CN218458215U

CN218458215U - Electromagnetically-driven extensible prosthesis

Info

Publication number: CN218458215U
Application number: CN202220876191.8U
Authority: CN
Inventors: 王威; 王兵; 赵沛喆; 饶珠明; 代雯
Original assignee: Tsinghua University; Fourth Medical Center General Hospital of Chinese PLA
Current assignee: Tsinghua University; Fourth Medical Center General Hospital of Chinese PLA
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2023-02-10
Anticipated expiration: 2032-04-15

Abstract

The utility model provides an electromagnetic drive's extension false body, including extension false body and external electromagnetic drive controller. Specifically, the prosthesis part comprises a moving body, a rotating body, a sealed shell, a transmission case, an annular permanent magnet and the like; the in vitro electromagnetic driving controller consists of electromagnetic modules connected by a plurality of sections of flexible materials, and the electromagnetic modules are internally provided with components such as coils, hall elements and the like. The utility model discloses only need once to operate and implant the false body, when prolonging the false body once more, through with external electromagnetic drive controller, dress and correspond the position at shank false body permanent magnet, produce alternating electromagnetic field drive permanent magnet and rotate, drive the rotator rotation and then impel the moving body to move forward to reach the effect of extension. The external electromagnetic driving module is strictly controlled by a computer program, and the extension length of the prosthesis can be accurately controlled by monitoring the external electromagnetic driving module through the Hall element, so that the accuracy and safety of a noninvasive extension operation are ensured, and a customized operation scheme can be performed according to the actual condition of a patient.

Description

Electromagnetically-driven extensible prosthesis

Technical Field

The utility model belongs to the field of medical equipment, concretely relates to electromagnetic drive's noninvasive automatic extension false body.

Background

Currently, in china, more than ten thousand cases of primary osteosarcoma per year, most patients not older than thirty years of age, are operated mainly by resection of the diseased bone and implantation of an artificial prosthesis. For teenagers, bones of the patients still have strong growth capacity after the operation, and the traditional metal prosthesis needs to be periodically operated for extension and revision, so that the risk and difficulty are greatly improved, the daily life and recovery of the patients are influenced, and the extension prosthesis becomes a reasonable choice.

Extensible prostheses can be broadly classified into three types, a combined prosthesis, a minimally invasive extensible prosthesis, and a non-invasive extensible prosthesis. The noninvasive and extendable prosthesis is disclosed in the late 70 s and early 80 s of the 29 th century, and is mainly characterized in that invasive surgery is not needed for extending the limbs after the prosthesis is implanted into a body, so that the risk of surgical infection and the incidence rate of complications are reduced, and the psychological burden and the economic burden of a patient are reduced. At present, the noninvasive and extensible prosthesis is widely used in developed countries to replace other extensible prostheses, the existing products in foreign countries mainly comprise Fitbone in Germany and Repiphysis in the United states, and related products in China are still in the beginning stage. At present the design that can prolong the false body to not having wound is mainly motor drive, the utility model discloses an electromagnetic drive mode arranges the control unit in externally, and the device structure of internal false body is simple relatively, and is more reliable and more stable in the use, has reduced the risk because of mechanical failure leads to.

SUMMERY OF THE UTILITY MODEL

In view of the problems mentioned in the background, it is an object of the present invention to provide an automatically extensible prosthesis which can be controlled in vitro.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an electromagnetically-driven extensible prosthesis comprises an extensible prosthesis body and an external electromagnetic driver, wherein the extensible prosthesis body comprises two fixed broach, a sealed shell, a moving body, a rotating body, a transmission main shaft and annular permanent magnets, the two fixed broach are respectively positioned at two ends of the prosthesis, one fixed broach is fixed at one end of the sealed shell, and the other fixed broach is fixed at one end of the moving body; the annular permanent magnet is positioned in the sealed shell and fixedly sleeved outside the transmission main shaft; one end of the rotating main shaft is matched with the rotating body and used for driving the rotating body to rotate, and the other end of the rotating main shaft is provided with a bearing which is fixed on the sealed shell and used for supporting the transmission main shaft; the rotating body is connected with the moving body in a lead screw mode, a rotation anti-back device is arranged on the periphery of the rotating body, and a limiting ring is arranged at one end, close to the transmission main shaft, of the rotating body and used for limiting the axial movement of the rotating body; one end of the moving body, which is provided with a fixed broach, is positioned outside the sealed shell, the other end of the moving body is positioned inside the sealed shell, and the sealed shell is provided with an anti-rotation limiter for limiting the circumferential rotation of the moving body; the external electromagnetic driver is matched with the extensible prosthesis body and used for driving the annular permanent magnet to rotate, and the external electromagnetic driver is provided with a communication interface.

Further, the external electromagnetic driver comprises at least two pairs of coil modules and a flexible connecting band for connecting the coil modules. Preferably, the flexible connecting band has elasticity.

Further, the coil module includes electrical coil, hall element, external electromagnetic actuator still includes control module, control module control electrical coil is long and the order of circular telegram, hall element original paper is used for detecting the change in magnetic field, and the circular telegram of accurate count coil module obtains the number of turns of permanent magnet rotation, and control module obtains the elongation of false body according to the pitch and the number of turns of rotation of rotator, and when the elongation reached predetermined elongation, the coil module was stopped to circular telegram.

Furthermore, the control module controls the two coil modules at the opposite sides to be electrified to generate a magnetic field to attract the corresponding magnetic poles of the annular permanent magnet in the prosthesis, after the magnetic poles are in place, the next pair of coil modules at the opposite sides are electrified to generate the magnetic field, the permanent magnet continues to rotate forwards, and the circular reciprocating manner drives the annular permanent magnet to drive the rotating body to rotate at a constant angular speed.

Further, the transmission main shaft is in interference fit with the rotating body.

Further, the bearing is a ball thrust bearing.

Further, the rotation anti-back device is a ratchet anti-back device, and a certain damping exists in the correct rotation direction of the ratchet anti-back device.

Further, the anti-rotation limiter is of a boss structure.

Furthermore, the sealing shell is provided with two circles of inward parallel annular bulges to form an annular groove for accommodating the limiting ring, and the limiting ring is fixed by the annular groove.

In one embodiment of the present invention, the external electromagnetic driving controller has a communication interface, is controlled by a computer, calculates the required number of power cycles by a predetermined extension length, the power-on cycle frequency is determined according to parameters such as the screw pitch and the extension speed, and the speed is reduced in advance when the preset length is about to be reached, so that the end time and the position are controlled accurately, and the situation that the inertia of a transmission system exceeds the preset extension length is avoided.

The utility model discloses owing to take above-mentioned structure, have as follows and have:

1. the built-in annular permanent magnet is provided with a plurality of magnetic poles, and the rotating speed is more stable under the control of an external electromagnetic field;

2. the prosthesis capable of being automatically extended is provided with an anti-rotation (anti-rotation boss) and anti-back-up (ratchet anti-back-up) device, and the ratchet anti-back-up device also ensures that certain damping still exists in the correct rotation direction, so that the prosthesis is prevented from being unnecessarily increased due to natural rotation of the annular permanent magnet when a patient moves daily;

3. the in vitro electromagnetic driving controller is connected through a flexible material, can be contracted and changed in diameter, and is suitable for limbs with different thicknesses;

4. a Hall element is arranged in the in vitro electromagnetic driving controller, the position of a built-in magnetic field is accurately positioned, and the number of rotation turns is measured;

5. the ball thrust bearing is used, so that friction loss is reduced;

6. the rotating speed of the external magnetic field is controlled, the starting is gradually accelerated, the speed is gradually reduced at a constant speed in the middle until the speed is stopped when the set length is reached, and therefore the length (the number of rotating circles) is accurately controlled and prolonged.

Drawings

Fig. 1 is a schematic diagram of the overall structure of the device of the present invention;

FIG. 2 is a cross-sectional view of an extendable prosthesis;

FIG. 3 is a partial enlargement of the drive spindle connection;

FIG. 4 is a schematic diagram of an in vitro electromagnetic drive controller;

FIG. 5 is a schematic diagram of the internal structure of the coil module before control;

in the figure, the position of the upper end of the main shaft,

1. extendable prosthesis

101. The top of the broach is fixed, 102 is a sealed shell, 103 is a moving body, 104 is a rotating body, 105 is a limiting ring, 106 is a transmission main shaft, 107 is an annular permanent magnet, 108 is a thrust bearing, 109 is a ratchet anti-back device, and 110 is a bottom of the broach is fixed;

2. external electromagnetic driving controller

201. The coil module 202 comprises a flexible connecting belt 203, an electrified coil 204 and a Hall element.

Detailed Description

The present invention will be described in further detail with reference to the attached drawings, but the present invention should not be construed as being limited thereto. The modification or decoration of the utility model can be realized without departing from the spirit and substance of the utility model, which belongs to the scope of the utility model.

An automatically extendable prosthesis driven by electromagnetism, as shown in figures 1 and 2, comprises an extendable prosthesis portion 1 and an extracorporeal electromagnetically driven controller 2.

The prosthesis 1 mainly comprises fixed broach 101/110 at two ends, a sealing shell 102, a moving body 103, a rotating body 104, a limiting ring 105, a transmission main shaft 106, an annular permanent magnet 107, a ratchet anti-back device 109, a ball thrust bearing 108 and the like. The annular permanent magnet 107 is fixedly connected with the transmission main shaft 106 and is in interference fit with the rotating body 104 by utilizing the groove, and the moving body 103 is connected with the rotating body 104 through a lead screw to realize the conversion of rotation and linear motion; the limiting rings 105 of the sealed shells at two ends limit the shafting freedom degree of the rotating body 104, and the boss structure at one end of the sealed shell limits the circumferential rotation of the moving body 103; the ratchet wheel anti-back device 109 ensures that the rotation only occurs in the direction that can make the moving body extend upwards, prevents the backward movement and ensures that a certain damping still exists in the correct rotation direction; the bottom ball thrust bearing 108 allows the spindle to maintain smooth rotation under high axial loading.

The in vitro electromagnetic driving controller 2 is composed of a coil module 201 and a flexible connecting band 202. The coil module 201 has an energized coil 203 and a hall element 204 inside. The hall element 204 is located inside the module, and can detect the magnetic field change generated by the rotation of the annular permanent magnet 106, thereby playing the role of positioning and speed measurement. The flexible connecting band 202 is made of flexible materials, has certain elasticity, has the functions of stretching and fixing, and ensures the connection stability on the basis of keeping the relative positions of the coil modules unchanged, wherein each section of connecting structure consists of 3 pieces.

Example 1

As shown in fig. 1, the present invention provides an automatic extensible prosthesis driven by electromagnetism, comprising an extensible prosthesis portion 1 and an external electromagnetic drive controller 2.

As shown in figures 2 and 3, the extendable prosthesis comprises fixed broach 101/110 at two ends, a sealing shell 102, a moving body 103, a rotating body 104, a limiting ring 105, a transmission main shaft 106, an annular permanent magnet 107, a ratchet anti-back device 109, a ball thrust bearing 108 and the like. The fixing broach 101/110 is inserted into the joint or bone and fixed by steel nails. The sealed housing 102 serves to isolate the internal cavity of the prosthesis from body tissue and prevent instrument failure. The ring-shaped permanent magnet 107 is a propelling device capable of automatically extending the prosthesis, outputs axial rotation, rotates at a proper rotating speed through an external controllable alternating magnetic field, and transmits the rotation at a proper speed to the rotating body 104 to drive the rotating body 104 to rotate. The rotating body 104 and the moving body 103 are connected through a screw rod, so that the rotating body 104 rotates and simultaneously drives the moving body 103 to axially move, thereby achieving the effect of extension. The transmission main shaft 106 is in interference fit with the rotating body 103 by using the groove.

The anti-rotation boss is adopted at the contact connection part of the sealing shell 102 and the fixed broach 101, so that the device can be prevented from being out of work due to the rotation of the moving body along with the rotating body. In addition, ratchet wheel anti-back 109 is adopted in the transmission part, so that the rotation can be ensured to be only in the direction that the moving body can be extended upwards, and the backward movement is prevented. Meanwhile, the ratchet wheel anti-back device 109 also ensures that certain damping still exists in the correct rotating direction, and ensures that the prosthesis cannot be unnecessarily lengthened due to the natural rotation of the annular permanent magnet 107 during the daily movement of the patient. The spacing ring 105 is fixed by the two segments of the convex parts of the sealing shell 102 during assembly, so that the rotating body 104 only has the unique degree of freedom of rotation without axial displacement, and the bearing capacity and the stability of the prosthesis in use are further enhanced.

The structure of the anti-rotation boss in this example may be an anti-rotation groove, that is, one end of the seal housing 102 and the moving body 103 are matched through the structure of the boss and the groove, so that the moving body 103 extends along the axial direction without circumferential rotation.

ISO standard ball thrust bearing 108 is selected for the bottom of the transmission device, and the main shaft can keep smooth rotation under the condition of high axial bearing.

As shown in fig. 4, the in vitro electromagnetic driving controller 2 is composed of a coil module 201 and a flexible connecting band 202. The flexible connecting band 202 is made of flexible materials, has certain elasticity, has the functions of stretching and fixing, and ensures the connection stability on the basis of keeping the relative positions of the coil modules unchanged, wherein each section of connecting structure consists of 3 pieces.

As shown in fig. 5, a cross-sectional view of the coil module 201 includes an energizing coil 203 and a hall element 204. When the in vitro electromagnetic driving controller works, the two coil modules 203 at the opposite sides are electrified to generate a magnetic field to attract the corresponding magnetic poles of the annular permanent magnet 107 in the prosthesis, and after the magnetic poles are in place, the next pair of coil modules 203 at the opposite sides are electrified to generate a magnetic field, the permanent magnet continues to rotate forwards, and the steps are repeated in a circulating manner to drive the annular permanent magnet 107 to drive the rotating body 104 at a constant angular speed. The hall element 204 constantly detects the change of the magnetic field, accurately counts the power-on cycle of the coil module, and detects the elongation of the prosthesis.

When the patient wears the external electromagnetic drive controller, the controller is sleeved outside the corresponding body part of the annular permanent magnet 107, and the relative position of each coil module is kept unchanged by utilizing the elasticity and fixation of the connecting structure 202, so that the stability of electromagnetic drive is ensured.

The external electromagnetic drive controller 2 is provided with a communication interface and is controlled by a computer, the required power-on cycle times are calculated through the preset extension length, the power-on cycle frequency is determined according to the parameters such as the screw pitch and the extension speed, the speed is reduced in advance when the preset length is about to be reached, the finish time and the position are controlled conveniently and accurately, and the phenomenon that the inertia of a transmission system exceeds the preset extension length is avoided.

Example 2

The electromagnetically-driven extensible prosthesis in the embodiment has a structure basically the same as that of embodiment 1, but the coil module 201 comprises an energizing coil 203 and a hall element 204, the external electromagnetic control driver 2 further comprises a control module, the control module controls energizing duration and sequence of the energizing coil pair, the hall element 204 is used for detecting changes of a magnetic field, energizing circulation of the coil module is accurately counted to obtain the number of rotation turns of the permanent magnet, the control module obtains the elongation of the prosthesis according to the thread pitch and the number of rotation turns of the rotating body 104, and when the elongation reaches a preset elongation, energizing of the coil module is stopped. The external electromagnetic control driver 2 further comprises a display and input module, the display module can display various parameters of the extensible prosthesis, such as information of a patient, initial information of the extensible prosthesis, the number of times of extension, the amount of extension and the like, the extension length can be set through the input module, the control module calculates the required number of times of power-on cycles, determines the frequency of the power-on cycles according to parameters of the pitch of the rotating body 104, the extension speed and the like, and decelerates in advance when the preset length is about to be reached, so that the finishing time and position can be accurately controlled, and the phenomenon that the preset extension length is exceeded due to the inertia of a transmission system is avoided. For example, the rotating speed of the external magnetic field is controlled, the starting is gradually accelerated, the speed is gradually reduced at a constant speed in the middle until the preset length is reached, and the speed is stopped, so that the extended length (the number of rotating circles) is accurately controlled.

Claims

1. An electromagnetically-driven extensible prosthesis comprises an extensible prosthesis body and an external electromagnetic control driver, and is characterized in that the extensible prosthesis body comprises two fixed intramedullary nails, a sealed shell, a moving body, a rotating body, a transmission main shaft and an annular permanent magnet, the two fixed intramedullary nails are respectively positioned at two ends of the prosthesis, one fixed intramedullary nail is fixed at one end of the sealed shell, and the other fixed intramedullary nail is fixed at one end of the moving body; the annular permanent magnet is positioned in the sealed shell and fixedly sleeved outside the transmission main shaft; one end of the rotating main shaft is matched with the rotating body and used for driving the rotating body to rotate, and the other end of the rotating main shaft is provided with a bearing which is fixed on the sealed shell and used for supporting the transmission main shaft; the rotating body is connected with the moving body in a lead screw mode, a rotation anti-back device is arranged on the periphery of the rotating body, and a limiting ring is arranged at one end, close to the transmission main shaft, of the rotating body and used for limiting the axial movement of the rotating body; one end of the moving body, which is provided with a fixed broach, is positioned outside the sealed shell, the other end of the moving body is positioned inside the sealed shell, and the sealed shell is provided with an anti-rotation limiter for limiting the circumferential rotation of the moving body; the external electromagnetic control driver is matched with the extensible prosthesis body and used for driving the annular permanent magnet to rotate, and the external electromagnetic control driver is provided with a communication interface.

2. The extendable prosthesis of claim 1, wherein said external electromagnetic control driver comprises at least two pairs of coil modules and a flexible connecting band connecting the coil modules.

3. The extendable prosthesis of claim 2, wherein the coil module comprises an energizing coil, a hall element, the external electromagnetic control driver further comprises a control module, the control module controls the energizing duration and sequence of the pair of energizing coils, the hall element is used for detecting the change of the magnetic field, the energizing cycle of the coil module is accurately counted to obtain the number of rotation turns of the permanent magnet, the control module obtains the elongation of the prosthesis according to the thread pitch and the number of rotation turns of the rotating body, and when the elongation reaches a predetermined elongation, the energizing of the coil module is stopped.

4. The extensible prosthesis of claim 3, wherein the control module controls the two coil modules at opposite sides to be electrified to generate a magnetic field, and attracts corresponding magnetic poles of the annular permanent magnet in the prosthesis, after the magnetic poles are in place, the next pair of coil modules at opposite sides are electrified to generate a magnetic field, and the permanent magnet continues to rotate forwards, and the operation is repeated in a cyclic mode, so that the annular permanent magnet is driven to rotate the rotating body at a constant angular speed.

5. The extensible prosthesis of claim 2, wherein the flexible connecting band is elastic.

6. The extensible prosthesis of any one of claims 1 to 5 wherein the drive shaft is an interference fit with the rotating body.

7. The extensible prosthesis of any of claims 1 to 5, wherein the bearings are ball thrust bearings.

8. The extendable prosthesis of any one of claims 1 to 5, wherein said rotational anti-back device is a ratchet anti-back device, said ratchet anti-back device being somewhat damped in the correct rotational direction.

9. The extendable prosthesis of any one of claims 1 to 5, wherein said anti-rotation stop is a boss structure.

10. The extensible prosthesis of any of claims 1 to 5 wherein the seal housing has two rings of inwardly parallel annular protrusions forming an annular recess for receiving the stop collar, the stop collar being retained by the annular recess.