"CATHETER-TYPE SAMPLING DEVICE"
This invention relates to a catheter-type device, and in particular relates in one embodiment to a medical or veterinary sampling device which is designed for insertion into channels, vessels, passageways, or body cavities of humans or animals so as to enable a sample to be taken and withdrawn therefrom.
As pointed out in prior Australian Patent Specification No.497345, one of the disadvantages of prior art catheter-type sampling devices has been their inability to sufficiently protect the sample from contaminating matter which may be picked up by the device as a result of the insertion and withdrawal of the device.
Prior Specification No. 497345 provides a catheter sampling device comprising an outer tube of resilient material having an open and a normally closed end, the closed end being shaped so as to permit unrestricted entry into a body through a channel thereof and having means associated therewith enabling the opening of the normally closed end and protrusion therethrough by an inner tube extending within the outer tube upon the inner tube being
pushed against the normally closed end, and a flexible elongated member moving within the inner tube having sample collecting means at the end thereof designed to enter the body beyond the inner tube, the normally closed end being reclosable upon retraction of the inner tube and elongated member back within the confines of the outer tube. In one embodiment of the device disclosed in this prior specification, the closed end of the outer tube is convexly rounded and provided with at least one diametrically extending incision to enable the closed end to be opened as described above.
In use of the device of the above mentioned prior specification, the inner tube is used to guide a swab stick attached to an appropriate rod or tube. The convexly rounded closed end of the outer tube is inserted into the appropriate channel of the body to the required depth. The inner tube, which may be marked to indicate the length to which it has to be inserted to open the closed end of the outer tube and to protrude for a nominal distance, is then pushed through the outer tube to that mark. The swab stick is then pushed through the inner tube to a previously determined mark which will allow the swab to protrude beyond the end of the inner tube to allow the obtaining of a sample from the required site. After taking of the sample, the swab stick is withdrawn to within the inner tube, the inner tube is retracted so that the normally closed end of the outer tube will again close and the entire device then withdrawn from the body.
It is one object of the present invention to provide an improved catheter-type sampling device for use in human or veterinary medicine, and the like, which is more economical to manufacture than similar sampling devices previously known, and yet which can be simply and conveniently used in practice.
According to the present invention there is provided a catheter-type device comprising an outer tubular member, and an inner elongate member extending within said outer tubular member coaxially therewith, said outer tubular member being provided at one end thereof with, a resilient tubular sleeve extending axially therefrom, and said inner member being adapted to move axially with, respect to said outer tubular member and said resilient tubular sleeve, so that, in use, one end thereof corresponding to said one end of the outer tubular member can be extended axially outwardly of said outer tubular member and said resilient tubular sleeve.
In one embodiment of this invention, the device is configured as a sampling device and is provided with sampling means at said one end of the inner member. Alternative means may, however, be provided at this end of the inner member, including an impregnated swab or a syringe or other means to administer a drug, antibiotic or similar medication, or other means to effect other forms of treatment or therapy within the body. In yet another alternative, the inner member may be simply tubular throughout its entire length, so that fluids or the like may be passed therethrough into the body.
Preferably, both the outer tubular member and the inner elongate member are constructed of relatively rigid plastics material which has sufficient resilience or flexibility to allow flexing or bending of the device in use. The. outer tubular member may be of any suitable length, depending on the intended use of the device, and the inner elongate member is of sufficient length, that in use of the device, the end of the inner member or the sampling or other means provided at that end may protrude -from the resilient tubular sleeve and extend axially of the outer tubular member, whilst the opposite end of the inner member still protrudes from the other end of the outer tubular member.
The resilient tubular sleeve preferably has an internal diameter substantially the same as the outer diameter of the outer tubular member so that the resilient tubular sleeve can be simply fitted over the end of the outer tubular member. If desired, some form of collar means may be provided to hold the resilient tubular sleeve in place on the end of the outer tubular member.
In one particularly preferred embodiment, the inner elongate member is itself tubular, and a sampling means is provided which comprises a simple swab stick inserted into one end of the tubular inner member. The swab stick may, for example, comprise an elongated wooden support having a cottonwool or similar swab at the free end thereof.
According to a further aspect of the present invention, there is provided a method of obtaining a. sample from or administering medical or other treatment to a selected site within a human or animal body characterised. by the use of a catheter type device as Broadly described above, which method comprises the steps of closing the end of the said catheter-type device by folding the resilient tubular sleeve back upon itself and the outer tubular member, inserting said closed end of the device onto an appropriate channel or passageway of the body until said closed end reaches the selected site within the body at which, the sample is to be taken or treatment administered, unfolding the resilient tubular sleeve at said selected site, and extending the end of the inner elongate, member axially outwardly of said outer tubular member and resilient tubular sleeve to obtain a sample from or to administer treatment at said selected site.
In use of the device of the present invention as a sampling device, the resilient tubular sleeve which normally extends axially from the outer tubular member is folded back upon itself and the outer member to close and seal that end of the outer tubular member. The inner elongate member is usually positioned within the outer tubular member prior to insertion of the device in the appropriate channel of the body with the sampling means positioned close to the end of the outer tubular member closed by the folded back resilient tubular member. The sampling
device is then inserted into the body channel with the closed end of the outer tubular member leading, and the resilient tubular sleeve is maintained in its position foldedback on itself as the device is passed through the channel to the site at which the sample is to be taken. Once the appropriate sampling site has been reached, the sampling device is withdrawn slightly to allow the resilient tubular sleeve to unfold and return to its normal position extending axially of the outer tubular member. The sampling means may then be passed through the outer tubular member and the resilient tubular sleeve by axial movement of the inner elongate member relative to the outer tubular member and a sample taken at the appropriate site with the sampling means extending axially outwardly of the outer tubular member and the resilient tubular sleeve.
Once a sample has been taken, the inner elongate member and the sampling means attached thereto may be withdrawn completely from the outer tubular member before the outer tubular member is removed from the body channel. In this way.
contamination of the sampling means is prevented both during insertion of the sampling device, and during withdrawal of the sample. After, the sampling means has been withdrawn from the device, the outer tubular member is withdrawn from the body channel to complete the sampling procedure. Conveniently, the sampling means is then removed from the end of the inner member and placed in an appropriate storage container.
In one particularly convenient embodiment of the present invention, the device also includes a cap which fits over the end of the outer tubular member at which the resilient tubular sleeve is located and is retained in position by frictional contact with, the collar means. This outer cap protects the resilient tubular sleeve and, incidentally, the sampling means in the device, prior to use thereof. After the sample has been taken, the cap may be used as a sample holder, and sealed with a small plug or the like.
Further features of the present invention will be apparent from the following description of
one embodiment of a catheter-type sampling device according to the invention which is illustrated in the accompanying drawings. In the drawings:
Fig.1 is a part-sectional view, taken along the longitudinal axis, of the embodiment of the sampling device in its normal position;
Fig.2 is a similar part-sectional view of the embodiment of the sampling device in the operative position in which it is inserted into the channel of the body; and
Fig.3 is a similar part-sectional view of the embodiment of the sampling device in the position for taking a sample.
The sampling device shown in the drawings is particularly intended for veterinary use, for example, in obtaining swabs of mares, however it will be appreciated that the dimensions of the device may be varied for other veterinary uses or for medical use in humans.
As shown in the drawings, the sampling device 10 comprises an outer tubular member 11 and an inner elongate member 12 extending within the member 11 coaxially therewith. Resilient tubular sleeve 13 is provided at one end of the outer tubular member 11 extending axially therefrom, the resilient sleeve 13 being retained in position by a collar member 14. Sampling means 15 is provided at the end of the inner member 12 adjacent the resilient sleeve
13, and the opposite end of the inner member 12 extends beyond the corresponding end of the outer tubular member 11. Sampling means 15 conveniently comprises a wooden swab stick 16 which is received within the tubular inner member 12, and a swab 17 of cottonwool or
similar material. As shown, an outer cap 18 may be provided to protect the resilient tubular sleeve 13, and cap 18 is conveniently retained in position by the resilient collar 14.
As shown in Fig.2 of the drawings, prior to insertion of the sampling device 10 into a body channel, the outer cap 18 is removed from, the device and the resilient tubular sleeve 13 is bent back on itself to close that end of the sampling device 10. The device 10 may then be inserted into the body, channel with the closed end leading to prevent contamination of the sampling means during insertion. As previously described, once the site to be sampled is reached by the closed end of the sampling device 10, the device is withdrawn slightly so that the resilient tubular sleeve 13 may return to its normal position extending axially from the outer tubular member 11. In this position, the inner member may be moved axially with respect to the outer tubular member 12 so that the sampling means 15 protrudes from the end of the resilient' tubular sleeve 13 and a sample is taken of the desired site. The inner member 12 and sampling means 15 are then retracted at least to within the outer tubular member 11, but preferably completely, from the outer tubular member 11, whilst that member remains in position. Finally, the outer tubular member is withdrawn from the body channel. It will be apparent from the fore going description that contamination of the sampling means is also prevented during withdrawal of the sampling means from the sample site, particularly if the inner member and sampling means are withdrawn completely from the outer tubular member before the latter is removed from the body channel.
If desired, the sampling means may then be removed from the inner member 12 , for example by breaking the wooden swab stick 16, and the wooden swab stick 16 with the swab 17 having the sample thereon is conveniently stored within the outer cap 18 and sealed therein by means of a small plug or the like.
As previously described, the device of the present invention may also be used in the form of a catheter-type, insertion device which will enable insertion of a syringe or similar tubular device or other treatment or therapy through an appropriate channel to a desired site in the body. As in the sampling device configuration, in these alternative configurations the means at one end of the inner member is covered by the folded resilient tubular sleeve during insertion of the device so that drugs or the like can be administered or other treatment effected at the desired site without the problems of contamination or drug application or other treatment during insertion prior to the desired site.
In another embαdiment of this invention, an intermediate tubular member may be included in the device, the intermediate mem ber being disposed within and extending coaxially with the outer tubular member, with the inner member extending axially of the intermediate mamber. In this embodiment, the intermediate mernb er may be extended outwardly of the outer member in use of the device to prevent collapsing of the resilient tubular sleeve as the inner msπber is extended and retracted from the outer faibular member.
It will be appreciated that the description of a preferred embodiment of the invention given above is given by way of illustration of the present invention only, and that many variations and modifications may be made thereto without departing from the spirit and scope of the present invention as broadly described above.