The evaluation of penile microvascular endothelial function using laser speckle contrast imaging in healthy volunteers

(A) Picture of the experimental set up for penile microvascular flowmetry using laser speckle contrast imaging (LSCI) coupled with iontophoresis of a vasodilator drug (acetylcholine) using a drug-delivery electrode (2) and a non-stimulated penile skin area (1). (B) Video images of the microvascular blood flow changes induced by acetylcholine iontophoresis (yellow, high flow) compared to a non-stimulated skin area (blue, low flow). (C) Representative example of the effects of the penile transdermal iontophoretic delivery of cumulative doses of acetylcholine on microvascular blood flow (red line), compared to a non-stimulated skin area (blue line).