Patent ID: 12213779

DETAILED DESCRIPTION

A method for evaluating shock absorption effect of a sports bra is provided, as shown inFIG.2, including:step 1, making a preparation for a subject: allowing the subject to wear a sports bra for a test and adhering 43 infrared reflective mark points on the subject's body and completing the preparation;step 2, acquiring static data: allowing the subject naturally to stand on a treadmill, and acquiring static coordinate data;step 3, performing the test: starting the treadmill, acquiring dynamic coordinate data for 5 minutes during a sporting process when a speed of the treadmill reaches 6-12 km/h, and immediately asking subjective perceptions of the subject after doing sports;step 4, converting coordinates: converting the dynamic coordinate data into coordinate data in which a thoracic vertebra point is defined as an origin, and calculating displacement amplitudes of subject's breast and a square root index S=√{square root over (S2left-right+S2up-down)} of the displacement amplitudes in a left-right direction and an up-down direction;step 5: processing data: numerically sorting the displacement amplitudes according to the square root index S to obtain a grading range value, that is a grading definition for the sports bra.

In an embodiment of the present disclosure, a system for evaluating shock absorption effect of a sports bra used for the method for evaluating shock absorption effect of a sports bra is provided, as shown inFIG.3, including: a data acquirer1and a data processor2. The data acquirer1and the data processor2are communicated with each other to transmit data. The data acquirer1is configured to acquire static coordinate data and dynamic coordinate data of human's motion and the data processor2is configured to perform coordinate conversion on data acquired by the data acquirer (1) and calculate an average value of breast amplitudes during the human's motion.

Data points sampled by the data acquirer1include 43 data points, including 29 points for a Helen Hayes model (see Table 1), 4 points for coordinate system conversion (see Table 2), and 10 points for recording breast movement (see Table 3).

TABLE 1Names and locations of the points in the Helen Hayes modelName of Mark PointsPositionTop Headhighest point of head when a subject is uprightFront Headon sagittal plane in front of headRear Headon sagittal plane on rear of headL/R. ShoulderacromionL/R. Elbowexternal epicondyle of humerusL/R. Wristmidpoint of the connection between ulnar styloidand radius styloidL/R. ASISanterior superior spineL/R. Thighin front of thighL/R. kneelateral femoral condyleL/R. Knee Medialmedial femoral condyleL/R. Calfin front of calfL/R. Anklelateral malleolusL/R. Ankle Medialmedial malleolusL/R. Toemiddle of second and third metatarsal headL/R. Heelcalcaneal tuberosityV. Sacralmidpoint of sacrum and fifth lumbar spinousprocessesR. Offsetlower edge of right scapula

TABLE 2Points required for coordinate conversionNamePositionvertebrae pointseventh cervical spinous processsternal anglemidpoint of sternal anglethoracic vertebral pointapproximately fourth to fifth thoracic(contour point of sternum angle)vertebra spinous processseventh to eighth thoracic vertebraseventh to eighth thoracic vertebraspinous process

TABLE 3Points on the breastNamePositionleft and right breast pointsnipplesupper point of left andmidpoint between a nipple andright nipplesupper edge of a breastlower point of left andmidpoint between a nipple andright nippleslower edge of breastmedial points of left andmidpoint between a nipple andright nipplesmedial edge of a breastlateral points of left andmidpoint between a nipple andright nippleslateral edge of a breast

The dynamic data are acquired by the data acquirer1under a dynamic state in which a speed is 10 km/h and the acquisition time is 5 minutes.

The breast amplitudes calculation performed by the data processor (2) takes the time between two consecutive heel strikes of a same foot in a gait cycle to calculate the square root index S of displacement amplitudes in the left-right direction and the up-down direction, respectively.

The system for evaluating shock absorption effect of the sports bra further includes a feedback data storage module3, the feedback data storage module3is configured to acquire subjective perception data of the subject associated with two aspects of bra comfort and breast shaking amplitude. The feedback data storage module3transmits the acquired data to the data processor2, and the data processor2is configured to sort the calculated amplitude data to obtain the bra grading range value. The bra comfort in the subjective perception can be divided into very uncomfortable, comfortable and very comfortable and the corresponding bra is divided into a low-strength bra, medium-strength bra and high-strength bra. The breast shaking amplitude is divided into small shaking, obvious shaking and severe shaking and the corresponding bra is divided into a high-strength bra, medium-strength bra and low-strength bra.

A coordinate conversion method used in the data processor2includes:step 1, establishing a global coordinate system: using X-axis as a frontal axis, and taking the right direction in left and right directions of human movement as a positive direction; using Y-axis as a sagittal axis, and taking the forward direction in forward and backward directions of human movement as a positive direction; using the Z-axis as a vertical axis, and taking an upward direction of vertical directions of human movement as a positive direction, thereby the global coordinate system is established;step 2, establishing a breast coordinate system: using three points D1, D2 and D3 of a mid-sagittal plane of the human body to determine the breast coordinate system i, wherein D1 is a sternal angle point, D2 is thoracic vertebral point (contour point of sternum angle) and D3 is an eighth thoracic vertebra point; D1 and D2 have the same height, {right arrow over (D2D1)} is Y axis, a normal vector {right arrow over (n)}={right arrow over (D2D1)}×{right arrow over (D2D3)} of the plane determined by D1, D2 and D3 is X axis, {right arrow over (D2D1)}×{right arrow over (n)} is Z axis, X axis is in left and right direction, the right direction is positive; Y axis is forward and backward direction, taking the forward direction as a positive direction; Z axis is in a vertical direction, taking the upward direction as a positive direction and thus the breast coordinate system is established;step 3, performing a conversion between the global coordinate system and breast coordinate system, wherein unit vectors of the global coordinate system are {right arrow over (e1)},{right arrow over (e2)},{right arrow over (e3)}; a unit vector of the breast coordinate system are {right arrow over (f1)},{right arrow over (f2)},{right arrow over (f3)}; for any point M, a vector {right arrow over (OM)} is the sum of a vector {right arrow over (Oo)} and a vector {right arrow over (oM)}, namely:

OM→=Oo→+o⁢M→(1)
the coordinate conversion is performed based on the equation (1); and

step 4, calculating a coordinate value of a detection point t under a motion state in the breast coordinate system, assuming that the coordinate of the detection point t at a time M in the global coordinate system is xmt,ymt,zmt, and the coordinate of the detection point t at a time M in the breast coordinate system is x′mt, y′mt, z′mt, and the coordinate of the original of the breast coordinate system in the global coordinate system is xot, yot, zot, the equation (1) may be represented by the unit vector:

xm⁢t⁢e1→+ym⁢t⁢e2→+zm⁢t⁢e3→=(xo⁢t⁢e1→+yo⁢t⁢e2→+zo⁢t⁢e3→)+(xm⁢t′⁢f1→+ym⁢t′⁢f2→+zm⁢t′⁢f3→)(2)
since {right arrow over (f1)}, {right arrow over (f2)}, {right arrow over (f3)} is converted from {right arrow over (e1)}, {right arrow over (e2)}, {right arrow over (e3)}, namely,

{f1→=a1⁢1⁢e1→+a2⁢1⁢e2→+a3⁢1⁢e3→f2→=a1⁢2⁢e1→+a2⁢2⁢e2→+a3⁢2⁢e3→f3→=a1⁢3⁢e1→+a2⁢3⁢e2→+a3⁢3⁢e3→(3)
Equation (4) can be obtained from equations (2) and (3):

[xm⁢t′ym⁢t′zm⁢t′]=❘"\[LeftBracketingBar]"a11a1⁢2a1⁢3a2⁢1a2⁢2a2⁢3a3⁢1a3⁢2a3⁢3|-1|xm⁢t-xo⁢tym⁢t-yo⁢tzm⁢t-zo⁢t|(4)

obtaining

|a1⁢1a1⁢2a1⁢3a2⁢1a2⁢2a2⁢3a3⁢1a3⁢2a3⁢3|
by converting between the global coordinate system and the breast coordinate system and substituting it into the equation (4) to obtain the coordinate x′mt, y′mt, z′mtof any detection point in the breast coordinate system.

A verification method for the above evaluation method and evaluation system, includes the following steps:step 1, processing data: corresponding subjective perception data collected in the above method and system to amplitude data measured by the subject one by one;step 2, determining whether the subject's subjective perceptions correspond to the obtained grading range values; andstep 3, the grading range values obtained by the evaluation method or evaluation system can be determined to be accurate when the strength grading corresponding to the subjective perceptions corresponds to the grading range obtained from the amplitude data, otherwise grading range values are inaccurate.

EMBODIMENT 1

The present disclosure is described below through specific embodiments.step 1, recruiting female subjects, selecting several eligible subjects through professional measurement, with the test environment as 24-26° C.; the eligible subjects referring to subjects having the size of the bra to be measured;step 2, allowing the subjects to wear uniform clothing including shorts and shoes and do warm-up exercises on the treadmill at a comfortable speed;step 3, allowing the female subjects to wear sports bra used for the experimental test and adhering a total of 43 infrared reflective mark points having specific positions as shown in tables 1, 2 and 3 on their bodies,the data acquirer1may adopt an infrared motion capture system to capture and track the motion of reflective mark points, for example, Motion Analysis infrared motion capture system purchased available from American Motion Analysis Corporation. Eight lenses of the infrared motion capture system are evenly distributed over the test site and the height from the ground is above 2 meters to ensure that the reflective mark points on the subjects may be captured by the lens.step 4, allowing the subject naturally to stand on a treadmill, finding a position where all the reflective mark points are not blocked, and acquiring static data for a few seconds for calibrating (a static calibration file is used for the calculation of coordinate conversion);step 5, starting the treadmill, allowing the subjects to slowly accelerate to a speed of 10 km/h for running, acquiring dynamic coordinate data for 5 minutes in sports when a speed in sports reaches 6-12 km/h, and immediately asking subjective perceptions of the subject after doing sports;subjective perceptions including bra comfort divided into very uncomfortable, comfortable and very comfortable and breast shaking amplitude divided into small shaking, obvious shaking and severe shaking;step 6, identifying mark points from acquired data by a software that comes with Motion, exporting the corresponding file and converting coordinates of each point into coordinate positions in which a thoracic vertebra point is defined as an origin;taking a duration from the left foot heel strike to the left foot heel strike again in a gait cycle, finding displacement amplitudes of points on the subject's breast in all directions during the gait cycle after wearing the sports bra and calculating a square root index S=√{square root over (S2left-right+S2up-down)} of the displacement amplitudes in a left-right direction and an up-down direction;step 7, numerically sorting data of all experimental sports bras according to the square root index S, and corresponding to subjective perceptions one by one to obtain grading definitions for the sports bra.

After measuring the sports bra through the above method steps, several somatosensory theoretical data of B and C cup are obtained, and the comfort level is inferred from the corresponding grade, and then compared with the subjective questionnaire, which shows a consistent in the comparison results. The specific test results are as follows:

17 bras with B cup and 15 bras with C cup are tested. Test is performed on 6 to 10 women for each bra. All the data are sorted from small to large, the specific S value is shown in the following table:

123456789B19.720.121.023.123.523.624.325.829.4C24.425.125.326.127.028.629.629.831.31011121314151617B32.032.233.635.436.037.438.438.6C31.634.035.036.038.540.0

According to the above sports bra test situation, the smaller the S value, the smaller the shaking amplitude, the higher the sports bra strength level, and the specific bra grading range value includes:the boundaries between high-strength and medium-strength sports bras for B cup and C cup are at an S value of about 27.6 MM and an S value of about 29.7 MM, respectively, andthe boundaries between medium-strength and low-strength sports bras for B cup and C cup are at an S value of about 35.7 MM and an S value of about 34.5 MM, respectively.

According to comparison between the subjects' subjective perceptions and grading ranges, it is concluded that taking B cup as an example, when the S value of the B cup is less than 27.6 MM, the subjects reported that the bra is very comfortable under exercise and the breast shaking amplitude is small during exercise, and the bra belongs to a high-strength sports bra; when the S value of the B cup is between 27.6 MM and 35.7 MM, the subjects reported that the bra is comfortable under exercise, and the breasts shake obviously during exercise, and the bra belongs to medium-strength sports bra; and when the S value of B cup is greater than 35.7 MM, the subjects reported that the bra is very uncomfortable under exercise, and the breasts shake severely during exercise, and the bra belongs to low-strength sports bras.

Obviously, the above-mentioned implementation of the present disclosure are merely examples to clearly illustrate the present disclosure, and are not intended to limit the implementations of the present disclosure. For those of ordinary skill in the art, other changes or modifications in different forms can be made on the basis of the above description. It is not possible to give an exhaustive list of all implementations here. Any obvious changes or changes derived from the technical solutions of the present disclosure are still within the scope of protection of the present invention as defined by the claims.