autograph AG-X manufactured by Shimadzu Corporation). The compression load when the thickness of the diaper becomes 30 mm is measured at each of the first measurement position and the second measurement position, and the average value of these two points is taken as the 30 mm compression load.

[0173] Regarding the side absorbent body 4S in the standard swollen state, it was confirmed that the compressive load when the thickness was compressed to 10 mm (hereinafter referred to as "10 mm compressive load") contributed to the above-mentioned 30 mm compressive load. That is, by adjusting the 10 mm compressive load of the side absorbent body 4S, the 30 mm compressive load of the test body 1a can be adjusted within the above-mentioned range.

[0174] From this viewpoint, the 10 mm compression load of at least one side absorbent body 4S is preferably 4.5 N or less, more preferably 4 N or less, and preferably 0.1 N to 4.5 N or less, more preferably 0.5 N to 4 N or less.

[0175] It is preferable that the 10 mm compressive load of both the pair of side absorbent bodies 4S, 4S is within the above-mentioned range.

[0176] The method for measuring the 10 mm compression load of the side absorbent 4S is as follows. First, take out the absorbent 4 from the diaper in the standard swollen state, and place it in a horizontal place without wrinkles or bends in a manner that the skin-facing surface of the absorbent 4 faces upward in the vertical direction. Next, use a material testing machine (such as Autograph AG-X made by Shimadzu Corporation) equipped with a rod-shaped compression test tool with a diameter of 2 cm to measure the compression load when the side absorbent 4S is compressed to a thickness of 10 mm. The measurement is performed at any three locations in the part where the absorbent core 40 is present in the side absorbent 4S, and their average value is taken as the 10 mm compression load.

[0177] Table 4 shows the 30 mm compression load and the 10 mm compression load of the side absorber.

[0178] [Table 4]

[0179] Compression properties Diapers 1 Diapers 3 Diapers 4 Diapers 5 2 fold 30mm compression load 7.52 10.21 5.77 6.88 Side absorber 10mm compression load 0.46 6.17 3.77 0.89

[0180] 〔Evaluation of gait impact I〕

[0181] The diapers 1, 3 and the manufactured diaper 4 were evaluated for gait influence by a method having the following steps (A), (B) and (C). In this evaluation method, 13 infants aged 12 to 25 months were used as test subjects.

[0182] First, in step (A), the subject is made to walk at least three walking cycles without wearing a diaper (hereinafter referred to as the "non-wearing state"), and the walking state is monitored by a three-dimensional motion capture device (VICON camera system × 16200Hz). In this monitoring, markers are attached to multiple parts of the subject's body, and the position information and movement information of the markers in the walking state are obtained to monitor the gait of the subject. In this monitoring, the subject is made to walk on a floor reaction force meter (force plate AMTI, 2000Hz) that measures the force received from the floor. The monitoring results obtained in this step (A) are used as the results of normal gait.

[0183] Next, in step (B), the test subject is made to walk at least three walking cycles respectively while wearing diapers 1, 3 and 4, and the walking state is monitored by the above-mentioned three-dimensional motion capture device. In this monitoring, the test subject is made to walk on the above-mentioned floor reaction force meter.

[0184] Diapers 1, 3, and 4 were prepared in a swollen state (hereinafter referred to as "swollen state") injected with 160 g of saline solution by the following method. When forming the swollen state, first, a mark (hereinafter referred to as "first mark") was made with a marker at the center of the length direction X (the fold of the crotch of the product) and the center of the width direction Y in an unused diaper, and another mark was made at a position 7 cm away from the center position marked with the first mark toward the ventral part A in the length direction X, and the position marked with the other mark was used as the injection point of the saline solution. Next, the part forming the waist opening WH of the diaper was grasped, and the crotch C of the diaper was drooped in such a way that the center position marked with the first mark became the lowest position, and 160 g of saline solution was injected into the injection point at an injection rate of 5 g / sec. A tube pump was used for this injection. After the injection of the saline solution, the diaper was left to stand in the above-mentioned drooping state for 1 minute, and it was used as a diaper in the swollen state.

[0185] The monitoring results obtained in the above step (B) are used as the results of gait while wearing.

[0186] In step (C), the results of the normal gait obtained in step (A) are compared with the results of the gait when wearing the device obtained in step (B). This comparison is performed using three-dimensional image analysis software (Visual 3D C-motion). Specifically, the measured values ​​of the coronal plane hip joint angle of the normal gait and the gait when wearing the device are compared.

[0187] The coronal plane hip angle is mainly an indicator of the amount of movement of the femur toward the side of the pelvis. Assuming that the pelvis has a pelvic coordinate system of XYZ axes and the femoral coordinate system of XYZ axes, the inclination angle of the X-axis or Z-axis of the femoral coordinate system rotated around the Y-axis of the pelvic coordinate system relative to the YZ plane or XY plane of the pelvic coordinate system is measured. In this evaluation method, in order to compare the value of the coronal plane hip angle at the position of 80% of the walking distance of a walking cycle in a normal gait and the gait when wearing the device, the value of the gait when wearing the device is subtracted from the value of the normal gait. "One walking cycle" is the period from the time when the left heel of the test subject touches the floor surface to the next time the left heel touches the floor surface when walking.

[0188] [Test Example 1]

[0189] The values ​​of the coronal plane hip joint angles at the position of 80% of the walking distance in one walking cycle and the total distance (cm) of the body center of gravity moving in the left and right directions were measured for the above-mentioned diapers 1, 3 and the manufactured diaper 4 (all in a swollen state), and the gait of the normal gait (naked) and the gait when wearing were compared. Fig.12 , 13 Indicated in.

[0190] exist Fig.12 , 13 In the table, ** (two asterisks) indicates that a significant difference was confirmed between the two compared objects at a significance level of p < 0.01 / N, * (one asterisk) indicates that a significant difference was confirmed at a significance level of p < 0.05 / N, and + (one positive sign) indicates that no significant difference was confirmed, but p < 0.1 / N. N is the number of tests.

[0191] like Fig.12 As shown, the manufactured diaper 4 has no significant difference in the frontal plane hip angle as a gait parameter from the naked body, but a tendency to be inferior to the comparative diaper 3 which has a significant difference from the naked body is observed. On the other hand, diaper 1 has no significant difference from the naked body, but no difference from diaper 3 is observed either.

[0192] like Fig.13 As shown, the total moving distance of the body center of gravity in the left-right direction, which is a gait parameter, of the manufactured diaper 4 is not significantly different from that of the naked body, but is significantly different from that of the manufactured diaper 3, and tends to be different from that of the manufactured diaper 1.

[0193] Thus, according to the gait influence evaluation method of the present invention, preferably the method using three-dimensional image analysis, it can be found that the manufactured diaper 4 has a smaller influence on gait than other diapers, and the difference in the degree of influence on gait can be clearly distinguished among a plurality of diapers.

[0194] [Test Example 2]

[0195] Using the above-mentioned diapers 1 and 3 and the manufactured diaper 5, the evaluation II of the gait influence degree described below was performed.

[0196] 〔Evaluation of gait impact II〕

[0197] In this evaluation method, 14 infants aged 18 to 20 months were used as test subjects. First, the test subjects were made to walk in a non-wearing state and in a state of wearing diapers 1, 3, and 5, and dynamic images of their walking were taken. At this time, the test subjects were made to walk on the above-mentioned floor reaction force meter.

[0198] Regarding the worn diaper in this evaluation method, the same method as the above-mentioned gait influence evaluation I is used, and physiological saline is injected into the diaper to make it swollen.

[0199] Next, OpenPose is used to obtain skeleton information for the dynamic image data of the test subject's walking. The skeleton information is extracted from the neck, shoulders, elbows, wrists, waist, knees, ankles and other parts in the dynamic image data, and the extracted parts are expressed by points and lines in synchronization with the dynamic image data, and the three-dimensional coordinate information of the parts is obtained. Based on the skeleton information, the stride (cm) and the distance between the two knees (cm) of the test subject when walking are calculated, and the average value is obtained. The stride based on the skeleton information is obtained by measuring the left and right distances between the midpoints of the line connecting the lateral malleolus and the medial malleolus. The distance between the two knees based on the skeleton information is obtained by measuring the distance between the center of the right knee and the center of the left knee.

[0200] Based on the skeleton information during walking, the step length is Fig.14 In the figure, the distance between the two knees (knee distance) is Fig.15 Regarding the step length and the distance between the two knees, the statistical difference (significant difference) between the two test examples was confirmed by a corresponding t-test.

[0201] Fig.15 The value of the distance between the two knees is shown in FIG. 1 , which is the time when the center of the knee is farthest from the vertical line from the body's center of gravity. The larger the value of the distance between the two knees, the more the left and right knees are separated when walking.

[0202] Fig.14 and Fig.15 In the table, ** (two asterisks) indicates that a significant difference was confirmed between the two compared objects at a significance level of p < 0.01, and * (one asterisk) indicates that the significant difference was confirmed at a significance level of p < 0.05.

[0203] like Fig.14 and Fig.15 As shown in the figure, in both the step length and the distance between the two knees (knee distance) as gait parameters, the manufactured diaper 5 has no significant difference from the naked body, but diapers 1 and 3 have significant differences from the naked body. In addition, in both the step length and the distance between the two knees (knee distance), diaper 5 and diaper 3 also have significant differences. According to the evaluation method of the gait influence degree of the present invention, preferably the method of calculating the three-dimensional image coordinates from the two-dimensional dynamic image data, the difference in the degree of influence on the gait can be clearly distinguished for a plurality of diapers.

[0204] Regarding the above-mentioned embodiment, the following evaluation method is further disclosed.

[0205] <1>

[0206] A method for evaluating the gait influence of an absorbent article, wherein the method evaluates the degree of influence of wearing the absorbent article on gait, wherein the method is characterized in that:

[0207] The method comprises the following steps (A) to (C):

[0208] (A) a step of causing a person to walk at least three walking cycles without wearing the absorbent article to be evaluated, and photographing a normal gait for monitoring;

[0209] (B) a step of walking at least three walking cycles while wearing the absorbent article to be evaluated, and photographing and monitoring the gait while wearing the article; and

[0210] (C) A comparison step of comparing the normal gait and the gait when wearing the device.

[0211] <2>

[0212] A method for evaluating the gait influence of an absorbent article, wherein the method compares and evaluates the degree of influence of wearing the absorbent article on gait for at least two different absorbent articles, wherein the method is characterized by:

[0213] The method comprises the following steps (D) to (F):

[0214] (D) a step of causing a person to walk for at least three walking cycles while wearing an absorbent article and photographing the person's gait while wearing the article for monitoring;

[0215] (E) the step of walking for at least three walking cycles while wearing another absorbent article and monitoring the gait by photographing the gait while wearing the article; and

[0216] (F) A comparing step of comparing the gait when the one absorbent article is worn with the gait when the other absorbent article is worn.

[0217] <3>

[0218] Above <1> or <2> The evaluation method of gait influence degree described in

[0219] In the monitoring step, dynamic image data is obtained,

[0220] The comparing step includes a three-dimensional analyzing step of performing analysis using three-dimensional information obtained from the dynamic image data acquired in the monitoring step.

[0221] <4>

[0222] Above <3> The evaluation method of gait influence degree described in

[0223] In the monitoring step, two-dimensional dynamic image data is obtained using an RGB camera, a black and white camera or a spectral camera.

[0224] The method includes a three-dimensional information acquisition step of calculating three-dimensional image coordinates based on the two-dimensional dynamic image data acquired in the monitoring step, thereby obtaining three-dimensional information used in the three-dimensional analysis step.

[0225] <5>

[0226] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0227] In the comparing step, coronal plane hip joint angles are compared.

[0228] <6>

[0229] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0230] In the comparing step, the pelvic angles are compared.

[0231] <7>

[0232] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0233] In the comparing step, sagittal plane hip joint angles are compared.

[0234] <8>

[0235] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0236] In the comparison step, the movement amounts of the center of gravity of the body are compared.

[0237] <9>

[0238] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0239] In the comparison step, the step sizes are compared.

[0240] <10>

[0241] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0242] In the comparison step, the distances between the two knees are compared.

[0243] <11>

[0244] Above <1> ~ <4> The method for evaluating gait influence according to any one of the above, wherein:

[0245] In the comparison step, the coronal plane hip joint angle obtained from the relationship with the coordinate system set in the pelvis or the sagittal plane hip joint angle obtained from the relationship with the coordinate system set in the pelvis is compared.

[0246] <12>

[0247] Above <5> The evaluation method of gait influence degree described in

[0248] In the comparison step, the integral value of the entire or a part of a walking cycle in the graph of the change in the coronal plane hip joint angle of a walking cycle is calculated, and the integral value is compared between the normal gait and the gait when wearing, or the gaits when wearing different absorbent articles are compared with each other.

[0249] <13>

[0250] Above <5> The evaluation method of gait influence degree described in

[0251] In the comparison step, the maximum value or the minimum value of the frontal plane hip joint angle in one walking cycle is compared between the normal gait and the gait when wearing the absorbent articles, or the gaits when wearing different absorbent articles are compared with each other.

[0252] <14>

[0253] Above <5> The evaluation method of gait influence degree described in

[0254] In the comparison step, the value of the frontal plane hip joint angle at the end of one walking cycle is compared between the normal gait and the gait when wearing the absorbent articles, or the gaits when wearing different absorbent articles are compared with each other.

[0255] <15>

[0256] Above <5> The evaluation method of gait influence degree described in

[0257] In the comparison step, the value of the frontal plane hip joint angle at a predetermined point in the swing phase of one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

[0258] <16>

[0259] Above <6> The evaluation method of gait influence degree described in

[0260] In the comparison step, an integral value of a whole or a part of a walking cycle in a graph of pelvic angle changes in a walking cycle is calculated, and the integral value is compared between a normal gait and a gait when wearing the absorbent article, or between gaits when wearing different absorbent articles.

[0261] <17>

[0262] Above <6> The evaluation method of gait influence degree described in

[0263] In the comparison step, the maximum value of the pelvic angle in one walking cycle is compared between a normal gait and a gait when wearing the absorbent article, or between gaits when wearing different absorbent articles.

[0264] <18>

[0265] Above <6> The evaluation method of gait influence degree described in

[0266] In the comparison step, the differential value in a predetermined area of ​​the graph of the pelvic angle change in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

[0267] <19>

[0268] Above <7> The evaluation method of gait influence degree described in

[0269] In the comparison step, the integral value of the entire or a part of a walking cycle in the graph of the sagittal plane hip joint angle change in a walking cycle is calculated, and the integral value is compared between the normal gait and the gait when wearing, or between the gaits when wearing different absorbent articles.

[0270] <20>

[0271] Above <7> The evaluation method of gait influence degree described in

[0272] In the comparison step, the difference between the maximum value and the minimum value of the sagittal plane hip joint angle in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

[0273] <21>

[0274] Above <8> The evaluation method of gait influence degree described in

[0275] In the comparison step, the total moving distance of the body center of gravity in the left-right direction in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or the gaits when wearing different absorbent articles are compared with each other.

[0276] <22>

[0277] Above <8> The evaluation method of gait influence degree described in

[0278] In the comparison step, the maximum or minimum value of the vertical movement distance of the body center of gravity in one walking cycle or 1 / 2 walking cycle is compared between the normal gait and the gait when wearing, or between the gaits when wearing different absorbent articles.

[0279] <23>

[0280] Above <8> The evaluation method of gait influence degree described in

[0281] In the comparison step, the difference between the maximum and minimum values ​​of the body center of gravity in the vertical direction in one walking cycle or 1 / 2 walking cycle, that is, the total moving distance, is compared between the normal gait and the gait when wearing, or the gaits when wearing different absorbent articles are compared with each other.

[0282] <24>

[0283] Above <1> ~ <23> The method for evaluating gait influence according to any one of the above, wherein:

[0284] Prior to step (B), or prior to step (D) and step (E), an acclimation step is performed to adapt the absorbent article to the body shape of a walking person.

[0285] <25>

[0286] Above <1> ~ <24> The method for evaluating gait influence according to any one of the above, wherein:

[0287] The absorbent article is a disposable diaper for infants.

[0288] <26>

[0289] Above <1> ~ <25> The method for evaluating gait influence according to any one of the above, wherein:

[0290] The absorbent article is a pants-type disposable diaper.

[0291] <27>

[0292] A gait influence evaluation system is provided, which evaluates the influence of wearing an absorbent article on gait, and the gait influence evaluation system is characterized by comprising:

[0293] an acquisition unit for acquiring dynamic image data obtained by photographing a walking person;

[0294] an extracting unit for extracting a specific part of a person in the acquired dynamic image data;

[0295] a calculation unit that calculates a gait parameter representing a gait using a temporal change in the position of the extracted specific part; and

[0296] A comparison and evaluation unit compares gait parameters of a normal gait calculated based on dynamic image data of a walking gait in a state where no absorbent article is worn, with gait parameters of a gait when wearing the absorbent article calculated based on dynamic image data of a walking gait in a state where the absorbent article is worn, or compares gait parameters of a plurality of gaits when wearing the absorbent article calculated based on dynamic image data of a walking gait in a state where different absorbent articles are worn, and outputs the comparison result.

[0297] <28>

[0298] A gait impact evaluation program, characterized in that:

[0299] Make the computer as above <27> The described gait impact evaluation system functions.

[0300] Industrial Applicability

[0301] According to the method for evaluating the degree of influence of an absorbent article on gait of the present invention, it is possible to evaluate with high accuracy the influence of an absorbent article such as a disposable diaper on the gait of a wearer.

Claims

1. A method for evaluating the gait influence of an absorbent article, wherein the method evaluates the degree of influence of wearing the absorbent article on gait, wherein: It includes the following steps (A)~(C): (A) a step of causing a person to walk at least three walking cycles without wearing an absorbent article to be evaluated, and photographing a normal gait for monitoring; (B) a step of walking at least three walking cycles while wearing the absorbent article to be evaluated, and photographing and monitoring the gait while wearing the absorbent article; and (C) a comparison step of comparing the normal gait and the gait when wearing the device, In the monitoring step, two-dimensional dynamic image data is obtained. The comparison step includes a three-dimensional analysis step, which uses the three-dimensional information obtained by calculating the three-dimensional image coordinates based on the two-dimensional dynamic image data obtained in the monitoring step, and the three-dimensional analysis step includes calculating the content of the position information of the walker's bones, joints or body center of gravity.

2. A method for evaluating the gait influence of an absorbent article, comprising: performing a comparative evaluation of the degree of influence of wearing of at least two different absorbent articles on the gait, wherein: It includes the following steps (D)~(F): (D) The steps of causing a person to walk for at least three walking cycles while wearing an absorbent article and photographing the person's gait while wearing the article for monitoring; (E) the step of walking for at least three walking cycles while wearing another absorbent article and monitoring the gait by photographing the gait while wearing the article; and (F) a comparison step of comparing a gait when the one absorbent article is worn with a gait when the other absorbent article is worn, In the monitoring step, two-dimensional dynamic image data is obtained. The comparison step includes a three-dimensional analysis step, which uses the three-dimensional information obtained by calculating the three-dimensional image coordinates based on the two-dimensional dynamic image data obtained in the monitoring step, and the three-dimensional analysis step includes calculating the content of the position information of the walker's bones, joints or body center of gravity.

3. The gait influence evaluation method according to claim 1 or 2, Features: In the monitoring step, two-dimensional dynamic image data is obtained using an RGB camera, a black and white camera or a spectral camera.

4. The method for evaluating gait influence according to claim 3, Features: The method includes a three-dimensional information acquisition step of calculating three-dimensional image coordinates based on the two-dimensional dynamic image data acquired in the monitoring step, thereby obtaining three-dimensional information used in the three-dimensional analysis step.

5. The method for evaluating gait influence according to claim 1 or 2, Features: In the comparison step, gait parameters obtained based on the position information of one or more of the bones, joints or center of gravity of the walker calculated in the three-dimensional analysis step are compared. The gait parameters include the frontal plane hip joint angle, the pelvic angle, the sagittal plane hip joint angle, the amount of movement of the body's center of gravity, the step length, or the distance between the two knees.

6. The method for evaluating gait influence according to claim 1 or 2, Features: In the comparing step, coronal plane hip joint angles are compared.

7. The method for evaluating gait influence according to claim 1 or 2, Features: In the comparing step, the pelvic angles are compared.

8. The method for evaluating gait influence according to claim 1 or 2, Features: In the comparing step, sagittal plane hip joint angles are compared.

9. The method for evaluating gait influence according to claim 1 or 2, Features: In the comparison step, the movement amounts of the center of gravity of the body are compared.

10. The gait influence evaluation method according to claim 1 or 2, Features: In the comparison step, the step sizes are compared.

11. The gait influence evaluation method according to claim 1 or 2, Features: In the comparison step, the distances between the two knees are compared.

12. The gait influence evaluation method according to claim 1 or 2, Features: In the comparison step, the coronal plane hip joint angle obtained from the relationship with the coordinate system set in the pelvis or the sagittal plane hip joint angle obtained from the relationship with the coordinate system set in the pelvis is compared.

13. The method for evaluating gait influence according to claim 6, Features: In the comparison step, the integral value of the entire or a part of a walking cycle in the graph of the change in the coronal plane hip joint angle of a walking cycle is calculated, and the integral value is compared between the normal gait and the gait when wearing, or the gaits when wearing different absorbent articles are compared with each other.

14. The method for evaluating gait influence according to claim 6, Features: In the comparison step, the maximum value or the minimum value of the frontal plane hip joint angle in one walking cycle is compared between the normal gait and the gait when wearing the absorbent articles, or the gaits when wearing different absorbent articles are compared with each other.

15. The gait influence evaluation method according to claim 6, Features: In the comparison step, the value of the frontal plane hip joint angle at the end of one walking cycle is compared between the normal gait and the gait when wearing the absorbent articles, or the gaits when wearing different absorbent articles are compared with each other.

16. The method for evaluating gait influence according to claim 6, Features: In the comparison step, the value of the frontal plane hip joint angle at a predetermined point in the swing phase of one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

17. The method for evaluating gait influence according to claim 7, Features: In the comparison step, an integral value of a whole or a part of a walking cycle in a graph of pelvic angle changes in a walking cycle is calculated, and the integral value is compared between a normal gait and a gait when wearing the absorbent article, or between gaits when wearing different absorbent articles.

18. The method for evaluating gait influence according to claim 7, Features: In the comparison step, the maximum value of the pelvic angle in one walking cycle is compared between a normal gait and a gait when wearing the absorbent article, or between gaits when wearing different absorbent articles.

19. The method for evaluating gait influence according to claim 7, Features: In the comparison step, the differential value in a predetermined area of ​​the graph of the pelvic angle change in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

20. The gait influence evaluation method according to claim 8, Features: In the comparison step, the integral value of the entire or a part of a walking cycle in the graph of the sagittal plane hip joint angle change in a walking cycle is calculated, and the integral value is compared between the normal gait and the gait when wearing, or between the gaits when wearing different absorbent articles.

21. The method for evaluating gait influence according to claim 8, Features: In the comparison step, the difference between the maximum value and the minimum value of the sagittal plane hip joint angle in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or between the gaits when wearing different absorbent articles.

22. The method for evaluating gait influence according to claim 9, Features: In the comparison step, the total moving distance of the body center of gravity in the left-right direction in one walking cycle is compared between the normal gait and the gait when wearing the absorbent article, or the gaits when wearing different absorbent articles are compared with each other.

23. The method for evaluating gait influence according to claim 9, Features: In the comparison step, the maximum or minimum value of the vertical movement distance of the body center of gravity in one walking cycle or 1 / 2 walking cycle is compared between the normal gait and the gait when wearing, or between the gaits when wearing different absorbent articles.

24. The method for evaluating gait influence according to claim 9, Features: In the comparison step, the difference between the maximum and minimum values ​​of the body center of gravity in the vertical direction in one walking cycle or 1 / 2 walking cycle, that is, the total moving distance, is compared between the normal gait and the gait when wearing, or the gaits when wearing different absorbent articles are compared with each other.

25. The method for evaluating gait influence according to claim 1 or 2, Features: The absorbent article is a disposable diaper for infants.

26. The method for evaluating gait influence according to claim 1 or 2, Features: The absorbent article is a pants-type disposable diaper.

27. A gait influence evaluation system for evaluating the influence of wearing an absorbent article on gait, wherein: include: an acquisition unit for acquiring dynamic image data obtained by photographing a walking person; Extracting a specific part of a person in the acquired dynamic image data using a skeleton information acquisition technology; a calculation unit that calculates a gait parameter representing the gait using the temporal change in the position of the extracted specific part; and A comparison and evaluation unit compares gait parameters of a normal gait calculated based on dynamic image data of a walking gait in a state where no absorbent article is worn, with gait parameters of a gait when wearing the absorbent article calculated based on dynamic image data of a walking gait in a state where the absorbent article is worn, or compares gait parameters of a plurality of gaits when wearing the absorbent article calculated based on dynamic image data of a walking gait in a state where different absorbent articles are worn, and outputs the comparison result.

28. A gait impact assessment program product, Features: The computer is made to function as the gait influence evaluation system according to claim 27.

Images