Patent Publication Number: US-2013243657-A1

Title: Automatic analyzing apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to an automatic analyzing apparatus which automatically analyzes a biological sample component such as blood, and in particular to a temperature adjusting mechanism of a measuring unit using an LED (Light-Emitting Diode) as a light source. 
     BACKGROUND ART 
     In recent years, the technological developments have increased the light intensity of LEDs (Light-Emitting Diodes) and have expanded the wavelength variations thereof. Furthermore, by making use of advantages such as high energy efficiency for light emission and small size, the range of application thereof has been expanded in various industrial fields. 
     Also in the field of automatic analyzing apparatus for clinical laboratory tests, demands for energy and space savings and cost reduction of the apparatus are high, and as one of the means for responding to these, the apparatus using an LED as a light source has been increasing. 
     When an LED is used as a light source, it is the stabilization of the light intensity that becomes a problem. It is generally known that the LED gives off heat from itself when it is energized and the light intensity and wavelength thereof are changed when temperature of a P/N junction is changed. 
     An automatic analyzing apparatus measures a concentration of a blood sample by irradiating a sample to be measured with light to measure a change in light intensity. Therefore, stabilization of the light intensity as a base value is essential. Also, from the demands of the market, it is desired that the start-up time of the apparatus is more reduced, and the light intensity is required to be stabilized in a shorter time. 
     When an LED is used as a measurement light source of an automatic analyzing apparatus, for example, Patent Document 1 suggests to perform the temperature control by mounting the LED on a member with a large heat capacity in order to obtain a stable light intensity. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     Japanese Patent Application Laid-Open Publication No. 2004-101295 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     Incidentally, when the junction temperature of the LED increases, the light emission amount thereof tends to decrease. Since the decrease in light intensity in a measurement system using light leads to the decrease in detection sensitivity, when the LED is used as a light source of an automatic analyzing apparatus for clinical laboratory test, heat generated in the ED is required to be efficiently removed. Also, the fluctuation of the LED light intensity due to temperature change has to be prevented. Furthermore, it is also necessary to achieve a stable state at a target temperature in a shorter time. 
     Heat of the LED is generated at a P/N junction, and is propagated by thermal conduction to either one of two leads that is connected to a light-emission lead. Therefore, by cooling down the lead to which heat is transmitted and stabilizing its temperature, the temperature of the P/N junction is stabilized to be low, so that the decrease in the light intensity is suppressed and the stable measurement can be achieved. 
     However, a lead has a cross section of about  0 . 5  mm to  1  mm square and is extremely thin in general, and a metal member with high thermal conductivity is required to be brought into contact with the lead in order to absorb heat by thermal conduction. On the other hand, a current which makes the LED emit light flows through a lead wire, and the lead wire is required to be electrically insulated. Thus, an insulating sheet is required to be provided between the lead and the metal member. Since a material with low electric conductivity generally has a low thermal conductivity, if an insulating sheet is provided between the lead and the metal member, the heat absorption amount from the LED is significantly decreased, and as a result, the temperature cannot be sufficiently adjusted and stabilization of the light intensity of the LED cannot be expected. 
     An object of the present invention is to provide an automatic analyzing apparatus capable of making an adjustment to a target temperature so as to stabilize the light intensity of an LED and also capable of making the adjustment to that temperature in a short time. 
     The above and other objects and novel characteristics of the present invention will be apparent from the description of the present specification and the accompanying drawings. 
     Means for Solving the Problems 
     The following is a brief description of an outline of the typical invention disclosed in the present application. 
     More specifically, an automatic analyzing apparatus according to the present invention is an automatic analyzing apparatus including: a light-emitting diode light source; and a temperature adjusting mechanism for the light-emitting diode light source, and the temperature adjusting mechanism is made up of a metal member provided with the light-emitting diode light source; a water-flowing pipe buried in the metal member and allowing constant-temperature bath water to flow therein; and a small metal piece member bringing only a heat-generating lead of the light-emitting diode light source into direct contact with the metal member. 
     Effects of the Invention 
     The effects obtained by typical embodiments of the invention disclosed in the present application will be briefly described below. 
     According to the present invention, in the automatic analyzing apparatus, since only the lead of the LED from which heat is generated is brought into direct contact with the metal member of the temperature adjusting mechanism, cooling is carried out by transmitting heat of the constant-temperature bath water only to the lead, which is a part required for temperature adjustment of the LED, from the metal member in a short time. In other words, the temperature adjusting mechanism can make an adjustment to a target temperature so as to stabilize the light intensity of the LED, and the adjustment to that temperature can be made in a short time. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIG. 1  is a schematic configuration diagram of an automatic analyzing apparatus of the present invention; 
         FIG. 2A  is a plan view of a temperature adjusting mechanism of the present invention provided with pins; 
         FIG. 2B  is a sectional view of the temperature adjusting mechanism taken along an A-A line of  FIG. 2A ; 
         FIG. 2C  is a bottom view of the temperature adjusting mechanism; 
         FIG. 3A  is a plan view of a temperature adjusting mechanism of an invention other than the present invention provided with a thermally conductive sheet; 
         FIG. 3B  is a sectional view of the temperature adjusting mechanism taken along an A-A line of  FIG. 3A ; 
         FIG. 3C  is a bottom view of the temperature adjusting mechanism; 
         FIG. 4A  is a plan view of a temperature adjusting mechanism of the present invention provided with pins and an insulating member; 
         FIG. 4B  is a sectional view of the temperature adjusting mechanism taken along an A-A line of  FIG. 4A ; 
         FIG. 4C  is a bottom view of the temperature adjusting mechanism; 
         FIG. 5A  is a plan view of a verification model in the temperature adjusting mechanism of  FIG. 3 ; 
         FIG. 5B  is a sectional view of the temperature adjusting mechanism taken along an A-A line of  FIG. 5A ; and 
         FIG. 5C  is a bottom view of the temperature adjusting mechanism. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted as much as possible. 
       FIG. 1  is a schematic configuration diagram of an automatic analyzing apparatus of the present invention. Note that, since the function of each unit of  FIG. 1  is publicly known, detailed descriptions thereof are omitted. 
     In the configuration of an automatic analyzing apparatus  1 , while moving vertically and rotating, a sampling arm  20  of a sampling mechanism  10  sucks a test sample in a sample container  101  placed on a sample disk  102  rotating laterally by using a sample dispensing probe  105  attached to the sampling arm  20 , and discharges the test sample to a reaction container  106 . As can be seen from  FIG. 1 , the sample disk  102  has a structure which can be applied to a universal arrangement in which the sample container  101  can be directly disposed not only on the sample disk  102 , but also on a test tube (not shown) 
     The configuration of the automatic analyzing apparatus  1  in  FIG. 1  will be further described. The sample dispensing probe  105  performs operations of sucking and discharging a sample along with the operation of a sample syringe pump  107 . A reagent dispensing probe  110  performs operations of sucking and discharging a reagent along with the operation of a reagent syringe pump  111 . The sample syringe pump  107  and the reagent syringe pump  111  can perform a fine operation, and also can strictly manage the dispensing accuracy under the control of a computer  103 . 
     An analytical item to be analyzed for each sample is inputted from an input device such as a keyboard  121  or a screen of a CRT  118 . The operation of each unit in the automatic analyzing apparatus  1  is controlled by the computer  103 . 
     Along with the intermittent rotation of the sample disk  102 , the sample container  101  is transferred to a sample suction position, and the sample dispensing probe  105  descends into the sample container  101  at a stop. When the tip of the sample dispensing probe  105  is brought into contact with the liquid level of the sample as a result of the descending operation, a detection signal is outputted from a liquid level detection circuit  151 , and the computer  103  controls to stop the descending operation of a driving unit of the sampling arm  20  based on the signal, 
     Next, after a predetermined amount of the sample is sucked into the sample dispensing probe  105 , the sample dispensing probe  105  ascends to a top dead center. While the sample dispensing probe  105  is sucking a predetermined amount of the sample, the fluctuation in pressure in a flow path between the sample dispensing probe  105  and the sample syringe pump  107  during the sucking operation is monitored by a pressure detection circuit  153  by using a signal from a pressure sensor  152 , if an anomaly is detected in the pressure fluctuation during the suction, there is a high possibility that a predetermined amount has not been sucked, and therefore an alarm is provided to analytical data in that case. 
     Next, the sampling arm  20  turns around in a horizontal direction, causes the sample dispensing probe  105  to descend at the position of the reaction container  106  on a reaction disk  109 , and then discharges the retained sample into the reaction container  106 . Next, the reaction container  106  containing the sample is moved to a reagent addition position. On a rotatable reagent disk  125 , reagent bottles  112  corresponding to a plurality of analytic items to be analyzed are disposed. The reagent dispensing probe  110  attached to the sampling arm  20  dispenses a predetermined amount of the reagent from the reagent bottle  112  to the reaction container  106  A mixture in the reaction container  106  having the sample and the reagent added thereto is agitated by an agitator  113 . 
     The reaction container  106  having the mixture accommodated therein is transferred to a position between a light source  114  and a photometer  115  serving as measuring means, and the light intensity is measured by the photometer  115  based on irradiated light from the light source  114  to the reaction container  106 , A light measurement signal is outputted for print through an A/D converter  116  and via an interface  104  to a printer  117 , or is outputted onto the screen of the CRT  118  and stored in a hard disk  122  serving as a memory. The reaction container  106  for which light measurement has been completed is cleaned at the position of a cleaning mechanism  119 . A cleaning pump  120  supplies washing water to the reaction container  106  and discharges waste liquid from the reaction container  106 . In the example of  FIG. 1 , a plurality of rows of container holders are formed on the sample disk  102  so that a plurality of rows of sample containers  101  can be concentrically set, and one position for sample suction by the sample dispensing probe  105  is set for each row. 
     As the light source  114 , an LED (Light-Emitting Diode) light source is used. Also, in order to stabilize the changes in the light intensity of the LED due to the temperature and enable the measurement with high reproducibility, a temperature adjusting mechanism for the LED is provided.  FIG. 2A  is a plan view of a temperature adjusting mechanism of the present invention provided with pins,  FIG. 2B  is a sectional view thereof taken along an A-A line of  FIG. 2A , and  FIG. 2C  is a bottom view thereof, Note that, for convenience of understanding, a constant-temperature bath is also shown in each sectional view of  FIG. 2  and subsequent figures. 
     As shown in  FIG. 2A  to  FIG. 2C , a temperature adjusting mechanism  201  mainly includes a metal member  202 , a pair of metal pipes (water-flowing pipes)  203 , and a pair of metal pins (small metal piece members)  204 . 
     The entire metal member  202  is covered with a heat insulator  205 . In the metal member  202 , a portion of the metal pipe  203  bent in a U shape is buried, and water from a constant-temperature bath  206  (constant-temperature bath water) flows into this metal pipe  203  to adjust the metal member  202  to a target temperature, As a material of the metal member  202 , for example, copper, iron, or the like is preferable because of high thermal conductivity. 
     The light source  114  is made up of a light-emitting unit  251  and leads  252  and  253  extending from the light-emitting unit  251 , In the example of  FIG. 2 , only the leads  252  and  253  are buried in the metal member  202 , However, the light-emitting unit  251  may also be buried in the metal member  202 . Since the LED has a structure in which either (me of the leads is connected to a light-emitting lead, only the one lead generates heat at the time of light emission. In the example of  FIG. 2 , the lead  252  generates heat, but the lead  253  does not generate heat. As shown in  FIG. 2B  and  FIG. 2C , of these leads  252  and  253 , only the heat-generating lead  252  abuts on the tips of the pins  204  of the temperature adjusting mechanism  201 , and is pushed by these pins  204  to be brought into direct contact with the metal member  202 . 
     More specifically, as particularly shown in  FIG. 2B , the metal member  202  has a gap  202   a  formed at a portion where the heat-generating lead  252  is buried. Also, a pair of through holes  202   b  each of which accommodates the pin  204  so that its main body  204   a  can project from and retract into the through hole is formed between the edge of the metal member  202  and the gap  202   a,  Thus, when the pin main bodies  204   a  projecting into the gap  202   a  abut on the lead  252 , the lead  252  is pushed onto a wall part of the metal member on a back side of the gap  202   a  (in an arrow direction in the drawing) to be brought into contact with the metal member  202 . 
     On the other hand, the non-heat-generating lead  253  is covered with a heat insulator (insulating member)  254  with insulating properties so as not to be influenced by the temperature change of the metal member  202 , Note that preferable materials of the pins  204  are similar to those of the metal member  202 . 
     With the structure described above, thermal resistance between the metal member  202  and the lead  252  is nearly eliminated, and therefore heat is transferred to the lead  252  in approximately the same time as the time in which heat of constant-temperature water is transferred to the metal member  202 . A contact surface between the metal member  202  and the metal pipes  203  is taken as widely as possible, whereby heat transfer efficiency is further improved, and as a result, the temperature can be adjusted to the target temperature in a short time. 
       FIG. 3A  is a plan view of a temperature adjusting mechanism of the invention other than the present invention provided with a thermally conductive sheet,  FIG. 3B  is a sectional view thereof taken along an A-A line of  FIG. 3A , and  FIG. 3C  is a bottom view thereof. A temperature adjusting mechanism  301  shown in  FIG. 3  is substantially different from the temperature adjusting mechanism  201  of the present invention in that no pin is provided. In the temperature adjusting mechanism  301 , the leads  252  and  253  are covered with a thermally conductive sheet  260  capable of transmitting heat of the metal member  202  and made of a soft insulating material in order to improve adhesiveness of the leads  252  and  253  to the metal member  202 . As shown in  FIG. 3C , the lead  252  is in indirect contact with the metal member  202  via the thermally conductive sheet  260 . 
     In this case, heat of constant-temperature water is transmitted to the metal member  202  in a short time, but a thermal conductivity of the thermally conductive sheet  260  described above is about 1/4000 to 1/6000 compared with that of a metal, and therefore thermal resistance is high after all. Moreover, since lead dimensions of a general LED are such that the cross-sectional area is about 0.5 mm and the length is about 20 mm, the heat transfer area is extremely small, and thermal conduction efficiency is low. 
     In other words, in the present invention, since the pins  204  that bring only the heat-generating lead  252  into direct contact with the metal member  202  are provided in the temperature adjusting mechanism of the LED, heat of the metal member  202  can be transmitted only to the lead  252  in a short time, and temperature adjustment for cooling to the target temperature can be made in a short time. This is particularly advantageous in the measurement of scattered light, in which values tend to vary due to that the measurement is carried out only with absolute values, because it is possible to promptly achieve the state in which desired reproducibility is obtained. Also, since influences due to temperature change of the light source  114  can be further decreased by covering the non-heat-generating lead  253  with the heat insulator  254 , the light intensity of the LED can be further stabilized, and measurement with higher reproducibility can be made. 
       FIG. 4A  is a plan view of a temperature adjusting mechanism of the present invention provided with pins and an insulating member,  FIG. 4B  is a sectional view thereof taken along an A-A line of  FIG. 4A , and  FIG. 4C  is a bottom view thereof. A temperature adjusting mechanism  401  shown in  FIG. 4  is an example in which an LED light source having the heat-generating lead  252  whose electric potential is lower than that of the non-heat-generating lead  253  is used. 
     In the temperature adjusting mechanism  401 , a portion of each metal pipe  203  buried in the metal member  202  is covered with an insulating member  402  in order to electrically insulate the metal pipes  203  and the metal member  202 . As the insulating member  402 , for example, a material similar to that of the thermally conductive sheet  260  can be suitably used. Note that the configuration other than that is similar to that of the temperature adjusting mechanism  201 , 
     In this case, the insulating member  402  covering the metal pipes  203  serves as a heat resistance, but since a significantly wider heat transfer area can be taken compared with the case in which the thermally conductive sheet  260  is present between the leads  252  and  253  and the metal member  202  like in the temperature adjusting mechanism  301 , thermal conduction efficiency is extremely high. 
     Thus, also when an element like this is used, temperature adjustment can be efficiently made in a short time compared with the case in which temperature adjustment is made in the state where the leads  252  and  253  are covered with the thermally conductive sheet  260 . 
     In the foregoing, the invention made by the inventors of the present invention has been concretely described based on the embodiments, However, it is needless to say that the present invention is not limited to the foregoing embodiments and various modifications and alterations can be made within the scope of the present invention. 
     EXAMPLES 
     Thermal conduction efficiency of the temperature adjusting mechanism is modeled and verified. 
     (Verification 1) 
       FIG. 5A  is a plan view of a verification model in the temperature adjusting mechanism of  FIG. 3 ,  FIG. 5B  is a sectional view thereof taken along an A-A line of  FIG. 5A , and  FIG. 5C  is a bottom view thereof. 
     In the configuration of a temperature adjusting mechanism  501  of this verification model, in order to make conditions uniform with those of verification of the temperature adjusting mechanism  401  shown in  FIG. 4 , which will be described further below, the insulating member  402  is provided to the metal pipes  203  of the temperature adjusting mechanism  301  of  FIG. 3 . 
     The insulting member  402  is a thermally conductive sheet with a thermal conductivity of 0.8 W/m·K, and a thickness a thereof is 1 mm. The metal pipe  203  has a width b of 40 mm, a pipe diameter c of 4 mm, and a buried depth d into the metal member  202  of 20 mm. The thermally conductive sheet  260  is made of a material similar to that of the insulating member  402  and has a length e of 10 mm and a thickness f of 1 mm. Also, the leads  252  and  253  are formed to have a side g of 0.5 mm. As a temperature condition, the heat-generating lead  252  at 47° C. is assumed to be cooled down to 37° C. 
     The amount of thermal conduction per unit time (second) under the conditions described above is calculated by applying to the following equations. 
         Q  (heat quantity)=λ(thermal conductivity)× S  (thermally conductive area)×( T   1   ×T   2  (temperature change))/ h  (thickness)
 
       λ (thermal conductivity)=thermally conductive sheet 260=0.8  W/m·K  
 
         S  (thermally conductive area)=area in which the heat-generating lead 252 and the thermally conductive sheet 260 are in contact with each other=0.5 mm×10 mm× 2  (because upper and lower parts of the lead 252 are in contact with the thermally conductive sheet 260)=10  mm   2 =10×10 −6    m   2  
 
         T   1   −T   2  (temperature change)=47−37=10  K  
 
         h  (thickness)=thickness  f  of thermally conductive sheet 260 =1  mm= 1×10 −3    m  
 
     Accordingly, the thermal conduction efficiency in the configuration of  FIG. 5  is as follows. 
         Q= 0.8  W/m·K× 10×10 −6   m   2 ×10  K/ 1×10 −3    m= 8×10 −2    W/S = 0.08  J  
 
     (Verification 2) 
     Next, the temperature adjusting mechanism  401  of the present invention shown in  FIG. 4  is modeled and verified with the same dimensions a to d and g as those of the temperature adjusting mechanism  501  of  FIG. 5 . It goes without saying that, since the thermally conductive sheet  260  is not present in the temperature adjusting mechanism  401 , it is not necessary to take the dimensions e and f into consideration. 
     In the verification of this temperature adjusting mechanism  401 , since the lead  252  and the metal member  202  are both made of metal, it is assumed that no thermal resistance is present and heat exchange occurs between the metal pipe  203  and the metal member  202 . 
       λ (thermal conductivity)=thermally conductive sheet (insulating member) 402=0.8  W/m·K  
 
         S  (thermally conductive area)=4 (pipe diameter)×π×½ (½ of a pipe circumference)×36×π×½+2+2 (length of pipe center part is used for simplification)×2 (because upper and lower parts of the metal pipe 203 are in contact with the thermally conductive sheet 402)=760.13  mm   2 =760×10 −6    m   2  
 
         T   1   −T   2  (temperature change)−47 37=10  K  
 
         h  (thickness)=thickness  f  of the thermally conductive sheet 260=1  mm = 1×10 −3    m  
 
     Accordingly, thermal conduction efficiency in the configuration of  FIG. 5  is as follows. 
         Q= 0.8  W/m·K× 760×10 −6    m   2  ×10  K/ 1×10 −3    m= 6.08  W/S= 6.08  J  
 
     Although the verification described above is merely an example, while a thermal conductivity per second of the temperature adjusting mechanism  501  of  FIG. 5  which has a general configuration is 0.08 J, a thermal conductivity of the temperature adjusting mechanism  401  of  FIG. 4  of the present invention is 6.08 J. Thus, the thermal conduction efficiency of the temperature adjusting mechanism  401  is 76 times larger than that of the temperature adjusting mechanism  501 . Accordingly, it can be understood that, while the amount of thermal conduction is determined by the surface area of the thin lead  252  in the case of  FIG. 5 , since the lead  252  and the metal member  202  are pressed and brought into tight contact with each other to adjust the temperature of the metal member  202  in the case of 
       FIG. 4 , heat can be instantaneously transmitted to the lead  252 , In other words, in the temperature adjusting mechanism of the present invention, since it is possible to take a large contact surface between the water-flowing pipes and the metal member, the entire thermal conduction efficiency can be increased, and an adjustment to the target temperature can be made in a shorter time, 
     INDUSTRIAL APPLICABILITY 
     The present invention relates to an automatic analyzing apparatus which automatically analyzes a biological sample component such as blood, and can be widely applied to an apparatus or system having a temperature adjusting mechanism of a measuring unit using an LED (light-emitting diode) as a light source, 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           1  automatic analyzing apparatus 
           10  sampling mechanism 
           20  sampling arm 
           101  sample container 
           102  sample disk 
           103  computer 
           104  interface 
           105  sample dispensing probe 
           106  reaction container 
           107  sample syringe pump 
           109  reaction disk 
           110  reagent dispensing probe 
           111  reagent syringe pump 
           112  reagent bottle 
           113  agitator 
           114  light source (light emitting diode light source) 
           115  photometer 
           116  A/D converter 
           117  printer 
           118  CRT 
           119  cleaning mechanism 
           120  cleaning pump 
           121  keyboard 
           122  hard disk 
           125  reagent disk 
           151  liquid level detection circuit 
           152  pressure sensor 
           153  pressure detection circuit 
           201  temperature adjusting mechanism 
           202  metal member 
           202   a  gap 
           202   b  through hole 
           203  metal pipe (water-flowing pipe) 
           204  metal pin (small metal piece member) 
           204   a  pin main body 
           205  heat insulator 
           206  constant-temperature bath 
           251  light-emitting unit 
           252  heat-generating lead 
           253  non-heat-generating lead 
           254  heat insulator (insulating member) 
           260  thermally conductive sheet 
           301  temperature adjusting mechanism 
           401  temperature adjusting mechanism 
           402  insulating member 
           501  temperature adjusting mechanism