JP3911194B2 - Diagnostic system using autofluorescence - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diagnostic system using an endoscope and using autofluorescence.
[0002]
[Prior art]
When a living tissue is irradiated with light (excitation light) having a specific wavelength such as ultraviolet rays, it tends to emit fluorescence. This phenomenon is called autofluorescence. In recent years, it has been discovered that the amount of fluorescent light due to autofluorescence decreases in affected areas such as cancer cells, and is attracting attention as an early detection method for diseases.
[0003]
Therefore, autofluorescence diagnosis in which excitation light is irradiated into a lumen and fluorescence is observed with an endoscope is being used. When performing such autofluorescence diagnosis, the light guide of the endoscope is usually connected to a white light source for observation, and another light guide is inserted into the treatment instrument insertion channel of the endoscope, and this light guide is fluorescent. Connected to the observation light source. When performing the fluorescence observation, an endoscope operator prevents light from the fluorescence observation light source from entering the light guide and allows light from the normal observation light source to enter the light guide. On the other hand, when performing normal observation, light from the light source for fluorescence observation is made incident on the light guide, and light from the light source for normal observation is not made incident on the light guide.
[0004]
Considering the lamp life of the fluorescence observation light source, it is desirable to turn on the fluorescence observation light source only during fluorescence observation. However, the amount of excitation light is not stable unless a certain amount of time has elapsed since the lighting of the fluorescence observation light source. Therefore, when performing fluorescence observation and normal observation using the apparatus as described above, the number of light to start the fluorescence observation is previously blocked by a shutter or the like so that the light from the light source for fluorescence observation does not enter the light guide. It was necessary to turn on the fluorescence observation light source with the shutter closed a minute ago, open the shutter at the start of fluorescence observation, and turn off the normal observation light source. Further, in order to prevent unnecessary consumption of the fluorescence observation light source, the fluorescence observation light source must be manually turned off immediately after the completion of the fluorescence observation.
[0005]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide a diagnostic system that can prevent unnecessary consumption of a light source for fluorescence observation without requiring a complicated operation.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, when a change in the captured image occurs for the first time when the fluorescence observation light source is turned off, the fluorescence observation light source is turned on, and the fluorescence observation light source is turned on. When the state in which the captured image does not change during lighting continues for the second time or longer, the light source for fluorescence observation is turned off.
[0007]
While the examination is performed by inserting the endoscope into the body cavity, the captured image continues to change. On the other hand, when the inspection is not performed, since the endoscope is hung on the hanger or placed on the cart, the captured image does not change. Therefore, according to the present invention, the fluorescence observation light source is automatically turned off when the inspection is not performed for a predetermined time or longer, and the fluorescence observation light source is automatically turned on when the inspection is started. That is, since the fluorescence observation light source is lit only when necessary, unnecessary wear of the fluorescence observation light source can be prevented without requiring a complicated operation.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows a diagnostic system according to the present embodiment. The diagnostic system 1 according to the present embodiment includes an electronic endoscope 100, an endoscope processor 200, a fluorescence observation light source 300, a keyboard 400, and a monitor 500.
[0009]
The electronic endoscope 100 is connected to the endoscope processor 200. The endoscope processor 200 causes a normal light beam such as a xenon lamp to enter the light guide 103 of the electronic endoscope 100 and controls the CCD 104 provided at the tip of the electronic endoscope 100 to output an image output from the CCD 104. The signal is processed, and a video signal in a predetermined format that can be displayed on the monitor 500, such as an NTSC signal, is output to the image switcher 400.
[0010]
In the lamp unit 204 of the endoscope processor 200, a lamp 204a, an iris (aperture) 204b, a color filter 204e, a shutter 204c, a condenser lens 204d, and an incident end 209a of the light guide 209 are arranged in this order. The normal light beam emitted from the lamp 204a is moderately adjusted by the iris 204b, passes through the shutter 204c, is further collected by the condenser lens 204d, and enters the incident end 209a of the light guide 209. The light that has entered the incident end 209 a of the light guide 209 passes through the light guide 209 and reaches the endoscope connection unit 210 of the endoscope processor 200, and the electronic endoscope 100 of the endoscope 100 passes through this endoscope connection unit 210. It enters the incident end 103 a of the light guide 103. The light incident on the incident end 103a of the light guide 103 of the electronic endoscope 100 passes through the light guide 103 of the electronic endoscope 100 and is emitted from the distal end of the insertion portion of the electronic endoscope 100 to irradiate the body cavity.
[0011]
The color filter 204e is a filter of three colors of red (R), green (G), and blue (B). The color filter 204 e inserts red (R), green (G), and blue (B) filters into the light beam emitted from the light source unit 204 in synchronization with the signal transfer timing of the CCD 104. The rotation control of the color filter 204e is performed by the timing control 205. Since the CCD 104 is configured to capture / transfer one image in 1/30 seconds, the color filter 204b switches the filters every 1/30 seconds. In addition, the filter is switched while the CCD 104 is transferring an image. Therefore, the CCD 104 sequentially captures images irradiated with red, green, and blue light. The captured image signal is transmitted to the first stage signal processing circuit 202 of the endoscope processor 200. The first stage signal processing circuit 202 discretizes this image signal and stores it in the image memory 207. Each image irradiated with red, green, and blue light is stored in a different area of the image memory 207, respectively. The post-stage signal processing circuit 203 of the endoscope processor 200 reads out and synthesizes each image irradiated with red, green, and blue light stored in the image memory 207, and further converts it into an NTSC video signal. By the so-called frame sequential method as described above, a color image can be output even if the CCD 104 is a monochrome CCD. The above control is performed by the system control 201 of the endoscope processor 200.
[0012]
The endoscope processor 200 includes a buffer memory 208 and an image comparison circuit 210. The buffer memory 208 is connected to the first stage signal processing circuit 202 and stores the image signal picked up by the CCD 104 as a color image in the same manner as the image memory 207. The buffer memory 208 has two areas for storing color images, and alternately stores the data transmitted from the first stage signal processing circuit 202 in the two areas. That is, when data transmitted from the first stage signal processing circuit 202 is transmitted to one area, an image captured one frame (1/10 second) ago is stored in the other area.
[0013]
The image comparison circuit 210 is connected to the buffer memory 208 and the first stage signal processing circuit 202, and the image signal output from the first stage signal processing circuit 202 and the previous frame stored in the buffer memory 208 (1/10 second). The image is compared, the image motion vector is calculated, and the image motion direction and the image motion amount are detected. The system control 201 can determine from the comparison result by the image comparison circuit 210 whether the current image has changed from the image one frame before. The image continues to change during the examination with the endoscope inserted into the body cavity. On the other hand, when the inspection is not performed, the state where the image does not change continues. Therefore, the system control 201 can determine from the comparison result by the image comparison circuit 210 whether or not the inspection by the electronic endoscope 100 is being performed.
[0014]
Further, the system control 201 calculates the average luminance of the color image from the contents of the image memory 207 at every interval (1/10 second) at which one color image is generated, and drives the iris 204b according to the average luminance. . That is, if the average luminance of the color image exceeds the predetermined value A, the iris 204b is driven so as to reduce the amount of light incident on the incident end 209a of the light guide 209. On the other hand, if the average luminance of the color image exceeds a predetermined value B (A> B), the iris 204b is driven so as to increase the amount of light incident on the incident end 209a of the light guide 209. A position sensor for detecting the current position of the iris is provided in the vicinity of the iris 204b, and the system control 201 grasps the position of the iris based on the output of the position sensor 204S. As described above, in this embodiment, the amount of light incident on the incident end 209a of the light guide 209 is controlled so that the average luminance of the color image is between A and B.
[0015]
The fluorescence observation light source 300 includes a lamp unit 304 that generates light including a spectrum that excites autofluorescence of living tissue such as ultraviolet rays. The excitation light generated by the lamp unit 304 enters the incident end of the fluorescence observation light guide 305. The distal end of the fluorescence observation light guide 305 is inserted into the treatment instrument insertion channel 107 from the treatment instrument port 107a of the electronic endoscope, and excitation light is directed from the distal end portion of the electronic endoscope 100 toward the living tissue in the body cavity. Can be irradiated. The signal output from the CCD 104 when the excitation light is irradiated is discretized by the first-stage signal processing circuit 202 and stored in the image memory 207, and converted into an NTSC video signal by the subsequent-stage signal processing circuit 203, as in the normal observation image. Is done.
[0016]
The image when the excitation light is irradiated is a fluorescence image, and an affected part such as a cancer cell generates weak fluorescence as compared with a healthy tissue. Therefore, a diseased part can be specified by comparing this fluorescent image with a normal observation image that is a captured image during normal observation. The operator of the diagnostic system 1 can switch between the fluorescence image and the normal image by operating the front panel switch 208 or the keyboard 400 of the endoscope processor 200. Signals from the front panel switch 208 and / or the keyboard 400 are input to the system control 201, and the system control 201 uses the signals to the shutter 204c provided in the lamp unit 204 of the endoscope processor 200 and the light source for fluorescence observation. Both shutters are controlled so that one of the shutters 304a provided in the lamp unit 304 of 300 is closed and the other is opened.
[0017]
The lamp control process of the diagnostic system 1 of the present embodiment configured as described above will be described below. FIG. 2 is a flowchart of a lamp control routine of the endoscope processor 200 according to this embodiment. This routine is a program stored in the memory 207 of the endoscope processor 200 and executed by the system control 201.
[0018]
This routine starts when the endoscope processor 200 is powered on. At the start of this routine, the light source lamp 304a of the fluorescence observation light source 300 is turned off. When this routine starts, step S101 is first executed.
[0019]
In step S101, 0 is substituted into the variable t. Next, the process proceeds to step S102.
[0020]
In step S102, the system control 201 determines based on the comparison result of the image comparison circuit 210 whether the current image has changed from the image one frame before. If the image has not changed (S102: NO), the process returns to step S101. On the other hand, if the image has changed (S102: YES), the process proceeds to step S103.
[0021]
In step S103, the variable t is compared with the constant α. If t <α in step S105 (S103: NO), the process proceeds to step S104, 1 is added to t, and then the process returns to step S102. On the other hand, if t ≧ α in step S103 (S103: YES), the process proceeds to step S105, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is turned on, and then the process proceeds to step S106.
[0022]
As described above, according to steps S101 to S105, the image picked up by the CCD 104 keeps changing continuously for a certain number of times α, that is, the time taken for the loop of S102 to S104 is T1, and the image is continuous for time αT or longer. As a result, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is turned on. When the inside of the body cavity is being observed with the electronic endoscope 100, the image captured by the CCD 104 continues to change, and therefore, when the predetermined time αT1 has elapsed after the start of observation, the lamp unit 304 of the fluorescence observation light source 300 automatically. The lamp lights up.
[0023]
In step S106, 0 is substituted into the variable t. Next, the process proceeds to step S107.
[0024]
In step S107, the system control 201 determines based on the comparison result of the image comparison circuit 210 whether the current image has changed from the image one frame before. If the image has changed (S107: YES), the process returns to step S106. On the other hand, if the image has not changed (S107: NO), the process proceeds to step S108.
[0025]
In step S108, the variable t is compared with the constant β. If t <β in step S108 (S108: NO), the process proceeds to step S109, 1 is added to t, and then the process returns to step S107. On the other hand, if t ≧ β in step S108 (S108: YES), the process proceeds to step S110, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is turned off, and then the process returns to step S101.
[0026]
As described above, according to steps S106 to S110, the state in which the image captured by the CCD 104 does not change continues continuously for a certain number of times β, that is, the image changes with the time taken for the loop of S110 to S113 as T2. In this configuration, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is extinguished when the non-continuous state continues for a time βT2 or more. When the observation inside the body cavity is temporarily stopped and the electronic endoscope 100 is placed on a hanger or placed on a cart, the image does not change. Accordingly, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is turned off. In order to prevent the lamp of the lamp unit 304 of the fluorescence observation light source 300 from being turned off during fluorescence observation, the value of the constant β is set so that the time βT2 becomes a sufficiently large value, for example, 1 minute or more.
[0027]
By controlling the lamp of the lamp unit 304 of the fluorescence observation light source 300 according to the above routine, the lamp of the lamp unit 304 of the fluorescence observation light source 300 is turned on during normal observation with the endoscope, When the observation inside the body cavity by the mirror is interrupted, the lamp is automatically turned off. Accordingly, since the lamp of the lamp unit 304 of the light source for fluorescence observation 300 is already lit at the start of fluorescence observation and the amount of light is stable, fluorescence observation can be immediately performed. On the other hand, when the observation inside the body cavity by the endoscope is interrupted, the lamp is automatically turned off. Therefore, unnecessary lighting of the fluorescent observation lamp is prevented, and the life of the fluorescent observation lamp can be extended.
【The invention's effect】
As described above, according to the diagnostic system of the present invention, unnecessary consumption of the fluorescence observation light source can be prevented without requiring a complicated operation.
[Brief description of the drawings]
FIG. 1 is a schematic view schematically showing a diagnostic system according to an embodiment of the present invention.
FIG. 2 is a flowchart of a lamp control routine of the endoscope processor according to the embodiment of the present invention.
[Explanation of symbols]
1 Diagnostic System 100 Electronic Endoscope 104 CCD
200 Endoscope Processor 201 System Control 204 Lamp Unit 204a Lamp 204b Iris 204S Position Sensor 207 Image Memory 208 Buffer Memory 209 Image Comparison Circuit 300 Light Source 304 for Fluorescence Observation Lamp Unit 304a Shutter

Claims (3)

An electronic endoscope equipped with an image sensor;
A light source for normal observation capable of irradiating light for normal observation into a body cavity observed by the electronic endoscope;
A fluorescence observation light source capable of irradiating excitation light into a body cavity observed by the endoscope;
Image monitoring means for monitoring a captured image captured by the image sensor and confirming whether a change has occurred in the captured image;
Control means for controlling the light source for fluorescence observation and the image monitoring means;
Have
The control means includes
If the change in the captured image occurs continuously for a first time when the light source for fluorescence observation is turned off, the light source for fluorescence observation is turned on,
A diagnostic system using autofluorescence, wherein the fluorescence observation light source is turned off when a state in which the captured image has not changed during the lighting of the fluorescence observation light source continues for a second time or longer.   The image monitoring means confirms whether or not a change has occurred in the captured image by comparing the latest captured image with a captured image captured one frame before the latest captured image. A diagnostic system using autofluorescence according to claim 1.   The said diagnostic system has the light source lighting means for fluorescence observation for the operator of a diagnostic system to light the said light source for fluorescence observation regardless of the state of the said light quantity change means, The claim 1 or Claim 2 characterized by the above-mentioned. A diagnostic system using autofluorescence as described in 1.

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