GB2393405A

GB2393405A - Oocyte handling system

Info

Publication number: GB2393405A
Application number: GB0319557A
Authority: GB
Inventors: Giles Andrew Bishop
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 2002-09-04
Filing date: 2003-08-20
Publication date: 2004-03-31
Anticipated expiration: 2023-08-20
Also published as: GB0220642D0; GB0319557D0; GB2393405B

Abstract

An oocyte handling system comprises a unit having an inlet, connected via a tube 22, fig.1 to a viewing chamber 20, and means suitable for drawing liquid with oocytes into the viewing chamber 20, such as a pump arrangement 18. Access means 42 are provided, by which oocytes can be removed during observation. Further disclosed is an apparatus as already described, further specifying heated dual lumen tubing 24,25, an oocyte recovery needle 3, valve 26, flushing liquid, a pump 18, a heated plate 44, and a removable oocyte receptacle 51. The arrangement may provide physical damage to oocytes normally caused by temperature variation and contamination by providing a heated and sealed unit.

Description

1 2393405

OOCYTE HANDLING SYSTEMS

This invention relates to oocyte handling systems.

Conventionally, an oocyte is extracted from a woman using a needle connected to a test tube via a length of tubing. Suction is applied to the test tube by a vacuum pump to cause a reduced pressure in the test tube that can suck the oocyte into the test tube. Often a flushing liquid is supplied along a secondary lumen of the needle to assist removal. Once the oocyte has been extracted, it is transferred to a suitable receptacle for viewing under a microscope.

The oocytes are then transferred to a dish for fertilization or other treatment.

One problem with this technique is that it involves appreciable handling of the oocyte.

This may result in physical damage to the oocyte, variations in temperature and exposure to contamination. It is an object of the present invention to provide alternative oocyte handling systems.

According to one aspect of the present invention there is provided an oocyte handling system comprising a unit having an inlet, a viewing chamber, means for drawing liquid with oocytes into the viewing chamber, access means to the viewing chamber by which oocytes can be removed under observation and tubing connected with the inlet by which oocytes and liquid can flow to the viewing chamber.

The apparatus preferably includes a source of a flushing liquid and means for supplying the flushing liquid to an outlet of the unit. The tubing is preferably arranged both to supply flushing liquid to an oocyte recovery needle and to supply liquid and oocytes from the needle to the inlet. The tubing may include a user-operable valve by which flushing and suction can be controlled. The unit preferably includes pumping means for pumping flushing liquid from a container in the unit and for applying suction to draw oocytes and liquid into the viewing chamber. The unit preferably includes a container for drained flush liquid after removal of oocytes. The viewing chamber preferably includes a magnifying viewing means, such as a microscope. The unit is preferably heated and the tubing may also be heated. The access means may include a self-closing material or a valve. The unit preferably includes a removable receptacle for oocytes removed from the viewing chamber. The unit may include means for supplying carbon dioxide enriched air to the removable receptacle.

According to another aspect of the present invention there is provided a oocyte handling system comprising a unit having an inlet/outlet, heated dual-lumen tubing connected at one end with the inlet/outlet and at its other end with a dual-lumen oocyte recovery needle, and a valve connected between the tubing and the needle to control flow to and from the needle, wherein the unit includes a container of flushing liquid for supply to the outlet, a viewing chamber, a pump for drawing liquid with oocytes from the tubing into the viewing chamber, access means to the viewing chamber by which oocytes can be removed under observation, a heated support and a removable receptacle on the support adapted to receive the oocytes after removal from the viewing chamber.

An oocyte handling system according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the system; and Figure 2 is a transverse sectional view across the unit of the system.

The system comprises a unit 1 connected by a tubing set 2 to a conventional dual-

lumen oocyte recovery needle 3.

The unit 1 is of elongate shape having recesses 10 and 1 1 on the upper and lower surfaces at its left-hand end in which are removably secured a flush cartridge 12 and a drain cartridge 13. The flush cartridge contains a quantity of a sterile saline solution or other liquid that is expended during use in flushing out oocytes from a patient's ovaries. The drain cartridge 13 fills with returned flush liquid and follicular fluid as the flush cartridge empties.

An inlet 14 and outlet 15 in the recesses 10 and 11 connect with the flush cartridge 12 and drain cartridge 13 respectively. The inlet 14 connects with an electric pump 16 that pumps liquid from the cartridge to the outlet 17 of the unit. Similarly, the drain inlet 15 connects with a pump 18 in the unit 1 that pumps liquid into the drain cartridge 13 from a viewing chamber 20 within the unit 1, which will be described in greater detail later. The pumps 16 and 18 may be completely separate of one another or they could have a common motor. The two pumps could be provided by a single pump, such as by different sides of a pumping chamber. The suction and flushing pressures can be accurately controlled by the pumps compared with previous arrangements involving syringes to apply the flush liquid and apply

/ the suction. The viewing chamber 20 has an inlet 21 connected to an inlet 22 of the unit 1, located adjacent the outlet 17, at the right-hand end ofthe unit.

The tubing set 2 has a connector 23 at one end connected to the outlet 17 and inlet 22 of the unit 1. The tubing set 2 has two lumens 24 and 25 in communication respectively with the outlet 17 and inlet 22. The opposite end of the tubing set 2 has a combined valve and coupling 26 with ports 27 and 28 connected with flush and suction lines 29 and 30 of the dual- lumen oocyte needle 3. The valve 26 has a manual control 31 that is switchable between three different positions, namely: flush and suction off: flush on and suction off; and flush off and suction on. In this way, the user can readily select between flushing and suction at a location close to where the needle is held. The tubing set 2 could be relatively short, where the unit 1 is located adjacent the patient, or could be longer, such as between about 2 and 4m, where the unit is located remotely, such as in an adjacent room. The tubing set 2 is heated such as by means of warmed water flowing in a jacket along the tube or, preferably, by electrical means, such as described in US5713864 and US6259074.

The viewing chamber 20 is of cylindrical shape extending on a vertical axis. On its upper side the chamber is closed by a window 40 above which is mounted a combined microscope and light 41 or other magnifying viewer. The field-of-view of the microscope 41

is sufficient to enable the entire volume of the chamber 20 to be viewed. At one side of the chamber 20 there is access means in the form of a selfclosing site 42. The site 42 is made of a resilient material having a passage pierced through it without removal of material so that an instrument can be pushed through the passage in sealing engagement with the passage and, when removed, the passage closes. The site 42 enables a pipette 43 to be pushed through it

into the viewing chamber 20. Alternatively, the site could be provided by a duckbill valve or similar, which allows the pipette 43 to be inserted but closes when the pipette is removed.

Beneath the viewing chamber 20 the unit 1 includes an electrically heated plate 44, which is thermostatically regulated to maintain the temperature of the viewing chamber at the desired temperature, around 37 C. Power for the pumps 16 and 18, the heated plate 44 and the heated tubing set 2 are supplied via an electrical cable 45 and an isolated power supply (not shown) within the unit 1.

The heated plate 44 also extends beneath a tray 50 projecting horizontally below the access site 42 and housing a removable receptacle in the form of a dish 51 containing an oocyte culture medium. The tray 50 is partly covered by a roof 52 to which is attached a gas -outlet 53, which communicates with a pipe 54. The pipe 54 connects with a cylinder 55 containing a mixture of air and an additional 5% carbon dioxide. This air and carbon dioxide mixture is used to reduce degradation of the culture medium in which oocytes are commonly bathed. In use, the power to the unit 1 and the gas supply 55 is turned on, the flush cartridge 12 is full of flush liquid and the drain cartridge 13 is empty. The pumps 16 and 18 are on so that pressure is applied to pump the flush liquid to the needle 3 and to suck material back to the unit 1. With the valve 26 initially off, there is no flow of liquid into or out of the needle 3.

The surgeon inserts the needle 3 and positions its tip (usually under ultrasound imaging) in the best position for extraction of oocytes. The surgeon may then apply suction or supply flushing liquid by operation of the valve 26, as he wishes. When suction is applied, the ooctyes, flushing liquid and uterine fluid flow along the suction lumen 25 and into the

viewing chamber 20. During passage to the viewing chamber 20 the oocytes are maintained at the ideal temperature and are protected from the environment within the tubing 2. The embryologist views the material in the viewing chamber 20 through the microscope 41 and selects the desired oocytes by inserting the pipette 43 through the access site 42 and manipulating its tip adjacent the oocyte. He then squeezes and releases the bulb 46 at the end of the pipette 43 to suck the oocyte into the pipette. He pulls out the pipette 43 and discharges the oocyte into the dish 51 on the tray 50. This is repeated until all the desired oocytes are removed. The dish 51 containing the oocytes is then removed and subsequently treated in the usual way.

Excess liquid from the viewing chamber 20 flows into the drain cartridge 13 for disposal. Preferably the outlet of the viewing chamber 20 to the drain cartridge 13 includes means to prevent the passage of oocytes. This may be in the form of a filter, a weir or the like. The present invention considerably reduces handling of the oocytes and maintains them in a carefully controlled environment. It also reduces the risk of spillage and contamination. The system can enable a more rapid selection of oocytes, thereby enabling fertilization to take place a short time after removal. The flush and suction valve enables the surgeon to use the system very easily and it can be apparent very quickly whether an oocyte has been successfully removed. The system only requires two people to operate and there can be less equipment to maintain than with previous arrangements.

Claims

1. An oocyte handling system comprising a unit having an inlet, a viewing chamber, means for drawing liquid with oocytes into the viewing chamber, access means to the viewing chamber by which oocytes can be removed under observation and tubing connected with the inlet by which oocytes and liquid can flow to the viewing chamber.

2. A system according to Claim 1, including a source of flushing liquid and means for

supplying the flushing liquid to an outlet of the unit.

3. A system according to Claim 2, wherein the tubing is arranged both to supply flushing liquid to an oocyte recovery needle and to supply liquid and oocytes from the needle to the inlet.

4. A system according to Claim 3, wherein the tubing includes a useroperable valve by which flushing and suction can be controlled.

5. A system according to Claim 2 or any claim dependent on Claim 2, including pumping means for pumping flushing liquid from a container in the unit and for applying suction to draw oocytes and fluid into the viewing chamber.

6. A system according to any one of the preceding claims, including a container for drained flush liquid after removal of oocytes.

7. A system according to any one of the preceding claims, wherein the viewing chamber includes magnifying viewing means.

8. A system according to Claim 7, wherein the magnifying viewing means is a microscope.

9. A system according to any one of the preceding claims, wherein the unit is heated.

10. A system according to any one of the preceding claims, wherein the tubing is heated.

A system according to any one of the preceding claims, wherein the access means includes a self-closing material or a valve.

12. A system according to any one ofthe preceding claims, wherein the unit includes a removable receptacle for oocytes removed from the viewing chamber.

13. A system according to Claim 12, including means for supplying carbon dioxide enriched air to the removable receptacle.

14. An oocytehandling system comprising a unit having an inlet/outlet, heated dual-

lumen tubing connected at one end with the inlet/outlet and at its other end with a dual-lumen oocyte recovery needle, and a valve connected between the tubing and the needle to control flow to and from the needle, wherein the unit includes a container of

flushing liquid for supply to the outlet, a viewing chamber, a pump for drawing liquid with oocytes from the tubing into the viewing chamber, access means to the viewing chamber by which oocytes can be removed under observation, a heated support and a removable receptacle on the support adapted to receive the oocytes after removal from the viewing chamber.

15. A system substantially as hereinbefore described with reference to the accompanying drawings.

16. Any novel and inventive feature or combination of features as hereinbefore described.