Design of a Surgical Pen-Type Probe for Real-Time Diagnosis of Vascular Flow Using Indocyanine Green (ICG) Fluorescence Dye

A surgical microscope is large in size, making portability impossible. The distance between the surgical microscope and the observation tissue is 15 to 30 cm, while the maximum adjustment range of the camera to the right and left is 30°. Therefore, surgical microscopes cause attenuation (above 58%) of the irradiation optical source owing to the long working distance. Moreover, the observation of tissue was dazzled with ambient light because the optical power source was strong (50 to 160 mW/cm2). Owing to the limited ability to adjust the camera to the right and left, a blind spot occurs with a surgical microscope. Therefore, it is difficult to clearly observe a tumor. In this study, a compact pen-type probe with a portable surgical microscope is proposed. The pen-type probe is small with a portable shape, and is capable of adjusting the working distance between itself and the observed tissue. It is also possible to adjust the viewing angle and fluorescence brightness. The proposed pen-type probe has no blind spots or optical density loss.