Abstract:
Embodiments of the invention include systems and methods for tracking a medical device. Systems configured for such tracking may include the capability to either or both detect tampering with the medical device and to effectively expose an encapsulated medical device to sterilization substances and associate the medical device with an identifying characteristic.

Description:
CROSS-REFERENCE TO RELATED APPLICATONS 
     This application claims priority to and is a divisional of U.S. patent application Ser. No. 12/109,534 filed on Apr. 25, 2008, which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the field of identification and tracking of parts, and more particularly relates to associating a medical device with identifying information provided as part of a capsule in which the medical device is placed, and tracking the medical device. 
     BACKGROUND 
     Implantable medical devices must be sterile prior to use in order to reduce the risk of infection in patients receiving such devices. Generally, there are two ways to provide sterile surgical devices. One way is to sterilize a device to be implanted immediately prior to implantation. Another way is to sterilize a device during the manufacturing process, and then to ship the device to a user in a sterilized condition. The first way is typically called providing a device “non-sterile,” because the manufacturer ships the device in a condition that is not adequately sterilized for implantation. The second way is typically called providing a device “sterile,” because the device is ready for implantation when shipped from the manufacturer. 
     There is a strong and growing need to track medical devices from their base materials and manufacture to their use, and throughout the intervening time. Tracking of medical devices may also be referred to as maintaining traceability of the devices. It is sometimes important to track medical devices so that patients can be notified of any information related to the safety or longevity of devices once implanted. The U.S. Food and Drug Administration is currently considering requiring that implantable medical devices be uniquely identified and tracked through the time of use of the devices. 
     It is relatively straightforward to uniquely identify and track sterile medical devices. Unique labels or other indicia are applied to the product and the labels or other indicia remain associated with the medical device until the device is used. In some instances, sterile product labels include adhesive portions that can be applied to a chart or file of a patient to conveniently associate the sterile medical device with a particular patient. 
     Non-sterile products provide a greater tracking challenge, although there are several reasons for preferring non-sterile shipment of medical devices. A larger number of non-sterile devices can be provided in groups or sets that present the devices in a manner where the devices are readily available for use. The large number of devices may represent a large number of sizes and optional configurations that provide surgeons with many alternatives in a convenient arrangement. Devices that are not used are simply returned to stock for sterilization prior to a subsequent use. Non-sterile devices do not have a definitively limited shelf life, as sterile products do. Non-sterile devices are less expensive to package and sterilize. Non-sterile devices can typically be more densely packaged into a common carrier than sterile devices. The primary reason that such non-sterile products are difficult to track, however, is that the products are difficult to mark, may not be marked at all, and may be identical to other products with which they are packaged, thus creating a possibility of confusion among parts. In many instances, specific non-sterile products are not tracked beyond their manufacturing facility, and may only be counted when reconciled for payment as one of many products that were not returned to a manufacturer for replenishment. 
     One way of tracking non-sterile medical devices would be to encapsulate the devices in a container that includes identifying information. Such a container may advantageously provide ready access to the device by sterilizing material such as steam or other cleaning solutions. It would also be advantageous in some tracking systems for non-sterile implants to be resistant to intentional or even incidental tampering that could disassociate identifying information from a medical device. 
     SUMMARY 
     An embodiment of the invention is a medical device tracking system. The system includes a medical device and a capsule for containing the medical device. The capsule of some embodiments has a body capable of multiple fluid sterilizations without degradation, the body including openings to permit ingress and egress of fluid sterilization substances. An identification tag may also be associated with the body, and the capsule may be configured such that removal of the medical device from the capsule is thereafter detectable. 
     Another embodiment of the invention is a medical device tracking system that includes a medical device, a first component, a second component, and a tracking device. The first component has transverse openings along the length of the first component to permit ingress and egress of fluid sterilization substances. The second component of some embodiments is coupled with the first component to encapsulate the medical device. The tracking device may be associated with the first component or the second component. 
     Yet another embodiment of the invention is a steam sterilizable apparatus for containing a medical device. The apparatus may include a capsule formed in an enlarged shape of the medical device to conform to the perimeter of the medical device, and an enclosure configured to cooperate with the capsule to contain the medical device within the capsule. One or both of the capsule and the enclosure may include openings to permit steam to enter and exit the capsule to sterilize the implant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal pedicle screw. 
         FIG. 2  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal pedicle screw. 
         FIG. 3  is a perspective view of a component of the tracking system illustrated in  FIG. 2 . 
         FIG. 4  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal pedicle screw. 
         FIG. 5  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal pedicle screw. 
         FIG. 6  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal post. 
         FIG. 7  is a perspective view of an embodiment of the invention that illustrates a tracking system including a spinal rod. 
         FIG. 8  is a perspective view of an embodiment of the invention that illustrates a tracking system including multiple capsules coupled to form an array. 
         FIG. 9  is a flowchart directed to method embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     A medical device tracking system is illustrated in  FIG. 1  that includes a medical device in the form of a spinal surgical screw  10  and a capsule  7  for containing the spinal surgical screw  10 . The medical device of this or any other embodiment of the invention may be any implant or instrument used in accomplish a medical procedure. The medical device of some embodiments is capable of undergoing one or more steam sterilization cycles, or other sterilization procedures, without degrading in a manner that would make the implant unsuitable for use in a medical procedure. The medical device of this or any other embodiment of the invention may consist of materials, by way of example, and without limitation, including titanium and its alloys, ASTM material, cobalt chrome, tantalum, ceramic, poly-ether-ether-ketone (PEEK), PEAK, various plastics, plastic composites, carbon fiber composites, coral, allograft, autograft, zenograft, and can include artificial materials which are at least in part bioresorbable, or any material suitable for human implantation. 
     In addition to being a surgical screw, such as spinal surgical screw  10 , the medical device may be a spinal post  17 , as illustrated in  FIG. 6 , or a spinal rod  18 , as illustrated in  FIG. 7 . The medical device of some embodiments may be, without limitation, a surgical screw of any variety, a spinal or other orthopedic plate, a surgical rod, an interbody spinal device, a vertebral disc arthroplasty device, a nucleus replacement device, a corpectomy device, a vertebrectomy device, a mesh device, a facet fixation or arthroplasty device, a structural bone graft, a staple, a tether of synthetic material or wire, or other spinal fixation instrumentation, an intramedullary nail, an external fixation device, a hip prosthesis or therapeutic device, a knee prosthesis or therapeutic device, or an instrument useful with any of the previously recited devices. 
     The capsule  7  illustrated in  FIG. 1  is a body capable of multiple fluid sterilizations without degradation. For example, the capsule  7  of various embodiments may not undergo meaningful loss of structural integrity, is not discolored, or does not lose information retained on the capsule  7  as a result of multiple fluid sterilizations. The sterilizations may be from steam sterilization or from application of a chemical sterilizing substance, or from any other effective sterilization substance or process. The capsule  7  that is shown includes a first component  1  and a second component  2 . The first component  1  of the illustrated embodiment has transverse openings  3  along the length of the capsule  7  to permit ingress and egress of fluid sterilization substances. In other embodiments, the second component  2  may alternatively or in addition have openings to permit passage of fluid sterilization substances. 
     In some embodiments, a tracking device such as an identification tag, indicia, or other marking is associated with the capsule  7 . The tracking device may be more specifically associated with one or both of the first component  1  and the second component  2 . The tracking device may be inscribe on a component, attached to a component, incorporated in the manufacture of a component, or in any way connected or associated with either component, a combination of the components, or provided as a supplement to the components. The tracking device may be anything that is capable of retaining identifying information. In some embodiments, the tracking device is a device suitable for scanning by an optical scanner such as a one or two dimensional bar code reader. The tracking device may also be a radio frequency identification (RFID) device that is readable through radio frequency transmission generated by an independently powered RFID device. The tracking device may be an RFID device that includes a transponder and is readable in response to a radio frequency signal transmitted to the RFID device. In some embodiments, the tracking device is a human readable visual and/or tactile device such as, but not limited to, alphanumeric characters, and may optionally include raised or lowered portions. 
     The capsule  7  may be configured such that removal of the spinal surgical screw  10  from the capsule  7  is thereafter detectable. As illustrated in  FIG. 1  removal of the spinal surgical screw  10  from the capsule  7  may include detaching the first component  1  from the second component  2  to permit removal of the spinal surgical screw  10 . The first and second components  1 ,  2  may be detached from one another by twisting, pulling, or otherwise creating stress in the components, or between one or both of the components. Alternatively, the first and second components  1 ,  2  may be detached or removed by cutting or otherwise degrading a portion of one or both of the first and second components  1 ,  2  or a connection between the components. 
       FIG. 2  shows a medical device tracking system having a medical device embodied in a spinal surgical screw  10  and a capsule  107  for containing the spinal surgical screw  10 . The illustrated capsule  107  is capable of multiple fluid sterilizations without degradation, and includes transverse openings  103  along the capsule  107  to permit ingress and egress of fluid sterilization substances. The capsule  107  shown comprises a first component  101  and a second component  102 . A pair of connecting components  108  provides coupling mechanisms in the illustrated embodiment. A tracking device  120  may be associated with the capsule  107 , and in particular with the second component  102  in the illustrated embodiment. As shown in  FIGS. 2 and 3 , the tracking device  120  is a two dimensional bar code marking on a side of the second component  102 . A second component  102  with a tracking device  120 , as illustrated in  FIG. 3 , may also be applicable to embodiments such as those illustrated in one or more of  FIGS. 1 ,  2 ,  7 , and  8 . A tracking device may also be applied to the first component  101  or to one or both of the connecting components  108 . In some embodiments, the capsule  107  ( FIG. 2 ) is configured such that removal of the spinal surgical screw  10  from the capsule  107  is thereafter detectable. In addition to detection resulting from alterations in the first and second components  101 ,  102 , detectable alterations to one or both of the connecting components  108  may result when a medical device is removed from a capsule  107 . 
       FIG. 4  shows a medical device tracking system having a medical device embodied in a spinal surgical screw  10  and a capsule  207  for containing the spinal surgical screw  10 . The illustrated capsule  207  is capable of multiple fluid sterilizations without degradation, and includes transverse openings  203  along the capsule  207  to permit ingress and egress of fluid sterilization substances. The capsule  207  shown comprises a first component  201  and a second component  202 . The second component  202  couples to the first component  201  by sliding engagement. A tracking device may be associated with the capsule  207 . A tracking device may be applied to one or both of the first component  201 , the second component  202 , or to additional components between the components or associated with them. In some embodiments, the capsule  207  is configured such that removal of the spinal surgical screw  10  from the capsule  207  is thereafter detectable. In addition to detection resulting from alterations in the first and second components  201 ,  202 , detectable alterations to components connecting the first and second components  201 ,  202  may result when a medical device is removed from a capsule  207 . 
       FIG. 5  shows a medical device tracking system having a medical device embodied in a spinal surgical screw  10  and a capsule  307  for containing the spinal surgical screw  10 . The illustrated capsule  307  is capable of multiple fluid sterilizations without degradation, and includes transverse openings  303  along the capsule  307  to permit ingress and egress of fluid sterilization substances. The capsule  307  shown comprises a first component  301  and a second component  302 . The second component  302  illustrated is coupled to the first component  301  along all or part of a perimeter  305  of the second component  302 . A tracking device  320  may be associated with the capsule  307 , and in particular with the first component  301  in the illustrated embodiment. As illustrated, the tracking device  320  may also be used as a gripping component to be grasped to pull the second component  302  away from the first component  301 . A tracking device may also be applied to the first component  301 . In some embodiments, the capsule  307  is configured such that removal of the spinal surgical screw  10  from the capsule  307  is thereafter detectable. In addition to detection resulting from alterations in the first and second components  301 ,  302 , detectable alterations to the interface between the first and second components  301 ,  302  may result when a medical device is removed from the capsule  307 . 
       FIG. 6  illustrates a medical device tracking system having a medical device embodied in a spinal post  17 . The tracking system includes a capsule  407  for containing the spinal post  17 . The illustrated capsule  407  is capable of multiple fluid sterilizations without degradation, and includes transverse openings  403  along the capsule  407  to permit ingress and egress of fluid sterilization substances. The capsule  407  shown comprises a first component  401  and a second component  402 . The second component  402  illustrated is coupled to the first component  401  at a distal end  404  of the first component  401 . Each of the segments of the distal end  404  of the first component  401  shown includes ratchet teeth  405  designed to interact with the second component  402  though slots  406  in the second component  402 . In an embodiment of the system, the ratchet teeth  405  only permit the second component to slide proximally along the first component  401 . Consequently, the spinal post  17  is captured between the first component  401  and the second component  402  as the second component is advanced proximally along the first component  401 . A tracking device may be associated with the capsule  407  or particularly one of its components. In some embodiments, the capsule  407  is configured such that removal of the spinal post  17  from the capsule  407  is thereafter detectable. In addition to detection resulting from alterations in the first and second components  401 ,  402 , detectable alterations to the interface between the first and second components  401 ,  402  may result when a medical device is removed from the capsule  407 . 
       FIG. 7  illustrates a medical device tracking system having a medical device embodied in a spinal rod  18 . The tracking system includes a capsule  507  for containing the spinal rod  18 . The illustrated capsule  507  is capable of multiple fluid sterilizations without degradation, and includes transverse openings  503  along the capsule  507  to permit ingress and egress of fluid sterilization substances. The capsule  507  shown comprises a first component  501  and a second component  502 . A tracking device may be associated with the capsule  507  or particularly one of its components. As illustrated, a tracking device  520  comprising a two dimensional bar code is a part of the second component  502 . In some embodiments, the capsule  507  is configured such that removal of the spinal rod  18  from the capsule  507  is thereafter detectable. In addition to detection resulting from alterations in the first and second components  501 ,  502 , detectable alterations to the interface between the first and second components  501 ,  502  may result when a medical device is removed from the capsule  507 . 
     In another aspect,  FIG. 7  illustrates the capsule  507  as a steam sterilizable apparatus for containing a medical device such as the spinal rod  18 . The capsule  507  shown is formed in an enlarged shape of the spinal rod  18 . In some embodiments, this enlarged shape enables steam or other sterilization substances to access the surface of a contained medical device, while not taking up any more volume than is necessary to access the surfaces of the medical device. The common, although enlarged, shape may also be useful to enable quickly identifying a medical device. Enlarged shapes of the invention may conform to the perimeter of the medical device. As used herein, the perimeter may include precisely the outer boundaries of a medical device, or may more generally include various approximations of the outer boundaries of a medical device. A capsule  507  of an embodiment includes a first component  501  and a closure, for example in the form of the second component  502 . The closure of some embodiments may also be incorporated into a single component that makes up a capsule. As illustrated, the capsule  507  includes openings  503  to permit steam to enter and exit the capsule  507  to sterilize the spinal rod  18 . In other embodiment, the second component  502 , or other parts of the first component  501 , may include openings to permit steam to enter and exit. 
     The coupling between the first and second components  1 ,  2 ;  101 ,  102 ;  201 ,  202 ;  301 ,  302 ;  401 ,  402 ;  501 ,  502  of some embodiments is such that once the components are coupled together, then separation of the components is detectable. This may be accomplished, without limitation, by applying adhesive between the components, by providing ratcheting or snap-fit connections designed to fracture relatively easily as compared to other portions of the mechanism when stressed, by melting, welding, or otherwise joining all or a portion of the components together, and by including a indicator device across a joint between or through the components that fracture, change shape, change color, or otherwise are altered by separation of the first and second components. Detectable separation of the components may occur at one or more connections between the components, or may include fracture or change within either or both of the first and second components. In some embodiments, the first and second components, and in some instances other components, form a mechanism configured such that removal of the medical device from the mechanism is detectable as specifically described, or in another manner. 
       FIG. 8  illustrates a system that may be essentially similar to the system described for  FIG. 1 , but additionally includes other capsules coupled with the capsule  7  described in association with  FIG. 1 . Each additional capsule is configured to receive one or more additional medical devices, such as, for example, spinal surgical screws  10 . The additional capsules may be formed in a common material piece as illustrated, or may be formed in multiple material pieces and bound together subsequently. One or more of the capsule and additional capsules may be configured such that removal of a respective medical device is thereafter detectable, as described in connection with any of the embodiments herein. 
       FIG. 9  graphically illustrates a method of tracking a medical device. The method includes capturing the medical device in a mechanism that includes an identifier, wherein the mechanism is configured such that removal of the medical device from the mechanism is thereafter detectable. The medical device captured may be similar to any of the medical devices illustrated in  FIGS. 1 ,  2 , and  4 - 8 , any medical device otherwise described herein, or any medical device suitable to receive an identifier. 
     The method of some embodiments also includes transferring the mechanism and captured medical device to a potential user. A mechanism and medical device may be transferred to a user who has purchased the medical device, who has accepted the medical device on consignment, who is receiving the medical device on loan, or who is otherwise in authorized possession of the medical device. A user under various embodiments of the invention may be a specific physician, a group of physicians, a hospital, a clinic, a governmental agency, or any person or group administering receipt of medical devices. The method may further include specifying sterilization of the captured medical device prior to potential implantation of the medical device. The form of sterilization may be particularly specified, or may be left to the discretion of the user. 
     Method embodiments may also include accepting return of the mechanism and captured medical device. The original manufacturer or provider of the medical device would typically accept return. However, as understood herein, accepting return may also include return being accepted by an agent or otherwise authorized party acting on behalf of the original manufacturer or provider of the medical device. In some, but not all instances, return of medical devices is a result of a provider sending multiple sizes and/or configurations of a medical device to a user with an understanding that not all of the medical devices will be employed in a planned procedure. 
     As shown in  FIG. 9 , some embodiments of the invention further include checking one or both of the medical device and the mechanism to determine if the medical device has been removed from the mechanism. Such a check may include one or more of determining if the mechanism is currently present and determining if the mechanism has been previously removed from the medical device. If the medical device has been removed from the mechanism, the medical device may be returned to a manufacturing or processing facility to be identified properly, or scrapped if tracking has been lost for the device. If the medical device has not been removed from the mechanism, a method under the invention may include subsequently transferring a previously delivered and returned mechanism and captured medical device to a previous potential user or to a new user. The term new user as used herein may also refer to a new potential user. The step of checking the medical device and mechanism for removal may occur at different or additional times in some other embodiments of the invention in order to verify continued, accurate tracking of a medical device. 
     Some embodiments of the invention may also include maintaining a record of the identifier, and therefore, maintaining a record of the medical device that has been associated with the identifier and the mechanism in which the identifier is embodied. Consequently, by maintaining a record of the identifier, information associated with the medical device may be effectively maintained. The types of information that may be maintained in certain embodiments include the location of the identifier and medical device at a particular time, the patient or patients in or on whom a medical device has been used, and the healthcare provider or providers who have used or handled a device. A healthcare provider may include physicians, nurses, technicians, hospitals, purchasing agents, governmental agencies, administrative staff, and others. Tracked information associated with a medical device may also include a date of use, a time of use, a condition treated, a particular surgical procedure, a procedure type, a number of times sterilized, and other information that might be useful in tracking the safety, utility, and efficacy of a medical device. An identifier and medical device may also be associated in some embodiments with manufacturing information, such as but not limited to, material type, lot number, country where manufactured, manufacturing facility, time of manufacture, and manufacturing process employed. 
     In any of the embodiments of the present invention, the medical devices may include, be made of, treated, coated, filled, used in combination with, or have a hollow space or opening for containing artificial or naturally occurring materials and/or substances suitable for implantation in the human body. These materials, and/or substances, may include any source of osteogenesis, bone growth promoting materials, bone derived substances or products, demineralized bone matrix, mineralizing proteins, ossifying proteins, bone morphogenetic proteins, hydroxyapatite, genes coding for the production of bone, and bone including, but not limited to, cortical bone, antibiotics, cancer treating substances, infection treating substances, substances to therapeutically affect clotting or stenosis, or other disease treating substances. The medical devices can include, at least in part materials that are bioabsorbable and/or resorbable in the body. 
     While the invention has been described with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that various modifications can be made to the invention itself without departing from the spirit and scope thereof. All changes and modifications that are within the spirit of the invention are hereby anticipated and claimed.