What is microplethysmography?

Microplethysmography is a non-invasive technique that measures small volume changes in a tissue bed. These changes are caused by the cyclic variation in blood volume that occurs with each heartbeat. The basic principle is that when the tissue expands, the skin surface moves up and the light intensity collected from the spot increases, and when the tissue contracts, the skin surface moves down and the light intensity decreases. The photodiode detects these changes and they are recorded on a PC.

Microplethysmography is used to assess microcirculation, which is the flow of blood in the smallest blood vessels of the body. Microcirculation is important for tissue health because it delivers oxygen and nutrients to cells and removes waste products. Microplethysmography can be used to detect microcirculatory disorders, such as those that occur in diabetes, and to monitor the effectiveness of treatments for these disorders.