[Evaluation of in vitro human blood transparentized using near-infrared light]

We developed a new technique for the in vitro imaging of transparent human blood and examined the resolution of a test chart in transparent blood. We utilized mainly three devices: a laser diode (wavelength 833 nm) that served as the light source, a near-infrared camera, and a fiberscope adapted for the camera. Blood was collected from a human femoral artery. We observed the images of transparent blood and the fiberscope image of a target in the blood using the light. These results indicate that further improvements in this system can be expected and real-time viewing by angioscope may be realized in vivo.