Automatic chemical analyzer

• US 4,451,433 A
• Filed: 11/06/1981
• Issued: 05/29/1984
• Est. Priority Date: 11/10/1980
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Umetsu, Hiroshi, Matsuoka, Yoshio, Sato, Hirotaka, Yamashita, Katsuji, Kida, Kei
• Primary Examiner(s): Marcus, Michael S.
• Application Number:
  US06/319,078
• Time in Patent Office: 935 Days
• Field of Search: 340/501, 340/618, 340/615, 340/619, 340/624, 340/620, 340/825, 364/497, 364/498, 364/500, 364/509, 422/64, 422/65, 422/63, 422/66, 422/67, 422/100, 73/308, 73/313, 222/58, 222/64, 222/67
• US Class Current: 422/63
• CPC Class Codes: G01N 2035/00673 of reagents
• CPC Class Codes: G01N 2035/1025 Fluid level sensing
• CPC Class Codes: G01N 2035/1086 Cylindrical, e.g. variable angle
• CPC Class Codes: G01N 35/00663 of consumables
• CPC Class Codes: G01N 35/02 using a plurality of sample containers moved by a conveyor system past one or more treatment or analysis stations G01N35/0098 and G01N35/0099 take precedence
• CPC Class Codes: G01N 35/1004 Cleaning sample transfer devices
• CPC Class Codes: G01N 35/1011 Control of the position or alignment of the transfer device
• CPC Class Codes: G01N 35/1083 with one horizontal degree of freedom
• CPC Class Codes: Y10T 436/119163 with aspirator of claimed structure
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

An automatic chemical analyzer suitable for chemically analyzing a number of analysis items is disclosed. Samples in sample containers are sequentially dispensed to an array of reaction vessels using a first pipetting tube. Reagent solutions selected in accordance with the analysis items are fed to the reaction vessels using a second conductive pipetting tube. The reaction solutions in the reaction vessels are measured by a photometer. When the reagent solutions are sucked into the second pipetting tube, the liquid levels of the reagent solutions in the reagent containers are detected by a liquid level sensor formed by the second pipetting tube and a conductive electrode. The amounts of the reagent solutions remaining in the reagent containers are determined based on the position of the liquid level sensor and the numbers of times of dispense allowed to the reagent solutions with respect to the analysis items are displayed on a cathode ray tube.

Claims

1. An automatic chemical analyzer comprising:

a reaction vessel for retaining a sample and reaction solution;

first pipetting means having a first pipetting tube for sucking the sample therein from a sample container and transporting the sample sucked in said first pipetting tube into said reaction vessel;

a reagent container containing the reagent solution;

second vertically movable pipetting means having a second pipetting tube for sucking the reagent solution therein from said reagent container and transporting the reagent solution sucked in said second pipetting tube into said reaction vessel;

sensor means for sensing a liquid level of the reagent solution in said reagent container, said sensor means being vertically movable with the movement of said second pipetting tube, said sensor means including a pair of electrically conductive members, one of which is said second pipetting tube and the other of which is a probe having a lower end positioned above an open end of said second pipetting tube;

pulse motor means for vertically moving said sensor means;

means for producing a detection signal when the probe of said sensor means is brought into contact with the reagent solution in said reagent container;

means for obtaining information relating to the amount of the reagent solution remaining in said reagent container based on the position of said sensor means within said reagent container when said sensor means produces said detection signal;

means for displaying the information relating to the amount of the remaining reagent solution; and

measuring means for measuring physical characteristics of the reaction solution in said reaction vessel.

2. An automatic chemical analyzer comprising:

a plurality of reaction vessels;

a plurality of reagent containers each containing reagent solution different from each other;

pipetting tube means made of electrically conductive material having an open end for introducing a reagent solution;

metal electrode means having a lower end positioned slightly above the open end of said pipetting tube means;

means for relatively moving a pair comprised of said pipetting tube means and said metal electrode means with respect to said reagent containers;

means for detecting a conductive signal which is produced when both said pipetting tube means and said metal electrode means are in contact with one of said reagent solutions;

pulse motor means for vertically moving said pair of said pipetting tube means and said metal electrode means together;

means for applying pulses to said pulse motor means to vertically move said pair of the pipetting tube means and the metal electrode means and stopping said pair of the pipetting tube means and the metal electrode means in accordance with the occurrence of said conductive signal during the down movement thereof;

means for calculating and storing information relating to the amount of the reagent solutions remaining in said corresponding reagent containers on the basis of height positions of said pipetting tube means when said conductive signals are obtained;

visual display means for displaying said information relating to the amount of said remaining reagent solutions stored in said calculating and storing means; and

measuring means for measuring physical characteristics of a reaction solution in a reaction vessel after the reagent solution has been charged therein.

3. An automatic chemical analyzer according to claim 2, wherein said information relating to the amount of the remaining reagent solutions is the possible number of times of pipetting.

4. An automatic chemical analyzer comprising:

a plurality of reagent containers each containing a reagent solution different from each other;

a train of reaction vessels each for retaining a sample and reagent solution, said reaction vessels being positioned at a reagent receiving position in order;

pipetting tube means made of electrically conductive material having an open end for introducing the reagent solution;

metal electrode means having a lower end positioned slightly above the open end of said pipetting tube means;

means for moving a pair comprised of said pipetting tube means and said metal electrode means together between said reagent receiving position and at least one of said reagent containers;

means for detecting a conductive signal which is produced when both said pipetting tube means and said metal electrode means are in contact with one of said reagent solutions;

pulse motor means for vertically moving said pair of the pipetting tube means and the metal electrode means together;

means for applying pulses to said pulse motor means to vertically move said pair of the pipetting tube means and the metal electrode means and stopping movement of said pair of the pipetting tube means and the metal electrode means in accordance with the occurrence of said conductive signal during the down movement thereof;

means for calculating and storing information relating to the amount of the reagent solutions remaining in said corresponding reagent containers on the basis of the number of pulses applied to said pulse motor means;

visual display means for displaying said information relating to the amount of said remaining reagent solutions stored in said calculating and storing means; and

measuring means for measuring physical characteristics of a reaction solution in a reaction vessel after the reagent solution has been put therein.

5. An automatic chemical analyzer comprising:

a plurality of reaction vessels;

a plurality of reagent containers each containing reagent solution different from each other;

pipetting tube means made of electrically conductive material having an open end for introducing a reagent solution;

metal electrode means having a lower end positioned slightly above the open end of said pipetting tube means;

means for moving a pair comprised of said pipetting tube means and said metal electrode means together relative to each of said reagent containers;

means for detecting a conductive signal which is produced when both said pipetting tube means and said metal electrode means are in contact with one of said reagent solutions;

pulse motor means for vertically moving said pair of the pipetting tube means and the metal electrode means together;

means for applying pulses to said pulse motor means to vertically move said pair of the pipetting tube means and the metal electrode means, said pulse applying means stopping the pulses to said pulse motor means responsive to the occurrence of said conductive signal during the down movement thereof to stop the movement of said pair of the pipetting tube means and the metal electrode means, said pulse applying means stopping the pulses to said pulse motor means when said pipetting motor means reaches a lower limit position;

means for converting and storing the number of pulses to be applied to said pulse motor means by said pulse applying means while said pair of the pipetting tube means and the metal electrode means moves from a reference position to said stopping position, into information relating to the amount of the reagent solutions contained remaining in said corresponding reagent containers;

visual display means for displaying said information relating to the amount of said remaining reagent solutions;

means for detecting that said pair of the pipetting tube means and the metal electrode means reaches a predetermined height position during the up movement thereof to stop said pulse motor means;

control means for causing said visual display means to display said information relating to the amount of the remaining reagent solutions when it is ordered to obtain said information from said converting and storing means, and causing the analysis operation to continue with regard to possible analysis items even if a reagent solution for an analysis item fails; and

measuring means for measuring physical characteristics of a reaction solution in a reaction vessel after the reagent solution has been introduced therein.

6. An automatic chemical analyzer comprising:

a plurality of reaction vessels;

a plurality of reagent containers each containing a reagent solution;

pipetting tube means made of electrically conductive material having an open end for introducing a reagent solution;

metal electrode means having a lower end positioned slightly above the open end of said pipetting tube means;

means for detecting a conductive signal which is produced when both said pipetting tube means and said metal electrode means are in contact with one of said reagent solutions in a reagent container;

pulse motor means for vertically moving a pair of said pipetting tube means and said metal electrode means together;

means for applying pulses to said pulse motor means to vertically move said pair of the pipetting tube means and the metal electrode means, said pulse applying means stopping the pulses to said pulse motor means responsive to the occurrence of said conductive signal during the down movement thereof to stop the movement of said pair of the pipetting tube means and the metal electrode means, said pulse applying means stopping the pulses to said pulse motor means when said pipetting tube means reaches a lower limit position;

means for detecting that said pair of the pipetting tube means and the metal electrode means reaches a predetermined height position during the up movement thereof to stop said pulse motor means;

means for calculating and storing information relating to the amount of the reagent solutions remaining in said corresponding reagent containers on the basis of height positions of said pipetting tube means when said conductive signals are obtained;

visual display means for displaying said information relating to the amount of said remaining reagent solutions stored in said calculating and storing means; and

measuring means for measuring physical characteristics of a reagent solution in a reaction vessel after the reagent solution has been introduced therein.

7. An automatic chemical analyzer according to claim 6, wherein said lower limit position of said pipetting tube means is set to correspond to the bottom surface of said reagent container.

8. An automatic chemical analyzer according to claim 6, wherein said height detecting means includes a photocoupler for detecting the arrival at said predetermined height.

9. An automatic chemical analyzer according to claim 6, wherein a lower end of said pipetting tube means is positioned above an opening of said reagent container when said up movement is stopped.

10. An automatic chemical analyzer according to claim 6, further comprising means for causing said calculating and storing means to produce an alarm signal for alarming when said conductive signal is not produced until said pipetting tube means moves to said lower limit position during the down movement thereof.

11. An automatic chemical analyzer comprising:

a plurality of reaction vessels;

a plurality of reagent containers each containing a reagent solution;

pipetting tube means made of electrically conductive material having an open end for introducing a reagent solution;

metal electrode means having a lower end positioned slightly above the open end of said pipetting tube means;

means for detecing a conductive signal which is produced when both said pipetting tube means and said metal electrode means are in contact with one of said reagent solutions in a reagent container;

pulse motor means for vertically moving a pair comprised of said pipetting tube means and said metal electrode means together;

means for applying pulses to said pulse motor means to vertically move a pair of the pipetting tube means and the metal electrode means and stopping said pair of the pipetting tube means and the metal electrode means in accordance with the occurrence of said conductive signal during the down movement thereof;

means for calculating and storing information relating to the amount of the reagent solutions remaining in said corresponding reagent containers on the basis of height positions of said pipetting tube means when conductive signals are obtained;

visual display means for displaying said information relating to the amount of said remaining reagent solutions stored in said calculating and storing means; and

measuring means for measuring physical characteristics of a reaction solution in a reaction vessel after the reagent solution has been introduced therein.

12. An automatic chemical analyzer according to claim 11, further comprising control means for causing the analysis operation to continue with regard to possible analysis items even if a reagent solution for an analysis item fails.