Abstract:
An arrangement for transferring an ovum from a follicle by implementing a technique of simultaneous flushing and aspiration, the arrangement comprising a double lumen needle having an elongate needle body with a cuspidated needle end to be inserted into a follicle, the needle lumen comprising an ovum pick-up lumen for removing an ovum from a follicle, and an interior flushing lumen made of a flexible material for inserting a flushing fluid into the follicle. The flexible inner lumen is elastically deformable when the ovum is passed through the outer ovum lumen. Also disclosed is a connector body.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under 35 U.S.C. 371 to international application No. PCT/NL00/00164, filed on Mar. 10, 2000. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an arrangement for transferring an ovum from a follicle with a combined aspiration and flushing technique and in accordance with the introductory part of claim  1 . 
     An arrangement of this type is known from Australian patent AU-B-68184/87. In this known arrangement the two tubes, that is to say, the inner tube and the outer tube, are made of stainless steel. The inner tube has an outside diameter that accurately fits in the inside diameter of the outer tube and is coaxially located inside the outer tube. For creating a flushing lumen between the inner tube and the outer tube, the inner tube is provided with an inward deformation running in longitudinal direction of the tube, seen in cross-sectional view of the tube, not exceeding 120°. The consequence of this local inward deformation is that the wall of the inner tube, seen in cross-sectional view of the tube, has an inwardly directed convex portion that connects to the remaining portion of the wall of the inner tube via rounded concave portions. In this way the lumen of the inner tube is reduced while at the same time a lumen is developed at the position of the inward deformation between the inner tube and the outer tube. The latter lumen is used as a flushing lumen for supplying the flushing fluid. The lumen, which is bounded by the inside wall of the inner tube is used as the ovum pick-up lumen. For a more detailed description and drawings of an arrangement according to this known state of the art, reference be made to Australian patent document AU-B-68184/87 mentioned above, whose contents, insofar as of importance for the present application, is deemed to be included herein by reference. 
     A similar arrangement is known from DE-A-3522782. In this arrangement however, the function of the two lumens is reversed. 
     The above-described known construction of an arrangement for transferring an ovum from a follicle has several disadvantages. The inner tube is to fit accurately within the outer tube, which necessitates accurate tolerances, both as regards the inside diameter of the outer tube and the outside diameter of the inner tube. Adhering to accurate tolerances always has a disadvantageous effect on the cost price. Another disadvantage is that the ovum pick-up lumen does not have a round cross section since the wall of the inner tube has a local inward deformation. Finally, when the point of the needle is made, for example by means of grinding, material is to be removed both from the outer tube and from the inner tube. In addition, the grinding is to be carried out with the flushing lumen in a certain orientation in order to guarantee that with the finished product the flushing lumen is in the right position relative to the point of the double lumen needle. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to improve an arrangement of the type defined in the opening paragraph so that the above disadvantages are avoided and, in addition, advantages are provided which will be discussed hereinafter. For this purpose, the invention is characterized by the features stated in the characterizing part of claim  1 . 
     The arrangement according to the invention has a number of characteristic advantages. The inner tube does not accurately fit in the outer tube, so that no accurate tolerances are necessary either for the outer tube or for the inner tube. The inner tube is made of a flexible material, so that the dimensions of the ovum pick-up lumen when an ovum passes can at least slightly adapt to the dimensions of the ovum. The flushing lumen is bounded by the inside wall of the inner tube, while the ovum lumen is bounded by the space between the outside wall of the inner tube and the inner wall of the outside tube. This implies that the flushing fluid used is in contact with metal only along the path from the distal end of the needle body to the outlet at the end remote from the distal needle end. This is deemed favourable. Metals are soluble in water only to a very small extent, it is true, but, nevertheless, an ovum should as much as possible be avoided contacting metals or fluids that have been in contact with metals. According to the state of the art, plastics can be manufactured having a composition that may be deemed utterly man-friendly. 
     The advantages of the invention turn out to be not only of a manufacturing nature, but also of importance for as good a protection of the ovum against possible damaging mechanical and chemical ambient influences during the transfer from the follicle to a receptacle, such as a glass test tube or the like to be connected to the outlet. Therefore, preferably an embodiment of the invention is utilized that is characterized in claim  2 . 
     Claim  3  relates to a practical embodiment of the invention. In this embodiment the inner tube has such outside shape that the latter can be contiguous to the inside wall of the outer tube and thus over this part of the circumference has an outside diameter that is at least substantially equal to the inside diameter of the outer wall. The remaining, second part of the outside wall of the inner tube can elastically be deformed in the direction of the first portion. It will then be favourable when, during the passage of an ovum, the second part of the inner tube is deformed as far as possible in the direction of the first part. Alternatively, the flushing lumen should not be closed off completely when in that case too it is deemed desirable to have supply of flushing fluid. 
     Claim  4  relates to an embodiment of the arrangement according to the invention in which the inner tube is connected at least at the distal end by gluing it to the inside wall of the outer tube. In the description of this embodiment with reference to the drawings it will further appear that this embodiment can be designed so that during the grinding process of the point to the needle body at the distal end of the needle the inner tube need not be taken into account at all and the material of the inner tube need not be ground either. 
     For connecting the inner tube to the flushing inlet for supplying the flushing medium, the embodiment according to claim  5  is of importance. This embodiment is possible due to the flexibility of the inner tube as a result of which it is possible to feed-in the inner tube in a bend through an opening in the outer tube. 
    
    
     The invention will now be further explained with reference to the drawing which shows an embodiment of the invention exclusively by way of non-limiting example and wherein: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a general side view of an arrangement according to the invention with a double lumen needle, a connector and tubings connected to the connector for supplying flushing fluid and discharging the ovum to the exterior; 
     FIG. 2 shows a side view in cross section on an enlarged scale of a part of the needle body of the arrangement of FIG. 1 near the distal needle end; 
     FIG. 3 shows a plan view of the needle end which is shown in FIG. 2; 
     FIG. 4 shows a cross sectional view along the line IV—IV in FIG. 2; 
     FIG. 5 shows once again a cross sectional view of FIG. 2, but now with a schematically shown ovum inside the ovum pick-up lumen; 
     FIG. 6 shows a cross-sectional view of the double lumen needle according to the arrows VI—VI in FIG. 5; and 
     FIG. 7 shows a side view in cross section on an enlarged scale of the connector of the arrangement of FIG.  1  and of the parts of the arrangement which are connected to the connector. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Like elements in the various Figures are denoted by like reference characters. 
     The arrangement of FIG. 1 comprises a double lumen needle having an elongate needle body  1 . As can be clearly seen in FIGS. 2,  3  and  5 , there is a sharp point  5  at the distal needle end  3  to be inserted into the follicle, because the distal end is locally tapered. Near the end  3  of the needle there is an ovum pick-up lumen  7  present inside the needle body  1  for removing an ovum  9  from a follicle, see FIG. 5, as well as a flushing lumen  11  for inserting a flushing fluid into the follicle. The needle body comprises an outer tube with an inner tube  15  therein, which extends over at least part of the length of the outer tube  13 . 
     The needle body  1  is connected to a connector  19  near the end  17  remote from the distal end  3 , see FIGS. 1 and 7. The connector  19  has a connector body  21  which is connected at a first end  23  to the needle end  17  of the needle body  1 , which end  17  is remote from the distal needle end. At a second end  25  the connector  19  has an inlet  27  for discharging the ovum  9  to the exterior. For this purpose, the connector  19  is connected to an ovum discharge tubing  29  of a suitable plastic material. At the end remote from the connector  19 , the ovum discharge tubing  29  is included in a stopper  31  of a suitable elastic material, such as silicon rubber, the ovum discharge tubing  29  being passed through as far as a slightly flange-like end  33 . The stopper  31  can be sealed in the neck of a glass receptacle  35 . For creating a partial vacuum in the receptacle  35 , a tube  37  is extended through the stopper  31  to the exterior, the end of which tube has a coupling  39  for a connection to a vacuum source. The outlet  27 , see again FIG. 7, is connected to the ovum pick-up lumen  7  via conduit means which are formed by a part of the ovum discharge tubing  29  and a part of the outer tube  13  of the needle body  1 . As can be seen in FIG. 7, the ovum discharge tubing  29  at the free end  41  is slid fluid tight over the outside wall of the outer tube  13  of the needle body  1 . To strengthen the connection from the ovum discharge tubing  29  to the connector  19 , a strengthening sleeve  43  of an elastic plastic material which is slightly less flexible than the material of the ovum discharge tubing  29  is installed around the ovum discharge tubing near the second end  25  of the connector. The channel means between the outlet  27  and the needle body end  17  located opposite the distal end, which channel determines a first fluid pathway for the aspiration of an ovum  9  is thus formed by the parts of the outer tube  13  of the needle body that run inside the connector body  21  and the ovum discharge tubing  29  connected to it in a clamping and fluid tight fashion. By realising a partial vacuum in the receptacle  35  via the tube  37 , at the end  3  of the needle body an ovum  9  can thus be aspirated from a follicle and transferred to the receptacle  35  via the ovum lumen  7  through the fluid pathway present in the connector  19  and through the ovum discharge tubing  29 . 
     Between the two ends  23  and  25  of the connector body  21  there is a flushing inlet  45  for supplying a flushing medium. For this purpose, a flushing medium supply tubing  47  is present whose end has a coupling  49  for connection to a source of flushing medium. Inside the connector body  21  there is a connector tube  51  to which the tubing  47  is connected in a clamping and fluid tight fashion. Furthermore, a sleeve  53  resembling the sleeve  43  is present to strengthen the connection from the supply tubing  47  to the connector body  21 . The flushing inlet  45  is in fluid communication to the flushing lumen  11  in a manner to be discussed in more detail for determining a second fluid pathway for flushing a follicle. 
     As will be apparent from the FIGS. 2 to  7 , both fluid pathways inside the connector  19  and also inside the needle body  1  are completely separated. 
     The inner tube  15  in cross section has dimensions that are considerably smaller than the inside diameter of the outer tube  13 , the inner tube  15  being made of a flexible plastic material selected for minimum presence of materials that might be harmful to the ovum  9 . As is especially distinct in FIG. 4, the flushing medium  11  is bounded by the inside wall of the inner tube  15 . The ovum lumen  7  is bounded by the space between the outside wall of the inner tube  15  and the inside wall of the outer tube  13 . 
     The central axis  55  of the inner tube  15  is located eccentrically relative to the central axis  57  of the outer tube  13 . This is especially distinct in FIG.  2 . The outside wall of the inner tube  15  is located along a first part  15 A of its circumference against the inside wall of the outer tube  13 . The remaining second part  15 B of the outside wall of the inner tube  15  is deformable under the influence of an external or internal pressure respectively, caused by the pressure exerted by an ovum  9  that passes while being aspirated by the ovum lumen  7  and the pressure of the flushing medium respectively, between a first position which is shown in FIGS. 5 and 6, in which the second part  15 B lies closer to the first part  15 A and a second position in which the second part  15 B lies more remote from the first part  15 A; see FIGS. 5 and 6. In essence, in said second position the inner tube  15  in the embodiment shown in cross section has more or less the shape of a double convex lens. 
     At the distal needle end  3  only the outer tube  13  of the needle body  1  is provided with a taper  59  tapering to a sharp point  5 . Therefore, only the outer tube needs to be ground. The inner tube  15  is cut off straight at the distal end  61 , at least in the embodiment shown. At that point and, if so required, also over a further part of the length, the inner tube is bonded to the inside wall of the outer tube  13  by means of gluing. 
     At a location within the connector  19 , see again FIG. 7, the outer tube  13  has an opening  63  through the wall. Through this opening  63  the flexible inner tube  15  within the connector body  21  is led out. The inner tube  15  ends at the end  65  remote from the distal end  61  at a location outside the outer tube  13  and within the connector body  21 , and within the tube  51  mentioned before. For this purpose, the tube has an end  67  with a cross section that is adapted to the cross section of the flexible tube  15 . With suitable means such as glue, the inner tube  15  is attached in fluid tight fashion to the end  67  of the tube  51 . In this way there is a fluid pathway from the coupling  49  through the supply tubing  47 , the tube  51  and the inner tube  15  for supplying the flushing medium  11  for flushing a follicle. Since there is provided by means of suitable measures that between the circumference of the opening  63  and the enveloping part of the inner tube  15  there is a fluid-tight sealing material, for example of the connector body  21  or other material specifically provided for this purpose and not shown in the drawing, there is provided that a seal against fluid is locally present. The two fluid pathways mentioned earlier for the supply of a flushing medium and the discharge of an ovum are thus completely separated from each other and at the connector  19  no fluid leaks to the environment. 
     Albeit the invention has been explained with reference to only a sole example of embodiment, the invention is by no means restricted to this. On the contrary, the invention comprises any possible embodiment of an arrangement within the definition of claim  1 . Those skilled in the art will appreciate that modifications and variations are possible. For example, the materials that are applied may be selected in accordance with the developing medical opinions and the developing technique in the field of materials. The inner tube  15  may have a different shape and be installed internally within the outer tube  13  in a different manner. The distal end of the inner tube may have a different shape than that shown in FIG.  3 .