Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N3/56—Investigating resistance to wear or abrasion
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/46—Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
  • A61F2/468—Testing instruments for artificial joints
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M99/00—Subject matter not provided for in other groups of this subclass
  • G01M99/007—Subject matter not provided for in other groups of this subclass by applying a load, e.g. for resistance or wear testing
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/44—Joints for the spine, e.g. vertebrae, spinal discs
  • A61F2/442—Intervertebral or spinal discs, e.g. resilient
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/50—Prostheses not implantable in the body
  • A61F2/76—Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing, e.g. alignment means
  • A61F2002/7695—Means for testing non-implantable prostheses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
  • F16D3/72—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members with axially-spaced attachments to the coupling parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
  • F16D3/76—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members shaped as an elastic ring centered on the axis, surrounding a portion of one coupling part and surrounded by a sleeve of the other coupling part
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/0014—Type of force applied
  • G01N2203/0021—Torsional
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/0014—Type of force applied
  • G01N2203/0026—Combination of several types of applied forces
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/003—Generation of the force
  • G01N2203/0032—Generation of the force using mechanical means
  • G01N2203/0037—Generation of the force using mechanical means involving a rotating movement, e.g. gearing, cam, eccentric, or centrifuge effects
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/0058—Kind of property studied
  • G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/0058—Kind of property studied
  • G01N2203/0089—Biorheological properties
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/02—Details not specific for a particular testing method
  • G01N2203/022—Environment of the test
  • G01N2203/0244—Tests performed "in situ" or after "in situ" use
  • G01N2203/0246—Special simulation of "in situ" conditions, scale models or dummies
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/02—Details not specific for a particular testing method
  • G01N2203/025—Geometry of the test
  • G01N2203/0256—Triaxial, i.e. the forces being applied along three normal axes of the specimen
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/02—Details not specific for a particular testing method
  • G01N2203/04—Chucks, fixtures, jaws, holders or anvils
  • G01N2203/0464—Chucks, fixtures, jaws, holders or anvils with provisions for testing more than one specimen at the time
  • G01N2203/0476—Chucks, fixtures, jaws, holders or anvils with provisions for testing more than one specimen at the time in parallel

Definitions

• the disclosure relates to the field of orthopedic simulators, and more particularly, to orthopedic specimen containers for use in an orthopedic simulator that performs testing of orthopedic test specimens.
• an orthopedic simulator may be employed to subject the orthopedic device to a large number of duty cycles that simulate the motion that the orthopedic device is likely to be subjected to after implantation into a body.
• the wear testing may take place in a container or chamber that contains a fluid bath that essentially simulates the internal environment within a body.
• a fluid bath that essentially simulates the internal environment within a body.
• bovine fluid is specified as the fluid in which the test specimen is immersed.
• test specimen In preparing a specimen for testing within an orthopedic simulator, which will apply various forces along and around different axes, the test specimen will be typically coupled at a test station to the various test machine components which will apply the forces to the test specimen. It is usually a very laborious and difficult process to install a test specimen into a test station.
• the orthopedic simulators are complicated machines, and. access to the holders or adapters for the test specimen is very limited and awkward. Exacerbating this issue, test specimens are often very delicate and the careful removal and insertion of test specimens requires great expertise and a deft touch in order to install the test specimens directly onto the orthopedic simulators.
• test specimen Once properly installed, and following the application of various forces over millions of cycles in a wear test, the test specimen needs to be inspected for the signs of wear.' This includes examining the test specimen and the fluid in which the specimen was immersed for contamination particles. The presence of such particles reveals wearing. A concern with the in situ installation of test specimens at the orthopedic simulators is the potential for contamination of the fluid so that the results of the wear test may be easily compromised.
• a specimen containment module comprising a specimen chamber for receiving a specimen, and a module interface that holds the specimen chamber and is configured for releasably attaching the module to a test machine while holding the specimen chamber.
• an orthopedic device test machine comprising at least one force applicator configured to apply force to an orthopedic device test specimen, and a specimen containment module configured to secure the test specimen and which is releasably attachable to the test machine with the secured test specimen.
• Figure 1 is a front perspective view of an orthopedic simulator constructed in accordance with embodiments of the present invention showing the insertability and removability of a specimen containment module in accordance with embodiments of the present invention.
• Figure 2 is an exploded perspective view of a specimen containment module constructed in accordance with embodiments of the present invention.
• Figure 3 depicts the specimen containment module of Figure 2 in an assembled view and in isolation.
• Figure 4 is a top view of a cross-section of the specimen containment module of Figure 3.
• Figure 5 is a side cross-sectional view of the specimen containment module of Figures 2-4.
• Figure 6 shows the specimen containment module, without a chamber for illustrative purposes, in an installed position within an orthopedic simulator of Figure 1.
• the embodiments of the present invention address and solve problems related to the preparation, insertion and removal of test specimens in orthopedic simulators or other such devices.
• the embodiments of the invention address concerns related to careftil preparation of test specimens at the bench-top, the potential damage during removal and insertion of delicate test specimen samples, mounting of one- piece specimens, and the potential for contamination of the test fluid.
• embodiments of the present invention which provide, for example, an orthopedic device test machine, such as a simulator, in which at least one force applicator is configured to apply force to the orthopedic device test specimen.
• the specimen containment module is configured to secure the test specimen remotely.
• the specimen containment module may then be releasably attached to the test machine while it holds the secured test specimen. This allows for the preparation work on the specimen to be performed at the bench-top. Also, a removable and releasably attachable specimen containment module allows for the careful removal and insertion of delicate test samples. Contamination potential is greatly reduced since the sample may be prepared and the specimen containment module sealed prior to installation at the test device. After testing, the specimen containment module may be readily detached from the test machine and removed to a clean room for determining the wear of the orthopedic device. Additionally, the separable nature of the specimen containment module facilitates the mounting of one-piece specimens, as well as facilitating the mounting of specimens in general. It is much easier to mount specimens at the specimen containment module on a workbench, rather than mounting them in situ at the orthopedic device test machine.
• Figure 1 is a perspective view of an orthopedic device test machine, such as an orthopedic simulator.
• the test machine 10 which may be a spinal wear implant test machine, for example, is able to provide forces Fx, Fy and Fz in the x, y and z directions. Additionally, torques may be applied around the x, y and z axes. The axes and motions are not depicted in Figure 1, so as not to obscure the present invention.
• the test machine 10 has a plurality of test stations 12. In the embodiment of Figure 1, there are six stations 12 in which specimens are subjected to the forces applied by the machine 10, and a control station 13 that holds the specimen that is not subjected to all of the forces provided at the other test stations 12.
• test machine 10 is being described as a spinal implant wear test machine for descriptive purposes, it is to be clearly understood that this is by way of illustration and example only and is not to be taken by way of limitation.
• the test machine 10 may be configured for other orthopedic simulation, such as simulating hip motion and forces for prosthetic hips, knee joints, etc.
• the test machine 10 in Figure 1 is depicted as having a specimen containment module 14 removed from one of the test stations 12.
• the arrow 15 shows the direction of installation and removal of the specimen containment module 14. The removal of the specimen containment module 14 as a unit helps to avoid environmental contamination, eases inspection, and simplifies specimen installation, as will be described in more detail.
• Figure 2 shows the specimen containment module 14 in an exploded view
• Figure 3 depicts an assembled specimen containment module 14 with in a sealed condition.
• the module 14 includes a base 16 and an upper connector 18.
• the base 16 and the upper connector 18 are releasably attached during installation to the test machine 10.
• the chamber base 16 may be made of any suitable material, such as Delrin® or other suitable material.
• a specimen mounting platform 19 is configured with features, such as pins 48, that help to pilot and provide anti-rotation functionality for the mounting of a lower specimen adapter 20.
• the specimen adapter 20 is particularly configured for holding a specific test specimen, in certain preferred embodiments. For example, in Figure 2, a lower portion 30a of a test specimen fits precisely within a recess 31 in the lower specimen adapter 20.
• the specimen containment module may either contain the lower specimen adapter 20 or this adapter 20 may be provided by the manufacturer of the test specimen 30.
• the base 16 also includes a recess 32 that is open-ended that interacts with a pin 40 at the test station 12 to allow a sliding installation of the specimen containment module 14 at the test station 12.
• Recesses 36 permit releasable fasteners 26, such as thumb screws, to provide an anchoring in the x and y directions, as well as providing clamping in the z direction.
• the upper connector 18 includes a slot 34 that is similar to slot 32 in the base 16.
• An additional recess 37 is similar to those recesses 36 in the base 16.
• the upper connector 18 may be releasably attached to the test machine 10.
• An upper specimen adapter 22 is attached to the upper connector 18 by any suitable means.
• the upper specimen adapter 22 is configured to retain an upper portion 30b of the test specimen.
• the upper specimen adapter 22 may also be provided by the maker of the test specimen.
• the base 16 includes a retaining ring 38 that projects upwardly from the surface of the base 16.
• a chamber 24 which may be made of clear acrylic, for example, is placed concentrically within the retaining ring 38 following the securing of the lower specimen adapter 20 that holds the lower portion 30a of the test specimen into the base 16. Together, the chamber 24 and the base 16 form a fluid container suitable for retaining a bath, such as bovine fluid, in which the test specimen 30 is immersed during testing.
• tubing 44 is provided that extends through the base 16 to provide a temperature control.
• This tubing 44 serves as a test fluid temperature control element.
• the fluid circulation tube 46 provides a temperature control fluid that may precisely maintain the bath contained within the fluid container 16, 24 at a precise temperature. The control for such a fluid temperature arrangement is not shown.
• a temperature probe 42 is provided to provide feedback of the temperature in the bath.
• bath fluid circulation tubes 46 are depicted that may be employed to circulate the bath in which the specimen is immersed during a test.
• the fluid may be circulated from test station to test station in one circulation loop.
• the bath fluid is not circulated but remains in individual loops in a non-circulating fashion. This prevents cross- contamination between test stations and other concerns.
• the upper connector 18 and upper specimen adapter 22 may be placed in the assembled position as shown in Figure 3. In this manner, the upper and lower portions 30a, 30b of the test specimen are placed into contact with one another. Bovine fluid or other test fluid may then fill the fluid container created by the base 16 and the chamber 24 and into a moat 27. Following the filling of the fluid container 16, 24, the specimen containment module 14 may be sealed, such as by a plastic flexible seal 39 that extends between the base 16 and the upper container 18 and which circumscribes the chamber 24.
• the seal 39 allows the specimen containment module 14 to be prepared remotely from the test machine 10 and sealed against the environment during: transport of the specimen containment module 14 to the test machine 10, installation of the specimen containment module 14 in a test station 12, through the duration of a test, removal of the specimen containment module 14 from the test station 12 and transport to a clean room or other remote environment where the seal 39 may be safely removed without threat of contamination.
• This sealed aspect of embodiments of the present invention thereby provide mobility and ease of handling of the test specimen without compromising the fluid or the test specimen.
• Figure 5 depicts the specimen containment module 14 in an assembled state, with a test specimen 30 retained between the upper specimen adapter 22 and the lower specimen adapter 20, for example.
• This specimen 30 is exemplary only, as types of test specimens and orthopedic devices other than spinal implants may be employed without departing from the scope of the invention.
• the specimen containment module as depicted in the figures allows for careful removal and insertion of the test specimens, which may be extremely delicate in certain examples. This allows the preparation work for the specimen to be performed at a bench-top in a clean room, rather than at the test machine itself, which may introduce many contaminants into the environment, such as oil, etc. Further, the remote nature of the mounting process facilitates the mounting of one-piece specimens, such as where the inferior and superior portions of a test specimen are permanently joined. Contamination potential is greatly reduced since the preparation of the test specimen 30 may be performed in a clean room and especially remotely from the test machine 10 itself.
• the specimen containment module 14 may also be employed to test many different types of test specimens, with a change of upper and lower adapters 22, 20 providing secure retention of different types of test specimens. Finally, once testing is completed, the releasable attachment capability of the specimen containment module allows the entire specimen containment module 14 to be removed from the test machine environment which prevents environmental contamination while easing the inspection and determination of the wear characteristics of the test specimen. It should be noted that other types of releasable fasteners, such as snap connections or other releasable fasteners may be employed without departing from the scope of the present invention.
• a specimen containment module 14 serving as a modular unit, may be slid in the direction of arrow 15 as depicted in Figure 1 into the test station 12.
• the locating pins (not shown in Figure 1, but shown as pin 32 in Figure 4) interact with the recesses 32, 34 in the base 16 and upper connector 18 as the specimen containment module 10 is slid into the test station 12.
• releasable fasteners 26 releasably attach the specimen containment module 14 to the test machine 10. Appropriate testing may then be performed, with forces being applied to the test specimen 30a, 30b through the upper specimen adapter 22 and the lower specimen adapter 20.
• the specimen containment module 14 may be removed by removing the releasable fasteners 26 and sliding the specimen containment module 14 as a modular unit from the test station 10. The specimen containment module 14 may then be detached from the test machine 10 and inspection and determination of the wearing of the specimen may be then performed in a manner that avoids contamination.
• the releasably attachable specimen containment module of the embodiments of the present invention allows for removal of the specimen containment module from the machine as a unit to avoid environmental contamination, ease inspection, and simplify specimen installation, among other advantageous benefits.

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• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Transplantation (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Biochemistry (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Cardiology (AREA)
• Physical Education & Sports Medicine (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Animal Behavior & Ethology (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
• Prostheses (AREA)
• Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)

Applications Claiming Priority (4)

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Citations (8)

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• 2007
  • 2007-01-10 EP EP07718357.2A patent/EP1977186A4/de not_active Withdrawn
  • 2007-01-10 WO PCT/US2007/000726 patent/WO2007084326A2/en active Application Filing
  • 2007-01-10 EP EP07716549.6A patent/EP1977216B1/de active Active
  • 2007-01-10 WO PCT/US2007/000733 patent/WO2007084330A2/en active Application Filing

Patent Citations (8)

Non-Patent Citations (1)

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