MX2008007191A

MX2008007191A - Articulated hand prosthesis

Info

Publication number: MX2008007191A
Application number: MXMX/A/2008/007191A
Authority: MX
Inventors: Puchhammer Gregor
Original assignee: Otto Bock Healthcare Ip Gmbh & Co Kg
Priority date: 2005-12-22
Filing date: 2008-06-05
Publication date: 2008-10-03

Abstract

The invention relates to a hand prosthesis comprising a chassis (1) and coupling elements (2) for fastening the hand prosthesis to an arm stump, and also comprising a joint for flexing and extending the hand prosthesis in relation to the coupling elements (2), the chassis (1) being maintained in a neutral position against a spring bias. The invention is characterized in that at least one spring element (3) is associated with the chassis (1) and has a progressive spring characteristic and provides an increasing counterforce with increasing flexion and extension angle.

Description

ARTICULATED HAND PROTESIS DESCRIPTION OF THE INVENTION The invention relates to a hand prosthesis comprising a chassis and coupling elements for fixing the hand prosthesis to an arm stump as well as at least one joint for the flexion and extension of the prosthesis. of hand in relation to the coupling elements, being that the chassis is retained in a neutral position against an elastic force. US 2004/0015240 Al discloses a hand prosthesis with gripping elements in a chassis comprising a semicircular rotating element. I enter: a base plate and a mounting plate a torsion spring is arranged and keeps the chassis with the motor-driven grip elements in a neutral position. By means of a sliding interlock plate the chassis can be locked in different angular positions. The object of the present invention is to improve a hand prosthesis in the sense that it provides an appearance as natural as possible. According to the invention, this problem is solved by a hand prosthesis according to the characteristics of the claim 1. The favorable embodiments and improvements of the invention are listed in the dependent claims. REF. : 193102 The hand prosthesis according to the invention comprising a chassis and coupling elements for fixing the hand prosthesis to an arm stump and at least one joint for the flexion and extension of the hand prosthesis in relation to the elements of coupling, being that the chassis is retained in a neutral position against an elastic force proposes at least one elastic element that is associated with the chassis, which has a characteristic curve of progressive elasticity and that with the increase of the flexion angles or extension provides an opposing force that increases progressively. In order to obtain the most natural appearance of the hand prosthesis, it is proposed to imitate in the most natural way possible the appearance of a natural hand, both in the function and in its aspect to provide greater acceptance of the prosthesis wearers. So that the impression of an artificial body part does not occur when in contact with other human beings or objects, a soft form of all the parts of the prosthesis that are on the surface and the directed incorporation of elastic parts in the hand are necessary. , in particular, in the area of the hand joint. The articulation of the hand prosthesis as such is configured as a loose joint that is maintained in a neutral or initial position by at least one elastic element. This elastic element is associated with the chassis and supports it against the other part of the articulation, in particular the coupling elements or interleaved components. The elastic element is configured so that there is a progressive characteristic elastic curve when increasing the angles of flexion or extension, so that in the neutral position of the hand a smooth characteristic and a slight mobility is possible within the neutral position and in a small angular interval around this. Against the respective end positions of the hand frame a greater counterforce is provided to avoid strong impacts on the limits of movement. This increases the natural character of the hand prosthesis. The elastic element can be configured as a torsion spring that is effective both in the direction of extension as well as in the direction of flexion. Alternatively, it is possible for an elastic element to be effective against stretching and bending, and it is also possible for several elastic components that become effective successively to form an elastic element. It is also possible that the elastic element is configured as an elastomer part that opposes an elastic force as a function of the angle of flexion or extension., particularly progressive, to the torsion around the flexion joint. The elastic element or elements can be configured interchangeable to allow them to be adapted to the respective hand prosthesis or the requirements of the user of the prosthesis. In addition to a single bend or extension it is proposed that the chassis be mounted on a rotating bearing about an axis, substantially parallel to the longitudinal extension of the arm trunnion in order to provide an additional movement component in the hand joint for a more possible natural of the hand prosthesis. In order to grasp an object before it can be lifted and stopped, it is proposed that there be an interlocking device in the joint that retains the ariculation in the selected position. This washing device should be provided for both the flexion-extension joint and the rotating joint. Fundamentally, it is also possible for such an interlocking device to be mounted separately in the hand prosthesis without the need for an elastic characteristic or corresponding replacement device. The interlock device may comprise, in particular, a front toothing that can be engaged to retain the hinge. This has the advantage of a disengagement facility and a very fine angular division, so that the hand prosthesis can be retained in almost any angular position at will. In order to provide the most natural aspect of the hand prosthesis, the flexion-extension joint is arranged in the central region of the hand of the chassis. The mechanism for the enclivement function can be connected, as in the case of a ballpoint pen, by means of a single drive and disconnected by means of a repeated drive. The actuation of the locking device can be either manual or carried out by means of a button or by means of an electric operating drive unit. The alignment of the articulation axis of the extension-flexion joint with an inclined angle, in particular obtuse in relation to the longitudinal extension of the arm stump, combines the properties of a flexion and a simultaneous abduction of the hand prosthesis. This is favorable for most daily operations. In the following, an embodiment of the invention will be explained in more detail by means of the attached figures. They show: Figure 1 a hand prosthesis in total representation in top floor view; Figure 2 a hand prosthesis according to figure 1 in side elevation view; Figure 3 an exploded perspective drawing of a hand prosthesis joint; FIG. 4 shows a sectional representation of the prosthesis joint in neutral position; 5 shows a section according to line A-A of FIG. 4; Figure 6 a representation according to figure 4 in a position rotated by 60 °; Figure 7 a sectional exploded view, in perspective of a enema or bending ene; Y Figure 8 a sectional representation of the bending interlock according to figure 7 in assembled position. FIG. 1 shows a top view in a global representation of a hand prosthesis 100 comprising a chassis 101 which, by means of an articulation device 10, is mounted on a tilting bearing around a turning axis 4 both in the direction of bending as well as in the extension direction. The articulation device 10 which will be referred to below as a joint comprises a mounting plate 1 for fixing it l. 101 hand chassis. In the joint? 0 there is further configured a box 200 for coupling the hand prosthesis 100 with fixation devices to an arm trunnion. The box 200 can be connected to the mounting plate 1 by means of a coupling element 2. It is also proposed that the box 200 and thereby the hand prosthesis 100 allow a turning movement about an axis 5. The axis of rotation 5 is substantially parallel to the longitudinal extension of the forearm. F, axis 4 of bending and extension swinging is orthogonal to the axis 5 of rotation. An elastic operating device 6 for a locking device disposed within the articulation 10 is disposed laterally in the articulation 10. By means of the operating element 6 it is possible to lock the hand-held frame 101 in a chosen angular position. It is also possible that the hand-held chassis 101 is transferred from the locked position to an unlocked position by putting it to work again. Figure 2 shows a side elevational view of the hand prosthesis 100 with the chassis 101 and the mounting plate 1 in which the hand frame 101 is fixed by suitable perforations 14 and fixing means. In Figure 2 the hand prosthesis 100 is in the neutral position and can perform a counter-clockwise extension movement as well as a bending movement clockwise, as it is indicated by the double arrow. The fingers can be operated individually or jointly by means of an engine 'inside the chassis 101 or of the box 200. The hand prosthesis 100 is retained in the neutral position in the joint 10 by an elastic element, by means of which an easy mobility of the chassis 101 from hand to neutral position. In Figure 3, the mounting plate 1 of the hand prosthesis, which is not shown in this figure, is mostly shown with a circular frame 11. In the mounting plate 1, perforations 14 are configured to fix additional components of the hand prosthesis. A central hole 13 is also configured at the center point of the frame 11 to receive a pivot 23 of a coupling element 2. A spring element 3 in the form of an elastomer body is arranged between the coupling element 2 and the mounting plate 1 or a corresponding element of the chassis 101. The elastic element 3 has a central bore 33 in which the pivot 23 is inserted in the assembled position. The pivot 23 penetrates the bore 13 of the mounting plate 1 in the coin position. In coupling element 2 which in turn can be fixed to a fixing part or the box 200 for reception in a boom pin, a pivot 21 is arranged or configured which houses a rotating bushing 41. In the mounting plate 1, a pivot 12 is also configured, which can not be identified in FIG. 3, which receives the opposite rotary bushing 42. The rotating bushings 41, 42 lie on the surface of the elastic element 3 and can roll on it. In Figure 4 the joint 10 of the hand prosthesis is shown in a sectional representation in a neutral position. Both rotating bushings 41, 42 are disposed on their respective mounting pivots 21, 22 and are in opposite depressions 34 of the elastic element 3. The elastic element 3 is placed inside the circular frame 11 configured in the mounting plate 11, wherein the outer periphery of the elastic element 3 corresponds by sections to the internal contour of the frame 11. In the present case the elastic element 3 is configured symmetrically, so that in both the direction of extension and also in the direction of flexion there are same elasticity coefficients. This can be varied depending on the purpose of use, so that there are different coefficients of elasticity in the extension and bending. Hollows 35 are formed in the elastic element that influence the elastic behavior. The larger the gaps 35 the smoother the assembly of the hand prosthesis around the neutral position is. In FIG. 5, it can be seen in a sectional representation that the frame 11 is configured monolithically with the mounting plate i, like the pivot 12 for the rotary sleeve 42. In the coupling element 2 the pivot 21 is configured monolithic like the pivot 23. If now the hand prosthesis 100 is rotated together with the mounting plate 1 relative to the coupling element 2 as shown in figure 6 it is they displace the pivots 21, 12 with respect to another one. The elastic element 3, in the present case configured as a piece of monolithic elastomer is compressed, whereby by means of the present configuration of the elastic element 3 it is possible to obtain a progressive elasticity characteristic. This can happen, for example, by means of components included within the elastic element 3 and its sequential activation as a function of the angle of rotation or by means of a corresponding contour. In the neutral position as shown in FIG. 3 the elastic element 3 has a relatively soft elastic characteristic, so that the hand prosthesis 100 swings relatively loose, like a natural hand when the forearm is moved. By means of the depressions 34, a preferred position of the neutral position is effected, so that by virtue of the resilient forces of the elastic element 3 the hand prosthesis 100 always returns back to it. The more the hand prosthesis 100 is rotated relative to the coupling element 2, the counterforce of the elastic element 3 increases, whereby a strong impact against the limit stops is avoided. This corresponds to the development of movement and the natural appearance of a hand and also takes care of the mechanical components of the hand prosthesis 100.

Alternatively to the monolithic configuration of the elastic element 3 this can also be configured of several separate elastic elements. For example it is possible to provide different elastic elements for extension and bending. Then the hand prosthesis is retained in the neutral position by two elastic elements. Figure 7 shows in detail an interlocking device 7 which is applied to the box 200. Inside the locking device 7, the mounting or base plate 1 is arranged to fix the hand frame 101. In the illustrated embodiment of the locking device 7, the elastic element described above is not shown. However, by virtue of the flat configuration of the elastic element 3, easy integration of the enclosing device 7 or of the extension into the housing 200 is possible. In the housing 200, an external toothing 201 with a collar 202 is formed. that surrounds it radially. In the free space between the outer toothing 201 and the collar 202, a ring 73 with internal toothing that can rotate together with the chassis 101 relative to the base plate 1 is introduced, the rotation is obtained by rolling balls 8 that move in the corresponding ball tracks inside the inner gear ring 73 and the bearing box 79 of the base plate 1. A sealing ring 9 if you see as a seal between the case 200 and the case 79 of the bearing. Within the bearing housing 79, an internal toothing 17 is formed in the region of the base plate 1. In the internal gear ring 73, it engages a front tooth disc 72 having an external toothing and a front gear. In the assembled state, when the hinge is locked, this front toothing disc 72 engages a second opposing front tooth disc 71 which also comprises an external toothing which meshes with the internal toothing of the bearing housing 79. The front teeth discs 71, 72 are pressed against each other by an elastic washer 80 and a disc spring 26 and are kept engaged. The disk spring 26 is supported by a pressure cap 77 against an elastic cap 6 as the drive device. The elastic cap 6 is fixed water-tight on the base plate 1 or the bearing case 79 by means of a holding ring 16. The disk spring and the spring washer 80 are supported by pressure discs 81, 82 in the front tooth discs 71, 72. A disengagement mechanism is disposed within the front teeth 71, 72, which, when driven, move the front teeth 17, 72 separating them in the axial direction. The pressure cap 77 can be displaced in the direction of the casing 200 and moves in the direction of the casing 200 a pressure sleeve 76 in which a disengagement pin 75 and a ball 7 8 are guided. The disk springs 26 press the pressure disk 82 in the direction of the case 200 and exert a force on a clutch sleeve 74 disposed around the pressure sleeve 76. The disengagement sleeve 74 has a peripheral transverse piece that penetrates between the front teeth, and which can intervene in positive connection with the front tooth disc 72 associated with the internal gear ring 73. The sphere 78 is guided inside the pressure sleeve 76 and intervenes in the release pin 7 5 in which a guide track is formed in the shape of the development of a heart eccentric, as in a ball-point pen. When the pressure cap now moves in the direction of the box 2 00, the disk spring 6 presses by means of the pressure disk 82 onto the clutch sleeve 74 and moves the front gear disk 72 axially away from the disk 71. of front teeth, so that a rotation around the joint axis 4 can take place. With the additional pressure of the pressure cap 77 the disc spring 26 which is loaded Before starting to integrate, the sphere 7 8 on the stationary disengagement bolt 7 5 is guided along the guide track as a heart eccentric in the direction of the stationary case 2 00 and has the effect that the pressure sleeve 76 is retained in the release pin 75 on the sphere 78. Therefore, rotation around the axis 4 is still possible. By the new actuation of the pressure cap 77 the sphere 78 continues to move in the guide track of the release pin 75. By moving the sphere 78 out of a dead latching position, the disengagement sleeve 74 will return to the locked position shown in FIG. 8. The mechanism operates analogously to a ball-point pen or to a tightening-tightening element. The same mechanism of the interlocking device 7 can also be executed to latch and unlock the rotation about the rotation axis 5.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. Hand prosthesis comprising a chassis and coupling elements for fixing the hand prosthesis to an arm stump as well as at least one joint for the flexion and extension of the hand prosthesis in relation to the coupling elements, the The chassis is retained in a neutral position against an elastic force, characterized in that the chassis is associated with at least one elastic element that has a characteristic curve of progressive elasticity and that with the increase of the angle of flexion or extension provides an opposing force that increases progressively.

2. Hand prosthesis according to claim 1, characterized in that the elastic element is configured as a torsion spring.

3. Hand prosthesis according to any of the rei indications 1 or 2, characterized in that an elastic element acts in each case against stretching or bending.

4. Hand prosthesis according to any of the preceding claims, characterized in that the elastic element is configured as an elastomer part.

5. Hand prosthesis according to any of the preceding claims, characterized in that the elastic element is constituted by several individual elastic elements.

6. Hand prosthesis according to any of the preceding claims, characterized in that the elastic element is interchangeable. Hand prosthesis according to any of the preceding claims, characterized in that in addition to the flexion and extension, the chassis is mounted rotatable about an axis, substantially parallel to the longitudinal extension of the arm stump. Hand prosthesis according to any of the preceding claims, characterized in that an interlock device is provided in the hinge which stops the hinge in a selected position. 9. Hand prosthesis according to claim 8, characterized in that the locking device comprises a front toothing associated with the articulation that can be engaged to stop the articulation. Hand prosthesis according to any of the preceding claims, characterized in that the axis of the chassis of the flexion-extension joint is arranged in the central region of the hand. Hand prosthesis according to any one of the preceding claims, characterized in that the articulation axis is oriented at an obtuse angle with respect to the longitudinal extension of the arm stump.