JP3351151B2 - Optical probe device for biological measurement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a biological oxygen monitor and the like.
A living body measurement device that measures metabolism in a living body mainly using near-infrared light, irradiates the living body with light from a light transmitting section provided in contact with the living body, and transmits and scatters the transmitted light from the living body to the living body. The present invention relates to an optical probe device that receives light at a light receiving unit provided in contact therewith. In particular, the present invention relates to a disposable optical probe device in which the optical probe device is detachably attached to a biological measurement device main body and can be made different for each patient.

[0002]

2. Description of the Related Art As an inexpensive and disposable optical probe device for measuring a living body using a plurality of wavelengths of 600 to 900 nm, there is a probe for a pulse oximeter. this is,
As shown in FIG. 1A, a plurality of light emitting diode chips LED (0.
5mm x 0.5mm square size)
Light source 2 in which... Are arranged by the number of wavelengths, and 1-2 from light source 2
A photodetector 3 such as a silicon photodiode provided so as to come into contact with a living body at a position separated by a distance of 1 cm is arranged. A cable 5 is connected to the probe 1 to supply a current for light emission of the light source 1 and to transmit an output signal from the detector 3 to the body of the living body measuring device. A connector 4 that is detachably connected to the main body is provided. This probe device is made of inexpensive parts so that it can be supplied as a disposable part so that different ones can be used for each patient, and has a structure in which the probe 1, the cable 5 and the connector 4 are integrally attached and detached.

FIG. 1B is a circuit diagram showing a case where two LEDs are provided as a light source.
Are turned on at different timings, and the transmitted scattered light is captured by the common detector 3. FIG. 1C shows the probe 1
Is a state in which the measurement is carried out by attaching to the living body 6 which is a subject.

[0004]

Since a pulse oximeter is usually worn on a finger and measures only the blood of the finger, the distance between the light transmitting part and the light receiving part is only 1 to 2 cm. Therefore, the distance between the light transmitting unit and the light receiving unit needs to be increased to 3 cm or more. As the distance between the light transmitting unit and the light receiving unit increases, the amount of transmitted light decreases. The amount of light transmitted by the living body is attenuated to about 1/10 every time the distance between the light receiving unit and the light transmitting unit is increased by 1 cm. Therefore, in the optical probe device of the oxygen monitor, the intensity of the light source must be increased.

In order to increase the light emission intensity, a large current must be passed. However, in a system in which a light-emitting diode chip is directly incorporated in a probe as a light source as in a conventional pulse oximeter, a large current can be passed in terms of heat radiation. In addition, the light emitting diode is in direct contact with the skin, and the temperature of the light emitting diode rises, which may cause a burn. In recent years, low-temperature burns have become a problem, and the temperature of the element that comes into contact with the skin is 4
It is not allowed to rise above 2 ° C. In this respect, in the method in which the light source is directly attached to the probe, the light intensity cannot be increased to a level usable by the oxygen monitor under the condition that the temperature of the light emitting diode does not rise to 42 ° C. or more.

According to the present invention, in order to obtain a disposable optical probe device having a large light intensity so that it can be used not only in a pulse oximeter but also in a biological measurement device such as an oxygen monitor, a light source is not directly attached to the probe. ,
It is an object of the present invention to guide light from the outside to a probe through an optical transmission path, and to realize a low-cost and replaceable probe unit while handling a plurality of wavelengths.

[0007]

An optical probe device according to the present invention includes a probe section, an optical transmission line, an optical connector section, a signal cable, and a signal connector section. The probe unit is provided so as to be in contact with the living body, and has a light transmitting unit having an end face for irradiating the living body with light, and the detection unit is provided so as to be in contact with the living body at a position distant from the light transmitting unit and receives transmitted scattered light by the living body It has a vessel. The optical transmission path has a cross-sectional area larger than the cross-sectional area of an optical fiber bundle that bundles a plurality of optical fibers that transmit light of each wavelength emitted from a monochromatic light source of a different wavelength, and one end is coupled to the light transmitting section of the probe section. Optical fiber. The optical connector section has two end faces facing each other so that the end face of the optical fiber bundle is positioned within the end face of the other end of the optical fiber in the optical transmission line, and is detachably connected. The signal cable is connected to the detector of the probe section, and a signal connector section for detachably connecting the signal cable to the living body measuring device and outputting a signal is provided at the end of the signal cable.

Since the light source is not directly attached to the probe, but is attached to the body of the living body measuring apparatus, it is not necessary to be inexpensive, and a light source having a large light output can be used. Therefore, for example, a semiconductor laser can be used. . The optical fiber for guiding light of each wavelength from the light source of the living body measuring device is attached to the living body measuring device main body, and it is not necessary to reduce the cost, and the optical fiber can be made of quartz. Such quartz optical fibers having a diameter of 0.1 to 0.2 mm are generally commercially available. Even if these optical fibers are bundled, for example, if the number is three or four, the diameter of the end face of the optical fiber bundle can be prevented from exceeding 1 mm. On the other hand, it is necessary that the optical fiber provided in the optical probe device be low-cost, and it is appropriate to use a plastic single-core optical fiber. Since a single-core optical fiber made of plastic having a diameter of about 1 mm is available, the optical connector unit is coupled so that the end face of the bundle of optical fibers that guides light of a plurality of wavelengths from the main body of the device falls within the end face of the single-core optical fiber made of plastic. can do. When a plastic optical fiber is used as an optical fiber provided in the optical probe device, the plastic optical fiber has a large loss at the time of transmission, but the length may be 0.5 to 1 m, so that it can be kept within a sufficiently practical attenuation range. And can be realized at low cost.

[0009]

The present invention solves the problem of the temperature of the light source by preventing the light source from coming into direct contact with the biological sample, and guides the light source provided in the body of the living body measurement device with an optical fiber bundle with little attenuation during transmission. By connecting to a single inexpensive optical fiber with a large thickness, multiple wavelengths can be transmitted efficiently, and even if an inexpensive material such as a plastic optical fiber is used, a conventional optical probe device using a light emitting diode as a light source can be used. 10-1 compared
It is possible to obtain a strong irradiation light quantity of 00 times.

[0010]

FIG. 2A shows an optical probe device 10 according to one embodiment.
Is a schematic cross-sectional view showing the body together with the biological measurement device main body 40. (B) is a perspective view showing the optical probe device 10 with a part cut away. In the optical probe device 10, the living body 6
The probe 11 is made of a flexible material such as rubber, and a prism 12 that bends an optical path as a light transmitting unit is attached to the probe 11 so as to contact the living body 6. The probe 11 also has a prism 12
A detector 13 such as a silicon photodiode is provided at a predetermined distance, for example, 3 cm away from the living body 6 so as to be able to contact the living body 6. To guide light of a plurality of wavelengths to the prism 12, one end of a plastic single-core optical fiber 16 as a transmission path is coupled to the prism 12. The prism 12 bends the light transmitted through the optical fiber 16 in a direction perpendicular to the living body 6. Optical fiber 1
The other end of 6 is provided with an optical connector section 18 which will be described in more detail later with reference to FIG. The detector 13 is connected to a signal cable 17 that guides the detection signal to the biological measurement device main body 40, and a signal connector portion 19 that is detachably connected to the biological measurement device main body 40 is provided at an end of the signal cable 17. .

As an example, four types of semiconductor lasers LD1 to LD4 for generating laser beams of different wavelengths are provided in the body 40 of the living body measuring apparatus. The semiconductor lasers LD1 to LD4 are used to guide the laser beams from the respective semiconductor lasers LD1 to LD4. Are provided with four single-core quartz optical fibers 20-1 to 20-4, and the four optical fibers 20-1 to 20-20 are provided.
-4 is bundled at the tip to form an optical fiber bundle 20.

FIG. 3 shows an example of an optical connector section for connecting the optical fiber bundle 20 and the optical fiber 16 of the optical probe device. Optical fiber 20 on body measuring device main body 40 side
-1 to 20-4 are thin having a diameter of 0.1 to 0.2 mm, and the four optical fibers 20-1 to 20-2
0-4 are bundled, and the front end is fixed by a sleeve 21 made of resin. The sleeve 21 is formed by molding a resin into a cylindrical shape as a whole so as to integrate the four optical fibers 20-1 to 20-4. The end faces of the optical fibers 20-1 to 20-4 are exposed. The end face of the area including the four optical fibers 20-1 to 20-4 has a diameter of 1
mm.

On the other hand, the optical connector 18 provided at the end of the optical fiber 16 on the side of the optical probe device 10 has a concave portion whose cross section in the direction perpendicular to the axial direction is circular so that the sleeve 21 is just fitted at the end. The end face of the optical fiber 16 is exposed at the center of the bottom surface of the concave portion. The end face of the optical fiber bundle 20 is optically coupled to the end face of the optical fiber 16 by fitting the sleeve 21 into the concave portion of the optical connector portion 18. The four optical fibers 20-1 to 20-4 are as thin as 0.1 to 0.2 mm, and if the optical fiber 16 on the probe side has a diameter of 1 mm, the optical fiber 16 and the optical fiber are not required even if the connector 18 itself has high positional accuracy. Connect the bundle 20 to the connector 1
8 can be easily optically coupled while suppressing light attenuation.

As a specific example, the semiconductor lasers LD1 to LD1
An LD 4 having an output of 60 mW, which is easily available, and an Esca SH4001 (a product of Mitsubishi Rayon Co., Ltd.) having a diameter of 1 mm and a length of 1 m is used as the optical fiber 16 will be described. As a result of the experiment, it was found that the optical loss at the optical connector shown in FIG. 3 was about 20% at the maximum. 780 nm, 805 nm, 830 n
If three wavelengths of m are used, Esca SH4001
Is 1 mm in diameter and 1 m in length, the transmittance is 7
Since it is 81% at 80 nm, 63% at 805 nm, and 70% at 830 nm, 780 nm, 805 nm, and 830 nm
The output Po (780), Po (805) and Po (83) of the laser light when transmitted through the optical fiber 16 in nm.
0) is as follows. Po (780) = 60 × 0.8 × 0.81 = 38.9 (m
W) Po (805) = 60 × 0.8 × 0.63 = 30.2 (m
W) Po (830) = 60 × 0.8 × 0.70 = 33.6 (m
W)

As shown in the embodiment of FIG.
If the number 2 is provided, the amount of light is attenuated by about 30% by the prism. In this case, the optical laser outputs Po '(780), Po' (805), and Po '(83) are applied to the living body.
0) is Po '(780) = 27.2 (mW) Po' (805) = 21.1 (mW) Po '(830) = 23.5 (mW) This light output intensity is 10 to 20 times that when the LED is directly mounted as in the conventional optical probe shown in FIG. In the embodiment of FIG. 2, the case where four wavelengths are used is described as an example. However, the number of wavelengths is not limited to this, and the number of wavelengths can be freely designed as long as it is two or more. The present invention has the following aspects. (1) An optical fiber bundle obtained by bundling single-core optical fibers made of quartz is used as an optical fiber bundle for transmitting light from a light source, and a single-core optical fiber made of plastic is used as an optical fiber of an optical transmission path. This makes it easier to realize a disposable and inexpensive optical probe device.

[0016]

According to the present invention, an inexpensive optical fiber having a large diameter, for example, a single-core plastic optical fiber, is used as a transmission path on the optical probe side, and a large output is provided by a semiconductor laser or the like provided on the body of the living body measuring apparatus. Since a bundle of a plurality of thin optical fibers for guiding light from the light source, for example, a bundle of single-core optical fibers made of quartz, is detachably coupled, a probe device of a biological measurement device such as an oxygen monitor having a high-intensity light source. As a result, a disposable inexpensive product can be realized. Further, since the light emitting section is provided on the apparatus main body side and does not directly contact the living body, there is no danger of a low-temperature burn even if a strong current is supplied for driving the light source. Since the transmission optical fiber provided in the probe can be made of plastic or the like, this portion can be realized particularly inexpensively, and light of a plurality of wavelengths can pass therethrough.

[Brief description of the drawings]

FIG. 1 is an example showing a conventional disposable optical probe device, where (A) is an external view, (B) is a circuit diagram thereof, and (C).
FIG. 2 is a schematic front sectional view showing a state of being attached to a living body.

FIGS. 2A and 2B are views showing one embodiment, in which FIG. 2A is a schematic cross-sectional view showing a living body measuring device main body, and FIG. 2B is a partially cutaway perspective view showing an optical probe unit thereof.

FIG. 3 is a partially cutaway perspective sectional view showing the connector section of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical probe apparatus 11 Probe 12 Prism of transmitting part 13 Detector 16 Plastic single core optical fiber 17 Signal cable 18 Optical connector part 19 Signal connector part 20 Single core optical fiber bundle made of quartz 20-1 to 20-4 Single core made of quartz Optical fiber LD1-LD4 Semiconductor laser

──────────────────────────────────────────────────続 き Continuing on the front page (72) Nobuyuki Katsuta, No. 1 Nishinokyo Kuwaharacho, Nakagyo-ku, Kyoto, Kyoto, Japan Inside the Sanjo Plant, Shimadzu Corporation (72) Inventor Takeshi Yamaguchi No. 1, Nishinokyo Kuwaharacho, Nakagyo-ku, Kyoto, Kyoto In Shimadzu Sanjo Plant (72) Inventor Shoichi Tsuneishi 1 in Nishinokyo Kuwaharacho, Nakagyo-ku, Kyoto, Kyoto Prefecture In Shimadzu Sanjo Plant (72) Inventor Tomomi Tamura 1 in Nishinokyo Kuwabaracho, Nakagyo-ku, Kyoto, Kyoto Shimazu Corporation (56) References JP-A-60-135028 (JP, A) JP-A-61-257629 (JP, A) JP-A-5-86304 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) A61B 5/145 A61B 10/00

Claims (1)

(57) [Claims] 1. A light transmitting unit provided to come into contact with a living body and having an end face for irradiating the living body with light, and provided to be in contact with the living body at a position distant from the light transmitting unit and receiving transmitted scattered light by the living body. It has a cross-sectional area larger than the cross-sectional area of a probe section equipped with a detector and an optical fiber bundle in which a plurality of optical fibers for transmitting light of each wavelength emitted from a monochromatic light source of a different wavelength are bundled. An optical transmission path having an optical fiber coupled to an optical section, and both end faces facing each other so that the end face of the optical fiber bundle is positioned within the end face of the other end of the optical fiber of the optical transmission path; and An optical connector for detachable connection, a signal cable connected to the detector of the probe section, and a signal cable provided at the end of the signal cable. A signal connector portion for outputting a signal to connected, removable optical probe device for a biological measurement with a.