Patent Application
20070139202
The present invention is related generally to radio frequency identification (RFID) tags and specifically to RFID tags encapsulated or partially encapsulated within objects using high and low temperature manufacturing methods and the use of those objects in the field of medicine.
The ability to quickly inventory instruments is critical in certain applications. For example, surgeons, nurses, and other medical personnel spend significant time delaying the end of a procedure in order to account for misplaced medical instruments. This delay increases costs to hospital and medical facilities (e.g., lost hours of operating theater teams) and increases risk to patients due to extended time under anesthesia. Current methods for generating a pre-procedure and post-procedure inventory of medical instruments are manual. For example, an individual makes a list of instruments assembled for use in the procedure. After the procedure, an individual checks instruments off against the list. This process is time consuming and prone to human errors.
Therefore, what is needed is an automated process that increases the speed of and reduces the errors in instrument verification applications.
In addition, the use of traditional methods of RFID tag attachment to medical instruments is not practical for a variety of reasons. For example, attaching an RFID tag to the surface of a medical instrument creates seams, depressions, and/or surfaces which facilitate the growth of bacteria or other organisms. Furthermore, many current RFID tag structures cannot withstand repeated sterilization processes.
Therefore, what is further needed is a seamless medical instrument having an encapsulated or partially encapsulated RFID tag.
The present invention is directed to the manufacture of an object having an encapsulated radio frequency identification (RFID) tag. In accordance with aspects of the invention, an RFID tag is affixed to a first portion of the object being manufactured. The first portion of the object, with the RFID tag affixed, is placed in a cavity of a mold. The first portion is then over-molded with a first material to generate a seamless object.
The present invention is also directed to the manufacture of an object having a partially encapsulated RFID tag. In accordance with aspects of the invention, an RFID tag is laminated with a suitable lamination material. The laminated RFID tag is then affixed to a mold. The laminated RFID tag is then over-molded with a first material to generate a seamless object.
The present invention is further directed to methods for tracking medical instruments having encapsulated or partially encapsulated RFID tags. In accordance with aspects of the invention, one or more instruments assembled for a medical procedure are scanned to generate a list of pre-procedure RFID tag identification numbers. The pre-procedure list of tag identification numbers is then stored. Upon completion of the procedure, one or more instruments are scanned to generate a list of post-procedure RFID tag identification numbers. The pre-procedure and post-procedure lists of tag identification numbers are compared to identify any missing instruments. If instruments are missing, the location of the medical procedure can be scanned to locate the identified missing instruments.
These and other advantages and features will become readily apparent in view of the following detailed description of the invention. Note that the Summary and Abstract sections may set forth one or more, but not all exemplary embodiments of the present invention as contemplated by the inventor(s).
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
The present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
Radio frequency identification (RFID) tags are electronic devices that may be affixed to items whose presence is to be detected and/or monitored. The presence of an RFID tag, and therefore the presence of the item to which the tag is affixed, may be checked and monitored by devices known as “readers.” Readers typically transmit radio frequency signals to which the tags respond. Each tag can store a unique identification number. The tags respond to the reader transmitted read signals by providing their identification number so that they can be identified.
Exemplary environment 1000 also includes one or more readers 1040. These readers 1040 may operate independently or may be coupled together to form a reader network. A reader 1040 may be requested by an external application to address the population of tags 1022. Alternatively, the reader may have internal logic that initiates communication. When the reader is not communicating with the population of tags, the reader 1040 typically does not emit RF energy. This allows other readers to act upon the same population of tags, but from a different orientation, so as to achieve as complete of coverage with RF signals into the entire population of tags as possible. In addition, the same reader may act upon the same population of tags using a different frequency to increase tag coverage.
Signals 1070 and 1080 are exchanged between a reader 1040 and the tags 1020 according to one or more interrogation protocols. Signals 1070 and 1080 are wireless signals, such as radio frequency (RF) transmissions. Upon receiving a signal 1070, a tag 1020 may produce a responding signal 1080 by alternatively reflecting and absorbing portions of signal 1070 according to a time-based pattern or frequency. This technique for alternatively absorbing and reflecting signal 1070 is referred to herein as backscatter modulation. The present invention is also applicable to RFID tags that communicate in other ways.
The object may be a product or component of a product having high monetary value. In an embodiment, because the tag is seamlessly embedded in the object, the tag cannot be removed without visibly damaging the object. This has added benefit of enhancing security by making theft more difficult. In a further embodiment, the object may be a product or component of a product having relatively low monetary value, but having high performance value. For example, an aircraft component may be relatively inexpensive but the proper performance of the component is critical to the operation of the aircraft. In these applications, a counterfeit product not operating up to specifications can have enormous monetary and social impacts.
As shown in
RFID chip 114 includes, among other components, a memory for storing a tag identification number, referred to herein as “the tag ID.” In an embodiment, the stored tag ID is unalterable. The memory may also store other information (e.g., object specific data), as required by a particular application.
Because tag 110 is seamlessly embedded within object 100, the tag is preferably a passive tag. In general, a passive tag receives operating power from an incident interrogation signal. As would be appreciated by a person of skill in the art, an active tag (i.e., a tag having an internal power source) or a pass-active tag could be used with the present invention, based on the needs of a particular application.
RFID tag 210 includes an RFID chip 214 and an antenna (not shown) coupled to a substrate 212. Tag 210 includes an upper laminate layer 202 proximate to the upper surface of tag substrate 212 and a lower laminate layer 204 proximate to the lower surface of tag substrate 212.
RFID chip 214 includes, among other components, a memory for storing the tag ID. In an embodiment, the stored tag ID is unalterable. The memory may also store other information (e.g., object specific data), as required by a specific application.
In step 310, manufacturing and/or sales information is associated with the tag ID of an RFID tag encapsulated or partially encapsulated in an instrument. Step 310 is optional. When present, step 310 is typically performed by an instrument manufacturer and/or wholesale or retail distributor. For example, in step 310, a reader interrogates the encapsulated RFID tag to obtain the tag ID. Then, either manually or through another method (e.g., by scanning a bar code), details about the manufacturing and/or sales of the instrument (e.g., instrument type, serial number, sale date, parties to sale) are associated with the tag ID in a database. The database containing the tag IDs and associated information may be maintained by the manufacturer, wholesaler, and/or retailer of the instrument. Alternatively, the database may be maintained by a third party. For example, a national or regional medical association may maintain a database for tracking certain types of medical instruments for anti-counterfeiting purposes.
A medical facility may keep an inventory of all instruments owned or under the control of the medical facility. For example, the medical facility may log new instruments as they arrive to the facility. In addition, periodic inventories of the instruments in the facility may be performed. In step 320, a reader, operated by or for a medical facility (e.g., hospital) interrogates an RFID tag encapsulated or partially encapsulated in the instrument to obtain the tag ID. The reader then transmits the tag ID and optional associated information to a database maintained by or on-behalf of the medical facility.
The medical facility database includes a plurality of entries such, at least one per tag ID/instrument pair. Each entry includes information associated with the instrument such as serial number, manufacturer, date received by facility, sterilization information, and use information. In an embodiment, the medical facility may query a third party database to obtain additional history information or to verify the authenticity of the instrument. In addition, the medical facility may query the manufacturer to obtain information related to the manufacture of the instrument.
In step 330, one or more medical instruments having embedded RFID tags are tracked during a medical procedure (e.g., an operation, a check-up). Step 330 includes steps 335-368. Current methods for tracking instruments used in a medical procedure are primarily manual. In these methods, an individual makes a list or count of instruments assembled for use in the procedure. After the procedure, an individual checks instruments off against the list. This process is time consuming and prone to human errors. In addition, the procedure cannot be ended until all instruments are accounted for. Therefore, the length of the instrument verification process may extend the time period during which a patient is under anesthesia, increasing the risk to the patient. An automated process that increases the speed of and reduces the errors in instrument verification is highly desirable.
In step 335, a tray of medical instruments assembled for a procedure is scanned with an RFID reader. For example, the tray can be scanned by a directional RFID reader or a portal-type RFID reader located at the entrance of the procedure (e.g., door to the theater) or embedded in the instrument tray. As would be appreciated by a person of skill in the art, other types of RFID readers can be used to perform the scan operation. The scan operation reads the tag ID for each instrument located on the tray (or in the area covered by the directional interrogation signal) and generates a pre-procedure list of instruments. The reader stores the pre-procedure list of tag IDs present at the location (e.g., operating theater).
In step 336, the list is compared to a pre-existing list of instruments required for a specific procedure. Procedure specific trays (e.g., a knee tray or a hip tray) are meant to ensure that all the instruments required for the operating procedure are available beforehand. Automated checking of the tray contents prior to the procedure will reduce the chance of discovering, part way through a procedure, a required instrument was not included on the tray.
In addition, during the course of the procedure, the RFID tags can be read in real-time to track changes in the instrument count. These mid-procedure scans can be used to account for various situations, including the addition of instruments to the procedure location as and when the instruments are needed. In step 338, changes to the list of instruments are made based on mid-procedure scans.
In step 340, after the medical procedure is completed, the tray of medical instruments (and/or an area covered by the directional interrogation signal) is scanned with the directional RFID reader. The scan operation reads the tag ID for each instrument located on the tray and generates a post-procedure list of instruments.
In step 350, the RFID reader compares the pre-procedure list to the post-procedure list to determine if all pre-procedure instruments have been accounted for.
In step 360, a determination is made whether any pre-procedure instruments are unaccounted for. If one or more pre-procedure instruments are unaccounted for, operation proceeds to step 365. If all pre-procedure instruments are accounted for, operation proceeds to step 368.
In step 365, the medical procedure location (e.g., operating theater) is searched using the directional RFID reader to find the missing pre-procedure instruments. In an embodiment, the reader performs an interrogation for specific tag identification numbers identified as missing. In an alternate embodiment, the reader performs a general interrogation for any tags within its interrogation field. Operation returns to step 360.
In step 368, information regarding the procedure (e.g, tag IDs used, date/time of pre-procedure scan, date/time of post-procedure scan, result of scan) are transmitted to the facility database. This information is stored as use information in the database. Step 368 is optional.
Although some or all of the steps associated with the procedure instrument tracking application are described above as provided by an application program executing on the reader, a person of skill in the art will recognize that a reader could interact with an application executing on a remote server to perform some or all of the above steps.
After all the pre-procedure instruments have been accounted for, the instruments are sent for sterilization. Any method for sterilization can be used with instruments having seamlessly embedded RFID tags. For example, autoclaving (steam sterilization) or Ethylene DiOxide (EtO) sterilization can be used. Step 370 traces the movement of an instrument through the sterilization process. Step 370 may be performed any time an instrument with an embedded RFID tag requires sterilization. Step 370 includes steps 372 and 374.
In step 372, a reader scans an instrument upon the start of the sterilization process (e.g., entry to the sterilization vessel) to obtain the tag ID of the instrument. The tag ID is transmitted to the medical facility database, along with an optional indication of an action being taken (e.g., sterilization). In addition, information related to the sterilization process (e.g., time started, type of sterilization, etc.) can be transmitted to the database and/or associated with the tag ID in the database.
In step 374, a reader scans the instrument upon completion of the sterilization process (e.g., exit from the sterilization vessel). The tag ID associated with the instrument is transmitted to the medical facility database along with an optional indication of the action being taken (e.g., sterilization). In addition, information related to the sterilization process (e.g., time ended, type of sterilization, etc.) can be transmitted to the database and/or associated with the tag ID in the database.
In certain circumstances, an employee, agent, or person associated with a medical facility may require immediate access to the history of an instrument. For example, prior to use of an instrument, a physician may access the sterilization history of the instrument. In step 380, the history of a medical instrument is accessed. Step 380 includes steps 382-386.
In step 382, a reader scans a medical instrument to obtain the tag ID associated with the instrument.
In step 384, the reader transmits a request for information related to the tag ID/instrument. In an embodiment, the request for information may be for a specific type of information or a specific field.
In step 386, the database transmits the requested information to the reader which then displays all or a portion of the received information to the user. Based on the displayed information, an action may be performed on the instrument. For example, the instrument may be inspected for defects.
Tracking of the instruments, according to one or more of the above steps, continues until the final, safe disposal of the instrument. In step 390, the instrument is scanned upon transfer of the instrument from the medical facility to a facility for final, safe disposal. An instrument may be disposed of or recycled, if determined to be defective or at the end of its expected lifespan.
In step 410, the tag is laminated between two layers to generate a laminated tag structure. Step 410 is optional.
In step 420, the tag is prepared for affixing to the first portion of the object. A tag can be affixed to the first portion of the object mechanically or chemically, for example. In an exemplary mechanical method, one or more location holes are cut into the laminated tag structure. As can be seen in
In step 430, the laminated tag structure is affixed to the first portion of the object. In the exemplary mechanical method depicted in
In the exemplary chemical method, the surface of the laminated tag structure having the adhesive is coupled to a surface of the first portion of the object. As would be appreciated by persons of skill in the art, other chemical methods for affixing a tag structure to an object can be used with the present invention.
In step 440, the first portion 520 of the object is placed in a mold cavity.
In step 450, the first portion of the object is over-molded with a suitable material to create the second portion of the object. For example, as shown in
In step 460, the mold is removed.
In step 610, the tag is laminated between two layers to generate a laminated tag structure.
In step 620, the tag is prepared for affixing to a mold. In an embodiment, a tag is affixed to the mold mechanically. In an exemplary mechanical method, one or more suspension holes are cut in the laminated tag structure.
In step 630, the laminated RFID tag is suspended in a mold cavity.
In step 640, the laminated tag structure 710 is over-molded with a suitable material to create the object. In an embodiment, the laminated tag structure 710 is over-molded with a high temperature thermoplastic. Over-molding a thermoplastic film, such as used to laminate the RFID tag in step 610, is a proven technology often referred to as in-mold decorating (IMD).
In step 650, the mold is removed.
In step 810, the tag is laminated between two layers to generate a laminated tag structure. Step 810 is optional.
In step 820, the tag is prepared for affixing to the first portion of the object. A tag can be affixed to the first portion of the object mechanically or chemically, for example. In an exemplary mechanical method, one or more location holes are cut into the laminated tag structure. As can be seen in
In step 830, the laminated tag structure is affixed to the first portion of the object. In the exemplary mechanical method depicted in
In the exemplary chemical method, the surface of the laminated tag structure having the adhesive is coupled to a surface of the first portion of the object. As would be appreciated by persons of skill in the art, other chemical methods for affixing a tag structure to an object can be used with the present invention.
In step 840, the first portion 920 of the object is placed in a mold cavity.
In step 850, the first portion 940 of the object is over-molded with a suitable material to create the second portion of the object. For example, as shown in
In an alternate embodiment, in step 950, the second portion 945 of the object is created using compression molding.
In step 960, the mold is removed.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
