A knee joint mechanical axis measurement system

Abstract

An embodiment of the present invention provides a knee joint mechanical axis measurement system, comprising: a femur positioning and adjusting device, which is installed on the femur during the operation; a tibia positioning and adjusting device, which is installed on the tibia during the operation; a navigator, including a fiducial device and a measuring device, which is installed on the femur positioning and adjusting device or the tibia positioning and adjusting device, and is used to cooperate with the navigation of the movement of the femur positioning and adjusting device to calculate and determine the femur mechanical axis according to the navigation data, and cooperate with the navigation of the movement of the tibia positioning and adjusting device to calculate and determine the tibia mechanical axis according to the navigation data; a data processing device, which is connected to the navigator and is used to obtain the femur mechanical axis and the tibia mechanical axis, and determine the knee joint mechanical axis at least based on the femur mechanical axis and the tibia mechanical axis. The measurement system of the present invention can improve the measurement accuracy and efficiency of the knee joint mechanical axis.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of orthopedic medical devices, and particularly to a knee joint force line measurement system. Background Art

[0002] In knee joint replacement surgery, restoring the normal force line of the knee joint is crucial to ensure the success of the surgery. The force line of the knee joint generally refers to a straight line from the center of the hip joint to the center of the ankle joint, and this line should pass through the center of the knee joint. If the force line deviates from the normal position, it may lead to excessive wear of the joint, uneven load distribution during knee joint movement, causing pain in the patient's knee joint and resulting in joint dysfunction, thus leading to the failure of the surgery.

[0003] Traditional knee joint replacement surgery usually relies on the vision and experience of surgeons to judge the osteotomy position and the prosthesis placement position, so the overall error is relatively large. Due to individual anatomical structure differences and potential errors during the surgical process, it is difficult for surgeons to ensure that the normal force line of the knee joint is accurately restored in each surgery. And this uncertainty will greatly lead to unsatisfactory alignment effects between the femur and the tibia, or with the prosthesis, etc. in the postoperative knee joint, and will long-term affect the surgical outcome. Summary of the Invention

[0004] Embodiments of the present invention provide a knee joint force line measurement system, including:

[0005] A femur positioning and adjusting device, which is installed on the femur during the surgery;

[0006] A tibia positioning and adjusting device, which is installed on the tibia during the surgery;

[0007] A navigator, including a fiducial marker and a measuring device, which is installed on the femur positioning and adjusting device or the tibia positioning and adjusting device, and is used to cooperate with the navigation of the movement of the femur positioning and adjusting device to calculate and determine the femur force line according to the navigation data, and to cooperate with the navigation of the movement of the tibia positioning and adjusting device to calculate and determine the tibia force line according to the navigation data;

[0008] A data processing device, which is connected to the navigator, and is used to obtain the femur force line and the tibia force line, and determine the knee joint force line at least based on the femur force line and the tibia force line.

[0009] In one embodiment, the femur positioning and adjusting device includes:

[0010] A tray module, including two tray components, which are respectively used to install the fiducial marker and the measuring device;

[0011] A fixing module, which is detachably connected to one tray component;

[0012] An adjustment module is installed on the fixed module and is connected to another tray assembly of the tray module, and is used to adjust the horizontal position and vertical position of the tray assembly relative to the fixed module, so that the fiducial and the measuring device can cooperate to determine the femoral alignment.

[0013] In one embodiment, the fixed module includes a bracket, and the bracket has a first part and a second part in the longitudinal direction of the femur;

[0014] The first part of the bracket is a plate body that can be connected to the femur. A beam is vertically penetrated through the first part. One end of the beam is provided with a connection assembly, and one of the tray assemblies is detachably connected to the connection assembly. The beam is perpendicular to the tray assembly, and the other end of the beam is used to point to the center of the knee joint;

[0015] The cross-section of the second part of the bracket is concave-shaped, having a bottom plate and two ear plates. The bottom plate is provided with an adjustment window. The adjustment module includes a positioning rod and an adjustment component. The adjustment component is arranged between the two ear plates and can move relative to the two ear plates. The positioning rod is penetrated through the adjustment window and the adjustment component, and one end is detachably connected to the other tray assembly.

[0016] In one embodiment, the positioning rod is L-shaped, including a horizontal rod body and a vertical rod body. The horizontal rod body penetrates through the adjustment window and the adjustment component. The vertical rod body is detachably connected to the other tray assembly. A positioning seat for connecting an osteotomy guide plate is also penetrated through the horizontal rod body;

[0017] The adjustment component includes a rotary fixed column and a rotary column sleeved on the rotary fixed column. The rotary column is provided with a through hole for the horizontal rod body to penetrate through. A positioning column is provided on the horizontal rod body, and a positioning through hole is provided on the rotary column. The positioning column is correspondingly connected to the positioning through hole, so that the rotary column is correspondingly connected to the positioning rod and can rotate relatively;

[0018] A first adjustment knob is also screwed on the rotary column. The first adjustment knob is perpendicular to the positioning rod and can abut against each other to lock the positioning rod and fix the relative position between the positioning rod and the rotary column;

[0019] A second adjustment knob is screwed on the ear plate. The second adjustment knob penetrates through the ear plate to lock and fix the rotary column, prohibiting the rotary column and the positioning plate from rotating around the rotary fixed column together, or moving away from the rotary column, so that the rotary column and the positioning plate can rotate around the rotary fixed column together.

[0020] In one embodiment, the tibia positioning and adjusting device includes:

[0021] Combined rod assembly, including multiple different combined rods, the fiducial and the measurer are detachably installed on different combined rods in the combined rod assembly;

[0022] Measuring module, installed at both ends of the combined rod assembly, for assisting in measuring the tibial alignment;

[0023] Among them, multiple different combined rods are respectively controlled by different rotation switches to drive the navigator and the measuring module to rotate alone or together with multiple combined rods in different dimensions to complete the measurement of the tibial alignment.

[0024] In an embodiment, the combined rod assembly includes a first combined rod and a second combined rod. The first ends of the first combined rod and the second combined rod in the same direction are flush and rotatably connected. A strip-shaped slot is provided along the length direction of the first combined rod, and the strip-shaped slot penetrates the first combined rod radially. A connecting hook is provided between the first combined rod and the second combined rod. The connecting hook is L-shaped, including a long rod and a short rod. The long rod extends into the first combined rod corresponding to the position of the strip-shaped slot and can move along the length direction of the first combined rod. The short rod is located outside the first combined rod and extends into the second combined rod and is connected to the second combined rod;

[0025] The tibial positioning and adjusting device includes a first rotation switch. One end of the first rotation switch is rotatably connected to a fixed rod. The fixed rod vertically penetrates through the strip-shaped slot and the long rod and can move relative to them. A locking member is also penetrated through the fixed rod. When the first rotation switch rotates, it can push the locking member to move along the fixed rod. When the locking member moves to abut against the long rod, the long rod is locked. When the locking member moves away from the long rod, the first combined rod and the second combined rod can rotate relative to each other and drive the fixed rod and the long rod to move along the strip-shaped slot.

[0026] In an embodiment, the first combined rod is longer than the second combined rod. An extension rod is sleeved outside the part of the first combined rod that is longer than the second combined rod. The extension rod is movably connected to the first combined rod for extending the first combined rod;

[0027] The combined rod assembly further includes a third combined rod. The first combined rod and the third combined rod are respectively located on both sides of the second combined rod. The first combined rod, the second combined rod and the third combined rod are in contact with each other and parallel to each other. The third combined rod is rotatably connected to the second combined rod to be able to swing relative to the second combined rod;

[0028] Two tray assemblies are symmetrically provided on the third combined rod for installing the measurer, and one tray assembly is provided on the first combined rod for installing the fiducial;

[0029] The measurement module includes a first measurement module and a second measurement module. The first measurement module is disposed at one end of the first joint rod and the third joint rod away from the second measurement module, and the second measurement module is disposed at one end of the extension rod away from the second joint rod.

[0030] In one embodiment, the second joint rod is provided with a limiting groove, and the third joint rod is provided with an arc-shaped guide member corresponding to the limiting groove. The arc-shaped guide member is located in the limiting groove, and the limiting groove can move along the arc-shaped guide member as the second joint rod swings.

[0031] The tibia positioning and adjusting device further includes a second rotation switch. One end of the second rotation switch extends into the second joint rod and is rotatably connected to the second joint rod. An elastic locking member is connected to the end of the second rotation switch located in the second joint rod. The elastic locking member can extend into the limiting groove and abut against the arc-shaped guide member, thereby locking the third joint rod.

[0032] In one embodiment, both the fiducial and the measurer include an inertial measurement module for outputting attitude data and a Bluetooth module for assisting in calculating the femoral mechanical axis and the tibial mechanical axis according to the attitude data.

[0033] When the navigator determines the femoral mechanical axis, the Bluetooth module of the fiducial determines the spatial position of the fiducial based on the data collected by the inertial measurement module, and determines the distance between two position points based on the position of the center of the femoral head to be measured. The Taylor series expansion algorithm and the Kalman filtering algorithm are used to calculate and process the formula of the distance to obtain the coordinate of the center position of the femoral head in the coordinate system of the fiducial.

[0034] When the femoral positioning and adjusting system rotates with the coordinate of the center position of the femoral head as the center point, the measurer collects corresponding attitude data based on the inertial measurement module, and calculates the collected attitude data and the coordinate of the center position of the femoral head based on its own Bluetooth module, thereby determining the femoral mechanical axis.

[0035] Wherein, the spatial position of the fiducial matches the spatial position of the intercondylar fossa point of the femur, and the distance is different for different patients.

[0036] In one embodiment, when determining the tibial mechanical axis, the navigator installs the fiducial device in the tray assembly on the first link of the tibial positioning and adjusting device, and correspondingly installs the measuring device in a tray assembly on the third link of the tibial positioning and adjusting device according to whether the affected limb is the left leg or the right leg. When the tibial positioning and adjusting device is fixed to the tibia, the navigator drives the probe of the first measurement module in the tibial positioning and adjusting device to point to the center of the knee joint, simultaneously adjusts the length of the first link, and drives the first link and the second link to move in different dimensions to adjust the relative positions between the fiducial device and the measuring device. The fiducial device obtains the attitude data of the tibia collected during the movement of the links between it and the measuring device, and calculates the tibial mechanical axis based on the attitude data and the position coordinates of the center of the knee joint.

[0037] Based on the disclosure of the above embodiments, it can be known that the beneficial effects of the embodiments of the present invention include that the designed knee joint mechanical axis measurement system can assist medical staff in accurately measuring the knee joint mechanical axis of patients in real time during the operation, process the collected data in real time, and timely feedback the mechanical axis measurement results to the medical staff during the operation to ensure the accurate alignment of the femur and the tibia during the operation, reduce human errors, improve the operation efficiency and success rate, ensure the functional recovery and the correctness of the mechanical axis of the patient's knee joint after the operation, and reduce postoperative complications.

[0038] Other features and advantages of the present application will be described in the subsequent description, and some of them will be obvious from the description or understood by implementing the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures specifically pointed out in the written description, claims, and drawings.

[0039] The technical solutions of the present application will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0040] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic structural diagram of the knee joint mechanical axis measurement system in the embodiments of the present invention.

[0042] Figure 2 It is a schematic structural diagram of the femur positioning and adjusting device in the embodiments of the present invention.

[0043] Figure 3This is a partial structural schematic diagram of the femoral positioning and adjusting device in the embodiment of the present invention.

[0044] Figure 4 This is a schematic diagram of the femoral cross-section determined by the fiducial and the measuring device respectively in the embodiment of the present invention.

[0045] Figure 5 This is a structural schematic diagram of the tibial positioning and adjusting device in the embodiment of the present invention.

[0046] Figure 6 This is a partial structural schematic diagram of the tibial positioning and adjusting device in the embodiment of the present invention.

[0047] Figure 7 This is a structural schematic diagram of the osteotomy guide plate in the embodiment of the present invention.

[0048] Figure 8 This is a schematic diagram of the navigator housing in the embodiment of the present invention.

[0049] Reference numerals:

[0050] 1 - Tray assembly; 2 - Bracket; 3 - First part; 4 - Second part; 5 - Beam; 6 - Connection assembly; 7 - Adjustment window; 8 - Positioning rod; 9 - Rotating fixing column; 10 - Rotating column; 11 - Positioning column; 12 - First adjustment knob; 13 - Second adjustment knob; 14 - Positioning seat; 15 - First joint rod; 16 - Second joint rod; 17 - Connection hook; 18 - Strip-shaped slot hole; 19 - First rotation switch; 20 - Fixed rod; 21 - Locking member; 22 - First measurement module; 23 - Third joint rod; 24 - Second measurement module; 25 - Limit slot; 26 - Arc-shaped guide; 27 - Second rotation switch; 28 - Elastic locking member; 29 - Extension rod; 30 - Osteotomy guide plate; 31 - Probe; 32 - Probing rod; 33 - Probing hammer. Detailed implementation manners

[0051] Next, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings, but it is not a limitation of the present invention.

[0052] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the following description should not be regarded as a limitation, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present disclosure.

[0053] The accompanying drawings included in the specification and constituting a part of the specification illustrate the embodiments of the present disclosure, and together with the general description of the present disclosure given above and the detailed description of the embodiments given below are used to explain the principles of the present disclosure.

[0054] These and other features of the present invention will become apparent from the following description of the preferred forms of the embodiments given as non - limiting examples with reference to the accompanying drawings.

[0055] It should also be understood that although the present invention has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present invention, which have the features as described in the claims and thus are all within the scope of protection defined hereby.

[0056] The above and other aspects, features and advantages of the present disclosure will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0057] Specific embodiments of the present disclosure will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well - known and / or repetitive functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis for the claims and a representative basis for teaching those skilled in the art to use the present disclosure in substantially any suitable detailed structure in various ways.

[0058] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", each of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0059] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0060] As Figure 1 shown, an embodiment of the present invention provides a knee joint alignment measurement system, including:

[0061] A femoral positioning and adjusting device, which is installed on the femur during the operation and can move relative to the femur;

[0062] A tibial positioning and adjusting device, which is installed on the tibia during the operation and can move relative to the tibia;

[0063] A navigator, including a fiducial and a measuring device, which is installed on the femoral positioning and adjusting device or the tibial positioning and adjusting device, and is used to cooperate with the navigation of the movement of the femoral positioning and adjusting device to calculate and determine the femoral alignment according to the navigation data, and cooperate with the navigation of the movement of the tibial positioning and adjusting device to calculate and determine the tibial alignment according to the navigation data;

[0064] A data processing device, which is connected to the navigator, and is used to obtain the femoral alignment and the tibial alignment, and determine the knee joint alignment at least based on the femoral alignment and the tibial alignment.

[0065] The data processing device in this embodiment may, but is not limited to, be a computer. After the navigator obtains the femoral attitude data and tibial attitude data with the assistance of the femoral positioning and adjusting device and the tibial positioning and adjusting device, and calculates the femoral mechanical axis and tibial mechanical axis respectively, it can upload them to the data processing device. The data processing device can calculate and determine the knee joint mechanical axis based on the femoral mechanical axis and tibial mechanical axis, and can further combine the angular algorithm based on the knee joint mechanical axis and the attitude data collected by the navigator to calculate the varus / valgus angle and anteroposterior tilt angle of the femur and tibia, and calculate and determine parameters such as the osteotomy angle and osteotomy amount accordingly. After obtaining these parameters, medical staff can perform osteotomy surgery based on the parameters.

[0066] Based on the above content, it can be seen that the knee joint mechanical axis measurement system designed in this embodiment can assist medical staff in accurately measuring the knee joint mechanical axis of patients in real time during the operation, process the collected data in real time, and timely feedback the mechanical axis measurement results to medical staff during the operation, ensuring the accurate alignment of the femur and tibia during the operation, reducing human errors, improving the determination efficiency and accuracy of osteotomy parameters, thereby improving the operation efficiency and success rate, effectively ensuring the functional recovery of the patient's knee joint and the correctness of the mechanical axis after the operation, and reducing postoperative complications.

[0067] As Figure 2 、 Figure 3 shown, the femoral positioning and adjusting device in this embodiment includes:

[0068] A tray module, including two tray components 1, which are respectively used to install a fiducial marker and a measuring device;

[0069] A fixing module, detachably connected to one tray component 1;

[0070] An adjusting module, installed on the fixing module and connected to the other tray component 1 of the tray module, is used to adjust the horizontal position and vertical position of the tray component 1 relative to the fixing module, so that the fiducial marker and the measuring device can cooperate to determine the femoral mechanical axis.

[0071] Specifically, the fixing module includes a bracket 2, and the bracket 2 has a first part 3 and a second part 4 in the length direction of the femur. The first part 3 of the bracket 2 is a plate body that can be connected to the femur. A beam 5 is vertically penetrated through the first part 3 of the bracket 2. One end of the beam 5 is provided with a connecting component 6, and one tray component 1 is detachably connected to the connecting component 6. The specific connection method is not fixed. For example, it can be connected using connecting nails or can be connected by means of a buckle. The specific method is not unique. The beam 5 is perpendicular to the connected tray component 1, and the other end of the beam 5 has a tip, such as connected with a nail, for pointing to the center position of the knee joint.

[0072] The second part 4 of the bracket 2 is located above the first part 3, and its cross-section is concave-shaped, having a bottom plate and two ear plates. The bottom plate is provided with an adjustment window 7. The adjustment module includes a positioning rod 7 and an adjustment component. The adjustment component is arranged between the two ear plates and can move relative to the two ear plates, that is, the adjustment component is movably connected to the two ear plates. The positioning rod 7 passes through the adjustment window 7 and the adjustment component, and one end is detachably connected to the other tray component 1.

[0073] Further, the positioning rod 7 is L-shaped, including a horizontal rod body and a vertical rod body. The horizontal rod body penetrates through the adjustment window 7 and the adjustment component. The vertical rod body is detachably connected to the other tray component 1. A positioning seat 14 for connecting the osteotomy guide plate 30 is also arranged on the horizontal rod body;

[0074] The adjustment component includes a rotating fixed column 9 and a rotating column 10 sleeved on the rotating fixed column 9. The rotating column 10 is provided with a through hole for the horizontal rod body to pass through. A positioning column 11 is arranged on the horizontal rod body, and a positioning through hole is arranged on the rotating column 10. The positioning column 11 is correspondingly connected to the positioning through hole, so that the rotating column 10 is correspondingly connected to the positioning rod 7 and can rotate relative to it. That is, the positioning rod 7 rotates around the positioning column 11 in the through holes of the adjustment window 7 and the rotating column 10, thereby adjusting the angle of the connected tray component 1, that is, adjusting the angle of the connected fiducial or measuring instrument.

[0075] A first adjustment knob 12 is also screwed on the rotating column 10. The first adjustment knob 12 is perpendicular to the positioning rod 7. One end of it can approach the positioning rod 7 as it rotates until it abuts against the positioning rod 7 to lock the positioning rod 7 and fix the relative position between the positioning rod 7 and the rotating column 10. That is, at this time, the positioning rod 7 cannot rotate horizontally. Only by loosening the first adjustment knob 12 and releasing the lock on the positioning rod 7 can the positioning rod 7 be driven to rotate horizontally.

[0076] A second adjustment knob 13 is screwed on the ear plate. One end of the second adjustment knob 13 passes through the ear plate and approaches the rotating column 10 as it rotates until it abuts against the rotating column 10 or extends into a part of its column body to lock and fix the rotating column 10 and prohibit the rotating column 10 and the positioning plate from rotating together around the rotating fixed column 9. Only when the second adjustment knob 13 is loosened and one end of it moves away from the rotating column 10 can the rotating column 10 and the positioning plate be driven to rotate together around the rotating fixed column 9 to adjust the pitching angle of the connected tray component 1.

[0077] For the human femur, when the human thigh rotates around the center point of the femoral head, a geometric positioning model can be established according to the relevant algorithms of rotation around a fixed point in space geometry, and then an algorithm scheme for joint center navigation positioning can be constructed to achieve hip joint center navigation positioning. For example, when using the femur positioning and adjusting device to measure the femur attitude data, the fiducial device and the measuring device can be respectively installed on two tray components 1. Here, the left and right legs are not distinguished. In this embodiment, the fiducial device is set on the tray component 1 of the first part 3 of the corresponding bracket 2, and the measuring device is set on the tray component 1 of the second part 4 of the corresponding bracket 2. Point the other end of the beam 5, that is, its tip, at the femoral canal opening point, which is also the center point of the knee joint. The first part 3 of the bracket 2 fits the distal end face of the femur, and then the whole driving device rotates around the center point of the femoral head, so that the fiducial device collects the motion process data and sends it to the measuring device. The measuring device calculates the current femoral mechanical axis angle, that is, determines the femoral mechanical axis. At this time, fix the measuring device so that its position cannot be adjusted.

[0078] As Figure 4 shown, the fiducial device in this embodiment is used to determine plane A in the figure, that is, the extension of the distal femoral condyle surface on the z-axis; similarly, the measuring device is used to determine plane B in the figure, that is, osteotomy plane B. After the femoral mechanical axis is determined, the medical staff can turn on the first rotation switch 19 and the second rotation switch 27 to adjust the angle of the fiducial device relative to the measuring device, including the varus / valgus angle and the anteversion / retroversion angle, and then adjust the angle between the measuring device and the fiducial device, that is, adjust the osteotomy angle. Upload all the measured angle values and the femoral mechanical axis to the data processing device, and it calculates and determines the osteotomy angle and the osteotomy amount (such as osteotomy thickness, etc.). After determining the osteotomy angle, the position of the positioning seat 14 can be fixed on the femur, and then the osteotomy guide plate 30 (as Figure 7 shown) is installed on the positioning seat 14 to restore the osteotomy angle, and the osteotomy thickness is determined by the osteotomy thickness scale on the osteotomy guide plate 30. Then the osteotomy operation can be carried out.

[0079] As Figure 5 , Figure 6 shown, the tibia positioning and adjusting device includes:

[0080] A combined rod assembly, including a plurality of different combined rods, and the fiducial device and the measuring device are detachably installed on different combined rods in the combined rod assembly;

[0081] A measuring module, installed at both ends of the combined rod assembly, for assisting in measuring the tibial mechanical axis;

[0082] Among them, the plurality of different combined rods are respectively controlled by different rotation switches to realize driving the navigator and the measuring module to rotate alone or together with multiple combined rods in different dimensions to complete the measurement of the tibial mechanical axis.

[0083] Further, the combined rod assembly includes a first combined rod 15 and a second combined rod 16. The first ends of the first combined rod 15 and the second combined rod 16 in the same direction are flush and rotatably connected. A strip-shaped slot 18 is provided on the first combined rod 15 along its length direction, and the strip-shaped slot 18 penetrates the first combined rod 15 radially. A connecting hook 17 is provided between the first combined rod 15 and the second combined rod 16. The connecting hook 17 is L-shaped and includes a long rod and a short rod. The long rod extends into the first combined rod 15 and corresponds to the position of the strip-shaped slot 18, and can move along the length direction of the first combined rod 15. The short rod is located outside the first combined rod 15 and extends into the second combined rod 16 and is connected to the second combined rod 16.

[0084] The tibia positioning and adjusting device includes a first rotation switch 19. One end of the first rotation switch 19 is rotatably connected to a fixed rod 20. The fixed rod 20 vertically penetrates the strip-shaped slot 18 and the long rod and can move relative to them. A locking member 21 is also penetrated on the fixed rod 20. The locking member 21 is plate-shaped, and a convex portion extending into the strip-shaped slot 18 is provided in the middle area. When the first rotation switch 19 rotates, it can push the locking member 21 to move along the fixed rod 20. When the locking member 21 moves to a position where its convex portion abuts against the long rod, the long rod is locked, and at this time, the first combined rod 15 and the second combined rod 16 cannot rotate to adjust the pitch angle. When the locking member 21 moves away from the long rod, the first combined rod 15 and the second combined rod 16 can rotate relative to each other and drive the fixed rod 20 and the long rod to move along the strip-shaped slot 18. That is, the provisions of the strip-shaped slot 18, the long rod, and the fixed rod 20 are for enabling the first combined rod 15 and the second combined rod 16 to rotate relative to each other.

[0085] In this embodiment, the first combined rod 15 is longer than the second combined rod 16. However, in order to enable the length of the first combined rod 15 to match the tibia lengths of different patients, an extension rod 29 is sleeved outside the part of the first combined rod 15 that is longer than the second combined rod 16. The extension rod 29 is movably connected to the first combined rod 15 for extending the first combined rod 15. The extension rod 29 and the first combined rod 15 can be locked or unlocked through a rotation switch, or can also be movably connected through other concave-convex structures and the like. The specific method is not unique.

[0086] The combined rod assembly further includes a third combined rod 23. The first combined rod 15 and the third combined rod 23 are respectively located on both sides of the second combined rod 16. The first combined rod 15, the second combined rod 16, and the third combined rod 23 are in contact with each other and parallel to each other. The third combined rod 23 is rotatably connected to the second combined rod 16 so as to be able to swing relative to the second combined rod 16. Two tray assemblies 1 are symmetrically provided on the first combined rod 15 for installing a measuring device. For example, when the affected limb is the left leg or the right leg, the tray assemblies 1 for installing the measuring device are different. A tray assembly 1 is provided on the third combined rod 23 for installing a reference device. The measuring module includes a first measuring module 22 and a second measuring module 24. The second measuring module 24 is connected to the end of the extension rod 29 far from the second combined rod 16. The first measuring module 22 is provided at the ends of the first combined rod 15 and the third combined rod 23 far from the second measuring module 24. In this embodiment, the second measuring module 24 includes a sliding seat connected to the extension rod 29, a probe rod 32 passing through the sliding seat and capable of sliding relative to the sliding seat, and a probe hammer 33 provided at one end of the probe rod 32. When measuring the line of force, the probe hammer 33 is used to abut against the ankle bone. A scale is provided on the probe rod 32. The first measuring module 22 includes a probe 31 provided with a scale and corresponding to the scale of the probe rod 32. The probe 31 is detachably connected to the third combined rod 23 through a column. Of course, the first measuring module 22 may also include other structural components, and the specific structure is not unique.

[0087] In order to control the swing of the third joint rod 23, a limiting groove 25 is provided on the second joint rod 16. An arc-shaped guide member 26 is provided on the third joint rod 23 corresponding to the limiting groove 25. The arc-shaped guide member 26 is located within the limiting groove 25, and the limiting groove 25 can move along the arc-shaped guide member 26 as the second joint rod 16 swings. The tibia positioning and adjusting device further includes a second rotation switch 27. The second rotation switch 27 is used to lock or release the second joint rod 16 and the third joint rod 23 to allow or prohibit their swing. Specifically, one end of the second rotation switch 27 extends into the second joint rod 16 and is rotatably connected to the second joint rod 16, that is, the second rotation switch 27 can rotate relative to the second joint rod 16. An elastic locking member 28 is connected to the end of the second rotation switch 27 located within the second joint rod 16. The elastic locking member 28 can be formed, for example, by connecting a spring to a clamping member. Of course, the specific method is not limited to this and can be flexibly set. The elastic locking member 28 is located below the limiting groove 25 and can be pushed into the limiting groove 25 when the second rotation switch 27 rotates to abut against the arc-shaped guide member 26, thereby restricting the relative movement of the arc-shaped guide member 26 relative to the limiting groove 25. In this way, the second joint rod 16 and the third joint rod 23 are locked to prohibit their relative swing. When the second rotation switch 27 is rotated to drive the elastic locking member 28 to move away from the limiting groove 25, the elastic locking member 28 is separated from the arc-shaped guide member 26. At this time, the second joint rod 16 and the third joint rod 23 are in an unlocked state and can swing relative to each other. That is, both the second joint rod 16 and the third joint rod 23 can swing relative to each other.

[0088] In the tibia positioning and adjusting device in this embodiment, the fiducial is arranged on the first connecting rod 15, and two are symmetrically arranged on the third connecting rod 23. The tray assemblies 1 corresponding to the left and right legs are used to install the measuring device. The position of the fiducial is located on the center line between the two tray assemblies 1 for installing the measuring device. In this embodiment, the fiducial is fixed to the tibial tubercle position, and the position relationship between the measuring device and the tibial navigation instrument body is always fixed. One end of the probe 31 in the second measuring module 24 points to the ACL point of the tibial plateau, that is, the center point of the knee joint. The hinge joint of the first connecting rod 15 and the second connecting rod 16 is fixed to the tibial tubercle. The pad in the first measuring module 22 fits against the front side of the tibia, and the hammer 33 is attached to the front side of the ankle joint. At this time, the scale corresponding to the indicating point of the probe 31 is consistent with the scale of the sliding seat on the probe rod 32 in the first measuring module 22, that is, the distances between the two ends of the tibia positioning and adjusting device relative to the tibia match. At this time, the tibia positioning and adjusting device is fixed to the tibia. For example, the upper end of the device is fixed to the tibia by a steel needle, and the lower end is fixed to the leg by a strap connected to the pad. Then, the second rotation switch 27 is turned on to control the second connecting rod 16 to drive the first connecting rod 15, that is, to drive the hammer 33 to swing in the xz plane, so that the inner and outer ends of the hammer 33 touch the inner and outer malleoli of the tibia in sequence to collect corresponding data. At the same time, the first rotation switch 19 is turned on to control the first connecting rod 15 to rotate in the zy plane and collect data. Then, based on the collected data, the tibial force line and osteotomy parameters are calculated. In the above process, the position of the measuring device is fixed, only the fiducial moves, and the relative position relationship between it and the measuring device is adjusted to determine the tibial force line and osteotomy angle.

[0089] Specifically, in this embodiment, both the fiducial and the measuring device include an inertial measurement module for outputting attitude data, and a Bluetooth module for assisting in calculating the femoral force line and tibial force line according to the attitude data. For example, the fiducial and the measuring device are mainly composed of an IMU sensor and a Bluetooth module. The IMU sensor includes a gyroscope, an accelerometer, a magnetometer, etc., which are responsible for data measurement and processing, including being able to output stable attitude data after Kalman filtering and integral filtering, and then collecting, calculating, and position integrating at a certain period, and finally obtaining the center coordinates of the femoral head; the Bluetooth module has an MCU, so it not only has Bluetooth transmission ability but also has data processing ability. For example, after the MCU receives the attitude data and the center coordinates of the femoral head, it calculates the femoral force line. Similarly, the navigator can also calculate the tibial force line. When preparing the navigator, as Figure 8 shown, the navigator housing 31 can be, but is not limited to, injection molded / 3D printed from medical nylon (or other plastic materials). Its surface is provided with a coordinate system to indicate the installation direction. Inside, there are a chip slot, a fixed circuit board, etc. The external housings can be hermetically connected by processes such as ultrasonic welding.

[0090] When the navigator determines the femoral mechanical axis, the Bluetooth module of the fiducial device determines the spatial position of the fiducial device based on the data collected by the inertial measurement module, determines the distance between two position points based on the position of the center of the femoral head to be measured, and uses the Taylor series expansion algorithm and the Kalman filter algorithm to calculate and process the formula of the distance, so as to obtain the coordinate of the center position of the femoral head in the coordinate system of the fiducial device; when the femoral positioning and adjustment system rotates with the coordinate of the center position of the femoral head as the center point, the measuring device collects corresponding attitude data based on the inertial measurement module, and calculates the collected attitude data and the coordinate of the center position of the femoral head based on its own Bluetooth module, and then determines the femoral mechanical axis; wherein, the spatial position of the fiducial device matches the spatial position of the intercondylar fossa point of the femur, and for different patients, the distance is different.

[0091] For example, medical staff can operate the femoral positioning and adjustment device to make the fiducial device rotate around the center point of the femoral head and collect corresponding data, and perform data iteration according to the algorithm flow. After the filtered data converges to the preset accuracy, the coordinate of the center of the femoral head is obtained, and the femoral mechanical axis vector can be determined accordingly. The specific algorithm is briefly described as follows: Assume that the coordinate of the center of the femoral head in the reference coordinate system (the coordinate system where the fiducial device is located) is , and the current position coordinate of the fiducial device calculated by the MEMS inertial navigation is , then the calculated distance between the two points is:

[0092]

[0093] Wherein, is the sampling point number of the fiducial device; is the distance from the intercondylar fossa point (the equivalent placement point of the fiducial device) to the center point of the knee joint. When the fiducial device is fixedly connected to the human body, this distance should be a fixed value, and for different humans, this distance is usually different.

[0094] When solving the above non-linear equation, perform Taylor series expansion on the above formula, and after ignoring the high-order terms, there is:

[0095]

[0096] Since the coordinate of the center of the femoral head is the quantity to be estimated and is a fixed value, therefore, the state model of the Kalman filter is selected as follows:

[0097]

[0098] Wherein, is the state vector, is the step discrete form of the state transition matrix.

[0099] Based on the above state model, the Kalman filter observation model can be calculated as follows:

[0100]

[0101] Wherein, is the observation vector at the th step, is the observation matrix at the th step, is the estimated value of the femoral head center position at the previous step.

[0102] According to the established Kalman filter state model and observation model, the coordinates of the femoral head center can be calculated by filtering using the Kalman filter algorithm, that is:

[0103] .

[0104] After obtaining the coordinates of the femoral head center, the femoral force line vector can be determined accordingly. The force line vector measured by the fiducial device needs to be transferred to the measuring device for osteotomy angle calculation. After the measuring device receives this vector, it calculates the angle relative to the force line vector according to the data collected by itself and the physical dimension data involved in the device, and the projection angles of this angle relative to the xz plane and the yz plane are the varus / valgus angle and the anteroposterior tilt angle in medicine. After knowing this angle, the osteotomy parameters can be further calculated by the data processing device.

[0105] When the navigator determines the tibial force line, the fiducial device is installed in the tray assembly 1 on the third connecting rod 23 of the tibial positioning and adjusting device, and the measuring device is correspondingly installed in a tray assembly 1 on the first connecting rod 15 of the tibial positioning and adjusting device according to whether the affected limb is the left leg or the right leg. When the tibial positioning and adjusting device is fixed to the tibia, the probe 31 of the first measuring module 22 in the tibial positioning and adjusting device is driven to point to the center of the knee joint, and at the same time, the length of the first connecting rod 15 is adjusted, and the first connecting rod 15 and the second connecting rod 16 are driven to move in different dimensions (since the two connecting rods are connected to each other, they move synchronously) to adjust the relative positions between the fiducial device and the measuring device. The fiducial device obtains the attitude data of the tibia collected during the movement of the connecting rods between it and the measuring device, and calculates the tibial force line based on the attitude data and the position coordinates of the center of the knee joint.

[0106] For example, first, the position of the center point of the knee joint is determined based on the probe 31 in the tibial positioning and adjusting device, and then the position of the sounding hammer 33 is adjusted to measure the left and right ankle positions of the tibia, the position of the sounding hammer 33, and the position of the fiducial device. After that, the tibial force line vector can be obtained by combining the following algorithm:

[0107] The reference module measures and normalizes the unit vectors at the left and right ankles respectively and Since the two vectors are in the reference module coordinate system and need to be transposed to the ACL point coordinate system, which is determined by the measurement module, let the transformation matrix from the reference module coordinate system to the ACL point coordinate system be Then the transformed vectors are:

[0108]

[0109] Then the angular bisector of the two vectors is the force line vector .

[0110]

[0111] The force line vector After being transformed back to the reference module coordinate system, we have:

[0112]

[0113] At this time, by driving the first joint rod 15 to adjust the left - right and up - down swing angles of the aligner, such that and , the correction of the force line is completed, and the plane perpendicular to the longitudinal axis of the measurement module at this time is the surgical cutting plane.

[0114] When measuring, the length of the first joint rod 15 needs to be matched with the tibia, and the scale indicated on the probe 31 should be as consistent as possible with that indicated on the probe rod 32, so that the probe 31, the probe rod 32, the first joint rod 15, and the tibia / force line approximately enclose a rectangle, and the corresponding sides are as parallel as possible. This can effectively reduce the measurement error. Moreover, it can be concluded therefrom that if we want to improve the measurement accuracy, when designing the required instruments, the length of the first joint rod 15 should be as long as possible.

[0115] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.

Claims

1. A knee joint force line measurement system, characterized in that: include: A femoral positioning and adjustment device is installed on the femur during surgery; The tibia positioning and adjustment device is installed on the tibia during surgery; A navigator, including a reference device and a measuring device, is installed on the femoral positioning and adjustment device or the tibial positioning and adjustment device, and is used to cooperate with navigation of the movement of the femoral positioning and adjustment device to calculate and determine the femoral force line according to the navigation data, and cooperate with navigation of the movement of the tibial positioning and adjustment device to calculate and determine the tibial force line according to the navigation data; A data processing device connected to the navigator, used to obtain the femoral force line and the tibial force line, and determine the knee joint force line at least based on the femoral force line and the tibial force line; The femoral positioning and adjusting device comprises: A tray module, comprising two tray assemblies, for mounting a reference device and a measuring device respectively; A fixed module is detachably connected to a tray assembly; An adjusting module, mounted on the fixed module and connected to another tray assembly of the tray module, for adjusting the horizontal position and vertical position of the tray assembly relative to the fixed module, so that the reference device and the measuring device can cooperate to determine the femoral force line; The tibia positioning and adjusting device comprises: A joint rod assembly comprises a plurality of different joint rods, wherein the reference device and the measuring device are detachably mounted on different joint rods in the joint rod assembly; A measuring module, mounted at both ends of the joint rod assembly, for assisting in measuring the tibial force line; Wherein, a plurality of different joint rods are respectively controlled by different rotation switches to realize the rotation of the navigator and the measurement module in different dimensions alone or together with a plurality of joint rods to complete the measurement of the tibial force line; The reference device and the measuring device both include an inertial measurement module for outputting posture data and a Bluetooth module for assisting in calculating the femoral force line and the tibial force line according to the posture data.

2. The knee joint force line measurement system according to claim 1, characterized in that: The fixing module comprises a bracket, and the bracket has a first part and a second part in the length direction of the femur; The first part of the support is a plate body, which can be connected to the femur. A beam is vertically provided on the first part. A connecting component is provided at one end of the beam. The tray component is detachably connected to the connecting component. The beam is perpendicular to the tray component, and the other end of the beam is used to point to the center of the knee joint. The cross-section of the second part of the bracket is concave-shaped, and has a bottom plate and two ear plates. The bottom plate is provided with an adjustment window. The adjustment module includes a positioning rod and an adjustment component. The adjustment component is arranged between the two ear plates and can move relative to the two ear plates. The positioning rod is passed through the adjustment window and the adjustment component, and one end is detachably connected to the other tray component.

3. The knee joint force line measurement system according to claim 2, characterized in that: The positioning rod is L-shaped and includes a horizontal rod body and a vertical rod body. The horizontal rod body passes through the adjustment window and the adjustment assembly. The vertical rod body is detachably connected to another tray assembly. A positioning seat for connecting the osteotomy guide plate is also provided on the horizontal rod body. The adjustment assembly includes a rotating fixed column, a rotating column sleeved on the rotating fixed column, the rotating column is provided with a through hole for the horizontal rod body to pass through, the horizontal rod body is provided with a positioning column, the rotating column is provided with a positioning through hole, the positioning column is correspondingly connected with the positioning through hole, so that the rotating column and the positioning rod are correspondingly connected and can rotate relatively; The rotating column is also threaded with a first adjusting knob, which is perpendicular to the positioning rod and can abut against each other to lock the positioning rod and fix the relative position between the positioning rod and the rotating column; A second adjusting knob is screwed on the ear plate, and the second adjusting knob passes through the ear plate to lock and fix the rotating column, prohibiting the rotating column and the positioning plate from rotating around the rotating and fixing column together, or moving away from the rotating column so that the rotating column and the positioning plate can rotate around the rotating and fixing column together.

4. The knee joint force line measurement system according to claim 1, characterized in that: The joint rod assembly comprises a first joint rod and a second joint rod, wherein the first ends of the first joint rod and the second joint rod in the same direction are flush and rotatably connected, a strip slot is provided on the first joint rod along its length direction, and the strip slot radially penetrates the first joint rod, and a connecting hook is provided between the first joint rod and the second joint rod, and the connecting hook is L-shaped, comprising a long rod and a short rod, the long rod extends into the first joint rod and corresponds to the position of the strip slot, and can move along the length direction of the first joint rod, and the short rod is located outside the first joint rod, extends into the second joint rod, and is connected to the second joint rod; The tibial positioning and adjustment device includes a first rotating switch, one end of which is rotatably connected to a fixed rod, the fixed rod is vertically penetrated in the strip slot and the long rod, and can move relative to them, and a locking piece is also penetrated on the fixed rod. When the first rotating switch is rotated, the locking piece can be pushed to move along the fixed rod, and when the locking piece moves to abut against the long rod, the long rod is locked. When the locking piece moves away from the long rod, the first combined rod and the second combined rod can rotate relative to each other and drive the fixed rod and the long rod to move along the strip slot.

5. The knee joint force line measurement system according to claim 4, characterized in that: The first joint rod is longer than the second joint rod, and an extension rod is provided on the outer sleeve of a portion of the first joint rod that is longer than the second joint rod. The extension rod is movably connected to the first joint rod to extend the first joint rod; The joint rod assembly further includes a third joint rod, wherein the first joint rod and the third joint rod are respectively located on both sides of the second joint rod, the first joint rod, the second joint rod and the third joint rod are close to each other and parallel to each other, and the third joint rod is rotatably connected to the second joint rod so as to be able to swing relative to the second joint rod; The third joint rod is symmetrically provided with two tray assemblies for mounting a measuring device, and the first joint rod is provided with a tray assembly for mounting a reference device; The measuring module comprises a first measuring module and a second measuring module. The first measuring module is connected to one end of the first joint rod and the third joint rod away from the second measuring module. The second measuring module is arranged at one end of the extension rod away from the second joint rod.

6. The knee joint force line measurement system according to claim 5, characterized in that: The second joint rod is provided with a limiting groove, and the third joint rod is provided with an arc-shaped guide piece at a position corresponding to the limiting groove, the arc-shaped guide piece is located in the limiting groove, and the limiting groove can move along the arc-shaped guide piece as the second joint rod swings; The tibial positioning and adjustment device also includes a second rotating switch, one end of which extends into the second combining rod and is rotatably connected to the second combining rod, and one end of the second rotating switch located in the second combining rod is connected to an elastic locking piece, which can extend into the limiting groove and resist the arc-shaped guide piece, thereby locking the third combining rod.

7. The knee joint force line measurement system according to claim 1, characterized in that: When the navigator determines the femoral force line, the Bluetooth module of the reference device determines the spatial position of the reference device based on the data collected by the inertial measurement module, and determines the distance between the two position points based on the center position of the femoral head to be measured, and uses the Taylor series expansion algorithm and the Kalman filter algorithm to calculate the formula of the distance to obtain the coordinates of the center position of the femoral head in the coordinate system of the reference device; When the femoral positioning and adjustment device rotates with the coordinates of the center position of the femoral head as the center point, the measuring device collects corresponding posture data based on the inertial measurement module, and calculates the collected posture data and the coordinates of the center position of the femoral head based on its own Bluetooth module, thereby determining the femoral force line; The spatial position of the reference device matches the spatial position of the intercondylar fossa of the femur, and the distance is different for different patients.

8. The knee joint force line measurement system according to claim 6, characterized in that: When determining the tibial force line, the navigator installs the reference device in a tray assembly on the first joint rod in the tibial positioning and adjustment device, and installs the measuring device in a tray assembly on the third joint rod in the tibial positioning and adjustment device according to whether the affected limb is the left leg or the right leg. When the tibial positioning and adjustment device is fixed on the tibia, the probe of the first measuring module in the tibial positioning and adjustment device is driven to point to the center of the knee joint, and the length of the first joint rod is adjusted at the same time, and the first joint rod and the second joint rod are driven to move in different dimensions to adjust the relative position between the reference device and the measuring device. The reference device obtains the posture data about the tibia collected by it and the measuring device during the movement of the joint rod, and calculates the tibial force line based on the posture data and the position coordinates of the center of the knee joint.

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