WO2012098380A1

WO2012098380A1 - Incubators

Info

Publication number: WO2012098380A1
Application number: PCT/GB2012/050080
Authority: WO
Inventors: Stephen M. FELLER
Original assignee: Isis Innovation Limited
Priority date: 2011-01-18
Filing date: 2012-01-16
Publication date: 2012-07-26

Abstract

An incubator comprises a plurality of walls (14) dividing the incubator into a plurality of chambers (12), and condition control means associated with each of the chambers so that the conditions in each of the chambers (12) can be controlled independently of the other chambers. Each of the chambers has a door (16) so that it can be opened independently of the other chambers.

Description

Incubators

Field of the Invention

The present invention relates to incubators, and in particular to incubators for providing a controlled environment for carrying out experiments in a laboratory, for example on cell cultures.

Background to the Invention

The use of incubators in the laboratory environment is very well known. Typically an incubator is in the form of a cabinet and has a single chamber containing a number of shelves, with a door on the front to allow access to the shelves. Gas sensors, such as oxygen and carbon dioxide sensors, and a thermometer are provided in the chamber, and a controlled supply of oxygen and carbon dioxide to the chamber, and a heater and a water reservoir in the chamber, are provided to control the environment in the chamber. The gases used and monitored will depend on the experiments and in other cases nitrogen and/or air levels can be controlled. Typically a large number of cell samples are stored in the incubator in separate containers.

It is a problem with this type of incubator that it is often used by several different users, and for different experiments, at once. As a result access to the chamber is required at different times for the different samples held in the incubator, with the result that the incubator is opened frequently. Each time the incubator door is opened the temperature, oxygen (O₂) and carbon dioxide (CO₂) (or other gas) levels diverge from the desired levels, and take some time to return to those levels after the door is closed.

Summary of the Invention

The present invention provides an incubator comprising a plurality of walls dividing the incubator into a plurality of chambers, condition control means associated with each of the chambers so that the conditions in each of the chambers can be controlled independently of the other chambers. Each of the chambers may have a door so that it can be opened independently of the other chambers.

The conditions may be any one or more of: temperature, oxygen level, nitrogen level, and carbon dioxide level. The condition control means may comprise temperature control means, such as a heater. There may be a heater associated with each chamber. Each heater may be mounted on a wall of the respective chamber to reduce the amount that it affects other chambers. Each heater may be mounted on, or adjacent to, the rear wall. Alternatively it may be mounted on, or adjacent to, a side wall, or it may be mounted in or under the floor of the chamber. Each heater may cover at least half of the wall, or substantially all of the wall. The heating means may comprise a plurality of heaters for each chamber, which may be mounted in any combination of these positions.

The condition control means may comprise a gas control valve arranged to control the supply of a gas to the chamber. The gas control valves for all of the chambers may be connected to a common gas supply. The gas may, for example, be oxygen or carbon dioxide or nitrogen or air.

Each chamber may have a fan located in it. Alternatively the heating means may be arranged to set up convection currents to circulate heat around the chamber. The heating means may be arranged to circulate heated gas around the chamber purely by convection. This can avoid the need for a fan or other device for moving air around the chambers.

Each chamber may have a water reservoir associated with it, and optionally located in it, to allow water to evaporate into the gas in the chamber. The incubator may further comprise a central controller arranged to control the operation of each of the condition control means thereby to control the conditions in all of the chambers. The controller may be arranged to define a target value for a condition for each of the chambers and to control the condition control means associated with each of the chambers so as to achieve the target value. Alternatively a separate controller can be provided for each chamber.

The incubator may further comprise a user interface arranged to allow a user to input a target value for the condition for each of the chambers. The user interface may be operable in two different modes to input the target values for the chambers in different ways. For example, in one of the modes, the user interface may be operable to input one target value and the controller may be arranged to use that target value to control the conditions in all of the chambers. In some embodiments, in one of the modes, the user interface is operable to input one target value separately for each chamber, and the controller is arranged to use each of the target values to control the condition in the respective chamber with which it is associated. In some embodiments, in one of the modes, the user interface is arranged to define at least partially a range of values for the condition in the chambers, and the controller is arranged to calculate target values for at least some of the chambers from the defined range. For example the user interface may be arranged to define the interval between the values in each of the chambers, or to define an upper and a lower value for the range. Alternatively a separate user interface can be provided for each chamber. Brief Description of the Drawings

Figure 1 is a schematic front view of an incubator according to an embodiment of the invention;

Figure 2 is a schematic section through one compartment of the incubator of Figure 1 ; Figure 3 is a schematic section through one compartment of an incubator according to a further embodiment of the invention; and

Figure 4 is a schematic section through one compartment of an incubator according to a still further embodiment of the invention. Description of the Preferred Embodiments

Referring to Figure 1 , an incubator according to one embodiment of the invention comprises an outer housing 10, the interior of which is divided into a plurality of chambers 12 by dividing walls 14. The dividing walls 14 are thermally insulated and gas-tight so that the environment in each chamber can be controlled largely independently of the others. In this embodiment the chambers 12 are all orientated in the same way, and aligned in columns and rows, each chamber 12 having its front in the front of the housing 10, and its rear wall defined by the rear of the housing 10. In this embodiment there are four rows of two chambers 12, though of course different numbers and configurations of chambers can be used. Any number of chambers from 4 to 24, or in some cases more, could be provided. Each chamber 12 has a door 16 in its front, and each door 16 can be opened and closed independently of the others. The doors are gas tight so that when they are closed the environment inside the chamber can be controlled as desired. Referring to Figure 2, each chamber 12 has within it a water reservoir 20, a thermometer 22, an O₂ sensor 24, a CO₂ sensor 26, a heater 28 and a fan 30. Each chamber 12 also has an O₂ inlet 32 which is connected to an O₂ supply 34 via a control valve 36, and a CO₂ inlet 38 which is connected to a CO₂ supply 40 via a control valve 42. The O₂ supply 34 and the CO₂ supply 40 are common to all the chambers 12, but as there is a pair of control valves 36, 42 for each chamber 12, the supply of O₂ and CO₂ to each chamber can be controlled independently of the other chambers. A controller 44 is arranged to receive signals from the thermometer 22, O₂ sensor 24, and CO₂ sensor 26 in each chamber, and to provide control signals to the O₂ control valve 36 and the CO₂ control valve 42, the heater 28 and the fan 30 for each chamber. This allows the controller 44 to monitor the conditions in each chamber and to control the conditions in each chamber independently of the others. A user interface 46 is provided on the incubator which is connected to the controller 44 and, as shown in Figure 1 , comprises a display screen 48 and user input buttons 50 which allow a user to determine how the conditions within each chamber 12 will be controlled. In this embodiment a menu-driven input is provided, although of course the input can take any suitable form. A shelf 50 is provided in each chamber 12 on which one or more sample trays 52 can be placed when the incubator is in use. It will be appreciated that Figure 2 is schematic. In practice the water reservoir 20, which may be formed of copper or stainless steel, or any other suitable material, will generally cover the whole of, or most of, the floor of the chamber 12. A liquid level sensor and controlled re-filling system can be included, but typically the reservoir is monitored and re-filled manually. The heater 30 is generally as large as possible so that the temperature can be kept as even as possible throughout the chamber 12 and be increased again quickly if it falls when the door 16 is opened. The heater may cover a large part, or even substantially all, of the rear wall of the chamber, or indeed one of the side walls or the ceiling of the chamber. In operation, the controller 44 can be set using the user interface 26 to set the temperature, CO₂ level and O₂ level of each chamber 12, and the controller is then arranged to monitor the temperature of each chamber by monitoring the signal from the thermometer 22, to monitor the O₂ level and CO₂ level of each chamber 12 by monitoring the signals from the O₂ and CO₂ sensors 24, 26, and to control the heater 28 and the O₂ control valve 36 and the CO₂ control valve 42 so as to maintain the conditions at the levels set.

The user interface can be used in three different modes. If the first mode is selected then the conditions in each of the chambers 12 are controlled in the same way. The user is therefore prompted by the user interface, for example via the display screen 50, to input target values for the temperature, O₂ level and CO₂ level, and the controller is then arranged to monitor the conditions in each of the chambers 12 and to control those conditions separately for each chamber, so as to maintain the target conditions in each chamber. As the external influences, such as external sources of heat and the effects of the experiment being performed in each chamber, will generally vary from one chamber to another, the individual control of each chamber helps to ensure that conditions are uniform for all chambers. In this mode, the user can also select some of the chambers to be actively controlled to maintain the target conditions and others not to be controlled. This means that any chambers which are not to be used can be left uncontrolled which reduces the power used by the incubator.

If the second mode is selected, the user is prompted to input target conditions for each of the chambers 12 individually. This is useful, for example, if different chambers are to be used for different unrelated experiments. It also allows some of the chambers 12 to be left uncontrolled if they are not all to be used.

If the third mode is selected, the user is prompted to define different target conditions in different chambers by inputting a relationship between one or more of the conditions in the different chambers. For example the temperatures of the chambers can be set by selecting some or all of the chambers to be in a controlled group, setting a lowest (or highest) temperature for one of the chambers, and setting fixed temperature intervals between the chambers in the group, such as 1 ° C or 5 ° C. The controller is arranged to provide a prompt for each of these steps and to record the values input by the user in response. It is then arranged to control the chambers so as to maintain their individual target conditions. For example this method could be used to set the temperatures of all eight of the chambers 12 to vary from 20⁰ C to 55 ° C in 5 degree intervals. Any one or more of the controllable conditions can be defined in this way. In a modification to this mode, the user can be prompted to input the lowest and the highest values for temperature (or O₂ or CO₂ level) and to identify which of the chambers are to be included in the group. The controller 44 is then arranged to calculate the intermediate conditions for the other chambers in the group so as to set them at equal intervals. For example six of the chambers 12 can be selected to have CO₂ levels that vary from 5% to 10% in intervals of 1 %.

The input modes described above can be defined separately for each of the controllable conditions of the incubator. For example the temperatures of the chambers can be set individually and the O₂ or CO₂ level, or both, set to vary in fixed intervals.

The display screen 48 is arranged to display for each chamber a status showing whether it is actively controlled or not, and if it is actively controlled, the target values of the conditions within it, and the actual values of those conditions.

The fan 30 in each chamber generally has only two settings: on or off. Where only some of the chambers are selected to be actively controlled, the fans in each of those chambers is arranged to be turned on so that it will circulate air in the chamber. For the other chambers which are not actively controlled the controller 44 is arranged to turn the fan off so as to minimize the power consumption of the incubator.

The incubator described above can be used in a wide variety of experiments, such as systems biology experiments, experiments on CO₂ fluctuation-sensitive cells such as rat skull osteoblasts, CO₂ gradient experiments in which the same experiment is carried out at different CO₂ levels in different chambers, temperature gradient experiments such as those carried out on temperature sensitive mutants (e.g. in chicken cells, mammalian cells, insect cells, Drosophila (whole animals) and yeast cells).

It will be appreciated that various modifications to the embodiments described above can be made which still fall within the scope of the invention. For example, in order to simplify manufacture, the thermometer 22 and the O₂ and CO₂ sensors 24, 26 can be mounted on the rear wall of the chamber opposite the door 16. Similarly the heater 28 and fan 30 can be mounted on the top, bottom or side walls, rather than the rear wall as shown. However it is advantageous for the heater 28 of each chamber 12 to be mounted on the rear wall as it has least effect on the temperature of other chambers when in that position. Also, the incubator can be arranged to operate with different gases in the chambers. For example the chambers can all be filled with nitrogen via the gas inlets so that experiments can be performed anaerobically, with just the temperatures of the chambers being actively controlled by the controller 44. In another modification a separate user interface can be provided for each chamber, with user inputs and a display screen. In this case the conditions for each chamber can be set using its own user interface. Each chamber can have its own controller associated with it so that control of each of the chambers is completely independent of the others.

Referring to Figure 3, in a modification to the embodiment of Figure 1 , all of the features of the system are essentially the same as in the embodiment of Figure 1 except the heating arrangement. In this embodiment, the fan 30 is omitted and the heater 28a is arranged to heat the chamber 12a by convection. Specifically the heater 28a is located on one of the walls of the chamber, which may be the rear wall as shown. The heater is arranged to cover at least half of the wall, and in this case substantially all of the wall. When the heater 28a is turned on it warms air in the part of the chamber that is nearest to it, which in this case is the rear part. Air in this part of the chamber therefore tends to rise, and air at the opposite end of the chamber, in this case the front end, tends to fall as it is then cooler than the air nearer the heater. This results in a convectional circulation of air around the chamber as shown in Figure 3 which tends to distribute the warming effect of the heater around substantially the whole chamber to keep it at an approximately even temperature throughout. The use of solely convection to move heated gas around the chamber can avoid the need for a fan, which can make the system simpler and cheaper.

Referring to Figure 4, in a further modification to the system of Figure 3, the heater 28b is located in the floor of each chamber 12b. In this case the heater will also set up convection currents in the chamber 12b, but these will be in the form of more localized currents of warm air rising upwards from the heater floor of the chamber and cooler air sinking from the cooler top of the chamber. However these currents can still approximately equalize the temperature throughout the chamber 12b without the need for a fan.

Claims

1. An incubator comprising a plurality of walls dividing the incubator into a plurality of chambers, condition control means associated with each of the chambers so that the conditions in each of the chambers can be controlled independently of the other chambers, wherein each of the chambers has a door so that it can be opened independently of the other chambers.

2. An incubator according to claim 1 wherein the condition control means comprises temperature control means.

3. An incubator according to claim 2 wherein the temperature control means comprises a heater associated with each chamber.

4. An incubator according to claim 3 wherein each heater is mounted on or adjacent to at least one wall of the respective chamber.

5. An incubator according to claim 4 wherein the wall is the rear wall.

6. An incubator according to claim 3 wherein each heater is mounted on or adjacent to the floor of the chamber.

7. An incubator according to any foregoing claim wherein the condition control means comprises a gas control valve arranged to control the supply of a gas to the chamber.

8. An incubator according to any foregoing claim further comprising a fan located in each of the chambers to circulate air in the chamber.

9. An incubator according to any of claims 1 to 7 wherein each heater is arranged to set up convection currents to circulate heat around the chamber.

10. An incubator according to any foregoing claim further comprising a water reservoir associated with each of the chambers arranged to allow water to evaporate into the gas in the chamber.

1 1. An incubator according to any foregoing claim further comprising a central controller arranged to control the operation of each of the condition control means thereby to control the conditions in all of the chambers.

12. An incubator according to claim 9 wherein the controller is arranged to define a target value for a condition for each of the chambers and to control the condition control means associated with each of the chambers so as to achieve the target value.

13. An incubator according to claim 12 further comprising a user interface arranged to allow a user to input a target value for the condition for each of the chambers.

14. An incubator according to claim 13 wherein the user interface is operable in two different modes to input the target values for the chambers in different ways.

15. An incubator according to claim 14 wherein, in one of the modes, the user interface is operable to input one target value and the controller is arranged to use that target value to control the conditions in all of the chambers.

16. An incubator according to claim 14 or claim 15 wherein, in one of the modes, the user interface is operable to input one target value separately for each chamber, and the controller is arranged to use each of the target values to control the condition in the respective chamber with which it is associated.

17. An incubator according to any of claims 14 to 16 wherein, in one of the modes, the user interface is arranged to define at least partially a range of values for the condition in the chambers, and the controller is arranged to calculate target values for at least some of the chambers from the defined range.

18. An incubator according to claim 17 wherein in said one of the modes the user interface is arranged to define the interval between the values in each of the chambers.

19. An incubator according to claim 17 wherein in said one of the modes the user interface is arranged to define an upper and a lower value for the range.

20. An incubator substantially as described herein with reference to any one or more of the accompanying drawings.