JPH04135551A - Optical three-dimensional image observing device - Google Patents

Abstract

PURPOSE:To exactly and easily grasp the three-dimensional structure of the inside of a body to be examined by processing a reflected light pulse which passes through a light opening/closing means and detecting a tomographic image of a measuring object, and constituting a three-dimensional image of the measuring object from this tomographic image. CONSTITUTION:By a pulse laser 6 in an optical three-dimensional image processor 20, light of scores of picoseconds is generated from an Nd:YAG laser and radiated to a pigment in a pigment laser 8 and excites it, and from this pigment laser 8, a light pulse of extremely short time width of several picoseconds is emitted. Subsequently, an opening timing of a car shutter 13 is set, and reflected light intensity is analyzed by sending a reflected light pulse from each point in a tissue guided by an optical fiber bundle 4 to an image pickup device 18, by which an optical tomographic image of a lesion 52 corresponding to an irradiation plane of the light pulse by the optical fiber bundle 4 is detected at every opening timing of the car shutter 13. By processing this optical tomographic image by a signal processor 19, a three-dimensional image containing a blood vessel, etc., in the inside of the tissue of the lesion 52 is obtained, and displayed on a monitor 30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an optical three-dimensional image observation device that constructs a three-dimensional image from an optical tomographic image of a measurement target.

[Prior Art] In recent years, the use of images in medical treatment has become widespread, and the importance of technology for measuring internal information of a subject in a non-invasive and non-contact manner is increasing.

Conventionally, non-invasive, non-contact measurement of information inside a subject such as a living body has been mainly performed using X-rays, but the use of X-rays poses problems such as radiation exposure and the imaging of biological functions. Due to this problem, fluoroscopy of the internal tissues of body cavities using an ultrasound endoscope has been performed.

However, the ultrasonic endoscope does not have very high spatial resolution and cannot obtain information such as physiological composition other than morphology, and furthermore, when using the ultrasonic endoscope, a medium such as water is required. Therefore, there is a problem that the procedure for observing the subject is complicated.

For this reason, various techniques for visualizing internal information of a subject using light have been proposed recently.
The prior art is disclosed in Japanese Patent No. 1-85417.

[Problems to be Solved by the Invention] However, when examining the inside of a subject such as a living body in detail, it is not easy to accurately understand the internal structure of the tissue from only tomographic images. A large number of tomographic images are required, which requires a great deal of labor. Furthermore, even in diagnosis related to metabolic functions such as intravascular oxygen saturation, only two-dimensional information can be obtained from tomographic images alone, and analysis requires a long time.

The present invention has been made in view of the above circumstances, and enables accurate and easy understanding of the three-dimensional structure inside a subject, and further enables not only structural measurements but also functional measurements. The purpose of the present invention is to provide an optical three-dimensional image observation device.

[Means for Solving the Problems] The optical three-dimensional image II detection device of the present invention includes a light pulse generation means for generating a light pulse for measurement, and a light pulse generated by the light pulse generation means for guiding the light pulse to a measurement target. Additionally, an optical fiber bundle that guides the reflected light pulses reflected inside the measurement object, a light input means that uniformly diffuses and inputs the light pulses into the optical fiber bundle, and a light input means that inputs the reflected light pulses at an arbitrary time. a light opening/closing means for passing light; and an image processing means for processing the reflected light pulses that have passed through the light opening/closing means to detect a tomographic image of the measurement target and constructing a three-dimensional image of the measurement target from this tomographic image. It is prepared.

[Function] In the present invention, the light pulses generated by the light pulse generation means are uniformly diffused and incident on the optical fiber bundle by the light incidence means, and guided to the measurement target by the optical fiber bundle.

The reflected light pulse reflected inside the object to be measured is guided by the optical fiber bundle, passed through the optical opening/closing means at an arbitrary time, and processed by the image processing means. As a result, a tomographic image of the measurement target is detected, and a three-dimensional image of the measurement target is constructed from this tomographic image.

[Example] Hereinafter, the present invention will be specifically explained with reference to the drawings.

The drawings show one embodiment of the present invention, and FIG. 1 is a system configuration diagram of an optical three-dimensional image observation device, FIG. 2 is an explanatory diagram showing an example of observation inside a body cavity by the optical three-dimensional image observation device, and FIG. 3 is an explanatory diagram showing the relationship between the time of reflected light and the tissue depth, Fig. 4 is an explanatory diagram showing the time-resolved waveform of reflected light intensity, Fig. 5 is a time chart showing the control timing of light opening/closing, and Fig. 6 is an explanatory diagram showing the measurement results, Fig. 7 is an explanatory diagram showing the configuration of the endoscope tip for suppressing scattered light, Fig. 8 is an explanatory diagram of the optical closing operation by the nonlinear optical element, and Fig. 9 is an illustration of observation. FIG. 10 is an explanatory view showing an optical fiber bundle for widening the viewing area, FIG. 10 is an explanatory view showing a lens array for widening the viewing area, and FIG. 11 is a front view of the lens array.

As shown in FIG. 1, the optical three-dimensional image observation device includes an endoscope 1
and an optical three-dimensional image processing device 20 to which this endoscope 1 is connected.
And this optical three-dimensional image processing system! Monitor 3 connected to 20
0.

The endoscope 1 includes a light guide 2 and an image guide 3 for observing the surface inside the subject, and the optical three-dimensional image processing device, in an elongated and visible insertion section that is inserted into the subject. An optical fiber bundle 4 connected to 20 is inserted therethrough.

The light guide 2 transmits illumination light incident from the light source 5 through a condensing lens (not shown), and illuminates the observation site through a light distribution lens (not shown) attached to the distal end of the insertion section. ing.

Further, the image guide 3 guides an optical image of the observation site formed by an objective lens (not shown) at the tip of the insertion section, and enables observation with the naked eye via an eyepiece (not shown) provided at the rear end surface. It has become.

Further, the optical three-dimensional image processing device 2o is equipped with a pulse laser 6 as a light pulse generating means, and this pulse laser 6 is composed of a Nd:YAG laser 7 and a dye laser 8.
It is composed of. The light emitted from the Nd:YAG laser 7 is emitted from the dye in the dye laser 8 (for example,
The light emitted from the dye laser 8 is reflected by a mirror 9 and separated into two by a beam splitter 10.

The light transmitted through the beam splitter 10 is reflected by the beam splitter 11, and then expanded from a thin beam into parallel light having a diameter comparable to that of the optical fiber bundle 4 by a beam expander 12 serving as a light input means. Ru. and,
The light is uniformly diffused and incident on the optical fiber bundle 4, and is irradiated onto a measurement target such as the affected area 40 through the optical fiber bundle 4.

The reflected light reflected at the affected area 40 is guided by the optical fiber bundle 4, passes through the beam expander 12, passes through the beam splitter 11, and is transmitted to a car (K e r r ) The light is incident on the shutter 13.

On the other hand, the light emitted from the dye laser 8 and reflected by the beam splitter 10 is transmitted to the beam splitter 14.
and is reflected by the mirror 15a of the delay mirror device 15. Further, the light reflected by the mirror 15a is reflected by the beam splitter 14 and enters a drive device 16 consisting of a photodiode or the like, and an electric signal from the drive device 16 causes the car shutter 13 to be opened. It has become.

The delay mirror device 15 includes a movable stage 15b to which the mirror 15a is fixed.
b is driven by a step motor 15c to move in the tapering direction, thereby changing the optical path length to the drive device 16.

The light that has passed through the car shutter 13 passes through a beam expander 17 and enters a highly sensitive imaging device 18, which is a combination of an image intensifier and an SIT camera, and the output signal from this imaging device t18 is The signal is processed by the signal processing device 19.

In the imaging device 18 and the signal processing device 19 as image processing means, the signal processing device 19 controls the step motor 15c of the delay mirror device t15, and the tomographic image of the measurement region detected by the imaging device 18 is controlled by the signal processing device 19. A three-dimensional image is constructed based on the image and displayed on the monitor 30.

Next, three-dimensional image observation of the inside of the subject using this pre-ball dimensional image observation device will be explained.

As shown in FIG. 2, for example, when observing a three-dimensional image of an organ 51 of a human body 50, the insertion section of the endoscope 1 is first inserted into the body cavity of the human body 50, and the tip of the endoscope 1 is inserted into the body cavity of the human body 50. to face the affected area 52 of.

Next, the pulse laser 6 in the front lens dimensional image processing device 20
Then, the Nd:YAG laser 7 generates light of several tens of picoseconds and irradiates the dye in the dye laser 8 to excite it, and this dye laser 8 emits a light pulse with an extremely short time width of several picoseconds. do.

This light pulse is transmitted to mirror 9, beam splitter 10.1
1, the beam is expanded by the beam expander 12, and uniformly enters the optical fiber bundle 4, and the affected area 52 to be measured is
Irradiated horizontally.

When the irradiated light pulse is reflected on the surface and deep part of the affected area 52, the reflected light pulse is guided from the optical fiber bundle 4 to the front lens dimensional image processing device 20, and is again narrowed by the beam expander 12. The light beam is converged into a beam, passes through the beam splitter 11, and enters the Kerr shutter 13.

At this time, the optical pulse emitted from the dye laser 6 and separated by the beam splitter 10 is guided to the beam splitter 14 → mirror 15a → beam splitter 14 → driving device 16, and is photoelectrically converted by this driving device 16. In response to the signal, the car shutter 13 is opened for a predetermined period of time, and the reflected light that has passed through the car shutter 13 is guided to the imaging device 18 via the beam expander 17.

The opening timing of the car shutter 13 is set by moving the mirror 15a of the delay mirror device 15 to change the optical path length and controlling the arrival time of the optical pulse to the drive device 16.

That is, as shown in FIG. 3, the time point at which the reflected light reaches the car shutter 13 with respect to the incident light on the affected area 52, t2. t3. Since tn, ..., tn vary depending on the tissue depth of the affected area 52, as shown in FIG. It can be obtained from the time-resolved waveform shown in .

Therefore, as shown in FIG. 5, the opening timing of the car shutter 13 is set at time t1. t2. t3. t4...
, tn, and the reflected light pulses from each point in the tissue guided by the optical fiber bundle 4 are transmitted to the imaging device 1.
8 and analyzes the intensity of the reflected light, it is possible to detect an optical tomographic image of the affected area 52 corresponding to the irradiation plane of the light pulse by the optical fiber bundle 4 at each opening timing of the car shutter 13. It is.

Then, at this time H, t2. t3. t4. ...,tn
By processing each optical tomographic image in the signal processing device 19, a three-dimensional image including the blood vessels 53 inside the tissue of the affected area 52 and the like is obtained, as shown in FIG. 6, and displayed on the monitor 30. I can do it.

Thereby, the internal structure of the tissue can be accurately and easily grasped, and the internal state of the affected area 52 can be accurately diagnosed. Furthermore, by repeating measurement by changing the wavelength of the dye laser 8 of the pulsed laser 6 and performing calculations between the tomographic images obtained by light pulses of different wavelengths, for example, oxygen in the blood vessel 54 can be measured. Three-dimensional display of physiological composition such as saturation level becomes possible. Therefore, it is possible to understand not only the internal tissue structure but also the state of metabolic function.
Comprehensive diagnosis can be made possible.

By the way, in this dimensional image observation device, the affected area 5
When the scattered light from 2 enters the imaging device W, 18, it becomes noise and causes image deterioration. Therefore, it is necessary to suppress the scattered light and extract only the straight component.

FIG. 7 shows an example in which a means for suppressing the scattered light is provided at the distal end of the endoscope 1, in which a lens 54. Aperture (diaphragm) 55. A collimator in which lenses 56 are sequentially arranged is provided to limit unnecessary light such as scattered light.

Incidentally, it is possible to effectively suppress scattered light by using a single mode fiber as the optical fiber bundle instead of using the collimator.

Further, as the light opening/closing means, the above-mentioned car shutter 13
In addition, as shown in FIG. 8, a nonlinear optical element 57 may be used, and as this nonlinear optical element 57, for example, C32 or the like is adopted.

This CS2 inputs a reference light to the reflected light from the measurement site that enters through the polarizing plate 58, thereby providing a second
Generates harmonics. The intensity of this second harmonic is proportional to the integral value of the product of the reflected light and the reference light when each of the reflected light and the reference light is a time interval, and is
．． A time-resolved waveform can be similarly obtained by transmitting the second harmonic from C82 in a narrow band through a filter 60 and detecting it with a camera 61 equipped with a photomultiplier tube or the like.

Furthermore, in order to effectively utilize the leading lens dimensional image observation device of the present invention, it is effective to widen the observation area, and an example thereof will be described below.

FIG. 9 shows an internal three-dimensional image of the distal end of the optical fiber bundle 62, in which each optical fiber 62a constituting the optical fiber bundle 62 is spread radially over a wide area around the affected area 52. It enables observation.

In this case, it is also possible to arrange a normal lens in front of the optical fiber bundle 4 to widen the observation area.
By using a lens array 63 as shown in FIG. 10, it is possible to further effectively widen the angle of view.

That is, the lens array 63 has a pitch that is slightly larger than the pitch between the optical fibers 48 constituting the optical fiber bundle 4, and each lens 63 is eccentric at the periphery.
As shown in FIG. 11, the light shielding portions 63b between the lenses 63a are made of black oxidized glass or the like.

By arranging this lens array 63 facing the front surface of the optical fiber bundle 4, the observation area can be widened, and the lens diameter of each lens 63a and the thickness of the light shielding part 63b can be adjusted appropriately. By setting and narrowing down the entrance numerical aperture or F value, even when the optical fiber 4a is a multimode fiber, the number of entrance modes can be reduced and dispersion within the fiber during optical transmission can be suppressed.

Furthermore, by appropriately setting the distance between the lens array 63 and the end face of the optical fiber bundle 4, it is possible to narrow down the spread of the incident light to each optical fiber 4a, so that separation in the direction of spread of the measurement plane is possible. Therefore, crosstalk of information between the optical fibers 4a can be avoided.

[Effects of the Invention] As described above, according to the present invention, a three-dimensional image can be obtained from an optical tomographic image of a measurement object, so the internal form of the measurement object can be accurately and easily captured, and further, This has the effect of making it possible to perform comprehensive measurements, including not only structural measurements but also functional measurements.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a system configuration diagram of the front lens dimensional image observation device, FIG. 2 is an explanatory diagram showing an example of observation inside a body cavity by the front lens dimensional image observation device, and FIG. 3 is an explanatory diagram showing the relationship between the time of reflected light and the tissue depth, Fig. 4 is an explanatory diagram showing the time-resolved waveform of reflected light intensity, Fig. 5 is a time chart showing the control timing of light opening/closing, and Fig. 6 is an explanatory diagram showing the measurement results, Fig. 7 is an explanatory diagram showing the configuration of the endoscope tip for suppressing scattered light, Fig. 8 is an explanatory diagram of the optical closing operation by the nonlinear optical element, and Fig. 9 is an illustration of observation. FIG. 10 is an explanatory view showing an optical fiber bundle for widening the viewing area, FIG. 10 is an explanatory view showing a lens array for widening the viewing area, and FIG. 11 is a front view of the lens array. 4... Optical fiber bundle 6... Pulse laser 12... Beam expander 13... Kerr shutter 18... Imaging device 19... Signal processing device Fig. 5 Fig. 7 Fig. 8 Figure 6 Figure 9 Figure 11

Claims (1)

[Scope of Claims] Optical pulse generating means for generating optical pulses for measurement; guiding the optical pulses generated by the optical pulse generating means to a measurement object, and guiding reflected optical pulses reflected inside the measurement object. an optical fiber bundle; a light input means for uniformly diffusing and inputting the light pulse into the optical fiber bundle; a light opening/closing means for passing the reflected light pulse at an arbitrary time; and a reflection having passed through the optical opening/closing means. An optical three-dimensional image observation apparatus comprising: an image processing means for processing light pulses to detect a tomographic image of the measurement target and constructing a three-dimensional image of the measurement target from the tomographic image.