JP3142389B2 - Optical diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical optical diagnostic apparatus such as an optical CT apparatus and, more particularly, to an optical diagnostic apparatus which is optimal for performing diagnosis while distinguishing a tissue of a subject.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of an optical CT apparatus. A subject 2 is mounted on the pulse stage 1. The pulse stage 1 is rotated stepwise by a predetermined angle by a driving device 3.

A single-wavelength laser oscillator 4 is provided. The laser beam output from the laser oscillator 4 is split by the beam splitter 5 into two, a signal laser beam q and a reference laser beam g. Among them, the signal laser beam q is applied to the subject 2, passes through the subject 2, and reaches the beam splitter 6. In this case, the tissue of the subject 2 has a characteristic of absorbing a specific wavelength. Therefore, when the signal laser beam q passes through the subject 2, a wavelength component corresponding to the tissue is absorbed.

On the other hand, the reference laser beam g is reflected by the mirror 7 and guided to the acousto-optic element 8, and the acousto-optic element 8
Is reflected by the mirror 9 and guided to the beam splitter 6.

The beam splitter 6 combines the signal laser beam qa transmitted through the subject 2 and the frequency-modulated reference laser beam ga, and guides the combined signal laser beam ga to the detector 10. The detector 10 converts the incident combined beam qg into an electric signal corresponding to the intensity of the signal laser beam qa, and the following amplifier 11 amplifies the converted electric signal and sends it to the frequency separator 12.

The frequency separator 12 separates a component of a required frequency band from the input electric signal and passes it to an image data processing device 13. The image data processing device 13 performs image data processing on the received electric signal. Thus, a tomographic image, that is, a CT image of the subject 2 is created.

The control device 14 controls the driving of the driving device 3 to rotate the pulse stage 1 and sends information on the rotation to the data processing device 13.

However, in such an optical CT apparatus, since the subject 2 is irradiated with the laser beam q of a single wavelength and a CT image is created based on the transmitted intensity, each tissue of the subject 2 can be clearly identified. It is difficult to differentiate and make a CT image. That is, since each tissue of the subject 2 has a characteristic of absorbing a specific wavelength to that tissue, a laser beam of each wavelength corresponding to the tissue must be transmitted in order to distinguish each tissue. For example, FIG. 4 shows a human epidermis,
The relationship between the absorption and scattering coefficients of the dermis, melanin, and hemoglobin is shown with the wavelength. Can not. Further, the obtained CT image is of a single color, and a plurality of data are separately required in order to clearly distinguish each tissue based on its density. Further, if the CT image is colored, each tissue can be distinguished. However, this requires complicated image data processing and takes a long processing time, and the CT image of the moving subject 2 can be obtained in real time. It is difficult to display.

[0009]

As described above, the subject 2
It is difficult to clearly distinguish each tissue from each other to form a CT image, and it is also difficult to colorize the CT image and display it in real time.

Accordingly, the present invention provides an optical diagnostic apparatus capable of clearly distinguishing each tissue of a subject by obtaining a color CT image of the subject rotating and moving in real time and observing a change in the state of the tissue of the subject. The purpose is to provide.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a laser beam is branched in two directions, one of the laser beams is irradiated on a subject, the other laser beam is frequency-modulated, and the laser beam transmitted through the subject is transmitted. A laser oscillating means for outputting a laser beam having a plurality of wavelength components, wherein the laser oscillating means outputs a laser beam having a plurality of wavelength components based on the intensity of a combined beam of the laser beam and the frequency-modulated laser beam; Light detection means for converting each electric signal corresponding to the intensity of each wavelength included in the combined beam; and image data processing means for obtaining a color tomographic image of the subject based on each electric signal from the light detection means. An optical diagnostic apparatus provided to achieve the above object.

[0012]

With such a means, a laser beam containing a plurality of wavelengths is output from the laser oscillating means and branched in two directions, one of which is irradiated on the subject and the other is frequency-modulated. The laser beam that has passed through the subject is combined with the frequency-modulated laser beam, and then converted into electrical signals for each wavelength by the light detection unit. Then, a color tomographic image of the subject is obtained by the image data processing means based on these electric signals.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. The same parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a configuration diagram of an optical CT apparatus. The laser oscillator 20 has three different wavelengths, for example, red,
It has a function of outputting a laser beam containing each wavelength of blue and green.

On the other hand, a light detecting means 21 is arranged at a position facing the pulse stage 1 from the laser oscillator 20 via the beam splitters 5 and 6. The light detection means 21 receives a combined laser beam QG of the signal laser beam Qa transmitted through the subject 2 and the frequency-modulated reference laser beam Ga, and receives each wavelength included in the combined laser beam QG, that is, red, It has a function of converting each wavelength of blue and green to an electric signal corresponding to its intensity.

The specific configuration will be described with reference to FIG. 2. A diffraction grating 22 is arranged on the optical path of the synthetic laser beam QG.
G is diffracted into laser beams a, b, and c in each direction unique to each wavelength. A photodetector 23 is arranged on the optical path of these laser beams a, b and c.

The photodetector 23 includes a lens 24, a microchannel plate (MCP) 25, and a parallel plate electrode 2.
6 and a CCD camera 27.
Among them, the parallel plate electrode 26 is formed by each of the electrodes 26a, 26b.
Are arranged opposite to each other, and a high voltage is applied between the electrodes 26a and 26b. These electrodes 26a, 26
When the pulse stage 1 makes one rotation, the photoelectrons incident on the CCD camera 27 turn into the high arrow b.
It changes to a value swept in the direction.

Accordingly, in the photodetector 23, the laser beams a, b, and c are guided to different positions h1, h2, and h3 on the microchannel plate 25 through the lens 24, and are converted into photoelectrons by the microchannel plate 25. To the parallel plate electrode 26. And
The traveling direction of photoelectrons is controlled by the parallel plate electrode 26, and C
It is designed to guide to predetermined positions f1, f2, f3 on the CD camera 27.

Here, the photoelectrons entering each of the positions f1, f2, and f3 have information on the absorption coefficient of the subject 2 at each of the red, blue, and green wavelengths.
The CCD camera 27 detects photoelectrons that have entered the respective positions f1, f2, and f3, and converts and outputs electric signals corresponding to the photoelectrons.

The image data processing device 28 has a function of inputting each electric signal from the CCD camera 27 and performing image data processing to obtain a color CT image of the subject 2.

The control device 29 has a function of controlling the driving of the driving device 3 to rotate the pulse stage 1 and transmitting information on the rotation to the image data processing device 28.

Next, the operation of the above-configured apparatus will be described.

The laser oscillator 20 outputs a laser beam including red, blue and green wavelengths. This laser beam is converted into a signal laser beam Q by the beam splitter 5.
And a reference laser beam S. Among them, the signal laser beam Q is applied to the subject 2, passes through the subject 2, and reaches the beam splitter 6. In this case, the tissue of the subject 2 has a characteristic of absorbing the specific wavelength as shown in FIG. 4 as described above. Therefore, when the signal laser beam Q passes through the subject 2, each wavelength component corresponding to each tissue is absorbed.

On the other hand, the reference laser beam S is reflected by the mirror 7 and guided to the acousto-optic element 8.
Is reflected by the mirror 9 and guided to the beam splitter 6.

The beam splitter 6 combines the signal laser beam Qa transmitted through the subject 2 and the frequency-modulated reference laser beam Sa. This combined laser beam QS enters the diffraction grating 22.

The diffraction grating 22 diffracts the incident combined laser beam QS into laser beams a, b, and c in respective directions unique to red, blue, and green wavelengths, and performs photodetector 23.
Lead to.

This photodetector 23 outputs each laser beam a,
b and c are led to different positions h1, h2 and h3 on the microchannel plate 25 through the lens 24, converted into photoelectrons by the microchannel plate 25, and guided to the parallel plate electrode 26.

The electrodes 26a, 2a of the parallel plate electrode 26
A high voltage that changes according to the rotation of the pulse stage 1 is applied between the electrodes 6a and 6b. The traveling direction of the photoelectrons incident between the electrodes 26a and 26b is controlled according to the applied voltage. Positions f1, f2, f3
Is swept in the direction of the arrow (a) passing through. For example, each electrode 2
The applied voltage between 6a and 26b changes in synchronization with the rotation angle of the pulse stage 1, and when the pulse stage 1 makes one rotation, the photoelectrons are swept in the direction of the arrow (a).

The photoelectrons incident on these positions f1, f2 and f3 have information on the absorption coefficient in the subject 2 at each of the red, blue and green wavelengths. , F3, and outputs respective electric signals corresponding to the intensities of the photoelectrons incident on the photoelectrons.

These electric signals are transmitted to the image data processing device 28.
The image data processing device 28 performs image processing based on each electric signal having each of red, blue, and green wavelength components to create a color CT image of the subject 2. In this case, the image data processing device 28 determines that each electric signal is red,
Since it has blue and green wavelength components, a color CT image can be obtained with a small amount of data processing.

As described above, in the above-described embodiment, the subject 2 is irradiated with the laser beams of the respective red, blue and green wavelength components, and the signal laser beam Qa transmitted through the subject 2 and the frequency-modulated laser beam are emitted. Combining with the beam Ga,
The combined laser beam QG is converted into electrical signals for each of red, blue, and green wavelengths, and a color CT image of the subject 2 is obtained based on these electrical signals. Each tissue of the subject 2 can be easily represented by a different color, and each tissue can be clearly distinguished.

Accordingly, a change in the state of each tissue of the subject 2 can be observed, and for example, diagnosis of a normal tissue and an abnormal tissue can be easily performed.

Further, since a color CT image is created from the intensities of the red, blue and green wavelengths, image processing is easy, and the color CT image of the subject 2 moving in real time is easy.
Can create images.

It should be noted that the present invention is not limited to the above-described embodiment, and may be modified without changing the gist of the present invention. For example, the laser oscillator 20 may include laser oscillators that output laser beams of respective wavelengths, and guide the laser beams output from the laser oscillators on the same optical path. In this case, the wavelength of each laser oscillator is
It may be changed according to the diagnosis or observation of the subject.

In place of the diffraction grating 22, an element prism for performing wavelength separation may be used.

The present invention is not limited to the CCD camera 27, but may be any as long as it detects photoelectrons on a plane and converts them into electric signals.

Further, the present invention is not limited to the color CT image.
From each electric signal of each wavelength component obtained by step 3, for example, only the red electric signal, each CT of each tissue corresponding to the wavelength is obtained.
An image may be obtained.

Further, the wavelength component output from the laser oscillator is not limited to red, blue and green, but may be another wavelength component.

[0039]

As described above, according to the present invention, each tissue of the subject can be clearly distinguished by obtaining a color CT image of the subject rotating and moving in real time, and the tissue of the subject can be clearly distinguished. An optical diagnostic device capable of observing a state change or the like can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an optical diagnostic apparatus according to the present invention.

FIG. 2 is a specific configuration diagram of a light detection unit in the device.

FIG. 3 is a configuration diagram of a conventional device.

FIG. 4 is a diagram showing a relationship between absorption and scattering coefficients and wavelength.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pulse stage, 2 ... Subject, 3 ... Driver, 5,
6 ... beam splitter, 7, 9 ... mirror, 8 ... acousto-optic element, 20 ... laser oscillator, 21 ... light detecting means, 22 ...
Diffraction grating, 23 photodetector, 28 image data processing device, 29 control device.

Claims (1)

(57) [Claims] 1. A laser beam is branched in two directions, one of the laser beams is irradiated to an object, the other laser beam is frequency-modulated, and the laser beam transmitted through the object and the frequency-modulated laser are In an optical diagnostic apparatus for obtaining a tomographic image of the subject based on the intensity of a combined beam with a beam, a laser oscillating means for outputting a laser beam having a plurality of wavelength components, and receiving the combined beam to generate the combined beam Light detecting means for converting into electric signals corresponding to the intensity of each of the wavelengths included, and image data processing means for obtaining a color tomographic image of the subject based on each electric signal from the light detecting means. An optical diagnostic device, characterized in that: