Input/Output Module and Overall Temperature Control of Samples
An automated storage and retrieval system for storing chemical and biological samples includes freezer chests maintained at an ultra-low temperature (e.g. −80° C.) or a cryogenic temperature. The freezer chests are located within a refrigerated (e.g. −20° C.) enclosure. Samples are loaded through a wall of the enclosure and are then transferred to an input/output buffer section in an ultra-low temperature or cryogenic freezer chest that is thermally segregated from a long-term storage section in the same freezer. Specialized input/output cassettes are used for transferring the samples through an input/output module into the system.
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This application claims priority to U.S. Provisional Patent Application No. 61/381,832, filed on Sep. 10, 2010 entitled “Large Automated Storage and Retrieval System for Storing Biological or Chemical Samples at Ultra-Low or Cryogenic Temperatures”.
FIELD OF THE INVENTIONThe invention relates to automated storage and retrieval systems for ultra-low temperature or cryogenic freezer systems used primarily to store biological or chemical samples. In particular, the present invention pertains to systems and methods for efficiently inputting and retrieving samples from the freezers without causing significant temperature rise of other samples stored within the system.
BACKGROUND OF THE INVENTIONStorage of biological and chemical samples is becoming widespread in the biotechnology and medical industries. To preserve many of these samples, the samples must be stored well below normal freezing temperatures. Generally speaking, a regular freezer operates from about −5° C. to −20° C., an ultra-low temperature freezer operates from about −50° C. to about −130° C. (preferably at about −80° C.), and a cryogenic freezer operates from about −140° C. to about −196° C. (the boiling point of liquid nitrogen). The present invention is directed to a large automated storage and retrieval system containing one or more ultra-low temperature or cryogenic freezer chests operating below about −65° C. The freezers are contained within a refrigerated enclosure, preferably maintained at about −20° C. Most biological samples stored in ultra-low temperature or cryogenic systems are contained in sealed plastic laboratory tubes held in tube storage racks in arrays of for example 48, 96 or 384 tubes. In some cases, the biological samples are stored in sample storage plates such as sealed microtiter or wellplates, rather than stored in sealed tubes held in a rack.
The inventors have discovered that introducing warm samples into the system, for example when samples arrive from a processing laboratory, can cause temperature rise among other samples stored in the system unless steps are taken to eliminate or mitigate the temperature rise. The present invention is directed primarily to maintaining the thermal integrity of samples during sample introduction into the system.
SUMMARY OF THE INVENTIONAs mentioned, the invention pertains to automated storage and retrieval systems for storing sample tube storage racks or plates at an ultra-low or cryogenic temperature. In particular, a system implementing the invention has a refrigerated enclosure maintained at a temperature of approximately −15° C. to −30° C., and one or more freezer chests, normally a bank of multiple freezer chests, located within the refrigerated enclosure. The freezer chests contain compartments that are preferably maintained, under normal operating conditions, at a designated temperature setting at or below −65° C., such as about −80° C. for an ultra-low temperature system. While samples are stored in the freezer chests, a sample input/output module is provided to pass samples through the wall of the refrigerated enclosure so that samples can be robotically transferred within the refrigerated enclosure to the freezers for storage. In accordance with one aspect of the invention, at least one freezer bay or a portion of one freezer bay is defined as an input/output buffer section and is thermally segregated from long-term sample storage sections in the same or other freezer bays. For example, the input/output buffer section can comprise an insulated wall in a single freezer bay thermally segregating the input/output buffer section and the sample storage section. Alternatively, selected nesting tubes in the freezer bay for storing cassettes holding vertical arrays of sample tube storage racks or plates can be separated and thermally isolated from other nesting tubes in the freezer bay by placing insulation in a selected row or column of nesting tubes otherwise intended to hold cassettes. Preferably, samples placed into the system through the sample input/output module are transferred to the input/output buffer section in order to cool the samples to a temperature at or near the designated temperature setting for the freezers (e.g. −80° C.) prior to transferring the samples to a long-term storage location in the same or different freezer chest. Typically, most samples will be fully cooled to the freezer set temperature within no more than five hours. In most cases, it is contemplated that the input/output buffer section will constitute part of one of the freezer bays, and the remaining section of that freezer bay will be used for long-term storage of samples. In that case, it is desirable that the temperature sensor for the refrigeration unit be located within the input/output buffer section of the freezer bay which is normally the section closer to the refrigeration unit. Testing has shown that such a configuration will cause the refrigeration unit to operate more aggressively to prevent temperature rise within the freezer bay that could otherwise affect samples outside of the input/output buffer section.
The preferred input/output module is designed to work in connection with the cassette puller described in co-pending U.S. patent application Ser. No. ______, filed on even date herewith, entitled “Cassette Puller”, Attorney Docket No. 5436-00018, and incorporated herein by reference. The input/output module holds multiple cassettes for transferring samples stored in tube storage racks or plates into the refrigerated enclosure from outside of the system and also for transferring samples from inside of the refrigerated enclosure to outside of the system. The most efficient use of the system is with specific input/output cassettes that are preferably configured so that the cassette puller in the above incorporated patent application is able to transfer the input/output cassettes within the refrigerated enclosure to and from the input/output module and to and from the above described input/output buffer section in the freezer. It is also preferred that the cassette puller be able to eject tube storage racks or plates from the input/output cassettes or place sample tube storage racks or plates onto shelves on the input/output cassettes. Preferably, this is done in essentially the same manner that the cassette puller places racks or plates in or ejects racks or plates from a storage cassette used for long-term sample storage in the ultra-low temperature or cryogenic freezers. The preferred configuration for the storage cassette is described in co-pending patent application Ser. No. ______, filed on even date herewith, entitled “Sample Storage Cassette for Ultra-Low or Cryogenic Temperatures”, Attorney Docket No. 5436-00019, and incorporated herein by reference.
The input/output module includes a manual loading/unloading station that provides a central interface for a user working with the system on an everyday basis. It is desirable that the input/output module be able to accommodate the introduction and removal of a low number of samples, e.g. 20 tubes in a single SBS tube rack or a higher number of samples, e.g. 10,000 tubes in roughly 100 SBS tube racks, as well as bulk introduction and removal of samples. The introduced samples can be warm, for example when arriving from a processing laboratory or alternatively the samples can be cold or ultra-cold such as when arriving on dry ice from a distant laboratory. When introducing ultra-cold samples, the system is desirably operated to minimize temperature rise of the introduced samples during the sample introduction process. On the other hand, when warm samples are introduced to the system, the system is desirably operate to protect the thermal integrity of samples already stored and minimize temperature rise of previously stored samples.
The preferred input/output module is located within the refrigerated chamber and includes carousel with multiple insulated sleeves that hold input/output cassettes. The exemplary carousel includes eight sleeves for holding eight separate input/output cassettes, although the number of sleeves can be more or less as the application requires. As the carousel is rotated, one of the indexing positions (loading/unloading position) corresponds to a loading/unloading station which is located adjacent an opening through the enclosure wall. At least one door or set of doors covers the opening. Optionally, an air purge system is provided to prevent moisture from encroaching through the input/output module into the refrigerated enclosure when samples are being loaded or unloaded. The door or set of doors is opened to provide access for a user located outside of the refrigerated enclosure to shelves on an input/output cassette located at the loading/unloading position on the carousel. Sample tube storage racks or plates are manually placed by the user on the respective shelves in the input/output cassette to load the system. Once the cassette is filled, the carousel rotates or indexes to the next position allowing the user to fill another input/output cassette if necessary. One of the other carousel indexing positions serves as a designated cassette transfer position and corresponds to the location that the cassette puller removes filled input/output cassettes from the carousel and places empty input/output cassettes into the carousel. The cassette puller transfers filled input/output cassettes to the input/output buffer section in the designated freezer bay as described above. On the other hand, it is preferred that the empty input/output cassettes placed into the insulated sleeves on the carousel be pre-cooled in the input/output buffer section in the designated freezer. In the case that the loaded samples are cold or ultra-cold samples, it is preferred that the carousel rotates 180° from the loading/unloading position to the designated cassette transfer position once the input/output cassette is loaded without stopping at any intermediate indexing positions. The direct 180° rotation to the designated cassette transfer position speeds the transfer of cold or ultra-cold samples to the cassette puller and eventually into the input/output buffer section of the designated freezer bay. Of course, the input/output module can be used to load and unload either warm or cold samples in process sequences other than described above if desired.
In another aspect of the invention, the input/output cassette is designed specifically to accommodate manual loading and unloading of samples. In this regard, the shelves on the input/output cassette extend forward beyond the sidewalls in the portion of the cassette in which samples are loaded and unloaded, thereby facilitating convenient access even with gloved fingers. In addition, the distance between the shelves is increased compared to a typical storage cassette. Further, storage cassettes may typically be about six feet tall, and it is desirable that the overall height of the input/output cassette be the same as the storage cassette to enable the cassette puller to effectively retrieve both types of cassettes from the freezer bays. On the other hand, it is not convenient for users to load samples below the height of their thigh or above the height of their shoulder. Therefore, in accordance with this aspect of the invention, the input/output cassettes include a sample storage portion that will typically be about three feet long and stand at a height off the ground to a height range corresponding to a typical user's thigh to shoulder. The sample storage portion of the input/output cassette has a plurality of generally spaced shelves, each for holding sample tube storage racks or plates. The input/output cassettes also include a top plate and a bottom plate. However, an upper portion of the input/output cassette spanning between the sample storage portion and the top plate is not intended to hold sample storage tube racks or plates. Likewise, a lower portion that is not intended to hold sample tube racks or plates spans between the bottom of the sample storage portion and a bottom plate. Desirably, the input/output cassette includes the same or at least compatible top plate and retrieval catch as the storage cassette as well as same or compatible guide legs on the bottom of the cassette so that the overall size and footprint of the input/output cassette is the same as or quite similar to the storage cassettes. This enables the input/output cassettes to be fully compatible with the cassette puller and nesting tubes in the freezer bays.
Another advantage of the invention is that the storage cassettes for long term storage of the samples can also, in the preferred system, fit into the sleeves in the input/output module, thereby enabling the storage cassettes to be removed from the system for maintenance of the storage cassettes or to substitute storage cassettes in the system with cassettes sized for different storage racks or plates. In the exemplary embodiment, shields cover the top and lower portion of the sleeves, but these sleeves can be made removable to facilitate the transfer of a storage cassette into and out of the system through the input/output module.
It should also be noted that the storage cassettes in some systems can be shorter than about 6 feet tall, for example about 3½ feet tall. In such a system, the input/output cassette described above does not require an upper portion that is not intended to hold sample storage tube racks or plates, but may very well include a lower portion that is not intended to hold sample tube racks or plates.
Other features and advantages of the invention may be apparent to those skilled in the art upon reviewing the following drawings and description thereof.
The refrigerated enclosure 10 provides a low temperature (−15° C. to −30° C., e.g., −20° C.) work space for the automated storage and retrieval system 12. The automated storage and retrieval system 12 is mounted to a traveling gantry 24 that is driven linearly along horizontal Y-axis rails 26. The gantry 24 moves over and above the top of the freezer chest 11 and also over and above the input/output module 14. The system 12 includes a robotic cassette puller 28 which moves with the gantry 24, thus providing the cassette puller 28 with access to storage cassettes or input/output cassettes stored in the freezers 11 and input/output cassettes residing in the input/output module 14. The invention is not limited to the specific configuration of the cassette puller 28. Nevertheless, it is preferred that the cassette puller be constructed in accordance with the description of co-pending U.S. patent application Ser. No. ______, entitled “Cassette Puller”, Attorney Docket No. 5436-00018, filed on even date herewith and incorporated herein by reference.
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The preferred methods of loading samples into the system using the input/output module 14 is now discussed in connection with
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It is desirable that the shields 106, 108 on the vertical sleeves 70 in the input/output module 14 be removable by a user outside of the system so that a full cassette 44, 30 in the sleeve 70 can be removed from or placed into the system. By removing the shields 106, 108 both input/output cassettes 44 and storage cassettes 30 can be removed from or placed into the system which can be particularly beneficial for maintenance. Further, it is convenient way to replace a storage cassette 30 with one having different shelf spacing. It is likely that users will find it convenient to load or unload full input/output cassettes 44 into a sleeve 70 (with the shields 106, 108 removed or nonexistent) under normal operation of the system, although it is possible.
Referring in particular to
In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different configurations, systems, and method steps described herein may be used alone or in combination with other configurations, systems and method steps. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims.
Claims
1. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature, the system comprising:
- a refrigerated enclosure maintained at a temperature of approximately −15° C. to −30° C.;
- at least one sample input/output module for passing samples through a wall of the enclosure; and
- one or more freezer chests located within the refrigerated enclosure and having a freezer bay for storing the samples that is maintained at a set temperature at or below −65° C. under normal operating conditions, wherein an input/output buffer section comprising a freezer bay or a portion of a freezer bay in one of the freezer chests is thermally segregated from long term sample storage sections in the same or other of said freezer chests; and
- further wherein samples placed into the system through the sample input/output module are transferred to the input/output buffer section in order to cool the samples to a temperature at or near the set temperature of the one or more freezer chests prior to transferring the samples to a long term storage location in one of the freezer chests removed from the input/output buffer section.
2. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 1 wherein the input/output module comprises:
- multiple input/output cassettes for transferring samples stored in tube storage racks or plates into the refrigerated enclosure from outside of the system and from inside the refrigerated enclosure to outside the system;
- a carousel;
- multiple bays on the carousel for holding one of said input/output cassette;
- a loading/unloading station including an opening through the enclosure wall, at least one door covering the opening and manually accessible from outside of the enclosure when the door is opened;
- wherein sample tube storage racks or plates can be manually placed on or removed from shelves on an input/output cassette located at the input/output station when the at least one doors are open.
3. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2 wherein the input/output module further comprises an air purging system to purge the space between the at least one or more doors of the input station and the carousel.
4. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2 further comprising:
- an array of storage cassettes removably located in one of the freezer chests for long term storage of samples stored in tube storage racks or plates; and
- a cassette puller located in the refrigerated enclosure that places input/out cassettes in and retrieves input/output cassettes from the bays on the carousel of the input/output module, and further transfers input/output cassettes and storage cassettes within the refrigerated enclosure to the one or more freezer chests, the cassette puller comprising in part a sleeve into which the respective cassette is lifted at least partially, the sleeve containing at least one access opening to allow removal of a selected tube storage rack or a plate on a shelf in the lifted cassette or allow placement of a tube storage rack or a plate on an empty shelf in the lifted cassette.
5. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2 wherein the input/output module further comprises an insulated housing surrounding the carousel and bays for holding input/output cassettes.
6. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2 wherein each bay in the carousel of the input/output module comprises a vertical sleeve for holding input/output cassettes in the respective bay, and the sleeve includes three thermally insulated walls.
7. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 6 wherein a front side of the sleeve includes a top shield covering a top portion of the sleeve and bottom shield covering a lower portion of the sleeve and an area between the shields that provides access to load and unload samples from an input/output cassette located in the sleeve when the input/out cassette is located at the loading/unloading position on the carousel.
8. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 1 further comprising multiple input/output cassettes each for holding sample tubes, storage racks or plates and each input/output cassette comprising:
- a sample storage portion having a plurality of generally vertical, spaced shelves each for holding a sample tube storage rack or plate;
- a top plate located above the sample storage portion with an upper portion that is not intended to hold sample tube storage racks or plates spanning between the sample storage portion and the top plate; and
- a bottom plate located below the sample storage portion with a lower portion that is not intended to hold sample tube storage racks or plates located between the sample storage portion and the bottom plate.
9. In an automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2, a method of loading samples through the input/output module into the system when the samples loaded into the system are warm compared to freezer set temperature, the method comprising the following steps:
- a) placing an empty input/output cassette in one of the bays on the carousel of the input/output module when the bay is located at a designated cassette transfer location;
- b) rotating the carousel to present the input/output cassette to the loading/unloading station;
- c) opening the one or more doors to provide manual access by a user to the shelves in the input/output cassette presented at the loading/unloading station;
- d) manually loading tube storage racks or plates into shelves on the input/output cassette located at the loading/unloading station;
- e) closing the one or more doors;
- f) repeating steps a) through e) as necessary to accommodate all of the samples that need to be loaded into the system;
- g) when the carousel rotates so that a loaded input/output cassette is located at the designated cassette transfer location, transferring the loaded input/output cassette to the input/output buffer section in the at least one freezer bay.
10. The method recited in claim 9 further comprising the following step:
- cooling empty input/output cassettes in the input/output buffer section prior to placing the empty input/output cassette in the bay on the carousel.
11. The method recited in claim 9 further comprising the following step:
- providing a dry air purge when the one or more doors are opened to provide manual access by a user to the shelves in an input/output cassette presented at the loading/unloading station.
12. The method recited in claim 9 wherein the input/output cassette includes a removable module with multiple shelves, and the multiple shelves are configured to be preloaded with tube storage racks or plates prior to loading the samples into the input/output cassette when it is located at the loading/unloading station.
13. In an automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2, a method of loading samples through the input/output module into the system when the samples being loaded into the system have a temperature at or near the freezer set temperature, the method comprising the following steps:
- a) placing an empty input/output cassette in one of the bays on the carousel of the input/output module when the bay is located at a designated cassette transfer location, wherein the empty input/output cassette is cooled in the input/output buffer section prior to placing the empty input/output cassette in the bay on the carousel;
- b) rotating the carousel 180° to position the pre-cooled, empty input/output cassette to the loading/unloading station;
- c) opening the one or more doors at the loading/unloading station to provide manual access by a user to shelves in the input/output cassette presented at the loading/unloading station;
- d). loading the cold tube storage racks or plates into the input/output cassette located at the loading/unloading station, while at the same time placing a next pre-cooled, empty input/output cassette from the input/output buffer section into a bay located at the designated cassette transfer location 180° around the carousel from the loading/unloading location;
- e) closing the one or more doors;
- f) rotating the carousel 180° to contemporaneously position the next pre-cooled, empty input/output cassette at the loading/unloading station and to position the loaded input/output cassette at a designated cassette transfer location;
- g) repeating steps a) through f) as necessary to accommodate all of the samples that need to be loaded into the system;
- h) when the carousel rotates so that a loaded input/output cassette is located at the designated cassette transfer location, transferring the loaded input/output cassette to the input/output buffer section in the at least one freezer bay prior to placing the next pre-cooled, empty input/output cassette into the bay on the carousel located at the designated cassette transfer position.
14. The method recited in claim 13 further comprising the following step:
- providing a dry air purge when the one or more doors are opened to provide manual access by a user to the shelves in an input/output cassette presented at the loading/unloading station.
15. The method recited in claim 13 wherein the input/output cassette includes a removable module with multiple shelves, and the multiple shelves are configured to be preloaded with tube storage racks or plates prior to loading the samples into the input/output cassette when it is located at the loading/unloading station.
16. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 1 wherein the input/output cassette further comprises tapered, rigid legs attached to the bottom of the cassette.
17. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 8 wherein the top plate has an upwardly extending retrieval catch.
18. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 17 wherein the top plate further includes guide holes for accepting locator pins on a cassette puller.
19. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 8 wherein the compartments in the a sample storage portion include sidewalls and the compartment shelves extend further forward than the sidewalls.
20. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 2 wherein an outer surface of the respective input/output cassettes includes position referencing stops for each compartment within the input/output cassette.
21. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature as recited in claim 8 wherein a sleeve is contained within each carousel bay and includes a shield covering the location of the upper portion and the lower portion when the input/output cassette is located within the sleeve in the bay.
22. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature, the system comprising:
- a refrigerated enclosure maintained at a low temperature of approximately −15° C. to −30° C.;
- at least one sample input/output module for passing samples through a wall of the enclosure;
- one or more freezer chests located within the refrigerated enclosure having a freezer bay maintained at a set temperature at or below −65° C. under normal operating conditions for storing samples;
- multiple input/output cassettes for holding sample tube storage racks or plates, each input/output cassette comprising a sample storage portion having a plurality of generally vertical, spaced shelves each for holding a sample tube storage rack or plate, the shelves being oriented generally vertical to one another, and a bottom plate located below the sample storage portion and a lower portion that is not intended to hold sample tube storage racks or plates spanning between the sample storage portion and the bottom plate.
23. An input/output cassette as recited in claim 22 further comprising a top plate located above the sample storage portion and an upper portion that is not intended to hold sample tube storage racks or plates spanning between the sample storage portion and the top plate.
24. An input/output cassette as recited in claim 22 wherein the input/output cassette further comprises tapered, rigid legs attached to the bottom of the cassette.
25. An input/output cassette as recited in claim 22 wherein the top plate has an upwardly extending retrieval catch.
26. An input/output cassette as recited in claim 22 wherein the top plate further includes guide holes for accepting locator pins on a cassette puller.
27. An input/output cassette as recited in claim 22 wherein the compartments in the sample storage portion include sidewalls and the compartment shelves extend further forward than the sidewalls.
28. An input/output cassette as recited in claim 22 wherein an outer surface of the input/output cassette includes position referencing stops for each compartment within the sample storage portion of the input/output cassette.
29. An automated storage and retrieval system for storing sample tube racks or plates at an ultra-low or cryogenic temperature, the system comprising:
- a refrigerated enclosure maintained at a temperature of approximately −15° C. to −30° C.;
- one or more freezer chests located within the refrigerated enclosure and having a freezer bay for storing samples that is maintained at a set temperature at or below −65° C. under normal operating conditions;
- said samples being stored in storage cassettes for long term storage;
- multiple input/output cassettes for transferring samples stored in tube storage racks or plates into the refrigerated enclosure from outside of the system and from inside of the refrigerated enclosure to outside of the system; and
- an input/output module comprising a carousel, multiple bays in the carousel for holding either input/output cassettes or storage cassettes, and an loading/unloading station including an opening through the enclosure wall, at least one door covering the opening and manually accessible from outside of the enclosure when the door is opened;
- wherein both input/output cassettes and storage cassettes can be removed from or placed into the input/output module at the loading/unloading station.
Type: Application
Filed: Sep 9, 2011
Publication Date: Mar 15, 2012
Applicant: HAMILTON STORAGE TECHNOLOGIES, INC. (Hopkinton, MA)
Inventors: Scott Collins (Westford, MA), Frank Hunt (Shrewsbury, MA), Julian Warhurst (Ashland, MA), Bruce Zandi (Lexington, MA)
Application Number: 13/229,075
International Classification: F25D 25/00 (20060101);