Hand model

Abstract

To provide a mechanism that preferably reproduces a movable range and a non-movable range of human fingers, and a mechanism that reproduces various expressions of the human fingers.SOLUTION: A hand model has a central member composed of a joint part and a metacarpal part. The joint part is composed of a first outside part and a first inside part. The first outside part rotatably accommodates the first inside part. The first outside part has at least one guide part. The guide part of the first outside part regulates rotation of one shaft around one rotation shaft among three rotation shafts of the first inside part.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present invention relates to a hand model.

Background Art

[0002] As background art in this technical field, there is Japanese Unexamined Patent Application Publication No. 2022-28002 (Patent Document 1). This publication describes "a joint structure of a humanoid hand including a wrist 110 provided on an extension of a lower arm portion 80, a back of the hand 115 connected to the wrist 110, and a plurality of fingers 120 including a thumb 120A connected to the back of the hand 115. The back of the hand 115 includes a notch portion 131 and a protruding portion 132 formed with the notch portion 131 therebetween at a portion on the side to which the wrist 110 is connected. The wrist 110 is connected via a first ball joint 141 embedded in a portion of the protruding portion 132 displaced from the position of the wrist 110 with its tip portion disposed within the notch portion 131 of the back of the hand 115, and is rotatable with respect to the back of the hand 115 about the first ball joint 141" (see the abstract).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 describes a mechanism of a joint structure at the end of a humanoid limb capable of performing human-like movements. However, Patent Document 1 does not discuss a mechanism for well reproducing the movable and immovable ranges of human fingers or a mechanism for reproducing various human finger expressions. Therefore, the present invention provides a mechanism for well reproducing the movable and immovable ranges of human fingers and a mechanism for reproducing various human finger expressions.

Means for Solving the Problems

[0005] To solve the above problems, for example, the configuration described in the claims is adopted. 。

Advantages of the Invention

[0006] According to the present invention, it is possible to provide a mechanism for favorably reproducing the movable range and immovable range of a human finger, and a mechanism for reproducing various expressions of a human finger. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0007]

Figure 1A

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DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described with reference to the drawings. In the following embodiments, the right hand will be taken as an example for explanation, but it can also be applied to the left hand by reversing the left and right. For example, by making the configuration of each component described below with the left and right reversed, the embodiments described below can be applied as a left hand hand model. Also, even in that case, the structure of each joint portion described below may be made common to the right hand hand model and the left hand hand model. Note that the hand model 1 in FIG. 1 etc. is designed in a shape imitating an adult hand in terms of its appearance. In another embodiment, the hand model 1 may be designed in a shape imitating the appearance of a hand of an infant or an elderly person, for example, with respect to the ratio of each part or the outer shape. Note that the outer shape of each part can be designed in consideration of, for example, a shape or contour that reproduces the degree of fleshing or the prominence of bones.

[0009] FIG. 1A is an example of an external view of the hand model 1 composed of a plurality of movable parts. The hand model 1 in FIG. 1A imitates a human hand and has, for example, a middle hand part 10 of each finger, a CM joint part (wrist midcarpal joint part) 20, each finger part 30, an MP joint part (middle phalangeal joint part) 40, an IP joint part (interphalangeal joint part) 50, etc. The CM joint part 20 is an example of a joint part. The MP joint part 40 is an example of a second joint part.

[0010] The hand model 1 in FIG. 1A is designed to have a size similar to that of a general adult hand, but is not limited thereto, and can be designed in various sizes, for example, a size similar to that of a hand of an infant or a young child. In particular, in a configuration where the hand model 1 is used as a prosthetic hand, the size of the hand model 1 may be a size based on the size of the hand of the wearer of the prosthetic hand or the average hand size with respect to the body type of the individual wearer of the prosthetic hand.

[0011] Also, the ratio of the size and length of each component shown in FIGS. 1A to 33 is similarly designed in a ratio corresponding to each part of a general adult finger. However, in another embodiment, it is also possible to design in a ratio corresponding to the ratio of the size and length of each part of a finger of an animal different from a human, particularly a primate mammal, such as a chimpanzee or an orangutan. In the hand model 1 having such a configuration, it is better to design the movable range and the non-movable range of the hand model 1 to correspond to the movable range and the non-movable range of the finger of each animal.

[0012] For example, if the hand model 1 is designed to be smaller than the size of an average adult hand, which is easier to carry around, it becomes easier for the user to carry the hand model 1 to various places. Thus, the user can easily practice sketching using the hand model 1 in various situations regardless of the location or time of day. In another example, if the hand model 1 is designed to be larger than the size of an average adult hand, which is easier to visually recognize even from a distance, then even a person who is at a position away from the hand model 1 (for example, a student taking an art or drawing class or lecture) in a classroom or the like can clearly visually recognize the hand model 1 and can easily practice sketching using the hand model 1. For example, in an art school, when multiple students are drawing using the same hand model 1, it is preferable to use such a large hand model 1.

[0013] The hand model 1 can preferably reproduce the movable and immovable ranges of human fingers. For example, the movable and immovable ranges of the hand model 1 may be designed to reproduce the movable and immovable ranges of human fingers in a normal state. However, the movable and immovable ranges of the hand model 1 do not necessarily have to reproduce the movable and immovable ranges of human fingers in a normal state. For example, in another embodiment, the hand model 1 may be configured to reproduce the movable and immovable ranges of a human hand in a state where at least one joint is dislocated or subluxated. Furthermore, for the movable and immovable ranges of the hand model 1, in the fingers of a patient suffering from inflammation or joint disease, such as osteoarthritis, etc., the movable and immovable ranges may be set around the angle at which pain begins to be felt for at least one joint. In such a configuration, it is even better if the angle at which pain begins to be felt can be selected based on statistical data regarding the target joint disease or changed each time.

[0014] For example, in hospitals, lectures, internships, training, etc. at universities, vocational schools, etc. related to medicine, nursing, welfare, etc., students and trainees can use the hand model 1 that reproduces the movable and immovable ranges of the hands of patients with injuries or disabilities to actually touch three-dimensional objects and learn about, for example, the movable and immovable ranges of the hands of people with dislocations or subluxations. In addition, for each individual hand model 1, it is also possible to assign different movable and immovable range settings to each joint according to the injury or disability, and reproduce one or a combination of multiple injuries or disabilities. Therefore, it is possible to efficiently present examples of various injury and disability states to students and trainees. Furthermore, the hand model 1 can also reproduce the finger states of animals with injuries or disabilities. The hand model 1 with such a configuration can also provide an opportunity for veterinarians, etc. to learn about the injury and disability states of animals that are rare to encounter.

[0015] In this specification, the five middle hand parts of the thumb part 110, index finger part 120, middle finger part 130, ring finger part 140, and little finger part 150 described later may also be collectively referred to as each finger middle hand part 10. Similarly, the thumb part 110, index finger part 120, middle finger part 130, ring finger part 140, and little finger part 150 of the hand model 1 may also be referred to as the thumb, index finger, middle finger, ring finger, and little finger.

[0016] Figure 1B is an example of an external view of a possible form of the hand model 1 in Figure 1A. Figure 1B(1) is a view of the hand model 1 with each finger part 30 separated, seen from the back of the hand. Figure 1B(2) is a view of the hand model 1 with each finger part 30 separated, seen from the palm side of the hand. Figure 1B(3) is a view of the hand model 1 with each finger part 30 brought closer, seen from the back of the hand. Figure 1B(4) is a view of the hand model 1 with each finger part 30 brought closer, seen from the palm side of the hand.

[0017] In the hand model 1 of the embodiment shown in FIGS. 1A and 1B, each finger portion 30 of the index finger portion 120, middle finger portion 130, ring finger portion 140, and little finger portion 150 is composed of a proximal phalanx portion 31, a middle phalanx portion 32, and a distal phalanx portion 33, and the thumb portion 110 is composed of a proximal phalanx portion 31 and a distal phalanx portion 33.

[0018] The middle hand portion 10 and the proximal phalanx portion 31 of each finger portion 30 are connected to each other via the MP joint portion 40. The proximal phalanx portion 31 and the middle phalanx portion 32 are connected to each other via the PIP joint portion (proximal interphalangeal joint portion) 51, and the middle phalanx portion 32 and the distal phalanx portion 33 are connected to each other via the DIP joint portion (distal interphalangeal joint portion) 52. In addition, in this specification, "proximal" means a position closer to the wrist end portion 60 or a virtual arm or body connected to the hand model 1, and "distal" means a position farther from the wrist end portion 60 or a virtual arm or body connected to the hand model 1.

[0019] The wrist end portion 60 is connected to the CM joint portion 20. More specifically, the wrist end portion 60 is fixedly connected to the inner portion 300 of the CM joint portion 20, and the wrist end portion 60 supports the inner portion 300 of the CM joint portion 20 so as to be rotatable with respect to the outer portion 220 of the CM joint portion 20. Note that the term "rotation" may be read as "revolution".

[0020] The CM joint portion 20 is composed of an inner portion 300 fixedly connected to the wrist end portion 60 and an outer portion 220 that rotatably houses the inner portion 300. The outer portion 220 of the CM joint portion 20 is integrally or fixedly formed with respect to the middle finger middle hand portion 135, as will be described in detail below with reference to FIGS. 2 to 4.

[0021] On the outer side 220 of the CM joint part 20, the thumb middle hand part 115, index finger middle hand part 125, ring finger middle hand part 145, and little finger middle hand part 155 are movably connected to the middle finger middle hand part 135 either directly or indirectly. In such a configuration, in particular, the thumb middle hand part 115, index finger middle hand part 125, ring finger middle hand part 145, and little finger middle hand part 155 may be movable with respect to the outer side 220 of the CM joint part 20.

[0022] The thumb part 110 corresponding to a human thumb includes a proximal phalanx 31 and a distal phalanx 33, an MP joint part 40 that rotatably connects the proximal phalanx 31 to the thumb middle hand part 115, and an IP joint part 50 that rotatably connects the proximal phalanx 31 and the distal phalanx 33.

[0023] The proximal phalanx 31, middle phalanx 32, and distal phalanx 33 of each finger part 30, and the MP joint part 40 and IP joint part 50 each have a similar configuration. In the following description, for example, the description of the proximal phalanx 31, middle phalanx 32, and distal phalanx 33, and the MP joint part 40 and IP joint part 50 of the middle finger part 130 corresponding to a human middle finger can be similarly applied to the index finger part 120, ring finger part 140, and little finger part 150.

[0024] Each finger part 30 corresponding to the four fingers of a human index finger, middle finger, ring finger, and little finger respectively includes a proximal phalanx 31, a middle phalanx 32, a distal phalanx 33, an MP joint part 40 that rotatably connects the proximal phalanx 31 to the middle hand part 10, a PIP joint part 51 that rotatably connects the proximal phalanx 31 to the middle phalanx 32, and a DIP joint part 52 that rotatably connects the distal phalanx 33 to the middle phalanx 32. In the following description, the PIP joint part 51 and the DIP joint part 52 may be collectively referred to as the IP joint part 50.

[0025] The PIP joint part 51 and the DIP joint part 52 have a similar or the same configuration as the IP joint part 50. The MP joint part 40 and the IP joint part 50 have different configurations with respect to the range of motion, particularly with respect to the degree of freedom of movement. These points will be described more specifically with reference to FIGS. 22 to 29 and the like.

[0026] Figure 2 is an example of an external view of the central member 200. In Figure 2, the central member 200 is illustrated in a state where the outer portion 220 of the CM joint portion 20 and the middle finger and middle hand portion 135 are fixedly connected, excluding the inner portion 300 of the CM joint portion 20.

[0027] The outer portion 220 of the CM joint portion 20 houses the inner portion 300 of the CM joint portion 20. The outer portion 220 of the CM joint portion 20 further has an outer portion 221 of the thumb CM joint portion 1011 that constitutes a part of the thumb CM joint portion 1011 for the thumb, which will be specifically described with reference to Figure 10. Furthermore, the outer portion 220 of the CM joint portion 20 has a first support protrusion 226 that supports the index finger middle hand portion 125 and a second support protrusion 227 that supports the ring finger middle hand portion 145.

[0028] The outer portion 220 of the CM joint portion 20 is an example of a first outer portion, and the inner portion 300 of the CM joint portion 20 is an example of a first inner portion. The thumb CM joint portion 1011 for the thumb is an example of a thumb joint portion. The outer portion 221 of the thumb CM joint portion 1011 is an example of a second outer portion.

[0029] As specifically described with reference to Figure 18, the index finger middle hand portion 125 may have a first support protrusion insertion hole 1810, and the ring finger middle hand portion 145 may have a second support protrusion insertion hole 1820. In such a configuration, the first support protrusion 226 is inserted into the first support protrusion insertion hole 1810, and the second support protrusion 227 is inserted into the second support protrusion insertion hole 1820, so that the index finger middle hand portion 125 and the ring finger middle hand portion 145 can be held by the outer portion 220 of the CM joint portion 20 while maintaining a state where they can rotate with respect to the outer portion 220 of the CM joint portion 20.

[0030] The outer portion 220 of the CM joint portion 20 has a first linear guide edge 222, a second linear guide edge 223, a first curved guide edge 224, and a second curved guide edge 225. The first linear guide edge 222 and the second linear guide edge 223 form the first guide portion 400. The first curved guide edge 224 and the second curved guide edge 225 form the second guide portion 500.

[0031] The central axis 230 indicated by the dashed line between L and L' is a straight line extending in the longitudinal direction of the central member 200. For example, it passes through the center of the partial spherical shell formed by the outer portion 220 of the CM joint portion 20 and the center of the spherical portion of the inner portion 300 of the CM joint portion 20, and is a straight line extending parallel to the plane in which the first curved guide edge 224 and the second curved guide edge 225 are present.

[0032] FIG. 3 is an example of an explanatory diagram for explaining the relationship between the outer portion 220 and the inner portion 300 of the CM joint portion 20. FIG. 3(A) shows the CM joint portion 20 in a state where the outer portion 220 and the inner portion 300 are separated. FIG. 3(B) shows the CM joint portion 20 in a state where the inner portion 300 is accommodated in the outer portion 220. In the actual use state, the CM joint portion 20 may be configured such that the outer portion 220 and the inner portion 300 cannot be separated without damage or deformation. However, after configuring the outer portion 220 from a plurality of members, the assembly may be facilitated by fitting a plurality of members in a manner that sandwiches the inner portion 300, or it may be configured to be separable after assembly.

[0033] The double-headed arrows labeled RD1 and RD2 shown in FIG. 3(B) indicate the possible first rotation direction (permissible first rotation direction) RD1 and the second rotation direction (permissible second rotation direction) RD2 of the inner portion 300 in the state of being accommodated in the outer portion 220. The inner portion 300 in the state of being accommodated in the outer portion 220 is preferably configured to restrict rotation in the third rotation direction (restricted rotation direction) RD3 indicated by the double-headed arrows in FIG. 4(A) at least in a partial range. Note that restricting includes preventing rotation, and a certain degree of play (rotation) is allowed.

[0034] Thereby, by restricting the rotational movement of the inner part 300 in three degrees of freedom, the outer part 220 can accommodate the inner part 300. The rotational movement in three degrees of freedom is, for example, a rotational movement consisting of pitch rotation, yaw rotation, and roll rotation with respect to the central axis 230. In the embodiment of FIG. 3(B), by restricting the roll rotation with respect to the central axis 230, the rotational movement of the inner part 300 in three degrees of freedom can be restricted. For example, it can be configured so as not to perform roll rotation, or so that roll rotation is more difficult to perform compared to pitch rotation or yaw rotation.

[0035] Note that the pitch rotation, yaw rotation, and roll rotation with respect to the central axis 230 are examples of rotations around the three rotation axes of the rotation of the inner part 300, respectively, and the roll rotation is an example of a one-axis rotation around one of the three rotation axes.

[0036] The middle finger middle hand part 135 has an inner wall part 340 of the middle finger middle hand part 135 between the palm side surface 360 of the middle finger middle hand part 135 and the back side surface 210 of the middle finger middle hand part 135. The inner wall part 340 forms an accommodation part 350 for the thumb middle hand part and a thumb ball part accommodation part 1520 to be described later on the thumb middle hand part side.

[0037] FIG. 32 is an example of an explanatory diagram for explaining the CM joint part 20 in a divided state. The CM joint part 20 may have a configuration according to FIG. 32 instead of a configuration according to FIGS. 3 to 5, for example. The outer part 220 of the CM joint part 20 having a configuration according to FIG. 32 is formed by combining a first half body 3210 and a second half body 3220.

[0038] The first half body 3210 is provided with an outer side portion 221 of the thumb CM joint portion 1011 and a first cylindrical member 3211. The second half body 3220 is provided with a second cylindrical member 3221 and a connection portion 3222 with the middle finger and middle hand portion 135. The first cylindrical member 3211 is adapted to allow a screw to be inserted therethrough, and the distance from the second cylindrical member 3221 can be adjusted by tightening or loosening the screw, whereby the frictional force generated between the inner side portion 300 can be adjusted. Regarding the outer side portion 221 as well, it may be configured by combining two half bodies like the first half body 3210 and the second half body 3220, and screw holes for inserting screws may be provided in each of the two half bodies so that the frictional force with the inner side portion 300 can be adjusted by inserting the screws. Connection portions similar to the connection portion 3222 with the middle finger and middle hand portion 135 are also provided on the first half body 3210, and they are paired and connected to the corresponding connection portions on the middle finger and middle hand portion 135 side to maintain a fixed connection between the middle finger and middle hand portion 135 and the CM joint portion 20. More specific configurations and functions of the individual components of the CM joint portion 20 will be described later.

[0039] For example, in the hand model 1 having the CM joint portion 20 configured according to FIGS. 3 to 5, FIGS. 32, etc., based on the frictional force generated between the outer side portion 220 of the CM joint portion 20 and the inner side portion 300 of the CM joint portion 20, the ease of movement and the ease of maintaining the posture of the CM joint portion 20 and the components distal to the CM joint portion 20 with respect to the arm end portion 60 can be adjusted. For example, in the hand model 1 used as a drawing model, by configuring a relatively large frictional force to be generated between the outer side portion 220 of the CM joint portion 20 and the inner side portion 300 of the CM joint portion 20, the CM joint portion 20 and the components distal to the CM joint portion 20 can be made less likely to move with respect to the arm end portion 60. Thereby, during the movement or storage of the hand model 1 after setting, it is possible to more reliably avoid the hand model 1 being deformed into an undesired posture with respect to the arm end portion 60 due to vibration, collision, acceleration change, etc.

[0040] For example, in the hand model 1 used as a prosthetic hand, by configuring it such that a relatively small frictional force is generated between the outer portion 220 of the CM joint portion 20 and the inner portion 300 of the CM joint portion 20, the state such as the angle of the CM joint portion 20 with respect to the arm end portion 60 can be made more likely to change according to the movement in the user's daily life. Thereby, according to the daily movement of the user wearing the prosthetic hand equipped with the hand model 1, particularly the movement of the arm wearing the prosthetic hand, for example, based on the change in the direction, speed, and acceleration of the movement, the state such as the angle of the CM joint portion 20 with respect to the arm end portion 60 changes, so that a natural movement similar to the movement of an actual human hand can be reproduced within a natural range of motion.

[0041] In the hand model 1, based on the above-described frictional force and the setting of the movable range and non-movable range of the hand model 1, even without an electrical control unit or drive unit, the movement of an actual human hand, such as shaking, etc., during the user's movement can be reproduced well. Furthermore, the hand model 1 may be configured such that the frictional force at each joint portion, for example, the frictional force generated between the outer portion 220 of the CM joint portion 20 and the inner portion 300 of the CM joint portion 20, can be adjusted. Such a configuration will be described later with reference to FIG. 32.

[0042] FIG. 4 is an example of an explanatory diagram for explaining the rotation of the inner portion 300 in the first rotation direction RD1. FIG. 4(A) shows the CM joint portion 20 in a state where the outer portion 220 of the CM joint portion 20 and the inner portion 300 of the CM joint portion 20 are separated. FIG. 4(B) shows the CM joint portion 20 in a state where the inner portion 300 of the CM joint portion 20 is accommodated in the outer portion 220 of the CM joint portion 20.

[0043] In FIG. 4(A), the first guide portion 400 is shown by a dashed line. The first guide portion 400 is a space sandwiched between the first linear guide edge 222 and the second linear guide edge 223 of the outer portion 220, and its width has a length through which the first guide protrusion 310 and the second guide protrusion 320 can pass. The first guide portion 400 is an example of at least one guide portion.

[0044] In FIG. 4(A), further, a central axis 230 passing through the center of the partial spherical shell formed by the outer portion 220 is shown. The third rotational direction RD3 to be restricted is the direction of rotation about this central axis 230.

[0045] In FIG. 4(A), the inner portion 300 has a first guide protrusion 310, a second guide protrusion 320, and a connection protrusion 330. The connection protrusion 330 is a connection portion for connecting the inner portion 300 to the arm end portion 60. A hook portion 410 is provided on the connection protrusion 330, and the hook portion 410 prevents the arm end portion 60 connected to the inner portion 300 via the connection protrusion 330 from idling.

[0046] In the embodiment of FIG. 4(A), the first guide portion 400 is formed as a linear void continuously connected between the palm side and the back side of the hand. Alternatively, the first guide portion 400 may be formed as a void divided into two, a first void on the palm side and a second void on the back side of the hand.

[0047] In FIG. 4(B), a part of the first guide portion 400 is indicated by a dashed line. In FIG. 4B, the first guide protrusion 310 is outside the range of the first guide portion 400, and the second guide protrusion 320 is within the range of the first guide portion 400.

[0048] In the state of FIG. 4(B), the first guide portion 400 represented by the dashed line is a space sandwiched between the first linear guide edge 222 and the second linear guide edge 223 of the outer portion 220, and its width has a length through which the first guide protrusion 310 and the second guide protrusion 320 can pass.

[0049] In the state of FIG. 4(B), the second guide protrusion 320 within the first guide portion 400 is restricted from moving in the width direction of the first guide portion 400 by the first linear guide edge 222 and the second linear guide edge 223. Thereby, the rotation in the third rotational direction RD3 around the central axis 230 of the inner portion 300 is hindered.

[0050] In particular, in a configuration where the width of the first guide portion 400 is adapted to the widths of the first guide protrusion 310 and the second guide protrusion 320, for example, a configuration where the first guide protrusion 310 and the second guide protrusion 320 contact the first linear guide edge 222 and the second linear guide edge 223 within the first guide portion 400, rotation in the third rotation direction RD3 around the central axis 230 of the inner portion 300 can be more reliably restricted.

[0051] The hand model 1 according to the present embodiment can preferably reproduce a state in which the fingers beyond the wrist are restricted in rotation with respect to the wrist when the human hand and arm perform radial abduction and palmar abduction.

[0052] Note that the third rotation direction RD3 may be understood as the direction of rotation defined by the roll angle with respect to the central axis 230. Similarly, the first rotation direction RD1 and the second rotation direction RD2 may be understood as the directions of rotation defined by the yaw angle and the pitch angle with respect to the central axis 230, respectively.

[0053] In the following description, rotation defined by the yaw angle will be described using the terms flexion and ulnar flexion. Similarly, rotation defined by the pitch angle will be described using the terms palmar flexion and dorsal flexion. Furthermore, similarly for each MP joint portion 40 and IP joint portion 50 of each finger portion 30, rotation defined by the yaw angle and rotation defined by the pitch angle with respect to the longitudinal axes of the proximal phalanx 31, middle phalanx 32, and distal phalanx 33 of each finger portion 30 will be described using the terms flexion and ulnar flexion, and the terms palmar flexion and dorsal flexion, respectively.

[0054] FIG. 5 is an example of an explanatory diagram for explaining the rotation of the inner portion 300 in the second rotation direction RD2. FIG. 5(A) shows the state where the inner part 300 is rotated toward the palm side from the central position of the inner part 300 shown in FIG. 5(B), as viewed in the direction from the back of the hand to the palm side and in the direction parallel to the central axis 230. In FIG. 5(A), the first guide protrusion 310 of the inner part 300 is located within the first guide part 400 on the palm side, and the second guide protrusion 320 and the connection protrusion 330 are located within the second guide part 500. Note that the central position of the inner part 300 is, for example, the position where the connection protrusion 330 of the inner part 300 overlaps with the central axis 230.

[0055] FIG. 5(B) shows the state where the inner part 300 is at the central position of the inner part 300, as viewed in the direction from the back of the hand to the palm side and in the direction parallel to the central axis 230. At the central position of the inner part 300, the connection protrusion 330 of the inner part 300 may, for example, overlap with the central axis 230 of the central member 200. In FIG. 5(B), the first guide protrusion 310 of the inner part 300 is located within the first guide part 400 on the palm side, and the second guide protrusion 320 is located within the first guide part 400 on the back of the hand, and the connection protrusion 330 is located within the second guide part 500.

[0056] FIG. 5(C) shows the state where the inner part 300 is rotated toward the back of the hand from the central position of the inner part 300 shown in FIG. 5(B), as viewed in the direction from the back of the hand to the palm side and in the direction parallel to the central axis 230. In FIG. 5(C), the second guide protrusion 320 of the inner part 300 is located within the first guide part 400 on the back of the hand, and the first guide protrusion 310 and the connection protrusion 330 are located within the second guide part 500. Although detailed description is omitted, when rotating along the second rotation direction RD2 as shown in FIG. 5(A) and FIG. 5(C), in order to have a movable range similar to the indirect movable range of a human wrist, at the limit position, the edge part on the CM joint part 20 side of the arm end part 60 and the outer part 220 come into contact with each other, and further movement is restricted.

[0057] FIG. 6 is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A). FIG. 6(A) is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A), viewed from above. FIG. 6(B) is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A), viewed from the side.

[0058] In the hand model 1 in the states of FIGS. 6(A) and 6(B), as described in relation to FIG. 5(A), since the first guide protrusion 310 of the inner portion 300 is located within the first guide portion 400, it is possible to more reliably limit the rotation of the arm end portion 60 fixedly connected to the inner portion 300 via the connection protrusion 330 in the third rotation direction RD3 within the outer portion 220.

[0059] The rotation of the finger portion with respect to the wrist portion, such as the rotation of the inner portion 300 in the third rotation direction RD3 restricted within the outer portion 220, is similarly restricted even in the anatomical structure of a human arm and hand having a structure different from that of this embodiment. Thereby, the hand model 1 can reproduce both the movable range and the immovable range of an actual human arm and hand well.

[0060] FIG. 7 is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A). FIG. 7(A) is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A), viewed from above.

[0061] FIG. 7(B) is an example of an external view of the hand model 1 when the CM joint portion 20 is in the state of FIG. 5(A), viewed from the side. FIG. 7(C) is an example of an enlarged view of the range 700 surrounded by the dashed line in FIG. 7(A).

[0062] In the hand model 1 in the states shown in FIGS. 7(A) to 7(C), as described in relation to FIG. 5(A), since the second guide protrusion 320 of the inner portion 300 is located within the first guide portion 400, the arm end portion 60 fixedly connected to the inner portion 300 via the connection protrusion 330 can more reliably limit the rotation of the arm end portion 60 within the outer portion 220 in the third rotation direction (the restricted rotation direction) RD3.

[0063] Similar to the case of FIG. 6, the rotation of the inner portion 300 in the third rotation direction RD3 restricted within the outer portion 220 is similarly restricted even in the anatomical structure of a human arm or hand with a structure different from that of this embodiment. Similar to the case of FIG. 6, also in the case of FIG. 7, the hand model 1 can well reproduce both the movable range and the non - movable range of an actual human arm and hand.

[0064] The arm end portion 60 preferably has a fixing member insertion hole 710 at its proximal end. It is more preferable that a fixing member provided on an object different from the hand model 1 can be inserted into the fixing member insertion hole 710. An object different from the hand model 1 is, for example, a pedestal for placing the hand model 1 on a desk or a shelf, a forearm member for integrating with the hand model 1 to form a larger body model, a connection portion between the hand portion of a forearm prosthesis or an upper - arm prosthesis, etc. In addition, a configuration may be adopted in which it is fixed by four small holes (the number of holes may be other numbers) provided around the fixing member insertion hole 710 shown in FIG. 7.

[0065] The user can move the entire hand model 1 while more stably maintaining the set state of the hand model 1 by holding the fixing member inserted into the fixing member insertion hole 710, or a pedestal or a forearm member having the fixing member. Thereby, the user can observe the hand model 1 in the same state from various angles of up, down, left, right, front, and back, and can stably perform exercises such as sketching.

[0066] Furthermore, when using the hand model 1 as a prosthetic hand, for example, during photography, it becomes easier to assume the same poses as family members, friends, etc. down to the details of the fingers, which can also contribute to improving the quality of life (QOL) of the prosthetic hand wearer. When using the hand model 1 as a prosthetic hand, if the hand model 1 can be replaced, by releasing the connection at the fixing member insertion hole 710, with, for example, a hand part having a different function or configuration, such as a hook-shaped hand part, it becomes possible to make appropriate selections according to the scenes of daily life, which is better.

[0067] The arm end portion 60 preferably has a concave portion 720 that corresponds to, for example, fits precisely with, the contour shape of the outer portion 221 of the thumb CM joint portion 1011, particularly the three-dimensional contour shape. Thereby, the movable range of the CM joint portion 20 can be designed more flexibly.

[0068] FIG. 8 is an example of an explanatory diagram for explaining the rotation of the inner portion 300 in the first rotation direction RD1. FIG. 8(A) shows a state in which the inner portion 300 has rotated toward the little finger side from the central position of the inner portion 300 shown in FIG. 8(B). In FIG. 8(A), the first guide protrusion 310 and the second guide protrusion 320 of the inner portion 300 are located within the first guide portion 400. The connection protrusion 330 is located within the second guide portion 500 and is in contact with the first curved guide edge 224.

[0069] FIG. 8(B) shows a state in which the inner portion 300 is at the central position of the inner portion 300. At the central position of the inner portion 300, the connection protrusion 330 of the inner portion 300 preferably overlaps, for example, with the central axis 230 of the central member 200.

[0070] The first curved guide edge 224 and the second curved guide edge 225 are preferably designed asymmetrically with respect to the center line L2-L2' passing through the centers of the first guide protrusion 310 and the second guide protrusion 320 of the inner portion 300. In particular, it is better if the first distance 820 between the thumb-side end point 810 of the first curved guide edge 224 and the center line L2-L2' is designed to be shorter than the second distance 840 between the little finger-side end point 830 of the second curved guide edge 225 and the center line L2-L2'. This is because it can mimic the movable and immovable ranges of an actual human wrist with a higher degree of accuracy. Note that the first distance 820 and the second distance 840 are distances when viewed in a direction parallel to the central axis 230.

[0071] FIG. 8(C) shows a state in which the inner part 300 has rotated toward the thumb side from the central position of the inner part 300 shown in FIG. 8(B). In FIG. 8(C), similar to FIG. 8(A), the first guide protrusion 310 and the second guide protrusion 320 of the inner part 300 are located within the first guide part 400. The connection protrusion 330 is located within the second guide part 500 and is in contact with the second curved guide edge 225.

[0072] FIG. 9 is an example of an external view of the hand model 1 when the CM joint part 20 is in the state of FIG. 8. FIG. 9(A) is an example of an external view of the hand model 1 when the CM joint part 20 is in the state of FIG. 8(A), viewed from the back of the hand. FIG. 9(B) is an example of an external view of the hand model 1 when the CM joint part 20 is in the state of FIG. 8(C), viewed from the back of the hand.

[0073] In the state of FIG. 9(A), when the arm end part 60 is moved while maintaining the state where the connection protrusion 330 is in contact with the first curved guide edge, at least one of the first guide protrusion 310 and the second guide protrusion 320 moves within the first guide part 400. When the arm end part 60 is moved so that the connection protrusion 330 moves away from the first curved guide edge 224 and then comes into contact with the second curved guide edge 225, at least one of the first guide protrusion 310 and the second guide protrusion 320 moves within the first guide part 400, and the hand model 1 transitions to the state of FIG. 9(B).

[0074] FIG. 10 is an example of an explanatory diagram for explaining the relationship among the thumb middle hand part 115, the index finger middle hand part 125, and the middle finger middle hand part 135. FIG. 10(A) is an example of an explanatory diagram for explaining a state in which the middle hand parts 10 (115, 125, 135) of the thumb, index finger, and middle finger are connected.

[0075] FIG. 10(B) is an example of an explanatory diagram for explaining a state in which the middle hand parts 10 (115, 125, 135) of the thumb, index finger, and middle finger are disassembled. The central member 200 is connected to the index finger middle hand part 125 via a hinge connection part (butterfly plate-like connection part) 1000 provided in the middle finger middle hand part 135. The middle finger middle hand part 135 and the index finger middle hand part 125 are slightly rotatable relative to each other around the hinge connection part 1000.

[0076] The central member 200 is connected to the thumb middle hand part 115 via the thumb CM joint part 1011 of the CM joint part 20. The thumb CM joint part 1011 is composed of an inner part 1020 of the thumb CM joint part 1011 and an outer part 221 of the thumb CM joint part 1011. The thumb CM joint part 1011 may be configured such that the thumb middle hand part 115 is rotatable relative to the middle finger middle hand part 135 with 1 to 3 degrees of freedom. The inner part 1020 of the thumb CM joint part 1011 is an example of a second inner part.

[0077] Regarding the rotation of the thumb middle hand part 115, it will be specifically described below with reference to FIGS. 11 to 17. FIG. 11 is an example of an explanatory diagram for explaining the movable range of the thumb middle hand part 115. FIG. 11(A) illustrates a state in which the thumb CM joint part 1011 has moved to the first outer position. At the first outer position of the thumb CM joint part 1011, the contact protrusion part 1100 of the thumb middle hand part 115 is in contact with the outermost contact position 1121 of the stopper wall part 1120 of the index finger middle hand part 125.

[0078] When the thumb middle hand part 115 rotates in the direction from the back of the hand to the palm side, the contact protrusion part 1100 contacts the stopper wall part 1120 of the index finger middle hand part 125. Thereby, the stopper wall part 1120 of the index finger middle hand part 125 restricts the thumb middle hand part 115 from rotating (palmar flexion) to the palm side beyond the palm surface.

[0079] Figure 11(B) shows a state where the thumb CM joint part 1011 has moved to the inner position. At the inner position of the thumb CM joint part 1011, the contact protrusion part 1100 of the thumb middle hand part 115 may be in contact with, for example, the inner wall part 340 of the middle finger middle hand part 135.

[0080] It is preferable that the thumb CM joint part 1011 can provide the thumb middle hand part 115 with the possibility of moving along a plurality of trajectories while moving from the first outer position to the inner position. For example, when the thumb middle hand part 115 moves from the first outer position to the inner position, it may be able to perform different rotational movements around the thumb CM joint part 1011, or may be able to take different states regarding inclination, orientation, and posture.

[0081] Figure 12 is an example of an external view of the hand model 1 when the thumb middle hand part 115 is in the state of Figure 11. Figure 12(A) is an example of an external view of the hand model 1 seen from the palm side when the thumb CM joint part 1011 is in the state of Figure 11(A).

[0082] Figure 12(B) is an example of an external view of the hand model 1 seen from the palm side when the thumb CM joint part 1011 is in the state of Figure 11(B). The thumb middle hand part 115 can smoothly move within the area of the index finger middle hand part 125 while moving from the state of Figure 12(A) to the state of Figure 12(B). Also, in any state, the MP joint part 40 and the IP joint part 50 of the thumb part 110 can rotate smoothly.

[0083] Similarly, in any state, the MP joint part 40 and the IP joint part 50 of the index finger part 120 to the little finger part 150 can also rotate smoothly. Since the state of the CM joint 1011 of the thumb does not inhibit the rotation of each MP joint 40 and IP joint 50 of each finger part 30, the hand model 1 according to the present embodiment can very well reproduce the form expressed by the human fingers.

[0084] FIG. 13 is an example of an explanatory diagram for explaining an expansion mechanism for expanding the rotation range of the middle part 115 of the thumb. FIG. 13(A) shows the middle part 115 of the thumb with the main body of the middle part 115 of the thumb and the expansion part 1300 separated. Also, in FIG. 13(A), as the expansion part 1300, the expansion part 1300 in the housed state and the expansion part 1300 in the expanded state are shown separately. The expansion part 1300 has a rotation convex part 1321. In the assembled state of FIG. 13(B), the rotation convex part 1321 is housed in the rotation concave part 1320 of the main body of the middle part 115 of the thumb. Thereby, the expansion part 1300 can rotate continuously from the housed state to the expanded state.

[0085] FIG. 13(B) shows the middle part 115 of the thumb with the expansion part 1300 housed therein. FIG. 13(C) shows the middle part 115 of the thumb with the expansion part 1300 expanded.

[0086] FIG. 14 is an example of an external view of the hand model 1 when the middle part 115 of the thumb is in the state of FIG. 13. FIG. 14(A) is an example of an external view of the hand model 1 when the middle part 115 of the thumb is in the state of FIG. 13(B) as seen from the palm side. FIG. 14(B) is an example of an external view of the hand model 1 when the middle part 115 of the thumb is in the state of FIG. 13(C) as seen from the palm side.

[0087] While moving from the state of FIG. 14(A) to the state of FIG. 14(B), the contact protrusion 1100 of the thumb middle hand part 115, for example, remains in contact with the outermost contact position 1121 of the stopper wall part 1120 of the index finger, the expansion part 1300 continuously rotates around the rotation part 1330, and the thumb middle hand part 115 can move further outward. When the state of FIG. 14(B) is reached, further movement of the expansion part 1300 is restricted because the movement of the expansion part protrusion 1301 is restricted by the stopper recess 1311.

[0088] Although not shown, a pin that fits into and rotates in the stopper recess 1311 is provided at the opposite end of the arc surface of the expansion part protrusion 1301 in the depth direction and the front direction of FIG. 13(A). The stopper recess 1311 is a groove on the arc and guides the pin on the arc. Thereby, the expansion part 1300 can be rotated on the arc, and the maximum movable range when expanded can be restricted.

[0089] Even while the expansion part 1300 moves from the accommodated state to the expanded state, the MP joint part 40 and the IP joint part 50 of the thumb part 110 can rotate smoothly. Similarly, in any state, the MP joint part 40 and the IP joint part 50 of the index finger part 120 to the little finger part 150 can also rotate smoothly.

[0090] Since the state of the expansion part 1300 does not hinder the rotation of the MP joint part 40 and the IP joint part 50 of each finger part 30, the hand model 1 according to the present embodiment can reproduce the form expressed by the human finger even better.

[0091] FIG. 15 is an example of an explanatory diagram for explaining two different postures of the thumb middle hand part 115. FIG. 15(A) is an example of an explanatory diagram for explaining a posture in which the front side of the thumb middle hand part 115 faces the back of the hand in a direction substantially parallel to the central axis 230. FIG. 15(B) is an example of an explanatory diagram for explaining a posture in which the front side of the thumb middle hand part 115 faces the palm side in a direction substantially parallel to the central axis 230.

[0092] In FIGS. 15(A) and 15(B), the direction in which the front side of the thumb middle hand part 115 faces is set as the direction perpendicular to the plane of the mounting recess 1500 for the MP joint part of the thumb middle hand part 115. Note that the front side of the thumb middle hand part 115 may be read as the back side of the thumb middle hand part 115. In the hand model 1, similar to a human finger, the front side (back side) of the thumb middle hand part 115 can face the palm side of the hand model 1.

[0093] FIG. 15(C) is an example of an external view of the thumb middle hand part 115 in the posture of FIG. 15(A) as seen from the palm side. FIG. 15(D) is an example of an external view of the thumb middle hand part 115 in the posture of FIG. 15(B) as seen from the palm side.

[0094] In the posture of FIG. 15(C), the rotating part 1330 of the thumb middle hand part 115 is located closer to the central member 200 than the thenar part 1510 of the thumb middle hand part 115. In the posture of FIG. 15(D), the thenar part 1510 of the thumb middle hand part 115 is located closer to the central member 200 than the rotating part 1330 of the thumb middle hand part 115. The thenar part 1510 can further move closer to the central member 200 until it contacts the thenar part receiving part 1520 of the middle finger middle hand part 135 from the posture of FIG. 15(D). Note that the maximum movable range when the thenar part 1510 moves closer to the central member 200 is designed as the position where the thumb middle hand part 115 contacts the outer part 220. Also, the thenar part receiving part 1520 may be configured to be spatially connected to the receiving part 350 for the thumb middle hand part 115. In such a configuration, the thenar part receiving part 1520 can also function as the receiving part 350 for the thumb middle hand part 115. Similarly, the receiving part 350 for the thumb middle hand part 115 can also function as the thenar part receiving part 1520.

[0095] Since the thumb middle hand part 115 can take different postures shown in FIG. 15, the hand model 1 of the present embodiment can very well reproduce various shapes expressed by a human hand.

[0096] Additionally, the hand model 1 of the present embodiment preferably has a function of preventing the reproduction of a shape that cannot be represented due to the limitations of the anatomical structure of the human hand. This point will be described more specifically with reference to FIGS. 17A and 17B.

[0097] FIG. 16 is an example of an external view of the hand model 1 when the middle phalanx of the thumb 115 is in the postures shown in FIGS. 15(B) and 15(D). FIG. 16(A) is an example of an external view of the palm of the hand model 1 when the middle phalanx of the thumb 115 is in the postures shown in FIGS. 15(B) and 15(D), as viewed from above. FIG. 16(B) is an example of an external view of the hand model 1 when the middle phalanx of the thumb 115 is in the postures shown in FIGS. 15(B) and 15(D), as viewed from the fingertip side toward the wrist side.

[0098] In FIG. 16(A), most of the middle phalanx of the thumb 115 overlaps the middle phalanx of the index finger 125 and the middle phalanx of the middle finger 135. In the hand model 1 of FIGS. 16(A) and 16(B), by bending the thumb portion 110 and further bending the remaining four fingers, a fist shape can be formed. The fist shape of the hand model 1 obtained in this way can very well reproduce the fist shape of a human hand because the middle phalanx of the thumb 115 is in the postures shown in FIGS. 15(B) and 15(D).

[0099] FIG. 17A is an example of an external view of the hand model 1 for explaining the movable range of the middle phalanx of the thumb 115 corresponding to the posture of FIG. 15(A). In FIG. 17A(1), the contact protrusion 1100 is in contact with the middle phalanx of the index finger 125 at the outermost contact position 1121 of the stopper wall portion 1120, similar to FIG. 15(A). In FIG. 17A(2), the contact protrusion 1100 is accommodated in the accommodation portion for the middle phalanx of the thumb 115 of the middle phalanx of the middle finger 135. At this time, the contact protrusion 1100 may be in contact with the accommodation portion 350 for the middle phalanx of the thumb 115.

[0100] The thumb middle hand part 115 corresponding to the posture of FIG. 15(A) can move between a state where the contact protrusion 1100 contacts the index finger middle hand part 125 at the outermost contact position 1121 of the stopper wall part 1120 as shown in FIG. 17A(1) and a state where the contact protrusion 1100 is accommodated in the accommodation part 350 for the thumb middle hand part 115, particularly a state where the contact protrusion 1100 contacts the accommodation part 350 for the thumb middle hand part 115, as shown in FIG. 17A(2).

[0101] The rotation around the thumb CM joint part 1011 of the thumb middle hand part 115, which is a rotation that stands vertically with respect to the plane of the drawing, is restricted within a very narrow rotation range in FIG. 17A(1) by the contact protrusion 1100 contacting the stopper wall part 1120, and similarly in FIG. 17A(2) by the outer surface near the expansion part accommodation region 1310 contacting the stopper wall part 1120. The very narrow rotation range is determined by, for example, the cavity width of the index finger middle hand part 125. Note that the rotation range may be restricted by contacting only the middle finger middle hand part 135 (the wall surface of the accommodation part 350 for the thumb middle hand part 115), or the rotation may be restricted by contacting both the stopper wall part 1120 and the middle finger middle hand part 135. In addition, the outer surface near the expansion part accommodation region 1310 may be regarded as the outer surface on the palm side of the thumb middle hand part 115.

[0102] Thereby, in the hand model 1 of the present embodiment, it is possible to more reliably restrict the movement of the thumb middle hand part 115 beyond the movable range assumed from the actual movable range of the thumb and the thenar of a human hand.

[0103] FIG. 17B is an example of an external view of the hand model 1 for explaining the movable range of the thumb middle hand part 115 corresponding to the posture of FIG. 15(B). Also in FIG. 17B(1), the contact protrusion 1100 is in contact with the index finger middle hand part 125 at the outermost contact position 1121 of the stopper wall part 1120. In FIG. 17B(2), the upper edge 1720 of the thumb middle hand part is in contact with the contact edge 1710 of the stopper wall part 1120.

[0104] The thumb middle hand part 115 corresponding to the posture of FIG. 15(B) can move between the state where the contact protrusion part 1100 contacts the index finger middle hand part 125 at the outermost contact position 1121 of the stopper wall part 1120 as shown in FIG. 17B(1) and the state where the upper edge 1720 of the thumb middle hand part contacts the contact edge 1710 of the stopper wall part 1120 as shown in FIG. 17B(2).

[0105] In addition, in FIG. 17B(2), although the movement of the thumb middle hand part 115 is stopped in the state where the upper edge 1720 of the thumb middle hand part contacts the contact edge 1710 of the stopper wall part 1120, depending on the inclination of the thumb middle hand part 115 with respect to the index finger middle hand part 125 and the middle finger middle hand part 135, etc., the thumb middle hand part 115 can move until the thenar part 1510 of the thumb middle hand part 115 is received in the thenar receiving part 1520 of the middle finger middle hand part 135, especially until it contacts the thenar receiving part 1520.

[0106] Also in that case, the upper edge 1720 of the thumb middle hand part may remain in contact with the contact edge 1710 of the stopper wall part 1120. Depending on the design of the upper edge 1720 of the thumb middle hand part and the contact edge 1710 of the stopper wall part 1120, in the state where the thenar part 1510 of the thumb middle hand part 115 is received in the thenar receiving part 1520 of the middle finger middle hand part 135, the upper edge 1720 of the thumb middle hand part may be configured to be separated from the contact edge 1710 of the stopper wall part 1120.

[0107] When the thumb middle hand part 115 is in the posture of FIG. 15(B), the rotation around the thumb CM joint part 1011 of the thumb middle hand part 115, that is, the rotation that stands up vertically with respect to the plane of the drawing, is restricted in both FIGS. 17B(1) and 17B(2) by the contact protrusion part 1100 contacting the stopper wall part 1120 in the state where the expansion part 1300 is exposed from the expansion part accommodation region 1310.

[0108] Therefore, compared with the hand model 1 in the states of FIGS. 17A(1) and 17A(2), that is, compared with the thumb middle hand part 115 in the postures of FIGS. 17A(1) and 17A(2), the thumb middle hand part 115 in the postures of FIGS. 17B(1) and 17B(2) can rotate around the thumb CM joint part 1011 of the thumb middle hand part 115 by a larger movable range than a very narrow rotation range determined by, for example, the cavity width of the index finger middle hand part 125, that is, by the rotation range expanded by the expansion part 1300, and can perform a rotation that rises vertically with respect to the plane of the drawing.

[0109] FIG. 18 is an example of an explanatory diagram for explaining the connection state of the middle hand parts 10 of each finger part 30. FIG. 18(A) shows a state in which the thumb middle hand part 115, the index finger middle hand part 125, the middle finger middle hand part 135 (central member 200), and the little finger middle hand part 155 are connected. FIG. 18(B) shows a state in which the thumb middle hand part 115, the index finger middle hand part 125, the middle finger middle hand part 135 (central member 200), and the little finger middle hand part 155 are separated. FIG. 18(C) shows an example of the hinge connection part 1000 that connects the middle hand parts 10 of each finger part 30.

[0110] Each hinge connection part 1000 may be oriented such that its longitudinal direction is inclined with respect to the direction of the central axis 230 of the central member 200. Thereby, although it has a configuration completely different from the anatomical configuration of a human hand, it is possible to better reproduce the movable range of a human hand having middle metacarpal bones of each finger that spread out slightly radially and connect to the CM joint.

[0111] For example, by the rotational movement of each finger middle hand part 10 around the hinge connection part 1000, the entire middle hand part 10 can take a state as described in FIGS. 19 and 20 below, and thereby, the hand model 1 can better imitate the movements, postures, and shapes of an actual hand.

[0112] FIG. 33 is another example of an explanatory diagram for explaining the connection state of the middle hand parts 10 of each finger part 30. FIG. 33(A) illustrates a state in which the thumb middle hand part 115, index finger middle hand part 125, middle finger middle hand part 135 (central member 200), and little finger middle hand part 155 are separated. FIG. 33(B) illustrates a state of the outer side part 220 of the CM joint part 20 of the middle finger middle hand part 135 (central member 200) in the embodiment of FIG. 33(A) as viewed in a direction from the back of the hand toward the palm side. FIG. 33(C) illustrates a state of the outer side part 220 of the CM joint part 20 of the middle finger middle hand part 135 (central member 200) in the embodiment of FIG. 33(A) as viewed in a direction from the distal end side toward the proximal end side of the middle finger middle hand part 135.

[0113] Unlike the embodiment of FIG. 18, in the embodiment of FIG. 33, spherical connection parts 3310 schematically indicated by broken-line circles are provided between the middle finger middle hand part 135 and the ring finger middle hand part 145, and between the ring finger middle hand part 145 and the little finger middle hand part 155, respectively. As the spherical connection part 3310, a ball joint or a joint member for the IP joint part 50 described in detail with reference to FIG. 28 can be used.

[0114] For example, in a configuration where a joint member for the IP joint part 50 is used as the spherical connection part 3310, the joint member for the IP joint part 50 is attached in a state rotated by approximately 90° compared to the IP joint part 50 of each finger part 30 so that the rotation direction corresponds to that of the hinge connection part 1000, whereby a rotation direction similar to that of the hinge connection part 1000 can be realized. In such a configuration, for example, a component corresponding to the proximal connection part 2811 shown in FIG. 28 is fixedly accommodated in a recess (not shown) provided in the middle finger middle hand part 135, and similarly, a component corresponding to the distal connection part 2821 is fixedly accommodated in a recess (not shown) provided in the ring finger middle hand part 145. Note that a component corresponding to the proximal connection part 2811 may be attached to the ring finger middle hand part 145, and a component corresponding to the distal connection part 2821 may be attached to the middle finger middle hand part 135.

[0115] Similarly, the hinge connection portion 1000 between the index finger middle hand portion 125 and the middle finger middle hand portion 135 can also be replaced with a spherical connection portion 3310 (for example, a joint member for the IP joint portion 50). However, in the configuration using the hinge connection portion 1000, it is easier to ensure a larger possible rotation range or rotation space for the rotation of the thumb middle hand portion 115 described above.

[0116] Furthermore, in the embodiment of FIG. 33(A), the little finger middle hand portion 155 has a third support protrusion 3320. Similar to the first support protrusion 226 and the second support protrusion 227 described with reference to FIG. 2, the third support protrusion 3320 serves to support the little finger middle hand portion 155. Therefore, as shown in FIGS. 33(B) and 33(C), a third support protrusion insertion hole 3330 is provided at a corresponding position on the outer side portion 220 of the CM joint portion 20.

[0117] Whether to provide each of the first to third support protrusions 226, 227, 3320 and the first to third support protrusion insertion holes 1810, 1820, 3330 on each finger middle hand portion 10 or on the CM joint portion side can be changed according to the design. Also, the lengths, shapes (for example, cylindrical shape, frustum of a cone shape, etc.), sizes (for example, diameter or width), and positions on the outer side portion 220 of each finger middle hand portion 10 and the CM joint portion 20 of the first to third support protrusions 226, 227, 3320 can be designed according to the design of the movable and non - movable regions of each component of the hand model 1, particularly each finger middle hand portion 10 and each finger portion 30, and their ease or difficulty of movement based on frictional force, etc. Similarly, the depths, shapes (circular shape, elliptical shape, linear shape, curved shape, etc.), and positions on the outer side portion 220 of each finger middle hand portion 10 and the CM joint portion 20 of the first to third support protrusion insertion holes 1810, 1820, 3330 can also be designed according to the design of the movable and non - movable regions of each component of the hand model 1, particularly each finger middle hand portion 10 and each finger portion 30, and their ease or difficulty of movement based on frictional force, etc.

[0118] For example, in a configuration where the first to third support protrusions 226, 227, 3320 are in contact with the first to third support protrusion insertion holes 1810, 1820, 3330 and sufficient frictional force is generated therebetween, the index finger middle hand part 125, the ring finger middle hand part 145, and the little finger middle hand part 155 can stably maintain their positional relationships with respect to the outer side part 220 of the CM joint part 20 against, for example, vibrations, impacts, and changes in acceleration associated with the movement and conveyance of the hand model 1. Thereby, for example, even when moving the hand model 1 from the preparation room to the art room for use as a drawing model, the shape of the hand model 1 can be stably maintained. As a result, a student who is drawing can resume drawing using the hand model 1 in the same state as during the previous drawing.

[0119] In this way, by combining the hinge connection part 1000 and the spherical connection part 3310 and appropriately setting the attachment positions and dimensions of the first to third support protrusions and the first to third support protrusion insertion holes, in the embodiment of FIG. 33(A), compared with the embodiment of FIG. 18, it is possible to imitate the movable range and immovable range of a human hand with higher reproducibility and stably maintain that state.

[0120] FIG. 19 is an example of an explanatory diagram for explaining the middle hand part 10 in a flatter state. FIG. 19(A) is a view of the back side of the middle hand part 10 of the four fingers of the index finger, middle finger, and little finger (hereinafter also referred to as the "four-finger middle hand part 10") in a flatter state. The middle hand part 10 of each finger part 30 is closer to each other compared to the embodiment of FIG. 20(A) described later. It is preferable that the middle hand parts 10 of each finger part 30 are in contact with each other.

[0121] FIG. 19(B) is a view of the four-finger middle hand part 10 in a flatter state as seen from the fingertip side toward the wrist side. The first virtual curve 1910 is a virtual curve passing near the center of the MP joint accommodation recess 1900 provided in each of the four-finger middle hand parts 10. The first virtual curve 1910 schematically represents the degree of bending of the four-finger mid-hand part 10 in the state of FIG. 19. Thereby, the swelling of the human hand can be reproduced better.

[0122] In the hand model 1 according to the embodiment of FIG. 19(B), the first virtual curve 1910 is represented by a curve that is convex upward in the figure, that is, convex from the palm to the back of the hand. However, depending on the design of the hand model 1, it may be linear.

[0123] Also, in terms of the design of the hand model 1, the first virtual curve 1910 can be a curve that is convex downward in the figure, that is, convex from the back of the hand to the palm. However, for example, when reproducing the structure of the human hand, avoiding such a structure can enhance the reality.

[0124] FIG. 19(C) is an example of an external view of the hand model 1 when the entire mid-hand part is in the postures of FIGS. 19(A) and 19(B). In the embodiment of FIG. 19(C), the palm part of the mid-hand part 10 of the hand model 1 is in relatively close contact with the installation surface.

[0125] FIG. 20 is an example of an explanatory diagram for explaining the mid-hand part 10 in a more rounded state. FIG. 20(A) is a view of the back side of the four-finger mid-hand part 10 in a more rounded state. The mid-hand part 10 of each finger part 30 is located farther apart compared to the embodiment of FIG. 19(A) described later. In FIG. 20(A), there are slight gaps 2000 along each mid-hand part 10 between the mid-hand parts 10 of each finger part 30.

[0126] FIG. 20(B) is a view of the four-finger mid-hand part 10 in a more rounded state as seen from the fingertip side toward the wrist side. The second virtual curve 2010 is a virtual curve that passes near the center of the MP joint accommodation recess 1900 provided in each of the four-finger mid-hand parts 10, similar to the first virtual curve 1910.

[0127] The second virtual curve 2010 schematically represents the degree of bending of the middle part 10 of the four fingers in the state of FIG. 20. The second virtual curve 2010 has a larger curvature than the first virtual curve 1910 in FIG. 19(B), which is also shown in FIG. 20(B).

[0128] The larger curvature of the second virtual curve 2010 compared to the first virtual curve 1910 can be realized by the rotation of each finger middle part 10 around the hinge connection part 1000 shown in FIG. 18(C), thereby enabling good reproduction of the swelling of the hand represented by the human hand.

[0129] With the above structure, in the state of FIG. 20(B), the innermost point 2020 of the little finger middle part 155, which is the innermost point of the little finger middle part 155 (the point closest to the central axis 230), moves toward the central axis 230 side up to the range of the middle finger middle part 135 in the hand model 1. In this case, it is better if the little finger middle part 155 is configured to be able to contact the thumb middle part 115 that has also rotated toward the central axis 230 side as shown in FIG. 15(D), for example.

[0130] With such a configuration, the hand model 1 can reproduce a state where, for example, when the tip of the thumb and the tip of the little finger are brought into contact in a human finger, the thenar eminence and the hypothenar eminence are in contact.

[0131] FIG. 20(C) is an example of an external view of the hand model 1 when the entire middle part 10 is in the postures of FIGS. 20(A) and 20(B). In the embodiment of FIG. 20(C), the palm of the hand model 1 is slightly separated from the installation surface by the entire middle part 10 and mainly contacts the installation surface with each finger part 30.

[0132] FIG. 21 is an example of an explanatory diagram for explaining the configuration of the finger part 30. FIG. 21(A) is a view of the thumb part 110, the thumb middle part 115, the middle finger part 130, and the central member 200 as seen from the back of the hand. The middle finger range 2120 in FIG. 21(A) will be described in more detail with reference to FIG. 22. FIG. 21(B) is a view of the thumb portion 110, the middle thumb portion 115, the middle finger portion 130, and the central member 200 as seen from the palm side.

[0133] In FIGS. 21(A) and 21(B), the index finger portion 120, the ring finger portion 140, the little finger portion 150, and their middle portions are not shown, but the following description regarding the middle finger portion 130 can be similarly applied to each of those finger portions 30.

[0134] FIG. 22 is an example of an explanatory diagram for explaining the middle finger range 2120 of FIG. 21. In FIG. 22, the middle finger portion 130 surrounded by the middle finger range 2120 of FIG. 21 and the tip portion of the central member 200 to which the middle finger portion 130 is connected are shown in a state where they are separated for each portion.

[0135] An MP joint portion 40 is provided between the distal end of the middle finger middle portion 135 and the middle finger proximal phalanx 2101, and the MP joint portion 40 rotatably connects the middle finger proximal phalanx 2101 to the middle finger middle portion 135 in the flexion / ulnar deviation direction and the dorsal flexion / volar flexion direction.

[0136] Note that the rotation in the flexion / ulnar deviation direction means the rotation of the middle finger proximal phalanx 2101 with respect to the middle finger middle portion 135 in the flexion direction from the little finger portion 150 toward the thumb portion 110, and the rotation of the middle finger proximal phalanx 2101 with respect to the middle finger middle portion 135 in the ulnar deviation direction from the thumb portion 110 toward the little finger portion 150. Also, the rotation in the dorsal flexion / volar flexion direction means the rotation of the middle finger proximal phalanx 2101 with respect to the middle finger middle portion 135 in the dorsal flexion direction of bending upward toward the back of the hand, and the rotation of the middle finger proximal phalanx 2101 with respect to the middle finger middle portion 135 in the volar flexion direction of bending toward the palm side.

[0137] A PIP joint portion 51 is provided between the middle finger proximal phalanx 2101 and the middle finger middle phalanx 2102, and the PIP joint portion 51 rotatably connects the middle finger middle phalanx 2102 to the middle finger proximal phalanx 2101 in the dorsal flexion / volar flexion direction while restricting rotation in the flexion / ulnar deviation direction.

[0138] Similarly, an interphalangeal joint portion 52 is provided between the middle phalanx portion 2102 and the distal phalanx portion 2103 of the middle finger. The interphalangeal joint portion 52 rotatably connects the distal phalanx portion 2103 of the middle finger to the middle phalanx portion 2102 in the dorsal flexion and palmar flexion directions, while restricting rotation in the radial flexion and ulnar flexion directions.

[0139] FIG. 23 is an example of an explanatory diagram for explaining the MP joint portion 40. FIG. 23(A) shows a state of the MP joint portion 40 as viewed from the back of the hand. FIG. 23(B) shows a state of the MP joint portion 40 as viewed in the direction from the ring finger portion 140 to the index finger portion 120. FIG. 23(C) shows the components of the MP joint portion 40 disassembled and illustrated.

[0140] A part of the MP joint base 2300 is fixedly attached to and housed in an MP joint receiving recess 1900 provided at the distal end portion of each finger middle part 10. A first rotating portion (MP joint radial-ulnar flexion portion) 2310 of the MP joint portion 40 is attached to the MP joint base 2300 via a second rotating portion (MP joint dorsal-palmar flexion portion) 2320 of the MP joint portion 40. Although detailed description is omitted, the MP joint base 2300 and the first rotating portion (MP joint radial-ulnar flexion portion) 2310 are each constituted by combining a plurality of members, and are assembled by sandwiching the second rotating portion (MP joint dorsal-palmar flexion portion) 2320 therebetween.

[0141] The distal connecting portion 2311 of the first rotating portion 2310 of the MP joint portion 40 is fixedly attached to and housed in a recess provided at the proximal end portion of each finger proximal phalanx portion 31. The MP joint part 40 is configured to be capable of flexion rotation and ulnar flexion rotation in a fourth rotation direction RD4 around the second rotation support part 2322. Although detailed description is omitted, the second rotation support part 2322 is formed in a rivet shape and is connected to the first rotation part 2310 by being fitted into a recess provided in the second rotation part 2320. Further, although not shown in FIG. 23, the front surface of the second rotation support part 2322 is covered by the proximal phalanx part 31, and when connecting to the first rotation part 2310 by the proximal phalanx part 31, the second rotation support part 2322 is not necessarily provided.

[0142] Further, the MP joint part 40 is configured to be capable of dorsiflexion rotation and palmar flexion rotation in a fifth rotation direction RD5 around the first rotation support part 2302. Regarding the specific rotation states of the first rotation part 2310 of the MP joint part 40 and the second rotation part 2320 of the MP joint part 40, they will be described below with reference to FIGS. 24 to 28.

[0143] FIG. 24 is an example of an explanatory diagram for explaining the rotation of the MP joint part 40. FIG. 24(A) shows the central member 200 and the middle finger proximal phalanx part 2101 in a state where the MP joint part 40 is flexed, that is, a state where the middle finger proximal phalanx part 2101 is rotated toward the thumb side, together with an enlarged view of the MP joint part 40 in that state. FIG. 24(B) shows a view of the central member 200 and the middle finger proximal phalanx part 2101 in the flexed state of FIG. 24(A) as viewed from the palmar side.

[0144] The rotation range of the MP joint part 40 is defined, on the one hand, by the configuration of the MP joint part 40 itself, and on the other hand, also by the shapes of the distal end contour 2200 of the middle finger middle part 135 and the proximal end contour 2210 of the middle finger proximal phalanx part 2101.

[0145] The rotation of the MP joint part 40 is, for example, a rotational movement combining palmar flexion - dorsiflexion which is a pitch rotation with respect to the longitudinal direction of the middle finger proximal phalanx part 2101 and flexion - ulnar flexion which is a yaw rotation. The rotation of the MP joint portion 40 causes the magnitude of the possible yaw angle to change based on the deviation from 0° of the pitch angle. The rotation of the MP joint portion 40 causes the possible yaw angle to decrease as the deviation from 0° of the pitch angle increases.

[0146] The change in the possible yaw angle according to the magnitude of the deviation from 0° of the pitch angle can be realized, in particular, by the fact that the distal end contour 2200 of the middle finger middle hand portion 135 and the proximal end contour 2210 of the middle finger proximal phalanx 2101 are designed to contact at a smaller yaw angle as the deviation from 0° of the pitch angle increases. The above configuration is the same for each finger portion 110, 120, 140, 150 other than the middle finger portion 130.

[0147] In particular, the flexion / ulnar deviation rotation range of the MP joint portion 40 is maximized when the dorsal flexion / volar flexion rotation of the MP joint portion 40 is 0°, and may decrease as the dorsal flexion / volar flexion rotation of the MP joint portion 40 increases. Thereby, the movable range and the immovable range in the human finger can be reproduced better.

[0148] The above rotation range can be realized by the fact that as the dorsal flexion / volar flexion rotation of the MP joint portion 40 increases, the distal end contour 2200 of the middle finger middle hand portion 135 and the proximal end contour 2210 of the middle finger proximal phalanx 2101 contact each other in a narrower flexion / ulnar deviation rotation range, preventing further flexion / ulnar deviation rotation.

[0149] FIG. 25 is an example of an external view of the hand model 1 for explaining the flexion and ulnar deviation of the middle finger portion 130. FIG. 25(A) is an example of an external view of the hand model 1 in which the flexion and ulnar deviation angles of the middle finger portion 130 are approximately 0°. In FIGS. 25(A), 25(B), and 25(C), the index finger portion 120 is flexed, and the ring finger portion 140 and the little finger portion 150 are ulnar deviated.

[0150] FIG. 25(B) is an example of an external view of the hand model 1 in which the middle finger portion 130 is flexed. FIG. 25(C) is an example of an external view of the hand model 1 with the middle finger part 130 flexed ulnarly.

[0151] FIG. 26 is an example of an explanatory diagram for explaining the rotation of the MP joint part 40. FIG. 26(A) shows the central member 200 and the middle finger proximal phalanx 2101 in a state where the MP joint part 40 is palmar flexed, that is, a state where the middle finger proximal phalanx 2101 is rotated toward the palm side, together with an enlarged view of the MP joint part 40 in that state, as viewed from the thumb side toward the little finger side.

[0152] FIG. 26(B) shows the central member 200 and the middle finger proximal phalanx 2101 in a state where the MP joint part 40 is dorsiflexed, that is, a state where the middle finger proximal phalanx 2101 is rotated toward the back side of the hand, as viewed from the thumb side toward the little finger side.

[0153] The palmar flexion rotation range of the MP joint part 40 in the state of FIG. 26(A) and the dorsiflexion rotation range of the MP joint part 40 in the state of FIG. 26(B) may be defined by the contact based on the shapes of the distal end contour 2200 of the middle finger middle part 135 and the proximal end contour 2210 of the middle finger proximal phalanx 2101. That is, it is preferable that the MP joint part 40 can be palmar flexed and dorsiflexed until the middle finger middle part 135 and the middle finger proximal phalanx 2101 come into contact with each other and stop.

[0154] Additionally or alternatively, the rotation range of palmar flexion or dorsiflexion of the MP joint part 40 may be designed based on the configuration of the MP joint part 40 itself, which will be described with reference to FIG. 28.

[0155] In particular, it is preferable that the rotation range of palmar flexion of the MP joint part 40 is designed to be larger than the rotation range of dorsiflexion of the MP joint part 40. Thereby, the movable range and the immovable range in a human finger can be reproduced better.

[0156] FIG. 27 is an example of an external view of the hand model 1 with different amounts of rotation of the MP joint part 40. FIG. 27(A) is an example of an external view of the hand model 1 in a state where the MP joint part 40 of each finger part 30 is palmar flexed by approximately 90°. FIG. 27(B) is an example of an external view of the hand model 1 in a state where the MP joint portion 40 of each finger portion 30 is palmar flexed by approximately 30° to 45°.

[0157] In the hand model 1 of FIG. 27(B), the MP joint portion 2710 of the little finger and the MP joint portion 2720 of the ring finger are palmar flexed only slightly more than the MP joint portion 2710 of the little finger and the MP joint portion 2720 of the ring finger in the hand model 1 of FIG. 27(A). Also, in the hand model 1 of FIG. 27(B), the MP joint portion 2720 of the ring finger is palmar flexed only slightly more than the MP joint portion 2710 of the little finger.

[0158] In either the hand model 1 of FIG. 27(A) or FIG. 27(B), the PIP joint portion 2730 of the little finger and the PIP joint portion 2740 of the ring finger are both substantially fully palmar flexed. The DIP joint portion 2750 of the little finger in FIG. 27(B) is palmar flexed more than the DIP joint portion 2750 of the little finger in FIG. 27(A), which is substantially straight and hardly palmar flexed or dorsiflexed. As a result, the middle phalanx portion 2760 of the little finger in FIG. 27(B) rises from the installation surface more than the middle phalanx portion 2760 of the little finger in FIG. 27(A). This is the same for the middle finger portion 130.

[0159] The postures of the hand model 1 shown in FIGS. 27(A) and 27(B) are examples of the postures that the hand model 1 can take. By individually moving the MP joint portion 40 and the IP joint portion 50 of each finger portion 30, the user can easily and variously change the posture of the hand model 1. In particular, continuously, from very slight changes to very large changes, postures that can be expressed by an actual human hand can be reproduced or imitated.

[0160] FIG. 28 is an example of an explanatory diagram for explaining the configuration of the IP joint portion 50. FIG. 28(A) shows a view of the assembled IP joint portion 50 and the disassembled IP joint portion 50 as seen from the back of the hand toward the palm side of the hand.

[0161] The IP joint portion 50 is composed of an IP joint fixing portion 2810 fixedly connected to the proximal middle phalanx 32 and the proximal phalanx 31 at the proximal connecting portion 2811, and an IP joint rotating portion 2820 fixedly connected to the distal distal phalanx 33 and the middle phalanx 32 at the distal connecting portion 2821.

[0162] The IP joint rotating portion 2820 has a rotating shaft body 2823 and can rotate together with the distal phalanx 33 and the middle phalanx 32 fixedly connected via the distal connecting portion 2821 around it. Incidentally, by providing a play (space) between the rotating shaft body 2823 and the distal connecting portion 2821, the IP joint portion 50 may be configured to be flexible and flexibly bendable.

[0163] The IP joint fixing portion 2810 has a fixing portion protrusion 2812. The fixing portion protrusion 2812 contacts the rotating portion step 2822 of the IP joint rotating portion 2820 to limit further rotation of the IP joint rotating portion 2820.

[0164] FIG. 28(B) is a view of the IP joint portion 50 of FIG. 28(A) viewed in the axial direction of the rotating shaft body 2823, respectively. A rotation range 2824 is provided between the two rotation portion steps 2822 of the IP joint rotation portion 2820. The two rotation portion steps 2822 respectively correspond to the maximum palmar flexion rotation position and the maximum dorsal flexion rotation position of the IP joint rotation portion 2820.

[0165] It is preferable that the positions of the two rotation portion steps 2822 and the size of the rotation range 2824 are the same, so that manufacturing and assembly can be carried out more inexpensively and simply. However, the positions of the two rotation portion steps 2822 and the size of the rotation range 2824 may be designed differently for each finger portion 30 to provide more variations.

[0166] FIG. 28(C) is a view of the state in which the IP joint portion 50 of FIG. 28(A) is in palmar flexion, viewed in the axial direction of the rotating shaft body 2823, respectively. In FIGS. 28(B) and 28(C), the positions 2813 of the fixing part protrusions 2812 represented by the dashed-line squares indicate the positions of the fixing part protrusions 2812 of the IP joint fixing part 2810 within the rotation range 2824 in their respective rotation states.

[0167] The embodiment of FIG. 28 can also be changed to a configuration in which the IP joint fixing part 2810 is fixedly connected to the distal phalanx part 33 or the middle phalanx part 32 on the distal side, and the IP joint rotating part 2820 is fixedly connected to the middle phalanx part 32 or the proximal phalanx part 31 on the proximal side.

[0168] FIG. 29 is an example of an explanatory diagram for explaining the dorsiflexion and palmar flexion of the DIP joint part 52. FIG. 29(A) shows the middle phalanx part 32 and the distal phalanx part 33 in a state where the DIP joint part 52 is dorsiflexed, that is, a state where the distal phalanx part 33 is palmar flexed and rotated toward the back of the hand, together with an enlarged view of the DIP joint part 52 in that state.

[0169] FIG. 29(B) shows the middle phalanx part 32 and the distal phalanx part 33 in a state where the DIP joint part 52 is flexed, that is, a state where the distal phalanx part 33 is dorsiflexed and rotated toward the palm side, together with an enlarged view of the DIP joint part 52 in that state.

[0170] In FIG. 29(A), the DIP joint part 52 is rotated to approximately the maximum dorsiflexion rotation position. In FIG. 29(B), the DIP joint part 52 is rotated to approximately the maximum palmar flexion rotation position. The middle phalanx distal end contour 2920 of the middle phalanx part 32 and the distal phalanx proximal end contour 2930 of the distal phalanx part 33 are preferably designed to contact each other precisely at the maximum dorsiflexion rotation position and the maximum palmar flexion rotation position. Note that instead of, or in addition to, the configuration that restricts the rotation range by the contact with the above-described fixing part protrusion 2812 and the rotation part step 2822, a configuration that restricts the rotation range by using the contact between the middle phalanx distal end contour 2920 and the distal phalanx proximal end contour 2930 can also be applied.

[0171] FIG. 30 is an example of an external view of the hand model 1 for explaining the movable ranges of the MP joint part 40 and the IP joint part 50. In the embodiment of FIG. 30, the index finger portion 120 of the hand model 1 is entirely dorsiflexed. In particular, the degree of dorsiflexion of the proximal phalanx portion 31 and the distal phalanx portion 33 is large. Further, the index finger portion 120 is ulnarly flexed and points toward the back side of the drawing.

[0172] The middle finger portion 130 is neither significantly flexed / ulnarly flexed nor dorsiflexed / palmarly flexed, and extends substantially straight. The ring finger portion 140 is entirely palmarly flexed, and the distal phalanx portion 33 of the ring finger portion 140 is in contact with the distal phalanx portion 33 of the thumb portion 110.

[0173] The little finger portion 150 is entirely more palmarly flexed than the ring finger portion 140. Since each finger portion 30 can independently flex / ulnarly flex and dorsiflex / palmarly flex, the hand model 1 can very well imitate and reproduce the movements, shapes, and poses of a human hand.

[0174] Another variation of the hand shape achievable by the hand model 1 according to this embodiment will be further described below with reference to FIG. 31. FIG. 31 is an example of another external view of the hand model 1 for explaining an example of the range of motion of the MP joint portion 40 and the IP joint portion 50.

[0175] FIG. 31(A) is an example of an external view of the hand model 1 with the index finger portion 120 and the middle finger portion 130 crossed. FIG. 31(B) is an example of an external view of the hand model 1 in the state of FIG. 31(A) viewed from the thumb side toward the little finger side.

[0176] In the hand model 1 of FIG. 31, the MP joint portion 3110 of the index finger portion 120 is ulnarly flexed, and the MP joint portion 3120 of the middle finger portion 130 is flexed and palmarly flexed. As a result, the index finger portion 120 and the middle finger portion 130 cross each other. Also, the DIP joint portion 3115 of the index finger portion 120 is palmarly flexed, and the middle finger DIP joint portion 3125 is dorsiflexed. Thereby, the crossed index finger portion 120 and middle finger portion 130 form a loop (void).

[0177] In this way, the hand model 1 can very well imitate and reproduce the movements, shapes, and poses of a human hand. As a result, when depicting the shape of the hand with reference to the hand model, a highly realistic expression can be achieved. In addition, in the above-described embodiment, in order to have a range of motion similar to that of the anatomical structure of a human arm and hand, the range of motion is restricted by the contact of adjacent members (for example, the intermediate hand part 10 and the proximal phalanx part 31 sandwiching the MP joint part 40) via the joint part. By doing so, the range of motion can be appropriately adjusted by finely adjusting the shapes of the ends of the respective members.

[0178] Also, in the above-described embodiment, for the sake of convenience of explanation, it was described in the form of providing a gap at the rotating parts of each joint part and hinge connection part. However, for the actual hand model 1, it is desirable to make the members of the rotating parts abut against each other without providing a gap so that, for example, even if the user releases the hand after setting the joints of the hand model 1, the rotation angle of the joints can be maintained in a fixed state by frictional force or the like. In that case, particularly for the CM joint part 20 and the thumb CM joint part 1011, it is advisable to make a strong abutment because a large load is applied to support the members at their tips.

[0179] For example, regarding the CM joint part 20, as shown in FIG. 32, the outer part 220 is composed of a plurality of members, for example, the first half body 3210 and the second half body 3220 of the outer part 220. Cylindrical members, for example, the first cylindrical member 3211 and the second cylindrical member 3221, protruding perpendicularly to the second rotation direction RD2 are provided on the inner sides of the respective members so as to penetrate through the cylindrical member insertion holes 3230 of the inner part 300. The two cylindrical members 3211 and 3221 are connected by screws or the like, and by tightening the screws or the like, the two cylindrical members 3211 and 3221 are configured to approach each other so that the contact force between the outer part 220 and the inner part 300 can be adjusted. In this way, the individual using the hand model can adjust the intensity of the abutment by themselves.

[0180] When configured in this way, a long-hole cylindrical member insertion hole 3230 may be provided in a portion of the inner portion 300 through which the cylindrical members 3211 and 3221 are inserted so as not to inhibit the rotation of the inner portion 300. Further, regarding the thumb CM joint portion 1011, in addition to the contact between the outer portion 221 and the inner portion 1020, a member may be provided on the thumb middle hand portion 115 to cover and contact the outer portion 221, so as to strengthen the contact force between the outer portion 221 and the inner portion 1020. In addition, in the above embodiment, each member of each joint portion has been described as an integral one, but it may be composed of a plurality of members. In this way, it is possible to easily adjust the frictional force in the contacting state.

[0181] The hand model 1 described with reference to FIGS. 1A to 31 has the individual components of the hand model 1 exposed for the purpose of explanation, but may be covered, for example, by a film structure made of resin or the like as a pseudo-skin structure. In such an embodiment, the appearance of the hand model 1 can be made even more similar to the appearance of a human hand. Additionally or alternatively, the hand model 1 may be covered by a clothing structure (such as a glove) made of cloth or fabric.

[0182] Further, by providing a fixing member insertion hole 710 in the upper end face above the arm end portion 60 in FIG. 7(A), for example, by inserting a rod-shaped fixing member provided on a pedestal into the fixing member insertion hole 710, the hand model 1 can be fixed at an angle other than the angle at which the fingers are positioned upward with respect to the wrist, and the convenience as a drawing sample for hand depiction can be improved.

[0183] Also, when the hand model 1 is used as a prosthetic hand, various hand shapes and postures that can occur in daily life, such as combining the fingers of the left and right hands, pointing with the fingers or using a cheek support with the prosthetic hand side (hand model 1), can be naturally and stably imitated and reproduced. Therefore, not only is it difficult for people around to notice that it is a prosthetic hand, but the quality of life (QOL) of the user himself / herself can also be improved.

[0184] Furthermore, the hand model 1 may include a drive unit or an actuator that can mechanically and electrically control and drive at least one of the above-described components, particularly at least one joint portion. Such a hand model 1 can also be used as a robotic hand, a robotic arm, a manipulator, an electric prosthesis, or the like. Even in such applications, the hand model 1 can very well reproduce the shape and posture of a human finger. Furthermore, depending on the output of the drive unit or actuator and the strength of each component, it is also possible to actually pinch or grasp an object.

[0185] For example, the user can use the hand model 1 configured with a drive unit that can mechanically and electrically control and drive the MP joint portion 40 and the IP joint portion 50 of the index finger portion 120 as an artificial hand. In such a case, the user can naturally change the state of the hand model 1 from a clenched hand state to a pointing state, so the convenience in daily life is greatly improved.

[0186] In such a configuration, the drive unit electrically connected to a battery, a communication device, a processing device, etc. is controlled based on a specific signal of a bioelectric potential such as an electroencephalogram (EEG) or a skin potential of the artificial hand wearer acquired by a detection device such as a wearable sensor. The specific signal may be, for example, a characteristic signal generated when the artificial hand wearer is conscious of "pointing" or when actually trying to point and contracting muscles such as the arm. The specific signal of the bioelectric potential detected by the detection device is sent to the processing device via the communication device, and then the processing device moves the drive unit based on the received specific signal of the bioelectric potential. Thereby, the artificial hand wearer can change the hand model 1, for example, from a clenched hand state to a pointing state, without operating a physical switch or the like. The above configuration is particularly applicable to the index finger MP joint portion 3110 of the hand model 1 used as an artificial hand. For example, it is better that the index finger MP joint portion 3110 can be rotated by a motor housed in the proximal phalanx 31 of the index finger portion 120 or in the distal end region of the index finger middle phalanx 125.

[0187] Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

[0188] Note that the above-described embodiments disclose at least the configurations described in the claims.

[0189] Further, the present invention includes at least the following embodiments (1) to (23). The present invention further includes a configuration combining the following embodiments (1) to (23).

[0190] Embodiment (1) Having a central member composed of a CM joint portion and a middle finger middle hand portion, The CM joint portion consists of a first outer portion and a first inner portion, The first outer portion rotatably houses the first inner portion, The first outer portion has at least one guide portion, The guide portion of the first outer portion restricts the rotation of one axis around one of the three rotation axes of the first inner portion Hand model.

[0191] Embodiment (2) The first inner portion has at least one guide protrusion, The guide portion restricts the rotation of the one axis by restricting the movement of the guide protrusion within the guide portion Hand model.

[0192] Embodiment (3) The outer part has, as the guide part, a first guide part sandwiched between a first guide edge and a second guide edge. The outer part restricts the movement of the guide protrusion and restricts the rotation of the inner part about the one axis by contact between the guide protrusion and the first guide edge or the second guide edge within the first guide part. Hand model.

[0193] Example (4) The guide protrusion contacts the first guide edge or the second guide edge on the back side or the palm side of the outer part. Hand model.

[0194] Example (5) The first inner part has, as the guide protrusions, a first guide protrusion and a second guide protrusion. The first guide protrusion contacts the first guide edge or the second guide edge on the back side or the palm side of the outer part. The second guide protrusion contacts the first guide edge or the second guide edge on the side opposite to the first guide protrusion. Hand model.

[0195] Example (6) The outer part has, as the guide part, a second guide part sandwiched between a third guide edge and a fourth guide edge. The first inner part has at least one connecting part. The outer part accommodates either or both of the first guide protrusion and the second guide protrusion within the first guide part according to the position of the connecting part within the range of the second guide part. Hand model.

[0196] Example (7) The first inner part is connected to the arm end via the connecting part. Hand model.

[0197] Example (8) The restricted rotation of the single axis passes through the center of the inner part and is a roll rotation around a rotation axis extending in the longitudinal direction of the central member. The hand model according to claim 1.

[0198] Example (9) The CM joint part has a thumb CM joint part. The thumb CM joint part has a second outer part fixedly attached to the first outer part, and a second inner part rotatably accommodated in the second outer part and connected to the middle phalanx of the thumb. Hand model.

[0199] Example (10) The second outer part accommodates the second inner part so that at least partial three-axis rotation is possible. Hand model.

[0200] Example (11) The middle phalanx of the middle finger is connected to the middle phalanx of the index finger. The middle phalanx of the index finger is provided with a stopper wall part. The middle phalanx of the middle finger is provided with an inner wall part. The range of the three-axis rotation of the middle phalanx of the thumb is restricted by contact with at least one of the stopper wall part and the inner wall part. Hand model.

[0201] Example (12) The middle phalanx of the thumb can take a first posture and a second posture based on rotation. In the first posture, the range of the three-axis rotation is restricted by contact with the stopper wall part. In the second posture, the range of the three-axis rotation is restricted by contact with the stopper wall part and the inner wall part. Hand model.

[0202] Example (13) The middle phalanx of the thumb has a contact protrusion part. The range of rotation of the three axes of the thumb middle hand part is restricted by the contact with the contact protrusion part and the stopper wall part. Hand model.

[0203] Example (14) The thumb middle hand part has an extension part, and the contact protrusion part is provided on the extension part. The extension part can be at least partially accommodated inside the thumb middle hand part. Hand model.

[0204] Example (15) The contact protrusion part is not accommodated inside the thumb middle hand part. Hand model.

[0205] Example (16) The extension part can shift from the accommodated state to the extended state while the contact protrusion part remains in contact with the index finger middle hand part. Hand model.

[0206] Example (17) The middle finger middle hand part is connected to the index finger middle hand part via a first rotation connection part and is connected to the ring finger middle hand part via a second rotation connection part. The ring finger middle hand part is connected to the little finger middle hand part via a third rotation connection part. Based on the rotation states of the first rotation connection part to the third rotation connection part and the rotation state of the thumb CM joint part, the thumb middle hand part and the little finger middle hand part can be in contact. Hand model.

[0207] Example (18) The middle finger middle hand part is directly or indirectly connected to the thumb middle hand part, the index finger middle hand part, the ring finger middle hand part, and the little finger middle hand part. At least one of these middle hand parts is connected to the base joint part of each finger part via an MP joint part. The base joint part can rotate in at least two axes via the MP joint part. Hand model.

[0208] Example (19) The rotation of the two axes is a rotation combining a pitch rotation and a yaw rotation with respect to the longitudinal direction of the base joint portion, Based on the deviation from 0° of the pitch angle, the magnitude of the possible yaw angle of the rotation of the two axes changes Hand model.

[0209] Example (20) The greater the deviation from 0° of the pitch angle, the smaller the possible yaw angle of the rotation of the two axes Hand model.

[0210] Example (21) The distal end of the middle part of each finger part and the proximal end of the base joint part of each finger part contact with a smaller yaw angle as the deviation from 0° of the pitch angle increases, thereby restricting the rotation of the two axes Hand model.

[0211] Example (22) A central member composed of a CM joint part and a middle finger middle part, The CM joint part has a first outer part and a thumb CM joint part, The thumb CM joint part has a second outer part fixedly attached to the first outer part, and a second inner part rotatably accommodated in the second outer part and connected to the thumb middle part Hand model.

[0212] Example (23) Having a central member composed of a CM joint part and a middle finger middle part, The middle finger middle part is directly or indirectly connected to the thumb middle part, the index finger middle part, the ring finger middle part, and the little finger middle part, At least one of these middle parts is connected to the base joint part of each finger part via an MP joint part, The base joint part is capable of rotating at least two axes via the MP joint part Hand model. Explanation of Signs

[0213] 1... Hand model, 10... Middle hand part, 20... CM joint part, 30... Finger part, 40... MP joint part, 50... IP joint part, 51... PIP joint part, 52... DIP joint part, 60... Wrist end part, 220... Outer part of CM joint part 20, 300... Inner part of CM joint part 20, 400... First guide part, 500... Second guide part, 1011... Thumb CM joint part, 1100... Contact protrusion part, 1300... Expansion part

Claims

1. A first metacarpal portion; A first finger portion; a first joint portion connecting the first metacarpal portion and the first finger portion; having The first joint portion has at least a first joint base portion and a first joint rotation portion, The first joint base has a proximal connection portion of the first joint portion and a first rotation support portion, The first joint rotation portion is A distal connection portion of the first joint portion; a first ring portion through which the first rotation support portion passes; a second ring portion having a through hole through which a second rotation support portion attached to an outer circumferential surface of the first ring portion passes; having The first finger portion is configured to be able to move relative to the first metacarpal portion via the first joint portion, the movement being a combination of a first rotation about a first rotation axis passing through the first ring portion and a second rotation about a second rotation axis passing through the through hole. Hand model.

2. The first joint base of the first joint portion is connected to the first metacarpal portion at the proximal connection portion, the second ring portion of the first joint portion has the distal connection portion and is connected to the first finger portion at the distal connection portion; the first ring portion surrounds the first rotation support portion so as to enable the first rotation about the first rotation axis; the second ring portion surrounds the first ring portion so as to enable the first rotation about the first rotation axis and the second rotation about the second rotation axis; The hand model according to claim 1 .

3. The first rotation is a pitch rotation related to palmar flexion and / or dorsiflexion of the first finger portion relative to the first metacarpal portion, The second rotation is a yaw rotation related to flexion and / or ulnar flexion of the first finger portion relative to the first metacarpal portion, As the pitch rotation of the first finger portion relative to the longitudinal direction of the first metacarpal portion or the first finger portion becomes larger, the movable range of the yaw rotation becomes narrower, The first metacarpal portion and the first finger portion have a contour shape in which, as the pitch rotation regarding the palmar flexion and / or the dorsiflexion becomes larger, the first metacarpal portion and the first finger portion come into contact with each other in a narrower rotation range of flexion and / or ulnar flexion, and further rotation of flexion and / or ulnar flexion is prevented. The hand model according to claim 2.

4. A first metacarpal portion, A first finger portion; a first joint portion connecting the first metacarpal portion and the first finger portion; having the first finger portion is configured to be capable of movement relative to the first metacarpal portion via the first joint portion, the movement being a combination of at least a first rotation about a first rotation axis and a second rotation about a second rotation axis; The first metacarpal portion has an extension portion and a first metacarpal main body portion capable of at least partially accommodating the extension portion, The extension portion is rotatably connected to the first metacarpal body portion, The extension portion has an extension portion main body portion that can be in a state housed within the first metacarpal portion main body portion and a state exposed to the outside of the first metacarpal portion main body portion in response to rotation of the extension portion relative to the first metacarpal portion main body portion, A second joint portion; a third joint portion that movably connects the first metacarpal portion to the second joint portion; A second metacarpal portion directly or indirectly connected to the second joint portion; and The first metacarpal portion is displaced to a position farther away from the second metacarpal portion in a first direction by changing a state in which the extension portion main body portion is housed within the first metacarpal portion main body portion to a state in which the extension portion main body portion is exposed outside the first metacarpal portion main body portion. Hand model.

5. The second metacarpal portion has a hollow portion and a second metacarpal body portion at least partially surrounding the hollow portion and limiting movement of the first metacarpal portion relative to the second joint portion based on contact with the expansion portion. The hand model according to claim 4.

6. The extension portion has a protrusion portion that limits movement of the first metacarpal portion relative to the second joint portion based on a contact position of the extension portion and the second metacarpal portion main body portion, The extension section is rotatably connected to the first metacarpal section main body so that, when the protrusion section is in contact with a part of the second metacarpal section main body at the contact position, the extension section main body can be accommodated in the first metacarpal section main body and exposed to the outside of the first metacarpal section main body in response to rotation of the extension section relative to the first metacarpal section main body. The hand model according to claim 5.

7. The third metacarpal part; a first connection portion that connects the second metacarpal portion to the third metacarpal portion so that the second metacarpal portion can move relative to the second joint portion and so that the second metacarpal portion can move relative to the third metacarpal portion while the expansion portion and the second metacarpal portion main body portion are in contact with each other; Further comprising The hand model according to claim 6.

8. The fourth metacarpal part; The fifth metacarpal part, a second connection portion that connects the fourth metacarpal portion to the third metacarpal portion such that the fourth metacarpal portion is movable relative to the second joint portion; a third connection portion that connects the fifth metacarpal portion to the fourth metacarpal portion such that the fifth metacarpal portion is movable relative to the second joint portion; Further comprising The hand model according to claim 7.

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