DESCRIPTION TECHNICAL FIELD The present invention concerns a device for transmitting vibrations at a finger prosthesis. The finger prosthesis is intended to replace e. g. a lost human finger, where the prosthesis finger can be attached to the human hand/metacarpus or a hand/metacarpus prosthesis to ensure the continued transmission of vibrations. Furthermore the finger prosthesis has structural parts and a prosthesis cover made of an elastic material.

BACKGROUND OF THE INVENTION AND PROBLEM When a living finger is lost or amputated, it can be replaced by a prosthesis.

This means a loss of contact sensation with the environment when the finger e. g. must grip or touch an object. The contact sensation is particularly important when small objects or objects with a characteristic surface friction must be gripped and/or recognised. Some known finger prostheses have internal structural parts made of metal or other hard material. Over these prostheses fits a cover which is usually made of a substantially elastic material. The friction of the prosthesis cover depends inter alia on the material from which it is made and usually differs significantly from the friction of a human finger. The prosthesis cover should also simulate the human skin and protect the structural elements from dirt. For repair or service the cover must be removed from the prosthesis finger, which is difficult for many users especially for users who have had both hands amputated.

The known finger prostheses with this design do not promote, or even dampen/weaken this contact sensation with the environment.

OBJECT OF THE INVENTION AND SOLUTION TO THE PROBLEM The object of the invention is to solve one or more of the above problems.

This is achieved with a device according to claim 1.

By attaching to a finger prosthesis with at least one inner structural part which is covered by a prosthesis cover of a substantially elastic material and at least partly arranged outside the prosthesis cover, a device intended to transmit vibrations caused e. g. by the device being moved over and in contact with a rough surface, the vibrations can be transmitted to a prosthesis fixing, the purpose of which is to connect the prosthesis to a hand prosthesis or a human hand so that the vibrations can be detected and experienced by the user of the prosthesis.

The device according to a preferred embodiment further comprises a plate and detachable fixing element intended to connect the plate with the inner structural parts.

DESCRIPTION OF THE DRAWINGS The invention will be described below in the embodiment example with reference to the figures as follows.

Fig. 1 shows a diagrammatic sketch from the side of a device according to the invention for a finger prosthesis.

Fig. 2 shows a diagrammatic sketch of a device according to the invention in a view from below.

Fig. 3 shows a diagrammatic sketch of a device according to the invention at a cross-section of fig. 1 viewed from the front.

DESCRIPTION OF EMBODIMENT EXAMPLE A device for transmission of vibrations is generally referenced in the drawings as 1. The device has a plate la, fixing element 1b and annular projection 1c.

A finger prosthesis 2 is shown in cross section in fig. 1, where the prosthesis has a structural part exemplified in fig. 1 by a thin-walled hollow part 2a, and a prosthesis cover 2b. The device 1 is arranged at a first end 2c of the prosthesis 2 and with substantially all or at least part of the plate la outside the prosthesis cover 2b, whereby the device 1 is easy to use for a user. At the end opposite the first end 2c is a prosthesis fixing (not shown). The purpose

of the fixing is to connect the finger prosthesis 2 to a hand prosthesis or human hand (not shown) so that vibrations can be detected and experienced by the user of the finger prosthesis 2.

The fixing element lb is connected to the plate la and intended to connect at least one of the structural parts e. g. part 2a of the prosthesis. The fixing element lb in a preferred embodiment has a locking part 1d attached to a spacer le which in turn is connected to the plate la. The structural part 2a has two through openings 2d, the size of which corresponds substantially to the cross-section of spacer le. The locking part 1d has a greater cross-section than the spacer le which thus creates a snap lock function when pressed through the opening 2d. The locking part Id is made of a resilient material e. g. soft plastic so it can be pushed through opening 2d and then substantially return to its original form. In the locked position, see fig. 1, the locking part ld acts to drive the plate la and hence the annular projection lc towards the prosthesis cover and the structural part 2a. The annular projection 1c thus distributes the clamping forces occurring in the prosthesis cover 2b between the plate la and the structural part 2a and positions the plate la in a particular position. High clamping forces lead to fixing of the plate la which is rigid and gives good transmission of vibrations. The annular projection 1c also constitutes a seal so that dirt, water or other elements are prevented from entering fixing element 1b and finger prosthesis 2. In the preferred embodiment the device 1 is made of plastic e. g. by injection moulding, where preferably the entire device 1 is made of the same material.

In alternative embodiments the plate is made of a harder material than e. g. the locking part ld. The preferred snap lock function makes it easy to attach and release device 1, which means e. g. that the user himself can exchange it e. g. on wear or if damage occurs.

In the preferred embodiment the plate la has a curvature which substantially follows a corresponding curvature on the end 2c of the finger prosthesis. The plate thus describes part of a substantially straight and circular cylinder. The curvature means that the plate lc is more rigid and can transmit vibrations better. The curvature also facilitates production of device 1 as a softer material can be selected for the plate 1 than otherwise, and hence supports the possibility of using the same material in the plate la as in the locking part ld.

The device 1 is preferably placed with a part projecting outside the finger

prosthesis end 2c, see fig. 1, so it is easily accessible to the user when e. g. he wishes to move the device 1 over a rough surface to cause vibrations, but also when he wishes to get a good grip e. g. when handling small objects or using the device as a tool.

Other alternative embodiments of the fixing device have a different number of fixing elements than that preferred, e. g. one, more than two or none of this type of fixing element. In the latter embodiment the plate la is attached directly to the prosthesis cover by means of glue or similar.

The invention should not be regarded as limited to the examples described above but may vary within the scope of the claims, e. g. the fixing element can comprise one or more screws.

LIST OF REFERENCES 1 device la plate lb fixing element lc annular projection Id locking part le spacer 2 finger prosthesis 2a structural part 2b prosthesis cover 2c first end 2d through opening