Simulation system

Abstract

This invention provides a simulation system. The simulation device comprising a musculoskeletal model including multiple muscle sites arranged along the skeleton includes: a measurement result acquisition unit that acquires a first measurement result and a second measurement result, the first measurement result being a measurement result of muscle strength measurement performed using multiple muscle sites belonging to the subject's SFL, and the second measurement result being a measurement result of muscle strength measurement performed using multiple muscle sites belonging to the subject's SBL; and an adjustment unit that, based on a comparison of the first and second measurement results, performs adjustment processing to adjust the muscle strength of at least one of the multiple muscle sites belonging to the SFL and the multiple muscle sites belonging to the SBL in the musculoskeletal model.

Description

Technical Field

[0001] This invention relates to a simulation system. Background Technology

[0002] In simulation systems that include musculoskeletal models comprising multiple muscle groups arranged along the skeleton, there is a known simulation system such as AnyBody (registered trademark), developed and popularized by Aalborg University in Denmark. In this simulation system, it is possible to change and simulate the muscle mass values ​​of each muscle constituting the musculoskeletal model.

[0003] Japanese Patent No. 5920724 discloses a structure for adjusting muscle strength by grouping multiple muscles into a unit. More specifically, it discloses an example of simulating how the values ​​of each of the six types of muscles included in a group of muscles (hip extensors, hip flexors, hip internal rotators, hip external rotators, hip abductors, and hip external rotators) change by setting clothing conditions (conditions 0 to 6). Summary of the Invention

[0004] In simulations of the effects of exercise on muscles, even with identical clothing conditions, muscle strength varies from person to person for each part of the body. Therefore, without taking these differences into account, it is impossible to perform simulations of the musculoskeletal system that best match the individual. Even using machine learning, solving this problem remains challenging.

[0005] The purpose of this disclosure is to provide a technique for efficiently improving the accuracy of musculoskeletal model simulations based on individual differences in muscle attachment patterns.

[0006] The simulation system is a musculoskeletal model comprising multiple muscle sites configured along the skeleton, including: The measurement result acquisition unit acquires a first measurement result and a second measurement result. The first measurement result is the result of a muscle strength measurement performed using multiple muscle parts belonging to the first anatomical train of the test subject. The second measurement result is the result of a muscle strength measurement performed using multiple muscle parts belonging to the second anatomical train of the test subject that are in an antagonistic relationship with the first anatomical train. The adjustment unit performs adjustment processing based on a comparison of the first measurement result and the second measurement result, adjusting the muscle part parameters of at least one of the plurality of muscle parts belonging to the first anatomical train and the plurality of muscle parts belonging to the second anatomical train in the musculoskeletal model.

[0007] Alternatively, the adjustment unit may be configured to perform the adjustment process based on the ratio of the first measurement result to the second measurement result.

[0008] Alternatively, the adjustment unit may perform the adjustment process such that the ratio of muscle region parameters belonging to the plurality of muscle regions of the first anatomical train to the ratio of muscle region parameters belonging to the plurality of muscle regions of the second anatomical train in the musculoskeletal model is close to the ratio of the first measurement result to the second measurement result of the subject.

[0009] Alternatively, the first dissecting train can be configured as the front surface line, and the second dissecting train as the rear surface line.

[0010] Alternatively, the first dissecting train can be configured as the front functional line, and the second dissecting train as the rear functional line.

[0011] According to this disclosure, the accuracy of musculoskeletal model simulations based on individual differences in muscle attachment patterns can be significantly improved. Attached Figure Description

[0012] The features, advantages, technical and industrial significance of representative embodiments of the present invention will be depicted in the following drawings for reference, wherein like symbols indicate like elements.

[0013] Figure 1 This is a block diagram of the simulation device. Detailed Implementation

[0014] Although the invention is described below by way of embodiments, the invention as defined in the claims is not intended to be limited to these embodiments. Furthermore, the structures described in the embodiments are not necessarily essential as methods for solving the problems. For clarity, the following description and drawings have been appropriately omitted and simplified. In the drawings, the same symbols are used for the same elements, and repeated descriptions are omitted as necessary.

[0015] Although the following embodiments are described in multiple parts or embodiments for convenience, they are not unrelated unless specifically stated otherwise. Rather, they are related as variations, applications, detailed descriptions, or supplementary descriptions of one another. Furthermore, in the following embodiments, when referring to the quantity of elements (including number, value, quantity, and range), they are not limited to that specific quantity unless specifically stated otherwise or explicitly limited in principle to a particular quantity. They may be more than or less than that specific quantity.

[0016] Furthermore, in the following embodiments, structural elements (including action steps, etc.) are not essential, unless specifically stated otherwise or explicitly deemed necessary in principle. Similarly, in the following embodiments, when referring to the shape or positional relationship of structural elements, etc., they are assumed to include those that are substantially similar or analogous to their shape, etc., unless specifically stated otherwise or explicitly deemed not to be so in principle. The same applies to the aforementioned quantities, etc. (including number, value, quantity, and range).

[0017] The following is for reference Figure 1 The simulation device 1 involved in the embodiments of this disclosure will now be described. Figure 1 This is a block diagram of simulation device 1. Simulation device 1 is a specific example of a simulation system that infers the fatigue or energy expenditure of each muscle part of a subject by using inverse dynamic analysis implemented through a musculoskeletal model. The musculoskeletal model includes bones and multiple muscle parts arranged along the bones. In simulation device 1, by adjusting the muscle part parameters of multiple muscle parts, the fatigue or energy expenditure of each muscle part of the subject can be inferred with higher accuracy for each subject. Simulation device 1 can be implemented by a single device or by distributed processing implemented by multiple devices.

[0018] like Figure 1 As shown, the analog device 1 includes a processor 2, a memory 3, a communication interface 4, an LCD 5 (Liquid Crystal Display), and an input interface 6.

[0019] Processor 2 has access to memory 3. Processor 2 is configured to communicate with external devices via communication interface 4. Processor 2 reads and executes programs stored in memory 3. Thus, processor 2 and other hardware function as a musculoskeletal model selection unit 10, a measurement result acquisition unit 11, an adjustment unit 12, an inverse dynamics analysis unit 13, and an output unit 14. In addition, memory 3 stores a musculoskeletal model database 15.

[0020] LCD5 is a specific example of an output device. Input interface 6 is a specific example of an input device. Input interface 6 typically consists of a touch panel superimposed on LCD5.

[0021] The musculoskeletal model database 15 contains multiple musculoskeletal models 16. Each musculoskeletal model 16 has initial values ​​(baseline values) for muscle site parameters for each of more than 600 muscle sites. As an example, the multiple musculoskeletal models 16 include AM50 model 16a, GM model 16b, and JAMA50 16c.

[0022] AM50 Model 16a, also known as the "50th Percentile American Male," is a musculoskeletal model that represents the 50th percentile (median) of American men. In short, AM50 Model 16a can be said to represent the average height, weight, build, and muscle mass of adult American men.

[0023] GM model 16b is a musculoskeletal model also known as the "Global Human Body Models Consortium" (GHBMC), and it is a globally standardized musculoskeletal model. That is, GM model 16b is a model based on data from a wide variety of races and sexes. In this embodiment, GM model 16b is equivalent to a so-called 50th-generation musculoskeletal model. However, it is not limited to this; GM model 16b can also be set to be equivalent to a so-called 5th-generation or 95th-generation musculoskeletal model.

[0024] JAMA 5016c is also known as the "Japanese Anthropometric Model for the 50th Percentile Japanese Male," a musculoskeletal model based on the 50th percentile of Japanese males. Therefore, JAMA 5016c reflects the average body type and muscle mass of Japanese people.

[0025] In this embodiment, "muscle location parameter" refers to a parameter related to a muscle location, typically referring to muscle mass or muscle strength. In other words, muscle mass or muscle strength is a specific example of a muscle location parameter. It is assumed that a normal proportional relationship exists between muscle mass and muscle strength. However, it has the property that while muscle strength decreases with age, muscle mass does not decrease to that extent. In this embodiment, the following description will continue as if the muscle location parameter is muscle strength.

[0026] The musculoskeletal model selection unit 10 retrieves the selected musculoskeletal model 16 from a plurality of musculoskeletal models 16 stored in the musculoskeletal model database 15 via the input interface 6. Typically, the musculoskeletal model 16 that is most similar to the musculoskeletal structure of the test subject is selected.

[0027] The measurement result acquisition unit 11 acquires a first measurement result and a second measurement result. The first measurement result is the result of a muscle strength measurement performed using multiple muscle sites belonging to the first anatomical train of the test subject. The second measurement result is the result of a muscle strength measurement performed using multiple muscle sites belonging to the second anatomical train of the test subject that are in an antagonistic relationship with the first anatomical train. The measurement result acquisition unit 11 is a specific example of a measurement result acquisition unit.

[0028] The first and second dissecting trains are specific examples of dissecting trains. Here, a dissecting train refers to a part that is affected by a load applied to it. The following examples can be cited as examples of dissecting trains.

[0029] Superficial Front Line (hereinafter referred to as SFL): The SFL (Superficial Fascial Line) is a fascial line running along the anterior surface of the body, extending from the top of the head to the toes, and serves to maintain posture and allow for forward flexion. Muscles belonging to the SFL include the extensor digitorum brevis, extensor digitorum longus, tibialis anterior, extensor hallucis longus, rectus femoris, vastus medialis, vastus lateralis, vastus intermedius, rectus abdominis, sternocleidomastoid, and sternocleidomastoid.

[0030] Superficial Back Line (hereinafter referred to as SBL): The SBL (Spine of the Foot) is a fascial line running along the posterior surface of the body, extending from the toes to the top of the head, and serves to maintain posture by allowing the body to bend backward. Muscles belonging to the SBL include the flexor digitorum brevis, gastrocnemius, biceps femoris, semitendinosus, semimembranosus, iliocostalis, longissimus, and spinae.

[0031] Front Functional Line (FFL): The FFL (Fascial Line of the Body) is a fascial line that runs diagonally across the front of the body and connects to the opposite shoulder and foot, facilitating diagonal movements and rotational motions. Muscles belonging to the FFL include the pectoralis major, rectus abdominis, and internal rotatores longus.

[0032] Back Functional Line (hereinafter referred to as BFL): The broad fascia (BFL) is a fascial line that runs diagonally across the back of the body, connecting to the opposite shoulder and foot, and facilitating diagonal movements and rotational motions. Muscles belonging to the BFL include the latissimus dorsi, gluteus maximus, and vastus lateralis.

[0033] SFL and SBL are antagonistic to each other. Similarly, FFL and BFL are antagonistic to each other. Therefore, if the first anatomical train is SFL, the second anatomical train becomes SBL, and if the first anatomical train is FFL, the second anatomical train becomes BFL.

[0034] For ease of explanation, the measurement result acquisition unit 11 will continue to be explained below as the case where the first dissection train is SFL and the second dissection train is SBL.

[0035] The first result of a muscle strength test using multiple muscle parts belonging to the SFL typically refers to the measurement result of lower limb extension force. Lower limb extension force is typically the joint torque in the knee joint when the lower limb is extended (hereinafter, knee joint torque during extension). The second result of a muscle strength test using multiple muscle parts belonging to the SBL typically refers to the measurement result of lower limb flexion force. Lower limb flexion force is typically the joint torque in the knee joint when the lower limb is flexed (hereinafter, knee joint torque during flexion).

[0036] The measurement result acquisition unit 11 typically acquires a first measurement result (knee joint torque during extension) and a second measurement result (knee joint torque during flexion) via the input interface 6.

[0037] The adjustment unit 12 performs an adjustment process based on a comparison of knee joint torque during extension and knee joint torque during flexion. This adjustment process modifies the muscle strength of at least one of the multiple muscle groups belonging to the SFL and the multiple muscle groups belonging to the SBL within the musculoskeletal model selected by the musculoskeletal model selection unit 10. Specifically, the adjustment unit 12 performs this adjustment process based on the ratio of knee joint torque during extension to knee joint torque during flexion. More specifically, the adjustment unit 12 performs this adjustment process in such a way that the ratio of muscle strength of the multiple muscle groups belonging to the SFL to the multiple muscle groups belonging to the SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 is close to the ratio of knee joint torque during extension to knee joint torque during flexion of the test subject. This is explained in detail below.

[0038] That is, it is known that the ratio of knee joint torque during extension to knee joint torque during flexion is usually 3:2. Hereinafter, this ratio will also be referred to as the baseline ratio. Therefore, in any of the musculoskeletal models stored in the musculoskeletal model database 15, the ratio of the initial values ​​of muscle strength of multiple muscle parts belonging to SFL to the initial values ​​of muscle strength of multiple muscle parts belonging to SBL is set to 3:2.

[0039] In contrast, as an example, the ratio of the subjects is set to 3.2:2. In this case, the adjustment unit 12 adjusts at least one of the muscle strengths of the multiple muscle parts belonging to SFL and the multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 in a manner that makes the ratio of the muscle strengths of the multiple muscle parts belonging to SFL to the multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 approximately 3.2:2. Specifically, the adjustment unit 12 adjusts at least one of the muscle strengths of the multiple muscle parts belonging to SFL and the multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 in a manner that makes the ratio of the muscle strengths of the multiple muscle parts belonging to SFL to the multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 consistent with 3.2:2.

[0040] In the aforementioned adjustment process, when the adjustment unit 12 only adjusts the muscle strength of multiple muscle parts belonging to the SFL in the musculoskeletal model, typically, the initial values ​​of the muscle strength of multiple muscle parts belonging to the SFL in the musculoskeletal model are uniformly doubled to 3.2 / 3.0 = 1.0667 times. That is, the initial values ​​of the muscle strength of the extensor digitorum brevis, extensor digitorum longus, tibialis anterior, extensor hallucis longus, rectus femoris, vastus medialis, vastus lateralis, vastus intermedius, rectus abdominis, sternocleidomastoid, and sternocleidomastoid muscles in the musculoskeletal model are uniformly doubled to 3.2 / 3.0 = 1.0667 times. As a result, the ratio of the muscle strength of multiple muscle parts belonging to the SFL to the muscle strength of multiple muscle parts belonging to the SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 is 3.2:2, which is approximately consistent with the inherent measured ratio of the test subject.

[0041] Similarly, when the adjustment unit 12 adjusts only the muscle strength of multiple muscle parts belonging to SBL in the musculoskeletal model in the above-described adjustment process, typically, the initial values ​​of the muscle strength of multiple muscle parts belonging to SBL in the musculoskeletal model are uniformly doubled to 3.0 / 3.2 = 0.9375 times. That is, the initial values ​​of the muscle strength of the flexor digitorum brevis, gastrocnemius, biceps femoris, semitendinosus, semimembranosus, iliocostalis, longissimus, and spinae muscles in the musculoskeletal model are uniformly doubled to 3.0 / 3.2 = 0.9375 times. As a result, the ratio of the muscle strength of multiple muscle parts belonging to SFL to the muscle strength of multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 becomes 3.2:2, which is approximately consistent with the inherent ratio of the test subject.

[0042] The inverse dynamics analysis unit 13 calculates the joint torques generated at each joint of the musculoskeletal model by performing a predetermined action using the adjustment unit 12 to adjust the muscle strength of each muscle part. The predetermined action includes, for example, the subject's sitting and walking movements, and other everyday movements, typically recorded by multiple sensors attached to the subject. Thus, the inverse dynamics analysis unit 13 infers the fatigue of each muscle part of the subject, or the subject's energy expenditure. The inverse dynamics analysis performed by the inverse dynamics analysis unit 13 typically uses "AnyBody" (registered trademark). "AnyBody" is a musculoskeletal biomechanics analysis software developed by Aalborg University in Denmark and widely used worldwide. It uses inverse dynamics analysis to calculate the forces (muscle activity, muscle strength and antagonistic muscle strength, tendon elasticity, joint force and joint torque, etc.) acting on various parts of the human body when a movement is applied to a human musculoskeletal model. However, it is not limited to this; the inverse dynamics analysis performed by the inverse dynamics analysis unit 13 can also use other commercially available software.

[0043] The output unit 14 typically displays the analysis results obtained by the inverse dynamics analysis unit 13 on the LCD 5.

[0044] The first embodiment has been described above. The first embodiment described above has the following features.

[0045] The simulation device 1 (simulation system) comprising a musculoskeletal model including multiple muscle sites arranged along the skeleton includes: a measurement result acquisition unit 11 (measurement result acquisition unit) that acquires a first measurement result and a second measurement result, wherein the first measurement result is a measurement result of muscle strength measurement performed using multiple muscle sites belonging to the subject's SFL (first anatomical train), and the second measurement result is a measurement result of muscle strength measurement performed using multiple muscle sites belonging to the subject's SBL (second anatomical train); and an adjustment unit 12 (adjustment unit) that performs adjustment processing based on a comparison of the first and second measurement results, adjusting the muscle strength (muscle site parameters) of at least one of the multiple muscle sites belonging to the SFL and the multiple muscle sites belonging to the SBL in the musculoskeletal model. Based on the above structure, the accuracy of musculoskeletal model simulation based on individual differences in muscle attachment methods can be efficiently improved.

[0046] Furthermore, the adjustment unit 12 performs adjustment processing based on the ratio of the first measurement result to the second measurement result. Based on the above structure, the musculoskeletal model can be customized according to the ratio of the first measurement result to the second measurement result.

[0047] Furthermore, the adjustment unit 12 performs adjustment processing in a manner that brings the ratio of muscle strength of multiple muscle parts belonging to SFL to muscle strength of multiple muscle parts belonging to SBL in the musculoskeletal model closer to the ratio of the first measurement result to the second measurement result of the subject. Based on the above structure, parameter adjustments can be performed for each anatomical train, focusing on the deviation between the measured ratio of the subject and the ratio of the model.

[0048] (Second Implementation) Next, the second embodiment of this disclosure will be described. The description will focus on the differences between this embodiment and the first embodiment described above, and repeated descriptions will be omitted.

[0049] In the first embodiment described above, the adjustment unit 12 adjusts at least one of the muscle strength of the multiple muscle parts belonging to SFL and the muscle strength of the multiple muscle parts belonging to SBL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 in a manner that makes the ratio of the muscle strength of the multiple muscle parts belonging to SFL in the musculoskeletal model selected by the musculoskeletal model selection unit 10 consistent with the measured ratio of the subject.

[0050] Instead, in the adjustment process of this embodiment, it is determined which side the measured ratio of the test subject has deviated from the reference ratio, and the muscle strength of multiple muscle parts belonging to the anatomical train on the deviated side is multiplied by a predetermined factor. For example, if the measured ratio of the test subject is 3.2:2, since it can be said that the measured ratio of the test subject has deviated from the reference ratio to the extension side, the adjustment unit 12 performs the adjustment process of multiplying the muscle strength of multiple muscle parts belonging to the SFL in the musculoskeletal model by a predetermined factor.

[0051] Specifically, when the variable R obtained from the following formula is positive, the adjustment unit 12 determines that the measured ratio of the experimental subject has deviated from the reference ratio towards the extension side; when the variable R is negative, it determines that the measured ratio of the experimental subject has deviated from the reference ratio towards the flexion side. In the following formula, T refers to the knee joint torque, ext refers to extension, flx refers to flexion, measured refers to the measured value, and standard refers to the model reference value (model initial value). Therefore, for example, Text.measured refers to the measured value of the knee joint torque during extension, and Tflx.standard refers to the model reference value (model initial value) of the knee joint torque during flexion.

[0052]

[0053] When the variable R is positive, meaning the subject's measured ratio has deviated from the baseline ratio towards the extension side, the adjustment unit 12 uniformly doubles the muscle strength of multiple muscle groups belonging to the SFL in the musculoskeletal model to 1.2 times. Similarly, when the variable R is negative, meaning the subject's measured ratio has deviated from the baseline ratio towards the flexion side, the adjustment unit 12 uniformly doubles the muscle strength of multiple muscle groups belonging to the SBL in the musculoskeletal model to 1.2 times. By uniformly doubling the muscle strength of multiple muscle groups belonging to the SFL or SBL to a predetermined multiple based on the sign of the variable R, the adjustment process implemented by the adjustment unit 12 is simplified.

[0054] Although the invention made by the inventor has been specifically described above based on the embodiments, the invention is not limited to the described embodiments, and various modifications can be made without departing from its spirit.

[0055] For example, in the first and second embodiments described above, the muscle strength of multiple muscle sites belonging to a specific anatomical train of a musculoskeletal model is multiplied by the same factor. However, instead, the factor multiplied for the muscle strength may vary for each of the multiple muscle sites, depending on the contribution of each of the multiple muscle sites to the movement during the muscle strength measurement.

[0056] Furthermore, in the first and second embodiments described above, the muscle strength measurement may also be performed independently for the right and left halves of the subject, and the adjustment unit 12 may perform the aforementioned adjustment process independently for the right and left halves of the musculoskeletal model.

[0057] Furthermore, in the first and second embodiments described above, the first and second anatomical trains were described as SFL and SBL, respectively. As mentioned above, the first and second anatomical trains could also be FFL and BFL. In this case, the first measurement result, which is the result of a muscle strength measurement using multiple muscle parts belonging to the first anatomical train, typically refers to the measurement result of shoulder joint internal rotation force. Shoulder joint internal rotation force is typically the joint torque in the shoulder joint during internal rotation. The second measurement result, which is the result of a muscle strength measurement using multiple muscle parts belonging to the second anatomical train, typically refers to the measurement result of shoulder joint external rotation force. Shoulder joint external rotation force is typically the joint torque in the shoulder joint during external rotation.

Claims

1. A simulation system comprising a musculoskeletal model including multiple muscle sites configured along a skeleton, and further comprising: The measurement result acquisition unit acquires a first measurement result and a second measurement result. The first measurement result is the result of a muscle strength measurement performed using multiple muscle parts belonging to the first anatomical train of the test subject. The second measurement result is the result of a muscle strength measurement performed using multiple muscle parts belonging to the second anatomical train of the test subject that are in an antagonistic relationship with the first anatomical train. The adjustment unit performs adjustment processing based on the comparison between the first measurement result and the second measurement result, adjusting the muscle part parameters of at least one of the plurality of muscle parts belonging to the first anatomical train and the plurality of muscle parts belonging to the second anatomical train in the musculoskeletal model.

2. The simulation system as described in claim 1, wherein, The adjustment unit performs the adjustment process based on the ratio of the first measurement result to the second measurement result.

3. The simulation system as described in claim 2, wherein, The adjustment unit performs the adjustment process in such a way that the ratio of muscle region parameters belonging to the plurality of muscle regions of the first anatomical train to the ratio of muscle region parameters belonging to the plurality of muscle regions of the second anatomical train in the musculoskeletal model is close to the ratio of the first measurement result to the second measurement result of the subject.

4. The simulation system according to any one of claims 1 to 3, wherein, The first dissecting train is the front surface line, and the second dissecting train is the rear surface line.

5. The simulation system according to any one of claims 1 to 3, wherein, The first dissecting train is the front functional line, and the second dissecting train is the rear functional line.

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