Patent Publication Number: US-2007122309-A1

Title: Specimen analyzer and specimen suction device

Description:
FIELD OF THE INVENTION  
      The present invention relates to a specimen analyzer for sucking a blood specimen, urine specimen or the like accommodated in a specimen container and analyzing the specimen and to a specimen suction device for sucking said specimens.  
     BACKGROUND  
      Specimen analyzers for automatically analyzing specimens of blood, urine or the like taken from a subject being tested have been used extensively. For analysis by such specimen analyzer, as a container for accommodating a specimen, sealed container such as evacuated blood-collection tube for collected blood or open container upper portion of which is made open are used. And one type of specimen analyzer is exclusively used for open container, and the other type is capable of coping with both sealed container and open container. In addition, such a specimen analyzer which is equipped with a carrying mechanism for carrying a number of containers automatically and executes automatic suction of specimen from each of containers, and another specimen analyzer which sucks specimens from containers one by one manually are available.  
      Further, many of specimen analyzers of this sort comprise a suction tube for sucking a specimen from a container, a penetrating-type washing member for washing the suction tube, and a sample preparation unit for preparing a sample by mixing a specimen and a reagent, and are designed to wash the suction tube used for suction of the specimen by the washing member, to move the suction tube to the sample preparation unit and to cause the suction tube to discharge a predetermined amount of specimen at the sample preparation unit. For example, U.S. Pat. No. 5,592,959 discloses a specimen analyzer comprising a penetrating-type washing member, which is constituted to wash a suction tube while it is being penetrated through penetrating path of the washing member.  
      With specimen analyzers of these types, it is necessary to insert a suction tube into an insertion port provided to the sample preparation unit and to move up and down the suction tube in the penetrating path of the washing member, thereby requiring high-positioning accuracy, high-assembly accuracy, high-dimensional accuracy of parts or the like. Further, along with miniaturization of analyzer and of amount of specimen prevailing recently, high dimensional accuracy or the like have been demanded. On the other hand, it is necessary that inside diameter of the penetrating path of penetrating-type washing member is slitly, i.e. not much, larger than outside diameter of the suction tube because of the structure of the penetrating-type washing member. Therefore normal washing operation is not possible even if the suction tube is bent slightly.  
      Further, when a specimen is sucked manually from an open container, in order to prevent erroneous suction operation, an operator preferably executes manipulations while confirming that end of the suction tube is being inserted into the specimen. However, in some cases, it is hard for the operator to confirm the end of the suction tube depending on position of the suction tube in a specimen analyzer, place of installation of the specimen analyzer, physical size of the operator or the like. If this is the case, the operator may attempt to execute suction manipulations by pressing interior surface of the container against the suction tube. However, there has been such a draw back that with conventional analysis apparatus equipped with an ordinary suction tube made of higher hardness metal (e.g., stainless steel), the suction tube causes plastic deformation if subjected to repeated external forces in transverse direction or excessive external forces, and normal operation is not possible.  
     SUMMARY  
      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.  
      The first aspect of the present invention relates to a specimen analyzer comprising:  
      a suction tube made of superelastic alloy for sucking a specimen from a specimen container whose upper portion is open;  
      a sample preparation unit having an insertion port for inserting the suction tube and preparing a sample by a specimen which is discharged from the suction tube inserted into the insertion port;  
      a movement mechanism for moving said suction tube between suction position for said suction tube to suck a specimen and insertion position where said suction tube is inserted into insertion port of said sample preparation unit; and  
      an analysis unit for analyzing a sample prepared by said sample preparation unit.  
      The second aspect of the present invention relates to a specimen analyzer comprising:  
      a suction tube made of superelastic alloy for sucking a specimen from a specimen container whose upper portion is open;  
      a washing unit having a penetrating path through which is penetrating said suction tube, a supplying path for supplying washing solution to said penetrating path and a drainage path for draining the washing solution from said penetrating path;  
      a movement mechanism for relatively moving said suction tube and said washing unit in lengthwise direction of said suction tube; and  
      an analysis unit for analyzing a specimen sucked by said suction tube.  
      The third aspect of the present invention relates to a specimen suction device comprising:  
      a suction tube made of superelastic alloy for sucking a specimen from a specimen container whose upper portion is open;  
      a movement mechanism for moving said suction tube; and  
      a specimen suction unit connected to said suction tube for sucking a specimen by said suction tube.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view showing whole specimen analyzer relating to an embodiment;  
       FIG. 2  is a front view of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 3  is a perspective view of the specimen analyzer shown in  FIG. 1  after housing is removed;  
       FIG. 4  is a front elevation of the specimen analyzer shown in  FIG. 1  after housing is removed;  
       FIG. 5  is a front elevation of a horizontal driving unit of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 6  is a front elevation of a vertical driving unit and horizontal driving unit of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 7  is an explanatory drawing showing left side of the vertical driving unit and horizontal driving unit of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 8  is a side sectional view showing composition of a washing unit;  
       FIG. 9  is an explanatory drawing showing left side of the vertical driving unit of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 10  is a sectional view looked at line C-C in  FIG. 8 ;  
       FIG. 11  is first half of fluid circuit diagram of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 12  is last half of fluid circuit diagram of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 13  is a fluid circuit diagram showing periphery of a drainage chamber;  
       FIG. 14  is a fluid circuit diagram showing periphery of a diaphragm pump;  
       FIG. 15  is a control block diagram of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 16  is a flowchart showing flow of operations of the specimen analyzer shown in  FIG. 1 ;  
       FIG. 17  is a schematic diagram showing an example of deformation of the suction tube;  
       FIG. 18  is a front view of the vertical driving unit and the horizontal driving unit showing positional relationship between the suction tube and the washing unit when the suction tube is at initial position; and  
       FIG. 19  is a side sectional view showing state where the suction tube is inserted into upper opening of a second mixing chamber. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT  
       FIG. 1  is a perspective view showing whole specimen analyzer S relating to an embodiment,  FIG. 2  is a front view of the specimen analyzer S,  FIG. 3  is a perspective view of the specimen analyzer S showing state where housing  1  is removed, and  FIG. 4  is a front elevation of the same after the housing is removed.  
      Said specimen analyzer S is communicably connected with a processing device PC having a display, an input device, a CPU and memory or the like (typically, a personal computer to which are installed necessary computer programs) (see  FIG. 15 ), and a sample analysis system is composed of the specimen analyzer S and the processing device PC. To the processing device PC is installed software for manipulations of the specimen analyzer S, various analysis related settings, display of analysis results or the like, and it is possible to give a command to the specimen analyzer S and to receive measurement data from the specimen analyzer S through communication with the specimen analyzer S. The specimen analyzer S is an apparatus (blood analysis apparatus) for measurements of blood (sample) accommodated in a blood-collection tube  3  which is a container whose upper portion is open (initial sample container), and comprises primarily an mesurement device  2  and a housing  1  for accommodating the mesurement device  2 .  
      The housing  1  is made from synthetic resin and rust-proofed steel plate or the like and is fixed to the mesurement device  2  using fastening means such as bolts or the like. At right lower portion of front of the housing  1  (left-side face in  FIG. 1 ) is formed a recess  5  and a suction tube  13 , which will be described later, is protruded from upper plane of the recess  5  (see  FIG. 2 ). This arrangement allows an operator to move the blood-collection tube  3  now he/she holds and to insert the suction tube  13  into the blood-collection tube  3  from lower portion. Besides, a start switch  6  composed of microswitch is provided in the back of the recess  5 , and the operator can give an instruction for blood suction by touching the start switch  6  while the suction tube  13  is being inserted into the blood-collection tube  3 .  
      The mesurement device  2  includes a sample preparation unit for preparing a mixed sample for analysis by quantitative determination, dilution or the like of blood in the blood-collection tube  3 , detection units D 1 , D 2 , D 3  for measuring (detection) of the blood subjected to dilution or the like, and a control unit for driving and controlling electrically said sample preparation unit and the detection units. A liquid sample suction device of the present embodiment comprises, of said sample preparation unit and control unit, components or mechanism for sucking a sample from a open container.  
      Said sample preparation unit is a portion for adjusting mixed samples for various analyses by sucking a predetermined amount of blood from the blood-collection tube  3  inside and mixing it with a reagent in a first mixing chamber MC 1  or in a second mixing chamber MC 2 . And the sample preparation unit includes a suction tube  13  for sucking a sample in the blood-collection tube  3 , a horizontal driving unit  20  for moving the suction tube  13  horizontally, a vertical driving unit  60  for moving said suction tube  13  vertically, a suction mechanism for venting said blood-collection tube  3  inside to atmosphere and sucking the sample in the blood-collection tube  3 , and a control unit for controlling operations of said horizontal driving unit, vertical driving unit and suction mechanism. The sample preparation unit relating to the present embodiment also includes a vertical driving unit  40  being moved horizontally by said horizontal driving unit  20 , which vertical driving unit  40  holds said blood-collection tube  3 , and is capable of moving vertically by a guide mechanism thereof.  
      Said suction tube  13  has transverse section in circular form, has a flow path inside elongating in longitudinal direction and a suction port for sucking a sample or air is formed around front edge thereof. Further, this suction tube  13  is a superelastic alloy pipe made of titanium-nickel alloy (Ti—Ni) which does not cause plastic deformation even if being bent, and will restore to the original straight state. As used herein the term “superelastic alloy” is meant to refer to an alloy which is bent lithely and has properties to return to its original form in the room temperature if a force is removed. Besides, lower end of the suction tube  13  is substantially horizontal plane and a suction port is opened to the lower end. Meanwhile, such suction tube  13  is not limited to those made of titanium-nickel alloy and may be made of other superelastic alloy such as copper-aluminum-nickel alloy (Cu—Al—Ni), titanium alloy (Ti), titanium-niobium-aluminum alloy (Ti—Nb—Al), copper-zinc-nickel alloy (Cu—Zn—Al) or the like.  
      Further, as shown in the fluid circuit diagram in  FIG. 11  and  FIG. 12 , a reagent container for accommodating reagents is provided to the mesurement device  2 . Specifically, the reagent container comprises a diluting fluid container EPK-V for accommodating diluting fluid (washing solution) EPK, a hemoglobin hemolytic agent container SLS-V for accommodating hemoglobin hemolytic agent SLS, a white blood cell classification hemolytic agent container FFD-V for accommodating white blood cell classification hemolytic agent FFD, and a white blood cell classification staining fluid container FFS-V for accommodating white blood cell classification staining fluid FFS.  
       FIG. 5  is a front elevation of a horizontal driving unit of the specimen analyzer shown in  FIG. 1 , and the horizontal driving unit  20  includes, as illustrated, a movement panel  21  to which is fixed said vertical driving unit  40  (described indetail later), a driving mechanism  22  for moving the movement panel  21  horizontally and a guide mechanism  23  for guiding horizontal movement of said movement panel  21 . Said movement panel  21  is composed of a vertically long plate made of metal or synthetic resin, and screw holes  24  for fixing a vertical driving unit  40  are provided to upper part and lower part thereof. The driving mechanism  22  is composed of a driving pulley  26  and a driven pulley pivotally mounted on the surface of a supporting panel  25  (plane at this side in  FIG. 5 ), a stepping motor  28  disposed at rear side of said supporting panel  25  for rotating driving of said driving pulley  26 , a timing belt  29  provided in tension state between said driving pulley  26  and driven pulley  27 , and a connecting member  30  fixed to both inner circumference plane of the timing belt  29  and rear of said movement panel  21 .  
      On upper-end edge of the supporting panel  25  is provided an upper guide  31  for guiding upper end of said movement panel  21 , whereas to portion under said timing belt  29 , that is a surface of the supporting panel  25 , is provided a lower guide  32  for guiding lower part of the movement panel  21 . Said guide mechanism  23  is composed of this upper guide  31  and the lower guide  32 . The upper guide  31  is composed of a horizontal part  31   a  protruding from the upper-end edge of the supporting panel  25  to surface side, and a vertical part  31   b  hanging downwardly from the leading edge of this horizontal part  31   a  so that said vertical part  31   b  is grasped by a rear-side grasping piece  33  being formed around the upper end of the movement panel  21  and a surface-side grasping piece  34  having approximately C-shaped section being formed in protruding fashion to surface side around the upper end. Meanwhile, the lower guide  32  includes a guide shaft  35  disposed inparallel with movement direction of the timing belt  29  at portion under the timing belt  29  and a sliding movement member  36  having a passage therein to allow for sliding movement of this guide shaft  35 , while this sliding movement member  36  is fixed to the rear of said movement panel  21 .  
      With such a configuration as mentioned, when the stepping motor  28  is driven, the connecting member  30  fixed to the timing belt  29  moves in left or right direction in  FIG. 4 , and this allows for the movement panel  21 , which is fixed to the connecting member  30 , to move left or right direction. In this case, since upper end and lower part area of the movement panel  21  are guided by said upper guide  31  and the lower guide  32 , respectively, a smooth movement is attained at movement without causing bumpy movements in fore and aft, left and right, and up and down directions.  
      Next, the vertical driving unit  40  will be described.  FIG. 6  is a front elevation of the vertical driving unit of the specimen analyzer S shown in  FIG. 1  and  FIG. 7  is an explanatory drawing showing left side of the vertical driving unit and the horizontal driving unit of the same. As shown in  FIGS. 6-7 , the vertical driving unit  40  includes a support  41 , a guide shaft  42  vertically supported by this support  41  and a suction-tube retaining part  43  which retains said suction tube  13  and moves slidingly on said guide shaft  42 .  
      Said support  41  is composed of an elongated back face part  41   a  which is parallel to said movement panel  21  or supporting panel  25 , a similarly elongated side face part  41   b  provided orthogonally to this back face part  41   a , and an upper face part  41   c  and a lower face part  41   d  provided orthogonally to the back face part  41   a  at upper end and lower end of said back face part  41   a . To said side face part  41   b  is formed an elongated guide slit  45  for guiding a guide bar  44  protruding horizontally from the suction tube retaining part  43 . Further, a guide shaft  42  is supported vertically between said upper face part  41   c  and lower face part  41   d . Meanwhile,  46  is a notch being formed to said back face part  41   a  to allow for penetration of a machine screw for fixing the vertical driving unit  40  to the movement panel  21  of said horizontal driving unit  20 .  
      The suction tube retaining part  43  includes a sliding movement part  43   a  in substantially cubic shape and an engagement part  43   b  being formed onto one plane (left plane in  FIG. 6 ) of this sliding movement part  43   a . As shown in  FIG. 7 , the engagement part  43   b  has a cross-shaped section and engages with concave part of cross-shaped section of the arm of the vertical driving unit, which will be described later, to move the suction tube  13  vertically. A shaft  47  is projectingly provided to other plane (plane of this side of the paper of  FIG. 6 ) of the sliding movement part  43   a , and a guide roller  48  is pivotally mounted to this shaft  47 . The guide roller  48  engages with a guide arm of the vertical driving unit  60 , which will be described later, and the suction tube retaining part  43  will move vertically being interlocked with the guide arm.  
      To the lower face part  41   d  of said support  41  is fixed via a bracket  49  a washing unit CS for washing inner and outer circumferences of the suction tube  13 . Further, liquid supplying and draining nipples  50 ,  51 ,  52  are fixed to lower part of the side face part  41   b  of the support  41  and are respectively connected to base end of the suction tube  13  and the washing unit CS via tubes  53 ,  54 ,  55 .  
       FIG. 8  is a side sectional view showing composition of the washing unit CS. As illustrated, the washing unit CS has cylindrical shape, and to this washing unit CS are provided a vertical penetrating path  15  through which the suction tube  13  is inserted loosely, a supplying path  16  for supplying washing solution to this penetrating path  15 , and a drainage path  17  for draining washing solution and blood in the penetrating path  15 . The penetrating path  15 , supplying path  16  and drainage path  17  all have transverse section in circular form.  
      The penetrating path  15  comprises a small-diameter part  15   a  having narrower clearance with regard to the suction tube  13  and a large-diameter part  15   b  provided under the small-diameter part  15   a  having broader clearance with regard to the suction tube  13 . A tapered part  15   c  in folding-fan shape is provided between the small-diameter part  15   a  and the large-diameter part  15   b . Diameter of the small-diameter part  15   a  is designed to be slightly greater than outer shape of the suction tube  13 , and this configuration allows the suction tube  13  to be loosely engaged with the small-diameter part  15   a.    
      The supplying path  16  is opened at upper end of the large-diameter part  15   b  of the penetrating path  15 , extends from the penetrating path  15  laterally, bent downwardly on the way, and is opened at lower plane of the washing unit CS. In the meantime, the drainage path  17  is opened at a portion close to the lower end of the small-diameter part  15   a  of the penetrating path  15 , extends from the penetrating path  15  laterally, bent upwardly on the way, and is opened at upper plane of the washing unit CS. Besides, the drainage path  17  is configured to have a diameter greater than that of the supplying path  16 .  
      A small nipple  18  and a large nipple  19  are mounted vertically to the washing unit CS, both are in partially embedded fashion. The small nipple  18  is connected to the supplying path  16  and is protruded downwardly from lower plane of the washing unit CS. To the lower end of the small nipple  18  is connected one end of a tube  55  for washing solution supplying. The large nipple  19  is connected to the drainage path  17  and is protruded upwardly from the upper plane of the washing unit CS. Further, to the upper end of the large nipple  19  is connected one end of a tube  54  for draining washing solution and sample.  
      Next, the vertical driving unit  60  of the suction tube  13  will be explained in detail.  FIG. 9  is an explanatory drawing showing left side of the vertical driving unit of the specimen analyzer S shown in  FIG. 1 .  FIG. 10  is a sectional view looked at line C-C in  FIG. 9 . The vertical driving unit  60  constitutes together with the vertical driving unit  40  mentioned previously a suction tube movement mechanism in the liquid sample suction device according to the present invention, and includes, as shown in  FIG. 9 , an arm  61  comprising an elongated body disposed along with horizontal direction, a screw shaft  64  which penetrates through this arm  61  in orthogonal direction (vertical direction) and is pivotally supported by bearings  63  disposed to a supporting panel  62 , and a nut portion  65  having screw part threadedly engaging with this screw shaft  64  and is fixed to said arm  61 , a slide rail  66  disposed to the supporting panel  62  so as to be in parallel with said screw shaft  64 , a sliding movement member  67  which is provided at one end (side end part in mesurement device  2 ) of said arm  61  and guides the arm  61  in vertical direction while slidably engaged with said slide rail  66 , and a stepping motor  68  fixed to said supporting panel  62 .  
      Pulleys  69 ,  70  are fixed respectively to upper end of said screw shaft  64  and output shaft of the stepping motor  68 , and a timing belt  71  is provided in tension state between these pulleys  69 ,  70 . Further, a guide arm  72  having ?-shaped section engaged with the guide roller  48  of said vertical driving unit  40  is fixed horizontally (vertically to the paper of  FIG. 9 ) to other end of said arm  61  (side end part in mesurement device  2 ). Said arm  61  has a recess  73  having cross-shaped section on the plane opposing to the engagement part  43   b  having cross-shaped section of said suction tube retaining part  43 , around end portion at said guide arm  72  side. As shown in  FIG. 10 , said engagement part  43   b  will be inserted into said recess  73  having cross-shaped section from arrow-X direction while keeping an appropriate clearance. It is designed that with this inserted state, the suction tube  13  will be positioned directly above the blood-collection tube  3  and when the suction tube  13  is to puncture a plug body  3   a  of the blood-collection tube  3 , up/down movement force of the arm  61  is conveyed directly to the suction tube retaining part  43 .  
      By appropriately controlling the stepping motor  28  of the horizontal driving unit  20  and the stepping motor  68  of the vertical driving unit  60  from control unit of said mesurement device  2 , it is possible to suck a sample by the blood-collection tube  3  or to supply a sample to mixing chambers MC 1 , MC 2 , by driving the suction tube retaining part  43 , namely suction tube  13 , horizontally or vertically. When sucking a sample, an operation that the suction tube  13  punctures the plug body  3   a  of the blood-collection tube  3  is included, the engagement part  43   b  of the suction tube retaining part  43  engages with the recess  73  having a cross-shaped section of the arm  61 , thereby conveying a large force to the suction tube retaining part  43 . Meanwhile, when the suction tube  13  moves above mixing chambers MC 1 , MC 2  and a sample is supplied to the mixing chambers MC 1 , MC 2 , a driving force of the stepping motor  68  of the vertical driving part  60  is conveyed to the suction tube retaining part  43  via the arm  61 , guide arm  72  and guide roller  48 .  
      The specimen analyzer S relating to the present embodiment includes, as shown in  FIGS. 3-4 , a first mixing chamber MC 1  for adjusting a mixed sample for measurements relating to red blood cells, hemoglobin and blood platelet, a second mixing chamber MC 2  for adjusting a mixed sample for measurements relating to white blood cells, a first detection unit D 1  for measurements relating to red blood cells, a second detecting unit D 2  for measurements relating to hemoglobin, and a third detection unit D 3  for measurements relating to white blood cells.  
      Said mesurement device  2  includes, as shown in  FIG. 15 , a control unit  100  for controlling said sample preparation unit and measurement units D 1 , D 2 , D 3 . This control unit  100  is composed of CPU, ROM, and RAM. The mesurement device  2  also includes a driving circuit unit  110  for driving electromagnetic valves SV 1 -SV 33 , SV 40 , SV 41 , and various pump motors  28 ,  68 , SP 1 , SP 2 , P, V, DP 1 , DP 2 , DP 3 , DP 4 , DP 5  or the like in the fluid circuit constituting the sample preparation unit or the like. The control unit  100  drives said electromagnetic valves or the like via the driving circuit unit  110 . The control unit  100  is capable of communicating with the processing device PC via a communication interface (not shown) and is capable of exchanging various signals and data with the processing device PC.  
       FIGS. 11-14  are fluid circuit diagrams showing composition of the fluid circuit of the specimen analyzer S relating to the present embodiment. In  FIGS. 11-14 , SP 1  and SP 2  are syringe pumps for sucking or supplying a sample (blood), CS is washing unit for washing the suction tube, and DP 1 -DP 5  are diaphragm pumps for quantitative determination of liquids such as diluting fluid, hemolytic agent, staining fluid or the like. Further, WC 1 -WC 2  are drainage chambers, EPK-C is EPK (diluting fluid) container, SV 1 -SV 33  are electromagnetic valves for flow path opening/closing. These valves SV 1 ˜SV 33  are normally-closed type valves.  
      As illustrated, the suction tube  13  is connected to the syringe pump SP 1  via a tube and when the syringe pump SP 1  functions, it is possible to suck a specimen by applying a negative pressure to the suction tube  13 . Further, it is possible to supply washing solution being supplied to the syringe pump SP 1  by driving the diaphragm pump DP 1  to the suction tube  13  by syringe pump SP 1  operation. Besides, to the supplying path  16  of the washing unit CS, it is connected to a container EPK-C via a tube so as to receive from the container EPK-C the washing solution. The drainage path  17  of the washing unit CS is connected to the drainage chamber WC 1  via a tube. This drainage chamber WC 1  is connected to a vacuum pump V via a chamber for buffering purpose of drainage spilled out the drainage chamber WC 1  and the drainage (washing solution, blood) is sucked by applying a negative pressure to the drainage path  17  by this vacuum pump via the drainage chamber WC 1 .  
      Next, referring to fluid circuit diagrams shown in  FIGS. 11-14  and to flow chart shown in  FIG. 16 , operations of the specimen analyzer S relating to the embodiment according to the present invention will be explained. The following description deals with, as one example of operations of the specimen analyzer S, analysis operation of white blood cells contained in a specimen. First, the specimen analyzer S is in stand-by state where the suction tube  13  is located at the lower limit and is protruded downwardly from upper plane of the recess  5 . Hereafter, this position of the suction tube  13  is referred to as the initial position. Namely, at this initial position, the suction tube  13  is exposed outside. Besides, when the suction tube  13  is in stand-by at the initial position, inside of the suction tube  13  is filled with a washing solution. Filling of the washing solution into the suction tube  13  will be descried later. When the suction tube  13  is at the initial position, the operator holds the blood-collection tube  3  by hand and lifts the blood-collection tube  3  upwardly from a position under the suction tube  3 . By this manipulation, the suction tube  13  is inserted into the blood-collection tube  3 .  
      In this case, the operator moves the blood-collection tube  3  while the suction tube  13  is being inserted, pushes lower end of the suction tube  13  by inner wall of the blood-collection tube  3 , and lower end of the suction tube  13  may hit bottom of the blood-collection tube. If this is the case, the suction tube  13  is exposed to an external force thereby resulting in deformation.  FIG. 17  is a schematic diagram showing an example of deformation of the suction tube  13 . As illustrated, when the suction tube  13  comes in contact with inner face of blood-collection tube  3  and a part of the suction tube  13  (e.g., lower end) is pressed, the suction tube  13  will be bent. The suction tube  13  is made of superelastic alloy and hence is bent easily, and when the external force is removed by that the blood-collection tube  3  is removed from the suction tube  13  or the like, it returns to its original straight profile by elasticity thereof.  
      While the suction tube  13  is being inserted to the blood-collection tube  3  and lower end of the suction tube  13  is immersed into the specimen, the operator touches a start switch  6  to initiate suction operation. Upon receiving such suction start instruction (Yes in step S 1 ), the control unit  100  drives the syringe pump SP 1  to cause quantitative suction of a predetermined amount of sample (step S 2 ), while position of the suction tube  13  is not moved, namely, the suction tube  13  is remained at the initial position. At the same time, a hemolytic agent is supplied from the hemolytic agent container FFD-V to the second mixing chamber MC 2  (step  3 ). In the meantime, here, supplying of the hemolytic agent to the second mixing chamber MC 2  is not necessarily executed after suction of the sample (specimen), and these operations are performed at the same time. Although, for the sake of simplified explanation, each of operations is explained to be executed sequentially in the following description, a part of operations is executed simultaneously.  
      In step S 3 , specifically, by opening valve SV 19  and closing valve SV 20 , and at the same time, by opening valve SV 22  and closing valve S 21 , diaphragm pump D 4  for FFD is negative pressure driven, and hemolytic agent FFD is replenished from the hemolytic agent container FFD-V to the diaphragm pump D 4  for FFD. Further, by closing valve SV 19  and opening valve SV 20 , and at the same time, by opening valve S 21  and closing valve S 22 , diaphragm pump D 4  for FFD is positive pressure driven, and hemolytic agent FFD is supplied by the diaphragm pump D 4  to the second mixing chamber MC 2 . Furthermore, by opening valve S 19  and closing valve S 20 , and at the same time, by closing valve S 21  and opening valve S 22 , the diaphragm pump D 4  for FFD is negative pressure driven, and hemolytic agent FFD is again replenished from the hemolytic agent container FFD-V to the diaphragm pump D 4  for FFD.  
      Subsequently, the suction tube  13  is moved up by operations of the horizontal driving unit  20  and vertical driving unit  30 , and at the same time, washing of the suction tube  13  is carried out (step S 4 ).  FIG. 18  is a front view of the vertical driving unit  20  and the horizontal driving unit  20  showing positional relationship between the suction tube  13  and the washing unit CS when the suction tube  13  is at the initial position. As illustrated, when the suction tube  13  is at the initial position, the suction tube retaining part  43  is located in proximity to the washing unit CS, and the washing unit CS will be located around upper end of the suction tube  13 . Specifically, step S 4  means that the suction tube  13  is in such initial state, and the first drainage chamber WC 1  is put into negative pressure state by closing valve SV 15  and valve SV 23 , and opening valve SV 14 . Following this, the suction tube  13  is moved up, and valve SV 11  and valve SV 51  are opened, and outer circumference of the suction tube  13  is washed simultaneously with moving-up operation of the suction tube  13 . In this instance, a washing solution is supplied from the supplying path  16  of the washing unit CS to inside of the penetrating path  15  and at the same time, the washing solution and sample (specimen) in the penetrating path  15  are discharged from the drainage path  17  by negative pressure. For the suction tube  13 , by this moving-up operation, front edge of the suction tube  13  (suction port) is moved up to a position located inside the washing unit CS (hereinafter referred to as the upper limit position). As mentioned, washing of the suction tube  13  by the washing unit CS is carried out while the suction tube  13  is being moved from the initial position to the upper limit position, and therefore, the suction tube can be washed along with substantially total length thereof.  
      The suction tube  13  is then lowered to the second mixing chamber MC 2  (step S 5 ).  FIG. 19  is a side sectional view showing state where the suction tube  13  is inserted into upper opening of the second mixing chamber MC 2 . As illustrated, an insertion port  80  for allowing insertion of the suction tube  13  is provided at upper part of the first mixing chamber MC 2 . This insertion port  80  has a size to permit insertion of insomuch as the suction tube  13  and should be made small as much as possible to prevent entry of foreign matters or the like. Accordingly, the insertion port  80  has a circular form slightly greater than outside diameter of the suction tube  13 . In step S 5 , the suction tube  13  is positioned at upper portion of the insertion port  80  and the suction tube  13  is lowered from this position and then, front edge of thesuction tube  13  reaches from the insertion port  80  till interior of the second mixing chamber MC 2 . In this instance, the suction tube  13  is in straight state since it is made of superelastic alloy, which ensures positive insertion of the suction tube  13  into the insertion port  80 . An insertion port is provided similarly to the first mixing chamber MC 1 , drainage chambers WC 1 -WC 3 , while explanation thereof is omitted here.  
      When the syringe pump SP 1  is driven while the suction tube  13  is being inserted into the suction port  80  as mentioned, whole blood sample (a part of sample sucked in step S 2 ) is discharged from suction port of the suction tube  13  to the second mixing chamber MC 2  (step S 6 ).  
      Upon completion of discharging, a staining fluid FFS is put into the second mixing chamber MC 2  (step S 7 ). Specifically, in step S 7 , by opening valve SV 22  and at the same time, closing valve SV 21  while staining fluid replenishment valve  40  is opened and staining fluid supply valve SV 41  is closed, diaphragm pump DP 5  for staining fluid supplying (diaphragm pump for FFS) is negative pressure driven, and staining fluid FFS is replenished to diaphragm pump DP 5  for FFS. Further, if the diaphragm pump DP 5  for FFS is positive pressure driven by closing valve SV 40  and opening valve SV 41 , and at the same time, by opening valve SV 21  and closing valve SV 22 , the staining fluid FFS is put into the second mixing chamber MC 2 .  
      Subsequently, hemolytic agent FFD is put into the second mixing chamber MC 2  (step S 8 ). Namely, the hemolytic agent FFD is put into the second mixing chamber MC 2  by closing valve SV 22 , valve SV 19 , by opening valve SV 21 , valve SV 20 , and by using the diaphragm pump DP 4  for FFD; and by preparing the whole blood sample through inflow stirring, a measurement sample, in which red blood cells are lysed and white blood cells are stained, is prepared in the second mixing chamber MC (step S 9 ).  
      Measurement (analysis) is then carried out by the WBC detection unit D 3  targeting the measurement sample (step S 10 ). Specifically, in step S 10 , a diaphragm pump DP 2  for charging is driven by opening valve SV 4 , valve SV 29 , valve SV 22 , and closing valve SV 21 , and measurement sample is charged accurately by a predetermined amount. Then valve SV 4 , valve SV 29 , valve SV 22  are closed to complete charging to the WBC detection unit D 3 . After that, by opening valve SV 9 , valve SV 31 , sheath liquid (diluting fluid) EPK is supplied from the EPK container EPK-C to the WBC detection unit. Subsequently, valve SV 3  is opened while valve SV 1  is closed, sample supply syringe pump SP 2  is driven, and measurement is taken in the WBC detection unit D 3 .  
      In above-mentioned measurement, the sample analyzer S prepares a measurement sample by mixing whole blood sample, hemolytic agent for white blood cell classification and staining fluid for white blood cell classification, and this measurement sample is measured by the optical detection unit D 3  by flow cytometry technique. Measurements here include measurement of white blood cell count and five classifications of white blood cells.  
      In addition, washing of interior of the suction tube  13  is performed (step S 11 ). Specifically, in step S 11 , the suction tube  13  is moved by operations of the horizontal driving unit  20  and vertical driving unit  30  and is lowered to the first mixing chamber MC 1 . Following this, by opening valve SV 22  and by closing valve SV 21  while valve SV 32  and valve SV 33  are being opened, the diaphragm pump DP 1  is negative pressure driven, and diluting fluid is replenished to the diaphragm pump DP 1 . Then, valve SV 22  is closed and valve SV 21 , valve SV 15 , valve SV 16  are opened, and after that, valve SV 15  is closed. By these manipulations, positive pressure is applied to the diaphragm pump DP 1 , and sample suction line (tube) and the suction tube  13  inside are then filled with washing solution. In this instance, surplus washing solution is discharged from suction port of the suction tube  13  to the first mixing chamber MC 1 . Interior of the suction tube  13  is thus washed. Drainaged is charged to the-first mixing chamber is drained to the drainage chamber WC 1  by opening valve SV 23 . At this time, inside of the suction tube  13  and sample supplying line are filled with the diluting fluid. It is then sucked by the syringe pump SP 1  under this state and an air gap is formed at front edge of the suction tube  13 . The suction tube  13  is then moved to the initial position by operations of the horizontal driving unit  20  and vertical driving unit  30  (step S 12 ).  
      As described in detail above, with the specimen analyzer S relating to the present embodiment, the suction tube  13  is made of superelastic alloy, and when the operator holds the blood-collection tube  3  and locates it to blood-collection position, the suction tube  13  maybe deformed easilyby contacting inner wall of the blood-collection tube to the suction tube  13 , and therefore, the operator is able to check visually front edge of the suction tube with ease. Accordingly, even if the suction tube  13  is subjected to an external force, the suction tube  13  made of superelastic alloy returns immediately to its original straight profile, if the external force is removed. Therefore, when the suction tube  13  advances through the penetrating path  15  of the washing unit CS, the suction tube  13  is in straight state, and is able to advance smoothly in the washing unit CS, thereby ensuring washing of the suction tube  13 . Besides, it is possible to insert the suction tube  13  surely into the first mixing chamber MC 1 , second mixing chamber MC 2  or an opening at upper part of the drainage chambers WC 1 -WC 3 . Further, since the suction tube is made of superelastic alloy, there is no opportunity to become swollen by absorbing moisture as frequently experienced with synthetic resin or the like, thereby securing higher accuracy of quantitative determination.  
      In the present embodiment, such a composition is explained above that the washing unit CS is fixed to the horizontal driving unit  20  and the suction tube  13  is driven by the vertical driving unit  20 , and outer circumference of the suction tube  13  is washed by the washing unit CS while the suction tube  13  is being moved up. However, the composition is not limited to this, and the washing unit CS may be moved up and down while the suction tube  13  is fixed, or both the suction tube  13  and the washing unit CS may be moved up and down. Alternatively, such a composition that the suction tube  13  is washed by the washing unit CS while the suction tube  13  is being lowered may be used.  
      In addition, such a composition is used that interior of the suction tube  13  is washed and at the same time, washing solution is filled to the interior of the suction tube  13 , by supplying washing solution to interior of the suction tube  13 , and therefore, it is not only possible to wash interior as well as outer circumference of the suction tube  13 , but also to execute quantitative determination of a specimen with higher accuracy by filling the suction tube  13  with washing solution.  
      Further, since such a composition is provided that the washing unit CS is fixed to the horizontal driving unit  20 , and the washing unit CS is moved horizontally together with the suction tube  13  in integrated fashion, while the suction tube  13  is being penetrated through the washing unit CS, when the suction tube  13  is to be washed, there is no need for accurate positioning so that the suction tube  13  is inserted into the penetrating path  15  of the washing unit CS.  
      Besides, the start switch  6 , which receives specimen suction start instruction from the operator, is disposed in the vicinity of the suction tube  13 , and therefore, when the operator moves the blood-collection tube  3  to the position where the suction tube  13  is inserted into the blood-collection tube  3  (suction position), the operator is able to manipulate the start switch with the hand holding the blood-collection tube  3 , and the operator is able to set the blood-collection tube to the suction position and to give suction start instruction easily and consecutively, thereby providing operability convenient to the operator.  
      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.