MXPA97001661A - Pru equipment and devices - Google Patents

Abstract

A test equipment for qualitatively or quantitatively determining the presence of one or more analytes in a fluid sample, comprising a test device together with a reading device, which is coupled to the test device and in which the coupling located with accuracy of the test device with the reading device, it is essential for the exact reading of the test result, in which the precisely located coupling of the test device with the reading device causes a "lock and key" interaction, that is, a unique 3-dimensional interaction between the test device and the reading initiation means of the reading device. Preferably, the read initiation means includes a switching actuation means comprising at least a fixed projection portion and at least a displaceable projection portion and a contact portion of the housing of the assay device, comprising a groove shaped to receive the fixed projection portion of the switching drive means, but not its movable projection portion, the contact portion also comprises an interface portion which contacts and displaces the movable portion of the switching drive means, when the fixed projection portion is housed inside the ran

Description

EQUIPMENT AND PROOF DEVICES FIELD OF THE INVENTION This invention relates to test equipment and devices for qualitatively or quantitatively determining the presence of one or more analytes in a fluid sample and particularly relates to means for facilitating the correct interaction between a test device and a reading device therefor. , which together form the essential parts of the test equipment.

BACKGROUND OF THE INVENTION In PCT Patent Application WO 95/13531, reading devices for test devices are described using test strips. Typically, the test device comprises an elongate housing containing the test strip and having in the housing one or more "windows" through which a region or test result region of the test strip can be observed. The preferred reading device includes a slotted receiving portion within which the test device can be inserted and in which the result of the test is determined by electromagnetic means, particularly the transmission of light through the test strip. For the exact determination of the test result, the detection zone of the test strip must be correctly located within the reading device in relation to the light path or other characteristics that form the reading system of the result. WO 95/13531 describes various ways in which correct reception of the test device within the reading device can be facilitated. A main objective of these test equipment, is that they should be usable by people without training and especially by the consumer at home. When a common consumer is invited to use any device which requires the physical coupling of one unit with another, it can be surprisingly common for this action to be performed incorrectly. The instructions illustrated and written carefully provided by the manufacturer can be misinterpreted, or often ignored. In the present context, where accurate reading of a sensitive test result is required, it is essential that accurate placement of the test device is achieved within the reading device. Any misalignment or incorrect coupling of these two units can lead to inaccurate or erroneous test reading. This problem is particularly acute where the reading system does not include any accessory to scan the test device to locate the appropriate portion to be read. The cost and complexity of the reading system can be substantially reduced, if the precise location of the detection zone within the test device is controlled during manufacturing and the device is presented to the reading device in a constant manner, in such a way that the detection zone is always in the same position in relation to the reading system. It is an object of the invention to provide a test equipment in which the probability of error of the user during the presentation of the test device to the reading device is substantially reduced. An associated objective is to provide a test equipment in which the reading of the test device is not started unless the test device has in fact been presented correctly to the reader or in which the user is alerted to the poor presentation of the test device. In WO 95/13531, some mechanisms are described to facilitate exact placement, but the present invention provides other improvements. The invention will be described with particular reference to the test kits useful in monitoring analytes of body fluid, and especially for monitoring at home urinary analytes of importance for the determination of the state of the human ovulation cycle.

This is by way of example only and it will be appreciated that the invention is useful in many other contexts, where other sample liquids and analytes are involved. Examples of other types of analyzes, in which the results of the exact assay are advantageous and where a device according to the invention may be appropriate, include assays for cancer markers, cardiac markers, blood glucose, drug abuse, hormones, markers of infectious diseases, tests in the monitoring of a therapeutic drug, quality control of raw material and manufacturing and tests for levels of output and contamination.

GENERAL DESCRIPTION OF THE INVENTION The invention provides a test equipment for qualitatively or quantitatively determining the presence of one or more analytes in a fluid sample, comprising a test device together with a reading device, which is coupled with the test device and in that the accurately located coupling of the test device with the reading device is essential for the accurate reading of the test result, in which the correct coupling of the test device with the reading device causes a "lock and key" interaction "between the test device and the means for initiating the reading of the reading device. In this specification, the "lock and key" interaction expression is used to represent a unique 3-dimensional spatial relationship between the test device and the reading device. In the preferred embodiments of the invention as set forth in detail herein, this occurs by means of 3-axis alignment of these two components. This 3-axis alignment is translated into a single-axis drive of a switching means, which initiates the reading of the test device. In one embodiment, the assay device is of the type consisting essentially of a porous carrier strip or the like within a hollow housing and in which the result of the assay is revealed by the specific binding of a labeled reagent within a detection zone. of the carrier strip, the presence of the labeled reagent within the detection zone is discernible by the reading device. Preferably, the reading device includes receiving means for receiving the test device and the read initiation means comprises a switching drive means or the like, which is movable by receiving the test device within the medium of receiving, in which the correct reception of the test device causes a contact portion of the housing to make displaceable contact with the switching drive means, the contact portion and the displaceable switching drive means which is cooperatively coupled with a "lock and key" coupling, in such a way that only by the correct reception of the test device, the switching actuation means can be moved to start the reading. As used herein, the term "switching drive means" is used to carry any means that directly or indirectly causes an electrical or electronic circuit to be switched on or off or altered to effect or affect the reading of a result. of testing. Typically, this will be a mechanical mechanism. The driving means may be part of or directly, for example physically, connected to a real switch, or where there may be an indirect or remote connection. The important consideration is that the correct coupling of the test device with the reading device affects only the switching drive means and consequently, the required electrical or electronic change is affected. Conveniently, the switching drive means comprises at least one fixed projection portion and at least one movable projection portion and the contact portion of the housing of the test device comprises a slot shaped to receive the fixed projection portion of the test device. switching actuation means, but not its displaceable projection portion, the contact portion also comprises a contacting interface portion, and displaces the displaceable portion of the switching actuation means, when the fixed projection portion is housed within of the slot. It is preferred that the receiving means incorporate a biasing means that presses the received test device against the switching drive means. In another preferred modality, the receiving means incorporates a cam means which flexes the test device away from the switching means, unless the test device is correctly received. Ideally, the cam means provides a "press fit" coupling of the test device and the receiving means, when the test device is correctly received. As a supplementary feature, the test device is preferably elongated and the receiving means comprises a slot into which at least part of the elongated test device can be adjusted, and the slot has at least one portion of projecting flange that it extends over the hole in the slot and which acts to retain the test device within the slot, when correctly received therein. In a preferred embodiment, the projecting shoulder portion is at one end of the slot and can couple one end of the elongated test device during insertion of the test device into the receiving means. Preferably, there is also a second projection shoulder portion at or near the other end of the slot also for retaining the test device therein. The invention also extends to any test device having the physical characteristics that allow it to cooperatively couple with a reading device in a "lock and key" manner as described herein. A specific embodiment of the invention will now be described in detail, with reference to Figures 1 to 10 of the accompanying drawings. These drawings are for the purpose of general illustration only and are not to scale. The reader of this specification should also take note of the technical content of WO 95/13531. The present invention is associated solely with ensuring accurate registration between the test device and the reading device. The manner in which the test device generates a readable test signal is not critical and neither is it the mechanism by which the reading device reads and interprets this signal and provides the information to the user. Examples of all these aspects are set forth in WO 95/13531.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 represents a general view of a reading device of the invention, with an open cover that reveals the main user-related characteristics of the device. Figure 2 represents a plan view of part of the device seen in Figure 1, showing in detail a slot for receiving a test device. Figure 3 is a partial cross-section of the reading device, taken on the longitudinal axis of the slot, showing the rear wall of the slot. Figure 4 is a partial cross-section of the reading device, taken again on the longitudinal axis of the slot, but observed in the reverse direction, showing the opposite wall of the slot. Figure 5 is a partial elevation view in and along the right end slot. Figure 6 is a general view of a test device, as it is held by the user in an appropriate orientation for insertion into the reading device. Figure 7 is a general view of the opposite side of the test device. Figure 8 is a partial cross-section elevation of the reading device and the test device during insertion, seen from the front of the reading device. Figure 9 is a plan view, partly in cross section and partially cut away from the slot, with the test device inserted correctly therein. Figure 10 is an enlarged plan view in partial cross-section of the switch mechanism of the reading device. With reference to Figure 1, the reading device comprises a generally flattened oval body 100 and an upper lid 101 cross-linked on the rear part 102 of the body. Each side 103 of the lid 101 curves sharply inwardly adjacent the joint, the body 100 is slotted through its upper surface 104, such that when the lid is closed, the device has a level outer surface. In this regard, the shape and proportions of the lid and body are solely aesthetic and are not carried in the present invention. There is no technical need for the device to have any cover at all. The upper surface 104 of the device disclosed by the open lid has a slot 105 towards its right side 106. The slot 105 has a rear surface 107 that slopes inwardly, which incorporates many operating characteristics which are important to the user . These operating characteristics are not of direct importance to the present invention, but as shown in Figure 1 these may include a push button 108, two indicator lights 1-09 and 110 and a display panel 111, small to carry the information to the user. The slot 105 has a flat base 112. At the left end 113 of the slot 105 is a surface 114 that slopes inwardly from the center of which a receiving slot 115 extends horizontally to the left side 116 of the device. The slot 115 extends almost to the left side of the device and terminates below a small cover 117 molded on the upper surface of the device. In Figure 1 the rear wall 118 of the slot 115 can be seen and the characteristics of a switching drive mechanism 119 for starting the reading of a test device (not shown), when inserted into the slot and also a rectangular cover 120 of a reading system (concealed within the body of the reading device for obtaining information from an inserted test device.) Switch 119 is described in the following in greater detail with reference to Figures 3, 9 and 10. The flat base 112 of the recess extends into the groove on the right side 121 of the groove 105, directly opposite the end 122 of the groove., the rim 123 of the device extends inwardly in a curved shape, convex to an apex 124, which is directly in line with the longitudinal axis of the slot. There is a small groove 125 in the inner surface of the lid 101 to receive the cover 117 at the end of the groove, when the lid is closed. Other features of the groove visible in Figure 1 are that it is substantially parallel across the side of most of its length, but a region 126 of the closest surface tapers in slightly as it approaches the deck. In the other, the open end 122 of the groove is a flange 127 that extends forward at the upper edge 128 of the rear wall 118. The groove is wider at its open end 122, because both of the front wall and the rear wall are staggered outwards in regions 129 and 130, respectively. With reference to Figure 2, these same characteristics of the groove 115 can be seen more clearly. The additional features visible in Figure 2 are that the rectangular cover 120 for the reading system extends outwardly from the rear wall 118 of the groove 115 and has sharply beveled edges 200. On the front wall 126 of the slot there are two spring-loaded, projecting buttons 201 and 202, one (201) which is directly opposite the drive switch 119 and the other (202) which is near the hole 122 of the slot, opposite to the flange 127 extending from the rear wall 118. The second button 202 has a beveled surface 203 adjacent the hole in the slot. Figure 3 shows the rear wall 118 of the slot 115. The switch actuator 119 is divided into three components. The general shape is circular, but consists of a central, diagonal portion 300 that extends across the entire width of the actuator and two arcuate portions 301 and 302, one on each side of the diagonal. The arcuate portions are fixed, but the central diagonal portion is inwardly squeezable to trigger reading by the device. Figure 3 also shows that a region 303 of the flat base 131 of the groove, adjacent the cover 117, is tilted up sharply to meet the end wall 304 of the groove below the cover. Figure 4 shows the opposite wall 126 of the slot 115, including the two spring-loaded buttons 201 and 202. The button 202 adjacent the hole 122 of the groove is asymmetrically and its upper part 400 is bevelled downwards and the left surface 203 (as seen in Figure 4) is also beveled. Located horizontally between the two buttons there is a rectangular slot 401, behind which there is a lighting system (not observed) which is part of the reading reading mechanism. The slot 401 is located directly opposite the cover 120 projecting from the reading system on the opposite wall of the slot. Again, the region 303 that slopes upward from the base 131 of the slot can be seen below the cover 117. The view along the slot 115 as seen in Figure 5, shows that the lower side 500 of the flange projecting has a curved, convex surface. Other features seen in Figure 5 are the bevelled pressure button 202, the cover 120 of the projecting reading system, the cover 117 at the far end of the slot and the base 303 that slopes upwardly below the cover. Figure 6 shows an assay device comprising an elongated body 600 and a removable lid 601. The left portion 602 (as seen in Figure 6) of the body 600 is narrower in cross section than the main portion 603 and tapers sharply at its left end 604. This taper results from: a) The front surface 605 of the device that is beveled to the far left; and b) The lower surface 606 which is sharply inclined towards the left end. There is a rectangular window 607, long on the front surface 605 of the narrowest portion 602 of the body, having slanted sides 608 that extend into the molded body. This window reveals a test strip 609 within the device and, as shown, this includes two zones 610 and 611 of the test result. With reference to Figure 7, which shows the opposite side of the test device, the opposite surface 700 of the narrowest portion 602 of the body also incorporates a rectangular window 701 slotted into the body. This window also reveals strip 609 and the same detection zones 610 and 611, as seen through the other window. On this same surface of the device, between the window 701 and the end tip 702 there is a pair of arcuate grooves 703 and 704 separated by a diagonal portion 705, which is flush with the remainder of the surface of the device at this point. Figure 8 shows the test device 600 being inserted in the reading device. The tip 702 of the test device body has been placed under the cover 117 and, at approximately the mid-point of the narrowest portion 602 of the body, is in contact with and placing the top of the pressure button 201, although this does not It is observed in this drawing. This is a stable position and requires finger pressure by the user down on the body 603 and / or the lid 601 of the device, to push the device in a more horizontal orientation within the slot, against the resistance created by the button pressure 201, which would be displaced by such movement. This drawing also shows, in dashed lines, the position that the test device needs to occupy, when it is inserted correctly in the reading device for accurate reading. This correct position requires that the test device be completely horizontal (relative to the base of the reading device) with the tip 702 fully received under the cover 117 and the far end 800 of the cover abutting with the portion 124 that it curves inward on the right side of the reading device. It can also be seen that the portion 606 that slopes upward from the tip 702 of the test device couples the slope 303 upwards from the base of the slot below the cover. When the test device is correctly inserted into the slot, the wider portion 603 of the body is received by snap fit under the shoulder 127 of projections of the rear wall 118 of the slot.

With reference to Figure 9, the correctly inserted test device is held in place by a combination of features. It is pushed against the back wall 118 of the slot by pressing the two pressure buttons 201 and 202. The protruding cover 120 of the reading system fits snugly within the window recess 701 in the body of the test device. The arcuate, fixed portions 301 and 302 of the commutating actuator are precisely fitted within the arcuate grooves 703 and 704 in the body of the test device and the diagonal, central portion 300 of the commutator is depressed by the diagonal body portion 705 between the two slots. The depression of the portion 300 of the switching actuator causes the reading of the test device by a mechanism described in the following with reference to Figure 10. The objective is to provide a unique three-dimensional situation, in which the actuator of Switching is triggered by the received test device. The positions of the cover 117 and the protruding ridge 127 are shown in dashed lines. The wider portion 603 of the body of the test device is housed within the flared hole facing away from the slot. Other features shown in Figure 9 are a lighting system 900 behind an optical diffuser 901 on the front wall 126 of the slot and a series of optical detectors 902 behind the cover 120 on the rear wall 118 of the slot. These chteristics are simply represented in diagrammatic form, since they are not critical to the present invention. Suitable examples of such chteristics are described in WO 95/13531. The chteristics observed within the partial cross-section of the test device are the test strip 609 sandwiched on each side by a sheet of transparent plastic 903 and 904, the two detection zones 610 and 611 on the strip and a pin 905 on the side. molding of the test device, which extends through the test strip and the coated sheets to provide during the manufacturing of the device, a precise location means for the two detection zones. Examples of these features are also fully described in WO 95/13531. Figure 10 shows the mechanism for actuating the switch of the reading device in greater detail. The actual switch 1000 which is connected to the electronic processor within the reading device is itself within the interior of the device, the body 100 and in the preceding drawings is only visible in Figure 9 in a partially sepe cut. The actual unit 119, which is visible on the back surface of the slot is a sepe mechanical construction, which contacts and operates the switch 1000 during use. As shown in Figure 10, the switch 1000 is located on a printed circuit board 1001. At the rear of the circuit board 1001 there are two switching contacts 1002 and 1003. The mechanical construction, which interacts with a correctly inserted test device, is located on the back wall of the slot. As already described, the mechanism comprises two fixed, outer portions 301 and 302 and a central movable portion 300, which is moved inwardly when the test device is correctly inserted. As shown in Figure 10, the movable portion 300 of the drive mechanism comprises a hollow shaft 1004, which is positioned between the two fixed portions of the mechanism and forms a free sliding bearing between 301 and 302. A threaded conduit 1005 is extends axially through the entire shaft and engages with a long, threaded screw 1006 held within the shaft. The shaft extends beyond the inner surface 1007 of the slot wall and terminates at a projection 1008. The width of the portion with projections of the shaft exceeds the width of the channel between the two fixed portions of the mechanism, which houses the volume of the spine. A space 1009 exists between the projection and the wall of the slot and within this space there is a helical spring 1010, the ends of which abut contact the projection and the surface of the interior wall. The spring 1010 acts to slightly offset the position of the shaft, such that the end 1011 of the screw abuts the switch when the mechanism is in its inactive position, which is as shown in Figure 10. The force 1010 is less than the force required to operate the switch. The threaded screw 1006 extends beyond the projection 1008. During the manufacturing of the reading device, the screw 1006 can be adjusted in such a way that the outer surface of the central axis 300 is at a distance A offset from the tips of the portions. fixed 301 and 302, when contact is established inside the switch. Control of this manufacturing adjustment can be achieved by detection of the switch contacts. During the recommended mode of insertion of the test device into the reading device, as generally illustrated in Figure 8, the "tip" of the test device is placed under the cover 117 and the pressure of the finger forces the test device downward, pivoting against the point of support created by the cover flange and "snapped" passes the various features, which are projected either from the wall into the slot vacuum. The cover 120 protruding and to a lesser extent the fixed portions of the actuating switch and the protruding flange 127, act as cams which force the body of the device away from the rear wall and against the two pressure buttons. As the test device is rotated downwards and the protruding cover and the fixed portions of the actuator switch begin to engage with their appropriate slots in the body of the test device, the pressure created by the pressure buttons forces the device of test to the rear wall of the groove and can be "snapped" into position under the projecting flange. The curvature of the underside of the protruding flange facilitates this final movement of the test device within its proper reading location. If the test device is molded of plastic material, such as polystyrene as is conventional today in mass produced diagnostic devices, it may have sufficient flexibility for distortion and facilitate this movement. In effect, the natural elasticity of the molding of the test device can be exploited to have advantage, due to the deformation and subsequent release when the test device is correctly received inside the reading device, it can increase the "snap fit" coupling. between these two components of the team. The edges of the molded test device and contact points on the reading device may be rounded to facilitate sliding movement between these components and to avoid situations in which the two components must be jammed together. It is also possible for the user to insert the test device into the slot, to reach its correct reading position by placing the tip of the device on the open end of the slot and pushing the device horizontally until it is fully contained in the slot. Upon completion of this alternative procedure, the assay device will again be accurately held in place by the various interactions described in the foregoing. If for any reason the test device is inserted incorrectly into the slot during normal use, accurate recording of these various characteristics will not be performed. The drive switch will not be depressed. If desired, a supplementary detection mechanism may be rporated to detect the presence of any improperly inserted test device, such that an alarm signal may be brought to the user that the test device is not in its correct location.

The body of the reading device, including the walls and base of the slot, can be molded of durable plastic material, such as polystyrene. The push buttons and the projecting portions of the switch drive mechanism are preferably made of stronger material, because they must withstand repeated contact with the disposable test devices for a prolonged period of use. The so-called "hard engineering plastic", such as ABS, is ideal. This has good dimensional stability and is harder than polystyrene. The material must have natural cushioning properties. A commercially available ABS, ideal is "Delrin". The precise form and relationship of the various features described in the foregoing, which provide a three-dimensional intersubject, positive when the test device is inserted correctly, are for the purpose of example only. The reader with skill will readily appreciate that a wide variety of alternative profiles and constructions can be used to achieve a functionally comparable positive intersubject action. By way of background and example, the invention facilitates the provision of reading devices of the test result and the associated sample test devices, which can provide quantitative, accurate test information in a simple, fast and cost-effective manner. cash. Such devices can be used in a wide range of situations such as hospitals, clinics, doctor's offices and at home. Depending on the circumstances, the analyte under investigation may also vary widely. Examples are organisms of infectious diseases or markers, metabolites in body fluids, indicators of a change in the health or condition of a patient and administrable or ingestible substances such as drugs or drug abuse. The formats of essay that are required, which can be realized by people without training, comparatively and in a special way in the home. The trials to be used in the home are mainly intended to detect physiological changes in the human body, with the aim of promoting the health, general good condition or lifestyle of the individual. The consumer is becoming increasingly aware of the health and the ability of the consumer to monitor their bodily functions, is being encouraged. In some cases, this may facilitate interaction between the individual consumer and the medical profession (GP). There are many indicative trials of physiological changes in the human body, which currently can only be performed using sophisticated laboratory techniques. To provide useful information that relates to the individual under test, such tests generally need to produce a result in precise numerical terms, for example the concentration of a specific analyte in a body fluid. Accordingly, there is a need for improved test systems, especially applicable to the sample test of body fluid in the home, which combines the convenience of testing the sample together with the simple and cost-effective numerical determination of the test result. . Many test devices are described in the literature of the art, with suggestions that, the test result can be read using optical equipment. The use of fluorescent emission or reflectance of light is frequently suggested. Such techniques are mostly appropriate for use in sophisticated laboratories, although optical reflectance is used in commercially available blood glucose tests. In WO 95/13531, reading systems are described using optical transmission through a test strip or a similar membrane. The combination of the test device / reader can be supplied to the consumer as a single test equipment. In general, however, while the reader will be a relatively permanent unit, which the consumer can use again and again (and which can be provided with an electronic data / memory processing accessory, which allows the results of many trials sequential tests are evaluated) the test devices will be destined to be used only once and then they will be discarded. Accordingly, the test devices can be supplied to the consumer separately from the reader, for example in multiple packs. By ensuring accurate intersubjection between the test device and the reader, and also by ensuring accurate recording of the location of the detection zone within the same test device, the test zone will be presented to the reader in a predetermined, constant position, every time a test device is inserted into the reader. The construction of the optical system within the reader (light source and detectors) can therefore be kept as simple as possible, because it is not essential for the detectors to include any scanning accessory, for example, which in any other way it could be required if the exact location of the detection zone is not known. Avoiding the need for a sophisticated optical reading system, the cost of the reader / monitor can be reduced. The simplification of the optical reading system can also allow the reader / monitor to be small in size, which will help in convenient use and not visible in the home. Of course, a scanning accessory can be included in the reader, if desired. An additional benefit of providing an internal registration system, which ensures the precise location of the detection zone within the testing devices, is that the automated manufacturing and quality control of the testing devices can be facilitated. Because it is contemplated, for example, in the case of an ovulation cycle monitor, that the consumer will need to use several test devices each month, the test devices may need to be manufactured in large quantities at low cost. Internal registration can facilitate automated manufacturing and high total throughput. In principle, any electromagnetic radiation can be used to carry out a transmission measurement. The electromagnetic radiation should preferably be able to become diffuse. Preferably, electromagnetic radiation is light in the visible range or near visible range. This includes infrared light and ultraviolet light. Generally, it is contemplated that the detectable material used as a mark in the assay is one which will interact with the light in the visible or nearly visible range, for example by absorption. The wavelength of the chosen electromagnetic radiation is preferably at or near a wavelength which is strongly influenced, for example absorbed, by the mark. For example, if the mark is a substance which is strongly colored, that is to say visible to the naked eye when the material is concentrated, the ideal electromagnetic radiation is light of a complementary wavelength. Direct particle markings, for example, metal sols (for example gold), non-metallic elemental sols (for example selenium, carbon), dye sols and colored latex particles (polystyrene) are ideal examples. For example, in the case of latex particles with blue dye, the ideal electromagnetic radiation is visible red light, which will be strongly absorbed by the blue particles. A major advantage of the use of diffuse light or other radiation in this context is that the reading of the test result is much less likely to be adversely influenced by stains or contaminating material on the test device. For example, grime or scratches on the test device in the region through which the radiation must be transmitted, could be strongly interfered with accuracy of determined result, if focus is used instead of diffusion of light. By use of a diffuse light source, it is possible to provide a reader of test result, which can accurately interpret result of a test carried out even in an essentially transparent test device without test result being affected adversely by secondary contamination or damage (eg, surface scratches) to test device. Advantageously, electromagnetic radiation of source is pulsed. By synchronizing detectors (sensors) in such a way that only operate in phase with pulse radiation source, it is possible to eliminate any background interference that must be caused by external radiation, for example ambient light. essays to be used in home will mostly be carried out under circumstances of natural daylight or even, more frequently, artificial light. Artificial light is usually of a pulsed nature (typically 50-100Hz) caused by alternating nature of electricity supplies. By adopting a pulsed radiation source for illumination of test device within reader, intrusion of natural daylight can be ignored. By selecting pulse frequency in such a way that it is sufficiently different from prevailing artificial light, any interference due to artificial light can also be avoided. Preferably, pulse frequency of energy should be at least about 1 kHz. An ideal pulse frequency is approximately 16 kHz. electronic components necessary to achieve synchronous pulse detection are familiar to those skilled in art. use of light in pulses is very advantageous, because it makes it unnecessary for monitor to be "light-tight". This not only simplifies construction of monitor, but reading of test result can be performed, while monitor is "open" thus simplifying operation for user. source of light or o electromagnetic radiation may consist entirely of conventional components. Ideal examples are commercially available LEDs, preferably chosen to give a suitable wavelength of light that is strongly absorbed by detectable material concentrated in test zone or zones. light of LEDs must be passed through a strong diffuser, before reaching test device. If desired, an arrangement of LEDs, which are energized in turn, can be used. Suitable diffusers can be made, for example of plastic materials and are commercially available. If necessary, light scattering properties of diffusion material can be increased by including particulate materials such as titanium dioxide and barium sulfate. An ideal diffusion material comprises polyester or polycarbonate, which contains titanium dioxide.

A good inclusion level for the particulate material is at least about 1% by weight, preferably about 2%. By the use of a diffuser, all the important regions of a test strip can be measured simultaneously and the differences in the light output of the source are eliminated. The detector or detectors for detecting outgoing light may be conventional components such as photodiodes, for example silicon photodiodes. Preferably, a second diffuser, which can be made of the same material as the primary diffuser, is located in front of the detector or detectors. This ensures the view observed by the detector, which is not affected by the presence or absence of a test strip in the reading head. Consequently, the monitor can be calibrated in the absence of a test strip, and then measure a test result in the presence of a test strip. By using a uniform light source, it is possible to provide a reading system for test strips and the like, which is relatively tolerant to variation in the placement of the test zone or zones from one strip to another, in the absence of a detector of exploration. However, several substantial benefits in terms of test accuracy are obtained, if the placement of the test zone is controlled, as described herein.

For the purpose of increasing the probability of conception, the test devices have already been sold on the market, which allows the user to check the urinary concentration of luteinizing hormone (LH) which forms a sharp peak, approximately one day before ovulation The daily test of the concentration of urinary LH is carried out, for example using the technology of "drip by stick" with the result of the test that is provided by a color end point, the intensity of the color is proportional to the concentration of LH. By providing the consumer with a color chart, which allows the daily result to be compared against a standard, the "appearance of the LH" can be detected with the naked eye. Unfortunately, the monitoring of LH concentration is a very rare example of an assay that is based on semiquantitative data, which is sensitive to such simple technology, being possible only due in relative concentration terms of the occurrence of LH is an event dramatic. For most other potentially useful assays, changes in analyte concentration in body fluids are much more subtle and only accurately detectable by instrumental means. Therefore, there is a need to extend the qualitative home use test technology currently available in the area of accurate quantitative testing. A convenient example, which is a logical extension of the current consumer interest in the pregnancy test to be used in the home and the ovulation prediction test, is the extension in the accurate monitoring of the ovulation cycle, not just to increase the probability of conception, but in fact to provide reliable information for the purposes of contraception. Proposals have been made to analyze bodily fluids with this goal in mind. A common theme is to monitor periodic fluctuations in various levels of the hormone metabolite in the urine. The improved test equipment of the invention can be used in the determination of any analyte in the body fluid, especially in the monitoring of the human ovulation cycle by the determination of one or more hormones or metabolites thereof in the body fluid, such as urine, for example either LH and / or estrone-3-glucuronide (E3G). In the last few decades there has been a lot of research carried out on ways to increase "natural" family planning, in which the physiological parameters that indicate the state of the ovulation cycle are monitored. In EP-A-706346, such a method is particularly described, which uses the measurement of urinary estradiol or its metabolites, especially estrone-3-glucuronide (E3G), to provide a warning of the start of the fertile phase. The related methods are described in EP-A-656118, EP-A-656119 and EP-A-656120. Associated test devices and test equipment are described in these specifications and also in WO 96/09553. Within this context it is contemplated that the test device of a sample of liquid for use in the home will generally include a porous carrier material, such as a strip, on which the sample liquid is applied such as urine can filter and in that the test result occurs by means of the specific binding of a detectable material in a precisely defined region (detection zone) of the carrier, such as a narrow line or a small spot, containing a specific binding reagent, immobilized. Therefore, the invention relates to the ways in which the location of a material detectable in such a detection zone can be accurately determined in a simple and cost-effective manner. Devices for use in the home for the analysis of urine, for example in pregnancy tests and ovulation prediction tests, are now widely available in the trade. Many such devices are based on the principles of immunochromatography and typically comprise a hollow housing constructed of plastic material containing a porous test strip carrying the predosed reagents.

Reagents within the device can include one or more reagents marked with a direct label, such as a coloring sol, a metallic sol (for example gold), or colored latex microparticles (for example polystyrene), which are visible to the eye when they concentrate on a comparatively small test area of the strip. The user only needs to apply a urine sample to a part of the housing to start the test. The result of the test becomes visible to the eye within a few minutes without further action by the user. Examples of such devices are described in EP-A-291194 and EP-A-383619. The collection of the sample is conveniently achieved by means of an absorbent member, which is part of the device and which can easily incorporate the sample liquid, for example from a stream of urine. Optionally, the absorbent member may protrude from the housing of the device to facilitate application of the sample. In addition to the specific samples of detectable materials already mentioned above, other materials may be used which block or reflect the electromagnetic radiation, instead of absorbing it, for example "white" particles such as latex particles in their colorless state, natural. Alternatively, the label may be a reagent or catalyst, which participates in the generation of a radiation-absorbing material or a material that blocks radiation, for example an enzyme, which reacts with a substrate to produce a detectable material, such as a colored material in the detection zone. It is generally contemplated that the housing material will be opaque, for example white or colored plastic material, but the housing may be translucent or indeed transparent, if desired. The illuminator may consist of a series of LEDs embedded in or placed behind a diffusion medium, which provides a uniform and diffuse illumination of the test strip that covers the reference and signal zones. The incorporation of a diffuser between the openings and the test strip is beneficial for the purposes of calibration. In order to calibrate each of the optical channels in the absence of the test strip, it is highly advantageous that each detector is a light collector of the same areas of the illuminator as it is in the housing when a test device is present. The diffuser can be selected to be the dominant diffuser in the optical path, such that the introduction of the test strip does not contribute significantly to the change in the distribution of illumination observed by the detectors. In addition, the diffuser element may allow the optical assembly to incorporate a "wipe-clean" surface advantageous for long-term repeated operation of the optical assembly. By modulating the intensity of the illuminator, the optical channels can be calibrated, without the help of moving parts, "invisible" to the user before the insertion of a test device. The test strip may consist of an optically diffuse layer of nitrocellulose or the like, preferably sandwiching between two layers of an optically clear film, for example of polyester such as "Mylar". The transparent film protects the nitrocellulose within which the test reactions are carried out. Performing reflectance measurements through transparent, thin films is particularly difficult, due to the problems that arise from specular reflections. The measurement of the transmission allows the optical components to be constructed orthogonal to the measuring surface and minimizes the adverse effects of reflection. The invention is particularly applicable to the reading of test strips made of nitrocellulose and similar diffusion membranes, which preferably do not exceed about 1 mm in thickness. The constituent parts of the housing can be molded of high impact plastic materials or the like, such as polystyrene and polycarbonate and held together by "push-fit" fasteners or threaded screws or any other appropriate mechanism. It will be appreciated that the general arrangement or arrangement and the general form of the monitor may be subject to very considerable variation from that described in the foregoing, without departing from the scope of the invention. The general shape and placement of the read head is dictated by the need to cooperate effectively with the test device, but this form can vary considerably. The placement and nature of the controls accessible to the user and the display characteristics of the information may also be subject to considerable variation and are dictated to a great extent by aesthetic considerations. The detailed electronic components of a monitoring device capable of assimilating, remembering and manipulating the concentration data of the analyte, as well as providing the preferred electronic characteristics of the device discussed herein and where appropriate future prediction events, such as as the fertility status in an ovulation cycle on the basis of such data, they can be easily provided by those with skill in the electronic technique, once they have been advised of the factors that such device must take into consideration and the information that in The device must provide for the user. The individual features can be entirely conventional and those familiar with the technique of electronics will appreciate that other combinations and arrangements of such characteristics can be employed to achieve the objects of the invention. For example, so-called "hard wiring" systems and "neural networks" can be used in place of conventional microprocessors based on "chip" technology. The information can be brought to the user by means of a liquid crystal display or an LED screen, for example. If desired, the information on the fertility status can be carried by a simple visual indication, for example a combination of colors showing, for example, green for infertility and red for fertility. Especially, if the device is intended primarily as an assistant for contraception, it must "be sure to be suspended" by showing a "fertile" signal.

Claims (10)

1. A test kit for qualitatively or quantitatively determining the presence of one or more analytes in a fluid sample, comprising a test device together with a reading device, which is coupled with the test device and in which the coupling accurately locating the test device with the reading device is essential for the accurate reading of the test result, characterized in that the precisely located coupling of the test device with the reading device causes a "lock and key" interaction between the test device and the means for initiating the reading of the reading device.

2. The test equipment according to claim 1, characterized in that the test device is of the type consisting essentially of a porous carrier strip or the like within a hollow housing and in which a test result is revealed by the specific binding of the test device. a labeled reagent within a detection zone of the carrier strip, the presence of the labeled reagent within the detection zone is discernible by the reading device.

3. The test equipment according to claim 1 or claim 2, characterized in that the reading device includes receiving means for receiving the test device and the read initiation means comprises a switching actuating means or the like, which it is displaceable by the reception of the test device within the receiving means, in which the correct reception of the test device causes a contact portion of the housing for contacting the displaceable switching drive means, the contact portion and the displaceable switching drive means, which is cooperatively coupled by means of a "lock and key" coupling, such that only by correct reception of the test device can the switching drive means be moved to initiate reading.

4. The test equipment according to claim 3, characterized in that the switching drive means comprises at least one fixed projection portion and at least one displaceable projection portion and the contact portion of the housing of the test device comprises a groove shaped to receive the fixed projecting portion of the switching drive means, but its movable projecting portion, the contact portion also comprises an interface portion which contacts and displaces the movable portion of the switching drive means, when the portion Fixed projection is housed inside the slot.

5. The test equipment according to claim 3 or claim 4, characterized in that the receiving means incorporates a biasing means that presses the received test device against the switching drive means.

6. The test equipment according to any of claims 3 to 5, characterized in that the receiving means incorporates a cam means that flexes the test device away from the switching drive means unless the test device is correctly received. by means of reception.

7. The test equipment according to claim 6, characterized in that the cam means provides a "press fit" coupling of the test device and the receiving means, when the test device is correctly received.

8. The test equipment according to any of the preceding claims, characterized in that the test device is elongated and the receiving means comprises a groove into which at least part of the elongated test device can be adjusted and in which the slot has at least one portion of projecting flange extending over the hole in the slot and which acts to retain the test device within the slot, when properly received therein.

9. The test equipment according to claim 8, characterized in that the projecting flange portion is at one end of the slot and can couple one end of the elongated test device during the insertion of the test device into the receiving means.

10. The test equipment according to claim 9, characterized in that there is a second shoulder portion projecting at or near the other end of the slot for retaining the test device therein. SUMMARY A test kit for qualitatively or quantitatively determining the presence of one or more analytes in a fluid sample, comprising a test device together with a reading device, which is coupled with the test device and in which the coupling accurately located the test device with the reading device, it is essential for the exact reading of the test result, in which the precisely located coupling of the test device with the reading device causes a "lock and key" interaction , that is, a unique 3-dimensional interaction, between the test device and the reading initiation means of the reading device. Preferably, the reading initiation means includes a switching actuation means comprising at least a fixed projection portion and at least a displaceable projection portion and a contact portion of the housing of the assay device, comprising a groove shaped to receive the fixed projection portion of the switching drive means, but not its movable projection portion, the contact portion also comprises an interface portion which contacts and displaces the movable portion of the switching drive means, when the fixed projection portion is housed within the slot.