Patent Application
20060245865
The present invention generally relates to automated chemical analyzers, such as, for example, automated immunoassay analyzers, and more particularly, to a carousel system which handles linear racks, each of which hold a plurality of samples or controls. The invention thus combines the immediate access to samples benefits of a carousel system with the benefit of enhanced automation by sequential presentation offered linear rack based systems.
Automating chemical analyses is a desirable objective in a number of situations. For example, in the clinic or hospital setting, a large number of patient blood or urine samples need to be analyzed on a daily basis for a wide variety of different antigens or analytes. Highly advanced systems have been developed for analyzing these types of samples, and for allowing different tests to be performed on different samples as well as for recording test results for subsequent use in, for example, patient assessment and care. Exemplary systems are described in U.S. Pat. No. 6,027,691; U.S. Pat. No. 5,902,548; U.S. Pat. No. 5,885,530; U.S. Pat. No. 5,885,529; U.S. Pat. No. 5,807,523; U.S. Pat. No. 5,723,092; U.S. Pat. No. 5,721,141; U.S. Pat. No. 5,632,399; U.S. Pat. No. 5,620,898; U.S. Pat. No. 5,318,748; U.S. Pat. No. 5,316,726; U.S. Pat. No. 5,258,309; U.S. Pat. No. 5,098,845; U.S. Pat. No. 5,084,240; U.S. Pat. No. 5,008,082 and U.S. Pat. No. 4,639,242 all of which are herein incorporated by reference. As another example, automated systems may be used for detecting contaminants in water sources, food products, etc.
Despite the advanced systems for automated chemical analysis, there remains a need for improving the level of automation, the mechanisms which allow random access to and testing of samples, and the speed in processing large numbers of samples (i.e., throughput). Presently, the current automated technologies either involve a carousels, which allow large numbers of samples or agents to be present and easily accessible, or linear racks and conveyers where the materials stored in the racks are easily presented for operations in a sequential manner. While the carousel systems have the advantage of easy access to large numbers of samples, the prior art systems suffer from having to empty the carousels in a batch like process in order to handle new samples. Conversely, while the linear rack based systems allow for easy automation, it is generally more difficult to retrieve a sample at different times to perform different tests.
It is therefore an object of this invention to combine the benefits of carousel systems and linear rack systems, while avoiding the disadvantages of both.
According to the invention, an improved sample handling system, which may be incorporated into automated chemical or biological (e.g., immunoassay) analyzers, includes one or more carousels with radially distributed slots, each of which can accommodate a linear rack containing a plurality of samples or controls distributed along the length of the linear rack. The linear racks preferably include receptacles for holding containers (e.g., test tubes) filled with samples or controls, and, more preferably, the containers can be of varying sizes. Preferably, the test tubes are labeled with a bar code or an RFID tag identifying the contents of the tube, and the linear racks are also labeled with a bar code or RFID tag. In a preferred configuration using bar coding, the bar codes on the test tubes and on the linear racks can be read at the same time using the same bar code reader. In operation, a computer controller will track information related to the location of linear racks and test tubes, and by associating bar code or RFID identity information of the rack and bar code or RFID identity information of the test tubes, the controller can easily manage retrieval, transfer, and pipetting operations of samples which need to be accessed a number of different times (e.g., for performing different tests on the same sample). Bar code labels may be permanently imprinted on linear racks or labels may be printed and applied to linear racks as well as to test tubes. Similarly, RFID tags might be affixed to and removable from both linear racks and test tubes.
Mechanical transfer devices, operated under computer control, engage the linear racks and transfer them, for example, from a rack loader into a carousel, between two adjacent carousels, and between a carousel and a separate control storage compartment. This may preferably be accomplished using a belt or chain drive which moves a transfer slide with a transfer pin mounted thereon, where the transfer pin engages a slot located, for example, in the bottom of the linear rack. A motor, operating under computer control, will cause the transfer pin to engage the slot in the linear rack and move the linear rack, for example, into a slot in the carousel. When in the carousel, the linear rack will be retained by, for example, a flat spring and button connection that fits within a depression in the bottom of the linear rack. By advancing the carousel slightly, the transfer pin can be moved out of the linear rack and to a position outside the circumference of the carousel through a channel formed in the bottom of the carousel. Preferably, a spring or other elastic device is used to hold the linear rack firmly in place against a side wall of the slot in the carousel.
Carousels offer the flexibility of random access to all samples, and immediate access to any sample. Once in the carousel, samples on the linear rack can be processed, for example, movement to a pipetting station or diluting station, movement to a second or third carousel, etc. Ideally, the length of time between loading the linear rack onto the carousel and the further processing will be handled under computer control which will consider the other samples on board the one or more carousels of the automated chemical or biological analyzer, the tests being conducted for each of the samples, as well as other factors such as rush or “STAT” tests to be conducted on a priority basis.
Movements of the one or more carousels, the mechanical transfer devices, pipetters and other components in the chemical and biological analyzer are preferably accomplished under computer control so as to minimize or eliminate involvement of technicians. This is accomplished by tracking the linear rack that is labeled with a bar code, RFID tag, or other device, tracking the positions of the linear racks in the carousel or carousels as well as the testing to be performed on the samples in the linear racks, and coordinating the movements of the transfer devices and pipetters.
The capacity of the automated chemical or biological analyzer can be made quite large by using multiple carousels in a series with transfer devices positioned to move linear racks between the carousels, as well as by using linear racks that can accommodate larger numbers of samples. In a preferred embodiment, the linear racks may hold five sample tubes, and the carousels may have twenty slots. Thus, an automated chemical or biological analyzer equipped with two carousels configured in the preferred embodiment may be processing up to two hundred samples at a time. After testing of the samples, the linear rack can be selectively removed from the carousel using the mechanical transfer device, and may be deposited in a rack loader or suitable storage area.
In one embodiment of the invention, controls are loaded into the carousel system on a linear rack in the same fashion as samples to be tested. These controls can be selectively stored in a slot on the carousel, or, more preferably, be stored in a storage area separate from a carousel. Transfers from the carousel to the storage area will be accomplished with a mechanical transfer device operating under computer control in the same fashion as discussed above. The controls can be selectively retrieved (e.g., transferred back onto the carousel followed by the carousel being rotated to pipetting position), for periodic calibration or testing of the automated chemical or biological analyzer, and then re-loaded into the storage compartment. In this embodiment, the user is not required to load controls by a separate operation (i.e., controls can be automatically loaded into the machine from the rack loader used for transporting linear racks of samples), and the controls can be periodically used multiple times without interrupting the operations of the chemical or biological analyzer.
The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
a and 4b are illustration of a sample rack in a left side view and a cross-sectional view respectively.
For illustrative purposes only,
At its core, the control system 101 manages and coordinates the operations of all of the subsystems by sending commands and be receiving signals from the subsystems via the control bus 102. In operation of an automated immunoassay analyzer, samples of biological material (e.g., blood, urine, plasma, etc.) are placed by in the sample subsystem 104. This can be accomplished manually, or by retrieving samples (and, most preferably in the preferred embodiment of this invention, linear racks containing samples) from a rack loader which has been loaded with samples obtained throughout, for example, a hospital or clinic. The samples within the sample subsystem 104 can be diluted prior to making measurements or can be tested in their undiluted state depending on direction from the control subsystem 101. Preferably, a bead subsystem 105 adds an appropriate substrate having a bound “analyte binding compound” to a test vessel in which, for example, an antibody-antigen binding interaction will be performed for testing for the amount of an antibody or antigen of interest in the sample. A large number of different analytes can be tested using beads or other substrates that are added to a test vessel. In addition, multiple tests for different analytes in the same sample can be performed simply by adding the appropriate bead with bound analyte to each of several test vessels, and then adding sample from the sample tubes on the linear racks to each of the test vessels (i.e., immunoassay or chemical analyzers which include bead subsystems 105 provide for significant flexibility in processing samples for test). The reagent subsystem 103 is used for adding reagents to test vessels under control of the control subsystem 101. Similarly, the incubator subsystem 106 incubates test vessels, preferably with vessel agitation, for predetermined periods of time prior to testing, and the luminometer subsystem 107 performs measurements on samples which have been combined with reagents and beads, and which have been incubated and washed (it being understood that some analyzers may utilize phosphorescence, fluorescence, or colorimetric changes instead of chemiluminescence (the preferred indicator in the immunoassay embodiment of this invention)).
Movement between stations is accomplished using the transfer subsystem 108. The control subsystem 101 coordinates the operations being performed within subsystems 102, 103, 104, 105, 106, and 107, and the transfers being performed by transfer subsystem 108, and preferably considers the tests being performed on all of the samples which have been loaded, thereby optimizing the order in which certain tests are performed. In addition, the control subsystem 101 preferably accommodates rush or “STAT” tests such that certain tests on certain samples can be performed preferentially to other tests on other samples present in the automated chemical or biological analyzer.
Preferably, the subsystems 103, 104, 105, 106, and 107, take advantage of identification technologies such as, for example, bar coding and RFIDs. That is, reagents loaded on a reagent subsystem 103 would be identified for the control subsystem 101, so that the position of a particular reagent would be known and managed by the control subsystem 101. Similarly, beads to be added to test vessels using the bead subsystem 105, would be added using bar coded or RFID tagged bead dispensers (not shown), such that the control subsystem 101 would be made aware of the location of the beads to be dispensed. Notification for replenishment of the reagents or beads may accomplished using sensors at the reagent subsystem 103 and the bead subsystem 105 which communicate information to the control subsystem 101 through the control bus 102. As will be discussed in more detail below, the sample subsystem 104 will utilize bar codes or RFID tags or other identification schemes to notify the control subsystem 101 of the location of a sample within the automated chemical or biological analyzer. By tracking the location of a linear rack and by having the identifying information of the test tubes associated with particular linear racks, the controller can accommodate random and immediate access to any sample in any rack in any carousel.
This invention is directed to the sample subsystem 104. The sample subsystem 104 can be employed in a wide variety of automated immunoassay analyzers, and should be applicable to any analyzer which requires access to multiple test samples for diagnostic purposes.
While
In the embodiment shown in
The control storage element 4 preferably provides an onboard storage space in the automated chemical or biological sample analyzer for control samples which may be used to calibrate the analyzer prior to the performance of certain tests and/or periodically during operation of the analyzer. The control storage element 4 preferably houses the control samples in a preferred storage environment which assures stability. For example, in most applications the environment will be designed to assure low evaporation rates for the control (e.g., low (e.g. refrigerator) temperatures, and possibly higher humidity). Furthermore, the control storage element 4 preferably has a housing which protects the control samples from exposure to dust or other contaminants, as well as any damaging radiant energy (e.g., light or uv light) during extended operation of the analyzer.
Preferably, the control samples are added to the analyzer in the same manner as samples to be tested. That is, they are loaded onto a linear rack which will be either transferred automatically from a rack loader using transfer mechanism 7 into the first carousel 2 or will be manually placed on the transfer mechanism 7 for insertion into the first carousel. Thereafter, under computer control, the linear rack containing the control samples will be passed to the second carousel 3 and then be passed into the control storage element 4. Preferably, the control storage element 4 will house at least two linear storage racks filled with control samples. When needed, a transfer mechanism will transfer the linear rack with control samples back into the second carousel 3, which will then transport the linear rack to the pipetting station 5. The control sample can then be either diluted at the diluting station 6, or pipetted directly into a test vessel (not shown), which preferably passes along, under computer control, outside of platform 1. Then, the with control sample will be moved back into the control storage element 4 using movements of carousel 3 and the transfer mechanism located between the carousel 3 and control storage element 4. The configuration thus has the advantage that the operator is not required to periodically load control samples (they are stored on board), and has the simplicity that operator does not need any special mechanism to load the controls (i.e., they are loaded in the same manner as samples to be tested). However, it should be understood that in some applications, it may not be desirable to have control samples on board, and in these applications the control storage element 4 might simply be eliminated (in which case, the linear rack with the control samples would simply occupy a slot within one of the carousels).
To assist in holding the linear rack firmly in position, each slot preferably includes an elastic spring member 13 which forces the linear rack against one of the side walls of the slot 11. Having the linear rack forced against a side wall of a slot may provide certain advantages in being able to more easily align the pipetter of pipetting station 5. Thus, in some applications, it may be preferable to have the elastic spring member 13 located on the same side of each slot in a carousel 2. Further, in some applications which will involve a transfer of a linear rack carrying test samples or control samples, it may be advantageous to have the spring members of adjacent carousels located on the opposite walls of the slots 11. As will be explained in more detail below in connection with FIG. 4a and 4b, when using a linear rack with openings on one side and a closed back member, it will be advantageous to have the springs 13 on one carousel on one side wall of slots 11 while the springs 13 on the other carousel are on the opposite side wall of slots 11, such that the springs 13 in each carousel always contact the closed back member of the linear rack.
While
As noted above, the carousels 2 and 3 preferably are each rotatable 360° in either the clockwise or counterclockwise direction, and movements are controlled by a computer in a coordinated fashion so as to allow alignment with a transfer mechanism to permit loading or retrieval of a linear rack in a slot, alignment of samples in the linear rack at a position accessible by a pipetter of pipetting station, transfer of a linear rack containing control samples into the control storage element 4, etc. The carousels 2 and 3 can be advanced any amount chosen under computer control, and are preferably not simple incrementally advanced devices. Further, as discussed above, the carousels 2 and 3 are preferably advancible in half increments so as to allow components of a linear transfer mechanism to either exit the carousel, or to allow insertion of the component into the carousel (via the grooved underside 28 of wedge region 12) to retrieve a linear rack therefrom. Specifically, with reference to
a and 4b show an isometric side view and a cross-sectional side view of the preferred linear linear racks 10 used in the practice of this invention. In the preferred embodiment, the linear rack 10 will hold a plurality of sample tubes 14 and, while five tubes 14 are shown in the drawings, the number can vary within the practice of the invention. The tubes 14 can be of varying size, and in an automated immunoassay analyzer embodiment contemplated by this invention, the tubes may range in diameter from 11 mm to 16 mm, and may range in height from 66 mm to 100 mm. To enable accommodating different sized tubes 14 and to allow for easy insertion into a station in the linear rack, the linear racks 10 may have a spring bias in a back wall of each station of the rack, and the front portion of each station may be open. However, it should be clear that the stations for accommodating the tubes 14 can be fully closed and may not require a spring bias mechanism.
a and 4b also make clear that the racks 10 do not need to be fully loaded during operation and use. That is, some stations may be empty.
The bar code shown on the end of the rack 10 in
a and 4b also show that the linear racks 10 preferably include a transfer pin slot 15 in its base. As will be described in more detail below, this transfer pin slot 15 is used by one or more transfer mechanisms within the automated chemical or biological analyzer to move the linear racks 10 between stations (e.g., between carousels, between the rack loader and a carousel, between a carousel and a control storage component). Movement of the linear rack 10 may be accomplished, for example, by an upwardly projecting element engaging the pin slot 15, then sliding the rack 10 in a given direction, then having the projecting element disengage from the linear rack 10 (such as by rotational movement of the carousel and withdrawal of the upwardly projecting element through the grooved region 28 in a wedge section 12 of the carousel). It should be understood that other types of features might be incorporated into a linear rack 10 to assist in transfer operations, and that if a transfer pin slot 15 is used, as in the preferred embodiment, the location of the transfer pin slot 15 on the linear rack 10 may vary within the practice of the invention. Further, linear racks 10 might include more than one feature to assist in movement between stations in the automated chemical and biological analyzer (e.g., more than one transfer pin slot 15, etc.).
a and 4b also show that the linear rack 10 may also be formed with a detent 16 (to be discussed in more detail below) to assist in loading the linear rack 10 into a carousel 2 or 3, and indentation region 18 which may assist in identifying the front end and back of the rack so that a technician does not insert the linear rack 10 in a rack loader incorrectly. It should be understood that the construction of the linear rack can vary considerably within the practice of the invention. The linear configuration allows for easy identification of a plurality of samples located at different spaces along the length of the linear rack 10, easy loading of samples into the rack by technicians, and easy handling of the rack 10 by an automated rack loader. Furthermore, the linear configuration of the racks 10, in conjunction with the carousels 2 or 3 of the present invention, permits the linear rack 10 to be transferred to a plurality of stations within an automated chemical or biological analyzer via simple linear movements of transfer devices (turning of the linear racks 10 is not required).
In
While the invention has been described in terms of its preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.
