JP5605735B2 - Aseptic environmental wear test equipment - Google Patents

Description

  The present invention is a wear test apparatus capable of performing a wear test in an aseptic environment, and preferably an aseptic environment capable of performing a wear test of a material used for an artificial joint or the like, for example, ultrahigh molecular weight polyethylene (UHMWPE) in an aseptic environment. The present invention relates to a mold wear test apparatus.

  For the artificial joint, a combination of a metal made of a titanium alloy or a cobalt-chromium-molybdenum alloy having good sliding compatibility and UHMWPE is often used. In this case, it is said that UHMWPE is mainly worn by joint movement, and macrophages phagocytose the wear powder to produce cytokine protein, which stimulates osteoclasts and causes bone lysis. When the bone to which the artificial joint is attached dissolves, the artificial joint loosens, so-called loosening, and re-operation is required.

  In this case, in order to verify the wear phenomenon of UHMWPE, it is necessary to perform a wear test on UHMWPE in the same environment as the living body, that is, in an aseptic environment. In addition, vitamin E or the like is added to prevent oxidation that tends to cause wear of UHMWPE, but a similar test is required to verify the amount of addition. The same applies when searching for another additive.

  There exists what is shown by following patent document 1 as this kind of abrasion test apparatus. This is because the pin-shaped test specimen (metal or UHMWPE) and the plate-shaped test specimen (UHMWPE or metal) are immersed in a lubricating liquid equivalent to body fluid and slid against each other in a state where they are pressed against each other. To do. However, in this prior art, since both the test specimen and the sliding part are exposed to air, the lubricant is denatured based on spoilage due to various germs in the air. Cannot be kept constant. Furthermore, the modification of the lubricating liquid may occur depending on the temperature.

  In such a test under the condition that the lubricating liquid is denatured, the form and amount of the worn article may change, and as a result, an appropriate result cannot be obtained. For this reason, it was necessary to constantly monitor the lubricating liquid, and it was necessary to replace it immediately when degeneration was observed. Therefore, it is necessary to always perform the test under supervision, and much effort and time are required for operations such as replacement of the lubricating liquid.

JP-A-11-51838

  The present invention solves such a problem, and allows the wear test to be performed in the same aseptic environment as in vivo.

Under the above-mentioned problems, the present invention presses and slides two sterilized test specimens in a state of being immersed in a lubricating liquid in an aseptic environment as described in claim 1, and wear characteristics of both test specimens and In an aseptic environment-type wear test apparatus for evaluating the situation, a cup containing one test specimen and a head to which the other test specimen is to be installed are placed at opposite lower and upper positions, and between the head and the cup. Besides Ru hung passing a flexible cover for covering sealed to the head and the cup, attach the nipple to the cup, it was attached to seal the channels that can be collected the depot wear materials and lubrication fluid and the time was cup nipple The aseptic environmental type wear test apparatus characterized by the above is provided.

Further, in the above-described aseptic environment type wear test apparatus, the present invention can arbitrarily select a level at which a pool can be collected by attaching a plurality of nipples to the cup by changing the height and angle of the nipple. A means according to claim 3, wherein the head can move up and down and its weight can be arbitrarily changed, and the pressing force of both test specimens can be adjusted, and the test attached to the head according to claim 4. A means for providing a specimen and a test specimen contained in a cup as a medical implant, and a means for providing a test specimen attached to a head and a test specimen contained in a cup as a biological tissue or a regenerated biological tissue according to claim 5. .

Furthermore, the head and the cup according to claim 6 can be slid back and forth with respect to the respective bases, the head and the cup are connected by a handle, and the head is attached with the cover attached by operating the handle. 8. A cartridge-type means for integrating the cup and the cup so as to be removable from the base thereof, and means for providing a plurality of sets of heads and cups for each base according to claim 7.

In addition, the means according to claim 8, wherein the head can be moved up and down by a fluid cylinder, and the head can fall freely or at an arbitrary speed by control of the fluid cylinder. The above-mentioned fungus environment-type wear test apparatus is provided with a means in which an air conditioner is attached and accommodated in a thermostatic box capable of adjusting the temperature.

According to the invention of claim 1, since the wear test is performed in an aseptic environment, not only the test specimens and the lubricating liquid, but also the head, cup and cover to which these are attached are naturally sterilized and the aseptic environment is obtained. This sterile environment will remain that way during the test. Therefore, the lubricant is not denatured, the test can be performed in the same environment as the living body, and it is not necessary to constantly monitor. In addition, it is easy to collect a stored matter in the cup such as a worn article or a lubricating liquid, and the stored matter can be collected without being contaminated during the test.

According to the means of claim 2, it is possible to collect the reservoirs at different levels. According to the means of claim 3, the pressing force of both the specimens can be changed. According to the means of Claim 4 and Claim 5, the wear test at the time of combining materials and biological tissues used for artificial joints or materials and biological tissues used for artificial joints can be verified in the same environment as in vivo. . According to the claimed means, the cartridge can be assembled and disassembled in an aseptic environment. According to the means of claim 7, many tests can be performed simultaneously. According to the means of claim 8, an impact test is also possible. According to the means of claim 9, by setting the temperature appropriately, a temperature environment imitating that in the living body can be obtained, and the temperature of the lubricating liquid can be kept constant, and the protein component contained in the lubricating liquid can be kept constant. Denaturation due to temperature can be prevented.

It is a front view of the principal part of the testing apparatus concerning the present invention. It is a side view of the principal part of the test device concerning the present invention. It is a side view of the principal part of the other example of the test apparatus which concerns on this invention. It is a side view of the principal part of the other example of the test apparatus which concerns on this invention. It is a partial front view of the principal part of the other example of the test apparatus which concerns on this invention. It is a cross-sectional top view of the principal part of the test apparatus which concerns on this invention. 1 is a front view of a test apparatus according to the present invention. 1 is a side view of a test apparatus according to the present invention. 1 is a side view of a test apparatus according to the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1 to FIG. 2, a test apparatus (hereinafter referred to as “apparatus”) according to the present invention has a box 1 in which the apparatus is accommodated. The upper table 4 is placed on the lower table 3 so as to be movable in the left-right (Y-axis) direction. The movement of the lower table 3 and the upper table 4 in the X-axis and Y-axis directions is preferably controlled by the ball screw / nut mechanisms 7 and 8 by the servo motors 5 and 6 because it is easy to control. A base 9 is placed on the upper table 4, and a cup 10 is fixed to the upper surface of the base 9. In this example, three cups 10 are provided, but the present invention is not limited to this.

  In this case, the cup 10 is made of a corrosion-resistant material such as stainless steel, a metal subjected to a corrosion-resistant treatment, a hard resin, or the like. In the latter case, if it is transparent, there is an advantage that the state of the test can be seen through. A lifting platform 11 is provided above the cup 10 so as to be movable in the vertical direction (Z-axis). A cable 12 is connected to the lifting platform 11, and the cable 12 is a column provided in the box 1. The direction is changed downward by a pulley 14 attached to the upper portion of 13 and a balance weight 15 is suspended from the end thereof. The weight of the balance weight 15 is balanced with the weight of the lifting platform 11, and the lifting platform 11 itself is weightless.

  Further, a weight 16 as a unit is placed on the lifting platform 11, and only the weight of the placed weight 16 is loaded downward. Further, a base 17 is attached to the lower part of the lifting platform 11, and a head 18 projects downward from the base 17. In this case, the head 18 has a three-stage cylindrical shape that is narrower toward the bottom, and the diameter of the largest diameter portion is set to be substantially the same as the diameter of the cup 10.

  In this case, the cup 10 and the head 18 may be fixed to the respective bases 9 and 17 with screws or the like (can be removed by loosening the screws), but the following is preferable. That is, slide plates 10a and 18a are provided on the upper portion of the cup 10 and the lower portion of the head 18, respectively. The slide plates 10a and 18a are slidable back and forth with respect to the respective bases 9 and 17, and are slid and pulled out. Or be able to push it in.

  In addition, in this example, as shown in FIG. 3 to FIG. 5, handles 19 extending vertically at the front ends of the slide plates 10 a and 18 a are respectively connected by bolts (precisely nuts) 20. 10 and the head 18 can be handled integrally. Therefore, the handle 19 can be detached or attached from the apparatus by grasping the handle 19. That is, the set including the cup 10 and the head 18 is a cartridge type. According to this, the sterilization treatment and the operation at the time of the test can be easily and quickly performed, and the operation in an aseptic environment (clean room or the like) is enabled.

  Further, a flexible cover 21 is stretched between the cup 10 and the head 18 to shield germs in the air. The reason why the cover 21 is flexible is that the head 18 and the cup 10 change the positions of the top, bottom, front, back, left, and right of each other during the test. The cover 21 of this example uses a resin bellows tube, and its upper and lower ends are inserted into the maximum diameter of the head 18 and the outer periphery of the cup 10 and are tightly bound by a band 22 or the like. Thereby, the inside of the cover 21 is shielded from outside air, so that various germs in the air do not enter.

  Furthermore, as shown in FIGS. 5 to 6, a plurality of nipples 23 are attached to the outer periphery of the cup 10, and worn articles, lubricating liquids, etc. (hereinafter referred to as storage) in the cup 10 are attached to the nipples 23. A channel 24 for removal is hermetically attached. In this case, the height at which the channels 24 (nipples 23) are provided is variously changed so that different levels of storage can be taken out from each channel 24.

  In addition, a bracket 25 protrudes behind the column 13, a fluid cylinder (air cylinder in this example) 26 is attached to the bracket 25 with the rod 26a facing downward, and a lever that rotates about the fulcrum 27 on the rod 26a. 28 is pivoted. Therefore, when high-pressure air is supplied to the positive pressure chamber of the air cylinder 26, the rod 26a extends, and the lever 28 pushes up the elevator 11 along with this. And the lifting / lowering base 11 falls freely or at arbitrary speed | rates by adjusting the air of a positive pressure chamber suitably, and extracting. In this example, one air cylinder 26 is used and all the elevators 11 are moved up and down at the same time. However, the air cylinders 10 may be attached to each of the elevators 10. Can be moved up and down individually. An overall view of such an apparatus is shown in FIGS.

  Next, a wear test using the above apparatus will be described. First, two test specimens 29 and 30 to be pressed and slid are selected. In this example, since this is an artificial joint wear test, the test specimen attached to the head 18 was made of metal or UHMWPE pin 29, and the test specimen housed in the cup 10 was UHMWPE or metal plate 30. At this time, not only the pins 29 and the plate 30, but also the members such as the head 18, the cup 10, the cover 21, and the handle 19 that may come into contact with the pins 29 and the plate 30 are sterilized. Here, the sterilization treatment and the aseptic environment based on the sterilization process include not only a completely aseptic condition but also a case where there are very few bacteria that can suppress growth in vivo. As this sterilization treatment, any one of gas sterilization, high-pressure steam sterilization and radiation sterilization or a combination thereof may be considered.

  Next, a pin 29 is attached to the head 18. In this structure, a hole is formed in the lower end of the head 18, and the pin 29 is inserted into the hole and fixed with a screw or the like. Further, the head 18 may be sewn to the lower end, or a chuck or the like may be attached to the head 18. Furthermore, the plate 30 is fixed to the cup 10, and this may be achieved by using an appropriate presser 31. By the way, all these operations are performed in an aseptic environment. That is, the head 19 and the cup 10 are brought into the clean chamber by grasping the handle 19, the cover 21 is removed, the pin 29 is attached to the head 18, and the plate 30 is fixed to the bottom of the cup 10 with the presser 31 described above.

  At this time, a lubricating liquid such as bovine serum corresponding to the joint fluid and body fluid is injected to make the same conditions as in the living body. Of course, this lubricating liquid must be sterilized, and the lubricating liquid is injected until at least the sliding surfaces of the pins 29 and the plate 30 are immersed. Then, the cover 21 is attached, and the handle 19 is held out of the clean room to reach the device, and is pushed into the bases 9 and 17 to be positioned at predetermined positions by a stopper mechanism, a distant mechanism, screwing or the like.

  The test preparation is now completed, and the weight 16 set in advance is placed on the lifting platform 11. At this time, it is necessary to remove the nut 20 and separate the handle 19 from the bases 9 and 17. In order to influence the weight of the weight 16 on the pin 29, the head 18 and the cup 10 (in this case, the cup 10) need to move independently up and down, front and rear, and left and right. Because it becomes. As a result, the lifting platform 11 presses the pin 29 with a predetermined pressing force by the weight of the weight 16.

  Thereafter, if the lower table 4 and the upper table 3 are moved to a predetermined position by controlling the servo motors 5 and 6, the aseptic environment is maintained and the lubricant is present on the sliding surface, and the predetermined amount is maintained. A sliding test with a pressing force of can be performed. The sliding range can be set to a certain range by controlling the servo motors 5 and 6, and a program in accordance with this purpose may be set up. By this test, the actual state of wear of the metal and UHMWPE can be observed, and the wear between the rotating portion of the artificial joint and its sliding surface and the wear of the living tissue such as metal or UHMWPE and cartilage can be verified.

  At the time of this test, an impact test based on the drop of the elevator 11 by the air cylinder 26 can be performed, and impact resistance such as cracking and chipping can be examined. Further, if an air conditioner or the like is attached to the box 1 so that the inside of the box 1 can be adjusted in temperature and kept at a constant temperature, the test environment further mimics the internal environment. Then, when collecting the stored substance in the cup 10, it may be sucked from the channel 24 described above. At this time, the channel 24 can separate and aspirate stored substances of various levels (for example, sediment and supernatant). Of course, the cup 10 may be brought into a clean room or the like and collected therein.

  By the way, the above test is not only measurement of the amount of wear by pressing force and time, but also wear powder and lubricating liquid etc. that are not contaminated with bacteria necessary for observing the phagocytic state due to macrophage of wear powder. It can also be obtained. In this case, the fact that there are three sets of the head 18 and the cup 10 means that many tests can be performed simultaneously, and in this respect, the number of sets may be further increased.

  The above is the basic form of the present invention, but the present invention may take various modified forms. For example, the head is not limited to one that can move up and down in the Z-axis direction. However, since the pin attached to the head needs to be able to change the pressing force against the plate, for example, the pin is biased downward with a certain elastic force against the head so that the elastic force can be adjusted. It is also possible to keep it.

  Further, the movement of each base may be only the X axis or the Y axis. At this time, if the pin has a narrow width, it can slide over a wide range by using a brush having a wide width instead of the pin. If the lifting platform is eliminated or the movement of the base is only one axis, the structure becomes extremely simple. Further, it is possible to rotate the head, and the simplest structure thereof is to attach a servo motor to the lower surface of the base on the head side and connect the output shaft to the head. According to this, there is an advantage that a large sliding distance can be taken and an experiment can be performed in a short time.

  It is also possible to make a hose enter the cup and to suck or supply air from the hose to depressurize or pressurize the inside of the hose. Depressurization or pressurization conditions are a matter of moldability of UHMWPE, but it enables a reference test in which the friction itself is performed under depressurization or pressurization to observe the state of wear powder, and particularly under reduced pressure. The test also has the effect of suppressing the growth of germs. Furthermore, the test specimen is not limited to metal and UHMWPE, and may be anything. In short, anything may be used as long as it slides in an aseptic environment and examines its wear and the like. Furthermore, it goes without saying that the present invention can also be applied to a sliding test that is not under aseptic environment.

DESCRIPTION OF SYMBOLS 1 Box 2 Base 3 Lower table 4 Upper table 5 Servo motor 6 Servo motor 7 Ball screw / nut mechanism 8 Ball screw / nut mechanism 9 Base 10 Cup 10a Slide plate 11 Lifting stand 12 Strip 13 Column 14 Pulley 15 Balance weight 16 Weight 17 base 18 head 18a slide plate 19 handle 20 nut 21 cover 22 band 23 nipple 24 channel 25 bracket 26 fluid cylinder 26a rod of rod 27 fulcrum 28 lever 29 test specimen (pin)
30 test specimen (plate)
31 Presser

Claims (9)

In a sterile environment-type wear test device that evaluates the wear characteristics and conditions of both test specimens by pressing and sliding two sterilized test specimens immersed in a lubricating liquid in an aseptic environment. others as well as installed in the lower position and the upper position, Ru hung passing a flexible cover for covering and sealing between the head and the cup to the head and the cup facing the head attaching a cup and the other test specimens for housing An aseptic environment type wear test apparatus, characterized in that a nipple is attached to the cup, and a channel capable of collecting a worn article or lubricant and a stored substance in the cup is sealed in the nipple . The aseptic environment-type wear test apparatus according to claim 1, wherein a plurality of nipples are attached to the cup by changing the height and angle, and a level at which a reservoir can be collected can be arbitrarily selected. The aseptic environment-type wear test apparatus according to claim 1 or 2, wherein the head can move up and down and its weight can be arbitrarily changed, and the pressing force of both test specimens can be adjusted. 4. The aseptic environmental wear test apparatus according to claim 1, wherein the test specimen attached to the head and the test specimen contained in the cup are medical implants. The aseptic environment-type wear test apparatus according to any one of claims 1 to 3, wherein the test specimen attached to the head and the test specimen contained in the cup are living tissue or regenerated living tissue.   The head and cup can be slid back and forth with respect to the respective bases, and the head and cup are connected with the handle, and the head and cup can be integrated with the cover attached by operating the handle. The aseptic environment type wear test apparatus according to any one of claims 1 to 5, wherein the apparatus is a cartridge type that can be removed from the base of the apparatus. The aseptic environment-type wear test apparatus according to claim 6, wherein a plurality of sets of heads and cups are provided for each base.   9. The aseptic environmental wear test apparatus according to claim 1, wherein the head can be moved up and down by a fluid cylinder, and the head can be dropped freely or at an arbitrary speed by controlling the fluid cylinder. An aseptic environment-type wear test apparatus in which the fungus environment-type wear test apparatus according to any one of claims 1 to 8 is housed in a constant temperature box to which an air conditioner is attached and temperature adjustment is possible.