GB2341321A

GB2341321A - Cell Collecting Device

Info

Publication number: GB2341321A
Application number: GB9819440A
Authority: GB
Inventors: James Philip Oliver
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-09-08
Filing date: 1998-09-08
Publication date: 2000-03-15
Also published as: GB9819440D0

Abstract

A cell collecting device particularly adapted for the collection of a cervical smear, which device comprises an elongate body 9 and a cell collecting head attached at one end of the body 9, wherein the cell collecting head is provided with a cell collecting surface 10 formed from a deformable, abrasive material and means are provided for adjusting the contour of the cell collecting surface, such as a pushrod 14 with spring biasing means (17) and retaining slots 18 for a projection 16.

Description

2341321 CELL COLLECTING DEVICE This invention relates to a device and a

method for collecting for diagnostic purposes cell specimens from a body cavity such as the vagina and more particularly to a device and method f or use in obtaining a sample of cells from the surface of the cervix (neck of the womb).

In many diagnostic procedures it is necessary f irst to collect a sample of cellular material, e.g. from the cervix, and then transfer the collected sample to a microscope slide where it is immediately fixed then sent to a laboratory for analysis. Errors in the testing procedure can be caused by failure to collect sufficient cells or sufficient cells from the most vulnerable areas.

Errors can also occur because collected cellular material is incompletely transferred to the slide or the sample is poorly spread across the slide with some areas being too thick or thin or distorted due to excess pressure rendering them obscure or unreadable.

Several devices are currently in use or have been proposed for use in such procedures. In the United Kingdom for the procedure known as the cervical smear test the most commonly used device is the Aylesbury Spatula which is a flat, shaped strip of wood. Other devices involve the use of plastic brushes. There are, however, several problems associated with the' use--6f 2 existing devices. Firstly, many devices, such as the wooden Aylesbury Spatula, have a rigid fixed-shape collecting surface. As biological structures, such as the cervix, can have an infinitely variable size and shape, with any fixed-shape collecting surface there will be inadequate surface contact on many occasions, which reduces the likelihood of obtaining a truly representative sample of cells for analysis and hence increases the possibility of some abnormal areas being missed. This is particularly important for the cervical smear test as research has shown there is a strong correlation between the amount of endo-cervical cells collected and the accuracy of the test results. For this reason some devices have an extended tip which helps to improve accuracy of cervical smear tests by extending into the entrance of the cervical canal and allowing endocervical samples to be collected therefrom. One such device, known as the Multispatula additionally has means for varying the geometry of its collecting surface by means of an extensible tip lying between two cell collecting wings. By varying the degree of extension of the central tip some variation in cervix size and shape can be accommodated. The collecting surface is itself, however, fixed in shape so that even with such a device it is practically impossible to get consistent results. In addition devices having rigid, fixed-shape collecting surfaces are in certain cases excessively abrasive and can therefore lead to bleeding from the delicate internal 3 linings of the body, e.g. from the endo-cervical membrane of the cervical canal. The presence of blood in a sample of cells makes interpretation more difficult for laboratory staff which again adversely effects the 5 accuracy of any test procedure.

With cell collecting brushes, e.g. cervical smear brushes, where the collecting surface is formed from bristles, generally of a flexible plastics material, problems of bleeding are reduced due to the reduction in abrasiveness of the collecting surface. Such devices, however, often fail to gather a sufficient cellular sample in cervical smear tests because of the presence of a natural mucus layer on the surface of the cervix which makes it very slippery. This mucus coats the bristles of the brush and prevents adhesion of the important cellular component of the sample. Further the soft bristles of some cervical brushes rather than fan out to form a broad collecting surface as required, tend to be pushed together when they meet with resistance, e.g. during the taking of a sample, leading to a narrow often inadequate collecting surface.

Further problems occur with existing devices during the transfer of the collected sample onto a microscope slide. As an example, with wooden spatulas, the sample resists transfer to the slide as wood being relatively hygroscopic encourages the sample to stay on the spatula.

4 Also the sample ideally should be spread evenly across the microscope slide surface to aid inspection. With rigid collecting surfaces the sample tends to be discharged non-uniformly onto the slide. It is also difficult to obtain even spread of the sample in practice when there is a high level of mucus in the sample. Also with existing devices the position and distribution of cells transferred onto the slide is often entirely random so the whole slide needs to be inspected under the microscope which is time consuming.

There is, therefore, a need for a device and method for collecting cell specimens, such as a cervical smear, which overcomes or mitigates the problems associated with existing such devices and methods.

According to the present invention there is provided a cell collecting device particularly adapted for the collection of a cervical smear, which device comprises an elongate body and a cell collecting head attached at one end of the body, wherein the cell collecting head is provided with a cell collecting surface formed from a deformable, abrasive material and means are provided for adjusting the contour of the cell collecting surface.

The means for adjusting the contour of the cell collecting surface may take any suitable form. it preferably includes means for applying a deforming force to the cell collecting surface. There may, for example, be provided means for exerting a force on the cell collecting surf ace so as to cause it to def orm. Such means may include a surface contour adjusting member actable on the cell collecting surface. Such a member preferably exerts the deformable force from the rear of the cell collecting surface, i.e. from the side facing the body to which it is attached. The f orce to be exerted on the cell collecting surface is preferably infinitely variable and easily adjustable. The surface contour adjusting member may take the form of a push rod capable of acting against the surface causing it to deform. The force exerted by the push rod may be varied by varying the length of the rod itself or its position with respect to the cell collecting surface. The rod may, for example, be telescopically extensible or it may be moveably mounted with respect to the cell collecting surface. For a particularly compact design the surface contour adjusting member, e.g. push rod, may be received within the elongate body. For receiving the surface contour adjusting member, the body may be provided with a through channel or slot which can act as a guide f or the relative movement of that member against the cell collecting surface.

Means may be provided f or urging the surface contour adjusting member, e. g. push rod, against the cell collecting surface so as to apply its deforming force 6 thereon. Also biasing means, e.g. a spring, may be provided on the body or surface contour adjusting member as required to bias the device towards or away from a particular deformed surface contour. Means may also be provided for locking the surface contour adjusting means into a desired position. Such locking means may take any suitable form as will be well known to the skilled man and may include corresponding projections and detents.

The cell collecting surface may be mounted upon a support and the surface contour adjusting member act against the support. In such cases the support should be of a flexible material which is able to flex upon application of the surface deforming force, e.g. upon extension of the member such as a push rod, through the elongate body.

The cell collecting surface, optionally mounted on a support, is preferably mounted upon the elongate body by flexible or resilient bearing elements. The bearing elements preferably bear or support the cell collecting surf ace in such a way as to maintain a maximum area of cell collecting surface available for sample collection in any contour position of the surface, e.g. even after deformation.

The cell collecting head may be integral with the elongate body or attached thereto by any suitable means such as physical (e.g. heat treatment), chemical (e.g.

7 adhesive) or mechanical (e.g. with complementary recesses, detents etc. ). Similar means may be used to attach the cell collecting surface to the support if present.

The cell collecting surface is formed of a deformable, abrasive material so that it is able to scrape the required surface in order to collect cellular material. The abrasive nature of the material may be an inherent characteristic of the material or take the form of physical features, e.g. ridges provided in an otherwise smooth plastic surface. It is particularly preferred that the material from which the cell collecting surface be formed be resilient in nature so that upon contact with the surface from which cells are to be obtained it is able to compress and mould around the contours of that surface to maximise surface contact and thereby cell collection. It is also advantageous for the material from which the cell collecting surface be formed to have a degree of porosity, for example to be cellular. It has been found that a cell collecting surface having open cells is able to collect cellular material by suction additional to any material collected by abrasive scraping. The material used for the cell collecting surface should, of course, be biologically compatible, i.e. be inert to the environment and tissue with which it is to be used. Suitable materials include natural and synthetic rubbers, such as silicone rubbers, and plastics 8 materials including polypropylene, polyethylene, polyester, polyvinylchloride, urethanes, polytherurethanes and polyurethanes with suitable additives and processing conditions to provide the required deformable, abrasive nature of the material. It is particularly preferred that the cell collecting surface be made from a foamed material such as a polyurethane foam having open cells on its surface.

The size and shape of the cell collecting surface should be such as to maximise the contact surface, but is preferably also such that it allows a view of the surface from which the cells are being collected, e.g. a view of the cervix. For this purpose the central portion of the cell collecting surface may be narrower than its extremes. This allows a minimum amount of material in that central portion which may be advantageous when a small area is to be sampled. In a cervical smear test, for example, it allows the cell collecting surface to be deformed so as to provide a small tip capable of being inserted into the cervical canal to collect endo-cervical material therefrom.

The elongate body acts as a handle f or the device to allow it to be manipulated and in particular to be rotated when the cell collecting surface is in contact with the surface from which the cells are to be collected, e.g. the cervix. The elongate body may be 9 telescopically jointed to allow its length to be varied. Further, gripping means may be provided to increase the ease of manipulation of the device.

In order to achieve efficient transfer of collected cellular material to a microscope slide, the cell collecting device of the present invention is preferably such that the cell collecting surface can be made planar or regularly curved to ensure maximum transfer. Transfer is also improved if means are provided for retaining the cell collecting surface in a particular contour position during transfer, e.g. if the cell collecting surface is held substantially rigidly during transfer. For this purpose a transfer supporting element may be provided which during transfer may be operable to rigidly support the cell collecting surface. The transfer supporting member may be separable from the rest of the device, for example it could take the form of a clip-on component for use during transfer only. The shape and dimensions of the transfer supporting member must be such as to adequately support the cell collecting surface during transfer and hold it in the desired transfer position, e.g. in a planar, arced or curved state.

It had been found that a particularly effective transfer of collected material is achieved when the cell collecting surface is of a resilient material as the collected sample can in effect be printed onto the slide.

This is particularly the case where the material of the cell collecting surface is porous or cellular in nature. The resultant print is also advantageous as reflects the distribution and position of the sampled cells in situ.

According to a further aspect of the present invention there is provided a method of collecting cellular material, which method comprises: providing a cell collecting device comprising an elongate body and a cell collecting head attached at one end of the body, which cell collecting head is provided with a cell collecting surface which is formed from a deformable, abrasive material and which device is provided with means for adjusting the contour of the cell collecting surface; inserting the cell collecting device into a body cavity, such as the vagina; placing the cell collecting surface in contact with the surface from which cells are to be obtained, e.g. in contact with the cervix; optionally rotating the device in contact with the surface; withdrawing the device from the body cavity; and transferring the collected cellular material onto a microscope slide.

The present invention is advantageous as improves the degree of contact between the sampling surface and the 11 surface from which cells are to be collected, e.g. the cervix, reduces patient discomfort, avoids bleeding and allows efficient transfer of collected material.

For a better understanding of the present invention and to show how the same may be put into effect, reference will now be made, for the purposes of illustration only, to the accompanying drawings in which:

Figure 1 is a diagrammatical view of a multiparous 10 and a primiparous cervix; Figure 2 is a plan view of a prior art cell collecting spatula;

Figure 3 is a diagrammatical view of the prior art device of Figure 2 shown in use collecting a cervical 15 smear;

Figure 4 shows a front elevational view of an embodiment of a cell collecting device according to the present invention; Figure 5 is a side elevational view of the 20 embodiment shown in Figure 4; Figure 6 is an exploded view of the embodiment of Figure 4 showing its component parts; Figure 7 is a side elevational view of a further component for use in the embodiment shown in Figures 4 to 25 6; and Figure 8 is a plan view of the component shown in Figure 7.

12 The purpose of the cervical smear test is to assist in the diagnosis and prevention of cervical cancer. it requires the collection of samples from the vulnerable area of the cervix 1 (see Figure 1) and in particular from the endo-cervix 2 and from the so-called transformation zone 3. Although the size and shape of the cervix will vary in any two individuals it is particularly different depending on whether the patient is primiparous, (i.e. has not had children) as shown in Figure la or multiparous, (i.e. has given birth to a child) as shown in Figure lb.

one prior art device for obtaining cervical smears, shown in Figure 2 is the Aylesbury Spatula which is a f lat wooden spatula having an elongate body 4 which can act as a handle and a cell collecting surface 5 defined between a short lobe 6 and a longer lobe 7. In order to collect cervical cell samples for determining whether any abnormal cells are present, the spatula 4 is held by the handle and inserted into the vagina until the spatula's long lobe 7 is positioned within the patient's endocervical canal entrance and the short lobe 6 is positioned against the exo-cervix. The spatula 4 is then rotated about the exo-cervix with the long lobe 7 pivoting in the endo-cervical canal entrance. The cell collecting surface 5 collects cells by abrasive scraping of the surf ace of the cervix. The spatula 4 is then withdrawn from the patient and if required, e.g. if the 13 patient is primiparous, is turned over and the other end 8 of the spatula is inserted to obtain a further sample. It is clear that the fixed shape of the cell collecting surface 5 is unable to take into account any irregularities in the surface of the cervix nor to effectively obtain samples from both a multiparous and primiparous cervix.

The embodiment of the present invention shown in Figures 10 4 to 6 is a disposable plastics device having an elongate body 9 having a cell collecting surface 10 attached at its distal end. The cell collecting surface 10 is formed from a polyurethane foam and is mounted on a support 11 of a flexible plastics material. The support 11 is in turn mounted on a pair of resilient bearing members 12a, 12b which extend integrally from the distal end of the elongate body 9. The body 9 is a hollow cylinder having a through channel 13 extending longitudinally therethrough. Received within the longitudinal channel 13 is a push rod 14 which extends the full length of the elongate body 9 and out of its distal end between the resilient bearing elements 12a, 12b. The push rod 14 either acts directly on the collecting surface support 11 or in the embodiment shown is received within a housing 15 attached to the rear of the support 11. The push rod 14 is slidable within the longitudinal channel 13 and the degree of its extension can be varied by manipulating a projection 16 extending substantially perpendicularly out 14 from the push rod 14. The length by which the push rod 14 extends is infinitely variable along the length of the longitudinal channel 13 and it may be retained in desired extended positions, for example by receiving the projection 16 within suitably arranged recesses or slots 18 provided on the elongate body 9. The push rod 14 is provided with an intermediate sprung portion 17 so that it may be biased towards or against a desired position. A gripping handle 19 is provided for fitting over the proximal end of the elongate body 9 to assist in manipulation, particularly rotation, of the device and to prevent undesired dropping out of the push rod 14.

The contour of the cell collecting surface 10 can be 15 varied by varying the extension of the push rod 14 which is capable of exerting a deforming force on the rear of the support 11 which is transferred onto the cell collecting surface 10. When fully extended the contour of the cell collecting surface 10 has the shape of a truncated cone and when fully retracted the contour of the cell collecting surface 10 is substantially planar. This planar, fully retracted position, is preferentially used during transfer of the collected cells from the cell collecting surface 10 onto a microscope slide (not shown). To assist in holding the cell collecting surface 10 in a rigid position during such transfer a transfer support may be provided. As shown in Figure 7, one embodiment of a transfer support 20 is a semi- circular cylindrical member which can be clipped onto the elongate body 9 so that a support surf ace 21 provided on the transfer support 20 fits underneath the collecting surface support 11. This will provide a firm platform to allow the cellular polyurethane collecting surface 10 to transfer the collected sample by a "printing" process onto a microscope slide. It may be that the ideal contour to give maximum deposition of material may be an arc rather than a substantially planar surface and such variation is envisaged with the present invention. The use of a separate clip-on component (e.g. transfer support 20) will also help to identify those devices which have been used in order to prevent inadvertent reuse of a device which would inevitably expose the second patient to risk of cross contamination.

The cell collecting surface 10 has a substantially propeller or dumbell type shape having a narrow central portion 22 extending to two enlarged terminal portions 23. This allows a physician carrying out a smear test a view of the cervix during sampling. The support 11 is of a similar shape and dimensions.

In use, the elongate body 9 gripped by the handle 19 is inserted into the vagina and upon contact with the cervix the projection 16 is manipulated to vary the contour of the cell collecting surface 10 so that it corresponds as closely as possible to the surface of the cervix being 16 sampled. With full extension the tip formed by the central portion 22 of the cell collecting surface 10 is able to extend into the endo-cervical canal and take samples theref rom. The device is then rotated by at least 18011 and preferably by at least 3600. Af ter sampling the device is withdrawn, the push rod fully retracted (if it is not already so retracted) and the transfer support 20 clipped into position. The collected sample is then printed, i.e. transferred, onto a microscope slide by pressing the planar surface of the cell collecting surface 10 against the slide.

The improved degree of contact between the sampling surface 10 and the cervix with this embodiment of the present invention is due in part to the natural elasticity or resilience of the polyurethane foam cell collecting surface, and the adjustable contour of that surface. The sliding piston arrangement of the push rod within the elongate body allows the operator to take into account whether the patient is primiparous or multiparous, and allows continual variation in the contour of the cell collecting surface by the action of the internal spring mechanism. The embodiment ensures that in use the contour of the cell collecting surface will tend to mould itself to the shape of the individual woman's cervix as pressure is applied, ensuring maximum contact with the sampling surface. Further, the moderately high density polyurethane foam used for the 17 sampling surface gives improved friction between the cellular and sampling surfaces. The moderate pliability of the material and the absence of hard edges proves beneficial in reducing the incidents of contact bleeding 5 from the delicate endothelial surface of the cervix.

Further as the foam has a characteristic of absorbency it proves beneficial in removing the mucus layer from the surface of the cervix which will in turn increase the harvest of cellular material by improving friction.

Additionally the individual minute pockets on the surface of the foam tend to act as traps for cellular material thus tending to increase the amount of tissue obtained.

The ability to change the contour of the sampling surface means that it can be rendered flat for the purposes of transposing the cellular sample onto the surface of a microscope slide which allows the operator to make a print of the sampling surface on the slide. In this way deposition of the material occurs in an ordered fashion with endo-cervical cells, (i.e. from the central canal of the cervix) at the centre of the print surrounded more peripherally by cells from the transformation zone and lastly cells from the external surface of the cervix. This will be of considerable benefit to the laboratory staff analysing the material as will allow them to identify important areas for close study with greater ease. The invention is in particular beneficial in terms of ease of use, accuracy and benefits to the interpretation of samples in the laboratory.

Claims

18 CLAIMS

1. A cell collecting device particularly adapted for the collection of a cervical smear, which device comprises an elongate body and a cell collecting head attached at one end of the body, wherein the cell collecting head is provided with a cell collecting surface formed from a deformable, abrasive material and means are provided for adjusting the contour of the cell 10 collecting surface.

2. A cell collecting device according to Claim 1, wherein the contour of the cell collecting surface is infinitely variable.

3. A cell collecting device according to claim 1 or 2, wherein the contour adjusting means comprises a surface contour adjusting member capable of exerting a deforming force on the cell collecting surface.

4. A cell collecting device according to Claim 3, wherein the surface contour adjusting member comprises a push rod.

5. A cell collecting device according to Claim 3 or 4, wherein the surface contour adjusting member is received within the elongate body.

19

6. A cell collecting device according to Claim 3, 4 or 5, wherein means are provided f or urging the surface contour adjusting member against the cell collecting surface.

7. A cell collecting device according to any preceding claim, wherein means are provided for biasing the cell collecting surface towards a desired surface contour.

8. A cell collecting device according to any preceding claim, wherein means are provided for locking the device with the cell collecting surface in a desired contour.

9. A cell collecting device according to any preceding claim, wherein the cell collecting surface is mounted on the elongate body by a flexible or resilient bearing element.

10. A cell collecting device according to any preceding claim, wherein the material from which the cell collecting surface is formed is resilient.

11. A cell collecting device according to Claim 10, wherein the material has a degree of porosity and/or is cellular.

12. A cell collecting device according to Claim 10 or 11, wherein the material is a polyurethane foam.

13. A cell collecting device according to any preceding claim, wherein the contour of the cell collecting surface may be made planar or regularly curved during transfer.

14. A cell collecting device according to any preceding claim, wherein means are provided for relating the cell collecting surface in a particular contour position during transfer.

15. A cell collecting device according to any preceding claim, which additionally comprises a transfer supporting element operable during transfer to rigidly support the cell collecting surface in a desired contour.

16. A method of collecting cellular material, which method comprises:

providing a cell collecting device comprising an elongate body and a cell collecting head attached at one end of the body, which cell collecting head is provided with a cell collecting surface which is formed from a deformable, abrasive material and which device is provided with means for adjusting the contour of the cell collecting surface; 25. inserting the cell collecting device into a body cavity, such as the vagina; placing the cell collecting surface in contact with the surface from which cells are to be obtained, e.g. in 21 contact with the cervix; optionally rotating the device in contact with the surface; withdrawing the device from the body cavity; and transferring the collected cellular material onto a microscope slide.

17. A cell collecting device substantially as herein before described with reference to and as illustrated in Figures 3 to 6 and 7 and 8 of the accompanying drawings.