Electronic endoscope system

1. An electronic endoscope system for evaluating a lesion of a living tissue in an organ of a living body, comprising:

an electronic endoscope configured to image the living tissue in the organ configured to be inserted into the organ at different depths and having

a light carrying bundle extending through at least a portion of the electronic endoscope in a longitudinal direction thereof and configured to carry light from a light source beyond a first end of the light carrying bundle to a second end of the light carrying bundle,

a light distribution lens positioned at a first end of the electronic endoscope and in front of the first end of the light carrying bundle and configured to distribute light from the first end of the light carrying bundle to illuminate the living tissue in the organ when the electronic endoscope is inserted into the living body,

an objective lens also positioned at the first end of the electronic endoscope and spaced from the light distribution lens and configured to receive light from the living tissue illuminated by the light from the distribution lens, and

a charge coupled device positioned behind the objective lens to receive light from the living tissue of the organ at different depths of the organ through the objective lens and configured to generate a plurality of captured images at different depths of the organ;

a processor configured to process the plurality of captured images of the living tissue at different depths of the organ received from the charge coupled device to evaluate a severity of the lesion in the organ; and

a monitor configured to display an evaluation result of the lesion on a screen,

wherein the processor is configured to evaluate the severity of the lesion in the organ by

calculating an image evaluation value, reflecting a progression of the lesion in the living tissue, for each of the plurality of captured images of the living tissue, the severity of the lesion being determined from the image evaluation values and a length of the lesion,

acquiring position information at imaging positions at the different depths in the organ in which each of light images are captured by the objective lens, in association with each of the captured images generated by the charge coupled device,

determining the presence or absence of the lesion in each of the captured images generated by the charge coupled device in a depth direction inside the organ, the processor determining the presence of the lesion in captured images generated by the charge coupled device when the image evaluation value of the captured images generated by the charge coupled device exceeds a predetermined threshold,

obtaining a start position and an end position of the lesion, which is continuously spreading in the depth direction inside the organ, to determine a length of the lesion in the depth direction by determining the presence or absence of the lesion in each of the captured images generated by the charge coupled device in the depth direction inside the organ,

setting the length of the lesion from the obtained start position and the end position of the legion, and

evaluating the severity of lesion in the organ using the set length of the legion and a representative value of the image evaluation values of the plurality of captured images generated by the charge coupled device of the lesion.

2. The electronic endoscope system according to claim 1 , wherein the processor is configured to use, when the lesions exist at a plurality of locations, one having a maximum length in the depth direction in which the lesion is continuously spread as the lesion to be evaluated.

3. The electronic endoscope system according to claim 1 , wherein the representative value is a maximum value among the image evaluation values of a captured lesion image generated by the charge coupled device.

4. The electronic endoscope system according to claim 1 , wherein

a memory is configured to store a sample-lesion correspondence between

a known evaluation level of the degree of severity of a previously-obtained sample lesion for each of previously-obtained lesion samples whose previously-obtained captured images generated by the charge coupled device are obtained from a plurality of previously-obtained captured images generated by the charge coupled device of an inside of the organ, and

a combination of the lesion-sample length of the previously-obtained sample lesion and a lesion-sample representative value of image evaluation values of the previously-obtained sample lesion,

the processor is configured to

obtain from the memory the sample-lesion correspondence and

evaluate the degree of severity of a lesion to be evaluated at the evaluation level using the lesion-sample correspondence, the length of the lesion to be evaluated obtained by imaging an inside of the organ, and the representative value of the lesion to be evaluated.

5. The electronic endoscope system according to claim 4 , wherein

the processor is configured to

generate a predictive model for predicting the evaluation level of the lesion to be evaluated,

set a lesion-sample representative value of a previously-obtained lesion sample corresponding to the representative value, the lesion-sample length corresponding to the length the lesion, and the evaluation level as learning data for each of the previously-obtained lesion samples obtained using the image group including images of the plurality of previously-obtained lesion samples having the determined evaluation level of the severity of the lesion,

obtain the predictive model by machine-learning of a correspondence between the lesion-sample representative value, the lesion-sample length and the evaluation level, and

cause the predictive model to predict an evaluation level of the lesion to be evaluated from the representative value of the lesion to be evaluated and the length of the lesion portion.

6. The electronic endoscope system according to claim 4 , wherein the monitor is configured to display a two-dimensional scatter diagram on the screen, in which the representative value of the lesion to be evaluated and the length of the lesion to be evaluated are plotted together with the lesion-sample representative value and the lesion-sample length.

7. An electronic endoscope system for evaluating a lesion of a living tissue in an organ of a living body, comprising:

an electronic endoscope configured to image the living tissue in the organ configured to be inserted into the organ at different depths and having

a light carrying bundle extending through at least a portion of the electronic endoscope in a longitudinal direction thereof and configured to carry light from a light source beyond a first end of the light carrying bundle to a second end of the light carrying bundle,

a light distribution lens positioned at a first end of the electronic endoscope and in front of the first end of the light carrying bundle, and configured to distribute light from the first end of the light carrying bundle to illuminate the living tissue in the organ when the electronic endoscope is inserted into the living body,

an objective lens also positioned at the first end of the electronic endoscope and spaced from the light distribution lens and configured to receive light from the living tissue illuminated by the light from the distribution lens, and

a charge coupled device positioned behind the objective lens to receive light from the living tissue of the organ at different depths of the organ through the objective lens and configured to generate a plurality of captured images at different depths of the organ;

a processor configured to evaluate a severity of the lesion of the living tissue in the organ by processing the plurality of captured images of the living tissue at different depths of the organ and received from the charge coupled device; and

a monitor configured to display an evaluation result of the lesion in a screen,

wherein the processor is configured to perform the evaluation by

calculating a pixel evaluation value, reflecting a progression of the lesion of the living tissue, for each pixel of the plurality of captured images of the living tissue,

calculating an image evaluation value, reflecting the progression of the lesion of the living tissue, for each of the plurality of captured images of the living tissue from the pixel evaluation values for one of the captured images, the severity of the lesion being determined based on the image evaluation values, and an area over which the lesion extends,

acquiring position information at imaging positions in the organ in which each of light images is captured by the objective lens, in association with each of the captured images generated by the charge coupled device,

determining the presence or absence of the lesion in each of the captured images generated by the charge coupled device in a depth direction inside the organ, the processor determining the presence of the lesion in a captured images generated by the charge coupled device when the image evaluation value of the captured images generated by the charge coupled device exceeds a predetermined threshold,

obtaining a start position and an end position of the lesion, which is continuously spreading in the depth direction inside the organ, to determine a length of the lesion in the depth direction by determining the presence or absence of the lesion in each of the captured images generated by the charge coupled device in the depth direction inside the organ,

setting the area over which the legion extends by determining pixels having a pixel evaluation value equal to or greater than a threshold for determining the lesion in the plurality of captured images generated by the charge coupled device obtained by imaging the lesion between the start position and the end position, and

evaluating the severity of lesion in the organ using the set area and a representative value of the image evaluation values of the plurality of captured images of the lesion generated by the charge coupled device.

8. The electronic endoscope system according to claim 7 , wherein the processor is configured to obtain the area based on a number of pixels obtained by counting pixels whose pixel evaluation value is equal to or greater than the threshold for determining the lesion in the captured image generated by the charge coupled device.

9. The electronic endoscope system according to claim 7 , wherein processor is configured to obtain the area based on a product of

an average value in a captured image of the lesion of an occupancy ratio, in the captured image generated by the charge coupled device, of pixels whose pixel evaluation value is equal to or greater than the threshold for determining the lesion, and

a length of the lesion to be evaluated calculated from the start position and the end position.