JPH0611439A - Measuring device for oxygen metabolism of vital organism tissue - Google Patents

Abstract

PURPOSE:To provide a measuring device for the oxygen metabolism of a vital organism with which measurement with high S/N is accomplished using a diameter as thin as allowing insertion through a body cavity. CONSTITUTION:An oxygen metabolism measuring device comprises a light source 2 which generates beams of light having different wavelengths one by one, a probe 8 which is to be inserted through a body cavity and irradiates a vital organism tissue 23 with beams from the light source 2, an optical element 14 which takes out only the beams of light as a reflection of the light from the light source 2 at the vital organism tissue 23, and a reflected light sensor 4a which measures the reflected light taken out by the element 14. The arrangement is further equipped with a diffused light sensor 4b to measure the beams of light diffused at the dep place in the tissue 23 and a computer 5 which controls the light source 2 and, in synchronization therewith, calculates the oxygen metabolism from signals given by the sensors 4a, 4b. The oxygen metabolism information calculated by the computer 5 is transmitted to and displayed on a display device 7.

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 control 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]

By the way, as described above, when inserting the optical fiber probe into the channel or body cavity of the endoscope, the outer diameter of the insertion portion of the probe is reduced so that the probe can be easily inserted. There is. Japanese Patent Application No. 3-194
In No. 459, an optical fiber probe is inserted from the aorta of the lower limb into the left ventricle of the heart, and in this case, the outer diameter of the probe is required to be around 3 mm. As described above, if the outer diameter of the insertion portion is reduced, the number of optical fiber bundles that configure the probe is also limited, and as a result, the amount of light that irradiates the measured portion and the amount of light that is detected are reduced, and the S / N ratio of the metabolic signal is reduced. May decrease, or in the worst case, metabolic measurement may not be possible.

In Japanese Patent Publication No. 2-57678, a method of transmitting and receiving light with a single optical fiber is shown, but it does not measure oxygen saturation in the living body. Since the light source and the photodetector must be arranged on the side within the NA of the optical fiber, it is impossible to arrange the light source and the photodetector when the light is guided to an extremely thin fiber.

The present invention has been made in view of the above circumstances, and has a small diameter that can be inserted into a body cavity and is capable of measuring the metabolism of living tissue with a high S / N ratio. The purpose is to provide a device.

[0008]

Means for Solving the Problems An apparatus for measuring oxygen metabolism of living tissue according to the present invention has a light source that sequentially generates light of a plurality of wavelengths and an insertion section that is inserted into a body cavity. A probe for measuring metabolism of living tissue by light, inserted through the inside of the insertion part, irradiating the living tissue with light from the light source from the proximal end surface and irradiating the living tissue from the front end surface; The first light transmitting means for transmitting the return light of the above from the front end surface and transmitting to the base end surface,
An optical device that is inserted through the insertion portion and that transmits the second return light from the biological tissue, and an optical device that separates the optical path of the light from the light source and the optical path of the first return light. An element, a first light detecting means for detecting the first returning light whose optical path is separated by the optical element, a second light detecting means for detecting the second returning light, and the first and the second Second
Computation means for processing and computing the output of the photodetection means and display means for displaying the computation result of the computation means.

[0009]

[Operation] The light from the light source is made incident from the proximal end surface and is irradiated to the biological tissue from the distal end surface by the first light transmitting means, and the first return light from the biological tissue is incident from the distal end surface. The optical path of the light from the light source and the optical path of the first return light are separated by the optical means, and the first return light is detected by the first light detecting means. A second light detection means detects the second return light, the calculation means processes and outputs the outputs of the first and second light detection means, and the display means calculates the calculation result of the calculation means. Is displayed.

[0010]

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

1 to 3 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. 3 and 4 are explanatory views showing the insertion state of the insertion portion into the heart.

As shown in FIG. 2, the oxygen metabolism measuring device 1
Is composed of an elongated scope 2 having a built-in optical fiber bundle, a main body 6 having a light source 3, 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 2
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, in 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
The reference numeral 2 is designed to be movable by operating the angle operation section 13 in conjunction with the angle operation section 13 provided on the operation section holding section 9.

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 a 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, 1 for generating light of 3, λ4
6b, 16c, 16d and the laser diode 16
Since the light of a, 16b, 16c, 16d is sequentially irradiated,
The laser diodes 16a, 16b, 16c, 16d
And a drive device 17 for sequentially driving the laser diode 16a, 16b, 16c, 16d, and an optical fiber bundle 18 inserted in the probe 8 in order.
To guide light to the laser diodes 16a, 16
The rotating disks 21a, 21b and 21c having the mirror 19 and the three holes 20 for reflecting the light from the lasers 16b and 16c, and the mirror 22 for reflecting the light from the laser diode 16d are provided. 21c
Are configured so that the positions of the respective mirrors 19 rotate with a constant phase difference in synchronization with the timing of the driving device 17.

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 17 and the scattered light optical fiber bundle 24.

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 3 is operated so that the tip part 11 closely contacts the heart wall, and the oxygen metabolism of the myocardium 26 at that part is measured. Furthermore, the measurement position is changed by operating the scope 2 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 20 and is guided to the optical fiber bundle 18. Scope 2 probe 8
Is inserted into the body cavity, and the tip portion 11 of the probe 3 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 20 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, passes through the scattered light optical fiber bundle 24, and detects 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 7. The computer 7 calculates the attenuation factor (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 8 so that the metabolism of the tissue can be known in real time.

Therefore, according to the oxygen metabolism measuring apparatus 1 of the first embodiment, the optical fiber bundle for irradiating the measured portion with light and the optical fiber bundle for measuring the light quantity of the reflected light irradiated on the measured portion are provided. Since they can be shared, the number of fibers constituting the probe can be reduced. From this, it becomes possible to realize a probe with a small diameter, that is, to apply it to many internal organs such as the heart and brain.

The first embodiment uses not only the myocardium but also the channel of the endoscope inserted in the stomach to measure the metabolism of the inner wall of the stomach while observing under the endoscope, and The metabolism of the brain parenchyma may be measured by inserting the probe 3, or the metabolism of the pancreas, gallbladder, liver, etc. may be measured by inserting the probe 3 from the bile duct and pancreatic duct in the same manner as described above.

Next, a second embodiment will be described.

FIGS. 4 and 5 relate to the second embodiment, and FIG.
Is a configuration diagram showing a configuration of a main part of the oxygen metabolism measuring device, and FIG. 5 is a configuration diagram showing a configuration of a modified example of the optical fiber bundle.

The second embodiment is an example in which one end of an optical fiber bundle is passed through an antireflection film. Since the oxygen metabolism measuring apparatus of the second embodiment is almost the same as that of the first embodiment, only the different structure will be described. To do.

As shown in FIG. 4, the laser diode 16
The respective lights generated from a, 16b, 16c, and 16d are guided to the optical fiber bundles 30a to 30d and collected into one optical fiber bundle 30. Then, similarly to the first embodiment, the laser diodes 16a, 16b, 16c, 16d are sequentially driven by the driving device 17 in FIG. 1, and the light having different wavelengths are sequentially emitted from the end face 31 of the optical fiber bundle 30. These beams of light are once used by the lens 3
The beam is expanded by 2, passes through the beam splitter 33, is focused again by the lens 34, and is guided to the optical fiber bundle 35. At the time of this light guiding, the end face of the optical fiber bundle 35 is coated with the antireflection film 36, and the Fresnel reflection is small, and the light is guided to the optical fiber bundle 35 with high efficiency and irradiated to the living tissue 23. Then, a part of the irradiated light is reflected and scattered on the surface of the living tissue 23, and the reflected and scattered light on the surface of the living tissue 23 propagates again through the optical fiber bundle 35 and is spread again by 34, and the beam splitter 33.
Is reflected in a substantially vertical direction by the lens 37, condensed by the lens 37, and received by the reflected light detector 4a.

By thus applying the antireflection film 36 to one end of the optical fiber bundle 35, the optical fiber bundle 3
0 of the light emitted from the end face 31 of the optical fiber bundle 35
The intensity of the Fresnel reflection light reflected by the end face of the is reduced from 4 to 5% to about 0.4%. As a result, the ratio of the light intensity applied to the living tissue 23 increases in the reflected light detector 4a, that is, the Fresnel reflection that causes noise is reduced, so that more accurate oxygen metabolism measurement can be performed.
Further, the antireflection film 36 is applied to the end face of the optical fiber bundle 35 on the side of the living tissue 23 to further improve the effect.

By blocking the reflected light from the mucus on the surface of the living tissue 23, Fresnel reflection due to the mucus on the surface of the living tissue 23 can be blocked. That is,
As shown in FIG. 5, the light propagating through the optical fiber bundle 35 passes through the polarizing plate 38 and is converted into linearly polarized light. Immediately after the polarizing plate 38, a quarter-wave plate 39 is arranged so that the crystal axis is 45 ° with respect to the linearly polarized light, and the linearly polarized light passes through the quarter-wave plate 39 and is circular. It becomes polarized light. When the circularly polarized light is reflected by the mucus or the like of the living tissue 23, the rotation direction is reversed. When the light again passes through the quarter-wave plate 39, the circularly polarized light becomes a linearly polarized light, the polarization direction thereof becomes 90 ° with the polarization direction of the polarizing plate 38, and the light is absorbed. As described above, by disposing the polarizing plate 38 and the quarter-wave plate 39 on the end surface of the optical fiber bundle 35 on the living body side, it is possible to block Fresnel reflection due to mucus or the like on the surface of the living tissue 23, and it is more accurate. Oxygen metabolism can be measured. In particular, the reflection caused by mucus may change depending on the contact between the probe 8 and the living tissue 23, which causes an error when calculating oxygen metabolism, but since this reflection can be effectively blocked, the error Can provide less oxygen metabolism. By applying this method to the first embodiment, also in the first embodiment, it is possible to block Fresnel reflection due to mucus or the like on the surface of the living tissue 23, and it becomes possible to measure oxygen metabolism more accurately. Needless to say.

Next, a third embodiment will be described.

FIG. 6 is a block diagram showing the structure of the main part of the oxygen metabolism measuring apparatus according to the third embodiment.

Since the oxygen metabolism measuring apparatus of the third embodiment is almost the same as that of the second embodiment, only the different structure will be explained.

The light emitted from the end face 31 of the optical fiber bundle 30 spreads at the angle of NALD. Usually, since laser light is used for the light source 2, the NA (NALD) of the light is sufficiently smaller than the NA (NAFB) of the optical fiber bundle 35.
The light emitted from the NALD becomes the parallel beam by the lens 32, passes through the beam splitter 33, and is incident on the optical fiber bundle 35 by the NALD again by the lens 33. At this time, a part of the light propagates in the optical fiber bundle 35, but a part of the light undergoes Fresnel reflection at the end face of the optical fiber bundle and returns with the spread of NALD. A part of this return light is reflected by the beam splitter 33 toward the reflected light detector 4a side. By arranging the light opaque member 40 such as a black disk in the NALD range on the optical path thereof. It is possible to block specular reflection from the light source. By the way, the light propagated in the optical fiber bundle 35 and applied to the living tissue 23 is scattered on the surface of the living tissue 23 and returns to the optical fiber bundle 35 again. The NA at this time is greatly expanded due to scattering, and the NA of the optical fiber bundle 35, that is, NAFB
To the reflected light detector 4a with a spread angle of. That is,
The light scattered by the living tissue 23 and spread at the NAFB angle is received by the reflected light detector 4a, but the light spread by the NALD coming directly from the light source including the specular reflection, that is, the Fresnel reflection is reflected by the light opaque member 40. Since the light can be blocked, it is possible to more accurately obtain the light intensity applied to the living tissue 23.

According to this example, the optical fiber bundle 35
Not only the end surface of the living tissue 23 side but also the Fresnel reflected light such as the boundary between the living tissue 23 and the mucus on the surface can be blocked, so that more accurate measurement can be performed. In particular, the reflection caused by mucus may change depending on how the probe 8 and the biological tissue 23 are in contact with each other. When calculating oxygen metabolism,
Although it causes an error, this reflection can be effectively blocked, so that oxygen metabolism with less error can be provided.

Next, a fourth embodiment will be described.

FIG. 7 is a block diagram showing the structure of the main part of the oxygen metabolism measuring apparatus according to the fourth embodiment.

In the oxygen metabolism measuring apparatus of the fourth embodiment, as shown in FIG. 7, the antireflection film 36 is removed in the second embodiment and the beam splitter 33 is replaced by the polarization beam splitter 4.
1, and further, the polarization maintaining fiber 42 is used as the optical fiber bundle, and other configurations are the second.
Same as the embodiment.

The polarization beam splitter 41 receives the S of incident light.
The polarization component can be reflected by 90 ° and the P polarization component can be transmitted. That is, the light emitted from the end face 31 of the optical fiber bundle becomes only P-polarized light when passing through the polarization beam splitter 41. Then, the P-polarized light propagates through the polarization maintaining fiber 42 and is applied to the living tissue 23.
The P-polarized light applied to the biological tissue 23 is scattered by P, S
The polarized light is mixed, passes through the polarization maintaining fiber, and only the S-polarized component is reflected by the polarization beam splitter 41. Thereby, the P-polarized light reflected from the end face of the optical fiber bundle 35 and the mucus of the living tissue 23 does not enter the reflected light detector 4a, and only the S-polarized light scattered by the living tissue 23 is received. Can be done. According to this method, in addition to the effect of the second embodiment, since the scattered light from the living tissue 23 can be received with little attenuation, a better S / N can be measured.

Next, a fifth embodiment will be described.

FIG. 8 is a block diagram showing the configuration of the main part of the oxygen metabolism measuring apparatus according to the fifth embodiment.

In the oxygen metabolism measuring apparatus of the fifth embodiment, as shown in FIG. 8, the antireflection film 36 is removed in the second embodiment, and the polarizing plate 43 is provided in front of the end face 31 of the optical fiber bundle 30.
And a polarizing plate 44 in front of the reflected light detector 4a.
Is the same as that of the second embodiment.

First, the light emitted from the end face 31 of the optical fiber bundle 30 is polarized by the polarizing plate 43 so as to be parallel to the incident face with the beam splitter 20. This polarized light is scattered by the living tissue 23 as described above, and various polarized lights are mixed. Furthermore, by arranging a polarizing plate 44, which transmits a polarized light component perpendicular to the polarizing plate 43, immediately before the reflected light detector 4a, it is possible to block the reflected light at the end of the optical fiber bundle 35. The polarization plane of the polarizing plate 43 does not have to be parallel to the incident plane, but the polarizing plate 43 and the polarizing plate 44 may be vertical. About the effect, No. 4
Since it is the same as the embodiment, its explanation is omitted.

Next, a sixth embodiment will be described.

FIG. 9 is a block diagram showing the structure of the main part of the oxygen metabolism measuring apparatus according to the sixth embodiment.

As shown in FIG. 9, the oxygen metabolism measuring apparatus of the sixth embodiment removes the antireflection film 36 in the second embodiment and monitors the light emitted from the end face 31 of the optical fiber bundle through the lens 45. This is an embodiment in which a third photodetector 46 is added, and other configurations are the same as those in the second embodiment.

The light emitted from the end face 31 of the optical fiber bundle 30 is split into two directions by the beam splitter 33. One enters the optical fiber bundle 35, the other passes through the lens 45, and is received by the third photodetector 46. In this embodiment, since the light emitted from the end face 31 of the optical fiber bundle 30 can be directly received by the photodetector 46, the light source 2
It is possible to quickly know the abnormality of the device by constantly monitoring the light emission state of.

Next, a seventh embodiment will be described.

10 to 12 relate to the seventh embodiment, FIG. 10 is a configuration diagram showing the configuration of an oxygen metabolism measuring device, FIG. 11 is an explanatory diagram explaining the operation of the oxygen metabolism measuring device, and FIG.
2 is a configuration diagram showing an example of the configuration of the comparison circuit and the display device of FIG.

As shown in FIG. 10, the oxygen metabolism measuring device 48 of the seventh embodiment has laser diodes 16a, 16b, 16c, which emit light of different wavelengths as in the first embodiment.
16d and the laser diodes 16a, 16b, 16
c, 16d, and a drive device 17 for driving the optical fiber bundles 50a, 50b, 50c, 50e on the base end side. 1
6c, 16d and the reflected light detector 4a,
The optical fiber bundles 50a, 50b, 50c, and 50e detect the light that has passed through the first optical fiber bundle 50 and the living tissue 23, which are randomly bundled into one optical fiber bundle 50f in the flexible tube 19. Optical fiber bundle 24 for scattered light, scattered light detector 4b for measuring light detected by the optical fiber bundle 24 for scattered light, and reflected light for amplifying output signals of the reflected light detector 4a and the scattered light detector 4b. Amplifying device 51 and scattered light amplifier 52, and first and second sample and hold 54 and 5 for holding the outputs of the reflected light amplifying device 51 and scattered light amplifier 52 in synchronization by a timing circuit 53.
5, an arithmetic circuit 56 for arithmetically operating the output of the first sample-and-hold 54, and a processing circuit 47 for processing the arithmetic result of the arithmetic circuit 56 to make it easy for the operator to understand.
In order to compare whether the output of the sample hold 55 is within an arbitrary range, the first display device 7 that displays the processing result is set to two arbitrary values, and the values are compared with the output. A second circuit comprising a comparison circuit 58 including a circuit and a device for stimulating visual and auditory sense such as a light emitting diode or a speaker for notifying an abnormality from the comparison result.
Display device 59. In the timing circuit 53, the laser diodes 16a, 16b,
The output timings of 16c and 16d, the timings of the sample and hold 54 and 55, and the operation timing of the arithmetic circuit 56 are controlled in synchronization with each other.

As in the first embodiment, the living tissue 23 is sequentially irradiated with light having different wavelengths, and the light reflected by the surface of the living tissue 23 and the light reflected while being scattered inside the living tissue 23 are received. To do. The operation up to this light reception is the same as that of the first embodiment, and therefore the description thereof is omitted. In addition, the reflected light detector 4
The signals detected by a and the scattered light detector 4b are input to the first and second sample and hold 54 and 55. The signal input to the first sample hold is the first
After the same operation as in the embodiment, is displayed as metabolic information.
This series of operations will be omitted.

The light intensity signal input to the second sample hold 55 is held by the timing circuit 53 in synchronization with the irradiation timing of the laser diode, that is, the light reception timing. This light output is compared with two values arbitrarily set by the comparison circuit 58. Further, when the light output is out of the two ranges, the second display circuit 59 notifies the operator of light or sound.

FIG. 11 shows the detailed operation of the comparison circuit 58. 11A and 11B show a contact state between the probe tip 11 and the living tissue 23. State of normal contact a-
0, b-0, there are gaps a-1, a-2, a on the irradiation side.
-3 widened and gaps on the detection side b-1, b-
2 and b-3 show a spread state.

The signal of the reflected light detector 4a is shown in FIG. 11 (c). In synchronization with the emission of light from the light source, the reflected light detector 4a emits light of wavelengths λ1 to λ4 with a pulse width of 0.2 μs for about 250
Light is sequentially received at intervals of μs. Note that the scattered light detector 4b also detects a signal approximately similar to that in FIG.

Then, the signals detected by the reflected light detector 4a and the scattered light detector 4b in this way are, by the second sample hold 55, one of the wavelengths λ1 as shown in FIG. 11 (d). The light is held in succession at intervals of 1 ms in synchronization with the above light. It should be noted that light having another wavelength of λ2 to λ4 or light having all wavelengths may be held and used.

Next, the a-0 to a-3, b-0 to b-
11 shows the contact state of No. 3 and the sample and hold outputs of the reflected light detector 4a and the scattered light detector 4b corresponding thereto.
It shows in (e). The contact state, the output of the reflected light detector 4a, and the output of the scattered light detector 4b are shown from the top. When the detection side is in contact with b-0 and the gap on the irradiation side expands to a-0 to a-3, the light intensity received by the reflected light detector 4a is the irradiation light in the case of a slight gap. Since the reflected light is directly received, it rises so as to reach a peak in the gap a-1, and when it further spreads, it sharply decreases. (Note that in the case of transmitting and receiving with one fiber bundle as in the first embodiment, the reflected light temporarily decreases as the gap increases.) On the other hand, the light intensity received by the scattered light detector 4b The light that enters the living tissue 23 also decreases with an increase in the gap, so that the light rapidly decreases. Further, when the irradiation side is in contact with a-0 and the gap on the detection side is widened, it is constant because it is in contact with the biological tissue 23 in the reflected light detector 4a, but is constant in the scattered light detector 4b. It decreases as the gap increases.

Therefore, the ranges V1 and V2 are set according to the difference in the living tissue 23 of the light reflected by the living tissue 23, and the difference in the living tissue 23 of the light passing through the living tissue 23 and the oxygen metabolism. Range V3, V
Set 4 and detect contact failure by detecting when it is out of this range. Other functions are the same as those in the first embodiment.

Normally, the light intensity scattered and received in the living tissue 23 changes within a range due to changes in oxygen saturation and blood volume of the living tissue 23, but the range exceeds a certain fixed range. There is no such thing. However, the biological tissue 23 and the tip portion 11 of the probe 8 (optical fiber bundle 50)
When a gap is generated in the area, the intensity of the detection light exceeds the range and is detected. That is, by detecting that the light intensity exceeds the range, it becomes possible to provide an accurate measurement of oxygen metabolism and thereby prevent misdiagnosis. Other effects are the same as those of the first embodiment.

Incidentally, FIG. 12 shows a comparison circuit 58 and a display device 59.
An example of a circuit that realizes is shown. Output of the sample hold 55 corresponding to the reflected light detector 4a (reference output)
Are connected to the positive side input terminals of the comparator 60a and the negative side input terminals of the comparator 60b, respectively. Further, the other input terminals of the comparators 60a and 60b have pull-up resistors 61a and 61b and a variable resistor 62 grounded.
a and 62b are connected, and the voltages of V1 and V2 are set by changing the values of the variable resistors 62a and 62b. Here, V1 and V2 are the maximum and minimum values of the output of the reflected light detector 4a when the contact is made normally. In addition, the sample hold 55 corresponding to the scattered light detector 4b
Output (detector output) is connected to the plus side and minus side of 60d of the comparator 60c. Further, the other input terminals of the comparators 60c and 60d are connected to the pull-up resistor 61 as described above.
c and 61d are connected to the variable resistors 62c and 62d which are grounded, and V3 and V4 are set, respectively. Where V3
, V4 is the maximum value and the minimum value of the output of the scattered light detector 4b within the fluctuation range of oxygen metabolism in the normal contact.

That is, the reference output is V1 or more or L2 or less, and the detector output is L3 or more or L4.
In the following cases, the comparator 60a or 60b, 60c
Alternatively, either 60d outputs a voltage. Then, the logical circuit 63 takes the OR to obtain the comparators 60a to 6a.
When at least one of 0d is ON, it outputs a voltage and directly drives the light emitting diode 64. Light emitting diode 64
Is more effective when you use visually recognizable colors such as red and yellow. A speaker may be used instead of the light emitting diode 64 to stimulate the hearing.

[0060]

As described above, according to the present invention,
INDUSTRIAL APPLICABILITY The biological tissue oxygen metabolism measuring device of the present invention can realize the metabolic measurement of a biological tissue having a high S / N with a small diameter that can be inserted into a body cavity, for example, an organ in the body cavity such as the heart or the brain. The effect is that it can be connected to early detection and diagnosis of.

[Brief description of drawings]

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

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

FIG. 3 is an explanatory diagram showing an insertion state of the insertion portion according to the first embodiment into the heart.

FIG. 4 is a configuration diagram showing a configuration of a main part of an oxygen metabolism measuring device according to a second embodiment.

FIG. 5 is a configuration diagram showing a configuration of a modified example of the optical fiber bundle according to the second embodiment.

FIG. 6 is a configuration diagram showing a configuration of a main part of an oxygen metabolism measuring device according to a third embodiment.

FIG. 7 is a configuration diagram showing a configuration of a main part of an oxygen metabolism measuring device according to a fourth embodiment.

FIG. 8 is a configuration diagram showing a configuration of a main part of an oxygen metabolism measuring device according to a fifth embodiment.

FIG. 9 is a configuration diagram showing a configuration of a main part of an oxygen metabolism measuring device according to a sixth embodiment.

FIG. 10 is a configuration diagram showing a configuration of an oxygen metabolism measuring device according to a seventh embodiment.

FIG. 11 is an explanatory view explaining the action of the oxygen metabolism measuring device according to the seventh embodiment.

FIG. 12 is a configuration diagram showing an example of a configuration of a comparison circuit and a display device of FIG. 10 according to a seventh embodiment.

[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 18 ... Optical fiber bundle 24 ... Optical fiber bundle for scattered light

[Procedure amendment]

[Submission date] July 20, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

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.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

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.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

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, an angle operation is performed so that the tip portion 11 closely contacts the heart wall.
The part 13 is operated to measure the oxygen metabolism of the myocardium 26 at that part. Furthermore, the measurement position is changed by operating the scope 2 and the angle operation unit 13, and the oxygen metabolism of each is measured to obtain the oxygen metabolism distribution of the heart wall.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

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 28 of the measured portion and is guided to the optical fiber bundle 18 is applied to the living tissue 23.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

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, passes through the scattered light optical fiber bundle 24, and detects scattered light. The light is received by the device 4b.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

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 digitally electrical signal conversion, con
It is 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.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

The oxygen metabolism thus obtained is displayed on the display device.
Displayed in location 7, it is possible to know the metabolism of the organization in real time.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023] The first embodiment not only the heart muscle, using a channel of an endoscope inserted into the stomach, or to measure the metabolism of gastric inner walls while observing endoscopically, probe from cerebrovascular
Insert the blanking 8, or by measuring the metabolism of the brain parenchyma, bile ducts, from said pancreatic duct likewise by inserting the probe 8, pancreas, gallbladder, may be measured hepatic metabolism and the like.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

The light emitted from the end face 31 of the optical fiber bundle 30 spreads at the angle of NALD. Usually, since laser light is used for the light source 2, the NA (NALD) of the light is sufficiently smaller than the NA (NAFB) of the optical fiber bundle 35.
The light emitted from the NALD becomes the parallel beam by the lens 32, passes through the beam splitter 33, and is incident on the optical fiber bundle 35 by the lens 34 again by the NALD. At this time, a part of the light propagates in the optical fiber bundle 35, but a part of the light undergoes Fresnel reflection at the end face of the optical fiber bundle and returns with the spread of NALD. A part of this return light is reflected by the beam splitter 33 toward the reflected light detector 4a side. By arranging the light opaque member 40 such as a black disk in the NALD range on the optical path thereof. It is possible to block specular reflection from the light source. By the way, the light propagated in the optical fiber bundle 35 and applied to the living tissue 23 is scattered on the surface of the living tissue 23 and returns to the optical fiber bundle 35 again. The NA at this time is greatly expanded due to scattering, and the NA of the optical fiber bundle 35, that is, NAFB
To the reflected light detector 4a with a spread angle of. That is,
The light scattered by the living tissue 23 and spread at the NAFB angle is received by the reflected light detector 4a, but the light spread by the NALD coming directly from the light source including the specular reflection, that is, the Fresnel reflection is reflected by the light opaque member 40. Since the light can be blocked, it is possible to more accurately obtain the light intensity applied to the living tissue 23.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction content]

First, the light emitted from the end face 31 of the optical fiber bundle 30 is polarized by the polarizing plate 43 so as to be parallel to the incident face with the beam splitter 20. This polarized light is scattered by the living tissue 23 as described above, and various polarized lights are mixed. Further, by arranging a polarizing plate 44, which transmits a polarized light component perpendicular to the polarizing plate 43, in front of the reflected light detector 4a, it is possible to block reflected light at the end of the polarization maintaining fiber 42 . The polarization plane of the polarizing plate 43 does not have to be parallel to the incident plane, but the polarizing plate 43 and the polarizing plate 44 may be vertical. For the effect,
Since it is similar to the fourth embodiment, the description thereof will be omitted.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

The oxygen metabolism measuring apparatus of the sixth embodiment is shown in FIG.
As shown, a third photodetector 46 that monitors the light emitted from the end face 31 of the optical fiber bundle through the lens 45.
Is added, and other configurations are the same as those in the second embodiment.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction content]

As shown in FIG. 10, the oxygen metabolism measuring device 48 of the seventh embodiment has laser diodes 16a, 16b, 16c, which emit light of different wavelengths as in the first embodiment.
16d and the laser diodes 16a, 16b, 16
drive device 17 for driving c, 16d and optical fiber bundles 50a, 50b, 50c, 50d, 50 having five proximal ends.
divided into e, optical fiber bundles 50a, 50b, 50c,
The incident end faces of 50d and 50e are the laser diode 1
6a, 16b, 16c, 16d and reflected light detector 4a
Facing each other, and the optical fiber bundles 50a, 50b,
50c, 50d, 50e are flexible tubes
First optical fiber bundle 50, each of which is randomly grouped in one optical fiber bundle 50f in 25 , scattered light optical fiber bundle 24 for detecting light that has passed through the living tissue 23, and the scattered light optical fiber bundle A scattered light detector 4b for measuring the light detected by 24, a reflected light amplifier 51 and a scattered light amplifier 52 for amplifying the output signals of the reflected light detector 4a and the scattered light detector 4b, and the reflected light amplification First and second sample and hold 54 and 55 for holding the outputs of the device 51 and the scattered light amplifier 52 in synchronization with each other by a timing circuit 53; an arithmetic circuit 56 for computing the output of the first sample and hold 54; In order to make the calculation result of the calculation circuit 56 easy for the operator to understand,
A processing circuit 47 for processing and a first for displaying the processing result
Display device 7 and a comparison circuit 58 including a circuit for setting any two values and comparing the output with the output in order to compare whether the output of the sample hold 55 is in an arbitrary range. In order to notify the abnormality from the comparison result,
The second display device 59 includes a device for stimulating visual and auditory senses such as a light emitting diode or a speaker. The timing circuit 53 controls the emission timings of the laser diodes 16a, 16b, 16c and 16d, the sample and hold timings 54 and 55, and the arithmetic operation timing of the arithmetic circuit 56 in synchronization with each other.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0059

[Correction method] Change

[Correction content]

That is, the reference output is V1 or more or V2 or less, and the detector output is V3 or more or V4.
In the following cases, the comparator 60a or 60b, 60c
Alternatively, either 60d outputs a voltage. Then, the logical circuit 63 takes the OR to obtain the comparators 60a to 6a.
When at least one of 0d is ON, it outputs a voltage and directly drives the light emitting diode 64. Light emitting diode 64
Is more effective when you use visually recognizable colors such as red and yellow. A speaker may be used instead of the light emitting diode 64 to stimulate the hearing.

[Procedure Amendment 14]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 15]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 16]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure Amendment 17]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

[Figure 9]

[Procedure 18]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

[Procedure Amendment 19]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 11

[Correction method] Change

[Correction content]

FIG. 11

Claims (1)

[Claims] 1. A light source that sequentially emits light of a plurality of wavelengths, a probe that has an insertion portion that is inserted into a body cavity, and that measures the metabolism of living tissue by the light from the light source. The light from the light source is incident on the living body tissue from the proximal end surface to irradiate the biological tissue through the distal end surface, and the first return light from the living tissue is incident on the distal end surface and transmitted to the proximal end surface. The first light transmission means, the second light transmission means for inserting the second return light from the living tissue through the insertion portion, the light path of the light from the light source, and the first light transmission means. An optical element that separates the optical path of the return light, a first light detection unit that detects the first return light whose optical path is separated by the optical element, and a second light detection unit that detects the second return light. The output of the first and second light detecting means Management and calculation means for calculating, biological tissue oxygen metabolism measuring apparatus, characterized by comprising display means for displaying the calculation result of the calculating means.