JPH0444699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipette lowering control device in an automatic biochemical analyzer.

As is well known, in biochemical analysis, it is essential to accurately weigh the amount of specimen or reagent in order to maintain and improve data reliability. Detecting the liquid level is extremely important in ensuring the amount of sample, etc. aspirated by the pipette.

Conventionally, as a device for detecting the liquid level in a container and lowering a pipette, an electrode rod D is disposed adjacent to a metal pipette P, as shown in FIG. A pipette lowering control device is well known, which is configured to lower the pipette P until a conductive liquid K such as a sample is present between the electrode D and the pipette P, and to detect the liquid level h in the container B. ing.

However, in such a conventional pipette lowering control device, the electrode rod D and the metal pipette P
There are problems such as the possibility of electrolytic corrosion caused by current flowing between Electrode rod D when suctioning
Also, since it is necessary to clean the cleaning equipment, the cleaning equipment also becomes complicated.

The present invention was made in view of the current situation, and its purpose is to enable the pipette to be made of a material that does not cause electrolytic corrosion, and to detect the liquid level without bringing the liquid level detection means into contact with the liquid. It is an object of the present invention to provide a pipette lowering control device for an automatic biochemical analyzer that is easy to handle and can always accurately control the pipette lowering.

In order to achieve such an object, the present invention has a pipette lowering control device in an automatic biochemical analyzer that moves up and down perpendicularly to the surface of the sample liquid to aspirate the liquid in the container and transfer it to other containers. a pipette for delivering liquid to A reflective surface is formed on a part of the tip of the fiber, and is disposed opposite to the reflective surface, and is inclined at an angle of A light-emitting fiber whose surface normal line is inclined with respect to the optical axis of the fiber and an end face for emitting reflected light from a semi-transparent membrane, and a light-emitting fiber arranged perpendicular to the surface of the liquid to be tested. , a light input fiber that vertically receives the light emitted from the light output fiber reflected on the test liquid surface, a pipette, a means for holding the light output fiber and the light input fiber, and the amount of light received by the light input fiber. The pipette is comprised of a detection means for detecting the liquid level from the height of the pipette, and a drive means for controlling the descent of the pipette based on the output of the detection means.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

As shown in FIG. 2, the pipette lowering control device according to this embodiment has a pipette P for sucking up reagents or specimens K made of non-metallic material such as glass.
It is composed of a light-emitting fiber F ₁ and a light-input fiber F ₂ , which are fixed to a pipette holder 1 that guides the pipette up and down by a driving means A such as a pulse motor or a servo motor, and this light-emitting fiber F ₁ The light source light 2 is transmitted from the tip of the light output fiber F ₁ to the container B.
irradiate the liquid surface Ka of the reagent or sample etc.
The light entrance fiber _F2 picks up the reflected light reflected by this liquid surface Ka, and sends the data to the detection means S that detects the liquid surface height h, and the detection means S detects the data and The driving means A of the pipette P is driven to control the lowering and stopping of the pipette P.

The light output fiber F ₁ and the light input fiber F ₂ have the same structure as known fibers for optical communication, but in particular, the light output fiber F ₁ is different from the light source light 2 as shown in FIG. The liquid surface Ka at a given angle θ ₁
A reflective surface 3 is formed at the tip of the light emitting fiber F1, and the light source light 2 reflected by the reflective surface 3 is reflected by a semi-transparent membrane 4 tilted inside the tip of the light-emitting fiber _F1 . The angle is corrected and the predetermined angle θ ₁
The light is irradiated from the tip of the light output fiber _F1 . still,
The tip of the light input fiber F ₂ is the light output fiber F ₁ .
Light source light 2 irradiated at a predetermined angle θ ₁ hits the liquid surface.
The end face is inclined so that the normal line of the surface does not coincide with the optical axis so that the reflected light reflected at a predetermined angle θ ₂ at Ka can enter at a right angle (θ 1 = θ 2 ).

Therefore, according to the pipette lowering control device according to the above embodiment, the pipette P is slowly lowered by the drive device A when a sample or reagent is aspirated. At this time, the light source light 2 continues to be irradiated from the light output fiber _F1 , but if the distance to the liquid surface Ka is large, the light source light 2 is reflected by the liquid surface Ka, but is incident. Since no light enters the working fiber _F2 , the pipette P continues to descend. And Pipette P
When the light is lowered to a predetermined position, that is, the optimal suction position, the light source light 2 irradiated from the light output fiber _F1
is reflected by the liquid surface Ka at a predetermined angle θ ₂ and enters the light input fiber F ₂ . In this state,
The detection means S operates to stop the drive means A, so that the pipette P stops descending, and the suction and transfer of the sample, reagent, etc. K is started. Note that the line DL shown by the imaginary line in FIG. 2 is the lowermost position of the pipette P, and when the pipette P is lowered to this position, the pipette P will rise without aspirating the sample K. , is recorded as an error in the data program.

Therefore, in the pipette lowering control device according to this embodiment, the liquid level height h can be determined without bringing the light output and light input fibers F ₁ and F ₂ , which are the liquid level detection means, into contact with the liquid K. Since the downward movement of the pipette can be stopped upon detection, the above-mentioned fibers F ₁ and F ₂ will not be electrolytically corroded, and when aspirating other reagents or specimens K, only the pipette P needs to be cleaned. In addition to simplifying the cleaning equipment, the pipette P itself can be made of non-electrolytic corrosion material such as non-metallic material, so the quality of the sample, reagent, etc. does not change, and the reliability of data can be maintained and improved. At the same time, the pipette P can be continuously controlled to descend into the sample or reagent K to a predetermined depth regardless of the increase or decrease in the sample amount or reagent amount.

In the above embodiment, the case where the light output fiber _F1 is configured as described above is explained as an example, but the explanation is not necessarily limited to this, and for example, a prism or the like may be used. , in short, the light source light 2 is set at a predetermined angle θ ₁ from the light output fiber F ₁
Any means may be used as long as it is irradiated onto the liquid surface Ka.

Since the present invention includes the above configuration, the pipette and the liquid level detection means are not electrolytically corroded by the specimen, etc., so that deterioration of the specimen, etc. can be prevented, data reliability can be maintained and improved, and cleaning is also easy. Since the pipette can always be controlled to descend to a predetermined depth of the sample, the pipette can accurately aspirate the sample. Furthermore, the reflected light is incident at right angles to the end face of the light input fiber without tilting the light output fiber and the light input fiber with respect to the normal line of the liquid surface to be tested, reducing incidence efficiency and sensitivity. The installation space for each fiber can be reduced without having to

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram schematically showing the configuration of a conventional pipette lowering control device, FIG. 2 is an explanatory diagram schematically showing the configuration of a pipette lowering control device according to an embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view of the tip of the light-emitting fiber. A...Driving means, B...Container, _F1 ...Light output fiber, _F2 ...Light input fiber, K...Liquid,
P...Pipette, S...Detection means, 2...Light source light.

Claims (1)

[Claims] 1. In a pipette lowering control device in an automatic biochemical analyzer, there is a pipette that moves up and down perpendicular to the surface of the sample liquid to aspirate the liquid in a container and send it to another container, and a pipette that A semi-transparent membrane arranged perpendicular to the optical axis and a part of the tip of the fiber are formed so that the normal line of the surface is inclined with respect to the optical axis of the fiber, and the light source light transmitted through the semi-transparent membrane is A reflective surface is formed on a part of the tip of the fiber, and the normal line of the surface is inclined with respect to the optical axis of the fiber. , an end face for emitting the reflected light from the semi-transparent membrane, a light emitting fiber arranged perpendicular to the test liquid surface, and an end face for emitting the light reflected from the test liquid surface. A light input fiber that vertically receives the emitted light; a means for holding the pipette, the light output fiber, and the light input fiber; a detection means for detecting the liquid level height from the amount of light received by the light input fiber; and a detection means. A pipette lowering control device for a biochemical analyzer, comprising a driving means for controlling the lowering of the pipette by the output of the pipette.