GB1592298A

GB1592298A - Incubator

Info

Publication number: GB1592298A
Application number: GB5249177A
Authority: GB
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1976-12-17
Filing date: 1977-12-16
Publication date: 1981-07-01
Also published as: DE2755349C2; FR2374645B1; FR2374645A1; DE2755349A1

Description

(54) INCUBATOR (71) We, EASTMAN KODAK COMPANY, a corporation organized under the Laws of the State of New Jersey, United States of America of 343 State Street, Rochester, New York 14650, United States of America do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to incubators for chemical analyzers of biological fluids.

Incubators are known for use in chemical analyzers in which a fluid sample is metered on to a slide which is analyzed after an appropriate period of incubation: Such an incubator is known to include a housing bounding a chamber which has a first location wherein slides are transferred into the chamber and a second location wherein slides are transferred out of the chamber. Temperature control means are provided for maintaining the temperature constant within the chamber.

Also, there are conveyor means for releasably holding the slides and moving them in the chamber, and drive means for the conveyor means.

Such an incubator is disclosed in U.S.

Patent Specification No. 3,574,064. The automated biological reaction instrument dis closed in that earlier specification includes two part-toroidal incubation chambers each embracing a portion of the circumference of a rotary conveyor table. The conveyor table has a plurality of slide carriers dispersed about its circumference. Serum is applied to a slide on the conveyor table which then carries the slide into the first incubation chamber. Upon emerging from the first in cubation chamber the slide is subjected to various treatments before the conveyor table carries it into the second incubation chamber.

After emerging from the second incubation chamber the slide is subjected to further treatments before it is removed from the conveyor table for inspection under a microscope.

Such a device has the disadvantage that it cannot perform incubation at a very specific temperature for a very specific time because the slide is moved into the first incubation chamber at an undetermined temperature.

Part of the difficulty of the prior art arrangement in controlling the temperature accurately for a predetermined period of time is because the conveyor means are rotating out of and into the incubation chambers. Thus, they too have to be brought up to temperature and hence tend to take the ambient temperature in the incubator below its desired value. Thus, the time for which the slide is at the desired incubation temperature is indeterminate. The same deficiences are true also in relation to the second incubation chamber.

In accordance with the present invention there is provided an incubator for use in a chemical analyser in which a fluid sample is metered on to a slide which is analyzed after an appropriate period of incubation, said incubator comprising a housing bounding a chamber, said chamber having a first location at which slides are transferred into the chamber and a second location at which slides are transferred out of the chamber, temperature control means for maintaining the temperature constant within said chamber, conveyor means disposed wholly within the chamber for releasably holding the slides and moving them in said chamber, and drive means for the conveyor means, which drive means is so constructed as to have a cycle of operation which stops the conveyor means in a position such that transfer of a slide into or out of the chamber can occur whilst the conveyor means is stationary.

The present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is an elevation, partially in section, of a chemical analyzer of the type in which the incubator of the present invention may be employed; Fig. 2 is an elevation of one form of incubator constructed in accordance with the present invention, with portions broken away to show the incubator rotor and the reflectometer; Fig. 3 is a top plan of the incubator shown in Fig. 2; Fig. 4 is a section taken on the line 44 of Fig. 3; and Fig. 5 is an enlarged elevation of the worm for the incubator drive mechanism.

An incubator according to the present invention is particularly suitable for use with a chemical analyzer of the type shown in Fig. 1 which forms the subject of our copending Application No. 52492/77 Serial No.

1,592,299. With reference to Fig. 1, there is shown a chemical analyzer 20 which comprises a sample tray 22, a reagent supply table 24, a metering device 26, an incubator 30, and analysis means 32. A slide handling mechanism 40 comprises an ejector mechanism 42 which is adapted to move a test element, such as a test slide 44, into a metering station where a drop of biological fluid is placed thereon, a forward transfer mechanism 50 which has a first claw mechanism 51 adapted to move a slide 44 from the metering station to a preheater 46 and a second claw mechanism 52 for moving a slide from the preheater to incubator 30, and a rear transfer mechanism 53 having claw mechanisms 54 and 55 for moving a slide from the incubator 30 to analysis means 32 and from analysis means 32 into a disposal chute 60.

A highly preferred form of slide for use with the disclosed apparatus is shown in British Patent Speclfication No. 1,440,464.

The slides disclosed in said Patent Specification are formed as a multilayer element containing the necessary reagents for reaction with components. of a biological fluid, such as blood serum, deposited thereon. Certain reactions colorimetrically produce a change in optical density which is sensed by a refectometer, the amount of light reflected from the element varying in accordance with the reaction and being indicative of the amount of a particular component present in the fluid.

In Figs. 2 and 3, there is shown an incubator 30 which comprises a housing 61 which defines a generally cylindrical, temperature-controlled chamber 62, a rotor 64 mounted for rotation within chamber 62 about a horizontal axis designated 66, preheater 46, and a drive mechanism 110, for rotor 64.

The housing 61 is formed in sections joined by fasteners 67 and comprises a pair of end walls 68, 69, joined by a cylindrical wall 70. Each of the walls includes an inner and outer component of metal separated by a layer of insulation 75. Heating elements 78, which may be of the type in which high resistance wires are embedded in silicone rubber, are affixed to walls 68, 69, as shown in Fig. 3. Heating elements 78 are connected to a control circuit (not shown) which includes thermistors in a feedback arrangement to control power to elements 78 for maintaining chamber 62 at a constant temperature, preferably 37 C. One of the thermistors is located in rotor 64, and is connected to the control circuit through slip rings 77 and brushes 79. A load slot 80 is provided in wall 68, and an unload slot 81 is provided in wall 69. (See Fig. 3).Slots 80, 81 are of a shape and size sufficient to allow the free passage of a slide 44 and the appropriate transfer mechanism, as described hereinafter.

With reference to Fig. 4, preheater 46 is supported relative to housing 61 such that an exit opening 82 communicates with load slot 80 of incubator 30. Preheater 46 comprises an electrically-heated metal block 86 and a pressure pad 87 which is biased toward block 86 by spring 90. When a slide 44 is moved into preheater 46 by claw mechanism 51, the contact of slide 44 with bevelled edge 92 on pressure pad 87 will cam the pad upwardly against spring 90 to permit the slide to be moved into the preheater. An antibackup tab 93 on pad 87 prevents the slide in the preheater from moving back out of preheater 46, as claw mechanism 52 returns to its forward position. Preheater 46 is adapted to raise a slide 44 from ambient temperature to a temperature near the temperature maintained in the incubator chamber 62.Thus, a slide entering chamber 62 does not materially affect the temperature therein, and a very precise temperature control can be maintained in the chamber.

Mounted for rotation within housing 61 is a slide conveyor in the form of a rotor 64 which comprises a rotor shaft 96 joumalled in housing 61, and a hub 97 fixedly mounted to shaft 96. A plurality of slide holding means are carried on hub 97, the slide holding means comprising radially extending support members 98. (See Fig. 2). Spring clips 100 are mounted on members 98 and are adapted to releasably hold a slide 44 against a surface 99 on each member 98. Clip 100 comprises a generally U-shaped flexible element 101 which is fixed to member 98 and supports a pressure member 102. It will be apparent that clip 100 could also be formed as an integral unit. Each of the claw mechanisms 52, 54, which are operable to transfer slides between rotor 64 and the analyzer elements, comprises spaced members which pass on opposite sides of pressure member 102 as the claw mechanisms move in and out of the chamber 62. As shown in Fig. 4, a forward edge portion 104 of the member 102 is shaped such that a slide 44 contacting the edge, as it moves into the incubator, will cause element 101 to he fle';el sufficiently to peru;, the slide to n bk tween pressure member 102 and surface 99.

An encoder wheel 106, carried on shaft 96, cooperates with a detector 107 to provide a means for locating a particular member 98 on rotor 64.

With reference to Figs. 2 and 3, there is shown a drive mechanism 110 which is provided to advance rotor 64 in precise increments and to hold the rotor in stationary position during loading and unloading operations. Drive mechanism 110 comprises a motor 112 which is operatively connected to a shaft 114 which carries a worm 116 thereon. Worm 116 is adapted to cooperate with a worm wheel 118 mounted on rotor shaft 96. Worm 116 and worm wheel 118 are designed such that one revolution of shaft 114 will advance rotor 64 sufficiently to move one slide handling member out of the load position and the next slide handling member into the load position. As shown in Fig. S, worm 116 has a thread 117 having a portion 119 disposed at a zero helix angle, i.e., there is no lead in this thread portion.

This arrangement facilitates the precise positioning of a slide handling member relative to the load and unload slots and to the slide transfer mechanisms, since the rotor is always stopped with the portion 119 in contact with wheel 118. A sensing mechanism 115 is adapted to cut power to motor 112 after one complete revolution of shaft 114, and just as thread portion 119 enters into driving engagement with wheel 118. Thus, if motor shaft 114 continues to turn for an instant after power is cut to motor 112, rotor 64 will not be moved out of position, since no movement of rotor 64 occurs when thread portion 119 is in engagement with wheel 118.It will also be apparent that by selecting the proper speed for motor 112, length of thread portion 119, and sequence of operation of transfer mechanisms 50, 53, it would be possible to continuously drive motor 112 during the loading and unloading operations.

Slides are moved out of the incubator 30 through unload slot 81 and are moved into a chamber 139 in analysis means 32. Analysis means 32, which is supported in incubator wall 69, is adapted to obtain a reflectance reading of a slide 44. As shown in Fig. 2, analysis means 32 comprises a light source 140, here shown as an incandescent bulb, a filter system shown at 141, a lens system (not shown) a mirror 142 which directs a beam of light against a slide 44 in the chamber 139, and a detection means shown at 146.

In operation, slides 44 are sequentially loaded into incubator 30 after a predetermined time in preheater 46. Analyzer 20 is adapted to be continuously operated and the temperature within incubator 30 is controlled such that slides are ready to be analyzed after they have made one revolution in incubator 30.

A control system for incubator 30, as well as for other functions of analyzer 20, could include a computer (not shown) which may take any of the various forms known in the art that include programmable minicomputers and programmable microprocessors. The instructions and method of programming such computers is well known in the art, and thus, no further explanation is considered necessary. In the use of such a computer, input data including sample indentification, calibration values, and desired tests for each sample would be keyed into the computer. Output signals from the computer would be utilized to provide input signals to the analyzer components to control their operation at the appropriate time in the machine cycle.Results from analysis means 32 would be transmitted to the computer which would perform the necessary calculations, according to a stored program, to arrive at a concentration for a particular sample.

This information, along with sample indentification would then be transmitted to a display or printout device.

By having the conveyor entirely within the incubation chamber, the components of the conveyor are always, during operation, at the required incubation temperature. Thus, the duration for which a slide is held at a particular temperature is more accurately specifiable and controllable.

WHAT WE CLAIM IS:- 1. An incubator for use in a chemical analyzer in which a fluid sample is metered on to a slide which is analyzed after an appropriate period of incubation, said in cubator comprising a housing bounding a chamber, said chamber having a first location at which slides are transferred into the chamber and a second location at which slides are transferred out of the chamber, temperature control means for maintaining the temperature constant within said chamber, conveyor means disposed wholly within the chamber for releasably holding the slides and moving them in said chamber, and drive means for the conveyor means, which drive means is so constructed as to have a cycle of operation which stops the conveyor means in a position such that transfer of a slide into or out of the chamber can occur whilst the conveyor means is stationary.

2. An incubator according to claim 1, wherein the conveyor means comprises a rotor mounted for rotation within the chamber, the rotor having a hub from which slide holding means extend radially.

3. An incubator according to claim 2, comprising a loading slot and an unloading slot which extend through the housing to and from

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Claims

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tween pressure member 102 and surface 99.

An encoder wheel 106, carried on shaft 96, cooperates with a detector 107 to provide a means for locating a particular member 98 on rotor 64.

With reference to Figs. 2 and 3, there is shown a drive mechanism 110 which is provided to advance rotor 64 in precise increments and to hold the rotor in stationary position during loading and unloading operations. Drive mechanism 110 comprises a motor 112 which is operatively connected to a shaft 114 which carries a worm 116 thereon. Worm 116 is adapted to cooperate with a worm wheel 118 mounted on rotor shaft 96. Worm 116 and worm wheel 118 are designed such that one revolution of shaft 114 will advance rotor 64 sufficiently to move one slide handling member out of the load position and the next slide handling member into the load position. As shown in Fig. S, worm 116 has a thread 117 having a portion 119 disposed at a zero helix angle, i.e., there is no lead in this thread portion.

This arrangement facilitates the precise positioning of a slide handling member relative to the load and unload slots and to the slide transfer mechanisms, since the rotor is always stopped with the portion 119 in contact with wheel 118. A sensing mechanism 115 is adapted to cut power to motor 112 after one complete revolution of shaft 114, and just as thread portion 119 enters into driving engagement with wheel 118. Thus, if motor shaft 114 continues to turn for an instant after power is cut to motor 112, rotor 64 will not be moved out of position, since no movement of rotor 64 occurs when thread portion 119 is in engagement with wheel 118.It will also be apparent that by selecting the proper speed for motor 112, length of thread portion 119, and sequence of operation of transfer mechanisms 50, 53, it would be possible to continuously drive motor 112 during the loading and unloading operations.

Slides are moved out of the incubator 30 through unload slot 81 and are moved into a chamber 139 in analysis means 32. Analysis means 32, which is supported in incubator wall 69, is adapted to obtain a reflectance reading of a slide 44. As shown in Fig. 2, analysis means 32 comprises a light source 140, here shown as an incandescent bulb, a filter system shown at 141, a lens system (not shown) a mirror 142 which directs a beam of light against a slide 44 in the chamber 139, and a detection means shown at 146.

In operation, slides 44 are sequentially loaded into incubator 30 after a predetermined time in preheater 46. Analyzer 20 is adapted to be continuously operated and the temperature within incubator 30 is controlled such that slides are ready to be analyzed after they have made one revolution in incubator 30.

A control system for incubator 30, as well as for other functions of analyzer 20, could include a computer (not shown) which may take any of the various forms known in the art that include programmable minicomputers and programmable microprocessors. The instructions and method of programming such computers is well known in the art, and thus, no further explanation is considered necessary. In the use of such a computer, input data including sample indentification, calibration values, and desired tests for each sample would be keyed into the computer. Output signals from the computer would be utilized to provide input signals to the analyzer components to control their operation at the appropriate time in the machine cycle.Results from analysis means

32 would be transmitted to the computer which would perform the necessary calculations, according to a stored program, to arrive at a concentration for a particular sample.

This information, along with sample indentification would then be transmitted to a display or printout device.

By having the conveyor entirely within the incubation chamber, the components of the conveyor are always, during operation, at the required incubation temperature. Thus, the duration for which a slide is held at a particular temperature is more accurately specifiable and controllable.

WHAT WE CLAIM IS:- 1. An incubator for use in a chemical analyzer in which a fluid sample is metered on to a slide which is analyzed after an appropriate period of incubation, said in cubator comprising a housing bounding a chamber, said chamber having a first location at which slides are transferred into the chamber and a second location at which slides are transferred out of the chamber, temperature control means for maintaining the temperature constant within said chamber, conveyor means disposed wholly within the chamber for releasably holding the slides and moving them in said chamber, and drive means for the conveyor means, which drive means is so constructed as to have a cycle of operation which stops the conveyor means in a position such that transfer of a slide into or out of the chamber can occur whilst the conveyor means is stationary.
2. An incubator according to claim 1, wherein the conveyor means comprises a rotor mounted for rotation within the chamber, the rotor having a hub from which slide holding means extend radially.
3. An incubator according to claim 2, comprising a loading slot and an unloading slot which extend through the housing to and from

said first and second locations, and which are disposed at opposite sides of the rotor and are aligned parallel with the axis of rotation of the rotor.
4. An incubator according to claim 3, comprising a preheater mounted adjacent the chamber and in communication with the loading slot, the preheater including first and second elements which bound a space slightly larger than a slide, the first element having associated with it means for heating it to a controlled temperature, and the second element being movable relative to the first element to permit entry of a slide into the preheater.
5. An incubator according to claim 3 or 4 wherein the slide holding means comprises a plurality of support members extending radially from the hub of the rotor and a spring clip mounted on each of said support members, each of the clips being so formed as to be cammed away from a surface of its support member by a slide as the slide enters the rotor from the loading slot.
6. An incubator according to any one of the preceding claims wherein the drive means comprises a worm, a portion of the thread of the worm having a helix angle of zero.
7. An analyzer comprising an incubator according to claim 3, 4 or 5, or claim 6 as appendant to claim 3, 4 or 5, analysis means located adjacent the unloading slot and a slide transfer mechanism adjacent the unloading slot for simultaneously moving a first slide out of the conveyor means and into the analysis means and a second slide out of the analysis means into a discharge chute.
8. An incubator according to claim 1, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.