Rope-driven six-degree-of-freedom parallel orthopedic external fixation support

Abstract

The utility model discloses a rope-driven six-degree-of-freedom parallel orthopaedic external fixation support, which comprises two fixing rings which are oppositely arranged, and supporting arms are hinged between the two fixing rings, and is characterized in that three supporting arms are hinged between the two fixing rings in a manner of being coplanar with the axis of a device; the three supporting arms are elastic supporting arms with axial telescopic allowance and are distributed in the annular direction, and the six inhaul cables are arranged between the supporting arms in a pairwise mode and connected between the two fixing rings. One end of the inhaul cable is connected to the two sides of one end of one supporting arm of one fixing ring, the other end of the inhaul cable is connected between the two supporting arms of the other fixing ring, one end of the inhaul cable is a control end, and the control end of the inhaul cable is connected with a retracting and releasing motor and can be controlled by the retracting and releasing motor to retract and release. The device has the characteristics of large working space, few singular points, convenience in installation, light mechanism weight, high precision and small interference to CT images.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of bone surgery fixing, in particular to a rope drive six degree of freedom parallel bone surgery external fixing support. BACKGROUND

[0002] In the fracture reduction and limb lengthening orthopedic treatment, the fracture end or the bone block of osteotomy needs to be adjusted and fixed to realize the reduction of bone deformity. At present, the bone external fixing frame device with manual adjustment and fixing function is usually used for the recovery positioning of the limb fracture in clinical treatment. The most commonly used bone external fixing frame device is usually a device with six degree of freedom rigid support structure. For example, the bone load detection method based on six-axis parallel bone external fixing device disclosed in application No. 201810623485.8 is realized by using the device with six degree of freedom rigid support structure. The device structure usually includes two fixed rings, and six telescopic adjustable support arms are hingedly arranged between the two fixed rings. When used, the metal bone needle (kirschner wire) is used to fixedly connect the two ends of the fixed ring with the bone block at both ends of the patient's limb fracture. During the rehabilitation process, the length of the six support arms can be adjusted according to the needs, and the six degree of freedom relative movement of the two fixed rings can be generated to assist the reduction and rehabilitation of the fracture.

[0003] However, during the treatment, the traditional six degree of freedom rigid support fixing frame has the problems of interference and mechanism bias, especially when the patient is taken CT image, the support arm will interfere with the shooting. Therefore, how to make the device realize the rehabilitation adjustment while reducing the interference and facilitating the CT image of the fractured limb becomes a problem to be considered and solved by the person skilled in the art. In addition, the human body support arm bone often needs a certain elasticity and flexibility space in the later stage of rehabilitation, which is more conducive to the rehabilitation of the bone. However, the traditional six degree of freedom rigid support fixing frame is usually a rigid structure before and after adjustment, which cannot better meet the use requirements of the later stage of bone rehabilitation. UTILITY MODEL CONTENT

[0004] In view of the above technical problems, the utility model solves the technical problems by adopting the following technical scheme:

[0005] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0006] The application relates to a rope-driven six-degree-of-freedom parallel orthopedic external fixation support, which comprises two fixed rings arranged oppositely, and support arms are hingedly arranged between the two fixed rings, characterized in that the support arms are three and are hingedly arranged between the two fixed rings in a plane with the device axis, the three support arms are elastic support arms with axial extension allowance and are arranged in a ring direction, and the six cables are arranged between the support arms and connected between the two fixed rings, one end of the cable is connected to the two sides of one end of the support arm of one fixed ring and the other end is connected between the two support arms of the other fixed ring, one end of the cable is a control end, and the control end of the cable is connected with a winding and unwinding motor and can be controlled by the winding and unwinding motor.

[0007] Thus, the device adopts rope driving and only has three rigid support chains, the influence of interference is reduced, the mechanism is lightweight, and wearing is more convenient when achieving the same effect. According to the relationship between the degree of freedom n and the number of ropes m, the rope-driven parallel robot is divided into three categories: ① m<=n, at this time, the mechanism cannot realize complete constraint, and needs to be maintained by external force; ② m=n+1, at this time, the mechanism realizes complete constraint positioning; ③ m>=n+1, at this time, the mechanism realizes redundant constraint positioning. The more the number of ropes is, the larger the working space is, and the less the singularity is. However, the rope can only provide pulling force and cannot provide pushing force, and the n-degree-of-freedom rope-driven parallel robot at least needs to introduce n+1 rope support chains to realize the determined motion, so that the elastic support arm is introduced in the device, the elastic force of the elastic support arm is used to provide the pushing force, so that the rope can meet the certain tension requirement under the condition that the number of the device drivers is equal to the number of the degrees of freedom. The device is designed to have six cables driven by six winding and unwinding motors and three rigid support chains with elastic support arms, and can realize spatial six degrees of freedom and has determined motion. Therefore, the device has the characteristics of large working space, few singular points, convenient installation, light mechanism, high precision and small interference to CT images. In addition, the elastic support arm and the rope in the scheme are mutually stressed, specifically, the support arm provides outward pushing force, the rope provides inward tension force (pulling force), and the fixed ring is simultaneously subjected to the outward pushing force and the inward tension force to keep fixed, so that the fixed ring has a certain elastic activity space and can better meet the use requirement in the later stage of bone rehabilitation.

[0008] Further, the three support arms are uniformly arranged in a ring direction. The stability can be better improved.

[0009] Further, the support arm comprises a first sleeve and a second sleeve which are slidably sleeved with each other, and a compression spring is arranged between the first sleeve and the second sleeve to act on both in an axial direction.

[0010] Thus, the structure is simple and can provide stable extension elastic force.

[0011] Further, the first sleeve end is screwed with a fastening bolt penetrating through the first sleeve and abutting against the second sleeve. In this way, when the adjustment is completed and the support arm needs to be converted into a rigid support arm, the fastening bolt can be tightened to fix the first sleeve and the second sleeve to each other, so that the full rigidity support is achieved (more suitable for the use requirement in the early stage of bone rehabilitation).

[0012] Further, the support arm is further provided with a pressure sensor for detecting the axial pressure of the support arm. In this way, the pressure of the feedback support arm can be better detected for control.

[0013] Further, the support arm is further provided with a pressure sensor for detecting the axial pressure of the support arm. In this way, the pressure of the feedback support arm can be better detected for control.

[0014] Further, the support arm is further provided with a pressure sensor for detecting the axial pressure of the support arm. In this way, the pressure of the feedback support arm can be better detected for control.

[0015] Further, the support arm is further provided with a pressure sensor for detecting the axial pressure of the support arm. In this way, the pressure of the feedback support arm can be better detected for control.

[0016] Further, the control end of the cable is wound around a fixed pulley arranged on the fixing ring at one end and then wound around a winding disc, and the winding disc is fixedly installed on the output shaft of the winding and unwinding motor. In this way, the winding and unwinding control of the cable can be conveniently realized by controlling the rotation of the winding and unwinding motor.

[0017] Further, the control end of the cable is wound around a fixed pulley arranged on the fixing ring at one end and then wound around a winding disc, and the winding disc is fixedly installed on the output shaft of the winding and unwinding motor. In this way, the winding and unwinding control of the cable can be conveniently realized by controlling the rotation of the winding and unwinding motor.

[0018] Further, the control end of the cable is wound around a fixed pulley arranged on the fixing ring at one end and then wound around a winding disc, and the winding disc is fixedly installed on the output shaft of the winding and unwinding motor. In this way, the winding and unwinding control of the cable can be conveniently realized by controlling the rotation of the winding and unwinding motor.

[0019] Further, the control end of the cable is wound around a fixed pulley arranged on the fixing ring at one end and then wound around a winding disc, and the winding disc is fixedly installed on the output shaft of the winding and unwinding motor. In this way, the winding and unwinding control of the cable can be conveniently realized by controlling the rotation of the winding and unwinding motor.

[0020] The utility model discloses the beneficial effects are: 1 compared to ordinary six degrees of freedom bone external fixator, the utility model reduces the total number of rigid support chain, and the support chain interference reduces, thereby increases the working space of mechanism, and simultaneously retains the parallel robot high rigidity, high bearing capacity, high precision and so on the advantage. 2 compared to ordinary six degrees of freedom bone external fixator, the utility model has the rope drive, and the cost is low, and the working space is big, and the singularity is small. 3 compared to ordinary six degrees of freedom bone external fixator, the rope drive bone external fixator of the utility model, the installation space is less, and the mechanism quality is light, and the precision is high and to CT image interference is small. 4 the utility model has six drive ropes, and can realize symmetrical layout, and the mechanism isotropy is better. 5 the utility model simple and compact structure, and the processing cost of manufacturing is low. 6 the utility model part modular degree is high, and maintenance is convenient, and the economy is good. Attached Figure Description

[0021] Fig. 1 This is a three-dimensional structural diagram of the bracket of this utility model.

[0022] Fig. 2 This is a front view of the bracket of this utility model. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments.

[0024] For specific implementation: see [link / reference] Figs. 1-2 As shown, a rope-driven six-degree-of-freedom parallel orthopedic external fixator includes two fixed rings arranged opposite each other, with a support arm hinged between the two fixed rings. The support arm consists of three arms, each hinged between the two fixed rings 1 and coplanar with the device's axis. The three support arms are elastic support arms with axial extension allowance and are distributed along the circumferential direction. The device also includes six cables 7, arranged in pairs between the support arms and connected between the two fixed rings. One end of each cable 7 is connected to both sides of one end of a support arm on one fixed ring, and the other end is connected between two support arms on the other fixed ring. One end of each cable is a control end, connected to a retractor / discharge motor 17, and can be controlled by the retractor / discharge motor 17 for retraction and extension.

[0025] Thus, the device adopts a rope drive and only three rigid support chains, reducing the influence of interference, and achieving the same effect, the mechanism is lightweight, and wearing is more convenient. According to the relationship between the degree of freedom n and the number of ropes m, the rope-driven parallel robot is divided into three categories: ① m≤n, at this time the mechanism cannot realize complete constraint, and needs to rely on external force to maintain force closure; ② m=n+1, at this time the mechanism realizes complete constraint positioning; ③ m≥n+1, at this time the mechanism realizes redundant constraint positioning. The more the number of ropes, the larger the workspace, and the less the singularity. However, ropes can only provide tension and cannot provide thrust. A simple n-degree-of-freedom rope-driven parallel robot requires at least n+1 rope support chains to achieve a certain motion, so an elastic support arm is introduced in the device to provide thrust with its elastic force, so that the rope can meet the certain tension requirement under the condition that the number of device drivers is equal to the number of degrees of freedom. The device is designed with six drive ropes driven by six winding and unwinding motors, and three rigid support chains with elastic support arms, which can realize spatial six degrees of freedom and have a certain motion. Therefore, it has the characteristics of large workspace, few singular points, easy installation, light mechanism, high precision and little interference to CT image. In addition, the elastic support arm and the rope in the scheme are mutually stressed, specifically, the support arm provides outward thrust, and the rope provides inward tension (tension), so that the fixed ring is simultaneously acted on by the outward thrust and the inward tension to remain fixed, and has a certain elastic space, which can better meet the use requirements of the later stage of bone rehabilitation.

[0026] Among them, the three support arms are uniformly distributed along the ring direction. It can better improve the stability.

[0027] Among them, the support arm includes a first sleeve 11 and a second sleeve 13 which are slidably sleeved with each other, and a compression spring 12 is arranged between the first sleeve and the second sleeve to act between them in the axial direction.

[0028] Thus, the structure is simple and can provide stable expansion and contraction elastic force.

[0029] Among them, the first sleeve end is threadedly connected with a fastening bolt 18 which penetrates the first sleeve and abuts against the second sleeve. Thus, when the adjustment is completed and the support arm needs to be changed into a rigid support arm, the fastening bolt can be tightened to fix the first sleeve and the second sleeve to each other to realize full-rigidity support (more suitable for the use requirements of the early stage of bone rehabilitation).

[0030] Among them, the support arm is further provided with a pressure sensor 10 for detecting the axial pressure of the support arm. Thus, the pressure of the support arm can be better detected and fed back to facilitate control.

[0031] Among them, the support arm is connected with the fixed ring through a hook joint 9 at both ends. It is convenient and flexible to rotate to realize degree of freedom adjustment.

[0032] Six convex mounting lugs 2 are evenly arranged on the outer periphery of the fixed ring, and the connecting ends of the support arms and the cables are mounted on the mounting lugs 2. This is more convenient for installation and reduces the weight of the device.

[0033] The fixed ring is provided with a plurality of through holes. This is convenient for installing the beaker needle and is beneficial to reduce the weight of the device.

[0034] The control end of the cable 7 is wound around a fixed ring at one end, and then wound around a winding disc fixedly installed on the output shaft of the winding and unwinding motor. In this way, the rotation of the winding and unwinding motor is controlled to realize the winding and unwinding control of the cable. In implementation, the fixed pulley 6 is installed on the pulley seat 5.

[0035] The other end of the cable is fixed to a pull ring on the fixed ring at the other end. This is convenient for fixing the cable.

[0036] The winding and unwinding motor 17 is a stepping motor. This makes the control more stable.

[0037] The winding and unwinding motor 17 is installed on the side of the fixed ring away from the other fixed ring. This can better avoid interference.

Claims

1. A rope-driven six-degree-of-freedom parallel orthopedic external fixation support, comprising two fixed rings arranged oppositely, and a support arm hingedly arranged between the two fixed rings, characterized in that, The three support arms are hinged between the two fixed rings in a plane with the axis of the device, are elastic support arms with axial extension allowance and are arranged in a circumferential distribution, and six cables are arranged between the support arms and connected between the two fixed rings, one end of the cable is connected to the two sides of one end of the support arm of one fixed ring and the other end is connected between the two support arms of the other fixed ring, one end of the cable is a control end, the control end of the cable is connected to a winding and unwinding motor and can be controlled by the winding and unwinding motor.

2. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The three support arms are arranged in a circumferential uniform distribution.

3. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The support arm comprises a first sleeve and a second sleeve which are slidably sleeved with each other, and a compression spring is arranged between the first sleeve and the second sleeve to act axially therebetween. A pressure sensor is further arranged on the support arm to detect the axial pressure of the support arm. A fastening bolt is threadedly screwed at the end of the first sleeve and abuts against the second sleeve.

4. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The two ends of the support arm are connected to the fixed ring through a hooke joint.

5. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, Six outward convex mounting lugs are uniformly arranged on the outer periphery of the fixed ring, and the connection ends of the support arm and the cable are mounted on the mounting lugs.

6. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The fixed ring is provided with a plurality of through holes.

7. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The control end of the cable is wound around a fixed pulley on one end of the fixed ring and then wound on a winding disc, and the winding disc is fixedly installed on the output shaft of the winding and unwinding motor.

8. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 7, wherein, The other end of the cable is fixed on a pull ring on the other end of the fixed ring.

9. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The winding and unwinding motor is a stepping motor.

10. The rope-driven six degree of freedom parallel orthopaedic external fixator of claim 1, wherein, The winding and unwinding motor is installed on the side of the fixed ring away from the other fixed ring.

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