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Photodynamic diagnosis (PDD) is a method to diagnose the possibility of cancer,
both by the principle that if a photosensitizer is injected into an organic tissue, it
is accumulated in the tissue of a malignant tumor selectively after a specific
period, and by a comparison of the intensity of the fluorescence of normal tissue
with abnormal tissue after investigating the excitation light of a tissue with
accumulated photosensitizer.
Currently, there are two methods of PDD: The first is a way to acquire incitement
fluorescence by using a photosensitizer, and the second is a way to use auto-fluorescence
by green fluorescence protein (GFP) and red fluorescence protein
(RFP) such as NADH+ active factors within the organic body. Since the selection
of the wavelength band of excitation light has an interrelation with fluorescence
generation according to the selection of a photosensitizer, it plays an important
role in PDD. This study aims at designing and evaluating light source devices that
can stably generate light with various kinds of wavelengths in order to make
possible PDD using a photosensitizer and diagnosis using auto-fluorescence. The
light source was a Xenon lamp and filter wheel, composed of an optical output
control through Iris and filters with several wavelength bands. It also makes the
inducement of auto-fluorescence possible because it is designed to generate a
wavelength band of 380-420nm, 430-480nm, 480-560nm. The transmission part
of the light source was developed to enhance the efficiency of light transmission.
To evaluate this light source, the characteristics of light output and wavelength
band were verified. To validate the capability of this device as PDD, the detection
of auto-fluorescence using mouse models was performed.
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