RU232887U1 - Traction finger prosthesis - Google Patents

Abstract

The utility model relates to the field of medical technologies, in particular to prosthetics of the fingers of the hand, and can be used to restore the functions of the fingers lost due to injuries or diseases, to compensate for the lost functions of the limb with a partially preserved stump of the proximal phalanx. Allows the patient to perform everyday actions for self-care and some types of light physical work.

The traction finger prosthesis contains two rods - the first and the second, each of which is fixed with the proximal end with the possibility of longitudinal movement and rotation on a rotary mechanism connected to the support and adjustment unit connected to the support plate fixed on the anatomical glove. Both rods are pivotally connected with the middle phalanx with their distal ends (see Fig. 1). The middle phalanx consists of two middle phalanx body plates and a central element of the middle phalanx body (see Fig. 2). The central element of the middle phalanx body is necessary when extending the finger to support the distal phalanx and prevent eversion of the distal phalanx. The distal end of the first rod is connected to the central element of the middle phalanx body, and the distal end of the second rod is connected to the middle phalanx body plates (see Figs. 1, 5). The middle and distal phalanges are pivotally connected to each other. The distal phalanx with a pad, which facilitates coupling with elements of the environment, is attached to the body of the middle phalanx by means of a hinge joint through an axial pin (not shown conditionally). The middle phalanx contains a drive for the distal phalanx, including a lever of the distal end of the second traction, connected to the distal phalanx through a traction link and a movable lever of the distal phalanx, which allows the distal phalanx to anatomically bend inward at an angle of degrees (see Fig. 5, 6).

The technical result that the utility model is aimed at achieving consists in increasing the reliability of the structure’s operation with the required accuracy.

Description

The utility model relates to the field of medical technologies, in particular to prosthetics of the fingers of the hand, and can be used to restore the functions of the fingers lost due to injuries or diseases, to compensate for the lost functions of the limb with a partially preserved stump of the proximal phalanx. Allows the patient to perform everyday actions for self-care and some types of light physical work.

A functional finger prosthesis with a preserved or surgically created finger stump is known, consisting of a wrist cuff secured to the palm and including a plate on the back of the palm. A lever mechanism with a receiving sleeve is mounted on the plate using a hinge, reproducing the movement of a cylindrical or pinch grip of a healthy finger when moving the stump placed in the receiving sleeve in a plane perpendicular to the plane of the palm. The lever mechanism consists of the following parts: "nail phalanx", "tendon", traction, arc traction, "middle phalanx", connected by a hinge to each other, the receiving sleeve secured to the traction. The parts of the lever mechanism - the hinge, "nail phalanx" and "middle phalanx" are made with voids using laser stereolithography. Moreover, the lever mechanism is attached to the plate by a hinge with the possibility of its rotation in a plane parallel to the plane of the palm (see Russian patent No. 190504, IPC A61F 2/54 (2006.01), 2019).

The disadvantage is that the design does not allow for the natural anatomical bending angle, which reduces comfort and quality of use.

A bidirectional biomechanical finger assembly for a user's residual finger is known, comprising: a metacarpophalangeal (MCP) hinge; a distal connector; and a hinge assembly, rotationally connected between the MCP hinge and the distal connector, the hinge assembly includes a multi-finger ring configured to receive and hold the residual finger and at least one adjacent finger, the multi-finger ring is selectively located on the hinge assembly, wherein: the hinge assembly is configured to use vertical movements of at least one of the residual finger and at least one adjacent finger in the multi-finger ring for hinge connection of the distal connector in a plane parallel to the xz plane and around one or more axes parallel to the y axis; and the MCP hinge is configured to use lateral movements of at least one residual finger and at least one adjacent finger within the multi-finger ring to articulate the distal connector in a plane parallel to the xy plane and around an axis parallel to the z axis (see patent - US2017181870 (A1) IPC A61F2/586, 2017).

The disadvantage is the structural complexity, which reduces the reliability of the structure.

An elastic rigid composite finger rod prosthesis is known. The first joint of the prosthetic finger consists of an elastic section, a connecting section and a rigid section, the near end of the elastic section of the first joint is pivotally connected to the finger post, the connecting section is rigidly connected to the first joint fixation frame through a screw, the first joint fixation frame is attached to the residual finger of the first joint of the human hand through the first joint binding belt, and the second far end of the rigid section of the first joint is pivotally connected to the second joint. The first connecting rod consists of an elastic section, a contact section and a rigid section, the near end of the elastic section of the first connecting rod is pivotally connected to the finger post, and the far end of the rigid section of the first connecting rod is pivotally connected to the second joint; the second joint is pivotally connected to the third joint, the near end of the second connecting rod is pivotally connected to the far end of the rigid section of the first joint of the artificial limb, and the far end of the second connecting rod is pivotally connected to the third joint. The movement power of the prosthetic finger is provided by the residual finger of the human hand (see patent - CN209933083 (U), IPC A61F 2/58, 2020).

The disadvantage is the low reliability of the design and, as a consequence, low accuracy of actions, since the first joint of the prosthetic finger consists of an elastic section, a connecting section and a rigid section, and at least the elastic section does not have stable characteristics. The last joint has a reduced bending angle due to design features and increased rigidity of the design.

The technical problem solved by the utility model consists of increasing the reliability of the design with the required accuracy and ensuring the possibility of realizing the natural anatomical angle of flexion of the distal phalanx.

The technical result that the utility model is aimed at achieving consists of increasing the reliability of the structure’s operation with the required accuracy.

The stated technical result is achieved due to the fact that a traction prosthesis of a finger of the hand has been developed, comprising a support plate having the possibility of fastening on an individual glove, middle and distal phalanges connected to each other by a hinge, a stump receiver, first and second rods fixed with their proximal ends on a rotary mechanism connected to the support plate through a cylindrical hinge attached to a support unit for adjusting the reach and horizontal angle; the first rod is made with guides, and the stump receiver is provided with a carriage installed in the guides of the first rod with the possibility of moving along them, the distal end of the second rod is made with a lever for connecting to the distal phalanx through a traction link and a movable lever of the distal phalanx.

The fastening of the rods with their proximal ends on a rotary mechanism connected to the support plate via a cylindrical hinge attached to the support unit for adjusting the reach and horizontal angle with the possibility of longitudinal movement and rotation makes it possible to adjust the position of the finger in space with the required accuracy depending on individual characteristics, which ensures increased reliability of the structure.

The implementation of the first traction with guides in which a stump receiver is installed, equipped with a carriage installed in the guides of the first traction with the ability to move along them during operation of the prosthesis, allows the latter to move when the stump installed in the stump receiver moves, providing a greater angle of flexion of the distal phalanx, which ensures increased reliability of the structure's operation with the required accuracy.

The implementation of the second traction, equipped at the distal end with a lever for connection with the distal phalanx through a traction link and a movable lever of the distal phalanx, made it possible to increase the reliability of the design and at the same time implement the natural anatomical angle of flexion with the required accuracy.

Fig. 1 – exploded diagram of a traction finger prosthesis;

Fig. 2 – exploded diagram of a traction finger prosthesis, 3/4 view;

Fig.3 – top view;

Fig.4 – general view, isometric view;

Fig. 5 – mechanism for driving the distal phalanx (view I Fig. 1);

Fig. 6 – the drive mechanism of the distal phalanx in a bent position.

The following positions are indicated on the figures:

Distal phalanx pad - 1

Distal phalanx - 2

Middle phalanx body lining - 3

Central element of the body of the middle phalanx - 4

Traction link - 5

Second pull - 6

First pull - 7

Carriage - 8 stump receiver mounts

Cult receiver - 9

Rotary mechanism – 10 fastening of the proximal ends of the first and second rods

Sliding washer - 11

Reach and horizontal angle adjustment element - 12

Oval mounting washer - 13

Support plate - 14

Anatomical glove – 15.

The traction finger prosthesis contains two rods - the first 7 and the second 6, each of which is fixed with the proximal end with the possibility of longitudinal movement and rotation on the rotary mechanism 10 connected to the support and adjustment unit 12 connected to the support plate 14 fixed on the anatomical glove 15. Both rods are pivotally connected with the distal end 16 to the middle phalanx 17 (see Fig. 1). The middle phalanx 17 consists of two covers 3 of the body of the middle phalanx 17 and the central element 4 of the body of the middle phalanx 17 (see Fig. 2). The two covers 3 of the body are connected to each other. The central element 4 is necessary when extending the finger to support the distal phalanx 2 and prevent its eversion. The distal end 16 of the first rod 7 is connected to the central element 4 of the middle phalanx body, and the distal end 16 of the second rod 6 is connected to the plates 3 of the middle phalanx body 17 (see Fig. 1.5). The middle 17 and distal 2 phalanges are connected to each other by a hinge. The distal phalanx 2 with the pad 1 is attached to the middle phalanx body by a hinge connection through an axial pin (not shown conditionally), which facilitates adhesion to elements of the environment.

The distal phalanx 2 is provided with a movable lever 19 of the distal phalanx, the distal end 16 of the second rod 6 is made with a lever for connection with the distal phalanx through a traction link and a movable lever for the possibility of bending the distal phalanx inward at an angle of 90 degrees, and the middle phalanx consists of two interconnected pads and a central element for supporting the distal phalanx and preventing its eversion when extending the finger, wherein the distal end of the first rod is connected to the said central element and the distal end of the second rod is connected to the said pads." The middle phalanx 17 contains a drive for the distal phalanx 2, which includes a lever 18 of the distal end 16 of the second rod 6, connected to which allows the distal phalanx 2 to anatomically bend inward at an angle of 90 degrees (see Fig. 5, 6).

The first rod 7 is made with guides 20, in which a stump receiver 9, made in the form of a ring, is installed with the possibility of free movement during operation of the prosthesis. For installation in the guides 20, the stump receiver 9 is equipped with a carriage 8, which ensures the movable fitting and free movement of the stump receiver 9 (see Figs. 1, 2, 3).

Anatomical glove 15, consists of a hard polymer, which ensures load distribution. The anatomical glove is made individually for the patient.

An element for adjusting the reach and horizontal angle 12 is attached to the anatomical glove 15. A rotary mechanism 10 for fastening the proximal part of the first 7 and second 6 rods is attached to the element for adjusting the reach and horizontal angle 12 through a cylindrical hinge 21 and a sliding washer 11.

The prosthesis is driven by the force created by the remaining part of the proximal phalanx through the stump receiver 9, made in the form of a ring. At the beginning of the movement, the kinematically connected units begin to move simultaneously: the first rod 7, the second rod 6, the stump receiver 9 with the carriage 8. The stump receiver 9, moving with the carriage 8 along the guides 20 along the trajectory of the stump movement, carries along the rods 6, 7, setting in motion, due to the difference in the axes of displacement, the middle phalanx 17, consisting of two plates 3 connected to each other and the central element 4. The movement of the distal phalanx 2 is carried out due to the radial displacement of the lever 18, located on the distal end 16 of the second rod 6, which carries along the traction link 5, kinematically connected to the movable lever 19 of the distal phalanx 2, which makes it possible to bend the distal phalanx 2 at an angle of 90 degrees to the middle phalanx 17 (see Fig. 6). The stump receiver 9 moves along the guides 20 of the first traction rod 7 to compensate for the difference in the axes of displacement of the first traction rod 7 and the second traction rod 6. The guides 20 are located in the center of the phalanx axis, which minimizes lateral displacements during flexion. Also, due to the hinged connection of the rotary mechanism 10 and the element for adjusting the reach and horizontal angle 12, horizontal displacement of the prosthesis relative to the palm is realized (rotation in the y plane).

As tests have shown, the proposed solution ensures increased reliability of the structure’s operation with the required accuracy and allows for the implementation of the natural anatomical flexion angle of the distal phalanx.

All elements of the finger traction prosthesis can be made from materials used in 3D printing using this technology. The stump receiver can be made from silicone.

The claimed device of a traction prosthesis can be used in the field of medical technologies, in particular in prosthetics of fingers of the hand, to restore the functions of fingers lost due to injuries or diseases to compensate for the lost functions of the limb with a partially preserved stump of the proximal phalanx.

Claims (1)

A traction prosthesis of a finger of the hand, comprising a support plate, having the possibility of fastening on an individual glove, middle and distal phalanges, connected to each other by a hinge, a stump receiver, first and second rods, fixed with their proximal ends on a rotary mechanism connected to the support plate through a cylindrical hinge attached to a support unit for adjusting the reach and horizontal angle; the first rod is made with guides, and the stump receiver is provided with a carriage installed in the guides of the first rod with the possibility of moving along them, the distal end of the second rod is made with a lever for connecting to the distal phalanx through a traction link and a movable lever of the distal phalanx.