CN110192841B - Grip testing device and method based on multi-directional instantaneous mutation disturbance torque effect - Google Patents

Abstract

The present disclosure proposes a grasping test device and method based on the multi-directional instantaneous sudden change disturbance torque effect, including: a hollow casing containing fluid; Force torque sensor, a torque sensor for detecting four-finger side force is arranged on the opposite side of the inner wall of the hollow shell; the hollow shell is arranged on the base, and the bottom of the base is connected to the electromagnet The electromagnet device is used to generate an instantaneous sudden change disturbance torque acting on the bottom of the base in a designated direction; the torque sensor detects the data signal of the person to be tested under the action of the instantaneous sudden change disturbance torque, and uses the data signal for evaluation after processing Precise hand grip function. Under the framework of Uncontrolled Manifold (UCM) assumption, the index of multi-finger dynamics signal synergy is calculated to evaluate the stable synergy of multi-finger finger force, and quantitatively evaluate the precise grasping function of hand function.

Description

Grip testing device and method based on multi-directional instantaneous mutation disturbance torque effect

technical field

The present disclosure relates to the technical field of grasping test devices, and in particular, to a grasping test device and method based on multi-directional instantaneous sudden change disturbance torque effect.

Background technique

Precise grasping and manipulation of the hand plays an important role in human production and life. The test and evaluation of hand grasping function plays an important role in the fields of neurophysiological analysis, neuropathological examination, and monitoring of hand function rehabilitation progress. An important requirement for grasping an object is to accurately perceive the center of gravity of the object, and to control the resultant moment of the object within a moderate range to meet the goal of grasping motion. Therefore, torque-aware control capability is a key mechanism in grasping control. The torque effect is further divided into the stable torque effect and the disturbance torque effect. When the magnitude and direction of the torque change with time, the torque effect is the disturbance torque effect. If the moment when the disturbance torque appears is random and abrupt, it is an instantaneous sudden change disturbance torque. Accurate perception and control of transient mutation perturbation torque is a more advanced requirement of nervous system function.

However, the inventor found in the research that there is still no relevant technical solution for accurately testing the five-finger precise grasping motion function under the multi-directional instantaneous mutation disturbance torque.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present specification is to provide a grasping test device based on the multi-directional instantaneous mutation disturbance torque effect, which can be used to evaluate the stable synergy of multi-finger finger force, quantitative evaluation of hand function precise grasping function, and evaluation of hand function damage, etc. Fields are of great value.

The embodiments of this specification provide a gripping test device based on the multi-directional instantaneous sudden change disturbance torque effect, which is achieved through the following technical solutions:

include:

a hollow shell containing fluid;

The inner wall of the hollow shell is provided with a torque sensor for detecting the lateral force of the thumb, and the opposite side of the inner wall of the hollow shell is provided with a torque sensor for detecting the lateral force of the four fingers;

The hollow shell is arranged on the base, and is connected with the electromagnet device at the bottom of the base;

The electromagnet device is used to generate an instantaneous sudden change disturbance torque acting on the bottom of the base in a designated direction;

The torque sensor detects the data signal of the person to be tested under the action of the instantaneous sudden change disturbance torque, and uses the data signal to evaluate the precise grasping function of the hand after processing.

The embodiments of the present specification provide a gripping test method based on the multi-directional instantaneous mutation disturbance torque effect, which is realized by the following technical solutions:

include:

The gripping test device is gripped by the test subject;

Grasp the bottom of the base of the test device to receive the instantaneous abrupt disturbance moment in the specified direction;

Lift the gripping test device stably to the specified height, keep it for the set time, and place it to the initial position stably. After the test, get real-time signals of three-dimensional force, three-dimensional moment and pressure center point;

Using the above-mentioned real-time signal data of three-dimensional force, three-dimensional moment and pressure center point, the index of multi-finger dynamic stability and synergy during the grasping process was calculated, and the precise grasping function of the hand was evaluated.

Compared with the prior art, the beneficial effects of the present disclosure are:

The device of the present disclosure is used for the functional evaluation of precise grasping of the hand and the precise quantitative evaluation of the degree of functional impairment and rehabilitation of the hand, and has important application value.

The evaluation method of the device of the present disclosure calculates the index of the synergy of the multi-finger dynamics signals under the framework of the uncontrolled manifold (UCM) assumption, which is used to evaluate the stable synergy of the multi-finger finger force, and the accurate grasping function of the hand function. Quantitative assessment.

Description of drawings

The accompanying drawings that constitute a part of the present disclosure are used to provide further understanding of the present disclosure, and the exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure.

1 is a structural diagram of a multi-finger grasping test device based on multi-directional instantaneous sudden change disturbance torque according to an embodiment of the present disclosure;

2 is a state diagram of a multi-finger grasping test device when a rope is straightened by a rated weight after the electromagnet is powered off according to an embodiment of the present disclosure;

3(a)-FIG. 3(d) are schematic diagrams of the base of the multi-finger grasping tester when generating instantaneous sudden change disturbance torque in different directions according to an embodiment of the present disclosure;

FIG. 4 is a specific experimental flow chart of the device of the embodiment of the disclosure;

In the figure, 1 is the top square hollow flat cover, 2 is the square hollow structure inside the test device, 4 is the thumb side six-dimensional force/torque sensor, 5 is the index finger side six-dimensional force/torque sensor, and 6 is the middle finger side six-dimensional force/torque sensor. Torque sensor, 7 is a six-dimensional force/torque sensor on the ring finger side, 8 is a six-dimensional force/torque sensor on the little finger side, 9 is a flat contact piece on the four-finger side, 10 is a flat contact piece on the thumb side, and 3 is a square grip test device Base, 11 is an elastic rope, 12 is a rated weight, and 13 is an electromagnet.

Detailed ways

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

Example 1

This embodiment discloses a grasping test device based on multi-directional instantaneous mutation disturbance torque effect. The device can generate disturbance torque states in four directions. By grasping the test device, five fingers in multiple directions can be accurately detected and recorded. Real-time dynamic signals such as the three-dimensional force, three-dimensional moment and the position coordinates of the pressure center point of each fingertip in the process of grasping the object under the action of the instantaneous mutation disturbance torque. The constraint matrix E is obtained from the finger force, and the constraint matrix E is used to convert the finger force into the finger mode (m). In the case of the mean free modulus, the uncontrolled manifold (UCM) was calculated. Under the framework of the Uncontrolled Manifold (UCM) assumption, the synergy index ΔV of polydactyly kinetic signals was calculated. The device can be used to evaluate the stability and synergy of multi-finger finger force, and has important value in the fields of quantitative evaluation of hand function, precise grasping function, and evaluation of hand function damage.

In this example, the signals of the center point of force, torque and pressure are used as the original signal. Taking the force signal as an example, the force data in the single-finger slope experiment is used to calculate the constraint matrix, which reflects the relationship between the force of a single finger and the resultant force, The force signal in the formal experiment calculates the finger mode m by calculating the change in finger force. It is the force signal in the three-dimensional direction generated by the fingertip.

Finger force is a three-dimensional force signal generated by the fingertip of the finger.

The specific structure of the test device of this embodiment is shown in Figures 1-2, including a tester water cup, a six-dimensional force/torque sensor 4 on the thumb side, and a six-dimensional force/torque sensor on the four-finger side (the six-dimensional force/torque sensor on the index finger side). Sensors 5, middle finger side six-dimensional force/torque sensor 6, ring finger side six-dimensional force/torque sensor 7, little finger side six-dimensional force/torque sensor 8) are in left and right relative positions, and are fixed in the square hollow structure inside the test device 2 On the upper side, the thumb-side sensor and the outer contact plane are fixedly connected by a connecting piece such as the thumb-side plane contact piece 10 , and the four-finger side is similarly fixedly connected by the four-finger side plane contact piece 9 . The inside of the tester is square and has a hollow structure, which is used to hold fluid and simulate the working state of a real water cup. The square base 3 of the gripping test device is a square cylinder, with an electromagnet 13 connected downward from the center, and the rated weight 12 is connected to the designated position of the base center at the front, rear, left, right and equal distances in turn by the elastic rope 11 . The top square hollow flat cover 1 should be on the device.

A six-dimensional force/torque sensor refers to a sensor that can measure three-dimensional force and three-dimensional torque. (In this disclosure, F _X is the force in the vertical direction, F _Y is the force in the front-to-back direction, F _Z is the force in the left-right direction, T _X is the moment about the vertical axis, T _Y is the moment about the sagittal axis, and T _Z is the moment about the coronal axis). A slash represents or.

In this embodiment, the placement positions of the five force and torque sensors on both sides on the bracket can be adjusted as required.

The six-dimensional force/torque sensor can also be replaced with other types of sensors, as long as real-time air force and torque data can be obtained holding the tester, or the same pressure sensor can be placed in a different location on the tester.

In one embodiment, the geometry of the tester cup may also be square or other shapes, so long as the tester can grasp the device.

In one embodiment, Figure 2 is a state diagram of the multi-finger gripping test device when the rated weight straightens the rope after the electromagnet is powered off. At this time, the electromagnet is powered off and the rated weight suddenly falls down under the action of gravity. , the elastic rope is stretched downward to generate a disturbance torque.

In one embodiment, when the electromagnet is energized, the rated weight is tightly attached to the electromagnet, and no force is generated on the elastic rope at this time. When the power is suddenly cut off, the attractive force of the electromagnet to the rated weight disappears, and the rated weight falls down under the action of gravity, pulling the elastic rope, thereby generating an instantaneous sudden change disturbance torque in the designated direction.

The rated weights are connected by ropes to the front, rear, left and right equidistant positions of the center of the gripping tester base to generate instantaneous sudden change disturbance moments in four specified directions.

Specifically, Figures 3(a)-3(d) respectively show the situation of instantaneous sudden change disturbance moment when the elastic rope is fixed at four positions of the base that are equidistant from the center of the base.

The device disclosed in the present disclosure can simultaneously detect and store real-time dynamic signal sequences such as three-dimensional force, three-dimensional moment and pressure center point of five fingertips. The structure of the instrument is designed in the form of a square column, and five six-dimensional force/torque sensors are combined inside. Among them, the sensor for measuring the force of the thumb and fingertip is in a relative position with the sensors of the other four fingers, and the distribution position and distance of the sensors are in line with the position of the fingers when the human hand is gripped in a cylindrical shape.

The present disclosure relates to the generation of multi-directional instantaneous sudden change disturbance torque: the present disclosure designs an electromagnet device at the position below the center of the base of the multi-finger precision grip tester, and uses elastic ropes to fix the rated weight on four designated positions around the base. When the iron is cut off, the rated weight suddenly falls and pulls the elastic rope to generate a disturbance torque in the specified direction. The four designated positions are four positions equidistant from the center in the front, rear, left and right directions of the center of the base.

The present disclosure relates to the simultaneous analysis of multi-channel real-time dynamic signals. Parameters such as constraint matrix E, finger mode m and performance variable PV are calculated to analyze the dynamic coordination between fingers, and the calculation results reflect the dynamic and stable synergy of multiple fingers. index. This patent proposes a method based on Uncontrolled Manifold (UCM):

The constraint matrix E is obtained from the finger force, and the finger force is transformed into the finger mode (m) by the E matrix. In the case of the mean free modulus, the uncontrolled manifold (UCM) was calculated. Under the framework of the Uncontrolled Manifold (UCM) assumption, an indicator of the synergistic effect of polydactyly dynamic stabilization during grasping is calculated.

Example 2

This embodiment discloses a grasping test method based on the multi-directional instantaneous sudden change disturbance torque effect, and the method may be based on the test device of the above-mentioned embodiment.

The experimental process is shown in Figure 4. First, the subject information is collected, and the experimental precautions and action norms are introduced. Connect the elastic rope at the designated position on the base, and the rated weight is connected by the rope. Change the connection position of the elastic rope so that the rated weight is located on the upper, lower, left and right sides of the base, respectively. When there is an instantaneous sudden change of disturbance torque in the designated direction Multifinger grip test. First of all, in the single-finger slope experiment, when the subject grasped the test device with five fingers, a single finger (task finger) completed the fingertip force rising and following task according to the given force index on the screen interface, and the non-specified finger (non-task finger) was Unconscious force is generated during this process, and force data is recorded for all fingers, and each finger is tested separately. In the formal experiment, the subjects used the five fingers of the right hand to grasp the multi-fingered precision grasping tester, held it up to the specified height steadily, held it for 10s, and then placed it to the initial position on the desktop. After the test, real-time signals of three-dimensional force, three-dimensional moment and pressure center point are obtained.

The constraint matrix (E) reflects the unconscious force produced by the non-task finger when the task finger produces force. The E-matrix was calculated using data from each subject's single-finger ramp experiments.

Among them, i,j={I,M,R,L}, where I represents the index finger (index), M represents the middle finger (middle), R represents the ring finger (ring), and L represents the little finger (little). j represents the task finger, F _i,j represents the force generated by the ith finger alone when the j finger is the task finger, and F _TOT,j represents the resultant force when the j finger is the task finger. The overall index EN _j is calculated from the average k _i,j of the non-task fingers. EN _j =∑k _i,j /3

For each single-finger trial, a linear regression of the force produced by a single finger on F _TOT,j over the specified time interval can be calculated, where the regression coefficients are matrix E. The term "modality" is used to denote the combination of the forces of all fingers when only a single finger is required to exert force, and the finger force is converted into a finger modality (m) using the E matrix.

Among them, df _j is the change of the force of a single finger, which can be obtained from the force data obtained by the experiment, and j={I,M,R,L}. Taking into account constraint effects, changes in performance variables PV (such as finger force) can be expressed as a function of these variables

dPV=[d _i d _m d _r d _l ]*E*m (4)

Among them, d _j is the finger coefficient, the task finger coefficient is unit 1, and the non-task finger coefficient is -1. In the case of the mean free modulus, the uncontrolled manifold (UCM) is calculated. It represents a combination of modal sizes consistent with stable values of performance variables. The manifold is a linear approximation of the null space spanned by the basis vectors, and the following equations are solved

0=[d _i d _m d _r d _l ]*E*e _i (5)

For each hypothesis, there is a nullspace basis vector, so the nullspace has one dimension. The basis vector e _i of the null space of each sample is numerically computed with MATLAB's null function. The modal modulus vectors obtained at each sampling point of the slope experiment are decomposed into the projection f _|| on the null space and the component f _⊥ perpendicular to the null space.

f _⊥ = mf _|| (7)

where n and k are the number of degrees of freedom and performance variables of the m vector, respectively. The variance per degree of freedom in UCM is estimated as

where |f _|| | ² is the square of the length of the deviation vector within the linearized UCM, f _|| is obtained from formula (6), and N _trial is the number of trials. Similarly, the variance in each degree of freedom perpendicular to the UCM is estimated as

和

分别被称为每自由度的方差分量V_UCM和V_ORT。两个方差分量(V_UCM和V_ORT)进一步结合成一个单一的协同指数ΔVf _|| is obtained by formula (7). The variance of all experiments in the mode space is quantified separately in the two subspaces. The variance of the modality space for each time sample is quantified separately in two subspaces. The first subspace (UCM) corresponds to no change in _FTOT . The second subspace is the Orthogonal Complement of UCM (ORT); the variance within the ORT changes F _TOT .

and

are called the variance components per degree of freedom V _UCM and V _ORT , respectively. The two variance components (V _UCM and V _ORT ) are further combined into a single synergy index ΔV

ΔV=(V _UCM -V _ORT )V _TOT (10)

where each variance index is normalized according to the number of degrees of freedom in the corresponding space; V _TOT represents the total variance. When ΔV>0, it indicates the existence of stable synergy. The larger the ΔV, the stronger the synergistic effect. According to the synergy index, the final index for evaluating the precise grasping function of the hand is calculated.

Among them, ΔV _average is the synergy index obtained from the control experiment of healthy subjects.

The present disclosure accurately tests the precise grasping function of the hand by analyzing the stability and synergy between the five fingers of the whole hand when the small torque changes during the grasping process, which is an analysis of multi-channel dynamic signals. The prior art mainly focuses on the evaluation of the two-finger grasping function of the thumb and the index finger, and the evaluation algorithm is different from that of the present application.

It is to be understood that, in the description of this specification, referring to the description of the terms "an embodiment", "another embodiment", "other embodiment", or "the first embodiment to the Nth embodiment" etc. means A particular feature, structure, material, or characteristic described in connection with this embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials and characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above descriptions are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims (6)

1. Grabbing testing arrangement based on multi-direction transient sudden change disturbance torque effect, characterized by includes:

a hollow housing, the hollow housing containing a fluid therein;

a torque sensor for detecting the lateral force of the thumb is arranged on the inner wall of the hollow shell, and a torque sensor for detecting the lateral force of the four fingers is arranged on the other side, opposite to the inner wall of the hollow shell;

the hollow shell is arranged on the base, and the bottom of the base is connected with the electromagnet device;

the electromagnet device is used for generating instantaneous sudden-change disturbance torque in a specified direction acting on the bottom of the base;

the moment sensor detects a data signal of a person to be tested under the action of the instantaneous sudden change disturbing moment, the data signal is used for processing and then evaluating the accurate hand grasping function, and the index of the stable synergistic action of the multi-finger force is calculated under the framework without control manifold hypothesis;

the electromagnet device comprises an electromagnet, a rated weight and an elastic rope, the electromagnet is connected with the base from the center downwards, and the rated weight is sequentially connected with the designated positions of the center of the base at equal distance from front to back, left to right and left by the elastic rope;

the device synchronously detects and stores three-dimensional force, three-dimensional moment and pressure central point real-time dynamics signal sequences of five finger fingertips.

2. The grip test device based on the multi-directional instantaneous abrupt disturbing torque effect as claimed in claim 1, wherein the torque sensor for thumb side force and the torque sensor for four finger side force are respectively and fixedly connected with the outer side contact plane of the hollow shell through respective corresponding contact pieces.

3. The grip test device according to claim 1, wherein the hollow housing has a square interior and the base is a square cylinder.

4. The grasping test method based on the multidirectional instantaneous sudden change disturbance torque effect is characterized by comprising the following steps of:

the gripping test device is gripped by a testee;

the bottom of a base of the gripping test device receives instantaneous sudden-change disturbance torque in a specified direction;

starting the stable end of the gripping test device to a specified height, keeping the stable end at the initial position after a set time, and obtaining a three-dimensional force, a three-dimensional moment and a pressure central point real-time signal after the test is finished;

calculating indexes of multi-finger dynamic stable synergistic effect in the gripping process by using the three-dimensional force, the three-dimensional moment and the real-time signal data of the pressure central point, calculating the indexes of the multi-finger force stable synergistic effect under the framework without control manifold hypothesis, and evaluating the accurate gripping function of the hand;

the method further comprises a single-finger slope experiment, under the condition that a test subject grasps the test device by five fingers, a single finger finishes a fingertip strength rise following task according to a given force index, each finger is tested respectively, and for each single-finger slope experiment, a single-finger pair F in a specified time interval is calculated_TOT,jLinear regression of the generated forces, wherein the regression coefficients are a constraint matrix; f_TOT,jRepresenting the resultant force generated when the j finger is the task finger;

the constraint matrix E reflects the unintended forces generated by the non-task finger when the task finger generates the force, the E matrix being calculated using data from the single-finger slope experiment for each subject;

wherein I, j ═ { I, M, R, L }, wherein I represents index of the index finger, M represents middle finger, R represents ring finger ring, and L represents little finger little;

j represents a task finger, F_i,jRepresenting the force, F, produced by the ith finger alone when the j finger is the task finger_TOT,jRepresenting the resultant force generated when the j finger is the task finger.

5. The method as claimed in claim 4, wherein the constraint matrix is used to convert finger force into finger mode.

6. The grip test method based on the multi-directional transient disturbance torque effect as claimed in claim 4, wherein the overall index EN_jAverage k by non-task finger_i,jCalculated to obtain EN_j＝∑k_i,j/3。

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