JP6371064B2 - Prosthetic finger flexion and extension mechanism using the remaining finger function - Google Patents

Description

  The present invention relates to a prosthetic finger for reconstructing a finger that has been cut while leaving some joints.

  For example, when a part of the upper limb is lost due to an accident or illness, a prosthetic hand is worn to compensate for this. Prosthetic hands include decorative prosthetic hands that are only for restoring the appearance, working prosthetic hands specialized for specific work, active prosthetic hands that allow other movements using other parts of the body via harnesses, etc. are categorized. Among them, the decorative prosthetic hand cannot perform any operation, and a working prosthetic hand or an active prosthetic hand is used when functional restoration is desired.

  The above-mentioned prosthetic hands for work are simple in which parts such as joint joints are eliminated as much as possible in order to directly transmit a strong force while focusing on durability so that it can cope with heavy work such as professional work, outdoors, factories, etc. Is desirable. In addition to supporting the body weight, it is desired to withstand a hand load of several tens of kg in order to hold the object so that it does not move or to guarantee the strength to withstand the transportation of the object. In addition, in order to be able to handle a rod-like long object, it is also desired that the accessory can be replaced according to the cross-sectional shape and diameter of the target object while also corresponding to the pronation and exterior of the carpal joint.

  In order to satisfy the above specifications, the prosthetic hand for work is constituted by a stump socket, a harness, a cuff, and a hand tool. The stump socket has a shape that covers the stump portion of the upper limb over a wide area, and is a component that reduces surface pressure and secures stability when worn by closely contacting the stump portion. The harness is a belt-like component used to fix or suspend a prosthetic hand to the body, and is used for a shoulder prosthesis, an upper arm prosthesis, an elbow prosthesis, and a forearm prosthesis for the purpose of preventing the fall. The cuff is a band that is attached to the arm of a forearm prosthesis. The cuff is a part that is intended to prevent the prosthesis from dropping when a heavy load is applied to the hand tool by bringing the socket and stumps into close contact. is there. The hand tool has a special shape corresponding to the content of work, and is mainly made of metal such as stainless steel. Examples of hand tools include metal fittings for fixing handles such as heels and sickles, metal fittings with a flat hand to suppress things, C-shaped metal fittings called curved folds, and double-fingered three-finger gangs. A metal fitting having a finger-light-bending shape is exemplified. These hand tools are not equipped with a mechanism that can be actively operated even if a movable part is provided, and the movable part is operated using the other hand.

  Further, the active prosthetic hand is a mechanical device configured to be able to move the movable part of the hand prosthesis hand attached to itself. It can be opened and closed by transmitting movement (for example, back and forth movement of the shoulder or opening and closing movement of the scapula) or power such as electricity or air pressure to a wire connected to the hand tool.

  The above-mentioned active prosthetic hand is based on the components of the prosthetic hand for work. For example, in the case of cutting higher than the elbow, in order to realize the function of bending and extending the elbow joint, the upper arm base, the elbow joint A forearm base is required. The upper arm base and the forearm base are components that connect the joints. The joint part is included as a carbon cloth or a glass cloth, and this is bonded and fixed in accordance with the mold of the upper arm part or the forearm part, whereby the outer shape of the arm and the joint part are integrally molded to ensure strength.

  The joint joint includes a shoulder joint, an elbow joint, a hand joint, and the like according to the corresponding joint. The elbow joint can fix the joint angle at an arbitrary angle by a ratchet mechanism, and the ratchet is opened and closed by, for example, transmitting the vertical movement of the shoulder through a serpentine wire. In addition, the hand joint enables the posture adjustment of the prongs and the outside of the hand tool, and the sliding resistance is adjusted to be stronger. In such an active prosthetic hand, the appearance is also restored by putting a decorative glove on the hand tool.

  In upper limb amputation, the most common is finger or palm amputation or loss. In this palm part cut or loss, there are many cases where the motor function and sensory function of the joint remain, and there is a possibility of various functional reconstructions. Many attempts have been made to utilize the remaining functions of fingers, mainly from the Hand Surgery Society and the Microsurgery Society, but recent advances in surgical treatment have been remarkable, especially with sharp blades, etc. In cutting cases, a high engraftment rate has been achieved by the recovery technique of joining the cut pieces. On the other hand, in the case of severe cutting such as abrasion damage, the road of reconstruction is still far away. Functional recovery with prosthetic braces should be an effective option in such cases, but the current situation is that the prosthetic prosthetic hand technology is lagging behind and therefore hardly supports various cases. For this reason, self-help tools such as spoons with thickened handles and hooks on the remaining part, and tweezers-type chopsticks are custom-made and used at some welfare workshops. However, it is not widespread because it is expensive in terms of functions, because it is limited to these functions, and because it has an unnatural appearance, it is not sufficient in terms of function and appearance.

  On the other hand, a movable artificial finger applicable to a case of finger cutting has been proposed (see, for example, Patent Document 1). This movable prosthetic finger is a proximal finger linked to the flexion of the MP joint with respect to finger cutting distal to the metacarpophalangeal joint (hereinafter referred to as “MP joint”), which is the joint of the base of the finger. It incorporates a mechanism that flexes a joint interphalangeal joint (hereinafter referred to as “PIP joint”) and a distal interphalangeal joint (hereinafter referred to as “DIP joint”). In this movable artificial finger, the bending motion of the MP joint is transmitted to the PIP joint and the DIP joint using an eccentric link mechanism, thereby generating a rotational motion of the fingertip. This is commercialized under the name X-Finger from Didrick Medical of the United States.

  In addition, a prosthetic hand is proposed in which a prosthetic finger is movable about at least one rotation axis by a driving device that is pressure-elastically or flexibly elastically coupled via a force transmission means (for example, a patent) See reference 2.) This prosthetic finger is rigidly connected to the drive device, so natural movement is achieved by the elastic deformation of the prosthetic finger that receives force compared to the conventional structure where natural movement cannot be obtained. Is. In order to realize a more natural prosthetic finger movement, at least a part of the prosthetic finger is added to the first driving device that connects the main body and the prosthetic finger so as to be rotatable around the first rotation axis. There has been proposed a prosthetic hand in which a prosthetic finger is provided with a second drive device that can rotate relative to the first rotation axis around the second rotation axis (for example, see Patent Document 3). reference.). For the same purpose, a plurality of artificial fingers attached to the main body are movable toward the main body and toward each other by the driving device, and at least two artificial fingers have different adjustment angle ranges with respect to the main body. A prosthetic hand adapted to move is proposed (for example, see Patent Document 4). These prosthetic hands described in Patent Documents 2 to 4 are provided with a driving device, and are moved by, for example, remote operation or myoelectric signals.

Special table 2007-502650 gazette Special table 2009-519795 gazette JP-T 2009-519796 Special table 2009-519797

  By the way, in daily life and business execution, as a function of the palm part in which a finger is involved, there are a picking function and a gripping function. In order to realize these functions, it is necessary to configure the finger MP joint, PIP joint, and DIP joint so that they can be moved actively and appropriately in conjunction with each other. However, for example, in daily object gripping, all the joints are not necessarily linked. For example, for the index finger (second finger) and the middle finger (third finger), the number of fingertip knobs is overwhelmingly large, and the fingertip knob is more stable when the PIP joint and DIP joint are fixed in the extended posture. No joint interlocking mechanism is required. On the other hand, for the ring finger (fourth finger) and the little finger (fifth finger), since there are many gripping operations, it is preferable to have a joint interlocking mechanism because it is easier to stably hold an object.

  Therefore, for cutting at the palm, depending on the type of finger to be reconstructed and the intended purpose of use, etc., the mobility of each joint, the possibility of active movement, or the interlocking between each joint Realization is required. The prosthetic limbs described in each of the patent documents are configured to move and interlock each joint in response to such a request.

  However, the movable prosthetic finger described in Patent Document 1 has a problem of becoming relatively heavy because it moves the joint by providing an eccentric link mechanism on each finger. In addition, it is complicated mechanically, and high strength is required for a small-sized component, which causes a problem that the manufacturing cost is high.

  Further, the prosthetic hands described in Patent Documents 2 to 4 are provided with a driving device and are configured to use a remote operation or a myoelectric signal, so that they are heavy and large. In addition, it is difficult to obtain the natural movement of the hand regardless of which method is used. In addition, since this prosthetic hand is provided with a driving device in the palm, it is difficult to apply to the case of finger cutting. Therefore, there has been a demand for a simple and lightweight artificial finger that can be applied to the case of finger cutting and is configured such that each joint is movable in conjunction with each other.

  The present invention has been made in the background of the above circumstances, and its purpose is to flex and extend a prosthetic finger for reconstructing a finger that has been cut leaving some joints with a bending and stretching function of the apex. To provide a mechanism.

In order to achieve such an object, the gist of the present invention is a prosthetic finger flexion and extension mechanism that can be operated using the remaining joint on the apex side by attaching it to a finger that has been cut leaving the MP joint. (A) a stump socket fitted to the remaining finger part; (b) a palm socket fitted to the palm part closer to the original side than the MP joint; and (c) a tip part of the stump socket. A first link that is pivotally attached to a first rotation shaft provided parallel to the rotation shaft of the MP joint at a position corresponding to the PIP joint, and the first link A cusp portion comprising a second link pivotally attached to a distal end portion of a second rotation shaft provided parallel to the rotation shaft of the MP joint at a position corresponding to the DIP joint. A link; and (d) a palm dorsal side of the palm socket and the first A bending traction line that is connected to the two links by a predetermined tension through the inner side of the palm than the first rotating shaft and the second rotating shaft; and the inner side of the palm socket and the second link And at least one of an extension traction line that is connected with a predetermined tension through the palm back side of the first rotation shaft and the second rotation shaft.

Thus, the distal end of the stump socket, the rotatably around the first rotation shaft and the second turning axis parallel to the rotation of the MP joint shaft (i.e. shaft Yoshiyubi times) and second links (i.e. Togayubi portion link) is attached, it is between its Togayubi portion link and fitted to the palm Tagged palm socket (i.e. Motogawa socket), the Togayubi portion link and a palm dorsal palm socket first rotation axis and the bending tractive lines connecting through the palm inward than the second pivot shaft, and, a palm inner Togayubi portion link and palm socket first Since at least one of the extension traction lines connected through the palm dorsal side than the rotation axis and the second rotation axis is provided with a predetermined tension, in the case where the former bending traction line is provided, When stump socket is pivoted on the palm inward around the MP joint, and the palm portion sockets Interval in Tenohirase side and end socket is widened. Therefore, the tension of the connected bending traction line is increased the palm dorsal palm socket, apex thereof bent tractive line is connected through the palm inward than the first rotation shaft and the second turning axis A tensile force acts on the finger link inside the palm. As a result, as the stump socket moves inward of the palm, the cusp link smoothly rotates inward of the palm and is bent inward of the palm with respect to the stump socket. On the other hand, in the case where the latter extension traction line is provided, when the stump socket is turned to the palm back side from the bent state as described above, the palm socket and the stump socket are connected to each other. The space inside the palm is widened. Therefore, the tension of the connected stretch tractive lines on the palm inside the palm socket is enhanced, leaflets its stretch tractive line is connected through the palm dorsal side of the first rotation shaft and the second turning axis A tensile force is applied to the finger link on the palm back side. As a result, as the stump socket turns to the palm dorsal side, the cusp link rotates smoothly to the palm dorsal side and extends to the palm dorsal side with respect to the stump socket. Become. In addition, the cusp link is composed of a first link and a second link that can rotate relative to each other on the second rotation shaft, but the bent traction line passes through the inner side of the palm than the first rotation shaft and the second rotation shaft. The extension traction line is connected to the second link through the palm dorsal side of the first rotation shaft and the second rotation shaft. When it is turned inward, or when it is turned to the palm dorsal side from that state, the first link and the second link are smoothly bent to the inside of the palm along with the turning, or smoothly to the palm dorsal side. Can be extended. Therefore, since a smooth bending / extending operation is realized even with the cusp link formed of two joints, the present invention is not limited to the case where only the DIP joint is lost, and the two joints of the PIP joint and the DIP joint are lost. This also applies to

  Therefore, when the prosthetic finger having the bending and stretching mechanism of the present invention is attached to the remaining portion of the cut finger, when the bending joint line is provided, if the remaining joint is bent, the remaining joint is bent. In the case where the cuspid link is smoothly bent along with the movement and the extension traction line is provided, when the remaining joint is extended, the phalangeal link is moved along with the extension of the residual joint. Smooth extension operation. As described above, a prosthetic finger for reconstructing a finger that has been cut while leaving some joints in a state of having a bending-extending function at the tip is obtained. Since bending and extension are performed in this way, when only one of the bending traction line and the extension traction line is provided, a function corresponding to only one of them can be obtained, but both are provided. In this case, the prosthetic finger can bend and stretch along with the bending and stretching operation of the stump.

  In addition, in the case where both the bending traction line and the extension traction line are provided, the tension of the other one of which is increased in accordance with the bending and stretching of the stump portion, on the other hand, the tension is reduced, so both Even if it is provided, the other does not hinder the bending and stretching operation by one of which the tension is applied. In the case where only one of the bending traction line and the extension traction line is provided, an elastic body such as a spring or rubber may be provided on the missing side so that the tensile force acts. If it does in this way, it will be necessary to operate either a bending end of a stump part against the tensile force of the elastic body, but a prosthetic finger can be operated actively in any bending and extension.

Here, preferably, the prosthetic finger flexion / extension mechanism restrains the bending traction line and the extension traction line so as not to leave the first link in a state in which the bending traction line and the extension traction line can be moved back and forth in the respective length directions. The restraint member is included. In this way, even when the cusp link is composed of two joints, one of the bending traction line and the extension traction line, the tension of which is reduced with the rotation of the stump socket, is the first. Since the link is not separated from the link, it is possible to prevent the bending traction line and the extension traction line from being caught and becoming difficult to return at the time of returning from the bending / extension operation.

  Preferably, the traction line restraining member is a columnar or cylindrical body provided on the first link in parallel with the first rotation axis and the second rotation axis, and the bending traction line and Each of the extension traction lines passes between the first rotation shaft and the traction line restraining member and between the traction line restraining member and the second rotation shaft, and the palm inner side of the first link. It reciprocates between the back of the palm. As the traction line restraining member, any member having an appropriate structure can be used as long as it can constrain the bending traction line and the extension traction line, but such a columnar or cylindrical one is simple and preferable.

Preferably, the palm socket and the point finger link are each provided with a through-hole through which the bending traction line and the extension traction line pass. In this way, the bending traction line and the extension traction line are held in the through hole as they are even if the tension is lowered with the rotation of the stump socket, so that the bending traction line and the extension traction line are restored when the bending / extension operation is restored. It is suppressed that it becomes caught and becomes difficult to return. That is, in this aspect, the palm socket and the point finger link provided with the through hole also serve as a traction line restraining member.

Preferably, the palm socket and the cusp link are manufactured by powder molding. According to powder molding using a 3D printer or the like, there is an advantage that a through hole can be easily formed at the same time as forming the outer shape.

  Preferably, the pointed finger link is entirely made of a flexible material. In this way, when a picking operation or the like is performed using a prosthetic finger, the force applied to the fingertip link from the surface of the object causes the tip finger link to be deformed as a whole, so that the force is reduced. It is transmitted to the finger remaining part in which the stump socket is fitted. Therefore, the force applied to the object by the picking operation or the hardness of the surface of the object can be sensed by the sense of touch of the finger remaining part.

  Further, the present invention is intended to perform the bending / extending operation of the fingertip using the bending / extension operation at least when the MP joint remains, but it can be applied to the electric prosthesis even when the MP joint is lost. For example, there is an advantage that smooth bending and stretching operations can be realized by transmitting the bending and stretching operations of the reconstructed MP joint to the tip of the finger.

  Preferably, the bending traction line and the extension traction line each include a plurality of lines. If each of the bending traction line and the extension traction line is provided, it is possible to perform the bending / extending operation of the fingertip link beyond the lost joint. Can be transmitted.

It is sectional drawing explaining the structure of the artificial finger of one Example of this invention. It is a top view which shows the whole artificial finger of FIG. It is a figure shown in the state which mounted | wore the artificial finger of FIG. It is a figure explaining the picking operation | movement of the artificial finger of FIG. It is a side view explaining the structure of the artificial finger of the other Example of this invention. It is a top view of the artificial finger of FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a cross-sectional view of a prosthetic finger 10 according to an embodiment of the present invention, and FIG. 2 is a plan view thereof. The prosthetic finger 10 is applied to a hand in which one finger is missing leaving the MP joint 12 and can be fitted to the pointed finger link 16 corresponding to the missing part of the finger and the stump 18 of the finger. A stump socket 20 is provided, and a palm socket 24 is fitted into the palm 22 of the hand.

  The stump socket 20 is made of, for example, a thermoplastic or thermosetting resin, and is formed in a laminated structure or integrally formed so as to have a substantially cylindrical shape so that the stumps 18 of the fingers are fitted in close contact with each other. doing. As shown in FIG. 1, the stump socket 20 is configured to have a dimension that is located on the distal end side with respect to the MP joint 12 of the finger that is entirely lost. On the inner peripheral side of the stump socket 20, a cushion material or the like for protecting the stump 18 is provided as appropriate.

  The pointed finger link 16 is made of the same metal or resin as the stump socket 20, and includes a first link 26 simulating a portion following the finger stump 18 and a finger following the first link 26. And a second link 28 imitating the tip. The first link 26 has a cylindrical shape or a substantially cylindrical shape in which a part of the circumferential direction (for example, the abdomen side of the finger) is opened, and can rotate around the first rotation shaft 30 corresponding to the PIP joint. It is attached to the tip of the stump socket 20. The second link 28 is formed in a cylindrical shape or a solid shape, and is attached to the distal end portion of the first link 26 so as to be rotatable around the second rotation shaft 32 corresponding to the DIP joint. Therefore, the point finger link 16 of the prosthetic finger 10 is in a connected state in which the first link 26 and the second link 28 can be independently rotated with respect to the stump socket 20.

  In the present embodiment, the first rotation shaft 30 and the second rotation shaft 32 correspond to the artificial finger rotation shaft, and both of them are provided so that the axial direction is substantially parallel to the MP joint 12. It has been.

  The palm socket 24 is made of the same metal or resin as the stump socket 20, and is securely fixed to the palm 22 using a fastening tool such as a band (not shown). ing. In this embodiment, the palm socket 24 corresponds to the original socket.

  Between the first link 26 and the palm socket 24, a pair of bending traction wires 34 and extension traction wires 36 having both ends fixed thereto are provided. These wires 34 and 36 are those that are not easily stretched or cut even if the operation described below is repeated. For example, a PE line (that is, a strand made of ultrahigh molecular weight polyethylene) that has a property of stretchability of about 1 to 2% and high wear resistance and is used for fishing lines is used.

  The bent pulling wire 34 connects the palm back side 24 a of the palm socket 24 and the palm inner side 28 a of the second link 28. Between the 1st rotation axis | shaft 30 and the 2nd rotation axis | shaft 32 of the 1st link 26, the wire restraining pin 38 is provided in parallel with them. The bent pulling wire 34 attached to the palm dorsal side 24a of the palm socket 24 passes between the first rotating shaft 30 and the cut end portion 18 and turns to the inner side of the palm. It passes between the pin 38 and turns to the palm back side, and further passes between the wire restraining pin 38 and the second rotation shaft 32 to turn inside the palm and is connected to the palm inside 28a of the second link 28. Yes. That is, the bending pulling wire 34 is provided so as to pass through the palm inner side than the first rotating shaft 30 and the second rotating shaft 32.

  Further, the extension pulling wire 36 attached to the palm inner side 24b of the palm socket 24 passes between the first rotation shaft 30 and the stump 18 and turns to the palm back side. It passes between the wire restraining pin 38 and the inside of the palm, and further passes between the wire restraining pin 38 and the second rotation shaft 32 and turns to the palm back side, to the palm back side 28b of the second link 28. It is connected. That is, the extension pulling wire 36 is provided so as to pass through the palm back side of the first rotation shaft 30 and the second rotation shaft 32.

  Further, the bending pulling wire 34 is fixed at a position inside the palm of the second link 28 relative to the second rotation shaft 32, and the extension pulling wire 36 is rotated secondly of the second link 28. The shaft 32 is fixed at a position on the palm back side.

  In FIG. 1, the bending traction wire 34 and the extension traction wire 36 are drawn in a loose state for easy understanding, but these two traction wires 34, 36 are both movements of the MP joint 12. It is stretched without loosening with a tension that does not hinder the movement, and is pressed against the first rotation shaft 30, the second rotation shaft 32, and the wire restraining pin 38. As shown in FIG. 2, the pulling wires 34 and 36 are provided so as to pass through, for example, the central part in the width direction of the finger.

  In addition, although illustration is abbreviate | omitted, the artificial finger | toe 10 is provided with the exterior material for decoration as needed, and covers and hides the structural member, reduces an uncomfortable feeling with respect to others, and protects a movable part.

  The prosthetic finger 10 configured as described above is used by being attached to the hand 40 as shown in FIG. FIG. 3 shows the case where the right hand finger is missing leaving the MP joint 12, and the stump socket 20 is fitted to the stump 18 and the palm socket 24 is fitted to the palm 22. Thus, the artificial finger 10 is attached to the hand 40.

  When the MP joint 12 of the index finger is bent as shown in FIG. 4 in the above-mentioned wearing state, the palm dorsal side extends at the position of the MP joint 12 and conversely the palm inner side contracts. The space on the back side of the palm with respect to the head socket 20 is widened and the space on the inside of the palm is shortened. Therefore, a pulling force acts on the bending pulling wire 34 located on the palm dorsal side at the position of the MP joint 12, and conversely, the tension acting on the extension pulling wire 36 located on the inner side of the palm is reduced (ie, loosened). .

  At this time, the first pulling shaft 30, the wire restraining pin 38, and the second rotating shaft 32 are positioned so that the bending pulling wire 34 is located on the palm side of the first rotating shaft 30 and the second rotating shaft 32. Since the second link 28 is connected to the palm inner side 28a of the second link 28 rather than the second rotation shaft 32, a tensile force toward the palm inner side acts on the second link 28. On the other hand, the extension pulling wire 36 passes between the first first rotating shaft 30, the wire restraining pin 38, and the second rotating shaft 32, and the palm dorsal side 28 b of the second link 28 than the second rotating shaft 32. Therefore, the pulling force toward the palm dorsal side of the second link 28 is reduced. As a result, the second link 28 bends inward of the palm according to the tension difference thus generated, that is, according to the amount of bending of the MP joint 12.

  The pulling force acting on the bending pulling wire 34 is such that the distance between the palm back side 24 a of the palm socket 24 and the second link 28 is also between the first rotation shaft 30 and the wire restraining pin 38. The wire restraining pin 38 acts in the direction of turning inward of the palm with respect to the first turning shaft 30 so as to be contracted. As a result, the first link 26 is also rotated inward of the palm about the first rotation axis 30 according to the bending amount of the MP joint 12. In this way, the bending operation of the MP joint 12 causes the first rotating shaft 30 corresponding to the PIP joint and the second rotating shaft 32 corresponding to the DIP joint to be smoothly bent according to the amount of bending.

  If the MP joint 12 is extended from the above bent state, the bent pulling wire 34 that passes through the inner side of the palm than the first rotating shaft 30 and the second rotating shaft 32 is loosened, and the first rotating shaft 30 and The extension pulling wire 36 passing through the palm back side of the second rotation shaft 32 is pulled. Therefore, in synchronization with the extending operation of the MP joint 12, the first rotating shaft 30 and the second rotating shaft 32 are smoothly extended. According to the present embodiment, a natural bending / extending operation of the pointed finger portion can be obtained only by bending and extending the MP joint 12 remaining on the missing finger in this way.

  In addition, the bending pulling wire 34 and the extension pulling wire 36 can each be composed of a plurality of wires. By increasing the number of wires, the force required to bend and extend the MP joint 12 is increased, but the force transmitted to the cusp link 16 during the finger bending / extending operation can be increased.

  In short, according to the present embodiment, the tip portion of the stump socket 20 is provided with a tip portion that is rotatable about the first rotation shaft 30 and the second rotation shaft that are parallel to the rotation shaft of the MP joint 12. A link 16 is attached, and a bent pulling wire 34 passes between the palm inner side 28 a of the pointed finger link 16 and the palm back side 24 a of the palm socket 24 through the inner side of the palm rather than the second rotating shaft 32. In addition, the extension pulling wire 36 is stretched between the palm dorsal side 28b of the cusp link 16 and the palm inner side 24b of the palm socket 24 through the palm dorsal side of the second pivot shaft 32. Therefore, when the stump socket 20 is rotated around the MP joint 12 to the inside of the palm, the gap between the palm socket 24 and the stump socket 20 on the palm dorsal side is widened and the gap inside the palm is also provided. Is shrunk.

  Therefore, the tension of the bending pulling wire 34 connected to the palm back side of the palm socket 24 is increased, and the tension of the extension pulling wire 36 connected to the inner side of the palm is reduced. Further, the bending pulling wire 34 passes through the palm inner side, the extension pulling wire 36 passes through the palm dorsal side from the first rotation shaft 30, and the second link 28 of the connected cuspid link 16 is connected to the inner side of the palm. A pulling force acts on the. As a result, as the stump socket 20 rotates inward of the palm, the cusp link 16 smoothly rotates inward of the palm and is bent inward of the palm with respect to the stump socket 20. Become. On the contrary, when the stump socket 20 is rotated to the palm dorsal side from this state, the pulling force to the palmar dorsal side acts on the cusp link 16 by the opposite action to the rotation to the palm inner side. Then, as the stump socket 20 turns to the palm back side, the cusp link 16 smoothly turns to the palm back side and extends to the palm back side with respect to the stump socket 20. It will be.

  Therefore, when the prosthetic finger 10 having the bending / extending mechanism of the present embodiment is attached to the cut end portion 18 of the cut finger and the remaining joint (MP joint 12) is bent, the apex is accompanied with the bending operation. If the finger link 16 smoothly bends and the remaining MP joint 12 is extended from this state, the pointed finger link 16 smoothly extends along with the extension operation. As described above, the prosthetic finger 10 for reconstructing the finger that has been cut leaving a part of the joint with the apex bending and stretching function is obtained.

  5 and 6 are a side view and a plan view, respectively, for explaining the configuration of a prosthetic finger 40 according to another embodiment of the present invention. The prosthetic finger 40 includes a pointed finger link 42 corresponding to a missing portion of the finger and a stump socket 44 for fitting to the stump 18 of the finger. This prosthetic finger 40 is also provided with a palm socket for fitting to the palm 22 (see FIGS. 1 and 3) of the hand, but is configured in the same manner as the prosthetic finger 10, Omitted.

  The stump socket 44 is made of, for example, thermoplastic or thermosetting resin, and is formed by powder molding using, for example, a 3D printer or the like, and includes a pair of bent pulling wires 46 and 46 and an extension. The through holes 50, 50, 52, 52 through which the pulling wires 48, 48 are passed, and the semi-cylindrical protrusions 54 to be engaged with the pointed finger links 42 are provided. The outer peripheral surface of the protrusion 54 is provided so as to extend in the direction along the MP joint 12 of the stump 18.

  The through holes 50 and 52 are both cut off at the notch provided in the central portion of the cut end socket 44, and the opening on the cut end 18 side and the opening on the fingertip link 42 side are cut off. Are formed so as to be opposite to each other with the protrusion 54 interposed therebetween. In other words, the through holes 50 and 52 are formed such that a pair of bending traction wires 46 and 46 and extension traction wires 48 and 48 intersect at a position closer to the stump 18 side than the protrusion 54, respectively. It is formed in the vicinity of both side surfaces so that the positional relationship changes. Further, the protrusion 54 is provided with a pair of threading holes 56 and 56 penetrating from the top to the cut end 18 side. These thread passage holes 56 are formed so as to gradually expand in the vertical direction in FIG. 5 (that is, the direction from the palm dorsal side toward the palm inner side) toward the top of the protrusion 54. 5 and 6, the cut end socket 44 is provided so as to be abutted against the end face of the cut end portion 18, but it is fitted with the cut end portion 18 in close contact like the artificial finger 10. You may comprise in a substantially cylindrical shape so that it may enter.

  The cusp link 42 is made of thermoplastic or thermosetting resin, like the artificial finger 10, and is formed by powder molding using a 3D printer or the like. A first link 58 simulating a portion following the end portion 18 and a second link 60 simulating a finger tip portion following the first link 58 are provided. Each of the first link 58 and the second link 60 has a substantially columnar shape provided with an external shape imitating the shape of a corresponding part of a finger, and a spring penetrating from the palm dorsal side to the inside of the palm. Accommodating holes 62 and 64 are provided, respectively.

  The first link 58 is provided with a semi-cylindrical recess 66 fitted to the projection 54 on the stump socket 44 side, and a semicircle similar to the projection 54 on the second link 60 side. A columnar protrusion 68 is provided. Further, the first link 58 is provided with a pair of thread passage holes 70, 70 penetrating from the inside of the spring accommodation hole 62 to the recess 66 so as to be positioned on an extension line of the thread passage holes 56, 56. A threading hole 72 penetrating from the spring accommodating hole 62 to the top of the protrusion 68 is provided. Similar to the thread passage hole 56, the thread passage hole 72 is formed so as to expand toward the tip. In addition, through holes 74 and 74 through which the bent pulling wire 46 is passed on the palm inner side than the spring accommodating hole 62, through holes 76 and 76 through which the extension pulling wire 48 is passed on the palm back side. Both are formed near both side surfaces. These through holes 74 and 76 are provided on the extended lines of the through holes 50 and 52 of the stump socket 44, respectively.

  Further, the second link 60 is provided with a semi-cylindrical recess 78 fitted to the projection 68 on the first link 58 side. Further, the second link 60 is provided with a thread passage hole 80 penetrating from the inside of the spring accommodation hole 64 to the recess 78 so as to be positioned on an extension line of the thread passage hole 72, and the spring accommodation hole 64. A pair of threading holes 82, 82 penetrating from the tip to the tip surface is provided. Further, the second link 60 has through holes 84 and 84 through which the bent pulling wire 46 is passed, and the end surface on the first link 58 side opens at a position inside the palm from the recess 78, and at the tip surface thereof The first link 58 includes through-holes 86, 86 that are provided obliquely from the inner side of the palm to the back of the palm so as to open to a position on the back of the palm relative to the recess 78, and through which the extension pulling wire 48 passes. It is provided in a slanting direction from the palm dorsal side to the palm inner side so as to open to a position on the palm dorsal side with respect to the recess 78 at the end face on the side and to open to a position inside the palm with respect to the recess 78 at the front end face Yes. That is, these through holes 84 and 86 are formed so as to intersect at a position on the tip side from the recess 78. Note that the ends of the bending pulling wire 46 and the extension pulling wire 48 are fixed to the tip of the second link 60.

  A tension coil spring 88 is accommodated in the spring accommodating hole 62 provided in the first link 58. A thread 90 passed through the thread passage holes 56 and 70 is hung on one end of the tension coil spring 88. Further, a thread 92 passed through the thread passage holes 72, 80, 82 is hung on the other end. The yarns 90 and 92 are provided such that their mutual distance is longer than the length of the tension coil spring 88 when no load is applied. Therefore, tension is applied to the yarns 90 and 92 by the tension coil spring 88. By providing the tension coil spring 88 and the threads 90 and 92 as described above, the first link 58 is pressed against the cut end socket 44, and the second link 60 is pressed against the first link 58. Is in a state. Since the projections 54 and 68 and the recesses 66 and 78 having a semi-cylindrical surface are formed between them, the end socket 44 and the first link are pressed against each other in this manner. 58 and the second link 60 can be relatively rotated around the rotation axes 94 and 96. These rotation shafts 94 and 96 correspond to the PIP joint and the DIP joint, respectively. Further, as is clear from the above description, the bending pulling wire 46 is provided through the inner side of the palm relative to the rotating shafts 94 and 96, and the extension pulling wire 48 passes through the palm dorsal side of the rotating shafts 94 and 96. Is provided.

  The spring accommodating hole 64 is prepared so that a spring similar to the tension coil spring 88 can be accommodated, but the spring is not accommodated therein, and the thread 92 is passed therethrough. Only. The tension coil spring 88 is provided for the purpose of applying tension to the yarns 90 and 92 as described above, and it is sufficient if the tension coil spring 88 is provided in any one of the spring accommodating holes 62 and 64. Further, the connecting portion of the stump socket 44, the first link 58, and the second link 60 has a semi-cylindrical surface as described above, and is simply pressed against each other by the tensile force acting from the tension coil spring 88. Therefore, the relative movement in the direction perpendicular to the paper surface of FIG. 5 and the relative rotation around the axis perpendicular to the paper surface of FIG. 6 are allowed to some extent. For this reason, these movements can occur when an external force is applied. However, when the external force is removed, the movement automatically returns to the illustrated positional relationship according to the tension acting on the threads 90 and 92. .

  In addition, the end edge socket 44, the first link 58, and the second link 60 all have an inclined end surface on the inner side of the connecting portion. Therefore, the cut end socket 44 and the first link 58, the first link 58 and the second link 60 are mutually connected by the protrusion 54, the recess 66 or the protrusion 68 and the recess 78 within the range allowed by these inclined surfaces. It will be made to rotate mutually while sliding.

  In the prosthetic finger 40 configured as described above, when the MP joint 12 of the stump 18 is bent and stretched as in the case of the prosthetic finger 10, the tension of the bending pulling wire 46 is increased and the extension pulling wire 46 is bent. Since 48 is loosened, the first link 58 and the second link 60 are bent according to the bending amount of the stump 18. Further, at the time of extension from the bent state, the tension of the extension pulling wire 48 is increased and the bending pulling pulling wire 46 is loosened, so that the first link 58 and the second link 60 are adapted to the extension amount of the stump 18. Can be extended. That is, as the stump 18 moves, the first link 58 is rotated with respect to the stump socket 44 and the second link 60 is rotated with respect to the first link 58. A bending and stretching operation up to the tip is obtained.

  In addition, although the said artificial finger 40 was provided with both the bending pulling wire 46 and the extension pulling wire 48, it is also possible to provide only any one according to the required movement. For example, when only the bending pulling wire 46 is provided, a bending operation up to the tip of the artificial finger 40 can be obtained along with the bending operation of the stump 18, but even if the stump 18 is extended from that state, The extension operation of the prosthetic finger 40 cannot be obtained. Therefore, the extension operation is performed dynamically, but such a configuration is acceptable if only the bending operation is necessary. Further, instead of providing the extension pulling wire 48, each of the palm dorsal side between the stump socket 44 and the first link 58 and the palm dorsal side between the first link 58 and the second link 60, respectively. If a tension force is applied by a tension coil spring or the like, it is necessary to bend the stump 18 against the tension force of the tension coil spring, but the force in the bending direction is excluded. The prosthetic finger 40 is extended according to the pulling force of the pulling coil spring. That is, even in this way, an active movement can be obtained.

  As mentioned above, although this invention was demonstrated in detail with reference to drawings, this invention can be implemented also in another aspect, A various change can be added in the range which does not deviate from the main point.

10 prosthetic finger, 12 MP joint, 16 pointed finger link, 18 stump, 20 stump socket, 22 palm, 24 palm socket, 26 first link, 28 second link, 30 first pivot , 32 Second rotation axis, 34 Bending traction wire, 36 Extension traction wire, 38 Wire restraint pin, 40 Prosthetic finger, 42 Point finger link, 44 End socket, 46 Bending traction wire, 48 Extension traction wire, 50 , 52 Through hole, 54 Protrusion, 56 Thread through hole, 58 First link, 60 Second link, 62, 64 Spring accommodating hole, 66 Recess, 68 Protrusion, 70 Thread through hole, 72 Thread through hole, 74 Through hole 76 through hole, 78 recess, 80 thread through hole, 82 thread through hole, 84 through hole, 86 through hole, 88 tension coil spring, 90 thread, 92 thread, 94, 96

Claims (5)

It is a prosthetic finger flexion and extension mechanism that can be operated using the remaining joint on the apex side by attaching it to the finger that has been cut leaving the MP joint,
A stump socket fitted to the remaining finger portion;
A palm socket that is fitted to the palm of the base from the MP joint;
First mounted for its axial center pivot at the first pivot axis provided parallel to the rotation of the MP joint in a position corresponding to P IP joint shaft to the distal end of the stump socket A link and a second rotation shaft provided in parallel to the rotation shaft of the MP joint at a position corresponding to the DIP joint at a tip portion of the first link are rotatably attached around its axis. Pointed links consisting of two links,
A bent traction line connected with a predetermined tension between the palm spine side of the palm socket and the second link through the inner side of the first rotating shaft and the second rotating shaft; and Between the palm inner side of the palm socket and the second link, at least one of the first rotation shaft and an extension traction line connected with a predetermined tension through the palm back side of the second rotation shaft. A prosthetic finger flexion and extension mechanism using the remaining finger part function. The bending tractive lines and the stretch tractive line movable fingers remaining functions of claim 1 in a state in which includes a traction wire restraining member that restrains so as not away from the first link before and after each lengthwise Prosthetic finger flexion and extension mechanism. The traction line restraining member is a columnar or cylindrical body provided on the first link in parallel with the first rotation axis and the second rotation axis, and each of the bending traction line and the extension traction line Is between the first rotation shaft and the traction line restraining member and between the traction line restraining member and the second rotation shaft, and between the palm inner side and the palm back side of the first link. The prosthetic finger flexion / extension mechanism using the finger part remaining function according to claim 2 , wherein The artificial finger bending and extending mechanism according to claim 1, wherein the palm socket and the point finger link are each provided with a through-hole through which the bending traction line and the extension traction line pass. The artificial finger bending and extending mechanism according to claim 4 , wherein the palm socket and the point finger link are manufactured by powder molding.

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