JPH0445784A - Apparatus for culture - Google Patents

Abstract

PURPOSE:To obtain the subject apparatus of a specific construction, designated to keep a material gas passage and a gas sensor at a high temperature than that in a culture chamber and capable of stably sensing a high gas concentration without growing various germs in the material gas passage. CONSTITUTION:An apparatus is obtained by providing gas sensors 13 and 14 in a material gas passage 10 for flowing a gas in a culture chamber 2 kept at a high humidity and simultaneously installing a heating means 31 and a control means 23 for controlling the gas concentration in the culture chamber. The heating means 31 is further controlled so as to keep the material as passage 10 and the gas sensors 13 and 14 at a high temperature than that in the culture chamber 2 with the control means 23. Thereby, an influence of the outside air temperature on the gas sensors 13 and 14 is eliminated to prevent moisture from condensing in the material gas passage 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a culture device for controlling an indoor gas environment and culturing cells and the like.

(B) Conventional technology Conventionally, this type of culture apparatus is used for culturing cell tissues such as cancer cells, as shown in Japanese Patent Application Laid-open No. 141279/1983.
Relatively high temperature indoors over +30”C and humidity 95%
The structure is such that the gas environment, such as carbon dioxide concentration and oxygen concentration, can be controlled in addition to the above-mentioned high temperature.

This gas concentration control is performed using a gas sensor that detects a predetermined gas concentration using infrared rays or changes in electrical conductivity. Output changes due to humidity. In particular, since the gas inside the culture chamber is at a high temperature, this effect is large.

Therefore, in the above-mentioned publication, the sample gas for detecting the concentration is cooled by a cooling device to a constant low temperature and dehumidified, and then sent to the gas sensor in a 100% constant temperature state.

Furthermore, when using an infrared sensor as a sensor, the amount of light that reaches the infrared detection element changes over time due to dirt in the optical path or deterioration of the light source itself. I was doing proofreading.

In FIG. 3, 100 is a data cell through which a data gas flows, 101 is a comparison cell filled with a comparison gas, 102 and 103 are an infrared light source, 104 is a chopper, and 105 is a detector, which outputs the infrared light transmitted through the comparison cell 101. Zero point calibration is performed periodically using

(c) Problems to be Solved by the Invention However, the configuration as disclosed in the above publication requires a cooling device, which increases the size of the entire device. Moreover, since the moisture in the sample gas is removed and discharged, the moisture in the culture chamber is wasted even if the sample gas is returned to the culture chamber.

Furthermore, the sensor is also affected by its own temperature. In particular, with infrared gas sensors, the amount of infrared rays emitted from the light source changes, so there is a problem in that the detection power changes when the outside temperature changes.

Furthermore, the zero point calibration method with the structure shown in FIG. 3 always requires two optical paths, making it expensive, and in reality, impurities also adhere to the outer surface of the comparison cell 101, so there is a problem that the zero point fluctuates. there were.

The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention provides a culture chamber maintained at high humidity, a material gas path for circulating gas in this culture chamber, a gas sensor provided in this material gas path, and a heating device. and a control means for controlling the gas concentration within the culture chamber, and the control means controls the heating means to maintain the material gas path and the gas sensor at a predetermined temperature higher than the temperature within the culture chamber. It is structured as follows.

Further, in the above culture apparatus, the sample gas introduced into the sample gas path is returned into the culture chamber.

Furthermore, in the above, an IHI type gas sensor is used as the gas sensor, and this infrared type gas sensor is provided with a filter that blocks transmission of wavelengths that are absorbed by humidity.

Further, in this culture apparatus, a means for circulating outside air is provided in the sample gas path where the gas sensor is located, and the control means uses this outside air to perform zero point calibration of the infrared gas sensor.

(E) Function According to the present invention, since the sensor is maintained at a constant temperature, stable concentration detection is possible without being affected by outside temperature. In addition, since moisture does not condense in the material gas path, bacteria do not grow.

Furthermore, since the water content of the sample gas is not removed, waste of gas and humidifying water can be prevented by returning the sample gas to the culture chamber.

Furthermore, if an infrared gas sensor is used as the sensor and a filter is provided to remove wavelengths that are absorbed by humidity, the detection power will not change even with changes in humidity.

Furthermore, if the zero point calibration is performed by circulating outside air through the sample gas path, two optical paths are not required for the zero point calibration.Example: The present invention will now be described in detail. FIG. 1 shows a configuration diagram of a culture apparatus 1 of the present invention. The inside of the culture chamber 2 of the culture device 1 is insulated with a heat insulating material 7, and a gas cylinder 3 filled with carbon dioxide and a gas cylinder 4 filled with nitrogen are routed through separate paths 5.
．． 6, each of which communicates with the culture chamber 2. A valve 8.9 consisting of a two-way valve is inserted in each path 5 and 6.

1O is a material gas path, which communicates the inlet 10a with the culture chamber 2, and includes an air pump 11, a filter 12 for removing dust from the circulating gas, a carbon dioxide gas concentration sensor 13, and an oxygen gas concentration sensor 14. The air pump 11 operates to suck the atmosphere in the culture chamber 2 as a sample gas from the inlet 10a, circulate it to each sensor 13 and 14, and then return it to the culture chamber 2 from the outlet 10b.

The carbon dioxide gas concentration sensor 13 is an infrared gas sensor as shown in an exploded view in FIG.

The sensor 13 includes a so-called modulation type pyroelectric infrared detector 15 developed in recent years, and a light source 16 such as a heater that generates far infrared rays. The infrared detector 15 houses an infrared detection part S in a shield box 17, and has a chopper C made of a slit member 19 driven by a piezoelectric bimorph vibrator 18 at a position corresponding to a through hole (not shown) formed in the shield box 17. A case 21 in which a through hole 20 is formed in a corresponding position.
The case 21 covers the entire body, and these parts are housed inside the case 21. The slit member 19 is constructed by attaching two plates with a slit formed thereon in an overlapping relationship, and opens and closes the slit by the piezoelectric bimorph vibrator 18 vibrating at the same frequency as the frequency of the drive voltage input to the chopper C. The infrared rays U entering through the through hole 20 and reaching the infrared detecting section S are intermittent, and an output corresponding to the amount of infrared rays is generated as an alternating current signal of the same frequency as the input frequency of the chipper C.

A sample gas is caused to flow between the light source 16 and the through hole 20 as indicated by the broken line arrow in FIG. 2, and the gas concentration is detected by utilizing the property that carbon dioxide in the sample gas absorbs infrared rays.

A sapphire glass 22 is fitted into the through hole 20, and a filter for removing wavelengths absorbed by humidity is coated thereon.

The oxygen gas concentration sensor 14 is a gas sensor that detects electrical conductivity, and the outputs of the sensors 13 and 14 are input to a control device 23 comprised of a microcomputer. The output of a sensor 24 that detects the temperature inside the culture chamber 2 is also input to the control device 23 .

Reference numeral 26 denotes an outside air path for introducing outside air, one end of which is open at an outside air introduction port 27, and the other end connected to the sample gas path 10 between the filter 12 and the carbon dioxide gas concentration sensor 13. An air pump 28 and a filter 29 are successively provided in the outside air path 26 , and the air pump 28 allows outside air (atmosphere) to flow through the sample gas path 10 .

The data gas path 10, the air pump 11, the filters 12 and 29, and the sensors 13 and 14 are housed in a heat insulating case 30 to be insulated from the outside air. A temperature sensor 32 for detection is provided, and the output of the sensor 32 is input to the control device 23.

34 is a heater for heating the inside of the culture chamber 2, and 35 is a container containing water for humidifying the culture chamber 2.

The control device 23 generates control outputs for the valves 8 and 9, controls the operation of the air pumps 11 and 28, and further controls conduction of the 5SRs 36 and 37 to control heat generation of the heaters 31 and 34.

Next, the operation of the control device 23 will be explained. Generally, in this type of seed culture device, the temperature in the culture chamber 2 is +30 to 40°C, the humidity is 95% or more, the carbon dioxide gas concentration is 5%, and the oxygen gas concentration is 5%.
There are many uses in %. In addition, nitrogen gas is used to control the oxygen gas concentration because the oxygen concentration in the atmosphere is approximately 2%, and when using it at 5%, it is necessary to lower the oxygen gas concentration in the culture chamber 2 with nitrogen gas. It is from.

Note that the carbon dioxide concentration in the atmosphere is about 0.03%, and for convenience of explanation, only the control of the carbon dioxide gas concentration will be described.

Based on the output of the sensor 24, the control device 23
7 to adjust the heat generation of the heater 34 to maintain the inside of the culture chamber 2 at a constant temperature of, for example, +37°C.

In addition, the pump 11 is operated to introduce the sample gas into the path 10 and let it flow through each sensor 13 and 14 to obtain outputs regarding carbon dioxide gas concentration and oxygen gas concentration from each sensor 13 and 14, and each valve 8 and 9 The gas environment inside the culture chamber 2 is adjusted by opening and closing.

Further, the control device 23 controls the 5 based on the output of the sensor 32.
By controlling SR3-6, the inside of the heat insulating case 30 is maintained at a constant temperature higher than the temperature inside the culture chamber 2. For example, if the culture chamber 2 is +37℃ as mentioned above, the insulation case 3
0 is maintained at +42°C. As a result, the temperature of the sample gas path 10 and the sensors 13 and 14 remains constant, so that the detection power does not change even with changes in outside air temperature. In addition, since the temperature of the path 10 is higher than that of the material gas, the moisture in the material gas does not condense within the path 10, so the inside of the path 10 is always kept dry, and bacteria do not propagate. , there is no possibility of detection errors caused by water droplets on the sensors 13 and 14. Furthermore, since this sample gas is returned to the culture chamber 2, water in the culture chamber 2 is not wasted.

Next, the control device 23 controls the air pump 1 once every 4 hours, for example.
There is no backflow of air when the air pump is stopped.

same as below. ), the air pump 28 is operated for 2 minutes, the outside air is distributed to each sensor 13 and 14, and the atmospheric carbon dioxide gas concentration and oxygen gas concentration detected by each are memorized, and since each atmospheric concentration is known, This executes the zero point calibration of the carbon dioxide longitudinal cable gas concentration sensor 13.

Therefore, it is no longer necessary to adopt a two-light path type structure for zero point calibration as in the past. In addition, this zero point calibration is performed by applying a filter to the sapphire glass 22 fitted into the through hole 20 of the carbon dioxide gas concentration sensor 13 to remove wavelengths that are absorbed by humidity. not affected by

Note that the control device 23 also executes span correction of the oxygen gas concentration sensor 14 at the same time. Furthermore, the outside air for zero point calibration may be introduced through a carbon dioxide adsorbent such as activated carbon or coal, thereby making it possible to stably control a carbon dioxide concentration as low as 1% or less for a long period of time.

(g) Effects of the Invention According to the present invention, the gas sensor is maintained at a constant temperature, so it is not affected by the outside temperature, and stable concentration detection is possible. Furthermore, since moisture does not condense in the sample gas path, bacteria do not grow, and water droplets do not adhere to the gas sensor and become undetectable.

Furthermore, since the water content of the sample gas is not removed, waste of gas and humidifying water can be prevented by returning the sample gas to the culture chamber.

Furthermore, if an infrared gas sensor is used as the sensor and a filter is provided to remove wavelengths that are absorbed by humidity, the detection power will not change even with changes in humidity. In addition, if the zero point calibration is performed by circulating outside air through the sample gas path, two optical paths are not required for the zero point calibration as in the conventional method, and an inexpensive culturing device can be provided.

[Brief explanation of the drawing]

FIG. II1 is a configuration diagram of the culture apparatus of the present invention, FIG. 2 is an exploded perspective view of a carbon dioxide gas concentration sensor, and FIG. 3 is a diagram illustrating conventional zero point calibration.

Claims (1)

[Scope of Claims] 1) A culture chamber maintained at high humidity, a material gas path through which gas within the culture chamber flows, a gas sensor provided in the material gas path, a heating means, and the culture chamber. and a control means for controlling the gas concentration of the culture chamber, and the control means controls the heating means to maintain the sample gas path and the gas sensor at a predetermined temperature higher than the temperature inside the culture chamber. Culture device. 2) The culture apparatus according to claim 1, wherein the sample gas introduced into the sample gas path is returned into the culture chamber. 3) The culture apparatus according to claim 1, wherein an infrared gas sensor is used as the gas sensor, and the infrared gas sensor is provided with a filter that blocks transmission of wavelengths absorbed by humidity. 4) The culture apparatus according to claim 3, wherein means is provided for circulating outside air through the sample gas path where the gas sensor is located, and the control means uses this outside air to perform zero point calibration of the infrared gas sensor.