Tongue movement function evaluation device

Abstract

To provide a tongue movement function evaluation device capable of quantitatively evaluating a tongue movement function using surface myoelectric signals from the suprahyoid muscle group.SOLUTION: Information processing means 20 performs muscle synergy analysis using biological signals from a suprahyoid muscle group myoelectric sensor 10 when the tongue is moved in one direction and in the other direction, extracts one muscle synergy activated when the tongue is moved in one direction and the other muscle synergy activated when the tongue is moved in the other direction, the one muscle synergy and the other muscle synergy being represented by a spatial pattern and a time pattern, and evaluates the tongue movement function using at least one of a coordination evaluation evaluated from an overlap ratio between the time pattern of the one muscle synergy and the time pattern of the other muscle synergy, a regularity evaluation evaluated from a similarity of activation per motion cycle for each time pattern of the one muscle synergy and the other muscle synergy, and a symmetry evaluation evaluated from a similarity between the time or spatial patterns of the one muscle synergy and the other muscle synergy.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tongue movement function evaluation device for evaluating the state of tongue movement. [Background technology]

[0002] The tongue plays an important role in chewing and swallowing. During chewing, it forms a bolus through coordinated movement with the lower jaw, and during swallowing, it sends the bolus into the pharynx, ensuring safe swallowing. However, tongue motor function declines due to aging and cerebrovascular disorders, and it is not uncommon for the tongue to atrophy or for the tip of the tongue to deviate to the side when protruding. As a result, problems occur with the formation of the bolus and its delivery into the pharynx, increasing the risk of aspiration and choking. Problems with articulation, such as clarity of pronunciation, may also occur. For these reasons, it is important to evaluate tongue motor function. Patent Document 1 proposes a tongue measurement device that includes a probe having a pair of current application electrodes and a pair of voltage measurement electrodes that are used in contact with the tongue, a current generation unit that outputs an alternating current to the pair of current application electrodes, a voltage measurement unit that measures the voltage of the pair of voltage measurement electrodes, an impedance calculation unit that calculates the impedance of the tongue based on the alternating current and the voltage measured by the voltage measurement unit, a memory unit that stores the relationship between the impedance of the tongue and an index that indicates the ability to move the tongue, and an index generation unit that uses the relationship stored in the memory unit to generate an index that indicates the ability to move the tongue that corresponds to the tongue impedance calculated by the impedance calculation unit. Patent Document 2 proposes a tongue movement measuring device that, when the measurement target area is the subject's oral cavity and the range of movement of the tongue when the subject protrudes the tongue outside the oral cavity, and at least two locations within the measurement target area are each designated as a first measurement point and a second measurement point, includes a first sensor that detects the subject's tongue approaching the first measurement point, a second sensor that detects the subject's tongue approaching the second measurement point, and a tongue movement information acquisition unit that acquires information related to the movement of the subject's tongue between the first measurement point and the second measurement point as tongue movement information from the detection results of the first sensor and the second sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-188029 [Patent Document 2] Japanese Patent Application Publication No. 2017-225503 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Documents 1 and 2, electrodes are brought into direct contact with the tongue or tongue movements are measured directly.

[0005] An object of the present invention is to provide a tongue motor function evaluation device that can quantitatively evaluate tongue motor function using surface myoelectric potential signals of the suprahyoid muscles. [Means for solving the problem]

[0006] The tongue motor function evaluation device of the present invention as described in claim 1 is a tongue motor function evaluation device for evaluating tongue motor function, comprising a suprahyoid muscle electromyography sensor 10 for detecting biosignals of the suprahyoid muscles, and an information processing means 20 for performing muscle synergy analysis using the biosignals from the suprahyoid muscle electromyography sensor 10 when the tongue is moved to one side and the other side, and extracting one muscle synergy activated when the tongue is moved to the one side and another muscle synergy activated when the tongue is moved to the other side, the extracted one muscle synergy and the other muscle synergy are expressed as spatial patterns and time patterns, and the tongue motor function is evaluated using at least one of the following evaluation criteria: coordination evaluated from the overlapping ratio between the time pattern of the one muscle synergy and the time pattern of the other muscle synergy; regularity evaluated from the similarity of activation in each movement cycle for each time pattern of the one muscle synergy and the other muscle synergy; and symmetry evaluated from the similarity of the time pattern or the spatial pattern between the one muscle synergy and the other muscle synergy. The present invention as set forth in claim 2 is characterized in that in the tongue movement function evaluation device as set forth in claim 1, in the coordination evaluation, the overlap rate is evaluated by the distance between centers of gravity in a histogram of relative difference signals. The present invention described in claim 3 is characterized in that, in the tongue movement function evaluation device described in claim 1, the regularity evaluation evaluates the similarity of the activation for each period using an autocorrelation coefficient. The present invention as set forth in claim 4 is characterized in that in the tongue movement function evaluation device as set forth in claim 1, in the symmetry evaluation, the similarity of the changes is evaluated by a cross-correlation coefficient. [Effects of the Invention]

[0007] According to the present invention, muscle synergies corresponding to tongue movement can be extracted simply by attaching a suprahyoid muscle electromyography sensor to the submandibular region, and tongue movement function can be quantitatively evaluated by numerically processing the features of the extracted muscle synergies. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing the configuration of a tongue movement function evaluation device according to one embodiment of the present invention; [Figure 2] Muscle synergy analysis [Figure 3] Photograph showing the structure of the electromyography sensor and where to wear it [Figure 4] Representative muscle synergy results for each subject group [Figure 5] Figure 4 shows the time pattern of two muscle synergies overlaid on each other. [Figure 6] Diagram showing how cooperation is assessed [Figure 7] Diagram showing how regularity is evaluated [Figure 8] Diagram showing how symmetry is evaluated [Figure 9] Figure showing the evaluation results of coordination, regularity, and symmetry DETAILED DESCRIPTION OF THE INVENTION

[0009] The tongue motor function evaluation device according to the first embodiment of the present invention includes a suprahyoid muscle electromyography sensor for detecting biosignals of the suprahyoid muscles, and an information processing means performs muscle synergy analysis using the biosignals from the suprahyoid muscle electromyography sensor when the tongue is moved to one side and the other side, and extracts one muscle synergy activated when the tongue is moved to one side and another muscle synergy activated when the tongue is moved to the other side. The extracted one muscle synergy and other muscle synergy are expressed as spatial patterns and time patterns, and tongue motor function is evaluated using at least one of the following evaluation criteria: coordination, which is evaluated from the overlapping ratio between the time pattern of one muscle synergy and the time pattern of the other muscle synergy; regularity, which is evaluated from the similarity of activation in each movement cycle for each time pattern of one muscle synergy and the other muscle synergy; and symmetry, which is evaluated from the similarity of the time pattern or the spatial pattern between one muscle synergy and the other muscle synergy. According to this embodiment, muscle synergies corresponding to tongue movement can be extracted simply by attaching a suprahyoid muscle electromyography sensor to the submandibular region, and tongue movement function can be quantitatively evaluated by numerically processing the features of the extracted muscle synergies.

[0010] In the second embodiment of the present invention, the tongue motor function evaluation device according to the first embodiment evaluates the coordination by evaluating the overlap ratio based on the distance between the centers of gravity in a histogram of relative difference signals. Tongue movement requires not only the tongue itself but also the coordinated movement of multiple surrounding muscles, such as the suprahyoid muscles, which support the base of the tongue. It has been confirmed that tongue motor function declines with aging and paralysis. According to this embodiment, the influence of aging and paralysis on tongue motor function can be evaluated by evaluating the coordination of muscle synergies extracted from the suprahyoid muscles.

[0011] In the third embodiment of the present invention, in the tongue motor function evaluation device according to the first embodiment, the regularity evaluation evaluates the similarity of activation for each movement cycle using an autocorrelation coefficient. According to this embodiment, by evaluating the reproducibility and regularity as a motor function for repeatedly generating the same movement, it is possible to evaluate the influence of age-related changes and paralysis on tongue motor function, and it can be used to evaluate tongue motor function as masticatory ability in addition to tongue motor function for swallowing and articulation.

[0012] In the fourth embodiment of the present invention, in the tongue motor function evaluation device according to the first embodiment, the similarity of changes is evaluated using a cross-correlation coefficient in the symmetry evaluation. According to this embodiment, the influence of age-related changes and paralysis on tongue motor function can be evaluated by evaluating the symmetry of muscle synergies in the suprahyoid muscles during tongue movement. [Example]

[0013] An embodiment of the tongue motor function evaluation device of the present invention will be described below. FIG. 1 is a diagram showing the configuration of a tongue motor function evaluation device according to one embodiment of the present invention. The tongue motor function evaluation device in this embodiment includes a suprahyoid muscle electromyography sensor 10 that detects biosignals of the suprahyoid muscle groups, an information processing means 20 that evaluates tongue motor function using the biosignals from the suprahyoid muscle electromyography sensor 10, and an output means 30 that outputs the evaluation results from the information processing means 20.

[0014] The suprahyoid muscle group electromyography sensor 10 detects surface electromyography signals (sEMG). The information processing means 20 performs muscle synergy analysis using the biosignals from the suprahyoid muscle electromyography sensor 10 when the tongue is moved to one side and the other side, and extracts one muscle synergy activated when the tongue is moved to one side and another muscle synergy activated when the tongue is moved to the other side. The extracted one muscle synergy and another muscle synergy are expressed as spatial patterns and time patterns, and tongue motor function is evaluated using at least one of the following evaluation criteria: coordination, which is evaluated from the overlapping ratio between the time pattern of one muscle synergy and the time pattern of the other muscle synergy; regularity, which is evaluated from the similarity of activation per movement cycle for each time pattern of one muscle synergy and the other muscle synergy; and symmetry, which is evaluated from the similarity of changes in the time pattern of one muscle synergy and the other muscle synergy.

[0015] The biological signal receiving unit 21 receives the time-series biological signals from the suprahyoid muscle group electromyography sensor 10 when the tongue is moved from one side to the other, and the received time-series biological signals are stored in the memory unit 22. The muscle synergy analysis unit 23 performs muscle synergy analysis using the time-series biological signals stored in the storage unit 22 when the tongue is moved in one direction and the other direction. The muscle synergies extracted by the muscle synergy analysis unit 23 are stored in the storage unit 22.

[0016] The coordination evaluation unit 24 evaluates coordination based on the overlapping ratio between the time pattern of one muscle synergy and the time pattern of the other muscle synergy. The coordination evaluation unit 24 evaluates the overlapping ratio based on the distance between the centers of gravity in the histogram of the relative difference signal. Tongue movement requires coordinated movements of multiple surrounding muscles. On the other hand, it has been confirmed that tongue motor function declines with aging and paralysis. In this way, by evaluating the coordination of muscle synergies extracted from the suprahyoid muscles, it is possible to evaluate the effects of aging and paralysis on tongue motor function.

[0017] The regularity evaluation unit 25 evaluates regularity for each time pattern of one-way muscle synergy and another-way muscle synergy based on the similarity of activation for each movement cycle. The regularity evaluation unit 25 evaluates the similarity of activation for each movement cycle using an autocorrelation coefficient. In this way, by evaluating the reproducibility and regularity of the motor function for repeatedly generating the same movement, the influence of age-related changes and paralysis on tongue motor function can be evaluated, and this can be used to evaluate tongue motor function as masticatory ability in addition to tongue motor function for swallowing and articulation.

[0018] The symmetry evaluation unit 26 evaluates the symmetry based on the similarity of the changes in the time patterns of one muscle synergy and the other muscle synergy. The symmetry evaluation unit 26 evaluates the similarity of the changes using a cross-correlation coefficient. In this way, by evaluating the symmetry of muscle synergies in the suprahyoid muscles during tongue movement, the influence of age-related changes and paralysis on tongue motor function can be evaluated. The cooperativeness evaluation evaluated by the cooperativeness evaluation unit 24, the regularity evaluation evaluated by the regularity evaluation unit 25, and the symmetry evaluation evaluated by the symmetry evaluation unit 26 are output by the output means 30.

[0019] As described above, the tongue motor function evaluation device in this embodiment can extract muscle synergies corresponding to tongue movement simply by attaching the suprahyoid muscle electromyography sensor 10 to the submandibular region, and quantitatively evaluate tongue motor function by numerically processing the features of the extracted muscle synergies.

[0020] Figure 2 shows muscle synergy analysis. In muscle synergy analysis, multiple muscle synergies can be extracted from the observed sEMG signals, which are expressed as a combination of the relative activity ratio (spatial pattern) of each muscle and the time-varying activity (temporal pattern). The concept of muscle synergy was introduced to elucidate the motor control system. Humans have multiple muscles and joints that operate to achieve a desired movement, and there are countless combinations of muscle output and joint angles. The concept of muscle synergy is based on the idea that each muscle is not controlled individually, but rather that each muscle module that works in coordination is controlled by a motor command at a lower level than the number of muscles. For example, patterned movements such as walking and standing up are composed of pre-defined muscle modules, and these movements are suitable for muscle synergy analysis. Furthermore, swallowing is a patterned movement composed of simple voluntary movements and reflex movements, and muscle synergy analysis allows the multiple movements that make up swallowing to be extracted as muscle synergies from sEMG signals. In this way, muscle synergy is based on the idea that multiple muscles move in an organized manner in response to a single command from the brain, and is evaluated by separating the observed signal into a spatial pattern, which is a weight matrix, and a temporal pattern, which is a basis signal, using non-negative matrix factorization.

[0021] Figure 2 shows signal analysis for extracting two muscle synergies from sEMG signals of the suprahyoid muscles. The muscle synergies consist of a spatial pattern (spatial pattern W) that represents the relative activity ratio of each muscle and a temporal pattern (temporal pattern C) that represents the time-varying activity of each muscle. In muscle synergy analysis, it is assumed that muscle activity M is composed of the relative activity ratio of each muscle (spatial pattern W) and the time-varying activity (temporal pattern C). Then, muscle contraction is considered positive, and M, W, and C are all treated as non-negative matrices. Using non-negative matrix factorization (NMF), a dimensionality reduction technique, the muscle activity matrix M (sEMG signals rectified using root mean square processing, etc.), which is a non-negative matrix, is decomposed into non-negative matrices W and C.

[0022] Figure 3 is a photograph showing the configuration of the myoelectric sensor and where it is attached. FIG. 3(a) shows the appearance of the myoelectric sensor, and FIG. 3(b) shows where the myoelectric sensor is attached. A 22-channel flexible electrode is used in the suprahyoid muscle group electromyography sensor 10. The 22-channel flexible electrode has a boomerang shape that can cover the entire suprahyoid muscle group without interfering with the larynx. The flexible substrate is entirely covered with silicone to protect it and insulate it from the human body, and sEMG signals are extracted via pure silver rod electrodes exposed from the silicone. The 22-channel flexible electrodes are positioned so that the center line of the electrode coincides with the midline of the mandible and does not come into contact with the mandible.

[0023] verification The measurements were performed by synchronizing the sEMG signals of the suprahyoid muscles with the movement of the tongue itself, which became the correct value during analysis. The subjects were instructed to move their tongues back and forth six times, according to their range of motion, smoothly at the same speed. The subjects placed their tongues against a device that limited their trajectory to the left and right, and performed tongue movements while checking the position of their tongues displayed on the AR glasses. The movement of the input unit during the test was recorded using motion capture, and the tongue movement relative to the measurement device was evaluated. Note that by defining a head coordinate system using motion capture, tongue movement relative to the head coordinate system can also be evaluated. Muscle synergy analysis was used to separate the signals of the suprahyoid muscles, and non-negative matrix factorization was used for muscle synergy analysis. By performing muscle synergy analysis, we were able to obtain muscle synergies activated when moving the tongue to the right and muscle synergies activated when moving the tongue to the left from the muscle activity of the suprahyoid muscles during tongue movement. The subjects were 19 in total, including 10 young men and 9 elderly men. Two muscle synergies were extracted from all subjects.

[0024] Figure 4 shows the representative muscle synergy results for each subject group, where Fig. 4(a) shows the young subjects and Fig. 4(b) shows the elderly subjects. The time patterns shown in red are synergies corresponding to tongue movement from the left edge to the right edge, and the time patterns shown in green are synergies corresponding to tongue movement from the right edge to the left edge. Comparing Figure 4(a) and Figure 4(b) reveals clear differences in both spatial and temporal patterns, but we focused on the temporal pattern to evaluate age-related changes. In this verification, the evaluation focused on the temporal pattern. However, when comparing the spatial pattern showing the tongue moving from the left end to the right end with the spatial pattern showing the tongue moving from the right end to the left end, as shown in Figures 4(a) and 4(b), a clear symmetry can be seen. For example, by flipping one spatial pattern (tongue moving from the left end to the right end) left and right and calculating the similarity (correlation coefficient) with the other spatial pattern (tongue moving from the right end to the left end), symmetry can be evaluated using the spatial patterns.

[0025] Fig. 5 shows two muscle synergies superimposed on the time pattern shown in Fig. 4. Fig. 5(a) shows a young subject, Fig. 5(b) shows an elderly subject, and Fig. 5(c) shows the first and second cycles of the movement extracted from Fig. 5(b). As shown in Figure 5, comparing the waveforms of muscle synergy time patterns between young and elderly people, the muscle synergies of elderly people have the following characteristics: the activity periods of two muscle synergies frequently overlap (coordination), the activity of the same muscle synergy changes differently in each movement cycle (regularity), and the balance between the left and right is different, resulting in asymmetric changes in the two muscle synergies (symmetry).

[0026] FIG. 6 is a diagram showing a method for evaluating cooperativeness. The coordination of tongue movements was defined as the ability to combine muscle synergies to generate efficient movements, and differences in muscle synergy activation among subjects were quantitatively evaluated. In left-right tongue movements, two types of muscle synergies corresponding to rightward and leftward movements were extracted. The activation of two muscle synergies with opposite movement directions shows alternating peaks. Therefore, the more the activation timing of the two muscle synergies does not overlap and they are activated independently, the more appropriately and smoothly muscle synergy switching is performed, and it can be determined that efficient and highly coordinated left-right tongue movements are achieved from the perspective of muscle force exertion. In Step 1, the relative difference signals (RDS) of the two types of muscle synergies were calculated. The relative difference signal is calculated by dividing the difference between the time patterns of two muscle synergies (time series data) by the sum of them, and the RDS and the lengths of the two muscle synergies are equal. Therefore, from the change in RDS, it is possible to grasp the proportion of phases during tongue movement in which two muscle synergies are simultaneously activated, and which muscle synergy is dominant (dominant), as time series changes. When RDS is 0, the two muscle synergies are activated at exactly the same level. The RDS can be expressed as a histogram. Because muscle synergies during left-right tongue movements exhibit alternating peaks, a histogram with a shape similar to the phase difference π is created. It can be qualitatively confirmed that the histogram peak shifts from the left and right to the center in the elderly group compared to the young group. Thus, due to aging and paralysis, the activation timing of two muscle synergies during left and right tongue movements in the elderly group changes to overlap. Therefore, coordination can be evaluated from the histogram characteristics. For example, by weighting the value of each bar graph, determining the centers of gravity in the negative and positive regions on the x-axis, and then calculating the distance between these centers of gravity, the coordination of muscle synergies due to aging and paralysis can be quantitatively evaluated. The larger the distance between the centers of gravity, the more independently activated the muscle synergies are, indicating higher coordination of the tongue during left and right movements. Evaluation of coordination using histogram characteristics is not limited to the center of gravity.

[0027] Thus, the muscle synergy coordination assessment showed that the functions of two types of muscle synergies for expressing left-right tongue movements overlap with aging and paralysis. This can be interpreted as a decrease in the freedom of tongue movement. Previous studies investigating the effects of age-related changes on tongue muscles have reported that aging causes atrophy of the muscle fibers and epithelial tissue of the tongue muscles and a decrease in elasticity, resulting in a decrease in the freedom of movement due to the activation of more muscles as a single mass. Furthermore, previous studies investigating the relationship between paralysis and muscle synergies have reported that muscle synergies in healthy individuals are fused together in multiple movements, such as walking and upper limb movements, while those in paralyzed individuals are reduced. Considering these changes in muscle activity due to aging and paralysis, it is inferred that the muscle synergies mobilized during left-right tongue movements change to become fused with aging and paralysis, resulting in the overlapping activity of muscle synergies. This indicates that by quantitatively evaluating the degree of overlap of activation between the two types of time patterns, it is possible to evaluate the effects of aging and paralysis on tongue movement from the perspective of muscle synergy coordination, based on the muscle synergies of the suprahyoid muscles.

[0028] FIG. 7 is a diagram showing a method for evaluating regularity. The regularity of tongue movement is evaluated from muscle synergies as a motor function for repeatedly generating the same movement. When the same movement is repeatedly generated, the time pattern of muscle synergies involved in generating the movement will also repeatedly activate in the same way. Therefore, the regularity of left and right tongue movement is evaluated by calculating the autocorrelation of the time pattern of left and right tongue movement. Autocorrelation is an index that indicates how similar changes in certain time series data are to their past history. If highly reproducible regular movements are repeatedly generated, the fluctuations in autocorrelation will also be periodic. The autocorrelation was calculated by substituting two identical time series data into the formula for calculating the autocorrelation coefficient shown in STEP 1 of Figure 7. In the young subjects, periodic changes in the autocorrelation coefficients of both types of muscle synergies can be confirmed. On the other hand, periodic increases and decreases cannot be confirmed in the autocorrelation coefficients of muscle synergies in the elderly subjects, indicating that the periodicity of muscle synergies is weak. In the subjects with paralysis, periodic peaks were confirmed, indicating that the two types of muscle synergies each achieved highly reproducible periodic changes during tongue movement.

[0029] The irregularity of muscle synergy can be expressed as ``|P| / (Ma)'', where P is the number of peaks of the autocorrelation coefficient, T is the number of periodic movements performed, and a is a variable that changes depending on the two types of synergy (a=0 for Synergy-A, b=1 for Synergy-B). The larger the value of "|P| / (Ma)", the more muscle synergies were activated in accordance with the periodic tongue movement, indicating a high degree of regularity in muscle synergies during tongue movement.On the other hand, the smaller the value, the more disrupted the periodicity in muscle synergies during tongue movement, indicating irregular activation of muscle synergies. As shown in Figure 7, the regularity of muscle synergies significantly decreases with aging. Such evaluation of the regularity of left and right tongue movement can be used to evaluate tongue motor function in terms of masticatory ability, in addition to tongue motor function for swallowing and articulation.

[0030] FIG. 8 is a diagram showing a method for evaluating symmetry. The symmetry of tongue movement is defined as the motor function to achieve similar movements in the left and right directions, and the similarity of the changes in the two muscle synergies is quantitatively evaluated using the cross-correlation coefficient. The symmetry of tongue movement is calculated by shifting two types of data in the same way as for regularity. The two muscle synergies change so that peaks alternate at equal intervals, and the correlation peak occurs when the data is shifted by approximately half a period. Therefore, the average period for each subject is used as the search interval, and the maximum value of the correlation is taken as the similarity between the two muscle synergies. The smaller this value, the lower the symmetry. From the graph of cross-correlation coefficients shown in STEP 1 of Figure 8, unlike in younger people, it is difficult to detect the existence of similar periodic changes between the two muscle synergies in the elderly. Furthermore, it was shown that the symmetry of synergy activation was significantly reduced in the elderly group. This result suggests that muscle imbalance is caused by the side that is usually used for chewing, called the primary chewing side, and by the tendency to move the tongue in the direction of dentures, which reduces the frequency of use of the tongue muscles on one side.

[0031] FIG. 9 is a diagram showing the evaluation results of cooperativeness, regularity, and symmetry. Coordination, regularity, and symmetry were compared between 10 young and 10 elderly subjects. As shown in Figure 9, significant functional decline due to aging (p<0.001) was confirmed for all three parameters: coordination, regularity, and symmetry. Note that for each parameter, the higher the value, the higher the evaluation (closer to normal).

[0032] In the verification of this embodiment, the tongue was moved left and right, but it may also be moved up and down or back and forth, and is not limited to these basic movements, and may be a compound movement such as a circular movement that combines basic movements. For example, in the case of a circular movement, a clockwise movement can be one movement and a counterclockwise movement can be the other movement, and further, a movement in the first quadrant can be one movement and a movement in the third quadrant can be the other movement. [Industrial Applicability]

[0033] According to the present invention, tongue movement function can be quantitatively evaluated by numerically processing the features of muscle synergies corresponding to tongue movement. [Explanation of symbols]

[0034] 10 Suprahyoid muscle electromyography sensor 20 Information Processing Means 21 Biological signal receiving unit 22 Memory section 23 Muscle Synergy Analysis Department 24 Collaboration Evaluation Department 25 Regularity Evaluation Unit 26 Symmetry Evaluation Unit 30 Output Method

Claims

1. A tongue motor function evaluation device for evaluating tongue motor function, a suprahyoid muscle electromyography sensor for detecting a suprahyoid muscle biosignal, In the information processing means, performing muscle synergy analysis using biosignals from the electromyography sensor of the suprahyoid muscles when moving the tongue to one side and the other side, and extracting one muscle synergy activated when moving the tongue to the one side and another muscle synergy activated when moving the tongue to the other side; the extracted one-muscle synergy and the other-muscle synergy are expressed as a spatial pattern and a temporal pattern, The tongue motor function is evaluated using at least one of the following as evaluation targets: coordination evaluation, which is evaluated from an overlapping ratio between the time pattern of the one muscle synergy and the time pattern of the other muscle synergy; regularity evaluation, which is evaluated from a similarity of activations in each movement cycle for each time pattern of the one muscle synergy and the other muscle synergy; and symmetry evaluation, which is evaluated from a similarity of the time pattern or the spatial pattern between the one muscle synergy and the other muscle synergy. A tongue movement function evaluation device characterized by:

2. In the evaluation of cooperation, the overlapping ratio is evaluated based on the distance between the centers of gravity in a histogram of the relative difference signals. The tongue movement function evaluation device according to claim 1 .

3. In the regularity evaluation, the similarity of the activation for each of the operation cycles is evaluated using an autocorrelation coefficient. The tongue movement function evaluation device according to claim 1 .

4. In the symmetry evaluation, the similarity of the changes is evaluated using a cross-correlation coefficient. The tongue movement function evaluation device according to claim 1 .

Images