RU2665386C1 - Passive rehabilitation exoskeleton - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to medicine. Passive rehabilitation exoskeleton comprises a frame with elements for fastening to the body, two pairs of coxal and talocrural levers, made in the form of three-dimensional shells, movably connected to each other and by free end of the coxal lever – to the frame, modules of the shoulder joint, shoulder, forearm, wrist and hands, hingedly connected to each other and by free end of the module of the shoulder joint – to the frame. Frame consists of a shoulder block in the form of a wide rhombic plate, having slits in the middle of the sides with elastic straps fixed therein with the possibility of reciprocating motion. Rhombic plate has elements of spatial hinges of the shoulder arc in the lateral corners, a beveled upper corner and an elongated rectangle rounded lower corner. Lower corner is connected to the lumbar block by rotation bearing. Lumbar block consists of an upper and a lower plates, connected movably with the possibility of reciprocating and rotational motion, through a steel pin of the lumbar ganglions, passing inside the holes made in the lower part of the lateral surface of the upper lumbar ganglions plate and through the rectangular grooves with rounded ends at the lateral surface of the lower lumbar ganglions plate. Lower plate is connected to a middle point of the lumbar module by means of rotation bearing. Lumbar module consists of a belt-beam, curved in the form of a human lumbar region, and has rounded rectangular thickenings at the ends and connections to coxal levers by means of rotation bearings of the hip joint. Coxal levers are made in the form of plates, Y-shaped in the lower part with an arcuate connection and having four pairs of slots with elastic straps fixed therein with the possibility of reciprocating motion and rounded rectangular thickenings in the upper part. Coxal levers are connected to the talocrural levers from below through rotation bearings of knee joints. Talocrural levers are made in the form of plates, Y-shaped in the lower part with an arcuate connection and having four pairs of slots with elastic straps fixed therein with the possibility of reciprocating motion. Each module of the shoulder joint is made in the form of a metal rod curved in the shape of a human shoulder joint with elements of spatial hinges at the ends. Modules of the shoulder are made in the form of plates, arch-shaped in the lower part according to a human shoulder shape with elements of spatial hinges at the edges. Plates of the shoulder modules have three pairs of slots with elastic straps fixed therein with the possibility of reciprocating motion and rounded rectangular thickenings in the middle part. Modules of the forearm are made in the form of two straight rods having elements of spatial hinges at the ends. Modules of the wrist is made in the form of a plate curved in the shape of a human wrist with elements of spatial hinges and connected by rotation bearings to the lateral plane of the hand through a short wrist lever made in the form of a plate bent in the shape of the lateral surface of the wrist. Hand is made in the form of a plate shaped as a curvilinear trapezoid, at the long side of which there are arched slots for the joints of the proximal phalanges of a man, and its profile is curved in the shape of human metacarpus. At the top of the plate there is a platform for fixing a servoactuator housing, implementing the reciprocating motions of the servoactuator lever connected thereto, wherein the servoactuator lever being a metal plate rounded at both sides with holes at the ends, connected to the rotation axis of the proximal phalanges by free end. Rotation axis of the proximal phalanges is made in the form of a rod in the form of an arc curved in the shape of a human metacarpus, having a connection with the elements of the proximal phalanges through movable bearings. Elements of the proximal phalanges are made in the form of plates in the form of open tubes having a rounded extension and curved in the form of proximal human phalanges connected to the middle phalanges by rotation bearings. Middle phalanges are lamellar in the form of open tubes, curved in the shape of human middle phalanges.EFFECT: invention provides reduced patient recovery time after the fusion of broken bones, muscles, ligaments and tendons of upper limbs, body and lower limbs.1 cl, 7 dwg

Description

The invention relates to the field of satisfying a person’s vital needs and can be used as a rehabilitation technique to create variable (from light to stress) conditions during rehabilitation after injuries of muscles, bones, ligaments, tendons of the upper limbs, trunk and lower extremities.

Known passive cargo exoskeleton containing a frame with elements of attachment to the body, two pairs of hip and ankle arms, interconnected by knee hinges with fixation elements and pivotally connected with their free ends with the frame and foot supports. The frame is made in the form of a two-part corset with longitudinal guides fixed on it, passing from the front to the back of the corset RU 2362598 C2, published on July 27, 2009.

The disadvantages of the device are the complexity and high cost along with the lack of additional degrees of freedom, which leads to a decrease in comfort and does not ensure the safety of movement.

A freight exoskeleton is known comprising a frame with fastening elements to the body, two pairs of hip and ankle arms made in the form of spatial shells interconnected by knee joints and articulated by their free ends with the frame and through the ankle fork with foot supports inserted into integrated shoes wherein the frame consists of a shoulder block in the form of a combination of X-shaped connected plates, L-shaped curved at the ends, and connected to it by a back gimbal unit through two about The pads of the lumbar block, consisting of a rocker arm curved in the shape of the lumbar region of the human body, where the supporting platform of the spinal gimbal is attached at the upper midpoint of the rocker arm, and the ends of the rocker arm with the cardan rings attachment elements are lowered and are at the level of the hip joints, with the connection the spatial shells of the hip levers with the frame is carried out by means of ring driveshafts with two degrees of freedom of rotation of the hip levers, the bases of which through angular consoles and are associated with sliding platforms installed on the spatial shells of the hip arms, with the possibility of moving the console along the arc guides of the platforms when changing the angle between the frame and the spatial shells of the hip arms, while the connection of the supporting platforms with the ankle fork is made detachable RU 2563209 C2, published on 09/20/2015 .

The disadvantage of this device is the lack of support of the shoulder girdle, which increases the load on the upper limbs of the user.

Known universal combined exoskeleton containing a frame system, motion drives, electronic control system and battery power source. The frame system consists of a carbon fiber panel repeating the shape of the rear of the human torso, and articulated levers of carbon fiber pipes. In this case, the drive arms of the carcass levers are made of solid-state airgel made of carbon nanotubes with an admixture of rubber in the form of cylinders with a diameter of 40 to 120 mm with a conical point on both sides. The actuators are attached to the levers by pinching the conical ends with synthetic fabric tapes impregnated with epoxy resin and strained with steel rivets RU 2552703 C2, published on 10.06.2015.

The disadvantages of the known device are the complexity and high cost, massive structure, the absence of additional degrees of freedom on the forearms and hands of the upper extremities, which reduces the comfort of movement of the user.

Known exoskeleton US 2014100493, including soft straps of the type "backpack", which mainly interacts with the waist, back and shoulders of the user. The chassis provides installation of two forced leg drives. Each exoskeleton leg performs functions similar to the movement of the human leg, including the hip joint, thigh, knee joint, calf, and is attached by cuffs to the user's leg in the thigh, lower leg, and under the sole of the user's foot is a plate. Power drives are presented in the exoskeleton's hip and knee joints.

The disadvantages of this design are: the complexity of the design and the high cost due to the use of power drives, the overall dimensions of the structure, large mass, insufficient mobility of the case, dependence on power sources, high maintenance requirements.

Known exoskeleton of the upper extremities containing at least one external framework for the limb, consisting of an element of the shoulder, the modules of the shoulder and forearm, elbow joint and wrist holder. The shoulder element, the shoulder and forearm modules are oblong. The shoulder element is provided with a support for fastening the outer frame. The forearm module is connected to the shoulder module by means of an elbow joint with the possibility of movement in the horizontal plane. The forearm module is connected to the cradle holder. The exoskeleton is additionally equipped with a support and adaptation element for attaching to a vest or wheelchair, to which at least one support for attaching an external frame is attached, with elastic elements and hooks for attaching the ends of the elastic elements. The shoulder module consists of proximal and distal nodes connected by upper and lower removable bars with the possibility of selection for anatomical adaptation. The forearm module consists of proximal and distal nodes connected by upper and lower removable bars with the possibility of selection for anatomical adaptation. The elbow hinge is made in the form of two articulated short shelves of L-shaped elements - proximal and distal. The height of the L-shaped elements depends on the circumference of the forearm in the area of the elbow of the person. The long shelf of the L-shaped proximal element of the elbow joint is transversely and rigidly connected to the distal node of the shoulder module. The proximal node of the forearm module is connected to the long shelf of the L-shaped distal element of the elbow joint with the possibility of rotation around an axis located along the forearm module. The hooks for attaching the ends of the elastic elements are fixed on the outer surfaces on the support for attaching the outer frame, the shoulder element, the proximal and distal nodes of the shoulder module, the proximal and distal nodes of the forearm module, the proximal and distal elements of the elbow joint RU 2629738 C2, published on 08/31/2017.

The disadvantages of the known solutions are massiveness, a small number of degrees of freedom of the hand, lack of elements of the carpal expanders, massiveness, limited only by the shoulder girdle, which limits the possibility of rehabilitation for injuries of the trunk or lower extremities.

The task to which the invention is directed is to reduce and facilitate the rehabilitation period of recovery after fractures of bones, muscle breaks, ligaments and tendons due to ergonomic fixation of the limbs and trunk to the elements of the exoskeleton with the ability to fully control the body in motion, increase the degrees of freedom of the upper limbs and lumbar region, reducing the weight and size of the structure, increasing operational reliability.

The claimed design allows you to remove excess load from the user's body for the period of rehabilitation without harm to health. Compensates the load on the upper limbs and enhances the grip of the user. The design provides the ability to easily detach and remove individual parts of the exoskeleton. During rehabilitation after injuries of the hand and / or forearm, supportive mechanisms are used that do not constrain the user's movements, enhance the effect and protect against dislocations and other injuries, holding the restored limb in an anatomically correct position. In this case, not the entire exoskeleton can be used, but only a part of it, for example, the arm.

The claimed technical result is achieved by the fact that in a passive exoskeleton containing a frame with elements of attachment to the body, two pairs of hip and ankle arms made of duralumin alloy in the form of spatial shells interconnected by knee rotation bearings passing free ends through rotation bearings into a lumbar block, which is a rocker belt of a duralumin plate, connected by a rotation bearing to a lumbar assembly repeating the movements of of the lumbar vertebrae passing through the rotation bearing into the shoulder block with a system of elastic straps for attaching the exoskeleton to the thoracic spine, the shoulder block, in turn, is connected by spatial joints with a pair of shoulder arches passing into the shoulder levers made in the form of a spatial shell of duraluminium alloy, connected with wrist elements through two pairs of forearm levers fixed with spatial hinges, transition from the wrist element representing a C-shaped arc to the metacarpal node it is carried out by a short wrist lever with a pair of rotation bearings, the metacarpal node is the spatial shell of the metacarpus with the servo drive of the translational mechanism, turning into the axis of rotation of the proximal phalanges of the index, middle, ring and little fingers, made in the form of spatial shells of the proximal phalanges of the corresponding fingers in a C-shaped form for ergonomic fixation, which in turn are connected by a pair of rotation bearings with elements of the middle phalanx made Also in the form of spatial shells of the middle phalanges of the corresponding fingers with a C-shape.

The claimed lumbar node allows you to add two degrees of freedom in the movement of the back: when tilted, the lumbar node is bent and stretched relative to the rocker arm and shoulder block, when the back is returned to its original position, the rigid frame straightens and contracts, without disturbing the user. The rotation of the user's body left and right is achieved due to rotation bearings between the lumbar node and the rocker arm. The use of spatial joints on the shoulder arches allows to achieve mobility of the shoulder joint in all anatomically possible degrees of freedom relative to the spatial sheath of the shoulder and shoulder block.

Using a pair of levers with spatial hinges located diametrically opposite to the proximal and distal nodes of the forearm on each arm gives two degrees of freedom: pronation and supination of the hand, flexion and extension of the forearm.

A short wrist lever allows you to maintain support for the wrist when bending and unbending the hand in one plane. The two-part elements of the proximal and middle phalanges, bent and unbent by a servo drive, allow to increase the user's grip force in proportion to the load on the servo drive. When using an electromechanical servo drive, its movement can be caused, for example, by a microcontroller by means of a built-in algorithm of actions or the state of the electromyographic signals of the user's muscles. It is also possible to replace the servo with mechanical elements of translational motion, such as springs and / or hydraulic compensators.

The invention is illustrated by the drawings of FIG. 1-7.

FIG. 1. Exoskeleton, where 9 - elastic belts; 10 - spatial hinges; 22 - bearings of rotation of the knee joint; 6 - module of the wrist; 26 - servo housing; 28 - proximal phalanges; 11 - rotation bearing of the upper lumbar block; 18 - rotation bearing of the lower lumbar block; 15 - hairpin lumbar node; 21 - bearings of rotation of the hip joint; 7 - brush module.

FIG. 2. Exoskeleton, where 2 is the ankle lever; 1 - hip lever; 20 - rocker-belt; 12 - lumbar node; 8 - shoulder block with shoulder arches; 4 - shoulder module with fasteners; 5 - module of the forearm; 7 - exoskeleton brush; 23 - the shaft of the shoulder module; 6 - module of the wrist.

FIG. 3. The arm of the exoskeleton, where 9 - elastic straps; 10 - spatial hinges; 6 - module of the wrist; 26 - servo housing; 7 - brush module; 4 - shoulder module; 32 - platform for mounting auxiliary equipment; 34 - eight-shaped clamps for elastic belts; 24 - module of the forearm; 27 - servo lever; 28 - axis of rotation of the proximal phalanx; 30 - middle phalanges; 29 - proximal phalanges; 25 - a short wrist lever with a pair of rotation bearings.

FIG. 4. Exoskeleton brush, where 10 are spatial joints; 6 - module of the wrist; 26 - servo housing; 7 - brush module; 31 - fastenings for fixing belts for the wrist and metacarpus; 24 - module of the forearm; 30 - middle phalanges; 29 - proximal phalanges; 28 - axis of rotation of the proximal phalanx.

FIG. 5. The lumbar block of the exoskeleton, where 9 are elastic belts; 21 - bearings of rotation of the hip joint; 15 - hairpin lumbar node; 20 - rocker-belt; 33 - platform for mounting auxiliary equipment; 14 - lower strip of the lumbar node; 13 - the upper bar of the lumbar node; 11 - rotation bearing of the upper lumbar block; 18 - bearing rotation of the lower lumbar block.

FIG. 6. The lumbar node of the exoskeleton, where 15 is the stud of the lumbar node; 14 - lower strip of the lumbar node; 13 - the upper bar of the lumbar node; 11 - rotation bearing of the upper lumbar block; 18 - rotation bearing of the lower lumbar block; 16 - hole in the lower part of the lateral surface of the upper lumbar node; 17 - rectangular grooves with rounding at the ends in the lateral surface of the lower lath of the lumbar node.

FIG. 7. Exoskeleton in working position.

The technical result provided by the totality of the features of the claimed invention is to reduce the recovery time of the patient after the broken bones, muscles, ligaments and tendons of the upper limbs, trunk and lower extremities are fused. This is possible due to the removal of part of the load from damaged areas of the body during the rehabilitation period of time with a complete imitation of body movement. The design repeats the anatomically correct movements of the limbs and torso due to hinges, allowing you to strengthen muscles and protects against dislocations, sprains and unnatural bends of the body. The light weight and ergonomic fastening of the passive exoskeleton makes it invisible to the user and provides comfortable movement.

The invention is a passive exoskeleton containing a frame with fastening elements to the body; two pairs of hip 1 and ankle 2 levers, made in the form of spatial shells, movably connected to each other and the free end of the hip lever with a frame; modules of the shoulder joint 3, shoulder 4, forearm 5, wrist 6 and brushes 7 pivotally connected to each other and the free end of the module of the shoulder joint with the frame, characterized in that the frame consists of a shoulder block 8 in the form of a wide rhombic shape plate having in the middle of the sides slots with elastic belts 9 fixed therein with the possibility of reciprocating movement and elements of spatial hinges 10 of the shoulder arch in the lateral corners, with a beveled upper angle and elongated in the form of a rectangle with a rounded bottom angle to them; connected by means of a rotation bearing 11 with a lumbar block 12, consisting of an upper 13 and a lower 14 laths of the lumbar block, movably movable with the possibility of reciprocating and rotational movement, through a steel pin of the lumbar assembly 15, passing inside the holes 16 made in the lower part of the side surface the upper lumbar assembly and through rectangular grooves 17 with rounded ends at the side surface of the lower lumbar assembly connected by means of a rotation bearing 18 to the middle the point of the lumbar module 19, consisting of a rocker-belt 20, curved in the shape of the lumbar region of a person having rounded rectangular thickenings at the ends and joints with hip levers using rotation bearings of the hip joint 21; moreover, the hip levers made in the form of plates in the lower part of the fork-shaped ones with an arcuate connection, having four pairs of slots with elastic straps fixed to them with the possibility of reciprocating movement and rounded rectangular thickenings in the upper part, and connected from below through rotation bearings of the knee joints 22 with ankle arms made in the form of plates in the lower part of the fork-shaped with an arcuate connection, having four pairs of slots with the possibility of being fixed in them th reciprocating movement with elastic straps; each module of the shoulder joint is made in the form of a metal rod 23, curved in the shape of the human shoulder joint with elements of spatial joints at the ends; shoulder modules are made in the form of plates in the lower part of an arcuate in the shape of a human shoulder with elements of spatial joints at the edges, having three pairs of slots with elastic belts fixed to them with the possibility of reciprocating movement and rounded rectangular thickenings in the middle part; moreover, the forearm modules are made in the form of two straight rods 24 having spatial hinge elements at the ends; and the wrist module is made in the form of a plate curved in shape of a human wrist with spatial joints and connected by rotation bearings to the lateral plane of the hand through a short wrist lever 25, made in the form of a plate bent in shape to the side surface of the wrist, and the brush is made in the form of a plate having the shape curved trapezoid, on the long side of which there are arched slots under the joints of the proximal phalanges of a person, and her profile is curved in the shape of a human metacarpus, and, located hydrochloric top platform for mounting the actuator body 26, realizing reciprocating translational movement connected to it a bearing rotation servo lever 27, which is a metal plate with holes at the ends on both sides rounded, free end connected to the rotation axis of the proximal phalanx 28; moreover, the axis of rotation of the proximal phalanges is made in the form of a rod in the form of an arc, curved in the shape of the human metacarpus, having a connection with the elements of the proximal phalanx 29 through movable bearings; wherein the elements of the proximal phalanges are made in the form of open-tube plates having a rounded elongation and curved in the shape of the human proximal phalanges, connected by rotation bearings to the middle phalanges 30, the middle phalanges being made in the form of plates in the form of open tubes, curved in the shape of the middle human phalanges.

The preferred aluminum alloy is D16AT aluminum alloy, since it has a low density, increased strength after hardening, is not toxic, and can be processed using standard equipment from machine shops.

Reliable fixation of the exoskeleton on the body is carried out by means of elastic belts 9 fastened with eight-shaped clamps 34 for elastic belts 35 on the hip lever 1, ankle lever 2, shoulder module 4 and shoulder block 8. If necessary, the user can use fixing tapes passed through the fastening for fixing straps 31 for the wrist and metacarpus.

If necessary, attach auxiliary equipment for measurement, control or servos, you can use the platform for mounting auxiliary equipment 32, 33.

The spatial joints of the forearm can be made of steel and / or fluoroplastic.

The limb parts have a lateral arrangement, which increases the load on the structure, compared with the frontal arrangement, but allows you to make the exoskeleton convenient and comfortable for the user due to the location hidden from soft tissues.

The detachable exoskeleton joints are the shoulder module 4, forearm 5, wrist 7, lumbar node 15 and shoulder block 8 with modules of the shoulder joints 3, which allow, if necessary, to use only the necessary exoskeleton node and / or faster for rehabilitation of a single element of the musculoskeletal skeleton put on an exoskeleton on the body.

After prolonged immobilization of the limbs, the exoskeleton will not allow dislocations to happen, since its hinges can only move in the directions anatomically correct for the human body, and the levers are inextensible, which removes the excess load in general. At the same time, the hands, fingers and forearms remain sufficiently mobile to perform rotation, supination, flexion and extension of the forearm, flexion and extension of the wrist, flexion and extension of the fingers. Servo drives allow you to increase the grip force due to mechanical bending and / or extension of the proximal phalanges, which in turn compress / expand the middle phalanges.

The user's body weight presses on the shoulder block, through which the load is transferred to the lumbar node, which can be blocked, and then to the lumbar block. In the lumbar block, the load is distributed to the two lower limbs in a proportion that depends on the tilt of the body to the right or left, after which it is transferred to the foot. If necessary, the free movement of the user's body, the lumbar node is not blocked, which makes it possible to bend back and forth and left and right due to movable bearings.

The exoskeleton is attached to the human body using a system of elastic straps with eight-shaped clamps. The wrist element, proximal and middle phalanges are attached to the body due to its spatial shape in the form of the letter “C”, which simplifies the process of fixation on the body.

The invention can be carried out as follows.

Example 1. A person undergoes rehabilitation after complex fractures of one or two upper limbs, due to which there was a prolonged immobilization, leading to muscle atrophy and increased likelihood of injuries such as dislocations of the joints, sprains and tearing of soft tissues. The exoskeleton of the arm is fixed on the body of the rehabilitated user from the middle phalanges of the fingers to the shoulder joint. In this case, the probability of injuries in the hand and forearm is excluded, since the forearm levers will allow supination and pronation of the hand within 180 ° relative to its neutral position, and the short arm of the wrist to bend and unbend the brush within 180 ° relative to its neutral position. The decrease in muscle tone of the forearms is compensated by servos that increase the grip of the user.

Example 2. In case of trauma to the lower extremities, trunk or injuries of the shoulder joint, the invention can be used in its entirety, providing support for weakened back muscles with a lumbar node, which will allow you to tilt back and forth and left and right within 30 ° relative to the neutral position of the human body. There is also support for the shoulder joint and its protection against dislocations with insufficient muscle tone. The shoulder arch is rigid and inextensible, therefore, does not allow the shoulder to move away from the shoulder joint, and spatial joints do not limit mobility. The lower limbs are strengthened by the frame of the ankle and hip levers, which protects against dislocation of the knee joint and allows you to redistribute the user's weight closer to the foot.

For the manufacture of a passive exoskeleton does not require special equipment. It can be made using standard equipment from mechanical workshops.

Claims (1)

Passive rehabilitation exoskeleton containing a frame with elements of attachment to the body; two pairs of hip and ankle arms made in the form of spatial shells, movably connected to each other and the free end of the hip lever with a frame; modules of the shoulder joint, shoulder, forearm, wrist and hands, articulated between each other and the free end of the module of the shoulder joint with the frame, characterized in that the frame consists of a shoulder block in the form of a wide plate of a rhombic shape having slots in the middle of the sides with secured in them with the possibility of reciprocating movement with elastic belts and elements of the spatial hinges of the shoulder arch in the lateral angles, with a beveled upper angle and elongated in the form of a rectangle with a rounded lower angle; connected by means of a rotation bearing to a lumbar block, consisting of upper and lower lumbar block strips, movably movable with the possibility of reciprocating and rotational movement, through a steel pin of the lumbar node passing inside the holes made in the lower part of the side surface of the upper plate of the lumbar block and through rectangular grooves with rounded ends at the side surface of the lower plate of the lumbar assembly, connected by a rotation bearing to the midpoint of the belt egg module consisting of a rocker-belts, the lumbar region of the human curved shape having rounded ends of rectangular and thickening compound with the hip levers via hip rotation bearings; moreover, the hip levers made in the form of plates in the lower part of the fork-shaped ones with an arcuate connection, having four pairs of slots with elastic straps fixed to them with the possibility of reciprocating movement and rounded rectangular thickenings in the upper part, and connected from below through rotation bearings of the knee joints with ankle arms made in the form of plates in the lower part of the fork-shaped with an arcuate connection having four pairs of slots with the possibility of being fixed in them reciprocating movement with elastic straps; each module of the shoulder joint is made in the form of a metal rod curved in the shape of the human shoulder joint with elements of spatial joints at the ends; shoulder modules are made in the form of plates in the lower part of an arcuate in the shape of a human shoulder with elements of spatial joints at the edges, having three pairs of slots with elastic belts fixed to them with the possibility of reciprocating movement and rounded rectangular thickenings in the middle part; moreover, the forearm modules are made in the form of two straight rods having elements of spatial hinges at the ends; and the wrist module is made in the form of a plate curved in the shape of a human wrist with spatial joints and connected by rotation bearings to the lateral plane of the hand through a short wrist lever made in the form of a plate bent in the shape of the side surface of the wrist, and the brush is made in the form of a plate having the shape of a curved trapezoid, on the long side of which there are arched slots under the joints of the proximal phalanges of a person, and its profile is curved in the shape of a human metacarpus, and is located second top pad for mounting the housing servo realizing reciprocating translational movement connected to it a bearing rotation servo arm, which is a metal rounded on both sides of the plate with holes at the ends, the free end connected with the rotation axis of the proximal phalanx; moreover, the axis of rotation of the proximal phalanges is made in the form of a rod in the form of an arc curved in the shape of the human metacarpus, which is connected to the elements of the proximal phalanges through movable bearings; wherein the elements of the proximal phalanx are made in the form of open-tube plates having a rounded extension and curved in the shape of the human proximal phalanx connected by rotation bearings to the middle phalanges, the middle phalanges being plate-like in the form of open tubes curved in the shape of the middle human phalanges.

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