Automatic analyzer and method for determining malfunction thereof

Patent metadata

Field	Value
Publication number	US-9470570-B2
Application number	US-201214239958-A
Country	US
Kind code	B2
Filing date	May 17, 2012
Priority date	Sep 20, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

An automatic analyzer which performs a suction operation a plurality of times on a same sample has a sample dispensing unit 9 , a liquid level sensor which detects the liquid level of the sample in a sample vessel 8 , an arithmetic unit 5 which computes a liquid level height h 1 at the end of a first suction operation of the two consecutive suction operations from a liquid level height h 0 and a sample suction volume V 1 detected at the start of the first suction operation, a storage unit 7 which stores the liquid level height h 1 computed by the arithmetic unit 5 , and a determination unit 18 which compares a liquid level height h 2 detected at the start of a second suction operation following the first suction operation with the liquid level height h 1 at the end of the first suction operation.

First claim

The invention claimed is:

1. An automatic analyzer which performs a suction operation a plurality of times on a same sample, the automatic analyzer comprising:
a sample dispensing unit;
a liquid level sensor for detecting a liquid level of the sample in a sample container;
calculation means for calculating a height of a liquid level at an end of a first suction operation of two consecutive suction operations from a height of a liquid level and a sample suction volume detected at a start of the first suction operation;
storage means for storing the height of the liquid level calculated by the calculation means; and
malfunction determination means for comparing a height of a liquid level detected at the start of a second suction operation following the first suction operation with the height of the liquid level at the end of the first suction operation and determining presence or absence of a failure in the first or second suction operation according to whether a difference between both liquid level heights exceeds a threshold value set in advance.

2. The automatic analyzer according to claim 1 , comprising:
a pressure sensor for measuring a suction pressure of the sample by the sample dispensing unit;
storage means for storing a pressure change amount detected by the pressure sensor; and
malfunction determination means for comparing pressure change amounts in the first and second suction operations and further determining the presence or absence of a failure in the first or second suction operation according to whether the difference between both pressure change amounts exceeds a pre-set threshold value when the difference between the height of the liquid level at the end of the first suction operation and the height of the liquid level at the start of the second suction operation is the threshold value or less.

3. The automatic analyzer according to claim 1 , comprising notification means for notifying that there is a malfunction when it has been determined by the malfunction determination means.

4. The automatic analyzer according to claim 1 , wherein when the difference between the height of the liquid level at the end of the first suction operation and the height of the liquid level at the start of the second suction operation exceeds the threshold value, the malfunction determination means determines that there is a malfunction in the first suction operation at an eventuality of the height of the liquid level at the end of the first suction operation being the larger, and determines that there is a malfunction in the second suction operation at an eventuality of the height of the liquid level at the start of the second suction operation being the larger.

5. The automatic analyzer according to claim 2 , wherein the pressure sensor is disposed between a sample probe and a sample dispensing cylinder.

6. The automatic analyzer according to claim 1 , wherein the liquid level sensor is an electrostatic capacitance type sensor.

7. An automatic analyzer which performs a suction operation a plurality of times on the same sample, the automatic analyzer comprising:
a sample dispensing unit;
a pressure sensor for measuring a suction pressure of the sample by the sample dispensing unit;
storage means for storing a pressure change amount detected by the pressure sensor; and
malfunction determination means for comparing pressure change amounts at the two consecutive suction operations and determining the presence or absence of a failure in the first or second suction operation according to whether the difference between both pressure change amounts exceeds a threshold value set in advance.

8. A malfunction determination method for an automatic analyzer which performs a suction operation a plurality of times on the same sample, comprising:
calculating a height of a liquid level at the end of a first suction operation of the two consecutive suction operations from a height of a liquid level and a sample suction volume detected at the start of the first suction operation; and
comparing a height of a liquid level detected at the start of a second suction operation following the first suction operation with the height of the liquid level at the end of the first suction operation and determining the presence or absence of a failure in the first or second suction operation according to whether the difference between both liquid level heights exceeds a threshold value set in advance.

9. The malfunction determination method for the automatic analyzer according to claim 8 , comprising comparing pressure change amounts in the first and second suction operations and further determines the presence or absence of a failure in the first or second suction operation according to whether the difference between both pressure change amounts exceeds a threshold value set in advance when the difference between the height of the liquid level at the end of the first suction operation and the height of the liquid level at the start of the second suction operation is the threshold value or less.

10. The malfunction determination method for the automatic analyzer according to claim 8 , comprising determining that there is a malfunction in the first suction operation when the height of the liquid level at the end of the first suction operation is large, and determines that there is a malfunction in the second suction operation when the height of the liquid level at the start of the second suction operation is large when the difference between the height of the liquid level at the end of the first suction operation and the height of the liquid level at the start of the second suction operation exceeds the threshold value.

11. A malfunction determination method for an automatic analyzer which performs a suction operation a plurality of times on the same sample, comprising comparing pressure change amounts at the two consecutive suction operations and determining the presence or absence of a failure in the first or second suction operation according to whether the difference between both pressure change amounts exceeds a threshold value set in advance.

Assignees

• Nishida Masaharu
• TAMEZANE Hideto
• Yamazaki Isao
• Kamihara Kumiko
• Mimura Tomonori
• Hitachi High Tech Corp

Inventors

• Nishida Masaharu
• TAMEZANE Hideto
• Yamazaki Isao
• Kamihara Kumiko
• Mimura Tomonori

Classifications

• G01N35/1011 Primary

  Control of the position or alignment of the transfer device · CPC title

• G01F23/00 Primary

  Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm · CPC title

• G01N2035/1025

  Fluid level sensing · CPC title

• G01N2035/009

  alarms, e.g. audible · CPC title

• G01L7/00

  Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements ({G01L11/004 takes precedence;} transmitting or indicating the displacement of mechanical pressure-sensitive elements by electric {, e.g., photoelectric} or magnetic means G01L9/00; measuring differences of two or more pressure values G01L13/00; measuring two or more pressure values simultaneously G01L15/00) · CPC title