FR3071717A1 - FLEXIBLE ANCHOR DEVICE FOR LOWER LIMBS PROSTHESIS - Google Patents

Abstract

The invention relates to a flexible ankle device for prosthesis of lower limb, characterized in that it is composed of a monolithic piece [1] offering a certain elasticity in terms of its dimensions and the nature of the material used for its manufacture , that this part comprises a device for interlocking and locking on the tibial element [2] and the foot [3] of the prosthesis associated therewith. The invention is advantageously suitable for light prostheses, comfort, and use for bathing and swimming in seawater.

Description

Title: Flexible ankle device for lower limb prosthesis

Technical area

The invention relates to an interchangeable flexible ankle device, mounted by interlocking at the interface between the "tibial" part and the "foot" part of a prosthesis.

State of the art

Those skilled in the art are familiar with lower limb prosthesis devices having an elastic connection at the ankle because this elasticity contributes to walking comfort. Numerous solutions have been provided in the form of mechanisms integrated into the prosthesis, often complex based on springs, of sill blocks. More recently, the use of carbon blades has brought the necessary flexibility to the prosthesis to ensure better quality of walking, or even running. All these systems are more or less complicated, more or less expensive. Aside from the use of carbon blades, they are not light and cannot be used for aquatic activities. Finally, their interchangeability is not guaranteed in the event of breakage or a slight modification due to growth in children.

Several patents describe systems proposing an articulation of a limb prosthesis below the level of the ankle. They are not monolithic and do not provide the characteristics sought in the context of the patient's leisure and relaxation use: lightness, ease of use, capacity for immersion in fresh water and in sea, easy interchangeability without tools.

Patent GB120445 describes an integrated articulation device, based on the articulation of a lever resting on one side on a block sill and on the other a spring. There is no possible interchangeability of the "ankle" element with respect to the "tibial" part and the "foot" part.

The patent US4229839 describes an interchangeable articulation device, based on the deformation of a silentbloc bonded between two mechanical parts connected to the "tibial" and "foot" parts by a threading system. Interchangeability requires the use of tools. The metal parts are not suitable for immersion in an aquatic environment.

Patent FR2511863 describes an artificial foot device, based on a mechanical “ankle + foot” assembly. The “ankle” function is not ensured by an interface between the “tibial” part and the “foot”.

--2-Patent DE3430207 describes an artificial leg device in which is implanted a mechanical articulation system, based on the deformation of silentblocs and connecting the "tibial" part to the foot by threaded elements.

US Pat. No. 5,019,109 describes a multiaxial rotation device for prosthetic ankle, based on the deformation of a silentblock integrated into the “foot” part, therefore not removable from the latter, and connected to the tibial part by a threaded element.

Patent WO9712567 describes an artificial ankle articulation device with damping elements and prosthesis produced with this articulation, based on the deformation of two silentblocks ensuring elasticity around a rotational movement.

The patent US5913902 describes an artificial foot device which allows flexibility of walking, based on a mechanical assembly with springs which ensure the elasticity of both the ankle and the front part of the foot.

Patent EPI663082 describes a foot prosthesis device, based on an assembly of blades which integrates both the elasticity of the foot and the ankle.

All these devices provide the flexibility sought for a better quality of walking. On the other hand, they do not bring simplicity, interchangeability, cost / performance ratio, comfort and relaxation as well as the capacity of immersion in particular in sea water.

The invention aims to combine lightness, predetermined elasticity, ability to go into the water and introduces the modularity function of the prosthesis which is expressed in three modules: the "tibial part", the "ankle" and the "foot" .

Statement of the invention

The invention relates to the field of medical equipment of the “internal limb prosthesis” type which can be used for comfort and relaxation situations, in particular in an aquatic or humid environment. It aims to combine lightness, resistance and elasticity. It brings flexibility between the two parts of the prosthesis: the “tibial part” and the “foot”, thus improving the course of the walk, therefore the patient's comfort. It is monolithic, removable, easily interchangeable, which allows the modularity of the prosthesis in three parts: "tibial part", "ankle" and "foot", therefore the replacement of a single module in case of wear, compensation of the growth phenomenon in children by changing the module

--3- "ankle", Ια modification of the degree of elasticity of the "ankle" module depending on the quality of the patient's walking.

The flexible ankle device for lower limb prosthesis, according to the invention, comprises:

. A bearing face and a fitting and locking device on the underside of the “tibial” part adapted for this purpose.

. A support face and a fitting and locking device on the upper face of the "foot" part of the prosthesis.

. A part characterized in that it has shapes and dimensions made of a deformable material, of the thermoplastic polyurethane type ensuring an elastic connection between the two parts of the prosthesis, namely the "tibial" part and the "foot".

According to a first improvement, the elastic deformable part of the "ankle" comprises cells of tubular shape extending over the entire width in the frontal plane and open at each end.

The preferred application of the invention is therefore bathing and relaxation, because of its hollow shapes:

- which do not retain water and allow rapid drying,

- which confer a lightness favorable to the comfort of the patient,

- which introduce flexibility to the prosthesis favorable to the progress of the walk,

- which allow quick and easy interchangeability, which can compensate for the growth phenomenon by replacing the single “ankle” element of the prosthesis.

The accompanying drawings illustrate the invention:

Figure 1 shows the flexible ankle mounted on the tibial part and the foot of the prosthesis.

Figure 2 shows the ankle alone

Figure 3 shows the end of the tibial part and that of the foot which receive the ankle.

Figure 4 shows the different volumes that make up the functionality of the anchor.

--4-Detailed description of at least one embodiment of the invention

Referring to Figure 1, the invention consists in creating a monolithic part, of particular geometry, in a deformable material of the thermoplastic polyurethane type. This part [1], called "ankle" comes to fit and lock on the one hand, in its upper part, on the basis of the "tibial element" [2] and on the other hand, in its lower part , on the upper support of the "foot" [3]. This requires a geometrical definition and a suitable dimensioning of these two bearing surfaces, specific to [2] and [3], constituting the "interfaces" of the prosthesis receiving this ankle. These two interfaces are part of the invention.

Referring to Figure 2, the shape [4] is locked on the lower base of the tibial part [6] (Figure 3) and the shape [5] on the upper part of the foot [7] (Figure (3) These two shapes [4] and [5] are monolithically connected by geometric shapes ensuring the elasticity necessary for the ankle.

Referring to Figure 3, the shapes [6] and [7] of the tibial element [2] and the foot [3] respectively, are part of the invention and provide the interchangeable connection of the ankle.

With reference to FIG. 4, the flexible anchor, produced by an additive manufacturing process, in particular by the FDM (Fused Deposition Modeling) process, is composed of several volumes:

- The volume [4] whose function is to ensure the connection by fitting and locking the ankle on the lower base of the tibial part [6].

- The volume [5] whose function is to ensure the connection by fitting and locking the ankle on the upper base of the foot part [7].

- The volume [8] whose function is to ensure the support of the connection by fitting and locking the ankle on the lower base of the tibial part [6].

- The volume [9] whose function is to ensure the support of the connection by fitting and locking the ankle on the upper base of the foot part [7].

- The volume [10], located forward in the direction of travel, consists of a tubular element.

- The volume [11], located behind the heel, is formed of two superimposed tubular elements each having a section in the shape of a crescent moon.

The function of the volumes [10, 11] is to ensure the desired elasticity between the "tibial" part [2] of the prosthesis and the "foot" part [3] of the prosthesis. These two volumes have a parameterized geometry which allows the elasticity of the ankle to be measured.

The flexible ankle is part of an immersible lower limb prosthesis for bathing and relaxation activities, the contours of the “tibial” part and the “foot” forming a large mesh allowing the passage and flow of water. .

--5--

Claims (6)

claims 1. Flexible ankle device for a lower limb prosthesis, characterized in that it is monolithic, interchangeable, immersible in particular with sea water, and comprises: . A support face (8) and a fitting and locking device (4) on the underside of the tibial part adapted for this purpose. . A bearing face (9) and a fitting and locking device (5) on the upper face of the foot part of the prosthesis. . A part (10, 11) characterized in that it has shapes and dimensions made of a deformable material, ensuring an elastic connection between the two parts of the prosthesis, namely the tibial part [2] and the foot [3] . 2. Device according to claim 1, characterized in that the elastic deformable part comprises tubular-shaped cells (10, 11) extending over the entire width in the frontal plane and open at each end 3. Device according to claim 2, characterized in that the volumes, shapes and dimensions of the parts [10] and [11] of the pin [1] are defined and parameterized according to the desired elasticity. 4. Device according to claim 1, characterized in that the fitting and the locking of the ankle are ensured by a removable system ensuring its interchangeability. 5. Device according to claim 1, characterized in that the shapes and dimensions of the “interface” parts [6] and [7], respectively of the tibial part [2] and of the foot [3] are associated with the shapes and dimensions of the parts [4] and [5] of the ankle [1]. 6. Device according to any one of the preceding claims, characterized in that the flexible ankle is part of an immersible lower limb prosthesis for bathing activities, the contours of the foot and of the tibial part forming a wide mesh leaving the passage and flow of water.