Abstract:
A blood analyzer has a light emitter for emitting light to an analysis sample which is a mixture of a blood specimen and a reagent. It also has a light receiver for receiving light of a plurality of wavelengths from the analysis sample over time, and for acquiring data of the amount of the received light corresponding to each of the wavelengths at a plurality of points of time. A selector selects the data corresponding to one of the wavelengths, based on the change of the amount of received light over time in the data acquired by the light receiver. An analysis section analyzes a characteristic of the blood specimen using the data which are selected by the selector. A blood analyzing method is also described.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from Japanese Patent Application 2006-092813 filed on Mar. 30, 2006, the disclosure of which is herein incorporated by reference in its entirety.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates to a blood analyzer and blood analyzing method, and specifically relates to a blood analyzer and blood analyzing method for optically analyzing analysis samples prepared by adding reagent to a blood specimen.  
       BACKGROUND  
       [0003]     Blood coagulation analyzers are known which prepare an analysis sample by adding a blood-coagulating reagent to a blood sample, and analyze the coagulation time of the blood by optically measuring the process of a coagulation reaction in the analysis sample. For the sake of generality, such an analysis sample made by adding a reagent to blood or made in any other manner may be referred to as a blood coagulation analysis sample.  
         [0004]     In blood coagulation analysis, interference substances such as hemoglobin, bilirubin chyle and the like present in the analysis sample (substances that optically interfere with the measurement of a target material and coexist in the sample together with the target material (for example, fibrinogen) being examined) may influence the optical measurement and hinder accurate analysis.  
         [0005]     When measurement is performed using long wavelength light (for example, 800 nm), hemoglobin and bilirubin do not affect the measurement and chyle only slightly affects the measurement, however, measurement sensitivity is low.  
         [0006]     Furthermore, the coagulation reaction changes the amount of light transmitted through the sample material, the change is proportional to the amount of coagulation factor (for example, fibrinogen) contained in the analysis sample. Therefore, there is little change in the amount of light in an analysis sample that has a low coagulation factor content, and accurate analysis can not be performed under long-wavelength light that has low measurement sensitivity.  
         [0007]     Therefore, in conventional blood coagulation analyzers use light at a wavelength in the vicinity of 660 nm for measurement to obtain suitable sensitivity wherein the interference substances do not influence very much so that the analyzers can perform analysis adequately.  
         [0008]     Conventionally, the interference substances present in a sample (serum and the like) are measured prior to performing the main measurement (for example, biochemical analysis) (for example, refer to Japanese Laid-Open Patent Publication Nos. S57-59151 and H06-66808, and U.S. Pat. No. 5,734,468).  
         [0009]     In the measuring method for degree of chyle, jaundice and hemolysis in serum disclosed in Japanese Laid-Open Patent Publication No. S57-59151, serum is irradiated by light at four wavelengths, and light absorption is primarily measured using short-wavelength light within the visible range (for example, 410 nm), and a serum sample that has measured light absorption greater than a fixed value is determined to be abnormal due to chyle and jaundice and hemolysis. Then, secondly the serum sample that has been determined to be abnormal is subjected to determination of the degree of chyle, jaundice, and hemolysis by comparing the light absorption measured at four wavelengths with several preset standards.  
         [0010]     In the chromogen (interference substance) measurement method disclosed in Japanese Laid-Open Patent Publication No. 6-66808, a sample blank liquid is prepared by mixing a blank reaction reagent with a specimen including suspension material (hemoglobin, bilirubin, chyle and the like), and measuring the degree of interference substance by irradiating the sample blank liquid with light at four wavelengths that include a wavelength at which the light is absorbed by chyle, and substantially not absorbed by hemoglobin and bilirubin. Specifically, the degree of chyle is calculated by assuming the degree of absorption represented by an exponential function of the wavelength, and determining a wavelength-absorption regression curve. Moreover, the amounts of hemoglobin and bilirubin are calculated by assuming a preset fixed relationship between absorptions at different wavelengths, and preparing and solving simultaneous linear equations related to the optical absorbance at the measurement wavelength.  
         [0011]     In the analyzer for determining the presence of hemolysis, jaundice, and lipemia in a serum sample disclosed in U.S. Pat. No. 5,734,468, the optical absorption of a serum sample in a needle tube is first measured by irradiating the serum sample aspirated into the needle tube disposed in a transparent part provided with a probe using light emitted from light emitting diodes. Then, a serum sample that has been determined to be measurable based on this optical absorption is transferred to a clinical analyzer where a main measurement is performed.  
         [0012]     In the conventional blood coagulation analyzers described above, the measurement wavelength is set with regard to the possibility that a sample contains interference substances. However, there are various contents of interference substances and coagulation factors depending on the sample, and the optimum wavelength for measurement will vary sample by sample. Therefore, conventional blood coagulation analyzers can only measure at preset wavelengths, thus reducing analysis accuracy.  
       SUMMARY  
       [0013]     The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary. A first blood analyzer embodying features of the present invention includes: a light emitter for emitting light to an analysis sample which is a mixture of a blood specimen and a reagent; a light receiver for receiving light of a plurality of wavelengths from the analysis sample over time, and for ouputting data of the amount of the received light corresponding to each of the wavelengths at a plurality of points of time; a selector for making a selection of the data corresponding to one of the plurality of wavelengths, the selection being based on a change, of an amount of light received over time, represented in the data output by the light receiver; and an analysis section for analyzing a characteristic related to blood coagulation of the blood specimen using the data which are selected by the selector.  
         [0014]     A second blood analyzer embodying features of the present invention includes: a light emitter for emitting light to an analysis sample which is a mixture of a blood specimen and a reagent; a light receiver for receiving light of a plurality of wavelengths from the analysis sample over time, and for ouputting data of the amount of the received light corresponding to each of the wavelengths at a plurality of points of time; a selector for making a selection of the data corresponding to one of the plurality of wavelengths, the selection being based on a change, of an amount of light received over time, represented in the data output by the light receiver; and an analysis section for analyzing a characteristic of the blood specimen using the data which are selected by the selector.  
         [0015]     A first blood analyzing method embodying features of the present invention includes steps of: a) emitting light to an analysis sample prepared using a blood specimen; b) storing data, representing an amount of light received from the blood coagulation analysis sample, for each of a plurality of light wavelengths, at a plurality of points in time; c) selecting the stored data corresponding to one of the plurality of wavelengths, based on a change, of the amount of light received light received over time, represented in the stored data; and d) analyzing a characteristic related to blood coagulation of the blood specimen using the data which are selected in step c).  
         [0016]     A second blood analyzing method embodying features of the present invention includes steps of: a) emitting light to an analysis sample prepared using a blood specimen; b) storing data, representing an amount of light received from the blood coagulation analysis sample, for each of a plurality of light wavelengths, at a plurality of points in time; c) selecting the stored data corresponding to one of the plurality of wavelengths, based on a change, of the amount of light received light received over time, represented in the stored data; and d) analyzing a characteristic of the blood specimen using the data which are selected in step c). 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a perspective view showing the general structure of an embodiment of the blood coagulation analyzer of the present invention;  
         [0018]      FIG. 2  is a top view showing the detection mechanism and transport mechanism of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0019]      FIG. 3  is a graph showing the light absorption spectrum of an interference substance (hemoglobin);  
         [0020]      FIG. 4  is a graph showing the light absorption spectrum of an interference substance (bilirubin);  
         [0021]      FIG. 5  is a graph showing the light absorption spectrum of another interference substance (chyle);  
         [0022]      FIG. 6  is a perspective view of the lamp unit of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0023]      FIG. 7  is a schematic view showing the structure of the lamp unit of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0024]      FIG. 8  is an enlarged perspective view of the filter part of the lamp unit shown in  FIG. 6 ;  
         [0025]      FIG. 9  briefly illustrates the internal structure of the detection part of the photometric part of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0026]      FIG. 10  is a cross section view illustrating the structure of the detection part of the photometric part of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0027]      FIG. 11  is a block diagram of the photometric part of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0028]      FIG. 12  is a block diagram of the control device of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0029]      FIG. 13  shows the measurement results of a specimen contaminated by interference substances measured by the photometric part of the blood coagulation analyzer of the embodiment of  FIG. 1 ;  
         [0030]      FIG. 14  shows the measurement results of a normal specimen measured by the photometric part of the blood coagulation analyzer of the embodiment of  FIG. 1 ; and  
         [0031]      FIG. 15  is a flow chart showing the sequence of the specimen analysis operation of the blood coagulation analyzer of the embodiment of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     The embodiments of the present invention are described hereinafter based on the drawings.  
         [0033]      FIG. 1  is a perspective view showing the general structure of an embodiment of the blood coagulation analyzer of the present invention.  FIG. 2  is a top view showing the detection mechanism and transport mechanism of the blood coagulation analyzer of the embodiment of  FIG. 1 .  FIGS. 3 through 14  illustrate the structure of the blood coagulation analyzer of the embodiment of  FIG. 1 . The general structure of an embodiment of the blood coagulation analyzer  1  of the present invention is described below with reference to  FIGS. 1 through 14 .  
         [0034]     This embodiment of the blood coagulation analyzer  1  of the present invention optically measures and analyzes the degree of activity and amount of specific substances related to blood coagulation and fibrinolysis, and uses blood plasma as a specimen (blood sample). In the blood coagulation analyzer  1  of the present embodiment, the specimen coagulation time is analyzed by optically measuring the specimen using a coagulation time method. Measurement items include PT (prothrombin time), APTT (active partial thromboplastin time), and Fbg (fibrinogen content) and the like.  
         [0035]     As shown in  FIG. 1 , the blood coagulation analyzer  1  comprises a detection device  2 , transport device  3  disposed in front of the detection device  2 , and a control device  4  electrically connected to the detection device  2 .  
         [0036]     The transport device  3  has the function of transporting a rack  151  holding a plurality of test tubes  150  (ten tubes in the present embodiment) that contain specimens to an aspiration position  2   a  (refer to  FIG. 2 ) of the detection device  2  so as to supply specimen to the detection device. Furthermore, the transport device  3  has a rack set region  3   a  that accommodates the racks  151  that hold the test tubes  150  containing unprocessed specimens, and a rack receiving region  3   b  that accommodates the racks  151  that hold test tubes  150  containing processed specimens.  
         [0037]     The detection device  2  is configured to obtain optical information relating to a supplied specimen by optically measuring a specimen supplied from the transport device  3 . In the present embodiment, optical measurement is performed on a specimen dispensed into a cuvette  152  (refer to  FIG. 2 ) of the detection device  2  from a test tube  150  loaded in the rack  151  of the transport device  3 . Furthermore, the detection device  2  includes a cuvette supplier  10 , rotating part  20 , specimen dispensing arm  30 , lamp unit  50 , two reagent dispensing arms  60 , cuvette transporter  70 , photometric part  80 , rush specimen acceptor  90 , cuvette disposal  100 , and fluid provider  110 , as shown in  FIGS. 1 and 2 .  
         [0038]     The cuvette supplier  10  is configured to sequentially supply a plurality of cuvettes  152  directly inserted by a user to the rotating part  20 . As shown in  FIGS. 1 and 2 , the cuvette supplier  10  includes a hopper  12  mounted on the device body via a bracket  11 , two induction plates  13  provided below the hopper  12 , support base  14  disposed at the bottom end of the two induction plates  13 , and catcher  15  provided at a predetermined distance from the support base  14 . The two induction plates  13  are disposed so as to be mutually parallel with a space therebetween so as to be smaller than the diameter of the flange of the cuvette  152  and larger than the diameter of the barrel of the cuvette  152 . The cuvettes  152  supplied into the hopper  12  are configured so as to move smoothly toward the support base  14  with the flange engaged at the top surface of the two induction plates  13 . Furthermore, the support base  14  functions to rotate the cuvette  152  that has fallen between the induction plates  13  to a position at which the cuvette  152  can be grabbed by the catcher  15 . The catcher  15  is provided to supply the cuvette  152 , which has been moved by the support base  14 , to the rotating part  20 .  
         [0039]     The rotating part  20  is provided to transport in a circular direction the cuvettes  152  received from the cuvette supplier  10 , and a reagent containers (not shown in the drawings) accommodating reagent for coagulating specimen (blood sample). As shown in  FIG. 2 , the rotating part  20  is configured by a circular reagent table  21 , annular reagent table  22  disposed on the outer side of the circular reagent table  21 , annular secondary dispensing table  23  disposed on the outer side of the annular reagent table  22 , and annular primary dispensing table  24  disposed on the outer side of the annular secondary dispensing table  23 . The primary dispensing table  24 , secondary dispensing table  23 , and reagent tables  21  and  22  are configured so as to be mutually and independently rotatable in both clockwise and counter clockwise directions.  
         [0040]     As shown in  FIG. 2 , the reagent tables  21  and  22  respectively include a plurality of holes  21   a  and  22   a  provided at predetermined spacing in the circumferential direction. The holes  21   a  and  22   a  of the reagent tables  21  and  22  are provided to load a plurality of reagent containers (not shown in the drawings) that hold reagent for coagulating the blood specimen. Furthermore, the primary dispensing table  24  and secondary dispensing table  23  respectively include a plurality of cylindrical holders  24   a  and  23   a  provided at predetermined spacing in the circumferential direction. The holders  24   a  and  23   a  are provided to hold the cuvettes  152  received from the cuvette supplier  10 . A specimen contained in a test tube  150  of the transport device  3  is dispensed to a cuvette  152  held by the holder  24   a  of the primary dispensing table  24  in a primary dispensing process. Furthermore, a specimen contained in the cuvette  152  loaded in the primary dispensing table  24  is dispensed to a cuvette  152  loaded in the holder  23   a  of the secondary dispensing table  23  in a secondary dispensing process.  
         [0041]     The specimen dispensing arm  30  functions to both aspirate specimen contained in a test tube  150  transported to the aspiration position  2   a  via the transport device  3 , and dispensing the aspirated specimen into a cuvette  152  transported to the rotating part  20 .  
         [0042]     The lamp unit  50  is provided for supplying light used for photometry performed by the photometric part  80 , as shown in  FIG. 2 . As shown in  FIGS. 6 and 7 , the lamp unit  50  is configured by a halogen lamp as a light source, collective lenses  52   a  through  52   c , disk-shaped filter part  53 , motor  54 , transmission light sensor  55 , optical fiber coupler  56 , and eleven beam splitter optical fibers  57  (refer to  FIG. 7 ).  
         [0043]     As shown in  FIG. 6 , the halogen lamp  51  is accommodated in a lamp case  51   a  having a plurality of fins to dissipate the heat generated by the halogen lamp  51  via air cooling. The collective lenses  52   a  through  52   c  function to collect the light emitted from the halogen lamp  51 . The collective lenses  52   a  through  52   c  are disposed on the optical path to guide the light emitted from the halogen lamp  51  to the optical fiber coupler  56 . Furthermore, the light emitted from the halogen lamp  51  and collected by the collective lenses  52   a  through  52   c  is transmitted through one filter among the optical filters  53   b  through  53   f  of the filter part  53 , which is described later.  
         [0044]     Furthermore, the filter part  53  of the lamp unit  50  is mounted on the motor shaft (not shown in the drawing) of the motor  54  so as to be rotatable, as shown in  FIG. 8 . The filter part  53  is provided with a filter plate  53   a  with five optical filters  53   b  through  53   f  that have respectively different light transmitting characteristics (transmission wavelengths). The filter plate  53   a  is provided with five holes  53   g  for mounting the optical filters  53   b  through  53   f , and a hole  53   h  that can be blocked so as to not transmit light. The five holes  53   g  are respectively provided with five optical filters  53   b ,  53   c ,  53   d ,  53   e , and  53   f  having respectively different light transmission characteristics (transmission wavelengths). The holes  53   g  and  53   h  are provided at predetermined angular intervals (equal spacing of 60 degrees in the present embodiment) in the direction of rotation of the filter part  53 . The hole  53   h  is a reserve hole for installing an addition filter when necessary.  
         [0045]     The optical filters  53   b ,  53   c ,  53   d ,  53   e , and  53   f  transmit light at wavelengths of 340 nm, 405 nm, 575 nm, 660 nm, and 800 nm, respectively, and do not transmit light of different wavelength. Therefore, the optical filters  53   b ,  53   c ,  53   d ,  53   e , and  53   f  have wavelength characteristics so as to transmit light at 340 nm, 405 nm, 575 nm, 660 nm, and 800 nm, respectively.  
         [0046]     Furthermore, the filter plate  53   a  is provided with six slits at predetermined angular intervals (60 degree intervals in the present embodiment) in the circumferential direction. Five of the six slits are normal slits  53   i , and the remaining slit is an origin point slit  53   j . The origin point slit  53   j  is a large width slit in the direction of rotation of the filter plate  53   a , whereas the other five normal slits  53   i  have smaller widths. The origin point slit  53   j  and normal slits  53   i  are formed at predetermined angular intervals (equal intervals of sixty degrees in the present embodiment) at intermediate angular positions between adjacent holes  53   g  and  53   h.    
         [0047]     Moreover, the filter part  53  is configured so as to continuously rotate when light is emitted from the lamp unit  50  to the cuvette  152  of the photometric part  80 . Therefore, the five optical filters  53   b  through  53   f  having different light transmitting characteristics and the single blocked hole  53   h  (refer to  FIG. 8 ) are sequentially arranged on the optical path of the light collected by the collective lenses  52   a  through  52   c  (refer to  FIG. 7 ) in conjunction with the rotation of the filter plate  53   a . Therefore, light of five different wavelengths are sequentially emitted.  
         [0048]     Light at a wavelength of 405 nm is absorbed by chyle, hemoglobin, and bilirubin, as shown in  FIGS. 3 through 5 . That is, chyle, hemoglobin, and bilirubin influence the photometric information measured using light at a wavelength of 405 nm. Furthermore, light at a wavelength of 575 nm is absorbed by chyle and hemoglobin, although essentially is not absorbed by bilirubin. That is, chyle and hemoglobin influence the photometric information measured using light at a wavelength of 575 nm. Light at wavelengths of 660 nm and 800 nm are absorbed by chyle, although essentially are not absorbed by bilirubin and hemoglobin. That is, chyle influences the photometric information measured using light at wavelengths of 660 nm and 800 nm. As shown in  FIG. 5 , chyle absorbed light from 405 nm in the low wavelength region to 800 nm in the high wavelength region, and chyle absorbed the more light at a wavelength of 660 nm than light at 800 nm. That is, chyle has less influence on photometric information measured using light at a wavelength of 800 nm than photometric information measured using light at 660 nm.  
         [0049]     The transmission light sensor  55  is provided to detect the passage of light through the origin point slit  53   j  and normal slits  53   i  in conjunction with the rotation of the filter part  53 , as shown in  FIG. 8 . The sensor  55  detects light from the light source through the slit via the light receiving unit as it passes through the origin point slit  53   j  and normal slits  53   i , and outputs a detection signal. The detection signal output by the sensor  55  has a longer output time when light passes through the origin point slit  53   j  than the output signal when light passes through the normal slits  53   i  since the origin point slit  53   j  has a larger width than the normal slits  53   i . Therefore, the filter part  53  can be monitored for normal rotation based on the detection signals from the sensor  55 .  
         [0050]     The optical fiber coupler  56  functions to direct the light that has passed through the optical filters  53   b  through  53   f  to the respective eleven beam splitter optical fibers  57 . That is, the optical fiber coupler  56  simultaneously guides light of like quality to the eleven beam splitter optical fibers  57 . Furthermore, the leading ends of the eleven beam splitter optical fibers  57  are connected to the photometric part  80 , and light from the lamp unit  50  is directed to the analysis sample within a cuvette  152  set in the photometric part  80 , as shown in  FIG. 2 . Specifically, the eleven beam splitter optical fibers  57  are disposed so as to supply light to ten insertion holes  81   a  and one reference light measurement hole  81   b  which are parts of the photometric part  80  described later, as shown in  FIG. 9 . Therefore, five kinds of light having different wavelength characteristics consecutively passes through the optical filters  53   b  through  53   f , and is supplied to the photometric part  80  via the beam splitter optical fibers  57 .  
         [0051]     As shown in  FIGS. 1 and 2 , the reagent dispensing arm  60  is provided to mix reagent with the specimen in the cuvette  152  by dispensing the reagent within a reagent container (not shown in the drawings) loaded on the rotating part  20  into a cuvette  152  held in the rotating part  20 . Thus, an analysis sample is prepared by adding reagent to the specimen. The cuvette transporter  70  is provided to transport the cuvette  152  between the rotating part  20  and the photometric part  80 . In the present embodiment, the photometric part  80  is provided to heat the analysis sample prepared by adding reagent to the specimen, and over time receive the light from the analysis sample that has been illuminated by light of a plurality of wavelengths via the lamp unit  50 , and measure the amount of transmitted light at a plurality of moments for each wavelength. Specifically, the photometric part  80  measures the amount of transmitted light over a time course using three types of light (405 nm, 660 nm, 800 nm) among five types of light (340 nm, 405 nm, 575 nm, 660 nm, and 800 nm) emitted from the lamp unit  50 .  
         [0052]     As shown in  FIG. 2 , the photometric part  80  is configured by a cuvette loader  81 , and detection unit  82  disposed below the cuvette loader  81 . The cuvette loader  81  is provided with ten insertion holes  81   a  for inserting cuvettes  152  (refer to  FIG. 2 ), and a single reference light measurement hole  81   b  for measuring a reference light and in which a cuvette is not inserted. The cuvette loader  81  has a built-in heating device (not shown in the drawing) for heating a cuvette  152  loaded in the insertion holes  81   a  to a predetermined temperature. The reference light measurement hole  81   b  is provided for monitoring the characteristics of the light emitted from the beam splitter optical fibers  57 . Specifically, characteristics such as fluctuation and the like originating in the halogen lamp  51  of the lamp unit  50  are detected as electrical signals by directly receiving the light emitted by the beam splitting optical fibers  57  via a reference light photoelectric conversion element  82   e  of the detection unit  82 . Signals corresponding to the transmission light of the analysis sample are corrected by subtracting the characteristics of the detected light from the signals corresponding to the transmission light of the analysis sample within the cuvette  152  inserted in the insertion hole  81   a . Thus, it is possible to suppress minute differences caused by the characteristics of the light in each photometric measurement.  
         [0053]     The detection part  82  of the photometric part  80  is configured so as to be capable of performing photometric measurements under a plurality of conditions on an analysis sample within a cuvette  152  inserted in the insertion hole  81   a . As shown in  FIGS. 9 and 10 , the detection part  82  is provided with a collimator lens  82   a , photoelectric conversion element  82   b , and preamp  82   c  corresponding to each insertion hole  81   a  in which a cuvette  152  is inserted, and a reference light collimator lens  82   d , reference light photoelectric conversion element  82   e , and reference light preamp  82   f  corresponding to the reference light measurement hole  81   b  (refer to  FIG. 1 ).  
         [0054]     As shown in  FIGS. 9 and 10 , the collimator lens  82   a  is disposed between the end of the beam splitter optical fiber  57  that guides the light emitted from the lamp unit  50 , and the corresponding insertion hole  81   a . The collimator lens  82   a  is provided to render the light beams emitted from the beam splitter optical fiber  57  in parallel rays. The photoelectric conversion element  82   b  is mounted on the surface on the insertion hole  81   a  side of the baseplate  83  so as to face the end of the beam splitter optical fiber  57  with the insertion hole  81   a  therebetween. The photoelectric conversion element  82   b  functions to detect the light transmitted through the analysis sample (hereafter referred to as “transmission light”) when light irradiates the analysis sample within the cuvette  152  inserted in the insertion hole  81   a , and outputs electric signals (analog signals) corresponding to the detected transmission light. The photoelectric conversion element  82   b  is disposed so as to receive five kinds of light emitted from the beam splitter optical fiber  57  of the lamp unit  50 .  
         [0055]     The preamp  82   c  is mounted on the opposite surface of the baseplate  83  relative to the insertion hole  81   a  so as to amplify the electric signal (analog signal) output from the photoelectric conversion element  82   b.    
         [0056]     As shown in  FIG. 11 , the baseplate  83  is provided with the photoelectric conversion elements  82   b  (reference light photoelectric conversion element  82   e ), preamps  82   c  (reference light preamp  82   f ), as well as amplifier part  82   g , A/D converter  82   h , logger  82   l , and controller  82   j . The amplifier  82   g  includes amp (L)  82   k  with a predetermined gain (amplification factor), amp (H)  82   l  with a gain (amplification factor) higher than the amp (L)  82   k , and switch  82   m . In the present embodiment, an electric signal from the preamp  82   c  is input to both the amp (L)  82   k  and amp (H)  82   l . The amp (L)  82   k  and amp (H)  82   l  are provided to further amplify the electric signals from the preamps  82   c . The switch  82   m  is provided to selectively either output the electric signals from the amp (L)  82   k  to the A/D converter  82   h , or output the electric signal from the amp (H)  82   l  to the A/D converter  82   h . The switch  82   m  is configured so as to perform a switching operation via the input of control signals from the controller  82   j.    
         [0057]     The A/D converter  82   h  is provided to convert the electric signals (analog signals) from the amplifier part  82   g  to digital signals. The logger  82   i  functions to temporarily save the digital signal data (photometric information) from the A/D converter  82   h . The logger  82   i  is electrically connected to the controller  4   a  of the control device  4 , and sends the digital signal data obtained in the photometric part  80  to the controller  4   a  of the control device  4 .  
         [0058]     As shown in  FIGS. 1 and 2 , the rush specimen acceptor  90  is provided to perform a sample analysis process on sample requiring immediate processing. The rush sample acceptor  90  is capable of performing an interrupt on behalf of a rush specimen when there is an on-going specimen analysis process being performed on a specimen supplied from the transport device  3 . The cuvette disposal  100  is provided to dispose of cuvettes  152  from the rotating part  20 . As shown in  FIG. 2 , the cuvette disposal  100  is configured by a cuvette waste part  101 , disposal hole  102  provided at predetermined spacing from the cuvette waste part  101  (refer to  FIG. 1 ), and waste box  103  provided below the disposal hole  102 . The cuvette waste part  101  is provided to move a cuvette  152  from the rotating part  20  to the waste box  103  via the disposal hole  102  (refer to  FIG. 1 ). A fluid provider  110  is provided to supply a fluid such as cleaning liquid to a nozzle provided on each dispensing arm during the shutdown process of the blood coagulation analyzer  1 .  
         [0059]     The control device  4  is configured by a personal computer  401 , and includes a controller  4   a  that includes a CPU, ROM, RAM and the like, a display  4   b , and a keyboard  4   c , as shown in  FIG. 1 . The display  4   b  is provided to display information relating to interference substances (hemoglobin, chyle (lipids), and bilirubin) present in the specimen, and analysis results (coagulation time) obtained by analyzing the digital signal data received from the photometric part  80 .  
         [0060]     The structure of the control device  4  is described below. As shown in  FIG. 12 , the controller  4   a  is mainly configured by a CPU  401   a , ROM  401   b , RAM  401   c , hard disk  401   d , reading device  401   e , I/O interface  401   f , communication interface  401   g , image output interface  401   h . The CPU  401   a , ROM  401   b , RAM  401   c , hard disk  401   d , reading device  401   e , I/O interface  401   f , communication interface  401   g , image output interface  401   h  are connected by a bus  401   i.    
         [0061]     The CPU  401   a  is capable of executing computer programs stored in the ROM  401   b , and computer programs loaded in the RAM  401   c . The computer  401  functions as the control device  4  when the CPU  401   a  executes an application program  404   a  described later.  
         [0062]     The ROM  401   b  is configured by a mask ROM, PROM, EPROM, EEPROM or the like, and stores computer programs executed by the CPU  401   a  and data and the like used in conjunction therewith.  
         [0063]     The RAM  401   c  is configured by SRAM, DRAM or the like. The RAM  401   c  is used when reading the computer program recorded in the ROM  401   b  and on the hard drive  401   d . The RAM  401   c  is further used as a work area of the CPU  401   a  when these computer programs are being executed. The hard disk  401   d  contains various installed computer programs to be executed by the CPU  401   a  such as an operating system and application programs and the like, and data used in the execution of these computer programs. Also installed on the hard disk  401   d  is the application program  404   a  used for blood coagulation time measurement of the present embodiment.  
         [0064]     The reading device  401   e  is configured by a floppy disk drive, CD-ROM drive, DVD-ROM drive or the like, and is capable of reading the computer programs and data stored on a portable recording medium  404 . Furthermore, the portable recording medium  404  may also store the application program  404   a  used for blood coagulation time measurement; the computer  401  is capable of reading the application program  404   a  from the portable recording medium  404  and installing the application program  404   a  on the hard disk  401   d.    
         [0065]     Not only may the application program  404   a  be provided by the portable recording medium  404 , it also may be provided from an external device connected to the computer  401  so as to be capable of communication over an electric communication line by means of the electric communication line (wire line or wireless). For example, the application program  404   a  may be stored on the hard disk of a server computer connected to the internet, such that the computer  401   a  can access the server computer and download the application program  404   a , and then install the application program  404   a  on the hard disk  401   d.    
         [0066]     Also installed on the hard disk  401   d  is an operating system providing a graphical user interface, such as, for example, Windows® of Microsoft Corporation, U.S.A. In the following description, the application program  404   a  of the present embodiment operates on such an operating system.  
         [0067]     The I/O interface  401   f  is configured by a serial interface such as a USB, IEEE1394, RS232C or the like, parallel interface such as SCSI, IDE, IEEE1284 or the like, analog interface such as a D/A converter, A/D converter or the like. The keyboard  4   c  is connected to the I/O interface  401   f , such that a user can input data in the computer  401  using the keyboard  4   c.    
         [0068]     The communication interface  401   g  is, for example, and Ethernet® interface. The computer  401  can send and receive data to and from the detection device  2  using a predetermined communication protocol via the communication interface  401   g.    
         [0069]     The image output interface  401   h  is connected to the display  4   b  configured by an LCD, CRT or the like, such that image signals corresponding to the image data received from the CPU  401   a  can be output to the display  4   b . The display  4   b  displays an image (screen) in accordance with the input image signals.  
         [0070]     In the present embodiment, the application program  404   a  for blood coagulation time measurement installed on the hard disk  401   d  of the control device  4   a  analyzes the coagulation time of analysis samples based on the amount of transmission light (digital signal data) of the analysis sample obtained by the photometric part  80  of the detection device  2 . The blood coagulation time is the time from the moment the blood coagulation reagent is added to a specimen in a cuvette  152  until the analysis sample with the added reagent loses flowability (coagulation time). The coagulation reaction in which the analysis sample loses flowability is a reaction that changes fibrinogen within the specimen to fibrin via the added reagent. In the blood coagulation analyzer  1  of the present embodiment, the coagulation time of the reaction dependent on the amount of fibrinogen within the specimen is measured by the amount of change of the transmission light of the analysis sample (the difference between the amount of transmission light before the reaction and the amount of transmission light after the reaction), as shown in  FIGS. 13 and 14 .  
         [0071]     When a sample containing interference substances (chyle) was measured in the blood coagulation analyzer  1  of the present embodiment, the measurement results measured at the low wavelength side of 660 nm were reduced by the influence of the interference substance (chyle), and the amount of transmission light was approximately 190 to 220, as shown in  FIG. 13 . When a wavelength of 660 nm was used, the change ΔH 1  of the amount of transmission light representing a blood coagulation reaction (the difference between the amount of transmission light before the reaction and the amount of transmission light after the reaction) also tended to be reduced by the influenced of interference substance (chyle). In contrast, measurement results measured on the high wavelength side at 800 nm were not as influenced by interference substances, and were higher than the amount of transmission light measured at 660 nm (approximately 190 to 220) at approximately 350 to 390. When a wavelength of 800 m was used, the change ΔH 2  of the transmission light representing a blood coagulation reaction (&gt;ΔH 1 ) is also not as influenced by the interference substance (chyle), and was not easily reduced. Therefore, when measuring specimens containing interference substances (chyle), performing the measurement at a wavelength of 800 nm in the high wavelength region captures a greater change in the amount of transmission light via the coagulation reaction than measurement at a wavelength of 660 nm in the low wavelength region.  
         [0072]     When a normal sample that did not contain interference substances was measured, the change ΔH  11  in the amount of transmission light measured at a low wavelength of 660 nm (ΔH 11 =approximately 980 (=transmission light before reaction (about 2440)−transmission light after reaction (about 1460)) was greater than the change ΔH 21  in the amount of transmission light measured at a high wavelength of 800 nm (ΔH 21 =approximately 720 (=transmission light before reaction (about 2630)−transmission light after reaction (about 1910)). Therefore, when measuring normal samples, measurement at a low wavelength 660 nm captures a greater change in the amount of transmission light via the reaction than measurement at a wavelength of 800 nm in the high wavelength region.  
         [0073]      FIG. 15  is a flow chart showing the sequence of the specimen analysis operation of the blood coagulation analyzer of the embodiment of  FIG. 1 . The specimen analysis operation performed by the blood coagulation analyzer  1  is described in detail below with reference to  FIGS. 1, 2 ,  8 ,  10 ,  11 , and  15 .  
         [0074]     First, the blood coagulation analyzer  1  is initialized by turning ON the power sources of the detection device  2  and control device  4  of the blood coagulation analyzer  1  shown in  FIG. 1 . In this way, an operation is performed to return each dispensing arm and the mechanism that moves the cuvettes  152  to the initial positions, and software stored in the controller  4   a  of the control device  4  is initialized.  
         [0075]     Then, the rack  151  loaded with test tubes  150  containing specimens is transported by the transport device shown in  FIG. 2 . Thus, the rack  151  is transported from the rack set region  3   a  to a position corresponding to the aspirating position  2   a  of the detection device  2 .  
         [0076]     In step S 1 , a predetermined amount of specimen is aspirated from the test tube  150  via the specimen dispensing arm  30  (refer to  FIG. 2 ). The specimen dispensing arm  30  is then moved above the cuvette  152  held on the primary dispensing table  24  of the rotating part  20 . Thereafter, the sample within the cuvette  152  is allocated by discharging the sample from the specimen dispensing arm  30  into the cuvette  152  of the primary dispensing table  24 .  
         [0077]     In step S 2 , a predetermined amount of specimen is aspirated from the cuvette  152  held in the holder  24   a  of the primary dispensing arm  24  via the specimen dispensing arm  30 . Thereafter, the secondary dispensing process is performed by discharging predetermined amounts of specimen from the dispensing arm  30  to a plurality of cuvettes  152  on the secondary dispensing table  23 . Then, the reagent dispensing arm  60  is actuated, and blood coagulation reagent within a reagent container (not shown in the drawing) which is loaded in the reagent tables  21  and  22  is added to the specimen within the cuvettes  152  on the secondary dispensing table  23 . Thus, analysis samples are prepared. Then, the cuvette transporter  70  moves the cuvette  152  containing the analysis sample from the secondary dispensing table  23  to the insertion hole  81   a  of the cuvette loader  81  of the photometric part  80 .  
         [0078]     In step S 3 , a plurality (ten types) of transmission light are obtained from the analysis sample by photometric measurement of the analysis sample within the cuvette  152  under a plurality of conditions via the detection part  82  of the photometric part  80 . Specifically, the cuvette  152  inserted in the insertion hole  81   a  of the cuvette loader  81  is first heated to a predetermined temperature by a heating device (not shown in the drawing). Thereafter, light is emitted from the beam splitter optical fiber  57  of the lamp unit  50  and irradiates the cuvette  152  on the cuvette loader  81 , as shown in  FIG. 10 . Light of five different wavelengths (340 nm, 405 nm, 575 nm, 660 nm, 800 nm) emitted from the beam splitter optical fiber  57  periodically illuminates via the rotation of the filter part  53  (refer to  FIG. 8 ). The light of each wavelength emitted that is emitted from the beam splitter optical fiber  57  and passes through the cuvette  152  and the analysis sample within the cuvette  152  is sequentially detected by the photoelectric conversion element  82   b . Then, the electric signals, which represent the amount of transmission light corresponding to the light of five different wavelengths that have been converted by the photoelectric conversion element  82   b , are amplified by the preamp  82   c  and sequentially input to the amplifier  82   g.    
         [0079]     In the amplifier part  82   g , the electric signals, which represent the amount of transmission light corresponding to the light of five different wavelengths output from the preamp  82   c  (refer to  FIG. 11 ), are input to the high amplification factor amp (H)  82   l  and normal amplification factor amp (L)  82   k . The controller  82   j  controls the switch  82   m  so as to output the electric signals that have been amplified by the amp (H)  82   l  are output to the A/D converter  82   h , and thereafter the electric signals that have been amplified by the amp (L)  82   k  are output to the A/D converter  82   h . The switch  82   m  repeatedly switches in accordance with the timing of the rotation of the filter part  53  (refer to  FIG. 8 ) in the lamp unit  50 . Thus, the electrical signals representing the transmission light corresponding to the light at five different wavelengths are respectively amplified by two different amplification factors in the amplifier part  82   g , and a total of ten electric signals are repeatedly output to the A/D converter  82   h . These ten electric signals are converter to digital signals by the A/D converter  82   h  and the digital signals are temporarily stored in the logger  82   l , and subsequently these digital signals are sequentially transmitted to the controller  4   a  of the control device  4 . Thus, the acquisition of a plurality (ten types) of transmission light data for an analysis sample is completed by the photometric part  80 . The amount of change at each wavelength (=amount of transmission light before reaction−amount of transmission light after reaction) is calculated from the received transmission light data by the controller  4   a  of the control device  4 . The obtained transmission light data are then stored in the RAM  401   c  of the control device  4 .  
         [0080]     In the present embodiment, after the transmission light data is obtained by the photometric part  80  in step S 3 , a determination is made in step S 4  as to whether or not the change (ΔH 1 ) of the amount of transmission light of the analysis sample measured at a wavelength of 660 nm is greater than a threshold value (T 11 ). The blood coagulation react induces an optical change in the analysis sample, and this optical change is represented as a change in the amount of transmission light. Therefore, when there is a large change in amount of transmission light, it may be considered indicative of a large optical change in the analysis sample caused by the blood coagulation reaction. The coagulation time can be measured with high precision using the large change in the amount of transmission light over time due to the large S/N ratio of the transmission light data.  
         [0081]     When the change ΔH 1  of the transmission light measured at 660 nm is greater than the threshold value (T 11 ) in step S 4 , a determination is made in step S 5  as to whether or not the amount of transmission light (bH 1 ) at 660 nm at the lag phase (the time from the initial preparation of the measurement sample to before the measurement sample is optically changed by the blood coagulation reaction) is greater than a predetermined threshold value (T 12 ). The coagulation reaction starts blood coagulation by changing the fibrinogen in the plasma to fibrin through many internal and external reaction systems. That is, blood coagulation does not soon start even though blood coagulation reagent is mixed with the plasma, rather a coagulation reaction normally starts after approximately seven seconds in external systems (PT measurement reagent), and normally after about 14 seconds in internal systems (APTT measurement reagent). Accordingly, the optical information at time point before the coagulation reaction is indicated (lag phase) is optical information representing conditions before an optical change has occurred via the coagulation reaction, and is identical to the optical information obtained from a diluted specimen to which blood coagulation reagent has not been added. Therefore, whether or not the transmission light data is usable for analysis can be determined by comparing the threshold value (T 12 ) and the amount of transmission light (bH 1 ) in the lag phase of a specimen diluted with reagent used for blood coagulation time measurement. When an analysis sample contains substantial interference substances, very little received light is detected by the photoelectric conversion element  82   b  of the photometric part  80 , and the amount of transmission light is reduced in the lag phase. Thus, when the amount of transmission light (bH 1 ) at 660 μm is less than the threshold value (T 12 ) in the lag phase, the interference substances greatly influence the amount of transmission light at this wavelength (660 nm) obtained by the photometric part  80 , and is determined that the data are not usable for analysis. The transmission light data during the lag phase is obtained using the data from the start of photometric measurement until a predetermined time has elapsed. Furthermore, the determination is not limited to this method inasmuch as the change in the amount of transmission light over time may be analyzed to determine the lag phase, and the transmission light data of this period may be used so as to differentiate the amount of transmission light and determine the degree of change of transmission light, and set the lag phase as the time from the start of photometric measurement until the differential value exceeds a predetermined value.  
         [0082]     When the amount of transmission light (bH 1 ) at 660 nm in the lag phase is greater than the threshold value (T 12 ) in step S 5 , the analysis item (for example, “PT”) coagulation time is determined in step S 6  by the CPU  401   a  of the control device  4  analyzing the transmission light data of the analysis sample measured at 660 nm from among the plurality of transmission light data measured by the photometric part  80 . Thereafter, the controller  4   a  output the analysis results such as coagulation time and the like.  
         [0083]     When the amount of transmission light (bH 1 ) at 660 nm in the lag phase is less than the threshold value (T 12 ) in step S 5 , however, a determination is made in step S 7  as to whether or not the change (ΔH 2 ) in the amount of transmission light of the analysis sample measured at 800 nm exceeds a threshold value (T 21 ). That is, in this case the transmission light data at 660 nm is greatly affected by the interference substances, and since these data can not be used for analysis a determination is made as to whether or not the transmission light data at 800 nm which were not much influenced by interferences substances are usable for analysis. When the change (ΔH 2 ) in the amount of transmission light at 800 nm is greater than a threshold value (T 21 ) in step S 7 , then a determination is made in step S 8  as to whether or not the transmission light (bH 2 ) at 800 nm in the lag phase exceeds a predetermined threshold value (T 22 ). When the transmission light (bH 2 ) at 800 nm in the lag phase exceeds the threshold value (T 22 ), analysis is performed using the 800 nm transmission light data. That is, in step S 9 , the coagulation time of the analysis item is determined by the CPU  401   a  of the control device  4  analyzing the transmission light data of the analysis sample measured at 800 nm from among the plurality of transmission light data measured by the photometric part  80 . Thereafter, the controller  4   a  output the analysis results such as coagulation time and the like. When the transmission light (bH 2 ) at 800 nm in the lag phase is less than the threshold value (T 22 ) in step S 8 , the CPU  401   a  does not execute analysis, and a measurement error flag is raised in the measurement results in step S 10 . Furthermore, since the 800 nm transmission light data, which are least affected by interference substances among all measurement wavelengths, are determined to be unusable for analysis even when the change (ΔH 2 ) of the amount of transmission light at 800 nm is below the threshold value (T 21 ) in step S 7 , and the CPU does not perform analysis and a measurement error flag is raised in the measurement results in step S 110 .  
         [0084]     When the change (ΔH 1 ) in the amount of transmission light measured at 660 nm is less than a threshold value (T 11 ) in step S 4 , a determination is made in step S 11  as to whether or not the change (ΔH 3 ) of the amount of transmission light of the analysis sample measured at 575 nm is greater than a threshold value (T 31 ). In this case, a determination is made as to whether or not the 575 nm transmission light data, which has higher measurement sensitivity, is usable for analysis since the change in the amount of 660 nm transmission light is inadequate.  
         [0085]     When the change (ΔH 3 ) in the amount of transmission light at 575 nm is greater than a threshold value (T 31 ) in step S 11 , then a determination is made in step S 12  as to whether or not the transmission light (bH 3 ) at 575 nm in the lag phase exceeds a predetermined threshold value (T 32 ). When the 575 nm transmission light (bH 3 ) is greater than the threshold value (T 32 ), then in step S 13  the CPU  401   a  of the control device  4  analyzes the transmission light data of the analysis sample measured at 575 nm from among the plurality of transmission light data measured by the photometric part  80 , and determines the coagulation time of analysis item. Thereafter, the controller  4   a  output the analysis results such as coagulation time and the like. When the transmission light (bH 3 ) at 575 nm in the lag phase is less than the threshold value (T 32 ) in step S 12 , the CPU  401   a  does not execute analysis, and a measurement error flag is raised in the measurement results in step S 14 .  
         [0086]     When the change (ΔH 3 ) in the amount of transmission light measured at 575 nm is less than a threshold value (T 31 ) in step S 11 , a determination is made in step S 15  as to whether or not the change (ΔH 4 ) of the amount of transmission light of the analysis sample measured at 405 nm is greater than a threshold value (T 41 ). In this case, a determination is made as to whether or not the 405 nm transmission light data, which has higher measurement sensitivity, is usable for analysis since the change in the amount of 575 nm transmission light is inadequate.  
         [0087]     When the change (ΔH 4 ) in the amount of transmission light at 405 nm is greater than a threshold value (T 41 ) in step S 15 , then a determination is made in step S 16  as to whether or not the transmission light (bH 4 ) at 405 nm in the lag phase exceeds a predetermined threshold value (T 42 ). When the 405 nm transmission light (bH 4 ) is greater than the threshold value (T 42 ), then in step S 17  the CPU  401   a  of the control device  4  analyzes the transmission light data of the analysis sample measured at 405 nm from among the plurality of transmission light data measured by the photometric part  80 , and determines the analysis item coagulation time. Thereafter, the controller  4   a  output the analysis results such as coagulation time and the like. When the transmission light (bH 4 ) at 405 nm in the lag phase is less than the threshold value (T 42 ) in step S 16 , the CPU  401   a  does not execute analysis, and a measurement error flag is raised in the measurement results in step S 18 . Furthermore, the CPU  401   a  does not execute analysis and a measurement error flag is raised in the measurement results in step S 18  even when the change (ΔH 4 ) of the amount of transmission light measured at 405 nm is less than the threshold value (T 41 ) in step S 15 .  
         [0088]     After completion of analyses by the CPU  401   a  of the control device  4  in steps S 6 , S 9 , S 13 , and S 17 , the analysis results such as coagulation time and the like obtained in steps S 6 , S 9 , S 13 , and S 17  are displayed on the display  4   b  of the control device  4  in step S 19 . When a measurement error flag is attached to the measurement results in step S 10 , S 14 , or S 18 , “measurement error” is displayed together with an error code on the display  4   b  of the control device  4 . Thus, a user is made aware of the error content via the error code displayed on the display  4   b  and refers to the error code in a technical manual. In this way the specimen analysis operation is completed by the blood coagulation analyzer  1 .  
         [0089]     In the present embodiment, a suitable measurement wavelength can be selected for each specimen, and high precision analysis can be performed on each specimen. That is, the wavelength used for analysis can be changed based on the change over time in the amount of transmission light, which changes in accordance with the progress of the blood coagulation reaction by selecting a wavelength to be used in the analysis based on the change (ΔH 1  through ΔH 4 ) in the amount of transmission light over a time course obtained by the photometric part  80 . Thus, a change in the amount of transmission light over time can be obtained which is scarcely affected by interference substances if a long wavelength is selected that is not readily absorbed by the interference substances contained in the specimen when it is found that an interference substance (chyle) influences the change in the amount of transmission light over time obtained by the photometric part  80 . As a result, the control device  4  can accurately analyze the coagulation time of a blood sample since the change in the amount of transmission light over time that is unaffected by interference substances is captured as a change induced in blood by the coagulation reaction.  
         [0090]     In the present embodiment, the transmission light of an analysis sample is measured in the lag phase at wavelengths of 800 nm,  660  nm, 575 nm, and 405 nm and compared to threshold values to determine whether or not the transmission light is within the analysis range of the control device  4 , and when the lag phase transmission light exceeds the analysis range of the control device  4 , the selected wavelength can be changed so as to select lag phase transmission light that is within the analysis range of the control device  4 . As a result, the control device  4  can perform accurate analysis since the analysis is not performed using low reliability transmission light that exceeds the analysis range.  
         [0091]     In the present embodiment, when accurate analysis can not be performed using data at a specific wavelength (for example 660 nm), data at another wavelength (for example, 800 nm) can be selected to perform accurate analysis because the configuration allows the selection of the wavelength used in the analysis in which transmission light data (amount of light received over time) are used for blood coagulation analysis. Furthermore, a first wavelength data may be used preferentially since a prioritized determination is made as to whether or not a first wavelength (660 nm) data, which are scarcely affected by interference substances and can be obtained with suitable measurement sensitivity, can be used for analysis. The first wavelength data is less affected by interference substances than data of a second wavelength (575 nm, 405 nm) that is shorter than the first wavelength. Furthermore, the first wavelength data is obtained with higher resolution than that of a third wavelength (800 nm) that is longer than the first wavelength. Therefore, it is verified that the first wavelength data are highly reliable. When an optical change in the analysis sample caused by the coagulation reaction can not be captured as an adequately large change in transmission light among the data at the first wavelength, it is possible to perform more accurate analysis by selecting data of a second wavelength (575 nm, 405 nm). When the second wavelength is unusable for analysis, the analysis is suspended or another wavelength can be selected. Moreover, when measurement is greatly affected by interference substances in the specimen, a third wavelength (800 nm) may be selected so as to use data obtained at the third wavelength, which is scarcely affected by the interference substance, for the analysis. When the third wavelength is unusable for analysis, the analysis is suspended or another wavelength can be selected. According to this configuration, a separate structure for optically measuring interference substances becomes unnecessary, thus rendering the apparatus more compact and lowering costs.  
         [0092]     The foregoing detailed description and accompanying drawings have been provided by way of explanation and illustration, and are not intended to limit the scope of the appended claims. Many variations in the presently preferred embodiments illustrated herein will be obvious to one of ordinary skill in the art, and remain within the scope of the appended claims and their equivalents.  
         [0093]     For example, the present embodiment has been described in terms of a configuration for selecting a wavelength to be used in analysis using the transmission light of the lag phase, and the change in the amount of transmission light at each wavelength. However, the present invention is not limited to this configuration. The wavelength used in the analysis may be selected using just the change in the amount of transmission light at each wavelength. In this case, transmission light data at 800 nm may be used for analysis when, for example, the change in the amount of transmission light at the 800 nm wavelength is greater than the threshold value, and transmission light data at 660 nm may be used for analysis when the change in the amount of transmission light at 800 nm is less than the threshold value.  
         [0094]     In the present embodiment, whether or not a specific wavelength can be used for analysis is determined by following order of steps: it is determined whether or not the change in the amount of transmission light at the specific wavelength exceeds a threshold; if the change in transmission light is found to be greater than the threshold value, then it is determined whether or not the transmission light during the lag phase at the particular wavelength exceeds a threshold value. However, the present invention is not limited to this configuration. For example, the order of the determination steps may be as follows: it is determined whether or not the transmission light at a specific wavelength during the lag phase exceeds a threshold value; if the amount of transmission light is found to be greater than the threshold value, then it is determined whether or not the change in the amount of transmission light at the particular wavelength exceeds a threshold value.  
         [0095]     The present embodiment has been described in terms of the detection device and control device being provided separately. However, the present invention is not limited to this configuration inasmuch as the functions of the control device may be provided in the detection device.  
         [0096]     The present embodiment has been described by way of example is photometric measurement (main measurement) of an analysis sample using the coagulation time method. However, the present invention is not limited to this configuration. Rather than the coagulation time method, the properties of blood coagulation of a specimen (blood sample) may be analyzed by photometric measurement of the analysis sample using a synthetic substrate method, immunoturbidity method or the like. It is also possible to analyze clinical items related to characteristics other than blood coagulation. Although plasma is used as a specimen in the present embodiment, serum may also be used according to the measurement item.