U.S. patent number 3,775,595 [Application Number 05/263,285] was granted by the patent office on 1973-11-27 for apparatus for processing chemical materials held in container structures.
This patent grant is currently assigned to Instrumentation Laboratory, Inc.. Invention is credited to David E. Blackmer, Thomas F. Kelley, Thomas A. Rosse, Jerrold Zindler.
United States Patent |
3,775,595 |
Rosse , et al. |
November 27, 1973 |
APPARATUS FOR PROCESSING CHEMICAL MATERIALS HELD IN CONTAINER
STRUCTURES
Abstract
Incubation apparatus for use with a cuvette having a projecting
processing control member and a plurality of chambers, at least one
of which contains a stored chemical material includes a cuvette
receptacle with adjacent heaters for incubating material in the
cuvette, sensor circuitry responsive to the control member of the
cuvette in the container receiving structure for producing an
output signal as a function of the data provided by the control
portion, and a timer responsive to the sensor circuitry for
providing a control signal as an indication of the incubation of
the cuvette. The receptacle also includes an interlock slot for
receiving the projecting control member.
Inventors: |
Rosse; Thomas A. (Lexington,
MA), Blackmer; David E. (Harvard, MA), Zindler;
Jerrold (Cambridge, MA), Kelley; Thomas F. (Canton,
MA) |
Assignee: |
Instrumentation Laboratory,
Inc. (Lexington, MA)
|
Family
ID: |
26723173 |
Appl.
No.: |
05/263,285 |
Filed: |
June 15, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
45758 |
Jun 12, 1970 |
3703336 |
Nov 21, 1972 |
|
|
Current U.S.
Class: |
235/375; 236/46R;
219/432; 236/3; 435/286.1; 435/303.1; 219/521; 700/266;
422/547 |
Current CPC
Class: |
G01N
35/00594 (20130101); G01N 2035/0436 (20130101); G01N
35/00693 (20130101) |
Current International
Class: |
G01N
35/00 (20060101); G01N 35/04 (20060101); B01l
003/00 (); G01n 021/24 (); G06f 009/04 () |
Field of
Search: |
;356/39,246,244,205,83,180 ;250/16SC
;235/151.35,61.6R,61.6A,61.6B,61.6H ;73/423A,53 ;23/23B,259
;219/521,432 ;236/3,46R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sloyan; Thomas J.
Parent Case Text
This application is a division of our copending patent application
Ser. No. 45,758, filed June 12, 1970, entitled "Analysis System
Employing a Plural Chamber Cuvette Structure," now U.S. Pat. No.
3,703,336, issued Nov. 21, 1972.
Claims
What is claimed is:
1. Apparatus for use with container structure having a processing
control portion having one or more segments and a plurality of
chambers, said process control portion having one or more data
providing segments and at least one of said chambers containing a
stored chemical material comprising:
structure for receiving said container structure, said container
receiving structure including interlock structure for cooperation
with said processing control portion, said interlock structure
preventing insertion into said container receiving structure of
container structures having processing control portions improperly
coordinated with said interlock structure,
processor apparatus adjacent said container receiving structure for
processing material in a container structure in said container
receiving structure,
sensor circuitry responsive to said processing control portion of
the container structure when said container structure is in said
container receiving structure for producing an output signal as a
function of data provided by said processing control portion,
said output signal responsive means including indicator means
responsive to said sensor circuitry output signal for providing a
control signal as an indication of the processing of the container
structure in said container receiving structure by said processor
apparatus.
2. The apparatus as claimed in claim 1 wherein said output signal
responsive means includes timer means.
3. The apparatus as claimed in claim 1 wherein said processor
apparatus comprises heater means adjacent said container receiving
structure for subjecting a container structure in said container
receiving structure to an incubation cycle.
4. The apparatus as claimed in claim 1 wherein said sensor
circuitry includes a light source and a plurality of light sensors,
said light source and said light sensors being arranged to respond
to said processing control portion and said container receiving
structure includes decoding logic for producing said control signal
as a function of the output signals of said light sensors.
5. The apparatus as claimed in claim 4 wherein said sensor
circuitry includes a plurality of first light transmitting channels
disposed between said light source and a corresponding plurality of
second light transmitting channels, each said second light
transmitting channel being disposed between a corresponding aligned
first channel and a corresponding light sensor, and said first and
second channels being spaced apart so that said processing control
portion may be interposed therebetween to control transmission of
light from said source to said sensors.
6. The apparatus as claimed in claim 1 wherein said processing
control portion is a projecting control member and said interlock
structure includes an interlock slot for receiving said projecting
control member.
7. The apparatus as claimed in claim 1 wherein said apparatus
includes two container receiving structures, each said container
receiving structure having cooperating processor apparatus, sensor
circuitry and indicator means, and the interlock structure of one
of said container receiving structures being different from the
interlock structure of the other container receiving structure so
that the same container structure cannot be inserted into both
container receiving structures.
8. The apparatus as claimed in claim 7 wherein said processing
control portion is a projecting control member and each said
interlock structure includes an interlock slot for receiving said
projecting control member.
9. The apparatus as claimed in claim 7 wherein each said processor
apparatus comprises heater means adjacent said container receiving
means for subjecting a container structure in said container
receiving means to an incubation cycle.
10. The apparatus as claimed in claim 9 wherein each said sensory
circuitry includes a light source and a plurality of light sensors,
said light source and said light sensors being arranged to respond
to said processing control portion and said container receiving
means includes decoding logic for producing said control signal as
a function of the output signals of said light sensors, and said
output signal responsive means includes timer means for producing
an incubation cycle duration indication.
11. The apparatus as claimed in claim 10 wherein said processing
control portion is a projecting control member and each said
interlock structure includes an interlock slot for receiving said
projecting control member.
12. The apparatus as claimed in claim 11 wherein said sensory
circuitry includes a plurality of first light transmitting channels
disposed between said light source and a corresponding plurality of
second light transmitting channels, each said second light
transmitting channel being disposed between a corresponding aligned
first channel and a corresponding light sensor, and said first and
second channels being spaced apart so that said projecting control
member may be interposed therebetween to control transmission of
light from said source to said sensors to define the duration of
said incubation cycle.
Description
SUMMARY OF INVENTION
This invention relates to analysis systems.
A need exists for instrumentation that produces accurate chemical
analysis data and which can be operated by untrained personnel.
Such instrumentation would assist laboratories in contending with
the shortage of skilled personnel and as such should minimize the
number of operations required, eliminate the need for calculations,
and present the analysis results directly, accurately and
unambiguously. Chemical analyses may be performed in a variety of
manners. In photometric analyses, for example, measurements may be
made directly, by comparison with a standard, or as a function of
the rate of chemical change. Such techniques are frequently
employed in the analysis of blood or other body fluids. Frequently
as part of a diagnostic procedure, a chemical analysis of a sample
of such fluids for enzymes, hemoglobin, chloresterol, glucose etc.
provides useful diagnostic information. While laboratory services
for performing such analyses are available, the use of such
services often entails a delay of several days or more before
analysis information is available.
It is an object of this invention to provide a novel and improved
analysis system which facilitates operation of analysis
instrumentation by untrained personnel.
Another object of the invention is to provide a novel and improved
instrumentation for use with prepackaged chemical materials which
enables such materials to be stored in a reliable manner, and to
easily be used in obtaining analysis information.
A further object of this invention is to provide novel and improved
analysis instrumentation.
Another object of the invention is to provide novel and improved
chemical analysis instrumentation particularly adapted for use in
the analysis of blood samples.
A further object of the invention is to provide a novel and
improved analysis system which enables the performance of complex
blood chemical analytical procedures with the minimum of trained
technique while obtaining data sufficiently accurate for diagnostic
purposes.
Another object of the invention is to provide a novel and improved
incubation system which can be used for a wide variety of blood
chemistry tests.
In accordance with the invention there is provided an apparatus for
use with container structure having a processing control portion
and a plurality of chambers, at least one of which contains a
stored chemical material. The apparatus includes receptacle means
for receiving the container structure, processor apparatus adjacent
the container receiving structure for processing material in a
container structure in the container receiving structure, sensor
circuitry responsive to the control portion of the container
structure in the container receiving structure for producing an
output signal as a function of the data provided by the control
portion, and indicator means responsive to the sensor circuitry
output signal for providing a control signal as an indication of
the processing of the container structure in the container
receiving structure by the processor apparatus.
In a particular embodiment, the processing control portion is a
projecting control member and the container receiving receptacle
means includes an interlock slot for receiving the projecting
control member. The sensor circuitry includes a light source and a
plurality of light sensors, the light source and the light sensors
being arranged to respond to the control portion and the container
receptacle including decoding logic for producing the control
signal as a function of the output signals of the light sensors. A
first group of light transmitting channels and a corresponding
second group of light transmitting channels are disposed between
the light source and the light sensors, each second light
transmitting channel being disposed between a corresponding aligned
first channel and a corresponding light sensor, and the first and
second groups of channels are spaced apart so that the control
portion may be interposed between them to control transmission of
light from the source to the sensors.
A plurality of container receiving structures are provided in a
preferred embodiment, each container structure having cooperating
processor apparatus, sensor circuitry and indicator means, and each
container receiving structure further includes an interlock slot
adapted to cooperate with a projecting control member of the
container to limit insertion of container structures into the
container receiving structures. Heaters are adjacent each container
receiving structure for subjecting a container to an incubation
cycle. The position of the interlock slot is coordinated with the
heat output of the processor. Thus the projecting control provides
an indication of both the magnitude and duration of the incubation
cycle.
Other objects, features and advantages of the invention will be
seen as the following description of a particular embodiment
progresses, in conjunction with the drawings, in which:
FIG. 1 is a perspective view of components of a biochemical
analysis system constructed in accordance with the invention;
FIG. 2 is a side view, with parts broken away, of the cuvette
assembly shown in FIG. 1;
FIG. 3 is a sectional view of the cuvette assembly taken along the
line 3--3 of FIG. 2;
FIG. 4 is a sectional view of the cuvette assembly taken along the
line 4--4 of FIG. 2;
FIG. 5 is a top plan diagrammatic view of the cuvette assembly and
an incubator unit of the apparatus shown in FIG. 1;
FIG. 6 is a diagrammatic sectional view taken along the line 6--6
of FIG. 5; and
FIG. 7 is a block diagram of the photometric system of the
apparatus shown in FIG. 1.
DESCRIPTION OF PARTICULAR EMBODIMENT
With reference to FIG. 1 there is shown a biochemical analysis
instrument that includes a housing 10 on which is mounted a
dispensing unit 12 having two dispensing channels 14-1 and 14-2. To
the right of the dispensing unit 12 is an incubator section 16 that
includes incubator chambers 18-1 - 18-8. At the top of each
incubator chamber is an interlock slot 20 and above each chamber is
an indicator light 22. A photometer section 24 is disposed above
the incubator section 16 and includes a slot 26 for receiving a
cuvette assembly 40; a card reader unit 28; a digital display 30; a
units display 32; a start button 34 and an alarm lamp 36. Used with
this instrument is a disposable cuvette assembly 40 and a
correlated card 42 which includes a data section 44 having
calibrating and control information and an instruction section 46.
In a typical system, a kit of twenty cuvette assemblies 40, a
supply of a standard (if necessary) for use with the cuvette
assemblies 40 and a control card 42 having coded calibrating and
control information correlated with the standard material and the
analysis to be performed is supplied for use with the instrument. A
different kit is provided for each type of analysis.
The cuvette assembly 40, as shown in FITS. 2-4, is formed of two
components, a top 48 and a body portion 50, both formed of suitable
material such as glass, or a polymeric material such as a
polyolefin, a polycarbonate, or an acrylic. A preferred material is
a transparent TPX methylpentene polyolefin material that has an
absorbtion of approximately 0.125 optical density at a wavelength
of 3400 Angstroms; a vicat softening point of 179.degree.C; and
excellent chemical resistance properties.
The body 50 has two side walls 52, 54, each 0.050 inch thick, that
taper outwardly from bottom to top at an angle of about 1.degree..
Side walls 52, 54 are joined together at their bottom by base wall
56. As indicated in FIGS. 2 and 3, three sample chambers 60-1, 60-2
and 60-3 and a handle chamber 62 are formed in the cuvette
assembly. These chambers are defined by lateral separator wall
members 64 that have a thickness at their upper ends of about 0.040
inch. Each sample chamber 60 has a transverse width between side
walls 52, 54 of about 3/8 inch and a lateral width of about 5/8
inch. The height of the cuvette assembly is 1 5/8 inches and its
length is four inches. Instruction and/or labeling information may
be secured to one or both inner surfaces of the handle chamber 62.
Formed in the outer surface of each side wall of the three sample
chambers 60 is an optical surface 70 about 9/16 inch in height and
having a surface finish in the order of five micro-inches. Each
surface is recessed about 0.005 inch to provide a protective zone.
In the optical area defined by surface 70, the side wall thickness
in each chamber 60 is maintained with a tolerance of 0.0004 inch of
the mean wall thickness of the three chambers. The optical path
lengths of the three chambers thus are identical within close
tolerances.
The cover member 48 has a downwardly projecting ridge 72 which
engages the upper surface of the body 50 and, after chemical
material has been introduced into one or more of the chambers 60, a
hermetic seal of the chambers 60 and 62 is provided as by
ultrasonic welding. In the upper wall of each chamber is formed a
frangible section 74 of reduced thickness which may be broken away
to permit introduction of materials such as a reconstituting agent
or the unknown to be analyzed into the sample chambers 60. An
interlock key 76, divided into two sections 76-1 and 76-2, projects
from the upper surface of the cover member 48. Either section 76-1
or 76-2 may be omittted thus varying the coding.
As shown in FIGS. 5 and 6, each incubator chamber 18 is of cast
aluminum and is disposed behind an aperture in the front wall 80 of
the instrument. Immediately behind wall 80 is a thermal insulator
member 82 which provides thermal isolation between areas outside
the instrument and the incubator resistance heater rod elements 84,
86. Four of the incubator chambers (18-1 - 18-4) have thermistor
controlled heaters set at 37.degree.C and controlled to maintain
temperature within 0.3.degree.C and the other four incubator
chambers (18-5 - 18-8) have thermistor controlled heaters set at
100.degree.C and controlled to maintain temperature within
1.degree.C. A light source 90 is associated with each pair of
incubator chambers 18 and four transmitting fiber optic channels
92, two in each direction, extend from light source 90 with their
remote ends supported in the corresponding insulator member 82. A
corresponding aligned pair of receiving fiber optic channels 94 are
secured in the opposed insulator member and are coupled via
photo-diodes 96 to timing and control logic 98 which provides three
different timing intervals and in turn operates indicator lamp 22
and an audible buzzer (not shown). Normally light from lamp 90 is
fed via transmitting fiber optic channels 92 to the receiving fiber
optic channels 94 for sensing by photosensors 96. When a cuvette
assembly 40 is inserted in a proper incubator chamber 18, the
location of projection 76 on the left or right side of assembly 40
being keyed to the position of interlock slot 20, one or both
sections 76-1, 76-2, (depending on the coding) block the
transmission of light to sensors 96 and operate timing logic 98 to
initiate a timing cycle. With this coding three different timing
cycles may be initiated, and it will be obvious that other
additional timing cycles may be obtained by varying the nature of
the coded control tab 76. At the end of the timing cycle selected,
logic 98 produces an output that energizes lamp 22 and the buzzer
to indicate to the operator that the cuvette assembly 40 in that
incubator chamber is ready for photometric analysis.
A block diagram of the photometric section of the instrument is
shown in FIG. 7. That section includes a shuttle 100 (disposed
behind port 26) which receives and secures the cuvette assembly 40
in a predetermined location and which is driven via shuttle drive
linkage by a motor 102. The shuttle drive sequentially positions
the three chambers 60 in an optical path 104 that extends from a
twenty watt quartz iodine radiation source 106 through filter wheel
108 to photodiode radiation sensor 110. The filter wheel 108 is in
the form of a disc and has six circumferentially disposed filter
elements and is rotated by a motor 112. The position of the filter
disc is sensed by cooperation of slots in the filter disc and a
plurality of photoelectric light sensors and logic
(diagrammatically indicated at 114) which provide a binary coded
output signal to compare circuit 116.
The card reader 28 which senses the data portion 44 of card 42 has
a light source 118 and light distributing system 120 teat has 50
output channels 122 arranged in 5 .times. 10 matrix. A check
channel is also provided to verify the proper positioning of the
card in the reader. Each sensor channel of the card reader includes
a light sensor 126, and one or more of the light sensors are
coupled to translating logic 128 which applies control signals over
output lines 130. The signals on line 130-1 are applied to control
the operation of dispenser 12; the signals on output line 130-2 are
applied as an input to comparison logic 116; the signals on output
lines 130-3 - 8 are applied to control the signal processing
circuitry that responds to material in the cuvette chambers; and
the output signal on line 130-9 is applied to the decimal display
unit. The data on the card identifies the particular test and has
dispensing information and calibration information as a function of
the particular test and the chemicals supplied for performing the
test. For example, output channel 130-2 applies a signal to compare
circuit 116 and that signal applies an output over line 132 to
control the filter wheel drive motor 112. Thus, in response to test
mode information stored on the card 42 that is correlated with a
particular cuvette assembly 40, on insertion of that card into the
card reader, the compare circuit 116 provides an output on line 132
to energize motor 112 and rotate filter wheel 108 until the proper
filter element is positioned in the optical path 104. Motor 112 is
then de-energized.
The output of radiation sensor 110 is applied to a log converter
circuit 134 which provides an output as a logarithmic function of
the input signal from photodiode 110. Connected in circuit with the
log converter arrangement is a switch 136 and a hold circuit 138.
The output of the log converter circuit is applied through a first
input of switch 140 to a digital voltmeter 142; along a second path
through differentiator 144, filter network 146 and absolute value
amplifier 148 to a second input of switch 140; and along a third
path through a first input of switch 150; scaling amplifier 152,
switch 154 and storage circuit 156. The output of storage circuit
156 is applied to the reference input of the digital voltmeter 142
and to error logic 158 which has an output that energizes error
indicator or alarm lamp 36 when the output of the hold circuit 156
deviates from preestablished limits as specified by data from the
card reader supplied on output line 130-8. Switch 150 has a second
input from a precision voltage source 160. The circuitry also
includes control logic 162 which responds to inputs from sensor 164
that provides an indication for position of the cuvette shuttle
100; inputs from the card reader over output lines 130-3; and
inputs from start button 34. The logic has outputs over line 170 to
control switch 136, over line 172 to control a switch in filter
network 146, over line 174 to control switch 154, over line 176 to
the digital voltmeter 142 and the error logic 158 in a strobing
operation, and on line 178 to control the shuttle drive motor 102.
Additional information concerning this circuitry may be had with
reference to U.S. Pat. No. 3,703,336.
A variety of biochemical analyses may be performed with this
apparatus. The following table indicates typical examples of the
types of tests that may be made with this apparatus: ##SPC1##
For each test, a kit of correlated material is supplied, a typical
kit including a set of twenty cuvettes 40, a supply of a standard
for use with the twenty cuvettes and calibrating data card 42 which
contains control data for the particular test including data on the
standard. The components of the kit are related, as by color coding
to facilitate operator handling.
This instrument as controlled by a card 42 and card reader 28 is
operable in the following three modes:
Standard R = (A.sub.X - A.sub.B)/A.sub.S - A.sub.B) .times. K
Absolute R = (A.sub.X - A.sub.B) .times. K
Rate R = dAx/dt .times. K
An illustrative example of each mode follows. Determination of
servum glucose uses the standard mode. All three cuvette chambers
60-1 - 60-3 contain 4 milliliters of liquid reagent (6 percent
orthotoluidine in glacial acetic acid) when it is received by the
user. Under the control of card reader 28 and the corresponding
"glucose" data card 42, the card reader has an output over channel
130-1 to control dispenser 12 and load dispenser channel 14-1 with
one hundred microliters with a glucose serum standard (containing a
precisely predetermined 200 milligrams per 100 milliliters, and
that is coordinated with the glucose data card 42) and channel 14-2
is loaded with one hundred microliters of a sample of the serum to
be analyzed (typically that of a patient). A cuverte is then
positioned so that chamber 60-2 and 60-3 are aligned with channels
14-1 and 14-2, respectively, and these volumes are discharged into
those chambers. Nothing is added to chamber 60-1. After the
chambers have been resealed and the contents mixed by inversion,
the cuvette assembly 40 is placed in one of the 100.degree.C
incubator units 18-5 - 18-8 and incubated for twenty minutes.
When the incubation period is complete, the lamp 22 above that
chamber lights (and an audible alarm is sounded). With the glucose
data card 42 in the card reader 28, the card causes motor 112 to
stop the filter wheel 108 so that the 6400 Angstrom filter is
disposed in the optical path 104 between the lamp 106 and
photodiode 110 by an output signal over line 130-2. Gain factors
are adjusted in the log converter circuit 134 by an output over
line 130-4 and in the scaling amplifier 152 by an output over line
130-6. The card reader also closes switch 150 so that the output
from the log converter circuit 134 is applied directly through
switch 150 to the scaling amplifier 152, and energizes an
appropriate decimal point, and the appropriate units display 32.
Depression of the start button 34 applies a signal over line 166 to
logic 162 which in turn generates a control signal over line 178 to
energize the shuttle drive motor 102.
Initially the cuvette assembly is in the position shown in FIG. 7
(position 1). The shuttle drive advances the cuvette assembly to
position 2 so that chamber 60-1 is positioned in the optical path
104. During these intervals, the shuttle position sensor 164
indicates to the logic circuitry 162 the position of the cuvette
and during these intervals, the logic circuitry 162 produces an
output over line 170 to close the switch 136 in the log converter
feedback path, applying the output signal from the log converter
through switch 136 and storage circuit 138 as a feedback to the log
converter circuit 134 in a zeroing operation. Since chamber 60-1
contains only the "blank" solution (no glucose standard or unknown
was added to this chamber) the intensity of light striking the
photosensor 110 and its output current corresponds photometrically
to the zero concentration of glucose. The log converter circuit 134
has this current applied to it and produces an output voltage equal
to the log of the input current. This output signal is fed back
through switch 136 and storage circuit 138 as a reference current
to the log converter circuit. Switch 136 is then opened and the
storage circuit 138 holds this voltage and continues to apply a
reference current to the log converter that is proportional to the
negative intensity of the blank solution.
The shuttle mechanism, after an interval of about two seconds in
position 2, advances the cuvette to position 3 so that standard
chamber 60-2 is positioned in the optical path 104. This action is
sensed by sensor 164 and applies a signal to logic circuitry 162 to
produce an output signal on line 174 to close switch 154. The gain
of the scaling amplifier 152 has been set from signals from the
card reader over line 130-6 to calibrate the scaling amplifier as a
function of the standard glucose solution supplied with the card.
During the interval that the "standard" in chamber 60-2 is in path
104, the current generated by sensor 110 causes the log converter
134 to produce an output voltage proportional to log of the
absorbance of the standard minus the absorbance of the blank
(A.sub.S -A.sub.B). After amplification in accordance with the
calibrating information from the card reader, this signal is stored
as a voltage in storage circuit 156 and applied to the reference
voltage input of the digital voltmeter 142.
The shuttle mechanism, again after interval of about two seconds,
advances the cuvette so that the third (unknown) chamber 60-3 is
positioned in the optical path 104. Sensor 164 produces a position
four output signal to the logic circuitry 162 and that circuitry
removes the output signal on line 174 so that switch 154 is opened.
The output from the log converter 134 is applied through switch 140
to the analog voltage input of the digital voltmeter 142. This
output with the chamber 60-3 in the optical path 104, is
proportional to the log of A.sub.X -A.sub.B (the absorbance of the
unknown minus the absorbance of the blank). The output of the
digital voltmeter applied to display 30 in response to the strobing
signal on line 176 is:
(A.sub.X - A.sub.B)/(A.sub.S - A.sub.B) .times. K
The number displayed is directly proportional to the concentration
of glucose in the unknown serum and the units display 32 indicates
that this number is displayed in units of milligrams per one
hundred milliliters.
Determination of hemoglobin by the Cyanmethemoglobin procedure
employs the absolute mode. In this measurement, chamber 60-1 is
empty and is unused in the analysis sequence, and each of chambers
60-2 and 60-3 as supplied in the kit has four milliliters of a
reagent. A potassium cyanide tablet is inserted into each chamber
60-2 and 60-3 by the technician to complete the reagent and the
dispenser 12 is controlled by output 130-1 of card reader 28 to
load fifty microliters of the patient's blood into dispenser
channel 14-2. The dispenser is then operated to discharge fifty
microliter sample of whole blood into cuvette chamber 60-3. The
contents of the cuvette assembly, after the chambers are sealed,
are mixed by inversion and the cuvette is incubated in a
37.degree.C unit for five minutes. When the incubation period is
complete (indicated by the corresponding light 22), the hemoglobin
control card 42 is placed in card reader 28 and the incubated
cuvette assembly 40 is placed in shuttle carrier 100. The card and
card reader produces an output on line 130-2 which causes the
filter drive motor 112 to position the 5050 Angstrom filter in the
optical path 104 and sets the gains of log converter 134 and
scaling amplifier 152. In addition, switch 140 is set to connect
the output of the log converter to the analog input of the digital
voltmeter in response to card reader output on line 130-7, and
switch 150 is set to connect precision voltage source 160 to the
reference input of the digital voltmeter 142 via scaling amplifier
152, switch 154 and storage circuit 156.
Upon depression of start button 34, logic 162 causes motor 102 to
advance the cuvette assembly 40 from position 1 through position 2
to position 3. Logic circuit 162 conditions switch 136 to maintain
the log converter circuitry in zeroing mode until position 3 is
reached (and chamber 60-2 is positioned in the optical path 104).
In this position the output of the log converter circuit 134 is
A.sub.S --the absorbance of the material in chamber 60-2. The log
converter zeroing operation is terminated by an output from sensor
164 via logic 162 to switch 136 as the cuvette 40 is advanced by
shuttle 100 to position the chamber 60-3 in optical path 104. The
output of the log converter 134 is now the value A.sub.X -A.sub.S
and is applied via switch 140 to the analog input of digital
voltmeter 142. The strobing pulse is generated by logic 162 on line
176 to gate the output value generated by digital voltmeter 142 to
digital display 30, and at the same time the strobing pulse applied
to the error logic to check whether the scaled precision voltage
value is within a preset limit as determined by an output from the
card reader on line 130-8. As in the other cases, if the output
voltage is outside those limits lamp 36 is energized. Display 30
displays the digital value of hemoglobin in grams per 100
milliliters, the digital voltmeter 142 having generating the ratio
(A.sub.X -A.sub.S) .times. k/v, the output being an absolute
absorbance measurement of the sample minus a standard.
Enzyme analyses made in a rate mode. For example, in a
determination of lactic dehydrogenase (LDH) by the Wacker method,
civette assembly 40 when received by the technician has a reagent
in powder form in chamber 60-2 only. Three milliliters of distilled
water are added to chamber 60-2 to reconstitute the reagent and the
materials then mixed by inversion and then incubated at 37.degree.C
for 10 minutes. When the incubation period is complete, 100
milliliters of serum is added to chamber 60-2, the chamber is
resealed and subjected to mixing and then reincubation at
37.degree.C. The corresponding LDH data card 42 is inserted in card
reader 28; filter wheel 108 is rotated to position the 3400
Angstrom filter in the optical path 104 in response to an output on
line 130-2; logic 162 is signalled that a rate mode of operation is
to be performed in response to an output on line 130-3; the log
converter 134 is calibrated in response to an output on line 130-4;
switch 140 is set to connect the output of amplifier 148 to the
analog input of digital voltmeter 142 in response to an output on
line 130-7; switch 150 is set to connect precision voltage source
160 to the reference input of digital voltmeter 142 in response to
an output on line 130-5; and the units are set by an output on line
130-9.
In this mode, after the incubated cuvette assembly 40 has been
inserted in shuttle 100 upon depression of start button 34, the
shuttle is advanced until chamber 60-2 is positioned in the optical
path 104. At that point motor 102 is stopped. The log converter 134
has been in a zeroing mode. The initial absorbance reading,
transformed to voltage, has been established by the zeroing
operation of the log converter circuit 134 ends. Starting from this
point a linearly increasing voltage ramp is monitored over a period
of time. This ramp signal is differentiated by differentiator
circuit 144 to provide a signal which is passed by filter 146 and
absolute value amplifier 148 through switch 140 to the analog input
of digital voltmeter 142. At the end of the timing interval, the
digital voltmeter is strobed by an output on line 176 to digitally
display a reading in international units of the amount of lactic
dehydrogenase in the serum.
Thus the invention provides a convenient and versatile system for
performing a variety of chemical analyses and is particularly
useful in performance of analyses of blood and other body fluids.
Both mode selection and calibrating information is furnished by a
control record. The analysis sequence is automatically performed in
any of the modes solely in response to depression of start button
34. No manual adjustments are required. The system is easily
operated by untrained personnel and enables analytical information
to be made available quickly, accurately and inexpensively.
While a particular embodiment of the invention has been shown and
described, various modifications thereof will be apparent to those
skilled in the art. For example, the sample chambers may be
disposed in a cuvette carrier rather than in one piece unit.
Therefore it is not intended that the invention be limited to the
disclosed embodiment or to details thereof and departures may be
made therefrom within the spirit and scope of the invention as
defined in the claims.
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