Fluorescence colposcope
The dual modal fluorescence colposcope was developed by integrating a NIR fluorescent imaging system into a conventional clinical colposcope (3ML LED, Leisegang, Berlin, Germany) in our previous research8. The wavelength of the excitation light source was consistent with the absorption peak of TMTP1-PEG4-ICG, which was 785nm. The color reflectance imaging and NIR fluorescence imaging of the cervix can be obtained simultaneously with the dual modal fluorescence colposcope by a visible-NIR camera. The magnification of 7.5×/15×/30× was provided, with the corresponding field of view was 35.0mm/16.4mm/8.6mm and the corresponding minimum discernible size was 70.1um/35.0um/24.8um. The working distance was 300mm, which ensured non-invasive operation. Besides, a software integrated with graphical user interface (GUI) was developed to facilitate the acquisition of the cervical images. The fluorescence image was overlapped on the color reflectance image for the convenience of spatial localization of the fluorescence signal. The color reflectance images, fluorescence images and the merge images were displayed simultaneously. The fluorescence colposcope possessed the advantages of real-time imaging, high resolution, high SBR and user-friendly control.