Non-invasive evaluation of microcirculation and metabolic regulation using flow mediated skin fluorescence (FMSF): Technical aspects and methodology

Abstract

This paper describes a new technique for noninvasive diagnostic analysis of metabolic regulation and the microcirculation. Flow Mediated Skin Fluorescence (FMSF) is based on monitoring the intensity of NADH fluorescence emitted from skin tissue on the forearm. The principles of the technique are discussed, in particular, concerning experimental procedures and the definition and interpretation of the measured parameters. The unique features and potential avenues for development of the FMSF technique are also outlined.

Can the microcirculatory response to hypoxia be a prognostic factor for Covid-19?

“…Our recent efforts have resulted in the development of a new diagnostic technique known as Flow Mediated Skin Fluorescence (FMSF) (Katarzynska et al, 2019a). FMSF measures changes in NADH fluorescence intensity as a response to blocking and releasing blood flow in the forearm, as a function of time.…”

The Effect of a 7-Week Training Period on Changes in Skin NADH Fluorescence in Highly Trained Athletes

“…FMSF enables recording of the changes in NADH fluorescence as a function of time in response to ischemia and reperfusion in forearm skin cells. During the measurement, AngioExpert emits light at the wavelength of 460 nm [6,7]. NADH molecules have autofluorescence capability at a wavelength of 460 nm [9].…”

“…NADH molecules have autofluorescence capability at a wavelength of 460 nm [9]. The changes in fluorescence intensity observed during the examination are produced in the most superficial skin cells (epidermis) [6,29], which is due to very shallow skin penetration by excitation light at the wavelength of 340 nm. About 90% of the recorded signal comes from the skin depth up to 0.5 mm.…”

“…About 90% of the recorded signal comes from the skin depth up to 0.5 mm. The activated skin region is not directly supplied with blood, but is supplied with oxygen by deeper blood vessels [6,7,29].…”

“…The FMSF method is based on the ability of NADH to autofluorescence. The fluorescence measured using the FMSF method reflects the dynamics of in vivo changes in NADH levels in most superficial layers of the skin [5][6][7]. Bugaj et al [5] have shown that exercise to exhaustion induces changes in skin NADH fluorescence, in other words, the values recorded after exercise were higher than those before exercise (increase in: basal NADH fluorescence 13%, maximal NADH fluorescence 7% and minimal NADH fluorescence 12%).…”