Endoscope system, image processing device, image processing method, and computer-readable recording medium

An endoscope system, comprising:

• a light source configured to emit excitation light to a subject to which a fluorescent agent has been administered;
• an image sensor configured to continuously image the subject and sequentially generate image data of the subject;
• an integrated circuit or graphics processing unit (GPU) configured to sequentially generate fluorescent image data in accordance with light intensity of a fluorescent wavelength component emitted from the fluorescent agent, based on the image data generated by the image sensor each time the image sensor generates the image data;
• and
• a processor configured to perform operations including:
• sequentially calculating a change amount of the light intensity based on two sets of temporally successive fluorescent image data each time the fluorescent image data is generated;
• determining whether the sequentially calculated change amount is equal to or greater than a first threshold indicating fluorescence expression;
• determining whether the sequentially calculated change amount is less than a second threshold indicating a steady state of fluorescence after it is determined that the change amount is equal to or greater than the first threshold;
• calculating a level of the light intensity of a fluorescent image corresponding to the fluorescent image data;
• determining whether the calculated level of the light intensity is equal to or greater than a fourth threshold for distinguishing noise;
• changing the method for calculating the change amount if it is determined that the level of the light intensity is not equal to or greater than the fourth threshold;
• and
• outputting a message that fluorescence of the fluorescent agent is in the steady state if it is determined that the change amount is less than the second threshold after it is determined that the change amount is equal to or greater than the first threshold.

An image processing device configured to be connected to an endoscope having an image sensor configured to image a region of a subject to generate image data, a fluorescent agent having been administered to the subject, and the region having been irradiated with excitation light, the image processing device comprising:

• an integrated circuit or graphics processing unit (GPU) configured to sequentially generate fluorescent image data in accordance with light intensity of a fluorescent wavelength component emitted from the fluorescent agent, based on the image data generated by the image sensor each time the image sensor generates the image data;
• and
• a processor configured to perform operations including:
• sequentially calculating a change amount of the light intensity based on two sets of temporally successive fluorescent image data each time the fluorescent image data is generated;
• determining determine whether the sequentially calculated change amount is equal to or greater than a first threshold indicating fluorescence expression;
• determining whether the sequentially calculated change amount is less than a second threshold indicating a steady state of fluorescence;
• determining whether the sequentially calculated change amount is equal to or greater than a third threshold for distinguishing noise;
• changing a method for calculating the change amount if it is determined that the change amount is not equal to or greater than the third threshold;
• and
• outputting a message that fluorescence of the fluorescent agent is in the steady state if it is determined that the change amount is less than the second threshold after it is determined that the change amount is equal to or greater than the first threshold.

An image processing method executed by an image processing device configured to be connected to an endoscope having an image sensor configured to image a region of a subject to generate image data, a fluorescent agent having been administered to the subject, and the region having been irradiated with excitation light, the method comprising:

• sequentially generating fluorescent image data in accordance with light intensity of a fluorescent wavelength component emitted from the fluorescent agent, based on the image data generated by the image sensor each time the image sensor generates the image data;
• sequentially calculating a change amount of the light intensity based on two sets of temporally successive fluorescent image data each time the fluorescent image data is generated;
• determining whether the sequentially calculated change amount is equal to or greater than a first threshold indicating fluorescence expression;
• determining whether the sequentially calculated change amount is less than a second threshold indicating a steady state of fluorescence after the change amount is determined to be equal to or greater than the first threshold;
• determining whether the sequentially calculated change amount is equal to or greater than a third threshold for distinguishing noise;
• changing a method for calculating the change amount if it is determined that the change amount is not equal to or greater than the third threshold;
• and
• outputting a message that fluorescence of the fluorescent agent is in the steady state if the change amount is determined to be less than the second threshold after the change amount is determined to be equal to or greater than the first threshold.

A non-transitory computer-readable recording medium with an executable program stored thereon for an image processing device configured to be connected to an endoscope having an image sensor configured to image a region of a subject to generate image data, a fluorescent agent having been administered to the subject, and the region having been irradiated with excitation light, the program causing the image processing device to execute operations comprising:

• sequentially generating fluorescent image data in accordance with light intensity of a fluorescent wavelength component emitted from the fluorescent agent, based on the image data generated by the image sensor each time the image sensor generates the image data;
• sequentially calculating a change amount of the light intensity based on two sets of temporally successive fluorescent image data each time the fluorescent image data is generated;
• determining whether the sequentially calculated change amount is equal to or greater than a first threshold indicating fluorescence expression;
• determining whether the sequentially calculated change amount is less than a second threshold indicating a steady state of fluorescence after the change amount is determined to be equal to or greater than the first threshold;
• determining whether the sequentially calculated change amount is equal to or greater than a third threshold for distinguishing noise;
• changing a method for calculating the change amount if it is determined that the change amount is not equal to or greater than the third threshold;
• and
• outputting a message that fluorescence of the fluorescent agent is in the steady state if the change amount is determined to be less than the second threshold after the change amount is determined to be equal to or greater than the first threshold.