Device for evaluating total knee joint tissue balance

Abstract

The invention belongs to the technical field of medical instruments, and provides a device for evaluating total knee joint tissue balance, which comprises a shell, a base connected with the bottom of the shell and a thickness adjusting gasket connected with the bottom of the base, and a strain gauge, a circuit mainboard and a battery are arranged in the shell; the shell comprises an upper shell body used for being matched with a prosthesis and a lower shell body fixedly connected with the upper shell body, and the upper shell body comprises a left upper half shell body, a right upper half shell body and a middle connecting part, wherein the left upper half shell body and the right upper half shell body are made of medical hard materials, and the middle connecting part is connected with the two upper half shell bodies and made of medical soft materials. The left side and the right side of the lower surface of the lower shell are provided with two sets of stress points corresponding to the two upper half shells respectively, and each stress point is provided with a strain gauge in a one-to-one correspondence mode. The upper shell matched with the arc-shaped prosthesis is divided into three parts, the two upper half shells on the left side and the right side transmit force through hard rubber, the middle connecting part is made of soft rubber, mutual restraint of the two sides is avoided, mutual influence of the left side and the right side is effectively reduced, and the accuracy of tension measurement of the left side and the right side is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a device for evaluating the balance of total knee joint tissue. Background Art

[0002] In artificial knee replacement surgery, dynamic measurement of soft tissue balance during flexion and extension of the knee joint is a necessary technology to achieve accurate and efficient surgery. In artificial knee replacement surgery, a device to assist soft tissue balance is placed in the knee joint, and the soft tissues in the inner and outer directions of the knee joint are forcefully opened to evaluate whether the elasticity and opening distance of the inner and outer soft tissues are equal during this process.

[0003] CN202310494380.8 discloses a device and method for obtaining soft tissue tension values ​​and / or evaluating soft tissue balance, wherein the gasket includes an upper shell and a lower shell, wherein strain sensors, circuit boards and batteries are provided inside the upper shell and the lower shell, and the upper shell of the gasket can cooperate with the extension / flexion gap plane gasket or arc-shaped gasket for precise measurement. However, the extension / flexion gap plane gasket or arc-shaped gasket of the aforementioned patent is an integral structure, usually made of a hard material as a whole. When evaluating the difference in tension between the left and right sides of the total knee joint tissue, the left and right sides affect each other more seriously, affecting the accuracy of the tension between the left and right sides of the total knee joint tissue. Summary of the invention

[0004] The present invention aims to solve the technical problems existing in the prior art, and an object of the present invention is to provide a device for evaluating the balance of total knee joint tissue.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a device for evaluating the balance of total knee joint tissue, comprising a shell, a base connected to the bottom of the shell, and a thickness adjustment gasket connected to the bottom of the base, wherein a strain gauge, a circuit board and a battery are arranged in the shell; the shell comprises an upper shell for cooperating with a prosthesis, and a lower shell fixed to the upper shell, the upper shell comprises two left and right upper half shells made of medical hard material, and an intermediate connecting part made of medical soft material connecting the two upper half shells; two groups of force points corresponding to the two upper half shells are arranged on the left and right sides of the lower surface of the lower shell, respectively, and a strain gauge is arranged at each force point in a one-to-one correspondence.

[0006] In the above technical solution, the two groups of force points on the bottom of the lower shell are used to centrally measure the pressure values ​​of the corresponding points on the left and right sides, and the force points are set at the bottom of the lower shell. After the force is applied, the deformation is directly transmitted to the strain gauge deformation, reducing the error caused by assembly. The upper shell body that matches the arc prosthesis is divided into three parts. The two upper half shells on the left and right sides use hard rubber to transmit force, and the middle connection part uses soft material to get rid of the mutual restraint of the two sides, effectively reduce the mutual influence of the left and right sides, and improve the accuracy of the tension measurement on the left and right sides.

[0007] In a preferred embodiment of the present invention, a group of force points includes at least three force points.

[0008] The above technical solution sets at least three stress points on one side, so that the stress is more uniform, making the measured data more accurate.

[0009] In a preferred embodiment of the present invention, a cantilever beam is provided on the lower surface of the lower shell, the force point is a downwardly protruding hemispherical force-bearing protrusion fixed to the lower end of the cantilever beam, and the strain gauge is fixed to the inner surface of the cantilever beam.

[0010] In the above technical solution, the stress point is set on the cantilever beam, which has better deformation followability; the hemispherical stress protrusion design and independent stress point improve the measurement accuracy.

[0011] In a preferred embodiment of the present invention, the cantilever beam is integrally provided with the lower shell, and the lower shell is provided with a U-shaped opening groove on the outer periphery corresponding to the force bearing point to form the cantilever beam.

[0012] In the above technical solution, the cantilever beam and the lower shell are arranged in one piece, thereby reducing the number of parts.

[0013] In a preferred embodiment of the present invention, a flexible U-shaped sealing member for sealing between the cantilever beam and the lower shell is provided in the U-shaped opening groove, and the U-shaped sealing member is made of soft silicone.

[0014] In the above technical solution, the flexible U-shaped seal can not only achieve sealing, but also reduce the influence of the lower shell on the force measurement of the force point.

[0015] In another preferred embodiment of the present invention, the intermediate connecting portion is a positioning protrusion protruding upward.

[0016] In the above technical solution, the positioning protrusion facilitates the positioning of the upper shell and the prosthesis when they are matched.

[0017] In another preferred embodiment of the present invention, the base is made of stainless steel; and / or the thickness adjusting gasket is a metal gasket made of stainless steel.

[0018] In another preferred embodiment of the present invention, the four sides of the lower end of the upper shell are fixedly welded to the four sides of the upper end of the lower shell.

[0019] The above technical solution is fixed by welding and has good sealing performance.

[0020] In another preferred embodiment of the present invention, the periphery of the lower end of the upper shell body is snap-fitted with the periphery of the upper end of the lower shell body via a groove-type structure.

[0021] The above technical solution, by providing a groove structure, facilitates the rapid positioning of the upper shell and the lower shell, and the welding is more reliable and the sealing is better.

[0022] In another preferred embodiment of the present invention, the upper end of the base has a positioning step for positioning the lower shell; and / or the base is provided with an oblique nail hole, through which the oblique nail fixes the base to the tibia.

[0023] The above technical solution positions the lower shell of the welded shell by providing a positioning step; and facilitates fixing the base on the tibia by providing oblique nail holes.

[0024] Compared with the prior art, the preferred technical solution of the present invention has the following beneficial effects:

[0025] 1) The upper shell that matches the arc-shaped prosthesis is divided into three parts. The two upper shells on the left and right sides use hard rubber to transmit force, and the middle connection part uses soft material to get rid of the mutual restraint between the two sides, effectively reduce the mutual influence between the left and right sides, and improve the accuracy of tension measurement on the left and right sides.

[0026] 2) A cantilever beam for directly fixing the strain gauge is integrated on the lower shell, reducing the number of parts; at the same time, soft silicone is filled around the cantilever beam to achieve sealing and reduce the influence of the lower shell on the force measurement of the force point.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 FIG. 1 is an exploded schematic diagram of a device for evaluating total knee joint tissue balance according to an embodiment.

[0030] Figure 2 It is a schematic diagram of the front structure of the upper shell in the embodiment.

[0031] Figure 3 It is a schematic diagram of the front structure of the lower shell in the embodiment.

[0032] Figure 4 It is a schematic diagram of the back structure of the lower shell in the embodiment.

[0033] Figure 5 It is a schematic structural diagram of the connection between the base and the thickness adjustment gasket in the embodiment.

[0034] The figure marks in the drawings of the specification include: holder 10, upper shell 20, upper half shell 21, middle connecting part 22, lower shell 30, force point 31, cantilever beam 32, cantilever beam inner surface 321, U-shaped opening groove 33, U-shaped seal 34, base 40, positioning step 41, oblique nail hole 42, thickness adjustment gasket 50, strain gauge 60, circuit main board 70, battery 80. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] In the description of the present invention, it is to be understood that the terms “longitudinal”, “lateral”, “vertical”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0038] The present invention provides a device for evaluating the balance of the entire knee joint tissue, such as Figure 1-5 As shown, in a preferred embodiment, the device includes a shell, a base 40 connected to the bottom of the shell, and a thickness adjustment gasket 50 connected to the bottom of the base 40. A strain gauge 60, a circuit main board 70 and a battery 80 are provided in the shell. The battery 80 is installed on the circuit main board 70. The strain gauge 60 is a resistive strain gauge. The strain gauge 60 is connected to the circuit main board 70 integrated with a measurement data processing module to realize measurement and information communication.

[0039] The housing includes an upper housing 20 for cooperating with the arc-shaped prosthesis, and a lower housing 30 fixedly connected to the upper housing 20, and a space for accommodating a strain gauge 60, a circuit board 70 and a battery 80 is formed between the upper housing 20 and the lower housing 30. The upper housing 20 includes two upper half shells 21 on the left and right sides made of medical hard materials, and an intermediate connecting part 22 made of medical soft materials connecting the two upper half shells 21, such as the two upper half shells 21 are made of hard plastic PC, and the intermediate connecting part 22 is made of soft plastic (such as soft silicone). Preferably, the upper surface of the upper half shell 21 is an arc surface that matches the prosthesis of each manufacturer or the personalized prosthesis, and the intermediate connecting part 22 is a positioning protrusion protruding upward. Two groups of force points 31 corresponding to the two upper half shells 21 are provided on the left and right sides of the lower surface of the lower housing 30, respectively, and a strain gauge 60 is provided at each force point 31 in a one-to-one correspondence, which is used to centrally measure the pressure values ​​of the corresponding points on the left and right sides.

[0040] The housing of the present invention is a measuring component, the base 40 is made of medical stainless steel, provides a measuring platform, and is provided with an oblique nail hole 42, through which the oblique nail fixes the base 40 on the tibia to achieve fixation of the base 40. The thickness adjustment gasket 50 is a metal gasket made of stainless steel, and the thickness adjustment gasket 50 is designed with different thicknesses, and cooperates with the base 40 to achieve different gap measurements.

[0041] During the operation, the device is inserted by holding the gripper 10. The specific connection method between the gripper 10 and the device is a prior art, which is not the innovation of the present invention and will not be described in detail here. After the device is inserted, the upper surface of the two upper half shells 21 and the force point 31 at the bottom of the lower shell are subjected to tissue tension, and the force point 31 is subjected to force to deform the strain gauge 60. The circuit main board 70 obtains the pressure data of the left and right sides according to the deformation of the strain gauge 60 (the specific acquisition method is a prior art and will not be described in detail here), so as to evaluate the difference in the tension between the left and right sides.

[0042] The upper shell 20 of the present invention that cooperates with the arc-shaped prosthesis adopts a hard rubber + soft rubber method. The two upper half shells 21 on the left and right sides use hard rubber to transmit force, and the middle connecting part 22 uses soft rubber, so that the two upper half shells 21 do not affect each other when transmitting force, effectively reducing the mutual influence between the left and right sides and improving the accuracy of tension measurement on the left and right sides.

[0043] like Figure 5 As shown, in the present invention, the upper end of the base 40 has a positioning step 41 for positioning the lower shell 30. When the shell is installed on the base 40, the positioning step 41 positions the four sides of the bottom of the lower shell 30. The positioning step 41 only limits the circumferential and lateral movement of the lower shell 30, and does not limit the vertical movement of the lower shell 30, thereby ensuring the force at the force point 31.

[0044] In the present invention, the four sides of the lower end of the upper shell 20 are welded and fixed to the four sides of the upper end of the lower shell 30, for example, by ultrasonic welding; preferably, the four sides of the lower end of the upper shell 20 are clamped with the four sides of the upper end of the lower shell 30 by a groove-type structure, and the specific clamping method is an existing structure, so as to achieve rapid positioning of the connection between the two, more reliable welding, and effective sealing.

[0045] like Figure 3 and Figure 4 As shown, in one embodiment, a group of force points includes at least three force points 31. For example, three force points 31 are set, and the three force points 31 are respectively located on the front side, the rear side and the outside away from the middle connecting part 22. Preferably, the three force points 31 on the left and right sides are set on opposite sides.

[0046] like Figure 3 and Figure 4 As shown, in another embodiment, a cantilever beam 32 is provided on the lower surface of the lower shell 30, and a force point 31 is a downwardly protruding hemispherical force-bearing protrusion fixedly connected to the lower end of the cantilever beam 32, and a strain gauge 60 is fixedly connected (for example, pasted) to the inner surface 321 of the cantilever beam 32. Preferably, the cantilever beam 32 is integrally arranged with the lower shell 30, and specifically, a U-shaped opening groove 33 can be provided on the outer periphery of the bottom of the lower shell 30 corresponding to the force point 31 to form the cantilever beam 32, which is an integrated cantilever beam 32, reducing the number of parts.

[0047] Further preferably, a flexible U-shaped seal 34 for closing the cantilever beam 32 and the lower shell 30 is provided in the U-shaped opening groove 33 . The U-shaped seal 34 is made of soft silicone to achieve sealing and reduce the influence of the lower shell 30 on the force measurement of the force point 31 .

[0048] In the description of this specification, the description with reference to the terms "preferred embodiment", "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0049] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A device for evaluating the balance of total knee joint tissue, comprising a housing, a base connected to the bottom of the housing, and a thickness adjustment gasket connected to the bottom of the base, wherein the housing is provided with a strain gauge, a circuit board and a battery, characterized in that ； The shell comprises an upper shell for cooperating with the prosthesis and a lower shell fixedly connected to the upper shell, wherein the upper shell comprises two upper half shells, a left upper half shell and a right upper half shell made of a medical hard material, and a middle connecting part, which is made of a medical soft material and connects the two upper half shells; Two groups of force points corresponding to the two upper half shells are arranged on the left and right sides of the lower surface of the lower shell, and one strain gauge is arranged at each force point in a one-to-one correspondence.

2. A device for evaluating total knee joint tissue balance according to claim 1, characterized in that: A group of stress points includes at least three stress points.

3. The device for evaluating total knee joint tissue balance according to claim 1, characterized in that: A cantilever beam is disposed on the lower surface of the lower shell, the force bearing point is a hemispherical force bearing protrusion protruding downward and fixedly connected to the lower end of the cantilever beam, and the strain gauge is fixedly connected to the inner surface of the cantilever beam.

4. A device for evaluating total knee joint tissue balance according to claim 3, characterized in that: The cantilever beam is integrally arranged with the lower shell, and the lower shell is provided with a U-shaped opening groove on the outer periphery of the corresponding force bearing point to form the cantilever beam.

5. The device for evaluating total knee joint tissue balance according to claim 4, characterized in that: A flexible U-shaped sealing member for sealing between the cantilever beam and the lower shell is arranged in the U-shaped opening groove, and the U-shaped sealing member is made of soft silicone.

6. A device for evaluating total knee joint tissue balance according to any one of claims 1-5, characterized in that: The middle connecting portion is a positioning protrusion protruding upward.

7. A device for evaluating total knee joint tissue balance according to any one of claims 1-5, characterized in that: The base is made of stainless steel; And / or the thickness adjusting gasket is a metal gasket made of stainless steel.

8. A device for evaluating total knee joint tissue balance according to any one of claims 1-5, characterized in that: The four sides of the lower end of the upper shell are welded and fixed to the four sides of the upper end of the lower shell.

9. The device for evaluating total knee joint tissue balance according to claim 8, characterized in that: The periphery of the lower end of the upper shell body is clamped with the periphery of the upper end of the lower shell body through a groove-type structure.

10. A device for evaluating total knee joint tissue balance according to any one of claims 1-5, characterized in that: The upper end of the base has a positioning step for positioning the lower shell; And / or the base is provided with an oblique nail hole, and the oblique nail passes through the oblique nail hole to fix the base on the tibia.

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