JPH0324848B2 - - Google Patents

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an endoscope apparatus using an imaging means.

(Conventional technology) In endoscopes for diagnosis and treatment inside body cavities,
In recent years, endoscopes have been developed in which a small solid-state image sensor, such as a CCD, is placed at the tip. Instead of the image fiber used in conventional fiberscopes, this type of endoscope uses a solid-state image sensor that converts the optical image of the object into an electrical signal, and converts this electrical signal into a television signal. The object is displayed as an image on a display device such as a CRT monitor via a converting processing circuit. This image is generally a color image, and the structure and color tone of the object provide diagnostic information.
Color images are usually R (red), G (green), and B (blue).
It is composed of type values (or their converted values), and these R, G, and B are physically determined by three types of optical values that determine the spectral reflection spectrum of the object based on the characteristics of human color perception. This is the amount integrated using a filter. Therefore, in order to obtain a color image, a method is adopted in which an image is taken using illumination light transmitted through the above-mentioned optical filter as a light source, or a method in which an image is taken with an image sensor in which the above-mentioned optical filter is arranged in a matrix on a CCD chip.

(Problem to be Solved by the Invention) However, in the color image as described above, the spectral reflection spectrum of the object is displayed as a color by averaging the spectral reflection spectrum over a wide spectral region. It has been difficult to display local changes with good sensitivity. For example, it has sometimes been difficult to detect subtle color changes between normal and diseased areas of the gastric mucosa, or differences in color due to the presence or absence of blood.

The present invention has been made in view of the above circumstances, and it is an endoscope that uses an imaging means to detect local changes in the spectral reflection spectrum of an object with high sensitivity and display them as a two-dimensional image. The purpose of the present invention is to provide an endoscope device that can perform the following functions.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a method for capturing multiple types of subject images for each band spectrum light by switching multiple types of narrow band spectrum light having different center wavelengths. an image forming means for forming an image on the means, an image memory storing the plurality of types of subject images based on signals from the imaging means, and comparing image data for each region corresponding among the plurality of types of images, The endoscope apparatus is provided with a calculation means for determining an enhancement method for the region based on this comparison value.

(Operation) The imaging means switches between plural types of narrow band spectrum light having different center frequencies, and forms a plurality of types of subject images for each of the band spectrum lights on the imaging means. Then, these plural types of subject images are temporarily stored in an image memory, and the image data of each corresponding area between the images is compared by a calculation means. The calculation means determines the display color of the image data based on the comparison value of each image data, for example, based on the wavelength used to collect the image with the higher image data. For example, if you are photographing with light that has band spectra in blue and red, and the image data of the subject image with blue light is high,
A blue-based color is assigned as the display color for this area. Note that this display color is not necessarily determined by hue, but may be displayed by saturation.

That is, according to the present invention, it is possible to obtain local color information on an object using light with a narrow band spectrum, and by storing this color information in a memory and further processing it with a calculation means, it is possible to obtain local color information on the object. Sensitively detects local changes in the spectral reflection spectrum2
It can be displayed as a dimensional image. Therefore, according to the present invention, by detecting and displaying local changes in the spectral reflection spectrum of the inner wall of a body cavity during endoscopic diagnosis, it is possible to detect subtle color changes in the inner wall, which are impossible with ordinary color images. It can be provided as diagnostic information, and can contribute to accurate diagnosis by detecting, for example, subtle color changes between normal and diseased areas of the gastric mucosa, and color differences depending on the presence or absence of blood.

(Example) The illustrated embodiment will be described below.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Reference numeral 1 denotes an endoscope having a solid-state image sensor 12 at its tip, and a light guide 11 that guides illumination light.
and a lens 13 that focuses the reflected light onto the solid-state image sensor 12.

2 is a light source unit, 21 is a rotating disk consisting of a plurality of interference optical filters, 22 is a drive section for the rotating disk 21, 23 is a control section that controls the drive section 22, 24 is a light source such as a Xe lamp, 2
5 is a light source control section. Note that the light source unit 2, light guide 11, and lens 13 constitute an imaging means.

3 is an image processor main body, 31 is a TV camera control section, 32 is an A/D converter, 33 is an image memory, 34 is a calculation section, 35 is a D/A converter, 3
6 is a system controller section. 4 is a display monitor.

FIG. 2 shows the interference optical filter rotating disk 21.
It is a front view showing an example, and the one shown is six different optical filters R, G, B and F1, F.
2 and F3, and the transmission spectrum characteristics of these optical filters are as shown in FIG.

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

In normal color image shooting, the rotating disk 2
1 R, G, and B filters are selected sequentially, an optical image of the object illuminated by the light guide 11 is captured by the solid-state image sensor 12, and the TV camera control unit 31 sequentially selects the R, G, and B video images. converted into a signal. This R, G, B video signal is then converted to A/
The images are digitized by a D converter 32 and sequentially stored in an image memory 33. The sequence during this time is synchronized by the system control unit 36. In other words, in synchronization with TV scanning,
The R, G, and B filters of the rotary disk 21 rotate and move, and this rotation is executed by a drive section 22 controlled by a rotation control section 23.

The R, G, and B video signals stored in the image memory 33 are read out at a normal display video frame rate, converted to analog video signals by the D/A converter 35, and displayed as a color image on the display monitor 4. will be displayed as .

Next, when observing minute changes in the spectral reflection spectrum of the object, the filters F1, F2, and F3 in the rotating disk 21 are sequentially selected (or only two types may be used), and each filter F1, F2, The reflection spectrum of the object under the F3 condition is optically/electrically converted by the image sensor 12 and shaped into a video signal by the TV camera control section 31. Then each filter F1,
The video signals under the conditions of F2 and F3 are digitized by the A/D converter 32 and stored in the image memory 33. Next, for example, a ratio for each pixel between the two types of image data on the image memory 33 is calculated by the calculation unit 34. The ratio value calculated for each pixel represents the magnitude of local change in the reflection spectrum of the object at the position corresponding to each pixel. FIG. 4 is an explanatory diagram thereof, and is a graph in which the spectral reflection spectra of the two positions P1 and P2 of the object and the spectral transmittance of the interference filter are superimposed. The video signal obtained from position P1 when shooting with filter F1 is proportional to the area S1 (F1) where the spectral transmittance curve of filter F1 and the reflection spectrum curve of P1 are superimposed, and similarly, the video signal obtained from position P1 when photographing with filter F1 is
The video signal at P1 obtained by photographing at is proportional to the area S1 (F2). and the ratio of these is S1
(F2)/S1(F1). Similarly, at the other point P2, the ratio of the video signal values obtained by the filters F1 and F2 is expressed as S2(F2)/S2(F1). In the example of FIG. 4, the value of the ratio at point P1 is less than 1, and the value of the ratio at point P2 is greater than 1. Therefore, by determining the values of these ratios, changes in the reflection spectrum at each point of the object can be known. In other words, as a method of displaying the degree of spectral change at each point, the value of the ratio is expressed as a change in hue, and if the ratio is greater than 1, the hue at that position is evaluated to be on the red side ( (See FIG. 3) A red tone is assigned, and if the ratio is less than 1, the color tone at that position is evaluated to be on the blue side (see FIG. 3), and a blue tone is assigned and displayed. In the example of Fig. 4, point P1
Point P2 is displayed in blue because its reflection spectrum is downward to the right and the ratio value is less than 1, and point P2 is displayed in red because its reflection spectrum is upward to the right and the ratio value is greater than 1. It happens. Then, calculation of the ratio of video signal values under two optical filters for each pixel as described above,
The assignment process to the hue is executed by the calculation unit 34, and the calculation result is stored in the image memory 3.
3, is D/A converted by a D/A converter 35, and displayed on the display monitor 4.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above embodiment, and can be modified as appropriate within the scope of the gist of the present invention.

For example, in the above embodiments, the ratio value is expressed in terms of hue, but it may also be expressed in terms of saturation, that is, the vividness of the color.

Furthermore, as another embodiment, the present invention can be similarly implemented in an endoscope apparatus that obtains a video signal by arranging an image sensor in the eyepiece of a normal fiberscope. Furthermore, in this embodiment, the interference optical filter constituting the imaging means may be placed in the eyepiece.

Further, as the imaging means, a wavelength variable laser (for example, a dye laser) can be used as a light source.

[Effects of the Invention] As detailed above, according to the present invention, in endoscopic diagnosis, by detecting and displaying local changes in the spectral reflection spectrum of the inner wall of a body cavity, it is possible to detect and display local changes in the spectral reflection spectrum of the inner wall of a body cavity. Subtle color changes in the heated interior walls can be provided as diagnostic information. As a result, early diagnosis of cancer and visualization of blood distribution become easier.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
This figure is a front view of the same interference optical filter as above, FIG. 3 is a spectral transmission spectral characteristic diagram of the optical filter, and FIG. 4 is an explanatory diagram of signals under filter conditions. 2, 11, 13...imaging means, 12...solid-state imaging device, 33...image memory, 34...computing means.

Claims (1)

[Scope of Claims] 1. In an endoscope device that displays a subject image in color based on a photographing signal from an imaging means, by switching between multiple types of narrow band spectrum light having different center wavelengths, each band spectrum light can be displayed in color. an image forming means for forming a plurality of types of subject images on the image capturing means; an image memory for storing the plurality of subject images based on signals from the image capturing means; 1. An endoscope apparatus comprising: a calculation means for comparing image data of the area and determining an enhancement method for the area based on the comparison value. 2. The endoscope apparatus according to claim 1, wherein the imaging means switches between a plurality of types of interference optical filters for the emission path of the light source light.