WO2006010878A1

WO2006010878A1 - Oocyte handling apparatus

Info

Publication number: WO2006010878A1
Application number: PCT/GB2005/002536
Authority: WO
Inventors: Philip Dabrowski; Richard Hingley
Original assignee: Smiths Group Plc
Priority date: 2004-07-30
Filing date: 2005-06-29
Publication date: 2006-02-02
Also published as: EP1773217A1

Abstract

Oocyte handling apparatus has a water reservoir (82) with an outlet (85) connected to the rear portion (24) of a tube (21) via a heater (89). The rear portion (24) of the tube (21) connects to a connector assembly (41) fitted in a test tube (40). The connector assembly (41) has a baffle (57) extending down from its upper end so that the warm water flows down one side of the connector, under the baffle and up the other side. The outlet (51) of the connector (41) connects with a forward portion (23) of the tube (21), which. extends to the hub (12) of an oocyte collection needle assembly (1), and which encloses an oocyte tube (18) connected at its forward end to the bore of the needle cannula (10). The rea3 end of the oocyte tube (18) extends through the connector (41) and into the test tube (40) so that it is warmed by the heated water. Water is returned to the reservoir (82) via a second tube (22) and a pump (86).

Description

OOCYTE HANDLING APPARATUS

This invention relates to apparatus of the kind for handling an oocyte including a first tube along which the oocyte can pass, a second tube extending along a major part of the length of the first tube in thermal contact with the first tube, the second tube being adapted to receive warmed fluid by which the temperature of the oocyte can be maintained while it is in the first tube, and a container for receiving the oocyte, the first tube opening into the container through a connector coupled with the container.

Conventionally, an oocyte is extracted from a follicle using a needle to which suction is applied so that the oocyte is aspirated into a test tube or other receptacle. 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

One problem with the apparatus used in this technique is that the temperature of the oocyte can fall appreciably during its passage along the needle, its associated tubing and into the test tube. It has been proposed in GB2394040 to enclose the tubing from the catheter within an outer jacket through which heated water flows in order to help maintain the temperature of the oocyte.

It is an object of the present invention to provide alternative apparatus for handling an oocyte.

According to the present invention there is provided apparatus of the above-specified kind, characterised in that the connector includes a fluid passage therethrough by which warmed fluid can be supplied through the connector to maintain temperature within the connector.

The fluid passage of the connector preferably includes a fluid outlet with which the second tube is connected, the first tube extending through the outlet such that warming fluid can flow out of the outlet around the first tube. The connector may include a baffle extending along a part of the length of the connector between an inlet and an outlet, the first tube extending from the outlet along one side of the baffle and out of the connector through a sealed opening, warmed fluid from the inlet flowing along the connector in one direction on one side of the baffle and back along the connector in the opposite direction on the opposite side of the baffle along the outside of the first tube and out of the outlet. The connector preferably has a cavity and two openings into the container, the first tube extending through one opening, and a vacuum tube opening into the container via the other opening such that vacuum can be applied to the container to draw material along the first tube. The connector preferably includes a first substantially rigid portion and a second compliant portion fitted on the rigid portion and in sealing engagement with the container. The first tube may connect with the bore of a cannula. The second tube may connect with an inlet to a cavity in a hub of the cannula. The apparatus may include a third tube connected to an outlet of the hub. The fluid may be a liquid. The liquid is preferably water and the apparatus may include a water reservoir having an outlet for water flowing out of the reservoir, an inlet for water returning to the reservoir, and a pump arranged to circulate the water around the apparatus, the pump being connected to the inlet of the reservoir.

Oocyte recovery apparatus 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 apparatus; and

Figure 2 is a cross-sectional view of a part of the apparatus along the arrow II of

Figure 1.

The apparatus includes a needle assembly 1 connected with a receptacle 2 via a tubing assembly 3 and which is warmed by means of heated water from a supply or water heater pump unit 4.

The needle assembly 1 is substantially conventional, comprising a single-lumen metal cannula 10 with a bevelled, pointed tip 11 at one end and attached with a plastics hub 12 at its rear end. The hub 12 differs from conventional oocyte recovery needle hubs in that the rear end of the cannula 10 terminates within a cavity 13 in the hub, which opens axially at the rear through a spigot 14. The cavity 13 also communicates with a rearwardly-angled side passage 15, which opens through a second spigot 16 disposed side-by-side with the first spigot 14. The rear end of the cannula 10 is attached to the forward end of a flexible small-bore oocyte tube 18 made of a plasties material, such as polyurethane, that is non-toxic to oocytes. The external diameter of the tube 18 is such as to leave clearance between its outside and the inside of the cavity 13 and the spigot 14 through which the tube extends.

The two spigots 14 and 16 on the hub 12 are received sealingly within the respective bores at the end of two flexible tubes 21 and 22 forming part of the tubing assembly 3. The two tubes 21 and 22 are preferably joined with one another side-by-side along their length by an integral link or they may be separate tubes. The passage along one tube 22 provides a return path for the heated water and this tube extends uninterrupted to a rear end connector 30 connected to the water supply unit 4. The other tube 21 is interrupted about midway along its length and is divided into a forward portion 23 and a rear portion 24 by the receptacle 2. Along its forward portion 23, the tube 21 encloses the oocyte tube 18, which extends from the needle assembly 1 to the receptacle 2 as a loose fit within the outer tube 21 so as to allow for passage of water along the outer tube.

The receptacle 2 is most clearly shown in Figure 2 and comprises a container in the form of a test tube 40 and a connector assembly 41 fitted sealingly in the open top 42 of the test tube. The test tube 40 is conventional, being of circular section and cylindrical shape, about 120mm long and may be of any conventional material, such as glass or plastics, compatible with the storage of oocytes. The connector assembly 41 comprises an upper T- shape tubular body 44 and a lower sleeve or bung 45 fitted onto the lower end of the body. The body 44 is moulded from a rigid plastics material and has a central upright cylindrical portion 46 with an externally tapered lower end 47 and an external annular channel 48 midway along its length. Towards the upper end of the body 44 two short, ribbed tubular stems 50 and 51 project laterally outwardly from opposite sides of the body, in line with one another and open into the cylindrical cavity or interior 6 of the body. The upper end of the body 44 has a circular opening 52 closed by a baffle member 54. The baffle member 54 has a circular disc 55 at its upper end, which closes and is bonded to the opening 52. The disc 55 has a small hole 56 through it towards one side. A rectangular baffle plate 57 projects downwardly from the disc 55, its width being slightly less than the internal diameter of the body 44 and its length being such as to leave a gap 58 between its lower end and the upper surface of the bung 45. The baffle plate 57 extends down and diametrically across axis of the two stems 50 and 51 so that the stems open into the body on opposite sides of the baffle. The bung 45 is of a resilient, compliant, elastomeric material, such as silicone rubber, and is generally of tubular shape having an open upper end 60. The bung 45 is closed at its lower end 61 by an integral end piece 62 having two small diameter passages 63 and 64 extending through it. The bung 45 is fitted on the lower end of the body 44 with the upper end 60 of the bung extending along the tapered portion 47 and locating in the annular channel 48. The lower end of the body 44 extends within the bung 48 and engages the upper surface of the end piece 62. A metal crimp band 66 is fastened tightly around the upper end 60 of the bung 45 where it overlies the channel 48 so as to retain the bung securely on the body 44. The bung 45 is oriented so that one of the passages 64 is aligned with the hole 56 in the disc 55 of the baffle and so that the other of the passages 63 located on the side adjacent the stem 50.

The oocyte tube 18 extends through the stem 50, is bent down the connector 41 on the left-hand side of the baffle plate 57 (as viewed in Figure 2) and extends through the passage 63 in the bung 45 as a sealing fit. The oocyte tube 18 projects through the lower end 61 of the bung 45 by about 12mm into the test tube 40 and its open, lower end is spaced from the lower end of the test tube by about 100mm. A small bore vacuum tube 70 projects down through the hole 56 in the top 55 of the baffle 54, along the opposite side of the baffle plate 57 from the oocyte tube 18 and through the other passage 64 in the bung 45. The open, lower end 71 of the vacuum tube 70 projects only a short distance through the bung 45, typically about 6mm, so that it is spaced above the lower end of the oocyte tube 18 by about 6mm. This spacing ensures that there is no risk that any material emerging from the oocyte tube will be drawn into the vacuum tube 70. The resilient nature of the bung 45 and the relative diameters of the tubes 18 and 70 and the passages 63 and 64 ensure a lealcproof seal between the outside of the tubes and the bung. The opposite end of the vacuum tube 70 extends to a vacuum source 72, which could be a pump, syringe, evacuated container or the like.

The outside of the stem 50 receives the rear end of the forward portion 23 of the tube 21. The other stem 51 is connected into the forward end of the rear portion 24 of the tube 21. The rear end of the rear portion 24 of the tube 21 connects to the rear end connector 30, which is coupled to a connector 80 on the casing 81 of the heated water supply 4. Inside, the supply 4 includes an unpressurized tank 82 of water 83 with an inlet 84 and an outlet 85. The inlet 84 is located above the water level and connects with the outlet of a water pump 86. The inlet of the water pump 86 connects via a pipe 87 with the connector 80 and, in particular, connects with a port on the connector that makes connection with the tube 22. The outlet 85 of the tank 82 is located below the water level and is connected via a pipe 88 to an electrical heater and temperature control unit 89, which operates to raise the temperature of water passing through the pipe to a regulated temperature of 37° C. This unit 89 maybe of any conventional kind such as including a temperature sensor to ensure the water is within a desired temperature range. The pipe 88 continues to the connector 80 so as to make connection with the other tube 21. Optionally, this pipe 88 may also connect to an air vent 90 via a stop cock 91, for a purpose that will be explained later.

In normal operation, the pump 86 draws water from the tube 22 and pumps it into the tank 82. The water 83 drawn from the return tube 22 is replaced by water from the other tube 21, thereby drawing water from the tank 82, through the heater 89 and into the tube. In this way, the pump 86 operates to circulate water outwardly along the tube 21, through the needle hub 12 and back along the return tube 22. It can be seen that the heated, outgoing water flows through the connector assembly 41, flowing down one side of the baffle plate 57 and up along its other side where it flows along the outside of that part of the oocyte tube 18 within the connector. The heated water continues to flow along the outside of the oocyte tube 18 along its entire length, from the connector 41 where it extends within the forward portion 23 of the outer tube 21. The heated water also flows into the cavity 13 in the cannula hub 12 via the spigot 14, which acts as the water inlet, to warm the forward end of the oocyte tube 18 and the rear end of the cannula 10 within the cavity. The pump 86 and heater 89 are turned on a short time before the apparatus is used so as to circulate the heated water and warm the apparatus before use.

When an oocyte is to be extracted, the cannula 10 is inserted in a follicle and suctioning is applied to the vacuum tube 70. This causes a reduced pressure within the receptacle 2 and hence in the oocyte tube 18 so that material in the follicle is sucked rearwardly along the cannula 10 and into the warmed oocyte tube. The material, including any oocyte, passes along the oocyte tube 18 and into the test tube 40. The construction of the apparatus ensures that the oocyte tube 18 is warmed along the major part of its length including within the connector assembly 41. It will be appreciated that the test tube 40 may be pre-warmed, insulated or enclosed within a heated holder so that its temperature is held as close as possible to body temperature.

By connecting the pump 86 to operate in a suction mode, that is, to draw water from the tubing rather than pump water into the tubing 3, the pressure of water within the tubing is minimized and hence the risk of leakage is reduced. If there should be a failure of any connection or a puncture, air will be drawn into the system instead of water leaking out. It will be appreciated that it is particularly important to ensure that water from the heating system does not enter and contaminate the test tube 40.

After use, water can be drained from the tubing 3 into the tank 82 by switching the stop cock 91 so that it isolates the tank outlet 85 and connects the section of the pipe 88 between the stop cock and the connector 80 to the air vent 90. The pump 86 then draws water from the tubing 3 into the tank 82 and, as this happens, it draws air into the tubing via the air vent 90. This allows the tubing 3 to be disposed of after use without the risk of water leaking out of it. In particular, the needle assembly 1 can be disconnected from the tubing 3, or the tubing cut close to the needle assembly, so that the needle can be disposed of in a suitable sharps box and the tubing disposed of separately.

The tubing arrangement can take various different forms from that described. In particular, it is not essential that the oocyte tube extend within the tube along which the heated fluid flows since it is only necessary that there be effective thermal contact between the heated fluid and the oocyte tube.

It is not essential to use a heated liquid as the warming fluid. Instead, a heated gas, such as air, could be used. This would typically be caused to flow through the system by means of a blower.

Claims

1. Apparatus for handling an oocyte including a first tube (18) along which the oocyte can pass, a second tube (23) extending along a major part of the length of the first tube in thermal contact with the first tube, the second tube (23) being adapted to receive warmed fluid (83) by which the temperature of the oocyte can be maintained while it is in the first tube (18), a container (40) for receiving the oocyte, and the first tube (18) opening into the container (40) through a connector (41) coupled with the container, characterised in that the connector (41) includes a fluid passage (51, 6, 50) therethrough by which warmed fluid can be supplied through the connector to maintain temperature within the connector.

2. Apparatus according to Claim 1, characterised in that the fluid passage of the connector (41) includes a fluid outlet (50) with which the second tube (23) is connected, and that the first tube (18) extends through the outlet (50) such that warming fluid (83) can flow out of the outlet around the first tube.

3. Apparatus according to Claim 1 or 2, characterised in that the connector (41) includes a baffle (57) extending along apart of the length of the connector between an inlet (51) and an outlet (50), that the first tube (18) extends from the outlet (50) along one side of the baffle (57) and out of the connector (41) through a sealed opening (63), and that warmed fluid from the inlet (51) flows along the connector (41) in one direction on one side of the baffle (57) and back along the connector in the opposite direction on the opposite side of the baffle (57) along the outside of the first tube (18) and out of the outlet (50).

4. Apparatus according to any one of the preceding claims, characterised in that the connector (41) has a cavity (6) and two openings (63 and 64) into the container (40), that the first tube (18) extends through one opening (63), and that a vacuum tube (70) opens into the container (40) via the other opening (64) such that vacuum can be applied to the container to draw material along the first tube (18).

5. Apparatus according to any one of the preceding claims, characterised in that the connector (41) includes a first substantially rigid portion (44) and a second compliant portion (45) fitted on the rigid portion and in sealing engagement with the container (40).

6. Apparatus according to any one of the preceding claims, characterised in that the first tube (18) connects with the bore of a cannula (10).

7. Apparatus according to Claim 6, characterised in that the second tube (23) connects with an inlet (14) to a cavity (13) in a hub (12) of the cannula (10).

8. Apparatus according to Claim 7, characterised in that the apparatus includes a third tube (22) connected to an outlet (15, 16) of the hub (12).

9. Apparatus according to any one of the preceding claims, characterised in that the fluid is water (83).

10. Apparatus according to Claim 9, characterised in that the apparatus includes a water reservoir (82) having an outlet (85) for water (83) flowing out of the reservoir, an inlet (84) for water returning to the reservoir, and a pump (86) arranged to circulate the water (83) around the apparatus, and that the pump (86) is connected to the inlet (84) of the reservoir (82).