JP2019136225A - Active prosthetic hand - Google Patents

Abstract

To provide an active prosthetic hand that contributes to improvement of life convenience of a prosthetic hand user, has a simple structure, and is lightweight and inexpensive.SOLUTION: An active prosthetic hand includes: a base with a fixation finger fixed thereto; a holder rotatably provided to the base and having a user's arm inserted therein; a movable finger provided at the tip side from the fixed finger; a cylindrical elastic member provided at the position between the fixed finger and the movable finger, and being stretchable; a hinge provided in parallel with the elastic member, the hinge that couples the fixed finger with the movable finger in a turning manner between an elongation position and a bending position; and a drive with a working fluid stored inside, the drive that sends the working fluid into the elastic member by pressurizing the working fluid using the rotational motion of the holder, and makes the elastic member extend so as to turn around the hinge, and thereby brings it from the elongation position to the bending position.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an active prosthesis that is used by an upper limb amputee.

  There are approximately 82,000 amputees in Japan. Most upper limb amputees use decorative hands. There are some decorative prosthetic hands that have a high decorativeness that does not seem strange to the eye, but the user cannot actively move them. On the other hand, the myoelectric prosthetic hand can actively move the finger using the myoelectric potential of the user's muscle. For this reason, although a user can hold an object by using a myoelectric prosthesis, there are many problems such as requiring training.

JP, 2006-67636, A

  As described above, the decorative prosthetic hand cannot hold the object and does not contribute to the improvement of the user's life convenience. Myoelectric prostheses have problems such as weight, cost, public system, and lack of training facilities, and are currently not widely used in society. For this reason, the demand and supply do not match while the prosthetic hand user is seeking a lightweight and inexpensive prosthetic hand.

  An object of the present invention is to provide an active prosthetic hand that has a simple structure, is lightweight, and is inexpensive, which contributes to the improvement of the life convenience of the prosthetic hand user.

  An active prosthetic hand according to an aspect of the present invention includes a base portion to which a fixed finger is fixed, a holder portion that is rotatably provided to the base portion and into which a user's arm is inserted, and a distal end than the fixed finger. A movable finger provided on the side, a tubular elastic member provided at a position between the fixed finger and the movable finger, and an extendable / contractible member, and a hinge portion provided in parallel with the elastic member, Rotation is performed between an extended position where the extending direction of the fixed finger and the extending direction of the movable finger are substantially parallel and a bending position where the extending direction of the movable finger intersects the extending direction of the fixed finger. A hinge part that movably connects the fixed finger and the movable finger, and a drive part in which a working fluid is stored, and pressurizing the working fluid using a rotational movement of the holder part, The working fluid is sent into the telescopic member and the hinge The elastic member is extended so as to pivot about, and a drive unit for the bending position from the extended position.

FIG. 1 is a schematic diagram illustrating the overall configuration of an active prosthesis according to the embodiment. FIG. 2 is a perspective view showing a state in which the active prosthesis shown in FIG. 1 is worn on the user. FIG. 3 is an enlarged perspective view of the active prosthetic hand driving unit and the finger unit shown in FIG. FIG. 4 is a schematic diagram schematically showing power transmission of the active prosthetic hand shown in FIG. FIG. 5 is an enlarged cross-sectional view showing the inside of the active prosthetic hand stretchable member and the hinge portion shown in FIG. 1 in an enlarged manner by cutting the stretchable member along a plane passing through its axis. FIG. 6 is a graph showing the relationship between the turning angle α of the holder portion and the pressure P inside the elastic member in an unloaded state. FIG. 7 is a graph showing the relationship between the extrapolation angle α and the angle θ formed by the hinge portion (see FIG. 5) in a no-load state. FIG. 8 is a graph showing the relationship between the turning angle α of the holder part and the pressure P inside the elastic member in the loaded state. FIG. 9 is a graph showing the relationship between the extrapolation angular velocity ω and the movable fingertip velocity v. FIG. 10 is a graph showing how the outside angle α and the pressure P inside the expansion / contraction member change with time. FIG. 11 is a schematic diagram schematically showing the second elastic member and the third elastic member according to the first modification. FIG. 12 is a perspective view showing a third band member, a flat plate portion, and a second elastic member according to the first modification shown in FIG. FIG. 13 is a perspective view showing a state where the third band member, the flat plate portion, and the second elastic member are attached to the upper arm of the user. FIG. 14 is a graph showing the relationship between the turning angle α of the holder portion and the measured value of the force applied from the third elastic member to the user's arm over time. FIG. 15 is a schematic view showing a holder portion, a conversion mechanism, and a piston rod of an active prosthetic hand according to a second modification. FIG. 16 is a schematic diagram showing the overall configuration of the active prosthetic hand of the third modified example. FIG. 17 is a schematic diagram schematically showing power transmission of the active prosthetic hand shown in FIG. FIG. 18 is an enlarged schematic view showing the vicinity of the holder portion, the finger portion, and the pump portion of the active prosthetic hand according to the fourth modified example. FIG. 19 is a schematic sectional view taken along the line F19-F19 in FIG. FIG. 20 is an enlarged schematic view showing the vicinity of the holder portion and pump portion (first fixing portion, second fixing portion, tube) of the active prosthesis of the fifth modification.

  Hereinafter, an embodiment of an active prosthetic hand will be described with reference to the drawings. The active prosthetic hand of the following embodiment is a type of prosthetic hand that does not use an electric power source such as a motor or a solenoid and an external power source such as a compressor, and can move the finger part in a non-electrical manner that can manually rotate the finger part. It is. Moreover, the following active prosthetic hand is a prosthetic hand used mainly for a patient having a cut stump in the forearm.

[First embodiment]
A first embodiment of an active prosthesis will be described with reference to FIGS. As shown in FIGS. 1 and 2, the active prosthesis 11 includes a base portion 12 having a plate shape bent in an L-shaped cross section, a finger portion 13 attached to the distal end side of the base portion 12, and a base portion 12. A second finger portion 14 attached to the distal end side, a drive portion 15 fixed to the base portion 12, and a holder portion 17 into which the distal end portion of the user's arm 16 (remaining limb) is inserted. The rotating shaft 18 that rotatably supports the holder portion 17 and the socket portion 21 for fixing the active prosthetic hand 11 to the user's arm 16 are provided.

  As shown in FIG. 3, the base portion 12 includes a first plate 22 that extends in a direction parallel to the axial direction of the user's arm 16 (the direction in which the finger portion 13 extends), and the axial direction of the user's arm 16. It has the 2nd board 23 extended in the direction which cross | intersects, and the 3rd board 24 for reinforcement straddling the 1st board 22 and the 2nd board 23. The base portion 12 has an “L” shape by the first plate 22 and the second plate 23. The first plate 22, the second plate 23, and the third plate 24 are integrally formed. The second plate 23 has a through hole 25 through which a rotation shaft 18 of the holder portion 17 described later is passed. The third plate 24 has a triangular shape.

  The drive unit 15 drives the turning operation of the finger unit 13. The drive unit 15 includes a cylindrical pump unit 26 provided integrally with the base unit 12, a piston rod 27 inserted inside the pump unit 26, and the holder unit 17 and the piston rod 27. It has an intervening conversion mechanism 28, and a feed pipe 32 connecting the pump part 26 and the elastic member 31 of the finger part 13.

  As shown in FIGS. 3 and 4, the pump part 26 is integrally formed with the outer shell part 33 formed in a cylindrical shape, a hollow bellows 34 housed inside the outer shell part 33, and the outer shell part 33. And a reinforcing rib 35 fixed to the base portion 12. The outer shell portion 33 has a boss 36 for supporting the rotating shaft 18 of the holder portion 17. The boss 36 is provided with a second through-hole 37 extending in the axial direction of the user's arm 16 (direction parallel to the piston rod 27). The rotation shaft 18 is passed through the second through hole 37. As will be described later, the pump unit 26 is three-dimensionally formed integrally with the base unit 12 by 3D printing. However, the pump unit 26 may have a structure that can be attached to and detached from the base unit 12 with, for example, a screw. The reinforcing rib 35 is provided integrally with the end portion of the outer shell portion 33 of the pump portion 26. The reinforcing rib 35 may be three-dimensionally formed integrally with the base portion 12 by 3D printing. Note that the bellows 34 can be omitted when the internal space of the pump portion 26 (the space defined by the outer shell portion 33 and the piston portion 27B of the piston rod 27) is airtight.

  The piston rod 27 can compress the bellows 34 in the axial direction by being pushed toward the inner portion of the cylindrical outer shell portion 33. The piston rod 27 has a shaft portion 27A having an elongated rod shape, and a substantially disc-shaped piston portion 27B (head) provided on the tip side of the shaft portion 27A. The piston rod 27 can move back and forth along the cylindrical axial direction of the pump portion 26. The piston portion 27B may be coated with various coatings such as fluororesin in order to improve the slipperiness with respect to the inner peripheral surface of the outer shell portion 33, or may be applied with lubricating oil such as grease. .

  As shown in FIG. 3, the tip of the shaft portion 27A is formed in, for example, a hemispherical shape, abuts on the cam surface 28A of the conversion mechanism 28, and can slide smoothly on the cam surface 28A. The bellows 34 is formed of a flexible resin material such as polyethylene. The bellows 34 has a bottomed cylindrical shape. The structure of the bellows 34 is substantially the same as that of the elastic member 31 of the finger 13 described later. The bellows 34 and the elastic member 31 may be formed of a rubber-like elastic material by 3D printing. Suitable materials for 3D printing include thermoplastic elastomers and silicone rubber.

  The conversion mechanism 28 includes a cam portion that converts the rotational motion of the holder portion 17 into the forward / backward motion of the piston rod 27. The conversion mechanism 28 (cam portion) has a shape in which an elongated flat plate is wound around the rotary shaft 18 and has a spiral shape with the rotary shaft 18 as the center. On the surface of the conversion mechanism 28, a smooth cam surface 28A with which the end of the piston rod 27 abuts is provided. The cam surface 28A may be coated with various coatings such as fluororesin in order to improve the slipperiness of the piston rod 27, or may be applied with lubricating oil such as grease.

  The feed tube 32 is configured by a general tube having flexibility formed of a synthetic resin or the like. The feed pipe 32 connects the bellows 34 in the pump part 26 and the elastic member 31 of the finger part 13. In the present embodiment, the feed tube 32 is provided so as to be exposed to the outside, but the feed tube 32 may naturally pass through the fixed finger 61 of the finger portion 13. By taking such a structure, it is possible to prevent the feed pipe 32 from being caught by surrounding structures during use.

  The holder portion 17 is provided to be rotatable with respect to the base portion 12. The holder portion 17 has a cup shape (cone shape) into which the vicinity of the stump of the user's arm 16 (remaining limb) is inserted. The holder portion 17 preferably has a cup shape or a cone shape complementary to the shape near the stump of the upper limb amputee, but may be a cup shape having a general frustum shape.

  The rotating shaft 18 includes, for example, a metal first portion 18A, a resin second portion 18B connected to the holder portion 17, and a flange portion 18C formed so as to protrude radially in the second portion 18B. And having. The second portion 18 </ b> B of the rotating shaft 18 is three-dimensionally formed integrally with the holder portion 17. Naturally, the rotary shaft 18 can be entirely formed of only a resin material by 3D printing, which will be described later.

  The first portion 18A may be inserted into a hole formed in the second portion 18B and fixed to the second portion 18B. Alternatively, a male screw may be formed on the outer peripheral surface of the first portion 18A, and the first portion 18A is first formed by engaging the male screw of the first portion 18A with the female screw formed on the second portion 18B. It may be fixed to the two portions 18B. Alternatively, even if the first portion 18A and the second portion 18B are integrally molded by performing 3D printing on the first portion 18A as an insert molding, using the first portion 18A as an insert for the second portion 18B. Good.

  A film may be formed on the inner peripheral surface of the holder portion 17 with a resin having rubber-like elasticity in order to increase the frictional force with the stump of the user's arm 16. This prevents the user's arm 16 from slipping with respect to the holder portion 17. Alternatively, for example, a sponge-like cushion member may be provided on the inner peripheral surface of the holder portion 17 in order to reduce pain at the stump of the arm when the user uses the active prosthesis 11 of the present embodiment for a long time. Good for.

  The rotating shaft 18 includes a through hole 25 provided in the second plate 23 of the base portion 12, a second through hole 37 formed in the boss 36 provided in the outer shell portion 33 of the pump portion 26, and the holder portion 17. The third through hole 38 formed in the reinforcing rib 35 is provided so as to penetrate therethrough. Therefore, the rotating shaft 18 is rotatably supported by the three bearings, and is prevented from being shaken during rotation. The flange portion 18 </ b> C is in contact with the reinforcing rib 35. When the user rotates the holder portion 17, a load is applied from the user's arm 16 to the holder portion 17 in a direction from the user's elbow to the forearm. The reinforcing rib 35 can receive this load.

  As shown in FIGS. 1 and 2, the socket portion 21 includes a support portion 41 provided along the user's forearm 16, a fixing portion 42 fixed to the user's upper arm, a support portion 41 and a fixing portion. And a connecting portion 43 that rotatably connects with 42. The support portion 41 includes a support portion main body 44 having an elongated flat plate shape, and a band member 45 for fixing the support portion main body 44 to the user's forearm 16. The support portion main body 44 is formed by connecting a plurality of elongated plate members 41A, and constitutes a single elongated flat plate shape as a whole. As shown in FIG. 3, a pair of long holes 46 are formed in each plate member 41A. The long hole 46 is elongated along the longitudinal direction of the plate material 41A. The long holes 46 in each plate 41A are parallel to each other. As shown in FIG. 3, the plate members 41 </ b> A are fixed by screws 47 passed through the long holes 46. For this reason, the user or the prosthetic limb orthosis uses the elongated hole 46 and the screw 47 to expand and contract, or by increasing or decreasing the number of the elongated plate members 41A used, the user's forearm 16 (remaining limb). The length of the support portion 41 can be adjusted as appropriate in accordance with the length. The band member 45 is passed through a pair of long holes 46 of one plate material 41A (in this embodiment, the plate material 41A farthest from the finger portion 13), and the user's forearm 16 and the plate material 41A (support portion) 41). The shape of the support portion 41 is not limited to an elongated flat plate shape. The shape of the support portion 41 may be, for example, an elongated shape (for example, a semi-cylindrical shape) having a curved cross section so as to fit the curve of the user's arm (forearm 16).

  As shown in FIGS. 1 and 2, the fixing portion 42 includes a flat fixing portion main body 51, a ring portion 52 formed in a ring shape so as to surround the user's upper arm, a second band member 53, and the like. Have. As shown in FIG. 2, the fixed body 51 is provided with a pair of second long holes 54. The second elongated hole 54 is elongated along the longitudinal direction of the fixed portion main body 51. The second long holes 54 are parallel to each other. The ring portion 52 is fixed to the fixing portion main body 51 by screws (not shown) passed through the pair of second long holes 54. For this reason, the user can adjust the position of the ring part 52 suitably through the 2nd long hole 54 and a screw. The second band member 53 is passed through the pair of second long holes 54. The second band member 53 is hooked inside the user's elbow. The second band member 53 fixes the fixing portion 42 to the user's elbow so that the support portion 41 and the fixing portion 42 fit snugly with respect to the user's elbow.

  The ring portion 52 includes a substantially cylindrical cylindrical portion 52A having an open portion that is partially opened, a pair of protruding pieces 52B that define the periphery of the open portion and protrude from the cylindrical portion 52A, and a pair of protruding pieces 52B. A dial member 52C having a penetrating bolt-shaped shaft portion and a finger-hooking dial, and a nut member (not shown) that engages with a male screw of the shaft portion of the dial member 52C. The pair of protruding pieces 52B are provided apart from each other. Each protruding piece 52B is provided with a hole through which the shaft portion of the dial member 52C passes. The shaft portion of the dial member 52C passes through the pair of protruding pieces 52B, the dial of the dial member 52C is positioned on one side of the pair of protruding pieces 52B, and the nut is positioned on the other side of the pair of protruding pieces 52B. .

  A user or a prosthetic limb orthosis can adjust the inner diameter of the ring portion 52 by tightening the dial member 52C with respect to the nut. That is, the inner diameter of the ring portion 52 can be reduced by rotating the dial member 52C in the clockwise direction, and the inner diameter of the ring portion 52 can be increased by rotating the dial member 52C in the counterclockwise direction. The connection part 43 is comprised with a metal general hinge. The connecting portion 43 connects the support portion main body 44 and the fixed portion main body 51 so that the fixed portion main body 51 can rotate with respect to the support portion main body 44.

  As shown in FIG. 3, the finger portion 13 is formed in an overall shape imitating a human index finger or middle finger. In the present embodiment, the number of the finger parts 13 is one, but the number of the finger parts 13 may be plural (for example, 2 to 5). When the number of the finger parts 13 is five, the second finger part 14 may be omitted.

  As shown in FIGS. 3 and 4, the finger portion 13 includes a hollow cylindrical fixed finger 61 fixed to the base portion 12, and a hollow cylindrical movable finger 62 provided on the tip side of the fixed finger 61. , A cylindrical expansion / contraction member 31 provided between the fixed finger 61 and the movable finger 62, a hinge portion 63 provided in parallel with the expansion / contraction member 31, and the fixed finger 61 and the movable finger 62. It has a biasing member 64 and a rubber finger sack 65 covering the periphery of the movable finger. Each of the fixed finger 61 and the movable finger 62 is formed in a hollow cylindrical shape, but may be configured with a solid structure to improve strength. The urging member 64 is formed in a belt shape by a resin material having rubber-like elasticity. More specifically, the urging member 64 is composed of a rubber band. The biasing member 64 is provided, for example, on the opposite side of the hinge portion with the elastic member 31 interposed therebetween. For this reason, the elastic member 31 is located between the hinge part 63 and the biasing member 64. The biasing member 64 applies tension to the fixed finger 61 and the movable finger 62 so as to maintain the extended position P1 in which the fixed finger 61 and the movable finger 62 are substantially parallel to each other.

  In this embodiment, the urging member 64 is made of a rubber-like elastic resin material. However, the urging member 64 may be made of a spring, or the entire active prosthesis 11 of the present embodiment. A rubber skin formed to cover the surface may be substituted. There are many such epidermis that faithfully reproduce human skin. In the present embodiment, such an epidermis can be obtained commercially and used on the upper side of the entire structure excluding the biasing member 64 of the active prosthesis 11 described above.

  The hinge part 63 connects the fixed finger 61 and the movable finger 62 so that the movable finger 62 can be rotated with respect to the fixed finger 61.

  As shown in FIGS. 3 and 4, the stretchable member 31 is formed of a hollow and bottomed bellows formed of a resin material. The elastic member 31 is made of polyethylene, for example. Thus, the elastic member 31 comprised of bellows has elasticity that expands and contracts in the axial direction (longitudinal direction) and flexibility that curves in a direction that intersects the axial direction. The elastic member 31 (bellows) of the present embodiment has a so-called bag shape and can be extended by supplying a working fluid therein. The elastic member 31 preferably has translucency.

  The telescopic member 31 stores air as a working fluid therein. In this embodiment, a so-called pneumatic operation type using air (gas) as a working fluid is employed. As a result, the output (grasping force) per weight of the active prosthesis 11 is increased. For this reason, the overall weight of the active prosthetic hand 11 is reduced, and the object to be grasped can be softly held by the characteristics of the compressible fluid possessed by the air. For this reason, the active prosthesis 11 of this embodiment can be suitably used also when holding a paper cup or the like containing soft food or beverage.

  The working fluid used in the active prosthesis 11 of the present embodiment is not limited to this, and may be a hydraulic operation type or a hydraulic operation type using a liquid such as water or oil. When water or oil is used as the working fluid, the advantage of being able to generate a large force when grasping the object due to the characteristics of the incompressible fluid, and even better finger responsiveness when grasping the object There is merit to become.

  The second finger portion 14 is fixedly provided with respect to the base portion 12. The second finger portion 14 has an overall shape imitating a human thumb, but is bent in a direction away from the finger portion at an intermediate position. Although the 2nd finger part 14 is formed in a hollow cylinder shape, it may be constituted by a solid structure for strength improvement. The second finger part 14 includes a parallel part 66 that is substantially parallel to the finger part 13, a side protrusion part 67 that extends in a direction away from the finger part 13, and a rubber-made first part that covers the side protrusion part 67. 2 finger sac 68. The side protrusion 67 is provided at a position that does not interfere with the rotation range of the finger 13.

  The base portion 12, the pump portion 26 (drive portion 15), the conversion mechanism 28 (drive portion 15), the piston rod 27 (drive portion 15), the holder portion 17, the second portion 18B of the rotating shaft 18, and the socket portion 21 described above. The support portion 41 (plate material 41A) and the fixing portion 42 are three-dimensionally molded (three-dimensionally shaped) by 3D printing technology using a 3D printer. That is, the base portion 12, the pump portion 26, the conversion mechanism 28, the piston rod 27, the holder portion 17, the second portion 18B, the support portion 41 (plate material 41A), and the fixing portion 42 are made of resin materials such as PLA, ABS, and polyamide. It is formed. As a 3D printing method used for the three-dimensional molding, an arbitrary method such as an optical modeling method, a powder method, a heat melting lamination method (FDM method), a sheet lamination method, an ink jet method, or the like can be adopted. The holder portion 17 may be formed in a general frustum-shaped cup shape (cone shape) as described above, but the shape near the stump of the upper limb amputee is scanned and a shape complementary to this is scanned. Naturally, the holder portion 17 having the concave portion (cup shape, cone shape) can be formed by 3D printing. Thus, as a result of forming most of the parts of the active prosthesis 11 of the present embodiment with a 3D printer, the active prosthesis 11 can be manufactured at a very low cost.

  Next, with reference to FIG. 2 to FIG. 5, the usage method and operation of the active prosthesis 11 of this embodiment will be described. The adjustment of the active prosthetic hand 11 to the upper limb amputee is performed by a prosthetic orthosis or the like who performs a fitting operation under a doctor's prescription. The prosthetic orthosis person can adjust the screw 47 to expand or contract the support portion 41 or increase or decrease the number of the elongated plate members 41A in a state where the vicinity of the stump of the forearm 16 is inserted into the holder portion 17. The length of the support portion 41 is adjusted according to the length of the remaining limb. The prosthetic orthosis person passes the forearm 16 of the user through the ring part 52 of the socket part 21 with the vicinity of the stump of the forearm 16 inserted into the holder part 17 and adjusts the dial member 52C and the nut to adjust the user's forearm. The ring part 52 is fixed to the upper arm. Further, the prosthetic orthosis wraps the first band member 45 around the user's forearm 16 to fix the forearm 16 and the support portion 41, and positions the second band member 53 on the inner side of the user's elbow. And the end of the support part 41 and the fixing part 42 are fixed so that they fit snugly on the elbow. As a result, the active prosthesis 11 can be firmly fixed to the user's arm 16.

  At this time, since the support part 41 is rotatably connected to the fixed part 42 via the connection part 43, the user is ensured to bend and extend the elbow. The user can open and close the finger portion 13 by rotating the forearm 16. The forearm 16 can be rotated by a supination operation (Supination) in which the palm is rotated upward and a pronation operation (Pronation) in which the palm is rotated downward. For example, when taking the right hand as an example, the pronation operation corresponds to the rotation of the right arm 16 of the right hand in the clockwise direction, and the pronation operation corresponds to the rotation of the right arm of the forearm 16 in the counterclockwise direction. Corresponds to rotating. In addition, it is known that the torque of human supination operation is 1.3 to 1.4 times the torque of pronation operation. For this reason, in this embodiment, the finger part 13 is rotated toward the second finger part 14 by the turning operation of the forearm 16 capable of generating a large torque, and the gripping operation is performed.

  As shown in FIG. 4, when the user rotates the forearm 16 outwardly, the holder portion 17, the rotation shaft 18, and the conversion mechanism 28 rotate around the rotation shaft 18. The tip of the shaft portion 27A of the piston rod 27 is in contact with the cam surface 28A of the conversion mechanism 28. The rotational movement of the rotary shaft 18 is converted into the forward / backward movement of the piston rod 27 by a cam mechanism constituted by the cam surface 28A and the tip of the shaft portion 27A. As a result, the piston rod 27 is inserted into the inner part of the pump part 26 and the bellows 34 inside the pump part 26 is compressed. As a result, the air in the bellows 34 is compressed and sent to the inside of the elastic member 31 via the feed pipe 32. The air sent to the expansion / contraction member 31 increases the pressure in the expansion / contraction member 31 and causes the expansion / contraction member 31 to extend in the axial direction by the internal pressure. At this time, in this embodiment, since the hinge part 63 is provided in parallel with the elastic member 31, the elastic member 31 extends so as to turn around the hinge part 63 around the hinge part 63. Thereby, in this embodiment, the elastic member 31 does not simply extend in the axial direction, but the movable finger 62 of the finger portion 13 rotates toward the second finger portion 14 around the hinge portion 63. At this time, the expansion / contraction member 31 overcomes the urging force of the urging member 64 and turns the expansion / contraction member 31 about the hinge portion 63. As a result, the extending direction of the fixed finger 61 intersects the extending direction of the movable finger 62 from the extended position P1 where the extending direction of the fixed finger 61 and the extending direction of the movable finger 62 are substantially parallel. The bending position P2. The user can grip the object to be gripped between the finger 13 (movable finger 62) and the second finger 14 by setting the finger 13 to the bending position P2.

  On the other hand, when releasing the gripping of the object, the forearm 16 that has been rotated outward by the user is moved back to the original position. As a result, the rotating shaft 18 and the conversion mechanism 28 of the holder portion 17 rotate in the direction opposite to the above-described supination operation, and the pushing of the piston rod 27 is released. Thereby, the internal pressure (the internal pressure of the bellows 34 of the pump part 26) of the expansion-contraction member 31 falls. As a result, the urging force of the urging member 64 and the restoring force of the telescopic member 31 are greater than the force in the direction in which the telescopic member 31 is extended, so that the telescopic member 31 is returned to its original length and the finger 13 Is returned from the bending position P2 to the extension position P1. As a result, the gripping of the object can be released. Even when a decorative skin is used for the biasing member 64, the finger 13 can be returned from the bending position P2 to the original extended position P1 by the biasing force (restoring force) of the skin.

  Subsequently, the inventors evaluated the performance of the active prosthesis 11 of the present embodiment. The evaluation results are shown in FIGS. FIG. 6 is a graph showing the relationship between the rotation angle α (rotation angle from the original position) of the holder portion 17 and the pressure P inside the elastic member 31 in a state where no load is applied to the finger portion 13. . Since the gripping force for gripping the object is calculated by multiplying the pressure P by a predetermined constant, it is proportional to the pressure P. According to FIG. 6, it is understood that if the forearm 16 (holder part 17) is rotated outwardly to increase the outward angle α, the pressure P increases in proportion to the outward angle α. On the other hand, if the forearm 16 (the holder portion 17) is rotated in this way and the forearm 16 is moved back so as to return to the original position to reduce the outside angle α, the pressure is increased accordingly. It is understood that P becomes smaller.

  FIG. 7 is a graph showing the relationship between the gyration angle α and the angle θ (see FIG. 5) formed by the hinge portion 63 in a state where no load is applied to the finger portion 13. The test (evaluation) in FIG. 7 is performed at the same time as the test (evaluation) in FIG. 6. In FIG. 6, attention is paid to the relationship between the extrapolation angle α and the pressure P, and in FIG. Some focus on the relationship of the angle θ formed. According to FIG. 7, when the forearm 16 (holder part 17) is rotated outwardly to increase the outward angle α, the fixed finger 61 and the movable finger 62 of the finger portion 13 form in proportion to the outward angle α. It is understood that the angle θ increases. On the other hand, if the forearm 16 (the holder portion 17) is rotated in this way, the forearm 16 is moved back so that the forearm 16 is returned to the original position to reduce the outside angle α. It will be understood that the angle θ formed by the finger 61 and the movable finger 62 becomes smaller. 6 and FIG. 7, it is understood that the bending angle changes as the pressure P inside the elastic member 31 increases. Therefore, according to FIGS. 6 and 7, the user can easily adjust the angle θ formed by the movable finger 62 with respect to the fixed finger 61 by operating the turning angle α of the holder portion 17.

  FIG. 8 is a graph showing the relationship between the turning angle α of the holder portion 17 and the pressure P inside the elastic member 31 in a state where a load is applied to the finger portion 13. In FIG. 8, the holder portion 17 is rotated and returned to the original state while the angle θ formed by the fixed finger 61 and the movable finger 62 of the finger portion 13 is held at, for example, 0.9 radians. The evaluation in FIG. 8 simulates a state in which a grasped object is grasped between the finger part 13 and the second finger part 14, and corresponds to a so-called load state test. According to FIG. 8, even when a load is applied to the finger portion 13, if the forearm 16 (holder portion 17) is rotated outwardly to increase the outward angle α, it is proportional to the outward angle α. It is understood that the pressure P increases. This means that the gripping force for gripping the object between the finger 13 and the second finger 14 is increased in proportion to the extrapolation angle α. On the other hand, when the user maintains the turning angle α constant, the gripping force for gripping the object is maintained substantially constant. Further, if the forearm 16 is operated in a revolving manner so that the forearm 16 (the holder portion 17) is returned to the original position from the state in which the forearm 16 is operated in a revolving manner, the outside angle α can be reduced. It is understood that P becomes smaller.

  FIG. 9 is a graph showing the relationship between the extrapolation angular velocity ω and the movable fingertip velocity v. According to this result, a fingertip speed of 850 mm / s at the maximum can be obtained, for example, in the supination operation. As a comparative example, a trade name “DMC Plus” manufactured by Otto Bock, which is a commercially available myoelectric prosthesis, is given. In this myoelectric hand, the fingertip speed is 130 mm / s. For this reason, in the active prosthetic hand 11 of this embodiment, the fingertip speed of 6 times or more of the myoelectric prosthetic hand of the comparative example can be exhibited at the maximum in the gripping operation. According to FIG. 9 and the comparative example, it is understood that the object can be quickly grasped and released. In addition, since the release operation | movement of a grip is dependent only on the urging | biasing force of the urging | biasing member 64, and the restoring force of the expansion-contraction member 31, fingertip speed has fallen rather than the holding | grip operation. However, it is possible to increase the fingertip speed during the releasing operation by reducing the friction between the elastic member 31 and the biasing member 64.

  FIG. 10 is a graph showing how the extrapolation angle α and the pressure P inside the telescopic member 31 change with time. In the experiment corresponding to FIG. 10, an operation of grasping and lifting a plastic bottle containing a beverage was performed. According to the active prosthesis 11 of the present embodiment, it is understood that when the user maintains the forearm wraparound angle α constant, the pressure P inside the telescopic member 31 is also maintained substantially constant. This means that the gripping force for gripping the object is maintained substantially constant.

  On the other hand, as a comparative example, a general myoelectric prosthetic hand test result (not shown) is given. In general, weak fluctuations occur in myoelectric potential. In the myoelectric prosthetic hand, the gripping force is increased or decreased by the myoelectric potential, so that the gripping force changes with a minute change in the myoelectric potential. For this reason, it is difficult for the myoelectric prosthetic hand of the comparative example to grip the object with the gripping force substantially constant as in the active prosthetic hand 11 of the present embodiment. Therefore, in the active prosthetic hand 11 of the present embodiment, the gripping force can be made substantially constant, and the gripping of the object is stabilized.

  According to the present embodiment, the active prosthetic hand 11 includes a base portion 12 provided with a fixed finger 61, a holder portion 17 provided so as to be rotatable with respect to the base portion 12, and a user's arm inserted therein, and a fixed finger. The movable finger 62 provided at the front end side than 61, the position between the fixed finger 61 and the movable finger 62, provided in parallel with the telescopic member 31 and the tubular telescopic member 31 that can be expanded and contracted. In the hinge part 63, the extending position P1 in which the extending direction of the fixed finger 61 and the extending direction of the movable finger 62 are substantially parallel to each other, and the extending direction of the movable finger 62 intersects the extending direction of the fixed finger 61. The hinge part 63 that connects the fixed finger 61 and the movable finger 62 so as to be rotatable between the bending position P2 and the drive part 15 in which the working fluid is stored. Use the pressurizing fluid to expand and contract Sending the working fluid within the timber 31 is extended an elastic member 31 to pivot about the hinge portion 63 includes a drive unit 15 to the position P2 bending from extended position P1, the.

  According to this configuration, a prosthetic finger and a finger joint can be configured with a simple structure in which one elastic member 31 and one hinge portion 63 are combined. Thereby, the number of the elastic members 31 can be reduced and the structure of the prosthetic hand can be simplified. As a result, the mechanism can be simplified, and the active prosthesis 11 with high mechanical efficiency and reduced force required for operation can be realized. According to the above configuration, for example, since the driving unit 15 and the elastic member 31 can be connected by a valveless circuit, the pressure loss is low and the reliability can be increased. In addition, since the movable finger 62 is moved using the working fluid, the working fluid is appropriately supplied to easily cope with an increase in the number of fingers and an increase in the number of joints. Further, the operation is easy for the user, and the training period can be shortened to realize the user-friendly active prosthesis 11. Furthermore, it can operate silently without a motor sound like a myoelectric prosthetic hand, and there is no danger of a short circuit even when wet. Further, not only the position adjustment of the myoelectric sensor is unnecessary as in the myoelectric prosthetic hand, but there is no problem of malfunction due to sweat. Furthermore, there is no malfunction caused by muscle fatigue.

  The elastic member 31 is a bellows. According to this configuration, the stretchable member 31 can be composed of a stretchable and flexible member. Further, the bellows has better durability than the rubber tube, and can realize the active prosthesis 11 that is lightweight and highly durable.

  The elastic member 31 is attached to the user's arm 16 and can be extended and contracted according to the length of the user's arm 16. 41, and a fixing portion 42 that can be fixed to the upper arm of the user. In general, the length of the remaining limb of the forearm 16 portion of the user who uses the active prosthesis 11 is different for each user. According to the present embodiment, the length of the support portion 41 is appropriately changed according to the length of the user's remaining limb (for example, the length using the long hole 46 is changed, or the number of the elongated plate members 41A is changed. It is possible to change the length to be increased / decreased), and the user-friendly active prosthesis 11 can be realized. Moreover, since the fixing | fixed part 42 can be rotated with respect to the support part 41, when using the active prosthesis 11, the user can ensure the freedom of bending and stretching of the elbow. As a result, the user-friendly active prosthesis 11 can be realized.

  The working fluid is air. For this reason, since the compressive fluid is used as the working fluid, the object to be grasped can be grasped softly. Further, the overall weight of the active prosthesis 11 can be reduced, and the active prosthesis 11 that is easy for the user to use can be realized. In addition, by incorporating the pump unit 26 in the active prosthesis 11 and driving the pump unit 26 by the user himself / herself, heavier compressors and valves, which are essential in the conventional pneumatic system, and electronic devices for controlling them are externally provided. Equipment becomes unnecessary. For this reason, the portability of the entire system is improved, and a lightweight and low-cost active prosthesis 11 can be realized.

  The base part 12, the holder part 17, the fixed finger 61, the movable finger 62, the hinge part 63, and the drive part 15 are formed of a resin material. According to this configuration, these structures can be realized in a light weight. In addition, since a metal material is not used as much as possible, cutting or the like is unnecessary, and the manufacturing cost can be reduced. Furthermore, by forming them with a resin material, they can all be formed with a 3D printer. Accordingly, it is not necessary to create a mold, and the manufacturing cost of the active prosthesis 11 can be significantly reduced.

  Hereinafter, modified examples of the active prosthesis 11 will be described with reference to FIGS. 11 to 19. In the following modifications, portions different from the above embodiment will be mainly described, and illustrations or descriptions of portions common to the above embodiment will be omitted.

[First Modification]
With reference to FIGS. 11 to 14, the active prosthetic hand 11 of the first modification will be described. The active prosthetic hand of this modification is an active prosthetic hand with a force feedback system that feeds back a gripping force for gripping an object to a user.

  The active prosthesis 11 includes a base part 12 having a plate shape bent in an L-shaped cross section, a finger part 13 attached to the distal end side of the base part 12, and a second finger part attached to the distal end side of the base part 12. 14, a drive unit 15 that is fixed to the base unit 12, a holder unit 17 into which the tip of the user's arm 16 (remaining limb) is inserted, and the active prosthesis 11 to the user's arm 16. And a socket portion 21 for fixing the same.

  The finger part 13 has an overall shape imitating a human index finger or middle finger. In the present embodiment, the number of the finger parts 13 is one, but the number of the finger parts 13 may be plural (for example, 2 to 5). The finger portion 13 includes a hollow cylindrical fixed finger 61 fixed to the base portion 12, a hollow cylindrical movable finger 62 provided on the tip side of the fixed finger 61, and the fixed finger 61 and the movable finger 62. A cylindrical expansion / contraction member 31 provided therebetween, a hinge portion 63 provided in parallel with the expansion / contraction member 31, a biasing member 64 provided across the fixed finger 61 and the movable finger 62, and the movable finger 62 And a rubber finger sack 65 covering the periphery.

  The active prosthesis 11 includes a recess 71 provided in the vicinity of the tip of the movable finger 62, a second elastic member 72 accommodated in the recess 71, a third band member 73 wound around the upper arm of the user, and a third A flat plate portion 74 attached to the band member 73; a third elastic member 75 attached to the flat plate portion 74 so as to come into contact with the arm 16 of the user; a second elastic member 72 and a third elastic member 75; And a second feed pipe 76 provided to connect the two. In the present embodiment, the concave portion 71 is provided in the movable finger 62 and the second elastic member 72 is disposed in the concave portion 71. However, the second elastic member 72 is disposed on the surface of the movable finger 62 without providing the concave portion 71. Of course it is good. Further, the installation position of the second elastic member 72 is not limited to the vicinity of the tip of the movable finger 62 (fingertip), and may be installed at other positions such as the vicinity of the tip of the second finger portion 14, for example.

  The 2nd expansion-contraction member 72 is comprised by the hollow and bottomed cylindrical bellows formed with the resin material. The 2nd expansion-contraction member 72 can be expanded-contracted in the axial direction. The 2nd expansion-contraction member 72 comprises the part contact | abutted to the holding | grip target object among the finger parts 13. FIG. Similarly, the third elastic member 75 is formed of a hollow and bottomed cylindrical bellows formed of a resin material. The 3rd expansion-contraction member 75 can be expanded-contracted in the axial direction. The 2nd expansion-contraction member 72 and the 3rd expansion-contraction member 75 have the structure substantially the same as the expansion / contraction member 31 of the said embodiment. The diameter of the second elastic member 72 is the same as the diameter of the third elastic member 75. Air is stored as a working fluid (second working fluid) in the second elastic member 72 and the third elastic member 75, but water or oil other than air may be used as the working fluid. . The second elastic member 72 and the third elastic member 75 may be formed of a rubber-like elastic material (such as a thermoplastic elastomer or silicone rubber) by 3D printing.

  Subsequently, the operation of the active prosthetic hand 11 of the present modification will be described with reference to FIGS. As shown in FIG. 11, for example, when the object is grasped between the finger part 13 and the second finger part 14, the second elastic member 72 comes into contact with the object, and the air in the second elastic member 72 Is fed into the third elastic member 75 via the second feed pipe 76. In a state where the object is gripped by the second elastic member 72, the pressure inside the second elastic member 72 and the pressure inside the third elastic member 75 are equal due to Pascal's principle. Therefore, by making the diameters of the second elastic member 72 and the third elastic member 75 equal, the upper arm of the user can be pressed by the third elastic member 75 with a force equal to the holding force for holding the object. Thereby, the gripping force for gripping the object between the finger part 13 and the second finger part 14 can be correctly fed back as a pressing force for the user's upper arm. For this reason, the user can grasp the object while grasping the degree of grasping force with which the object is grasped when grasping the object.

  Thus, the user can hold, for example, an opened pouch jelly (jelly stored in a resin bag having a film layer formed by aluminum vapor deposition), a paper cup containing a beverage, and the like.

  Subsequently, the inventors evaluated the performance of the active prosthesis 11 of this modification. The evaluation results are shown in FIG. In the evaluation, a test was conducted in which the opened pouch jelly was lifted and moved using the active prosthesis 11 of the present modification. FIG. 14 is a graph showing the relationship between the turning angle α of the holder portion 17 and the measured value of the force applied from the third elastic member 75 to the user's arm 16 over time. The measured value of the force applied from the third elastic member 75 to the user's arm 16 is a measured value of the pressing force applied as a gripping force feedback to the user's upper arm.

  In FIG. 14, the first protrusion 81 that appears first from the start of evaluation is a control example (control). In the control example, the experimenter uses the finger of the hand on the opposite side to the hand on which the active prosthetic hand 11 is worn, and the movable finger 62 of the finger 13 (the second elastic member 72 attached to the movable finger 62). When the opened pouch jelly is held between the second finger part 14 and the second finger part 14 is held, the measured value of the force fed back as a force sense (pressing force) to the user's upper arm by the third elastic member 75 is 0. .75 to 0.9N. This simulates a state in which the gripping force is fed back to the upper arm of the user while the gripping target is gripped with a gripping force of 0.75 to 0.9N. A gripping force suitable for gripping the opened pouch jelly is in the range of 0.3 to 1.9 N indicated by a broken line in FIG.

  The experimenter remembered the previous feedback sensation (force sense shown in FIG. 14 as the first protrusion 81), and performed the test of grasping the object three times while receiving feedback by this force sense feedback system. . As a result, there are some variations as shown in FIG. 14 in which the measured force values (gripping force and force sensation fed back to the experimenter) indicated by the second protrusion 82, the third protrusion 83, and the fourth protrusion 84 in FIG. However, it was confirmed that the gripping force indicated by the first protrusion 81 was reproduced in all three trials. Thus, it was confirmed that the pouch jelly opened by the experimenter can be gripped with an appropriate gripping force (within a range of 0.3 to 1.9 N).

  According to FIG. 14, it is understood that the gripping force feedback to the user's upper arm is correctly performed as the object is gripped. Moreover, in all three trials, it was within the range of 0.3 to 1.9 N which is a gripping force suitable for gripping the opened pouch jelly. For this reason, according to the active prosthetic hand 11 with the force feedback system of this modification, it was confirmed that the pouch jelly can be gripped with an appropriate gripping force without blowing out the contents of the opened pouch jelly. Further, according to the active prosthetic hand 11 of the present modification, it is confirmed that the object can be gripped with a gripping force that does not crush the object even when the object to be gripped is a paper cup containing beverage or other soft food. It was done.

  According to the first modification, the active prosthetic hand 11 is provided on the movable finger 62, stores the second working fluid therein, and compresses the bottomed cylindrical second expansion and contraction by contacting the grasped object. A bottomed member that is provided at a position that contacts the member 72 and the user's arm and that presses the user's arm by receiving and extending the second working fluid sent from the compressed second elastic member 72 A cylindrical third elastic member 75.

  According to this configuration, the gripping force for gripping the gripping object can be fed back to the user's arm by the second stretchable member 72 and the third stretchable member 75. As a result, the user can grasp the gripping force at any time.For example, even when gripping a soft gripping object such as a pouch jelly, a food, or a paper cup containing a beverage, the user can adjust the gripping force appropriately. It is possible to prevent the object to be gripped from being crushed by the active prosthetic hand 11. Since the force feedback system is realized by connecting the second elastic member 72 and the third elastic member 75 with a simple valveless circuit, the active prosthesis 11 can be realized at low cost and the force sense is highly reliable. A feedback system can be realized.

[Second Modification]
With reference to FIG. 15, the active prosthetic hand 11 of the 2nd modification is demonstrated. In the active prosthetic hand 11 of this modification, the conversion mechanism 28 is provided integrally with the holder portion 17 instead of the rotating shaft 18. The conversion mechanism 28 (cam portion) has a shape in which an elongated flat plate is wound around the holder portion 17 and has a spiral shape with the holder portion 17 as the center.

  In this modification, the rotating shaft 18 is omitted, and the holder portion 17 is rotatably attached to the base portion 12 via, for example, a pin 85 or a bolt. Therefore, in this modification, the rotating shaft 18 is omitted, and thus the distance between the holder portion 17 and the finger portion 13 is remarkably shortened.

  According to this embodiment, the drive unit 15 includes the conversion mechanism 28 that converts the rotational motion of the holder portion 17 into a linear motion in a direction in which the working fluid in the pump portion 26 is pressurized. The conversion mechanism 28 includes the holder portion. 17 and a single unit. According to this configuration, a mechanism for pressurizing the working fluid in the pump unit 26 using the rotational motion of the holder unit 17 can be realized simply and in a small space. Further, since the conversion mechanism 28 is provided integrally with the holder portion 17, no additional space is required to provide the conversion mechanism 28, and the distance from the holder portion 17 to the movable finger 62 is shortened. Can do. As a result, the active prosthesis 11 can be reduced in size, and the distance from the stump of the user's arm 16 to the tip of the finger portion 13 can be made natural without being too long. Thereby, the user-friendly active prosthesis 11 can be realized.

[Third Modification]
With reference to FIG. 16, FIG. 17, the active prosthesis 11 of the 3rd modification is demonstrated. In the active prosthesis 11 of this modification, the conversion mechanism 28 is integrated with the holder portion 17 as in the second modification. Moreover, the finger part 13 is comprised by five pieces. Each finger portion 13 includes a fixed finger 61 (second fixed finger), a movable finger 62 (second movable finger), and a cylindrical expansion / contraction member 31 (fourth expansion / contraction) provided at a position between them. Member) and a hinge part 63 (second hinge part) for connecting the fixed finger 61 (second fixed finger) and the movable finger 62 (second movable finger).

  The number of joints (extensible member 31 and hinge part 63) of each finger part 13 is increased, and the number of joints is two or three. Furthermore, in this modification, since the finger part 13 is comprised by five, the 2nd finger part 14 provided fixedly is abbreviate | omitted. The configuration of each expansion / contraction member 31 (fourth expansion / contraction member) and each hinge portion 63 (second hinge portion) is the same as the configuration of the expansion / contraction member 31 and the hinge portion 63 of the above embodiment.

  The position of the pump unit 26 of the drive unit 15 is provided at a position deviated from between the base unit 12 and the holder unit 17. More specifically, the pump unit 26 is provided near the user's elbow and at a position outside the elbow. In this modification, since the plurality of finger parts 13 are rotated by one pump part 26, the internal volume of the bellows 34 accommodated in the pump part 26 of this modification is the bellows of the pump part 26 of the above embodiment. It is preferable that it is larger than the internal volume of 34. Of course, the number of pump units 26 may be plural, and a plurality of pump units 26 described in the above embodiment may be arranged. The support part 41 integrated with the base part 12 is attached to the base side end.

  The operation of the active prosthetic hand 11 of this modification will be described with reference to FIGS. In the active prosthetic hand 11 of this modification, when the user rotates the holder part 17 outwardly, the conversion mechanism 28 integrated with the holder part 17 rotates to press the piston rod 27. As a result, the bellows 34 in the pump unit 26 is compressed, and the working fluid (air) in the bellows 34 is sent through the feed pipe 32. If this mechanism is a mechanism for rotating the finger portion 13 from the extended position P1 to the bent position P2 using a working fluid (air or the like) as in this modified example, a feed pipe 32 is connected to each expansion / contraction member 31 (actuator). The active prosthesis 11 having the five finger portions 13 can be easily realized by increasing the number of finger portions 13 and the number of joints.

  In this modification, the feed pipe 32 is branched into five in the middle, and supplies pressurized air to the five fingers 13. In FIG. 17, only one (index finger) is extracted from the five fingers 13. In the finger part 13 corresponding to the index finger in FIG. 17, air is supplied to each elastic member 31, and each elastic member 31 extends so as to turn around the corresponding hinge part 63. Thereby, the finger part 13 rotates from the extended position P1 to the bending position P2. Such rotation from the extended position P1 to the bending position P2 occurs in each finger portion 13, and the user can hold the object. When the user cancels the rotation of the holder portion 17, each finger portion 13 extends from the bending position P <b> 2 to the extended position P <b> 1 by the biasing force of the biasing member 64, the restoring force of the telescopic member 31, the restoring force of the bellows 34, and the like. Returned to

  Note that the rotation direction of the finger portion 13 corresponding to the thumb is generally opposite to the rotation direction of the finger portion 13 corresponding to the other index finger, middle finger, ring finger, and little finger. It matches and does not cause any discomfort to the user. According to this modification, not only can the number of finger portions 13 be increased following the human body, but the number of joints can be increased following the human body. As a result, not only a more natural active prosthesis 11 can be realized, but also an active prosthesis 11 which is natural in appearance and does not give a sense of refusal to the user can be realized.

  According to this modification, the active prosthetic hand 11 includes the second fixed finger 61 provided on the base portion 12, the second movable finger 62 provided on the tip side of the second fixed finger 61, and the second fixed finger. A cylindrical fourth telescopic member 31 provided between the first movable finger 61 and the second movable finger 62, and a second hinge part 63 provided in parallel with the fourth telescopic member 31; 2 The extending position P1 where the extending direction of the fixed finger 61 and the extending direction of the second movable finger 62 are substantially parallel to each other, and the extending direction of the second movable finger 62 intersects the extending direction of the second fixed finger 61. A second hinge part 63 that connects the second fixed finger 61 and the second movable finger 62 so as to be rotatable between the bending position P2 and the drive part 15 uses the rotational movement of the holder part 17; And pressurizing the working fluid to send the working fluid into the fourth telescopic member 31 to provide a second hinge. 63 a fourth elastic member 31 is extended so as to pivot about and to the position P2 bending from extended position P1.

  According to this configuration, the working fluid can be supplied from one pump part 26 to both the elastic member 31 and the fourth elastic member. Thereby, even when the number of the finger parts 13 is increased, the structure is not complicated, and the active prosthetic hand 11 closer to a human hand can be realized with a simple structure.

  In this modification, the drive unit 15 includes a pump unit 26. The pump unit 26 is provided at a position deviated from between the base unit 12 and the holder unit 17, and the working fluid is stored therein. The working fluid is sent into the telescopic member 31 by pressurizing the working fluid. According to this configuration, the base portion 12 and the holder portion 17 can be arranged closer to each other. As a result, the active prosthetic hand 11 can be reduced in size, and the distance from the holder part 17 to the movable finger 62 can be shortened to realize an active prosthetic hand that is easy to use and looks natural.

[Fourth Modification]
With reference to FIG. 18, FIG. 19, the active prosthesis 11 of the 4th modification is demonstrated. In this modification, the configuration of the pump unit 26 in the drive unit 15 is different from that in the above embodiment. The pump unit 26 is not a built-in bellows 34 but a flat pump having a so-called rotary plate (vane).

  The holder portion 17 is rotatably attached to the base portion 12 by pins 85 and bolts. The pump unit 26 (drive unit 15) is provided in a compact manner at a position between the base unit 12 and the holder unit 17. The shape of the pump part 26 has a substantially disk shape.

  The pump unit 26 (drive unit 15) includes a cylindrical case 86 integrated with the holder unit 17, a first plate unit 91 fixed to the base unit 12, and a second plate fixed to the holder unit 17. And a balloon-like portion 93 provided between the first plate-like portion 91 and the second plate-like portion 92. The balloon-like portion 93 stores air that is a working fluid therein, and is connected to the expansion / contraction member 31 via the feed tube 32. Also in this modification, the working fluid is not limited to air, and may be a liquid such as water or oil. When the internal space of the pump portion 26 (the space defined by the first plate-like portion 91, the second plate-like portion 92, and the case 86) is configured to be highly airtight, the balloon-like portion 93 is omitted. You can also.

  Next, the operation of the active prosthetic hand 11 of this modification will be described. When the user rotates the holder portion 17 outwardly, the second plate-like portion 92 rotates accordingly. As a result, the second plate-like portion 92 rotates with respect to the first plate-like portion 91. And the balloon-shaped part 93 located between the 1st plate-shaped part 91 and the 2nd plate-shaped part 92 is compressed between the 1st plate-shaped part 91, the 2nd plate-shaped part 92, and the case 86, Air is sent toward the elastic member 31. As a result, the elastic member 31 extends so as to turn around the hinge portion 63, and the finger portion 13 rotates from the extended position P1 to the bending position P2. Thereby, the object to be grasped can be grasped between the finger part 13 and the second finger part 14. When the user releases the looping operation of the holder portion 17, the internal pressure of the elastic member 31 and the internal pressure of the balloon-like portion 93 are reduced, and the urging force of the urging member 64 is greater than the force in the direction of extending the elastic member 31. Since the restoring force of the elastic member 31 is increased, the finger portion 13 returns from the bending position P2 to the extending position P1.

  According to this modification, the drive unit 15 rotates with respect to the first plate-like portion 91 as the holder portion 17 rotates with the first plate-like portion 91 fixed to the base portion 12 and the holder portion 17 rotating. A second plate-like portion 92, and a balloon-like portion 93 provided between the first plate-like portion 91 and the second plate-like portion 92 and storing the working fluid therein. And a balloon-like portion 93 that is sandwiched between the first plate-like portion 91 and the second plate-like portion 92 and sends the working fluid into the telescopic member 31 when the holder portion 17 rotates.

  According to this configuration, the pump portion 26 can be easily formed flat, and the conversion mechanism 28 is not necessary, whereby the distance between the holder portion 17 and the movable finger 62 can be shortened. As a result, the active prosthetic hand 11 can be reduced in size, and the distance from the stump of the user's arm 16 to the tip of the movable finger 62 can be made a natural length without being too long. As a result, the user-friendly active prosthesis 11 that is easy to use and natural in appearance can be realized. On the other hand, when the length of the user's forearm (residual limb) is short, the length of the active prosthesis 11 can be increased by adopting the above-described embodiment including the conversion mechanism 28.

[Fifth Modification]
With reference to FIG. 20, the active prosthetic hand of the fifth modification will be described. In this modification, the pump unit 26 (drive unit 15) does not include the bellows 34, but includes a plurality of bottomed tubes 94 that store air therein. Therefore, in this modification, the pump part 26 is provided in a ring shape around the holder part 17. The plurality of tubes 94 are provided substantially parallel to the central axis C of the holder portion 17.

  The pump part 26 (drive part 15) includes a disk-shaped first fixing part 96 fixed to the base part 12, a second fixing part 97 provided in a flange shape on the base side of the holder part 17, and a first fixing. A plurality of tubes 94 passed between the portion 96 and the second fixing portion 97. The tube 94 is fixed at one end to the first fixing portion 96 via a string-like connector 95 and fixed at the other end to the second fixing portion 97 via the string-like connector 95. The tube 94 is a stretchable / flexible tube made of rubber or the like, and has a bottomed cylindrical shape with a sealed end. The tube 94 stores air as a working fluid therein. The tube 94 is connected to the extensible member 31 of the finger portion via a plurality of feed tubes 32.

  The operation of the active prosthetic hand 11 of this modification will be described. When the user rotates the holder part 17 outwardly, the second fixing part 97 rotates with respect to the first fixing part 96. Thereby, the plurality of tubes 94 are stretched so as to form a spiral shape. As a result, the air inside the tube 94 is compressed and pushed out to the telescopic member 31 side via the feed tube 32. By such a mechanism, the finger part 13 is rotated from the extended position P1 to the bending position P2. As a result, the object to be grasped can be grasped between the finger part 13 and the second finger part 14. When the user cancels the revolving operation of the holder portion 17, the internal pressure of the elastic member 31 and the internal pressure of the tube 94 are reduced, and the urging force and expansion / contraction of the urging member 64 are more than the force in the direction of extending the expansion / contraction member 31. Since the restoring force of the member 31 is increased, the finger portion 13 is returned from the bending position P2 to the extending position P1.

  According to this modification, the drive unit 15 is configured by the elastic tube 94 provided outside the holder unit 17 and substantially parallel to the central axis C of the holder unit 17, and the tube 94 includes the above-described tube 94. The working fluid is stored, and the tube 94 is fixed to the base portion 12 at one end and fixed to the base portion side of the holder portion 17 at the other end, and extends when the holder portion 17 rotates with respect to the base portion 12. The working fluid is sent into the telescopic member 31.

  According to this configuration, the drive unit 15 can be arranged in a ring shape around the holder unit 17. Further, the conversion mechanism 28 is unnecessary, and using the principle that the tube 94 is spirally extended, the working fluid inside the tube 94 is sent to the expansion / contraction member 31 to extend the expansion / contraction member 31 and the finger 13 is extended. It can be rotated from the position P1 to the bending position P2. As a result, the drive unit 15 can be made space-saving, and the active prosthesis 11 can be miniaturized, and the distance between the holder unit 17 and the tip of the movable finger 62 can be shortened. Further, it is easy to increase or decrease the number of tubes 94 as necessary. As a result, the active prosthesis 11 that is natural and easy to use can be realized because the distance from the stump of the arm 16 of the user to the tip of the finger 13 is short. On the other hand, when the length of the user's forearm (residual limb) is short, the length of the active prosthesis 11 can be increased by adopting the above-described embodiment including the conversion mechanism 28.

  So far, the embodiment and some modified examples have been specifically described with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and constituent elements are not limited to the scope of the invention. It can be transformed and embodied. For example, in the above-described embodiment and each modification, the elastic member 31 is disposed at a position between the fixed finger 61 and the movable finger 62. However, the arrangement of the elastic member 31, the fixed finger 61, and the movable finger 62 is not limited thereto. It is not limited. For example, all or part of the fixed finger 61 may be arranged inside the elastic member 31, or all or part of the movable finger 62 may be arranged inside the elastic member 31. Naturally, it is possible to realize one active prosthesis 11 by appropriately combining the components described in the above embodiment and some modified examples.

Below, the invention concerning another form is appended.
[1]
A base portion provided with fixed fingers;
A holder part rotatably provided with respect to the base part and into which a user's arm is inserted;
A movable finger provided on the tip side of the fixed finger;
A cylindrical expansion / contraction member provided at a position between the fixed finger and the movable finger and capable of expanding and contracting;
A hinge portion provided in parallel with the telescopic member, wherein the movable finger extends in the extending position where the extending direction of the fixed finger and the extending direction of the movable finger are substantially parallel, and the extending direction of the fixed finger. A hinge portion that connects the fixed finger and the movable finger so as to be rotatable between a bending position where the extending directions of the fingers intersect, and
A pump unit in which a working fluid is stored, and the working fluid is pressurized using the rotational movement of the holder unit, so that the working fluid is sent into the telescopic member and swivels around the hinge unit. A pump part that extends the telescopic member to bring the bending position into the bending position;
A second finger provided fixedly;
Active prosthetic hand with.
[2]
The active prosthesis according to [1], further comprising a biasing member that biases the movable finger toward the extended position.

DESCRIPTION OF SYMBOLS 11 ... Active prosthetic hand, 12 ... Base part, 15 ... Drive part, 17 ... Holder part, 26 ... Pump part, 28 ... Conversion mechanism, 31 ... Expansion member, 41 ... Support part, 42 ... Fixed part, 61 ... Fixed finger, 62 ... movable finger, 63 ... hinge part, 72 ... second elastic member, 75 ... third elastic member, 91 ... first plate-like part, 92 ... second plate-like part, 93 ... balloon-like part, 94 ... tube, P1 ... extension position, P2 ... bending position.

Claims (11)

A base portion with fixed fingers fixed;
A holder part rotatably provided with respect to the base part and into which a user's arm is inserted;
A movable finger provided on the tip side of the fixed finger;
A cylindrical expansion / contraction member provided at a position between the fixed finger and the movable finger and capable of expanding and contracting;
A hinge portion provided in parallel with the telescopic member, wherein the movable finger extends in the extending position where the extending direction of the fixed finger and the extending direction of the movable finger are substantially parallel, and the extending direction of the fixed finger. A hinge portion that connects the fixed finger and the movable finger so as to be rotatable between a bending position where the extending directions of the fingers intersect, and
A driving unit in which the working fluid is stored, and the working fluid is pressurized using the rotational movement of the holder unit, so that the working fluid is sent into the telescopic member and swivels around the hinge unit. Extending the telescopic member to move from the extended position to the bent position;
Active prosthetic hand with.   The active prosthetic hand according to claim 1, wherein the elastic member is a bellows. A second telescopic member having a bottomed cylindrical shape that is provided on the movable finger, stores the second working fluid therein, and is compressed by coming into contact with a grasped object;
A bottomed cylindrical first that is provided at a position that abuts on the user's arm and receives the second working fluid sent from the compressed second elastic member and presses the user's arm to extend. 3 elastic members;
An active prosthesis as claimed in claim 1. A second fixed finger provided on the base portion;
A second movable finger provided on the tip side of the second fixed finger;
A cylindrical fourth expansion / contraction member provided at a position between the second fixed finger and the second movable finger and capable of expanding and contracting;
A second hinge portion provided in parallel with the fourth telescopic member, wherein an extension position in which a direction in which the second fixed finger extends and a direction in which the second movable finger extends are substantially parallel; A second hinge portion for connecting the second fixed finger and the second movable finger so as to be rotatable between a bending position where the extending direction of the second movable finger intersects the extending direction of the fixed finger; ,
With
The driving unit pressurizes the working fluid using a rotational motion of the holder unit, and thereby sends the working fluid into the fourth telescopic member to turn around the second hinge unit. The active prosthetic hand according to claim 1, wherein the four elastic members are extended from the extended position to the bent position. An elongated flat plate-like support that is mounted on the user's arm and can be expanded and contracted according to the length of the user's arm;
A fixed portion coupled to the support portion so as to be rotatable with respect to the support portion, and fixed to the upper arm of the user;
An active prosthesis as claimed in claim 1.   The active prosthetic hand according to claim 1, wherein the working fluid is air. The drive unit includes a conversion mechanism that converts a rotational motion of the holder unit into a linear motion in a direction in which the working fluid in the drive unit is pressurized,
The active prosthesis according to claim 1, wherein the conversion mechanism is provided integrally with the holder part.   2. The active prosthetic hand according to claim 1, wherein the base portion, the holder portion, the fixed finger, the movable finger, the hinge portion, and the driving portion are formed of a resin material.   The drive unit includes a pump unit, and the pump unit is provided at a position away from between the base unit and the holder unit, and stores the working fluid therein and pressurizes the working fluid. The active prosthetic hand according to claim 1, wherein the working fluid is sent into the telescopic member. The drive unit is
A first plate-like portion fixed to the base portion;
A second plate-like portion that is fixed to the holder portion and rotates with respect to the first plate-like portion as the holder portion rotates;
A balloon-like portion provided between the first plate-like portion and the second plate-like portion and storing the working fluid therein, wherein the holder portion rotates when the holder portion rotates with respect to the base portion. A balloon-like portion that is sandwiched between one plate-like portion and the second plate-like portion and sends the working fluid into the elastic member;
The active prosthesis of claim 1 having   The drive unit is configured by a stretchable tube provided substantially parallel to the center axis of the holder unit on the outside of the holder unit, and stores the working fluid inside the tube. One end is fixed to the base portion and the other end is fixed to the base portion side of the holder portion. The holder portion is rotated by rotating with respect to the base portion, and the working fluid is sent into the elastic member. The active prosthetic hand according to claim 1.