JPH03212262A - Nuclear magnetic resonance(nmr) endoscope - Google Patents

Abstract

PURPOSE:To obtain an image based on the NMR of a wide inspection part including a diseased part by installing a loop antenna in which the shape of a loop is changed by the insertion in shiftable manner into an insertion part and the driving-out from the insertion part. CONSTITUTION:An endoscope 1 is equipped with a flexible insertion part 2, and an operating part 3 is continuously installed at the rear edge of the insertion part 2. The insertion part 2 is constituted of a curved part 11 which can be curved and installed continuously to the top edge part of a soft part 9 installed on the operating part 3 side, and a top edge part 12. In front of the top edge part 12, a loop antenna 17 is installed, and connected with the signal wires 18a and 18b which is inserted through the insertion part 2. The loop antenna 17 is made of a copper wire or the embraced wire made of spring member and a gold-plated wire, or superelastic alloy and copper wire, and a loop shape is formed by the elasticity. When the insertion part 2 is inserted, the signal wire 18a is pulled to this side, and the loop shape of the antenna 17 is contracted so as to be smaller than the outer shape of the top edge part 12, and driven out towards the front part, and the loop shape of the antenna 17 is increased in stable manner, guided by a guiding slit 30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an NMR endoscope that allows a loop antenna to be introduced into the body and allows observation of an affected area from outside the body using nuclear magnetic resonance (NMR).

[Prior art] Conventionally, in the detection and diagnosis of epidermal cancer, etc. that occur on the inner surface of the human digestive tract, particularly in the upper layer of the stomach wall, etc., the site of occurrence is detected using an endoscope or XS photography, etc., and biological tissue from that site is collected. The common method was to diagnose whether the tumor is malignant or not. However, with these conventional methods, the sample collection site is relatively wide, making it impossible to make an immediate diagnosis.
In addition, there are problems in that it takes a lot of effort to collect the living tissue, and furthermore, it causes more damage to the human body.

On the other hand, in recent years, a non-invasive method for diagnosing the human body that utilizes the nuclear magnetic resonance (hereinafter abbreviated as NMR) phenomenon has been developed. For example, it is abbreviated as nuclear magnetic resonance imaging (hereinafter referred to as MR) that utilizes the NMR phenomenon. ), a human body is placed in a magnetic field, a high frequency (magnetic field) of a predetermined frequency is applied, and nuclei with spin in the human body are excited, and NMR signals of a predetermined frequency from the excited nuclei are detected and processed by a computer. By doing this, it is possible to obtain tomographic images of the human body.

Tomographic images obtained by this MRI are extremely useful for diagnosis of cancer and the like. That is, it is generally known that NMR signals generated by cancer cells and normal cells have different relaxation times, and by measuring these relaxation times, it is possible to diagnose whether or not it is cancer.

However, the MRI requires processing a huge amount of NMR signals in order to obtain a tomographic image, and therefore requires a high-speed, large-capacity computer, making the entire device large and expensive.

Additionally, when an abnormality is visually discovered during endoscopic observation, there has been a desire to determine to some extent whether or not the abnormality is, for example, malignant. However, when MRI is used in combination, there is a problem in that it is difficult to associate visually abnormal locations with tomographic images.

In order to deal with the above problems, for example, Japanese Patent Laid-Open No. 59-88
As shown in Japanese Patent No. 140, an NMR endoscope has been proposed in which a high-frequency antenna coil is provided at the distal end of an endoscope insertion portion to form a high-frequency magnetic field and detect an NMR signal. According to this NMR endoscope, by pressing the high-frequency antenna coil against an abnormal region and detecting the NMR signal of the abnormal region, it becomes possible to detect and diagnose physiological changes in the abnormal region, such as whether or not it is cancer. .

Further, Japanese Patent Application Publication No. 62-50048 proposes a solid-state NMR probe in which a high-frequency antenna coil is provided in an integrated circuit to reduce the size of the probe.

By the way, the size of the antenna coil of the above-mentioned prior art is fixed, and it is possible to obtain an image of only a certain range of the affected area.

The present invention has been made in view of the above circumstances, and is
The R loop antenna can be inserted into the body endoscopically,
Another object of the present invention is to provide an NMR endoscope that can obtain NMR-based images of a wide range of examination areas, including affected areas.

[Means for Solving the Problems] In order to achieve the above object, the NMR endoscope of the present invention includes a loop antenna that is movably inserted into the insertion section and whose loop shape changes as it is drawn out from the insertion section. It is equipped with the following.

[Operation] In the NMR endoscope of the present invention, the loop antenna is movably provided within the insertion section, and by moving the loop antenna and letting it out from the insertion section, the shape of the loop of the loop antenna changes.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings. , FIGS. 1 to 3 relate to the first embodiment of the present invention, and FIGS.
FIG. 2 is a sectional view of the distal end of the endoscope, FIG. 2 is a circuit diagram of the NMR measuring device, and FIG. 3 is an explanatory diagram showing how the endoscope is used.

In FIG. 3, an endoscope 1 includes an elongated, for example, flexible insertion section 2, and a large-diameter operation section 3 is connected to the rear end of the insertion section 2. As shown in FIG. A flexible universal cord 6 extends from the side of the operating section 3, and a connector 7 is provided at the tip of the universal cord. The endoscope 1 is connected via the connector 7 to a control device 8 that includes a light source section and a signal processing circuit section. Further, the control device 8 is connected to a monitor 4, and outputs a video signal to the monitor 4 to display a mirror image of the congratulations on the screen of the monitor 4.

The insertion portion 2 includes a bendable bending portion 11 connected to the tip of a flexible portion 9 provided on the operation portion 3 side, and
1 and a distal end section 12 connected to the distal end section 1.

The bending portion 11 can be bent vertically and horizontally by rotating a bending operation knob 13 provided on the operation portion 4.

A loop antenna 17 is provided in front of the distal end portion 12, and receives the signal Fi! passed through the insertion portion 2. 18a,
18b. The loop antenna 17 is a copper wire,
Spring material, gold-plated wire, superelastic alloy and copper wire are used to form a loop shape due to elasticity.

The signal lines 18a and 18b extend outside from the operating section 3, and are connected to a tuning circuit 19 that constitutes the NMR measuring device 16.
and the NMR signal detection circuit 21. Furthermore,
Tuning circuit 19 is connected to the output of high frequency generator 22 .

The endoscope 1 includes an NMR device 26 disposed so as to surround a subject 24 placed on a bed 23 during NMR measurement.
It is now used in combination with This NMR apparatus 26 is equipped with means for generating a static magnetic field, such as a permanent magnet, a normal magnet, or a superconducting magnet.

In FIG. 1, an objective lens system 27 and a light distributing lens system (not shown) are provided on the distal end surface of the distal end portion 12. A solid-state image sensor 28 is provided behind the objective lens system 27, and the imaging surface of the solid-state image sensor 28 and the objective lens system 27 are connected to each other.
The imaging positions of the two images are aligned. A signal line 29 is connected to the back of the solid-state image sensor 28, and these two signal lines transmit drive pulses for driving the solid-state image sensor 28 and I5B read out from the solid-state image sensor 28. It looks like this. The signal line 29 is connected to a signal processing circuit (not shown) of the control device 8 via the insertion portion 2, the universal cord 6, and the connector 7. Note that an output end face of a light guide (not shown) is provided behind the light distribution lens system, and the illumination light emitted from the light source section of the control device 8 is transmitted through the light guide and observed through the light distribution lens system. It is designed to irradiate the area.

One signal line 18a among the signal lines 18a and 18b
is inserted movably through the insertion portion 2, and its tip is inserted through a network tuning circuit 30 provided within the distal end portion 12. Further, the other signal line 18b is fixedly inserted through the insertion portion 2. The tip of the signal line 18a inserted through the network tuning circuit 30 is connected to one end of the loop antenna 17, and the signal line 18b is connected to one end of the loop antenna 17.
The tip of the loop antenna 17 is connected to the other end of the loop antenna 17. The loop antenna 17 is formed in a loop shape, and a part of the antenna 17 is fitted into a guiding slit 34 provided in the longitudinal direction of the insertion portion 2 of the hood 31 fitted around the outer periphery of the tip portion 12. When the signal line 18a is moved toward the tip, the guiding slit 34 guides the antenna 17 that is extended forward from the tip 12, and gradually increases the outer diameter of the loop while maintaining the loop shape. It's supposed to be bigger.

The network tuning circuit 30 detects the extended length of the loop antenna 17 and automatically tunes the antenna 17.

The NMR measuring device 16 including the loop antenna 17 is configured as shown in FIG. 2, for example.

That is, the loop antenna 17 has a tip end 1, for example.
A capacitor box 32 provided within 2 is connected. Then, the high frequency generated from the high frequency generator 22 and tuned by the tuning circuit 19 to the resonance frequency corresponding to the nuclide to be measured is transmitted to the antenna 1 via the capacitor box 32.
7, and the high frequency magnetic field is output from the antenna 17 to the living body. Inside the capacitor box 32, a capacitor C1 and an antenna 1 are connected in parallel to the antenna 17.
A variable pull capacitor C2 connected in series with 7 is built in, and these capacitors C1 and C2 form a matching circuit that performs impedance matching between the antenna 17 side and the high frequency generator 22 side.

In this embodiment, the antenna 17 serves both as a transmitter and a receiver, and an NMR signal from a living body is received by the antenna 17, and this NMR signal is transmitted via a capacitor box 32 to
The signal is input to the MR signal detection circuit 21.

The NMR signal detection circuit 21 then uses the relaxation time (TI
, T2) etc. (NMR parameters) can be obtained.

Next, the operation of this embodiment configured as above will be explained.

As shown in FIG. 3, a subject 24 is placed on a bed 23 and a static magnetic field is applied to the subject 2 by an NMR device 26. In this state, the insertion section 2 of the endoscope 1 equipped with the loop antenna 17 for NMR measurement is inserted into the oral cavity of the subject 24, and illumination light is transmitted from the control device 8 to the light guide (not shown) of the endoscope 1. For example, the upper layer of the stomach wall is observed on the screen of the monitor 4 using the objective lens system 27 and the solid-state image sensor 28.

When inserting the insertion section 2, the signal line 18a is pulled toward the proximal side to reduce the loop shape of the anti-noise 17 to make it smaller than the outer shape of the distal end section 12, so that there is no problem with insertion. After that, press the signal wire 18a in the direction of the tip 12 (indicated by the arrow direction in FIG. 1). As a result, the signal line 18a moves toward the tip, and the antenna 17 connected to the signal line 18a moves to the tip 12.
It is rolled out from the front. The antenna 17 stably maintains its loop shape while being guided by the guiding ring 1-30, and gradually increases in size.

After enlarging the loop shape of the antenna 17, the abnormal area 33
A high frequency wave is sent to the antenna 17 via the high frequency generator 22, the tuning circuit 19, and the condenser box 32, and a high frequency magnetic field is output from the antenna 17 to the abnormal region 33. Note that the direction of the high-frequency magnetic field is preferably perpendicular to the direction of the static magnetic field. And NMR from abnormal site 33
By receiving the signal with the antenna 17 and measuring it with the NMR signal detection circuit 21, it becomes possible to determine whether or not there is a physiological change in the abnormal region 33, for example, cancer.

Next, if it is desired to inspect the abnormal region 33 from a wider range, the signal line 18a is pushed further toward the distal end from the operating section 3. This makes the loop shape of the antenna 17 even larger.

1 In this embodiment, when inserting the insertion section 2 into a body cavity, the loop shape of the loop antenna 17 is made smaller than the distal end portion 12, and the loop antenna 17 is made larger during the examination so that the loop shape is smaller than that of the distal end portion 12. The insertability of the antenna 17 can be improved, and a wide range of test sites can be measured.

FIG. 4 is a perspective view of the distal end of an endoscope according to a second embodiment of the present invention.

In the loop antenna 17 of this embodiment, a loop is formed in a plane parallel to the tip surface of the tip portion 12. Note that the same reference numerals are given to the same constituent members as in the first embodiment, and the explanation thereof will be omitted.

A loop antenna 17 is located near the edge of the tip surface 37 where the objective lens system 27 and light distribution lens system 36 of the tip portion 12 are provided.
A guide member 38.38 for guiding the is protruding.

The guide members 38 and 38 are connected to the loop antenna 1 connected to the signal lines 18a and 18b movably inserted through the insertion section 2.
The base portion of the antenna 17 is bent so as to maintain the loop shape of the antenna 17 so that the loop shape 2 is included in a plane parallel to the tip surface 37. And the signal lines 18a, 1
When 8b is pressed, the loop shape of the antenna 17 expands or contracts in a plane parallel to the tip surface 37.

The other configurations are the same as in the first embodiment.

In this embodiment, when inserting the insertion section 2 into the body cavity, the signal line 1
8a and 18b toward the hand side, so that the loop shape of the antenna 17 is smaller than the outer diameter of the tip portion 12. When inspecting the abnormal site 33, the signal lines 18a and 18b are shown in the direction of the tip 12 in the direction of the arrow in FIG. ) to enlarge the loop shape of the antenna 17.

Other functions and effects are similar to those of the first embodiment.

FIG. 5 is a sectional view of the distal end portion of an endoscope according to a third embodiment of the present invention.

The loop antenna 17 of this embodiment is provided on the outer periphery of the tip portion 12. Further, the endoscope 1 is of a side viewing type. Note that the same reference numerals are given to the same constituent members as in the first embodiment, and the explanation thereof will be omitted.

3. Four parts 41 are provided on the outer peripheral wall of the tip end 12, and the loop antenna 17 wound once is housed in the recess 41. One end of the loop antenna 17 is connected to the insertion section 2
The other end is connected to a signal line 18b that is inserted fixedly through the insertion portion 2. Further, an objective lens system (not shown) is provided on the outer circumferential wall of the tip portion 12 so as to have a viewing direction perpendicular to the plane of the paper of FIG.

The other configurations are the same as in the first embodiment.

In this embodiment, when inserting the insertion section 2, the signal line 18a is pulled toward the proximal side, and the antenna 17 is housed in the four parts 4.1. When inspecting an abnormal area, connect the signal wire 18a to the tip 12.
Push in the direction (indicated by the arrow direction in FIG. 5) to make the loop shape of the annular 17 larger.

The function and effect of this function are the same as those of the first embodiment.

In each of the above embodiments, the solid-state image sensor is placed on the right side of an electronic endoscope, but the present invention may also be applied to an optical endoscope equipped with an image guide means.

[Effects of the Invention] As explained above, according to the present invention, it is possible to endoscopically insert an NMR loop antenna into the body, and to obtain images based on NMR of a wide range of examination areas including the affected area. can.

[Brief explanation of drawings]

Figures 1 to 3 relate to the first embodiment of the present invention.
The figure is a cross-sectional view of the tip of the endoscope, Figure 2 is a circuit diagram of the NMR measuring device, and Figure 3 shows how the endoscope is used. FIG. 4 is a perspective view of the distal end of the endoscope according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional view of the distal end of the endoscope according to the third embodiment of the present invention. be. 2... Insertion part 12... Tip part 16...
・NMR measurement device 17...Loop 77 antenna
18a, 18b...Signal line 5 Procedural amendment (gi) 2, 1990, 7J111, Title of invention NMR endoscope 3, Relationship with the person making the amendment case

Claims (1)

[Claims] NMR equipped with an NMR loop antenna in the endoscope insertion section
An NMR endoscope, characterized in that the loop antenna is movably inserted through the insertion section and drawn out from the insertion section, thereby changing the shape of the loop of the loop antenna.