Analyzers having means to control humidity

Abstract: Analyzers are known in which humidity control is provided in the supply means for test elements. Described herein is an improved analyzer arrangement in which the level of humidity at which stacks of test elements (E) are stored prior to use is controlled. The analyzer (10) comprises test element supply means (20), a sample dispenser (50, 52), an incubator (60) and a transfer mechanism (40, 42) for transferring test elements from the supply means (20) to the dispenser (50, 52) and then into the incubator (60). The supply means (20) in which the test elements are stored comprises a cartridge storing compartment (84) and a humidity control compartment (86). The humidity control compartment (86) is divided into first and second compartments (102, 104), each containing either water-addition means (114) or water-deletion means (116). The compartments (102, 104) are provided with respective access openings (108, 110) which connect them to the cartridge storing compartment (84). A movable door (112) is provided for selectively closing off and opening up access openings (108, 110) associated with respective ones of the compartments (102, 104) to allow air to flow from either compartment (102, 104) into the storage compartment (84).

Description: This invention relates to analyzers and is more particularly concerned with analyzers having humidity control. Conventional analyzers have been constructed to provide some level of climate control in parts thereof. The most frequent climate control is temperature control provided in the incubator, that is, in the portion where test samples are reacting with reagents prior to a reading being made at a detecting station. Such temperature control can include means for blowing air over the samples and over heating elements, as described in US Patent Re. 30730 and US-A-3 616 264. It is also been known that climate control is equally important in the storage area or supplying means of test elements, particularly when so-called "dried" slide-like test elements are used. For example, as in Japanese Kokai No. 62/030962, analyzers have been known to provide a dessicant inside a cartridge which is positioned adjacent a plurality of such test elements while stored. However, this arrangement is not acceptable in analyzers having a large storage area for test elements prior to sample addition. In particular, some of the other test elements may require moistening air, which would be deleterious to such dessicants. For example, test elements for the assays of total protein, magnesium, albumin and calcium need a high relative humidity of about 33%, whereas those for the assays of LDH, CK, AST and gamma glutamyltransferase need only 15%. Yet another approach, currently used in analyzers available under the trademark "Ektachem 700" analyzers from Eastman Kodak Company, is to provide two separate storage areas of cartridges. In one area, for test elements which prefer to be stored under dry conditions, a dessicant is stored with them. This is the only humidity control, that is, it removes moisture only, and does so passively. In the other storage area, test elements are placed which prefer a higher degree of relative humidity, and a salt pad capable of adding or removing moisture within a range is present. In this other area, the addition of moisture is passive only - there is no attempt to make the air in the storage area more uniform in content. In some of the "Ektachem 700" analyzers, cartridges of test elements are supplied in a twin-track arrangement, with a pusher blade accessing either track, as described in US-A-4 512 952. Although such a system has provided control of the relative humidity, there have been instances in which better and more rapid control was needed. For example, test elements and cartridges stored with only a dessicant present can become too dry when used in desert conditions, for example. The problem with the storage atmosphere being too dry is that it induces reduced storage life. Thus, it has been discovered that conditions can be experienced in which both water addition and deletion are alternately required to the atmosphere of the storage area over a period of time. Merely storing a drying means or a wetting means in a cartridge or its storage area does not permit a rapid opposite change in the relative humidity in such a cartridge, particularly when such means are passive only, as defined herein. Accordingly, it has been a problem prior to this invention that the storage area or supplying means for slide-like test elements has not been able to provide the proper relative humidity for storage that each kind of test element needs. A further problem is that control of such relative humidity has been cumbersome. It is therefore an object of the present invention to provide an analyzer which maintains slide-like test element supplying means, while stored prior to use, at the proper level of relative humidity, even when the test elements are stored and/or used under extreme conditions. More specifically, in accordance with the present invention, there is provided an analyzer comprising:- test element supply means for supplying test elements for a variety of different assays, the test element supply means including at least one track constructed to support a plurality of cartridges each containing test elements and means for moving each cartridge along the track; an incubator for incubating a test element after a sample has been deposited thereon; transfer means for transferring a test element from the test element supply means to the incubator, the transfer means including means for independently accessing each track to contact a test element in a cartridge, and humidity control means for controlling the relative humidity of the test element supply means, comprising separate water-adding means and water-subtracting means for each of the tracks and control means for controlling the relative humidity of each track. Accordingly, it is an advantageous feature of the invention that an analyzer is provided which provides positive water-addition and/or water deletion to the atmosphere in the portion which stores and supplies test elements for use as needed. The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:- Figure 1 is a perspective, partially schematic simplified view of a analyzer constructed in accordance with the present invention. Figure 2 is a sectioned elevational view of test element storage and supply means of the analyzer shown in Figure 1, the sectioned view being taken through the portion of the analyzer holding the water and dessicant containers; Figure 3 is a plan sectioned view taken generally along the line 3-3 of Figure 2; Figure 4 is a sectioned elevational view illustrating a second embodiment of the test element storage and supply means according to the present invention; Figure 5 is a sectioned elevational view illustrating a third embodiment of the test element storage and supply means according to the present invention; Figure 6 is a sectioned plan view similar to that shown in Figure 3, but of fourth embodiment of the test element storage and supply means according to the present invention; and Figure 7 is an elevational view similar to that shown in Figure 2, but illustrating a fifth embodiment of the test element storage and supply means according to the present invention. The invention is hereinafter described with respect to a preferred type of a) storage and supply means for test elements, b) test elements and cartridges, and c) transfer means, incubator, and detector station. In addition, it is useful for other kinds of storage and supply stations, other kinds of test elements and cartridges, and other kinds of transfer means, incubator and detector stations. The invention is based on the determination that both water addition means and water deletion means should be supplied to all stacks of test elements stored in the analyzer, in an alternative fashion, and not as a source within each cartridge individually, but rather to the supply means which house the cartridges. Furthermore, the air is to be actively forced to flow and travel from the means for adding or deleting moisture to the stacks of elements. As used herein, "active" humidity control distinguishes from "passive" humidity control in that in the former, air is positively forced to travel between the humidity control and the stacks of elements. In the latter "passive" system, there is simply a humidity control means somewhere "in the box", and the user hopes that its influence is adequate over elements present even at far distant reaches. Thus, Figure 1 shows an analyzer 10 constructed in accordance with the present invention. The analyzer 10 comprises, as is conventional, a test element storage and supply station 20, a test element transfer means 40, means 50 for dispensing a body liquid on to a test element removed from station 20 by transfer means 40, an incubator 60 for incubating a test element containing body liquid so dispensed, and a detector station 70 such as a reflectometer, for detecting changes in the test elements after incubation, preferably while still in the incubator. The storage and supply station 20 preferably comprises a housing 22 having walls which completely enclose a plurality of stacks of test elements E and is shown more clearly in Figure 2. Each stack is preferably enclosed in a movable cartridge 24, 24', etc., up to 24 n for n+1 cartridges and n+1 stacks, all of which is conventional. (Only three are shown in Figure 1 for purposes of illustration). Any suitable means can be provided for inserting and removing cartridges, such as door 26. Each cartridge 24, 24', ..., 24 n is preferably limited to generally identical test elements for a single assay so that different assays are provided by different cartridges. The cartridges and assays are preferably of the type available under the trademark "Ektachem" cartridges and slides from Eastman Kodak Company. The transfer means 40 preferably utilizes a pusher blade 42 which is insertable into the top of a cartridge through a slot 44, as shown in Figure 4. The dispensing means 50 preferably uses a disposable tip 52, as shown in Figure 1, and automated means (not shown) for aspirating several aliquots of a sample of body liquid into tip 52, and then dispensing one aliquot at a time. Incubator 60 is preferably a rotating incubator with a plurality of stations around its circumference for holding a test element which has been inserted therein by blade 42, as indicated by arrow 62, after an aliquot has been dispensed on to it by dispensing means 50. Useful examples of such transfer means, liquid-dispensing means, incubator and detector station include, but are not limited to, those provided by analyzers available under the trademark "Ektachem" analyzers from Eastman Kodak Company. All parts of the analyzer are preferably controlled by computing means 95, as shown in Figure 2, and related input and output devices, such as a keyboard and CRT display (not shown), all of which are conventional. Concerning storage and supply station 20 in particular, this station can have any configuration, a linear one being illustrated. In Figure 2, a track 30 is shown which comprises opposed rails 32, 32'. On these rails 32, 32', a carrier 34 reciprocates, preferably as driven by a motor (not shown). Carrier 34 includes cut-out portions or apertures 36 which mate with and support a cartridge 24 n . Alternatively, housing 22 can be arcuate (not shown) and track 30 can be an annular ring or portion thereof which rotates about a fixed point. In either case, it is the environment within housing 22 and cartridges 24, 24'...24 n for which the relative humidity is to be controlled. In accordance with the present invention, means are included in housing 22 for adding or deleting water to this atmosphere, preferably in a mutually exclusive manner. More specifically, a wall 80 extends horizontally across the bottom of station 20, preferably just under the path of movement of the cartridges, as indicated by arrows 82 in Figure 1. This separates the housing 22 into an upper compartment 84 and a lower one 86. Near one end 88 of wall 80, an access opening 90 is provided. Under opening 90, fan 92 is disposed, as shown in Figures 1 and 2, to force air to flow or travel through opening 90 and into upper compartment 84 and the cartridges 24, 24', ..., 24 n . (Each cartridge includes a lower aperture 94, as shown in Figure 2, which allows the insertion of a rod 96, as shown in Figures 1 and 4, operated by a motor 97 to raise the stack of test elements up into position to engage blade 42, as is conventional.) To allow the fan to force drier, or wetter air into compartment 84, compartment 86 is further subdivided by wall 100 to form two enclosed subcompartments 102 and 104, as better noted in Figure 2. A separating wall 106 is positioned between them, and access openings 108 and 110 are provided in wall 100 for each of the subcompartments 102, 104. A door 112 is provided for each of openings 108 and 110. Subcompartment 102 contains either means for adding moisture to the air or means for removing moisture, while the other one contains the other. For example, subcompartment 102 can contain a sponge 114 saturated with water, whereas subcompartment 104 contains a dessicant 116. Alternatively, sponge 114 can be replaced by a misting device (not shown) which turns on a fine mist when opening 108 is uncovered. Both subcompartments 102 and 104, as well as compartment 86, preferably have an endwall 120 which completes their enclosure, as shown in Figures 2 and 3. However, endwall 120 includes air return openings 122, 124 only at subcompartments 102, 104, as shown in Figure 2, which cooperates with air return aperture 125 in wall 80 (Figures 1 and 4) to allow air to recirculate. To drive fan 92, a motor 126 is provided, (shown in phantom, Figure 3) preferably mounted on wall 120. The rotation 128 of the blade of fan 92 clears this wall. Door 112 requires openings 130, 132 to cooperate with openings 108, 110 respectively (Figure 2). These openings 130, 132 are positioned so that either opening 130 is aligned with opening 108 while opening 132 is not aligned with opening 110, as shown, or vice versa. Door 112 is operated so as to add moisture, or remove it, as is dictated by at least one humidity sensor 134 positioned within compartment 84. The response of the sensor is received by computing means 95, which in turn operates fan 92 and the door 112 as follows: To control the movement of door 112 and thus the change in alignment of openings 130 and 132, door 112 preferably is driven by a single motor 140, as shown in Figure 2, preferably mounted on wall 120. Any connection between motor 140 and door 112 is useful. For example, a rack and pinion connection is provided when edge 142 of door 112 is a rack and a pinion gear 144 is mounted on drive shaft 146 of motor 140, as shown in Figure 3. Opposite edge 148 of door 112 slides on shoulder 150. In this fashion, access to both subcompartments is controlled by a single motor. To ensure that motor 140 provides that either opening 108 is solely accessible, or opening 110 is solely accessible, or neither opening is accessible, openings 130 and 132 are positioned, as shown in Figure 3, so that solid portions 152 and 154 of door 112 remain available to cover opening 108 as the door moves first to the left to first phantom position 160, and then to the second phantom position 162. Similarly, solid portion 164 is positioned to the right of opening 132 to allow the door to cover opening 110 when the opposite end is in the phantom position 162. Because fan 92 is not constantly on, an auxiliary fan (not shown) can be used to recirculate air in compartment 84. More than one track can be provided as a source of cartridges, as shown in Figure 4. In this embodiment, one track is selected for cartridges requiring generally a first relative humidity level, and the other for those requiring a different relative humidity level, so that each track has its own set of water-addition means and water-deletion means. Parts similar to those previously described bear the same reference numeral, to which the distinguishing suffix A is appended. Thus, a housing 22A is provided for storage and supply of test elements from cartridges C, for transfer via blade 42A in means 40A to a dispensing station using dispensing probe 50A. However, in this case, there are two tracks 30A and 30'A, side-by-side, separated by a common housing wall 180. They can be linear as shown, or any other shape, for example, that of annular rings. The tracks are shown generically, as they can be configured in any convenient form including that shown in Figure 2. Alternatively, each track can be radially separable, as indicated by arrow 190, to allow a used cartridge C to fall through housing 22A and out a trap door (not shown) in the bottom of housing 22A. Preferably, tracks 30A and 30A' cooperate with sensors 192 to indicate which cartridge is where. The cartridges of one track are accessible independently of those of the other. As in the previous embodiment, each track 30A, 30A' has its own set of water-adding means 114A, 114A' and water-deleting means 116A, 116'A, as shown in phantom Figure 4. The door-operating means providing access to 114A, 116A, or 114A', 116A', are constructed similarly to that of the embodiment shown in Figures 2 and 3. In this case, there is a separate door and motor (not shown) for each of the two tracks. By this construction, the relative humidity for track 30A and its cartridges can be maintained at a different level than that of track 30'A and its cartridges. Because pusher blade 42 necessarily passes over both track 30A and 30'A on track 198, and a cartridge of each track necessarily intersects the blade path 198, it is desirable that a seal be maintained at the top, in conjunction with the blade passage, to ensure that there is minimal air mixing between the two tracks. A preferred embodiment to achieve these results is as follows: The top portion 200 of housing 22A accommodates the passage of blade 42 and a test element dealt off the top of a stack from track 30A, 30A'. More specifically, top portion 200 has a blade entrance port 202 and an exit port 204 fixed in the housing, and floating members 210, 212. The floating members are displacably seated on annular valve seats 214 disposed around an opening 216 which will allow a cartridge to be raised up into the path 198 to be engaged at groove 44 by blade 42. Members 210, 212 are each biased downwardly against seats 214 by a compression spring 218. Because each member 210, 212 serves as a substitute blade guide if its cartridge is not raised up, a groove 220 horizontally extends through the member. As each member 210, 212 is pushed up out of blade path 198 if its cartridge is raised up, a space 230 is formed in portion 200 to accommodate member 210, 212 when spring 218 is compressed. (Movement upward of a stack of elements E by rod 96 also causes cartridge C to be raised up against one of members 210, 212). Although not essential, member 210, 212 can be constructed so that top portion 230 thereof, from which boss 231 extends to receive spring 218, can be easily removed from bottom portion 232 (not shown) to fix any test element jams which may occur. The fan for positive air-displacement need not be vertically disposed. Instead, it can be mounted to force air to flow first horizontally and then vertically, as shown in Figure 5. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix B is appended. Thus, housing 22B has an upper compartment 84B and a lower compartment 86B as before, with an access opening 90B connecting the two compartments. Cartridges C are moved along a track in compartment 84B, as with the previous embodiments, and two subcompartments, of which only subcompartment 102B is shown, provide either water-adding means or water-deleting means, such as water-filled sponge 114B. A door 112B is operated by a motor 140B as described previously. However, unlike the previous embodiments, fan 92B operated by its motor 126B, is disposed to blow air first horizontally through lower compartment 86B and then up into upper compartment 84B through access opening 90B as shown by arrows 250. It is not necessary that a single door be used for both access openings from the subcompartment, as shown in Figure 6. Parts similar to those previously described bear the same reference numeral, to which the distinguishing suffix "C" is appended. Thus, wall 100C which separates compartment 86C from the subcompartments has a rack 142C and pinion gear 144C operated by drive shaft 146C to open doors 112C and 112'C over the access openings, as before. However, door 112C is separate from door 112'C, each being biased by a tension spring 260 into a closed position. A post 262 on one end of rack 142C either pushes door 112C open, or pulls door 112'C open, according to the direction of travel of rack 142C. Sensors 264 and 266 sense the door positions and the rack positions respectively. The door mechanism for opening and closing air flow from the subcompartments and the fan can be a passive one, that is, one not requiring a motor, as shown in Figure 7. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix "D" is appended. Thus, track 30D has an upper compartment 84D and two lower subcompartments 102D, 104D containing a sponge 114D providing moisture addition and a dessicant 116D to remove moisture respectively as described before. Rail 32D and carrier 34D function as before. However, intermediate compartment 86 is omitted, and two fans 92D and 92D' are used in place of one, each fan being confined to a subcompartment. The door mechanism in this case is a flexible flap 112D and 112D' for each subcompartment. The flaps are only secured at edge 300 so that each flap is free to lift up when either its associated fan is operating thus allowing air flow, as indicated by arrow 302, into upper compartment 84D to add or subtract moisture. Either fan can be a conventional "muffin" fan, that has access ports 304 drawing air from around the sponge, or dessicant. Air returns 122D and 124D are provided as before.

Claims: An analyzer comprising:- test element supply means (20) for supplying test elements (E) for a variety of different assays, the test element supply means (20) including at least one track (30; 30A, 30A'; 30D) constructed to support a plurality of cartridges (24, 24', ..., 24 n ; C) each containing test elements (E) and means (32, 32', 34; 32D, 34D) for moving each cartridge (24, 24', ..., 24 n ; C) along the track (30; 30A, 30A'; 30D); an incubator (60) for incubating a test element (E) after a sample has been deposited thereon; transfer means (40, 42) for transferring a test element (E) from the test element supply means (20) to the incubator (60), the transfer means (40, 42) including means (198, 200, 202, 204, 210, 212, 218, 220) for independently accessing each track (30; 30A, 30A'; 30D) to contact a test element (E) in a cartridge (24, 24', ..., 24 n ; C), and humidity control means (92, 102, 104, 108, 110, 112, 114, 116, 126, 140; 114A, 114A'; 116A, 116A'; 92B, 102B, 112B, 114B, 126B, 140B; 92D, 92D', 102D, 104D, 112D, 112D', 114D, 116D) for controlling the relative humidity of the test element supply means (20), comprising separate water-adding means (114; 114B; 114D) and water-subtracting means (116; 116B; 116D) for each of the tracks (30; 30A, 30A'; 30D) and control means (95, 134; 192) for controlling the relative humidity of each track (30; 30A, 30A'; 30D). An analyzer according to claim 1, wherein the test element supply means (20) includes two tracks (30A, 30A') and sealing means (210, 212, 214, 216, 218, 231) are provided for preventing substantial intermixing of atmospheres between the two tracks (30A, 30A') when the transfer means (40, 42, 198, 200, 202, 204, 210, 212, 218, 220) moves a test element (E) out of the tracks (30A, 30A'). An analyzer according to claim 1 or 2, wherein the control means (95, 134;) comprise a humidity sensor (134,) disposed along a respective one of the tracks (30; 30A, 30A').

Inventors: MUSZAK MARTIN FRANK C O EASTMA, SHAW JAMES DAVID C O EASTMAN K, MUSZAK, MARTIN FRANK, C/O EASTMAN KODAK COMPANY, SHAW, JAMES DAVID, C/O EASTMAN KODAK COMPANY
Applicants: EASTMAN KODAK CO, CLINICAL DIAGNOSTIC SYSTEMS, INC.
Application year: 1991
Main classification: G01N35
IPC codes: G01N35, G01N1, G05D22