WO2017212128A1

WO2017212128A1 - Kinematic partial hand prosthesis

Info

Publication number: WO2017212128A1
Application number: PCT/FR2017/000114
Authority: WO
Inventors: Oscar Feltrin; Adeline BERNHARDT
Original assignee: Oscar Feltrin; Bernhardt Adeline
Priority date: 2016-06-08
Filing date: 2017-06-07
Publication date: 2017-12-14
Also published as: FR3052354A1

Abstract

The invention relates to a prosthesis for a partially amputated hand, comprising a socket (E) to be mounted on the patient's functional metacarpal portion, a socket (F) to be mounted on the immobile portion of the wrist, a device (Z) comprising the central pulley (A), the spacers (Q1) and (Q2), the freely rotatable actuators (B) and (C) which are used for flexing or extending the long fingers, the support for the long fingers and a mechanical thumb.

Description

CINEMATIC PROSTHESIS OF PARTIAL HAND

The present invention relates to a prosthesis for a partial amputation of the hand. This partial hand prosthesis concerns all patients whose wrist joint is still functional and some of the metacarpal is still existing. The partial hand prosthesis is provided with movable knuckle fingers operating independently of one another. The putting in function of the fingers being done by the movement of the wrist. This prosthesis characteristic also makes it possible to produce a total hand prosthesis with electrical operation.

In the field of kinematic function hand prostheses, solutions are given as in US Pat. No. 2,549,716 which relates to a mechanical hand with flexing and extension of the long fingers, but not usable for a partial amputation of a hand, a another patent US Pat. No. 2,867,819 which is a direct pull on each finger without power distribution, US Pat. No. 1,298,502 which involves a total amputation of the hand, another US Patent No. 2006 / 0129248A1 which also involves an amputation total of hand as well as the patent FR 2,557,450 as well as the patent FR2557450. Other patents: US6379393, GB 237085, US 2006/224249, only for amputations of total hands or forearms, moreover the draw of the cable is at the level of the shoulder, the patent FR2957245 which is a The electrically operated total hand patent FR 3010895 which is mechanical gearing taking a place equal to 1/3 of the palmar width and cable references not allowing to be aligned with the prosthetic fingers. The present invention seeks to remedy these drawbacks and to offer a simple solution of realization.

The present invention concomitant prosthesis for partial hand amputation whose wrist is functional. For the demonstration we will take as an example an extreme case where the amputee only has a portion of the metacarpal without the thumb, which will allow us to illustrate the operation of the prosthetic thumb A cover covers the metacarpal portion of the amputated hand, a second carabiner is attached to the wrist. These two housings are integral and movable together by two rotational devices located on either side of the wrist, and an independent mechanical thumb can be attached to the movable housing of the metacarpal.

According to an advantageous form of this invention, the rotation of the wrist allows the pulling of two cables which actuate a pulley which can rotate in both directions, depending on whether the user is extending or flexing the wrist. The rotation of this pulley A (FIG. 1), as will be described above, rotates two actuators located on each side thereof and consequently the movement of the four long fingers and their respective phalanges.

According to another advantageous form of the invention, each actuator makes it possible to draw a pair of long fingers in flexion or in extension with U-shaped cables allowing the balanced distribution of the forces.

According to another advantageous aspect of the invention, the crossing of the two flexion and extension pull cables L1, L2 (FIG. 1) enables the actuators to draw on the prosthetic fingers in correspondence with the flexion or the extension. wrist.

According to another advantageous characteristic of the invention, the dimensions of the actuators and of the central pulley can be realized in a diam

thus making it possible to equip prostheses of different dimensions.

The invention will be described with reference to the accompanying drawings by way of example and not limitation of an embodiment of the invention. The prosthesis is intended to be mounted on a partial hand amputation stump using known fastening means. The partial hand prosthesis consists of 7 essential parts;

1- a cover E (Fig.1), intended to be mounted on the metacarpal portion of the patient and on which will be fixed the entire device for movement of the fingers, and the fingers, using the axes H1, H2 , H3, H4,

2- a device that supports the prosthetic fingers, the pulley A (Fig.1) acting as a differential and whose cables R1 and R2 drive the actuators B and C allowing either the flexion or the extension of the long fingers,

3- a cover F (Fig.1), intended to be mounted on the fixed part of the wrist and on which will be fixed on the palmar side a pull cable L1 with a resin Fp of the palmar side and the back side a pull cable L2 with a resin Fd, each passing through the respective guides M1 and M2, and to allow the bending action of the fingers in harmony with the flexion of the wrist, the cables L1 and L2 intersect before the nest E, the pull cable dorsal passing through the through hole K (Fig.1),

4- two joints G and G1 (Fig.1) to articulate the two slots E and F and thus pull on the cable L1 or L2 to put in extension or flexion the long fingers, it should be noted that when the cable L1 is drawn, the cable L2, automatically rolls in the opposite direction on the pulley A,

5- an independent mechanical thumb (Fig.5) with several positions in closure and lateral positions adjustable by a friction device, provides a long-fingered counterforce,

6- a device Z (Fig.1) comprising;

two supports V1, V2 on which is fixed an axis X (Fig.1) which supports the central pulley A, the spacers Q1 and Q2 and the rotational actuators B, C which serve to draw in flexion or extension of the long fingers,

the supports A1, A2, A3, A4 (FIG. 1) on which are articulated the first phalanges of the fingers II, III, IV, V, the other phalanges articulating around the axes X1, X2, X3, X4,

four tubes J1, J2, J3, J4 (FIG. 1) which serve to position the bars H1, H2, H3, H4, which are fixed to the mobile socket E,

7. a device formed of a pulley P2 (Fig.2) and an axis of a blocking plate B1 which allows the holding of the finger II in extension while the other fingers can flex.

The fingers, the actuators and the pulley A can be made of different diameters and widths in order to adapt to the mobility of the wrist and the type of amputation of the patient.

According to one aspect of the invention, the device Z is provided with a pulley A (FIG. 1, 3) which serves as a differential and in which through the hole T2 (FIG. 1, 4) pass the cables R1 and R2 which balance the pulling forces of the actuators B and C which themselves balance the forces of the fingers two by two, the assembly allows an instantaneous balancing of the four long fingers. Pulley A has an axial hole T4 (FIG. 1, 3, 4) which is of the same size for parts B, C, Q1, Q2 and which allows it to be free to rotate about the X axis (FIG. .1), it also comprises a transverse hole T1 (Fig.3,4) perpendicular to the hole T5 to allow the attachment of the cable L1 using a node, the hole T1 to insert the node to the inside the pulley, it also comprises a transverse hole T3 (Fig.3,4) perpendicular to the hole T6 to allow the attachment of the cable L2 with the aid of a node, the hole T3 allows to insert the node to the inside the pulley. The hole T2 serves as a passage for the cables R1 and R2 (Fig.1, 3.4) which are fixed to the actuators B and C (Fig.1, 3) to the respective holes P, P 'and, N, N' ( Fig.3) this hole T2 allows cables R1 and R2 (Fig.4) to slide, and therefore to balance the pulling forces of the actuators B and C. The actuators B and C (Fig.1, 3.4) are provided on the pull flange adjacent to the central pulley A of two holes each, P and P '( Fig.3) on the actuator B, and N and N 'on the actuator C (Fig.3) for fixing the cables R1 and R2. The actuators B and C are kept apart from the pulley A by the spacers Q1 and Q2 (Fig.1, 3.4) to position the actuators B and C in front of the respective fingers and to leave a movement space for the pulling cables. R1 and R2 (Fig.1, 3,4). The last phalanges of the long fingers are articulated around the axes X1, X2, X3, X4 (Fig1).

The operation of the invention will now be described below.

When the stump of the user is moving, that is to say, if the latter makes a bending or extension movement, the cover E and the cover F (FIG. joints G and G1, which pulls either on the cable L1 and releases the cable L2, or pulls on the cable L2 and releases the cable L1. These cables integral with the pulley A are partially wound in the concave portion thereof (Fig.1, 3.4), each with a reverse winding and fixed inside the holes T5 or T6 by a sliding knot at inside the respective holes T1 and T3 at one end and at the other end the pull cable of the flexion fingers L2 is fixed on the dorsal portion of the fixed housing F and the pull cable of the fingers L1 extension on the part palmar of the fixed socket element F. both L1 and L2 cables crossing before the socket E (Fig.1, 3) rotate ^AI ^~ pôûlië7Tët therefore B and C actuators in the direction of bending and drawing allow the movement of the fingers in the proper direction with respect to the movement of the wrist, that is to say that if the wrist movement is in flexion, the fingers are also in the flexion movement, and if the movement of the wrist is extension, the fingers are also in the extension movement. The pulley A has a through hole T2 through which the pull cables R1 and R2 pass, so when one of the actuators B or C forces more the other or is blocked, the force exerted by the cables L1 or L2, is transmitted to the actuator offering the least resistance. In addition, these actuators B and C and the pulley A may have different diameters depending on the mobility of the wrist of the user. Actuators B and C are both designed in the same way, for the explanation we will take as an example of operation on two fingers only (Fig.1, 3,4), these two fingers, Il and III are moved by the actuator B and articulate around their respective axes and supports, A1 and A2 (Fig.1) for the first phalanges and the X1 and X2 axes for the last phalanges, it is obvious that the other two fingers are actuated by the same way. The actuator B is provided with two through holes T11 and T12, through these through holes, the cable S1 pulls the fingers II and III in flexion, and through these same holes, also passes the cable S3 which pulls the same fingers in extension (Fig., 4). The cable S1 is fixed by a knot made on this cable to the hole T13 (Fig.1), dorsal side on the second phalanx of the finger II, passes through the handles W2, W1 (Fig.1), through the holes T11 and T12 of the actuator B, passes through the handles W3, W4 (Fig.2) and is fixed by another node made on this cable to the hole T14 of the second phalanx of the finger III back side, the cable thus forming a U. The cable S'3 (Fig.2), is fixed by means of a node made on this cable to the palmar side to the second phalanx of the finger II to the hole T15 (Fig.1, 2), passes through the handle W5 (fig.2) and attaches to the hole T30 on the pulley P2 (Fig.2) which is free in rotation about the axis E3 (Fig.2), and fixed to the hole T40 of the same pulley P2 and in the continuity of the winding direction, the cable S3 passes through the return hole T17 (Fig.1, 2), passes through the hole T1 (Fig.1, 2) of the actuator B (Fig.1, 2) then through the hole T12, passes through the T18 dorsal return hole, passes through the handle W6 (Fig.2) and will be fixed to the tr or T16 of the second phalanx of the finger III by a palmar side knot. When these two cables S1 and S3 are adequately tensioned, they compensate each other and allow instantaneous adaptation of the phalanges to the object to be taken. When the cable S1 stretches, the cable S3 is released and allows the fingers to flex, the holes T11 and T12 (Fig.1, 3.4) allow to obtain a balance of forces on each finger either in extension mode or in flexion mode.

According to another advantageous characteristic of the invention, an independent thumb P1 (FIG. 5) can be fixed to the cover E with orthopedic resins provided for this purpose, this thumb comprises positioning by the notches C1, C2 (FIG. 5, 6) machined on the piece Pr (Fig, 5, 6). The part Pr is rotated on the part Su (Fig, 5, 6), the screw E1 and the disk spring M1 (Fig.5, 6) act as a brake regulator. To prevent the screw E1 (Fig, 6, 7) from loosening its support Se during the handling of the thumb, tightening the screw E2 blocks the screw E1 (Fig.6) and maintains a constant friction force at thumb. The displacement of the rod Ax (Fig, 5), which is the support of the prosthetic thumb, on the axis Ay makes it possible to position this thumb forward, with two blockages, one on the notch C1 and the other on the notch C2 , the flat spring Re (Fig, 5) serves as a non-return lock to the force exerted by Rxort Rss. On the rod Ax, a cam Ca is in free rotation and allows when the thumb is pushed far enough beyond the second notch to keep raised the flat spring Re and release the blockages C1 and C2 and allows the thumb by the intermediate torsion spring Rx (Fig.5) to return to its initial position at first notch C1. The pin Pe fixed on the part Pr (Fig.5, 6) makes it possible to regulate the maximum movements of the cam in order to raise or not the spring Re. The guide R3 in the shape of U is fixed on the base Ax with the screws E3 , E3 (Fig.5) and allows to channel one end of the spring, the other being fixed on the axis Am which serves to support the spring Rx.

According to another of the advantageous features of the invention, the pulley A (FIG. 1, 3, 4) can be replaced by a toothed wheel on which there always remains the hole T2 which serves as a pull for the cables R1 and R2 which regulate the pulling actuators B and C, and which can be driven by a micromotor that substitutes L1 pull cables and L2 for bending or extension of the four long fingers, thus obtaining a hand operated electric by a single motor that allows the four long fingers instant adaptation to the object to take with positionable thumb.

According to another of the features of the invention, the prosthesis is provided on its dorsal portion at the base of the finger II, a pulley P2 (Fig.2) provided with two holes T30.T40 (Fig.2), this pulley is in free rotation around the axis formed by the screw E3. The cable S3 is fixed on the hole T40 (Fig.2), the cable S'3 which is attached to the hole T15 (Fig.2) is fixed to the hole T30 of the pulley P2 by completing the turn of this pulley to almost join the S3 cable (Fig.2). A lug C4 (Fig.2) which is on the lower flange of the pulley P, is positioned slightly recessed relative to the lug C3 (Fig.2). The lever B1 is rotated on the screw E4, the disk spring M3 serves as a brake to the rotation of this lever. Thus when the finger II is in extension, if a lateral pressure is exerted on the lever B1 (Fig.2) of the side of the pin C3, the latter via the pin C4 blocks the rotation of the pulley P2 and holds the finger II in extension while the other fingers can flex, thus obtaining a finger positioning useful in the case of using a computer keyboard. If pressure is exerted on the lever B1 on the part opposite the lug C3 (FIG. 2), the pulley is released in rotation, thus the finger II becomes free in flexion.

In the invention described above it should be noted that there is no means of return or blocking on any long finger or any phalanx that could slow down the operation of the device, and it is understood that the we can adopt or use different types of materials or different forms without departing from the scope of the invention.

Claims

1.- Kinematic hand prosthesis with movable phalanges and positionable thumb, characterized in that it comprises;

-l)° a socket (E), intended to be mounted on the metacarpal part of the patient and on which a set of finger movement devices will be fixed using axes (H1, H2, H3, H4) and the socket (F) using the joints (G) and (G1),

-2)° a pulley (A) moved by the pulling cables (L1, L2) and provided with a hole (T2) through which the cables (R1) and (R2) pass, the cable (R1) is fixed to the hole (N) of the actuator (C) on one side and to the hole (P) of the actuator (B) on the other, the cable (R2) is fixed on one side to the hole (Ν') of the actuator (C) and to the hole (Ρ') of the actuator (B), the cables (L1) and (L2) are of the same length and are tensioned in the same way, which balances the forces of pulling of the actuators (B) and (C) which drive the long fingers by the cables (S1, S2, S3, S4), either in flexion or in extension,

-3) ° an independent inch including positioning by the notches (C1), (C2) machined on the part (Pr), the part (Pr) is in rotation on the part (Su), the screw (E1) and the disc spring (M1) act as a brake regulator, a flat spring (Re) serves as a non-return blocker to the force exerted by the spring (Rx), on the flat bar (Ax) a cam (Ca) is in free rotation, a pin (Pe) fixed on the part (Pr) makes it possible to regulate the maximum movements of the cam in order to lift or not the spring (Re), a guide (R3) in the shape of (U) is fixed on the flat bar (Ax) with screws (E3, E4) and allows one end of the spring to be channeled, the other being fixed on the axis (Sr) which serves as a support for the spring (Rx),

-4)° two joints (G) and (G1) which allow the two sockets (E) and (F) to be articulated and therefore to pull on the cable (L1) or (L2) to either extend or flex long fingers, when the cable (L1) is in traction, the cable (L2) automatically winds in the opposite direction on the pulley (A) which acts as a differential,

-5)° a device (Z) which serves as a support for two supports V1, V2 on which is fixed an axis (X) which supports the pulley (A) which acts as a differential, the spacers (Q1) and (Q2) which are integral with the pulley (A), the actuators (B) and (C) all free to rotate and which serve to pull the long fingers in flexion or extension, this device is provided with supports (A1), (A2) , (A3), (A4) on which the first phalanges of the fingers, II, III, IV, V, are articulated, the other phalanges articulated around the axes (X1, X2, X3, X4), four tubes (J1 , J2, J3, J4) serve as positioning for the axes (H1, H2, H3, H4),

-6)° a pulley (P2) comprising a lug (C4) which is located on its lower flange positioned back from the lug (C3) when the finger II is extended, the lever (B1) is rotating on the screw (E4), the disc spring (M2) serves as a brake on the rotation of this lever, when the lever (B1) is pushed towards the lug (C3), this blocks the rotation of the pulley ( P2) and keeps only finger II in extension, to free the movement of finger II, a push exerted on the lever (B1) at the other end allows the lug (C3) to be released and finger II to become functional.

2 - Hand prosthesis according to claim 1, characterized in that the device (Z) for movement of the fingers is fixed on the socket (E) by the axes (H1, H2, H3, H4).

3.- Hand prosthesis according to claims 1, 2 and 3 characterized in that ^" the actuators ^" (B) ef (C) ^" are ^" pôûiws on ^~ the ^~ pull flange ^{^} adjacent to the central pulley (A) of two holes each, (P) and (Ρ') on the actuator (B), and (N) and (Ν') on the actuator (C) which allow the fixing of the cables (R1) and (R2), the actuators (B) and (C) are held apart from the pulley (A) by the spacers (Q1) and (Q2) to allow the pulling actuators (B) and (C) to be wedged in flexion and extension opposite of the respective fingers and to leave space for movement for the cables of drawing (R1) and (R2), the last phalanges of the long fingers articulate around the axes (X1,X2,X3,X4).

4. - Hand prosthesis according to the preceding claims, characterized in that the actuator (B) is provided with two through holes (T11) and (T12), through these through holes, the cable (S1) pulls the fingers II and III in flexion, and through these same holes, also passes the cable (S3) which pulls these same fingers in extension, the cable (S1) is fixed by a knot to the hole (T13) on the second phalanx of finger II, passes through the handles (W2), (W1), through the holes (T11) and (T12) of the actuator (B), passes through the handles (W3), (W4) and is fixed by a knot to the hole ( T14) of the second phalanx of finger III, the cable thus forming a U, the cable (S'3) does the same on the dorsal part, it is fixed on the palmar side of the second phalanx of finger II to the hole (T15) , passes through the handle (W5) and is fixed to the hole (T30) by making a half-turn on the pulley (P2), another cable (S3) fixed to the hole (T40) adjacent to (T30), leaves again in the same direction as if these two cables were one, making a loop around the freely rotating pulley (P2) in the continuity of the cable (S'3), leaves this same pulley and passes through the hole return (T17), passes through the hole (TU) of the actuator (B) then through the hole (T12), passes through the return hole (T18) on the dorsal side, passes through the handle (W6) and goes fix to the hole (T16) of the second phalanx of finger III by a knot, when the cable (S1) tightens, the cable (S3) relaxes and allows the fingers to move, the holes (T11) and (T12) allow to obtain a balance of forces on each finger.

5. - Hand prosthesis according to claim 1, characterized in that the element acting as a differential is a pulley (A) which has an axial hole (T4) which allows it to be free to rotate around the axis (X), it also includes a transverse hole (T1) perpendicular to the hole (T5) to allow the fixing of the cable (L1) using a knot, the hole (T1) allows the knot to be inserted at the inside the pulley (A), it also includes a transverse hole (T3) perpendicular to the hole (T6) to allow the fixing of the cable (L2) using a knot, the hole (T3) allows insert the knot inside the pulley (A), the hole (T2) serves as a passage for the cables (R1) and (R2) which are fixed to the actuators (B) and (C) at the respective holes (P), (Ρ') and, (N), (Ν') and which by their pulling rotate these two pulleys, this hole (T2) allows the cables (R1) and (R2) to slide, and therefore to balance the pulling forces of the actuators (B) and (C).

6. - Hand prosthesis according to claim 1, characterized in that the pulley (A) acting as a differential can be replaced by a toothed wheel which can be driven by a micromotor, the extension and flexion of the long fingers does not require plus in this case pulling cables (L1) and (L2) and we obtain an electrically operated hand which, using a single motor, sets the four long fingers in motion.

7. - Hand prosthesis according to claims 1,2 characterized in that the independent thumb (P1) is fixed to the socket (E) with orthopedic resins, this thumb includes positioning by the notches (C1), (C2 ) machined on the part (Pr), the part (Pr) is rotating on the part (Su), the screw (E1) and the disc spring (M1) act as a brake regulator, a flat spring (Re) serves as a non-return lock for the force exerted by the spring (Rx), on the flat bar (Ax), a cam (Ca) rotates freely and allows, when the thumb is pushed sufficiently beyond the second notch, to maintain lifted the flat spring (Re) and releases it from the locking notches (C1) and (C2) and allows the thumb via the torsion spring (Rx) to return to its initial position, therefore to the first notch (C1 ), a pin (Pe) fixed on the part (Pr) makes it possible to regulate the maximum movements of the cam in order to lift or not the spring (Re), a guide (R3) in the shape of (U) is fixed on the bar plate (Ax) with screws (E3) and

on the axis (Sr) which serves as support for the spring (Rx).

8- hand prosthesis according to claims 1,2,3,4,5,7 characterized in that the pulley (P2) comprises a lug (C4) which is located on its lower flange positioned recessed relative to the lug (C3) when the finger II is extended, a lever (B1) which rotates on the screw (E4), the disc spring (M2) serving as a brake on the rotation of this lever, when the lever (B1) is pushed towards the lug (C3), this blocks the rotation of the pulley (P2) and maintains extension only the finger II, to restore the movement of the finger II, a push exerted on the lever (B1 ) at the other end allows the lug (C3) to be released and finger II to become functional.