JPS5822094Y2 - boundary detection device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a boundary detection device for detecting boundaries between different liquids separated into layers.

For example, when blood is submitted for analysis in a clinical test or the like, serum is separated from the blood in pretreatment.

If this serum separation is not carried out efficiently, there will be a delay in sample provision, even if automatic testing equipment with high throughput is available.
Its original processing power cannot be fully utilized.

For this reason, various improvements have been made to automate and increase the efficiency of serum collection.

An example of an optical detection method is to detect the boundary between serum and blood clot in a test tube by shining light from outside, and then lower the lower end of the serum suction nozzle just past the detection boundary, and then suck up only the serum. There has always been something that has been done.

However, with this type of device, the test tube must be completely transparent, and the boundary between serum and blood clot cannot be accurately determined by writing on the test tube, pasted labels, scratches, etc. There were some inconveniences such as the inability to detect the

Furthermore, depending on the specimen, the boundary between serum and blood clot may not be clearly separated, resulting in turbidity, so when such a specimen is measured using the optical method described above, the boundary between serum and blood clot may be far above the true interface. Boundaries are detected at different positions, which reduces the amount of serum absorbed, resulting in drawbacks such as extreme variation in the amount of sample provided depending on the individual specimen.

This idea was created in view of the problems mentioned above.
A light emitting/receiving axis is provided with a light emitter and a light receiver at one end, and the tip of the light emitting/receiving axis is inserted into the sample container and approached orthogonally toward the separation interface of the different liquids separated into layers. The insertion depth of the transmitting and receiving light axes is controlled based on the amount of light received by the light receiver, and as a result, the sample container does not need to be made of transparent material, and it is free from scratches, dirt, letters written on it, etc. The tip of the transmitting/receiving optical axis is made of a transparent material, and the tip surface of the transparent material is a plane inclined at a predetermined angle with respect to a plane orthogonal to the transmitting/receiving optical axis. By refracting the transmitted light from the transmitting/receiving optical axis using the tip surface of this transparent material and irradiating this transmitted light obliquely to the boundary surface, the measurement accuracy is greatly improved compared to conventional methods. The present invention provides a boundary detection device as described above.

Hereinafter, an example in which this invention is applied to a serum fractionation device will be described in detail with reference to the drawings.

In FIG. 1, a light emitting/receiving axis 1 connects each optical fiber to a light emitting optical fiber 2 formed by bundling a large number of optical fibers, and a light receiving optical fiber 3 configured similarly to the light emitting optical fiber 2. are randomly tied together with adhesive, each with a light,
l:1. , l, forms a traveling path of 2.

The light emitting/receiving axis 1 thus formed has a light emitting optical fiber 2 and a light receiving optical fiber 3 at its base end.
are separated, and a projector 4 is provided on the proximal end surface of the former, and the lights t and l from this projector 4 enter, and the light exits from here to the proximal end surface of the latter, which has been split. The light-receiving surfaces of the light-receiving element 5 that receives the transmitted light t2 and photoelectrically converts it are opposed to each other.

Further, as shown in an enlarged view in FIG. 2, a transparent material 9 such as glass or plastic is integrally attached to the tip of the transmitting/receiving optical axis 1.

The front end surface 9a of this transparent material 9 is connected to the above-mentioned light emitting/receiving axis 1.
The plane is inclined at a predetermined angle with respect to a plane orthogonal to the plane.

Therefore, the transmitted light tl from the light projector 4 is transmitted while being reflected inside the light projecting optical fiber 2, and is refracted at an angle corresponding to the tip surface 9a of the transparent material 9 at the tip and is emitted. The light tl is irradiated obliquely to the boundary surface.

The reflected light (light t2) resulting from this irradiation enters the light-receiving optical fiber 3 through the transparent substance 9, is transmitted while being reflected inside, and is emitted from its base end surface. , when the front end surface 9a of the transparent material 9 and the boundary surface are sufficiently far apart, the optical axis of the light 7.1 is located at the front end surface 9a.
Since the light receiving optical fiber 3 is bent, the reflected light hardly hits the tip end face of the light receiving optical fiber 3, and therefore the amount of light incident on the light receiving element 5 is extremely small.

When the distance between the tip end surface 9a and the boundary surface becomes extremely close, the amount of light incident on the light receiving element 5 rapidly increases because it is no longer affected by the decrease in the amount of light received due to the deviation of the optical axis.

Furthermore, reference numeral 10 denotes a cylindrical slippery member having a surface smoothness such as Teflon resin, which covers the outer periphery of the transmitting/receiving optical axis 1 and the transparent material 9 provided at its tip.
This prevents the transmitting/receiving optical axis 1 from getting dirty due to immersion in the specimen.

FIG. 3 shows a state where the above-mentioned light emitting/receiving axis 1 is inserted into a test tube 6 together with a serum suction nozzle 11.

In the figure, the projection/reception optical axis 1 is attached to a holder 12 supporting a serum suction nozzle 11, and positioned so that its tip protrudes slightly below the tip of the suction nozzle 11.

The holder 12 is connected to a moving device (not shown), which moves the suction nozzle 7 together with the test tube 6 along with the light emitting/receiving axis 1.
It is designed so that it can be inserted inside the case and pulled out from there.

Further, 13 is a light amount measurement circuit for measuring the amount of light received by the light receiving element 5, and 14 is a discrimination circuit connected to the output side of this measurement circuit 13. When compared with the reference value Ls, the discrimination signal, that is, when the tip of the light emitting/receiving axis 1 approaches the interface between the serum 7 and the blood clot 8 in the test tube 6, the amount of received light Lx reaches the reference value Ls. The signal is configured to be emitted.

This discrimination signal is sent to a control circuit 15, which controls each operation of the moving device and the suction nozzle 11.

That is, after the test tube 6 containing the serum 7 and the blood clot 8 in a separated state is positioned directly below the transmitting/receiving optical axis 1 and the suction nozzle 11, the transmitting/receiving optical axis 1 is connected to the suction nozzle 1.
1 and is lowered at a predetermined speed, but when a discrimination signal is input to the control circuit 15, the lowering operation is stopped and the suction operation is performed.

Next, the characteristics of the boundary detection device configured as described above will be explained using FIGS. 4a and 4b.

For comparison with the device of the present invention, FIG.
This figure shows the characteristics of a boundary detection device that is equipped with a transparent material 16 whose front end surface 16a is parallel to the boundary surface of the substrate.

That is, FIGS. 4a and 4b are graphs showing the results of comparative measurements of three different specimens A, B, and C using each of the boundary detection devices described above, and the horizontal axis is the boundary surface 1. The vertical axis indicates the amount of light received.

Furthermore, the interface between serum and blood clot is clearly separated in the order of A<B<C.

In this case, in Figure a, the light t1 is irradiated perpendicularly to the boundary surface, so even if the distance between the boundary surface and the tip of the transmitting/receiving optical axis 1 is long, the amount of light received is relatively large. As a result, the characteristic curve becomes gentle.

Therefore, when the tip of the light emitting/receiving axis 1 is moved by the moving device and the amount of received light Lx reaches the stop position, that is, the reference Ls, the light emitting/receiving axis 1 stops, but the distance between this stop position and the true boundary surface is The order in which the boundary surface is clear, that is, specimen C(B(A
order, and their separation distances d□, d2. As is clear from the drawings, the difference between d3 and d3 is extremely different, and the amount of serum aspirated varies significantly depending on each specimen.

On the other hand, in the figure, the light t1 is irradiated obliquely to the boundary surface, so if the distance between the boundary surface and the tip of the transmitting/receiving optical axis 1 is far, the amount of light received will not be extremely small; When the light beams are sufficiently close to each other, the amount of light received by the light emitting/receiving axis 1 increases significantly, and as a result, its characteristic curve rises rapidly.

Therefore, the stopping position of the transmitting/receiving optical axis 1 and the true boundary surface are the same as above, the specimen C (B (A order), but the separation distance d1
．． d2. Since the difference between d3 is small, the variation in the amount of serum aspirated between each specimen is extremely small.

In this example, the transmitting and receiving light axes inserted into the sample container are made of optical fibers, so the diameter can be reduced, making the device much smaller than the conventional system that uses a pair of transmitting and receiving devices. Moreover, the shape of the shaft can be changed according to the object to be measured.

FIG. 6 shows another embodiment of this invention.

It should be noted that other parts of this embodiment are the same as those of the first embodiment, so explanations of symbols and drawings thereof will be omitted.

In the figure, the projection/reception optical axis 20 has a cylindrical shape, and the tip thereof is made of glass, plastic, etc. whose tip end surface is a plane inclined at a predetermined angle with respect to the plane perpendicular to the projection/reception optical axis 20, as in the above-described embodiment. A transparent material 9 is integrally attached.

In addition, a pair of condensing lenses 2 is provided on the base end side of the light emitting and receiving optical axis 200.
1 and 22 are arranged, and a half mirror 23 tilted by 45 degrees with respect to the axis of the projection/reception optical axis 20 is arranged above the condenser lens.

Reference numeral 24 denotes a light projector, that is, a light source, provided above the mirror 23 and on the extension axis of the light emitting/receiving axis 20, and the light t1 from the light source 24 passes through the mirror 23, and A beam-like optical path is formed within the projection/reception optical axis 20 by the pair of lenses 21 and 22, and as a result of being refracted and emitted by the tip surface 9a of the transparent material 9, this light t1 is obliquely directed to the boundary surface. irradiated.

Furthermore, the reference numeral 25 denotes a light-receiving element that is disposed opposite to the mirror 23 and perpendicular to the axial direction of the projection/reception optical axis.

Therefore, the reflected light from the irradiation passes through the transparent material 9 and the lenses 21 and 22 and hits the .

If a boundary detection device is constructed using the light emitting/receiving axis 20 constructed in this manner, the detection characteristics shown in FIG. 4 can be obtained as in the first embodiment.

FIG. 7 shows a modification of FIG. 6, in which the transparent material 30 is formed into a long round rod shape.

The front end surface of the transparent material 30 is formed into a plane that is inclined at a predetermined angle with respect to the plane perpendicular to the light projection axis, as in the above-described embodiment.

In this embodiment, only the transparent substance 30 needs to be immersed into the specimen, so the diameter of the detection part can be made smaller as the amount of specimen is reduced.
Moreover, the structure becomes simple.

As described above for each of the embodiments, in the boundary detection device according to the present invention, a light emitting and receiving axis is provided with a light emitter and a light receiver at one end, and the tip of this light emitting and receiving axis is inserted into a sample container. The device approaches orthogonally toward the separation interface of different liquids separated into layers, and the insertion depth of the emitting and receiving optical axes is controlled based on the amount of light received by the receiver, so conventional optical detection is not possible. Compared to other methods, it is not affected by scratches or dirt on sample containers such as test tubes, or by letters written on them or labels pasted on them, and the sample container itself must be made of opaque material. Moreover, since the diameter of the part inserted into the sample container can be made smaller as the amount of sample is reduced, even a small amount of sample can be detected effectively.

Further, the tip of the light emitting/receiving axis is made of a transparent material, and the tip surface of the transparent material is formed into a plane inclined at a predetermined angle with respect to a plane perpendicular to the light emitting/receiving axis. The surface refracts the transmitted light from the projection/reception optical axis and irradiates the transmitted light obliquely to the boundary surface. Therefore, depending on the specimen, such as serum, the boundary between serum and blood clot may occur. The detection characteristics shown in Figure 4 can be obtained even when the samples are not clearly separated and are cloudy, so detection is performed at the closest distance to the true interface, and the detection characteristics of each sample are It has various advantages, such as extremely small variations and greatly improved measurement accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a boundary detection device according to this invention;
FIG. 2 is a partially enlarged sectional view of the tip of the transmitting and receiving optical axis, and FIG. 3 is a schematic side view showing the moving part of the boundary detection device according to this invention.
FIGS. 4a and 4b are graphs showing the detection characteristics of the boundary detection device,
Fig. 5 is a partially enlarged sectional view of the tip of the transmitting and receiving optical axis of a boundary detection device for comparison with the present invention, Fig. 6 is a schematic side sectional view showing another embodiment of this invention, and Fig. 7 is a further modification of the present invention. It is a side cross-sectional schematic diagram which shows another Example. 1.20...Emission/reception optical axis, 4,24...
Emitter, 5.25...Receiver, 9,30...
...transparent substance, 9a, 30a...tip surface,
7...Serum, 8...Blood clot, 15...
...Control circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A light emitting/receiving axis having a light emitter and a light receiver provided at one end thereof, which is inserted into a sample container at the tip of the light emitter/receiver and directed toward the separation interface of different liquids separated into layers. The insertion depth of the light emitting and receiving light axes is controlled based on the amount of light received by the light receiver, and the tip of the light emitting and receiving axes is made of a transparent material, and the transparent material The front end surface of the transparent material is a plane inclined at a predetermined angle with respect to a plane perpendicular to the projection/reception optical axis, and the transmitted light from the projection/reception optical axis is refracted by the front end surface of the transparent material and irradiated obliquely to the boundary surface. A boundary detection device characterized by being configured as follows. 2. Utility model registration claim 1, characterized in that the above-mentioned light emitting and receiving axis is constituted by bundling together an optical fiber having a light emitter at one end and an optical fiber having a light receiver at one end. The boundary detection device described. 3 The transmitting/receiving optical axis has a cylindrical shape, and the transparent material is attached to the tip thereof, and the emitter and receiver are optically branched from each other via a no-fler, and the light from the emitter is 2. The boundary detection device according to claim 1, wherein the light forms a beam-like optical path within the projection/reception optical axis via a lens. 4. The boundary detection device according to claim 2, wherein the projection/reception optical axis and the outer periphery of the transparent material are covered with a slippery member having surface smoothness.