WO2021201742A1

WO2021201742A1 - A cell monitoring device for use inside a humid incubator and a humid incubator system

Info

Publication number: WO2021201742A1
Application number: PCT/SE2021/050245
Authority: WO
Inventors: Erik Gatenholm; Hector Martinez; Anton ANDRÉN; Niclas Johansson; Diana CERVANTES
Original assignee: Cellink Ab
Priority date: 2020-04-03
Filing date: 2021-03-19
Publication date: 2021-10-07

Abstract

The disclosure relates to a cell monitoring device for use inside a humid incubator, comprising: i. an outer casing, in open or closed arrangement, comprising a bottom, a top, a front part, a rear part, and a first and second side parts; ii. a sample tray adapted to receive at least one sample vessel, said sample tray being positioned within or on top of the outer casing; iii. at least one heat source, such as an imaging system, an optical unit and/or a live cell camera, arranged in fixed or movable position within the outer casing; and iv. one or more mass flow devices arranged within the outer casing; characterized in that the one or more mass flow device(s) have the capacity to cause a mass flow within the outer casing and/or the surrounding environment, such as an incubator, thereby levelling temperature differences created by heat emitted from the heat source(s) within the casing and/or the surrounding environment, thereby minimizing condensation in the at least one sample vessel(s). The disclosure further relates to a humid incubator system and a computer program.

Description

A cell monitoring device for use inside a humid incubator and a humid incubator system

Technical field

The present disclosure relates to a cell monitoring device for use inside a humid incubator, a humid incubator system and a computer program. More specifically, the disclosure relates to a cell monitoring device for use inside a humid incubator, a humid incubator system and a computer program as defined in the introductory parts of claim 1, claim 15 and claim 17.

Background art

This invention relates to improved instruments and modules used inside incubators to reduce condensation. In particular, the present application relates to cell culture imaging devices and systems with a fan and mass flow configuration designed to reduce and/or eliminate condensation problems in a cell culture vessel for optimal cell culture conditions and live-cell monitoring.

The present invention is a system able to decrease the temperature differences inside enclosed chambers generally used to perform experiments such as cell culture. These chambers or incubators have active systems to control temperature and gas concentrations. Additionally, some are designed to promote high relative humidity conditions.

These incubators use a high humidity to reduce the evaporation of liquids contained in a vessel that has a loose-fitting lid. The air above the surface of the liquid is saturated with vapor while the surrounding air is not and because of this difference the vapor tries to distribute by diffusion to create an equilibrium. The gas concentration and the temperature are modified depending on the experiments performed in the incubator, e.g. at 37°C, 5% CO2 for a mammalian cell culture.

In such instruments, condensation is an issue since the volume of liquid lost by condensation alters the volume in the experiment, introducing a difficult to track variable. Condensation is the physical process where matter changes from gas to liquid, in the mentioned enclosed chambers condensation occurs when the temperature of a surface inside the chamber is below the temperature point at which the air saturated with water vapor turns into liquid, dew point. At constant temperature, the dew point is proportional to humidity i.e. at 37°C and 95% relative humidity the dew point is 36.1°C meaning that theoretically any surface below this point will get condensation. Since the difference in temperature needed to create condensation in high humidity chambers is especially small, the introduction of any type of device producing heat increases the probability of condensation in the surroundings of the heat source, altering the conditions inside this type of incubators.

To avoid condensation inside the mentioned incubators, different solutions have been created trying to keep the heat away from the liquid containing vessels as well as heating/cooling the surfaces of the liquid containing vessels prone to condensation (see e.g. US2017/0037355 related to an "INCUBATION AND DETECTION DEVICE".

A problem with the solutions of the prior art is that heaters/coolers are expensive and require extensive testing, since the heaters/coolers need to be able to stand high humidity and warm temperature.

There is thus a need for improved and alternative solutions within this field, minimizing the problems of condensation in sample vessels, and to avoid disturbing the experiments performed in cell incubators.

Summary

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem(s). According to a first aspect there is provided a cell monitoring device for use inside a humid incubator, comprising: i. an outer casing, in open or closed arrangement, comprising a bottom, a top, a front part, a rear part, and a first and second side parts; ii. a sample tray adapted to receive at least one sample vessel, the sample tray being positioned within or on top of the outer casing; iii. at least one heat source, such as an imaging system, composed of an optical unit and/or a live cell camera, arranged in fixed or movable position within the outer casing; and iv. one or more mass flow devices arranged within the outer casing; characterized in that the one or more mass flow device have the capacity to cause a mass flow within the outer casing and/or a surrounding environment, such as a humid incubator, thereby levelling temperature differences created by heat emitted from the heat source within the casing and/or the surrounding environment, thereby minimizing condensation in the at least one sample vessel(s).

Thus, the inventors have surprisingly found out that by using a mass flow device, such as a fan, for creating a mass flow, which levels out temperature differences in an incubator, the problems of the prior art can be solved. Hereby, excessive costs can be avoided and the system can be simplified. Specifically, the inventors have been able, using mass flow devices, especially fans, to create a flow in a specific direction and with a suitable potency to be able to drag hot air away in such a way that the main function of the device is not disturbed. To this end, it is important to stress that in a cell culturing or cell monitoring device, where living cells are growing, a controllable and non-disturbing environment is very important, e.g. uncontrolled vibrations, noise, changes in temperature and atmosphere conditions should be avoided as far as possible.

According to some embodiments, the invention can be applied to bioreactors or cell monitoring devices, such as a live-cell imaging device, and other condensation prone devices placed inside humid incubators.

Thus, the principles of the invention are applicable to a wide range of devices, having the common challenge of levelling temperature from a heat source so that condensation is minimized and/or eliminated.

According to some embodiments, the mass is a gas, such as air.

The principles of the invention can be applied to any mass flow that can be used for distributing heat. Gaseous flow (air) is the preferred choice for practical reasons.

According to some embodiments, the heat source, in the form of an imaging system, is movable within the casing underneath the sample tray so that each sample vessel of the sample tray can be monitored by the imaging system.

In a cell monitoring system, the vessels containing cells should be possible to monitor with minimum disturbance for the cultured cells, and therefore the imaging system must typically be movable, which in practice means that the heat source moves within the device casing. Hence, the mass flow devices and the mass flow created must be able to take care of this situation. As shown in the present application, the inventors have been successful in creating a mass flow device coupled to a cell monitoring system, such as a live-cell imaging system, thereby levelling temperature with a movable imaging system. Especially, as proof of concept this has been shown for the CELLCYTE system.

According to some embodiments, the device further comprises a gantry system arranged at least partly within the outer casing, said gantry system comprises a framework of connected extended members, said framework comprising: a first extended member being configured to extend in at least a latitudinal direction, and at least one second extended member being configured to extend in a longitudinal direction, said longitudinal direction being perpendicular to said latitudinal direction and a gantry frame structure extending along an orthogonal direction being perpendicular to the latitudinal direction and the longitudinal direction, at least one movement member, the heat source, in form of an imaging system arranged on the gantry frame structure, wherein the imaging system comprises a detection layer and an illumination layer, and wherein the gantry frame structure comprises an internal orifice enabling the sample tray to be positioned within said orifice, and said detection layer is arranged within the outer casing and attached to a lower portion of the frame structure, and under the sample tray, such that the detection layer is movable in a planar direction in relation to the sample tray in response to actuation of said at least one movement member.

The cell monitoring device of this embodiment relates e.g. to the CELLCYTE system (provided by CELLINK AB; www.cellink.com). This device is an open cell monitoring device, to be used inside an incubator. It was found out by the inventors that not only the use of mass flow devices, such as fans, was important, but also the power and position of the mass flow devices within the casing of the device in order to minimize and preferably eliminate condensation. Solutions used when trying to solve a condensation problem in a closed cell monitoring system does not necessarily apply to an open cell monitoring system. A mass flow device having too high power was efficient in creating a mass flow, but also in emitting heat, thereby causing additional heating problems in the whole incubator, resulting in undesired condensation. Therefore, using too powerful mass flow devices may result in the incubator being overheated, which is deteriorating for the cell culture and would affect any experiment performed in such incubator. Hence, it is important to use a mass flow device having a sufficient capacity to create a mass flow so that the heat emitted from the primary heat source(s), such as a camera, is transported away and levelled out, without creating unnecessary heat. Thus, it is a balance and task of optimizing the position, direction and power of the mass flow devices for any specific cell monitoring device placed inside an incubator, so that a specific mass flow is created.

According to some embodiments, a first mass flow device is arranged to create a mass flow from the surrounding environment, such as the incubator, into the casing, and a second mass flow device is arranged to create a mass flow from the casing to the surrounding environment, such as the incubator.

Thus, by exchanging mass with the environment surrounding the device casing, e.g. with the incubator in which the device is used, mass can be moved from locations where it is hotter, such as in the proximity of the heat source, to locations where it is cooler, such as in the bottom of an incubator, and vice versa. In this way, temperature differences can be levelled out to such an extent that condensation is minimized and/or eliminated in the sample vessels.

According to some embodiments, the first mass flow device is arranged at the bottom of the casing, and the second mass flow device is arranged at the front, rear or side parts of the casing.

According to some embodiments, the first mass flow device is arranged at the bottom of the casing, close to the front part, and the second mass flow device is arranged at the rear part of the casing.

Thus, in one workable solution it showed important to place mass flow devices at the bottom of the case to bring air of lower temperature into the casing and having a mass flow device in the back (rear) of the casing getting air of higher temperature out of the system, equalizing temperature differences that is causing condensation. Placing the fans for cooling down the system at the front and the fan to drag out the hot air at the back of the case was also important since the inventors needed to drag the hot air to one point, in this case the back (rear), and then take it out.

According to some embodiments, the casing further is equipped with vents or holes allowing mass to flow in and out of the casing to the incubator. Hereby, when suitable, mass can be exchanged with the surroundings via holes/vents allowing a more "passive" levelling of temperature differences.

Thus, the invention has the capacity to level temperature differences of heat source(s) having a wide range of power and therefore heat emission.

According to some embodiments, the sample tray comprises sample vessels in the form of 96- well plates with 0.1 ml liquid per well, 48 well plates with 0.5mL per well, 24 well plates with lmL per well, 12 well plates with lmL per well and 6 well plates with 2ml per well.

Thus, the invention has the capacity to eliminate condensation in sample trays and sample vessels of a great variety.

According to some embodiments, the mass flow device is a fan.

Typically, the mass flow device is a fan, which e.g. can be of radial or axial type. Typically, axial type fans are preferred, since radial fans tend to produce more heat and vibrations.

According to some embodiments, each mass flow device have the following characteristics: i. a potency in the range of 1-10 W, preferably in the range of 2-3 W; and/or ii. a maximum mass flow rate capacity in the interval of 0,25 - 5 m³/min, preferably in the interval of 0,5-2, 5 m³/min.

For some preferred embodiments related to the CELLCYTE device, it has been shown that potencies in the range of 1-10 and especially 2-3 W is a good optimization, as well as mass flow rates in the order of 0,25 - 5 m³/min, and especially 0,5-2, 5 m³/min.

According to some embodiments, the cell monitoring device further comprises at least one control unit and a data storage unit. For example, the mass flow devices can be controlled by the same processor/computer controlling the monitoring device. Alternatively, another processor/computer may be used.

According to some embodiments, the cell monitoring device further comprises at least one temperature sensor for detecting temperature variations in the device. Temperature sensor(s) that can detect temperature variations of 0.1°C and upwards can be used, and a PID (proportional-integral-derivative) controller can be used to regulate the mass flow. By "temperature variations" is meant variations up and/or down in temperature, such as a higher temperature as a result of heat emitted from the one or more heat sources, and a lower temperature(s) as a result of mass flow from a cooler to a warmer location.

According to a second aspect there is provided a humid incubator system, comprising: a humid incubator; the cell monitoring device of the first aspect; and means to control temperature, gas concentration and/or humidity condition within the incubator.

Hereby, a complete system for incubating and culturing cells is provided, having the advantage of minimized and/or eliminated condensation in the sample vessels. By a "humid incubator system" is meant any chamber with a regulated environment for cell culturing purposes.

According to some embodiments, the volume of the incubator is typically in the range of 10 to 1000 I, preferably 50-500 I, more preferably 100-250 I.

Hence, a large variation of incubator sizes can be used.

According to a third aspect, there is provided a computer program for controlling the operation of the one or more mass flow devices of the cell monitoring device of the first aspect, comprising instructions, which when executed cause the program to control the operation of the one or more mass flow devices. For example, this can be done as a response to temperature variations detected by the at least one temperature sensor of the monitoring device, and/or as a response to any other input

In this way, the mass flow devices can be controlled by a computer program. For example, the mass flow devices can be controlled by the same processor/computer controlling the monitoring device. Alternatively, another processor/computer may be used.

Effects and features of the second and third aspects are to a large extent analogous to those described above in connection with the first aspect. Embodiments mentioned in relation to the first aspect are largely compatible with the second and third aspects.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure. Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

Brief descriptions of the drawings

The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figure 1 shows the cell monitoring device (1) according to an embodiment of the present disclosure. More in detail, Figure 1 is a diagram disclosing a cell monitoring system for automatic cell monitoring comprising an outer casing (2), a sample tray (3) positioned within the outer casing, a gantry system (4) arranged at least partly within the outer casing, and an imaging system arranged on the gantry system. The heat source (not shown) in the form of an optical unit is within the casing, as well as the mass flow device(s) (not shown).

Figure 2 is a top view showing the sample tray (inner dashed line) (3) and the casing (outer dashed line)(2), including the movable heat source (the imaging device), as well as mass flow device(s) 6, 7 and 8

Figure 3 shows various solutions (11 concepts) of fans and bottom holes that were studied according to the invention.

Figure 4 shows condensation test results for the different fan solutions (11 concepts) studied. Figure 5 shows a diagram of the air flow using concept 11. The arrows show the mass flow caused by the mass flow devices.

Detailed description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

The first aspect of this disclosure (figure 1 and 2) shows a cell monitoring device 1 for use inside a humid incubator, comprising: i. an outer casing (2), in open or closed arrangement, for example comprising a bottom 11, a top 12, a front part 13, a rear part (back) 14, and a first and second side parts 15,16 (even though other configurations and designs are fully possible, as long the technical effect of the invention can be achieved); ii. a sample tray 3 adapted to receive at least one sample vessel, the sample tray being positioned within or on top of the outer casing; iii. at least one heat source 5, such as an imaging system, an optical unit and/or a live cell camera, arranged in fixed or movable position within the outer casing; and iv. one or more mass flow devices arranged within the outer casing; characterized in that the one or more mass flow devices have the capacity to cause a mass flow within the outer casing and/or the incubator thereby levelling temperature differences created by heat emitted from the heat sources within the casing and/or the surroundings, e.g. the incubator, thereby minimising condensation in at least one sample vessels.

Limiting or eliminating condensation in sample vessels is an objective according to the present disclosure. It is preferred than no condensation occurs, or at least only a small amount. Some dew may be acceptable, if not accumulating over time. However, no dew at all is what is desired (condensation problem thereby solved).

The cell monitoring device can be any type of cell monitoring device, such as an incubator, a bioreactor, a cell monitoring device, such as a live-cell imaging device (including the CELLCYTE device provided by CELLINK AB). Also, the cell monitoring device can be a system further comprising means for dispensing biological material, such as cells and/or single cells, to the sample vessel(s).

The casing can have be an open (have mass flow communication with the surroundings) or closed arrangement, in which closed arrangement the casing has essentially no direct mass flow communication with the surroundings. The casing may have many different shapes and sizes, and typically its size is as small as possible for practical and manufacturing reasons.

One or more sample trays including sample vessels are typically positioned within or on top of the casing, even though other positions are fully possible. For a live-cell imaging device, it is practical if the sample tray is positioned so that an optical unit can monitor the sample vessels of the sample tray. In such embodiment, the sample tray may for example be positioned on top of the casing, so that the samples can be monitored by an optical unit positioned within the casing, below the sample tray. In such embodiment, the top of the casing is typically transparent or open. The sample tray may for example comprise sample vessels in the form of 96-well plates with 100pL liquid per well, 48 well plates with 0.5mL per well, 24 well plates with lmL per well, 12 well plates with lmL per well and/or 6 well plates with 2ml per well.

The heat source(s) may be any type of device emitting heat, such as an optical unit, a live-cell camera (such as acA2440-35um - Easier ace; https://www.baslerweb.com/en/products/cameras/area-scan-cameras/3ce/aca2440- 35um/#tab-specs) (power 2,5 W), a microscope or the like, or any other type of device typically used in a cell monitoring device. Depending on the power of and the heat emitted from the heat source(s), the arrangements of mass flow devices may differ. According to some embodiments, the monitoring device may comprise more than one heat source, and the heat sources may be positioned in different locations of the device, such as an optical unit within the casing, and means for dispensing biological material to the sample vessels above the sample tray. For such embodiments, the choice and positioning of the mass flow devices may need to be optimised for each individual heat source, and/or for the entire monitoring device, so that condensation in the sample vessels is minimized or, preferably, eliminated.

For example, using the CELLCYTE cell monitoring device, the heat source is a camera that has a typical power of 2.5 W, and a temperature that typically is in the range of 42-55 °C. Typically, one could expect that the heat source(s) used in cell monitoring devices are optical units having a power value of about 0,5-10 W, for example in the interval of 1-5 W, or in the interval of 2-3 W. Such optical units will emit heat so that the optical unit, during operation of the device, exhibits an outer temperature of e.g. about 37- 60 °C, such as about 40-55 °C. Hence, the arrangement of mass flow device must be configured so that the heat emitted from the heat source is redistributed from the air in close proximity of the heat source to other places of the device and/or its surrounding environment.

The mass flow devices, typically in the form of axial or radial fans having a suitable potency, may be arranged in different ways depending on the size, shape and details of the casing, heat source and other components of the device. Typically, the fans may be covered by a metallic mesh to protect users from being hurt (by accidentally putting their fingers into the fans). The exact solution for each specific cell monitoring device may need to be optimized. For the CELLCYTE device, the fans were attached by screws, and a metallic tray was placed between the fans and the case. The fans may e.g. have a potency in the range of 1-10 W, preferably in the range of 2-3 W. A skilled person would know where to get such fans. For example, the fan (e.g. as the back (rear) fan used in concept 11) can be "https://www.digikey.com/product- det3il/en/delta-electronics/EFB0612HHA/603-1026-ND/1014357". This fan has a mass flow rate of 0.594 m³/min (CFM (cubic feet per minute) of 21.2), and a maximum speed of 4800 rpm. Maximum power is about 2-3W, such as 2.16 W or 3.0 W. Further, for example, the fan (e.g. as the bottom fans of concept 11) can be "EK-Vardar EVO 120ER White BB (500- 2200rpm)". This fan has a max air flow of 77 CFM = 131 m³/h (2.18 m³/min), and speed 500- 2200 rpm. Maximum power is 2.16 W.

The mass flow rate caused by each mass flow device should be on a level suitable for efficiently distributing the heat emitted by the heat source, without emitting unnecessary additional heat. Thus, a balance between power and mass flow rate capacity must be chosen. This level may be different for different devices, depending on heat source, it position, the design of the casing and the entire cell monitoring device, as well as the characteristics of the surrounding environment. For the CELLCYTE system, which device has been used as a proof of concept for the invention, a maximum mass flow rate (per fan) in the interval of about 0.25 - 5 m³/min is suitable, preferably in the interval of 0.5-2.5 m³/min. In order to obtain a mass flow that allows a suitable and sufficient distribution of heat in accordance with the invention, it is preferable if the mass flow is configured so that cooler air is distributed to the location of the heat source, and that heat emitted from the heat source is distributed to a location of the monitoring device and/or the surrounding environment where it can be easily "absorbed" by the surrounding air, without any direct impact on the condensation in the sample vessels. This can be obtained for example by placing a first mass flow device so that it can distribute air from the environment surrounding the casing of the monitoring device(typically cooler air) into the casing, and placing a second mass flow device so that it can distribute air close to the heat source (typically warmer air) out of the casing to the surrounding environment. Especially, it is advantageous if the first and second mass flow device can cooperate to create a continuous mass flow from the surrounding environment into the casing in close proximity of the heat source, and out again from the casing to the surrounding environment. Hereby, any heat emitted by the heat source is continuously distributed to other locations of the monitoring device and especially the environment surrounding the casing of the monitoring device, such as an incubator, in which the monitoring device is placed. A solution in accordance with this principle can be seen in concept 11 of figure 3 and 4, and is further disclosed in figure 5. If a movable heat source is used, it is important that the mass flow created by the mass flow devices will allow redistribution of air within the entire volume of the casing, in which the movable heat source can move.

Especially, in accordance with the embodiment disclosed in figure 2, 3, 4 and 5, it has shown to be preferable that at least a first mass flow device is positioned at the bottom of the casing, allowing cooler air from underneath the bottom of the casing of the monitoring device into the casing to cool down the heat source, and that one mass flow device is positioned at the back (rear part) of the casing, thereby allowing heat emitted from the heat source to be distributed out from the casing. In this way a continuous flow of mass is created, having the overall effect that temperature differences in the monitoring device and in the surrounding environment is levelled out, thereby minimizing condensation in the sample vessels. Other configurations are also fully possible, such as 1, 2, 3 or 4 mass flow device at the bottom of the casing, and 1, 2, 3 or 4 mass flow device at the back of the casing, as long as the mass flow created is sufficient, and heat emitted from the mass flow devices is minimized. Generally, it appears important to provide a slightly stronger mass flow of cool air into the casing, compared to the mass flow of warm air out from the casing at the back, according to this embodiment. Air can also escape e.g. via the top of the casing, which typically is open.

For condensation to occur, heat is typically transferred to the sample vessels from the heat source via the air in the incubator, or via heating of the top layer of the casing, or both.

The mass may be a gas or a liquid, such as air or water. Typically, the mass is air. Inside an incubator, the temperature for mammalian cell culture applications may e.g. vary between about 20-40 °C, and often a temperature around 37 °C is used. The humidity is typically above 90% relative humidity for mammalian cell culture applications.

As can be seen from figure 1 and 2, the heat source, in the form of an imaging system, may be movable within the casing underneath the sample tray so that each sample vessel of the sample tray can be monitored by the imaging system.

In one specific embodiment (see figure 2), the device further comprises a gantry system 4 arranged at least partly within the outer casing 2, said gantry system comprises a framework of connected extended members, said framework comprising: a first extended member being configured to extend in at least a latitudinal direction, and at least one second extended member being configured to extend in a longitudinal direction, said longitudinal direction being perpendicular to said latitudinal direction and a gantry frame structure extending along an orthogonal direction being perpendicular to the latitudinal direction and the longitudinal direction, at least one movement member, the heat source, in form of an imaging system 5 arranged on the gantry frame structure, wherein the imaging system comprises a detection layer and an illumination layer and wherein the gantry frame structure comprises an internal orifice enabling the sample tray 3 to be positioned within said orifice, and said detection layer is arranged within the outer casing 2 and attached to a lower portion of the frame structure, and under the sample tray 3, such that the detection layer is movable in a planar direction in relation to the sample tray 3 in response to actuation of said at least one movement member. This embodiment refers e.g. to the CELLCYTE system. Two mass flow devices 6, 7 are positioned at the bottom, to the front, of the device, and one mass flow device 8 is positioned at the back of the device. The principle mass flow generated by these mass flow devices can e.g be as shown in figure 5, where the two mass flow devices at the bottom causes a mass flow into the casing, and the mass flow device to the back causes a mass flow out of the casing. Hereby, as a result of the mass flow redistributing air, the higher temperature (T2) inside the casing, as a result of heat emitted from the heat source (not shown), is levelled with the lower temperature outside the casing.

The casing may be equipped with holes or vents in order to ventilate air to the surroundings. Especially, the bottom of the casing may be equipped with holes in order allow mass to flow in and out of the casing to the surroundings, e.g. the incubator. Such holes may have the size of approximately 1 cm, even though other sizes may also be used.

The second aspect of this disclosure shows a humid incubator system, comprising: the cell monitoring device of the first aspect; and means to control temperature, gas concentrations and/or humidity conditions within the incubator. The volume of the incubator may be of any suitable size, e.g. depending on the cell monitoring device used. The volume may e.g. be in the range of 10 to 1000 I, preferably 50-500 I, more preferably 100-250 I. Examples of humid incubator systems to be used are Heracell VIOS 160i, ThermoFisher, Forma Series II water jacketed CO2, ThermoFisher. Galaxy 170R/S co2 incubators and eppendorf vials.

The third aspect of this disclosure provides a computer program for controlling the operation of the one or more mass flow devices of the cell monitoring device of the first aspect, comprising instructions, which when executed cause the program to control the operation of the one or more mass flow devices, as a response to temperature variations detected by the at least one temperature sensor of the monitoring device.

According to some embodiments, temperature sensors that can detect temperature variations of 0.1°C and upwards can be used, and a PID (proportional-integral-derivative) controller can be used to regulate the mass flow. The person skilled in the art realizes that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

EXAMPLES

In the present invention, the inventors have created a mass flow specifically designed to reduce the temperature differences surrounding the heat source, such as an optical unit, of a cell culturing or cell monitoring device, such as a live cell imaging device, inside a humid incubator, therefore avoiding condensation in the sample vessels.

In the specific examples, the cell culturing/monitoring device used was the CELLCYTE device. The incubator used were Heracell VIOS 160i, ThermoFisher and 2 different incubators from Forma Series II water jacketed CO2, ThermoFisher. To develop the temperature differential reducing system, the inventors studied the different available options and chose to use mass flow, especially air flow, to distribute the heat, since this method offers a wider solution compatible with live cell imaging systems. To determine the correct air flow system, different possibilities were tried regarding the air flow direction and the device used to create the flow. The tests were performed using a live-cell imaging system where the camera was in constant movement to test for broader and advanced scenarios in this type of instruments. About the devices creating the air flow, different types of fans were evaluated (Table 1) for potency of the air flow and heat created, measured as temperature in the source and the incubator, respectively.

Table 1.

To determine the best air flow direction, the fans were placed at different positions in the case of the live-cell imaging system and in different combinations (Figure 3). The main test was the evaluation of condensation/dew formation on the lid of liquid containing vessels (Figure 4). After extended tests and analysis of the results, the inventors concluded that the fan solution that eliminates traceable condensation (as documented by taking images) is the one presented in Figure 4 (concept 11). This solution consists of two axial fans located at the front and under the heat source case, the fans create an air current sucking air from the exterior of the case, the lower part of the incubator generally contains the colder air since heat tends to migrate from lower to higher points, the current encounters the heat source cooling it by dragging the hot air away at the same time it keeps constant temperature under and above the liquid containing vessels (Figure 5).

Claims

1. A cell monitoring device for use inside a humid incubator, comprising: i. an outer casing (2), in open or closed arrangement, comprising a bottom (11), a top (12), a front part (13), a rear part (14), and a first and second side parts (15, 16); ii. a sample tray (3) adapted to receive at least one sample vessel, said sample tray being positioned within or on top of the outer casing; iii. at least one heat source (5), such as an imaging system, comprising an optical unit, arranged in fixed or movable position within the outer casing; and iv. one or more mass flow devices (6, 7, 8) arranged within the outer casing; characterized in that the one or more mass flow device(s) (6, 7, 8) have the capacity to cause a mass flow within the outer casing and/or a surrounding environment, such as the incubator, thereby levelling temperature differences created by heat emitted from the heat source(s) within the casing and/or in the surrounding environment, such as in the incubator, thereby minimizing condensation in the at least one sample vessel(s).

2. The cell monitoring device according to claim 1, wherein the device is, a bioreactor or a cell monitoring device, such as a live-cell imaging device.

3. The cell monitoring device according to claim 1 or 2, wherein the mass is a gas, such as air.

4. The cell monitoring device according to any of the preceding claims, wherein the heat source, in the form of an imaging system, is movable within the casing underneath the sample tray so that each sample vessel of the sample tray can be monitored by the imaging system.

5. The cell monitoring device according to any one of the preceding claims, wherein the device further comprises a gantry system arranged at least partly within the outer casing, said gantry system comprising a framework of connected extended members, said framework comprising: a first extended member being configured to extend in at least a latitudinal direction, and at least one second extended member being configured to extend in a longitudinal direction, said longitudinal direction being perpendicular to said latitudinal direction and a gantry frame structure extending along an orthogonal direction being perpendicular to the latitudinal direction and the longitudinal direction, at least one movement member, the heat source, in form of an imaging system arranged on the gantry frame structure, wherein the imaging system comprises a detection layer and an illumination layer, and wherein the gantry frame structure comprises an internal orifice enabling the sample tray to be positioned within said orifice, and said detection layer is arranged within the outer casing and attached to a lower portion of the frame structure, and under the sample tray, such that the detection layer is movable in a planar direction in relation to the sample tray in response to actuation of said at least one movement member.

6. The cell monitoring device according to any one of the preceding claims, wherein a first mass flow device is arranged to create a mass flow from the surrounding environment, such as the incubator, into the casing, and a second mass flow device is arranged to create a mass flow from the casing to the surrounding environment, such as the incubator.

7. The cell monitoring device according to claim 6, wherein the first mass flow device is arranged at the bottom of the casing, and the second mass flow device is arranged at the front, rear or side parts of the casing.

8. The cell monitoring device according to claim 7, wherein the first mass flow device is arranged at the bottom of the casing, close to the front part, and the second mass flow device is arranged at the rear part of the casing.

9. The cell monitoring device according to any one of the preceding claims, wherein the casing further is equipped with vents or holes allowing mass to flow in and out of the casing to the incubator.

10. The cell monitoring device according to any one of the preceding claims, wherein the sample tray comprises sample vessels in the form of 96-well plates with 100pL liquid per well, 48 well plates with 0.5mL per well, 24 well plates with lmL per well, 12 well plates with lmL per well and 6 well plates with 2ml per well.

11. The cell monitoring device according to any of the preceding claims, wherein the mass flow device is a fan.

12. The cell monitoring device according to any one of the preceding claims, wherein each mass flow device have the following characteristics: i. a potency in the range of 1-10 W, preferably in the range of 2-3 W; and/or ii. a maximum mass flow rate capacity in the interval of 0.25 - 5 m³/min, preferably in the interval of 0.5-2.5 m³/min.

13. The cell monitoring device according to any one of the preceding claims, further comprising at least one control unit and a data storage unit.

14. The cell monitoring device according to any one of the preceding claims, further comprising at least one temperature sensor for detecting temperature variations in the device.

15. A humid incubator system, comprising: a humid incubator; the cell monitoring device of claims 1-14; and means to control temperature, gas concentration(s) and/or humidity condition(s) within the incubator.

16. The humid incubator system according to claim 15, wherein the volume of the incubator is in the range of 10 to 1000 I, preferably 50-500 I, more preferably 100-250 I.

17. Computer program for controlling the operation of the one or more mass flow devices of the cell monitoring device of claims 1-14, comprising instructions, which when executed cause the program to control the operation of the one or more mass flow devices, as a response to temperature variations detected by the at least one temperature sensor of the monitoring device.