GB2570018A

GB2570018A - Prosthesis

Info

Publication number: GB2570018A
Application number: GB1815008.6A
Authority: GB
Inventors: Macabuag Nate; Lakey Ben
Original assignee: Mitt Wearables Ltd
Current assignee: Mitt Wearables Ltd
Priority date: 2018-09-14
Filing date: 2018-09-14
Publication date: 2019-07-10
Anticipated expiration: 2038-09-14
Also published as: WO2020053597A1; GB2570018A8; GB2570018B; GB2570018B8; GB201815008D0; CN110897764A

Abstract

A prosthesis 10 (e.g. for an arm or leg) includes: (i) a flexible sleeve 12 for receiving a residual limb therein, (ii) a constrictor 14 on the flexible sleeve for reducing the periphery of the flexible sleeve and tightening the sleeve around the limb, (iii) a rigid mount 16a, 16b, secured to the sleeve and spaced axially along the sleeve from the constrictor, defining a cavity extending axially from the sleeve for receiving a portion of the limb, (iv) a tool 18 (e.g. a pen, an artificial hand, an electrical tool etc.), (v) a connector (22, 26) for securing a first portion of the tool to the mount, and (vi) a fulcrum defined by the rigid mount and tool when the tool is secured to the mount by the connector, about which the tool is pivotable relative to the mount between: (a) a retained condition, in which a second portion of the tool abuts the mount and the tool is held securely on the mount; and (b) a spaced condition, in which the second portion of the tool is spaced from the mount and may be released from the mount. A magnet/magnets (30, 32 Fig 2) on the tool or mount biases the second portion of the tool towards the mount and within the retained condition.

Description

PROSTHESIS

BACKGROUND

The present invention relates to a prosthesis. More particularly, the present invention relates to a prosthesis including: a flexible sleeve that, in use, extends beyond a user’s joint; a constrictor for reducing the perimeter of the sleeve on a first side of the user’s joint proximal the user’s body; a rigid mount secured to the sleeve on a second side of the user’s joint distal the user’s body; a tool securable to the mount; and a connector (including at least one magnet) for retaining the tool on the mount.

Various types of prostheses are known. For example: US7,611,476 “Vacuum-sealed orthotic prosthetic, and other body worn devices” describes various prostheses including a flexible sleeve extendable over a user’s joint, a strap for reducing the perimeter of the sleeve on a first side of the user’s joint proximal the user’s body, and an artificial body part (i.e. a tool) secured to the sleeve on a second side of the user’s joint. US514,225 “Artificial leg” describes a flexible sleeve (for receiving a user’s hip); a waist strap at a first axial end of the sleeve for securing the sleeve around a user’s waist; an upper leg residual limb receiving socket (i.e. a mount) at a second axial end of the sleeve; and a lower leg (i.e. a tool) secured to the socket. US3,262,131 “Artificial leg with detachable stump supporting sock” describes a prosthesis including: a rigid mount for receiving a user’s lower leg stump / residual limb therein; a flexible sleeve that extends from the mount over the user’s knee; an annular elastic border for reducing the perimeter of the flexible sleeve around the user’s upper leg; leg bars extending from the rigid mount; and screws or rivets for securing the leg bars to the rigid mount A drawback of known devices is that they require dexterous use of both hands to remove and substitute prosthesis tools. This makes them unsuitable for users of hand or arm prostheses. It is an object of the present invention to address this drawback and to provide a prosthesis that facilitates removal and substitution of tools using one hand only.

SUMMARY OF THE INVENTION

According to the invention, there is provided a prosthesis that includes: a flexible sleeve for receiving a residual limb therein, the sleeve defining a longitudinal axis; a constrictor on the flexible sleeve for reducing the periphery of the flexible sleeve, in use, to tighten the sleeve around a proximal limb; a rigid mount secured to the sleeve and spaced axially along the sleeve from the constrictor, the rigid mount defining a cavity extending axially from the sleeve for, in use, receiving therein a portion of a residual limb received within the sleeve; a tool; a connector for securing a first portion of the tool to the mount; a fulcrum defined by the rigid mount and tool when the tool is secured to the mount by the connector, about which fulcrum the tool is pivotable relative to the mount between: (i) a retained condition, in which a second portion of the tool abuts the mount; and (ii) a spaced condition, in which the second portion of the tool is spaced from the mount; and a magnet on the tool or mount for biasing the second portion of the tool towards the mount, thereby resisting relative movement of the tool and mount from the retained condition towards the spaced condition, wherein the connector: does not permit the too! to be released from the mount when the tool and mount are in the retained condition; and permits release of tool from the mount when the too! and mount are in the spaced condition.

Typically, the mount defines a first spigot, and the tool defines a corresponding first recess that is sized and shaped to receive the first spigot therein.

Generally, the tool defines a second spigot, and the mount defines a corresponding second recess that is sized and shaped to receive the second spigot therein.

Preferably, the first spigot and the second recess are spaced axially along the mount.

Typically, when the tool is in the retained condition: relative axial movement of the tool and mount; relative rotation of the tool and mount, and movement other than relative rotation towards the spaced condition; and relative tangential movement of the tool and mount, is prevented by abutting contact: between the first spigot defined by the mount and the tool; and between the second spigot defined by the tool and the mount.

Generally, the mount is made of first and second parts, with each of the first and second parts of the mount secured to the sleeve, and wherein: (i) the first spigot is defined by the first part of the mount; and (ii) the second recess is defined by the second part of the mount.

Preferably, the first part of the mount and the second part of the mount extend along the sleeve, along diametrically opposite sides of the sleeve.

Typically, the second part of the mount extends along at least 90% of the axial length of the cavity defined by the mount, in use, to extend: from within 5cm of the free end of a user’s limb; to just short of the user’s limb joint.

Generally, the first part of the mount extends axially from: the axial end of the sleeve distal the constrictor; the axial end of the first part of the mount distal the constrictor; and the axial end of the cavity defined by the mount distal the constrictor.

Preferably: the sleeve; and the cavity defined by the mount, are open at both axial ends.

Typically, the first spigot defined by the first part of the mount is located on the first part of the mount that protrudes axially from: the second part of the mount; and the cavity defined by the mount.

Generally, the first part of the mount is spaced from the second part of the mount with the sleeve bridging the space there between.

Preferably, when the tool is secured to the mount, the tool protrudes axially beyond the axial ends of the mount and sleeve distal the constrictor.

Typically, at least one vent aperture is defined by the mount.

Generally, the sleeve defines at least one vent aperture coincident with the at least one vent aperture defined by the mount.

Preferably: a first magnet is disposed on the first spigot defined by the mount; a second magnet is aligned in polar opposite configuration with respect to the first magnet within the tool adjacent to the first recess defined by the tool; at least one third magnet is associated on the tool adjacent to the second spigot defined by the tool; and at least one fourth magnet is aligned in polar opposite configuration with respect to the at least one third magnet within the mount adjacent to the second recess defined by the mount.

Typically, the wall thickness of the mount or tool in the vicinity of the first, second, third or fourth magnets is less than the wall thickness of the surrounding area of the mount or tool.

Generally, the wall thickness of the mount or tool in the vicinity of the first, second, third or fourth magnets is less than 1mm.

Preferably, silicone is applied to the radial inner surface of the sleeve, in use to increase the coefficient of friction of the radial inner surface of the sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a first perspective exploded view of a prosthesis according to a preferred embodiment of the invention;

Figure 2 is a second perspective exploded view of the prosthesis in Figure 1;

Figure 3 is a perspective view of the prosthesis in Figure 1, with a tool in a retained condition;

Figure 4 is a perspective view of the prosthesis in Figure 1, with the tool in a spaced condition; and

Figure 5 is a perspective view of the prosthesis in Figure 1, secured to a user.

In this specification: (i) “a residual limb” is intended to mean a damaged limb portion beyond a healthy joint; and (ii) “proximal limb” is intended to mean a limb portion on the side of a healthy joint opposite the residual limb, closer to the body.

DESCRIPTION OF THE INVENTION

With reference to Figures 1 to 5, a prosthesis 10 includes a sleeve 12, a constrictor 14, a mount 16 and a tool 18.

The prosthesis 10 is particularly suited for persons with a hand or arm disability.

The sleeve 12 is: tubular defining a longitudinal axis A-A shown in Figures 1 and 2; open at both axial ends; and made of a flexible, breathable fabric. The sleeve 12 is sized and shaped to: receive a user’s residual limb extending below the elbow via a fist axial end 12a of the sleeve 12 (generally referred to as the proximal end); and extend beyond the user’s elbow over a portion of the user’s proximal limb (i.e. the upper arm portion).

Silicone strips (not shown) (preferably, platinum-cured silicone rubber strips) are applied to the radial inner surface of the sleeve 12 to increase the coefficient of friction of the inside of the sleeve 12. Preferably, the silicone strips are aligned perpendicularly to the longitudinal axis A-A of the sleeve 12. In use, the silicone strips inhibit sliding of the sleeve 12 along a user’s residual limb or proximal limb.

Electrode sensors (not shown and optionally made of conductive thread) may be incorporated (e.g. stitched or woven) into the sleeve 12. Furthermore, the sleeve 12 could be made of a sweat wicking, ventilating material with sufficient cushion to protect the user from rigid edges of the mount 16. The sleeve 12 should have sufficient structural rigidity to hold itself open into a tubular shape unaided - facilitating insertion of a user’s limb therein without the use of another hand to hold the sleeve 12 open. The inner surface of the sleeve could have varied surface texture to provide different coefficients of friction with the user’s skin at different areas. For example, portions of the inner surface of the sleeve 12 could be smooth to facilitate free movement of the sleeve over the user’s elbow, while other portions of the inner surface of the sleeve 12 could be sticky to grip the proximal limb.

The constrictor 14 is secured at or near the first axial end 12a of the sleeve 12, and is in the form of a strap with Velcro (RTM). In use, the strap 14 is looped around a user’s proximal limb (i.e. between the user’s elbow and shoulder), tightened around the proximal limb and secured in this tightened configuration by the Velcro (RTM). Effectively, the constrictor 14 reduces the periphery of the flexible sleeve 12, thereby tightening the first axial end 12a of the sleeve 12 around the user’s proximal limb. It will be appreciated that, since the perimeter of the elbow joint is typically greater than that of the humerus, the constrictor 14 inhibits the first axial end 12a of the sleeve 12 from passing the elbow.

Although the constrictor 14 has been described in the form of a strap with Velcro (RTM), it will be appreciated that the constrictor could adopt any other form. For example, the constrictor could comprise: a woven string (e.g. shoe lace) with a drawstring lock or with beads along its length to catch and lock the string at predetermined increments; an inextensible wire with a spool (optionally, motorised) regulated by a pawl and ratchet mechanism; webbing (e.g. nylon, polypropylene or cotton) with a ladder lock to form a loop and vary the perimeter length; or an elastic undersized U-shaped member that can be splayed to locate over a user’s proximal limb.

The mount 16 is made of a rigid plastic material and defines a cavity extending axially from the sleeve 12 for receiving a distal portion of the residual limb therein. The cavity defined by the mount 16 is open at both axial ends.

The mount 16 is secured to the sleeve 12, but axially spaced along the sleeve 12 from the constrictor 14.

The mount 16 comprises first and second parts 16a and 16b, each of which are: spaced from each other; movable relative to each other; and secured to the sleeve 12. Typically, the first and second parts 16a and 16b are disposed on diametrically opposite ends of the sleeve 12 and extend axially along the sleeve 12. The sleeve 12 also bridges the gap between the first and second parts 16a and 16b of the mount 16.

The first part 16a of the mount 16 extends: beyond the second axial end 12b of the sleeve 12 (generally referred to as the distal end); the axial end of the second part 16b of the mount 16 distal the constrictor 14; and the axial end of the cavity defined by the mount 16 (distal the constrictor 14). Whereas, the second part 16b of the mount 16 extends along at least 90% of the axial length of the cavity defined by the mount 16 and does not extend beyond the second axial end 12b of the sleeve 12. In use, the second part 16b of the mount 16 extends: from within 5cm of the free / distal end of the user’s limb; to just short of the user’s elbow.

Optionally, the second part 16b of the mount 16 extends axially along the medial side of the sleeve 12, and defines recesses along its length.

Each mount portion 16a and 16b defines a vent aperture 20, which vent aperture 20 is coincident with a corresponding vent aperture defined by the sleeve 12. These vent apertures facilitate ventilation / airflow to the user’s residual limb. A first spigot 22 is defined by the first part 16a of the mount 16. The first spigot 22 extends diametrically beyond the second axial end 12b of the sleeve 12. A second recess 24 is defined by the second part 16b of the mount 16. The first spigot 22 and the second recess 24 are axially spaced along the mount 16.

In use, the first spigot 22 and the second recess 24 and extend from or towards the sleeve 12 along the coronal plane of the user’s body.

Although the mount 16 has been described as comprising first and second parts 16a and 16b, it will be appreciated that the mount 16 could comprise a single integrally made part.

The radial inner surface of the mount 16 in the vicinity of the cavity defined thereby could be lined with a flexible, resilient material that accommodates variations in user residual limb sizes and that accommodates swelling of the residual limb during wear.

The tool 18 could comprise a pen, an artificial hand, an Ottobock Michelangelo (RTM) hand, or any other tool useful to the user. The too! 18 defines: a first recess 26 corresponding to / complementary to the first spigot 22 defined by the first part 16a of the mount 16, i.e. sized and shaped to receive the first spigot 22 therein; and a second spigot 28 corresponding to / complementary to the second recess 24 defined by the second part 16b of the mount 16, i.e. sized and shaped to be received within the second recess 24. The first recess 26 and the second spigot 28 are axially spaced along the tool 18.

Although: the first spigot 22 has been described as extending from the mount 16 with the corresponding first recess 26 described as being defined by the tool 18; and the second spigot 28 has been described as extending from the tool 18 with the corresponding second recess 24 described as being defined by the mount 16, it will be appreciated that the recesses and spigots on the mount and too! could be swapped around. For instance, the first spigot could be defined by the too! and the second spigot could be defined by the mount, while the mount and tool define first recess and second recess, respectively.

Where the tool 18 is an electric tool, the tool 18 and mount 16 could include complementary adaptors that enable electric communication between the mount 16 and too! 18 when the too! 18 is connected to the mount 16. A battery (not shown) could also be housed by the mount 16. A first magnet 30 is disposed on the first spigot 22 defined by the first part 16a of the mount 16. A second magnet 32 is disposed on the tool 18 adjacent to the first recess defined by the too! 18. Four third magnets 34 are disposed on the too! 18 adjacent to the second spigot 28 defined by the too! 18. And, four fourth magnets 36 are disposed on the second part 16b of the mount 16 adjacent to the second recess 24 defined by the mount 16.

Preferably, the first and fourth magnets 30 and 36 are located within the mount 16 and the second and third magnets 32 and 34 are located within the tool 18. It is also preferred that the wall thickness of the mount 16 or tool 18 in the vicinity of the first, second, third or fourth magnets 30, 32, 34 and 36 is less than the wall thickness of the surrounding area of the mount 16 or tool 18. Typically, the wall thickness of the mount 16 or tool 18 in the vicinity of the first, second, third or fourth magnets 30, 32, 34 and 36 is less than 1mm, preferably, around 0.5mm.

The tool 18 is securable to the mount 16 by receiving: the first spigot 22 on the mount 16 within the first recess 26 defined by the tool 18; and the second spigot 28 on the tool 18 within the second recess 24 defined by the mount 16. Reception of the first spigot 22 within the corresponding first recess 26, coupled with opposing first and second magnets 30 and 32, act as a connector, securing a second portion of the tool 18 (i.e. a portion adjacent to the first recess 26) to the mount 16.

It will be appreciated that, with the first and second parts 16a and 16b of the mount 16 disposed on diametrically opposite ends of the sleeve 12, attachment of the tool 18 to both first and second parts 16a and 16b of the mount 16 induces the first and second parts 16a and 16b of the mount 16 to “clamp” on to the limb, thereby better to transmit forces between: the tool / mount on the one hand; and the limb on the other hand.

When the tool 18 is secured to the mount 16, the tool 18 protrudes axially beyond both: the axial end of the mount 16 distal the constrictor 14; and the second axial end 12b of the sleeve 12. A fulcrum 38 is defined by the mount 16 and tool 18 when the too! 18 is secured to the mount 16 by the connector (22, 26, 30 and 32), about which fulcrum 38 the tool 18 is pivotable relative to the mount 16 between: * a retained condition (shown in Figures 3 and 5), in which a first portion of the tool 18 (i.e. a portion adjacent to the first recess 26 defined by the tool 18) abuts the mount 16; and * a spaced condition (shown in Figure 4), in which the first portion of the tool 18 is spaced from the mount 16 (more specifically, in which the first spigot 22 on the mount 16 is no longer received within the first recess 26 defined by the tool 18).

Opposed first and second magnets 30 and 32 bias the second portion of the tool 18 towards the mount 16, thereby resisting relative movement of the too! 18 and mount 16 from the retained condition towards the spaced condition. it wili be appreciated that: the third and fourth magnets 34 and 36 could be ferrous bodies and not magnets, which ferrous bodies are attracted by the first and second magnets 30 and 32; or the first and second magnets 30 and 32 could be ferrous bodies and not magnets, which ferrous bodies are attracted by the third and fourth magnets 34 and 36.

The connector (22, 26, 30 and 32) does not permit the tool 18 to be reieased from the mount 16 when the tool 18 and mount 16 are in the retained condition.

For the connector (22, 26, 30 and 32) to permit the tool 18 to be released from the mount 16, the too! 18 and mount 16 must be pivoted relative to each other towards the spaced condition.

It will be appreciated that, when the connector (22, 26, 30 and 32) connects the tool 18 to the mount 16 and the tool 18 is in the retained condition, abutting contact: between the first spigot 22 defined by the mount 16 and the tool 18; and between the second spigot 28 defined by the tool 18 and the mount 16 prevents: • relative axial movement of the tool 18 and mount 16 (i.e. movement of the tool 18 in the direction show as B-B in Figure 3); • relative rotation of the tool 18 and mount 16 (i.e. rotation of the tool 18 shown with arrows C-C in Figure 3), and movement other than relative rotation towards the spaced condition; and • relative tangential movement of the tool 18 and mount 16 (i.e. movement of the tool 18 in the direction shown as D-D in Figure 3).

It will be appreciated that the method for removing the tool 18 from the mount 16 can be effected simply by impacting the tool 18 to cause the tool 18 to pivot relative to the mount 16 towards the spaced condition, and thereafter permitting the connector (22, 26, 30 and 32) to release the too! 18 from the mount 16. It will also be appreciated that, when the tool 18 is secured to the mount 16 (with the tool in the retained condition), the tool 18 is able to resist forces and moments (other than moments causing pivoting of the tool 18 towards the spaced condition) without causing relative movement of the tool 18 and mount 16. This arrangement enables tools 18 to be removed and substituted by disabled users having limited use of one hand.

Claims

1. A prosthesis including: a flexible sleeve for receiving a residual limb therein, the sleeve defining a longitudinal axis; a constrictor on the flexible sleeve for reducing the periphery of the flexible sleeve, in use, to tighten the sleeve around a proximal limb received therein; a rigid mount secured to the sleeve and spaced axially along the sleeve from the constrictor, the rigid mount defining a cavity extending axially from the sleeve for, in use, receiving therein a portion of a residual limb received within the sleeve; a tool; a connector for securing a first portion of the tool to the mount; a fulcrum defined by the rigid mount and tool when the tool is secured to the mount by the connector, about which fulcrum the tool is pivotable relative to the mount between: (iii) a retained condition, in which a second portion of the tool abuts the mount; and (iv) a spaced condition, In which the second portion of the tool Is spaced from the mount; and a magnet on the tool or mount for biasing the second portion of the tool towards the mount, thereby resisting relative movement of the tool and mount from the retained condition towards the spaced condition, wherein the connector: does not permit the tool to be released from the mount when the tool and mount are in the retained condition; and permits release of too! from the mount when the tool and mount are in the spaced condition.

2. The prosthesis according to claim 1, wherein the mount defines a first spigot, and the tool defines a corresponding first recess that is sized and shaped to receive the first spigot therein.

3. The prosthesis according to claim 2, wherein the too! defines a second spigot, and the mount defines a corresponding second recess that is sized and shaped to receive the second spigot therein.

4. The prosthesis according to claim 3, wherein the first spigot and the second recess are spaced axially along the mount.

5. The prosthesis according to claim 4, wherein, when the tool is in the retained condition: relative axial movement of the tool and mount; relative rotation of the tool and mount, and movement other than relative rotation towards the spaced condition; and relative tangential movement of the tool and mount, is prevented by abutting contact: between the first spigot defined by the mount and the tool; and between the second spigot defined by the tool and the mount.

6. The prosthesis according to claim 5, wherein the mount is made of first and second parts, with each of the first and second parts of the mount secured to the sleeve, and wherein: (i) the first spigot is defined by the first part of the mount; and (ii) the second recess is defined by the second part of the mount.

7. The prosthesis according to claim 6, where the first part of the mount and the second part of the mount extend along the sleeve, along diametrically opposite sides of the sleeve.

8. The prosthesis according to claim 7, wherein the second part of the mount extends along at least 90% of the axial length of the cavity defined by the mount, in use, to extend: from within 5cm of the free end of a user’s limb; to just short of the user’s limb joint.

9. The prosthesis according to claim 8, wherein the first part of the mount extends axially from: the axial end of the sleeve distal the constrictor; the axial end of the first part of the mount distal the constrictor; and the axial end of the cavity defined by the mount distal the constrictor.

10. The prosthesis according to claim 9, wherein: the sleeve; and the cavity defined by the mount, are open at both axial ends.

11. The prosthesis according to claim 10, wherein the first spigot defined by the first part of the mount is located on the first part of the mount that protrudes axially from: the second part of the mount; and the cavity defined by the mount.

12. The prosthesis according to claim 11, wherein the first part of the mount is spaced from the second part of the mount with the sleeve bridging the space there between.

13. The prosthesis according to claim 12, wherein when the tool is secure to the mount, the tool protrudes axially beyond the axial ends of the mount and sleeve distal the constrictor.

14. The prosthesis according to claim 13, wherein: (i) at least one vent aperture is defined by the mount; and (ii) the sleeve defines at least one vent aperture coincident with the at least one vent aperture defined by the mount.

15. The prosthesis according to claim 14, wherein: a first magnet is disposed on the first spigot defined by the mount; a second magnet is aligned in polar opposite configuration with respect to the first magnet within the tool adjacent to the first recess defined by the tool; at least one third magnet is associated on the tool adjacent to the second spigot defined by the tool; and at least one fourth magnet is aligned in polar opposite configuration with respect to the at least one third magnet within the mount adjacent to the second recess defined by the mount.

16. The prosthesis according to claim 15, wherein: (i) the wall thickness of the mount or tool in the vicinity of the first, second, third or fourth magnets is less than the wall thickness of the surrounding area of the mount or tool; and (ii) the wall thickness of the mount or tool in the vicinity of the first, second, third or fourth magnets is less than 1mm.

17. The prosthesis according to claim 16, wherein silicone is applied to the radial inner surface of the sleeve, in use to increase the coefficient of friction of the radial inner surface of the sleeve.