CA1047379A - Test system - Google Patents
Test systemInfo
- Publication number
- CA1047379A CA1047379A CA290,936A CA290936A CA1047379A CA 1047379 A CA1047379 A CA 1047379A CA 290936 A CA290936 A CA 290936A CA 1047379 A CA1047379 A CA 1047379A
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- test
- code
- carrier member
- reagent
- instrument
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Abstract
ABSTRACT OF THE DISCLOSURE
A test system for the semi-automatic quantitative analysis of chemical constituents in a test fluid which comprises test devices having test reagents and coding means associated therewith and an instrument which receives the test devices and is programmed by the device code means for automatically reading the particular test reagents associated with the particular test device being used. Preferably the test reagents are in a dry form, immobilized in or on a carrier member which upon contact with the test fluid can be manually presented to the instrument. Another preferable embodiment of the present device comprises the use of the code means to calibrate the instrument each time a test device is introduced thereto.
A test system for the semi-automatic quantitative analysis of chemical constituents in a test fluid which comprises test devices having test reagents and coding means associated therewith and an instrument which receives the test devices and is programmed by the device code means for automatically reading the particular test reagents associated with the particular test device being used. Preferably the test reagents are in a dry form, immobilized in or on a carrier member which upon contact with the test fluid can be manually presented to the instrument. Another preferable embodiment of the present device comprises the use of the code means to calibrate the instrument each time a test device is introduced thereto.
Description
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BACXGROUND OF THE INVENTION
Classical instrumental analytical chemistry has always required that a test reagen~ which usually com-; prises several separate components, be physically manipu-lated and manually contacted with the fluid being tested.
This is usually followed by manually presenting the chemi-cal reactants to an instrument for a quantitative readout or estimation of the reaction products. Recently, however, completely automatic instruments have been developed to eIiminate the need for manual manipulation of the chemical : ::
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1 reactants and which give programmed readouts. Such instru-ments are almost always extremely expensive and complicated and the servicing of such instruments requires highly skilled technicians.
On the other hand, when attempts are made to simplify automatic systems, one usually encounters the problem that semi-automatic instrument parameters must be set manu-ally. In such instruments there is always the danger that the instrument will be incorrectly programmed by the technician. Thus, a proper balance must be made between complex automatic instruments which require highly skilled service personnel and semi-automatic or manual instruments which require the programming and/os manipulation thereof by relatiYely unskilled technical operatoTs.
12 Another disad~antage associated with awtomatic and semi-automatic instrumental analysis systems is that when a malfunction occurs in the instrument, all analytical activity is suspended and recourse must be had to alter-native procedures which are not familiar to the technician.
DESCRIPTION OF THF PRIOR ART
The prior art relatting to automatic and semi-automatic analytical chemistry instruments is so extensi~e as ~o be beyond the scope of this specification. As for the pre-ferred and specifio embodiments of this in~ention, there ~` 25 is no known direct prior art.
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SUM~ARY OF TH~ INVI~NTION
The present invention relates to a simplified ~wo component test system ~or ~emi-automatically determining any selected ones of a plurality of constituents in a test fluid. One component consists of a plurality of diffeTent coded test de~ices each con~aining one or more immobilized test reagents which give detectable chemical responses or reactions to the particular constituents in the ~est fluid being assayed. The second component comprises a test instrument adapted to receiYe any selected one of the coded test devices~ This instrument contains a code sens-ing means and a reaction sensing means which is automati-cally activated by the code sensing means to read ~hose test reagents associated with the test device presented to the înstrument. A readout means is included which is coupled to the code sensin~ means and the reaction sensing ;I means to correlate the response of the instrument to the particular device presented to the instrument and to report the resul~s thereof. Preferred embodiments comprise the use 1 20 of dry or immobilized test reagents incorporated with ~I carrier mem~ers, such as strips of transparent plastic oil, I to form the test devices,of the present invention. These ,I test devices can be used independently of the instrument if , the ~esponse thereof is chromo~enic Another preferred em-bodiment is ~he use of a code means associated with the test `, device which not only provides for the programming of the instrument according to the test device presented but also automatically calibrates the instrument each time ~ test is ~`` conducted.
37~3 RIEF DESCRIP~ION OF THE DRAWINGS
Figure 1 is a plan view showing fifteen diffeTent test devices o the type which is useful in the test system of the present invention.
Figure 2 is a block diagram showing one form of an instrument which is used to read the response of ~he ~est devices shown in Figure 1.
Figure 3a to 3f are diagrammatic side-elevational views of a part of the instrument shown in Figures 2 and 4.
~igure 4 is a block diagram similar to Figure 2 show-ing in mo~e detail the circuitry of an exemplary embodiment of the instrument shown in Figure 1.
D~SC~IPTION OF THE PRE~ERRED EMB~DIMENTS
The test devices of the present invention each com-prise three components: ~1) one or more test reagents which are specifically reactable with the particular sub-stance or substances to be detected în the test fluid;
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BACXGROUND OF THE INVENTION
Classical instrumental analytical chemistry has always required that a test reagen~ which usually com-; prises several separate components, be physically manipu-lated and manually contacted with the fluid being tested.
This is usually followed by manually presenting the chemi-cal reactants to an instrument for a quantitative readout or estimation of the reaction products. Recently, however, completely automatic instruments have been developed to eIiminate the need for manual manipulation of the chemical : ::
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1 reactants and which give programmed readouts. Such instru-ments are almost always extremely expensive and complicated and the servicing of such instruments requires highly skilled technicians.
On the other hand, when attempts are made to simplify automatic systems, one usually encounters the problem that semi-automatic instrument parameters must be set manu-ally. In such instruments there is always the danger that the instrument will be incorrectly programmed by the technician. Thus, a proper balance must be made between complex automatic instruments which require highly skilled service personnel and semi-automatic or manual instruments which require the programming and/os manipulation thereof by relatiYely unskilled technical operatoTs.
12 Another disad~antage associated with awtomatic and semi-automatic instrumental analysis systems is that when a malfunction occurs in the instrument, all analytical activity is suspended and recourse must be had to alter-native procedures which are not familiar to the technician.
DESCRIPTION OF THF PRIOR ART
The prior art relatting to automatic and semi-automatic analytical chemistry instruments is so extensi~e as ~o be beyond the scope of this specification. As for the pre-ferred and specifio embodiments of this in~ention, there ~` 25 is no known direct prior art.
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SUM~ARY OF TH~ INVI~NTION
The present invention relates to a simplified ~wo component test system ~or ~emi-automatically determining any selected ones of a plurality of constituents in a test fluid. One component consists of a plurality of diffeTent coded test de~ices each con~aining one or more immobilized test reagents which give detectable chemical responses or reactions to the particular constituents in the ~est fluid being assayed. The second component comprises a test instrument adapted to receiYe any selected one of the coded test devices~ This instrument contains a code sens-ing means and a reaction sensing means which is automati-cally activated by the code sensing means to read ~hose test reagents associated with the test device presented to the înstrument. A readout means is included which is coupled to the code sensin~ means and the reaction sensing ;I means to correlate the response of the instrument to the particular device presented to the instrument and to report the resul~s thereof. Preferred embodiments comprise the use 1 20 of dry or immobilized test reagents incorporated with ~I carrier mem~ers, such as strips of transparent plastic oil, I to form the test devices,of the present invention. These ,I test devices can be used independently of the instrument if , the ~esponse thereof is chromo~enic Another preferred em-bodiment is ~he use of a code means associated with the test `, device which not only provides for the programming of the instrument according to the test device presented but also automatically calibrates the instrument each time ~ test is ~`` conducted.
37~3 RIEF DESCRIP~ION OF THE DRAWINGS
Figure 1 is a plan view showing fifteen diffeTent test devices o the type which is useful in the test system of the present invention.
Figure 2 is a block diagram showing one form of an instrument which is used to read the response of ~he ~est devices shown in Figure 1.
Figure 3a to 3f are diagrammatic side-elevational views of a part of the instrument shown in Figures 2 and 4.
~igure 4 is a block diagram similar to Figure 2 show-ing in mo~e detail the circuitry of an exemplary embodiment of the instrument shown in Figure 1.
D~SC~IPTION OF THE PRE~ERRED EMB~DIMENTS
The test devices of the present invention each com-prise three components: ~1) one or more test reagents which are specifically reactable with the particular sub-stance or substances to be detected în the test fluid;
(2) a carrier member for the test reagent OT reagents, and
(3) a code means associated with the test device which identifies the particular test device presented to the test instrument, which instrument will be described herein-ater.
Each of the test reagents associated with the test devices of the present invention usually comprises one or more chemical constituents which specifically react with the substance in the test fluid to give a detectable chemical response which relates to the amount of the con-stituent in the test fluid, which response may be measured instr~llentally. This response may be spectral, such as by the selective reflectance of visual, ultraviolet or infrared
Each of the test reagents associated with the test devices of the present invention usually comprises one or more chemical constituents which specifically react with the substance in the test fluid to give a detectable chemical response which relates to the amount of the con-stituent in the test fluid, which response may be measured instr~llentally. This response may be spectral, such as by the selective reflectance of visual, ultraviolet or infrared
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1 radiant energy or it may be any other physical or chemical effect of any specific reactlon between the test reagent and the constituent being detected, which effect is measur-able using instTumental reaction sensing means. The test eagent is preferably in a dry or substantially dry form and is incorporated with a carrier member as will be described hereinafter.
Specific test reagents will be described in detail in the Examples; however, it should be noted here that preferable test reagent systems comprise one o~ more chemicals which can be combined prior to use and ~etain their react;~ity for extended periods of time. Anothe~
preferable feature of such test reagents is the ability thereo to detect the level of the par~icular constituent 1~ being assayed in the concentration range usually encoun-tered in the test fluid The second essential component of ~he test device is the carrier member. This component comprises a means for retaining or holding the test reagent and preferably for allowing facile contact between the test reagent and test fluid. Although a simple containeT may suffice or such a carrier member, it has been found that a bibulous matrix such as paper is ideally suited for incorporating the test reagent in a dry or substantially dTy format. As will be explained more fully in the descTiption of Figure 1 and later in the operation of the present test system, it is preferable to utilize ~ strip of transparent plastic film to hold individual paper matrices into or onto which the test reagents are impregnated. In such an embodiment the
1 radiant energy or it may be any other physical or chemical effect of any specific reactlon between the test reagent and the constituent being detected, which effect is measur-able using instTumental reaction sensing means. The test eagent is preferably in a dry or substantially dry form and is incorporated with a carrier member as will be described hereinafter.
Specific test reagents will be described in detail in the Examples; however, it should be noted here that preferable test reagent systems comprise one o~ more chemicals which can be combined prior to use and ~etain their react;~ity for extended periods of time. Anothe~
preferable feature of such test reagents is the ability thereo to detect the level of the par~icular constituent 1~ being assayed in the concentration range usually encoun-tered in the test fluid The second essential component of ~he test device is the carrier member. This component comprises a means for retaining or holding the test reagent and preferably for allowing facile contact between the test reagent and test fluid. Although a simple containeT may suffice or such a carrier member, it has been found that a bibulous matrix such as paper is ideally suited for incorporating the test reagent in a dry or substantially dTy format. As will be explained more fully in the descTiption of Figure 1 and later in the operation of the present test system, it is preferable to utilize ~ strip of transparent plastic film to hold individual paper matrices into or onto which the test reagents are impregnated. In such an embodiment the
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papar matrix and the trans~arent plastic film together form khe carrier member and the part of the test device comprisin~ the test reagent incorporated in~o the matrix is called th~ reagen~ blo~k.
Alternatively, the carrier member may compxise simply a strip of transparent plastic film on which the test re-agents are affixed by any sui~able means such as, for example, by a polymeric material. In such an exemplary embodiment the test reagent is dissolved or dispersed in an organic solvent solution of a polymer, such as cellulose acetate, and th~ solution or dispersion is cast or other-wise applied onto the transparent film and dried.
The carrier members ~described hereinabova may be in the form of individual strips to which one or several paper matrices are at~ached, or they may ~e in ~he form of continuous rolls of plastic ~ilm comprising units of ~`
individual test devices which may be torn o~f, contacted with the test solution and presented ~o the ins~rument.
The third component of the test devica is the code means. This enables the instrument to determine which of several test devices, having one or more different test reagents associated therewith, is presented so that the instrument ls programmed to read that particular test de-vice. The code means is preferably a distinctive indicia or placement thereof associated with the carrier member~ said code means being specific or a particular test device and recognizable by the instrumen The code means may be a series of characters or ma~ks, each peculiar to a particular test de~ice in a series of device~. ~he code means may also ~e a particular color which the code sensing means of the instrument can recognize, as will be explained more fully
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papar matrix and the trans~arent plastic film together form khe carrier member and the part of the test device comprisin~ the test reagent incorporated in~o the matrix is called th~ reagen~ blo~k.
Alternatively, the carrier member may compxise simply a strip of transparent plastic film on which the test re-agents are affixed by any sui~able means such as, for example, by a polymeric material. In such an exemplary embodiment the test reagent is dissolved or dispersed in an organic solvent solution of a polymer, such as cellulose acetate, and th~ solution or dispersion is cast or other-wise applied onto the transparent film and dried.
The carrier members ~described hereinabova may be in the form of individual strips to which one or several paper matrices are at~ached, or they may ~e in ~he form of continuous rolls of plastic ~ilm comprising units of ~`
individual test devices which may be torn o~f, contacted with the test solution and presented ~o the ins~rument.
The third component of the test devica is the code means. This enables the instrument to determine which of several test devices, having one or more different test reagents associated therewith, is presented so that the instrument ls programmed to read that particular test de-vice. The code means is preferably a distinctive indicia or placement thereof associated with the carrier member~ said code means being specific or a particular test device and recognizable by the instrumen The code means may be a series of characters or ma~ks, each peculiar to a particular test de~ice in a series of device~. ~he code means may also ~e a particular color which the code sensing means of the instrument can recognize, as will be explained more fully
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hereinafter, The code means may also simply consist of an opaque area, the placement of which is distinctive for each test device. Other code means and formats will be apparent from the above and the ensuing di~closure.
Exemplary of the various types of indicia which may serve as code means for the ~est devices o the present invention are: s~mbols such as diamonds, squares, circles, and so ~orth; several marks of the same ~ype such as a series of parallel bars; names, such as ~he name of the particular test, iOeO glucose, protein, and so forth;
colors; numbers; slots; holes, and so forth. The only limiting factor in selec~ing the indicia for the code m~ans is that the instrument code sensing means mus~ be capable of recognizing the indicia and dis~inguishing one from another as well as coxrela~ing the particular indicia to the test device.
-! A preferable code means is shown in Figure 1 and will be described more fully later; however, basically this preferable means comprises an opaque area or code blGck placed on a transparent strip or carrier in predetermined spacial relationship with one or more reagent areas ~r blocks on the same strip, the location of the reagent block or blocks with respect to the code block being dif-~erent for each of the test devices used with the test instrument. In use, a test device pre~ented to the in~tru-ment is advanced to a position which interrupts a light path between a light source and light sensing means, such as a photosensitive element, the relative positions oE the code block and the reagent block being indicative o~ a 30 specific test device, `
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l Referring now to the test instrument, there are four facets of this instrument which will be-described. The first is that the instrument must be capable of receiving or is adapted to receive the test devices of the present invention, Secondly, the instrument must have a code sens-ing means associated therewith in order to read the code means of the test device and translate this signal into a calibration reference signal and a command for the in-strument to read the particular test reagent or reagents of the test device. Third, the instrument must have a reaction sensing means or receptor to detect ~nd accumulate the response from the reaction of the test reagent and the constituent in the test fluid being detected. The fourth component or facet of the instrument is the readout means which translates the response of ~he code sensing means and -the reaction sensing means into a value which is indicative of the quantity of the constituent being assayed in the test fluid.
These facets or components will now be individually discussed.
The irst facet or aspect of the test instrument is that it must be able to receive ~he test de~ice relating thereto. In other words, if the test de~ice response is a color change on a paper matrix, the test instrument must be capable of receiving the paper mat~ix, and the reaction sensing means of the instrument must be capable of reading the response, for example, by reflectance spectrophotometry.
The code sensing means may be any electronic device, . .
component or circuit which can readJ identify and elec-tronically process the indicia of the code means of the test device to enable the instrument to identify the . . . . . .
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1 particular test being presented. The code sensing means may also perform other functions such as that of a light sensitive detector which can be used to command the instru-ment to read a response at a particular time. This will be explained more fully hereinafter.
More specifically, the code sensing means may be a light sensitive detector comprising a light source direct-ing a light beam at a photosensitive element or pho~osensor or it may be a complex word or symbol reader such as those used to read numbers on commercial o~ financial instruments or notes. Additionally, the code sensing means may be a color sensing device which identifies a pa~ticular color or shade of color and correlates the color or shade with a particular test device, Shades of gray may also be used to ide,ntify the device. The code sensing means may also be one which identifies a particular number of parallel bars or opaque marks on the test device and accordingly identi-fies a specific device. It will be appreciated from the above, that numerous code means and code sensing means may , 20 be used in conjunction with the present invention, The third part of the test instrument is the reaction sensing means. This component or means basically comprises the part of the test ins,trument which recognizes and quan-titatively measures the extent of the chemical reaction 2S be~ween ~he test reagents associated with the test device and the particular constituents or chemicals being tested for in the test fluid. The reaction sensing means may simply be a photosensitive element or photosensor such as a photoelectric cell which measures the light reflected from a reagent block after a chromogenic reaction between the constituent and the test reagent, or it may comprise more complex analytical instrumentationO The controlling con-_ g 737~
1 sideration is that the reaction sensing means must be cap-able of detecting and quantitatively measuring the above -noted chemical reaction, and of generating a signal which is supplied to the input of the readout means which will now be described.
The readout means correlates the output from the code sensing means and the reaction s~nsing m~ans such that (1) the instrument recognizes the particular tes~ device being presented and (2) the signal or signals generated from the reaction sensing means are processed to give an indication of the amount of a particular constituent in the fluid being tested.
A particularly advantageous and preferable readout means of the test instrument of the present invention comprises the use of an apparatus or electronic circuit comprising an input scaler, an access scaler and a read -only me~ory connected in such a fashion that the signal or output from the reaction sensing means is decoded to provide an indication of a characteris~ic or significant quantitative value or range of values for the test fluid, such as p~, clinical levels of glucose, protein, and so - forth. Such circuitry is further described in the specific embodiments which follow' Referring now to Figure 1 of the dTawing, each of the test devices numbered 1 to 15 illustrated therein comprises a strip of transparent plastic film which forms a base member 16 to one end portion o which one or more square paper matrices 18 is affixed. The other end portion of mem-ber 16 provides a handle for the test device- The matrices 18 are incorporated with test rea~ents which ~r~ ~n~cifi-cally reactable with various characteristiCS or constituents . ., , ~-,- ~; - . - , :.
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1 in test fluids such ~s urine. In the drawing, pH repTesents a matrix incorporated with reagent to form a reagent bl~ck for determination of the pH, while P, G, K, BI, BL and U
respectively r~present reagent blocks which are specifically reactable with protein, glucose, ketones, bilirubin, occult blood and urobilinogen. In the test devices shown, the code means is an opaque area or printed area 17 which is identi-fied in the drawing by the word "code".
In Figu~e 1 $he test device 1 is shown as having seven test blocks 18 and a code block 17 disposed in spaced Tela-tion on strip 16 beginning at the ri~ht hand end thereof.
The positions of the code block and reagent blocks of device 1 are indicated by the letters P-l to P-8 shown thereabove. It will be observed that with the devices 1 to 15 disposed in the vertical alignment shown, each of the devices 2 to 15 has one or more spaced reagent blocks there-; on, beginning at the right hand end thereof, and one code ; block. Each of th~ reagent blocks and code blocks is in vertical alignment with one of the positions P-l to P-8.
For example, on test device 7, the code block is in position P-3 and the pH, glucose and protein reagent bloc~s are in positions P-6, P-7 and P-8 respectively. P-O represents a start position on the handle portion of the strip 16 and P-9 I represe~ts a stop position beyond the right hand end of strip 16, the significance of which will appear hereinafter.
The utilization of the test devices shown in Figure 1 with-in the framework of the present invention will be more fully described hereinafter as will the preparation of a test de-vice.
3~ Figure 2 is partially a block diagram showing $he various components of a test instrument as well as a perspective view of a test device as shown in Figure 1 and ce~tain xela~ed instrument c~mponents. This figure also ~hows the relationship of the test device to the test instrumentO In this fi~ure; the test device shown is the test device 10 of Figure 1 which comprises a code means 17 consisting of an opaque white block and reagent blocks 18a, 18b and 18c affixed to a strip of transparent film 16. The reagent blocks 18a, 18b, and 18c are paper matrices impreg-nated respec~ively with pH, pro~ein and occult blood speci-fic test reagents.
The instrument diagrammed in Figure 2 comprises a trans-parent glass or plastic table 43 sui~ab~ ~mounted for reciprocating movement and connected to a suita~le recipro-ca~ing actuator mechanism ~5, The actuator 45 is operable to move the ~able 43 across a light beam from a source 37 conveyed via fibre op~ics 40, as will be more fully des-cribed in Figures 3a to 3f. The ~able 43 may be provided with positioning means, such as guide lines 43a and 43b or suitable shoulder means ~not shown) to aid in proper place-ment of a test device 10 thereon.
Actuator 45 is controlled by a timer 21 via path 39 which is in turn controlled ~y a start switch 44 via path 46. ~ delay circuit, not shown, may be associated with timer 21 to provide a time lag between actuation of start switch 44 and initial movement of the table 43, during which ;~ time lag a test device 10 can be placed on table 43. The light emitted from fibre optics 40 is directed toward a photosensitive element 41 suitably mounted below table 43~
: Upon a~tuation of start switch 44, the table 43 is moved from its start position in the direction indicated in Figure 2 to cau~e the code block 17 of device 10 to move : into and interrupt the beam from light source 37, the light .. . . . . .
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1 thereupon being reflected back through fibre optics 40a to a photosensitive element 38 which is suitably mounted in a position above ~he level of table 43. As the code block 17 passes b~yond the light beam, said beam passes through the transparent film 16 in the space between code block 17 and the next adjacent reagent block 18a and through table 43, striking the photosensitive element 41. Reagent block 18a which for purposes o~ description will be assumed to have reacted specifically to the pH of ~he ~est fluid to produce a response, then moves into the light beam, again inter-rupting the light striking photosensitive element 41, Ligh~
is then reflected to photosensitive element 38 in an amount dependent upon the pH of the test fluid and the response of reagent block 18a. The reagent blocks 18b and 18c are then successively moved into readout position with movement o the table 43 in the direction indicated in Figure 2j and the response of the reagent in each block is sensed by the . photosensitive element 38. Figures 3a ~o 3f give a more detailed description of the movement of table 43 and the functioning of code blork 17 as a code means.
The response of photosensiti~e element 38 is an ; electrical signal which ,is conducted over path 22 to the . calibrate and amplify module 2~. The module 23 processes the initial calibrate signal from code block 17 as well as . 25 the subsequent signals generated from the reagent blocXs l 18a, 18b and 18c. The signal from photosensitive elemen~
41, which is interrupted when the light beam 1S interrupted by any of the blocXs 17, 18a, 18b and 18c, is conducted over path 42 to the code sensor and read signal module 19 .
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The logic by which the code sensor interprets the interrupted signal will be explained hereinafter; however, the photosensitive element 41 may also determine when the readout circuit is to process the output of the reaction sensing means. This is accornplished by suitable circuitry, to be described, which analyzes the response of the photo-sensitive element 41 as the test device 10 moves through the beam from light source 37, causing a light-to-dark-to-light cycle which is repeated for each of the test reagent areas.
With such circuitry the read command is given with the blocking of the beam from light source 37 to photosensi-tive element 41.
The timer 21 is connected to a test sequence selector 35 via path 36. Selector 35 interprets the signa~ received from the code sensor 19 via path 20 and identifies the test device 10 to a function generator 29 via path 28. Function generator 29 is connected to module 23 via path 24. The calibrate and amplify module 23 include~ a gating circuit controlled by test sequence selector 35 via path 27 to allow only the signals originating from the test reagent areas to reach function generator 29.
The signal output of function generator 29 is trans-mitted to a decoder 31 via path 30, said decoder also being connected to the test sequence selector 35 via path 34.
The decoder 31 processes the output signals rom the func~
tion generator 29 and instructs a printer 33 via path 32 to give a visual quantitative representation of the readout from function generator 29.
Referr~ng now to Figures 3a to 3f, the following is ;, 30 a de~ailed description of how code block 17 of Figures 2 and 4 functions as a code means for test device 10. In its :
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1 start position as shown in Figure 3a, table 43 is position-ed such ~ha~ the ligh~ beam emitting from fiber optics 40 in no ~ay impinges thereon and simply strikes photosensitive element 41. A test device 10 is contacted with a test fluid and placed on table 43 as shown in Figure 3a. Actuator 45 (not shown in Figures 3a to 3e) then moves table 43 and test device 10 in the direction shown by the arrow in Figure 3a to their extreme le~tward position shown in Figure 3b. In this position the light beam passes through the transparent film 16 and glass table 43 and again impinges upon photo-sensitive element 41.
Upon reaching this position the actuator 45 is reversed and appropriate electronic circuity associated with photo-sensitive elements 41 and 38 activated, and the table 43 and test device 10 commence movement in the direction of the arrow shown in Figure 3b. As the table 43 and device 10 move across the light beam, code block 17, whlch is highly reflective and preferably white, in position P4 ~see Figu~e 1~, interrupts the light impinging upon-photosensitiv~ ele-, ment 41 and re1ects light back to photosensitive element 38 as shown in Figure 3c. The amount of light reflected , back to photosensitive element 38 is used to calibrate the instrument, as will be described hereinafter, and interrup-tion of the light beam striking photosensitive element 41 is interpreted by ~he instrument electronics as representing a block in position P4 ~See Figure 1).
The device lO continues movement in the direction shown in Figure 3d and ~he light beam again strikes element 41 upon the passage of block 17 therethrough. C~ntinuing light striking element 41 when the device 10 is in position P5 is ~' interpreted by the instrument as no block present in this ~, .
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1 position and the instrument records this fact. Continuing movement of device 10 causes reagent block 18a in position P6 ~Figure 1~ to interrupt the light beam. It will be assumed for purposes of explanation that the reagent in this block has specifically responded to the pH of the fluid being tested to give a chromogenic change. The ligh~ re-flected back from block 18a varies according to the pH of the test fluid. This is received by photosensitive element 38, and the resultant signal is processed as will be ex-` 10 plained hereinafter. The device 10 continues its travel~
moving block l~a beyond the ligh~ beam so that it again passes through tra~spaTent ~ilm 16 and glass table 43 and ., '- stri~es photosensitive element 41 as shown in Figure 3f.
Continued movement of table 43 causes this procedure to 4e repeaked with respect to blocks 18b and 18c, which will be assumed for purposes of explanation to have respectively responded to protein and blood in the test fluid, af'ter which the table,43 and device 10 return to the noTmal staTt-ing position shown in Figure 3a.
It will be appreciated that the initial movement of the table 43 and device 10 in the direction shown in Figure 3a can be accom,plished by manual movemen~ thereof as opposed to a motor drive.
Considering Figures l, 2 and 3a to 3f, the logic for the coding of the device and instrument can be desc~ibed as follows: The test device starts its travel with the light beam at position P-0. If the photosensitive element 41 senses that the light beam is interrupted by an opaque area in position P~l, and if it subsequently senses that the ~,~ 30 light beam is int~rrup,ted by an opaque area at position P-2 the test sequence selector 35 makes the decision that the .:
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1 test device being read is test device number l shown în Figure 1. Accordingly~ the electronics of the instrument are programmed to read pH, protein, glucose, ketone, bili-rubin, occult blood and urobilinogen test reagent areas, in ~hat order, as the device being read moves successively through positions P-2 to P-8 to stop at position P-9. If, on the other hand, the instrument does not see an opaque area until the device being read reaches position P-6 and at position P-7 senses another opaque area, the sequence selec-to~ 35 identifies the device being read as device 14, and the instrument is programmed to read glucose and protein as the device moves successively through positions P 7 and P-8 to stop position P-9.
The opaque code block 17 may have ~wo functions: one is for identifying the particular test de~ice to the instru-ment as p~eviously described, and the other is to calibrate the instrument Calibration is performed by the reaction sensor 38 looking at the calibration block 17 sampling the reflected light and converting the reflected l-ight level into electrical signals used to standardize the electronic circuitry pre-programmed for each of the test devices.
The following is a description of a speci~ic embodi-ment of the present invention. It will be appreciated that -this is merely exemplary and that numerous changes can be made therein.
With reference to Figure 4, the system is initially calibrated for use by inserting a first test device such '~ as for example strip 1 in Figure 1, which has been dipped into a zero calibra~ion solution and ~hereafter inserting a second test device which has been dipped into a high posi-ti~e solution~ wheTeby the system is calibrated to measure .. ..... .. .
;37~
1 input reactions which fall within the ran~e selec~ed by the use of the two calibration test de~ices. More specifically, the first or zero calib~ation test device may, for example9 be dipped in a normal urine sample to thereby provide nega-tive responses on each reagent b~ock thereof, and the second or high positive calibratlon test device may be dipped into solutlon such as a synthetic urine which provides ~he maxi-mum high positive values foT each reagent block thereof.
More specifically, with placement of the zsro calibra-tion test de~ice 10 on the table 43 and advancement of the test device 10 to move the code block 17 into readout posi-tion, photosensor 41 detects the code block 17 and provides suitable signals o~er path 42 to the code sensor circuit 19.
The code sensor circuit 19 in a more basic embodiment may comprise a simple stepping switch which advances one count ~! as each of the successive blocks is mov~d into readout posi-tion. In such arrangement, the count output of the counter in the sensor 19 in effect represents a position on the test device, Thus, if each of the reagent a-reas shown in test device 1, Figure 1, has the same assigned posi~ion on . each strip, the count output will therefore identify such reagent.
I In a more sophistic~ted embodiment, the photosensor means 41 may comprise a plurality o sensors which electroni-cally or mechanically detect which one of the strips shown ' in Figure 1 is being processed, and in such event the count ' output from the code sensor 19 will represent correspond-~` ingly different reagents for the different test devicesO For ~` the purpose of convenience the more basic embodiment is described hereinafter.
.
. , ~ . . . .
.
~, ~ ~7 ~3 l With continued movement of the test device 10 to move the first reagent block, such as 18a, beneath the read head, the light beam is reflected back to photosensor 38 which, via path 22, provides an output signal which has a value re-lated to the amount of light reflected by reagent block 18a.
As shown in Figure 4 the resultant signal is fed to the in-put of a voltage controlled oscillator 5~ of ~he calibratç
and amplify circuit 23 for translation into an output signal whlch will vary in frequency from approxlmately 10 to 100 KHz with the value o~ the voltage of the signal inpu~ ~here-to by photosensor 38 The frequency output o~ voltage controlled oscillator 50 is fed through gate S2 under the control of the output signal from sequence control circuit 54 via path 27. In ad-dition, as the block 18a is moved into position, the light beam is interrupted, and a read si~nal is output by photo-sensor 41 over pa~h 42 to the input of a code sensor circuit 19. ' :
Sequence control circuit 54 via path 64 inputs a sig-nal to ~imer 21 which responsively provides a signal for 1/10 of a second over path 70 and path 27 to gate 52, enabling the same to gate, or a period of 1/10 o~ a second, the out-put signal of the voltage controlled oscillator 50, the latter sign~l representing the amount of light reflected by i ~he reagent block 18a.
The frequency signal output o gate 52 as applied over .;~ conductor 72 is fed to a counter 74, which in one embodiment comprised a pair of logic circuits, commercially available as 74197, serially connected to effect the division of the ~ 30 frequency signa~ output by a factor of 256. The output : of coun~er 74 is fed to a zero register 78 over path 76.
. - 19 -', ' ~ 7 ~7~
1 Thus, for a gated period of 1/10 second, the zero register 78 will count the pulses output from counter 74 which repre-sent the amount of reflected light from the first reagent block of the zero calibration test device.
- At the end of 1/10 of a second readout period~ the timer 21 removes the timing signal from path 70 and sequence circuit 54.removes the gating signal from gate 52 to termi-nate the signal input to counter 74 and register 78. In addition, sequence circuit 54 via load path 80 enables the eight bit count which exists on the output of the zero regis-ter 78 to be transferred to a buffer register 82. The same load signal from sequence circuit 54 is also fed oveT con-ductor 80 to the load input of a memory circuit 84 to cause the parallel transfer of the eight bit output of buffer reg-ister 82 into a first section of a memory 84 which has been I preassigned to store the zero calibration word. The zero . word fo~ the fiTst reagent block has now been stored in memory 84. Bufer register 82 may comprise ~wo logic cir-cuits, commercially available as 741979 having ~heir eight . 20 bit input parallel connected to the eight bit output of the ¦ zero register 78, and memory circuit 84 may comprise a pair of 7489 devices which have their eight bit inputs parallel I connected to the eight bit outputs of buffer register 82.
: ! It will be apparent that as the actuator 45 causes the 1 25 table 43 to sequentially advance the blocks on the carrier strip into ~he readout position, the systcm will operate to provide a zero word in the corresponding section of memory 84 for use in the testing of unknown blocks. In one embodi-ment, up to seven diffe~ent types of reagent blocks may be included on the various strips, and accordingly the memory 84 was provided with the capacity to store eight different ,:
~ 7~'.3 1 words to represent the zero value for the eight differen~
reagents, and eight different words which rep~esent the high positive value for each such reagent.
A test device which has been dipped into the high -positive solution is now placed on the carrier for the purpose of providing a word input into memory 84 which i represen~s ~he high positive value or each of the reagent ; blocks such as 18a, 18b and 18c on the test device 10.
i As the start button 44 is operated, and actuatoT 45 advances code block 17 to the readout position, the code sensor circuit 19 operates to provide output signals over path 60 to identiy to the system the particular test device being processed.
Photosensor 41 in detecting the entry of the block 18a into the readout position outputs a read signal via path 42 to cause the code sensor 19 to output a signal via path 20 to the sequence circuit 54 which outputs a signal over path 86 to the load input of zero register 78. As a result, the parallel bit output of the first zero word in ; 20 memory 84 is input to ~he zero register 78. Memory 84 outputs the complement of the number stored in memory 84 over path 102, and as a result, the input to the zero regis-ter 78 is the 256 comple~ent of the number which was stored in memDry 84 in the zero calibration step~ As will be shown, the purpose o the transfer of the complement of the zero calibration word to the zero registe~ 78 effects sub-traction o the value represented by such word from the high positive calibration signal which is to be now provided.
.~, . .
, - 21 -.
-~ . : ., . , - . , - . . .
:~4737~
l That is, with the advance-of block 18a into the readout position photosensor 38 detects the light ref~ected and outputs over path 22 to the.voltage controlled oscillator 50 a signal having a value related to the a~ount of re-$1ected light. The output of the voltage controlled oscil-lator 50 is gated to counter 74 for l/10 of-a second under the control of timer 21 and sequence circuit 54 in the manner heretofore described. Counter 74, in turn, outputs a pulse to the zero ~egister 78 fOT each 256 input pulses, which signals represent the high positive ~alue in the calibration step for the first block 18a.
As the signals are input to the z~rs r~gister 78 as a result of the inputting of a word ~epresenta~ive.of the high positive value for the first block 18a, the zero ~ 15 register 78 is serially clocked from the value o~ the comple- ment signal stored therein toward the total count capacity of the registe~ 78 (count 255 in the present example). The input signal over path 76 after count 255 is reached in ¦ ; register 78 results in an empty signal output oveT pa~h 90 to the clock input of a flip-flop circuit 92. Flip-flop circuit 92, vîa the Q output and path 94, enables a gate 96 , I
to gate the signals output from voltage controlled oscilla-tor 50 to the clock input on a divider register 100 via p.ath 1 98.
: ! 25 Digressing briefly, and by way of example, assuming. reagent block 18a is responsive to pH, and that the zero , . , count represented by the word stored in memory 84 as a result of zero calibration was a numerical value of 20, and .. that the numerical value of the word stored in memory 84to represent the high positive value was 200, the complement input to zero register 78 is 256 minus 20 or 236 at the ~ - 22 -`:
.. . .
~737~) 1 start of the count input during the high positive readout for reagent block 18a. As the signals are now input over path 76 to the ze~o register 78 during the high positive c~llbration, the count advances from the complement input 236, and as the count is advanced by the pulse inpu~ over path 76 to a count of 256, a pulse over empty conductor 90 to the ~lip-flop 92 causes the further pulses output from the voltage controlled oscillator 50 to be fed ove~ gate 96 and path 98 to the divideT register 100.
The divider register lO0 may be a pair of logic cir-cuits, commercially available as 74197, which are serially connected to the output path 98 and which therefore outputs a pulse over path 104 in response to each 256 counts input over path 98. .The signal output over conductoT 104 after each 256 counts input to divider register 100 is fed to a one-shot clrcuit 106, which is of the type commercially available as a 74121, the output of which is connected over path 108 to the clock input of buffer register 82. The . buffer register 82 thus acts as a counter for the high posi-: Z0 tive value minus the zero calibration value as divided by . 256.
- As the test device is advanced to bring successive ones o~ the reagent blocks 18b and 18c. (etc.) beneath the .~ readout position, successive high positive eight bit words 25 . ` are stored in memory 84 to indicate the high positive value for each of the different reagent blocks of the test device.
Summarily, at this. time memory 84 includes up to seven words which represent the zero value of each of the reagents .which is to be tested, and the seven words which re~resent the high positive value of each of the reagents to be tested.
.
~ 3 -,. ~ : ' . -, 1 Digressing briefly at this time, reference is made to a read only memory 110 which is a device commercially available as an IM 5600 and which is preloaded for use with the different thresholds of each of the reagents. More specifically, with reference to the Table shown below, it will be seen that a pH test block may have five differen~
reaction ranges respectively represented by correspondingly different counts output by the divider register 100 (i.e., counts 0-255). The read only memory 110 is preloaded in a known manner to indicate the discrete thresholds for each of the different reagents. Thus, in a typical example, the first pH reaction range is shown to be 0-2, the second pH
reaction range is shown to be 3-44.
,, .
I TABLE
, j . ~ - .
1 15 ~ Decode Points aRange) i
: , ~ ~, . .; .
~ 3 ~ ~
hereinafter, The code means may also simply consist of an opaque area, the placement of which is distinctive for each test device. Other code means and formats will be apparent from the above and the ensuing di~closure.
Exemplary of the various types of indicia which may serve as code means for the ~est devices o the present invention are: s~mbols such as diamonds, squares, circles, and so ~orth; several marks of the same ~ype such as a series of parallel bars; names, such as ~he name of the particular test, iOeO glucose, protein, and so forth;
colors; numbers; slots; holes, and so forth. The only limiting factor in selec~ing the indicia for the code m~ans is that the instrument code sensing means mus~ be capable of recognizing the indicia and dis~inguishing one from another as well as coxrela~ing the particular indicia to the test device.
-! A preferable code means is shown in Figure 1 and will be described more fully later; however, basically this preferable means comprises an opaque area or code blGck placed on a transparent strip or carrier in predetermined spacial relationship with one or more reagent areas ~r blocks on the same strip, the location of the reagent block or blocks with respect to the code block being dif-~erent for each of the test devices used with the test instrument. In use, a test device pre~ented to the in~tru-ment is advanced to a position which interrupts a light path between a light source and light sensing means, such as a photosensitive element, the relative positions oE the code block and the reagent block being indicative o~ a 30 specific test device, `
..
~737~
l Referring now to the test instrument, there are four facets of this instrument which will be-described. The first is that the instrument must be capable of receiving or is adapted to receive the test devices of the present invention, Secondly, the instrument must have a code sens-ing means associated therewith in order to read the code means of the test device and translate this signal into a calibration reference signal and a command for the in-strument to read the particular test reagent or reagents of the test device. Third, the instrument must have a reaction sensing means or receptor to detect ~nd accumulate the response from the reaction of the test reagent and the constituent in the test fluid being detected. The fourth component or facet of the instrument is the readout means which translates the response of ~he code sensing means and -the reaction sensing means into a value which is indicative of the quantity of the constituent being assayed in the test fluid.
These facets or components will now be individually discussed.
The irst facet or aspect of the test instrument is that it must be able to receive ~he test de~ice relating thereto. In other words, if the test de~ice response is a color change on a paper matrix, the test instrument must be capable of receiving the paper mat~ix, and the reaction sensing means of the instrument must be capable of reading the response, for example, by reflectance spectrophotometry.
The code sensing means may be any electronic device, . .
component or circuit which can readJ identify and elec-tronically process the indicia of the code means of the test device to enable the instrument to identify the . . . . . .
.
~ 7 ~
1 particular test being presented. The code sensing means may also perform other functions such as that of a light sensitive detector which can be used to command the instru-ment to read a response at a particular time. This will be explained more fully hereinafter.
More specifically, the code sensing means may be a light sensitive detector comprising a light source direct-ing a light beam at a photosensitive element or pho~osensor or it may be a complex word or symbol reader such as those used to read numbers on commercial o~ financial instruments or notes. Additionally, the code sensing means may be a color sensing device which identifies a pa~ticular color or shade of color and correlates the color or shade with a particular test device, Shades of gray may also be used to ide,ntify the device. The code sensing means may also be one which identifies a particular number of parallel bars or opaque marks on the test device and accordingly identi-fies a specific device. It will be appreciated from the above, that numerous code means and code sensing means may , 20 be used in conjunction with the present invention, The third part of the test instrument is the reaction sensing means. This component or means basically comprises the part of the test ins,trument which recognizes and quan-titatively measures the extent of the chemical reaction 2S be~ween ~he test reagents associated with the test device and the particular constituents or chemicals being tested for in the test fluid. The reaction sensing means may simply be a photosensitive element or photosensor such as a photoelectric cell which measures the light reflected from a reagent block after a chromogenic reaction between the constituent and the test reagent, or it may comprise more complex analytical instrumentationO The controlling con-_ g 737~
1 sideration is that the reaction sensing means must be cap-able of detecting and quantitatively measuring the above -noted chemical reaction, and of generating a signal which is supplied to the input of the readout means which will now be described.
The readout means correlates the output from the code sensing means and the reaction s~nsing m~ans such that (1) the instrument recognizes the particular tes~ device being presented and (2) the signal or signals generated from the reaction sensing means are processed to give an indication of the amount of a particular constituent in the fluid being tested.
A particularly advantageous and preferable readout means of the test instrument of the present invention comprises the use of an apparatus or electronic circuit comprising an input scaler, an access scaler and a read -only me~ory connected in such a fashion that the signal or output from the reaction sensing means is decoded to provide an indication of a characteris~ic or significant quantitative value or range of values for the test fluid, such as p~, clinical levels of glucose, protein, and so - forth. Such circuitry is further described in the specific embodiments which follow' Referring now to Figure 1 of the dTawing, each of the test devices numbered 1 to 15 illustrated therein comprises a strip of transparent plastic film which forms a base member 16 to one end portion o which one or more square paper matrices 18 is affixed. The other end portion of mem-ber 16 provides a handle for the test device- The matrices 18 are incorporated with test rea~ents which ~r~ ~n~cifi-cally reactable with various characteristiCS or constituents . ., , ~-,- ~; - . - , :.
.~ .
~;~3~ ~7 ~
1 in test fluids such ~s urine. In the drawing, pH repTesents a matrix incorporated with reagent to form a reagent bl~ck for determination of the pH, while P, G, K, BI, BL and U
respectively r~present reagent blocks which are specifically reactable with protein, glucose, ketones, bilirubin, occult blood and urobilinogen. In the test devices shown, the code means is an opaque area or printed area 17 which is identi-fied in the drawing by the word "code".
In Figu~e 1 $he test device 1 is shown as having seven test blocks 18 and a code block 17 disposed in spaced Tela-tion on strip 16 beginning at the ri~ht hand end thereof.
The positions of the code block and reagent blocks of device 1 are indicated by the letters P-l to P-8 shown thereabove. It will be observed that with the devices 1 to 15 disposed in the vertical alignment shown, each of the devices 2 to 15 has one or more spaced reagent blocks there-; on, beginning at the right hand end thereof, and one code ; block. Each of th~ reagent blocks and code blocks is in vertical alignment with one of the positions P-l to P-8.
For example, on test device 7, the code block is in position P-3 and the pH, glucose and protein reagent bloc~s are in positions P-6, P-7 and P-8 respectively. P-O represents a start position on the handle portion of the strip 16 and P-9 I represe~ts a stop position beyond the right hand end of strip 16, the significance of which will appear hereinafter.
The utilization of the test devices shown in Figure 1 with-in the framework of the present invention will be more fully described hereinafter as will the preparation of a test de-vice.
3~ Figure 2 is partially a block diagram showing $he various components of a test instrument as well as a perspective view of a test device as shown in Figure 1 and ce~tain xela~ed instrument c~mponents. This figure also ~hows the relationship of the test device to the test instrumentO In this fi~ure; the test device shown is the test device 10 of Figure 1 which comprises a code means 17 consisting of an opaque white block and reagent blocks 18a, 18b and 18c affixed to a strip of transparent film 16. The reagent blocks 18a, 18b, and 18c are paper matrices impreg-nated respec~ively with pH, pro~ein and occult blood speci-fic test reagents.
The instrument diagrammed in Figure 2 comprises a trans-parent glass or plastic table 43 sui~ab~ ~mounted for reciprocating movement and connected to a suita~le recipro-ca~ing actuator mechanism ~5, The actuator 45 is operable to move the ~able 43 across a light beam from a source 37 conveyed via fibre op~ics 40, as will be more fully des-cribed in Figures 3a to 3f. The ~able 43 may be provided with positioning means, such as guide lines 43a and 43b or suitable shoulder means ~not shown) to aid in proper place-ment of a test device 10 thereon.
Actuator 45 is controlled by a timer 21 via path 39 which is in turn controlled ~y a start switch 44 via path 46. ~ delay circuit, not shown, may be associated with timer 21 to provide a time lag between actuation of start switch 44 and initial movement of the table 43, during which ;~ time lag a test device 10 can be placed on table 43. The light emitted from fibre optics 40 is directed toward a photosensitive element 41 suitably mounted below table 43~
: Upon a~tuation of start switch 44, the table 43 is moved from its start position in the direction indicated in Figure 2 to cau~e the code block 17 of device 10 to move : into and interrupt the beam from light source 37, the light .. . . . . .
.
~ 37 ~
1 thereupon being reflected back through fibre optics 40a to a photosensitive element 38 which is suitably mounted in a position above ~he level of table 43. As the code block 17 passes b~yond the light beam, said beam passes through the transparent film 16 in the space between code block 17 and the next adjacent reagent block 18a and through table 43, striking the photosensitive element 41. Reagent block 18a which for purposes o~ description will be assumed to have reacted specifically to the pH of ~he ~est fluid to produce a response, then moves into the light beam, again inter-rupting the light striking photosensitive element 41, Ligh~
is then reflected to photosensitive element 38 in an amount dependent upon the pH of the test fluid and the response of reagent block 18a. The reagent blocks 18b and 18c are then successively moved into readout position with movement o the table 43 in the direction indicated in Figure 2j and the response of the reagent in each block is sensed by the . photosensitive element 38. Figures 3a ~o 3f give a more detailed description of the movement of table 43 and the functioning of code blork 17 as a code means.
The response of photosensiti~e element 38 is an ; electrical signal which ,is conducted over path 22 to the . calibrate and amplify module 2~. The module 23 processes the initial calibrate signal from code block 17 as well as . 25 the subsequent signals generated from the reagent blocXs l 18a, 18b and 18c. The signal from photosensitive elemen~
41, which is interrupted when the light beam 1S interrupted by any of the blocXs 17, 18a, 18b and 18c, is conducted over path 42 to the code sensor and read signal module 19 .
,''' . ... . ., ~ . :. - :
'f~ ib~t7~
The logic by which the code sensor interprets the interrupted signal will be explained hereinafter; however, the photosensitive element 41 may also determine when the readout circuit is to process the output of the reaction sensing means. This is accornplished by suitable circuitry, to be described, which analyzes the response of the photo-sensitive element 41 as the test device 10 moves through the beam from light source 37, causing a light-to-dark-to-light cycle which is repeated for each of the test reagent areas.
With such circuitry the read command is given with the blocking of the beam from light source 37 to photosensi-tive element 41.
The timer 21 is connected to a test sequence selector 35 via path 36. Selector 35 interprets the signa~ received from the code sensor 19 via path 20 and identifies the test device 10 to a function generator 29 via path 28. Function generator 29 is connected to module 23 via path 24. The calibrate and amplify module 23 include~ a gating circuit controlled by test sequence selector 35 via path 27 to allow only the signals originating from the test reagent areas to reach function generator 29.
The signal output of function generator 29 is trans-mitted to a decoder 31 via path 30, said decoder also being connected to the test sequence selector 35 via path 34.
The decoder 31 processes the output signals rom the func~
tion generator 29 and instructs a printer 33 via path 32 to give a visual quantitative representation of the readout from function generator 29.
Referr~ng now to Figures 3a to 3f, the following is ;, 30 a de~ailed description of how code block 17 of Figures 2 and 4 functions as a code means for test device 10. In its :
` ' ~ ~7 ~ ~
1 start position as shown in Figure 3a, table 43 is position-ed such ~ha~ the ligh~ beam emitting from fiber optics 40 in no ~ay impinges thereon and simply strikes photosensitive element 41. A test device 10 is contacted with a test fluid and placed on table 43 as shown in Figure 3a. Actuator 45 (not shown in Figures 3a to 3e) then moves table 43 and test device 10 in the direction shown by the arrow in Figure 3a to their extreme le~tward position shown in Figure 3b. In this position the light beam passes through the transparent film 16 and glass table 43 and again impinges upon photo-sensitive element 41.
Upon reaching this position the actuator 45 is reversed and appropriate electronic circuity associated with photo-sensitive elements 41 and 38 activated, and the table 43 and test device 10 commence movement in the direction of the arrow shown in Figure 3b. As the table 43 and device 10 move across the light beam, code block 17, whlch is highly reflective and preferably white, in position P4 ~see Figu~e 1~, interrupts the light impinging upon-photosensitiv~ ele-, ment 41 and re1ects light back to photosensitive element 38 as shown in Figure 3c. The amount of light reflected , back to photosensitive element 38 is used to calibrate the instrument, as will be described hereinafter, and interrup-tion of the light beam striking photosensitive element 41 is interpreted by ~he instrument electronics as representing a block in position P4 ~See Figure 1).
The device lO continues movement in the direction shown in Figure 3d and ~he light beam again strikes element 41 upon the passage of block 17 therethrough. C~ntinuing light striking element 41 when the device 10 is in position P5 is ~' interpreted by the instrument as no block present in this ~, .
,`
~ .
' ' . :'. '' : ..
~737~
1 position and the instrument records this fact. Continuing movement of device 10 causes reagent block 18a in position P6 ~Figure 1~ to interrupt the light beam. It will be assumed for purposes of explanation that the reagent in this block has specifically responded to the pH of the fluid being tested to give a chromogenic change. The ligh~ re-flected back from block 18a varies according to the pH of the test fluid. This is received by photosensitive element 38, and the resultant signal is processed as will be ex-` 10 plained hereinafter. The device 10 continues its travel~
moving block l~a beyond the ligh~ beam so that it again passes through tra~spaTent ~ilm 16 and glass table 43 and ., '- stri~es photosensitive element 41 as shown in Figure 3f.
Continued movement of table 43 causes this procedure to 4e repeaked with respect to blocks 18b and 18c, which will be assumed for purposes of explanation to have respectively responded to protein and blood in the test fluid, af'ter which the table,43 and device 10 return to the noTmal staTt-ing position shown in Figure 3a.
It will be appreciated that the initial movement of the table 43 and device 10 in the direction shown in Figure 3a can be accom,plished by manual movemen~ thereof as opposed to a motor drive.
Considering Figures l, 2 and 3a to 3f, the logic for the coding of the device and instrument can be desc~ibed as follows: The test device starts its travel with the light beam at position P-0. If the photosensitive element 41 senses that the light beam is interrupted by an opaque area in position P~l, and if it subsequently senses that the ~,~ 30 light beam is int~rrup,ted by an opaque area at position P-2 the test sequence selector 35 makes the decision that the .:
,............. : , ~ \ .
~ 7 ~
1 test device being read is test device number l shown în Figure 1. Accordingly~ the electronics of the instrument are programmed to read pH, protein, glucose, ketone, bili-rubin, occult blood and urobilinogen test reagent areas, in ~hat order, as the device being read moves successively through positions P-2 to P-8 to stop at position P-9. If, on the other hand, the instrument does not see an opaque area until the device being read reaches position P-6 and at position P-7 senses another opaque area, the sequence selec-to~ 35 identifies the device being read as device 14, and the instrument is programmed to read glucose and protein as the device moves successively through positions P 7 and P-8 to stop position P-9.
The opaque code block 17 may have ~wo functions: one is for identifying the particular test de~ice to the instru-ment as p~eviously described, and the other is to calibrate the instrument Calibration is performed by the reaction sensor 38 looking at the calibration block 17 sampling the reflected light and converting the reflected l-ight level into electrical signals used to standardize the electronic circuitry pre-programmed for each of the test devices.
The following is a description of a speci~ic embodi-ment of the present invention. It will be appreciated that -this is merely exemplary and that numerous changes can be made therein.
With reference to Figure 4, the system is initially calibrated for use by inserting a first test device such '~ as for example strip 1 in Figure 1, which has been dipped into a zero calibra~ion solution and ~hereafter inserting a second test device which has been dipped into a high posi-ti~e solution~ wheTeby the system is calibrated to measure .. ..... .. .
;37~
1 input reactions which fall within the ran~e selec~ed by the use of the two calibration test de~ices. More specifically, the first or zero calib~ation test device may, for example9 be dipped in a normal urine sample to thereby provide nega-tive responses on each reagent b~ock thereof, and the second or high positive calibratlon test device may be dipped into solutlon such as a synthetic urine which provides ~he maxi-mum high positive values foT each reagent block thereof.
More specifically, with placement of the zsro calibra-tion test de~ice 10 on the table 43 and advancement of the test device 10 to move the code block 17 into readout posi-tion, photosensor 41 detects the code block 17 and provides suitable signals o~er path 42 to the code sensor circuit 19.
The code sensor circuit 19 in a more basic embodiment may comprise a simple stepping switch which advances one count ~! as each of the successive blocks is mov~d into readout posi-tion. In such arrangement, the count output of the counter in the sensor 19 in effect represents a position on the test device, Thus, if each of the reagent a-reas shown in test device 1, Figure 1, has the same assigned posi~ion on . each strip, the count output will therefore identify such reagent.
I In a more sophistic~ted embodiment, the photosensor means 41 may comprise a plurality o sensors which electroni-cally or mechanically detect which one of the strips shown ' in Figure 1 is being processed, and in such event the count ' output from the code sensor 19 will represent correspond-~` ingly different reagents for the different test devicesO For ~` the purpose of convenience the more basic embodiment is described hereinafter.
.
. , ~ . . . .
.
~, ~ ~7 ~3 l With continued movement of the test device 10 to move the first reagent block, such as 18a, beneath the read head, the light beam is reflected back to photosensor 38 which, via path 22, provides an output signal which has a value re-lated to the amount of light reflected by reagent block 18a.
As shown in Figure 4 the resultant signal is fed to the in-put of a voltage controlled oscillator 5~ of ~he calibratç
and amplify circuit 23 for translation into an output signal whlch will vary in frequency from approxlmately 10 to 100 KHz with the value o~ the voltage of the signal inpu~ ~here-to by photosensor 38 The frequency output o~ voltage controlled oscillator 50 is fed through gate S2 under the control of the output signal from sequence control circuit 54 via path 27. In ad-dition, as the block 18a is moved into position, the light beam is interrupted, and a read si~nal is output by photo-sensor 41 over pa~h 42 to the input of a code sensor circuit 19. ' :
Sequence control circuit 54 via path 64 inputs a sig-nal to ~imer 21 which responsively provides a signal for 1/10 of a second over path 70 and path 27 to gate 52, enabling the same to gate, or a period of 1/10 o~ a second, the out-put signal of the voltage controlled oscillator 50, the latter sign~l representing the amount of light reflected by i ~he reagent block 18a.
The frequency signal output o gate 52 as applied over .;~ conductor 72 is fed to a counter 74, which in one embodiment comprised a pair of logic circuits, commercially available as 74197, serially connected to effect the division of the ~ 30 frequency signa~ output by a factor of 256. The output : of coun~er 74 is fed to a zero register 78 over path 76.
. - 19 -', ' ~ 7 ~7~
1 Thus, for a gated period of 1/10 second, the zero register 78 will count the pulses output from counter 74 which repre-sent the amount of reflected light from the first reagent block of the zero calibration test device.
- At the end of 1/10 of a second readout period~ the timer 21 removes the timing signal from path 70 and sequence circuit 54.removes the gating signal from gate 52 to termi-nate the signal input to counter 74 and register 78. In addition, sequence circuit 54 via load path 80 enables the eight bit count which exists on the output of the zero regis-ter 78 to be transferred to a buffer register 82. The same load signal from sequence circuit 54 is also fed oveT con-ductor 80 to the load input of a memory circuit 84 to cause the parallel transfer of the eight bit output of buffer reg-ister 82 into a first section of a memory 84 which has been I preassigned to store the zero calibration word. The zero . word fo~ the fiTst reagent block has now been stored in memory 84. Bufer register 82 may comprise ~wo logic cir-cuits, commercially available as 741979 having ~heir eight . 20 bit input parallel connected to the eight bit output of the ¦ zero register 78, and memory circuit 84 may comprise a pair of 7489 devices which have their eight bit inputs parallel I connected to the eight bit outputs of buffer register 82.
: ! It will be apparent that as the actuator 45 causes the 1 25 table 43 to sequentially advance the blocks on the carrier strip into ~he readout position, the systcm will operate to provide a zero word in the corresponding section of memory 84 for use in the testing of unknown blocks. In one embodi-ment, up to seven diffe~ent types of reagent blocks may be included on the various strips, and accordingly the memory 84 was provided with the capacity to store eight different ,:
~ 7~'.3 1 words to represent the zero value for the eight differen~
reagents, and eight different words which rep~esent the high positive value for each such reagent.
A test device which has been dipped into the high -positive solution is now placed on the carrier for the purpose of providing a word input into memory 84 which i represen~s ~he high positive value or each of the reagent ; blocks such as 18a, 18b and 18c on the test device 10.
i As the start button 44 is operated, and actuatoT 45 advances code block 17 to the readout position, the code sensor circuit 19 operates to provide output signals over path 60 to identiy to the system the particular test device being processed.
Photosensor 41 in detecting the entry of the block 18a into the readout position outputs a read signal via path 42 to cause the code sensor 19 to output a signal via path 20 to the sequence circuit 54 which outputs a signal over path 86 to the load input of zero register 78. As a result, the parallel bit output of the first zero word in ; 20 memory 84 is input to ~he zero register 78. Memory 84 outputs the complement of the number stored in memory 84 over path 102, and as a result, the input to the zero regis-ter 78 is the 256 comple~ent of the number which was stored in memDry 84 in the zero calibration step~ As will be shown, the purpose o the transfer of the complement of the zero calibration word to the zero registe~ 78 effects sub-traction o the value represented by such word from the high positive calibration signal which is to be now provided.
.~, . .
, - 21 -.
-~ . : ., . , - . , - . . .
:~4737~
l That is, with the advance-of block 18a into the readout position photosensor 38 detects the light ref~ected and outputs over path 22 to the.voltage controlled oscillator 50 a signal having a value related to the a~ount of re-$1ected light. The output of the voltage controlled oscil-lator 50 is gated to counter 74 for l/10 of-a second under the control of timer 21 and sequence circuit 54 in the manner heretofore described. Counter 74, in turn, outputs a pulse to the zero ~egister 78 fOT each 256 input pulses, which signals represent the high positive ~alue in the calibration step for the first block 18a.
As the signals are input to the z~rs r~gister 78 as a result of the inputting of a word ~epresenta~ive.of the high positive value for the first block 18a, the zero ~ 15 register 78 is serially clocked from the value o~ the comple- ment signal stored therein toward the total count capacity of the registe~ 78 (count 255 in the present example). The input signal over path 76 after count 255 is reached in ¦ ; register 78 results in an empty signal output oveT pa~h 90 to the clock input of a flip-flop circuit 92. Flip-flop circuit 92, vîa the Q output and path 94, enables a gate 96 , I
to gate the signals output from voltage controlled oscilla-tor 50 to the clock input on a divider register 100 via p.ath 1 98.
: ! 25 Digressing briefly, and by way of example, assuming. reagent block 18a is responsive to pH, and that the zero , . , count represented by the word stored in memory 84 as a result of zero calibration was a numerical value of 20, and .. that the numerical value of the word stored in memory 84to represent the high positive value was 200, the complement input to zero register 78 is 256 minus 20 or 236 at the ~ - 22 -`:
.. . .
~737~) 1 start of the count input during the high positive readout for reagent block 18a. As the signals are now input over path 76 to the ze~o register 78 during the high positive c~llbration, the count advances from the complement input 236, and as the count is advanced by the pulse inpu~ over path 76 to a count of 256, a pulse over empty conductor 90 to the ~lip-flop 92 causes the further pulses output from the voltage controlled oscillator 50 to be fed ove~ gate 96 and path 98 to the divideT register 100.
The divider register lO0 may be a pair of logic cir-cuits, commercially available as 74197, which are serially connected to the output path 98 and which therefore outputs a pulse over path 104 in response to each 256 counts input over path 98. .The signal output over conductoT 104 after each 256 counts input to divider register 100 is fed to a one-shot clrcuit 106, which is of the type commercially available as a 74121, the output of which is connected over path 108 to the clock input of buffer register 82. The . buffer register 82 thus acts as a counter for the high posi-: Z0 tive value minus the zero calibration value as divided by . 256.
- As the test device is advanced to bring successive ones o~ the reagent blocks 18b and 18c. (etc.) beneath the .~ readout position, successive high positive eight bit words 25 . ` are stored in memory 84 to indicate the high positive value for each of the different reagent blocks of the test device.
Summarily, at this. time memory 84 includes up to seven words which represent the zero value of each of the reagents .which is to be tested, and the seven words which re~resent the high positive value of each of the reagents to be tested.
.
~ 3 -,. ~ : ' . -, 1 Digressing briefly at this time, reference is made to a read only memory 110 which is a device commercially available as an IM 5600 and which is preloaded for use with the different thresholds of each of the reagents. More specifically, with reference to the Table shown below, it will be seen that a pH test block may have five differen~
reaction ranges respectively represented by correspondingly different counts output by the divider register 100 (i.e., counts 0-255). The read only memory 110 is preloaded in a known manner to indicate the discrete thresholds for each of the different reagents. Thus, in a typical example, the first pH reaction range is shown to be 0-2, the second pH
reaction range is shown to be 3-44.
,, .
I TABLE
, j . ~ - .
1 15 ~ Decode Points aRange) i
7 45-128
8 129-213
9 214-25S
As the read only memory 110 is addressed by the system in a manner to be shown, it w ll output the 256 com-plement of the threshold indicated over path 114 to a de-coder 112 for the purpose of comparison with the signals input thereto by the divider register 100 in a manner to be described.
, I
I Returning now to the readout of the unknown reagent blocks o~ a test device, as the device is placed on table 43 and the code block 17 is advanced to the readout position, ~; 30 the photosensor 41 provides an output signal to code sensor 19 over path 42, and, over path 60, sensor 19 provides an ID signal to an access register 116, which identifies the particular str;p being processed. As the actuator 45 '., ~ ~ 7 ~ ~
1 advances the table 43 to move the first reagent block 18a with the unknown reagent into readout position, code sensor 19 provides a signal over path 60 to the access regis~er 116 which identifies the reagent block which is being read out.
As noted above, in a less complicated arrangement code sensor 19 may comprise a simple s~epping device which ad-vances one word as each ~eagent block is detected, and the reagent blocks on thç test device in the present example will be represented by ~he cou,nt output of the stepping device over path 60 ~i.e. code block 17 would be 00~ reagent block 18a would be 001, reage~t block 18b would be 002, etc.). The access rqgister 116 in reponse to the count signal over path 60 provides a ~hree bit word to a buffer counter 121 which identifies the particular reagen~ block being processed ~in the present example, 001 to identify the pH reagent block 18a).
The three bit signal output of access register 116, which identifies the particular reagent block belng pro-' ' cessed, is also fed out over path 120 to a coincident cir- ' cuit 122. Assuming that the printer 128 ~which may include a conventional stepper print wheel with the desired charac-ter reading thereon) is ln a positi.on other than pH5, the signal output from the printer fed over path 130 to coin-cident circuit 122 w~ll be different from that fed over path 120, and coincident circuit 122 thereupon responsively `, provides a signal output over path 124 and an OR gate 126 to the stepping input of the printer 128 to cause the printer ~o advance until such time as the desired position tpH5) is reached. At that time the signal input from the :
.~
~., .. . ; ~ . . . . .
~ ~ ~ 7 ~ 7 9 1 printer on path 130 and the signal input over pa~h 120 from the access register will be coincident and the signal output over path 124 will be removed to terminate the stepping of the printer 128.
Returning to the readout position, as block 18a is moved into the readout position, the read sign~l over path 42 from photosensor 41 via code sensor 19 and sequence cir-cuit 54 is operated a~ before to enable gate 52 to gate the signal output of the vol~age controlled oscillator 50 over path 72 to the counter circuit 74 and over path 76 to the zero register 78.
As before, sequence circuit 54 is also operated with receipt of the read signal to output a load signal over path 86 to cause thç complement of the zero calibration value for the first reag~nt block (18a) to be fed over path 102 to the zero regi$tçr 78.
In addition, while a read signal over path 42 indicates that a reagent block is m the readout position, sequence circuit 54, via the access input to memory 84, is also operative to advance the memory 84 one more access step to cause said memory to output the corresponding span word for : the pH reagent to the divider register 100.
With the complement of the zero calibration value from the pH reagent now in the zero register 78 and the high posi-tive value now in divider register 100, and timer 21 oper-ated as before describe~ in response to the read signal out-put ~rom photosensor 41~ the output signals of the voltage con~rolled oscillator 50 are gated over gate 52 and the des-; cribed path to the zer~ register 78. Zero register 78 counts up from the zero calibration value (which in ~he : present example was 236~ in the direction of the total .
: . . . . . -`gL737~
1 count 256 of the register. As c~unt 255 is reached, ~he following count over path 76 causes the zero r~gister 78 to provide an output signal over path 90 to flip-flop 92 to cause the output ~f the ~oltage controlled oscillator 50 to S be gated through g~te ~6 ~ the divider register 100 over path 98.
The divider: regis~er 100, as noted above, registers the complement of the high positive value, and the signal input over path 98 drives the divider register 100 from such value to count 256 ? whereupon register 100 outputs a signal over path 104 to the one shot circuit ~06 and ove~ path 132 to the.clock input o~` ~he decoder register 112.
It will be recallcd that-the access register 116 on path 118 and bu$fer 121 caused the complement of the first threshold (See Table~ for the p~ reagent which was loaded , I into read only memory 110 to be output over path 114 to the decoder register 112. Accordingly, as the clock inputs ¦ are received over pàth 132 3 the decodeT register 112 ad-vances from the complemçn~ for threshold 2 (25~ in the present example), and a~ s~ch~time as the total count of - , , ~ .
256 is reached9 the signal over conductor 134 to a one shot circuit 136 resul~$ in an output signal over path 138 to .
ll buffer 140 which, PV~ path 142, causes printer 128 to ad-:: ~ vance one step.
:~
. 25 Bu~fer 140 a~$orb$ ~he count output from the one shot circuit 136 which is~:oper~tive at a much higher rate than the printer device 128,. That :is, as seen in the Table, the pH reagent may ha~e as m~ny as five thresholds, and in the event that signals representing the highest value threshold are input over path 132 to the decoder register 112 9 the buffer may store as many as five counts before the printer . '` ' ' .
, 67~
1 128 is advanced to represent the change of threshold. The buffer 140 outputs the s~ored signals over conductor 142 and OR gate 126 to the step inpu~ of the printer 128 to cause the wheel to advance over the successive steps. At such time as the buffer 140 is empty, a signal over empty conduc-'tor 146 is fed tD the ha~mer input of the printer 128 to cause the printer to printout the value to which the printer wheel has been advanced by the output signals of buffer 14G.
- All of the circuits, wi~h the exception of the access regis~'er 116 and ~he low calibration and high calibration value set in memory 84 are reset as each block is advanced into,the readout position by reason of the detection there-of by photosensor 41 and the signal supplied therefrom to the code sensor 19 and sequence control 54. Accordingly, the system is oper,atlve with e.ach successive readout of a reagent block to compare such ~alue with the threshold values stored in ~hç.read only memory 110 and to provide an output signal which,controls the printer 128 to provide a printout of such infor~ation.' -, .
~XAM~L~
- This Example describes the preparation o ~he device 14 shown ln Figure 1~ Such test devices are for quanti-: tatively determining p.rotein and glucose in bi.ological fluids such as urine.
Pre~aration o~ Pro~ein Test Rea~ent Sheets of Eatma~ an~ Dikeman No. 6Sl filter paper, approximately 10 cm square, were saturated with the follow-, ing solution: '' ~ ~ 7~ ~
1 ~.2 parts of 2M aq~eous s~dium cltra~e) ) 100 ml 7.8 paTts o~ 2M aqueous citric acid Tetrabromophenol blue (0.08 weight) ) 100 ml in 95% ethanol To~al Volume ~00 ml The wet sheets were dried at 100C for 15 minutes, and further cut lnto squares O . 5 cm x O . 5 cm.
Preparation of Glucose Tes~ Rea~ent Shee*s af Eatman and Dikeman No. 641 filter paper were saturated wï~h the following solu~ion:
Sodium Alginate 5, O g Polyoxyethylene Sorblt~n Mon~oleate Wetti~g Age~t (1% solubion) S0.0 ml Gelatin 12.0 g o-Tolidine~2HCi 2.5 g Buffer (p~ ~,8 - 5.0, consisting of citric acld 22,2 g/300 ml and sodium citr~te 9q.8 g/300 ml~ 300.0 ml .
Glu~o$e.. Oxidas~ 18.2 g Peroxidase (hqrs,eFadish) 380.0 mg 95% Btha~p~ 125.0 ml The sheets were dried a described abo~e ln the protein test preparation and cut into 0.5 cm squares.
. . ' .
- Preparation of Test Devices Tran~parent polysty~ene film approximately 0.0254 cm thick was cut into strips 8.2 çm long by 0.5 cm wide.
~, .
Squares of prptein test reagent paper prepared as above were attached ~o;one end of each strip. Squares of glucose . test reagent papers were attached to the plastic strips ::~ spaced apprQximately 2 mm inwardly from the protein test .
'', :, - - :
73~
1 squares. Blallk squares of white paper 0.5 cm square were then attached to the strips spaced approximately 2 mm in-wardly from the glucose test squares. Alternatively white opaque areas m~y be printed on the test strips in place of the white paper squares. The result was test device 14 as shown in Figure 1.
USE OF THE TEST DEVI CBS
.
A test device as prepared above is momentarily dipped into and removed from a urine test fluid, and the excess fluid remove~ from the device by shaking. Prior to contact with the test fluid, the protein test reagent area is a yellow color. Upon contacting protein in the fluid, the color changes from yellow (negative) to a bluish green (over 1000 mg %), depending upon the amount of protein in the fluid. The results are reported in the following increme~ts:
negative ? trace, 30 mg % (~), 100 mg % (++) 300 mg % t~ and over 1000 mg % ~
The glucose test reagen~ area is a red color prior to contacting the test fluid and changes to a deep purple upon contacting glucosç in saîd ~luld. The results are reported as negativç, small, moderate and large.
Upon remoral of the excess fluld from the test devic~
'I the start switçh 44 of the test instrument is depressed . .
and the test d,evice 14 is plaeed in ope~ative position on the table 43 of the test inst~ument. The test device 14 ~;l moves wi~h the table ~3 ~hrough the light beam ~rom position " P-O toward positio~ P~9. W~en the device 14 reaches posi-tion P-6, thç light bea~ i5 interrupted by code block 17 and ~' the light is thereupon re~lected from this white code block back to de~ector 38, to cause the instrument to be auto-' ~ ~ ~
..
.~ .
. ~ -- - . , , ; . . , 7~7~
1 matically calibrated by means of the calibrate module 23.
With continued movement of test device 14 the light beam is a~ain interrupted by the gl~cose test area in position P-7.
The code sensor and re.ad signal module 19 in conjunc~ion with test sequence selector 35 determines that the device is a glucose-prot,ein,test device and the function generator 29 is advise~ ac~ordingly. When f,he light beam is centered on the glucose test area, the read command is activated and the decode to print ~odule 31 advises the printer 33 to report the proper results ~rom ne~ative to large, depending upon the amount o gl~cose in the urine test fluid. The proçedure is repeated $o.r the protein test reagent when , the light beam is centerçd on ~he protein test area in ; position P-8. Upon reaching position P-9, the actuator 45 returns the table 4~ to its Start position9 and the instrument automatically shuts itsel~ off.
~.
' ' ~ " :
' ' :. .. :.,.
.~,.., -', , : ' ,.
.
As the read only memory 110 is addressed by the system in a manner to be shown, it w ll output the 256 com-plement of the threshold indicated over path 114 to a de-coder 112 for the purpose of comparison with the signals input thereto by the divider register 100 in a manner to be described.
, I
I Returning now to the readout of the unknown reagent blocks o~ a test device, as the device is placed on table 43 and the code block 17 is advanced to the readout position, ~; 30 the photosensor 41 provides an output signal to code sensor 19 over path 42, and, over path 60, sensor 19 provides an ID signal to an access register 116, which identifies the particular str;p being processed. As the actuator 45 '., ~ ~ 7 ~ ~
1 advances the table 43 to move the first reagent block 18a with the unknown reagent into readout position, code sensor 19 provides a signal over path 60 to the access regis~er 116 which identifies the reagent block which is being read out.
As noted above, in a less complicated arrangement code sensor 19 may comprise a simple s~epping device which ad-vances one word as each ~eagent block is detected, and the reagent blocks on thç test device in the present example will be represented by ~he cou,nt output of the stepping device over path 60 ~i.e. code block 17 would be 00~ reagent block 18a would be 001, reage~t block 18b would be 002, etc.). The access rqgister 116 in reponse to the count signal over path 60 provides a ~hree bit word to a buffer counter 121 which identifies the particular reagen~ block being processed ~in the present example, 001 to identify the pH reagent block 18a).
The three bit signal output of access register 116, which identifies the particular reagent block belng pro-' ' cessed, is also fed out over path 120 to a coincident cir- ' cuit 122. Assuming that the printer 128 ~which may include a conventional stepper print wheel with the desired charac-ter reading thereon) is ln a positi.on other than pH5, the signal output from the printer fed over path 130 to coin-cident circuit 122 w~ll be different from that fed over path 120, and coincident circuit 122 thereupon responsively `, provides a signal output over path 124 and an OR gate 126 to the stepping input of the printer 128 to cause the printer ~o advance until such time as the desired position tpH5) is reached. At that time the signal input from the :
.~
~., .. . ; ~ . . . . .
~ ~ ~ 7 ~ 7 9 1 printer on path 130 and the signal input over pa~h 120 from the access register will be coincident and the signal output over path 124 will be removed to terminate the stepping of the printer 128.
Returning to the readout position, as block 18a is moved into the readout position, the read sign~l over path 42 from photosensor 41 via code sensor 19 and sequence cir-cuit 54 is operated a~ before to enable gate 52 to gate the signal output of the vol~age controlled oscillator 50 over path 72 to the counter circuit 74 and over path 76 to the zero register 78.
As before, sequence circuit 54 is also operated with receipt of the read signal to output a load signal over path 86 to cause thç complement of the zero calibration value for the first reag~nt block (18a) to be fed over path 102 to the zero regi$tçr 78.
In addition, while a read signal over path 42 indicates that a reagent block is m the readout position, sequence circuit 54, via the access input to memory 84, is also operative to advance the memory 84 one more access step to cause said memory to output the corresponding span word for : the pH reagent to the divider register 100.
With the complement of the zero calibration value from the pH reagent now in the zero register 78 and the high posi-tive value now in divider register 100, and timer 21 oper-ated as before describe~ in response to the read signal out-put ~rom photosensor 41~ the output signals of the voltage con~rolled oscillator 50 are gated over gate 52 and the des-; cribed path to the zer~ register 78. Zero register 78 counts up from the zero calibration value (which in ~he : present example was 236~ in the direction of the total .
: . . . . . -`gL737~
1 count 256 of the register. As c~unt 255 is reached, ~he following count over path 76 causes the zero r~gister 78 to provide an output signal over path 90 to flip-flop 92 to cause the output ~f the ~oltage controlled oscillator 50 to S be gated through g~te ~6 ~ the divider register 100 over path 98.
The divider: regis~er 100, as noted above, registers the complement of the high positive value, and the signal input over path 98 drives the divider register 100 from such value to count 256 ? whereupon register 100 outputs a signal over path 104 to the one shot circuit ~06 and ove~ path 132 to the.clock input o~` ~he decoder register 112.
It will be recallcd that-the access register 116 on path 118 and bu$fer 121 caused the complement of the first threshold (See Table~ for the p~ reagent which was loaded , I into read only memory 110 to be output over path 114 to the decoder register 112. Accordingly, as the clock inputs ¦ are received over pàth 132 3 the decodeT register 112 ad-vances from the complemçn~ for threshold 2 (25~ in the present example), and a~ s~ch~time as the total count of - , , ~ .
256 is reached9 the signal over conductor 134 to a one shot circuit 136 resul~$ in an output signal over path 138 to .
ll buffer 140 which, PV~ path 142, causes printer 128 to ad-:: ~ vance one step.
:~
. 25 Bu~fer 140 a~$orb$ ~he count output from the one shot circuit 136 which is~:oper~tive at a much higher rate than the printer device 128,. That :is, as seen in the Table, the pH reagent may ha~e as m~ny as five thresholds, and in the event that signals representing the highest value threshold are input over path 132 to the decoder register 112 9 the buffer may store as many as five counts before the printer . '` ' ' .
, 67~
1 128 is advanced to represent the change of threshold. The buffer 140 outputs the s~ored signals over conductor 142 and OR gate 126 to the step inpu~ of the printer 128 to cause the wheel to advance over the successive steps. At such time as the buffer 140 is empty, a signal over empty conduc-'tor 146 is fed tD the ha~mer input of the printer 128 to cause the printer to printout the value to which the printer wheel has been advanced by the output signals of buffer 14G.
- All of the circuits, wi~h the exception of the access regis~'er 116 and ~he low calibration and high calibration value set in memory 84 are reset as each block is advanced into,the readout position by reason of the detection there-of by photosensor 41 and the signal supplied therefrom to the code sensor 19 and sequence control 54. Accordingly, the system is oper,atlve with e.ach successive readout of a reagent block to compare such ~alue with the threshold values stored in ~hç.read only memory 110 and to provide an output signal which,controls the printer 128 to provide a printout of such infor~ation.' -, .
~XAM~L~
- This Example describes the preparation o ~he device 14 shown ln Figure 1~ Such test devices are for quanti-: tatively determining p.rotein and glucose in bi.ological fluids such as urine.
Pre~aration o~ Pro~ein Test Rea~ent Sheets of Eatma~ an~ Dikeman No. 6Sl filter paper, approximately 10 cm square, were saturated with the follow-, ing solution: '' ~ ~ 7~ ~
1 ~.2 parts of 2M aq~eous s~dium cltra~e) ) 100 ml 7.8 paTts o~ 2M aqueous citric acid Tetrabromophenol blue (0.08 weight) ) 100 ml in 95% ethanol To~al Volume ~00 ml The wet sheets were dried at 100C for 15 minutes, and further cut lnto squares O . 5 cm x O . 5 cm.
Preparation of Glucose Tes~ Rea~ent Shee*s af Eatman and Dikeman No. 641 filter paper were saturated wï~h the following solu~ion:
Sodium Alginate 5, O g Polyoxyethylene Sorblt~n Mon~oleate Wetti~g Age~t (1% solubion) S0.0 ml Gelatin 12.0 g o-Tolidine~2HCi 2.5 g Buffer (p~ ~,8 - 5.0, consisting of citric acld 22,2 g/300 ml and sodium citr~te 9q.8 g/300 ml~ 300.0 ml .
Glu~o$e.. Oxidas~ 18.2 g Peroxidase (hqrs,eFadish) 380.0 mg 95% Btha~p~ 125.0 ml The sheets were dried a described abo~e ln the protein test preparation and cut into 0.5 cm squares.
. . ' .
- Preparation of Test Devices Tran~parent polysty~ene film approximately 0.0254 cm thick was cut into strips 8.2 çm long by 0.5 cm wide.
~, .
Squares of prptein test reagent paper prepared as above were attached ~o;one end of each strip. Squares of glucose . test reagent papers were attached to the plastic strips ::~ spaced apprQximately 2 mm inwardly from the protein test .
'', :, - - :
73~
1 squares. Blallk squares of white paper 0.5 cm square were then attached to the strips spaced approximately 2 mm in-wardly from the glucose test squares. Alternatively white opaque areas m~y be printed on the test strips in place of the white paper squares. The result was test device 14 as shown in Figure 1.
USE OF THE TEST DEVI CBS
.
A test device as prepared above is momentarily dipped into and removed from a urine test fluid, and the excess fluid remove~ from the device by shaking. Prior to contact with the test fluid, the protein test reagent area is a yellow color. Upon contacting protein in the fluid, the color changes from yellow (negative) to a bluish green (over 1000 mg %), depending upon the amount of protein in the fluid. The results are reported in the following increme~ts:
negative ? trace, 30 mg % (~), 100 mg % (++) 300 mg % t~ and over 1000 mg % ~
The glucose test reagen~ area is a red color prior to contacting the test fluid and changes to a deep purple upon contacting glucosç in saîd ~luld. The results are reported as negativç, small, moderate and large.
Upon remoral of the excess fluld from the test devic~
'I the start switçh 44 of the test instrument is depressed . .
and the test d,evice 14 is plaeed in ope~ative position on the table 43 of the test inst~ument. The test device 14 ~;l moves wi~h the table ~3 ~hrough the light beam ~rom position " P-O toward positio~ P~9. W~en the device 14 reaches posi-tion P-6, thç light bea~ i5 interrupted by code block 17 and ~' the light is thereupon re~lected from this white code block back to de~ector 38, to cause the instrument to be auto-' ~ ~ ~
..
.~ .
. ~ -- - . , , ; . . , 7~7~
1 matically calibrated by means of the calibrate module 23.
With continued movement of test device 14 the light beam is a~ain interrupted by the gl~cose test area in position P-7.
The code sensor and re.ad signal module 19 in conjunc~ion with test sequence selector 35 determines that the device is a glucose-prot,ein,test device and the function generator 29 is advise~ ac~ordingly. When f,he light beam is centered on the glucose test area, the read command is activated and the decode to print ~odule 31 advises the printer 33 to report the proper results ~rom ne~ative to large, depending upon the amount o gl~cose in the urine test fluid. The proçedure is repeated $o.r the protein test reagent when , the light beam is centerçd on ~he protein test area in ; position P-8. Upon reaching position P-9, the actuator 45 returns the table 4~ to its Start position9 and the instrument automatically shuts itsel~ off.
~.
' ' ~ " :
' ' :. .. :.,.
.~,.., -', , : ' ,.
.
Claims (12)
1. A test system for determination of chemical con-stituents in a fluid comprising a carrier member, at least one test reagent on said carrier member reactable with a specific constituent in a fluid, code means on said carrier member at a predetermined distance from said at least one test reagent, code sensing means for sensing the predeter-mined distance between said code means and said at least one test reagent, reaction sensing means responsive to reaction of said at least one test reagent to provide an output signal, and readout means controlled by said code sensing means and responsive to the output signal from said reaction sensing means.
2. A test system as in Claim 1 wherein said carrier member is transparent, said at least one test reagent is in-corporated with a bibulous paper which is attached to said carrier member and said code means is an opaque area.
3. A test system as in Claim 1 wherein said readout means is calibrate and wherein said reaction sensing means is responsive to said code means to provide a calibra-te output signal to said readout means for calibration of the latter.
4. A test device for determination of a chemical constituent in a fluid and which is adapted for use with an instrument responsive to code means on the device, said device comprising a carrier member, at least one test re-agent on said carrier member, said at least one test reagent being reactable with a specific constituent in a fluid, and code means on said carrier in a predetermined spaced re-lation with respect to said at least one test reagent for indicating to an instrument by such spaced relation the particular at least one test reagent on said carrier member.
5. A test device as in Claim 4 wherein said carrier member is transparent and said code means is an opaque area.
6. A semi-automatic test system for determination of chemical constituents in a fluid, comprising a carrier member, a plurality of test reagents on said carrier member in predetermined relation, each of said test reagents being reactable with a specific constituent in a fluid and code means on said carrier member for use in identifying the test reagents located on said carrier member, code sensing means for sensing said code means, reaction sensing means operable responsive to reactions of said test reagents respectively to provide output signals, and readout means controlled by said code sensing means and responsive to the output signals from said reaction sensing means.
7. A test system as in Claim 6 wherein the carrier mem-ber comprises a strip of transparent plastic film, said test reagents are incorporated with bibulous matrices which attached to said carrier member and said code means is an opaque area positioned on said carrier a predetermined distance from one test reagent.
8. A test system as in Claim 6 wherein said reaction sensing means is initially responsive to said code means to provide an output signal to said readout means for calibra-tion of the latter.
9. A semi-automatic test system for determination of chemical constituents in a fluid, comprising a test device comprising a strip of transparent plastic film, a plurality of test reagents on said strip in predetermined spaced re-lation, each of said test reagents being reactable with a specific constituent in a fluid, and an opaque area on said strip at a predetermined location relative to the test reagents; movable, transparent table means adaptable to receive said test device; a light source for directing a light beam toward said table means, movement of said table means with said test device thereon causing said opaque area and said test reagents to be moved through positions in which they successively interrupt said light beam; light responsive Code sensing means positioned to receive said light beam when not so interrupted; reaction sensing means operable responsive to reactions of said test reagents when said test reagents are respectively in interrupting relation to said light beam to provide output signals; function means connected to said code sensing means and operative to in-terpret the relative positions of the opaque area and the test reagents; and readout means cooperable with said function means and responsive to the output signal from said reaction sensing means.
10. A test device for determination of chemical con-stituents in a fluid and which is adapted for use with an instrument responsive to code means on the test device, said test device comprising a carrier member, a plurality of test reagents on the carrier member in predetermined relation, each of said test reagents being reactable with a specific constituent in a fluid, and code means on said carrier member for indicating to an instrument the particular test reagents which are on said carrier member.
11. A test device as in Claim 10 wherein the carrier member comprises a strip of transparent plastic film, said test reagents are incorporated with bibulous matrices which are attached to said carrier member and said code means is an opaque area position on said carrier member in a predetermined position with respect to said test reagents.
12. A test device as in Claim 10 adapted for use with a calibratable instrument, the code means of said test device indicating to the instrument the amount of calibration ad-justment therein necessary when said test device is used with said instrument.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US435001A US3907503A (en) | 1974-01-21 | 1974-01-21 | Test system |
| CA214,829A CA1033651A (en) | 1974-01-21 | 1974-11-28 | Test system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047379A true CA1047379A (en) | 1979-01-30 |
Family
ID=25667762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA290,936A Expired CA1047379A (en) | 1974-01-21 | 1977-11-15 | Test system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1047379A (en) |
-
1977
- 1977-11-15 CA CA290,936A patent/CA1047379A/en not_active Expired
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