DE102010053114B4 - hand prosthesis - Google Patents

Abstract

Hand prosthesis
Wherein the prosthetic hand comprises a plurality of fingers and a thumb (27),
- Wherein the fingers (21, 22, 23) and the thumb (27) are articulated on a hand housing (10),
- wherein in the hand housing (10) has a rotatable shaft (13) is provided, whose axis extends transversely to the articulation of the fingers on the hand housing (10),
- wherein the shaft has a Antriebsseilrad (15) which receives a Wellenantriebsseil (11),
- Wherein the shaft (13) further for actuating each finger (21, 22, 23) and the thumb (27) each have a driven pulley (17, 18, 19) for receiving in each case an output cable (17a, 18a, 19a),
Wherein each output cable (17a, 18a, 19a) communicates with one finger (21, 22, 23) and another drive cable with a thumb (27),
- At least the driven pulleys (17, 18, 19) for the fingers an elastic connection with the shaft ...

Description

The invention relates to a hand prosthesis, wherein the hand prosthesis comprises a plurality of fingers and a thumb, wherein the fingers and the thumb are articulated hinged to a hand housing, wherein in the hand housing, a rotatable shaft is provided, whose axis is transverse to the articulation of the fingers on the hand housing wherein the shaft comprises a Antriebsseilrad receiving a Wellenantriebsseil, wherein the shaft further for actuating each finger and the thumb each have a drive pulley for receiving a respective output cable, each drive cable with one finger and another drive cable with a thumb communicates with at least the drive pulleys for the fingers have a resilient connection with the shaft.

The human hand is an extremely complex entity. It consists of 27 bones, 36 joints, 39 muscles, each with 32 degrees of freedom and it can generate up to 50 kg of clamping force. Making a prosthesis that has properties similar to that of a human hand seems impossible. However, many attempts have been made to provide hand prostheses that can perform a variety of functions that can be done by the human hand.

A hand prosthesis should not only allow the essential usual movements of a human hand, but in particular allow the prosthesis wearer also participate in working life. The essential handles that a human hand is able to perform are the so-called bottle handle, the hook handle, the tweezer handle and the ball handle.

Prostheses that partially control the above-mentioned handle types are known in the art. For example, from the CH 77453 A a hand prosthesis known, which allows the so-called tweezers handle. From the DE 2426711 A1 An adaptive hand prosthesis is known, in which a drive pair is assigned to each pair of fingers. About these two pairs of rollers a cable is guided in each case, which is attached to the fingers. The pairs of rollers of the fingers are driven by another cable.

From the US 2004/0054424 A1 is a hand prosthesis known in which the individual fingers are each driven in pairs by a cable.

About another cable these cables are connected to an actuator.

From the AT 85749 B a hand prosthesis is known in which the fingers or parts of the fingers are movable via gear members, wherein the gear members via cables in communication with a drive means.

The DE 19755465 A1 shows an artificial hand, in which the fingers are driven by piston-cylinder drives.

From the DE 27 51 192 A1 is the drive of the fingers on cables and friction gear known.

In addition, so-called "Sunday hands" are known, the activities allow, as they are needed in the home, such as the Lateralgriff to hold flat objects or the Palmalgriff, for example, to hold writing instruments. In addition, science is working on the production of so-called myoelectric hands, which are modeled on the human hands in their appearance, in particular with regard to a skin-like surface material and also with respect to their functioning. The finger movements are controlled by small electric motors, sensors, and precision gears that can receive their control signals from forcing conditions of the forearm muscles and perform certain signals for a particular grip. From this fine mechanical structure results in a holding force of about 10 kg, but also a strong dependence of the surface currents of temperature and humidity fluctuations in the environment. Another disadvantage is that such hand prostheses are very expensive. There are also high annual maintenance and repair costs. Alone due to the cost, the use of such prosthetic hand is quite limited; It is quite certain that such hand prostheses can not be exported to third world countries, since such prices can not be realized there.

A hand of the type mentioned, for example, a hook handle and the tweezer grip but also allows a ball handle, shows the DE 2925225 A1 , The individual fingers and the thumb are driven by a separate electromotive drive. It is known in this hand that the individual fingers can be moved completely separated from each other. This happens because the drive cable wheels for the fingers are connected by a spiral spring with the shaft.

The object underlying the invention is therefore to provide an inexpensive and robust hand prosthesis, especially for heavy manual activities available that allows a variety of different types of grip, so in particular the bottle handle, the hook handle, the tweezer handle, but also the ball handle. Because these are the hand movements that usually have to be done in working life.

To solve the problem is proposed according to the invention in a hand prosthesis of the type mentioned that the elastic connection in the storage of each driven pulley, the shaft has a polygonal section. From this it is clear that both each finger and the thumb are each assigned a drive part. By a forceps-shaped movement of the thumb with the index finger of the hand prosthesis of the so-called tweezers handle is realized. The realization of the hook as well as the bottle handle is made possible when both the fingers and the thumb make a smooth, closing movement. Also a ball handle is possible.

The ball handle is a handle in which, for detecting an object such as an apple or a ball, at least the individual fingers cover a different gripping path, just by the outer contour of the object to be gripped, for example an apple. If the fingers and the thumb were rigidly connected by the shaft, the individual fingers would always travel the same gripping path as the shaft rotates, causing, for example, a hook handle to be realized, or the bottle handle, as required, to cylindrical objects to capture, but not the ball handle. Characterized in that according to the invention the driven pulleys are at least for the fingers in each case elastically connected to the shaft, it is achieved that upon rotation of the shaft by a certain angle, the individual fingers can travel different gripping paths when hitting the object. This is due to the elastic mounting of the driven pulleys for the fingers of the hand prosthesis on the shaft. In this context, it is important to mention that such an elastic support of the thumb is not required as a counter-holder; if the fingers themselves are elastically mounted, this is sufficient to realize the ball handle.

Advantageous features of the invention and further embodiments can be found in the dependent claims.

Thus, a cushion made of an elastomer is provided in particular for the elastic connection between the driven pulley and the shaft. Furthermore, the shaft in the region of the driven pulley on a polygonal section, wherein the cushion rests on the polygonal section. Accordingly, according to a further feature of the invention, the respective driven pulley in the region of the passage of the shaft is also polygonal, so that the pad rests on both sides in a polygonal receptacle.

According to an advantageous feature of the invention, a finger on several phalanges, which are hinged together. By using multiple phalanges, and in particular three phalanges, as is also known from the natural hand, the gripping movement is more accurate overall, which opens up the possibility to fully embrace even small objects. In this context, it is provided in particular that the output cable for operating the respective finger runs on the inside of the hand prosthesis in the phalanges. That is, the output cable below the joints through which the individual phalanges are communicated with each other is arranged to extend in the phalanges.

To ensure that the fingers and the individual phalanxes after relief of the respective output cable in its initial position, d. H. go back as possible a stretched position, it is provided that the individual phalanges are connected by spring elements with each other. The same applies to the articulation of the finger as a whole on the hand housing insofar as there is provided a spring which causes the return movement. In the same way as the training of the fingers has been made, this also applies to the thumb. The thumb also has several thumb members, which are hinged together. Also, the drive cable for actuating the thumb extends in the region of the inside of the hand prosthesis in the individual thumb members, wherein the individual thumb members and the thumb itself are connected by spring elements. The spring elements are advantageously designed as spiral springs, and provided here in particular as so-called leg springs.

According to another particular feature of the invention, the thumb is arranged laterally pivotable on the hand housing. By a pivoting of the thumb laterally by up to 90 degrees on the one hand causes the thumb can dive between the fingers and insofar as a so-called torque-free gripping, for example, is realized by cylindrical bodies. Also, by the pivoting of the thumb and forefinger toward each other to the realization of the so-called tweezers handle possible. By the pivoting of the thumb to the outside, d. H. in an area outside the actual handle, the realization of the hook handle is possible, which is required, for example, when the handle of a bucket to be detected.

Another feature of the invention is characterized in that the fingers and the thumb are detectable in any position. The realization of this feature is of particular interest when a weight over a certain time, for example, to be transported with a hook handle.

The operation of the hand prosthesis is effected by a movement of the body, and in particular of the shoulder region of the arm, on which the hand prosthesis is arranged by a forearm adapter, relative to the hand prosthesis. That is, the shaft drive cable communicates with the body of the prosthesis wearer in such a way that when moving the upper body relative to the hand prosthesis, the shaft drive rope is pulled or released, thus pass the fingers in the grip position or in the extended position. Specifically, this is accomplished by providing a shoulder strap that communicates with the shaft drive cable.

By the detectability of both the fingers and the thumb it is now possible that after receiving a certain load, for example by grasping the handle of a briefcase by a movement of the shoulder area to the rear, after locking the fingers and the thumb of the prosthesis wearer's shoulder in the starting position can bring back without loosening the handle. In this context, it is particularly provided that the shaft has an external toothing, in which a bolt can be inserted. This latch sits on the hand-held housing and thus prevents rotation of the shaft.

Another feature of the invention is characterized in that the fingertips of the respective finger or thumb member have an elastomeric pad to allow safe detection of even objects with a smooth surface.

With reference to the drawings, the invention will be explained in more detail below by way of example.

1 shows the hand prosthesis in the attached state;

2 shows the hand in perspective view;

2a exemplifies a phalanx;

3 shows a view of the open hand housing in the unlocked state of the shaft;

4 shows a view according to 3 in the locked state of the shaft;

5 shows the shaft in perspective view;

5a shows a section of the shaft according to 5 , wherein only one driven pulley is shown.

Out 1 is the one with 1 identified forearm adapter, which is attached to the forearm of the prosthesis wearer. The forearm adapter presents itself as an approximately sleeve-shaped elongated structure, as this 1 can be seen. The forearm adapter 1 is releasably but non-rotatably connected to the hand prosthesis. In addition, the hand prosthesis against the forearm adapter can be fixed rotatably.

The prosthetic hand, like this 2 can be seen, shows the drive shaft cable 11 that through a connecting rope 8th associated with a shoulder strap, which is not shown. In any case, it is that through the connecting cable 8th with appropriate movement of the shoulder or the upper arm, the drive shaft cable 11 is tense or is relaxed. The drive shaft cable 11 is in connection with the wave 13 ( 3 et seq.). The wave 13 takes the drive rope wheel 15 in rigid connection, wherein the Antriebsseilrad 15 a groove 15a for the shaft drive cable 11 owns that on the Antriebsseilrad 15 is articulated. With a wrap angle of almost 360 degrees, the drive pulley decreases 15 in the groove 15a the aforementioned drive shaft cable 11 on. Next to the drive rope wheel 15 that stuck with the shaft 13 is connected, can be found on the shaft driven pulleys 17 . 18 and 19 , wherein the driven pulleys 17 . 18 and 19 one output cable each 17a . 18a . 19a exhibit that from the hand case 10 are led out and with the with 21 . 22 and 23 designated fingers in connection. The output ropes are, in order to be able to return a corresponding gripping path, placed at a wrap angle of substantially more than 180 degrees on the respective driven pulley.

In addition to the aforementioned driven pulleys 17 . 18 and 19 the shaft has another driven pulley 25 on, that is an output cable 25a picks up that from the hand case 10 to the thumb 27 is guided. The training of the wave 13 with the driven pulleys and the drive pulley results in particular clearly from the 5 , In particular, it can be seen there that the driven pulleys 17 . 18 and 19 not directly with the wave 13 but in each case by an elastomeric pad, each with 29 is designated, elastically yielding to the shaft 13 are connected. Optionally, as a resilient connection and a coil spring 28 be provided ( 5a ). This concerns as mentioned the driven pulleys 17 . 18 and 19 , wherein the driven pulley 25 for the operation of the thumb rigid with the shaft 13 connected is. Each driven pulley 17 . 18 and 19 has a quadrangular passage 29a on, with the shaft in the area of the spring 28 or the elastomeric pad 29 also a polygonal, especially square section 13a having. The legs of the spiral spring 28 are with the driven pulley 17 . 18 . 19 connected while the spiral of the spring 28 non-rotatable on the quadrangular section 13a is stored. Depending on the elasticity of the elastomer pad 29 or the spring 28 receives the respective driven pulley a certain slip. The slip occurs when under stress of the drive shaft cable 11 to train in the finger, which is in communication with its associated Abtriebsseilrad, encounters a resistance, whereas the other fingers feel no resistance. That is, the wave 13 turns under the elastomeric pad 29 of Abtriebsseilrades, whose finger runs on the resistance, through.

The type of training of the fingers is in the view of 2 , Every finger 21 . 22 and 23 consists of three phalanges, 21a . 21b . 21c ( 22a to 22c ; 23a to 23c ). It has already been mentioned that through the output ropes 17a . 18a . 19a the individual fingers with the hand case 10 keep in touch. The individual phalanges 21a to 21c stand by the joints 33 in contact with each other. In the area of the joints 33 are torsion springs 35 , with such a leg spring 35 as a spiral spring, the two-sided outgoing in the 90 degree angle leg 35a has, with which the spring on the housing of the joint 33 of each phalanx is supported ( 2a ). The bias of the springs 35 is such that the individual fingers always in the direction of the arrow 40 be deflected. In this connection it should be mentioned that the fingers 21 . 22 and 23 with the hand housing also by a joint 33 are connected, being in the joint 33 also a thigh spring 35 is located, which ensures that the finger overall in the direction of the arrow 40 swings. That is, when shortening the drive shaft cable 11 The fingers and the individual phalanxes are against the force of the torsion springs 35 opposite the direction of the arrow 40 moves, which leads to the desired gripping movement.

The thumb 27 also consists of individual links 27a . 27b and 27c , where the limbs 27a . 27b and 27c through one joint each 33 communicate with each other, being in the two joints 33 each one just such leg spring 35 is used as described previously with respect to the fingers. The thumb member 27a is in the direction of the arrow 45 swiveling through the hand housing 10 received. The pivoting must be done manually, but the thumb can be locked in several positions. Is the thumb in the position according to 2 and in particular aligned with the finger 21 , then the so-called tweezers grip can be performed. Is the thumb in an intermediate position between the fingers 21 and 22 , then the so-called bottle grip, which takes place without torque, takes place, since the thumb in the gap between the two fingers 21 . 22 dips. Will the thumb 27 upwards in the direction of the arrow 45 pivoted, the hook handle can be done.

The ball handle is in the position of the thumb according to 2 performed. Here are the individual fingers due to the elastic storage of the individual fingers on the shaft 13 tracked the contour of the object, as has already been described in sufficient detail elsewhere.

The locking of both the fingers and the thumb results in the view of 3 and 4 , From the 3 and 4 is a bar 50 recognizable, wherein the bolt 50 a gearing 51 has, with a corresponding toothing 55 on the wave 13 can be brought into engagement. Provided for this purpose is a sliding member 56 that to the lock in the direction of the arrow 58 displaceable from the hand housing 10 is included. Here comes the bar 50 in engagement with the teeth 55 ( 4 ).

The fingertips of the phalanges 21c . 22c . 23c each have an elastomeric pad 60 to be able to capture even smooth objects.

LIST OF REFERENCE NUMBERS

1

forearm adapter

8th

connecting cable

10

hand housing

11

Shaft or drive rope

13

wave

13a

polygonal section

15

Antriebsseilrad

15a

groove

17

Abtriebsseilrad

17

output wire

18

Abtriebsseilrad

18a

output wire

19

Abtriebsseilrad

19a

output wire

21

finger

21a

phalanx

21b

phalanx

21c

phalanx

22

finger

22a

phalanx

22b

phalanx

22c

phalanx

23

finger

23a

phalanx

23b

phalanx

23c

phalanx

25

Abtriebsseilrad

25a

output wire

27

thumb

27a

Daum link

27b

Daum link

27c

Daum link

28

spiral spring

29

elastomeric pad

29a

passage

33

joints

35

Leg spring

35a

Thighs of thigh feather

40

arrow

45

arrow

50

bars

51

gearing

55

gearing

56

pusher member

58

arrow

60

Elastomer support (fingertip)

Claims (18)

Hand prosthesis, - whereby the hand prosthesis several fingers and a thumb ( 27 ), the fingers ( 21 . 22 . 23 ) and the thumb ( 27 ) on a handheld housing ( 10 ) are articulated articulated, - wherein in the hand housing ( 10 ) a rotatable shaft ( 13 ) is provided, whose axis is transverse to the articulation of the fingers on the hand housing ( 10 ), the shaft being a drive cable wheel ( 15 ), which has a shaft drive cable ( 11 ), where the wave ( 13 ) continue to actuate each finger ( 21 . 22 . 23 ) and the thumb ( 27 ) each a driven pulley ( 17 . 18 . 19 ) for receiving a respective output cable ( 17a . 18a . 19a ), wherein each output cable ( 17a . 18a . 19a ) with one finger each ( 21 . 22 . 23 ) and another drive cable with a thumb ( 27 ), wherein at least the driven pulleys ( 17 . 18 . 19 ) for the fingers an elastic connection with the shaft ( 13 ), characterized in that the elastic connection in the region of the storage of each driven pulley ( 17 . 18 . 19 ) the wave ( 13 ) a polygonal section ( 13a ) having. Hand prosthesis according to claim 1, characterized in that the elastic connection between the respective driven pulley ( 17 . 18 . 19 ) and the wave ( 13 ) as a pillow ( 29 ) is formed of an elastomer. Hand prosthesis according to claim 2, characterized in that the at least one cushion ( 29 ) on the polygonal section ( 13a ) rests. Hand prosthesis ( 10 ) according to any one of the preceding claims, characterized in that the driven pulley ( 17 . 18 . 19 ) for the passage ( 29a ) the wave ( 13 ) is also polygonal. Hand prosthesis according to one of the preceding claims, characterized in that a finger ( 21 . 22 . 23 ) several phalanges ( 21a c, 22a c, 23a -C), which are hinged together. Hand prosthesis according to claim 5, characterized in that the output cable ( 17a . 18a . 19a ) for the operation of the finger ( 21 . 22 . 23 ) on the inside of the hand prosthesis in the phalanges ( 21a c, 22a c, 23a -C) runs. Hand prosthesis according to claim 5 or 6, characterized in that the phalanges ( 21a c, 22a c, 23a C) by spring elements ( 35 ) communicate with each other in such a way that the individual phalanges are stretched. Hand prosthesis according to one of the preceding claims, characterized in that the finger ( 21 . 22 . 23 ) by a spring element ( 35 ) with the hand housing ( 10 ) in such a way that the finger is stretched. Hand prosthesis according to one of the preceding claims, characterized in that the thumb ( 27 ) several thumb links ( 27a -C), which are hinged together. Hand prosthesis according to claim 9, characterized in that the output cable ( 25a ) for the operation of the thumb ( 27 ) on the inside of the hand prosthesis in the thumb members ( 27a . 27b . 27c ) runs. Hand prosthesis according to claim 9 or 10, characterized in that the individual thumb members ( 27a . 27b . 27c ) by spring elements ( 35 ) in such a way that the individual thumb members ( 27a . 27b . 27c ) are stretched. Hand prosthesis according to claim 8, characterized in that the spring element ( 35 ) is designed as a spiral spring, in particular as a leg spring. Hand prosthesis according to one of the preceding claims, characterized in that the thumb ( 27 ) laterally pivotable but lockable on the hand housing ( 10 ) is arranged. Hand prosthesis according to one of the preceding claims, characterized in that the fingers ( 21 . 22 . 23 ) and the thumb ( 27 ) are detectable in every situation. Hand prosthesis according to one of the preceding claims, characterized in that the shaft ( 13 ) an outer toothing ( 51 ) into which a bolt ( 50 ) can be inserted. Hand prosthesis according to one of the preceding claims, characterized in that the fingertips of the respective finger or thumb member an elastomer pad ( 60 ) exhibit. Hand prosthesis according to one of the preceding claims, characterized in that the shaft drive cable ( 11 ) is in communication with the body of the prosthesis wearer such that upon movement of the upper body or the upper arm relative to the hand prosthesis, the wave drive cable is pulled or released. Hand prosthesis according to one of the preceding claims, characterized in that the prosthetic hand on a forearm adapter ( 1 ) is releasably attached.

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