JPH078228B2 - Incubator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a culture device for controlling a gas environment in a room and culturing cells and the like.

(B) Conventional Technology In order to culture a cell tissue such as a cancer cell, this seed culture device has conventionally been used in a room + as shown in JP-A-60-141279.
The temperature is set to a relatively high temperature of 30 ° C or higher, the humidity is set to a high humidity of 95% or higher, and the gas environment such as carbon dioxide concentration and oxygen concentration can be controlled.

This gas concentration control is performed by using infrared rays or a gas sensor that detects a predetermined gas concentration by utilizing a change in electric conductivity. These sensors measure the temperature of the material gas to be measured by the sensor or The output changes due to the influence of humidity. Especially, since the gas in the culture chamber has high humidity, this influence is great.

Therefore, in the above publication, the material gas for detecting the concentration is cooled by a cooling device to be dehumidified at a constant low temperature and sent to the gas sensor as a 100% constant humidity state.

Further, when an infrared type sensor is used as the sensor, the amount of light reaching the infrared detecting element changes over a long period of time due to dirt on the optical path or deterioration of the light source itself.
The zero point calibration was performed by the structure as shown in the figure.

In FIG. 3, 100 is a reference cell in which a reference gas flows, 101 is a reference cell in which a reference gas is sealed, 102 and 103 are infrared light sources, and 104.
Is a chopper, and 105 is a detector for periodically performing zero-point calibration using the output of infrared rays transmitted through the comparison cell 101.

(C) Problems to be Solved by the Invention However, since the cooling device is required in the configuration of the above publication, the entire device becomes large. Further, since the water content of the material gas is removed and discharged, even if the material gas is returned to the culture chamber, the water content inside the culture chamber is wasted.

Moreover, the sensor is also affected by its own temperature. In particular, in the infrared gas sensor, since the amount of infrared rays generated from the light source changes, there is a problem that the detected force changes when the outside air temperature changes.

Furthermore, in the zero point calibration method having the structure as shown in FIG. 3, two optical paths are always required, which is expensive, and in reality, impurities adhere to the outer surface of the comparison cell 101, so that 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 is directed to a culture chamber maintained at high humidity, a reference gas path for circulating gas in the culture chamber, a gas sensor provided in the reference gas path, and heating. And a control unit for controlling the gas concentration in the culture chamber, the control unit controls the heating unit so as to maintain the material gas path and the gas sensor at a predetermined temperature higher than the temperature in the culture chamber. It is configured as follows.

Further, in the above culture device, the material gas introduced into the material gas path is returned to the culture chamber.

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

Further, in this culture device, means for circulating the outside air is provided in the material gas path in which the gas sensor is located, and the control means uses this outside air to calibrate the zero point of the infrared gas sensor.

(E) Action According to the present invention, since the sensor is maintained at a constant temperature, stable concentration detection can be performed without being affected by the outside air temperature. In addition, since there is no doubt that water is in the source gas path, bacteria will not grow.

Further, since the water content of the sample gas is not removed, if the sample gas is returned to the culture chamber, the waste of the gas and the humidifying water can be prevented.

Furthermore, if an infrared gas sensor is used as a sensor and a filter that removes wavelengths absorbed by humidity is provided, the detected power does not change even when the humidity changes.

If the zero point calibration is performed by circulating the outside air through the sample gas path, the zero point calibration does not require two optical paths.

(F) Example Next, an example of the present invention will be described. FIG. 1 shows a block diagram of a culture device 1 of the present invention. The inside of the culture chamber 2 of the culture device 1 is insulated by a heat insulating material 7, and a gas cylinder 3 enclosing carbon dioxide and a gas cylinder 4 enclosing nitrogen are connected to the culture chamber 2 via separate paths 5 and 6, respectively. It is a form that can be passed. Valves 8 and 9 consisting of two-way valves are provided in each of the paths 5 and 6.
Are installed respectively.

Reference numeral 10 denotes a reference gas path, which has an inlet 10a communicating with the culture chamber 2, where an air pump 11, a filter 12 for removing dust in the circulating gas, a carbon dioxide gas concentration sensor 13 and an oxygen gas concentration sensor 14 are provided. Is installed, the air pump 11
Sucks the atmosphere in the culture chamber 2 as a reference gas from the inlet 10a and circulates it to each sensor 13 and 14, and then the outlet 10b.
It operates so as to return it to the inside of the culture chamber 2 again.

The carbon dioxide gas concentration sensor 13 is an infrared gas sensor as shown in the exploded view of FIG. The sensor 13 is composed of a so-called modulation type pyroelectric infrared detector 15 which has been developed in recent years and a light source 16 such as a heater which generates far infrared rays. Infrared detector 15 is shield box 17
The infrared detector S is housed inside, and a chopper C composed of a slit member 19 driven by the piezoelectric bimorph oscillator 18 is provided at a position corresponding to a through hole (not shown) formed in the shield box 17, and further at a position corresponding to that. The case 21 having the through holes 20 formed therein is entirely covered, and these parts are incorporated in the case 21. The slit member 19 is
It is configured by attaching two plates having slits in a superposed relationship, and the piezoelectric bimorph vibrator 18 vibrates at the same frequency as the frequency of the drive voltage input to the chopper C to open and close the slits and to enter through the through holes 20. And infrared detector S
The infrared ray U that reaches to is intermittently generated, and an output corresponding to the infrared ray amount is generated as an AC signal having the same frequency as the input frequency of the chopper C.

A material gas is circulated between the light source 16 and the through hole 20 as indicated by a broken line arrow in FIG. 2, and the gas concentration is detected by utilizing the property that infrared rays are absorbed by carbon dioxide in the material gas.

A sapphire glass 22 is fitted into the through hole 20, and a filter for removing a wavelength absorbed by humidity is applied and formed there.

The oxygen gas concentration sensor 14 is a gas sensor of a type that detects electrical conductivity, and outputs of the sensors 13 and 14 are input to a control device 23 configured by 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.

26 is an outside air path for introducing outside air,
One end is opened at 27, and the other end is connected to the material gas path 10 between the filter 12 and the carbon dioxide gas concentration sensor 13. An air pump 28 and a filter 29 are sequentially provided on the outside air path 26, and the outside air (atmosphere) is circulated to the material gas path 10 by this air pump 28.

The material 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, and the temperature in the heater 31 and the case 30 is kept in the case 30. 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, 35 is the culture chamber 2
It is a container containing water for humidification.

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

Next, the operation of the control device 23 will be described. Generally, this seed culture apparatus has many applications in which 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%. Further, nitrogen gas is used to control the oxygen gas concentration because the oxygen concentration in the atmosphere is about 21%, and when it is used at 5%, it is necessary to lower the oxygen gas concentration in the culture chamber 2 by nitrogen gas. Is.

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 controls the SSR 37 to control the heat generation of the heater 34 so that the inside of the culture chamber 2 is, for example, + 37 ° C.
Etc. to maintain a constant temperature.

In addition, the pump 11 is operated, the reference gas is introduced into the path 10,
The gas environment in the culture chamber 2 is adjusted by circulating the gas through the sensors 13 and 14 and obtaining outputs related to the carbon dioxide gas concentration and the oxygen gas concentration from the sensors 13 and 14 to open and close the valves 8 and 9.

Further, the controller 23 uses the output of the sensor 32 to
Is controlled to maintain the inside of the heat insulating case 30 at a constant temperature higher than the temperature inside the culture chamber 2. For example, if the culture chamber 2 is + 3 ° C., the inside of the heat insulating case 30 is maintained at + 42 ° C. As a result, the reference gas path 10 and each sensor 13
Since the temperatures of 14 and 14 are constant, the detected force does not change even when the outside air temperature changes. Further, since the temperature of the route 10 is higher than the temperature of the source gas, the water content in the source gas is
Therefore, the inside of the passage 10 is always maintained in a dry state, no germs propagate, and the sensors 13 and 14 do not have a water drop to cause a detection error. Also, since this source gas is returned to the culture chamber 2,
There is no waste of water in the culture chamber 2.

Next, the control device 23 stops the air pump 11 once every four hours (for example, there is no backflow of air while the air pump is stopped. The same applies hereinafter), and the air pump 28 is operated for 2 minutes to detect each sensor 13 for outside air and the outside air. The carbon dioxide gas concentration and the oxygen gas concentration of the atmosphere which are distributed to each of the air conditioners 14 are detected and stored, and since the respective concentrations of the atmosphere are known, the zero point calibration of the carbon dioxide gas concentration sensor 13 is executed by this.

Therefore, it is not necessary to adopt a two-optical path structure for zero point calibration as in the conventional case. Further, in this zero point calibration, the sapphire glass 22 fitted in the through hole 20 of the carbon dioxide gas concentration sensor 13 is formed with a filter for removing the wavelength absorbed by humidity, so that the humidity of the outside air introduced. Not affected by.

The controller 23 also executes span correction of the oxygen gas concentration sensor 14 at the same time. Further, the outside air for zero-point calibration may be introduced through a carbon dioxide adsorbent such as activated carbon or coal, whereby a low carbon dioxide concentration of, for example, 1% or less can be stably controlled for a long period of time.

(G) Effect of the Invention According to the present invention, since the gas sensor is maintained at a constant temperature, stable concentration detection is possible without being affected by the outside air temperature. In addition, since moisture does not condense in the sample gas path, bacteria do not grow, and the water droplets do not adhere to the gas sensor and become undetectable.

Further, since the water content of the sample gas is not removed, if the sample gas is returned to the culture chamber, the waste of the gas and the humidifying water can be prevented.

Furthermore, if an infrared gas sensor is used as a sensor and a filter that removes wavelengths absorbed by humidity is provided, the detected power does not change even when the humidity changes. In addition, if the zero point calibration is performed by circulating the outside air through the source gas path, it is possible to provide an inexpensive culture device as a whole without the need for two optical paths for the zero point calibration as in the conventional case.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a culture device of the present invention, FIG. 2 is an exploded perspective view of a carbon dioxide gas concentration sensor, and FIG. 3 is a diagram for explaining a conventional zero point calibration. 1 ... Incubator, 2 ... Incubator, 10 ... Data gas path,
13 …… Carbon dioxide gas concentration sensor, 14 …… Oxygen gas concentration denser, 22 …… Sapphire glass, 23 …… Control device, 26 …… Outside air path, 30 …… Insulation case, 31 …… Heater, 32 …… Temperature sensor.

Claims (4)

[Claims] 1. A culture chamber maintained at high humidity, a material gas path for circulating a gas in the culture room, a gas sensor provided in the material gas path, a heating means, and a gas concentration in the culture room. And a control means for controlling the heating means, the control means controlling the heating means so as to maintain the material gas path and the gas sensor at a predetermined temperature higher than the temperature in the culture chamber. 2. The culture apparatus according to claim 1, wherein the material gas introduced into the material gas path is returned to the culture chamber. 3. The culture device 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 for blocking transmission of wavelengths absorbed by humidity. 4. The culture according to claim 3, wherein a means for circulating outside air is provided in a material gas path in which the gas sensor is located, and the control means performs zero point calibration of the infrared gas sensor using this outside air. apparatus.