Histological specimen cassette

A histological specimen cassette for use in connection with a larger histological specimen cassette, wherein each histological specimen cassette has an internal chamber that includes a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and an internal chamber or cavity, where the internal chamber or cavity is positioned between the sidewalls, the front and back walls and partially bound by the bottom wall, having a plurality of apertures that extend through the bottom wall and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the histological specimen cassette being dimensioned such that the histological specimen cassette can fit entirely within the void of the larger histological specimen cassette when the lid is in the closed position.

TECHNICAL FIELD OF THE INVENTION

The present invention pertains to the field of histological examination. More particularly, this invention pertains to cassettes for treating tissue samples in preparation of microscopic histological examination.

BACKGROUND OF THE INVENTION

Cassettes of the type disclosed in U.S. Pat. No. 5,928,934 and 5,665,398, the disclosures of which are incorporated herein by reference in their entireties, are used to store, treat, and hold tissue samples in preparation of performing microscopic histological examination of such tissue. Typically, a cassette comprises a receptacle portion that forms a cavity and a lid. The receptacle and lid each typically have numerous small apertures that allow fluid to pass through the cassette and into the cavity. The lid is often attached to the receptacle by a hinge in a manner such that the lid can be used to selectively open and close the cavity of the receptacle.

During the treatment of a tissue sample in preparation of microscopic examination, the tissue sample is typically placed in the cavity of a cassette with the lid of the cassette closed to prevent the tissue sample from inadvertently falling out of the cavity. The cassette is then typically immersed in sequence any number of various fluids such as formaldehyde, ethanol, xylene, and molten paraffin. The apertures in the receptacle and lid of the cassette allow such fluids to pass into the cavity of the cassette and make contact with the tissue sample. In the timing of these steps, a tissue sample is dehydrated, cleared and infiltrated with molten wax within the cassette. Multiple tissue samples in multiple cassettes can be treated in this manner simultaneously.

The treatment procedures typically concludes with the tissue sample resting in molten paraffin. The lid of the cassette is thereafter opened and the tissue sample is removed from the cassette and placed in the cavity of an embedding mold. The cassette is then placed above the tissue sample in the embedding mold and additional paraffin is used to secure the tissue sample to the bottom surface of the cassette. This additional paraffin is allowed to solidify in and around the apertures of the receptacle and thereby provides a firm attachment of the tissue sample to the cassette. As such, the cassette can then be used to hold the wax infiltrated tissue sample as an investment casting of the tissue sample to be sliced by a microtome.

SUMMARY OF INVENTION

The present invention is directed to an improved histological examination cassette. In one aspect of the invention, a histological specimen cassette is configured and adapted for use in connection with a larger specimen cassette that has an internal chamber that creates a parallelepiped void that typically has a length of at least 31.75 millimeters, a width of at least 25.4 millimeters, and a height of at least 5.08 millimeters. The histological specimen cassette comprises a receptacle and a lid. The receptacle has a bottom wall, opposite side walls, opposite front and back walls, and a cavity. The cavity is positioned between the sidewalls and between the front and back walls of the receptacle and is partially bound by the bottom wall. The bottom and top walls have a plurality of apertures that extend through the bottom and top walls and that create fluid passageways into the cavity. The lid also has a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity. The lid is movable between an opened position and a closed position relative to the receptacle. When the lid is in the closed position, the lid engages the receptacle and the cavity is partially contained by the lid. The histological specimen cassette is dimensioned such that the histological specimen cassette can fit entirely within the void of the larger specimen cassette when the lid is in the closed position.

In another aspect of the invention, a histological specimen cassette for use in connection with a larger histological specimen cassette is disclosed. The histological specimen cassette includes a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom wall having a plurality of apertures that extend through the bottom wall and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position, and a larger histological specimen cassette has an internal chamber that includes a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and an internal chamber, the internal chamber being positioned between the sidewalls, the front and back walls and partially bound by the bottom wall, wherein the internal chamber includes a parallelepiped void that has a length of at least 31.75 millimeters, a width of at least 25.4 millimeters, and a height of at least 5.08 millimeters, the histological specimen cassette being dimensioned such that the histological specimen cassette can fit entirely within the void of the larger histological specimen cassette when the lid is in the closed position.

In yet another aspect of the invention, an assembly is disclosed. The assembly includes a first histological specimen cassette having a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom wall having a plurality of apertures that extend through the bottom wall and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position, and a second histological specimen cassette having a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom wall having a plurality of apertures that extend through the bottom wall and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position, wherein the cavity of the second histological specimen cassette has a parallelepiped void that has a length of at least 31.75 millimeters, a width of at least 25.4 millimeters, and a height of at least 5.08 millimeters, wherein the first histological specimen cassette fits entirely within the void of the second histological specimen cassette when the lid is in the closed position to create an assembly.

In yet another aspect of the present invention, an assembly is disclosed. The assembly includes a first histological specimen cassette having a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom and top walls have a plurality of apertures that extend through the bottom and top walls and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position and a second histological specimen cassette that has an internal chamber that creates a parallelepiped void that has a length of at least 31.75 millimeters, a width of at least 25.4 millimeters, and a height of at least 5.08 millimeters wherein the first histological specimen cassette fits entirely within the void of the second histological specimen cassette when the lid is in the closed position to create the assembly.

Still yet another aspect of the present invention is that a method for utilizing two histological specimen cassettes is disclosed. The method includes placing a first histological specimen cassette entirely within a void of the second histological specimen cassette for histological specimen examination, wherein the first histological specimen cassette comprises a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom and top walls have a plurality of apertures that extend through the bottom and top walls and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position and the second histological specimen cassette that has an internal chamber that creates a parallelepiped void that has a length of at least 31.75 millimeters, a width of at least 25.4 millimeters, and a height of at least 5.08 millimeters.

In another aspect of the present invention, a histological specimen cassette is disclosed. This histological specimen cassette includes a receptacle and a lid, the receptacle having a bottom wall, opposite side walls, opposite front and back walls, and a cavity, the cavity being positioned between the sidewalls and between the front and back walls, the cavity being partially bound by the bottom wall, the bottom and top walls have a plurality of apertures that extend through the bottom and top walls and that create fluid passageways into the cavity, the lid having a plurality of apertures that extend through the lid and that create additional fluid passageways into the cavity, the lid being movable between an opened position and a closed position relative to the receptacle, the lid engaging the receptacle when the lid is in the closed position and the cavity being partially bound by the lid when the lid is in the closed position, wherein the front wall slopes toward the bottom wall at an angle from about fifteen degrees to about twenty-three degrees from the bottom wall to create a writing surface to provide identification for the histological specimen cassette. This is for both the host (outer) cassette and the specimen containing inner cassette. The ability to write/label the identification on both the inner and outer cassette pair is essential to the chain of custody and positive identification (ID) for experimental and diagnostic protocol.

These are merely some of the innumerable aspects of the present invention and should not be deemed an all-inclusive listing of the innumerable aspects associated with the present invention. These and other aspects will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings.

Reference characters in the written specification indicate corresponding items shown throughout the drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of a histological examination specimen preparation cassette in accordance with the invention is shown by itself inFIGS. 1-6. The cassette20comprises a receptacle22and a lid24. The lid24and the receptacle22are preferably injection molded together out of polymeric material, which is preferably solvent resistant, as a single monolithic part in the configuration shown inFIGS. 2-6. The lid24is attached to the receptacle22via a thin bridge portion26that acts as a hinge and allows the lid and receptacle to pivot thereabout relative each other. However, the bridge portion26is configured and adapted to be frangible so that, if desired, the lid can be easily separated from the receptacle by ripping the bridge portion in half along the pivot axis.

The receptacle22comprises opposite front28and back30walls, opposite side walls32, and a bottom wall34. The receptacle22also comprises a cavity36that extends down into the receptacle and that is partially bound by the bottom wall34of the receptacle. The cavity36is further bound by four intermediate walls38that slope from the bottom wall34to the top perimeter edge40of the cavity. Two of the cross directed intermediate walls38are generally perpendicular to the back wall30of the receptacle22and diverge from each other as they extend upward. These two intermediate walls38eventual merge into the side walls32adjacent the top perimeter edge40of the cavity36. The other two intermediate walls38are generally perpendicular to the side walls32of the receptacle22and also diverge from each other as they extend upward. One of these two intermediate walls38eventual merges into the back wall30adjacent the top perimeter edge40of the cavity36, and the other of these two intermediate walls eventual merges into the front wall28adjacent the top perimeter edge of the cavity36.

The outer front wall28slopes toward to the back wall30as it extends upward and is preferably oriented between fifteen and twenty-three degrees from the bottom wall34of the receptacle22. More preferably, the front wall28is preferably oriented between sixteen and eighteen degrees from the bottom wall34of the receptacle22. More preferably still, the front wall28is preferably oriented seventeen degrees from the bottom wall34of the receptacle22. As such, the front wall28extends front to back more than two tenths of the front to back length of the entire receptacle22. Each of the sidewalls32, the bottom wall34, and the intermediate walls38preferably comprises a plurality of apertures42to allow fluid to pass through such walls. Preferably the apertures42that extend through the bottom wall34are drafted in a manner such that the apertures increase in size as they tend from the exterior of the cassette into the cavity36. This increases the paraffin adhesion of a tissue specimen to the exterior of the cassette20by creating interlocking geometry between the cassette and the solidified paraffin. The front wall28is preferably devoid of apertures to permit identification (ID) labeling. A first larger rectangular opening44preferably extends through the rear intermediate wall38and the lower portion of the back wall30. A second rectangular opening46preferably extends down through the intersection of the front intermediate wall38and the front wall30. Each of the first and second openings is centrally positioned between the side walls32.

The lid24of the cassette20preferably comprises a main rectangular portion50, a thumb release tab52, a rectangular ring protrusion54, a locking tab56, and an arcuate guiding and locking protrusion58. The main rectangular portion50of the lid24is preferably thin and planar and comprises a plurality of apertures60that extend therethrough. The thumb release tab52preferably extends from the front edge64of the main rectangular portion50in a coplanar manner adjacent one of the side edges62of the main rectangular portion. The rectangular ring protrusion54preferably extends downwardly (assuming the lid24is in its closed position as described below) from the main rectangular portion50in a direction generally perpendicular to the plane of the main rectangular portion. However, the rectangular ring also comprises a chamfer65that is angled in a manner such that the chamfer mates with the sloped intermediate walls38of the receptacle22when the lid24is closed. The locking tab56also extends downwardly from the main rectangular portion50adjacent the front edge64of the main rectangular portion and forms a locking tang66, which can also be referred to as a finger tab, that extends forward of the front edge. The locking tab56is preferably centrally positioned between the side edges62of the main rectangular portion50. The arcuate back guiding protrusion58preferably extends downward from the rectangular ring protrusion54and curves aft as it extends therefrom.

As mentioned above, the lid24is able to pivot about the receptacle22by flexing the bridge portion26. Thus, the bridge portion26creates a pivot axis that is parallel to and aft of the back wall the receptacle22, and about which the lid24is able to pivot relative to the receptacle. When the lid24is in an open position relative to the receptacle22, such as shown inFIGS. 2-6or as shown inFIG. 1, the cavity36of the receptacle22is open from above. Alternatively, when the lid24is in a closed position relative to the receptacle22, such as shown inFIG. 7, the rectangular portion50of the lid covers the top of the cavity36. As the lid24is pivoted from an opened position to the closed position, the locking tab56of lid moves into the second opening46of the receptacle22where the locking tang66of the locking tab engages the front wall28of the receptacle and resiliently deflects the locking tab rearward until the locking tang reaches a position beneath the front wall. Thereafter, the locking tab56resiliently deflects back to its neutral position where the locking tang66engages against underside of the front wall28in a manner preventing the lid24from moving back to its opened position unless more than a threshold force is exerted between the lid and the receptacle22. Alternatively, the locking tang66of the locking tab56can be configured to extend rearward from the remainder of the locking tab and to lock beneath the intermediate wall38adjacent the front wall28.

Additionally, as the lid24is pivoted from an opened position to the closed position, the guiding protrusion58of the lid moves into the first opening44of the receptacle22. If the bridge portion26is severed, the guiding protrusion58of the lid24can be inserted into the first opening44and used to create an alternative hinge connecting the lid to the receptacle22. In such a case, the guiding protrusion58of the lid24interlocks with the receptacle22and prevents the lid from separating from the receptacle when the lid is in its closed position. When the lid24is in the closed position, the rectangular ring protrusion54of the lid extends into the cavity36of the receptacle22where it prevents tissue samples from slipping out of the cavity between the lid and receptacle. Because the chamfer65of the rectangular ring protrusion54is sloped to match the slope of the intermediate walls38of the receptacle22a face-to-face seal is created that becomes tighter in a progressive manner as the lid24is closed.

Moreover, when the lid24is in the closed position, the thumb release tab52extends above the front wall28of the receptacle22in a spaced apart manner. This allows a person to exert a prying force upward on the thumb release tab52while also pressing downward on the front wall28of the receptacle22in a manner overcoming the forward or rearward threshold force that otherwise prevents the lid24from moving back into an opened position.

The lid24and receptacle22are dimensioned such that the entire cassette20, with its lid in the closed position, can be positioned within the cavity80of another larger cassette82, as shown inFIG. 7. More specifically, lid24and receptacle22are dimensioned to fit within a parallelepiped void having a length of 31.75 millimeters, a width of 25.4 millimeters, and a height of 5.08 millimeters. Furthermore, the distance between the side edges62of the rectangular portion50of the lid24is greater than the front to back length of the rectangular portion of the lid. Additionally, the side to side width of the cavity36of the receptacle22is greater than the front to back length of the cavity. However, the overall side to side width of the cassette20is less than the front to back length of the entire cassette.

The above mentioned configuration the cassette20allows the cassette to serve the same purpose as a standard prior art cassette, without occupying as much physical space as such a prior art cassette. Additionally, the configuration the cassette20allows the cassette to be placed within the cavity of another prior art cassette in a manner such that the cassette can be used in tissue treatment devices that are specifically configured for prior art standard size cassettes.

Furthermore, it should be understood that when introducing elements of the present invention in the claims or in the above description of the preferred embodiment of the invention, the terms “have,” “having,” “includes” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.” Similarly, the term “portion” should be construed as meaning some or all of the item or element that it qualifies.

Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.