JPH06319726A - Device for measuring oxygen metabolism of bio tissue - Google Patents

Abstract

PURPOSE:To obtain accurate oxygen metabolism data with a high detection sensitivity by bringing the light emitting surface and light receiving surface of near infrared rays into close contact with biotissue. CONSTITUTION:A probe 8 is constituted of an optical fiber bundle guiding the light from a light source to biotissure and guiding the light reflected from the surface of the biotissure to a reflected light detector, an optical fiber bundle for scattered light guiding the light reaching the deep part of the biotissure to be scattered to scattered light detector, and the flexible tube covering both optical fiber bundless. The optical fiber bundle and the optical fiber bundle for scattered light are arranged at the leading end part 11 the probe 8 so that the line connecting the emitting surface 11a of the optical fiber and the incident surface of the optical fiber for the scattered light become right-angled to the angle direction of the leading end part 11 of the probe 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for measuring oxygen saturation in living tissues and organs, that is, biological information relating to oxygen metabolism, using light, and particularly measuring oxygen metabolism in tissues of heart and brain. The present invention relates to a biological tissue oxygen metabolism measuring apparatus suitable for

[0002]

2. Description of the Related Art Light in the red to near-infrared region has high permeability to living tissues and its light-absorbing property to oxygen-binding substances such as hemoglobin, myoglobin, and cytochrome oxidase that regulate oxygen metabolism in the living body. It has the characteristic of corresponding change in absorption spectrum. Utilizing such characteristics, USP4223680, USP42816
45, a method for measuring oxygen metabolism of various organs such as heart and brain in the living body is shown.

[0003] In recent years, an endoscope that uses an optical image fiber bundle to observe not only the stomach and the large intestine but also blood vessels has been used in general medicine. Such an endoscope has a feature that a disease can be diagnosed accurately and early by directly observing an organ that cannot be seen from outside the body from the inside of the body cavity. Further, the endoscope is provided with a hole called a channel, and a treatment tool such as biopsy forceps or an electric scalpel can be inserted into the body from the outside of the body through the channel, and the diagnosis of a lesion part which cannot be understood only by observing the endoscope can be performed. It is used for treatment.

Recently, in order to diagnose gastric ulcer, cancer and the like, an optical fiber probe is inserted through an endoscope channel to measure the oxygen metabolism state of a lesion site in a body cavity. Furthermore, studies have also been conducted to determine the oxygen metabolism of the myocardium by directly inserting an optical fiber probe into the ventricle of the heart under fluoroscopy. Regarding the previous examination, "Medical reflection spectrum analyzer using optical fiber probe", Medical Electronics and Bio-Optics Vol.28 No.3 (1990), JP-A-59-2305
No. 33, Japanese Patent Application No. 3-194459 for later consideration.
Detailed in the issue.

[0005]

However, when the living tissue is irradiated with light by the optical fiber probe, if both the emitting surface and the light receiving surface are not in close contact with the living tissue, the detection sensitivity is lowered and accurate oxygen metabolism is not achieved. Although information cannot be obtained, no consideration is given to such a problem in the above-mentioned conventional example.

The present invention has been made in view of the above-mentioned circumstances, and the oxygen of the living tissue which has a high detection sensitivity by having both the emitting surface and the light receiving surface in close contact with the living tissue and can obtain accurate oxygen metabolism information. It is an object to provide a metabolism measuring device.

[0007]

Means and Actions for Solving the Problems An apparatus for measuring oxygen metabolism of living tissue according to the present invention has a light source that emits near-infrared light and an insertion portion that is inserted into a body cavity. With a probe to measure the metabolism of biological tissue by
The probe has a bending mechanism that bends a distal end portion of the insertion portion, is inserted through the insertion portion, and light from the light source is incident from a proximal end surface and irradiates the biological tissue from the distal end surface. A light transmitting unit and a second light transmitting unit that is inserted through the insertion portion and transmits return light from the living tissue, the tip end surface of the first light transmitting unit and the second light transmitting unit. Since the bending mechanism section is arranged in a direction intersecting with the direction in which the bending mechanism section bends the tip section of the insertion section, the emitting surface and the light receiving surface should both be in close contact with the living tissue. Is possible.

[0008]

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

1 to 4 relate to the first embodiment, FIG. 1 is a block diagram showing the configuration of an oxygen metabolism measuring apparatus for measuring oxygen metabolism of living tissue, and FIG. 2 is a perspective view showing the appearance of the oxygen metabolism measuring apparatus. FIG. 3 is an external view showing the configuration of the tip of the probe,
FIG. 4 is an explanatory diagram showing a state in which the insertion portion is inserted into the heart.

As shown in FIG. 2, the oxygen metabolism measuring device 1
Is composed of an elongated scope 3 having a built-in optical fiber bundle, a main body 6 having a light source 2, a reflected light detector 4a, a scattered light detector 4b and a computer 5 which will be described later, and a display device 7 for displaying oxygen metabolism. To be done. The scope 3
Holds a scope 8 and a probe 8 composed of an elongated and thin flexible tube with a built-in optical fiber bundle so that light can be transmitted and received in a body cavity, for example, the heart, stomach, large intestine, brain, etc. The probe 8 is composed of an operation holding portion 9 and an extension cable 10 connected to the main body device 6, and the probe 8 includes a rigid tip portion 11 and a movable portion 12 provided continuously to the tip portion 11. , This movable part 1
2 is an angle operation unit 1 provided in the operation holding unit 9.
It is adapted to be movable by operating the angle operation unit 13 in conjunction with the position 3.

As shown in FIG. 1, the main body device 6 takes out only a light source 2 which sequentially emits light having different wavelengths, and only light which is emitted from the light source 2 and is reflected by a living tissue 23. An optical element 14 including a beam splitter, a reflected light detector 4a for measuring light reflected from the living tissue 23 taken out by the optical element 14, and a light scattered to the deep portion of the living tissue 23 are measured. A scattered light detector 4b, a computer 5 for controlling the light source 2 and calculating oxygen metabolism from signals obtained from the reflected light detector 4a and the scattered light detector 4b in synchronization therewith, and the reflected light detection The analog signal of the detector 4a and the scattered light detector 4b is converted into a digital signal, and the A / D converters 15a and 15b for inputting to the computer 5 are provided. By transmitting the calculated oxygen metabolism by computer 5 on the display device 7, and displays the oxygen metabolism in the display device 7.

The light source 2 has different wavelengths λ 1, λ 2, λ
Laser diodes 16a, 16 for generating light of 3, λ4
b, 16c, 16d and the laser diode 16a,
A drive device 17 for sequentially driving the laser diodes 16a, 16b, 16c, 16d for sequentially irradiating the light beams 16b, 16c, 16d, and the laser diode 16
The laser diodes 16a, 16b, 16 are used to sequentially guide the respective lights of a, 16b, 16c, 16d to the optical fiber bundle 18 inserted in the probe 8.
The rotating disk 21a, 21b, 21c having a mirror 19 for reflecting the light from c and three holes 20 and the mirror 22 for reflecting the light from the laser diode 16d, the rotating disks 21a, 21b, 21c are The positions of the respective mirrors 19 are configured to rotate with a constant phase difference in synchronization with the timing of the drive unit 17.

Further, the probe 8 guides the light from the light source 2 to the living tissue 23, and at the same time, the living tissue 23.
The optical fiber bundle 18 for guiding the light reflected from the surface to the reflected light detector 4a, and the scattered light optical fiber bundle 24 for guiding the light reaching the deep part of the biological tissue 23 and scattered to the scattered light detector 4b. The flexible tube 25 covers the optical fiber bundle 18 and the scattered light optical fiber bundle 24.

Here, at the tip portion 11 of the probe 8, as shown in FIG.
The line connecting 1a and the incident surface of the scattered light optical fiber bundle 24 (not shown, but arranged on the opposite side of the emission surface 11a) is a probe 8 movable by operating the angle operation unit 13. It is arranged so as to be perpendicular to the angle direction (arrow in the figure) of the tip portion 11.

The operation of the oxygen metabolism measuring apparatus 1 of the first embodiment thus constructed will be described.

For example, as shown in FIG. 3, when measuring the metabolism of the myocardium, the probe 8 is inserted through the femoral artery,
Under fluoroscopy, the aorta is inserted into the left ventricle, and the tip 11 is pressed against the heart wall, which is the living tissue 23. At this time, as shown in FIG. 3, the angle operation part 13 is operated so that the tip part 11 comes into close contact with the heart wall, and the oxygen metabolism of the myocardium 26 at that part is measured. Further, the measurement position is changed by operating the scope 3 and the angle operation unit 13, and the oxygen metabolism of each is measured to obtain the oxygen metabolism distribution of the heart wall.

First, the light source 2 sequentially generates pulsed lights of four different wavelengths. For example, these wavelengths are near infrared light of 650 nm to 950 nm which is absorbed by cytochrome, hemoglobin, and myoglobin containing oxygen metabolism information. Each of these lights passes through the optical element 14 and is guided to the optical fiber bundle 18. Scope 3 probe 8
Is inserted into the body cavity, and the tip 11 of the probe 8 is
The light that is in contact with the living tissue 23 of the measured portion and is guided to the optical fiber bundle 18 is applied to the living tissue 23.

A part of the light applied to the living tissue 23 is reflected on the surface of the living tissue 23 and propagates through the optical fiber bundle 18 again. This reflected light is reflected in the vertical direction by the optical element 14 such as a beam splitter and detected by the reflected light detector 4a. Further, a part of the light applied to the living tissue 23 reaches one end of the scattered light optical fiber bundle 24 while scattering the deep portion of the living tissue 23, and passes through the scattered light optical fiber bundle 24 to detect scattered light. The light is received by the device 4b.

Further, the reflected light detector 4a and the scattered light detector 4b are connected to A / D converters 15a and 15b, and the light detected by the reflected light detector 4a and the scattered light detector 4b is The digital electric signal is converted and input to the computer 5. The computer 5 calculates the attenuation rate (OD) by taking the index of the ratio of the signal of the scattered light detector 4b to the signal of the reflected light detector 4a at each wavelength. Furthermore, the simultaneous equations are solved based on the attenuation rate at each wavelength to obtain the oxygen metabolism of cytochrome, hemoglobin, and myoglobin.

The oxygen metabolism thus obtained is displayed on the display device 7, and the metabolism of the tissue can be known in real time.

Here, the tip 11 of the probe 8 and the living tissue 23 may have a lower detection sensitivity depending on the contact state, but the tip 11 of the probe 8 and the living tissue may be operated by operating the angle operation unit 13. 23 can be brought into close contact. At this time, as shown in FIG. 3A, the exit surface 11a of the optical fiber bundle 18 and the entrance surface of the scattered light optical fiber bundle 24 are arranged perpendicular to the angle direction (not shown, but disposed on the opposite side of the exit surface 11a). 3), the output surface of the optical fiber bundle from the biological tissue 23 and the optical fiber bundle for scattered light are compared with the case where they are arranged parallel to the angle direction, as shown in FIG. 3B. It is possible to obtain accurate oxygen metabolism information without separating the incident surfaces of.

Next, the second embodiment will be described. 5 and 6 relate to the second embodiment, FIG. 5 is an explanatory view for explaining a plurality of optical fibers for transmitting lights of different wavelengths, and FIG. 6 shows one optical fiber formed from the plurality of optical fibers of FIG. It is explanatory drawing explaining a fiber.

Since the second embodiment is almost the same as the first embodiment, only the different structure will be described.

As shown in FIG. 5 (a), different wavelengths λ from the laser diodes 16a, 16b, 16c, 16d.
The light of 1, λ2, λ3, and λ4 is bundled with four fiber bundles 30.
a, 30b, 30c and 30d respectively receive light, and the respective fibers of the fiber bundles 30a, 30b, 30c and 30d are randomly arranged as shown in FIG. The probe 8 is inserted and guided to the tip of the probe 8.

As shown in FIG. 6A, the fiber bundle 30
a, 30b, 30c, 30d, the scattered light optical fiber bundle 24, and the branched portion of the reflected light fiber bundle 31 for transmitting the reflected light from the living tissue 23 (B in the figure),
As shown in (b), the fiber bundles 30a, 30b, 30
When forming one fiber bundle 30 from c and 30, the coating of each fiber bundle 30a, 30b, 30c and 30d is shifted. The other structure is the same as that of the first embodiment.

According to the second embodiment having such a configuration, in addition to the effect of the first embodiment, light of a plurality of wavelengths is emitted from random positions on the tip surface of the probe 8, so that a plurality of wavelengths are emitted. Irradiation can be performed uniformly, and oxygen metabolism can be measured accurately. Further, the fiber bundles 30a, 30b, 30c, 30d
Since the single fiber bundle 30 is formed by shifting the coating of (1), there is also an effect that the fiber bundle is hard to break.

[0027]

As described above, according to the oxygen metabolism measuring apparatus for a living tissue of the present invention, both the emitting surface and the light receiving surface of the near infrared light are brought into close contact with the living tissue. There is an effect that information on oxygen metabolism can be obtained, which can lead to early detection and diagnosis of pathological conditions.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an oxygen metabolism measuring apparatus for measuring oxygen metabolism of living tissue according to a first embodiment.

FIG. 2 is a perspective view showing the external appearance of the oxygen metabolism measuring device according to the first embodiment.

FIG. 3 is an external view showing the configuration of the tip of the probe according to the first example.

FIG. 4 is an explanatory diagram showing an insertion state of the insertion portion according to the first embodiment into the heart.

FIG. 5 is an explanatory diagram illustrating a plurality of optical fibers that transmit lights of different wavelengths according to the second embodiment.

FIG. 6 is an explanatory diagram illustrating a single fiber formed from the plurality of optical fibers in FIG.

[Explanation of symbols]

 1 ... Oxygen metabolism measuring device 2 ... Light source 4a ... Reflected light detector 4b ... Scattered light detector 5 ... Computer 7 ... Display device 8 ... Probe 11 ... Tip part 18 ... Optical fiber bundle 24 ... Optical fiber bundle for scattered light

Claims (1)

[Claims] 1. A light source that emits near-infrared light, a probe that has an insertion portion that is inserted into a body cavity, and that measures the metabolism of a biological tissue by light from the light source, wherein the probe comprises: A first light transmitting unit that has a bending mechanism that bends the distal end of the insertion portion, is inserted through the insertion portion, and emits light from the light source from the proximal end surface and irradiates the living tissue from the distal end surface; A second light transmitting unit that transmits the return light from the living tissue by being inserted through the insertion portion; and a front end face of the first light transmitting unit and a front end face of the second light transmitting unit. The oxygen metabolism measuring device for a biological tissue, wherein the bending mechanism section is arranged in a direction intersecting with a direction in which the distal end portion of the insertion section is bent.