A SAMPLING DEVICE

Abstract: A sampling device for taking out a sample of a cell-containing liquid fluid, such as an amniotic fluid, from a human or an animal body comprises a syringe (10) with a fluid chamber and a sampling tube (29, 30). A volume of fluid may be drawn along a first path into the fluid chamber via the sampling tube and subsequently expelled from the fluid chamber along a second path. The device further comprises a valve device (14) having a first position, in which a cell filter (17) is included in one of said first and second paths, a second position in which the other of said paths is defined so as to by-pass the cell filter, and a third position, in which the fluid chamber is in communication with a removable fluid sample receptacle (27).

Description: A SAMPLING DEVICE The present invention relates to a sampling device for taking out a sample of a cell-containing liquid fluid from a human or an animal body. A sampling device of this type for taking out a sample of a cell-containing amniotic fluid from an amniotic cavity is known from EP 0471721. The present invention provides a sampling device by means of which it is possible to take out not only a sample with an increased concentration of cells, but also a fluid sample in the same operation. The sampling device according to the invention for taking out a sample of a cell-containing liquid fluid from a human or an animal body comprises a fluid chamber, a sampling tube, means for drawing a volume of fluid along a first path into the fluid chamber via the sampling tube and for subsequently expelling fluid from the fluid chamber along a second path, cell-filtering means for filtering cells from said fluid, and a valve device having a first position, in which the cell- filtering means is included in one of said first and second paths, and a second position, in which the other of said paths is defined so as to by-pass the cell filtering means, and the sampling device according to the invention is characterized in that the valve device has a third position, in which the fluid chamber is in communication with a removable fluid sample receptacle. The sampling device according to the invention may be used not only for taking out a sample of an amniotic fluid for the purpose described in the above EP 0471721, but also for taking out samples of other kinds of cell-containing liquid body fluids, such as blood, and the free end of the sampling tube may be defined by or connected to a hollow needle or cannula fcr penetrating the wall of a body cavity from which a sample should be taken out . When the sampling tube has been placed in communication with an amniotic cavity, a blood vessel, or another fluid containing cavity of an animal or human body, and the valve device has been positioned in of its said first and second positions, a suitable volume of body fluid is drawn into the fluid chamber via the sampling tube. Subsequently, the valve device may be positioned in the other of said first and second positions and in said third position. When the valve device is in its third position, a minor part of the fluid volume is expelled from the fluid chamber so as to at least partly fill the fluid sample receptacle. A major part of the fluid volume is expelled from the fluid chamber when the valve device is in said other position. This major part, which has passed the cell-filtering means or cell-retaining means may be returned to the body cavity via the sampling tube . Thus, the sampling device according to the invention may be used for taking out a volume of a liquid sample, for filtering cells from such sample, for retaining a minor part of the sample, and for almost immediately returning the major part of the filtered fluid to the body cavity from which it was withdrawn. The valve device may be of any suitable type, such as a manually operatable three-way valve or cock, and the fluid chamber may, for example, be defined by a syringe barrel and by a piston displaceably arranged therein. The sample receptacle may have a vent, which may, for example, comprise a filter of the type allowing gaseous, bu net liquid fluid to pass. When the valve device is in its third position it may define a third fluid flow path including the filtering means, so that the sample collected in the fluid sample receptacle have been filtered. Preferably, the valve device is placed in its second position when the fluid volume is drawn into the fluid chamber and is by-passing the filtering means. The valve device may then be placed in its third position and as a first expulsion step a minor part of the fluid volume may be transferred from the fluid chamber to the fluid sample receptacle via the filtering means. The valve device may now be placed in its first position, whereafter the remaining major part of the fluid volume is expelled from the fluid chamber and returned to the body cavity via the first path which includes the filtering means. The sample receptacle may be of any suitable type and may, for example, be in the form of a hose or a tube section which may be closed at opposite ends. When a sample has been collected in the receptacle its opposite ends may be closed for example by means of clamps, whereafter the sample containing receptacle may be removed from the sampling device . In the preferred embodiment of the invention the valve device, the cell-filtering means, and the fluid sample receptacle are arranged in a common housing, a free end portion of the sampling tube extending outwardly from said housing. A syringe defining the fluid chamber may be rigidly mounted on the housing so as to obtain a unitary sampling device . According to another aspect the present invention relates to a method for operating the sampling device described above, said method comprising positioning the valve device in one of said first and second positions, drawing a volume of body fluid into the fluid chamber from a human or an animal body via the sampling tube, positioning the valve device in its third position, expelling a first part of the fluid volume from the fluid chamber so as to at least partly fill the sample receptacle with liquid fluid, positioning the valve device in the other of said first and second positions, and expelling a second part of the fluid volume from the fluid chamber so as to return filtered fluid to said body. The invention will now be further described with reference to the drawings, wherein Fig. 1 is a perspective view showing an embodiment of the sampling device according to the invention, Fig. 2 is a longitudinally sectional view of part of the valve device shown in Fig. 1 in an enlarged scale, Fig. 3 is a top plane view of part of the sampling device shown in Fig. 1, an upper housing part having been removed, Fig. 4 is a cross sectional view of the valve and the surrounding housing, Fig. 5 is a longitudinal sectional view of a cell filtering device, and Figs. 6-8 diagrammatically illustrate the function of the sampling device. The sampling device shown in the drawings comprises a syringe barrel or cylinder 10 having its one end mounted to a housing comprising an upper shell 11 and a lower shell 12. A piston 13 is displaceably arranged within the cylinder 10. A three- way valve or cock 14 comprising a valve housing 15 and a valve member or valve plug 16 rotatably mounted in the valve housing is arranged within the housing defined by the upper and lower shells 11 and 12. The sampling device further comprises a cell retaining or filtering device 17 and a vent filter 18 positioned within the housing defined by the shells 11 and 12. The valve housing 15 has a number of radially extending tube stubs defining liquid inlet and outlet passages. Thus, the syringe chamber defined within the cylinder 10 communicates with a valve passage 18 as best shown in Figs. 2 and 6-8. A valve passage 19 communicates with a flexible tube or hose 30 (Figs. 6-8 ■ extending outwardly from the housing 11, 12 though a tubular exit 20, and the free outer end of the tube or hose may be connected to a hollow needle or cannula 2S (Figs. 6-8) . A valve passage 21 is connected to a filter outlet end 22 via a hose (not shown) and a valve passage 23 is connected to a filter inlet end 24 via a hose 25 (Figs. 1 and 6-8) . Finally, a valve passage 26 is connected to a fluid sample receptacle 27, which is indicated in Figs. 6-8, but not shown in the other Figures. The fluid sample receptacle 27 is vented through the filter 28. The operation of a sampling device will now be described with reference to Figs. 6-8. When the valve member 16 is placed in the position indicated in Fig. 6 the hollow needle or cannula 29, which is connected to the free end of the hose 30 may penetrate the wall of a body cavity, such as an amniotic cavity. The piston 13 may then be withdrawn so as to suck a volume of liquid body fluid into the cylinder 10. Now, the valve member 16 is turned to the position indicated in Fig. 7, and a small part of the liquid fluid is expelled from the cylinder 10. The fluid expelled passes though the filter 17 and into the sample receptacle 27 while air is vented through the filter 28. The valve member 16 may now be rotated to the position indicated in Fig. 8, and the remaining part of the liquid fluid may be expelled from the cylinder 10. The fluid expelled passes the filter 17 retaining cells therein, and the filtered fluid is returned to the body cavity via the hose 30 and the cannula 29.

Claims: CLAIMS 1. A sampling device for taking out a sample of a cell- containing liquid fluid from a human or an animal body and comprising a fluid chamber, a sampling tube, means for drawing a volume of fluid along a first path into the fluid chamber via the sampling tube and for subsequently expelling fluid from the fluid chamber along a second path, cell-filtering means for filtering cells from said fluid, and a valve device having a first position, in which the cell filtering means is included in one of said first and second paths and a second position in which the other of said paths is defined so as to by-pass the cell filtering means, characterized in that the valve device has a third position, in which the fluid chamber is in communication with a removable fluid sample receptacle. 2. A sampling device according to claim 1, wherein the sample receptacle has a vent. 3. A sampling device according to claim 2, wherein the vent comprises a filter of the type allowing gaseous, but not liquid fluid to pass. 4. A sampling device according to any cf the claims 1-3, wherein the sample receptacle is a hose or tube section which may be closed at opposite ends. 5. A sampling device according to any of the claims 1-4, wherein the valve device, the cell-filtering means, and the fluid sample receptacle are arranged in a common housing, a free end portion cf the tube extending outwardly from said housing. 6. A method for operating the sampling device according to any of the claims 1-5, said method comprising positioning the valve device in one of said first and second positions, drawing a volume of body liquid into the fluid chamber from a human or an animal body via the sampling tube positioning the valve device in its third position, expelling a first part of the fluid volume from the fluid chamber so as to at least partly fill the sample receptacle with liquid fluid, positioning the valve device in the other of said first and second positions, and expelling a second part of the fluid volume from the liσuid chamber so as to return filtered fluid to said bodv.

Inventors: HANSEN GERNER, LAURIDSEN JAN, NILSSON TOM, SUNDBERG KARIN, HANSEN, GERNER, LAURIDSEN, JAN, NILSSON, TOM, SUNDBERG, KARIN
Applicants: AMNITEC AS, HANSEN GERNER, LAURIDSEN JAN, NILSSON TOM, SUNDBERG KARIN, AMNITEC A/S, HANSEN, GERNER, LAURIDSEN, JAN, NILSSON, TOM, SUNDBERG, KARIN
Application year: 1995
Main classification: A61B10
IPC codes: A61B10