JP6891391B2 - Optical measuring instrument - Google Patents

Description

The present invention relates to an optical measuring instrument. More specifically, the present invention relates to a portable optical measuring instrument used as an absorbance measuring instrument or the like.

As a kind of optical measuring instrument, for example, in Patent Document 1, a measurement sample is irradiated with light emitted from a light source, and fluorescence emitted from the measurement sample is received by a light receiving unit in the measurement sample. A small fluorescence measuring instrument for measuring the concentration of a target substance is disclosed.
In such a fluorescence measuring instrument, for example, when the PCR method (polymerase chain reaction) is used for parent-child identification and DNA measurement of bacteria and viruses, a liquid measurement sample is heated to a constant temperature or a cycle. A heater is provided to heat the PCR tube containing the measurement sample for the purpose of repeatedly heating with a specific temperature pattern.
When heating the measurement sample, for example, if only the lower part of the PCR tube is heated, the water content in the measurement sample evaporates and dew condensation occurs on the ceiling surface in the PCR tube, and as a result, the concentration of the target substance in the measurement sample. Will change.
To prevent such changes in concentration, heating both the top and bottom of the PCR tube is performed.

On the other hand, in recent years, in the life science field, there has been a demand for miniaturization of optical measuring instruments in order to make them easy to carry for the purpose of using them for point-of-care inspections.
In order to meet such a demand, the fluorescence measuring instrument disclosed in Patent Document 1 is miniaturized by integrally molding the entire housing with a resin.

However, in such a miniaturized fluorescence measuring instrument, the heat of the PCR tube is generated due to the fact that the light source and the measuring unit are arranged close to each other or the measuring unit and the light receiving unit are arranged close to each other. It is transmitted to the light source and the light receiving part, and these temperatures rise. As a result, the light conversion efficiency of the light emitting element changes in the light source, and the signal intensity value of the light receiving element changes in the light receiving portion, so that a highly accurate measurement result cannot be obtained. There is a problem.

Japanese Unexamined Patent Publication No. 2014-32064

The present invention has been made based on the above circumstances, and even when the size is reduced so that the sample container can be easily carried, the light source and the light receiving unit are caused by heat transfer from the sample container. It is an object of the present invention to provide an optical measuring instrument capable of obtaining highly accurate measurement results by suppressing an increase in the temperature of the above.

The optical measuring instrument of the present invention guides a light source that causes measurement light to enter a measurement unit in which a sample container containing a measurement sample is arranged via a light guide path and detection light emitted from the measurement unit. An optical measuring instrument having a light receiving unit that receives light through an optical path.
A heating mechanism for heating the sample container arranged in the measuring unit is provided.
A first light guide path forming body in which a first light guide path for incidenting measurement light from the light source into the measurement unit is formed inside, and a first light guide path forming body.
A second light guide path forming body in which a second light guide path for guiding the detection light emitted from the measurement unit to the light receiving unit is formed inside, and a second light guide path forming body.
A sample tube receiving hole into which the sample container is inserted, and a sample bracket formed at a position where the light passing holes through which the measurement light and the detection light pass, which communicate with the sample tube receiving hole, face each other. Have and
The first light guide path forming body is held so that the end portion of the first light guide path faces and communicates with one of the light passing holes of the sample bracket, and the second light guide path forming body is formed. Is held so that the end of the second light guide path faces and communicates with the other of the light passage holes of the sample bracket.
The sample tube receiving hole has a shape in which the sample container and the sample bracket are in close contact with each other when the sample container is inserted into the sample tube receiving hole.
The heating mechanism has at least one of a heater for heating the upper part and a heater for heating the lower part of the sample container arranged in the measuring unit.
The sample bracket is made of a heat insulating material.
And the heating mechanism or the sample container, the light source and a region other than the light path between the light receiving portion, the first light guide path forming member and said second light guide path forming body the sample bracket It is characterized in that a heat insulating layer is provided between the two.

In the optical measuring instrument of the present invention, the heat insulating layer may be formed of a resin member, a heat insulating sheet or an air layer.

In the optical measuring instrument of the present invention, the heat insulating layer may be formed of a resin member in contact with the outer surface of the sample container.

In the optical measuring instrument of the present invention, a heat insulating layer is provided in a region other than on the light guide path between the heating mechanism or the sample container and at least one of the light source and the light receiving portion. Therefore, even when the optical measuring instrument of the present invention is configured as a small device that can be easily carried, the heat of the sample container is blocked by the heat insulating layer, and the heat transfer from the sample container causes the light source and the light source. The temperature rise of the light receiving unit is suppressed, and as a result, a highly accurate measurement result can be obtained.

It is a top view which shows an example of the structure of the optical measuring instrument of 1st Embodiment of this invention. It is a front view of the optical measuring instrument of FIG. FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 1 is a sectional view taken along line BB in FIG. FIG. 2 is a cross-sectional view taken along the line CC in FIG. It is sectional drawing which shows typically the state which the sample tube is attached to the optical measurement mechanism in the optical measuring instrument of FIG.

Hereinafter, the present invention will be described in detail.
<First Embodiment>
1 is a plan view showing an example of the configuration of the optical measuring instrument according to the first embodiment of the present invention, FIG. 2 is a front view of the optical measuring instrument of FIG. 1, and FIG. 3 is AA in FIG. FIG. 4 is a sectional view taken along line BB in FIG. 1, FIG. 5 is a sectional view taken along line CC in FIG. 2, and FIG. 6 shows a sample tube in the optical measuring mechanism in the optical measuring instrument of FIG. It is sectional drawing which shows typically the mounted state.
The optical measuring instrument 10 is used for measuring the concentration of a substance to be measured in a measurement sample as an absorbance, and the substance to be measured is amplified by, for example, Escherichia coli, a protein, or a polymerase chain reaction (PCR). The obtained DNA, dye, and the like.

In the optical measuring instrument 10, the optical measuring mechanism 18 is provided in the upper region (upper side in FIG. 1) in the housing 11, and the optical measuring mechanism 18 is provided in the lower region (lower side in FIG. 1) in the housing 11. A battery chamber 19 for accommodating a drive battery is provided. Further, a single-sided lid 12 for inserting and removing the sample tube W is formed at a position corresponding to the optical measurement mechanism 18 on the upper surface side (left surface side in FIG. 4) of the housing 11. Further, in the lower (lower part in FIG. 1) region on the upper surface side of the housing 11, an operation unit 16 in which a power button or the like is arranged is formed. Further, on the lower surface side (right side in FIG. 4) of the housing 11, support legs 17 for supporting the housing 11 on a horizontal support surface are provided so as to project.

The optical measurement mechanism 18 includes a first light guide path forming body 21 in which a first light guide path 21H for incident measurement light from a light source 24 is formed inside a measuring unit 20 in which a sample tube W is arranged. It has a second light guide path forming body 26 in which a second light guide path 26H for guiding the detection light emitted from the measuring unit 20 to the light receiving unit 28 is formed inside.
The first light guide path 21H and the second light guide path 26H are each composed of a linear through hole extending linearly, and the first light guide path 21H and the second light guide path 26H are positioned coaxially with each other. The first light guide path forming body 21 and the second light guide path forming body 26 are arranged therein.

The light source 24 is held in a state of being fitted into one end (left end in FIG. 6) that does not face the second light guide path 26H in the first light guide path 21H. Further, the light receiving unit 28 is held in a state of being coaxially fitted with the optical axis of the light source 24 at one end (right end in FIG. 6) of the second light guide path 26H that does not face the first light guide path 21H.
By holding the light source 24 in the state of being fitted in the first light guide path 21H, it becomes easy to set the optical axis of the light source 24 substantially in parallel with the axis of the first light guide path 21H, and therefore, the light source is received. The light source can be distributed in the direction of the unit 28 with high efficiency.
The diameter of the first light guide path 21H on the light source 24 side may be the same as or different from the diameter of the second light guide path 26H on the light receiving portion 28 side, but unnecessary scattered light and reflected light may be different. From the viewpoint of reducing stray light, it is preferable that the diameter of the second light guide path 26H on the light receiving portion 28 side is smaller than the diameter of the first light guide path 21H on the light source 24 side.

The first light guide path forming body 21 and the second light guide path forming body 26 are made of an elastic body, and in particular, absorb stray light such as scattered light and reflected light and efficiently transmit the light from the light source to the light receiving portion. It is preferably made of a light-absorbing elastic body capable of forming a light-absorbing material.
As the light-absorbing elastic body, specifically, a black silicone resin such as polydimethylsiloxane (PDMS) in which carbon black or carbon nanotubes are dispersed can be preferably used.

The optical measurement mechanism 18 is provided with a sample bracket 25 in which a sample tube W in which a measurement sample is loaded is inserted, and a tapered sample tube receiving hole 29 having a tapered diameter toward the bottom is formed in the center thereof. There is. In the sample tube receiving hole 29, light passing holes 27A and 27B through which the measurement light and the detection light pass are formed at positions facing each other in the lower region (lower side in FIG. 6), respectively. At the bottom of the sample tube receiving hole 29, there is an opening having a size such that when the sample tube W is inserted into the sample tube receiving hole 29, the bottom of the sample tube W protrudes downward by about 1.5 mm. It is formed.

The sample bracket 25 extends linearly in the left-right direction (horizontal direction in FIG. 6) with the sample tube receiving hole 29 sandwiched therein, and communicates with the light passing holes 27A and 27B of the sample tube receiving hole 29. Containment recesses 23A and 23B are formed. Then, in the accommodation recesses 23A and 23B, the first light guide path forming body 21 and the second light guide path forming body 26 are illuminated, respectively, and the ends of the first light guide path 21H and the second light guide path 26H are illuminated. It is held in a press-fitted state so as to communicate with the passing holes 27A and 27B, respectively.

In the sample tube receiving hole 29, when the sample tube W is pressed against the sample tube receiving hole 29 of the sample bracket 25 by the lid 12, the sample tube W and the sample bracket 25 are brought into close contact with each other, and the sample with respect to the light guide path is formed. The shape is such that the tube W is positioned.
The sample tube receiving hole 29 can have a shape and size corresponding to a PCR tube or a sample tube, for example, a 1.5 mL sample tube or a 2.0 mL sample tube.

The sample bracket 25 is preferably made of a material having heat insulating properties, and for example, one made of a polycarbonate resin can be used.
The sample bracket 25 is preferably black from the viewpoint of suppressing the intrusion of stray light from the outside.

The diameters of the first light guide path 21H and the second light guide path 26H are larger than the diameters of the light passage holes 27A and 27B of the sample bracket 25, respectively. As a result, the first light guide path forming body 21 and the second light guide path forming body 26 are press-fitted and held with respect to the sample bracket 25, but even when deformation occurs due to press-fitting, the optical path hole 27A and 27B can be reliably positioned within the openings of the first light guide path 21H and the second light guide path 26H.

As the light source 24, for example, an LED such as a white LED can be used, and as the light receiving unit 28, a photodiode such as an RGB color sensor can be used. By using an RGB color sensor as the light receiving unit 28, the absorbance at each wavelength of RGB can be measured.
For example, the protein concentration can be quantified by the BCA method from the absorbance of light having a wavelength of about 560 nm, or by the Bradford method from the absorbance of light having a wavelength of about 600 to 700 nm.

The optical measurement mechanism 18 includes a heating mechanism that heats the measurement sample in the sample tube W to a constant temperature, repeatedly heats it in a periodic temperature pattern, or heats it for optical measurement under a constant temperature condition. It is equipped.

The heating mechanism of the optical measurement mechanism 18 can heat the sample tube W from above and below. Specifically, the upper heater member 30A provided on the back surface side of the lid 12 of the housing 11 and arranged so as to be pressed against the sample tube W and in contact with the upper surface of the sample tube W when the lid 12 is closed. It may consist of a lower heater member 30B arranged so as to come into contact with the lower surface of the sample tube W protruding from the hole penetrated in the lower part of the sample tube receiving hole 29.
As the upper heater member 30A and the lower heater member 30B, sheet-shaped heaters in which a stainless steel resistance wire pattern is attached to each of the polyimide films can be used.

The upper heater member 30A and the lower heater member 30B can independently control the temperature state. The set temperature of each heater can be room temperature to 150 ° C.
As for the heating temperature of the upper heater member 30A and the lower heater member 30B, it is preferable that the temperature of the upper heater member 30A is higher than the temperature of the lower heater member 30B from the viewpoint of preventing dew condensation on the ceiling surface of the sample tube W.

It is preferable that the optical measurement mechanism 18 is provided with a cooling fan that rapidly cools the heated sample tube W with circulating cooling air.

Then, in the optical measuring instrument 10 of the first embodiment of the present invention, a heat insulating layer is formed in a region other than on the light guide path between the heating mechanism or the sample tube W and at least one of the light source 24 and the light receiving unit 28. Is provided.
Specifically, the heat insulating layer includes a first heat insulating layer 32A arranged between the sample bracket 25 and the first light guide path forming body 21 in contact with the sample bracket 25, and the sample bracket 25 and the second guide. It is composed of a second heat insulating layer 32B arranged in contact with the optical path forming body 26.
Positions of the first heat insulating layer 32A and the second heat insulating layer 32B facing the first light path 21H and the second light path 26H in the first light path forming body 21 and the second light path forming body 26. The light passing holes 38A and 38B through which light passes are formed in the above, respectively.

The first heat insulating layer 32A and the second heat insulating layer 32B are each formed of a heat insulating sheet having a substantially uniform thickness. The heat insulating sheet can be made of, for example, paper, polymer, rubber or the like.
The thickness of the first heat insulating layer 32A and the second heat insulating layer 32B is preferably, for example, 10 to 3000 μm.

To give an example of the dimensions of each part of the optical measuring instrument 10, the housing 11 has a vertical width (vertical length in FIG. 1) of 150 mm, a horizontal width (horizontal length in FIG. 1) of 70 mm, and a height (FIG. 1). The length in the direction perpendicular to the paper surface) is 30 mm, and the weight is 300 g. Further, the thickness of the heat insulating layers 32A and 32B is 1.5 mm. The diameter of the light passing hole 27B of the sample tube receiving hole 29 in the sample bracket 25 is φ1.7 mm and the thickness is 8 mm, and the diameter of the sample tube receiving hole 29 is φ1.7 mm at the minimum and φ3.0 mm at the maximum. is there. Further, the distance between the light source 24 and the light receiving unit 28 is 25 mm.

The optical measurement in the optical measuring device 10 is performed as follows. That is, in the optical measurement mechanism 18, the measurement light emitted from the light source 24 irradiates the liquid measurement sample in the sample tube W received in the sample tube receiving hole 29 in the measurement unit 20. The light irradiated to the measurement sample in the sample tube W is absorbed according to the concentration of the substance to be measured. The detection light emitted through the sample tube W without being absorbed reaches the light receiving unit 28, the amount of the light is measured, the absorbance is acquired, and the concentration is calculated. Specifically, when light passes through the measurement sample, its transmittance is exponentially attenuated with respect to the optical path length according to the concentration of the substance to be measured. Therefore, a calibration curve is prepared by measuring a standard solution of a substance to be measured at a known concentration as a reference sample in advance, and the concentration is calculated from the absorbance of the substance to be measured in the measurement sample by comparing with the amount of light. Can be done.
In the optical measuring instrument 10, when the heat treatment is performed by at least one of the upper heater member 30A and the lower heater member 30B, the temperature of the sample tube W rises to generate heat. The heat generated from the sample tube W is blocked by the sample bracket 25 and the first heat insulating layer 32A and the second heat insulating layer 32B.

In the optical measuring instrument 10 according to the first embodiment, a heat insulating layer made of a heat insulating sheet is provided in a region other than on the light guide path between the heating mechanism or the sample tube W and at least one of the light source 24 and the light receiving unit 28. It is actively provided. Therefore, even when the optical measuring instrument 10 is configured as a small one that can be easily carried, the heat generated by the sample tube W is blocked by the heat insulating layer, and the heat is transferred from the sample tube W. The temperature rise of the light source 24 and the light receiving unit 28 is suppressed. As a result, highly accurate measurement results can be obtained.

Although the first embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the above effect can be obtained even if one of the upper heater member 30A and the lower heater member 30B is provided as the heating mechanism.

<Second embodiment>
The optical measuring instrument according to the second embodiment of the present invention has the same configuration as the optical measuring instrument according to the first embodiment, except that the heat insulating layer is composed of an air layer.
The air layer can be, for example, a plate-shaped void having a substantially uniform thickness, and the thickness of the air layer is preferably, for example, about 100 to 3000 μm.

According to such an optical measuring instrument, the same effect as that of the optical measuring instrument according to the first embodiment can be obtained.

Although the second embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the shape of the air layer may be a structure in which the contact area between the sample bracket and the light guide path forming body is small and suppressed, and is not limited to a plate-like continuous one having a substantially uniform thickness. Specifically, the air layer is, for example, an intermittent void having a shape in which grooves are formed in the sample bracket and the light guide path forming body, respectively, and the sample bracket and the light guide path forming body are partitioned by line contact with each other. be able to.

<Third embodiment>
The optical measuring instrument according to the third embodiment of the present invention has the first heat insulating layer, except that the sample bracket is made of a heat insulating material and the first heat insulating layer and the second heat insulating layer are not provided. It has the same configuration as the optical measuring instrument according to the embodiment.
Specifically, the sample bracket and the first light guide path forming body and the second light guide path forming body are arranged in direct contact with each other, and the heat insulating layer is composed of only the sample bracket.

According to such an optical measuring instrument, the same effect as that of the optical measuring instrument according to the first embodiment can be obtained.

Although the third embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made.

10 Optical measuring instrument 11 Housing 12 Lid 16 Operating unit 17 Support leg 18 Optical measuring mechanism 19 Battery chamber 20 Measuring unit 21 First light guide path forming body 21H First light guide path 23A, 23B Containment recess 24 Light source 25 Sample bracket 26 Second light guide path forming body 26H Second light guide path 27A, 27B Optical path hole 28 Light receiving part 29 Sample tube receiving hole 30A Upper heater member 30B Lower heater member 32A First heat insulating layer 32B Second heat insulating layer 38A, 38B Optical Path Hole W Sample Tube

Claims (3)

A light source that causes measurement light to enter the measurement unit where the sample container containing the measurement sample is placed via the light guide path, and a light receiving unit that receives the detection light emitted from the measurement unit via the light guide path. An optical measuring instrument having
A heating mechanism for heating the sample container arranged in the measuring unit is provided.
A first light guide path forming body in which a first light guide path for incidenting measurement light from the light source into the measurement unit is formed inside, and a first light guide path forming body.
A second light guide path forming body in which a second light guide path for guiding the detection light emitted from the measurement unit to the light receiving unit is formed inside, and a second light guide path forming body.
A sample tube receiving hole into which the sample container is inserted, and a sample bracket formed at a position where the light passing holes through which the measurement light and the detection light pass, which communicate with the sample tube receiving hole, face each other. Have and
The first light guide path forming body is held so that the end portion of the first light guide path faces and communicates with one of the light passing holes of the sample bracket, and the second light guide path forming body is formed. Is held so that the end of the second light guide path faces and communicates with the other of the light passage holes of the sample bracket.
The sample tube receiving hole has a shape in which the sample container and the sample bracket are in close contact with each other when the sample container is inserted into the sample tube receiving hole.
The heating mechanism has at least one of a heater for heating the upper part and a heater for heating the lower part of the sample container arranged in the measuring unit.
The sample bracket is made of a heat insulating material.
And the heating mechanism or the sample container, the light source and a region other than the light path between the light receiving portion, the first light guide path forming member and said second light guide path forming body the sample bracket An optical measuring instrument characterized in that a heat insulating layer is provided between the two. The optical measuring instrument according to claim 1, wherein the heat insulating layer is formed of a resin member, a heat insulating sheet, or an air layer. The optical measuring instrument according to claim 2, wherein the heat insulating layer is formed of a resin member in contact with the outer surface of the sample container.

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