Reading devices for teststrips

DESCRIPTION

Test and reading equipment especially applicable to the testing of body fluid samples.

Object of the invention

The object of the invention is to provide a device with a test device for the associated samples that can provide quantitatively accurate test information in a simple, fast and cost-effective manner and a device for reading the test results. The equipment can be used in a wide range of situations such as hospitals, clinics, professional offices, and even domestically. Depending on the circumstances, the analyte to be investigated can vary widely. Examples are infectious disease organisms, markers, metabolites in body fluids indicative of changes in a patient's health or disorders, and administrable or ingestible substances, such as drug or drug abuse.

The invention particularly concerns, but not exclusively, the tests that can be carried out by people not professionally trained and especially at a particular level.

Background of the invention

The devices for domestic use as a pregnancy test were well established. In the case of the pregnancy test, which simply needs to provide the user with a “yes / no” result, the technology now available allows the test result to be read visually easily without the need for any auxiliary equipment.

The tests for domestic use first try to detect the physiological changes in the human body, with the aim of promoting the health, general well-being or lifestyle of the individual. The consumer was becoming incessantly aware of health, and the possibility of consumers to visualize their bodily functions was being encouraged. In many cases this can facilitate interaction between the individual consumer and the medical profession.

There are many indicative tests of physiological changes in the human body that normally can only be carried out using sophisticated laboratory techniques. In order to provide useful information concerning the individual under test, such tests generally need to result in precise numerical terms, eg the concentration of a specific analyte in the body fluid.

Accordingly, there is a need for a test device, especially applicable to the testing of body fluid samples at home, which combines the convenience of a sample test together with a simple and cost-effective determination of the test results.

Many staon test devices described in the technical literature with suggestions that the test result can be read using optical equipment. The use of emission fluorescence, or optic reflectance, is often suggested. Such techniques are, most of the time appropriate for use in sophisticated laboratories.

In Document EP-A2-212599, which describes multizonal analytical elements that have a detectable signal concentration zone, the suggestion is made that the detectable signal indicative of an assay produced in the zone can be measured by electromagnetic radiation, such as light, transmitted through the area. EP-A-212599 indicates that the element can be made of porous fiber materials, such as paper and nitrocellulose. However, practical details are not provided to indicate that precise measurements could be made using transmitted light. Description of the invention

Through the invention it has been achieved that quantitative information can be obtained by reading transmission of a band or similar test if the incident electromagnetic radiation is uniform throughout the region of the test strip, which surrounds and extends more beyond the test area.

With the invention it is feasible to "read" the results of a test carried out by concentrating a detectable material in a comparatively small area of ​​a support in the form of an unattached sheet, which is the thickness of which the electromagnetic radiation, like light, is transmitted which at least one portion of one face of said support was exposed to the incident electromagnetic radiation which is substantially uniform throughout the entire portion, said portion including the aforementioned zone, and the electromagnetic radiation emerging from the opposite face of the mentioned support is measured to determine the result of the mentioned test.

Preferably, the incident electromagnetic radiation is of substantially uniform intensity.

This uniformity can be achieved, for example, by providing a collimated source of electromagnetic radiation, using conventional focusing means such as lenses or light guides to provide parallel incident electromagnetic radiation that essentially falls along the entire exposed portion of the support.

Preferably, according to the invention, the incident electromagnetic radiation is diffuse and the series of the exposed portion of the support uniformly in a randomly dispersed manner.

Structurally, the test device that is part of the invention comprises a porous support strip permeable to the liquid or sheet through the thickness of which the electromagnetic radiation is diffusely transmitted. Said support strip is inside a box, and includes at least one detection zone in which a test result is revealed by specific binding of a material directly or indirectly detectable to a binding agent immobilized in said detection zone. The detection of said material was carried out in response to the aforementioned electromagnetic radiation, said box having regions of transmission of the electromagnetic radiation allowing the electromagnetic energy of an external source to pass through said device, said detection zone being found in the path of elec radiation.

ES 1 030 898 U Tromagnetic between the aforementioned regions of electromagnetic radiation transmission.

Preferably, the porous support strip or sheet comprises paper, nitrocellulose or the like, preferably of a thickness not exceeding 1 mm.

Therefore, the invention provides equipment with a test device and a reader of test results in combination in which:

a) said device comprises a porous strip or sheet acting as a liquid permeable support through the thickness of which electromagnetic radiation is diffusely transmitted. Said support includes at least one detection zone in which the test result is revealed by a specific binding of a material directly or indirectly detectable to a binding agent immobilized in the aforementioned detection zone;

b) said box or cover, if present, has electromagnetic radiation transmission regions that allow electromagnetic radiation from an external source to pass through the aforementioned device. Said detection zone is on the road between said transmission regions;

c) said test result reader has means to receive at least a portion of said device, said portion including said detection zone to present said detection zone to the reading means. Said reading means incorporate a source of uniform electromagnetic radiation and one or more sensors located in such a way that in the insertion of said device into the receiving means, electromagnetic radiation can pass through said device and the intensity of the radiation. Electromagnetic emerging from said device can be detected by means of said sensor (s).

Preferably, said receiving means incorporates means connected to the corresponding interconnection means in said device to ensure that in the reception of said device through the reader of said detection zone (s) are located and maintained in a predetermined spatial relationship relating to said reading means.

Preferably, said receiving means includes actuating means activated by said receivers of said devices. Said actuating means cause the initiation of said reading of said detection zone (s).

If the test device is supplied with a box, it is advantageous that said device box includes internal registration means which are coupled with the corresponding registration means associated with said supports such that said detection zone within said device box is located in a predetermined spatial relationship relative to said recording means in the device box. Preferably, said internal recording means comprises a point or the like in said support fitted in a hole, said detection zone is in a predetermined location in said support relative to said hole or indentation.

During the manufacture of said test device, the corresponding recording means mentioned can be used to facilitate or control the proper formation, e.g. ex. by means of reagent printing techniques, of said detection zone in said support. In addition, or alternatively, the proper placement of said support inside the device case can be facilitated or controlled by means of said registration.

Accordingly, the invention provides a test result reader, for use in conjunction with a device and test comprising a porous strip or support sheet permeable to the liquid through the thickness of which the electromagnetic radiation is transmitted, and said support includes a detection zone in which the test result is revealed by means of a specific binding of materials directly or indirectly detectable to a binding agent immobilized in said detection zone. The detection of said material is carried out in response to said electromagnetic radiation.

Said test result reader comprises:

a) receiving means for receiving at least a portion of said test device, and said portion includes said detection zone;

b) reading means associated with said receiving means and said receiving means comprise:

i) at least one source of uniform diffuse radiation (preferably) electromagnetic radiation; and ii) one or more sensors capable of detecting the intensity of said electromagnetic radiation; so that said source and said sensor (s) are placed in such a way that when said portion of the said test device receives within said receiving means, said detection zone is arranged in the path between said source and the (s) ) mentioned sensor (s).

The combination of the test device / reader can be provided to the consumer as a simple test package. In general, however, considering that the reader will have a relatively permanent unit which the consumer can use over and over again (and which can be provided with electronic memory / data processor equipment that enables the results of many sequential tests can be evaluated) the test devices are intended for use only once and then discarded. Accordingly, the test devices can be supplied to the consumer separately from the reader p. ex. In several packages.

To ensure the precise interconnection between the test device and the reader, and also

In order to ensure accurate registration of the location of the detector area within the test device itself, the test zone will be presented to the reader in a constant predetermined position each time a test device is inserted into the reader. . The construction of the optic system within the reader (light source and sensors) can therefore be made as simple as possible, because it is not essential for the sensors to include any scanning equipment, for example, which might otherwise be required if The exact location of the detection zone is not known. To avoid the need for a sophisticated optical reading system, the cost of the reader / monitor can be reduced. The simplification of the optic detection system can also enable the reader / monitor to be small in size which helps conveniently and is not annoying at home. Of course, scanning equipment can be included in the reader if desired.

An additional benefit of providing an internal registration system that ensures the precise location of the detection zone within the test device is that the automated manufacturing and quality control of the test devices can be facilitated. Due to its conception, for example, in the case of an ovulation cycle monitor, for which the consumer would need to use several test devices each month, the test device may need to be manufactured in large numbers at low cost. Internal registration can facilitate automatic manufacturing and high performance.

In principle, you can use any electromagnetic radiation to measure the transmission in the invention. Electromagnetic radiation should be able to become diffuse. Preferably electromagnetic radiation is light in the visible range or near the visible one. This includes infrared and ultraviolet light. It is generally anticipated that the detectable material used as a marker in the assay is one that interacts with the light in the visible range or near the visible one, e.g. ex. by absorption. The wavelength of the electromagnetic radiation chosen was preferably at or near a wavelength, in which it was strongly influenced, eg absorbed, by the marker. For example, if the marker is a substance that is strongly colored, that is, visible to the human eye when the material is concentrated, the ideal electromagnetic radiation is light of complementary wavelength. Particularly direct markers, for example, metallic soles (eg gold), non-metallic elemental soles (eg selenium, carbon), red soles and colored lax latex particles (polystyrene), are ideal examples. For example, in the case of blue-stained latex particles, the ideal electromagnetic radiation is visible red light which will be strongly absorbed by the blue particles.

Preferably, the transmitted electromagnetic radiation reached by the sensor should be diffuse. The diffusion can be achieved as a result of the transmission of the electromagnetic radiation through the support strip or sheet, but more preferably it is achieved by the source of the electromagnetic radiation that emits the energy in a highly diffuse form. The source produces highly diffuse radiation and the strip or support sheet traversed from which the radiation is subsequently transmitted is in comparative terms a much more flexible diffuser.

A primary window of the use of diffused light or other radiation in the context of the invention is that the reading of the test results is much less likely to be adversely influenced by stains or contaminating materials in the test device. For example, dirt or particles in the test device in the region through which the radiation must be transmitted could interfere strongly in the accuracy of the determined result if another light is used that is not diffused. By using a diffuse light source with the invention, it is possible to provide a test result reader that can interpret precisely the result of a test carried out even in an essentially transparent test device without the test result being adversely affected by contamination or minor damage (eg particles) in the test device.

The electromagnetic radiation of the source can be pulsed. By synchronizing the detectors (sensors) in such a way that they work only in phase with the pulsed radiation source, it is possible to eliminate any background interference caused by external interference eg ambient light. It is anticipated that the tests will generally be carried out under circumstances of natural light or, even more often, artificial light. Artificial light is normally of a pulse nature (topically 50-100 Hz) caused by the alternating nature of the electrical supply: By adopting a pulsed radiation source for the illumination of the test device within the reader, the intrusion of light Doa natural can be ignored. By selecting the pulse rate in such a way that there are sufficient differences of the dominant artificial light, any interference due to the artificial light can also be eliminated. Preferably the pulse frequency of the energy should be at least about 1 kHz. The electronics needed to achieve the perception of synchronous pulses are familiar to those experienced in the field.

The use of pulsed light is very advantageous because it becomes unnecessary for the monitor to be "light proof." This not only simplifies the construction of the monitor but the reading of the test result can be done while the monitor was "open", thus simplifying the use for the user.

The light source or other electromagnetic radiation can comprise completely conventional components. The ideal examples are commercially available LEDs, preferably chosen to give a light of suitable wavelength that is strongly absorbed by the detectable materials concentrated in the test zone (s).

Suitable diffusers can be made, for example, of plastics materials, and are commercially available. If necessary, the pro4

ES 1 030 898 U Pieces of the scattered light of the diffuser material can be improved by including particulate materials such as titanium dioxide and barium sulfate. An ideal diffuser material comprises polyester or polycarbonate, which contains titanium dioxide. A good level of inclusion for particulate materials is at least about 1% by weight, preferably about 2%. Through the use of a diffuser, all the relevant regions of a test strip can be measured simultaneously, and the differences in the light output of the source are eliminated.

The sensor (s) for detecting the emerging light may be conventional components such as photodiodes, eg silica photodiodes.

Preferably, a second diffuser was located, which can be made of the same materials as the first diffuser, between the sensor (s). This ensures that the vision of the sensor is not affected by the presence or absence of a test strip in the reading head. Accordingly, the monitor can be calibrated in the absence of the test band, and then measure a test result in the presence of a test strip.

By using a uniform light source in accordance with the invention it is possible to provide a reading system for the test strip and the like which is relatively tolerant of variation in the placement of the test area (s). from one strip to another, in the absence of a scanning sensor. Additional benefits are obtained if the placement of the test area is controlled, as described in this Document. For the purpose of improving the probability of conception, the test devices have been put up for sale which allows the user to visualize the urinary concentration of luteinizing hormone (LH) which has a pronounced peak approximately one doa before ovulation. The daily urine test of the LH concentration is performed, for example, using "dip rod" technology with the result of the test supplied by the colored end point, the color intensity is proportional to the LH concentration. By providing the consumer with a color chart that makes it possible to compare the daily results with a pattern, the “rise in LH” can be detected simply with the naked eye. Unfortunately, the visualization of the LH concentration is a very rare example of a test based on semi-quantitative data which is carried out with such a simple technology, being possible only because in terms of relative concentration the rise in LH is an event dróastico. For most of the other potentially useful tests the changes in analyte concentration in human fluids are much more subtle and only detectable with precision by instrumental means.

There is therefore a need to extend the qualitative test technology for domestic use currently available, in the area of ​​quantitatively accurate tests. A convenient example, which is a logical extension of the present interest of consumers by the pregnancy test and the domesticated ovulation prediction test, is the extension in the precise visualization of the ovulatory cycle, not merely to improve the Probability of conception without, however, to provide reliable information for contraception proposals. Purposes have been made to analyze body fluids with this goal in mind. A common theme is to visualize the periodic fluctuations of various metabolic hormones in the urine.

This invention can be used in the determination of any body fluid analyte, especially in the visualization of the human ovulation cycle by determining one or more hormones or metabolites of the foregoing in body fluids, such as urine, for example LH and / or estrone-3-glucoronide (E3G).

Within the preferred context of the present invention it was conceived that a test device for domestic liquid samples would include a porous support material such as a strip, through which the application of the sample liquid as urine can be filtered and in which the result The test occurs by means of a specific junction of a detectable material in a precisely defined region (detection zone) of the support, such as a narrow line or small point, containing an immobilized specific binding agent. This invention therefore has to do with the ways in which the location of a detectable material in such a detection zone can be precisely determined in a simple and cost-effective manner. Home use devices for urinalysis, for example in pregnancy tests and ovulation prediction tests, are now widely available commercially. Many of these devices are based on the principles of immunochromatography, and typically comprise a hollow box constructed of plastic material containing a porous test strip that carries the pre-dosed reagents. The reagents within the device may include one or more marker reagents of a direct label, such as sun ink, a metallic sun (eg gold), or a latex microparticle (eg. polystyrene), which are visible to the naked eye when they are concentrated in a comparatively small test area of ​​the strip. The user merely needs to apply a urine sample to a part of the box to start the test. The result of the test is converted to the naked eye in a few minutes without any further action by the user. Examples of such devices are described in Documents EP-A291194 and EP-A-383619, the disclosure of which is incorporated in this reference. The placement of samples is conveniently achieved by means of the absorbent member that is part of the device and which can quickly absorb the sample liquid, eg from the urine flow. Optionally, the absorbent member can protrude from the device case to facilitate the application of the sample.

Description of the drawings

To complement the description that is being made and in order to help a better understanding of the features of the invention, this description is attached,

ES 1 030 898 U as an integral part thereof, a set of drawings where, for illustrative and non-limiting purposes, the following has been represented:

Figure 1 shows a general view of a sheet of porous material, for example, paper, during the course of depositing the reagent in the sheet and the subdivision of the sheet into test strips.

Figure 2.- Shows an exploded view of the test device that is part of the object of the invention incorporating the test strip represented in Figure 1.

Figure 3.- Shows a cross-section of the test device represented in Figure 2, located inside the reading head of a monitor in accordance with the invention working by light transmission through the test strip. The Y axis is distorted to show the arrangement of the components.

Figures 4a, 4b and 4c.- They show individual views of an exploded view of the main characteristics corresponding to a complete monitor according to the invention. Thus, Figure 4a shows the lid and the upper half of the box, while Figure 4b shows the electro-magnetic base plate incorporating a reading head, Figure 4c showing the lower half of the box and the associated battery container .

Figure 5.- Shows the reading head on a larger scale, represented in figure 4b.

Figure 6 shows a view below the test device that receives a notch of the reading head represented in the previous figure.

Figure 7 shows a cross-sectional view of an end part of the test device itself, intended for insertion into the notch of the reading head housing.

Figure 8 shows, finally, schematically, the basic functions that may be required in an electroanal monitor to be used in accordance with the invention follow its application to the human ovulation cycle.

Preferred Embodiment of the Invention

Referring to Figure 1, the sheet (100) of porous material, eg nitrocellulose, is intended to be divided into a plurality of identical test strips (101) along the central axis AA and side axes BB .

The parallel lines (102-107) of the test reagents are placed on the sheet (100) before the subdivision. With the example proporasite alone, the reagents are supposed to be a first antibody immobilized on the lines (102) and (107), and a second different antibody immobilized on the lines (103) and (106). The reagent arrangement may be by means of a "pen" (108) or the like handled by a mechanism to the computer-controlled "xy" plotter (not shown) and fed with appropriate buffered reagent solutions via a flexible measuring tube (109) . If the sheet material (100) is nitrocellulose, reagents such as antibodies and antigens can be immobilized by simple direct application on nitroleculose, followed by a blockage of the sheet material, for example with albumin or polyvinyl alcohol. After reagent deposition and blocking, two lines (104) and (105) of mobile marker reagents, such as antigens (eg E3G) or other antibody (e.g. anti-LH) marked for example with a direct particulate marker such as colored laatex. This arrangement can be for example by means of another pen (not shown). On the other hand, the labeled reagent (s) can be kept in a separate or similar porous pad, rather than being applied directly to the test strip material.

To achieve the precise location of the reagent lines, each longitudinal periphery (110), (111) of the sheet (100) will be traversed by a plurality of small identical holes (112) each located within the width of the designated strip (113). The holes (112) will be made in the sheet (100) before the deposition of any reagent. The untreated sheet will be placed on a frame (not shown) or similar operating surface by means of a bar (114) pressed down on each side periphery of the sheet. Only one of these bars is (partially) shown. Each bar has a plurality of points that project downwards (115), each of which is located precisely in each of the holes (112). The trace of the pen that deposits the reagents is recorded precisely with the position of the bar holding the sheet, and according to this the deposition of the reagents is made in a precise predetermined line in relation to the perforations of the sheet.

After all the necessary depositions of the reagents and other treatments of the sheet, the sheet is subdivided by counting means (not shown) into individual identical strips (101). Each individual strip therefore contains a location hole (112) with two lines containing reagents or reaction zones (eg (102) and (103)) located relatively to the hole (112) in a precise predetermined position that It extends along the width of each strip. In a location away from the hole (112) there is a region (eg (104)) of the strip that supports the mobile marked reagent. The exact position of the marked reagent relative to the hole is not necessarily as critical as the location of the reaction zones.

By way of example only, the individual strips will typically have a length of about 40 mm to about 80 mm, and a width of about 5 mm to about 10 mm as is conventional in the technique of the test devices. A detection zone containing reagent such as the reaction zones (102) and (103), will typically be a line of about 1 mm wide moving laterally along the strip. A small point, e.g. Circular with a diameter of about 1 mm to about 3 mm, it is an alternative. The detection zone is therefore only a relatively small portion of the total area of ​​the strip. If appropriate for the purposes of the test, multiple detection zones containing the same or different reagents may be placed in each strip. This may need to use more than one marked component, multiple mobile marked components can be placed upstream on the strip or anywhere inside the device (eg on a sample application pad or wick,

ES 1 030 898 U as described below).

Referring to Figure 2, the test device that is part of the invention comprises a plastic box having two upper and lower halves (200) and (201) adapted to contain the test strip (101) and also a member Sample absorbent absorber (202) that can extend outside the end (203) of the assembled box In the assembled device, the receiving absorbent member (202) overlaps the end (204) of the test strip adjacent to the labeled reagent deposited. The upper half (200) of the box includes a window or opening (205) through which both detection zones (102) and (103) can be observed from outside the box. The upper half of the box contains on its outer surface (206) a circular depression (207) in the longitudinal access of the box just beyond the observation window relative to the end (203) of the box that accommodates the receiving member of the sample. Inside the upper half is a tip or pin (208) extended downward located directly below the depression (207). The diameter of the point or pin extended downwards (208) is the same as that of the hole (112) in the test strip (101), so that the strip can be positively located within the assembly device in the pin.

The lower half (201) of the box also includes a transmitted or open light window (209) which, in the assembled device, is directly opposite the result window (205) in the upper half of the box.

In the assembled device, the act of enclosing the strip and the absorbent member between the upper and lower half of the box causes the overlapping portions (204) and (211) of the strip and the absorbent member to fold together to provide a Good moisture conductive joint.

The box material is generally projected to be opaque eg white or colored plastic materials, but the box can be translucent or even transparent if desired.

Referring to Figure 3, the test device (300) is seen located within a slot (301) in a monitor (302). This region of the test device includes the two opposite windows (205) and (209).

The monitor box has a height to receive the portion of the test device that incorporates the results window. On the opposite sides of the slot there is a light source (303) and a reading head (304).

The slot incorporates a button or protrusion (305) which can fit into the depression (207) of the outer face of the test device box. The precise positive location of the box inside the slot is therefore achieved. Because the depresioán is in a fixed position relative to the internal tip or pin (208) inside the test device, and therefore the registration hole (112) in the test strip (101), the two detection zones (102) and (103) of the strip are located in a precise position relative to the reading head. The hole in the test strip therefore acts as a positive reference in the course of manufacturing the test devices and ensures that after the device has been used and presented to the monitor, the detection zones in the strip will be in the same position relative to the reading head every time. According to this, there is no need for the reading head to incorporate a scanning device to locate the detection zones in each device presented.

The light source or illuminator (303) incorporates a plurality of LEDs (306) to generate the light, and this illuminates the test strip via a diffuser (307) and the observation window (209) in the lower half of the box of the test device. The light passes through the thin band of nitrocellulose (101) and exits the strip device through the result window (205) in the upper half of the box. Immediately outside the window (205) is the second diffuser (308). After passing through the second diffuser (308), the light finds a plate (309) that has a plurality of openings (310-314). There are five openings in total, two of which (311, 313) are adjacent to the detection zones and the other (310, 312, 314) are in positions on each side of these openings of the detection zones. The openings are cleft corresponding to the detection lines of the strip. The width of each of the two apertures (311) and (313) that correspond to the detection zones themselves is twice the width of each of the other three openings that act as controls.

The light passing through these openings travels down to the corresponding slot (315-319) on a baffle plate (320). At the far end of each slot is a light detector (321). The detectors (321) are identical in size and specifications. On the front face (322) of the baffle plate (320), each slot is of the same size as that of the corresponding opening. On the rear face of the deflector adjacent to the light detectors each slot is the same size as the face of the light detector adjacent to it. Accordingly, the two slots (316, 318) associated with the openings of the detection zone are on parallel sides. The three slots (315, 317 and 319) associated with the control opening increase in size as they progress towards the light detector.

The groove in the monitor can also accommodate gripping means or disposition such as one or more plates loaded with springs or tips (not shown) for further improvement of the positive location of the test device within the groove.

Ideally, the same optical signal is derived from each opening outside the precise position of the line opposite the openings: The openings can be of different sizes to achieve this objective. The dimensions of the reference zone should be chosen to correspond as closely as possible with the actual area of ​​the strip detection zone.

To reduce the possibility of crossings between the openings, the test strip should be kept as close as possible to the openings when the test device is located in the groove in

EN 1 030 898 U the monitor.

As described above, there are five channels of septic measurement in the reading device. In addition, there may be the reference electrogenic channel sector that provides the calibration of the electrogenic gain in the detector circuit.

A tepic test strip can show a gradient of detectable marker concentration along its length, against which the detectable marker must be measured in a reaction zone. To accommodate these measurements, they are also made on each side of the reaction zone in the test strip. The signal of the reaction zone can be expressed as a proportion of the total registered signal of the two adjacent reference areas in the band.

The five measurement channels are divided into two reaction zones and three reference zones. A reference zone located between the two reaction zones provides an epic reference measurement for both measurements of the reaction zone.

A reflectance measurement system must be mounted on one side of the test strip. In order to achieve the same level of compactness for a five-channel reading device, the use of (relatively) expensive custom components will be required. A transmission design can be made entirely of commercially available high-volume electro-electronic components, facilitating the production of a monitor that is compact and relatively inexpensive.

The five guards (321) are mounted on the back of a baffle plate. Each detector sees the test strip through an opening in the deflector. The deflector prevents the light seen through an opening from falling into adjacent detectors, and also provides accommodation for the tolerance of line placement. The position of the test area within the field of view of a detector should vary from one edge of the opening to the other on the X axis. Any variation in the signal from this effect is a function of the angular displacement relative to the center of the measurement detector. The depth of the baffle can be chosen to control the possible angular displacements of the test area with respect to the detector, and to maintain the accuracy of the reading.

The projection (305) is maintained in a precise location with respect to the openings. The reference point is located in the depression (207) in the box of the test device. This depression will also be placed precisely with respect to the inner tip (208) molded in the test device, in which the test strip is placed through its own hole of situation pierced through the strip. The reaction zones are located precisely with respect to the location hole. In this way, within the manufacturing tolerances, the reaction zones are maintained in precise positions with respect to the openings through which the detectors see the test strip.

The illuminator may consist of a series of LEDs embedded in or placed behind a diffuser medium that provides a uniform and diffuse illumination of the test strip covering the reference and signal areas.

The incorporation of a diffuser between the openings and the test strip is beneficial for calibration purposes. To calibrate each of the oeptic channels in the absence of the test strip it is highly desirable that each detector is collecting light from the same areas of the illuminator as is the case when a test device is present. The diffuser can be selected to be a dominant diffuser in the oeptic path such that the introduction of the test strip does not contribute significantly to changes in the distribution of the illumination observed by the detectors. In addition, the diffuser element may enable the oesic assembly to incorporate a clean, desirable surface for repeated long-term embodiments. The septic channels can be calibrated, without the help of mobile parts, "invisible" to the user before the insertion of the test device.

The test strip may consist of an epoxy diffuse layer of nitrocellulose or the like, preferably forming a sandwich between two other layers of optically clean film eg of polyester as "Mylar". The clean film protects the nitrocellulose within which the test reactions take place. Performing reflectance measurements through the thin transparent film is particularly difficult due to problems from the mirror reflections. The measurement of the transmission allows the septic to be constructed orthogonally to the dividing surface and minimize the adverse effects of the reflection. The invention is particularly applicable to the reading of test strips of nitrocellulose and similar diffuse membranes that preferably do not exceed approximately 1 mm thick.

Returning to Figure 4a, the monitor comprises a molded case, eg of plastic material, which generally has a rounded oval shape. The box mainly comprises an upper half (400) and a lower unit, only the upper half thereof being seen in Figure 4a. Towards the right side of the box (400) there is a recess (401) that has an inclination towards the rear of the rear face (402). The rear face (402) incorporates an opening (403) for a push button (not shown), and a window (404) to reveal a display panel (not shown) and two windows (405) and (406) to display colored lights or other indicators (another time not shown) to carry the information to the user. Extending from the left end of the recess (401) is a long slot (407) to provide access to the reading head (not shown). The recess (401) and the recess (407) are closed by means of a cover (408) that is attached to the back of the box by two hinges (409) and (410). The upper surface (411) of the box (400) is slightly recessed to accommodate the lid when closing, so that the exterior of the closed device has a relatively smooth continuous surface to the user. The lid can be lifted to show the features accessible to the monitor user. The lid is closed by means

ES 1 030 898 U of a spring closure (not seen in Figure 4a) that extends upwardly through a hole (412) at the edge of the front (413) of the case. The front edge (413) of the box incorporates an additional hole (414) through which an additional indicator (not shown) can be revealed.

Returning to Figure 4b, the circuit base plate (430) is rounded rectangular in shape to match the internal shape of the box and carries all the operating characteristics of the monitor. That includes a push button (431) that the user can press to start monitoring an ovulation cycle. When the base plate was mounted inside the box and covered by the upper half of the previous one, the push button is accessible through the opening (403). To the right of the push button is an indicator panel that is a liquid crystal display that is visible to the user through the window (404). To the right of the indicator panel are two light guides (433) and (434) that transfer, for example, colored lights (such as green and red) from two similar LEDs or lanterns (not shown). The integrated circuits and the appropriate memory circuits (435, 436) are mounted on the motherboard. An additional light guide (437) mounted on the front edge (438) of the motherboard can carry light from another LED (not shown) to the opening (414). This light may indicate, for example, to the user that a test is required. This light can be of different colors of the lights associated with the indicator panel, eg yellow. A battery connector (439) hangs below the motherboard to connect it to the batteries contained in the lower case (see figure 4c). Also on the front of the motherboard is a switch (440) operable by the spring closing of the cover (408).

The reading head (441) comprising a central receiving slot (442) to accommodate one end of the test device (not shown) is mounted on the left end of the base plate. On the front of the receiving slot (442) was an illuminator (443) and immediately opposite the end of the slot was an optic sensor system (444) so ​​that light can pass through the slot (and through a device test when inserted) and evaluated using the sensor.

Returning to Figure 4c, the lower half (460) of the box has the general oval shape to match the upper half (400) and provide accommodation for the base plate (430). The front edge (461) of the case (460) accommodates a spring closure (462) to tighten the cover (408) when it is closed. The closure (462) is released by pressure from the front face (463) eg applied by the tip of the finger. The floor (464) of the box includes a chamber for the battery (below), and a small access hole (465) was arranged towards the right end of the box through which the battery connector (439) can pass and join the batteries (466). The batteries are retained by a cover (467) that can be disengaged from the bottom side (468) of the case.

The constituent parts of the box may be molded with high impact materials or similar plastic materials such as polystyrene and polycarbonate and held together by "push-in" clamps or threaded screws or any other appropriate mechanism.

Returning to the enlarged illustration of the reading head, it is still seen in Figure 5, the slot (442) for the receiver of a test device is parallel in shape, but its width is increased at its right end (500) , in a staggered manner to provide a pair of shoulders or stirrups (501, 502) against which a corresponding increased portion of a test device can be supported. This can facilitate the effective insertion of a test device into the reading head. Inside the narrowed working part (503) of the groove was a button (504) mounted on the wall of backings (505) of the groove, which must be fully depressed to activate the reading mechanism. Proper insertion of the test device causes adequate depression of this button.

Also in the rear wall (505) of the groove there is a fixed position tip (506) which can engage with the corresponding hole in an inserted test device. Also on the back wall (505) was a light transmitter panel (507) which covers the optic sensors. The panel (507) extends outwardly behind the plane of the rear wall (505) of the slit and has inclined edges (508, 509) to give it a characteristic profile. At the opposite end of the front wall (510) of the groove there are two points (not seen in Figure 5) that are skewed outwardly in the groove, eg by means of spring mechanism contained within the boxes (551, 512).

These same characteristics are illustrated in Figure 6, which is a direct view down on the receiving groove. The two skewed points (600, 601) are seen. The purpose of these tips is to provide forcing means to press and insert the test device against the back wall (505) of the slit. If the receiving portion of a test device has holes or depressions in an appropriate manner to accommodate the fixed position tip (506) and the projecting panel (507), the test device can be pressed sufficiently close to the rear wall of the slit. to depress the button (504) and start the optic sensor procedure.

Figure 7 shows, in cross-section, part of a test device (700) having a profile that can cooperate with the features seen in Figure 6. This test device can be inserted into the slit with the enlarged central portion (701 ) that rests on the shoulders (501, 502). The front end (702) of the test device has a slightly beveled edge (703) to facilitate insertion of the split front tip (600). The test device comprises a recessed box containing a porous test strip (704) that sandwiched between two sheets (705, 706) of transparent material. As described above, the strip (704) was precisely positioned within the box of the test device by means of a door (707) extending through a hole (708) in the strip. On the outer face of the test device box at a co9 point

ES 1 030 898 U corresponding to the center of the position tip (707) is a conical hole (709) which can accommodate the position point fixed (506) in the reading slot. Each side of the test device box has an opening (710, 711) which, when the test device is inserted correctly, will be adjacent to the light source (443) and the light sensors (404), respectively. The profiles of these two openings are different and in particular the profile of the opening (711) on the same face of the test device as the conical hole (709) was shaped to coincide with the profile of the projecting panel (507) that covers the light sensors This ensures that the reading head operates only when the test device is inserted in the correct orientation to ensure that the button (504) was depressed. It was appreciated that the general arrangement and general shape of the monitor can be subject to a very considerable variation from that described above without departing from the scope of the invention. The general form and disposition of the reading head was dictated by the need to effectively cooperate with the test device but this form can be varied considerably. The distribution and nature of the controls accessible to the user and characteristics of the information shown may also be subject to considerable variations and are largely dictated by esthetic considerations.

The detailed electronics of the monitoring device capable of assimilating, memorizing and handling the data of the concentrations of the analysis, as well as providing the preferred electronic characteristics of the device discussed in this, and in which the appropriate predicted future events, such as fertility status in an ovulation cycle on the basis of such data, It can quickly be supplied by those experienced in electro-technical technology once they have been informed of the factors that such a device should take into consideration, and the information that the device must provide for the user. By way of example, the basic functions that may be required in such devices are underlined in Figure 8 of the accompanying drawings and briefly described below. The individual characteristics may be entirely conventional, and those familiar with the electronics technique will appreciate that other combinations or arrangements of such characteristics may be employed to achieve the purpose of this invention. For example, the so-called "hard cable" and "neural network" systems can be used instead of conventional microprocessors based on "integrated circuit" technology.

As shown in Figure 8, the combination essentially comprises a reading unit (800) for obtaining the information of the test device, such as a test strip, the reading head comprising an illuminator (801) and a reader (802) (represented here as a photodiode). The reading unit feeds the converter unit (803) to convert the optic signal into a form usable by the microprocessor (804).

As an optional feature, a calibration system (805) is provided to convert the signal derived from the reading unit into the corresponding data, for example, into an absolute concentration value.

A timer, such as a clock (806) may be required to regulate measurements within a cycle. The microprocessor (804) processes, memorizes and interprets the results in the light of previous events, particularly recorded from previous cycles. The user interface (807) generally comprised at least means, such as a push-button, that the user can operate at the beginning of a cycle to start the operation of the device as a whole. The power supply (808) must include means, such as an auxiliary memory capacitor (809) to prevent loss of historical data when the batteries need to be replaced.

The information can be carried to the user by means of a liquid crystal display or LED, for example. If desired, fertility status information can be carried by a simple visual indication, eg a color scheme showing, for example, green for infertility and red for fertility. Especially if the device was first desired as an aid to contraception, it should show "lack of security" by means of a "fertile" signal.

As described above, the characteristics (803) and (806) together correspond to the characteristic (435) (figure 4b), and the characteristic (804) corresponds to the characteristic (436) (figure 4b).

Transmission spectrophotometry is a technique widely used for quantification of dye concentration in clear liquid solutions. Commercially available spectrophotometers generally require substantial modifiers to make measurements of diffuse solutions (dispersion). Transmission spectrophotometry was not generally thought of as an adequate procedure to measure very diffuse samples, so it is generally only adopted when an alternative approach cannot be applied. For the purposes of this invention, transmission measurements offer positive benefits over the usual reflectance approaches previously used in test strips.

Some conventional strip tests use reflectance measures to assess the concentration of the dye on the surface of the strip (eg glucose monitors). The chemistry of these tests occurs in a very thin layer of the surface of the test strip. In contrast, the chemistry of the preferred strip devices of the invention takes place through the thickness of the test strip. Due to the variation in the deposition of the flow and reagents, the concentration of the detectable label captured in a reaction zone may differ according to the depth.

The effects of curvature, surface of materials, finish and effect of solvents can vary the proportion of specular reflection to diffuse. For reflectance measurements, it is the light diffusely reflected from the surface of the strip that carries the signal information (i.e.

EN 1 030 898 U that light will interact with the detectable markers), while the specularly reflected light will not contain information (since this light is the component that just bounces off the surface without interacting with the detectable markers on the diffuse strip). Without resorting to bulky and expensive systems, it is difficult to design a reflectance measurement system that minimizes specular reflection to a degree compatible with the transmission measurements, especially using diffused light in accordance with the invention.

Reflectance systems require the use of a test surface that can be removed from the optic path with the purpose of calibrating. This reference surface must not deteriorate if it is part of the optic assembly.

In addition, mechanical movements are required to displace that reference material when a test strip needs to be mediated. These problems have been avoided in the invention.

In addition to the specific examples of detectable materials already mentioned herein, the invention may use as marker materials those that block or reflect electromagnetic radiation, rather than absorb it, eg "white" particles as latex particles in their natural state. colored. Alternatively, the label may be a reagent or catalyst that participates in the generation of an absorbing radiation or radiation blocking material eg. an enzyme that reacts with a substrate to produce a detectable material, such as a colored material, in the detection zone.

ES 1 030 898 U