Phototherapy device, phototherapy method, and computer-readable recording medium

A phototherapy device comprising:

• a treatment light emitter configured to emit treatment light for causing a reaction of a drug;
• a narrow band light emitter configured to emit narrow band light having part of wavelength band of a visible light range;
• an imager configured to obtain a narrow band light image which is formed using the narrow band light applied onto an application position of the treatment light;
• a narrow-band-light image variation calculator configured to:
• compare a first narrow band light image obtained before an application of the treatment light with a second narrow band light image obtained after the application of the treatment light;
• extract a structure of mucous surface from each of the first narrow band light image and second narrow band light image;
• calculate, as a variation over time, a difference in intelligibility of the extracted structure of mucous surface;
• a display image generator configured to generate a display image including information based on the calculated variation over time, wherein the narrow band light comprises a wavelength band equal to or greater than 390 nm and equal to or smaller than 445 nm and a wavelength band equal to or greater than 530 nm and equal to or smaller than 550 nm.

A phototherapy device comprising:

• a treatment light emitter configured to emit treatment light for causing a reaction of a drug;
• a narrow band light emitter configured to emit narrow band light having part of wavelength band of a visible light range;
• an imager configured to obtain a narrow band light image which is formed using the narrow band light applied onto an application position of the treatment light;
• a narrow-band-light image variation calculator configured to:
• compare a first narrow band light image obtained before an application of the treatment light with a second narrow band light image obtained after the application of the treatment light;
• extract a structure of mucous surface from each of the first narrow band light image and second narrow band light image;
• and
• calculate as a variation over time, a difference in homogeneity of the extracted structure of mucous surface;
• a display image generator configured to generate a display image including information based on the calculated variation over time, wherein the narrow band light has a wavelength band equal to or greater than 390 nm and equal to or smaller than 445 nm and a wavelength band equal to or greater than 530 nm and equal to or smaller than 550 nm.