JP4284565B2 - Artificial joint mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel artificial joint mechanism. Specifically, the present invention relates to a technique that is particularly suitable for a knee joint and can perform an operation close to that of a human body and provides a suitable artificial joint mechanism for a robot, a prosthetic leg, or the like.
[0002]
[Prior art]
Conventionally, as a joint in a robot, a prosthetic leg, etc., an oilless bearing is provided on one pair, a shaft is provided on the other pair, and the two pairs are configured to be freely rotatable, or one pair has a hard smooth convex surface and the other pair. Some have a soft, smooth concave surface and are configured by a combination of both.
[0003]
[Problems to be solved by the invention]
By the way, if a robot, prosthetic leg, or the like intended for operation close to the human body is composed of a shaft and a bearing, the weight above the joint (robot body, human body, etc.) must be supported by the shaft and the bearing. Or there was a problem in the durability of the bearing. In particular, in the case of a knee joint, the impact is great at the time of ground contact in the initial stage of the stance, and it is inevitable to increase the size and weight of the shaft and the bearing in order to achieve a shaft and bearing structure that can withstand this.
[0004]
Also, in joints with a combination of a hard smooth convex surface and a soft smooth concave surface, friction on the contact surface (joint surface) is a problem, and it is difficult to supply synovial fluid to the contact surface to prevent wear of both. It was. Such wear results in the removal of the members that form the double pair. For example, when used as a prosthetic body in the human body, the wear powder also causes a problem of promoting the induction of cancer cells.
[0005]
Therefore, the present invention eliminates the above-mentioned drawbacks, enables operation close to a human joint, is resistant to impact in the direction of gravity, can improve durability, and causes problems such as wear at the even number. It is an object to provide no artificial joint mechanism.
[0006]
[Means for Solving the Problems]
  The artificial joint mechanism of the present invention has a pair of pairs and a connecting means for connecting these two pairs, and magnets are provided on the joint surface side of each pair so that both pairs repel each other,A magnet provided in one pair even so that the coupling means is configured so that the other pair is biased in the bending direction with respect to one pair as it changes from the extended state (extended position) to the bent state (bending position). The magnetic strength of the other pair is weakened as it goes in the deviating direction, and the magnetic strength of the other pair of magnets is expanded so that the part facing the one pair of magnets becomes stronger with bending. The distance between one kinematic pair and the other kinematic pair is made constant from the position to the bending position.
[0007]
Therefore, in the artificial joint mechanism of the present invention, a gap due to the repulsive force of the magnet is always generated between the pair and the shock applied to the artificial joint mechanism can be absorbed by the gap. Since the surfaces are not in contact, even if the joint is bent, both pairs will not wear, and since there are no components that receive impact like the conventional joint shaft, the artificial joint mechanism has excellent durability. Can be provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the artificial joint mechanism of the present invention will be described below with reference to the accompanying drawings.
[0009]
1 to 4 show the basic configuration of the artificial joint mechanism of the present invention.
[0010]
The artificial joint mechanism 1 includes an upper pair 2, a lower pair 3, an upper magnet 4 embedded in the joint surface of the upper pair 2, a lower magnet 5 embedded in the joint surface of the lower pair 3, and an upper pair 2 and 6 are provided.
[0011]
The upper pair 2 is formed at the lower end of the upper bone body 7, and the lower pair 3 is formed at the upper end of the lower bone body 8.
[0012]
The upper pair 2 is integrally formed at the lower end of the upper bone body 7, and the shape thereof is a columnar shape larger than the diameter of the upper bone body 7, in a direction orthogonal to the axial direction of the upper bone body 7, And it forms so that the front end of a mutual outer peripheral surface may correspond (refer FIG. 1).
[0013]
The upper surface of the lower pair 2 is substantially the same as the shape of the upper pair 2 viewed from the bottom surface, and is formed in a substantially smooth surface.
[0014]
An upper magnet 4 made of a permanent magnet is embedded in a substantially central portion of the upper pair 2 in the left-right direction. The upper magnet 4 has a semicircle when viewed from the side, and is, for example, magnetized with an N pole on the outer peripheral surface side and an S pole on the center side (see FIGS. 1 and 3). In order to set the outer peripheral surface side to N pole and the center side to S pole, it is preferable to arrange a large number of small magnets 4a, 4a,... Magnetized in the radial direction (see FIG. 4).
[0015]
A lower magnet 5 made of a permanent magnet is embedded in a substantially central portion of the lower pair 3 in the left-right direction so as to face the upper magnet 4 of the upper pair 2. The lower magnet 5 is magnetized with the N pole on the upper side and the S pole on the lower side. Therefore, in all states where the artificial joint mechanism 1 changes from the extended position to the bent position, the upper pair 2 and the lower pair 3 Are urged in a direction in which they are separated from each other by a repulsive force acting between them.
[0016]
The connecting means 6 for connecting the upper pair 2 and the lower pair 3 has one end connected to the side surface of the upper bone body 7 and the other end connected to the side surface of the lower bone body 8. And 3 are prevented from separating. It is preferable that the connecting means 6 is composed of a member that does not extend in the pulling direction, and is not extended by the repulsive force between the upper magnet 4 and the lower magnet 5.
[0017]
The artificial joint mechanism 1 is bent at a central angle of approximately 90 degrees from the extended position (see FIG. 1) (see FIG. 3). In all of the states, the upper pair 2 and the lower pair 3 are Repel each other, and a gap 9 is formed between them.
[0018]
When an impact is applied to the artificial joint mechanism 1, the impact works against the repulsive force between the upper magnet 4 and the lower magnet 5, so that the gap 9 between the upper pair 2 and the lower pair 3 is The shock will be absorbed.
[0019]
【Example】
Details of the artificial joint mechanism according to the present invention will be described below according to the first embodiment shown in FIGS.
[0020]
In the first embodiment, the present invention is applied to an artificial knee joint mechanism.
[0021]
The artificial knee joint mechanism 10 is a kind of hinge joint, and is an upper pair 11 corresponding to the lower joint head of the femur in the human body, a lower pair 12 corresponding to the upper joint glenoid of the tibia in the human body, and an upper pair. 11 between the upper magnets 13 and 13 embedded in the lower end surface (joint surface), the lower magnet 14 embedded in the upper end surface (joint surface) of the lower pair 12, and the upper pair 11 and the lower pair 12 The shock absorbing pads 15 and 15 corresponding to the meniscus in the human body and the upper pair 11 and the lower pair 12 are connected to each other on the left side and the right side to connect to the cruciate ligament in the human body. Means 16 and 16 are provided (see FIG. 5). FIG. 5 is a perspective view of the prosthetic knee joint mechanism 10 in the extended position as viewed from the rear side with the connecting means 16 and 16 omitted.
[0022]
The upper pair 11 is formed at the lower end of the upper bone 17, and the lower pair 12 is formed at the upper end of the lower bone 18.
[0023]
The upper pair 11 is made of titanium (Ti) alloy, cobalt (Co) alloy, ultra-high molecular weight polyethylene, alumina (aluminum oxide), or the like, and the shape thereof is almost the same as the joint head at the lower end of the femur in the human body. Is formed. That is, the upper pair 11 is thicker than the upper bone body 17 and is formed with two knob-like protrusions 11a and 11b that are divided into left and right in the extended position and protrude downward and rearward. A groove 11c that opens downward and rearward is formed between the protrusions 11a and 11b.
[0024]
Of the protrusions 11a and 11b, the outer protrusion (the outer (腓) condyle in the human body) 11a is formed slightly larger than the inner protrusion (the inner (shin) condyle in the human body) 11b. The joint surfaces of the portions 11a and 11b are not spherical, and the curvature radii r1 and r1 are small at the front and rear portions of the joint surface, and the curvature radius r2 is large at the center (see FIG. 6).
[0025]
The lower pair is formed of titanium (Ti) alloy, cobalt (Co) alloy, ultra-high molecular weight polyethylene, alumina (aluminum oxide) or the like, similar to the upper pair 11, and the shape of the upper joint of the tibia in the human body It is formed almost the same as the fovea. In other words, the lower pair 12 is formed such that the upper end surface thereof is substantially the same size as the upper pair 11 viewed from the bottom side, and the portion corresponding to the outer protrusion 11a (the outer (腓) side in the human body). The joint surface of the condyle (hereinafter referred to as “outer joint surface”) 12a is slightly concave, and the joint surface (the inner (shin) side condyle in the human body) corresponding to the inner protrusion 11b ( (Hereinafter referred to as “inner joint surface”) 12b is substantially flat, and a portion (hereinafter referred to as “glenoid central part”) 12c between the outer joint surface 12a and the inner joint surface 12b is the upper pair. 11 grooves 11c.
[0026]
Since the upper magnets 13 and 13 are embedded in the two protrusions 11a and 11b of the upper pair 11 respectively, and the shapes thereof are substantially the same, only one of them will be described.
[0027]
The upper magnet 13 is made up of a plurality of small magnets 20, 20,... In a base material 19 formed in a sector shape with a central angle of about 270 degrees by cutting out a slightly thick disk at a central angle of about 90 degrees. -Is embedded (see FIGS. 9 and 10). Specifically, the rod-shaped small magnets 20, 20,... Magnetized at opposite ends with different polarities are arranged on the outer peripheral surface of the base material 19 at intervals of approximately 30 degrees at the central angle and in the thickness direction. Are arranged so that the magnetic poles on the outer peripheral surface side of all the small magnets 20, 20,... In addition, the magnetic field by each small magnet 20, 20, ... will be described later.
[0028]
The small magnet 20 is attached to the base material 19 by forming a bottomed hole in the base material 19 and fitting the small magnet 20 in the bottomed hole and fixing it with an adhesive. In addition, a screw groove may be formed in the small magnet 20 and the small magnet 20 may be screwed into the bottomed hole.
[0029]
And when the artificial knee joint mechanism 10 is in the extended position, such an upper magnet 13 is arranged so that the base material 19 is positioned so that the fan-shaped notched portion is located at the front upper portion when viewed from the side. 11 protrusions 11a and 11b are embedded in substantially the center in the left-right direction.
[0030]
The base material 19 is made of the same material as the upper pair 11, and the surface of the upper pair 11 is coated with, for example, hydroxyapatite (HAp) in a state where the base material 19 is embedded in the upper pair 11. Is given.
[0031]
The lower magnet 14 is configured by a large number of small magnets 21, 21,... Embedded in the outer joint surface 12 a, the inner joint surface 12 b, and the glenoid central portion 12 c of the lower pair 12. Specifically, like the upper magnet 13, the rod-shaped small magnets 21 whose opposite ends are magnetized are respectively connected to the outer joint surface 12 a, the inner joint surface 12 b, and the glenoid central portion 12 c of the lower pair 12. The small magnets 21, 21,... Are attached so that their upper portions are, for example, N poles.
[0032]
Therefore, regardless of whether the artificial knee joint mechanism 10 is in the extended position or the bent position, the opposing magnetic poles of the upper magnets 13 and 13 and the lower magnet 14 have the same polarity. And the lower kinematic pair 12 are always repelled.
[0033]
In addition, the magnetic field by each small magnet 21, 21, ... will be described later. Further, as described in the description of the small magnets 20, 20,... In the upper magnet 13, the small magnet 21 may be attached to the lower pair 12 by screwing.
[0034]
In addition, the surface of the lower pair 12 to which the small magnets 21, 21,... Are attached is coated with, for example, hydroxyapatite (HAp) similarly to the upper pair 11.
[0035]
For example, the upper pair 11 and the lower pair 12 are made of a titanium alloy that is a main material of the upper pair 11 and a shape that is slightly smaller than the final shape, and each magnet 13, 13, or 14 is embedded therein. Thereafter, coating with hydroxyapatite is performed, and NC cutting is performed by an NC lathe to be processed into a final shape.
[0036]
And each magnetic field of the upper magnets 13 and 13 and the lower magnet 14 is as shown below, and each of the small magnets 20, 20,..., 21, 21,. Arranged or magnetized to form.
[0037]
That is, when viewed from the front, the magnetic field of the upper magnets 13 and 13 has the smallest magnetic strength at the left and right ends, and increases as it goes to the center, and is greatest at the center of each of the upper magnets 13 and 13. Between 13 and 13, the magnetic strength is slightly reduced (see FIG. 9). Further, the magnetic field when the upper magnet 13 is viewed from the side is such that the small magnet 20 located at the front end when the upper pair 11 is in the extended position has the smallest magnetic strength, and in FIG. 10, it goes counterclockwise in the circumferential direction. Accordingly, as the upper pair 11 changes from the extended position to the bent position, the small magnets 20, 20 facing the small magnets 21, 21,. The magnetic strength of... Is increased (see FIGS. 10, 11, and 12).
[0038]
On the other hand, when viewed from the front, the magnetic field of the lower magnet 14 has the largest magnetic strength at the left and right ends, and decreases as it goes to the center, and is the smallest at the center of each of the outer joint surface 12a and the inner joint surface 12b. The magnetic field strength in the glenoid central part 12c is slightly increased. Further, the magnetic field when the lower magnet 14 is viewed from the side is such that the small magnets 21, 21,... Located at the front end have the largest magnetic strength, and the magnetic strength decreases as going backward. (See FIGS. 10, 11, and 12).
[0039]
In order to change the magnetic strength in each of the magnets 13 and 14, it is only necessary to change the magnetic strength of each of the small magnets 20, 20,... In addition, when embedding the small magnets 20, 20,..., 21, 21,... With the same magnetic force in each pair 11, 12, the magnetic strength can be changed by adjusting the embedding depth. it can.
[0040]
As a result, when the upper pair 11 and the lower pair 12 are viewed from the front, in the mutual magnetic field, a portion having a large magnetic force and a portion having a small magnetic force face each other, and a repulsive force is generated if they are shifted in the left-right direction. Both pairs 11 and 12 are positioned so that their centers substantially coincide. In addition, you may make it the repulsive force by both the magnets 13 and 14 become large as it goes to the side seeing from the front. If it does in this way, the dispersion | distribution effect | action of the load concerning the impact-absorbing pad 15 and 15 mentioned later can be supplemented.
[0041]
When the upper pair 11 and the lower pair 12 are viewed from the side, the magnetic strength of the upper magnets 13 and 13 facing the lower pair 12 increases as the upper pair 11 shifts from the extended position to the bent position. However, as will be described later, as the upper pair 11 shifts from the extended position to the bent position, it is biased backward, and when the upper pair 11 is bent backward while being bent, Due to the relationship with the magnetic strength of the lower magnet 14, the repulsive force is constant in the process of bias.
[0042]
Thereby, when the artificial knee joint 10 is applied as a prosthetic leg of a human body and various ligaments remaining on the human body are used, excessive tensile force is not applied to the ligaments, and damage to the remaining ligaments ( (Elongation) can be prevented.
[0043]
When the artificial knee joint mechanism 1 bends, the upper pair 11 is biased backward as it moves from the extended position to the bent position. Such deviation is mainly due to the configuration of the connecting means 16 described below.
[0044]
The connecting means 16 corresponds to a cruciate ligament in the human body, and is composed of a front cross body 22a and a rear cross body 22b. The front cross body 22a is formed between the rear end portion in the groove 11c of the upper pair 11 and the lower pair 12. The rear cross body 22b is provided so as to connect the front end portion of the central glenoid center portion 12c, and the rear cross body 22b is arranged in the front-rear direction of the groove portion 11c of the upper pair 11 and the rear portion of the glenoid center portion 12c. It connects so that an edge part may be connected (refer FIG. 13). Note that FIG. 13 exaggerates the front cross body 22a and the rear cross body 22b by separating the upper pair 11 and the lower pair 12 vertically so that the front cross body 22a and the rear cross body 22b can be easily understood. Indicated.
[0045]
Accordingly, as shown in FIGS. 14 to 16, as the transition from the extended position to the bent position is performed, the upper pair 11 is biased backward, and the movement close to the movement of the lower joint head of the femur in the human body is performed. Can be realized.
[0046]
Further, the front cross body 22a and the rear cross body 22b are made of a member that does not extend in the pulling direction, for example, a medical thread. When the artificial knee joint mechanism 10 is used for a robot, the front cross body 22a and the rear cross body 22b may be configured by link mechanisms. In such a case, a shaft member, a bearing member, and the like are required to configure the link mechanism. However, the repulsive force by the upper magnets 13 and 13 and the lower magnet 14 is always acting between the pair 11 and 12. The shaft member and the bearing member are not overloaded.
[0047]
In addition to the cruciate ligament, the knee joint in the human body has a collateral ligament, quadriceps muscle, patella ligament, and the like, so that the operation of the artificial joint mechanism 10 is closer to the operation of the human knee joint. Preferably has the same configuration as each of the ligaments, muscles and the like.
[0048]
The shock absorbing pad 15 is substantially C-shaped when viewed from above, and the distance between both ends thereof is substantially the same as the size in the front-rear direction of the pair 11, 12, and the width in the left-right direction of the center portion. However, the distance between the portion facing the upper magnet 13 on the left or right side of the lower pair 12 and the left end or right end of the lower pair 12 is substantially the same or slightly smaller, and the cross-sectional shape of the shock absorbing pad 15 is It is formed in a wedge shape (see FIGS. 17 and 18).
[0049]
The shock absorbing pads 15 and 15 are interposed between the upper pair 11 and the lower pair 12 and are interposed between the left side and the right side thereof. Specifically, shock absorbing pads 15 and 15 are arranged on the upper surface of the lower pair 12 so as to surround the upper joint surface 12a and the lower joint surface 12b, respectively, and on the upper surfaces of the shock absorbing pads 15 and 15, It arrange | positions so that the part which approached the front side, the rear side, and the outer side slightly from the lower end part of each protrusion 11a and 11b of the upper pair 11 may contact.
[0050]
As a result, the upper pair 11 is placed on the upper surface of the lower pair 12 via the two shock absorbing pads 15, 15, and the repulsive force between the upper magnets 13, 13 and the lower magnet 14 is increased between the upper pair 11 and the lower pair 11. It acts between the kinematic pair 12.
[0051]
Therefore, when an impact is applied to the upper pair 11, the impact is absorbed by the impact absorbing pads 15, 15 and the repulsive force between the upper magnets 13, 13 and the lower magnet 14.
[0052]
The shock absorbing pad 15 corresponds to a meniscus in a human body, and a fluid 24 such as sodium hyaluronate or physiological saline and a gel substance 25 such as silicon are enclosed in an outer shell 23 made of an elastic member such as silicon. (See FIG. 17). Although it is preferable to enclose the fluid 24 and the gel substance 25 in the outer shell 23, only one of them may be encapsulated.
[0053]
In particular, when the artificial joint mechanism of the present invention is applied to a human body by applying it to a prosthetic leg, it is preferable to enclose the gel substance 25 together with a fluid 24 in an outer shell 23, but the artificial joint mechanism of the present invention is used in a robot. When applying to the knee joint, it is sufficient to enclose only the fluid 24 in the outer shell 23. In addition, when applied to a robot, fluid silicon that is considered to be harmful to the human body may be used as the fluid 24.
[0054]
Thus, a large impact is applied to the artificial knee joint 10 in the extended position, particularly when standing at the start of walking, and both the magnets 13 and 14 are embedded in the upper pair 11 and the lower pair 12 respectively. And the impact absorbing pads 15 and 15 absorb the repulsive force.
[0055]
Further, in the displacement from the extended position to the bent position, the upper pair 11 is biased backward by the front cross body 22a and the rear cross body 22b, and the same movement as the knee joint in the human body is realized.
[0056]
Further, even if the upper pair 11 is rotated and biased backward during the displacement from the extended position to the bent position, the repulsive force between the upper magnets 13 and 13 and the lower magnet 14 is substantially constant, so that the stable upper The movement of the even number 11 can be realized.
[0057]
In addition, by covering the artificial knee joint mechanism 10 with artificial skin and filling the synovial fluid between the upper pair 11 and the lower pair 12, the movement between the pair 11 and 12 becomes smoother.
[0058]
FIG. 19 and FIG. 20 show a modified example 15A of the shock absorbing pad.
[0059]
The shock absorbing pad 15A has a large number of slit-shaped small holes 15a, 15a,... Formed on the side portion of the outer shell body 23 so that the inside and the outside of the outer shell body 23 communicate with each other. Further, only the gel substance 25 is accommodated in the outer shell body 23.
[0060]
Such an impact absorbing pad 15A is preferably used when the artificial knee joint mechanism 10 is covered with artificial skin and the synovial fluid inherent in the human body is filled between the upper pair 11 and the lower pair 12.
[0061]
When the shock absorbing pad 15A is disposed between the upper pair 11 and the lower pair 12, the shock absorbing pad 15A is positioned in the synovial fluid inherent to the human body. It penetrates into the inside through the small holes 15a, 15a,..., And thus the gel substance 25 stored in the outer shell body 23 can move smoothly without hindrance.
[0062]
In such a shock absorbing pad 15A, since the original fluid is used as the synovial fluid, there is no influence on a part of another human body as compared with the case where an artificial fluid is used.
[0063]
The small holes 15a, 15a,... Are formed in the side portion of the outer shell body 23 in the upper pair 11 and the lower pair 12 or the gel substance 25 like the upper and lower surfaces of the outer shell body 23. When the small holes 15a, 15a,... Are formed in the contact portions, the shock absorbing pad 15A moves between the upper pair 11 and the lower pair 12 with the load applied to the shock absorbing pad 15A. Sometimes, the small holes 15a, 15a,..., And the upper pair 11, the lower pair 12, and the gel material 25 are rubbed, and the two pairs 11, 12, the gel material 25, and the outer shell 23 have poor scratch resistance. This is due to the reason that the distribution of synovial fluid is worsened.
[0064]
21 to 28 show a second embodiment of the artificial joint mechanism of the present invention.
[0065]
The second embodiment differs from the first embodiment in that an electromagnet is used as a magnet, a balance between the left and right sides is provided, and a knee joint reverse folding preventing means is provided. Therefore, only the main part is shown in the drawing, the description is made only for the above differences, and the other parts are attached to the same parts in the artificial joint mechanism according to the first embodiment in each part of the drawing. The same reference numerals are used to omit the description.
[0066]
The upper magnet 27 embedded in the upper pair 26 of the artificial knee joint 10A according to the second embodiment has a uniform magnetic force of each of the small magnets 28, 28,... And the depth embedded in the base material 19. The upper magnet 27 forms a constant magnetic field on the side facing the lower pair 29 while changing from the extended position to the bent position (see FIGS. 21 and 22).
[0067]
Each small magnet 31 of the lower magnet 30 embedded in the lower pair 29 is an electromagnet, and is controlled to form a predetermined magnetic field while changing from the extended position to the bent position as follows.
[0068]
That is, when viewed from the side, the magnetic field formed by the lower magnet 30 has a concave shape with a weak magnetic strength at the center as a whole in the extended position (see FIGS. 23, 24, and 25). The weak part moves backward as it goes from the extended position to the bent position.
[0069]
As a result, the upper magnet 27 is positioned in a portion where the magnetic force of the lower magnet 30 is weak, and the portion where the magnet strength is weak shifts backward as the bending proceeds, and accordingly, as the transition from the extended position to the bent position proceeds. The upper pair 26 is biased backward. This compensates for the backward bias of the upper pair 26 made by the cross bodies 22a and 22b, and a smoother bias is performed.
[0070]
In this embodiment, only the lower magnet 30 is an electromagnet, but only the upper magnet 27 can be an electromagnet, and both the upper magnet 27 and the lower magnet 30 can be electromagnets.
[0071]
Pressure sensors 32 and 32 are interposed at the left and right ends between the shock absorbing pad 15 and the upper surface of the lower pair 29 (see FIGS. 21 and 22), and the pressures detected by these pressure sensors 32 and 32. Is output as a signal to each of the small magnets 31, 31,... Of the lower magnet 30 to balance the left and right loads and improve the result force.
[0072]
That is, for example, when the pressure sensor 32 on the left side of the lower pair 29 detects more pressure than the pressure sensor on the right side, more small magnets 31, 31,. An electric current is applied to increase the magnetic strength and increase the repulsive force to the upper pair 26. Thereby, even if the load applied to the lower pair 29 is left and right unbalanced, the left and right balance of the upper pair 26 can be maintained.
[0073]
For the pressure sensor 32, the invention (sensory information acquisition device) according to the application filed on Dec. 8, 1997 (Japanese Patent Application No. 9-336808) by the present applicant can be applied. Various pressure sensors can be applied.
[0074]
A lid 33 corresponding to the patella in the human body is provided in front of the upper pair 26, and a reverse folding preventing member 34 is provided below the lid 33 and in front of the lower pair 29. The lid 33 and the reverse folding preventing member 34 are attached to the inner side surface of the artificial ligament 35, and the upper end of the artificial ligament 35 is connected to the upper pair 26 and the lower end thereof is connected to the lower pair 29 ( (See FIGS. 26, 27, and 28).
[0075]
As a result, in the bent position, the lid 33 is positioned in front of the upper pair 26 and has the same external shape as when the knee joint in the human body is bent (see FIG. 28), and the artificial knee joint mechanism 10A more similar to the human body. Can be.
[0076]
An electromagnet 36 is embedded in the rear portion of the reverse folding preventing member 34, and a magnetic body 37 is embedded in a portion of the lower pair 29 facing the electromagnet 36. The electromagnet 36 of the reverse folding preventing member 34 is controlled so as to be excited in the extended position, whereby the artificial knee joint mechanism 10A is not folded in reverse (see FIG. 27).
[0077]
The reverse bending of the knee joint may occur due to the moment when the lower leg is swung forward from the knee joint. According to the artificial knee joint mechanism 10A, the electromagnet 36 of the reverse bending preventing member 34 is provided. Is attracted to the magnetic body 37 embedded in the front end of the lower pair 29, and this is a gap 38 having a triangular cross section viewed from the side between the front ends of the upper pair 26 and the lower pair 29. Thus, even if the upper pair 26 is likely to be folded backward, the reverse folding preventing member 34 located between the lower pair 29 is obstructed and the reverse folding is prevented.
[0078]
In this embodiment, the electromagnet 36 of the reverse folding preventing member 34 is attracted to the magnetic body 37 provided on the lower pair 29, but a similar magnetic body may be provided on the upper pair 26.
[0079]
【The invention's effect】
  As is clear from the above description, the artificial joint mechanism of the present invention has a pair of pairs and a connecting means for connecting the two pairs, and the magnets are connected to the joints of the pairs so that both pairs repel each other. Provided on each side,A magnet provided in one pair even so that the coupling means is configured so that the other pair is biased in the bending direction with respect to one pair as it changes from the extended state (extended position) to the bent state (bending position). The magnetic strength of the other pair is made weaker as it goes in the direction of the bias, and the magnetic strength of the other pair of magnets is expanded so that the part facing the one pair of magnets becomes stronger with bending. The distance between one kinematic pair and the other kinematic pair was made constant from top to bottomIt is characterized by that.
[0080]
Therefore, in the artificial joint mechanism of the present invention, there is a gap due to the repulsive force of the magnetic force between the pair, and the impact can be absorbed by the repulsive force. There is no wear on the joint surface, and there is no need to provide a joint shaft as in the prior art.
[0081]
The artificial joint mechanism of the present invention can be applied not only to a uniaxial joint as shown in the above embodiment and each example but also to a biaxial joint or a multiaxial joint.
[0082]
Also,Since the coupling means is configured so that the other pair is biased in the bending direction with respect to one pair as the position changes from the extended position to the bent position, a movement closer to the joint of the human body can be realized.
[0083]
Also,Since the magnetic strength of the magnet provided in one pair is weakened as the other pair goes in the direction of bias, the bias in the bending direction of the other pair can be made smoother and the movement of the human body more Allows operation close to.
[0084]
Also,During the change from the extended position to the bent position, the magnetic strength of the other pair of magnets is increased so that the portion facing the one of the paired magnets becomes stronger with bending. Since the interval between them is constant, the distance between the even number can be made constant regardless of whether it is in the extended position or the bent position, for example, when used as a prosthetic body in the human body An excessive load is not applied to the ligament remaining in the human body.
[0085]
Claim 2In the described invention, since the magnet provided in at least one pair is an electromagnet, the gap between the pair can be controlled, and the other pair can be smoothly biased in the bending direction, The movement closer to the movement of the joints of the human body can be made possible.
[0086]
Claims 3 and 4Since the shock absorbing pad is interposed between one pair and the other pair, even if there is a sudden shock, the shock can be absorbed by the shock absorbing pad. It can be done and the even number will not be damaged.
[0087]
Claims 5 and 6In the artificial joint mechanism using an electromagnet for at least one of the magnets, the position between one pair and the other pair is appropriately separated in the direction perpendicular to the bending direction. Since the pressure sensor is interposed between the two sensors, the repulsive force at the position separated in the direction perpendicular to the bending direction between the two pairs is adjusted by controlling the electromagnet using the pressure difference detected by the pressure sensor as a signal. Even if the load applied to the even number is unbalanced, it is possible to balance the other pair even with respect to the one even number and improve the result force.
[0088]
Claims 7 to 12In the invention described in (1), the reverse folding preventing member is disposed on the side between the one pair and the other pair, where the angle between the one pair and the other pair increases when bent, An electromagnet is provided at a position facing one pair of the reverse folding preventing member or the other pair, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet. Since the reverse folding preventing member is attracted to one pair or the other pair even in the extended position, even if the other pair is likely to be folded in the extended position, the reverse folding between the pair is prevented. A member will get in the way, and the reverse bending of the artificial joint mechanism can be prevented.
[0089]
In the above embodiment and each example, the artificial joint mechanism of the present invention is applied to a knee joint. However, the present invention is not limited to this, and various joints such as an elbow joint and a finger joint. Can be applied to.
[0090]
In addition, the shape or structure of each part shown in the above-described embodiment and each example is merely an example of the embodiment to be performed in carrying out the present invention. The range should not be interpreted in a limited way.
[Brief description of the drawings]
FIG. 1 conceptually shows the basic structure of an artificial joint mechanism according to the present invention together with FIGS. 2 to 4, and this figure is a side view showing the artificial joint mechanism in an extended position.
FIG. 2 is a front view showing an artificial joint mechanism in an extended position.
FIG. 3 is a side view showing an artificial joint mechanism in a bent position.
FIG. 4 is a side view showing another example of the upper magnet.
FIG. 5 and FIG. 20 show a first embodiment in which the artificial joint mechanism according to the present invention is applied to the artificial knee joint mechanism. FIG. 5 shows the artificial knee joint mechanism separated vertically. It is a disassembled perspective view shown.
FIG. 6 is a side view for explaining the joint surface of the upper pair.
FIG. 7 is an enlarged front view showing the upper magnet.
FIG. 8 is an enlarged side view showing the upper magnet.
FIG. 9 is a front view showing an upper pair and a lower pair separated in a vertical direction together with a graph showing the magnetic strength of the upper magnet and the lower magnet.
FIG. 10 is a side view showing an upper pair and a lower pair separated in a vertical direction together with a graph showing the magnetic strength of the upper magnet and the lower magnet in the extended position.
FIG. 11 is a side view showing an upper pair and a lower pair separated from each other in a vertical direction together with a graph showing the magnetic strength of the upper magnet and the lower magnet in a bent state of 90 degrees.
FIG. 12 is a side view showing the upper pair and the lower pair separated from each other in a vertical direction together with a graph showing the magnetic strength of the upper magnet and the lower magnet in a bent position bent approximately 150 degrees.
FIG. 13 is an exploded perspective view seen from the rear showing the upper pair and the lower pair separated from each other in order to exaggerate the cross body.
FIG. 14 shows the movement of the upper pair even with FIGS. 15 and 16, and this figure is a side view in the extended position.
FIG. 15 is a side view showing a state bent 90 degrees.
FIG. 16 is a side view of a bent position bent by 150 degrees.
FIG. 17 is a plan view of a state where the shock absorbing pad is cut in the horizontal direction as viewed from above.
FIG. 18 is a vertical sectional view showing a state cut in a direction perpendicular to the bending direction.
FIG. 19 is an enlarged view of a modified example of the shock absorbing pad, together with FIG. 20, and is a plan view.
FIG. 20 is a side view.
FIG. 21 and FIG. 28 show a second embodiment in which the artificial joint mechanism according to the present invention is applied to the artificial knee joint mechanism, and this figure shows a state where the shock absorbing pad is cut in the horizontal direction. It is the top view which looked at from the upper part.
FIG. 22 is a vertical sectional view showing a state cut in a direction perpendicular to the bending direction.
FIG. 23 is a side view showing an upper pair and a lower pair separated in a vertical direction together with a graph showing the magnetic strength of the lower magnet in the extended position.
FIG. 24 is a side view showing the upper pair and the lower pair separated from each other in the vertical direction, together with a graph showing the magnetic strength of the lower magnet in a state where it is bent by 90 degrees.
FIG. 25 is a side view showing the upper pair and the lower pair separated from each other in the vertical direction together with a graph showing the magnetic strength of the lower magnet in a bent position bent approximately 150 degrees.
FIG. 26, together with FIG. 27 and FIG. 28, shows the movement of the lid and the reverse folding preventing member, and this figure is a side view in a slightly bent state from the extended position.
FIG. 27 is a side view showing a state in which the reverse folding preventing member is interposed between the upper pair and the lower pair to prevent the upper pair from being folded backward.
FIG. 28 is a side view of a bent position.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Artificial joint mechanism, 2 ... Upper pair even, 3 ... Lower pair, 4 ... Upper magnet, 5 ... Lower magnet, 6 ... Connection means, 10 ... Artificial knee joint mechanism, 11 ... Upper pair, 12 ... Lower pair, 13 ... Upper magnet, 14 ... lower magnet, 15 ... shock absorbing pad, 16 ... coupling means, 10A ... artificial knee joint mechanism, 26 ... upper pair, 27 ... upper magnet, 28 ... small magnet, 29 ... lower pair, 30 ... lower magnet 31 ... Small magnet, 32 ... Pressure sensor, 34 ... Reverse folding prevention member, 36 ... Electromagnet, 37 ... Magnetic body

Claims (12)

A pair of kinematic pairs and a coupling means for linking these two kinematic pairs, and magnets are provided on the joint surface side of each pair so that both pairs repel each other;
The above-mentioned connecting means is configured such that the other pair is biased in the bending direction with respect to one pair even as it is bent (extended) from the extended state (extended position),
The magnetic strength of the magnet provided in one pair is made weaker as it goes in the direction in which the other pair is biased,
The magnetic strength of the other pair of magnets is increased between the extended position and the bent position so that the part facing the one pair of magnets becomes stronger with bending, and the distance between one pair and the other pair. An artificial joint mechanism characterized in that is constant .  2. The artificial joint mechanism according to claim 1, wherein a magnet provided on at least one of the pair is an electromagnet.  2. The artificial joint mechanism according to claim 1, wherein an impact absorbing pad is interposed between one pair and the other pair.  3. The artificial joint mechanism according to claim 2, wherein an impact absorbing pad is interposed between one pair and the other pair.  3. The artificial joint mechanism according to claim 2, wherein a pressure sensor is interposed at a position between one pair and the other pair that is appropriately separated in a direction orthogonal to the bending direction. Artificial joint mechanism.  5. The artificial joint mechanism according to claim 4, wherein a pressure sensor is interposed at a position between one pair and the other pair that is appropriately separated in a direction orthogonal to the bending direction. Artificial joint mechanism.  2. The artificial joint mechanism according to claim 1, wherein a reverse-folding preventing member is provided between one pair and the other pair, and when the angle between one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.  3. The artificial joint mechanism according to claim 2, wherein a reverse-fold preventing member is provided between the one pair and the other pair, and when the angle between the one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.  4. The artificial joint mechanism according to claim 3, wherein a reverse folding preventing member is provided between one pair and the other pair, and on the side where the angle between one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.  5. The artificial joint mechanism according to claim 4, wherein a reverse folding preventing member is provided between one pair and the other pair, and on the side where the angle between one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.  6. The artificial joint mechanism according to claim 5, wherein a reverse-folding preventing member is provided between one pair and the other pair, and when the angle between one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.  7. The artificial joint mechanism according to claim 6, wherein a reverse-folding preventing member is provided between one pair and the other pair, and when the angle between one pair and the other pair increases when bent. An electromagnet is provided at a position facing one pair or the other pair of the reverse folding prevention member, and a magnetic material is provided at a position of the one pair or the other pair facing the electromagnet, and the extended position The artificial joint mechanism according to claim 1, wherein the electromagnet is excited to attract the reverse folding preventing member to one pair or the other pair.

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