Abstract:
An automated cold storage apparatus, and related method thereof, provides a sample process management system that is a revolutionary approach to the storage and retrieval regarding critical samples. The system—a significant technological breakthrough in laboratory automation—is the first ultra low temperature robotic system capable of being validated. Samples in containers are stored and retrieved robotically through an airlock climate-control chamber that is automatically dehumidified by a dry gas purge, such as a carbon dioxide or nitrogen purge or the like. This purge rapidly reduces ambient humidity to a desirable relative humidity (RH), e.g., less than about 15% RH, virtually eliminating the accumulation of frost. Microplates are systematically identified using barcode technology, for example. Once through the climate-controlled chamber, the containers (i.e., samples) are robotically transferred to the rotary mechanism. This mechanism transports the containers to a derived nest location upon the storage means, such as a carousel or to one of the stationary addresses.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority from U.S. Provisional Application Serial No. 60/227,166, filed on Aug. 23, 2000, entitled “Automated Storage and Retrieval Apparatus for Freezers and Related Method Thereof,” and 60/299,597, filed on Jun. 20, 2001, entitled “Automated Storage and Retrieval Apparatus for Freezers and Related Method Thereof,” the entire disclosures of which are hereby incorporated by reference herein. 
     
    
     
       FIELD OF INVENTION  
         [0002]    This invention relates to an automated storage and retrieval apparatus for ultra low temperature freezers, and more particularly an apparatus that improves the overall quality of the climate associated with storing items therein.  
         BACKGROUND OF INVENTION  
         [0003]    Advancements in biotechnology and medical science require the analysis of ever-increasing numbers of various biological samples. Many biological samples must be stored at below-freezing temperatures in order to preserve them for future reference, analysis, or use. For example, DNA, RNA, cells and protein samples, as well as the reagents necessary for conducting various analyses of these samples, must be stored at ultra-cold temperatures to prevent degradation that would interfere with reliable analyses of the biological products.  
           [0004]    Storage below −80° C. is generally required for successful preservation of biomolecules, cells, and tissue (morphology and viability) for extended periods of time. However, shelf life and the ability to recover living cells are dramatically improved at about −196° C. (−196° C. being the boiling point of liquid nitrogen). The National Institute of Standards and Technology has suggested that the term cryogenics be applied to all temperatures below −150° C. (−238° F. or 123° above absolute zero on the Kelvin scale). Some scientists regard the normal boiling point of oxygen (−183° C. or −297° F.), as the upper limit. The term ultra low temperature is probably not officially recognized by any standards body. However, it is generally agreed that a freezer refers to a storage device that operates from about −5° C. to −20° C., an ultra low operates from about −50° C. to about −90° C., and a cryogenic freezer operates from about −140° C. to −196° C.  
           [0005]    There are many problems associated with placement and retrieval of samples from ordinary laboratory freezer compartments. For instance, in an ordinary freezer compartment, containers of samples must be stored in front of and on top of each other to maximize use of the available space. Even if the containers are of standard sizes, and therefore easily stackable and even if a positional inventory of the samples is kept, it is still necessary to shuffle the containers around manually in order to retrieve a desired container. This is problematic because it requires keeping the freezer door open for possibly extended periods of time. Keeping the freezer door open causes the interior temperature of the freezer compartment to rise temporarily, which can cause thawing of samples housed near the door of the freezer. Once the freezer is closed and the temperature decreases, the samples refreeze. This repeated freezing and thawing can cause more rapid degradation of samples. Keeping the freezer door open also allows frost to build up in the freezer compartment. With repeated openings of the door, the frost eventually can freeze containers to the bottom of the freezer compartment or to each other. As a result, the door must be kept open longer in order to break containers out of the frost, which only exacerbates the problem.  
           [0006]    The increasing need for high quality bio-repositories in hospitals, research institutions, and pharmaceutical clinical research laboratories provides a market for automated ultra-cold storage devices that will improve sample quality, organize storage, provide rapid access to all specimens, and maintain electronic records of all specimens stored within the container.  
           [0007]    U.S. Pat. No. 5,921,102 to Vago, herein incorporated by reference, utilizes a storage apparatus particularly with automatic insertion and retrieval. Drawbacks of the Vago approach, but not limited thereto, are that it fails to provide the climate control associated with the freezer and the various interchanging devices, and other features and aspects.  
           [0008]    There is therefore a need in the art for an automated cold storage apparatus, and related method thereof, that can provide, among other things a more organized storage and retrieval apparatus, less accumulation of moisture and frost within the cold storage compartment, less temperature fluctuation from sample withdrawal, and rapid random access to all specimens.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention automated cold storage apparatus, and related method thereof, provides a sample process management system that is a revolutionary approach to the storage and retrieval of critical samples. The system—a significant technological breakthrough in laboratory automation—is the first ultra low temperature robotic system capable of being validated. Samples in containers are stored and retrieved robotically through an airlock climate-control chamber (access means) that is automatically dehumidified by a dry gas purge, such as a carbon dioxide or nitrogen purge or the like. This purge rapidly reduces ambient humidity to a desirable relative humidity (RH), e.g., less than about 15% RH, virtually eliminating the accumulation of frost. Microplates or storage containers, or the like, are systematically identified using barcode technology, for example. Once through the climate-controlled chamber, the containers (i.e., samples) are robotically transferred to the rotary mechanism. This mechanism transports the containers to a derived nest location upon the storage means, such as a carousel or one of the stationary addresses. For illustrative purposes only, the carousel and stationary nests may have a combined capacity of 1,000 standard microplates. It is contemplated that various capacities may be designed.  
           [0010]    The preferred embodiments of the present invention automated storage and retrieval apparatus, and related method thereof, operate at an ultra low temperature of about −50° C. to about −90° C. It should be understood that the apparatus may operate in a range of −50° C. up to ambient temperature or greater. The normal design operating temperature of the freezer compartment of the present invention is about −80° C. It should be noted that the present invention is contemplated to operate at conditions colder than ultra low temperatures in the range of about −140° C. to about −90° C. Conveniently, if the freezer fails for whatever reason—maintenance or scheduled outage—then liquid carbon dioxide can be pumped into the system and keep it at approximately −78° C. The ultra low freezer set point (approximately 78° C.) of the apparatus can be backed up by installing a cylinder of liquid carbon dioxide.  
           [0011]    In one aspect, the present invention features an automated storage and retrieval apparatus for storing containers at ultra low temperatures or other preferred temperatures. The apparatus comprising: a freezer compartment, the freezer compartment having a side wall; a storage carousel disposed inside the freezer compartment for holding the containers; a climate-controlled chamber disposed on the side wall; a climate system for controlling the climate of the chamber; and an interchange mechanism configured. The interchange mechanism is configured to: interchange a container between the interchange mechanism and the climate-controlled chamber while in a chamber exchange position, and interchange a container between the interchange mechanism and the carousel while in a carousel exchange position. The chamber also being configured to: isolate the container from the interchange mechanism as container is deposited from the exterior or placed into the exterior, and isolate the container from the exterior as container is exchanged between the chamber and the interchange mechanism.  
           [0012]    In some embodiments, the carousel can be replaced with a stationary storage rack, and additional storage racks may be added. The interchange mechanism is configured to interchange a container between the interchange mechanism and the rack(s) while in a rack exchange position(s).  
           [0013]    In a second aspect, the present invention provides an automated storage and retrieval apparatus for storing containers at ultra low temperatures or other preferred temperatures. The apparatus comprising: a freezer means for freezing the containers; a storage means disposed inside the freezer means for holding the containers; a chamber means for interchanging the containers between the exterior and the freezer means; a climate system control means for controlling the climate of the chamber means; and an interchange means. The interchange means for: interchanging a container between the interchange means and the chamber means while in a chamber exchange position, and interchanging a container between the interchange means and the storage means while in a storage exchange position. The chamber means for: isolating the container from the interchange means as container is deposited from the exterior or placed into the exterior, and isolating the container from the exterior as container is exchanged between the chamber means and said interchange means.  
           [0014]    In a third aspect, the present invention provides a method for automatically depositing and storing containers, as well as a method for storing and retrieving containers in a freezer compartment of an automated apparatus. The apparatus comprising: a freezer means for freezing the containers; a storage means disposed inside the freezer means for holding the containers; a chamber means for interchanging the containers between the exterior and the freezer means; a climate system control means for controlling the climate of the chamber means; and an interchange means. The interchange means for: interchanging a container between the interchange means and the chamber means while in a chamber exchange position, and interchanging a container between the interchange means and the storage means while in a storage exchange position. The chamber means for: isolating the container from the interchange means as container is deposited from the exterior or placed into the exterior, and isolating the container from the exterior as container is exchanged between the chamber means and said interchange means.  
           [0015]    An advantage of the present invention automated storage and retrieval apparatus for ultra low temperature freezers, and related method thereof, is that the apparatus can operate in a stand-alone mode or can be integrated into a completely automated laboratory. It is scalable to meet the needs of small laboratories as well as large institutions that will require long-term storage of large numbers of samples.  
           [0016]    Another advantage of the present invention is that the apparatus can be designed as a slide-in unit for existing ultra-cold freezers, which will keep the majority of the hardware in the door so as to be insulated from the freezer compartment, minimizing both the number of low-temperature hardware components and the actual alteration to the freezer itself A reduced number of moving components is continuously exposed to the design temperature of about −80° C., reducing the cost of production.  
           [0017]    Further advantages of the present invention are attributed to the improved sample quality, lowered operating costs, and reduced maintenance of the automated storage and retrieval apparatus.  
           [0018]    Finally, an advantage of the present invention is that it provides ultra-low temperature automation or lower and user-friendly information technology in a proven reliable manner.  
           [0019]    These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The foregoing and other objects, features and advantages of the present invention, as well as the invention itself, will be more fully understood from the following description of preferred embodiments, when read together with the accompanying drawings, in which:  
         [0021]    [0021]FIG. 1 shows a schematic plan view of the automated storage and retrieval apparatus.  
         [0022]    [0022]FIG. 2A shows a schematic perspective view of the automated storage and retrieval apparatus.  
         [0023]    [0023]FIG. 2B shows a perspective partial view of the door or wall of a compartment and/or housing.  
         [0024]    [0024]FIG. 3 shows a schematic cross-sectional view of the climate controlled chamber with the exterior door in open and closed positions.  
         [0025]    [0025]FIGS. 4A and 4B show a schematic frontal view and plan view, respectively, of the related translation mechanisms of the climate controlled chamber.  
         [0026]    FIGS.  5 A- 5 D show a schematic representation of select positions of the rotational alignment of the interchange mechanism.  
         [0027]    [0027]FIGS. 6A and 6B comprise a flow chart illustrating the operation for depositing and storing a storage container or the like in the automated storage and retrieval apparatus.  
         [0028]    [0028]FIGS. 7A and 7B comprise a flow chart illustrating the operation for retrieving the targeted or desired storage container or the like in the automated storage and retrieval apparatus.  
         [0029]    [0029]FIG. 8 shows a schematic perspective view of the storage carousel of the automated storage and retrieval apparatus.  
         [0030]    [0030]FIG. 9 shows a perspective view of an individual vertical rack from the carousel of FIG. 8, comprised of a plurality of storage trays,  
         [0031]    [0031]FIGS. 10A and 10B show a schematic perspective view of the storage trays and their related cooperation with the vertical supports of the carousel.  
         [0032]    [0032]FIGS. 11A and 11B are schematic perspective views of the interchange mechanism and related components.  
         [0033]    [0033]FIG. 12 shows a schematic block diagram of the general features of the control system of the automated storage and retrieval apparatus.  
         [0034]    [0034]FIG. 13 shows a schematic block diagram of an exemplary computer system associated with an embodiment of the automated storage and retrieval apparatus.  
         [0035]    [0035]FIGS. 14A and 14B show schematic perspective views of an alternative embodiment of the automated storage and retrieval apparatus.  
         [0036]    FIGS.  15 A- 15 D show schematic plan views of an alternative embodiment of the automated storage and retrieval apparatus providing expanded network system of cooperating freezer apparatuses.  
         [0037]    [0037]FIG. 16A and 16B show schematic perspective front/exterior views of the housing of the climate control chamber with related components in both the closed and open position, respectively.  
         [0038]    [0038]FIG. 17A and 17B show schematic perspective back/interior views of the housing of the climate control chamber with related components in both the closed and open position, respectively. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0039]    Turning now to the drawings, the present invention is schematically shown in the plan view of FIG. 1 and perspective view of FIG. 2A, which includes an automated storage and retrieval apparatus  1  having one or more storage carousels  20  disposed in a freezer compartment  10 , with one or more optional stationary racks  26 ,  27 , an interchange mechanism  40 , and a climate controlled chamber  60  that is generally disposed on a wall  11  of the freezer compartment  10  or associated housing  2 . A central control system  80  is coupled to the storage carousel  20 , interchange mechanism  40 , and climate controlled chamber  60  for controlling their operations. Generally, the control system  80  controls the operation of the apparatus so that the containers can be loaded from the exterior into the climate-controlled chamber  60  for retrieval by the interchange mechanism  40  for insertion onto the carousel  20  in the freezer compartment  10 . Stored containers subsequently can be retrieved from the carousel  20  by the interchange mechanism  40  and available to be taken away to the exterior through the climate controlled chamber  60 .  
         [0040]    [0040]FIG. 2B shows a perspective partial view of the wall  11  of the compartment and/or door of the housing. Mounted on the wall  11  are the climate-controlled chamber  60  and a touch screen interface  82 . As will be discussed later, it is envisioned that a control system and computer system can be accessed directly by using the touch screen interface  82  and/or remotely by a stand-alone personal computer or with a local area network (LAN).  
         [0041]    Next, details of the climate controlled chamber  60  will be provided, as best shown in FIGS. 3 and 4A- 4 B. A particularly desirable feature is that the climate-controlled chamber  60  prevents ambient, humid air from entering the interior of freezer compartment  10  during storage container insertion and retrieval. The Chamber  60  has an interior door  61  to allow communication between freezer compartment  10  and chamber  60 , and an exterior door  62  to allow communication between the exterior environment (or adjacent area)and chamber  60 . The chamber  60  has a climate control system  66  that provides an air purging capability to cool and dehumidify the air in the chamber  60  before interior door  61  is opened. A scanning reader device  65 , preferably a barcode reader, is situated in the chamber  60  to identify storage containers as they are inserted into and retrieved from chamber  60 . Information relative to the storage containers is transmitted from reader device  65  to central and/or remote processor.  
         [0042]    Still referring to FIGS. 3 and 4A- 4 B, the storage containers  3  are carried by a transport tray  63  that is slidably mounted on two channels  67 ,  68 . The transport tray  63  can transport the container  3  to the exterior as the exterior door  62  is open, as indicated by the dashed lines. Alternatively, the transport tray  63  can transport the container  3  to the interior of the freezer compartment  10  as the interior door  61  is open, as indicated by the dotted lines. In one embodiment, the interior door  61  may slide open and close on a track (not shown). A climate control system  66  is in communication with the chamber  60  that dehumidifies and cools the chamber  60  while the container is isolated therein, i.e., both exterior and interior doors are closed. The climate control system  66  includes a dry gas or dry air purge (i.e., nitrogen, carbon dioxide, or the like), that rapidly reduces ambient humidity to any desired level, e.g., less than about 25% relative humidity (RH) and as low as about 1% RH. In fact, any compressed gas from which moisture has been removed will reduce the humidity in the airlock, and will cool the airlock by adiabatic expansion to about −10° C. to about 0° C., or as desired.  
         [0043]    A preferred embodiments of the present invention automated storage and retrieval apparatus, and related method thereof, operate at an ultra low temperature from about −50° C. to about −90° C. It should be understood that the apparatus may operate in a range of −50° C. up to ambient temperature or greater. The normal design operating temperature of the freezer compartment of the present invention is about −80° C. It should be noted that the present invention is contemplated to operate at conditions colder than ultra low temperatures in the range of about −140° C. to about −90° C. Conveniently, if the freezer fails for whatever reason—maintenance or scheduled outage—then liquid carbon dioxide can be pumped into the system and keep it at approximately −78° C. Thus, the ultra low freezer-set point of the apparatus can be backed up by installing a cylinder of liquid carbon dioxide.  
         [0044]    One skilled in the art would appreciate that various types and substitutes for interior and exterior chamber doors can be used. Moreover, a single door can be utilized which can rotate between interior and exterior sides.  
         [0045]    Additional details pertaining to the climate controlled chamber  60  will be provided, as best shown in the perspective views of FIGS.  16 A- 16 B and FIGS.  17 A- 17 B. The front/exterior view and the back/interior view of climate controlled chamber  60  are shown in FIGS.  16 A- 16 B and FIGS.  17 A- 17 B, respectively. Referring to front/exterior view of FIG. 16A, the chamber  60  includes a chamber housing  91  having its exterior door  62  in a closed position with a deep well micro-plate  92  placed thereon the transport tray  63 . It should be appreciated that a shallow well micro-plate may be used, as well as any other size, type, or number of containers, which can be accommodated for storage and interchange. Also shown is a tray-motor and gear box housing  93 , reading device  65 , and air purge port  94 . FIG. 16B shows the chamber  60  having its exterior door  62  in an open position.  
         [0046]    Referring to the back/interior view of FIGS.  17 A- 17 B, there is shown the chamber  60  including an interior door-motor gear and motor housing  95  and lead screw  96 , and having its interior door  61  in a closed position. FIG. 17B shows the chamber  60  having its interior door  61  in an open position with the deep well micro-plate  92  placed thereon the transport tray  63 .  
         [0047]    Additional details of the cooperation between the freezer compartment  10 , carousel  20 , stationary racks  26 ,  27 , interchange mechanism  40 , and climate-controlled chamber  60  are schematically shown referring to FIGS.  5 A- 5 D. The interchange mechanism  40  is configured to interchange containers between it and the carousel  20  (See FIG. 5B), stationary storage racks  26 ,  27  (See FIGS.  5 C- 5 D, respectively), and the climate-controlled compartment  60  (See FIG. 5A). Various storage means besides the disclosed carousels or stationary racks are contemplated, such storage means include the following but are not limited thereto automated stackers, and with possible additional hardware, rectangular arrays of storage nests (or any predetermined shaped carousel/rack including linear, oval, pentagonal, hexagonal, etc.). The interchange mechanism  40  requires a picking mechanism  41  for horizontally translating the interchange tray  44  for interchanging the container  3  with the carousel  20  or the climate controlled chamber  60 . Various picking mechanisms include, but not limited thereto lead screws, picking devices, vacuum devices, side gripping fingers, vertical pincers, and conveyors. The interchange mechanism  40  further comprises a vertical transporter  42  configured to allow the interchange mechanism  40  to be translated vertically over a plurality of discrete heights. Various vertical transporters include, but not limited thereto lead screws, chain drives, and conveyors. Further yet, the interchange mechanism  40  comprises a rotary transporter  43  that is configured to rotate the interchange mechanism  60  to a plurality of discrete circumferential positions. Various rotary mechanisms include, but not limited thereto lead screws, pivot devices, gear drives, belt or chain drives, pneumatic or hydraulic devices, and conveyors.  
         [0048]    With regards to control operations, the present invention automation and robotic motions described herein are provided in part by the control system  80  and processor  81 . It should be noted that the following exemplary sequences of operations may be varied, partially omitted, overlapped to reduce the total elapsed time of operation, or reordered in an alternative sequence.  
         [0049]    Operation for depositing  600  a storage container is provided in the flowchart of FIGS.  6 A- 6 B. In a first step,  601 , the exterior door  62  opens and transport tray  63  exits, and storage container  3  is placed in chamber  60 . In step  602 , the exterior door  62  closes, transport tray  63  returns to chamber  60  and storage container&#39;s barcode is scanned by reader device  65 , and storage location is assigned. In step  603 , exterior door  60  and interior door  61  are in closed position while air purging system  66  cools and dehumidifies air in the chamber  60 . In step  604 , the interior door  61  opens, the transport tray  63  transports the container  3  inward, a picking mechanism  43  is advanced into the chamber  60  to pick up the storage containers and then retracts to place the container  3  on interchange tray  44 , and the interior door closes. In step  605 , the storage carousel  20  is rotated to rotationally align the correct vertical rack  23  with the future position of the interchange mechanism  40 . In step  606 , the interchange mechanism  40  is actuated vertically by a vertical transporter  42  to vertically align with correct height of targeted storage tray  28 . In step  607 , a rotary transporter  43  rotates the interchange mechanism  40  to rotationally align with correct vertical rack  23 . In step  608 , the picking mechanism  43  is advanced substantially horizontally to place the storage container  3  on storage tray  28 . In step  609 , the picking mechanism  43  is vertically lowered a desired nominal distance, e.g., approximately ⅛-inch, and retracted substantially horizontally to disengage the storage container  3 . In step  610 , the processor records relevant storage container information in the database. In step  611 , provided no other activity is required at the storage carousel  20  (or at any stationary storage rack  26 ,  27 ) the interchange mechanism  40  is rotated to rotationally align with interior door  61  of the chamber  60  and the interchange mechanism  60  is vertically actuated to vertically align with interior door  61 , for a resting state. It should be noted that a similar process and aspect applies to the stationary racks  26 ,  27 , except that the racks do not rotate.  
         [0050]    Next, the operation for retrieving  700  the desired or targeted containers  3  from the storage trays  28 , is.provided in the flowchart of FIGS.  7 A- 7 B. In a first step  701 , a storage container identification (ID) for a desired or targeted container is entered electronically or via data input device such a display panel integral with the apparatus housing or a remote there from, both of which being operatively connected to the control system  80 . In step  702 , a central processor  81  locates relevant storage container information in the database and location of storage container in storage carousel  20  (or stationary storage racks) is determined. Optionally, step  703  , if security is required, then an access code is entered via data input device such a display panel integral with the apparatus housing or a remote processor, and confirmed by central processor  81  to allow access to the desired storage container  3 . In step  704 , the storage carousel  20  is rotated to rotationally align the correct vertical rack  23 , containing the desired storage container  3 , with the future position of the interchange mechanism  40 . In step  705 , the interchange mechanism  40  is actuated vertically by a vertical transporter  42  to vertically align with the correct height of a desired storage tray  28 . In step  706 , the rotary transporter  43  rotates the interchange mechanism  40  to rotationally align with correct vertical rack  23 . In step  707 , the picking mechanism  43  is advanced substantially horizontally to retrieve the storage container  3  from storage tray  28 . In step  708 , the picking mechanism  43  is vertically raised a desired nominal distance, e.g., approximately ⅛-inch, and retracted horizontally to engage and withdraw the storage container  3 . In step  709 , the interchange mechanism  40  is rotated to rotationally align with interior door  61  of chamber  60 . In step  710 , the exterior door  62  and interior door  61  are in closed positions while air purging system  66  cools and dehumidifies air in chamber  60 . In step  711 , the interior door  61  opens, the transport tray  63  extends as the picking mechanism  43 , advancing into chamber  60  to disengage the storage container in the chamber  60 . In step  712 , the picking mechanism withdraws into the freezer compartment and the interior door  61  closes, and the reader device  65  reads the barcode ID of the storage container to confirm that it matches the ID that was entered in step  701  of the present invention retrieval process. In step  713 , the exterior door  62  opens, allowing access to the storage container  3 . It should be noted that a similar process and aspect applies to the stationary racks  26 ,  27 , except that the racks do not rotate.  
         [0051]    Next, details pertaining to the storage carousel  20  will be discussed, as schematically shown in FIGS.  8 - 9 . The perspective view as shown in FIG. 8 includes a carousel  20  having some racks  23  omitted for illustration purposes. The carousel  20  comprises an annular ring of vertical racks  23  arranged circumferentially between an upper horizontal plate  29  (shown in dashed lines) and a lower horizontal plate  30 . The carousel may be various sizes, dimensions, and shapes, including linear, rectangular, pentagonal, and hexagonal or the like. A base plate  31 , acts as a bearing brace to the support storage carousel  20  while allowing rotation of carousel  20  about the vertical axis. Rotation of carousel  20  is actuated by a motor driveshaft  32 , which runs through lower horizontal plate  30  and base plate  31  to communicate with a motor (not shown). The motor is preferably mounted beneath the floor of freezer compartment  10 , where the refrigeration equipment is housed, and where the motor is not exposed to the ultra-cold temperatures of freezer compartment  10 . Storage carousel  20  may rest on a ball bearing system to provide reduced friction at ultra-cold temperatures. The self-lubricating bearing system, e.g., graphite ceramic, may be used as well as other types known to those skilled in the art. Vertical racks  23  are mounted to upper horizontal plate  29  and lower horizontal plate  30  with right-angle braces or the like. The vertical racks  23  comprise a vertical support  33  and a plurality of adjustable storage trays  28  to hold a plurality of storage containers  3 , which could be of standard or varying size.  
         [0052]    [0052]FIG. 9 is a perspective view of an individual vertical rack  23 , comprised of a plurality of storage trays  28 .  
         [0053]    Next, details pertaining to the storage trays  28  and cooperation with the vertical support  33  of the carousel  20  will be discussed, as best shown in FIGS.  10 A- 10 B. Storage trays  28  have a flat, horizontally oriented support surface  34  with an open center  35  to allow the interchange mechanism  40  to engage the storage containers  3  either for placement onto storage tray  28  or for retrieval from storage tray  28 . The storage trays  28  have a flat vertically oriented attachment surface  36  positioned at a right angle to the proximal edge of storage trays  28 , which allows connection of storage trays  28  to vertical support  33  of the vertical racks  23  by an attachment assembly  37  (partially shown). Other configurations of the attachment assembly  37  are contemplated according to the type of interactions between the various components and subsystems. The distal edge of storage trays  28  is open and outward facing to allow access to the storage containers. Other configurations of the storage trays  28  are contemplated according to the type of interactions between the various components and subsystems. Vertically oriented raised guides  38  are situated on lateral edges of storage trays  28  to prevent storage containers from becoming misaligned on storage trays  28 . The raised guides  38  can be stamped out of the surface of storage trays  28 , or other suitable means known to those skilled in the art.  
         [0054]    Next, details of an exemplary embodiment of the interchange mechanism  40  will be discussed, as best shown in FIGS.  11 A- 11 B. In this particular embodiment the interchange mechanism  40  comprises a pair of guide rails  45  and  46  that are located with their axes vertically within the freezer compartment  10  and they extend for a substantial length as required by the discrete heights of the various interchange operations. The guide rails  45  and  46  are slidably mounted on the interchange plate  47 . A vertical lead screw  48  having an axis length-wise within the freezer compartment  10  is actuated by a motor  53 , located below the freezer compartment, for vertically translating the interchange plate  47  to a desired height. A vertically mounted rotating square shaft  49  is driven by a motor  54  mounted beneath the floor of freezer compartment  10 . The square shaft  49  drives the interchange tray  44  using a gear train, such as the square shaft gear  50  and tray gear  51 , as shown. The drive gear mates with a rack  52  in communication with the interchange tray  44 . During operation, the square shaft  49  rotates in a clockwise direction to drive the gear train and rack  52 , thereby driving the interchange tray  44  horizontally into an extended position, as shown by the dashed lines. While in the extended position, the interchange tray  44  is capable of retrieving or dropping off a container. Next, the square shaft  49  rotates in a counter-clockwise direction to drive the gear train and rack  52  in an opposite direction, causing the rack  52  and interchange tray  44  to retract to a rest position. The rotary transporter  43 , driven by a motor (not shown) mounted beneath the floor of the freezer compartment  10 , rotates the interchange mechanism  40  to rotationally align with correct vertical rack  23  or stationary storage rack  26 ,  26 , and interior door  61  of the chamber  60 , or any other position as required. The rotary transporter  43  may be pivoted, rotated, or translated using a means known to those skilled in the art.  
         [0055]    It should be noted that the motors for the storage carousel  10 , vertical transporter  42 , rotary transporter  43 , picking mechanism  42 , and transport tray  63  can be a variety of types of motors known to those skilled in the art, including but not limited thereto servo motors and stepper motors, or any direct current (DC) motor with suitable position or velocity controllers. In the various preferred embodiments disclosed herein, the motors are mounted outside of the freezer compartment  10  to extend the life of the component and improve the overall serviceability of the apparatus. With the exception of the transport tray  63  the drive shafts are mounted through a series of sophisticated thermal seals and thermal couplers designed to maintain temperature stability throughout all operating cycles. In a choice embodiment, the servomotors may be of a SMART MOTOR by Antimatics, Corp. These type of servo motors are microprocessor controlled, ensuring accurate placement and monitoring of the robotics operating within the critical environment; however, any position or velocity controlled motors may be used.  
         [0056]    Next, the general features of the present invention control system  1280  will be discussed, as shown in the block diagram of FIG. 12. The control system  1280  interfaces with a computer system  1281  that may be integral with the housing  2  or remote via a wire or wireless communication, or any combination thereof. Moreover, the control system  1280  may be in communication with and integrated with a laboratory information management system (LIMS)  1282 . The control system  1280  is operatively connected with the various motors  1283 , actuators  1284 , position sensors  1285 , and identification sensors  1286 . It is contemplated that that the information derived from the sample or work pieces carried in the containers  3  while practicing the present invention will provide an information technology platform for the user. The computer system  1281  is intended to be a user-friendly, utilizing Windows-based platform or any other operating system, and may be integrated with a variety of laboratory information management systems. It is envisioned that the control system  1280  and computer system  1281  can be accessed directly by using a touch screen interface or remotely by a stand alone personal computer or with a local area network (LAN).  
         [0057]    The present invention apparatus provides the user the capability, among other things, to set top-level user-definable parameters to control container (sample) access based on research groups, research campaigns or individual laboratories. For instance, sample data can be configured by the user to meet the user&#39;s particular research requirements. The database can then search the user&#39;s sample populations to find all the samples that match the user&#39;s requested research parameters. Moreover, time/temperature profiles and sample access histories are maintained continuously. The present invention allows the user to set sample migration thresholds. This feature, employing sample usage frequencies, prompts the movement of low demand samples into longer-term storage units—maximizing the efficiency of the user&#39;s sample process management system. Furthermore, the present invention apparatus enables the user to generate a variety of reports in support of the user&#39;s quality assurance needs. Finally, the user will benefit from the present invention&#39;s information technology by receiving excellent sample security, optimal sample visibility, optimal quality assurance, sample migration control and flexible data management.  
         [0058]    Next, exemplary embodiments of the control system and computer system will be discussed, as best shown in FIG. 13. The controls and processing of present invention may be implemented using hardware, software or a combination thereof and may be implemented in one or more computer systems or other processing systems, such as personal digit assistants (PDAs). In an example embodiment, the invention was implemented in software running on a general purpose computer  1300  as illustrated in FIG. 1300. Computer system  1300  includes one or more processors, such as processor  1304 . Processor  1304  is connected to a communication infrastructure  1306  (e.g., a communications bus, cross-over bar, or network). Computer system  1300  includes a display interface  1302  that forwards graphics, text, and other data from the communication infrastructure  1306  (or from a frame buffer not shown) for display on the display unit  1330 .  
         [0059]    Computer system  1300  also includes a main memory  1308 , preferably random access memory (RAM), and may also include a secondary memory  1310 . The secondary memory  1320  may include, for example, a hard disk drive  1312  and/or a removable storage drive  1314 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive  1314  reads from and/or writes to a removable storage unit  1318  in a well known manner. Removable storage unit  1318 , represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive  1314 . As will be appreciated, the removable storage unit  1318  includes a computer usable storage medium having stored therein computer software and/or data.  
         [0060]    In alternative embodiments, secondary memory  1310  may include other means for allowing computer programs or other instructions to be loaded into computer system  1300 . Such means may include, for example, a removable storage unit  1322  and an interface  1320 . Examples of such removable storage units/interfaces include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as a ROM, PROM, EPROM or EEPROM) and associated socket, and other removable storage units  1322  and interfaces  1320  which allow software and data to be transferred from the removable storage unit  1322  to computer system  1300 .  
         [0061]    Computer system  1300  may also include a communications interface  1324 . Communications interface  1324  allows software and data to be transferred between computer system  1300  and external devices. Examples of communications interface  1324  may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via communications interface  1324  are in the form of signals  1328 , which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface  1324 . Signals  1328  are provided to communications interface  1324  via a communications path (i.e., channel)  1326 . A channel  1326  (or any other communication means or channel disclosed herein) carries signals  1328  and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels.  
         [0062]    In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage drive  1314 , a hard disk installed in hard disk drive  1312 , and signals  1328 . These computer program products arc means for providing software to computer system  1300 . The invention includes such computer program products.  
         [0063]    Computer programs (also called computer control logic) are stored in main memory  1308  and/or secondary memory  1310 . Computer programs may also be received via communications interface  1324 . Such computer programs, when executed, enable computer system  1300  to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable processor  1304  to perform the functions of the present invention. Accordingly, such computer programs represent controllers of computer system  1300 .  
         [0064]    In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system  1300  using removable storage drive  1314 , hard drive  1312  or communications interface  1324 . The control logic (software), when executed by the processor  1304 , causes the processor  1304  to perform the functions of the invention as described herein.  
         [0065]    In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine to perform the functions described herein will be apparent to persons skilled in the relevant art(s).  
         [0066]    In yet another embodiment, the invention is implemented using a combination of both hardware and software.  
         [0067]    In an example software embodiment of the invention, the methods described above were implemented in VISUAL BASIC control language, but could be implemented in other programs such as, but not limited to, C++ programming language.  
         [0068]    Next, details of an alternative second embodiment of the present invention will be discussed, as best shown in FIGS.  14 A-B. The storage carousel is fixed in place (i.e., no rotation) providing a fixed hotel  1420 . The storage containers  1403  are accommodated on shelves  1428  in the same manner as in the storage carousel. However, the interchange mechanism  1440  is located in the central core  1439  of the fixed hotel  1420 . The interchange mechanism  1440  includes an interchange tray  1444 , and may rotate about its axis and travel vertically as previously discussed herein. The interchange mechanism  1440  retrieves storage containers from shelves, takes them to a vertical position aligned with an access portal  1437 , and moves them through the portal  1437  to the exterior of the freezer via the climate controlled chamber  1460 . It is noted that the access portal  1437  is a fixed hole in the fixed hotel  1420  allowing samples to access the interchange mechanism  1440 . One or more access portals may be used if one wishes to mate several fixed hotels  1420  or rotating carousels together, or provide more than one point of access portal  1437 . Furthermore, the access portal may be movable if one wishes to provide rotational movement to one “slice” of the hotel  1420 .  
         [0069]    An advantage of this second embodiment approach, but not limited thereto is that it may be accommodated in a cylindrical freezer compartment, occupying less space. In addition, this apparatus and method obviates the need for a rotational mechanism for the carousel (unless one wishes to have a movable access port). All other aspects of the design are the same as previously described above.  
         [0070]    In addition, as a third alternative embodiment, one could also have a second carousel outside the one depicted in FIGS.  14 A- 14 B, so as to allow for greater storage space. In this embodiment the inside carousel could rotate so as to allow a vertical arrangement and rotational alignment of access ports to access any compartment in the outer carousel.  
         [0071]    Next, details of providing an expanded network system of cooperating freezer apparatuses  1501  will be discussed, as best shown n FIGS.  15 A-D. The plurality storage of carousels  1520  (or stationary storage racks  1526 ,  1527  and fixed hotels), interchange mechanism  1540 , and climate control chamber  1560  operate with the methods and aspects described herein. The plurality of storage carousels  1520  (stationary racks or fixed hotels) operates in an enclosure  1502 . The enclosure  1502  may be equipment housing-type as previously discussed to accommodate a freezer unit or plurality of freezer units. Alternatively, the enclosure  1502  may be an entire room, or a plurality of rooms, as disclosed in the U.S. Pat. No. 5,921,102 Vago patent. The configurations shown in FIGS.  15 A-D are illustrative in nature and are not intended to be exhaustive as other combinations and designs are contemplated. Essentially, the containers  1503  are interchanged, stored, deposited, and retrieved among the storage carousels  1520  (including stationary storage racks  1526 ,  1527 ), interchange mechanism  1540 , and climate-controlled chamber  1560  using the aspects and methods previously disclosed herein, while recognizing the enclosure  1502  may be a room or equipment housing, or any combination thereof. A control system  1580  is operatively connected to the various components and subsystems, wherein the controls and processor are locally or remotely located.  
         [0072]    The interchange mechanism  1540  cooperate with multiple locations allowing containers  1503  to pass among carousels  1520  and stationary racks  1526 ,  1527 , and of course the climate-controlled chamber  1560 . As shown in FIGS.  15 C-D, to accomplish this task, a translating mechanism  1590  is provided to translate or shift the interchange mechanism  1540  to the target carousel(s)  1520  or stationary racks  1526 ,  1527 . Various means are contemplated for translating the interchange mechanism  1540 , including but not limited thereto, track devices, wheels, conveyors, pulleys, suspension devices, belts, gears, or other robotic devices.  
         [0073]    Some advantages of the present invention automated storage and retrieval apparatus for ultra low temperature freezers, and related method thereof, are that it provides a more organized storage and retrieval apparatus, less accumulation of moisture and frost within the cold storage compartment, less temperature fluctuation from sample withdrawal, and rapid random access to all specimens.  
         [0074]    Moreover, another advantage of the present invention is that the apparatus can operate in a stand-alone mode or can be integrated into a completely automated laboratory. It is scalable to meet the needs of small laboratories as well as large institutions that will require long-term storage of large numbers of samples.  
         [0075]    Another advantage of the present invention is that the apparatus can be designed as a slide-in unit for existing ultra-cold freezers, which will keep the majority of the hardware in the door so as to be insulated from the freezer compartment, minimizing both the number of low-temperature hardware components and the actual alteration to the freezer itself. A reduced number of moving component is continuously exposed to the normal design temperature of about  31  80° C., reducing the cost of production.  
         [0076]    Further advantages of the present invention are attributed to the improved sample quality, lowered operating costs, and reduced maintenance of the automated storage and retrieval apparatus.  
         [0077]    Still further, an advantage of the present invention is that the climate-controlled chamber prevents ambient, humid air from entering the interior of freezer compartment during storage container insertion and retrieval.  
         [0078]    Finally, an advantage of the present invention is that it provides ultra-low temperature automation and user-friendly information technology in a proven reliable manner. It is contemplated that the present invention apparatus may provide an operation temperature below and above the ultra low operating temperature.  
         [0079]    The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is this indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced herein.