Finger movement assistance device

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

Technical Field

[0001] The present invention relates to a finger movement assisting device for assisting the bending and stretching movements of fingers.

Background Art

[0002] For the purpose of rehabilitation and daily life assistance for patients with paralysis in the hand due to cerebrovascular disorders, brain injuries, etc., a finger movement assisting device has been proposed that is worn on the back of the fingers of the hand to assist the bending and stretching movements of the fingers (see, for example, Patent Document 1). The finger movement assisting device of Patent Document 1 has a multi-joint link train structure in which a plurality of link members are connected in a row, and the link train bends by controlling the lengths of two linear members extending from the base end portion to the tip end portion with a motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the conventional finger movement assisting device described above, in order to obtain a smooth cooperative movement with the three joints (DIP joint, PIP joint, and MP joint) that constitute the inner skeleton of the finger, it is necessary to make the joint pitch of the link train as short as possible. Therefore, the number of parts increases and the structure becomes complicated. In addition, the linear member that transmits the force for bending the link train may buckle when a large compressive force acts, and there is a limit, for example, in the assisting force when grasping an object.

[0005] The present invention has been made in view of such conventional problems, and an object thereof is to provide a finger movement assisting device that has a simple structure and enables good cooperative movement with finger joints.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides a finger movement assisting device for assisting the bending and stretching movements of fingers, comprising a back plate member to be worn on the back of the hand of the wearer, a belt-like member arranged to extend along the back of the finger and having flexibility, a driving unit for driving the belt-like member to reciprocate in its longitudinal direction, a first support member provided at the tip of the belt-like member, a first annular holding member connected to the first support member and holding the portion on the fingertip side of the finger, a second support member for inserting and supporting the belt-like member and rotatably connected to the back plate member in the bending and stretching direction of the finger, and a second annular holding member connected to the second support member and holding the portion closer to the base of the finger than the first annular holding member.

[0007] Preferably, the finger movement assisting device further comprises a rotation support member pivotally supported on the back plate member and connecting and supporting the second support member, and the belt-like member is inserted through the second support member and supported at a predetermined distance from the back of the finger.

[0008] Also preferably, in the finger movement assisting device, the first annular holding member is detachable from the first support member, and the second annular holding member is detachable from the second support member.

[0009] Also preferably, in the finger movement assisting device, the first annular holding member is rotatably connected to the first support member around a single axis in the radial direction, and the second annular holding member is rotatably connected to the second support member around a single axis in the radial direction.

[0010] Also preferably, the finger movement assisting device further comprises a link mechanism portion for rotatably connecting the first support member and the second support member to each other, and the link mechanism portion has a rotation center between the first support member and the second support member biased toward the joint side of the finger.

Advantages of the Invention

[0011] According to the finger movement assisting device of the present invention, smooth and good coordinated movement can be achieved between the exoskeleton body that assists the bending and straightening of the finger and the finger joints that are the endoskeletons. Further, since the belt-like member that transmits the bending and straightening assisting force does not have links or joints, the structure can be simplified and the manufacturing cost can be suppressed.

Brief Description of the Drawings

[0012]

Figure 1

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Figure 12B

Mode for Carrying Out the Invention

[0013] 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. Also, unless otherwise specified, "upper" refers to the dorsal side of the finger, and "lower" refers to the ventral side of the finger.

[0014] FIG. 1 is an external perspective view of a finger movement assisting device 1 according to an embodiment of the present invention. The finger movement assisting device 1 of the present embodiment includes a dorsal member 10 that is worn in contact with the back of the wearer's hand, a drive unit 11 provided on the dorsal member 10, and an exoskeleton body 20 driven by the drive unit 11. Further, the exoskeleton body 20 is worn on the dorsal side of each finger of the wearer and includes outer joints 21, 21,... that assist the bending and extending movements of each finger.

[0015] First, the dorsal member 10 is a plate-shaped member formed in a shape following the back of a human hand, and can be integrally molded, for example, from a relatively hard general-purpose synthetic resin material such as polypropylene, polystyrene, or ABS resin. Also, the dorsal member 10 may be manufactured from light metal or a composite material of metal and synthetic resin. Further, a cushion layer such as urethane foam may be provided on the inner surface of the dorsal member 10 to enhance the adhesion to the back of the wearer's hand. Mounting members such as straps, belts, or gloves (not shown) for winding and wearing the finger movement assisting device 1 on the hand are provided at both ends of the dorsal member 10. Such a mounting member preferably has a detachable part such as a hook-and-loop fastener or a one-touch buckle.

[0016] Drive units 11, 11 for driving a belt-like member 30, which will be described later, to reciprocate back and forth in the longitudinal direction are provided on the outer surface of the dorsal member 10. Here, FIG. 2 is a diagram for exemplarily explaining the configuration of the drive unit 11. As shown in the figure, the drive unit 11 includes a controller 12, an electric rotary motor 13 whose torque and rotational speed are controlled by the controller 12, and a transmission mechanism 14 that transmits the torque output by the rotary motor 13 to two belt-like members (shown by broken lines) 30, 30.

[0017] Specifically, for example, the transmission mechanism 14 includes 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 second bevel gear 17 fixed to an intermediate portion of the rotary shaft 16 and meshing with the first bevel gear 15 of the rotary motor 13 to rotate, and two spur gears 18, 18 fixed to both ends of the rotary shaft 16.

[0018] On the lower surface of the belt-like 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 belt-like member 30 mesh with the spur gears 18 of the transmission mechanism 14, thereby constituting a so-called rack and pinion mechanism. With the transmission mechanism 14 having such a structure, the forward and reverse rotational motion of the rotary motor 13 is converted into a linear motion for feeding out and pulling in the belt-like member 30.

[0019] The controller 12 for driving and controlling 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, 19. For example, when the wearer tries to move a finger, the myoelectric sensor 19 detects the myoelectric potential generated in the muscle, and can control to assist the flexion and extension motion 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 flexion and extension direction and flexion and extension speed of the finger.

[0020] Note that the drive unit 11 is not limited to the embodiment shown in FIGS. 2 and 3 as long as it reciprocally drives the belt-like member 30 in the longitudinal direction. Further, in this embodiment, one rotary motor 13 in the drive unit 11 assists the flexion and extension of two fingers, but a configuration may be adopted in which one rotary motor 13 drives one belt-like member 30 to independently assist the flexion and extension motions of each finger. Further, although not shown, the transmission mechanism 14 may be provided with a speed reducer or a torque limiter.

[0021] Next, the configuration of the exoskeleton body 20 worn on the back side of the finger will be described. As described above, the exoskeleton body 20 has a plurality of outer joints 21, 21, ··· corresponding to each finger. Since the outer joints 21, 21, ··· for each finger have the same structure except for different dimensions, here, the structure of the outer joint 21 for assisting the flexion and extension of the index finger (second finger) will be described in detail as a representative. 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.

[0022] The belt-like member 30 provided in the outer joint 21 has a length and width that can be arranged to extend along the back of the finger of the hand, and is a member having flexibility in its longitudinal direction. Here, "having flexibility" means that the belt-like member 30 has a bending elastic modulus and a second moment of cross-section that are small enough to allow the deflection (amount of bending deformation) generated with the gripping motion of the wearer. Further, the belt-like 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 motion of the finger. Such a belt-like member 30 can be manufactured from a plate-like material of synthetic resin or metal, but it is preferably made to contain synthetic resin from the viewpoint of weight reduction. As such a synthetic resin, for example, polyethylene, polypropylene, polystyrene, or epoxy resin can be used. Also, a fiber-reinforced plastic in which glass fiber or carbon fiber is impregnated with epoxy resin or phenolic resin, or a composite material in which metal fiber or wire is coated with synthetic resin may be used as the material of the belt-like member 30.

[0023] As illustrated in FIGS. 6A and 6B, teeth (rack gears) 301, 301, ··· orthogonal to the longitudinal direction are formed at equal interval pitches on the lower surface of the belt-like member 30. Note that the arrangement of the teeth 301, 301, ··· may be formed over a length region from the proximal end of the belt-like member 30, that is, the rear end on the side where the drive unit 11 is located, to a position corresponding to the movement stroke. Also, 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 along the longitudinal direction on the upper surface of the belt-like member 30.

[0024] A first support member 41 is fixed to the tip of the strip 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 fingertip side of the wearer is connected to the lower part of the first support member 41. As the material of the first annular holding member 51, a hard synthetic resin similar to that of the first support member 41 can be used. However, as long as it can hold the finger, the first annular holding member 51 may be an elastic ring or a fibrous belt having tensile strength.

[0025] 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 connecting shaft portion 51a in the radial direction thereof. Thereby, the degree of freedom of the lateral movement of the finger held by the ring 52 is ensured, and an unnecessary sense of restraint can be reduced.

[0026] Also, it is preferable that the first annular holding member 51 is detachable from the lower part of the first support member 41. As shown in Fig. 7, the lower part of the first support member 41 is formed by split plate portions 411a and 412a that can be opened and closed with respect to 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 at the portion where these two split plate portions 411a and 412a come into contact with each other.

[0027] The upper parts of the split plate portions 411a and 412a are formed as pressing bars 411b and 412b. The pressing bars 411b and 412b are biased by springs 414 and 414 inside the first support member 41 in the 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 repulsive force of the springs 414 and 414, the split plate portions 411a and 412a can be opened, and the connecting shaft portion 51a of the first annular holding member 51 can be removed from the lower part of the first support member 41. Also, by pushing the connecting shaft portion 51a having a taper 51c at the tip into the notch hole 413, the split plate portions 411a and 412a are pushed apart, and the first annular holding member 51 can be easily connected to the first support member 41.

[0028] In this way, by making the first annular holding member 51 detachable from the first support member 41, the first support member 41 can be connected after passing a finger through the first annular holding member 51 in advance. Therefore, the attachment of the finger movement assisting device 1 to the hand can be facilitated.

[0029] The outer joint 21 also includes a second support member 42 that slidably supports the belt-like member 30 between the carapace member 10 and the first support member 41. As shown in FIG. 8, a guide hole 421 for inserting the belt-like member 30 and making it slidable in the front-rear direction is formed through the second support member 42. A protrusion 421a for engaging with the groove 30a on the upper surface of the belt-like member 30 and guiding its movement is formed in the guide hole 421.

[0030] The second support member 42 is rotatably connected to the carapace member 10 in the vertical direction in which the finger bends and extends. As the material of the second support member 42, similar to the above-described first support member 41, for example, a hard synthetic resin or a light metal can be used.

[0031] A second annular holding member 52 for inserting and holding the root 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, in addition to the hard synthetic resin similar to the above-described first annular holding member 51, an elastomer or a fiber material can be used.

[0032] The second annular holding member 52 is preferably rotatably connected to the second support member 42 around the connecting shaft portion 52a in the radial direction. Further, the second annular holding member 52 is preferably detachable from the lower part of the second support member 42, similar to the structure of the connecting portion illustrated in FIG. 7. Thereby, the wearer can connect the second support member 42 after passing a finger through the second annular holding member 52 in advance, thereby facilitating the attachment of the finger movement assisting device 1 to the hand.

[0033] Note that the finger movement assist device 1 according to the present embodiment includes a rotation support member 60 that operates in cooperation with the outer joints 21, 21, ··· that assist the flexion and extension of the four fingers excluding the thumb (see FIG. 9). The rotation support member 60 is a plate-like member with a certain thickness and can be integrally formed of 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 is rotatably supported by a bracket portion 101 protruding forward from the left and right ends of the carapace member 10.

[0034] 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 part of the rotation support member 60. That is, each second support member 42 is connected and supported by the rotation support member 60 in front of the rotation support member 60.

[0035] As shown in FIG. 9, four guide holes 601 are formed through the rotation support member 60 for inserting the belt-like members 30 of the respective outer joints 21 so as to be slidable in the front-rear direction. Protrusion portions 601a are formed in the guide holes 601 to engage with the groove portions 30a on the upper surface of the belt-like members 30 and guide their movement.

[0036] As described above, in the exoskeleton body 20 of the present embodiment, the second support member 42 of each outer joint 21 is rotatably connected to the carapace member 10 in the finger flexion and extension direction via the rotation support member 60, and the belt-like member 30 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 belt-like member 30 is supported at a predetermined distance from the back of the finger. That is, the distance between the belt-like member 30 and the finger gradually increases from the fingertip to the root according to the height positions of the guide hole 601 and the guide hole 421 (see FIGS. 4 and 5).

[0037] In this way, by adopting a structure in which the height peak position of the belt-like member 30 supported by the rotation support member 60 is moved forward and the belt-like member 30 is fed out from above toward the fingertips, it is possible to maximize the assisting force for bending the finger in accordance with the movement of the finger joints which are the internal skeleton (see FIG. 5). Conversely, since it is also a structure in which the belt-like member 30 is drawn in from the fingertips upward while moving the height peak position of the belt-like member 30 backward, it is possible to prevent undesirable discomfort such as tension and warping from occurring when assisting the extension of the finger (see FIG. 4). Therefore, smooth and good coordinated operation can be realized between the outer skeleton body 20 and the finger joints which are the internal skeleton. Further, since the belt-like member 30 for transmitting the flexion / extension assisting force does not have links or joints, the structure of the finger movement assisting device 1 can be simplified, and the manufacturing cost can be suppressed.

[0038] Furthermore, it is preferable that the outer joint 21 includes a link mechanism portion 70 that rotatably connects the first support member 41 and the second support member 42 to each other. Here, FIG. 10 is a side view of the link mechanism portion 70 according to an embodiment, FIG. 11 is an exploded perspective view of the link mechanism portion 70, and FIGS. 12A and 12B are perspective views for explaining the operation of the link mechanism portion 70.

[0039] The link mechanism portion 70 is configured to include 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, for example, by sheet metal pressing. The hook 71 includes a straight portion 71a extending rearward from the first support member 41 and a folded-back portion 71b folded obliquely downward from the end of the straight portion 71a. The sheath 72 has a form extending obliquely forward and downward from the second support member 42, and a housing portion 72a capable of housing the folded-back portion 71b of the hook 71 so as to overlap on the side surface is formed. Then, the tip of the folded-back portion 71b of the hook 71 and the tip of the sheath 72 are pivotally supported by a rivet pin 73 so as to be rotatable.

[0040] 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 biased toward the side where the finger joint is located. And it is preferable that the rotation center of the link mechanism portion 70 coincides as much as possible with the finger joint axis which is the inner skeleton. Thereby, the distance between the first support member 41 and the second support member 42 and their mutual rotation locus can be adapted to the flexion and extension movement of the finger joint, and thus the smooth cooperative movement between the outer skeleton body 20 and the finger joint can be further improved.

[0041] In addition, the present invention may be applied to a hand movement assistance system configured to arrange a drive unit 11 for driving the belt-like member 30 on the forearm side rather than the carapace member 10 of the hand so as to assist the movements of the wrist joint and the finger joint simultaneously.

Explanation of Reference Numerals

[0042] 1 Finger movement assistance device 10 Carapace member 11 Drive unit 12 Controller 13 Rotation motor 14 Transmission mechanism 15 Bevel gear 16 Rotation shaft 17 Bevel gear 18 Spur gear (pinion gear) 20 Outer skeleton body 21 Outer joint 30 Belt-like member 41 First support member 42 Second support member 51 First annular holding member 51a Connection shaft portion 52 Second annular holding member 52a Connection shaft portion 60 Rotation support member 70 Link mechanism portion 71 Hook 72 Sheath 101 Bracket portion 301 Tooth (rack gear) 421 Guide hole 601 Guide hole 603 Connection part

Claims

1. A finger movement assisting device for assisting the bending and stretching movement of a finger, comprising: a back plate member worn on the back of the wearer's hand; a belt-shaped member arranged to extend along the back of the finger and having flexibility; a driving unit for driving the belt-shaped member to reciprocate in its longitudinal direction; a first support member provided at the tip of the belt-shaped member; a first annular holding member connected to the first support member and holding the portion on the fingertip side of the finger; a second support member that supports the belt-shaped member by inserting it therethrough and is rotatably connected to the back plate member in the bending and stretching direction of the finger; a second annular holding member connected to the second support member and holding the portion closer to the base of the finger than the first annular holding member; the lower part of the first support member is composed of two split plate parts that can be opened and closed with respect to each other; a notch hole is formed at the portion where the split plate parts come into contact with each other for rotatably engaging the constricted portion of the connecting shaft portion of the second annular holding member; the pressing bar at the upper part of the split plate part is biased by a spring inside the first support member in a direction in which the split plate part is always closed; by pressing the pressing bar inward against the elastic repulsive force of the spring, the split plate part can be opened and the connecting shaft portion can be removed from the lower part of the first support member; a finger movement assisting device capable of connecting the first annular holding member to the first support member by pushing the connecting shaft portion having a taper at its tip into the notch hole, thereby spreading the split plate part.

2. A finger movement assisting device for assisting the bending and stretching movement of a finger, comprising: a back plate member worn on the back of the wearer's hand; a belt-shaped member arranged to extend along the back of the finger and having flexibility; a driving unit for driving the belt-shaped member to reciprocate in its longitudinal direction; a first support member provided at the tip of the belt-shaped member; a first annular holding member connected to the first support member and holding the portion on the fingertip side of the finger; a second support member that supports the belt-shaped member by inserting it therethrough and is rotatably connected to the back plate member in the bending and stretching direction of the finger; a second annular holding member connected to the second support member and holding the portion closer to the base of the finger than the first annular holding member; a link mechanism portion that rotatably connects the first support member and the second support member to each other, and includes a hook connected to the first support member via a straight portion and a sheath connected to the second support member. The hook has a folded-back portion that is folded back from the end of the straight portion. The folded-back portion and the sheath are pivotally supported by a rivet pin so as to be rotatable. A finger movement assisting device that biases the rotation center between the first support member and the second support member toward the joint side of the finger. **Claim 3** Further comprising a rotation support member that is pivotally supported by the carapace member and connects and supports the second support member. The finger movement assisting device according to claim 1 or 2, wherein the belt-like member is inserted through the second support member and is supported at a predetermined distance from the back of the finger. **Claim 4** The finger movement assisting device according to claim 1 or 2, wherein the first annular holding member is rotatably connected to the first support member around a single axis in the radial direction thereof, and the second annular holding member is rotatably connected to the second support member around a single axis in the radial direction thereof.

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