Light touch maintenance device, light touch maintenance method, and program

Abstract

A light touch keeping apparatus including: a contact load evaluation unit that uses a contact load between a subject and a support as a basis to determine whether or not the subject is in a light touch state; and an exercise intervention control unit that controls, when the subject is not in the light touch state, exercise intervention to the subject so as to keep the light touch state.

Description

[Technical Field]

[0001] The present invention relates to a technique for maintaining a light touch state. [Background technology]

[0002] The light touch effect is the effect of reducing center of gravity sway when a person lightly touches a support such as a wall or bar with their fingertips using a force (1N or less) that does not provide mechanical support. Applying the light touch effect to rehabilitation training that maintains a standing posture can improve postural stability.

[0003] In conventional technologies, various sensory feedback methods are used to maintain a light contact load of 1 N or less between the fingertip and the support. For example, Non-Patent Document 1 discloses a technology that uses sound to provide feedback when the contact load between the fingertip and the force plate exceeds 1 N. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Marco Baccini, Lucio A. Rinaldi, Gianluca Federighi, Luca Vannucchi, Matteo Paci, Giulio Masotti, "Effectiveness of fingertip light contact in reducing postural sway in older people", Age and Ageing, Volume 36, Issue 1, January 2007, Pages 30-35. Summary of the Invention [Problem to be solved by the invention]

[0005] When subjects are performing a highly difficult task such as standing on an unstable surface, they may try to rely on a support even when the risk of falling is low.

[0006] As a result, a force touch (contact load of 5N or more) occurs, which not only fails to achieve the light touch effect but also may lead to learning incorrect posture control. In this case, even if sensory feedback as in Non-Patent Document 1 is performed, the light touch state cannot be maintained.

[0007] The present invention has been made in consideration of the above points, and aims to provide a technology that enables a subject to maintain a light touch state even when performing a highly difficult task that makes it easy for the subject to lose posture. [Means for solving the problem]

[0008] According to the disclosed technology, the target fingertips a contact load evaluation unit that determines whether the subject is in a light touch state based on a contact load between the subject and a support; If the subject is not in a light touch state, the subject is Extend the fingers An exercise intervention control unit that controls exercise intervention to reduce the contact load by presenting electrical stimulation to the muscles, A fall risk assessment unit is further provided to assess the risk of the subject falling, the fall risk assessment unit calculates a distance between the zero moment point of the subject and a position of the center of sole pressure of the subject, and the exercise intervention control unit determines a target intensity of exercise intervention for the subject based on the distance; The exercise intervention control unit If the distance is greater than a first predetermined threshold and less than a second predetermined threshold, decreasing the target intensity of the exercise intervention as the distance increases; The distance is The second If the difference is greater than the threshold, it is determined that no exercise intervention should be performed on the subject. A light touch maintenance device is provided. [Effects of the Invention]

[0009] The disclosed technology provides a technology that enables a subject to maintain a light touch state even when performing a highly difficult task that makes it easy for the subject to lose posture. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating the functional configuration of a light touch maintaining device. [Figure 2] FIG. 1 is a configuration diagram related to the implementation of a light touch maintenance system. [Figure 3] FIG. 2 is a detailed configuration diagram of a light touch maintaining device. [Figure 4] 10 is a flowchart of a process. [Figure 5] FIG. 1 is a diagram showing a determination model for exercise intervention target intensity. [Figure 6] FIG. 2 is a diagram illustrating an example of a hardware configuration of a light touch maintaining device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. Hereinafter, the subject for which a light touch state is maintained is a person. The subject for which a light touch state is maintained is referred to as a "subject."

[0012] (Outline of the embodiment) In this embodiment, in situations where the risk of falling is low and the light touch state cannot be maintained, the light touch state is maintained by exercise intervention to the subject's fingertips rather than sensory feedback to the subject. Furthermore, by designing exercise intervention taking into account the risk of falling, it is ensured that no forced exercise intervention is performed when the risk of the subject falling increases.

[0013] 1 shows an example of the functional configuration of a light touch maintaining device 100 according to this embodiment. The functional configuration shown in FIG. 1 corresponds to the functional configuration for performing processing in a PC, which will be described later.

[0014] As shown in Fig. 1, the light touch maintaining device 100 in this embodiment includes a contact load assessment unit 10, a fall risk assessment unit 20, an exercise intervention target intensity calculation unit 30, and an exercise intervention unit 40. An overview of each unit is as follows. The exercise intervention target intensity calculation unit 30 and the exercise intervention unit 40 may be collectively referred to as an exercise intervention control unit.

[0015] The contact load evaluation unit 10 evaluates whether the contact state is a light touch state based on the contact load between the subject's fingertip and the support object. In other words, it determines whether the subject is in a light touch state.

[0016] The fall risk assessment unit 20 calculates parameters that are the basis for assessing the subject's risk of falling, based on the subject's center of gravity position and floor reaction force, and calculates a fall risk assessment index.

[0017] The exercise intervention target intensity calculation unit 30 calculates the exercise intervention target intensity based on the finger contact load and the fall risk assessment index using a model for determining the exercise intervention target intensity.

[0018] The exercise intervention unit 40 calculates exercise intervention parameters according to the exercise intervention target intensity, and issues instructions to a device that performs exercise intervention on the subject.

[0019] In the following, a more specific example of the light touch maintaining device 100 will be described in the following embodiments.

[0020] (Example) In this example, the subject's light touch state is maintained when the subject performs a right-legged standing task. The light touch in this example involves the subject placing their right index finger in contact with a load measuring device (e.g., a pressure sheet) fixed to a platform at about waist height. An electrical stimulation device is used to provide exercise intervention to the subject, and electrical stimulation is presented to the muscle that extends the subject's index finger (e.g., the extensor digitorum communis).

[0021] <Implementation example> Fig. 2 shows an example of implementation of the light touch maintenance device 100 in this embodiment. The PC 100 in Fig. 2 corresponds to the light touch maintenance device 100 shown in Fig. 1. The entire configuration shown in Fig. 2 may be called a light touch maintenance device or a light touch maintenance system. Here, the entire configuration shown in Fig. 2 will be called a light touch maintenance system 200.

[0022] 2, the light touch maintenance system 200 of this implementation example includes a load measuring device 110, a three-dimensional motion analysis device 120, a floor reaction force meter 130, a PC (personal computer) 100, and an electrical stimulation device 150. As shown in FIG. 2, the load measuring device 110, the three-dimensional motion analysis device 120, and the floor reaction force meter 130 are connected to the PC 100.

[0023] The load measuring device 110 measures the contact load of the fingertips. The three-dimensional motion analysis device 120 and floor reaction force meter 130 measure the position of the center of gravity of the body (COM), the floor reaction force of the sole (GRF), and the position of the center of pressure of the sole (COP), which are used to evaluate the risk of falling. Note that the position of the center of gravity of the body (COM), the floor reaction force of the sole (GRF), and the position of the center of pressure of the sole (COP) may be calculated by the PC 100 from the measurement data obtained by the three-dimensional motion analysis device 120 and the floor reaction force meter 130.

[0024] The PC 100 evaluates the subject's light touch state and risk of falling based on information from the load measuring device 110, the three-dimensional motion analysis device 120, and the floor reaction force meter 130, and determines the exercise intervention target intensity and electrical stimulation parameters based on the evaluation. The electrical stimulation device 150 presents electrical stimulation to the subject's index finger extensor muscle based on the electrical stimulation parameters corresponding to the exercise intervention target intensity determined by the PC 100.

[0025] <Detailed configuration example> 3 shows a detailed configuration example of the light touch maintaining device 100. FIG. 3 corresponds to a more detailed view of each unit in the functional configuration shown in FIG.

[0026] 3, the contact load evaluation unit 10 has a finger contact load (f) measurement unit 11 and a finger contact load evaluation unit 12. Here, the finger contact load (f) measurement unit 11 is a functional unit that inputs a signal from a finger load measurement device 110 (such as a surface pressure sheet) and outputs a vertical load (f) to the finger contact load evaluation unit 12.

[0027] The fall risk assessment unit 20 includes a body center of gravity (COM) measurement unit 21, a foot plantar floor reaction force (GRF) measurement unit 22, a foot plantar center of pressure (COP) measurement unit 23, a zero moment point (ZMP) calculation unit 24, and a fall risk assessment index ZMP-COP distance (d) calculation unit 25.

[0028] Here, the body center of gravity (COM) measurement unit 21 is a functional unit that calculates the COM from data obtained by the three-dimensional motion analysis device 120, and the plantar floor reaction force (GRF) measurement unit 22 and the plantar center of pressure (COP) measurement unit 23 are functional units that calculate the GRF and COP, respectively, from data obtained from the floor reaction force meter 130.

[0029] The exercise intervention target intensity calculation unit 30 calculates the exercise intervention target intensity by using an exercise intervention target intensity determination model 31 and an exercise intervention target intensity (f a ) calculation unit 32. The exercise intervention unit 40 has an electrical stimulation parameter determination model 41 and an electrical stimulation control unit 42.

[0030] <Processing operation> Next, the operation of the light touch maintaining device 100 shown in Fig. 3 will be described with reference to the flowchart in Fig. 4. In Fig. 4 and the following description, the f measurement, COM measurement, COP measurement, etc. are described as being performed in order, but this is for the sake of convenience, and in reality, these measurements are performed in parallel.

[0031] <s1> In S1 (step 1), the finger contact load (f) measuring unit 11 measures the vertical contact load f(t) between the subject's index finger and the platform at time t using a surface pressure sensor placed on a platform at about waist height of the subject, and outputs the measured vertical contact load f(t) to the finger contact load evaluating unit 12.

[0032] <s2> The finger contact load evaluation unit 12 compares the contact load f(t) between the subject's fingertip and the platform, which is input from the finger contact load (f) measurement unit 11, with a threshold value (1 N in this case), and determines whether the current contact load f(t) is greater than 1 N. Note that the threshold value of 1 N is just an example.

[0033] If f(t) is smaller than 1N, the patient is in a light touch state, so exercise intervention is not performed and t is updated to t+1. If f(t) is larger than 1N, exercise intervention is required to achieve a light touch state, so f(t) is updated to the exercise intervention target intensity (f a ) calculation unit 32. a The processing in the calculation unit 32 will be described later in S8.

[0034] <s3> In S3, the body center of gravity (COM) measurement unit 21 uses the three-dimensional motion analysis device 120 to measure the position coordinates of the markers attached to the body of the subject, thereby determining the body center of gravity position COM(t)=(COM x ,COM y ,COM z ) and outputs the calculation result to a zero moment point (ZMP) calculation unit 24.

[0035] <s4> In S4, the floor reaction force (GRF) measuring unit 22 measures the floor reaction force GRF(t)=(F x ,F y ,F z ) and outputs the calculation result to a zero moment point (ZMP) calculation unit 24.

[0036] <s5> In S5, the plantar pressure center position (COP) measurement unit 23 measures the plantar pressure center position COP(t)=(COP x ,COP y ) and outputs the measurement result to a fall risk evaluation index ZMP-COP distance (d) calculation unit 25.

[0037] <s6> In S6, the zero moment point (ZMP) calculation unit 24 calculates the zero moment point (ZMP) of the subject from the COM(t) input from the body center of gravity position (COM) measurement unit 21 and the GRF(t) input from the plantar floor reaction force (GRF) measurement unit 22.

[0038] The zero moment point is a virtual point on the floor where the sum of the moments acting on the body's center of gravity is 0. In other words, when the ZMP is equal to the COP, no rotational moment that would cause the body's center of gravity to tip over acts on it, meaning that the posture is most stable. Here, we consider the body when in a static standing posture as a single inverted pendulum, and ZMP(t) = (ZMP x ,ZMP y ) is calculated from the balance of the moment around the body center of gravity using the following equations (1) and (2). The calculation result is output to a fall risk evaluation index ZMP-COP distance (d) calculation unit 25.

[0039] ZMP x (t)=COM x -(F x / F z )COM z (1) ZMP y (t)=COM y -(F y / F z )COM z (2) <s7> In S7, the fall risk assessment index ZMP-COP distance (d) calculation unit 25 calculates a fall risk assessment index from the center of pressure (COP) position (COP(t)) input from the center of plantar pressure measurement unit 23 and the zero moment point (ZMP) (ZMP(t)) input from the ZMP calculation unit 24.

[0040] In this embodiment, as a fall risk assessment index, the distance d(t) between the ZMP and the COP is calculated from the following equations (3) to (5). The larger d is, the more likely the posture is to become unstable, which means a higher fall risk. The calculated d(t) is the intensity of the exercise intervention target (f a ) and is output to the calculation unit 32.

[0041] d x (t)=ZMP x -COP x (3) d y (t)=ZMP y -COP y (4)

[0042]

Number

[0043] The exercise intervention target intensity f a (t) is the target intensity of the exercise intervention to make the contact load of the fingertip of the subject in a light touch state (1 N or less) in consideration of the fall risk.

[0044] f a The possible range of is 0 < f - f a < 1, f - 1 < f a < f. In this embodiment, as an example, the following model in which the exercise intervention target intensity f a changes according to the fall risk assessment index d is set.

[0045]

number

[0046] where d L , d H are determined by conducting preliminary experiments as follows:

[0047] d L : Maximum value of d when standing still with eyes open and both feet on a hard floor d H : Maximum value of d when standing on one leg with eyes closed on a soft floor In addition, d H If you are unable to maintain balance during the conditions that determine d H is 70% of the value of d at that moment. Note that "70%" is just an example.

[0048] The exercise intervention target intensity determination model that has been set is stored in a storage device such as a memory.

[0049] <s8> In S8, the exercise intervention target intensity (f a The contact load f(t) (>1N) between the finger and the platform is input to the finger contact load evaluation unit 12, the fall risk evaluation index d(t) is input to the fall risk evaluation index ZMP-COP distance (d) calculation unit 25, and the exercise intervention target intensity decision model read out from the storage device is input to the calculation unit 32. These are used to calculate the exercise intervention target intensity (f a ) is calculated.

[0050] Exercise intervention target intensity (f a ) The calculation unit 32 applies the current f and d to the exercise intervention target intensity determination model to determine the exercise intervention target intensity f a (t) is found, and f a (t) is output to the electrical stimulation control unit 42.

[0051] <About the electrical stimulation parameter determination model> Here, a determination model for determining electrical stimulation parameters corresponding to electrical stimulation for generating an exercise intervention target intensity at the fingertip will be described.

[0052] As an example, the pulse width is set to 200 μs, the current to 10 mA, and the stimulation intensity is adjusted by varying the frequency between 0 and 200 Hz. A preliminary experiment is conducted to determine the change in load on the fingertip when the frequency is changed, and a model for determining electrical stimulation parameters according to the target intensity of exercise intervention is created. The created model for determining electrical stimulation parameters is stored in a storage device such as a memory.

[0053] <s9> In S9, the electrical stimulation control unit 42 is configured to receive the exercise intervention target intensity (f a ) The calculation unit 32 calculates the exercise intervention target intensity f a (t) is input, and the electrical stimulation parameter determination model read from the storage device is input. a The electrical stimulation parameters are determined by applying the above to the model, and the determined electrical stimulation parameters are provided to the electrical stimulation device 150, causing the electrical stimulation device 150 to perform movement intervention on the fingertip.

[0054] In this embodiment, the subject's contact point with the support is a single point, the fingertips, but multiple exercise intervention points may be provided, for example, by having both hands contact fixed points such as parallel bars. The attachment position of the load measuring device 110 may also be changed to the fingertips, palms, walls, safety bars, etc. The fall risk assessment index may be the velocity of center of gravity sway or area, and the exercise intervention target intensity determination model may be changed as appropriate. The device that performs the exercise intervention on the subject may also be replaced by a vibrating glove, etc.

[0055] <Hardware configuration example> The light touch maintenance device 100 can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on the cloud.

[0056] That is, the light touch maintenance device 100 can be realized by executing a program corresponding to the processing performed by the light touch maintenance device 100 using hardware resources such as a CPU and memory built into a computer. The program can be recorded on a computer-readable recording medium (such as a portable memory) and stored or distributed. The program can also be provided via a network such as the Internet or email.

[0057] Fig. 6 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 6 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected by a bus BS.

[0058] A program for realizing processing on the computer is provided by a recording medium 1001 such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0059] The memory device 1003 reads and stores the program from the auxiliary storage device 1002 when instructed to start the program. The CPU 1004 realizes the functions related to the light touch maintenance device 100 in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, various measuring devices, exercise intervention devices, etc. The display device 1006 displays a GUI (Graphical User Interface) etc. according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the calculation results.

[0060] (Effects of the embodiment) The technology according to the present embodiment enables training while maintaining a light touch even in highly difficult tasks that tend to cause poor posture, thereby maximizing the effectiveness of posture control learning for the subject and contributing to improving balance ability.

[0061] (Summary of the embodiment) This specification discloses at least the following light touch maintaining device, light touch maintaining method, and program. (Section 1) a contact load evaluation unit that determines whether the subject is in a light touch state based on a contact load between the subject and a support; an exercise intervention control unit that controls exercise intervention on the subject so as to maintain the light touch state when the subject is not in the light touch state; Equipped with a light touch maintaining device. (Section 2) A fall risk assessment unit is further provided to assess the risk of the subject falling, The exercise intervention control unit performs exercise intervention control for the subject based on the evaluation result by the fall risk evaluation unit. 2. A light touch maintaining device as described in paragraph 1. (Section 3) the fall risk assessment unit calculates a distance between the zero moment point of the subject and a center of pressure of the sole of the subject; The exercise intervention control unit determines a target intensity of the exercise intervention for the subject based on the distance. 3. A light touch maintaining device as described in paragraph 2. (Section 4) The exercise intervention control unit determines parameters to be given to a device that executes the exercise intervention based on the target intensity. 4. A light touch maintaining device as described in paragraph 3. (Section 5) A light touch maintenance method executed by a light touch maintenance device, comprising: a contact load evaluation step of determining whether the subject is in a light touch state based on a contact load between the subject and a support; an exercise intervention control step of controlling exercise intervention for the subject so as to maintain the light touch state when the subject is not in the light touch state; Equipped with a light touch maintaining method. (Section 6) A program for causing a computer to function as each part of the light touch maintenance device described in any one of paragraphs 1 to 4.

[0062] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0063] 100 Light Touch Maintenance Device, PC 200 Light Touch Maintenance System 110 Load measuring instrument 120 3D motion analysis equipment 130 Floor reaction force meter 150 Electrical Stimulator 10 Contact load evaluation section 20 Fall Risk Assessment Section 30 Exercise intervention target intensity calculation section 40 Exercise intervention department 11 Finger contact load (f) measurement unit 12 Finger contact load evaluation unit 21 Body center of gravity (COM) measurement unit 22 Ground reaction force (GRF) measurement unit 23 Center of pressure (COP) measurement unit 24 Zero Moment Point (ZMP) Calculation Unit 25 Fall risk assessment index ZMP-COP distance (d) calculation section 31 Exercise intervention target intensity determination model 32 Exercise intervention target intensity (fa) calculator 41 Electrical stimulation parameter determination model 42 Electrical stimulation control unit 1000 Drive Device 1001 Recording media 1002 Auxiliary storage 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input Device

Claims

1. a contact load evaluation unit that determines whether or not the subject is in a light touch state based on a contact load between the subject's fingertip and a support; and an exercise intervention control unit that controls exercise intervention to reduce the contact load by providing electrical stimulation to muscles that extend the fingers of the subject so as to maintain the light touch state when the subject is not in the light touch state, A fall risk assessment unit is further provided to assess the risk of the subject falling, the fall risk assessment unit calculates a distance between the zero moment point of the subject and a position of the center of sole pressure of the subject, and the exercise intervention control unit determines a target intensity of exercise intervention for the subject based on the distance; The exercise intervention control unit reduces a target intensity of the exercise intervention as the distance increases when the distance is greater than a predetermined first threshold and less than a predetermined second threshold, and decides not to perform the exercise intervention on the subject when the distance is greater than the second threshold. Light touch maintenance device.

2. The exercise intervention control unit performs exercise intervention control for the subject based on the evaluation result by the fall risk evaluation unit.

2. The light touch maintaining device of claim 1.

3. A light touch maintenance method executed by a light touch maintenance device, comprising: a contact load evaluation step of determining whether the subject is in a light touch state based on a contact load between the subject's fingertip and a support; and an exercise intervention control step of controlling, when the subject is not in a light touch state, an exercise intervention to reduce the contact load by presenting electrical stimulation to muscles that extend the subject's fingers so as to maintain the light touch state; A fall risk assessment step of assessing the risk of the subject falling, In the fall risk assessment step, the light touch maintenance device calculates a distance between the zero moment point of the subject and a center of pressure on the sole of the subject, and in the exercise intervention control step, the light touch maintenance device determines a target intensity of exercise intervention for the subject based on the distance; In the exercise intervention control step, the light touch maintenance device reduces a target intensity of the exercise intervention as the distance increases when the distance is greater than a predetermined first threshold and less than a predetermined second threshold, and determines not to perform the exercise intervention on the subject when the distance is greater than the second threshold. How to maintain a light touch.

4. A program for causing a computer to function as each unit in the light touch maintaining device according to claim 1 or 2.

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