Non invasive method to measure red blood cells transit time through the microcirculation of the brain

Abstract

Among the factors affecting oxygen supply to the tissues, red blood cells’ transit time through the microcirculation occupies an important place. Now, this transit time depends on two essential parameters: 1- the erythrocytes’ rheological properties; 2- the haemodynamic conditions existing locally in vivo. Therefore, lonely measurements of red blood cells’ deformability by in vitro methods do not allow a complete survey of microcirculatory status. We describe a new non invasive method providing quantitative characteristics of the distribution of red blood cells’ transit time through the cerebral microcirculation. This technique has been used in a clinical trial and has given objective criteria of Nafronyl’s (LIPHA Company - France) efficacy in elderly’s vascular dementia.