JP2001286456A - Organism optical measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organism optical measurement device for measuring organic metabolism materials using light, capable of irradiating light to a subject and detecting light without making the subject feel physical disorder. SOLUTION: Light is irradiated to an organism and the light transmitted inside the organism is detected by bringing sides of optical wave-guides 103 and 106 such as optical fibers into contact with the subject 105. Therefore, the irradiation of light and detection of light transmitted in the organism can be achieved with a small number of optical parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological light measuring device for measuring the concentration of metabolites in a living body or a change in the concentration using light.

[0002]

2. Description of the Related Art The concentration of metabolites in a living body represented by oxidized hemoglobin, reduced hemoglobin, and myoglobin or a change in the concentration is measured using light represented by near-infrared light having high permeability to living tissue. A biological light measurement device for imaging a change in density is described in Japanese Patent Application Laid-Open No. 9-98972.

In order to irradiate a living body with light or to detect light, such a living body optical measuring device irradiates a living body with light using an optical waveguide represented by an optical fiber, or detects and detects light. Need to be

[0004]

In order to solve this problem, Japanese Patent Application Laid-Open No. 11-4830 proposes an optical waveguide used for light irradiation or light detection typified by an optical fiber. The tip is in vertical contact with the scalp of the subject. Thus, for example, the brain function (eg, visual function) of the occipital region of the subject in a supine position
Was not always easy to measure.

[0005] As a proposal which can solve this problem, Japanese Patent Application Laid-Open No. 8-184593 can be mentioned. In this proposal, an optical fiber is arranged in parallel with the subject's scalp, and a right-angle prism is arranged at the tip of the optical fiber to bend the optical path and irradiate the subject with light. However, in the embodiment described in this proposal, the number of optical components increases. In addition, since the brain function is measured with the hard prism placed under the head, the subject may feel uncomfortable.

Accordingly, an object of the present invention is to provide a living body light measuring device in which an optical fiber is arranged in parallel with the scalp of a subject, and irradiation and detection of light on the subject can be realized with a smaller number of optical devices. Is to provide.

[0007]

In order to solve the above-mentioned object, according to the present invention, the side of an optical fiber arranged substantially in parallel with an object to be inspected is brought into direct contact with the object to be inspected, and the light is transmitted from the optical fiber to a living body. Or to detect light that has propagated in the living body.

Further, according to the present invention, an object to be inspected is irradiated with light via a probe, and the light transmitted through the object to be inspected is detected, whereby a metabolite concentration in the organism or a change in the concentration is measured. In the optical measurement device, the probe may be configured such that a side surface of the first optical waveguide used for irradiating the test object with light or a second optical waveguide used for detecting light propagated in the test object is formed on the side surface of the probe. It was configured to be able to contact the test object.

Further, according to the present invention, an object to be inspected is irradiated with light via a probe, and the light transmitted through the object to be inspected is detected, whereby the concentration of a metabolite in the organism or a change in the concentration is measured. In the optical measurement device, each of the side surfaces of the first optical waveguide used for irradiating the object to be inspected with light and the second optical waveguide used for detecting light propagated in the object to be inspected, It was configured to allow contact with the body.

Further, according to the present invention, in the above configuration, the probe penetrates the inside thereof, and the first optical waveguide or the second optical waveguide, or the first optical waveguide and the second optical waveguide are connected to each other. It was configured to have a hole into which one or more optical waveguides could be inserted.

Further, the present invention provides a biological light measurement for measuring a metabolite concentration or a change in the concentration in a living body by irradiating the test object with light through a probe and detecting light propagated in the test body. In the apparatus, the probe includes a fixture for fixing a first optical waveguide used for irradiating light to the object to be inspected and a second optical waveguide used for detection of light propagated in the object to be inspected, and A hollow tube connected to each of the fixtures and penetrating the probe to the probe bottom surface, and wherein the first optical waveguide and the second optical waveguide are each Provided is a biological light measurement device, which is configured to be connected to a test object via a side surface of a hollow tube.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical measuring device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an exemplary embodiment according to the present invention. 101 is a light source of the biological light measurement device. The light source here is not limited to a laser, but generally means a device that emits light, such as a light emitting diode, a super luminescent diode, and a lamp. The light emitted from this light source is connected to the optical waveguide 103 via the adapter shown at 102. The shape of the optical waveguide here is not limited, such as an optical fiber and a slab type optical waveguide. However,
In the following embodiments, an optical fiber, which has the highest availability among optical waveguides, will be described as an example. The optical fiber includes a core and a clad having a higher light refractive index than the core, and the clad exists around the core.

The other end of the optical fiber is in contact with the device under test shown at 105 via the probe shown at 104. This test subject indicates an arbitrary place on the living body such as the head, arm, and chest. Furthermore, an organ such as a lung, a trachea, a stomach, and a uterus that can guide light from outside the body in an endoscopic manner may be used. In the present embodiment, as an example, the part of the subject is the head.

As shown in FIG. 1, a part of the side surface of the optical waveguide 103 is in contact with the object to be inspected. Also, the optical waveguide 1
Reference numeral 06 denotes a detection optical fiber arranged to detect light emitted from the optical waveguide 103.
Similarly, a part of the side surface is in contact with the test object.
This optical waveguide 106 is connected to a detector 108 via an adapter 107. Here, in the living tissue, since the cell tissue scatters light, a part of the light emitted from the tip of the optical waveguide 103 reaches the tip of the optical waveguide 106.

Further, the actual living body includes blood composed of oxyhemoglobin and reduced hemoglobin in addition to the living tissue. For example, these hemoglobins have a wavelength of 700
Since light is absorbed in the wavelength range from nanometers to around 900 nanometers, using a light source in this wavelength band makes it possible to measure, for example, a change in blood volume (change in absorption coefficient) in a living body due to brain activity. In addition, including the present embodiment, the optical waveguide used in the present invention may be made of glass represented by quartz, acrylic resin, or organic polymer represented by fluorine resin. . Also, there is no problem even with a composite material using these glass material and polymer material.

The fact that the absorption coefficient in a living body can be actually detected by using the embodiment shown in FIG. 1 will be described with reference to the embodiments shown in FIGS. Reference numeral 201 denotes a phantom (a biological sample) that simulates the light scattering characteristics of a biological tissue. The size of this phantom 201 is 200 mm x 200 mm x 20 m
m, and a cylindrical hole having a diameter of 10 mm was formed in the center thereof. In addition, an irradiation optical fiber 202 and a detection optical fiber 203 are arranged on the upper part. These arrangement intervals are 30 mm. Further, each optical fiber is shielded by using a jacket, but only about 5 mm of the tip has no jacket and the cladding is exposed, and is brought into contact with the phantom surface. This situation simulates a situation where the side surface of the optical fiber is brought into contact with a living body such as the scalp.

Next, a method for simulating an increase in the absorption coefficient inside a living body will be described. First, before simulating an increase in the absorption coefficient, the light scatterer A204 was inserted into the center of the phantom 201. On the other hand, to simulate after the absorption coefficient increases,
Light scatterer B205 was inserted into the center of the same phantom. This light scatterer B has a three-layer structure, and the central layer has a large absorption coefficient. Comparing the state where the light scatterer A is inserted and the state where the light scatterer B is inserted, the absorption coefficient inside the phantom is locally increased in the state where the light scatterer B is inserted. This increase in blood volume simulates, for example, a local increase in blood volume due to brain activity.

Next, with reference to FIG. 3, an experimental result obtained by optically measuring the increase in the absorption coefficient inside the phantom will be described. FIG.
Is a graph showing the results of this experiment. (A) and (B) in the graph indicate periods (time) during which the light scatterers A and B were inserted, respectively. When the absorption coefficient inside the phantom increases, the light applied to the phantom is absorbed, and as a result, the detected light intensity decreases.

According to FIG. 3, when the light scatterer B is inserted, the transmitted light intensity (corresponding to the detected light intensity) is smaller than when the light scatterer A is inserted. From this experimental result,
It has been clarified that the optical fiber for a biological optical measurement device shown in FIG. 1 can detect a change in an absorption coefficient in a living body.

Further, FIGS. 4A and 4B respectively show
2 shows a modification of the structure of the optical fiber shown in FIG. 1. An example is shown in which a part of the tip of the optical fiber 401 is cut off, and the cut off part is brought into contact with the skin of the inspected body 402 to irradiate light to a living body or to detect light propagated in the living body. I have. As shown in FIG. 4A, a metal 403 typified by gold, silver, or copper may be applied or vapor-deposited on the tip of the optical fiber 401 to increase the light-wave coupling coefficient between the living body and the optical fiber. Absent. Also, as shown in FIG.
An optical fiber 404 that removes the entire cladding layer 405 and brings the core layer 406 into contact with the device under test may be used.

FIG. 5 shows an embodiment of the structure of a probe used when the optical fiber is brought into contact with a living body. In FIG. 5A, reference numeral 501 denotes a probe main body, which has a hole 5 for inserting an optical fiber.
03 is open. Further, a flexible fixture 502 such as a rubber band or a string is attached to the probe body. In this embodiment, two fixing devices are shown.
In this embodiment, the lower part of the probe body 501 is connected to the device to be inspected by connecting these two wires.

Further, the structure of the probe body 501 will be described. The probe main body is colored with a color that hardly transmits light such as black (a color that absorbs light). Probe body 5
The hole 503 formed in the side surface of FIG.
As shown in (A), a cross-sectional view taken along the line AA), it penetrates toward the lower part of the probe while drawing a gentle curve.
By using this method, the area (place) where the optical fiber contacts the skin of the test object is limited to the measurement area at the tip of the optical fiber. As a result, except at the end of the optical fiber,
Since there is no need to irradiate the living body with light or detect light that has propagated inside the living body, the position accuracy of the place where the light is radiated or the light is detected increases. In addition, since this hole has a gentle curved structure, the optical fiber is harder to drop out of the probe than in the case of a straight line, and the reliability of mounting is improved.

Furthermore, for the purpose of fixing the optical fiber inside the probe, it is necessary to fix the optical fiber from the side of the probe using a screw. Therefore, the example of FIG. 5 shows a structure of a probe provided with a fixing portion 504 such as a screw hole for fixing an optical fiber from the side surface of the probe 501 as an example. The structure of the probe shown in FIG. 5 is a structure in which the optical fiber exits from the side surface of the probe 501. For this reason, it is also possible to measure a brain function represented by the visual cortex existing in the occiput while sleeping.

Next, in addition to the embodiment shown in FIG. 5, the structure of a probe capable of inserting an irradiation optical fiber and a detection optical fiber into one holder is shown in FIG. Reference numeral 601 in FIG. 6A indicates a probe holder. In this figure, the irradiation optical fiber 602 and the detection optical fiber 6 are shown.
3 shows an embodiment of the structure of a holder into which two pieces of No. 03 can be inserted respectively. On the side of the holder 601,
There are four holes into which the irradiation optical fiber 602 and the detection optical fiber 603 can be inserted. Further, the position of the optical fiber for irradiation and the position of the optical fiber for detection are arranged at a certain interval.

Next, FIG. 6B is a sectional view taken along line BB of FIG.
The cross-section shows a cut-off state, showing the internal structure of the holder. For the purpose of guiding the optical fiber to the lower portion of the holder 601, similarly to the structure shown in FIG. 5, the hole portion starts from the side surface of the holder and penetrates the bottom surface of the holder with a gentle shape. In the figure, the structure related to the two holes opened on the front side is shown, but the structure opened on the back side is shown.
The same structure is applied to the three holes.

FIG. 6C shows the positions of the holes on the surface in contact with the object to be inspected when the holder is viewed from the bottom. Corresponding to the four holes drilled on the side of the holder, there are also four holes on the bottom. As an example, these holes are arranged at intervals of 30 mm when measuring a change in blood volume accompanying brain activity in the head of an adult.

As a result, in the probe structure shown in this figure, the irradiation optical fiber and the detection optical fiber
They are arranged at 0 mm intervals. When light is irradiated and detected by the method described in Japanese Patent Application Laid-Open No. 9-98972, it becomes possible to image the change in blood volume inside the region where the probe is arranged.

In the embodiments shown in FIGS. 1, 5 and 6, it is possible to insert an optical waveguide typified by an optical fiber used for measurement into a probe and to contact them with an object to be inspected. The structure of the probe having the structure is shown.

Further, as a modified example of these embodiments, light irradiation and light detection can be performed without bringing an optical waveguide typified by an optical fiber used for light irradiation or light detection into contact with an object to be inspected. An example of the probe is shown in FIG. Reference numeral 701 shown in FIG. 7A is a probe for a biological optical measurement device.
1 is a light irradiation adapter 702 and a light detection adapter 70
3 is provided.

Next, an example of a specific structure of these adapters is shown in FIG. This adapter is an adapter 704 capable of fixing an optical waveguide 705 represented by an optical fiber. Further, a fixing tool 706 typified by a screw or the like is provided on the adapter 704. (B) The figure shown on the right in the drawing is the vertical direction (D
FIG. 4D is a partial cross-sectional view of FIG. The left side of the figure corresponds to the direction in which the optical waveguide 705 is inserted, while the right side of the figure is connected to the probe body. This structure is characterized in that a projection 707 in the shape of the letter "L" of the alphabet is provided on the right side to fix the insertion position of the optical fiber. Due to the provision of the protrusion 707, the optical fiber inserted from the left side of the drawing can be fixed at a fixed position at the back.

FIG. 7C is a view showing a cut-away state taken along the line CC of FIG. 7A, and shows a hollow tube 708 penetrating inside the probe 701. The inner wall surface of the hollow tube 708 is coated with a material that reflects light, such as gold, silver, and copper. Examples of the coating means include vapor deposition and application of a paste-like metal.

[0033]

As described above, according to the present invention, by using the side surface of an optical waveguide typified by an optical fiber, the optical waveguide is arranged substantially parallel to a test object such as the scalp of a subject.
With less number of optical components without subject feeling uncomfortable,
It is possible to realize a living body light measurement device that can irradiate and detect light to a subject.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a biological optical measurement device and an optical waveguide provided by the present invention.

FIG. 2 is a diagram illustrating an optical system used for confirming the operation principle of the biological optical measurement device and the optical waveguide according to the present invention.

FIG. 3 is a view showing experimental results obtained using the optical system shown in FIG. 2;

FIG. 4 is a diagram showing one embodiment of the structure of the optical waveguide according to the present invention.

FIG. 5 is a structural view showing an example of a biological optical measurement device according to the present invention and a holder used in the optical waveguide.

FIG. 6 is a structural view showing another example of a biological optical measurement device according to the present invention and a holder used in the optical waveguide thereof.

FIG. 7 is a structural view showing still another example of a biological optical measurement device according to the present invention and a holder used in the optical waveguide.

[Explanation of symbols]

101: light source for biological light measuring device, 102: light irradiation adapter, 103: irradiation optical waveguide, 104: probe, 1
05: object to be inspected, 106: optical waveguide for detection, 107: adapter for detection, 201: phantom (biological simulation sample) simulating light scattering characteristics of living tissue, 202: optical fiber for irradiation, 203: optical fiber for detection , 204: light scatterer A, 205: light scatterer B, 401: optical fiber for biological optical measurement device, 402: test object, 403: material reflecting light represented by gold, silver, copper, 404: Optical fiber, 50
1: probe body, 502: flexible fixture, 5
03: hole, 504: fixing part such as screw hole, 601: probe holder, 602: irradiation optical fiber, 603: detection optical fiber, 701: probe for biological optical measurement device,
702: light irradiation adapter, 703: light detection adapter, 704: adapter, 705: optical waveguide typified by an optical fiber, 706: fixing tool typified by a screw, 70
7: “L” shaped protrusion, 708: hollow tube.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G059 AA01 BB12 CC16 CC18 EE02 GG01 GG02 GG10 HH01 HH06 JJ17 KK01 4C038 KK01 KL05 KL07 KM00 KY01 KY04 KY11

Claims (8)

[Claims] An object to be inspected is irradiated with light through a probe, and by detecting light propagating in the object to be inspected,
In a living body optical measurement device for measuring a metabolite concentration or a change in the concentration in a living body, a probe is used to detect a first optical waveguide used for irradiating the test object with light or light transmitted through the test subject. A side surface of a second optical waveguide used in the above-mentioned method is configured to be able to contact the object to be inspected. 2. The probe according to claim 1, wherein the probe has a hole penetrating therethrough for guiding the first optical waveguide or the second optical waveguide to a bottom surface of the probe, and the first optical waveguide is provided. 2. The biological optical measurement device according to claim 1, wherein a side surface of the second optical waveguide is configured to be able to contact the object to be inspected on the bottom surface of the probe. 3. The probe according to claim 1, wherein the probe has a fixing part for fixing the first optical waveguide or the second optical waveguide to the probe, and a flexible fixture for fixing the probe to the device under test. The biological optical measurement device according to claim 2, comprising: 4. The probe according to claim 1, wherein the probe has the hole into which at least one of the first optical waveguide and the second optical waveguide can be inserted. Biological light measurement device. 5. The method according to claim 1, wherein the first optical waveguide and the second optical waveguide are made of glass, a polymer, a fluororesin, or a composite material using a plurality of these materials. Item 2. The biological light measurement device according to Item 1. 6. The living body light according to claim 1, wherein said first optical waveguide and said second optical waveguide are arranged at intervals of 30 mm on a surface in contact with said object to be inspected. Measuring device. 7. An object to be inspected is irradiated with light through a probe, and light transmitted through the object to be inspected is detected.
In a biological optical measurement device for measuring a metabolite concentration in a living body or a change in the concentration, a first optical waveguide used for irradiating the probe with light to the test object and detection of light propagated in the test object A biological light measurement device characterized in that each side surface of a second optical waveguide used in the method is configured to be able to come into contact with the object to be inspected. 8. An object to be inspected is irradiated with light through a probe, and light transmitted through the object to be inspected is detected.
In a biological optical measurement device for measuring a metabolite concentration or a change in the concentration of a metabolite in a living body, the probe includes a first optical waveguide used for irradiating the test object with light and detection of light propagated in the test object. A fixture for fixing the second optical waveguide used for each, and a hollow tube connected to each of the fixtures, penetrating the inside of the probe and leading to the bottom of the probe, and The biological light measurement device, wherein the first optical waveguide and the second optical waveguide are configured to be connected to the object to be inspected through side surfaces of the hollow tubes.