JPH0113852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a biochemical component analysis device using laser light;
In particular, the present invention relates to a biochemical component analyzer that can non-invasively measure biochemical components by attenuating the energy of laser light that has penetrated into living tissue.

In recent years, in the medical field, it has become essential to measure biochemical components, especially components contained in fluids such as blood, from both preventive and therapeutic medicine.
A great deal of diagnostic information has been obtained from these specimen tests.

In conventional general sample testing, a predetermined body fluid is collected from a living tissue, the body fluid is subjected to necessary separation and purification processes, and then a chemical reaction is performed to measure the components in the body fluid. Therefore, with such conventional measuring devices, it takes a relatively long time to obtain measurement results, and it is impossible to know the results in real time, especially when analyzing biochemical components simultaneously with or in conjunction with treatment. There was a problem that I could not do it.

In addition, in conventional laboratory tests, the collection of body fluids places a large burden on the test subject.For example, in stress tests known as tests for diabetes, etc., blood is collected from the test subject multiple times. The problem was that it placed a burden that could not be ignored.

The present invention was developed in view of the above-mentioned conventional problems, and its purpose is to be able to continuously measure biochemical components in a non-invasive manner, and to measure biochemical components in real time without placing a burden on the subject. An object of the present invention is to provide a biochemical component analyzer using laser light that enables analysis.

In order to achieve the above object, the device of the present invention consists of a core forming a central light guide path and a cladding forming an outer skin of the core, and a part of the cladding is removed so that the skin surface of the living body can be brought into direct contact with the core. an optical fiber having a detection portion with a side surface of the core exposed; a laser light source that guides infrared laser light of a predetermined wavelength to the optical fiber; measuring the energy of the reflected laser light emitted from the optical fiber; It is characterized in that it includes a measurement calculation unit that measures biochemical components of the living body based on the measurement results, and measures the biochemical components non-invasively.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows the main parts of a biochemical component analyzer according to the present invention. Here, 10 is an optical fiber, and a core 12 forming a central light guide path.
and a cladding 14 forming an outer skin, and a detecting section 16 is formed by removing the cladding 14 to expose the core 12 in a part thereof.

As described later, the detection medium for biological components in the present invention is carbon dioxide laser light, which is infrared light with a wavelength of approximately 10 μm. An infrared optical fiber is used.
Generally, the optical refractive index of the core and cladding of an optical fiber is determined mainly by the material of the fiber, but even if the material is the same, the refractive index changes somewhat depending on the wavelength of the light. Therefore, in the present invention, the basic refractive index of the core and cladding is determined by the material of the infrared fiber, and variations depending on the wavelength of the selected carbon dioxide laser beam are added to this.

When the laser beam 100 is guided to the optical fiber 10 formed in this way and the detection section 16 is pressed against the mucous membrane tissue 18 such as the lips, the detection section 16 detects the inside of the tissue 18 that is in direct contact with the core 12. The laser beam 100 penetrates a depth proportional to its wavelength and is totally reflected, making it possible to measure biochemical components such as tissue sugar concentration non-invasively and continuously. Become.

In the present invention, a laser beam, particularly a carbon dioxide laser beam having a wavelength of about 10 μm, is used as the detection medium. This is because carbon dioxide laser light is a single wavelength light, so it can be transmitted within an optical fiber with the same refractive index.
This is because it is extremely suitable for measuring biological components based on the attenuation rate.

Note that devices have also been considered that do not use a part of the optical fiber 10 as the detection section 16, but instead use, for example, an ATR (internal multiple total reflection) prism as the detection section.
However, a device using this ATR prism as a detection section is not preferable because loss of laser light occurs at the junction between the optical fiber and the ATR prism. Furthermore, loss of laser light and phase shift occur at the junction, making it difficult to obtain a sufficient S/N ratio, which poses a problem in performing accurate measurements. Also, when diagnosing newborns,
Since it is difficult to press the detection unit 16 against the lips, it is necessary to use other skin surfaces, such as the armpit, the base of the foot, and the ear. However, since ATR prisms have a certain size and thickness, they are inappropriate for use on these skin surfaces. However,
The detection unit 16 of the device according to the present invention includes an optical fiber 10
Since the detection part 16 is thin and string-like, it can be used not only for the mucous membrane tissue 18 such as the lips, but also for the detection part 16, which is a thin string-like structure.
Can also be used on other skin surfaces 18 such as underarms, ears, etc.
There is no problem in the diagnosis of newborns.

FIG. 2 is a detailed explanatory diagram of an embodiment of the biochemical component analyzer according to the present invention, in which carbon dioxide laser light is guided to the optical fiber 10, and the detection unit 16
Tissue sugar concentration can be continuously measured non-invasively by multiplexing laser light reflected on mucosal tissue such as the lips within a depth of about 30 microns and measuring its absorption spectrum.

Laser light output from a laser light source 30 consisting of a carbon dioxide laser is focused by a collimator 32 into an extremely thin parallel beam. Then, this laser beam is separated into two directions by a half mirror 34,
One is directed to the detection unit 16, and the other is sent to the control circuit of the laser light source 30. The half mirror 34 is made of germanium or the like, and its material is arbitrarily selected depending on the wavelength of the laser beam.

The control circuit of the laser light source 30 includes a power meter 38 that monitors the laser output, and a laser light output detector 4.
4 and an output stabilizing circuit 40, the laser beam reflected by the half mirror 34 is further divided into two by the half mirror 42, one is supplied to the power meter 38, and the output of the laser beam is monitored by a meter display, The other laser beam is supplied to the laser beam output detector 44, and the output stabilizing circuit 40
A feedback circuit including a laser light source 3
The output of 0 can be stabilized and controlled.

The laser beam that has passed straight through the half mirror 34 passes through a shutter 46 and then passes through another half mirror 48.
In the embodiment, the light is divided into two into the optical fiber 10 for measurement and the optical fiber 50 for calibration. That is, the laser beam that has passed straight through the half mirror 48 is transmitted to the detection unit 1 via the optical fiber 10.
On the other hand, the laser beam reflected from the half mirror 48 is guided to the calibration section 52 via the calibration optical fiber 50. This calibration section 52 is the detection section 16
It is formed in the same structure. In order to alternately switch the light guiding timing of both laser beams, an optical chopper 54 is provided in both light guiding paths, and the optical chopper 54 has a slit plate 54a that crosses both light guiding paths, and a slit plate 54a that rotates the slit plate 54a. motor 5
4b, and the laser light to the detection unit 16 and the calibration unit 52 can be alternately switched. In addition, in order to obtain a sufficient number of laser beam reflections per unit length in the detection section 16 and the calibration section 52, as shown in FIG. A bent portion is formed, and the reflection angle of the laser beam 100 guided from the input end of each optical fiber 10, 50 is set to be an acute angle at this bent portion.

The laser beam incident on the detection unit 16
A very small amount, usually several tens of microns, penetrates into the subject's lip mucosa when it is pressed against it, and at this time, a portion of the laser light energy is absorbed by the mucosal tissue, and as mentioned above, , this amount of absorption is approximately proportional to the sugar concentration in the mucosal tissue. Therefore, the output of the laser light multiple reflected within the detection unit 16 is reduced by the amount absorbed by the living tissue, and by measuring this reduced absorption, it is possible to analyze the biochemical components in the living tissue. becomes. That is, in the embodiment, the laser beam emitted from the detection section 16 passes through the optical fiber 10, is focused into a thin parallel beam by the collimator 56, and is then supplied to the measurement calculation section 60 through the half mirror 58.

On the other hand, the core of the calibration section 52 is immersed in a calibration solution such as physiological saline, and after undergoing a known attenuation in advance, the light enters the measurement calculation section 60 from the half mirror 58. As described above, this calibration section 52 also has the same configuration as the detection section 16, and the energy absorbed by the calibration liquid changes depending on the frequency, intensity, and other conditions of the guided laser beam. By comparing and measuring the output of the detection unit 16 with the output of the detection unit 16, it becomes possible to accurately measure biochemical components.

The measurement calculation section 60 includes a laser beam energy detector 62
The laser beams output from the detection section 16 and the calibration section 52 are supplied to the detector 62 via the lens 64 at alternate timing, and the energy thereof is electrically detected. The output of the detector 62 is amplified by an amplifier 66, then converted to a digital signal by an A-D converter 68, and then sent to a minicomputer 7 via an interface 70.
2 and subjected to desired arithmetic processing, the measured values are output and recorded. In the embodiment, the data from the minicomputer 72 is expressed as sugar concentration per unit volume, and is displayed on a predetermined display or printed by a printer.

FIG. 4 shows waveforms of the embodiment of FIG. 2,
A pulsed laser beam is supplied to the detection section 16 and the calibration section 52 in response to the start signal, and is output as a sample signal and a reference signal, respectively. Then, both outputs are combined into a composite signal by a half mirror 58, and as a result, by comparing both outputs included in the composite signal, an accurate Measurement becomes possible.

FIG. 5 shows a specific external view of the biochemical component analyzer according to the present invention, in which the laser light source 30, its oscillation control unit, and laser light guiding device are housed in the main body 80, and the front surface of the main body 80 is shown in FIG. There is a detection part 1
6 is exposed at a position suitable for close contact with the subject's lips, and since the optical fiber 10 on which this detecting section 16 is formed has some flexibility, the position of the detecting section 16 is also adjusted to the main body 80. It is possible to move to some extent. A desktop computer 82 is provided near the main body 80 and performs predetermined calculations and data output operations. Furthermore, cooling water is supplied from a cooler 84 to the laser light source 30 (not shown) in the main body 80 to prevent the laser light source from overheating.

FIG. 6 shows an actual measurement state using the analyzer shown in FIG. By guiding a laser beam of a predetermined wavelength from It becomes possible to measure non-invasively.

FIG. 7 shows the absorption spectrum of laser light in a sugar aqueous solution, and it is understood that as the sugar concentration increases, the absorbance also increases, and this absorbance changes significantly depending on the wavelength. It is understood that by selecting a predetermined wavelength, sugar concentration can be measured with high resolution. That is, in the embodiment shown in FIG. 7, by selecting a wavelength of approximately 9.65 microns and supplying laser light of this wavelength to the detection unit 16, it is possible to measure the sugar concentration in the lip tissue extremely accurately. It becomes possible.

In this example, the case where biochemical components are measured using mucous membrane tissues such as the lips was explained as an example. By utilizing the fact that the portion 16 is made of a part of the optical fiber 10 and has a string shape, the detection portion 10 is attached to the skin surface such as the ear or the base of the foot.
It is also possible to measure biochemical components by placing the

Furthermore, by providing the laser light source 30 with a wavelength variable function for outputting laser light, the wavelength of the laser light can be arbitrarily selected to match the living tissue.

As explained above, according to the present invention, the detection section is directly brought into close contact with the skin surface of the human body, and the laser beam of a predetermined wavelength is guided to the detection section in this close contact state, so that the reflected laser light emitted from the detection section is Biochemical components can be analyzed by measuring the energy of , which has the advantage of allowing continuous non-invasive measurements.

In addition, instead of forming the optical fiber that guides the laser beam and the detection part as separate parts, by forming the detection part in a part of the optical fiber, it is possible to detect This prevents loss of laser light and phase shift at the junction with the body, making it possible to analyze and measure biochemical components extremely accurately.Furthermore, since the shape of the detection part is string-like like an optical fiber, Measurements can be made using the skin surface of the body, such as the ear, and are extremely effective in diagnosing newborns.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of the biochemical component analyzer of the present invention, FIG. 2 is a schematic explanatory diagram showing a preferred embodiment of the biochemical component analyzer according to the present invention, and FIG. An explanatory diagram of the optical fiber of the embodiment shown in the figure, FIG. 4 is a waveform diagram of the main part of the embodiment of FIG. 2, FIG. 5 is a specific external view of the embodiment of FIG. 2, and FIG. FIG. 7 is an explanatory diagram showing a measurement state in the analyzer, and FIG. 7 is an explanatory diagram showing an analysis example of the present invention. Corresponding members in each figure are designated by the same reference numerals. 10...Optical fiber, 12...Core, 14...
Cladding, 16...Detection unit, 18...Skin surface of living body (mucosal tissue), 30...Laser light source, 50...
...Calibration optical fiber, 52...Calibration section, 54...
Optical chipper, 60...Measurement calculation unit, 86...Test, 100...Laser light.

Claims (1)

[Claims] 1. Consisting of a core forming a central light guide path and a cladding forming an outer skin of the core, a part of the cladding is removed so that the skin surface of the living body can be directly attached to the side surface of the core. an optical fiber having an exposed detection portion; a laser light source that guides infrared laser light of a predetermined wavelength to the optical fiber; and measuring the energy of the reflected laser light emitted from the optical fiber, and based on the measurement results. A biochemical component analysis device using a laser beam, comprising: a measurement calculation unit that measures biochemical components of the living body, and measures biochemical components non-invasively. 2. In the device according to claim 1, a bent portion is formed in front of the detection section of the optical fiber to make the angle of incidence of the laser beam on the detection section an acute angle, thereby increasing the number of times the laser beam is reflected per unit length at the detection section. A biochemical component analyzer using laser light, which is characterized by: 3. In the device according to claim 1 or 2, a calibration optical fiber is provided through which a portion of the laser beam is guided, and the output of the optical fiber having the detection section and the output of the calibration optical fiber are provided. A biochemical component analysis device using a laser beam, characterized in that a measurement and calculation circuit compares and measures the following. 4. In the device according to claim 3, an optical chopper is provided in the light guide path of the laser light to the optical fiber having the detection section and the calibration optical fiber, and the light guide of the laser light is controlled at alternate timing. A biochemical component analyzer using laser light.