JPH05115467A - Metabolic information measuring system - Google Patents

Abstract

PURPOSE:To provide the metabolic information measuring system which can exactly measure the metabolic information of a biotissue. CONSTITUTION:While a fiber 7 for irradiation which emits inspecting light to the cardiac muscle 19 and a fiber 8 for photodetection which receives the inspecting light are provided in a probe 4, the light emitted from laser diodes 9a to 9d is varied in irradiation angle by an irradiation angle varying device 10 and is made incident on an incident end 7b of the fiber 7 for irradiation. The light introduced into the fiber 7 for irradiation is made into the circular conical light having a steroscopic angle equal to the incident angle and is cast to the cardiac muscle 19. The metabolic information of the biotissue is measured by measuring the inspecting light transmitted through the cardiac muscle 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring metabolic information of biological tissue, which is suitable for measuring biological information such as oxygen saturation in biological tissue and organs such as heart and brain using light, that is, oxygen metabolism. Regarding

[0002]

2. Description of the Related Art Light in the red to near-infrared region has high permeability to living tissues and its light absorption and oxygen binding information to substances that control oxygen metabolism of living organisms such as hemoglobin, myoglobin, and cytochrome oxidase. It has features such as corresponding changes in absorption spectrum.

Utilizing such characteristics, USP422
As shown in 3680, US Pat. No. 4,281,645, a method of measuring oxygen metabolism of various organs such as heart and brain in a living body is known. This is 700-1300n
Light in the near-infrared region of m is applied to an organ or a tissue in a living body, reflected light reflected from the deep organ or tissue or light transmitted therethrough is detected, and light intensity between wavelengths is compared and calculated. It measures blood volume, hemoglobin and cytochrome oxygenation.

Here, the cytochrome is a pigment protein (oxidized Cu2 + reduced Cu +) having copper existing in the mitochondria of cells. Usually, 80% is an oxidative type, but during ischemia, it becomes a reducing type early. Therefore, the redox state of cytochrome can be measured from the absorption amount at each wavelength, and it can be used as an index of tissue oxygen metabolism.

When myocardial infarction occurs, myocardial necrosis is caused in the worst case, but in early or acute cases, myocardial activity is stopped but sometimes it is not. In such a case, PTCA and bypass are effective. So far
I used PET to diagnose whether myocardium was alive or dead, and decided to perform bypass surgery.
ET devices are extremely expensive and not very popular.

When measuring the myocardial tissue, the scope is actually inserted from the aorta of the lower limb and, as shown in FIG. 4, the distal end portion 2 of the scope 1 is pressed against the myocardial tissue 3 and placed in advance in the coronary artery. Diagnosis is made by occluding a balloon for a predetermined period of time and measuring the metabolic changes in myocardium. At this time, if myocardium is dead, there is no metabolic change,
Can diagnose whether myocardium is alive or dead.

By the way, Japanese Patent Application Laid-Open No. 59-230533, which is known as a conventional metabolic information measuring apparatus, projects light from a light source onto a living tissue through a light projecting fiber,
The reflected light from the living tissue is transmitted to the light receiving part using a plurality of optical fiber bundles, and after being separated by different wavelength filters provided on the end faces, the intensity of the reflected light is measured for each wavelength and the target living body It measures the information of the organization.

Further, Japanese Patent Publication No. 61-11614 discloses
Near-infrared regions including light of various wavelengths within a spectrum range of 700 to 1300 nm are alternately and intermittently projected onto a living tissue in a predetermined cycle, and reflected light from the living tissue is received by a light receiving unit, Information on the target biological tissue is measured by measuring the intensity of reflected light for each wavelength.

[0009]

By the way, USP42
In both patents of 23680 and USP 4281645,
The applicant emphasizes that when measuring oxygen metabolism using light in the near infrared region, the light path must be relatively long. In other words, the fact that it spans a long path can include the metabolic information of the deep part in the target tissue.

Further, in the case of irradiating and detecting the metabolism of an organ with light from one direction (this is called a reflection system), in order to achieve the above-mentioned object, the light irradiation part and the detection part are separated from each other by several centimeters. States that it is necessary. “Monitoring cerebral oxygen metabolism during external circulation using near-infrared biometrics” In artificial organ 19 (1) 535-538 (1990), the irradiation part and the detection part are 3 to measure oxygen metabolism in the brain. 4 cm apart.

In recent years, an endoscope which uses an optical fiber bundle to observe not only the stomach and large intestine but also the inside of blood vessels has been used in general medicine. This endoscope has a characteristic that a disease can be diagnosed accurately and early by directly observing an organ that cannot be seen from the outside from the body cavity.

Furthermore, the endoscope is provided with a hole called a channel, and a treatment instrument such as biopsy forceps or an electric scalpel can be inserted into the body through the channel from the outside. Used for medical treatment.

Recently, an optical fiber probe for measuring oxygen saturation using this channel is inserted to diagnose metabolic information of a lesion site, or an optical probe is directly inserted under X-ray fluoroscopy to detect organs. Studies are being conducted to determine the oxygen metabolism of.

Regarding the optical probe, "Medical reflection spectrum analyzer using optical fiber probe" Medical Electronics and Biotechnology Vol.28 No3 (1990), JP-A-59-2305
Detailed in 33.

By the way, the above-mentioned optical fiber probe has a small outer diameter at the insertion portion of the probe so that it can be inserted into the body cavity, and therefore the irradiation portion for irradiating light and the detecting portion for detecting are extremely close to each other. While being placed,
The irradiation angle is fixed.

Since pulsed light having a time width sufficiently longer than the speed of light is used, light passing through the tissue surface without detecting a relatively long path is detected. That is, such a method measures the metabolic information only on the surface of the tissue, and the metabolic information in the deep tissue cannot be measured because it is strongly influenced by the epidermis of the tissue, the body fluid attached to the surface of the epidermis, and blood.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a metabolic information measuring device capable of accurately measuring metabolic information of a living tissue.

[0018]

In order to achieve the above object, the present invention provides a living body by emitting a test light for measuring metabolic information of a living tissue and detecting the test light transmitted through the living tissue. In measuring tissue metabolism information, an inspection light emitting means for emitting the inspection light, and an optical transmission means for optically transmitting the inspection light emitted from the inspection light emitting means to emit it to a biological tissue, It is provided with the inspection light receiving means for receiving the inspection light transmitted through the living tissue and the optical axis changing means capable of changing the incident angle of the light incident on the light transmitting means.

[0019]

When the inspection light emitted from the inspection light emitting means is incident on the light transmitting means at an incident angle, the inspection light emitted from the light transmitting means is a cone having a solid angle equal to the incident angle. It becomes irradiation light in the shape of a circle and is applied to the living tissue. When the biological tissue is irradiated with light having a certain irradiation angle, the reflected light scattered near the surface of the biological tissue is received by the inspection light receiving means, and the light incident along the optical axis is irradiated to the biological tissue. The reflected light that has been transmitted through the deep portion of and is scattered is received.

Therefore, the irradiation depth (detection depth) of the irradiation light on the living tissue can be changed by changing the irradiation angle, that is, the incident angle that is incident on the incident end of the inspection light emitting means, and the information of the living tissue can be accurately obtained. Can be measured.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment, and FIG. 1 shows a schematic structure of a metabolic information measuring apparatus for living tissue.
Reference numeral 4 is a metabolic information detection probe, and 5 is an insertion portion of the probe 4.

The insertion section 5 is internally provided with an irradiation fiber 7 as an optical transmission means for optically transmitting the inspection light and a light receiving fiber 8 as an inspection light receiving section for receiving the inspection light. An irradiation window 7a of the irradiation fiber 7 and a light reception window 8a of the light reception fiber 8 are provided at the tip of the insertion portion 5.

Reference numeral 9 is a light source for irradiation as an inspection light emitting means, which emits near-infrared light of 700 nm to 950 nm which is absorbed by cytochrome and hemoglobin containing oxygen metabolism information. ~ 9d.

These first to third laser diodes 9a
Beam splitters 10a to 10c are provided on the emission sides of the to 9c, and a mirror 10d is provided on the emission side of the fourth laser diode 9d. Then, 700 nm emitted from the first to fourth laser diodes 9a to 9d
Near-infrared light of 950 nm is guided to the irradiation angle changing device 10 as the optical axis changing means.

The irradiation angle varying device 10 includes a scanner 11
The rotating mirror 12 that is rotated by
Two lenses 1 are provided on the reflection optical path of the rotating mirror 12.
3, 13 are provided. The two lenses 13a and 13b are installed so that the rotary mirror 12 and the incident end 7b of the irradiation fiber 7 are located at their respective focal positions.

The near-infrared light received by the light-receiving fiber 8 is received by the light-receiving element 14, and the light-receiving element 14 uses the near-infrared light to measure blood volume, oxidative and reduced hemoglobin levels, and oxygen metabolism of living tissue. It is connected to a spectrum analyzer 15 that measures changes in the enzyme.

The irradiation light source 9, the irradiation angle varying device 10 and the spectrum analyzing device 15 are connected to a control device 16, and the spectrum analyzing device 15 is connected to a display device 17.

According to the metabolic information detecting probe 4 thus constructed, the insertion portion 5 of the probe 4 is inserted into the body cavity by penetrating the chest wall of the living body and the like, and the distal end portion of the insertion portion 5 is made into the living tissue. The measurement target part of the myocardium 19 is contacted.

In this state, when pulse lights are sequentially emitted from the first to fourth laser diodes 9a to 9d, they are reflected by the rotary mirror 12 of the irradiation angle varying device 10, and the reflected light is transmitted by the lenses 13a and 13b. It is incident on the irradiation fiber 7 of the probe 4.

Since the two lenses 13a and 13b are installed so that the rotary mirror 12 and the incident end 7b of the irradiation fiber 7 are located at the respective focal positions, the two lenses 13a and 13b are reflected by the rotary mirror 12 and are reflected by the lens 13.
The light is incident on the incident end 7b of the irradiation fiber 7 by the lens 13b at an angle equal to the angle of incidence on a.

The light thus incident at an angle with respect to the optical axis of the irradiation fiber 7 has a conical shape having a solid angle equal to the incident angle from the irradiation window 7a, as shown in FIG. 2 (a). The irradiation light becomes the irradiation light and is applied to the myocardium 19.

As described above, when the light having a certain irradiation angle is applied to the myocardium 19, as shown in FIG.
The reflected light scattered near the surface of is received by the light receiving fiber 8 through the light receiving window 8a.

Further, as shown in FIG. 2C, when the myocardium 19 is irradiated with the light incident along the optical axis of the irradiation fiber 7, the reflected light transmitted through the deep part of the living tissue of the myocardium 19 and scattered. Is received by the light receiving fiber 8 through the light receiving window 8a. Therefore, the irradiation depth (detection depth) of the irradiation light to the myocardium 19 can be changed by changing the irradiation angle, that is, the incident angle that is incident on the incident end 7b of the irradiation fiber 7.

The pulsed light is, for example, near-infrared light having a wavelength of 700 nm to 950 nm which has absorption in cytochrome and hemoglobin containing oxygen metabolism information, and can effectively capture the reflected light that has passed through the deep part of the living tissue. This reflected light can be detected by the spectrum analyzer 15 and the detection light of each wavelength can be calculated to measure the changes in blood volume, oxidative and reduced hemoglobin levels, and oxygen-metabolizing enzyme in the living tissue.

FIG. 3 shows a second embodiment. A laser diode 20 having a divergence angle (NA) is used as a light source for irradiation, and the laser light emitted from this laser diode 20 is magnified α to β times. Variable zoom lens 21
It is configured so as to enter the entrance end 7b of the irradiation fiber 7.

The divergence angle is NA, the laser diode 20 having the divergence angle is NALD, and the magnification of the zoom lens 21 is α.
The light emitted from the irradiation window 7a of the irradiation fiber 7 can have a divergence angle of NA = NALD × (α to β), and the irradiation angle, that is, the irradiation angle, that is, the first embodiment. The irradiation depth (detection depth) of the irradiation light to the myocardium 19 can be changed by changing the incident angle that is incident on the incident end 7b of the irradiation fiber 7.

[0038]

As described above, according to the present invention, the incident angle of light incident on the light transmitting means for optically transmitting the inspection light emitted from the inspection light emitting means to the biological tissue is emitted. By arranging the optical axis changing means that can change the incident angle, the incident angle of light incident on the light transmitting means can be changed, so that the irradiation depth (detection depth) of the irradiation light on the biological tissue can be changed.
Can be varied, and the metabolic information of the living tissue can be accurately measured.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a metabolic information measuring device according to a first embodiment of the present invention.

2 (a) to (c) are side views of a probe used in the metabolic information measuring apparatus of the embodiment.

FIG. 3 is a schematic configuration diagram of a metabolic information measuring device according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a general measurement state of a myocardium.

[Explanation of symbols]

4 ... Probe, 5 ... Insertion part, 7 ... Irradiation fiber, 8
... Receiving fiber, 9 ... Irradiation light source, 10 ... Irradiation angle varying device.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Further, in the case of irradiating and detecting the metabolism of an organ with light from one direction (this is called a reflection system), in order to achieve the above-mentioned object, the light irradiation part and the detection part are separated from each other by several centimeters. States that it is necessary. “Monitoring cerebral oxygen metabolism during extracorporeal circulation using near-infrared biometrics” In artificial organ 19 (1) 535-538 (1990), the irradiation unit and the detection unit are 3 to 3 in order to measure oxygen metabolism in the brain. 4 cm
Separated.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

In recent years, an endoscope which uses an optical fiber bundle to observe not only the stomach and large intestine but also the inside of blood vessels has been used in general medicine. This endoscope is the body
By directly observing internal organs that cannot be seen from the inside of the body cavity, it is possible to accurately and early diagnose diseases.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Further, the endoscope is provided with a hole called a channel, and a treatment tool such as a biopsy forceps or an electric scalpel can be inserted into the body from the outside of the body through the channel to diagnose a lesion portion which cannot be detected by image diagnosis. Used for medical treatment.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

The irradiation angle varying device 10 includes a scanner 11
The rotating mirror 12 that is rotated by
Two lenses 13 are provided on the reflection optical path of the rotating mirror 12.
a and 13b are provided. The two lenses 13a and 13b are installed so that the rotary mirror 12 and the incident end 7b of the irradiation fiber 7 are located at their respective focal positions.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiko Omagari 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Yoshio Tashiro 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Inventor Issei Nakamura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Koichi Umeyama 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Yoshinao Daimei 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Shuichi Takayama 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Seiji Yamaguchi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olin Scan Optical Industry Co., Ltd. in

Claims (1)

[Claims] 1. A metabolic information measuring device for measuring metabolic information of a biological tissue by emitting an inspection light for measuring metabolic information of the biological tissue and detecting the inspection light transmitted through the biological tissue. Inspection light emitting means for emitting
With respect to the optical transmission means for transmitting the inspection light emitted from the inspection light emitting means to the biological tissue and emitting the inspection light, the inspection light receiving means for receiving the inspection light transmitted through the biological tissue, and the optical transmission means. A metabolic information measuring device, comprising: an optical axis changing means capable of changing a light incident angle of incident light.