Body balance assessment method

Abstract

Disclosed in the present invention is a body balance assessment method. The method comprises: creating a height model of an object to be subjected to assessment; by means of a feature value which is output by a pressure distribution sensor, calculating support plane information and pressure center information of said object in an assessment area; outputting weight information by means of a mechanical sensor; and establishing a composite model, inputting the height model, the supporting plane information, the pressure center information and the weight information, so as to output a balance assessment result. In the present invention, an assessment behavior for a standard human body pose is established, data of a subject with respect to the behavior is collected, and a balance assessment parameter, by means of which the subject can be assessed during a behavioural process, is obtained by means of calculation, thereby assisting in assessing an invisible balance risk of the subject.

Description

A method for evaluating body balance Technical Field

[0001] The present invention belongs to the technical field of human body function assessment, and in particular relates to a body balance assessment method. Background Art

[0002] Balance assessment refers to collecting the physical parameters of the human body in a specific environment through testing methods and outputting parameters about the body's balance through statistical analysis. Balance assessment has important practical significance for judging the functional status of the human body, and medical or non-medical physical therapy and prevention can be made in a timely manner based on the assessment results.

[0003] The Chinese patent application with the prior art application number 201810036115.4 provides a human body balance assessment method, which collects pressure center data of the body to be measured; uses a multi-scale entropy algorithm to process the pressure center data to obtain the area value under the multi-scale entropy curve, and the area value is used as the complexity of the pressure center data to measure the balance of the body to be measured; determines the center of gravity trajectory of the pressure center data, calculates the area of ​​the figure formed by the center of gravity trajectory to obtain the pressure center trajectory area, which is used to measure the balance of the body to be measured; and measures the balance of the body to be measured by the ratio of the trajectory area to the complexity.

[0004] The Chinese patent application with the prior art application number 202010060322.0 discloses a human balance detection method and system, including the steps of: selecting a test environment; placing a shooting device in the test environment, and the shooting device records the entire process of the tester maintaining the balance test action to obtain balance test data; and performing subsequent processing on the balance data to obtain a balance analysis result.

[0005] The Chinese patent application with prior art application number 201611154377.8 relates to a system and method for evaluating body balance, wherein a pressure plate is used to detect the pressure distribution of the subject's body on the pressure plate to obtain plantar pressure information, and send it to a host computer through a communication device; a first posture sensor is used to detect data of the subject's head to obtain first posture information, and send it to the host computer through a communication device; a second posture sensor is used to detect data of the subject's torso to obtain second posture information, and send it to the host computer through a communication device; the host computer is used to calculate the movement of the subject's body center of gravity based on the received plantar pressure information, first posture information, and second posture information of the subject and evaluate the subject's body balance obstacle location; the host computer evaluates the influence of the subject's vestibular system on body balance based on the received first posture information; the host computer evaluates the subject's proprioception ability based on the received second posture information.

[0006] It is quite obvious that in order to obtain indicators about human balance, the existing technology uses the center of gravity as an element. However, the human body is not a regular object and the physical center of gravity cannot be directly obtained. Therefore, indicators that can represent the center of gravity are usually obtained through different algorithms, and the balance of the human body is further evaluated based on the center of gravity. However, this evaluation method is somewhat narrow and single-minded, mainly reflected in the neglect of other factors that maintain the balance of the human body and the impact of the human body on balance in different postures.

[0007] Summary of the Invention

[0008] Before introducing the present invention, let us first understand several factors that affect the balance of the human body.

[0009] From the description of physics, we know that the elements that maintain the balance of an object include mass, center of mass and support surface. Then the elements that maintain the balance of a human body correspond to weight, center of gravity and support surface.

[0010] The present invention aims to solve the problems of the prior art and proposes the following technical solutions:

[0011] A method for evaluating body balance, comprising:

[0012] Create a height model of the subject to be evaluated;

[0013] The support surface information and pressure center information of the object to be evaluated in the evaluation area are calculated by outputting characteristic values ​​of the pressure distribution sensor;

[0014] Output weight information through mechanical sensors;

[0015] A composite model is established, and the height model, support surface information, pressure center information and weight information are input to output the balance assessment results.

[0016] In this application, the composite model is:

[0017] y=y x +y y +y z , the worse the balance ability, the smaller y;

[0018] in,

[0019] In the above formula,

[0020] F x 、F y and F z are the translation equations of the object, M x 、M y and M z They are the rotation equations, l xmin 、l xmax 、lymin 、l ymax G is the maximum and minimum distance from the center of gravity to the support surface. h is the center of gravity height, S l and S r They are the support surfaces from the left and right shoulders to the soles of the feet, m is the mass of the body, S d is the support surface area; K1-K6 are weight parameters.

[0021] The method described in the present application is applied to different postures of the subject to be evaluated, including standing posture with feet together, standing posture with feet facing horizontally, vertically and diagonally, standing posture in weight-bearing and weight-reducing states, sitting state and sitting-to-stand transition state.

[0022] The method described in this application is more specifically as follows:

[0023] Setting an evaluation area, wherein a pressure distribution sensor is arranged in the evaluation area;

[0024] Obtaining, through a pressure distribution sensor, an output characteristic value generated by the action of the object to be evaluated on the pressure distribution sensor, wherein the characteristic value includes sensor position information and a pressure signal;

[0025] Based on the characteristic values ​​output by the pressure distribution sensor, the support surface information and pressure center information of the object to be evaluated in the evaluation area are calculated, and the mechanical sensor outputs the weight information. Based on the support surface information, pressure center information, and weight information output by the mechanical sensor, the evaluation model outputs the evaluation result.

[0026] As a preferred embodiment of the above technical solution, the initial evaluation parameters are corrected using support surface information, weight information, and height information to obtain the evaluation result.

[0027] As a preferred embodiment of the above technical solution, the method is applied to different posture states of the object to be evaluated. In different states, the constructed models are also different, and the balance capabilities are also different.

[0028] Stand with your feet together: the support surface is the area of ​​your feet, and the height of your center of gravity is related to your body height.

[0029] Standing with your feet aligned horizontally, vertically, and diagonally: The further you move your feet to the sides, the larger the support surface, the lower your center of gravity, and the better your stability. For the same distance, standing diagonally provides the largest support surface, while standing vertically provides the smallest. Balance is best when standing diagonally, followed by horizontally, and worst when standing vertically.

[0030] Standing with or without weight: The support surface and the center of gravity height remain unchanged, but the balance ability changes with the weight. Within a certain range, the greater the weight, the better the balance.

[0031] Sitting state and sit-stand transfer state: During the process, the support surface, the front and back and height position of the center of gravity are changed, and the balance ability also changes accordingly.

[0032] As a preferred embodiment of the above technical solution, when the method is applied to different posture states of the object to be evaluated, the evaluation area includes a fixed standing area and a continuously adjustable seating area, and the adjustment of the seating area is used to quantitatively determine the evaluation benchmark reference system of the object to be evaluated.

[0033] As a preferred embodiment of the above technical solution, the method for adjusting the seating area to quantitatively determine the evaluation benchmark reference system of the object to be evaluated is:

[0034] Determine whether the pressure center of the subject to be evaluated on the seating area is located in the target area. If not, adjust the subject's sitting posture so that the pressure center is located in the target area.

[0035] The vertical height of the seating area relative to the standing area is continuously adjusted from a low position to a high position. At the same time, the characteristic value output by the pressure distribution sensor in the seating area is obtained to calculate the support surface information of the seating area. The support surface information stops when it extends from the middle of the seating area to the edge and covers the edge.

[0036] The horizontal distance of the seating area relative to the standing area is continuously adjusted from the near position to the far position, and the minimum position of the characteristic value output by the pressure distribution sensor at the edge of the seating area is determined and reset to that position.

[0037] As a preferred embodiment of the above technical solution, on the basis of quantitatively determining the evaluation benchmark reference system of the object to be evaluated, the vertical height and horizontal distance of the seating area relative to the standing area are continuously adjusted to obtain the adjusted evaluation posture of the object to be evaluated, and the initial evaluation parameters are corrected through the support surface information, weight information, and height information to generate a formula for evaluating balance ability.

[0038] The beneficial effects of the present invention are:

[0039] (1) The present invention defines a composite evaluation model based on support surface information, pressure center information, and body weight information to output evaluation results. This method solves the narrowness and singleness of evaluating human balance based solely on center of gravity yaw. It considers more other factors that maintain balance and the influence of different people's different body postures on balance, making the output evaluation results more objective.

[0040] (2) The composite evaluation model based on support surface information, pressure center information, and weight information of the present invention has better universality for different evaluation application scenarios and can evaluate the balance of the human body in different states. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic structural diagram of an evaluation device according to the present invention;

[0042] FIG2 is a schematic diagram showing the connection of the signal modules of the evaluation device;

[0043] FIG3 is a schematic diagram of the signal processing process of the evaluation device;

[0044] FIG4 is a schematic diagram of the process of the evaluation operation;

[0045] Figure 5 is a schematic diagram of the support surface in a standing position;

[0046] FIG6 is a schematic diagram of the support surface when standing with feet apart;

[0047] FIG7 is a schematic diagram of the support surface S collecting standard S in a sitting state;

[0048] Figure 8 is a schematic diagram of indicators for maintaining human balance;

[0049] Figure 9 is a schematic diagram of a standing position with both feet horizontally aligned;

[0050] Figure 10 is a schematic diagram of a standing position with both feet vertically aligned;

[0051] Figure 11 is a schematic diagram of a standing state with both feet tilted;

[0052] Figure 12 is a schematic diagram of a standing weight loss state;

[0053] Figure 13 is a schematic diagram of a standing weight-bearing state;

[0054] Figure 14 is a schematic diagram of a sitting position;

[0055] Figure 15 is a schematic diagram showing the support surface of the seat when it is adjusted forward and backward to change the human body's sitting or standing state;

[0056] FIG16 is a schematic diagram showing how the height of the human body's center of gravity is changed by adjusting the seat height. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0058] From the description of physics, we know that the elements that maintain the balance of an object include mass, center of mass and support surface. Then the elements that maintain the balance of a human body correspond to weight, center of gravity and support surface, as shown in Figure 8.

[0059] As shown in Figure 1, the evaluation device of the present invention includes a standing area 1, an intelligent continuously adjustable seat 2, which is surrounded by a surround-type safety armrest 3. It also includes a display, a trolley, evaluation training software and accessories. Array-type distributed pressure sensors are arranged on the standing area 1 and the intelligent continuously adjustable seat 2. The standing area 1 is located in front of the intelligent continuously adjustable seat 2. Accessories include a network cable and a power cable.

[0060] The above-mentioned intelligent continuously adjustable seat 2 means that the seat 2 can realize continuous adjustment in vertical height and continuous adjustment in horizontal direction away from or close to the standing area 1. The continuous adjustment recorded in the present invention is different from the gear-type adjustment (that is, setting several fixed positions and adjusting the position between several fixed positions). The continuous adjustment of the present invention refers to obtaining the position information of the seat 2 at any time within the range that can be obtained by the sensor. For example, the seat 2 can be driven by a telescopic motor, and the driving structure can be implemented using existing technology.

[0061] Figures 2-4 illustrate the operating principle of the evaluation device, with Figure 2 showing the connections between the device's signal modules, Figure 3 showing the signal processing process, and Figure 4 showing the evaluation process flow. The communication interface module of the evaluation software in the host computer terminal unpacks the data packets as agreed upon and transmits the unpacked raw voltage values ​​of each contact piezoresistive sensor to the data acquisition module. The data acquisition module sequentially obtains the raw voltage values ​​of each contact piezoresistive sensor and then correlates them with the calibration coefficients in the data calibration calculation module to derive the pressure value of each stressed contact piezoresistive sensor. The data access module and data warehouse management module store, assign, and transmit the position and output pressure value of each contact piezoresistive sensor. The data extraction and analysis module extracts, analyzes, and displays multiple parameters for a single pressure center or multiple pressure centers based on the position and pressure values ​​of the stressed contact piezoresistive sensors. The data modeling and rapid assessment module performs feature modeling based on pressure distribution based on the parameters extracted and analyzed by the data extraction and analysis module, and performs correlation analysis for different postures to achieve integrated balance assessment.

[0062] Each pressure detection plate is connected to a high-speed gigabit network switch in a cascaded fashion and communicates with the host computer via Ethernet. The number of sensors used for sitting detection and assessment is 2,400 (one plate * 40cm * 60cm * one plate / cm²) plus four high-precision mechanical sensors, with a sensor density of one sensor per cm². The number of sensors used for standing detection and assessment is 9,600 (one plate * 40cm * 60cm * four plates / cm²) plus four high-precision mechanical sensors, with a sensor density of four sensors per cm². The sensor range for sitting detection and assessment is 0.8kg / cm², while the range for standing detection and assessment is 6kg / cm². Each force plate consisting of four mechanical sensors has a range of 150kg, with an overload of 120%.

[0063] Based on the above-mentioned evaluation device, a body balance evaluation method is provided, which is:

[0064] An evaluation area is set up, in which pressure distribution sensors are arranged. The evaluation area is the standing area 1 and the intelligent continuously adjustable seat 2. According to different evaluation conditions set for the object to be evaluated, one or two of the areas, namely the standing area 1 and the intelligent continuously adjustable seat 2, can be selected to work.

[0065] The pressure distribution sensor is used to obtain output characteristic values ​​generated by the action of the object to be evaluated on the pressure distribution sensor. The characteristic values ​​include sensor position information and pressure signals. Each sensor on the pressure distribution sensor can independently obtain and output pressure information. The output values ​​include sensor position information (i.e., the row and column position within the corresponding evaluation area) and pressure signals (including whether there is pressure and the vertical direction of the pressure).

[0066] The real-time weight of the object to be evaluated is obtained as the output characteristic value through a force plate composed of high-precision mechanical sensors.

[0067] The support surface information and pressure center information of the object to be evaluated in the evaluation area are calculated based on the characteristic values ​​output by the pressure distribution sensor, the mechanical sensor outputs the weight information, and the evaluation model based on the support surface information, pressure center information and weight information outputs the evaluation result.

[0068] The pressure center information is used to characterize the center of gravity of the object to be evaluated. However, due to the irregularity of the human body, it is difficult to accurately calibrate the center of gravity in the physical sense through measurement methods. Therefore, the projection point of the center of gravity of the object to be evaluated on the evaluation area is calculated using the characteristic values ​​output by the pressure distribution sensor.

[0069] The displacement of the pressure center in the X direction reflects the difference in muscle tension of the trunk and limbs and the labyrinthine deviation. When the labyrinth is obstructed on one side, there is a left-right displacement, that is, the center of gravity deviates from the left to the right. When the labyrinth is obstructed on both sides, the center of gravity shifts backward.

[0070] The displacement of the center of pressure in the Y direction reflects the increase or decrease of anti-gravity muscle tension; central damage causes a tendency to fall backward, that is, the center of gravity deviates backward.

[0071] The weight information is the value detected by the mechanical sensor in the pressure plate on the evaluation area when the subject to be evaluated is in a standing state. In addition, the height of the subject to be evaluated is measured and input into the evaluation model before the evaluation.

[0072] Typically, the human body is in different postures in the evaluation area. Even a well-balanced object will experience a sway that is difficult to see with the naked eye. Once the human body sways, the pressure center COP of the object to be evaluated in the evaluation area will also swing within the support surface S.

[0073] Assuming the human body is a rigid body, the equations of motion for a simple rigid body can be divided into translational equations and rotational equations, respectively related to the net external force and acceleration during motion, and the torque and angular acceleration during rotation. The length, width, height, and mass of a rigid body influence its equations of motion by affecting the rotational torque and the position of its center of gravity.

[0074] The translation equation is: F = ma, m is the mass of the human body, and a is the acceleration of the rigid body. a can be obtained by first calculating the offset speed through the measured forward and backward and left and right offset speeds, and then differentiating it with respect to time. The resultant force F of the translation equation can be obtained; the rotation equation is: M = Iα, because I is only related to the distance and weight from the rigid body point to the center of gravity, the same rigid body I does not change, and can be calculated through the "Inertia Parameters of Adult Human Body", α is the angular acceleration, the initial center of gravity position can be set as the origin, and subsequent angular velocity and angular acceleration changes all change around this point. At this time, the torque M can be obtained. Combining the above, we can get:

[0075] are the translation equation and rotation equation of the object respectively, l xmin 、l xmax 、l ymin 、l ymax G is the maximum and minimum distance from the center of gravity to the support surface. h is the center of gravity height, S l and S r They are the support surfaces from the left and right shoulders to the soles of the feet, m is the mass of the body, S d is the support surface area; K1-K6 are weight parameters.

[0076] K1 and K2 are and The weight parameters of y are as follows: when the rigid body remains unchanged, the larger the values ​​of F and M are, the more violent the rigid body is moving, the worse its balance ability is, and the smaller y is. When the rigid body is in equilibrium, F and M are 0.

[0077] K3 is the weight parameter of the ratio of the center of gravity to the support surface x, y. When the ratio is 1, the balance ability is the best, and the closer it is to 0, the worse the balance ability.

[0078] K4 is the height of the center of gravity G h The weight parameter, G h The smaller it is, the better the balance.

[0079] K5 is the weight parameter of the human body's oblique support surface, which can be set to 0 in a static state.

[0080] K6 is the ratio of human body weight to support surface. For a certain weight, the smaller the ratio, the worse the balance ability and the smaller y.

[0081] above It can be decomposed into the translation and rotation equations in the x, y, and z directions as shown below:

[0082] The overall balance ability is: y = y x +y y +y z .

[0083] A method for evaluating body balance is provided. The method is applied to different posture states of an object to be evaluated. In different posture states, different models are constructed, and the balance ability evaluated is also different.

[0084] Stand with your feet together: At this time, the support surface S d is the area of ​​the feet, S l S r The support surfaces on the left and right sides, the center of gravity height G h Related to the body height h, as shown in Figure 5, the feet are together when standing.

[0085] Stand with your feet horizontally, vertically, and diagonally: the more your feet move to the sides, the more your support surface S d The larger the center of gravity height G h The lower the angle, the better the stability. When both feet move the same distance, the support area is largest when standing diagonally, and smallest when standing vertically. Balance is best when standing diagonally, followed by horizontally, and worst when standing vertically. As shown in Figure 6, the more the feet move sideways, the better the balance.

[0086] Standing with or without weight: The support surface and the center of gravity height remain unchanged, but the balance ability changes with the weight. Within a certain range, the greater the weight, the better the balance.

[0087] Sitting state and sit-stand transfer state: During the process, the support surface and center of gravity height are changed, and the balance ability also changes accordingly.

[0088] As a specific application of the above method, it can be applied to balance assessment of different postures of the object to be assessed.

[0089] When used for balance assessment in a standing position, the assessment area is the standing area, an assessment time T can be set, the frequency of the sensor's output results can be set, and the balance of the object to be assessed can be further calculated through the assessment model.

[0090] When used in a sitting state, the evaluation area is the seat area (when sitting, most of the body's weight basically falls on the seat, and the body's balance is mainly reflected in the upper body). An evaluation time T can be set to set the frequency of the sensor's output results.

[0091] In the sitting state, it is necessary to set a support surface S collected under a standard state, that is, the standard is that the sensor in the evaluation area can just detect a continuous and complete pressure distribution. As shown in Figure 7 (B), in this state, the filling area is when the object to be evaluated is just sitting completely and stably on the seat; in the state (A) in Figure 7, the sensor detects a V-shaped notch in the pressure distribution state, which is a non-standard state.

[0092] When used for sit-stand transfer, a standard starting state and ending state need to be set for the object to be evaluated. The starting state needs to be used to quantitatively determine the evaluation benchmark reference system of the object to be evaluated through adjustment of the seat area. The ending state is based on the standard that the center of pressure COP on the standing area is located within the support surface S after the object to be evaluated completes standing.

[0093] As a preferred embodiment of the above technical solution, the method is applied to different posture states of the object to be evaluated. In different states, the constructed models are also different, and the balance capabilities are also different.

[0094] Stand with your feet together: the support surface is the area of ​​your feet, and the height of your center of gravity is related to your body height.

[0095] Standing with the feet aligned horizontally, vertically, and diagonally: The further the feet move to the sides, the larger the support surface, the lower the center of gravity, and the better the stability. For the same distance, standing diagonally provides the largest support area, while standing vertically provides the smallest. Balance is best when standing diagonally, followed by horizontally, and worst when standing vertically, as shown in Figures 9, 10, and 11.

[0096] Standing with and without weight: The support surface and the center of gravity height remain unchanged, but the balance ability changes with the weight. Within a certain range, the greater the weight, the better the balance, as shown in Figures 12 and 13.

[0097] Sitting state and sit-stand transfer state: During the process, the support surface, the front and back position of the center of gravity and the height are changed, and the balance ability also changes accordingly, as shown in Figures 14, 15 and 16.

[0098] The method for adjusting the seating area to quantitatively determine the evaluation benchmark reference system of the object to be evaluated is as follows:

[0099] Determine whether the pressure center of the subject to be evaluated on the seat area is within the target area. If not, adjust the subject's sitting posture so that the pressure center is within the target area. The target area is a preset value, and different target areas can be set. Generally, the support surface S in the standard sitting state is used as the indicator state of the target area, that is, only consider whether the support surface S of the subject to be evaluated is in a state that can just detect a continuous and complete pressure distribution.

[0100] The vertical height of the seat relative to the standing area is continuously adjusted from a low position to a high position. Simultaneously, the seat area obtains characteristic values ​​output by the pressure distribution sensor to calculate the seat area's support surface information. The system stops when the support surface information extends from the center of the seat area to the edge and covers the edge. Since the human body's thighs are suspended in the air and not in contact with the seat when the body is in a low position, as the body rises, the thighs gradually approach the seat. When the support surface information extends from the center of the seat area to the edge and covers the edge, it indicates that the thighs are in contact with the seat and are standing on the ground.

[0101] The horizontal distance of the seating area relative to the standing area is continuously adjusted from the near position to the far position, and the minimum position of the characteristic value output by the pressure distribution sensor at the edge of the seating area is determined and reset to that position; this process includes the following states:

[0102] (1) The calf is tilted close to the seat. Due to the tilt of the calf, the thigh will generate a certain pressure value on the sensor; (2) The calf is perpendicular to the standing area. The thigh has the least contact with the sensor and the pressure value generated is also the smallest; (3) The calf is tilted away from the seat, the same as state (1).

[0103] In addition, based on the quantitative determination of the evaluation benchmark reference system of the subject to be evaluated, the vertical height and horizontal distance of the seating area relative to the standing area are continuously adjusted to obtain the adjusted evaluation posture of the subject to be evaluated, and the initial evaluation parameters are corrected using the support surface information, weight information, and height information.

[0104] In addition, additional parameters for balance assessment can be calculated:

[0105] Among them, S ABC The area of ​​the triangle with ABC as the vertices is obtained by the cross product of the two-dimensional vectors. S is the area of ​​the supporting surface. Decompose the supporting surface into n triangles and calculate the area.

[0106] Standing swing speed

[0107] Where V is the instantaneous velocity of the swing,

[0108] Center of pressure calculation:

[0109] m_fPressure[i][j] is the output value of the pressure sensing device in row i and column j on the pressure distribution sensor, M*N is the size of the pressure distribution sensor, and X and Y are the horizontal and vertical coordinates of the pressure center on the pressure distribution sensor, respectively;

[0110] Total pressure Weight:

[0111] Where MechanicalValue is the output value of the pressure sensor, FrameCount is the number of data frames obtained, and n is the number of force sensors. Calculate the sum of the output values ​​of the pressure sensors in each frame and then take the average.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same.

Claims

1. A method for evaluating body balance, characterized in that: The method is: Create a height model of the subject to be evaluated; The support surface information and pressure center information of the object to be evaluated in the evaluation area are calculated by outputting characteristic values ​​of the pressure distribution sensor; Output weight information through mechanical sensors; A composite model is established, and the height model, support surface information, pressure center information and weight information are input to output the balance assessment results.

2. A method for evaluating body balance according to claim 1, characterized in that: The composite model is: y=y x +y y +y z , the worse the balance ability, the smaller y is; in, In the above formula, F x 、F y and F z are the translation equations of the object, M x 、M y and M z are the rotation equations, l xmin , l xmax , l ymin , l ymax G is the maximum and minimum distance from the center of gravity to the support surface. h is the height of the center of gravity, S l and S r are the support surfaces from the left and right shoulders to the soles of the feet, m is the mass of the body, S d is the support surface area; K1-K6 are weight parameters.

3. A method for evaluating body balance according to claim 2, characterized in that: The method is applied to different postures of the subject to be evaluated, including standing posture with feet together, standing posture with feet facing horizontally, vertically and diagonally, standing posture in weight-bearing and weight-reducing states, sitting state and sitting-to-stand transition state.

4. A method for evaluating body balance according to claim 3, characterized in that: When the method is applied to different posture states of the object to be evaluated, the evaluation area includes a fixed standing area and a continuously adjustable seating area, and the adjustment of the seating area is used to quantitatively determine the evaluation benchmark reference system of the object to be evaluated.

5. A method for evaluating body balance according to claim 4, characterized in that: The method for adjusting the seating area to quantitatively determine the evaluation benchmark reference system of the object to be evaluated is: Determine whether the pressure center of the subject to be evaluated on the seat area is located in the target area, and if not, adjust the sitting posture of the subject to be evaluated so that the pressure center is located in the target area; The vertical height of the seat area relative to the standing area is continuously adjusted from a low position to a high position, and at the same time, the characteristic value output by the pressure distribution sensor in the seat area is obtained to calculate the support surface information of the seat area, and the support surface information is stopped when it extends from the middle of the seat area to the edge and covers the edge; The horizontal distance of the seating area relative to the standing area is continuously adjusted from the near position to the far position, and the minimum position of the characteristic value output by the pressure distribution sensor at the edge of the seating area is determined and reset to the position.

6. A method for evaluating body balance according to claim 5, characterized in that: On the basis of quantitatively determining the evaluation benchmark reference system of the object to be evaluated, the vertical height and horizontal distance of the seating area relative to the standing area are continuously adjusted to obtain the adjusted evaluation posture of the object to be evaluated, and the human body's balance ability is evaluated through the support surface information, weight information, height information and the projection relationship of the human body's center of gravity.

7. A method for evaluating body balance according to claim 6, characterized in that: According to formulas (5), (6), (7), (8) and (9), the supplementary parameters for balance assessment are calculated as follows: Support surface area In the formula, S ABC is the area of ​​the triangle with ABC as vertices, the area of ​​the triangle is calculated according to the cross product of the two-dimensional vector, S is the area of ​​the support surface, the support surface is decomposed into n triangles, and the area is calculated; Standing swing speed Where V is the instantaneous swing speed, The pressure center is calculated according to equations (7) and (8): In equations (7) and (8), m_fPressure[i][j] is the output value of the pressure sensing device in row i and column j on the pressure distribution sensor, M*N is the size of the pressure distribution sensor, and X and Y are the horizontal and vertical coordinates of the pressure center on the pressure distribution sensor, respectively; Total pressureWeight: Where MechanicalValue is the output value of the pressure sensor, FrameCount is the number of data frames obtained, and n is the number of force sensors. The sum of the output values ​​of the pressure sensors in each frame is calculated and then the average is taken.

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