WO2021215513A1

WO2021215513A1 - Finger motion assistance device

Info

Publication number: WO2021215513A1
Application number: PCT/JP2021/016355
Authority: WO
Inventors: 文成金子; 小笠原　伸浩; 陽平里
Original assignee: 学校法人慶應義塾; 株式会社菊池製作所
Priority date: 2020-04-23
Filing date: 2021-04-22
Publication date: 2021-10-28
Also published as: JPWO2021215513A1

Abstract

A finger motion assistance device 1 comprises a shell member 10 mounted on the back of a hand, bendable belt-shaped members 30 positioned so as to extend along the backs of fingers, drive units 11 which are provided to the shell member 10 and which drive the belt-shaped members 30 so that the belt-shaped members 30 move reciprocally in the longitudinal direction thereof, first support members 41 provided to the distal-end parts of the belt-shaped members 30, first annular retaining members 51 which are connected to the first support members 41 and which retain fingertip portions, second support members 42 through which the belt-shaped members 30 are inserted and which are linked so as to be able to rotate with respect to the shell member 10, and second annular retaining members 52 which are connected to the second support members 42 and which retain base-side portions of the fingers.

Description

Finger movement assist device

The present invention relates to a finger movement assisting device for assisting a finger bending and stretching movement.

For the purpose of rehabilitation of patients with hand paralysis due to cerebrovascular accidents and brain injuries and assistance in daily life, a finger movement assist device that is attached to the back of the fingers to assist the bending and stretching movements of the fingers has been proposed. (See, for example, Patent Document 1).
The finger movement assisting device of Patent Document 1 has an articulated link row structure in which a plurality of link members are connected in a row, and the length of two linear members extending from the base end portion to the tip end portion is controlled by a motor. By controlling, the link row bends.

Japanese Patent No. 6501358

According to the conventional finger movement assisting device, the joint pitch of the link row is made as short as possible in order to obtain a smooth cooperative movement with the three joints (DIP joint, PIP joint and MP joint) constituting the endoskeleton of the finger. There is a need to. Therefore, the number of parts is large and the structure is complicated. In addition, the linear member that transmits the force for bending the link row may buckle when a large compressive force is applied, and there is a limit to the auxiliary force when gripping an object, for example.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a finger movement assisting device which has a simple structure and has a good cooperation with a finger joint.

In order to solve the above problems, the present invention is a finger movement assisting device for assisting the bending and stretching movement of a finger, so as to extend along the back of the back member of the wearer's hand and the back of the finger. A band-shaped member arranged in the band, a drive unit that drives the band-shaped member to reciprocate in the longitudinal direction thereof, a first support member provided at the tip of the band-shaped member, and the first support. A first annular holding member that is connected to the member and holds a portion of the finger on the fingertip side and the band-shaped member are inserted and supported, and are rotatably connected to the back member in the bending / stretching direction of the finger. It is a finger movement assisting device including a second support member to be formed and a second annular holding member connected to the second supporting member and holding a portion on the base side of the finger with respect to the first annular holding member.

The finger movement assisting device further includes a rotation support member that is rotatably pivotally supported by the back carapace member and connects and supports the second support member, and the band-shaped member is inserted into the second support member. Therefore, it is preferable that the finger is supported at a predetermined distance from the back of the finger.

Further, in the finger movement assisting device, it is preferable that the first annular holding member is detachable from the first supporting member and the second annular holding member is detachable from the second supporting member.

Further, in the finger movement assisting device, the first annular holding member is rotatably connected to the first support member around one axis in the radial direction thereof, and the second annular holding member is rotatably connected around one axis in the radial direction thereof. It is preferable that the second support member is rotatably connected to the second support member.

Further, the finger movement assisting device is a link mechanism portion that rotatably connects the first support member and the second support member, and is a rotation between the first support member and the second support member. It is preferable to further provide a link mechanism portion in which the center of motion is biased toward the joint side of the finger.

According to the finger movement assisting device according to the present invention, it is possible to realize a smooth and good cooperative movement between the exoskeleton body that assists the bending and stretching of the finger and the knuckle joint that is the endoskeleton. Further, since the band-shaped member that transmits the bending / stretching assisting force does not have a link or a joint, the structure can be simplified and the manufacturing cost can be suppressed.

It is external perspective view of the finger movement assisting apparatus according to one Embodiment of this invention. It is a top view for exemplifying the structure of the drive part. It is a side view for exemplifying the structure of the drive part. It is a side view of the outer joint when the index finger is extended. It is a side view of the outer joint when the index finger is bent. It is a top view which illustrates the strip-shaped member. It is a side view which illustrates the strip-shaped member. It is a front view which illustrates the 1st support member and 1st ring holding member. It is a front view which illustrates the 2nd support member and the 2nd annular holding member. It is a front view which illustrates the rotation support member. It is a side view which illustrates the link mechanism part. It is an exploded perspective view of the link mechanism part. It is a perspective view of the link mechanism part when an outer joint is flexed. It is a perspective view of the link mechanism part when the external joint is extended.

Hereinafter, a preferred embodiment of the finger movement assisting device according to the present invention will be described with reference to the drawings. In the following description, "front" refers to the direction from the base of the finger toward the fingertip, and "rear" refers to the opposite direction. Unless otherwise specified, "upper" refers to the dorsal side of the finger and "lower" refers to the ventral side of the finger.

FIG. 1 is an external perspective view of the finger movement assisting device 1 according to the embodiment of the present invention. The finger movement assisting device 1 of the present embodiment includes a back carapace member 10 that is attached in contact with the back of the wearer's hand, a drive unit 11 provided on the back carapace member 10, and an exoskeleton body driven by the drive unit 11. Has 20 and. Further, the exoskeleton body 20 is attached to the dorsal side of each finger of the wearer, and includes

external joints

21, 21, ...

First, the back member 10 is a plate-shaped member molded into a shape that resembles the back of a human hand, and can be integrally molded with a relatively hard general-purpose synthetic resin material such as polypropylene, polystyrene, or ABS resin. can. Further, the carapace member 10 may be manufactured of a light metal or a composite material of a metal and a synthetic resin. Further, a cushion layer such as urethane foam may be provided on the inner surface of the back member 10 to improve the adhesion with the back of the wearer's hand. At both ends of the back member 10, attachment members such as a strap, a belt, or a glove (not shown) are provided for attaching the finger movement assisting device 1 by wrapping it around the hand. Such a mounting member preferably has a detachable portion such as a hook-and-loop fastener or a one-touch buckle.

On the outer surface of the back carapace member 10,

drive units

11 and 11 are provided to drive the band-shaped member 30 described later so as to reciprocate back and forth in the longitudinal direction thereof. Here, FIG. 2 is a diagram for exemplifying the configuration of the drive unit 11. As shown in the figure, the drive unit 11 represents the controller 12, the electric rotary motor 13 whose torque and rotation speed are controlled by the controller 12, and the torque output by the rotary motor 13 in two strip-shaped members (broken lines). It is provided with a transmission mechanism 14 for transmitting to 30, 30.

Specifically, the transmission mechanism 14 is, for example, a bevel gear 15 fixed to the drive shaft 131 of the rotary motor 13, a rotary shaft 16 orthogonal to the drive shaft 131, and a rotary motor 13 fixed to an intermediate portion of the rotary shaft 16. It has a second bevel gear 17 that meshes with the first bevel gear 15 and rotates, and two

spur gears

18 and 18 fixed to both ends of the rotating shaft 16.

On the lower surface of the strip-shaped member 30, a large number of

teeth

301, 301, ... Are formed at equal intervals along the width direction orthogonal to the longitudinal direction. As illustrated in FIG. 3, the

teeth

301, 301, ... Of the strip-shaped member 30 mesh with the spur gear 18 of the transmission mechanism 14 to form a so-called rack and pinion mechanism. The transmission mechanism 14 having such a structure converts the forward / reverse rotary motion of the rotary motor 13 into a linear motion of feeding and pulling in the band-shaped member 30.

The controller 12 that drives and controls the rotary motor 13 controls the rotation of the rotary motor 13 based on, for example, the myoelectric potentials detected by the

myoelectric sensors

19 and 19. For example, the myoelectric sensor 19 can detect the myoelectric potential generated in the muscle when the wearer tries to move the finger, and can control the finger to assist the bending and stretching movement of the finger corresponding to the detected muscle. Further, the rotary motor 13 may be controlled via an operation input unit (not shown) such as a joystick to manually operate the bending / stretching direction and the bending / stretching speed of the finger.

The drive unit 11 is not limited to the embodiment shown in FIGS. 2 and 3 as long as it reciprocates the strip-shaped member 30 in the longitudinal direction. Further, in the present embodiment, one rotary motor 13 in the drive unit 11 assists the bending and stretching of two fingers, but one rotary motor 13 drives one strip-shaped member 30 to bend and stretch each finger. May be configured to independently assist. Further, although not shown, the transmission mechanism 14 may include a speed reducer or a torque limiter.

Next, the configuration of the exoskeleton body 20 attached to the back side of the finger will be described. The exoskeleton body 20 has a plurality of

external joints

21, 21, ... Corresponding to each finger as described above. The outer joints 21, 2, 1, ... For each finger have the same structure except for the dimensions. Therefore, here, the outer joints for assisting the bending and stretching of the index finger (second finger) are represented here. The structure of the joint 21 will be described in detail. FIG. 4 is a side view of the outer joint 21 when the index finger is extended, and FIG. 5 is a side view of the outer joint 21 when the finger is bent.

The band-shaped member 30 provided on the outer joint 21 is a member having a length and width that can be arranged so as to extend along the back of the fingers of the hand and having flexibility in the longitudinal direction thereof. Here, "having flexibility" means that the strip-shaped member 30 has a flexural modulus and a moment of inertia of area that are small enough to allow the deflection (bending deformation amount) generated by the gripping motion of the wearer. Means that. Further, the band-shaped member 30 has a rigidity that does not buckle with respect to the maximum compressive force output by the drive unit 11 when assisting the bending operation of the finger. Such a strip-shaped member 30 can be manufactured of a synthetic resin or a metal plate-shaped material, but it is preferable to include a synthetic resin from the viewpoint of weight reduction. As such a synthetic resin, for example, polyethylene, polypropylene, polystyrene, epoxy resin and the like can be used. Further, a fiber-reinforced plastic obtained by impregnating glass fibers or carbon fibers with an epoxy resin, a phenol resin or the like, or a composite material in which a metal fiber or a wire is coated with a synthetic resin may be used as the material of the band-shaped member 30.

As illustrated in FIGS. 6A and 6B, teeth (rack gears) 301, 301, ... Are formed on the lower surface of the strip-shaped member 30 at equal intervals. The arrangement of the

teeth

301, 301, ... May be formed over a length region from the base end of the band-shaped member 30, that is, the rear end on the side where the drive unit 11 is located to the position corresponding to the moving stroke. Further, a groove portion 30a that engages with the guide hole 601 of the rotation support member 60 and the guide hole 421 of the second support member 42, which will be described later, may be formed on the upper surface of the strip-shaped member 30 along the longitudinal direction.

The first support member 41 is fixed to the tip of the band-shaped member 30. As the material of the first support member 41, a relatively hard synthetic resin or light metal can be used. A first annular holding member 51 for inserting and holding the wearer's fingertip side is connected to the lower part of the first support member 41. As the material of the first annular holding member 51, the same hard synthetic resin as the first support member 41 can be used. However, the first annular holding member 51 may be an elastic ring or a fibrous belt having tensile strength as long as it can hold a finger.

As shown in FIG. 7, it is preferable that the first annular holding member 51 is rotatably connected to the first support member 41 around the radial connection shaft portion 51a. As a result, the degree of freedom of lateral movement of the finger held by the ring 52 is ensured, and an unnecessary feeling of binding can be reduced.

Further, it is preferable that the first annular holding member 51 is removable from the lower part of the first support member 41. As shown in FIG. 7, the lower portion of the first support member 41 is a

split plate portion

411a, 412a that can be opened and closed with each other. A notch hole 413 for rotatably engaging the constricted portion 51b of the connecting shaft portion 51a of the first annular holding member 51 is formed in a portion where the two

split plate portions

411a and 412a are in opposite contact with each other.

The upper parts of the

split plate portions

411a and 412a are the

pressing bars

411b and 412b. The

pressing bars

411b and 412b are urged by the

springs

414 and 414 inside the first support member 41 in a direction in which the

split plate portions

411a and 412a are always closed. By pressing the

pressing bars

411b and 412b inward against the elastic rebound force of the

springs

414 and 414, the

split plate portions

411a and 412a are opened and the connecting shaft portion 51a of the first annular holding member 51 is first supported. It can be removed from the lower part of the member 41. Further, by pushing the connecting shaft portion 51a having the taper 51c at the tip portion into the notch hole 413, the

split plate portions

411a and 412a are expanded, and the first annular holding member 51 is easily connected to the first supporting member 41. be able to.

By making the first annular holding member 51 detachable from the first supporting member 41 in this way, the first supporting member 41 can be connected after passing the finger through the first annular holding member 51 in advance, and thus the finger movement assist. The device 1 can be easily attached to the hand.

The outer joint 21 also includes a second support member 42 that slidably supports the band-shaped member 30 between the back carapace member 10 and the first support member 41. As shown in FIG. 8, the second support member 42 is formed with a guide hole 421 through which the strip-shaped member 30 is inserted so as to be slidable in the front-rear direction. The guide hole 421 is formed with a protrusion 421a for engaging the groove 30a on the upper surface of the strip-shaped member 30 and guiding the movement thereof.

The second support member 42 is rotatably connected to the back member 10 in the vertical direction in which the fingers bend and stretch. As the material of the second support member 42, for example, a hard synthetic resin or a light metal can be used as in the case of the first support member 41 described above.

A second annular holding member 52 for inserting and holding the base side of the wearer's finger is connected to the lower part of the second support member 42. As the material of the second annular holding member 52, an elastomer, a fiber material, or the like can be used in addition to the hard synthetic resin as in the case of the first annular holding member 51 described above.

It is preferable that the second annular holding member 52 is rotatably connected to the second support member 42 around the connecting shaft portion 52a in the radial direction thereof. Further, it is preferable that the second annular holding member 52 is detachable from the lower part of the second support member 42, similarly to the structure of the connecting portion illustrated in FIG. 7. Thereby, the wearer can connect the second support member 42 after passing the finger through the second annular holding member 52 in advance, whereby the finger movement assisting device 1 can be easily attached to the hand.

The finger movement assisting device 1 according to the present embodiment includes a rotation support member 60 that operates in cooperation with

external joints

21, 21, ... That assist the bending and stretching of four fingers other than the thumb (FIG. 9). reference). The rotation support member 60 is a thick plate-shaped member, and can be integrally molded with a hard synthetic resin, a light metal, or the like. The rotation support member 60 has limb portions 602 extending downward from its left and right ends, and each limb portion 602 can rotate to a bracket portion 101 projecting forward from the left and right ends of the back carapace member 10. It is pivotally supported by.

Further, the second support member 42 of each outer joint 21 and the rotation support member 60 are connected by a rod-shaped connecting portion 603 extending forward from the lower portion of the rotation support member 60. That is, each second support member 42 is connected and supported to the rotation support member 60 in front of the rotation support member 60.

As shown in FIG. 9, the rotation support member 60 is formed through four guide holes 601 for inserting the band-shaped member 30 of each outer joint 21 so as to be slidable in the front-rear direction. The guide hole 601 is formed with a protrusion 601a for engaging the groove portion 30a on the upper surface of the strip-shaped member 30 and guiding the movement thereof.

As described above, in the exoskeleton body 20 of the present embodiment, the second support member 42 of each outer joint 21 rotates with respect to the back carapace member 10 in the bending / stretching direction of the finger via the rotation support member 60. The strip-shaped member 30 is freely connected and is inserted into the guide hole 601 of the rotation support member 60 and the guide hole 421 of the second support member 42, so that the strip-shaped member 30 is a predetermined distance from the back of the finger. It has a structure that is supported only at a distance. That is, the distance between the band-shaped member 30 and the finger gradually increases from the fingertip to the base depending on the height positions of the guide hole 601 and the guide hole 421 (see FIGS. 4 and 5).

In this way, the height peak position of the band-shaped member 30 supported by the rotation support member 60 is moved forward, and the band-shaped member 30 is extended from above toward the fingertips to form an endoskeleton. The assisting force of bending the finger according to the movement of the knuckle can be maximized (see FIG. 5). On the contrary, since the band-shaped member 30 has a structure in which the height peak position of the band-shaped member 30 is moved backward and the band-shaped member 30 is pulled upward from the fingertip, tension or warp or the like is formed when assisting the extension of the finger. It is possible to prevent such an undesired discomfort from occurring (see FIG. 4). Therefore, a smooth and good cooperative operation can be realized between the exoskeleton body 20 and the knuckle joint which is the endoskeleton. Further, since the band-shaped member 30 that transmits the bending / stretching assisting force does not have a link or a joint, the structure of the finger movement assisting device 1 can be simplified and the manufacturing cost can be suppressed.

Further, it is preferable that the outer joint 21 is provided with a link mechanism portion 70 that connects the first support member 41 and the second support member 42 so as to be mutually rotatable. Here, FIG. 10 is a side view of the link mechanism unit 70 according to one embodiment, FIG. 11 is an exploded perspective view of the link mechanism unit 70, and FIGS. 12A and 12B are for explaining the operation of the link mechanism unit 70. It is a perspective view of.

The link mechanism portion 70 includes a hook 71 fixed to the first support member 41 and a sheath 72 fixed to the second support member 42. These hook 71 and sheath 72 are manufactured by, for example, sheet metal stamping. The hook 71 includes a straight portion 71a extending rearward from the first support member 41 and a folded portion 71b folded diagonally downward from the end of the straight portion 71a. The sheath 72 has a form extending diagonally forward and downward from the second support member 42, and a housing portion 72a that can be accommodated is formed so that the folded portion 71b of the hook 71 overlaps the side surface. The tip of the folded portion 71b of the hook 71 and the tip of the sheath 72 are rotatably and pivotally supported by the rivet pin 73.

With such a link mechanism portion 70, the mutual rotation center between the first support member 41 and the second support member 42 can be deviated to the side where the knuckles are located. The center of rotation of the link mechanism portion 70 preferably coincides with the joint axis of the finger, which is the endoskeleton, as much as possible. Thereby, the distance between the first support member 41 and the second support member 42 and their mutual rotation loci can be adapted to the bending and stretching motion of the knuckle, and thus the exoskeleton body 20 and the knuckle can be smoothly connected to each other. The cooperative operation can be further improved.

The present invention is applied to a hand movement assisting system in which a driving unit 11 for driving a band-shaped member 30 is arranged on the forearm side of the back member 10 of the hand to assist the movements of the wrist joint and the finger joint at the same time. May be applied.

1 Finger movement assist device 10 Back member 11 Drive unit 12 Controller 13 Rotating motor 14 Transmission mechanism 15 Bevel gear 16 Rotating shaft 17 Bevel gear 18 Spur gear (pinion gear)
20 Exoskeleton body 21 Exoskeleton 30 Belt-shaped member 41 First support member 42 Second support member 51 First annular holding member 51a Connection shaft 52 Second annular holding member 52a Connection shaft 60 Rotational support member 70 Link mechanism 71 Hook 72 sheath
101 Bracket 301 teeth (rack gear)
421 Guide hole 601 Guide hole 603 Connection

Claims

It is a finger movement assisting device for assisting the bending and stretching movement of the finger.
The back member attached to the back of the wearer's hand,
A band-shaped member arranged so as to extend along the back of the finger and having flexibility,
A drive unit that drives the strip-shaped member to reciprocate in the longitudinal direction thereof,
A first support member provided at the tip of the band-shaped member and
A first annular holding member that is connected to the first support member and holds a portion of the finger on the fingertip side.
A second support member that is rotatably connected to the back carapace member in the bending / stretching direction of the finger while the band-shaped member is inserted and supported.
A finger movement assisting device including a second annular holding member connected to the second supporting member and holding a portion on the base side of the finger with respect to the first annular holding member.
A rotary support member that is rotatably pivotally supported by the carapace member and connects and supports the second support member is further provided.
The finger movement assisting device according to claim 1, wherein the band-shaped member is supported by being inserted into the second support member so as to be separated from the back of the finger by a predetermined distance.
The finger movement assisting device according to claim 1 or 2, wherein the first annular holding member is removable from the first support member, and the second annular holding member is removable from the second support member. ..
The first annular holding member is rotatably connected to the first support member about one axis in the radial direction, and the second annular holding member is rotatably connected to the second support member around one axis in the radial direction. The finger movement assisting device according to any one of claims 1 to 3, which is rotatably connected.
A link mechanism portion that rotatably connects the first support member and the second support member to each other, and the center of rotation between the first support member and the second support member is on the joint side of the finger. The finger movement assisting device according to any one of claims 1 to 4, further comprising a link mechanism portion biased to.