JP2017083244A - Light measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light measuring device in which a measuring light path length is substantially defined as a constant size regardless of the shape and the size of a sample tube to be used and capable of obtaining a highly accurate measuring accuracy.SOLUTION: A light measuring device according to the present invention includes: a structure having a sample tube reception hole part for receiving a sample tube having a taper part whose outer diameter becomes gradually smaller as heading to the bottom part and an incident opening of the measuring light for the sample tube arranged in the sample tube reception hole part and an outgoing opening of the detection light from the sample tube. The structure includes a protrusion part for locating an insertion position of the sample tube by abutting against the outer peripheral surface of the taper part of the sample tube at a level on which an inner peripheral surface of the sample tube reception hole part is formed with the incident opening.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light measuring device such as an absorbance measuring device or a fluorescence measuring device.

In recent years, in the life science field, as a request for an optical measuring device such as an absorbance measuring device or a fluorescence measuring device, it is required to be small and easy to carry for the purpose of use in a point-of-care test.
For example, Patent Document 1 discloses a solid-state light source that irradiates a measurement sample in a sample case with excitation light, a fluorescence measurement device that detects fluorescence, and a fluorescence collection optics that guides fluorescence emitted from the measurement sample to the fluorescence measurement device. A fluorescence measuring device is described in which the system is embedded in a resin transparent to excitation light and light containing fluorescence. In this fluorescence measuring instrument, a PCR tube having a tapered tip is used as a sample case, and the PCR tube is set by being inserted into a sample case insertion portion in a housing made of the resin.

JP 2014-032064 A

Sample tubes with various sizes and shapes are known for storing liquid measurement samples. For example, the target sample injection amount is, for example, 0.2 ml (for PCR), 1.5 ml, 2.0 ml, or the like. For this reason, in the fluorescence measuring device described in Patent Document 1, the installation state of the sample tube with respect to the measuring device main body is different for each sample tube used. In addition, since the sample tubes have tolerances that inevitably occur in manufacturing, even when the same type of sample tubes are used, the installation state with respect to the measuring instrument main body can be different.
When the installation state of the sample tube changes, the measurement optical path length, which is the distance that the light from the light source passes through the measurement sample, will change, even if the same optical measurement device is used for the analysis sample of the same concentration, There may be a difference in measurement results.

  The present invention has been made based on the above circumstances, and the measurement optical path length can be made substantially constant regardless of the shape and size of the sample tube used. An object of the present invention is to provide an optical measurement device capable of obtaining measurement accuracy.

The optical measuring device of the present invention is a sample tube receiving hole for receiving a sample tube having a tapered portion whose outer diameter is gradually reduced toward the bottom, and a measurement for the sample tube disposed in the sample tube receiving hole. And a light guide path space in which an opening for incident light for light and an opening for emitting light for detection from the sample tube open at positions facing each other on the inner peripheral surface of the sample tube receiving hole. And
The insertion position of the sample tube is positioned with respect to the structure by contacting the outer peripheral surface of the tapered portion of the sample tube at the level where the entrance opening is formed on the inner peripheral surface of the sample tube receiving hole. It has the projection part which carries out.

In the light measurement device of the present invention, it is preferable that the protrusion is positioned at a level position of the optical axis of the measurement light passing through the light guide space.

  According to the optical measurement device of the present invention, since the insertion position of the sample tube with respect to the sample tube receiving hole is positioned with respect to the structure by the protrusion, the measurement is performed regardless of the shape and size of the sample tube used. The optical path length can be made substantially constant, and a highly accurate measurement result can be obtained.

It is sectional drawing which shows the outline of a structure in an example of the structure which concerns on the optical measurement apparatus of this invention. It is an enlarged view which shows the PQRS surrounding part in FIG. It is sectional drawing which shows roughly the structure of the principal part in the other example of the structure which concerns on the optical measurement apparatus of this invention. It is the sectional view on the AA line in FIG.

  The light measurement device of the present invention is configured as a small portable device that is easy to carry, and is used, for example, to measure the concentration of a measurement target substance in a liquid measurement sample accommodated in a sample tube. Is. In the following, the light measurement device of the present invention will be described by taking as an example an apparatus configured as an absorbance measuring device. Examples of the substance to be measured include Escherichia coli, protein, DNA obtained by amplification by polymerase chain reaction (PCR), dye, and the like.

The light measurement device of the present invention includes a sample tube receiving hole for receiving a sample tube, an opening for measurement light incident on the sample tube disposed in the sample tube receiving hole, and a detection light from the sample tube. And a light guide path space that opens to positions facing each other on the inner peripheral surface of the sample tube receiving hole.
The sample tube 45 is, for example, a microtube or the like, and has a tapered portion 46 whose outer diameter decreases toward the bottom (see FIG. 1).

FIG. 1 is a cross-sectional view showing an outline of the configuration of an example of a structure according to the light measurement apparatus of the present invention. FIG. 2 is an enlarged view showing a PQRS surrounding portion in FIG.
The structural body 10 is configured such that the light source unit 20 and the light receiving unit 25 are held by the light guide path forming member 11 and the sample bracket 30 is provided on the light guide path forming member 11.

  The light guide path forming member 11 has, for example, a block shape, a through hole 13 extending horizontally with respect to the bottom surface forming the columnar light guide path space 12, and a truncated cone shape having a small diameter toward the bottom opening on the top surface. And a central through-hole 16 that forms a space portion. The central axis of the central through hole 16 is orthogonal to the central axis of the through hole 13.

The light guide path forming member 11 is preferably made of, for example, a light-absorbing material, and in particular, made of an elastic material having an absorptivity for light other than detection light emitted from the sample tube. Preferably it is. Thereby, reflection and scattering of light other than the detection light can be suppressed on the wall surface of the light guide path space 12, and only the detection light can be incident on the light receiving unit 25.
Specifically, a silicone resin such as black polydimethylsiloxane (PDMS) in which carbon black, carbon nanotubes, and the like are dispersed can be preferably used as the elastic material having light absorption.

  A light source unit 20 is disposed at one end of the through hole 13 in the light guide path forming member 11, and a light receiving unit 25 is disposed at the other end of the through hole 13.

  The light source unit 20 includes a substrate 21 and a light source 22 provided on the substrate 21. The light source 22 is provided in the light guide path space 12 of the light guide path forming member 11 with its optical axis positioned coaxially with the central axis of the light guide path space 12. As the light source 22, for example, a white LED that emits white light can be used.

  The light receiving unit 25 includes a sensor substrate 26 and a light receiving sensor 27 provided on the sensor substrate 26. The light receiving sensor 27 is provided in a state where the light receiving surface faces the light source 22 in the light guide path space 12 of the light guide path forming member 11. As the light receiving sensor 27, for example, a photodiode such as an RGB color sensor can be used.

  The sample bracket 30 includes a plate-like portion 31 that extends horizontally and a truncated cone-like tubular portion 32 that extends perpendicularly to the plate-like portion 31 on the bottom surface side of the plate-like portion 31. The sample bracket 30 is provided with a cylindrical portion 32 fitted into the central through-hole 16 of the light guide path forming member 11, whereby the sample tube receiving hole 18 is formed by the internal space of the cylindrical portion 32. Is formed.

  The cylindrical portion 32 of the sample bracket 30 is formed with communication holes 38 a and 38 b that allow the internal space of the cylindrical portion 32 and the light guide path space 12 of the light guide path forming member 11 to communicate with each other. The communication holes 38a and 38b are positioned coaxially with the central axis of the light guide path space 12 of the light guide path forming member 11, and the measurement light entrance opening 14a and the detection light exit opening 14b are provided in the sample tube. Openings are formed at positions facing each other on the inner peripheral surface of the receiving hole 18. Thereby, an optical path of measurement light and detection light from the light source 22 to the light receiving sensor 27 through the sample tube receiving hole 18 is formed with the optical axis O as the central axis of the light guide path space 12.

  A cylindrical support portion 34 is formed on the upper surface of the sample bracket 30 so as to surround the periphery of the sample tube insertion opening of the cylindrical portion 32 so as to extend in the vertical direction. An elastic body 40 such as a sponge is provided on the inner peripheral surface of the support portion 34. The support portion 34 functions as a position restricting member in the radial direction of the sample tube 45 disposed in the sample tube receiving hole portion 18. Therefore, the sample tube 45 has a posture in which the central axis extends in the vertical direction, It is arranged in the tube receiving hole 18. Since the elastic body 40 is provided on the inner peripheral surface of the support portion 34, the elastic body 40 is elastically deformed according to the outer diameter of the sample tube 45, so that the dimensional difference of the used sample tube 45 is reduced. Can be absorbed.

Thus, in the structure according to the present invention, the outer peripheral surface of the tapered portion 46 of the sample tube 45 at the level where the measurement light incident opening 14a is formed on the inner peripheral surface of the sample tube receiving hole portion 18. And a projection 35 that positions the insertion position of the sample tube 45 with respect to the structure 10. The level of the incident opening 14a refers to a level within the range of the upper edge level position L _H and the lower edge level position L _L of the incident opening 14a. The protrusion 35 may be positioned at a level within the range, but is positioned at the level of the central axis of the light guide path space 12, that is, the optical axis O of the measurement light passing through the light guide path space 12. It is preferable. Thereby, the difference in the measurement optical path length L _O due to the difference in the shape and size of the sample tube 45 to be used can be made as small as possible, and the measurement can be performed with high accuracy. The measurement optical path length L _O is a distance through which the measurement light passes through the measurement sample in the sample tube 45, and in this example, is indicated by the size of the inner diameter of the sample tube 45 on the optical axis O of the measurement light. .

  The protrusion 35 is an outer peripheral edge of the cylindrical portion 32 that passes through the opening edge position of the sample tube receiving hole 18 in a cross section including the central axis C of the sample tube receiving hole 18 and the central axis of the light guide path space 12. As long as the shape protrudes in the direction of the central axis of the sample tube receiving hole 18 with respect to an imaginary straight line N parallel thereto.

  The protrusion 35 in this example is configured by an annular protrusion extending over the entire circumference in the circumferential direction of the sample tube receiving hole 18, and the top is positioned at the level position of the optical axis O of the measurement light. Specifically, the annular protrusion is a first inclined surface constituting the inner peripheral surface of the sample tube receiving hole 18 in a cross section including the central axis C of the sample tube receiving hole 18 and the optical axis of the light guide. 33a and a second inclined surface 33b. The first inclined surface 33 a and the second inclined surface 33 b are different in inclination angle with respect to the central axis of the sample tube receiving hole 18, and the ridge line portion by the inclined surfaces 33 a and 33 b is a tapered portion of the sample tube 45. 46 abuts the outer peripheral surface of 46. The protrusion 35 may have a shape having a convex curved surface.

When one structural example of the structure 10 is shown, the inner diameter of the through hole 13 (light guide path space 12) in the light guide path forming member 11 is φ3.0 mm. The inner diameters of the communication holes 38a and 38b in the sample bracket 30 are φ1.7 mm. The diameter of the sample tube insertion opening of the sample tube receiving hole 18 is φ7 mm, and the inner diameter at the level of the incident opening 14 a is φ3 to φ4 mm. The distance between the light source 22 and the light receiving sensor 27 is 35 mm, and the measurement optical path length L _O is 2.5 to 4.0 mm.

Hereinafter, the optical measurement in the light measuring device (absorbance measuring device) provided with the structure 10 will be described.
In the structure 10, the measurement light emitted from the light source 22 is applied to the liquid measurement sample in the sample tube 45 received in the sample tube receiving hole 18, and the measurement sample in the sample tube 45 is irradiated with the measurement light. The light for detection emitted through and transmitted is detected by the light receiving sensor 27. At this time, the measurement light is absorbed according to the concentration of the measurement target substance contained in the measurement sample, and the light amount is reduced. Specifically, when the measurement light passes through the measurement sample, the transmittance attenuates exponentially with respect to the measurement optical path length in accordance with the concentration of the measurement target substance. Therefore, by measuring the light amount of the detection light emitted through the measurement sample in the sample tube 45, the degree of decrease in the light amount of the measurement light, that is, the concentration of the measurement target substance according to the absorbance is measured. Can do. The concentration of the measurement target substance is determined by, for example, preparing a calibration curve in advance using a standard solution of the measurement target substance having a known concentration as a reference sample, and calculating the amount of detection light detected by the light receiving sensor 27. It can be obtained by comparing with the calibration curve.

Thus, in the optical measurement apparatus provided with the structure 10 described above, the protrusion 35 formed on the inner peripheral surface of the sample tube receiving hole 18 in the structure 10 is used to the sample tube receiving hole 18. The maximum outer diameter of the sample tube 45 that is allowed to be inserted is regulated. That is, the projection 35 is brought into contact with a position having a constant outer diameter dimension in the tapered portion 46 of the sample tube 45. Thereby, the insertion position of the sample tube 45 is positioned with respect to the structure 10. As a result, since the projection 35 is positioned at the level of the entrance opening 14a, the measurement optical path length L _{O is set} to a substantially constant size regardless of the shape and size of the sample tube 45 used. be able to. Therefore, according to the above-described optical measurement device, there is almost no measurement error due to the fluctuation of the optical path length L _{O for} each sample tube 45, and a highly accurate measurement result can be obtained.

  As described above, the optical measuring device of the present invention is configured as a small portable device that is easy to carry, and can obtain highly accurate measurement results, and does not require optical adjustment or the like. Therefore, for example, it is suitable for a point-of-care inspection.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, the protrusion does not need to be an annular protrusion formed so as to extend over the entire circumference in the circumferential direction on the inner peripheral surface of the sample tube receiving hole, and may be constituted by a columnar protrusion, for example.
FIG. 3 is a cross-sectional view schematically showing a configuration of a main part in another example of a structure according to the light measurement apparatus of the present invention. 4 is a cross-sectional view taken along line AA in FIG. In this structure, a plurality of columnar protrusions 36 abut on the outer peripheral surface of the tapered portion 46 of the sample tube 45 at the upper edge level position (the position of the line AA) of the entrance opening 14a, and the protrusion portion 35 is configured. ing. The number and position of the columnar protrusions 36 are not particularly limited as long as the sample tube 45 can be supported in an appropriate posture. 3 and 4 are drawn with emphasis on the columnar projections 36 for easy understanding, but in actuality, the hole for receiving the sample tube on the optical axis O of the measuring light is shown. The distance between the inner peripheral surface of the portion 18 and the outer peripheral surface of the tapered portion 46 of the sample tube 45 is, for example, about 0.3 to 0.5 mm.
Even if the structure having such a structure is provided, the same effect as that of the optical measurement device including the structure according to the above-described embodiment can be obtained.

  In the structure, the sample bracket is not essential, and the trial tube may be directly inserted into and removed from the light guide path forming member. In this case, what is necessary is just to form a projection part in the predetermined position in the internal peripheral surface of the center through-hole in a light guide path formation member. However, when the light guide path forming member is formed of an elastic material, it may be difficult to insert and remove because the friction with the sample tube made of polypropylene, for example, increases. Therefore, in the optical measurement device of the present invention, the structure is preferably configured to include a sample bracket.

  Furthermore, in the optical measurement device of the present invention, the measurement sample in the sample tube is heated chemically or physically, or the measurement sample in the sample tube is heated for optical measurement under a certain temperature condition. A heating mechanism may be provided. In such a configuration, it is preferable that a cooling fan or a Peltier element for rapidly cooling the heated sample tube with the circulating cooling air is provided.

  In the above description, the embodiment in which the light measurement device of the present invention is configured as an absorbance measurement device has been described. However, the light measurement device may be configured as a fluorescence measurement device that detects fluorescence emitted from a measurement sample as detection light.

DESCRIPTION OF SYMBOLS 10 Structure 11 Light guide path formation member 12 Light guide path space 13 Through-hole 14a Incident opening 14b Outgoing opening 16 Central through-hole 18 Sample tube receiving hole 20 Light source part 21 Substrate 22 Light source 25 Light receiving part 26 Sensor substrate 27 Light receiving sensor DESCRIPTION OF SYMBOLS 30 Sample bracket 31 Plate part 32 Cylindrical part 33a 1st inclined surface 33b 2nd inclined surface 34 Support part 35 Projection part 36 Columnar protrusion 38a Communication hole 38b Communication hole 40 Elastic body 45 Sample tube 46 Tapered part

Claims (2)

A sample tube receiving hole for receiving a sample tube having a tapered portion whose outer diameter gradually decreases toward the bottom, a measurement light incident opening for the sample tube disposed in the sample tube receiving hole, and the A structure having an opening for emitting light for detection from the sample tube and a light guide path space opened at positions facing each other on the inner peripheral surface of the hole for receiving the sample tube;
The inner peripheral surface of the sample tube receiving hole is in contact with the outer peripheral surface of the tapered portion of the sample tube at a level where the entrance opening is formed, and the insertion position of the sample tube is set with respect to the structure. An optical measuring device having a protrusion for positioning.   The optical measurement apparatus according to claim 1, wherein the protrusion is positioned at a level position of an optical axis of measurement light passing through the light guide path space.

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