JPH0623766B2 - Automatic analyzer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic analyzer, and more particularly to a biochemical automatic analyzer for clinical examination capable of stabilizing analysis performance and increasing reliability.

[Conventional technology]

In a biochemical automatic analyzer for clinical examination, it is essential to stabilize the reaction liquid during analysis at a constant temperature, for example, 37 ± 0.05 ° C, in order to stabilize analysis accuracy and increase reliability. It is a condition. On the other hand, in order to maintain the activity of the reagent that mixes the sample and causes the color reaction, it is necessary to keep the reagent at a low temperature of approximately 15 ° C. or lower, and the temperature around the device is, for example, 15 to 35 ° C. In order to satisfy both requirements under uncertain conditions, the conventional device is disclosed in Japanese Patent Laid-Open No. 59-
As described in Japanese Patent No. 230162, it was configured as follows. Normally, in order to control the temperature of the controlled object with high accuracy even if the ambient temperature is indefinite, both the cooling part and the heating part are provided, and the temperature of the object is controlled by the temperature sensor provided in the control system. Then, the cooling section or the heating section is controlled by the deviation between the control point and the temperature detected by the sensor, and in this case, it is usually difficult to control the cooling section accurately. The heating unit is controlled as a continuous operation. Even in the above-mentioned conventional apparatus, a compression refrigerator is used as the cooling unit, cold water is made as the cold water tank by using the evaporator part in the heat cycle, and the cold water is circulated between the reagent storage part with the pop. , Keeps the reagent contained in the reagent reservoir cool. On the other hand, a constant temperature bath is provided adjacent to the cold water bath, and this constant temperature bath is connected to the cold water bath described above through pores to use cold water as a cooling source. A temperature sensor is provided, the heater is controlled by the deviation between the output of this temperature sensor and the control point to control the water in the constant temperature tank to a predetermined temperature, and this constant temperature water is circulated between it and the reaction tank with a pump. The temperature of the reaction tank was kept constant.

[Problems to be solved by the invention]

In the above-mentioned conventional technology, the temperature of the circulating water to the reaction tank is controlled in the constant temperature tank instead of directly controlling the temperature of the droplet in the reaction tank, and the temperature of the reaction tank and the reaction tank are controlled by this constant temperature water. Since the temperature of the reaction liquid in the immersed reaction cell is maintained, the temperature of the reaction tank located away from the constant temperature tank can be controlled even if the temperature inside the constant temperature tank is controlled with high accuracy and stability. In order to keep the target temperature stable by circulating constant temperature water, the circulation path of constant temperature water from the constant temperature tank to the reaction tank and the reaction tank are strictly insulated so that the temperature around the equipment is not affected. In addition, even if the heat insulation is adequate and the circulating water flowing into the reaction tank is accurately controlled to the target temperature, reagents and washing water injected into the reaction cell from the outside and the circulating water in the reaction tank are required. If there is a temperature difference between the two and heat exchange between them, the water in the reaction tank Once again there is a problem that is affecting these deviates from the target temperature. Further, in order to prevent this, it may be considered to heat the reagent to the target temperature before injecting it into the reaction cell, but this makes the structure complicated and cannot be put to practical use.

An object of the present invention is to provide an automatic analyzer which has a simple structure and which can prevent the target temperature of the reaction tank from changing due to cold reagents or washing water injected into the reaction cell.

[Means for solving problems]

The configuration of the present invention taken to achieve the above object forms a transfer path in which a plurality of reaction vessels that receive a sample and a reagent cooled to a temperature lower than the constant temperature liquid are transferred while being immersed in the constant temperature liquid. In an automatic analyzer equipped with a reaction tank and a circulation system in which a constant temperature liquid that has exited the temperature control tank is circulated so as to return to the temperature control tank through the reaction tank and a cooling unit, the temperature control tank is heated. Means and the first temperature detecting means are arranged in proximity to each other, and second temperature detecting means for detecting the temperature of the constant temperature liquid in the reaction tank is provided in the reaction tank,
The operation of the heating means is controlled so as to reduce the difference between the temperature (T _p ) detected by the first temperature detection means and the set temperature (T _c ) for the temperature control tank, and the second temperature is controlled. The temperature (T
_o ) and a preset target temperature (T _i , for example 37 ± 0, 05), when the difference occurs, the set temperature (T _c ) is changed according to the magnitude of the difference. It is characterized in that a control means is provided.

[Action]

In the above-described automatic analyzer of the present invention, the second temperature detecting means (hereinafter referred to as the second temperature sensor) provided in the reaction tank directly detects the reaction tank temperature, and when this temperature deviates from the target temperature, Is the resetting of the control temperature of the circulating constant temperature water in the temperature control cylinder in which the heater as the heating means and the first temperature detecting means (hereinafter referred to as the first temperature sensor) are provided close to each other. However, the temperature is constantly controlled so that the reaction tank temperature does not deviate from the target temperature even if a reagent or washing water is injected into the reaction cell or other disturbances occur. As a result, the reactor temperature is always controlled to the target temperature. In addition, since the heater and the first temperature sensor are provided adjacent to each other, the response is fast, and a part of the circulating constant temperature water controlled to a constant temperature by the temperature control tube is returned to the circulation pump suction port sufficiently. Since the stirring is performed in the temperature control cylinder, the circulating constant temperature water flowing into the reaction tank has significantly less temperature pulsation, and the reaction tank temperature accurately matches the target temperature and is stably maintained.

〔Example〕

The present invention will be described in detail below with reference to the embodiments shown in FIGS.

FIG. 1 is a block diagram showing an embodiment of the automatic analyzer of the present invention. In FIG. 1, 1 is, for example, Freon R-1.
A compression type refrigerator using 2 as a refrigerant, including a compressor 2, a condenser 3,
The expansion valve 4, the evaporator 5 and the like are connected as shown. Reference numeral 6 denotes a cold water tank, which is provided with an evaporator of the compression refrigerator 1, a cooling pipe 7 for cooling the circulating water of the reaction tank, a take-out port 8 and a return port 9 of the circulating cold water to the formula chemical cooler 14. The outer circumference is covered with a heat insulating material 10, and the upper part is covered with a heat-insulating lid 11. The water 12 contained in the cold water tank 6 is cooled by the vaporization of the refrigerant of the compression refrigerator 1 in the evaporator 5 to become cold water. 13 is cold water 12, cold water tank 6 and reagent cooler 14
It is a cold water circulation pump for circulating between and, and its discharge port is connected to an inflow port 15 provided on the lower surface of the reagent cooler 14. On the other hand, an outlet 16 is provided in the upper part of the reagent cooler 14 and is connected to the return port 9 of the cold water tank 6. The outer periphery of the reagent cooler 14 is also insulated with a heat insulating material 17, a reagent container 18 is accommodated therein, and a lid 19 which is detachably insulated is prepared on the upper portion thereof. Further, the outlet 20 of the cold water tank 6 and the suction port of the cold water circulation pump 13 are insulated from each other by the pipe 20, and the discharge port of the cold water circulation pump 13 and the reagent cooler 1
The inflow port 15 of No. 4 is insulated by a pipe 21, and the outflow port 16 of the reagent cooler 14 and the return port 9 of the cold water tank 6 are connected by an insulated pipe 22.

On the other hand, the structure of the reaction tank side will be described. 23 is a reaction tank circulation pump, 24 is a tubular temperature control tube, and a pipe connection port 25,
26 and 27 are provided, and a rod-shaped heater 28,
For example, a first control temperature sensor 29 using platinum as a temperature detecting material is sealed inside and installed in close proximity thereto. Reference numeral 30 denotes an annular reaction tank having a U-shaped cross section with an open upper part, and an inflow pipe port 31 and an outflow pipe port 32 for circulating constant temperature water are provided on the lower bottom surface part thereof.
A second control temperature sensor 34 similar to the control temperature sensor 29 described above for detecting the water temperature of the circulating constant temperature water 33 in the reaction tank 30 is provided so as to be immersed in the circulating constant temperature water 33. Reference numeral 35 denotes, for example, a prismatic reaction cell made of a material such as glass which is transparent and has good optical characteristics and good thermal conductivity, into which the sample and the reagent are respectively injected and mixed. A plurality of reaction cells 35 are held by a reaction disk 36, and the lower part thereof is immersed in the circulating constant temperature water 33 in the reaction tank 29 to bring the reaction liquid in which the sample and the reagent are mixed by the circulating constant temperature water 33 to a predetermined reaction temperature. Hold. The reaction disk 36 is provided with a predetermined intermittent rotation operation around a photometer (not shown) also by a drive mechanism (not shown) to measure the reaction of the reaction liquid in the reaction cell 35 in time series. The reaction solution for which the measurement has been completed is discarded, and the reaction cell 35 is washed with a washing device (not shown) and used for re-measurement. With the above configuration, the discharge port of the reaction tank circulation pump 23 is the pipe connection port 25 at the lower part of the temperature control tube 24 and the pipe connection port 27 at the upper part of the temperature control tube 24.
Is the inflow pipe port 31 of the reaction tank 30, the outflow pipe port 32 of the reaction tank 30 is the cooling pipe 7 of the cold water tank 6, and the outlet of the cooling pipe 7 is the suction port of the reaction tank circulation pump 23 via the three-way connecting pipe 41. Further, the central pipe connection port 26 of the temperature control tube 24 is connected to the suction port of the reaction tank circulation pump 23 via the three-way connection pipe 41 by the pipes 37, 38, 39, 40 and 42, respectively. Reference numerals 43 and 44 denote amplifiers for converting and amplifying the outputs of the control temperature sensors 29 and 34, respectively, to voltages, 45 and 46 are A / D converters, 47 is a control unit of the present temperature control device including a μ-computer system, and 48 Is a DC power supply, 49 is an AC power supply applied to the heater 28, 50 is a connection of the application of the AC power supply 49 to the heater 28 in response to a signal from the control unit 47,
It is a solid state relay (hereinafter abbreviated as SSR) that disconnects.

In the apparatus having the above configuration, when the refrigerant that has flowed out of the expansion valve 4 is vaporized in the evaporator 5 by the heat pump operation of the compression refrigerator 1, the heat of vaporization from the water 12 in the cold water tank 6 is absorbed, The water 12 in the water tank 6 is cooled. Although not shown, the operation of the compression refrigerator 1 is controlled by detecting the temperature of the cold water 12. The cold water 12 is circulated to the reagent cooler 14 by the cold water circulation pump 13 to keep the reagent cooler 14 at about 15 ° C.
The reagent container 18 therein is kept cold by maintaining the following low temperature. On the other hand, the constant temperature water 33 circulating through the reaction tank 30 flows out of the reaction tank 30 and flows through the pipe 39 through the cooling pipe 7 of the cold water tank 6 so that the constant temperature water 33 is cooled by the cold water 12 around the cooling pipe 7 and the reaction tank circulation pump 23. Is sent to the temperature control tube 24.
A temperature control cylinder within 24 temperature T _p of the circulating constant-temperature water 33 in the cylinder is detected by the control temperature sensor 29, an amplifier 43, amplified, to the A / D converted control unit 47 by the A / D converter 45 If the temperature is transmitted and the temperature is lower than the preset control temperature T _c , the SSR 50 is turned on and the heater 28 heats it, and if it is higher, the heater 28 is turned off.
ON-OFF control is performed at the control temperature _Tc so that the temperature remains unchanged. The circulating constant temperature water controlled to have a constant temperature in this way is sent to the reaction tank 30 while returning a part to the inlet of the reaction tank circulation pump 23 at the outlet of the temperature control tube 24, and the reaction liquid in the reaction cell 35 in the tank is removed. Maintain the target temperature. Here the temperature T _o of the circulating constant-temperature water 33 in the reaction vessel 30 is detected by the second temperature sensor 34, amplified, and sent to A / D conversion to the control unit 47,
It is compared with the target temperature T _i given to the control unit 47 in advance, and if there is a difference, the control temperature T _c in the temperature control cylinder 24 is changed and reset in the control unit 47 so as to eliminate the difference. It The temperature control process of this control unit 47 is shown in FIG. In FIG. 2, the detection of the temperature T _p of the circulating constant temperature water 33 in the temperature control cylinder 24 in the alternate long and short dash line and the O of the heater 28 are detected.
N / OFF is processed in an extremely short cycle in order to reduce the temperature pulsation of the circulating constant temperature water 33, but the control temperature T _c can be changed or reset by the temperature T of the circulating constant temperature water 33 in the reaction tank 30.
_It is necessary to consider the delay time N _L until _o stabilizes.

As is clear from the above description of the temperature control operation of the control unit 47, the circulating constant temperature water 33 in the reaction tank 30 due to the temperature change around the apparatus or continuous injection of cold reagent or washing water into the reaction cell 35 is performed. even if the temperature T _o is deviation occurs with respect to the target temperature T _i, the temperature control cylinder in a direction for eliminating the deviation 24
Since the control temperature T _{c in} the reaction cell is always managed by the control unit 47, the reaction liquid in the reaction cell 35 is always maintained accurately and stably at a predetermined reaction target temperature.

Further, the flow velocity of the circulating constant temperature water 33 in the reaction tank 30 gives noise to the photometer, and therefore its upper limit value is determined. However, the temperature pulsation of the circulating constant temperature water 33 can be improved by improving the flow velocity around the heater 28 in the temperature control cylinder 24, that is, improving the thermal conductivity and sufficiently stirring the flow path. Significantly reduced. According to this embodiment, the temperature control tube 2
4, a part of the circulating constant temperature water 33 leaving
Since it is returned to the suction side of the circulating constant temperature water 33, even if the flow rate of the circulating constant temperature water 33 in the reaction tank 30 is controlled to be small, the flow rate in the temperature control tube 24 is increased and the circulating constant temperature water 33 is stirred. In addition, since the heater 28 and the temperature sensor 29 are arranged very close to each other, the temperature pulsation of the circulating constant temperature water 33 can be reduced.

Further, although the temperature control cylinder 24, the reaction tank 30 and the pipes 38, 39, 40, 42, etc. connecting them are not particularly concerned with heat insulation in the above description, in this case as well, the circulating constant temperature water 33 in the reaction tank 30 is used. Accuracy and stability are minimally affected by the temperature.

As described above, according to the embodiment of the present invention, in the cold water tank 6 for keeping the reagent cold, the circulating constant temperature water 33 to the reaction tank 30 is cooled through the cooling pipe 7 to cool the reaction tank circulation pump 23. The heater 28 and the control temperature sensor 29 are sent to the temperature control tube 24 in which the circulating constant temperature water 33 whose temperature is controlled by the ON / OFF operation of the heater 28 is supplied to the reaction tank 30 and a part thereof is reacted. By returning to the inlet of the tank circulation pump 23, while increasing the thermal conductivity in the heater part,
Sufficient stirring is given to the circulating constant temperature water 33 to make the temperature pulsation in the temperature control extremely small, and further, the temperature of the circulating constant temperature water 33 in the reaction tank 30 is detected by the control temperature sensor 34 to obtain the target reaction temperature. Since the deviation is eliminated by resetting the control temperature in the temperature control tube 24, the temperature of the reaction tank, that is, the temperature of the reaction solution in the reaction cell 35 is accurately and stably set to the target reaction temperature. It can be controlled, the analysis accuracy is improved, the stability is improved, the reliability is increased, and an extremely large effect is obtained.

In the above description, the temperature control operation is processed by the microcomputer system, but the temperature control operation may be processed by an electronic circuit composed of a multiplexer, a comparator including an operational amplifier, or the like, and the same effect can be expected.

Further, the cold water tank 6 for cooling the reagent is used as the cooling means for the circulating constant temperature water 33 to the reaction tank 30, but it goes without saying that this may be a single cooling device.

〔The invention's effect〕

As described above, according to the present invention, the temperature of the circulating constant temperature water in the reaction tank can be stably maintained at the target reaction temperature with high accuracy, and the analysis accuracy and reliability can be improved. There is an effect.

[Brief description of drawings]

FIG. 1 is a block diagram of a reaction tank temperature control device of one embodiment of the automatic analyzer of the present invention, and FIG. 2 is a flow chart showing one embodiment of the operation of the control unit of FIG. 6 ... Cold water tank, 7 ... Cooling pipe, 23 ... Reaction tank circulation pump, 24 ... Temperature control tube, 28 ... Heater, 29 ... First control temperature sensor, 30 ... Reaction tank, 33 ... Circulating constant temperature water, 34 ... second control temperature sensor, 35 ... reaction cell, 37, 38, 39, 40, 42 ... piping, 47
...... Control unit, 50 ...... Solid state relay.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-132566 (JP, A) JP-A-61-219865 (JP, A) Practical application Sho-60-176172 (JP, U)

Claims (1)

[Claims] 1. A reaction vessel that forms a transfer path for transferring a plurality of reaction vessels that receive a sample and a reagent cooled to a temperature lower than that of a constant temperature liquid while being immersed in the constant temperature liquid, and a constant temperature that leaves the temperature control tank. In an automatic analyzer equipped with a circulation system in which a liquid is circulated so as to return to the temperature control tank through the reaction tank and the cooling unit, a heating means and a first device are provided in the temperature control tank.
Second temperature detecting means for detecting the temperature of the constant temperature liquid in the reaction tank is provided in the reaction tank, and is detected by the first temperature detecting means. The operation of the heating means is controlled so as to reduce the difference between the predetermined temperature and the set temperature for the temperature control tank, and the temperature detected by the second temperature detection means and the target temperature given in advance. An automatic analyzer characterized by comprising control means for changing the set temperature according to the magnitude of the difference when the difference occurs.