Abstract:
A sample identification system that may be used to track and correlate a sample container in a laboratory analyzer or the like is set forth. The exemplary laboratory analyzer employs at least one carrier that supports at least one sample tube. The sample identification system includes a first optical reader that has a first field of view that is sufficient to expose the first optical reader to targeted visual indicia that identifies the carrier. The system further includes a second optical reader that has a second field of view that is sufficient to expose the second optical reader to targeted visual indicia identifying the sample tube held by the carrier. One or more decoders may be used to extract the identification information from the targeted visual indicia. The identification information then may be provided to a process controller, which may use the information for one or more predetermined purposes. One such purpose may be to use the identification information derived from the first and second readers to direct manipulation of the content of the sample tube. In various embodiments, the system may employ one or more masks to enhance the accuracy of the identification process. Further, the system may be adapted to replace a legacy identification system of an existing apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The present invention is generally directed to laboratory apparatus that are used in the analysis and/or manipulation of sample materials. More particularly, the present invention is directed to a sample identification system that is suitable for use in automated laboratory apparatus that are used in the analysis and/or manipulation of biological samples, such as blood, urine, etc.  
         [0003]     2. Background Art  
         [0004]     Manual, semi-automated and automated analyzers for measuring certain parameters of or otherwise manipulating a biological sample obtained from a patient are well-known. In such systems, the biological sample must be carefully tracked and correlated with either or both the patient and/or the particular process that is to be executed on the sample. Preferably, the tracking and correlation are automated to reduce the potential for human error.  
         [0005]     One embodiment of a hematology analyzer in which a sample tube is identified during aspiration of blood contained in the tube is set forth in U.S. Pat. No. 4,609,017, entitled “Method and Apparatus for Transporting Carriers of Sealed Sample Tubes and Mixing the Samples” issued Sep. 2, 1986, to Coulter et al. In the analyzer disclosed in the &#39;017 patent, a plurality of sealed blood sample tubes are housed in a carrier. Several of these carriers are vertically stacked with the sample tubes lying horizontally. The carriers are successively deposited onto a horizontal conveyor belt that moves them longitudinally in a semi-inverted mode as the carrier is transported from the stack to a sample aspiration station. Aspiration is accomplished by pushing a sample tube partially out from the carrier and into engagement with a sealed piercing tip of an aspiration probe. The tube is then retracted from the aspiration probe and returned to the carrier. The other tubes in the carrier are similarly aspirated as the carrier is stepped to align each tube with the aspiration probe.  
         [0006]     Each sample tube includes a barcode that uniquely identifies the sample tube within the system. A barcode reader is fixed over the path of the carrier and the barcode for each sample tube is scanned as the sample tube is driven into engagement with the aspiration probe.  
         [0007]     Commercial analyzers that are constructed to include many of the features of the apparatus disclosed in the &#39;017 patent are available from Beckman Coulter, Inc. In some of these systems, both the sample tube and the corresponding carrier are identified with barcodes. One barcode is fitted on the carrier and is used to uniquely identify the carrier. Alternatively, a plurality of duplicate barcodes uniquely identifying the carrier may be positioned adjacent each sample tube position of the carrier. Another barcode is used to uniquely identify each individual sample tube within the corresponding carrier. A single barcode reader is used to read both the carrier barcode and the barcode of the sample tube. The barcode reader employs a non-scanning laser and receiver that are both fixed to the frame of the system. The motion of the carrier and the sample tube with respect to the laser and receiver are used to effect a barcode scan to identify the carrier and corresponding sample tube during an aspiration cycle in which an amount of the sample is aspirated from the tube.  
         [0008]     The foregoing configuration is suitable for use in systems in which the barcodes are of high quality. However, when the sample tube with barcode labels or carrier barcode labels have a low contrast, poor edge quality, or other defects, the bar-code read rate performance rate can decreases. Accordingly, an improved sample identification system is needed.  
       SUMMARY  
       [0009]     A sample identification system that may be used to track and correlate a sample container in a laboratory analyzer or the like is set forth. The exemplary laboratory analyzer employs at least one carrier that supports at least one sample tube. The sample identification system includes a first optical reader that has a first field of view that is sufficient to expose the first optical reader to targeted visual indicia that identifies the carrier. The system further includes a second optical reader that has a second field of view that is sufficient to expose the second optical reader to targeted visual indicia identifying the sample tube held by the carrier. One or more decoders may be used to extract the identification information from the targeted visual indicia. The identification information then may be provided to a process controller, which may use the information for one or more predetermined purposes. One such purpose may be to use the identification information derived from the first and second readers to direct manipulation of the content of the sample tube. In various embodiments, the system may employ one or more masks to enhance the accuracy of the identification process. Further, the system may be adapted to replace a legacy identification system of an existing apparatus.  
         [0010]     Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.  
         [0012]      FIG. 1  illustrates one embodiment of an analyzer that may employ the improved sample identification system disclosed herein.  
         [0013]      FIGS. 2 and 3  illustrate one manner in which the embodiment of the analyzer shown in  FIG. 1  employs visual indicia for identification of the carrier and sample tubes.  
         [0014]      FIG. 4  illustrates one embodiment of an improved sample identification system in an operative position with respect to the carrier and sample tubes.  
         [0015]      FIG. 5  illustrates the embodiment of the improved sample identification system shown in  FIG. 4  in a raised position to execute, for example, a maintenance operation.  
         [0016]      FIG. 6  compares the natural fields of view and modified fields of view of the optical readers employed in one embodiment the sample identification system shown in  FIG. 4 .  
         [0017]      FIG. 7  is a perspective view of one embodiment of a mask that may be used in the sample identification system shown in  FIG. 4 .  
         [0018]      FIG. 8  illustrates one manner in which the improved sample identification system shown in  FIG. 4  may be retrofitted on an apparatus to replace an existing legacy scanning system. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     An apparatus that may employ an improved sample identification system constructed in accordance with one embodiment of the present invention is shown generally at  10  of  FIG. 1 . As shown, the apparatus  10  includes a sample processing section  12  that is bounded on its sides by a carrier input station  15  and a carrier output station  20 . The carrier input station  15  includes a plurality of individual carriers  25  that are stacked vertically on top of one another. Each of the individual carriers  25  supports a corresponding plurality of sample tubes  30  that contain a biological material, such as blood, that is to be processed and/or analyzed by the apparatus  10 .  
         [0020]     Sample processing section  12  includes a conveyor system  35  that receives the individual carriers  25  for transport to a processing station  40 , which may include a sample aspiration system  45  and a sample identification system  50 . In this embodiment, conveyor system  35  transports the carriers  25  in a semi-inverted orientation as it concurrently rocks the carriers  25  to mix the contents of sample tubes  30 . A more detailed description of such an exemplary system can be found in U.S. Pat. No. 4,609,017, entitled “Method and Apparatus for Transporting Carriers of Sealed Sample Tubes and Mixing the Samples”, issued to Coulter et al. on Sep. 2, 1986.  
         [0021]     Once conveyor system  35  has transported the carrier  25  so that the first sample tube  30  of the carrier  25  is proximate aspiration system  45 , the first sample tube  30  is driven downward into engagement with the aspiration system  45  and an amount of the material contained in the sample tube is aspirated. Sample identification system  50  reads separate visual indicia corresponding to the sample tube  30  being aspirated and the carrier  25  and provides the identification information to a processing unit, shown generally at  55 . The read operation performed by the sample identification system  50  may take place prior to the aspiration, during the aspiration, or subsequent to the aspiration.  
         [0022]     Processing unit  55  may comprise a programmable personal computer, programmable controller, embedded microcontroller, state machine, etc., and preferably includes one or more human interface devices (i.e., keyboard, display, mouse, etc.) to facilitate user interaction and definition of processing parameters. A communication link  60  may be used to transmit data to and/or receive data from a central processing system  65 . Central processing system  65  may be used to control and keep track of the results from a plurality of analyzers/sample processors in the laboratory environment.  
         [0023]     Processing unit  55  may use the data acquired during the read operation for a number of different purposes. For example, the acquired data may be used to correlate the analysis results with the proper sample tube. Further, the acquired data may be used to direct the processing station  40  to execute a particular process or processing sequence using the identified sample tube. This method of using the acquired data is particularly suitable in apparatus having a plurality of processing stations capable of executing different processes or apparatus having a single processing station/section capable of executing different processes with a plurality of processing tools. The particular process that is to be executed on the contents of an individual sample tube may be dictated by the central processing system  65  based on the sample tube identification information provided by processing unit  55 . Further, processing unit  55  may be used to communicate the results of a process executed at processing station  40  along with the corresponding sample tube identification data to the central processing system  65 . Other uses of the identification data are also contemplated, the foregoing uses being merely exemplary.  
         [0024]      FIGS. 2 and 3  illustrate a plurality of sample tubes  30  supported in a carrier  25  and the corresponding visual indicia used to identify each. In the illustrated embodiment, each sample tube  30  includes a barcode label  70  that uniquely identifies the sample tube  30  in the analysis apparatus  10 . The barcode label  70  also may include alphanumeric characters  75  that correspond to the barcode identification information. Similarly, carrier  25  includes one or more barcode labels  80  that identify the carrier  25  in the apparatus  10 . In the illustrated embodiment, a plurality of barcode labels  80  are employed. Each barcode label  80  of this embodiment is disposed immediately adjacent a corresponding opening in the carrier  25  that receives a sample tube  30 . Barcode labels  80  uniquely identify both the individual carrier  25  and the position of the corresponding sample tube  30  within the carrier  25 . Again, the barcode labels  80  may include alphanumeric characters  85  that correspond to the identification data of the barcode.  
         [0025]     The basic relative movement between a sample tube  30  and aspiration system  45  is also illustrated  FIGS. 2 and 3 . As shown, carrier  25  is first moved in the direction of arrow  90  to place the sample tube  30  in the second from last carrier slot in a position juxtaposed aspiration system  45 . With the carrier  25  in this position, sample tube  30  is driven from its corresponding carrier slot and into engagement with a hollow needle/tube  95  of the aspiration system  45 . An amount of material is then aspirated to or extracted from the interior of sample tube  30 . Once aspiration is complete, the sample tube  30  is again driven into its corresponding carrier slot and the conveyor system  30  drives carrier  25  in the direction of arrow  90  until the sample tube in the last carrier slot is juxtaposed aspiration system  45 . At this point, the aspiration cycle is repeated for the last sample tube  30 .  
         [0026]     Carrier  25  may be constructed in a variety of different manners. One construction that can be used to accommodate sample tubes  30  of different shapes and sizes is shown in U.S. Pat. No. 4,534,465, entitled “Cassette for Supporting Test Tubes of Different Diameters and/or Lengths”, issued Aug. 13, 1985, to Rothermel et al.  
         [0027]      FIG. 4  illustrates a sample identification system  50  constructed in accordance with one embodiment of the present invention. In this embodiment, two optical readers  100  and  105  are employed. Optical reader  100  has a field of view, shown generally at  110 , that is sufficient to expose the reader to visual indicia  80  identifying the carrier  25 . The visual indicia  80  may take the form of the barcode labels shown in  FIGS. 2 and 3 . Optical reader  105  has a field of view, shown generally at  115 , that is sufficient to expose the reader to visual indicia  70  identifying the sample tube  30  that is under process. The visual indicia  70  may take the form of the barcode labels shown in  FIGS. 2 and 3 , alphanumeric characters, etc.  
         [0028]     In one embodiment, optical readers  100  and  105  are area scan cameras that provide a two-dimensional image of the visual indicia  70  and  80 . Optical readers suitable for use in the illustrated system are available from Jadak Technologies, Inc., of Liverpool, N.Y. The two-dimensional images corresponding to visual indicia  70  and  80  are processed in a decoder  120 . Decoder  120  analyzes the acquired images and extracts the identification information. The identification information may then be provided to processing unit  55  as a digital electronic identification signal that corresponds to the extracted identification information. Although decoder  120  may be located proximate optical readers  100  and  105  as shown, it may likewise be located at a location that is some distance from the readers or may be in the form of individual decoders that are integrated within and respectively associated with each of the readers  100  and  105 .  
         [0029]     As shown in  FIG. 4 , optical readers  100  and  105  may be fixed within a housing  125 . Housing  125  includes an arm  130  that is secured to a support bracket  135  at a pivot joint  140 . Support bracket  135 , in turn, is in fixed positional alignment with the frame of apparatus  10 . In the illustrated embodiment, support bracket  135  is directly secured with a pole  145  that is connected to the frame of apparatus  10 .  
         [0030]     As apparent from a comparison of  FIGS. 4 and 5 , housing  125 , and the components secured therein, can be rotated between the operative position shown in  FIG. 4  and a maintenance position shown in  FIG. 5 . Rotation of the housing  125  occurs about pivot joint  140 . While in the operative position, housing  125  is prevented from rotating about pivot joint  140  by a locking pin  150  that is secured within an aperture  155  that extends through bracket  135  and arm  130 . When access to the components within the housing  125  is desired, the locking pin  150  is removed from aperture  155  thereby allowing the housing  125  to freely rotate about pivot joint  140  to the position shown in  FIG. 5 . The locking pin  150  may then be inserted into a further aperture  160  to prevent the housing  125  from rotating back to the operative position.  
         [0031]     In many instances, space requirements will mandate the placement of optical readers  100  and  105  in close proximity with one another. However, such close placement can be problematic. One of the problems that may arise can be understood with reference to  FIG. 6 , which includes a plurality of different line types representing various fields of view encountered by readers  100  and  105  when the readers are positioned to detect the visual indicia  70  and  80 . These fields of view represent the maximum horizontal and vertical range (see the x-y axes shown in  FIG. 3 ) within which a reader can acquire a two-dimensional image. More particularly, optical reader  100  has a natural field of view designated by line  165  with respect to the carrier  25 . The natural field of view  165  has a height L 1  and a width W 1 . Similarly, optical reader  105  has a natural field of view designated by line  170  with respect to the sample tubes  30 . The natural field of view  170  has a height L 2  and a width W 2 .  
         [0032]     There are several problems associated with the natural fields of view  165  and  170 . Notably, the fields of view  165  and  170  are overlapping with one another. Still further, the widths W 1  and W 2  of the fields of view  165  and  170  are often significantly wider than the widths of the individual visual indicia  80  and  70  that are to be respectively read and decoded by optical readers  100  and  105  and decoder  120 . As a result, the images generated by each optical reader  100  and  105  will include visual information from indicia that are adjacent the indicia that is to be acquired and decoded. In the illustrated example, optical reader  100  has a natural field of view  165  that will generate an image that includes the targeted visual indicia  80  at the particular carrier slot that is to be read and decoded as well as additional visual indicia. For example, additional visual indicia  80  may fall within the field of view  165  from adjacent carrier slots. Still further, additional visual indicia  70  from one or more sample tubes  30  that are vertically and/or horizontally adjacent to the targeted visual indicia  80  may fall within the field of view  165 . Similarly, optical reader  105  has a natural field of view  170  that will generate an image that includes the targeted visual indicia  70  from the particular sample tube that is to be read and decoded as well as additional visual indicia. For example, additional visual indicia  70  may fall within the field of view  170  from sample tubes  30  contained in adjacent carrier slots. Still further, additional visual indicia  80  from one or more carrier slots that are vertically and/or horizontally adjacent to the targeted visual indicia  70  may fall within the field of view  170 .  
         [0033]     Images including extraneous visual indicia information beyond the particular visual indicia  70  and  80  that are targeted can result in misidentification of the targeted sample tube  30  and carrier  25 . Software solutions to this problem can be difficult to implement and are not easily transferred between systems having different design criterion (i.e., reader placement, indicia type and location, etc.).  
         [0034]     An alternative approach to addressing the field of view problems that may arise in a given implementation of the sample identification system  50  is shown and described in connection with  FIGS. 4, 6  and  7 . More particularly, the sample identification system  50  includes a mechanical mask  175  having a first aperture  180  spaced from the lens of optical reader  100  and a second aperture  185  spaced from the lens of optical reader  105 . Generally stated, the mask  175  is designed to limit the natural fields of view  165  and  170  of the optical readers  100  and  105 , respectively, and thereby reduce and/or eliminate extraneous visual indicia from the acquired images. By reducing and/or eliminating such extraneous visual indicia, the acquired images may be more easily processed and the likelihood that a sample tube/carrier will be misidentified is substantially reduced.  
         [0035]     In the illustrated embodiment, mask  175  is in the form of a plate that is secured to a face of housing  125 . Mask  175  also may include a centrally disposed opening  190  that accommodates an illumination lamp  195  that directs light toward one or both of the visual indicia  70  and  80 .  
         [0036]     One construction of the mask  175  is represented in  FIG. 7 . As shown, apertures  180  and  185  may each be generally rectangular in shape. Since the particular design of the visual indicia  80  illustrated in  FIGS. 2 and 3  is wider and shorter than the particular design of the visual indicia  70 , aperture  180  is wider and shorter than aperture  185  in this construction. However, it will be recognized that other shapes and dimensions for the apertures  180  and  185  may be employed, provided that the desired limiting of the natural fields of view  165  and  170  is achieved.  
         [0037]     The effect of using mask  175  can be understood with reference to  FIG. 6 . More particularly, the natural field of view  165  of optical reader  100  has been reduced to the modified field of view area enclosed by line  200 . Similarly, the natural field of view  170  of optical reader  105  has been reduced to the modified field of view area enclosed by line  205 . Modified field of view  200  has a length L 3  and a width W 3  that are substantially smaller than the length L 1  and width W 1  of the natural field of view  165  of reader  100 . Preferably, the dimensions of the modified field of view  200  allow optical reader  100  to acquire a complete image of the targeted visual indicia  80  while concurrently precluding the reader from acquiring any identification information from adjacent, non-targeted visual indicia.  
         [0038]     Likewise, modified field of view  205  has a length L 4  and a width W 4  that are substantially smaller than the length L 2  and width W 2  of the natural field of view  170  of reader  105 . Preferably, the dimensions of the modified field of view  205  allow optical reader  105  to acquire a complete image of the targeted visual indicia  70  while concurrently precluding the reader from acquiring any identification information from adjacent, non-targeted visual indicia.  
         [0039]     The sample identification system  50  may be adapted for retrofitting into an existing analysis apparatus having, for example, a single barcode scanner. As shown in  FIG. 4 , system  50  may be secured with an existing portion of the frame of the apparatus  10  by a support, such as bracket  135 , so that the readers  100  and  105  are positioned to accurately acquire images of the targeted visual indicia.  
         [0040]      FIG. 8  shows one manner in which system  50  may be retrofitted into apparatus  10  with minimal, if any, impact on existing electronic hardware and software. To this end, the legacy scanning components and corresponding control circuitry (i.e., the single barcode scanning unit described above) are replaced by the components shown generally at  210 . Legacy processing unit  215  may operate in the same manner as processing unit  55  described above. However, the legacy processing unit  215  has input/output signals that were used with the legacy scanning system. Accordingly, the legacy processing unit  215  is designed to transmit specific signals to initiate a barcode read cycle and to receive status signals indicating proper operation of the legacy scanning system. Further, the legacy processing unit  215  is designed to receive digital data corresponding to the targeted barcodes in a predetermined data format. In this example, data was provided to the legacy processing unit  215  in standard RS-232 format using the prior sample identification system. However, other signal and data formats may likewise have been used by the legacy processing unit and the corresponding system  210  is designed to interact with the legacy process unit using the existing signal and data formats.  
         [0041]     System  210 , as shown in  FIG. 4 , may be disposed in housing  125 , and, as shown in  FIG. 8 , may include a pair of readers  100  and  105  that each also may include a corresponding decoder circuit. The output signals provided by readers  100  and  105  at lines  300  and  305 , respectively, may be in the form of standard RS-232 signals. Since other portions of the updated system  210  may operate at a different logic signal level, such as TTL or the like, the standard RS-232 signals at lines  300  and  305  are provided to the inputs of corresponding level translator circuits  220   a  and  220   b.  The level translated signals from the output of the level translators  220   a  and  320   b  are provided to the input of a logical “OR” gate  225 . The resulting logic signal at line  230  may be provided to the input of a further level translation circuit  235  for conversion from a logic level RS-232 signal to a standard level RS-232 signal at output line  240 , which is provided as the data input to the legacy processing unit  215 .  
         [0042]     The generation and transmission of non-data signals between the legacy processing unit  215  and the readers/decoders  100  and  105  is coordinated by plural state machines  245  that cycle through their various states in response to a system clock  250  as well as one or more synchronous sample identification requests signals provided at output  255  of legacy processing unit  215 . In response to the clock signal and signals at output  255 , state machines  245  generate time coordinated requests to each of the readers/decoders  100  and  105  at output  260  and  265 , respectively, which the readers/decoders use to initiate reading of the respective visual indicia and transmission of the resulting data to the legacy processing unit number  215 . State machines  245  also generate legacy signals at output  270 , which are provided to the input of legacy processing unit  215  to mimic the operation of the components of the legacy system that have been replaced by updated system  210 .  
         [0043]     While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.