Abstract:
A method and apparatus are provided for data management authentication in a clinical analyzer. The clinical analyzer includes a sensor for receiving a user sample to be measured and a processor for performing a predefined test sequence for measuring a predefined parameter value. A memory is coupled to the processor for storing predefined parameter data values. An authentication password is associated with each data transmission by the clinical analyzer and read by an associated computer system to validate each data transmission. The authentication password is generated by the clinical analyzer utilizing predetermined information in each data transfer.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a clinical analyzer, and, more particularly, to a new and improved method and apparatus for data management authentication in a clinical analyzer. 
     DESCRIPTION OF THE PRIOR ART 
     The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example lactate, cholesterol and bilirubin should be monitored in certain individuals. In particular, the determination of glucose in body fluids is of great importance to diabetic individuals who must frequently check the level of glucose in their body fluids as a means of regulating the glucose intake in their diets. While the remainder of the disclosure herein will be directed towards the determination of glucose, it is to be understood that the procedure and apparatus of this invention can be used with other diagnostic systems. 
     Diagnostic systems, such as, blood glucose systems include a biosensor used to calculate the actual glucose value based on a measured output (either current or color) and the known reactivity of the reagent sensing element used to perform the test. The test results typically are displayed to the user and stored in a memory in the blood glucose monitor. It is desirable to periodically transfer the multiple stored values from the blood glucose monitor to a separate computer, for example to enable analysis by a doctor for the blood glucose monitor user. 
     One known communications protocol for such data transfer is the ASTM Standard E1381-91, “Specification for Low-Level Protocol to Transfer Messages Between Clinical Laboratory Meters and Computer Systems” and ASTM Standard E1394-91, “Standard Specifications for Transferring Information Between Clinical Meters and Computer Systems”. ASTM Standard E1381-91 defines the low-level data transfer protocol and ASTM Standard E1394-91 defines the data format. 
     Multiple commercially available clinical analyzer are available for patient use. Due to differences between various commercially available clinical analyzer, a need exists for a method and apparatus for data management authentication in a clinical analyzer to validate data transmissions and to identify a particular type of clinical analyzer. Otherwise if a patient changes to a different type of clinical analyzer, then analysis by the patient&#39;s doctor of the data transfers from the different clinical analyzer likely would provide erroneous results. 
     SUMMARY OF THE INVENTION 
     Important objects of the present invention are to provide a new and improved method and apparatus for data management authentication in a clinical analyzer; to provide such method and apparatus that eliminates or minimizes the need for user interaction; and to provide such method and apparatus that overcome some disadvantages of prior art arrangements. 
     In brief, a method and apparatus are provided for data management authentication in a clinical analyzer. The clinical analyzer includes a sensor for receiving a user sample to be measured and a processor for performing a predefined test sequence for measuring a predefined parameter value. A memory is coupled to the processor for storing predefined parameter data values. An authentication password is associated with each data transmission by the clinical analyzer to an associated computer system. The authentication password is read by the associated computer system to validate each data transmission. The authentication password is generated by the clinical analyzer utilizing predetermined information in each data transmission. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein: 
     FIG. 1 is an enlarged perspective view of a clinical analyzer shown in an open position in accordance with the present invention; 
     FIG. 2 is an enlarged perspective view of the clinical analyzer of FIG. 1 shown in a closed position; 
     FIG. 3 is a block diagram representation of clinical analyzer circuitry in accordance with the present invention of the clinical analyzer of FIG. 1; 
     FIG. 4 is a flow chart illustrating exemplary sequential steps of a data management authentication method in accordance with the present invention of the clinical analyzer of FIG. 1; and 
     FIG. 5 is a chart illustrating an exemplary message format including an authentication password in accordance with the present invention of the clinical analyzer of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Having reference now to the drawings, in FIGS. 1 and 2 there is illustrated a clinical analyzer designated as a whole by the reference character  10  and arranged in accordance with principles of the present invention. Clinical analyzer  10  includes a clam-shell type enclosure  12  formed by a base member  14  and a cover member  16 . Base and cover members  14  and  16  are pivotably attached together at a first end  18  and are secured together by a latch member  20  at a second, opposite end  22 . A display  24 , such as a liquid crystal display (LCD) is carried by the cover member  16 . To turn the clinical analyzer  10  on and off, a manually movable slide  28  mounted on the cover member  16  is moved between an open position shown in FIG. 1 and a closed position shown in FIG.  2 . 
     In the closed or OFF position of FIG.  2 . the slide  28  covers the display  24 . A thumb grip  30  carried by the slide  28  is arranged for manual engagement by a user of the clinical analyzer  10  to select the ON and OFF positions. The thumb grip  30  also is movable from left to right in the OFF position of slide  28  for selecting a system test operational mode. When a user moves the slide  28  to the ON position of FIG. 1, the display is uncovered and a sensor  32  is presented. The sensor  32  extends through a slot  34  and is positioned outside the enclosure  12  for the user to apply a blood drop. A right button  42  and a left button or switch  44  (or switches A and B) are carried by the enclosure  12  for operation by a user to select predefined operational modes for the clinical analyzer  10 , and for example, to set, recall and delete blood glucose readings and to set date, time, and options. 
     Referring also to FIG. 3, there is shown a block diagram representation of clinical analyzer circuitry designated as a whole by the reference character  50  and arranged in accordance with principles of the present invention. Clinical analyzer circuitry  50  includes a microprocessor  52  together with an associated memory  54  for storing program and user data. The display  24  is operatively controlled by the microprocessor  52 . A meter function  56  coupled to the sensor  32  is operatively controlled by the microprocessor  52  for recording blood glucose test values. A battery monitor function  58  is coupled to the microprocessor  52  for detecting a dead battery (not shown) condition. An alarm function  60  is coupled to the microprocessor  52  for detecting predefined system conditions and for generating alarm indications for the user of clinical analyzer  10 . A data port or communications adapter  62  couples data to and from a connected computer system  64  via a communications link  66 . An ON/OFF input at a line  28 A responsive to the user ON/OFF operation of the slide  28  is coupled to the microprocessor  52  for performing the blood test sequence mode of clinical analyzer  10 . Microprocessor  52  contains suitable programming to perform the methods of the invention as illustrated in FIGS. 4 and 5. 
     In accordance with the invention, an authentication password generally designated by  504  in FIG. 5 is associated with each data transmission or message generally designated by  500  by the clinical analyzer  10 . The authentication password  504  is read by the associated computer system  64  to validate each data transmission. The authentication password  504  is generated by the clinical analyzer  10  utilizing predetermined information in each data transmission. 
     Referring to FIG. 4, there are shown exemplary steps for password computation of the invention starting at a block  400 . First a fourteen day average glucose is computed and stored as AVG as indicated at a block  402 . A number of minutes since midnight (hrs*sixty+mins), is computed and stored as MINS as indicated at a block  404 . A number of days since an predetermined date, such as Dec. 31, 1989, to the present date is computed, (full years*three hundred sixty five+leap years*one+number of days elapsed in current year), and stored as DAYS as indicated at a block  406 . An eight bit random number is generated and stored as RND as indicated at a block  408 . Then the password is computed, passwd=RND*two hundred fifty six+((AVG +MINS+DAYS) MODULO two hundred fifty six) as indicated at a block  410 . This completes the sequential steps as indicated at a block  412 . 
     FIG. 5 illustrates an exemplary message format generally designated by  500  of the invention used for each data transfer from the clinical analyzer  10  to the associated computer system  64 . Each data transfer or message  500  includes a message header  502  including a predefined field containing the authentication password  504 . Another predefined field in the message header  502  contains a current date stamp  506  for the message  500 . Each data transfer or message  500  includes a plurality of data records  508 . In FIG. 5, five example data records  508  are shown and labeled R 1 , R 2 , R 3 , R 4  and R 5 . An authentication password  504  of −18572 is shown with a date stamp  506  of Jun. 16, 1997, time 1307 or 1:07PM. The fourteen day average glucose is shown as  189  in record R 1  including the universal test ID is “GlucoseA”. 
     The ASTh E1394-91 standard defines a header record that advantageously is used for the message header  502 . The authentication password  504  is contained in one field within the header record defined as an “access password” field by the ASTM E1394-91 standard. The clinical analyzer  10  transmits the authentication password  504  as a signed integer, a 16 bit value. The signed integer is actually transmitted as a sequence of ASCII (American National Standard for Information Interchange) characters which represent the integer. The range for the authentication password  504  is from “−32767” to “32768”. 
     The eight most significant bits of the authentication password  504  is an 8-bit random number, that must change randomly from transmission to transmission of messages  500 . The eight least significant bits of the authentication password  504  is based on the date and time of the message contained in time stamp field  506  of the header record  502  and the  14  day average glucose contained in a result record  508  when the universal test ID is “GlucoseA”, as shown in data record RI in FIG.  5 . The computed part of the password is calculated by adding the number of minutes since midnight to the number of days since Dec. 31, 1989, plus the 14 day average glucose (in mg/dL). Only the 8 least significant bits of the computation are kept. If the clinical analyzer  10  provides glucose values in mmol/L, then the 14 day average value is first converted to mg/dL (multiply by 18 and rounded to an integer) before being added in the password calculation. 
     The 8-bit random part (most significant byte) is concatenated to the 8-bit computed part (least significant byte) which results in a 16 bit value for the authentication password  504 . The authentication password  504  is interpreted as a 16 bit signed integer ranging in value from −32767 to 32768. It is transmitted as the sequence of ASCII characters which represent the integer. 
     When computer system  64  receives the transmission from a particular clinical analyzer  10 , it converts the ASCII characters in the password field to an integer. The 8 most significant bits are ignored, the 8 least significant bits are verified against the calculation of the authentication password  504  as detailed above. For example, the authentication password  504  of −18572 is compared with a computed value by the computer system  64 . The computer system  64  uses the same equation, shown in block  410  in FIG. 4 for computing the authentication password  504 , as used by the clinical analyzer  10 . The DAYS value of the number of days since Dec. 31, 1989 until the date stamp date of Jun. 16, 1997 is calculated by (7 full years*three hundred sixty five+2 leap years*one day/leap-year+number of days elapsed in current year (31+28+31+30+31+16) which equals 2724. The time calculation (minutes since midnight) equals ((13 hours*60 minutes/hour)+7 minutes) which equals 787. The computation is verified as follows (2724+787+189) which equals 3700 or OE74 total in hexadecimal, keeping the least significant 8-bits in hexadecimal or 74 in hexadecimal which equals 116 decimal. The access password is −18572 in decimal or B774 in hexadecimal. Keeping the least significant bits of the result leave  74  in hexadecimal which equals  116  decimal. Thus, the authentication password  504  agrees with the computed value for the example data transfer message  500  of FIG.  5 . Only when the authentication password  504  agrees with the computed value is the clinical analyzer  10  identified as a valid meter. 
     While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawings, these details are not intended to limit the scope of the invention as claimed in the appended claims.