Electromagnetically driven automatic lengthening prosthesis

Abstract

The application provides an electromagnetic driving automatic lengthening prosthesis, which comprises a lengthening prosthesis and an extracorporeal electromagnetic driving controller. Specifically, the prosthesis part is composed of a moving body, a rotating body, a sealed shell, a transmission box and an annular permanent magnet, etc. The extracorporeal electromagnetic driving controller is composed of multiple electromagnetic modules connected by flexible materials, and the electromagnetic modules are provided with coils, Hall elements and other components. The prosthesis is implanted by one-time surgery, and when the prosthesis is lengthened again, the extracorporeal electromagnetic driving controller is worn on the leg prosthesis permanent magnet corresponding position, an alternating electromagnetic field is generated to drive the permanent magnet to rotate, the rotating body is driven to rotate and the moving body is driven to move forward, so that the lengthening effect is achieved. The extracorporeal electromagnetic driving module is strictly controlled by a computer program, and the Hall element is used for monitoring, so that the length of the prosthesis lengthening can be accurately controlled, the accuracy and safety of the non-invasive lengthening surgery are ensured, and a customized surgical plan can be made according to the actual situation of the patient.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to an electromagnetically driven non-invasive automatic lengthening prosthesis. Background Technology

[0002] Currently, there are over 10,000 cases of primary osteosarcoma in China each year, with the majority of patients under the age of 30. Surgery primarily involves removing the diseased bone and implanting an artificial prosthesis. For adolescents, the bones still have strong growth potential after surgery. Traditional metal prostheses require periodic lengthening and revision surgeries, significantly increasing the risks and difficulty, and impacting the patient's daily life and recovery. Therefore, lengthening prostheses have become a reasonable option.

[0003] Stretchable prostheses can be broadly categorized into three types: composite prostheses, minimally invasive stretchable prostheses, and non-invasive stretchable prostheses. Non-invasive stretchable prostheses emerged in the late 1970s and early 1980s. Their biggest advantage is that limb lengthening after implantation does not require invasive surgery, thus reducing the risk of surgical infection and complications, and alleviating the psychological and financial burden on patients. Currently, non-invasive stretchable prostheses have replaced other stretchable prostheses in developed countries and are widely used. Existing international products include Fitbone from Germany and Repiphysis from the United States, while related products in China are still in their early stages. Current designs for non-invasive stretchable prostheses primarily rely on motor drive. This invention employs an electromagnetic drive method, placing the control unit externally. The internal prosthesis structure is relatively simple, resulting in greater stability and reliability during use and reducing the risk of mechanical failure. Summary of the Invention

[0004] In view of the problems mentioned in the background art, the object of the present invention is to provide an automatically elongated prosthesis that can be controlled outside the body.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An electromagnetically driven extendable prosthesis includes an extendable prosthesis body and an external electromagnetic actuator. The extendable prosthesis body includes a fixed medullary needle, a sealed outer shell, a movable body, a rotating body, a drive shaft, and a ring-shaped permanent magnet. Two fixed medullary needles are located at opposite ends of the prosthesis, one fixed to one end of the sealed outer shell and the other fixed to one end of the movable body. The ring-shaped permanent magnet is located inside the sealed outer shell and is fixedly sleeved outside the drive shaft. One end of the drive shaft engages with the rotating body to drive its rotation, and the other end has a bearing fixed to the sealed outer shell to support the drive shaft. The rotating body and the movable body are connected by a lead screw. The rotating body has a rotation anti-reverse device on its outer periphery, and a limiting ring is located at the end of the rotating body near the drive shaft to limit its axial movement. The movable body has a fixed medullary needle at one end outside the sealed outer shell and the other end inside the sealed outer shell. The sealed outer shell has an anti-rotation limiter to limit the circumferential rotation of the movable body. The external electromagnetic actuator engages with the extendable prosthesis body to drive the ring-shaped permanent magnet to rotate.

[0007] Furthermore, the external electromagnetic actuator includes at least two pairs of coil modules and a flexible connecting strip connecting the coil modules. Preferably, the flexible connecting strip is elastic.

[0008] Furthermore, the coil module includes an energized coil and a Hall element. The external electromagnetic actuator also includes a control module. The control module controls the energizing duration and sequence of the energized coil pair. The Hall element is used to detect changes in the magnetic field and accurately count the energizing cycles of the coil module to obtain the number of rotations of the permanent magnet. The control module obtains the elongation of the sculpt based on the pitch and number of rotations of the rotating body. When the elongation reaches the predetermined elongation, the energizing of the coil module is stopped.

[0009] Furthermore, the control module controls the two coil modules on opposite sides to generate a magnetic field, which attracts the corresponding magnetic pole of the annular permanent magnet inside the prosthesis. After the magnetic pole is in place, the next pair of opposite coil modules are energized to generate a magnetic field, and the permanent magnet continues to rotate forward. This cycle repeats, driving the annular permanent magnet to drive the rotating body to rotate at a constant angular velocity.

[0010] Furthermore, the transmission spindle is interference-fitted with the rotating body.

[0011] Furthermore, the bearing is a ball thrust bearing.

[0012] Furthermore, the rotational anti-reverse device is a ratchet anti-reverse device, which has a certain damping in the correct rotational direction.

[0013] Furthermore, the anti-rotation limiter has a boss structure.

[0014] Furthermore, the sealing housing has two inwardly parallel annular protrusions forming an annular groove to accommodate the limiting ring, and the limiting ring is fixed by the annular groove.

[0015] The present invention, by adopting the above-described structure, has the following advantages:

[0016] 1. The built-in ring-shaped permanent magnet has multiple magnetic poles, making the rotation speed more stable when controlled by an external electromagnetic field;

[0017] 2. The automatically elongating prosthesis is designed with anti-rotation (anti-rotation boss) and anti-retraction (ratchet anti-retraction) devices. The ratchet anti-retraction device also ensures that there is still a certain amount of damping in the correct direction of rotation, ensuring that the prosthesis will not grow unnecessarily due to the natural rotation of the ring permanent magnet during the patient's daily activities.

[0018] 3. The external electromagnetic drive controller is connected by flexible materials, which can stretch and change the diameter, making it suitable for limbs of different thicknesses;

[0019] 4. The external electromagnetic drive controller is equipped with a Hall element to accurately locate the position of the built-in magnetic field and measure the number of rotations;

[0020] 5. Use ball thrust bearings to reduce friction loss;

[0021] 6. Control the rotation speed of the external magnetic field, gradually increase it at the start, maintain a constant speed in the middle, and gradually decrease the speed when it is about to reach the set length until it stops, thereby accurately controlling the extension length (number of rotations). Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention;

[0023] Figure 2 This is a cross-sectional view of an extendable prosthesis;

[0024] Figure 3 This is a magnified view of the connection point of the main drive shaft;

[0025] Figure 4 This is a schematic diagram of an external electromagnetic drive controller;

[0026] Figure 5 This is a schematic diagram of the internal structure of the control front coil module;

[0027] In the picture,

[0028] 1. Can lengthen the implant

[0029] 101. Top fixed spindle needle; 102. Sealed outer shell; 103. Moving body; 104. Rotating body; 105. Limiting ring; 106. Transmission spindle; 107. Ring permanent magnet; 108. Thrust bearing; 109. Ratchet anti-reverse device; 110. Bottom fixed spindle needle.

[0030] 2. External electromagnetic drive controller

[0031] 201. Coil module, 202. Flexible connecting strip, 203. Energized coil, 204. Hall element. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings, but this should not be construed as limiting the invention. Any modifications or refinements to the present invention that do not depart from its spirit and essence are within the scope of the invention.

[0033] like Figure 1 and 2 The electromagnetically driven, automatically extendable prosthesis shown includes an extendable prosthesis part 1 and an external electromagnetic drive controller 2.

[0034] The prosthesis 1 mainly consists of two fixed spindle pins 101 / 110 at both ends, a sealed outer shell 102, a movable body 103, a rotating body 104, a limiting ring 105, a transmission spindle 106, a ring-shaped permanent magnet 107, a ratchet anti-reverse device 109, and a ball thrust bearing 108. The ring-shaped permanent magnet 107 is fixedly connected to the transmission spindle 106 and is interference-fitted with the rotating body 104 using a groove. The movable body 103 and the rotating body 104 are connected by a lead screw to realize the conversion between rotation and linear motion. The limiting rings 105 at both ends of the sealed outer shell restrict the axial freedom of the rotating body 104, and the boss structure at one end of the sealed outer shell restricts the circumferential rotation of the movable body 103. The ratchet anti-reverse device 109 ensures that rotation only occurs in the direction that allows the movable body to extend upward, preventing backlash and ensuring that there is still a certain amount of damping in the correct direction of rotation. The ball thrust bearing 108 at the bottom allows the spindle to maintain smooth rotation under high axial load.

[0035] The external electromagnetic drive controller 2 consists of a coil module 201 and a flexible connecting strip 202. The coil module 201 contains an energized coil 203 and a Hall element 204. The Hall element 204, located inside the module, detects changes in the magnetic field generated by the rotation of the ring-shaped permanent magnet 106, thus serving for positioning and speed measurement. The flexible connecting strip 202 is made of flexible material, possessing elasticity and the functions of extension, retraction, and fixation. Each connecting structure consists of three strips, ensuring connection stability while maintaining the relative positions of the coil modules.

[0036] Example 1

[0037] like Figure 1 As shown, the present invention provides an automatically extendable prosthesis driven by electromagnetic force, including an extendable prosthesis part 1 and an external electromagnetic drive controller 2.

[0038] like Figure 2 , 3 As shown, the extendable prosthesis consists of fixed pins 101 / 110 at both ends, a sealing shell 102, a movable body 103, a rotating body 104, a limiting ring 105, a drive spindle 106, a ring-shaped permanent magnet 107, a ratchet anti-retraction device 109, and a ball thrust bearing 108. The fixed pins 101 / 110 are inserted into the joint or bone and fixed using steel nails. The sealing shell 102 isolates the internal cavity of the prosthesis from human tissue, preventing device failure. The ring-shaped permanent magnet 107 is the automatic extension device for the prosthesis, outputting axial rotation. Through an externally controllable alternating magnetic field, it rotates at a suitable speed and transmits this rotational speed to the rotating body 104, causing it to rotate. The rotating body 104 and the movable body 103 are connected by a lead screw; therefore, as the rotating body 104 rotates, it drives the movable body 103 to move axially, thus achieving the extension effect. The drive spindle 106 uses a groove for interference fit with the rotating body 103.

[0039] At the contact connection between the sealed outer shell 102 and the fixed spinal cord needle 101, an anti-rotation boss is used to prevent the device from malfunctioning due to the movement of the movable body rotating with the rotating body. Additionally, a ratchet anti-retraction device 109 is used in the transmission part to ensure that rotation only occurs in the direction that allows the movable body to extend upwards, preventing backward movement. Simultaneously, the ratchet anti-retraction device 109 also ensures that a certain amount of damping remains in the correct rotation direction, preventing unnecessary growth of the prosthesis due to the natural rotation of the annular permanent magnet 107 during daily activities. The limiting ring 105 is fixed by the protrusions of the two sections of the sealed outer shell 102 during assembly, ensuring that the rotating body 104 has only rotational freedom and no axial displacement, further enhancing the load-bearing capacity and stability of the prosthesis.

[0040] In this example, the structure of the anti-rotation boss can also be an anti-rotation groove, that is, one end of the sealing shell 102 and the moving body 103 are connected by the structure of the boss and the groove, so that the moving body 103 extends along the axial direction without circumferential rotation.

[0041] The bottom of the transmission device uses ISO standard ball thrust bearing 108, which enables the spindle to maintain smooth rotation under high axial load.

[0042] like Figure 4As shown, the external electromagnetic drive controller 2 consists of a coil module 201 and a flexible connecting strip 202. The flexible connecting strip 202 is made of flexible material and has a certain degree of elasticity, with the functions of extension, retraction and fixation. Each connecting structure consists of 3 strips, ensuring connection stability while maintaining the relative positions of each coil module.

[0043] A cross-sectional view of coil module 201 is shown below. Figure 5 As shown, it consists of an energized coil 203 and a Hall element 204. When the external electromagnetic drive controller is working, the two coil modules 203 on opposite sides are energized to generate a magnetic field, attracting the corresponding magnetic pole of the annular permanent magnet 107 inside the prosthesis. After the magnetic pole is in place, the next pair of opposite coil modules 203 are energized to generate a magnetic field, and the permanent magnet continues to rotate forward. This cycle repeats, driving the annular permanent magnet 107 to drive the rotating body 104 at a constant angular velocity. The Hall element 204 constantly detects changes in the magnetic field, accurately counts the energizing cycles of the coil modules, and detects the elongation of the prosthesis.

[0044] When the patient wears the external electromagnetic drive controller, the controller is placed on the outside of the corresponding body part of the annular permanent magnet 107 and fixed by the elasticity of the connecting structure 202, so that the relative position of each coil module remains unchanged, thus ensuring the stability of the electromagnetic drive.

[0045] The external electromagnetic drive controller 2 is controlled by a computer. It calculates the required number of energizing cycles based on the preset elongation length, determines the energizing cycle frequency based on parameters such as pitch and elongation speed, and decelerates in advance when it is about to reach the preset length. This facilitates precise control of the end time and position and avoids exceeding the preset elongation length due to the inertia of the transmission system.

[0046] Example 2

[0047] The electromagnetically driven extendable prosthesis in this example has a structure that is basically the same as that in Embodiment 1, but the coil module 201 includes an energized coil 203 and a Hall element 204. The external electromagnetic control driver 2 also includes a control module. The control module controls the energizing duration and sequence of the energized coil pair. The Hall element 204 is used to detect changes in the magnetic field and accurately count the energizing cycles of the coil module to obtain the number of rotations of the permanent magnet. The control module obtains the elongation of the prosthesis based on the pitch and number of rotations of the rotating body 104. When the elongation reaches the predetermined elongation, the energizing of the coil module is stopped. The external electromagnetic control actuator 2 further includes a display and input module. The display module can display various parameters of the extendable prosthesis, such as patient information, initial information of the extendable prosthesis, number of extensions, extension amount, etc. The input module can set the extension length. The control module calculates the required number of energizing cycles, determines the energizing cycle frequency based on parameters such as the pitch and extension speed of the rotating body 104, and decelerates in advance when the preset length is about to be reached, so as to accurately control the end time and position and avoid exceeding the preset extension length due to the inertia of the transmission system. For example, controlling the rotation speed of the external magnetic field, gradually increasing the speed at the start, maintaining a constant speed in the middle, and gradually decreasing the speed when the set length is about to be reached until it stops, thereby accurately controlling the extension length (number of rotations).

Claims

1. An electromagnetically driven extendable prosthesis, comprising an extendable prosthesis body and an external electromagnetic control actuator, wherein the extendable prosthesis body includes a fixing pin, a sealed outer shell, a movable body, a rotating body, a transmission spindle, and a ring-shaped permanent magnet; two fixing pins are respectively located at both ends of the prosthesis, one fixing pin being fixed to one end of the sealed outer shell and the other fixing pin being fixed to one end of the movable body; the ring-shaped permanent magnet is located inside the sealed outer shell and is fixedly sleeved outside the transmission spindle; one end of the transmission spindle cooperates with the rotating body to drive the rotating body to rotate, and the other end is provided with... The bearing is fixed on the sealed housing and is used to support the transmission main shaft. The rotating body and the moving body are connected by a lead screw. The rotating body has a rotation anti-reverse device on its outer periphery. A limiting ring is provided at one end of the rotating body near the transmission main shaft to limit the axial movement of the rotating body. The moving body has one end with a fixed spindle located outside the sealed housing and the other end located inside the sealed housing. The sealed housing has an anti-rotation limiter to limit the circumferential rotation of the moving body. The external electromagnetic control actuator cooperates with the extendable prosthesis body to drive the rotation of the ring permanent magnet. in, The external electromagnetic control actuator includes at least two pairs of coil modules and a flexible connecting strip connecting the coil modules; The coil module includes an energized coil and a Hall element. The external electromagnetic control driver also includes a control module. The control module controls the energizing duration and sequence of the energized coil. The Hall element is used to detect changes in the magnetic field and accurately count the energizing cycles of the coil module to obtain the number of rotations of the permanent magnet. The control module obtains the elongation of the sculpt based on the pitch and number of rotations of the rotating body. When the elongation reaches the predetermined elongation, the energizing of the coil module is stopped.

2. The extendable prosthesis according to claim 1, characterized in that, The control module controls the two coil modules on opposite sides to generate a magnetic field, which attracts the corresponding magnetic pole of the annular permanent magnet inside the prosthesis. After the magnetic pole is in place, the next pair of opposite coil modules are energized to generate a magnetic field, and the permanent magnet continues to rotate forward. This cycle repeats, driving the annular permanent magnet to drive the rotating body to rotate at a constant angular velocity.

3. The extendable prosthesis according to claim 1, characterized in that, The flexible connecting strip is elastic.

4. The extendable prosthesis according to any one of claims 1 to 3, characterized in that, The transmission spindle is interference-fitted with the rotating body.

5. The extendable prosthesis according to any one of claims 1 to 3, characterized in that, The bearing is a ball thrust bearing.

6. The extendable prosthesis according to any one of claims 1 to 3, characterized in that, The rotational anti-reverse device is a ratchet anti-reverse device, which has a certain damping in the correct rotational direction.

7. The extendable prosthesis according to any one of claims 1 to 3, characterized in that, The anti-rotation limiter has a boss structure.

8. The extendable prosthesis according to any one of claims 1 to 3, characterized in that, The sealing shell has two inward parallel annular protrusions forming an annular groove to accommodate the limiting ring, and the limiting ring is fixed by the annular groove.

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