AU4375301A - Analytical devices and methods of use thereof - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT TITLE OF INVENTION ANALYTICAL DEVICES AND METHODS OF USE THEREOF Name and Address of Applicant: Unilpath Limited of Wade Road, Basingstoke, Hampshire RG24 OPW, England The following statement is a full description of this invention, including the best method of performing it known to me:- WO095/13541 PCTIEP94/0 3598 ANALYTICAL~ DEVICES AND METHODS OF USE THEREOF This' invention relates to the construction and use of analytical' devices, especially those adapted for use by relatively unskilled persons for example in the home.

Home-use devices for the analys is of urine, for example in pregnancy tests and ovulation prediction tests, are now widely available commercially. Many such devices are based on the principles of immunochromatography, and typically comprise a hollow casing constructed of plastics material containing a porous assay strip carrying pre-dosed reagents. The user merely needs to apply a urine sample to one part of the casing to initiate the assay. The assay result becomes visible by eye within a few minutes without further action by the user. Examples of such devices are **described in EP-A-291l94 and EP-A-383619, the disclosures of which are incorporated herein by reference.

Sample collection is conveniently achieved by means of. a ****bibulous member which forms part of the device and which can readily take up sample liquid,, eg. from a urine stream.

Optionally the bibulous member can protrude from the casing e*e* o soo eof the device to facilitate sample application. In any event, the bibu.Lous,. member is, narwally located at or near 0 an extremity of the device so that the bibulous member can be introduced into a source of sample liquid, such as a urine stream, while minimising the likelihood of direct contact between the sample liquid and the hands of the user. Devices of this type are s ometimes supplied with a cap which the user can place over the bibulous member after sample application. The benefits of the cap are primarily hygienic.

In 'order to reveal the assay result, the casing of the WO W095/13541 PCT/EP94/03598 2 Preferably, in the interests of economy of materials and to minimise environmental impact, only a single cover means is provided, said single cover means being arranged to enclose said bibulous sample receiving member and said window means but not both simultaneously.

Desirably, said cover means provide(s) means for handholding said device while either or both of said bibulous sample receiving member and said window means are enclosed thereby.

In a particularly convenient form of the invention, said casing is elongate and said first extremity is one end thereof. In this embodiment, it is preferable that said cover means is/are telescopically receivable over either or both ends of said elongate casing.

The analytical devices of the invention provide a number of o advantages over devices of the prior art: a) The device can be made smaller without loss of hygiene o and convenience for the user, or loss of accuracy of the assay result. Indeed, accuracy may be improved. Because the observation window is enclosed during collection of the S sample, the observation window can be located much closer to the sample collector. If the assay device comprises an assay strip within the casing, the working length of the strip can be shorter and the speed and accuracy of the test improved. A smaller device may be made more cheaply because it requires less raw material.

b) The device can be provided to the user in a form which is immediately ready for use. The device can be provided wrapped inside a moisture-impervious pouch or sachet which can, for example, be simply torn open in the conventional manner to release the device. On opening the pouch, the device is found with the cover means enclosing the WO 95/13541 PCT/EP94/03598 .3 daily, testing of body fluid samples is needed.

.Calculation and interpretation of the individual assay results typically require the use of an electronic device such as a microprocessor. It is generally envisaged that whereas the microprocessor or similar unit will be retained for a long time by the user, the testing of body fluid samples will be conducted using a plurality of disposable testing devices which are used only once and then thrown away.

Hence, during the repetitious assay procedure, a disposable analytical device will be used to sample the body fluid and to perform the basic assay. Thereafter the user will present the disposable device to the permanent reader/microprocessor in order for the individual assay result to be recorded and interpreted. Typically this may involve engagement or insertion of a portion of the disposable device into a slot or other shaped orifice in the structure of the reader/microprocessor, to facilitate positive location of the disposable device in relation to Sa reading head which forms part of the reader/microprocessor. Because the reader/microprocessor is an item of equipment which the user must retain for repeated use, it is easy to imagine that the user may have 25 misgivings about such a procedure. The exterior of the disposable analytical device may easily become contaminated with. sample..fluid. Such. contaminating fluid. might be transferred to the permanent reader/microprocessor, and for reasons of hygiene there may be reluctance to retain and re-use such a contaminated item. We believe that in order to promote consumer acceptance of such an analytical system, it is necessary to min-.:ise the likelihood of sample contamination on the portion of the disposable assay device which is to be engaged with the reader/microprocessor.

Moreover, if body fluid is transferred therefrom into the WO 95/13541 PCTIEP94/03598 4 14. Extended portion 14 is being located in a recess 40 of a reader/monitor 41. Within recess 41 is a reading sensor (represented by window 42) which when the testing device is properly inserted in the recess is adjacent to the reading window 17 of the assay device. The exterior of the casing of reader 41 can incorporate other features such as operating controls 43, a visual output 44, such as a liquid crystal display panel, and access 45 to the interior of the device e.g. for battery replacement.

The device of Figure 1 can conveniently be made from plastics polystyrene) mouldings, with the upper and lower halves of the casing sealed together if necessary, for example by ultrasonic welding. The interior of casing 10 can contain a porous carrier strip extending from V, portion 13 of the casing along the length of the casing and past reading window 17. Access of liquid sample to the porous strip within the casing should only be effected via sample receiving member 16, and this is-greatly facilitated 20 by the fact that cap 15 encloses reading window 17 during sample collection. Cap 15 can be a separate single ooooo plastics moulding. The outer casing of reader 41 can also be easily manufactured from one or more plastics mouldings.

-5 The skilled reader will appreciate that the detailed construction of the device within casing 10 is not critical to the present invention.. Neither are the .electronic or other constructional features within the casing of reader 41.

It will be appreciated that the overall shape and dimensions of casing 10 and cap 15 can be subject to considerable variation from that described above without departing from the principles of the invention. Similarly the interactive shapes of portion 14 and the recess or other engaging location in the reader casing can be varied.

Purely by way of example of such immaterial variations that

Claims (3)

1. An analytical device for determining the presence and/or concentration of any analyte in a sample liquid comprising: a hollow casing; means within said casing for selectively capturing said analyte in sample liquid applied thereto; a bibulous sample liquid receiving member at or adjacent to a first extremity of said casing, said receiving member providing means for collecting sample liquid and transporting collected sample liquid into said casing; a cover means engageable with said casing to enclose said Sbibulous sample receiving member; and a cover means releasably engangeable with said casing to enclose said window means.

2. An analytical device according to claim 1, 13 wherein only a single cover means is provided, said single cover means being arranged to enclose said bibulous sample receiving member and said window means but not both simultaneously.

3. An analytical device according to claim 1 or claim 2, wherein said cover means provide(s) means for hand-holding said device while either or both of said WO 95/13541 PCTIEP94/03598 6 sample receiving member, said device is hand-held by means of said cover means enclosing said bibulous sample receiving member to facilitate presentation of said window means-to means for reading the result of said analysis. DATED ~1 Signed for and on behalf of UNILEV'PLC Unilever Australia Limited 0*