PROSTHETIC SOCKET DESIGNED TO ADAPT IN PARTICULAR TO A VARIATION IN VOLUME OF AN AMPUTEE LIMB
The prosthetic socket with an elastomer inner layer and adjustable design addresses the challenge of volume variation in amputated limbs, enhancing comfort and proprioception by securely fitting to the limb without frequent remakes.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- PROTUNIX
- Filing Date
- 2022-10-26
- Publication Date
- 2026-05-22
AI Technical Summary
Existing prosthetic sockets fail to adequately adapt to variations in the volume of an amputated limb over time, leading to discomfort and the need for frequent remakes, which compromises proprioception and comfort.
A prosthetic socket with an inner layer made of elastomer material and a rigid structure, featuring longitudinal cuts and overlapping lips, along with a tension band and adjustment device, allowing for adjustable fit to accommodate volume changes.
The socket effectively adapts to variations in limb volume, maintaining comfort and proprioception by ensuring a secure fit without excess ridges or discomfort, reducing the need for frequent remakes.
Smart Images
Figure 00000012_0000 
Figure 00000012_0001 
Figure 00000013_0000
Abstract
Description
Title of the invention: PROSTHETIC SOCKET DESIGNED TO ADAPT IN PARTICULAR TO A VARIATION IN VOLUME OF AN AMPUTEE LIMB FIELD OF INVENTION
[0001] The invention relates to a prosthetic socket which is designed to adapt to a variation in volume or a variation in shape of an amputated limb, said socket being designed to accommodate a stump.
[0002] Amputees, whoever they may be, would like to regain the sensation of their lost limb, with good proprioception and as few constraints as possible.
[0003] Proprioception will be understood as the set of nerve information transmitted to the brain, particularly through the skin, enabling the regulation of posture and body movements. STATE OF THE ART
[0004] Sockets are known which are fixed to an amputated limb, by receiving a stump, and which are associated with an articulated device, or not; allow the amputated limb to be extended, the device aiming to replace the missing part of the limb: document FR 3 011 176 describes an example of a socket which has an inner layer of silicone (which is an elastomeric material) covered at least partially by a rigid structure, the whole being fitted into an outer layer of silicone.
[0005] The inner silicone layer provides a certain comfort for the patient: the layer being soft and elastic, it adapts to the movement of the limb accommodated in the socket.
[0006] Unfortunately, this flexibility is not sufficient and does not allow the socket to be adapted to a variation in the volume of the limb accommodated over a long period: for example, after an operation, the shape and size of the stump will vary for a year or more, depending on whether the patient has a disorganization of the lymphatic and vascular system or not, whether or not he works the muscles of the amputated limb, etc.
[0007] It is therefore necessary to remake the ill-fitting socket in the case of suction. If the patient has a standard prefabricated liner on the skin, they can place a cap between the liner and the socket to compensate for the loss of volume (which reduces proprioception by 50%). PRESENTATION OF THE INVENTION
[0008] There is therefore a need to have a socket whose internal diameter can adapt to the variations in size of the limb accommodated.
[0009] The invention relates to this purpose to a prosthetic socket for an amputated limb, suitable for receiving a stump of said amputated limb and suitable for adapting to variations in volume of said amputated limb and / or said stump, said socket extending along a longitudinal direction and comprising an inner layer made at least partially of elastomer material, in the shape of a sock, suitable for enveloping said stump and at least partially said amputated limb, said inner layer being covered at least partially with a rigid structure, said rigid structure comprising at least two masts which extend along a direction parallel or substantially parallel to said longitudinal direction, as well as a receiving shell of said stump, said shell being connected to one end of each of said at least two masts.
[0010] The socket according to the invention is remarkable in that said inner layer comprises at least one cutout which extends along said longitudinal direction, or substantially along the longitudinal direction from a free edge of said layer into said receiving shell, the inner layer having two longitudinal lips made at least partially of elastomer material, which extend on either side of said at least one cutout and which overlap at least partially one another along a contact surface which extends along a direction parallel to a tangential direction of said inner layer or along a direction inclined with respect to said tangential direction.
[0011] The overlapping of the lips allows them to be separated from each other and the opening of the inner layer to be enlarged or reduced: thus, the inner layer can adapt to variations in volume. Furthermore, the elastomer material used to make the inner layer adhere to each other, which keeps the inner layer in position on the skin of the treated limb.
[0012] The socket according to the invention may also include the following features, taken separately or in combination:
[0013] - the two inner lips have two complementary shapes which fit together one with the other along said cut,
[0014] - the inner layer has a regular inner layer thickness and the two Lips overlapping one on top of the other present a combined thickness that is equal to or nearly equal to the thickness of the inner layer. In this way, the overlapping of the lips does not create an excess ridge that would be bothersome for the patient.
[0015] - the cutout is positioned against at least one of said two masts of said rigid structure,
[0016] - the socket includes at least one flexible tension band, which extends at least partially around said inner layer,
[0017] - said at least one flexible tension band is made of a material comprising polyamide and covers at least partially one of said two mats,
[0018] - said at least one flexible tension band is associated with an adjustment device, ensuring the tightening or loosening of said flexible tension band around said inner layer,
[0019] - said adjustment device is fixed to said rigid structure,
[0020] - said device comprises a cable connected on one side to one end of a strip of flexible tension and on the other hand to an adjustment knob of the adjustment device ensuring the traction or release of said cable, said knob being manually operable,
[0021] - in the case where the socket is designed to accommodate a patient's thigh (by (example), it may present an anteroextreme socket portion, which is positioned on an anteroextreme face of the patient's thigh, one of the two said masts erecting in said anteroextreme part of said socket and the other of said two masts erecting on the inner layer in a diametrically opposite manner with respect to a central axis of said inner layer, to be positioned under the ischium or substantially under the ischium of a patient when the patient wears said socket. PRESENTATION OF THE FIGURES
[0022] Other advantages and features of the invention will become apparent upon examination of the detailed description of a non-limiting embodiment and the accompanying drawings, in which:
[0023] [Fig. 1] is a rear and slightly left profile view of a socket according to the invention illustrated in perspective,
[0024] [Fig.2] is a side and slightly right profile view of the socket of the [Fig. 1] illustrated in perspective,
[0025] [Fig.3] is a front view of a socket according to an alternative embodiment of a socket according to the invention,
[0026] [Fig.4] is a cross-sectional view of an internal layer of the socket,
[0027] [Fig. 5] is a cross-sectional view of an internal layer of the socket, illustrating a first cut and a first method of covering the lips of the inner layer, on either side of the cut,
[0028] [Fig. 6] is another example of a cross-sectional view of an internal layer of the socket, illustrating a second cut and a second method of covering the lips of the internal layer, on either side of the cut, and
[0029] [Fig.7] is a perspective and exploded view of an adjustment device, allowing the manual adjustment of the tension of a retaining band in position around the inner layer of the socket.
[0030] METHOD OF IMPLEMENTATION
[0031] Fig. 1 illustrates a socket 1 which is designed to receive a right thigh and the stump of a right thigh amputated at the level of the top of the knee.
[0032] The socket 1 is illustrated as seen from behind (arrow A), the left part (arrow G) of the socket 1 being positioned under the ischium of a person, and the right part (arrow D) of the socket corresponding to the part of the socket which is positioned on the outside of the thigh.
[0033] The socket comprises an inner layer 2 of the socket, made of silicone (an elastomeric material), which is slipped around the stump and positioned around the thigh. It should be understood that the inner layer of the socket could be made of an elastomeric material other than silicone, without departing from the scope of the invention.
[0034] The inner silicone layer 2 is in the form of a sock which is positioned against the patient's skin (skin of the stump and the amputated limb).
[0035] The inner layer 2 has a substantially constant thickness, so that there is no excess thickness that could be the source of discomfort or inconvenience for the patient.
[0036] Around the inner layer 2, the socket has a rigid structure 3.
[0037] The rigid structure includes an end shell 30, (also called apple picker by prosthetists) which has an internal cavity of shape substantially complementary to that of the stump to accommodate it.
[0038] This internal cavity can be made in the following way:
[0039] First, a mold is formed on the skin of the stump to obtain a negative of the shape of the stump and part of the thigh.
[0040] Then, a plaster cast is poured into the mold, in order to have a life-size replica of the stump and thigh.
[0041] After plaster correction: Silicone is then molded over the replica.
[0042] Finally, the carbon shell is laminated, that is to say, resin is formed with carbon fiber is used around the replica to create the hull.
[0043] The end shell 30 is also designed to allow the attachment of a device intended to replace the missing limb.
[0044] This device has not been shown to simplify the reading of the figures. In the context of our example, it may be an articulated device, simulating a knee, and a lower leg part carrying at its end an articulated foot.
[0045] The device can be fixed at the bottom 31 of the shell 30.
[0046] Two masts 32 and 33 are made integral with the edge of the hull 30 and extend sen possibly on either side of the inner sock-shaped layer 2, from the bottom of the inner sock-shaped layer 2 going towards the top of the inner sock-shaped layer.
[0047] The mast 32 is designed to be positioned under the patient's ischium, that is to say substantially inside his thigh, a little towards the back of the thigh (if we considered that the section of the socket represented a clock, the position of the mast 32 would be between 7 and 8 o'clock).
[0048] The mast 33 is designed to be positioned outside the thigh, slightly to the right (anteroexternal face of the thigh), substantially towards the front of the thigh (if we were to consider once again that the section of the socket represented a clock, the position of the mast 32 would be around 2 o'clock).
[0049] The positioning of the masts 32 and 33 ensures that the back of the patient's thigh, which is in the inner sock-shaped layer 2, is not covered with any rigid material.
[0050] This allows the patient to have considerable comfort when sitting because the back of his thigh only rests on the inner silicone layer: it does not rest on a mast.
[0051] The masts 32 and 33 each extend in the direction L (or substantially in the direction L) along which the socket 1 extends, that is to say in the longitudinal direction of the amputated limb which will be received in the socket.
[0052] It should be understood that the longitudinal direction is not necessarily an axis parallel to the axis of the socket: it could be inclined without departing from the scope of the invention. The longitudinal axis is an axis that runs from a point on the shell 30 to a point on the opening of the inner layer 2.
[0053] According to the invention, the sock-shaped inner layer 2 has a cutout 4, which extends from the opening 20 of the inner layer (the opening 20 being the opening through which the amputated limb is introduced into the inner layer) to the level of the shell 30 which covers the inner layer 2, along the longitudinal direction L of the socket.
[0054] More specifically, the cutout 4 extends below the edge 34 of the hull 30, the edge 34 being the edge which delimits the upper free end of the hull 30 and from which the masts 32 and 33 extend upwards.
[0055] More specifically, the cutout 4 extends to the level of the change in curvature of the internal cavity of the shell 30, but it does not continue to the bottom of the cavity.
[0056] The cutout 4 is designed to allow the inner layer 2 to be adjusted around the amputated limb. In this way, the socket 1 adapts to the perimeter of the limb accommodated in the inner layer 2.
[0057] Figures 4, 5 and 6 illustrate the cut 4 made in the thickness of the layer internal 2.
[0058] The inner layer 2 is illustrated in cross-sectional view in [Fig.4], which shows that the cut 4 was not made radially: the cut 4 is made along an inclined direction Di with respect to a tangent direction Dt to the surface of the inner layer 2: said cut forms an inclined plane 40 with respect to tangent direction Dt, which defines a contact plane between two edges of the layer 2.
[0059] The edges together form two lips 21 and 22 which overlap when the inner layer is positioned around the amputated limb, following the contact plane 40.
[0060] The silicone adheres so well that the two lips 21 and 22 can hardly slide against each other along the contact plane. Thus, the inner layer 2 is held around the limb by the overlapping of the lips 21 and 22.
[0061] If the cut had been made transversely (i.e., perpendicular to a tangential plane), the contact plane between the lips 21 and 22 would be transverse (perpendicular to the tangential plane), and the lips 21 and 22 would not remain together on their own. Indeed, the separating force that occurs when the amputated limb grows, for example, is oriented in a direction tangent to the limb (therefore tangent to the wall of the inner layer 2). The two lips then tend to move apart tangentially. If the cut had been made transversely, there would be no resistance to the separation of the lips 21 and 22, which would not slide against each other: the lips would move apart without resistance.
[0062] The plane 40 along which the lips 21 and 22 are positioned one on top of the other makes it possible to create this resistance since the silicone ensures an adhesion of the two lips along a plane which approaches the tangential direction and along which the two lips tend to be separated from each other, the contact plane 40 thus creating a force opposite to the force of separation of the inner layer along the cut 4 (see [Fig.5]).
[0063] Fig. 6 illustrates yet another cutting embodiment.
[0064] The cutout bears the reference 5 on [Fig.6] and the lips of the inner layer 2 have the same references 21 and 22 as on figures 4 and 5.
[0065] The cutout 5 has a V shape, so that the lips 21 and 22 have complementary shapes that fit together (male and female shapes).
[0066] The V-shaped cut allows the lips 21 and 22 to position themselves on top of each other along two inclined planes 50 and 51 with respect to a tangential direction of the layer at the level of the lip overlap.
[0067] The force required to detach the two lips 21 and 22 from each other from the cutout 5 is even greater than that required to detach the lips 21 and 22 of cut 4 shown in figures 4 and 5.
[0068] Cutting embodiment 5 is thus used to make a socket for an active patient, cutting embodiment 4 being used for example for a less active patient.
[0069] The cut could also have a shape other than those illustrated in Figures 5 and 6: for example, the cut could be made with a transverse part, contiguous to a radial part, itself contiguous to a transverse part. It could also be made by an inclined part, contiguous to a radial part, itself contiguous to another inclined part.
[0070] These embodiments have not been shown but the invention also includes these examples of embodiments.
[0071] To ensure that the lips 21 and 22 of the cutout 4 (or of the cutout 5) are held in position, the cutout is to be positioned under a mast of the rigid structure 3, for example against the mast 33 of the socket which is positioned on the outside side of the front thigh, as shown in [Fig.1].
[0072] The mast 33 thus exerts pressure on the two superimposed lips 21 and 22, which further increases the resistance to opening of the inner layer.
[0073] It should be understood that the cutout could be positioned inside the rigid structure against the other mast 32, without going outside the scope of the invention.
[0074] It is also advantageously provided that the two lips superimposed one on the other 21 and 22 together have a superposition thickness E which is equal or substantially equal to the thickness of the inner layer: this makes it possible not to create ridges for the mast 33, the ridges (or the variation in thickness of the inner layer) being able to create discomfort or pain for the patient: The lips together form an inner layer thickness - it is not two layers which are superimposed forming a double thickness, but two parts of one and the same thickness which overlap.
[0075] It can be seen in figures 1 to 3 that the socket also includes tension bands which at least partially surround the inner layer 2, and even the masts 32 and 33.
[0076] Tension bands can be of two types: they can be semi-rigid (flexible resin) or flexible (nylon bands).
[0077] The tension bands 6 shown in the embodiment of Figures 1 and 2 are substantially semi-rigid and associated with a tension adjustment device 7 shown in [Fig.7], by means of a cable 8 included in the device 7:
[0078] The cable 8 can be linked by one of its ends to one end 60 of the band 6, as shown in figures 1 and 2.
[0079] The cable 8 can pass through a through gallery made in the masts 32 and 33.
[0080] The cable tension adjustment device 7 is fixed to one of the masts 32 or 33 (i.e., to the rigid structure). Preferably, it is fixed to mast 33, which is more easily accessible to the patient and will not cause any discomfort in the crotch area.
[0081] The device 7 includes a manually operated knob 70, which allows the cable 8 to be tensioned more or less depending on whether the knob is driven in rotation in one direction or another.
[0082] One end of the cable 8 can be fitted with a pin 80 adapted to fit into a slot 81 of a terminal block 82 which fits into a rail 71 of the device 7. Both ends of the cable are fixed. The cable length is adjusted by turning the knob 70, which allows the cable 8 to be tightened or loosened and the band 6 to be pulled to hold the inner layer 2 tightly against the skin of the patient's amputated limb.
[0083] The strip 6 could also be attached by its end directly into the domino 82 (not illustrated embodiment), without going out of the scope of the invention.
[0084] An alternative embodiment is also illustrated in [Fig.3]: in this alternative, the retaining bands 6 go around the entire internal layer 2 / masts 32, 33.
[0085] In this embodiment, the shell 30 is equipped with a vacuum valve 35.
[0086] The vacuum valve 35 allows air to be drawn inside the socket, to create a suction effect and thus maintain the socket against the skin of the patient's amputated limb.
[0087] It is understood from the preceding description how the invention makes it possible to propose a socket which adapts to a change in circumference of the amputated limb of a patient: thanks to the presence of the cut, judiciously made in a given direction, the inner layer can adapt to a variation in limb circumference, by making the two lips 21 and 22 overlap more or less.
[0088] It is also understood how the lips are held in position, thanks to the shape of the cut combined with the silicone (or other elastomeric material) in which the inner layer is made.
[0089] It is also understood how the lips are also held in position between the patient's skin and the mast behind which they are positioned.
[0090] It is further understood how the judicious positioning of the masts allows a patient to rest their amputated limb on a support without discomfort, since the judiciously positioned masts are not located at the rear of the amputated limb, which is intended to rest on a support (seat for a leg socket, table for a arm socket...
[0091] It should be understood that the invention is not specifically limited to the example described above and that it could be extended to the implementation of any equivalent means: in particular, the socket could include two cutouts, more than two masts etc.
Claims
Demands
1. A prosthetic socket (1) for an amputated limb, capable of receiving a stump of said amputated limb and capable of adapting to variations in the volume of said amputated limb and / or said stump, said socket (1) extending along a longitudinal direction (L) and comprising an inner layer (2) made at least partially of elastomeric material, in the shape of a sock, capable of enveloping said stump and at least partially said amputated limb, said inner layer (2) being covered at least partially by a rigid structure (3), said rigid structure (3) comprising at least two struts (32, 33) extending in a direction substantially parallel to said longitudinal direction (L), as well as a receiving shell (30) of said stump, said shell (30) being connected to one end of each of said at least two struts (32, 33), said inner layer (2) comprising at least one cutout (4,5) which extends substantially along the longitudinal direction (L) from a free edge of said layer (2) into said receiving shell (30), the inner layer (2) having two longitudinal lips (21, 22) made at least partially of elastomeric material, which extend on either side of said at least one cutout (4, 5) and which overlap at least partially one another along a contact surface (40, 50, 51) which extends in a direction parallel to a tangential direction (Dt) of said inner layer or in a direction inclined (Di) with respect to said tangential direction (Dt), characterized in that the two inner lips (21, 22) have two complementary shapes which fit together along said cutout (4, 5).
2. Socket according to the preceding claim, characterized in that said inner layer (2) has a regular inner layer thickness (E) and in that the two lips (21, 22) superimposed one on the other together have a superposition thickness which is substantially equal to the inner layer thickness.
3. Socket according to any one of the preceding claims, characterized in that said cutout (4, 5) is positioned against at least one (33) of said two masts (32, 33) of said rigid structure (3).
4. A socket according to any one of the preceding claims, characterized in that it comprises at least one flexible tension band (6), which extends at least partially around said inner layer (2).
5. Socket according to claim 4, characterized in that said at least one flexible tension band (6) is made of material comprising polyamide and covers at least partially one at least of said two masts (32, 33).
6. Socket according to any one of claims 4 or 5, characterized in that said at least one flexible tension band (6) is associated with an adjustment device (7), ensuring the tightening or loosening of said flexible tension band (6) around said inner layer (2).
7. Socket according to claim 6, characterized in that said adjustment device (7) is fixed on said rigid structure (3).
8. Socket according to any one of claims 6 or 7, characterized in that said device comprises a cable (8) connected on one side to an end of flexible tension band (6) and on the other side to an adjustment wheel (70) of the adjustment device (7) ensuring the traction or release of said cable (8), said wheel (70) being manually actuable.
9. Socket according to any one of the preceding claims, designed in particular to accommodate a patient's thigh, characterized in that it has an anteroextreme socket portion, which is positioned on an anteroextreme face of the patient's thigh, in that one (33) of the two said masts (32, 33) is erect in said anteroextreme portion of said socket (1) and in that the other (32) of said two masts (32, 33) is erect on the inner layer (2) in a diametrically opposite manner with respect to a central axis of said inner layer, to be positioned substantially under the ischium of a patient when the patient wears said socket (1).