Histopathology cassettes with RFID tags

Abstract

There is disclosed a histopathology cassette comprising a substantially rectangular base and a perimetral sidewall extending upwardly from the base, the perimetral sidewall comprising four sidewall portions, and a radio frequency identification, RFID, tag incorporated within the perimetral sidewall, wherein the RFID tag comprises a chip element and an antenna element, and wherein the antenna element is disposed in at least three of the sidewall portions. Also disclosed is a tracking system comprising a plurality of RFID readers, and at least one histopathology cassette comprising an RFID tag. Also disclosed is a storage cabinet for storing a plurality of histopathology cassettes or slides, each comprising an RFID tag, the storage cabinet comprising at least one storage rack and an RFID reader mounted inside the storage cabinet and configured to read the RFID tags of histopathology cassettes or slides stored in the storage cabinet.

Description

HISTOPATHOLOGY CASSETTES WITH RFID TAGS

[0001] This invention relates to histopathology cassettes incorporating radio frequency identification (RFID) tags, and also to a tracking system and a storage cabinet for such histopathology cassettes.BACKGROUND

[0002] In the field of histopathology, it is common for tissue specimens to be taken from a patient and treated in various ways so as to preserve the tissue specimens and to prepare them in a manner that facilitates study and diagnosis. For example, a tissue specimen obtained by way of a biopsy may first undergo fixation, for example in a solution of formalin, so as to immobilise and preserve the tissue specimen in as life-like a state as possible. The fixated tissue specimen is then dehydrated, for example by replacing water in the fixated tissue specimen with ethanol, and optionally treated with further chemical solutions as required. The dehydrated, fixated tissue specimen is then embedded in a paraffin wax embedding medium and the paraffin wax embedding medium is allowed to cool and solidify, resulting in a solid wax block containing the fixated tissue specimen. Subsequently, thin sections of the embedded tissue specimen can be cut from the block using a microtome, and the thin sections of the embedded tissue specimen can be mounted on microscope slides, hereinafter histopathology slides, for examination by a medical professional. Histopathology slides can be retained for many years, as can the paraffin wax block containing the embedded tissue specimen. This allows further sections of the embedded tissue specimen to be cut at a later date for further examination. Moreover, there are stringent regulations in place regarding the proper preservation and storage of human tissue specimens, and it is important to be able to take new sections of a previously-obtained tissue specimen for diagnostic and monitoring purposes. Indeed, in some instances it may not be possible or may be undesirable to obtain a new tissue specimen from a patient, so it is important that the various tissue specimens are properly stored and easily retrievable at a later date.

[0003] During various of the processing steps outlined above, a tissue specimen, whether in its fresh state, fixated state, dehydrated state or embedded state, will be contained in a specialised cassette. The cassette typically takes the form of a generally rectangular tray with a slatted or perforated base and a perimetral sidewall. A slatted or perforated lid member can be removably fitted to the top of the perimetral sidewall so as to define a parallelepiped storage volume within the cassette. A front portion of theperimetral sidewall may have a sloped outer face configured to receive a label that identifies the cassette and optionally its contents. The slatted or perforated configuration of the base and the lid member allow fluids to enter into and exit from the storage volume, thus allowing treatment of a tissue specimen held within the storage volume.

[0004] Histopathology cassettes are generally provided in several different standardised sizes, adapted for different sizes of tissue specimen. The standardised sizes mean that the cassettes can easily be stored in standardised storage racks or trays, whether for temporary storage and transport, or for more permanent archive storage. The cassettes are typically made of plastics materials and may come in different colours for different types of tissue samples. The materials from which the cassettes are made need to be able to withstand harsh chemicals such as formalin and other organic solvents, as well as organic and inorganic acids and alkalis. The cassettes also need to be able to withstand heat due to molten paraffin wax and remain stable for many years.

[0005] It will be appreciated that histopathology cassettes, with their tissue sample contents, will pass through a number of different processing steps in a histopathology laboratory. It is vitally important to be able to keep track of each cassette and its contents at all stages of processing, otherwise cassettes and their contents may be lost or misplaced, or a tissue sample from one patient may accidentally become associated with the medical records of a different patient, which could have disastrous consequences.

[0006] Accordingly, in a histopathology laboratory, each histopathology cassette is provided with a label in the form of a 1 D or 2D barcode, as well as a human-readable identification number. The barcode needs to be scanned with a barcode scanner at each processing step so as to maintain a record of the location of the cassette and its contents, and to link diagnostic images and data obtained from the contents of the cassette with the correct patient record.

[0007] Problems can arise because the label with the barcode and human-readable number may become separated from the cassette due to the various harsh chemicals that are used to treat the tissue specimen. In addition, the adhesive used to stick the label to the cassette may weaken over time, allowing the label to fall off when the cassette is in archive storage. Another problem is that the use of barcodes requires a laboratory technician manually to scan each cassette as it arrives at or leaves a processing station, and if the technician accidentally does not scan a barcode on a cassette, its location may become unknown until the barcode is next scanned. Moreover, the location of the cassette is only established to the point of the most recent barcode scan. If a cassette is subsequently moved to a new location and not scanned, its location will remain unknownuntil such time as the cassette is next scanned. Accordingly, if a cassette falls off a laboratory bench or goes missing in transit, it may be impossible to find the cassette again.

[0008] More recently, attempts have been made to improve on the use of barcode labels by employing RFID tags in histopathology cassettes. Examples are known from US2010 / 0127067 and LIS2013 / 0022518. However, there remain a number of shortcomings with these prior art arrangements.

[0009] In particular, the RFID tags employed in the prior art histopathology tags have only a very short detection range, for example a few centimetres, and are designed so that a histopathology cassette with an RFID tag is scannable by holding the cassette directly in front of an RFID reader at a workstation at a distance of at most a few centimetres. In this regard, the functionality is very similar to an optically readable barcode label.BRIEF SUMMARY OF THE DISCLOSURE

[0010] Viewed from a first aspect, there is provided a histopathology cassette comprising a substantially rectangular base and a perimetral sidewall extending upwardly from the base, the perimetral sidewall comprising four sidewall portions, and a radio frequency identification, RFID, tag incorporated within the perimetral sidewall, wherein the RFID tag comprises a chip element and an antenna, and wherein the antenna is disposed in at least three of the sidewall portions.

[0011] In some embodiments, the RFID tag comprises a central chip element and an antenna comprising a pair of antenna elements, extending in opposite directions from the chip element. In these embodiments, the central chip element may be disposed in a first sidewall element, and the two antenna elements may extend from the central chip element in opposite directions in the first sidewall element. A first one of the antenna elements extends around a first corner and continues along a second sidewall portion of the cassette. A second one of the antenna elements extends around a second corner and continues along a third sidewall portion of the cassette, the third sidewall portion being opposed to the second sidewall portion. Optionally, the first one of the antenna elements may further extend around a third corner and continue along a fourth sidewall portion of the cassette, the fourth sidewall portion being opposed to the first sidewall portion. Optionally, the second one of the antenna elements may further extend around a fourth corner and continue along the fourth sidewall portion of the cassette. Optionally, both of the first and second antenna elements extend into the fourth sidewall portion.

[0012] In some embodiments, the RFID tag comprises a chip element and an antenna comprising a single antenna element. The single antenna element extends from the chipelement through at least three adjoining sidewall portions, optionally through all four sidewall portions.

[0013] The chip element and the antenna may be embedded in the perimetral sidewall so as to be sealed and protected from exposure to fluids when the cassette undergoes processing steps. This may be achieved by forming the cassette by way of injection moulding, and positioning the RFID tag appropriately within a mould prior to injecting liquid plastics into the mould.

[0014] Alternatively, the perimetral sidewall of the cassette may be formed with a cavity between inner and outer surfaces of the perimetral sidewall, the cavity adapted to receive the chip element and the antenna of the RFID tag so that the antenna can extend around the sidewall portions as described above.

[0015] The cavity can be sealed after the RFID tag has been fitted into the perimetral wall, for example by gluing or welding, for example ultrasonic welding, one or more coping or capping members to the top of the perimetral sidewall. Alternatively, the cavity with the inserted RFID tag may be sealed by injecting a sealing compound into the cavity.

[0016] Sealing the RFID tag in the cavity or embedding the RFID tag within the cassette during injection moulding helps to provide additional isolation from the various solvents and chemicals to which a histopathology cassette is typically exposed. These include formaldehyde, ethanol, xylene and wax, sometimes at elevated temperatures and pressures. Advantageously, the chip element of the RFID tag may itself already be configured to be resistant to the various solvents and chemicals and elevated temperatures, for example by appropriate selection and design of the chip package. Advantageously, the RFID tag may itself already be configured to be resistant to the various solvents and chemicals and elevated temperatures, for example by appropriate selection and design of a dielectric substrate on or in which the antenna is disposed. Histopathology cassettes can be subject to rough handling, and it is therefore advantageous to provide several levels of protection from external chemical and physical conditions.

[0017] The base of the cassette may be slatted or perforated so as to allow passage of fluid therethrough.

[0018] The cassette may further comprise a removable lid portion that is engageable with the perimetral sidewall so as to define a storage volume in the cassette.

[0019] The lid portion may be slatted or perforated so as to allow passage of fluid therethrough.

[0020] The provision of a removable lid portion allows a tissue specimen to be securely held in the storage volume, for example when the tissue specimen is undergoing fixation or embedding.

[0021] The slatted or perforated base and, where provided, lid portion allows treatment chemicals to be applied to the tissue specimen while the tissue specimen is held within the storage volume.

[0022] In preferred embodiments, the antenna comprises first and second antenna elements, and the first and second antenna elements are each configured as a conductive trace on or in a dielectric substrate. The conductive trace of each of the first and second antenna elements may have a meander portion. Thus, it is possible to have an electrical length that is greater than a physical length of the flexible dielectric substrate. For example, a flexible dielectric substrate having a length of approximately 100mm (in some examples about 97mm) and a width of approximately 5mm can accommodate a central chip element and first and second antenna elements each having a meander portion and each having a trace length of approximately at least 110mm (in some examples, a total trace length of approximately 220mm, for example 222mm). The substrate may have a thickness of no more than 0.2mm, optionally no more than 0.1mm.

[0023] The dielectric substrate may be a flexible dielectric substrate.

[0024] However, in some embodiments, it may be desirable for the dielectric substrate to be relatively rigid. For example, the RFID tag may comprise a substantially rigid dielectric substrate that is configured to hold a shape with a linear base and two substantially parallel and coextensive linear sidewalls extending at right angles from opposed ends of the linear base. In some embodiments, the linear sidewalls may have top extensions that are arranged substantially parallel to the linear base and extend towards each other. An advantage of embodiments with a substantially rigid dielectric substrate, or a dielectric substrate that can hold a substantially II shaped configuration or a shape extending over four sides of a rectangle, is that an RFID tag with such a dielectric substrate may be easier to insert in the channel of a histopathology cassette, or may provide a better defined shape around which a histopathology cassette may be injection moulded. In such embodiments, the dielectric substrate may have a greater thickness than a flexible dielectric substrate. For example, the dielectric substrate may have a thickness of at least 0.5mm, or at least 1.0mm.

[0025] In some embodiments, the first and second antenna elements each comprise a meander portion comprising at least 10 changes of direction. Typically, a change of direction will be approximately a 90 degree change of direction. Each meander portion may comprise, for example 10, 12, 14, 16, 18, 20 or more changes of direction.

[0026] Each meander portion may have a generally crenelated configuration. Crenels of the crenelated meander portion may have a height of approximately 4mm. Crenels of the crenelated meander portion may have a width of approximately 3mm.

[0027] Ends of the first and second antenna elements distal from the chip element may comprise patch elements. For example, a conductive patch element of width approximately 4mm and length approximately 20mm, for example 21mm, may be provided at the distal end of each meander portion.

[0028] The chip element may have dimensions of approximately 2mm by 1.2mm by 0.5mm.

[0029] The RFID tag is preferably a passive type RFID tag that modulates an interrogating electromagnetic signal with a characteristic modulation that allows the RFID tag to be uniquely identified. The specifics of such RFID tags will be known to the skilled reader. Passive type RFID tags do not require a battery for operation.

[0030] In embodiments of the present disclosure, the antenna element or antenna elements are not configured to form a complete loop around the perimetral sidewall of the histopathology cassette. In embodiments of the present disclosure, the antenna element or antenna elements do not overlap on themselves or constitute more than one turn around the perimetral sidewall. In embodiments of the present disclosure, the antenna element or antenna elements do not have a helical-wound configuration, but are configured to extend for less than one complete loop or circuit around the perimetral sidewall of the histopathology cassette. This can help to reduce unwanted induction effects in the antenna elements.

[0031] By configuring the antenna so as to extend around at least three of the four sidewall portions, a number of surprising technical advantages are obtained. The RFID tag embedded in the cassette can be interrogated and identified from a much greater distance that is possible with a barcode scanner or a known histopathology cassette with a small RFID tag in only one sidewall portion. The additional antenna length enables greater sensitivity and interaction with an interrogating electromagnetic signal. Moreover, extending the antenna around three of the sidewall portions means that the antenna has portions that are orthogonal to each other, and this can avoid loss of sensitivity due to an antenna being aligned in a direction in which it does not interact sufficiently with the interrogating electromagnetic signal. As a result, it becomes possible to detect and identify an RFID tag in a cassette from a distance of over 1m, or over 2m, or over 3m, or over 5m, or up to 6m, or up to 9m, or up to 10m. This means that an RFID reader can be mounted at a workstation, for example in a ceiling or on a wall of a laboratory, and can automatically detect and log all cassettes that pass under or close to the reader without the need for anyextra scanning step by the laboratory technician. RFID readers can also be mounted at other strategic locations, for example at various points on the ceiling or walls, or at doorways, or on laboratory workstations, thus establishing a system that can track and locate any number of cassettes within a given environment.

[0032] Additionally, where a plurality of RFID readers are provided in a laboratory, for example mounted in the ceiling or on walls and optionally at various workstations or doorways, it is possible to use triangulation techniques so as to pinpoint a real-time location of any given cassette within the laboratory. This can be integrated into a laboratory information management system.

[0033] It is also possible to use handheld RFID scanners to locate cassettes with greater precision, for example where a collection of cassettes is present in a carrying case or storage drawer and it is desired to pinpoint the location of a particular cassette.

[0034] In addition to the RFID tag, each histopathology cassette may also be provided with human- or machine-readable indicia, such as an identification code, a barcode, or a 2D barcode such as a QR code. The human- or machine-readable indicia are preferably printed or etched directly onto a visible surface of the histopathology cassette. The printed or etched indicia are preferably resistant to solvents including water, ethanol and formalin. Where the indicia are directly printed on the surface of the histopathology cassette by way of a solvent-resistant ink, the ink is preferably flash dried before the histopathology cassette is used.

[0035] Viewed from a second aspect, there is provided a tracking system comprising a plurality of RFID readers, and at least one histopathology cassette of the first aspect.

[0036] The RFID readers may be mounted in a ceiling or walls of a laboratory. The RFID readers may be mounted at or above doorways. Alternatively or in addition, RFID readers may be mounted at processing stations, for example on or above laboratory benches, or incorporated into processing station equipment such as fixation stations, dehydration stations, wax stations, microtomes, microscopes, staining stations and the like.

[0037] In the context of the present application, the term “RFID reader” is used to denote a device comprising at least one antenna configured to transmit an RFID interrogation signal and to receive an RFID response signal from an RFID tag. An RFID reader may additionally comprise circuitry to control the RFID interrogation signal or to interpret the received RFID response signal. Alternatively, the circuitry may be located at a location away from the at least one antenna. For example, a plurality of wall or ceiling mounted antennas (RFID readers) in different locations may be operatively connected to a single central RFID processor, for example by way of a network. In this way, it may only benecessary to install RFID reader antennas around a laboratory, with all signal processing being done centrally. This may result in a cheaper and more efficient installation than one in which each RFID reader includes its own RFID processing circuitry.

[0038] The RFID readers are operatively connected to a computer system comprising a database. The database stores a unique identification code of the RFID tag of the at least one histopathology cassette. The database may optionally associate the unique identification code of the RFID tag with a unique patient identifier so as to identify the patient from whom the tissue specimen has been obtained. The database may further associate the unique identification code of the RFID tag with the contents of the at least one histopathology cassette. The database may further associate the unique identification code of the RFID tag with data relating to the tissue specimen contained in the at least one histopathology cassette. The data may include image data. The data may include diagnostic data. The data may include text data. The data may include numerical data.

[0039] The tracking system may be configured to analyse signals obtained from the plurality of RFID readers so as to determine a position within the laboratory of any given histopathology cassette. The determination may be made by way of triangulation. The determination may be made by analysing respective response signal strengths for a given RFID tag in a given histopathology cassette received by different RFID readers. Alternatively or in addition, position determination may be achieved by using phased array RFID reader antennas that are configured to perform beamsteering.

[0040] Triangulation may be undertaken on the basis of measuring received signal strength (RSS), for example by calculating a received signal strength indicator (RSSI) a given RFID tag at a plurality of (generally at least three) RFID readers. RSSI can be a good indication of how well a given RFID tag will respond in a given environment, and can give a general indication of a distance of an RFID tag from an RFID reader. In order to improve accuracy, and to take into account environmental factors, it may be advantageous also to determine other parameters, such an RFID tag read rate (the number of times a given RFID tag is read per second), and / or response time (the amount of time it takes for a given RFID tag to respond for the first time to an interrogating signal).

[0041] The system may further comprise at least one handheld RFID scanner. The at least one handheld RFID scanner may be used to pinpoint a location of a given histopathology cassette once a general location has been determined by way of the RFID readers. This may be useful to find a given histopathology cassette in a tray of other histopathology cassettes.

[0042] The system of the second aspect may also comprise at least one histopathology slide provided with an RFID tag.

[0043] A histopathology slide is a microscope slide on which is mounted a slice or section taken from a tissue sample that has been processed and embedded in paraffin wax. As previously explained, processed tissue samples embedded in wax are transported and stored in histopathology cassettes, and slices or sections of the wax- embedded tissue samples are taken using a microtome. The slices or sections are then mounted on a glass microscope slide, usually under a glass cover slip, and optionally stained to aid visualisation. In addition to each histopathology cassette being provided with an RFID tag as in the first aspect, each histopathology slide may also be provided with an RFID tag. The form factor of RFID tags for histopathology slides will be different to the form factor of the RFID tags for the histopathology cassettes. Typically, an RFID tag on a histopathology slide will be substantially planar, and it may extend in two dimensions within the plane of the histopathology slide.

[0044] It will be noted that a single wax-embedded tissue sample from a single histopathology cassette will typically generate a plurality of histopathology slides each comprising a different slice or section of the same tissue block. Accordingly, the plurality of histopathology slides may be assigned individual identifiers as a subset of a higher level identifier of the histopathology cassette containing the tissue block in question. In turn, the higher level identifier of the histopathology cassette is associated with a patient record identifier to link everything together with the hospital or laboratory records for a given patient.

[0045] Viewed from a third aspect, there is provided a storage cabinet for storing a plurality of histopathology cassettes or slides, each comprising an RFID tag, the storage cabinet comprising at least one storage rack and an RFID reader mounted inside the storage cabinet and configured to read the RFID tags of histopathology cassettes or slides stored in the storage cabinet.

[0046] The at least one storage rack may comprise a horizontally slidable storage rack moveable between an opened position, allowing access to the histopathology cassettes or slides held in the storage rack, and a closed position, in which the storage rack is contained within the storage cabinet. The at least one storage rack may be mounted to the inside of the storage cabinet by runners so as to allow for easy movement between opened and closed positions.

[0047] The storage cabinet may comprise at least five, or at least ten, or at least fifteen, or at least twenty storage racks. The storage racks may be arranged in parallel with each other as a vertical stack of substantially horizontal storage racks.

[0048] Each storage rack may be configured to hold a plurality of histopathology cassettes or slides in a substantially two dimensional array. In other words, each storagerack may be configured to hold M rows of histopathology cassettes in N columns, where N and M are positive integers, the same or different. In some embodiments, N may be at least 4, optionally at least 5, optionally at least 6. In some embodiments, M may be at least 5, optionally at least 10, optionally at least 20, optionally at least 30. The histopathology cassettes or slides may be stored horizontally, vertically, or at some angle therebetween. Generally speaking, vertical or near vertical storage allows a larger number of histopathology cassettes or slides to be stored in a single storage rack while still allowing easy access. The storage rack may be provided with dividers and grooves that define a plurality of storage locations each adapted to receive a single histopathology cassette or slide.

[0049] Accordingly, each histopathology cassette or slide stored in the storage cabinet will have a unique location, addressable by specifying a particular storage rack and a particular row and column of the storage rack.

[0050] The RFID reader may be mounted on an inside wall of the storage cabinet. For example, the RFID reader may be mounted on an inside rear wall, an inside side wall, an inside lower wall or an inside upper wall. Optionally, more than one RFID reader may be mounted inside the storage cabinet.

[0051] The at least one RFID reader may have a generally flat or planar configuration so as not to interfere with the movement of the storage racks between opened and closed positions.

[0052] By providing the at least one RFID reader inside the storage cabinet, it becomes easier to read the plurality of RFID tags and to perform an inventory of the contents of the storage cabinet. This is particularly the case where the storage cabinet comprises a metal housing, which might otherwise form a Faraday cage that could shield the RF tags within the storage cabinet from an external RFID reader mounted in a ceiling or wall of the room in which the storage cabinet is located.

[0053] The at least one RFID reader may be configured to determine not just the presence of a given histopathology cassette or slide within the storage cabinet, but also a location of the given histopathology cassette or slide, with reference to storage rack and row and column within the storage rack. This may be achieved by known techniques such as time-of-flight, signal strength and / or triangulation.

[0054] The at least one storage rack may be provided with or interact with an electrical switch in the storage cabinet configured to activate the at least one RFID reader when the storage rack is moved to the closed position. In this way, the RFID reader may perform a scan of the contents of the storage cabinet each time a storage rack is moved from theopened to the closed position. Thus, it is possible to maintain an up-to-date inventory of the contents of the storage cabinet each time is opened and closed, since it is during times that a storage rack is in the opened position that histopathology cassettes or slides will be removed from or added to the storage cabinet.

[0055] In the various aspects and embodiments outlined above, the RFID readers may interrogate the RFID tags using a standard RFID protocol. Anti-collision algorithms such as the adaptive Q algorithm may be employed to distinguish between different RFID tags in a given environment. The RFID readers and RFID tags may be configured for operation in an ultra high frequency (UHF) band (typically from around 400MHz to 1000MHz), or a microwave band (typically from around 2400 to 6000MHz) when using passive RFID tags. Generally speaking, higher frequency bands allow for greater range. It has been found that RFID readers and RFID tags operating in frequency bands of the order of 10s of MHz and below do not allow detection over distances of 1 metre.

[0056] RFID readers and RFID tags operating in microwave bands may use parts of the electromagnetic frequency spectrum that are also used for WiFi communication. WiFi signals can be used as part of a real-time location system (RTLS), although currently this generally requires the use of active RFID tags. Advances in WiFi router technology may either allow modulation of their frequencies or may allow the integration of RFID readers and RFID tags. This may enable access to new protocols for the router and therefore may enable the implementation of a multi-functional / multi-channel WiFi router capable of reading both active and passive RFID tags.

[0057] In order to take advantage of the pre-existing hospital infrastructure, hospitals and laboratories may in future wish to utilise their WiFi routers to be used for both data connectivity and transfers, as well as to read RFID tags. Currently WiFi is not capable of reading passive RFID tags, but battery-free RFID tags may become a requirement in many areas within a hospital setting where the inclusion of a battery may not be appropriate, such as autoclave, biological high-risk areas, chemical processing, high temperature areas, etc. Accordingly, passive RFID tags are preferred, both for safety reasons and to avoid the expense of battery replacement and the risk of RFID tags becoming undetectable without power.

[0058] As noted above, RFID tags generally comprise a chip element and an antenna element. Commercially-available RFID chip elements are programmed with a unique reference code at manufacture. Typically, the unique codes are allocated under the Electronic Product Code (EPC) standard, for example as administered by EPCglobal®, a not-for-profit joint venture set up by the Uniform Code Council and EAN International. This means that every RFID chip element will have a unique reference code, which means thatan RFID tag incorporating the chip element can be uniquely identified. An EPC is typically a 24 digit alphanumeric sequence that is programmed into the RFID chip element during manufacture of the RFID tag. In most instances, EPCs are encoded on RFID tags which can be used to track all kinds of objects including: trade items, fixed assets, documents, or reusable transport items. An EPC typically comprises a header, and EPC manager number, an object class and a serial number. The specifics of EPC syntax will be understood by those skilled in the art, and will not be described further in the present application.

[0059] In a hospital and / or histopathology laboratory setting, it is also known to assign a unique internal identifier to each patient sample. This enables tracking of patient cases through a complex series of processing steps in preparation for sample analysis and diagnosis. The histopathology department at the Leeds Teaching Hospitals NHS Trust, for example, uses a Leeds Histology number (LH number). This unique identifier comprises the letters LH, followed by the year the case was created, and then a 5-digit unique identifier, e.g., LH23-99999.

[0060] Given that a patient case may contain multiple samples (bits of tissue), there is also a secondary level or sub-identifier which captures these additional tissue samples. This takes the form of a letter i.e. ‘A’, ‘B’, ‘C’, etc. which is tagged onto the end of the Leeds Histology number, for example LH23-99999_A.

[0061] The tissue sample is then embedded in wax within a histopathology cassette. At this stage, an additional sub-identifier is used, for example LH23-99999_A_1.

[0062] Any slides sectioned from this sample cassette may be identified by a unique 3- digit number identifier, for example LH23-99999_1_1_1.

[0063] Other internal identifier schemas may be used. What is important is that in each schema, there is an overarching identifier in a first format that identifies a particular patient case, with a first subset in a second format that identifies a particular tissue sample relating to the patient record, a second subset (a subset of the first subset) in a second format that identifies individual cassettes containing tissue from the particular tissue sample, and a third subset (a subset of the second subset) in a third format that identifies individual slides bearing tissue sections taken from an individual cassette.

[0064] Typically, the second and third formats will include the overarching identifier of the first format, but with additional data elements identifying the cassette and / or slide as appropriate.

[0065] The identifier data, whether in the first format, second format or third format, is typically encoded in the form of an optically-readable 1D or 2D barcode applied to acontainer holding the tissue sample, or to a histopathology cassette, or to an individual slide, as appropriate.

[0066] The nomenclature used by the histopathology laboratory therefore contains important process information that enables a robust, trackable and above all, safe system for patient tissue sample production, identification, and analysis.

[0067] Deploying an RFID-based, real-time tracking system raises an important problem. Each RFID tag has its own unique identifier (usually made up of a 24-digit alpha-numeric sequence, often referred to as an EPC or Electronic Product Code value), which can be used to enable tracking and identification of each RFID-tagged patient sample, but this is not natively linked to the process logic in the histopathology laboratory and needs to be linked to both the Histology number and the patient identifiers. This can be managed in a database managed by the histopathology laboratory by linking the EPCs of the RFID tags with patient and / or sample identifiers used in the histopathology laboratory.

[0068] However, many RFID chip elements may have sufficient spare memory to allow additional identifying data to be written to and read from the chip element after manufacture. Accordingly, it is possible for a histopathology laboratory (or other user of the system of embodiments of the present disclosure) to supplement the EPC value that is already programmed into the chip element of each RFID tag with a local identifier, such as a patient or sample identifier, thus allowing the RFID tags to be directly associated with particular patient or sample records without the need to correlate between EPC and local identifiers each time an RFID tag is interrogated.

[0069] For example, when an empty histopathology cassette or slide, incorporating an RFID tag, is selected for preparation with a tissue sample, it may be readied for use by placing the cassette or slide in a printer. If the printer incorporates an RFID reader linked to the tracking system, it becomes possible to read the EPC value, associate the EPC value with a desired local patient or sample identifier, and to write the local patient or sample identifier to the chip element of the RFID tag, either in place of or to supplement the existing EPC value. Optically-readable indicia representative of the local patient or sample identifier, for example in the form of a 1D or 2D barcode, can be printed on the cassette or slide by way of the printer so as to provide an additional way of identifying the cassette or slide and its tissue sample.

[0070] It may not be necessary to use a printer provided with an RFID reader. Instead, the chip element of the RFID tag of an empty cassette or slide may simply be programmed with an appropriate local patient or sample identifier (either by overwriting the EPC or by supplementing the EPC) at a workstation comprising an RFID reader and an RFID writer without also printing optically-readable indicia on the cassette or slide.

[0071] In this way, it becomes possible to track the cassettes or slides in a real time location system using either the EPC, or the local patient or sample identifier, or both, depending on the identifier data that is written in the chip element of the RFID tag.BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:Figure 1 shows an example of a histopathology cassette;Figure 2 shows another example of a histopathology cassette provided with a lid portion;Figure 3 shows a further example of a histopathology cassette provided with a lid portion;Figure 4 shows an RFID tag for use with the histopathology cassettes of Figures 1 to 3;Figure 5 shows a comparison of maximum read distance at different interrogation frequencies for two different RFID tags;Figure 6 shows, in schematic form, an RFID-enabled histopathology cassette in a laboratory and an RFID reader mounted at the ceiling;Figure 7 shows a plan view of a histopathology laboratory provided with a plurality of RFID readers;Figure 8 shows a storage cabinet for storing a plurality of histopathology cassettes or slides; andFigure 9 shows a schematic plan view of a laboratory space with an RFID reader mounted in each of four corners.DETAILED DESCRIPTION

[0073] Figure 1 shows an example of a histopathology cassette 1 comprising a substantially rectangular base 2 and a peripheral sidewall 3 extending upwardly from the base 2. The peripheral sidewall 3 comprises four sidewall portions 4, 5, 6, 7. In Figure 1 , each sidewall portion 4, 5, 6, 7 is substantially at right angles to its adjoining neighbour sidewall portions, and substantially orthogonal to the base 2.

[0074] The base 2 is preferably provided with perforations 8, for example by way of being slatted, so as to allow fluid to pass through the base 2.

[0075] One of the sidewall portions 4 (at the front of the cassette 1) may have a sloped outer face 9. The sloped outer face 9 provides a convenient surface on which human readable indicia may be provided, for example by way of an adhesive label, or direct printing, writing or etching.

[0076] Although not shown in Figure 1 , the cassette 1 may have a removable openable lid portion 10. This is shown in Figure 2, which shows an underside of a cassette 1. The removable or openable lid portion 10 may be hingedly connected to one of the sidewall portions 6, and may have a tab portion 11 so as to facilitate opening and closing of the lid portion 10. The lid portion 10 may have a snap-fit engagement with at least a portion of the peripheral sidewall 3 so as to allow a tissue specimen (not shown) to be securely contained in the cassette 1 when the lid portion 10 is closed. The lid portion 10 may also be provided with perforations 8, for example by way of being slatted, so as to allow fluid to pass through the lid portion 10.

[0077] Returning now to Figure 1 , the peripheral sidewall 3 may comprise a cavity 12 between inner and outer surfaces of the peripheral sidewall 3. The cavity 12 may be formed in at least three of the sidewall portions 4, 5, 7. In the embodiment of Figure 1 , the cavity 12 has a generally U-shaped configuration.

[0078] Figure 3 shows an alternative histopathology cassette 1 , similar in construction to the histopathology cassette of Figures 1 and 2, but with a cavity 12 that is formed in all four of the sidewall portions 4, 5, 6, 7. In the Figure 3 embodiment, the cavity 12 extends inwardly from either end of the fourth sidewall portion 6, but the ends 13 of the cavity 12 do not meet. This can facilitate correct placement of an RFID tag within the cavity 12.

[0079] The cassette 1 may be made of a plastics material. The cassette 1 may be made of a synthetic resin material The cassette 1 may, for example, be made of one or more of polyurethane resin, polyoxymethylene resin, or acrylonitrile-butadiene-styrene copolymer. The cassette 1 may be made of polyurethane 8150, for example Hei-Cast 8150.

[0080] Figure 4 shows an RFID tag 20 comprising a flexible dielectric substrate 21 and a central chip element 22 mounted on the dielectric substrate 21. The RFID tag 20 further comprises first and second antenna elements 23, 24 that extend from the chip element 22 in opposite directions along the dielectric substrate 21. The first and second antenna elements 23, 24 comprise electrically conductive traces that may be etched or printed or otherwise formed on or in the dielectric substrate 21. The traces of the first and second antenna elements 23, 24 may each comprise a meander portion 25 so as to increase theirelectrical length relative to a spatial length that is available on or in the dielectric substrate 21.

[0081] In the example in Figure 4, the flexible dielectric substrate 21 has a length of 9.7cm, a width of 0.5cm and a thickness of about 0.1mm. The central chip element 22 has dimensions of approximately 2mm by 1.2mm and a thickness of about 0.5mm. The first antenna element 23 comprises a conductive trace connected at a proximal end to the central chip element 22 and extending to a distal end at one end of the flexible dielectric substrate 21. The second antenna element 24 comprises a conductive trace connected at a proximal end to the central chip element 22 and extending to a distal end at the other end of the flexible dielectric substrate 21. The total length of the conductive trace of both the first and second antenna elements 23, 24 (if the conductive trace were stretched into a straight line, i.e. the electrical path length) is approximately 22.2cm. The conductive trace of each of the first and second antenna elements 23, 24 comprises a distal conductive patch element 26 connected to the central chip element 22 by way of a meander portion 25. In the meander portions 25, the conductive trace has a crenelated configuration with 14 right-angled turns. The meander portions 25 allow the conductive trace to have a longer electrical length than the physical length available on the flexible dielectric substrate 21. In the example shown in Figure 4, the distal patch portions 26 each have a length of about 2.1cm and a width of about 0.4cm. Each meander portion 25 has a horizontal extent of about 1 ,6cm, but an electrical length of at least twice the horizontal extent.

[0082] A chip element 22 that has been found to be effective is the LXMS21ACMF-218 chip available from Murata Manufacturing Co., Ltd., although other chip elements may be used as required.

[0083] The RFIG tag 20 of Figure 4 displays substantial mirror symmetry on either side of the central chip element 22. However, in other variations, the first and second antenna elements 23, 24 may have different configurations from each other, or different electrical path lengths.

[0084] The RFID tag 20 of Figure 4 is inserted into the cavity 12 of the histopathology cassette 1 of Figures 1, 2 or 3, with the central chip element 22 positioned centrally in the sidewall portion 4 at the front of the histopathology cassette 1. The flexible dielectric substrate 21 is thus substantially parallel to the peripheral sidewall 3 and coextensive with at least three of the sidewall portions 4, 5 and 7 (Figure 1) or can extend to a fourth sidewall portion 6 (Figure 3).

[0085] Although not shown in Figures 1 to 3, the RFID tag 20 is preferably sealed in the cavity 12, for example by applying a resin filling to the cavity 12 after the RFID tag 20 has been inserted, or by integrally moulding the RFID tag 20 into the histopathology cassette 1during an injection moulding process. This allows the RFID tag 20 to be protected from any harsh environments to which the histopathology cassette 1 may be exposed, including heat and chemical solvents.

[0086] In some variations, the dielectric substrate 21 is not a flexible dielectric substrate, but instead can hold a substantially U-shaped configuration without external support. This can facilitate insertion of the RFID tag 20 into a histopathology cassette 1.

[0087] By allowing the incorporation of an RFID tag 20 comprising antenna elements 23, 24 with a greater electrical path length, it is possible to increase a distance from which the RFID tag 20 can be read by an RFID reader, which opens up new possibilities in histopathology sample management in a laboratory.

[0088] The chip element 22 is coded with a unique identification code. When the RFID tag 20 is interrogated by an electromagnetic signal transmitted from an RFID reader (not shown), an RF current is induced in the antenna elements 23, 24 and passes to the chip element 22. The chip element 22 can modulate the RF current using the unique identification code, and the antenna elements 23, 24 have then be used to transmit a modulated RF signal back to the RFID reader. The RFID reader can detect the modulated RF signal from the RFID tag 20 and can decode the modulated RF signal to recover the unique identification code. The unique identification code can be compared against a list of identification codes stored in a computer database so as to identify the RFID tag 20 and to confirm its presence in a given location.

[0089] Figure 5 shows a comparison between a planar RFID tag of length 35mm by width 5mm disposed on a single sidewall of a dummy cassette and an embodiment of the present disclosure comprising an RFID tag of length 97mm by width 5mm disposed on three sidewalls of a dummy cassette. The RFID detection and read range of the planar RFID tag on the dummy cassette is always less than 1m, whereas the RFID detection and read range of the embodiment of the present disclosure is always above 1m, regardless of relative orientation of the RFID tag to the RFID reader. The best results are obtained at RFID reader operating frequencies above 950MHz.

[0090] In addition, by appropriate control of at least one, preferably more than one, RFID reader, it is possible to pinpoint a location of a given RFID tag 20, and hence of a given histopathology cassette 1 , in a laboratory environment.

[0091] After dissection of patient tissue, a tissue sample is into the RFID-enabled histopathology cassette 1. The tissue sample and the unique RFID identification code of the RFID tag are associated in a computer system with a specific patient record, for example by way of a laboratory number. The histopathology cassette 1 with the tissuesample is then subjected to various processing steps, for example fixation and dehydration of the tissue sample, and the tissue sample in the histopathology cassette is then embedded in paraffin wax. The histopathology cassette 1 with the wax embedded tissue sample may be referred to as an RFID block. The RFID-block is linked to a specific patient record by way of the laboratory number and the unique RFID identification code. The location of the RFID block can be tracked in real time, therefore any transport of the RFID block within a histopathology department can be tracked ‘live’.

[0092] The RFID block can be tracked by wall or ceiling mounted RFID readers, comprising RFID antennas, which are placed around various processing areas across the laboratory, e.g., tissue dissection room, tissue processing room, tissue embedding area, tissue trimming area, tissue sectioning area and tissue staining area. Advantageously, RFID readers antennas are also placed in the block / slide storage areas to create an effective tracking system.

[0093] Specific processing stations, for example dissection stations, fixation stations, dehydration stations, embedding stations, microtomes, microscopes, staining stations etc. may be provided with integral RFID readers configured automatically to read the RFID tags of histopathology cassettes that pass through the processing stations. This removes the need for an operator manually to scan a barcode on the histopathology cassette each time a cassette enters or leaves the station. In this way, it is possible to track any given histopathology cassette through an entire laboratory pathway, from initial placement of a fresh tissue sample into the cassette all the way through to eventual storage or archive. This allows improved auditing, which is very important when handling human tissue samples. The pathway tracking can also enable the provision of useful predictive information as to when useful diagnostic data relating to the tissue sample will be available for consideration by medical staff.

[0094] Furthermore, if an RFID block is misplaced or lost, the tracking system can search all areas for that specific RFID tag, and its location can be found.

[0095] In addition to the large, wall or ceiling mounted fixed antennas, precise tracking of the RFID blocks may be supplemented using handheld RFID scanners that enable the user to pinpoint the precise location, or to home into a signal.

[0096] It is often necessary to perform further work or testing on wax embedded tissue samples, and in existing laboratory scenarios this involves manually finding the relevant histopathology cassette with the wax embedded tissue sample (i.e. a non-RFID enabled block) once a request has been made. Locating the histopathology cassette is time consuming and labour intensive, and can lead to delays in diagnosis if the histopathology cassette cannot be found quickly. Data suggests up to 7 hours per working day arewasted through this activity. Moreover, loss of histopathology cassettes and wax embedded tissue samples could lead to patient harm.

[0097] Wall or ceiling mounted RFID readers with a relatively large detection and identification range can be used to track the location of the RFID block in larger areas, and a handheld RFID scanner can then be used to pinpoint the location of the RFID block. Individual processing stations can also be provided with built-in RFID readers so as to monitor and audit passage of an RFID block through the laboratory. This technology can also be used to record movement of RFID blocks from areas within pathology and between departments, external organisations, research facilities and long-term storage areas.

[0098] Figure 6 shows, in schematic form, an RFID block (histopathology cassette 1) on a worktop 60. A ceiling mounted RFID reader 61 transmits an interrogation signal and the RFID tag 20 in the RFID block responds by emitting a response signal, which is received by the RFID reader 61. In the illustrated example, the read range of the RFID tag 20 in the histopathology cassette 1 is up to 6m.

[0099] In a wall or ceiling mounted RFID reader, fixed antennas transmit radio frequency signals that stimulate RFID tags to broadcast information back to the fixed antennas, thus allowing detection of specific RFID tags.

[0100] When considering the signal strength of the RFID tag, a combination of factors must be examined.

[0101] As discussed above, one factor is the small form factor of a histopathology cassette 1 , and this is addressed by adapting the cassette to incorporate an RFID tag with longer antenna elements that extend around at least three sides of the cassette.

[0102] One of the many advantages which derives from integrating RFID technology into the cassette is that mistakes due to misidentified blocks or failure to scan correctly can be avoided. An example might be when a block ‘A’ is scanned (using a prior art barcode scanner) into the tracking system during the sectioning stage of the process. The computer screen displays the required ‘protocol” (stains, number of sections, types of sections, etc). Once successfully sectioned, the user will move on to the next block, so block ‘B’ is picked up and placed onto the block holder of the microtome for sectioning. If the user forgets to scan block ‘B’ into the tracking system using a barcode scanner, the protocol for block ‘A’ remains displayed on screen, which leads to inappropriate sectioning of block ‘B’.

[0103] The system of the present disclosure can prevent the above-mentioned scenario by always supplying the most up-to-date information immediately from the interpretation of signalling and proximity. Once a block is placed into the microtome for sectioning, theRFID signal can be used to display the correct protocol each time, and thus avoiding the need to scan a block or be reliant on user interactions. RFID readers with a small detection range, mounted at particular workstations, could be used for this purpose. Some RFID readers may require physical contact in order for a read to take place.

[0104] Using customised RFID-enabled cassettes and appropriate wall or ceiling mounted RFID readers will provide the best coverage for the assets. The read range may be optimised through the strategic positioning of the wall or ceiling mounted RFID readers. This may also extend to doorways, corridors, offices, and laboratories. This tracking information can be stored locally on a server and integrated into hospital systems, allowing other departments to track their patient tissue.

[0105] Figure 7 shows a schematic plan view of a laboratory space 70 with a plurality of wall and ceiling mounted RFID readers in the form of RFID antennas 71 mounted at strategic locations. The RFID antennas 71 may be mounted to a wall or ceiling by way of a mount 72. The mount 72 may allow the RFID antennas to be rotated or moved so as to aid in tracking. The RFID antennas are operatively connected, for example by suitable cabling, to RFID processing circuitry 73. Several RFID antennas may share the same RFID processing circuitry 73. The RFID processing circuitry 73 may control the RFID interrogation signals emitted by the RFID antennas, and may interpret the RFID response signals emitted by RFID-enabled histopathology cassettes 1 in the laboratory 70. The RFID processing circuitry may also control the mounts 72. The RFID processing circuity 73 is connected to a host server 74 containing a database of patient and / or tissue records and histopathology cassette identification data.

[0106] It can be seen that strategic positioning of the RFID antennas enables substantially complete coverage of the laboratory space 70 to be achieved. Triangulation techniques can be used to determine the location of any particular RFID-enabled histopathology cassette 1 , for example by comparing the signal strength of a received RFID response signal at different RFID antennas.

[0107] The host server 74 may comprise an SQL server, and may record data relating to histopathology cassette 1 location and events, as well as other data.

[0108] Figure 8 shows a storage cabinet 80 for storing a plurality of histopathology cassettes 1, each comprising an RFID tag 20. The storage cabinet 80 may also be adapted to store a plurality of histopathology slides, each comprising an RFID tag (of a different form factor to the RFID tag 20 used for histopathology cassettes) The storage cabinet 80 shown in Figure 8 has ten storage racks 81 that are slidable into and out of the storage cabinet 80 in the manner of drawers. One of the storage racks 81 is shown fully removed from the storage cabinet 80 for clarity. An RFID reader (for example, an RFIDantenna 71 , not shown in Figure 8) is mounted inside the storage cabinet 80. Figure 8 indicates how the RFID antenna 71 can emit an RFID interrogating signal 82 towards the storage racks 81. The RFID reader is disposed on an inner wall or surface of the storage cabinet 80.

[0109] Each storage rack 81 can hold a plurality of histopathology cassettes 1 or slides in a two-dimensional array. The cassettes 1 or slides may be held horizontally or vertically or at an angle. Generally, the cassettes 1 or slides are all held at a similar orientation, and can be held between grooved dividers or the like. Each cassette 1 or slide thus has a uniquely identifiable address or position within the storage cabinet 80, the address or position being defined by a storage rack 81 identifier and a row and column within a given storage rack 81.

[0110] Each storage rack 81 is horizontally slidable between an opened position, allowing access to the histopathology cassettes 1 or slides held in the storage rack 81 , and a closed position, in which the storage rack 81 is contained within the storage cabinet 80. Each storage rack 81 is preferably mounted to the inside of the storage cabinet 80 by runners so as to allow for easy movement between opened and closed positions.

[0111] The RFID reader may be mounted on an inside wall of the storage cabinet. For example, the RFID reader may be mounted on an inside rear wall, an inside side wall, an inside lower wall or an inside upper wall. Optionally, more than one RFID reader may be mounted inside the storage cabinet.

[0112] The at least one RFID reader may have a generally flat or planar configuration so as not to interfere with the movement of the storage racks between opened and closed positions.

[0113] By providing the at least one RFID reader inside the storage cabinet, it becomes easier to read the plurality of RFID tags and to perform an inventory of the contents of the storage cabinet. This is particularly the case where the storage cabinet comprises a metal housing, which might otherwise form a Faraday cage that could shield the RF tags within the storage cabinet from an external RFID reader mounted in a ceiling or wall of the room in which the storage cabinet is located.

[0114] An RFID reader (for example, and RFID antenna 71 and optionally also an RFID processing circuit 73, not shown in Figure 8) can be configured to determine not just the presence of a given histopathology cassette 1 or slide within the storage cabinet 80, but also a location of the given histopathology cassette 1 or slide, with reference to storage rack 81 and row and column within the storage rack 81.

[0115] Advantageously, each storage rack 81 is provided with or interacts with an electrical switch (not shown in Figure 8) in the storage cabinet 80 configured to activate the RFID reader inside the storage cabinet 80 when the storage rack 81 is moved to the closed position. In this way, the RFID reader can perform a scan of the contents of the storage cabinet 80 each time a storage rack 81 is moved from the opened to the closed position. Thus, it is possible to maintain an up-to-date inventory of the contents of the storage cabinet 80 each time is opened and closed, since it is during times that a storage rack 81 is in the opened position that histopathology cassettes 1 or slides will be removed from or added to the storage cabinet 80.

[0116] The following table gives examples of laboratory equipment or processing stations that may usefully be equipped with RFID readers configured to identify and log the presence or passage of histopathology cassettes or slides that incorporate RFID tags.Table 1 :

[0117] Figure 9 shows a schematic plan view of a laboratory space 70 with four RFID readers in the form of RFID antennas 71 mounted at corner locations of in the ceiling ofthe laboratory space 70. The RFID response signals issued by an object, for example a histopathology cassette 1, with a passive RFID tag are automatically detected and recorded in a database for location detection. The laboratory space 70 may be notionally divided equally into cells 90 arranged in a grid, as shown in Figure 9. Each RFID reader has an interrogation range which is defined as the maximum distance at which the RFID reader can recognize an RFID tag, for example the RFID tag 20 shown in Figure 4. In the example shown in Figure 9, each RFID reader by itself can only cover around a third of the laboratory space 70. However, by providing four RFID readers, one in each corner, the entire laboratory space 70 can be covered, with the detection ranges of the RFID readers overlapping each other in parts of the laboratory space 70. For larger laboratory spaces 70, additional RFID readers may be provided to ensure good coverage. When an object with an RFID passive tag is placed inside one of the cells 90, the RFID readers will first detect the tag. A passive tag derives its power from the signals it receives from the RFID reader and transmits a response signal back to the RFID reader. The strengths of the Received Signal Strength Indicator (RSSI) signals received by the RFID readers are collected. Each of the four RFID readers will record the specific RSSI of the RFID tag within a given cell 90 and the data are stored in a database. As the RFID positioning system is expected to be two-dimensional, RSSI signal data picked up by the various RFID readers will be taken at a specific height. For example, if the selected area 70 is divided into thirty six cells 90, the RSSI signal for each cell 90 position will be recorded. This data collection procedure can be repeated six times to find the average RSSI value of each position point to each of the four RFID readers, and the cell 90 in which the RFID tag is located can thus be determined.

[0118] It is also possible to use an RFID reader with a phased array antenna, for example an Impinj® xArray™ RAIN RFID reader. Such an RFID reader uses a phased array antenna with dual linear polarised antenna elements to allow beamsteering and to define up to 52 antenna beams organised into nine sectors. Each beam can be either horizontally or vertically polarized. An on-board processor controls the beam direction, orientation and polarization. The RFID reader has the capability to steer its antenna beam to read RFID tags over a wide area and detect item location and movement.

[0119] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article isused, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0120] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0121] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

CLAIMS:

1. A histopathology cassette comprising a substantially rectangular base and a perimetral sidewall extending upwardly from the base, the perimetral sidewall comprising four sidewall portions, and a radio frequency identification, RFID, tag incorporated within the perimetral sidewall, wherein the RFID tag comprises a chip element and an antenna element, and wherein the antenna element is disposed in at least three of the sidewall portions.

2. The cassette as claimed in claim 1, wherein the antenna element comprises first and second antenna elements extending in opposite directions from the chip element.

3. The cassette as claimed in claim 2, wherein the chip element is disposed in a first one of the four sidewall portions.

4. The cassette as claimed in claim 3, wherein the first antenna element extends from the chip element inside the first sidewall portion, along the first sidewall portion, around a first corner, and along a second sidewall portion adjoining the first sidewall portion.

5. The cassette as claimed in claim 3 or 4, wherein the second antenna element extends from the chip element inside the first sidewall portion, along the first sidewall portion, around a second corner, and along a third sidewall portion adjoining the first sidewall portion.

6. The cassette as claimed in claim 5 depending from claim 4, wherein the third sidewall portion is opposed to the second sidewall portion.

7. The cassette as claimed in any one of claims 4 to 6, wherein the first or second antenna element extends along substantially all of the respective second or third sidewall portion.

8. The cassette as claimed in any one of claims 4 to 6, wherein the first or second antenna element extends along more than three quarters of the respective second or third sidewall portion.

9. The cassette as claimed in any one of claims 4 to 6, wherein the first or second antenna element extends along more than half of the respective second or third sidewall portion.

10. The cassette as claimed in any one of claims 4 to 6, wherein the first or second antenna element extends along more than one quarter of the respective second or third sidewall portion.

11. The cassette as claimed in any one of claims 4 to 10, wherein the first or second antenna element extends around a third or a fourth corner and along at least part of a fourth sidewall portion opposed to the first sidewall portion.

12. The cassette as claimed in claim 5 or 6 depending from claim 4, wherein the first antenna element extends from the second sidewall portion around a third corner and along at least part of a fourth sidewall portion opposed to the first sidewall portion, and wherein the second antenna element extends from the third sidewall portion around a fourth corner and along at least part of the fourth sidewall portion.

13. The cassette as claimed in claim 1, wherein the antenna element comprises a single antenna element extending from the chip element.

14. The cassette as claimed in claim 13, wherein the chip element is disposed in a first one of the four sidewall portions, and wherein the antenna element extends along the first sidewall portion, around a first corner, along a second sidewall portion, around a second corner, and along a third sidewall portion.

15. The cassette as claimed in claim 13, wherein the antenna element further extends around a third corner and along a fourth sidewall portion.

16. The cassette as claimed in any preceding claim, wherein the RFID tag is embedded in the perimetral sidewall.

17. The cassette as claimed in claim 16, wherein the cassette is injection moulded plastics material.

18. The cassette as claimed in any one of claims 1 to 15, wherein the perimetral sidewall comprises a cavity between inner and outer surfaces of the perimetral sidewall,the cavity adapted to receive the chip element and the antenna element of the RFID tag so that the antenna element can extend around the three sidewall portions.

19. The cassette as claimed in claim 18, wherein the cavity is sealed by way of at least one capping or coping element disposed on a top of the perimetral sidewall.

20. The cassette as claimed in any preceding claim, wherein the base is slatted or perforated so as to allow passage of fluid therethrough.

21. The cassette as claimed in any preceding claim, further comprising a removable lid portion that is engageable with the perimetral sidewall so as to define a storage volume in the cassette.

22. The cassette as claimed in claim 21 , wherein the lid portion is slatted or perforated so as to allow passage of fluid therethrough.

23. A tracking system comprising a plurality of RFID readers, and at least one histopathology cassette as claimed in any one of claims 1 to 22.

24. The tracking system of claim 23, wherein the plurality of RFID readers are mounted in a ceiling or walls of a laboratory.

25. The tracking system of claim 23 or 24, wherein the plurality of RFID readers are incorporated in laboratory equipment.

26. The tracking system as claimed in any one of claims 23 to 25, wherein each RFID reader comprises at least one antenna configured to transmit an RFID interrogation signal and to receive an RFID response signal from an RFID tag.

27. The tracking system as claimed in claim 26, wherein each RFID reader additionally comprises circuitry to control the RFID interrogation signal and / or to interpret the received RFID response signal.

28. The tracking system as claimed in claim 26, wherein multiple RFID readers are networked to a common RFID control circuitry to control the RFID interrogation signals and / or to interpret the received RFID response signals.

29. The tracking system as claimed in any one of claims 23 to 28, wherein the RFID readers are operatively connected to a computer system comprising a database.

30. The tracking system as claimed in claim 29, wherein the database stores a unique identification code of the RFID tag of the at least one histopathology cassette.

31. The tracking system of claim 30, wherein the database: i) associates the unique identification code of the RFID tag with a unique patient identifier so as to identify the patient from whom a tissue specimen has been obtained; ii) optionally associate the unique identification code of the RFID tag with the contents of the at least one histopathology cassette; iii) optionally associates the unique identification code of the RFID tag with data relating to the tissue specimen contained in the at least one histopathology cassette, optionally wherein the data includes one or more of image data, diagnostic data, text data, and / or numerical data.

32. The tracking system as claimed in any one of claims 23 to 31 , configured to analyse signals obtained from the plurality of RFID readers so as to determine a position within the laboratory of any given histopathology cassette.

33. The tracking system as claimed in claim 32, wherein the determination is made by way of triangulation, optionally wherein the determination is made by analysing respective response signal strengths for a given RFID tag in a given histopathology cassette received by different RFID readers.

34. The tracking system of any one of claims 23 to 33, further comprising at least one handheld RFID scanner.

35. The tracking system of any one of claims 23 to 34, further comprising at least one histopathology slide provided with an RFID tag.

36. A storage cabinet for storing a plurality of histopathology cassettes or slides, each comprising an RFID tag, the storage cabinet comprising at least one storage rack and an RFID reader mounted inside the storage cabinet and configured to read the RFID tags of histopathology cassettes or slides stored in the storage cabinet.

37. The storage cabinet as claimed in claim 36, wherein the at least one storage rack comprises a horizontally slidable storage rack moveable between an opened position, allowing access to the histopathology cassettes or slides held in the storage rack, and a closed position, in which the storage rack is contained within the storage cabinet.

38. The storage cabinet as claimed in claim 36 or 37, wherein the storage racks are arranged in parallel with each other as a vertical stack of substantially horizontal storage racks.

39. The storage cabinet as claimed in any one of claims 36 to 38, wherein each storage rack is configured to hold a plurality of histopathology cassettes or slides in a substantially two dimensional array.

40. The storage cabinet as claimed in claim 39, wherein each storage rack is provided with dividers and grooves that define a plurality of storage locations each adapted to receive a single histopathology cassette or slide.

41. The storage cabinet as claimed in any one of claims 36 to 40, wherein the at least one RFID reader is mounted on an inside wall of the storage cabinet.

42. The storage cabinet as claimed in any one of claims 36 to 41 , wherein the at least one RFID reader is configured to determine both a presence of a given histopathology cassette or slide within the storage cabinet, and also a location of the given histopathology cassette or slide, with reference to storage rack and row and column within the storage rack.

43. The storage cabinet as claimed in any one of claims 36 to 42, wherein the at least one storage rack is provided with or interacts with an electrical switch in the storage cabinet configured to activate the at least one RFID reader when the storage rack is moved to the closed position.

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