Observation of capillary flow in human skin during tissue compression using CCD video-microscopy

Recent technological advances of the CCD video-camera have made microscopes more compact and greatly improved their sensitivity. We newly designed a compact capillaroscopy which was composed with a CCD video-probe equipped a contact-type objective lens and illuminator. In the present study, we evaluated usefulness of the instrument for a bed-side human capillaroscopy to observe the capillary flow in various dermal regions. The influences of tissue compression on the dermal capillary blood flow were also investigated to confirm the utility for clinical applications. Our capillaroscopy visualized the nutritional capillary blood flow in almost all parts of skin surface. Our observations showed that a level of vertical stress similar to arterial pressure was required to stop the capillary flow. From these demonstrations the present CCD video-probe based capillaroscopy would be useful for clinical applications as a bed-side human capillaroscopy.