WO2009005368A1

WO2009005368A1 - Imaging system

Info

Publication number: WO2009005368A1
Application number: PCT/NO2008/000248
Authority: WO
Inventors: Morten Iversen; Esben Wingerei; Arne Sunde; Lesley Hutchins
Original assignee: Cellcura As
Priority date: 2007-06-29
Filing date: 2008-06-30
Publication date: 2009-01-08

Abstract

The present invention concerns A digital wide field imaging station, suitable for egg recovery in in-vitro fertilization (IVF), comprising a support (2, 102), a table top (3, 104), a rear wall (5, 104) and a hood (5, 105), an imaging device comprising a transpar-ent object table (31, 131) for supporting a sample with an inverted microscope under-neath, the microscope comprising a lens system (62, 162), a mirror (61, 161) and a video camera (63, 163), wherein the object table is integrated in the table top, the hood covers a part of the rear wall, the object table and a surrounding work space of the table top, the hood having an opening facing the operator of the station, the rear wall com-prises vents (43, 143) in the part of the rear wall within the hood, supplying an essen-tially horizontal laminar flow of controlled air towards the operator, a screen (42, 142) connected to the video camera is positioned above and outside of the hood for magnified viewing a sample on the object table.

Description

Imaging system

The present invention concerns a digital wide field imaging station comprising, suitable for egg recovery in in- vitro fertilization (IVF), and a method for extracting eggs from a sample. The invention also concerns the use of the station and a method for egg recov- ery.

Background of the invention

Many couples and women in their fertile years are incapable of conceiving children and rely in an increasing degree on artificial reproductive technology (ART) as methods for conception. Among these is in- vitro fertilization wherein egg cells are collected from the female to be joined with sperm cells in vitro and subsequently reintroduced into the donating female or a different female (surrogate mother) after impregnation.

During the in vitro stage of the procedure(s), and even as soon as immediately after the egg cells have been collected from the female, the egg cells are very sensitive to fluctuations in the environment such as variations in temperature, pH, radiation, oxidative stress (impact from the air) and even to gentle physical handling. The extraction of eggs, also called egg recovery, from a sample is therefore a delicate operation under microscope that requires stable environmental conditions with minimum fluctuations and quick work from the operator.

The egg cells (collected through suction), are initially placed in a culture well or dish and subjected to numerous washing steps with different media as well as an inspection to determine their quality under microscope. During these initial steps, the eggs are most vulnerable and highly sensitive to environmental changes.

Sperm cells are also subjected to diverse procedures under microscopic observation to determine their quality and possibility for fertilization, e.g. their mobility, their shape, their viability, before being used for IVF or intracytoplasmic sperm injection (ICSI). After fertilization, the embryo developed is also monitored under microscope for inspection and evaluation before being transferred to the recipient.

Thus there is a need for quick and reliable imaging for all of the above operations, especially for egg recovery, under stable controlled environmental conditions. In the classic in vitro fertilization procedures, several units more or less adapted for the different steps of the procedures, such as examination, washing, transfer, fertilization, counting, etc., are normally used. Each unit performs a separate task, and the modules may be placed around in a lab or in several rooms when space is lacking. Such individ- ual steps performed at different locations have as a consequence that the cells are exposed to different environments and unnecessary handling, resulting in the cells becoming stressed. In addition, there is a risk of spilling samples and unintentionally swapping samples. Studies have shown that a gentle handling of the cells, together with a physiological atmosphere, stable temperature, cleanliness and low radiation is of utmost im- portance in order to obtain cells and pre-embryos of good quality and a high success rate. Thus, there exists a need for units suitable for interconnection with other units to keep the spatial distance of transfer for the cells to a minimum, wherein the handling of the cells is performed under strictly controlled conditions in a safely traceable manner.

The equipment or units used today in IVF are often equipment inherited from other fields of related technology which are not exactly adapted to the given purpose. The units used in a lab do not necessarily fit well together, have different types of sterile air supply systems and have no intercommunication with each other. The operators of this equipment therefore work in demanding conditions including noise from different air supply systems, different heights on workbenches, and different heights of equipment making the working position less than optimal for such accurate work. This is especially true for microscopes used in IVF, such as in procedures of egg recovery, sample extraction and evaluation etc.

The need to insert some of the equipment, such as microscopes for egg recovery (and ICSI equipment) into sterile air hoods also makes awkward work for the operator since a good working position is difficult with high positioned oculars inside a hood. The operator often must bend down to the sample on the microscope stage in order to position the sample, as the oculars and lenses are in the way and then stretch up to see though the oculars. Also the hood must be adjusted up and down in accordance with these operations. Thus, there is a need for imaging equipment wherein the operator may have a more ergonomic work position.

Prior art

Standard stereomicroscopes with oculars, which are integrated in a work bench inside a sterile air cabinet are known and produced by for example K-Systems, www.k- systems.dk. Such current workstations have several shortcomings. The stations are normally adapted to standing work, inherited from conventional lab work where the operator walks a lot around in the lab for various reasons. Often a high stool is provided for the operator in order to relax the legs somewhat from all day standing, but a good balance or ergo- nomic working position is seldom obtained. However, in order to perform quick and precise work, such as in IVF, with maximum concentration, a seated position as in a normal work desk would be preferable.

The covering of the front hoods in the current workstation are in addition limited as the oculars for the microscopes need to accessible from outside of the hood. This results in hoods with large openings in front, risking contamination and temperature change of the atmosphere even though sterile or clean air is provided from within the hood.

The K-system IVF workstation may be provided with a built in monitor for operators to discuss the viewed sample or for education. However, a monitor inside the hood, will suffer from reflection in the front glass hood, and it will be difficult for the operators to point at the details on the monitor, which in turn may lead to misunderstandings and faults in choice of material from the samples. If the hood is raised to avoid these problems, there will be an increased risk of air contamination.

EP 0 124 980 describes an inverted microscope with a rigid stage, mounted on a table top wherein a video camera is used for retrieving images which are shown on a monitor.

The microscope according to EP 0 124 980 has its lenses positioned up-side down ,com- pared to a regular microscope, underneath the glass stage which eases access to the sample as no oculars are present. Handles on the side of the stage are used to focus the lenses and to switch between different magnification lenses. The focused image is reflected by a mirror into a conventional video camera.

The inverted microscope described in EP 0 124 980 provides a stage with important size, especially in height, due to the microscope parts vertically stacked and comprised within the stage. Samples may be placed on the relative large stage area, but have the risk of a large drop if pushed over the edge by accident. The stage comprises the handles for focusing the microscope and the stage must therefore be placed on top of a normal work table or work bench, which may provide under arm support for the operator while focusing, but not while moving the sample. The light source must also be supported by a stand, which is not attached to the stage and may tip, and in any case limits the movements of the operator's hands. Work benches with laminar flow are available, such as Telstar horizontal laminar flow bench supplied by Progen Scientific Ltd.

Brief description of the invention

The present invention therefore concerns A digital wide field imaging station, suitable for egg recovery in in-vitro fertilization (IVF), comprising a support, a table top, a rear wall and a hood, an imaging device comprising a transparent object table for supporting a sample with an inverted microscope underneath, the microscope comprising a lens system, a mirror and a video camera, wherein

- the object table is integrated in the table top,

- the hood covers a part of the rear wall, the object table and a surrounding work space of the table top, the hood having an opening facing the operator of the station,

- the rear wall comprises vents (43, 143) in the part of the rear wall within the hood, supplying an essentially horizontal laminar flow of controlled air towards the operator,

- a monitor (42, 142) connected to the video camera is positioned above and outside of the hood for viewing a sample on the object table.

The invention also concerns the use of the device and a method for egg recovery according to the claims.

The invention will further be described in greater detail by the help of example embodiments below, which are not to be construed as limiting the scope of the invention. Combinations of the embodiments are also within the scope of the invention.

Drawings

Fig. 1 shows a first embodiment of an imaging station according to the present inven- tion;

Fig. 2 shows a side view section of the digital wide field imaging device in fig. 1. Fig. 3 shows a second embodiment of an imaging station according to the present invention;

Fig. 4 shows a side view section of the digital wide field imaging device in fig. 3.

Fig. 5 shows an enlarged side view section of the digital wide field imaging device in fig. 3.

Detailed description

The imaging stations 1 and 100 as shown in figures 1-2 and 3-5 respectively, are built up as a work bench comprising a support 2, 102 a table top 3, 103, a rear wall 4, 104 and a hood 5, 105.

The Support

The support 2, 102 may be of any shape and form suitable for the location of the station and the user and supports the table top 3, 103 and optionally the rear wall 4, 104. hi the shown embodiments, two side members with one or more transverse elements are used for support of the station. The side members comprise adjustable feet 21, 121 in order to level the station. In addition, the side members may comprise one or more integrated couplings for connecting the station to other modules, such as in an IVF work station. The couplings may be for power, data, heating and ventilation such as the coupling 22 shown in fig. 1. The coupling may alternatively be positioned on other parts of the station. The support may be height adjustable, such as telescopic, in order to provide opti- mal working conditions for the user.

hi addition the side pieces and transverse elements may comprise additional equipment such as pedals for operating equipment as discussed bellow (not shown).

The Table Top

The table top 3, 103 is in preferably shaped in an ergonometric favourable manner, preferably providing support for the under arms, of an operator sitting or standing at the station such as shown in figure 1 , preferably sitting, which is of importance in order to execute precise work at in a quick manner. Unlike conventional microscope stations, the table top 3, 103 is completely smooth, and may be without any protruding parts, especially in the main work area. The imaging device may be integrated fully or partly in the table top or be attached directly to the underside of the table top 3, 103, as described in further detail below. The object table of the imaging device is totally integrated in the table top and the glass object table 31, 131 of the device is flush with the table top 3, 103. This solution provides a totally flat work area where no samples may tip and they may smoothly be moved or pushed in the desired location. In addition, the smooth work area is easy to clean as there may be no protruding parts, or only a strict number of protruding parts collecting dirt.

The glass object table 31, 131 may optionally contain one or several lighting sources, such as a LED-ring (Light Emitting Diodes) to illuminate the sample from underneath; so that light will be reflected into the imaging device, depending on the type of sample analyzed.

The table top 3, 103 also comprises integrated heating in order provide stable temperature conditions for the samples being inspected or treated, such as 37,5⁰C. Preferably the heating system is interconnected with other modules within a workstation. The heat- ing may be provided by electric heating cables or a medium passing through pipes in the table top. Preferably, meshed cables or heating mats providing homogenous heating of the table top may be used. Each table has one or more temperature sensor(s) integrated in order to adjust the heating correctly. In addition, the table top may comprise hot spots 32 where the heating is somewhat increased compared to the rest of the table in order to quickly heat up samples that have cooled, for example outside of the imaging station, such as due to transport.

hi order to log the samples being treated or analysed and/or the users of the station, the table top 3 may be equipped with a registration scanner 33 connected to a data system within the station or a central data system to which the station is connected. The scanner may of course alternatively be place in other parts of the station, such as on the side wall inside of the hood 5 in order to keep the table top free of objects and making it easier to clean. The scanner 33 may be a bar code scanner and/or RF-ID (Radio Frequency Identification) scanner, registering a labelled sample or the operator carrying a bar code into the system. Thus, all samples and operators may be traced according to regulations in place or to be implemented. The scanner may also be used in combination with a locking system connected to a tracing system, which for example could demand the registration of the sample and/or operator before the module or a monitor is turned on.

In the embodiment of figures 3-5, further optional equipment is available on the table- top, such as electrical socket(s) 144, an egg counting button 134, and a reflex detector 135, which registers when a sample dish is in place over the object table glass 131 and initiates operations, such as for example IR temperature readings, lighting, egg counting button etc. Such equipment, e.g. egg counting button and sensors/detectors etc. may also be integrated smoothly in the table top for ease of cleaning.

The rear wall

The support 2, 102 also supports the rear wall 4, 104 in the shown embodiments. However, the rear wall may alternatively be stretching down between the side pieces 2, 102. Alternatively the rear wall may be an interior wall of a building, making up both the support and the rear wall, and supporting the table top. The imaging station is often used as a receiving unit in IVF wherein a Petri dish or similar container is being received from the operating room. Time is of the essence in finding an egg and retrieving it for transfer to a second container. In some clinics, the operating room is not close to the rVF-lab and samples have to be transported from other rooms and into the lab. However, in the embodiment of figures 1-2, the rear wall 4 of the station 1 comprises a "hole in the wall" 41, that is, an opening in the rear wall of the station intended to be directed towards the operating theatre room so that the container with sample may be received without any delay. The opening 41 preferably has an internal horizontal support surface flush with the table top 3. It may have a door, or even an "air lock" device, which may be opened and closed manually or by a motorized device either directly or remotely by the station operator or from the operating theatre room. The air lock system would prevent a draft of non-sterile air into the station and could enable purging the sample with sterile air before entering the station.

The egg recovery process is the most sensitive procedure within the IVF workflow and requires stringent control of atmosphere and temperature. On each side of the opening 41, within the hood, from the table top level and up, are vents 43 supplying an essentially horizontal laminar flow of sterile air flowing from a series of openings in the rear wall of the station towards the operator over the table or work space. In the embodiment of figures 3-5 the entire rear wall within the hood have similar vent openings 143, providing such air flow.

The air provided by the vents 43, 143 is may be supplied by an integrated unit or preferably by an external atmosphere unit, which may be connected to the station, such as by the inlet 22, or via connected modules with similar couplings. The external unit replaces the ventilation devices mounted above the work space in traditional work benches or hoods and limits fan noise to the minimum. The speed and amount of laminar horizontal air flow is adjusted to the shaped hood which provides better control of the atmosphere by reducing turbulence and making it possible to limit the volume of atmosphere to be controlled as the shield only needs to have a height covering the required instruments or sufficient space for the operator's hands, contrary to conventional hoods. The external unit may provide a controlled environment by supplying sterile air, or a preferred gas composition at correct temperature and humidity. Another main advantage of an external atmospheric unit is that fan noise from the unit is reduced to a minimum. Fan noise is known by operators to be disturbing and tiring during work and is caused by fan positioned in the top of a station directly over the operator. Such noise disturbs the operator or may even cause the operator to switch it off.

Image screen

The image provided by the imaging device is shown on a screen/monitor 42, 142 mounted on the rear wall above the hood 5, 105. The screen 42, 142 is preferably mounted flush with the wall 4, 104 of the station, or behind a transparent shield such as a glass plate or acrylic plate, in order to facilitate cleaning and disinfecting the station. Preferably, such a shield is anti-reflex treated, such as by a transparent non-reflecting coating. The screen may in addition to showing images from the imaging device of the sample and the operations being performed, show additional information such as data on the sample being treated, temperature readings from different locations, air composition, name of sample, etc. The screen is preferably a large screen, such as a LCD (Liquid Crystal Display) or plasma widescreen of high resolution in order to improve the operator's ability to find the eggs.

The positioning of the screen 42, 142 above the hood 5, 105 enables easy viewing without disturbing reflexes, such as may be the case when viewing a monitor inside a conventional lab workbench with a transparent hood. In addition, the easy and clear access to the screen makes it easy for operators or students/teaching personnel to point at the screen at specific details. Thus, the improved viewing and easy access to the screen con- tributes to improved security and quality of work being performed at the station.

The Hood

A transparent hood 5 or 105 is placed over the working space, sealing off the work space in the rear towards the rear wall 4, 104 and towards the table 3, 103. The hood has an opening in the front facing the operator for the sterile air supplied through the horizontal vents 43, 143 in the rear wall 4, 104 to escape.

hi the embodiments of figures 1-5 the hood 5, 105 may support one or more IR (Infra Red) temperature sensor(s) 51, 151.

In the present embodiment of figures 1-2 the IR sensor 51 , positioned centrally in the ceiling of the hood 5, measures the temperature of the liquid media of the sample being examined. When no sample is present on the object table, it may measure the surface temperature of object table, i.e. the glass object table 31. This novel method of surveying the temperature of the media, instead of the table top, provides the operator with a direct reading of the temperature of the actual sample and not its surroundings, such as in conventional set ups. The temperature reading makes it possible for the operator to quickly assess if the temperature of the medium containing the sample is correct or needs cooling or heating. The IR sensor may also be connected to the heating system of the table top 3, preferably through a controlling system, which may regulate the tem- perature of the table according to the temperature measurement of the sample, and thus compensate for possible fluctuations in temperature in the samples.

hi the embodiment of figures 3-5 another IR sensor 151 is shown extending a distance down from the ceiling of the hood 105 for more precise and/or local temperature reading of the sample, but may otherwise function as described above.

The hood 5, 105 provides the necessary shielding of the samples being analysed or treated without hindering the operator's movement physically. The operator may freely observe the work being performed, both directly and on screen as the hood also provides free viewing of the screen. In order facilitate the use of long pipettes, which are often used in this type of work, the hood may also comprises two "shoulders" or areas of increased internal height for storing and operating long objects, such as pipettes.

The hood may be detachable, and preferably hinged in its rear upper edges of the shoulders, preferably with spring loading, in order to swing the hood up for cleaning of the table top, or installation of equipment.

The hood 5, 105 may support several additional sensors, such a sensor measuring the temperature of the table top, the air, etc. as well as lighting equipment as described below. Lighting

The hood may also support one or more light sources 52, 152, 153 for illuminating the sample on the object table.

When inspecting organic live material like human eggs, one challenge is creating an illumination that gives enough contrast, as the material to be viewed is almost transparent. On conventional microscopes the light source is very close to the object to be viewed and it therefore fairly easy to create an angled light, which fills the entire field of view. This is usually accomplished with a mirror and a halogen lamp, hi the present invention, the distance from light source and the sample is much longer, in order not to obstruct the operator, which poses challenges.

The light source in the first embodiment of figures 1-2 is preferably LED, providing evenly distributed white light, hi this embodiment the LEDs provides a light source 52 with a light area of about 100 mm x 100 mm which provides a 98% even, uniform flat white light, especially suitable for illuminating the sample. In this manner the entire sample is illuminated from a distance of about 30 cm making it easier for the operator to find an egg in the sample. The light source 52 may be used alone or in addition to optional light sources integrated in the table top as mentioned above, such as in or around the glass 31, or reflected from underneath the sample. Both light sources being adjustable in intensity in order to obtain the best lighting and contrast of the sample.

hi the second embodiment of figures 3-5 illuminations is also mounted underneath the top of the acrylic clean air cabinet at a distance, which leaves ample space for handling a sample dish. The illumination is comprised of a flat panel of LED backlight 152 (such as 100x100mm) to give a uniform background with variable light intensity, hi addition, an angled fiber optic focused halogen light source 153, which creates shadow and con- trast is attached to the ceiling of the hood. The intensity of both light sources can be individually adjusted. The halogen light 153 is shown in more detail in figure 5, where the fiber optic cable 154 and focusing lenses 155 are shown. The focusing may be used to adjust the size of the illuminated field of the sample as well as to adjust contrast.

With the current invention the distance between the object and the light source is for example about 250-300 mm, which necessitates a totally different illumination than conventional microscopes. The combination of an LED backlight 152 and a focused angled fiber optic halogen light source 153 gives a very good contrasting image. Adjusting the intensity of the two light sources gives the flexibility between increasing the LED backlight for samples with darker fluids (higher blood content) for a bright field and reducing the LED intensity to achieve almost dark field illumination. One important criteria is that the halogen light source is placed outside the field of view of the camera and that the angle in relation to the sample is small, such as less than 20 degrees, pref- erably less than 15 degrees, most preferable less than about 10 degrees from the vertical.

The focusing and adjustment of the illumination may preferably be adjusted by foot pedals, leaving the operators hands free to handle the sample and move such levers outside of the hood. Alternatively the light intensity of any of the lights may be adjusted by the scrolling function on a computer mouse (not shown), which may be placed on an adjacent work table or on the table top outside of the hood, or by panels integrated in the table top for easy cleaning.

Image station for Egg recovery

The problem currently encountered in larger clinics when the lab performing egg recovery is located at a distance from the operating room, is that samples are cooled some- what during the transport to the lab. In the present station the problem of a cooled sample may be corrected by the interconnected system of the IR sensor 51, 151 and the heated table top increasing its temperature to correct the sample temperature, as mentioned above. However, in some cases an increased temperature of the entire table top may not be desirable, such as if other samples or the like are present on the table and therefore the hot spots 32 may be used, where the temperature is higher than in the rest of the table, e.g. 0,5⁰C higher. By placing a sample on a hot spot, the sample is heated more quickly to the correct temperature. Like the object table area, the hot spot(s) may also be surveyed by IR sensor which may also control the temperature, and which may provide a correct reading of the media temperature when a sample is placed on a hot spot. This novel method is by far safer and more reliable than the traditional heating blocks used to heat samples today, where only the temperature of the heating block is registered, which may be very different from the temperature of the sample, i.e. the egg and the medium in which it sits.

As described above the present imaging station is without oculars and relies on screens only. Although this solution may need getting used to by some operators, it provides for a far better ergonomic working position for the operator who will not have to lean forward and/or stretch upwards to the oculars, a movement which strains the back and is both uncomfortable and unhealthy over time. Instead, the operator may be seated in a normal working position, like in normal desk and perform the same functions as before by viewing on screens.

Imaging device

The mirror 61, 161, lens system 62, 162 and CCD camera (Charge-Coupled device) 63, 163 are arranged horizontally under the tabletop with a light path turned 90 degrees upwards through glass stage 31, 131 and dish with sample. By placing the mirror directly under the glass object table 31, 131 the vertical space occupied by the imaging device is kept to a minimum as all lenses and camera devices are positioned in the horizontal light path underneath the tabletop. This is yet another advantage for the operator's ergo- nomics as the imaging device is not in the way of the operators legs, and enables the operator to sit in a chair at the station, as at a normal work desk.

The camera 63, 163 is connected to a computer, which displays live image on the screen 42, 142 directly in front of the operator. The focusing and zoom of the camera may also be operated and adjusted using foot pedals underneath the tabletop, such as in the cross- piece (not shown), or by panels integrated in the table top, or by mouse or keyboard outside of the hood or on an adjacent table.

A section of the inverted digital wide field-imaging device is shown in figure 2 and 5. Underneath the glass object table 31, 131 a mirror 61, 161 is positioned reflecting the image to a lens system 62, 162 which magnifies and focuses the image onto a digital camera 63, 163 such as a high resolution CCD camera. The lens is preferably telecen- tric, such as object telecentric to obtain dimensional and geometric invariance of images within a range of different distances from the lens and across the whole field of view or image space telecentric, in order for the digital image sensor to have a minimum of colour crosstalk and shading problems. The field of view may be at least 30 mm x 40 mm and the telecentric lens projects the entire or half the sample image onto the chip which shows the image directly on screen.

Magnification is in this embodiment in the range of from about 1 x to about 100 x and may be both digitally and/or optical. Even at this magnification the telecentric lens and CCD chip covers all or at least half the area of the sample. The large area of the light source illumination the entire sample leaves the entire image on the screen illuminated making it optimal for the operator to find an egg in one or maximum two passes over the imaging device. This concept would not be possible with conventional microscope components within the same geometrical layout and dimensions where both the light- ing, viewing distance and the viewed sample area are in a different arrangment. Only recent development in CCD chips together with modern digital data processing makes the present invention possible.

The lens 62, 162 may be an auto focus lens and/or a zoom lens which may help the op- erator in the work being performed.

The imaging station may also comprise optical and/or digital image enhancement devices such as filters (optical or digital) in order for the operator to even more easily distinguish samples, such as the eggs. Alternatively, an external module may provide such image processing facilities.

Summary

Although the imaging device and station 1, 100 according to the present invention may be sold and operated as a stand-alone unit, it is also readily adapted for use in connection with other equipment in IVF-laboratory and for IVF procedures. Depending on the size of the lab and the procedures performed at the lab, the station may be operated closely together with one or more modules preferably interconnected and sharing for example a control and docketing system, table top heating, electrical power, ventilation and atmosphere control, etc.

The imaging station according to the present invention may provide digital video foot- age of procedures performed, such as egg recovery, both for educational purposes, advisory purposes and for documenting the procedures.

The advantages of this microscope compared to a conventional microscope is the clean surface with no objects in the way of handling the dish combined with a large high quality image on a screen directly in front of the operator which is positive for ergonomics.

In sum, the imaging station according to the present invention provides for:

1. Quality management and of the procedures performed;

2. An improved handling of samples due to reduction of risks and a stabilised environment; 3. Improved ergonomic working positions for operators;

4. Advanced information and documentation systems compliant with current regulations.

5 A method for egg recovery

The method according to the invention is concerned with the in vitro handling procedure of eggs recovery, preferably human eggs, comprising scanning a sample on the digital wide field imaging device and extracting an egg based on an image provided by the device and shown on a screen. o In detail the method may comprise the following steps:

a) Receiving a sample containing one or several eggs in a media;

b) Optionally registering the identification of the sample by a bar code and/or RF-scanner in the station;

c) Continuously measuring the sample temperature during inspection and re-5 co very;

d) Illuminating the sample by at least two light sources from at lest two different angles in relation to the sample;

e) Visualising the sample by a digital wide field imaging device on a screen;

f) Performing egg retrieval from the sample and transferring the egg to anothero container;

wherein all the above steps are performed within a hood of a imaging station with controlled atmosphere provided by horizontal laminar flow of gas, under stable conditions with respect to the temperature and atmosphere composition.

Claims

1. A digital wide field imaging station, suitable for egg recovery in in- vitro fertilization (FVF), comprising a support (2, 102), a table top (3, 104), a rear wall (5, 104) and a hood (5, 105), an imaging device comprising a transparent object table (31, 131) for supporting a sample with an inverted microscope underneath, the microscope comprising a lens system (62, 162), a mirror (61, 161) and a video camera (63, 163), characterized in that

- the object table is integrated in the table top,

the rear wall comprises vents (43, 143) in the part of the rear wall within the hood, supplying an essentially horizontal laminar flow of controlled air towards the operator,

- a screen (42, 142) connected to the video camera is positioned above and outside of the hood for viewing a sample on the object table.

2. A digital wide field imaging station according to claim 1 , wherein the object table is flush with the table top.

3. A digital wide field imaging station according to claim 1 or 2, wherein the object table comprises a light source illuminating the sample from underneath, preferably by

LED, more preferably by a LED ring.

4. A digital wide field imaging station according to any of the claims 1-3, wherein the mirror of the inverted microscope is positioned directly under the object table reflecting the image of a sample into the lens system, the lens system projecting, focusing and optionally magnifying the image of the sample onto the video camera or a CCD- chip.

5. A digital wide field imaging station according to any of the claims 1-4, wherein the lens system is a telecentric lens, such as object telecentric or image space telecentric.

6. A digital wide field imaging station according to any of the claims 1-5, wherein the magnification of the imaging device is between Ix and 10Ox, provided by optical devices and/or digital magnification.

7. A digital wide field imaging station according to any of the claims 1-6, wherein the image of the sample is filtered by a physical filter and/or a digital filter and/or processed digitally.

8. An imaging station according to any of the claims 1-7, wherein the hood (5) supports one or more light sources (52, 152) illuminating the sample on the object table.

9. An imaging station according to claim 8, wherein the light source comprises a flat panel of LED backlight (152) providing even distributed flat white light adjustable in intensity, preferably providing a light area of about 100 mm x 100 mm.

10. An imaging station according to claim 9, wherein the hood in addition comprises an angled focusable light (153) adjustable in intensity for creating shadow and contrast, preferably comprising a fibre optic halogen light.

11. An imaging station according to any of the 10, wherein the angled light is placed outside the field of view of the camera and the angle in relation to the sample is less than 20 degrees, preferably less than 15 degrees, most preferable less than about 10 degrees from the vertical.

12. An imaging station according to any of the claims 9-11, wherein the focusing of the light and adjusting of the light intensity of the light sources are operated by foot operated means.

13. A digital wide field imaging station according to any of the claims 1-12, wherein the table top comprises integrated heating by electric cables, heating mats or a medium in pipes, providing stable temperature conditions for the sample, preferably in the range of 35 to 39°C, more preferably 37.5°C.

14. A digital wide field imaging station according to claim 13, wherein the table top comprises one or more hot spots (32), with a higher temperature than the rest of the table top, preferably +0.5 ⁰C.

15. An imaging station according to any of the claims 1-14, wherein the hood supports one or more TR sensor (51) measuring the temperature of one or more of the object table, the table top, a hot spot(s) (32) or a sample(s).

16. An imaging station according to any of the claims 13-15, wherein heating of the 5 table top and/or the hot spots is regulated by one or more temperature sensor(s), and/or

FR sensor(s) (51) above the table top.

17. An imaging station according to any of the claims 1-16, wherein the table top comprises a reflex detector (135), which registers when a sample dish is in place over the object table glass, preferably initiating operations, such as IR temperature readings io of the sample.

18. An imaging station according to any of the claims 1-17, wherein the controlled air is sterile air or gas composition, preferably provided by an external atmosphere unit.

19. An imaging station according to any of the claims 1-18, wherein the rear wall comprises the screen (42), preferably mounted flush with the wall of the station or be- i₅ hind a transparent shield such as a glass plate or acrylic plate.

20. An imaging station according to any of the claims 1-19, wherein the station comprises couplings for connecting the station to other modules, such as in an IVF work station, the couplings being one or more of: physical couplings holding the modules together, power, data, heating and ventilation or sterile air or gas stream.

₂o 21. A method for in vitro handling and/or inspections of a sample comprising scanning a sample on the digital wide field imaging station according to any of the claims 1- 20 and handling and/or inspecting the sample based on an image provided by the station.

22. A method according to claim 20, for egg recovery, preferably human eggs, com- ₂₅ prising scanning a sample on the digital wide field imaging station according to claims

1-20 and extracting an egg based on an image provided by the device or station shown on a screen.

23. A method of egg recovery, suitably within IVF, comprising the following steps:

a) Receiving a sample containing one or several eggs in a media; b) Optionally registering the identification of the sample by a bar code and/or RF-scanner in the station;

c) Continuously measuring the sample temperature during inspection and recovery, preferably by an IR-sensor;

e) Visualising the sample by a digital wide field imaging device on a screen;

f) Performing egg retrieval from the sample and transferring the egg to another container;

wherein all the above steps are performed within a hood of an imaging station with controlled atmosphere provided by horizontal laminar flow of gas, under stable conditions with respect to the temperature and atmosphere composition.

24. The use of the digital wide field imaging station according to any of the claims 1-20 for egg recovery within in vitro fertilization (IVF).