Creation method for human body simulation model

Abstract

To provide a creation method for a human body simulation model capable of expressing difference in head back and forth positions relative to the chest part and difference in curve situations of the cervical spine.SOLUTION: Measurement data is determined by measuring two of the 6th thoracic spinous process to the 11th thoracic spinous process of the body. The measurement data is determined by measuring the cervical fossa and the 7th spinous process of cervical vertebra or the first thoracic spinous process of the human body with a virtual line connecting any two of the 6th thoracic spinous process to the 11th thoracic spinous process as a line A. When a virtual line connecting the cervical fossa and the 7th spinous process of cervical vertebra or a virtual line connecting the cervical fossa and the first thoracic spinous process is a line B and an angle made by the line A and the line B is a feature amount b, a shape surrounding the neck of the human body simulation model reflects the line B, and roundness of the back of the human body simulation model reflects the feature amount b.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for creating a human body simulation model used in numerical simulations and the like. [Background technology]

[0002] For example, in Patent Document 1, (a) a first evaluation method is used to evaluate whether the head is supported in a vertical direction via the neck without using muscle force, and it is evaluated that the head is supported in a vertical direction via the neck 25 without using muscle force; and (b) a second evaluation method is used to evaluate whether the angle of the pelvis relative to the thighs is within the limit angle at which pain is not felt when the angle of the pelvis relative to the thighs is narrowed, and it is evaluated that the angle of the pelvis relative to the thighs is such that pain is not felt when the angle of the pelvis relative to the thighs is narrowed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5906809 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 assumes that the head is held vertically and that muscle strain is small. In other words, Patent Document 1 does not anticipate considering strain on the head and neck when the head is not held vertically, for example, when walking, doing desk work, or sitting with the head resting on a pillow.

[0005] To see the load when the posture is not vertical, it is necessary to measure the joint angles around the neck and the muscle load in that state. Furthermore, to represent individual differences in the skeletal shape around the head and neck, it is necessary to be able to represent differences in the anterior-posterior position of the head relative to the chest and differences in the curvature of the cervical vertebrae. This disclosure discloses an example of a method for creating a human body simulation model that takes these points into consideration. [Means for solving the problem]

[0006] A method for creating a human body simulation model for use in numerical simulation is, for example, as follows. That is, when the measurement data is determined by measuring any two of the spinous processes of the sixth to eleventh thoracic vertebrae of a human body, and the imaginary line connecting any two of the spinous processes of the sixth to eleventh thoracic vertebrae is defined as line A, and the measurement data is determined by measuring the cervical fossa of a human body and the spinous process of the seventh cervical vertebra or the spinous process of the first thoracic vertebra, and the imaginary line connecting the cervical fossa and the spinous process of the seventh cervical vertebra or the imaginary line connecting the cervical fossa and the spinous process of the first thoracic vertebra is defined as line B, and the angle between line A and line B is defined as feature b, it is desirable that the shape of the neck circumference of the human body simulation model reflects line B, and that the curvature of the back of the human body simulation model reflects feature b.

[0007] As a result, this method for creating a human body simulation model makes it possible to obtain a human body simulation model that can be used to consider the strain on the head and neck when the head is not held vertically, for example, when walking, doing desk work, or sitting with the head resting on a pillow. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a human body simulation model created by a creation method according to a first embodiment. FIG. [Figure 2] FIG. 1 is a diagram illustrating the human skeleton. [Figure 3] 1 is a diagram showing a human body simulation model created by a creation method according to a first embodiment. FIG. [Figure 4] FIG. 1 is a diagram illustrating the posture of a human body. [Figure 5] FIG. 1 is a diagram illustrating the posture of the human head. [Figure 6] FIG. 1 is a diagram illustrating the posture of the human head. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following "embodiments of the invention" are examples of embodiments that fall within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiments.

[0010] (First embodiment) <1. Overview of the human body simulation model> The method for creating a human body simulation model (see FIG. 1) according to this embodiment relates to a method for creating a human body simulation model (particularly above the lumbar vertebrae) for numerical simulation used in developing and evaluating, for example, bedding pillows, vehicle seat headrests, etc.

[0011] <Outline of creation procedure> The creator of a human body simulation model (hereinafter referred to as "model") first measures the bodies of multiple people and creates measurement data. Note that "creator" is a collective term for one or more people who create the model. Therefore, even if the person who takes the measurements and the person who operates the computer are different individuals, both are considered "model creators."

[0012] Next, the creator reflects the measurement data of the human body in a model that can be numerically simulated using a computer. That is, the creator actually measures specific parts of the human body (see Figure 2) to collect measurement data, and then uses the measurement data to create a model (see Figures 1 and 3) that reflects the measurement data.

[0013] <2. Details of how to create a human body simulation model> 2.1 Measurement data (see Figure 3) (a) Measurement data determined by measuring any two of the 6th to 11th thoracic vertebrae spinous processes of a human body, where the imaginary line connecting any two of the 6th to 11th thoracic vertebrae spinous processes is defined as line A. In this embodiment, the imaginary line connecting the 7th to 10th thoracic vertebrae spinous processes is defined as line A.

[0014] (b) Measurement data determined by measuring the cervical fossa of a human body and the spinous process of the seventh cervical vertebra or the spinous process of the first thoracic vertebra, in which the imaginary line connecting the cervical fossa and the spinous process of the seventh cervical vertebra or the imaginary line connecting the cervical fossa and the spinous process of the first thoracic vertebra is designated as line B. In this embodiment, the imaginary line connecting the cervical fossa and the spinous process of the seventh cervical vertebra is designated as line B.

[0015] (c) The angle between line A and the perpendicular line is called chest angle a. (d) The angle between line A and line B is defined as feature b. (e) The junction point between the seventh cervical vertebra and the first thoracic vertebra is the neck junction point (hereinafter referred to as the CT point). In FIG. 3, the CT point is the midpoint between the cervical fossa located on line B and the seventh cervical spinous process. In other words, in this embodiment, the CT point is defined in association with line B.

[0016] (f) The junction of the 11th thoracic vertebra and the 1st lumbar vertebra is the lumbar junction point (hereinafter referred to as the TL point). The TL point corresponds to the lower end of the thoracic vertebrae. Therefore, the TL point is set approximately near the lower end of the thoracic vertebrae.

[0017] 2.2 Model reflecting measurement data <Thoracic vertebrae model> The thoracic vertebrae of the model shown in FIG. 3 (hereinafter referred to as the thoracic vertebrae model) are displayed by polygonal lines connecting the TL points and the CT points.

[0018] It is desirable that the angles formed by adjacent straight lines (hereinafter also referred to as relative angles), as well as the number and length of line segments, of the polygonal line be selected to match the characteristics of the actual human skeleton so as to look natural.

[0019] Therefore, in the model shown in Fig. 3, the shape of the neck circumference reflects line B, and the curvature of the model's back reflects feature b. In the model shown in Fig. 3, the angle between line B and the thoracic spine model is 90 degrees, and the tangent to the thoracic spine model at point TL is parallel to line A.

[0020] <Cervical vertebrae model> The model cervical vertebrae (hereinafter referred to as cervical vertebrae model) shown in Figure 3 is displayed with polygonal lines connecting the mastoid processes and CT points. It is desirable to select the relative angles, number of line segments, and length of the polygonal lines so that they appear natural and match the characteristics of the actual human skeleton.

[0021] Since the cervical and thoracic vertebrae are connected continuously, the angle d of the lower cervical vertebrae at the CT point is affected by the curvature of the cervical spine. Therefore, it is desirable to determine the angle d so that it looks natural and matches the characteristics of the actual human skeleton.

[0022] The angle d in the model shown in Figure 3 is 8°. In this model, the lengths of all the line segments are the same, and the relative angles are also the same. Each relative angle is the value obtained by dividing the cervical curvature angle c by the number of line segments minus 1. The cervical curvature angle c is an angle or measurement that appears natural in accordance with the characteristics of the actual human skeleton.

[0023] 3. Features of the Model According to This Embodiment In the model according to this embodiment, the shape of the neck area reflects the B line, and the roundness of the model's back reflects the feature b.

[0024] As a result, this model creation method makes it possible to obtain a model that can be used to examine the strain on the head and neck when the head is not held vertically, for example, when walking, doing desk work, or sitting with the head resting on a pillow, as shown in Figure 4.

[0025] Furthermore, the body landmarks used in the above model (7th thoracic vertebra spinous process, 10th thoracic vertebra spinous process, cervical fossa, 7th cervical vertebra spinous process, mastoid process, etc.) are skeletal landmarks. These landmarks can be easily located by palpation on the actual body. Therefore, it is easy to obtain real coordinate data from the human body.

[0026] This will in turn make it easier to quantify the degree of thoracic and cervical curvature of the human body and obtain it as distributed data, which will increase the reliability of the "head, neck, and thorax representation model" created based on this measurement data.

[0027] When determining the position that places the least strain on the head and neck, it is necessary to determine the position of the anterior-posterior position of the head relative to the thorax when the chest angle is determined to place the least strain on the muscles.

[0028] This model changes the thoracic spine curvature and also changes the cervical spine curvature, and the origin for defining this is line B, which connects the cervical fossa and the spinous process of the 7th cervical vertebra. At the very least, the anterior-posterior position of the center of gravity of the head is aligned with the ear canal.

[0029] To reflect the position of the center of gravity of the head in the model, the relative position to the mastoid process is used. Specifically, the anterior-posterior position of the head's center of gravity is defined as the position on line B, with the distance between the cervical fossa and the spinous process of the 7th cervical vertebra being 100%, and the position of the center of gravity of the head is defined as a percentage from the front of that.

[0030] Furthermore, because line B is included in the chest, it is effective as a chest-side reference for the placement of muscles around the neck, and the above is suitable for defining head position. However, the length of line B changes according to body dimensions, and its angle also changes depending on the thoracic spine curvature and chest angle. Therefore, it is preferable to define the position of the center of gravity of the head using the ratio on line B (see Figures 5 and 6).

[0031] (Other embodiments) The method for creating a human body simulation model according to the above-described embodiment relates to a method for creating a human body simulation model (particularly, the upper part above the lumbar vertebrae) for numerical simulation used in developing and evaluating, for example, a pillow for bedding, a headrest for a vehicle seat, etc. However, the present disclosure is not limited to this.

[0032] The above-described embodiment is a method for creating a human body simulation model for use in numerical simulation. However, the present disclosure is not limited to this. That is, the present disclosure may also be applied to, for example, creating a so-called "mannequin" using a model created based on the method for creating a human body simulation model.

[0033] Furthermore, the present disclosure is not limited to the above-described embodiments as long as it conforms to the spirit of the disclosure described in the above-described embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-described embodiments are combined, or a configuration in which any of the components illustrated or described with reference numerals in the above-described embodiments is eliminated. [Explanation of symbols]

[0034] a… Chest angle b... feature amount CT… Neck junction TL…Lumbar joint point

Claims

[Claim 1] A method for creating a human body mimic model for use in numerical simulation, Measurement data is determined by measuring any two of the sixth to eleventh thoracic vertebrae spinous processes of a human body, wherein an imaginary line connecting any two of the sixth to eleventh thoracic vertebrae spinous processes is defined as line A; Measurement data determined by measuring the cervical fossa and the spinous process of the seventh cervical vertebra or the spinous process of the first thoracic vertebra of a human body, wherein an imaginary line connecting the cervical fossa and the spinous process of the seventh cervical vertebra or an imaginary line connecting the cervical fossa and the spinous process of the first thoracic vertebra is defined as line B; When the angle between the line A and the line B is defined as a feature b, A method for creating a human body simulation model, in which the neck area of ​​the human body simulation model is shaped to reflect the B-line, and the curvature of the back of the human body simulation model is shaped to reflect the feature b.

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