Method and system for characterizing a pigmented biological tissue

Method for determining the content of a non-fluorescent chromophorous compound (34), called the first compound, in a tissue (30) of a biological entity, said biological tissue (30) comprising moreover a fluorescent chromophorous compound (33), called the second compound, said method comprising at least one iteration of the following operations:

• emission by emission means (11, 12), in the direction of said tissue (30), of a first so-called measurement optical radiation (111), and a second so-called reference optical radiation (121), each chosen so as to induce a fluorescence radiation of said second compound (33), each of said first and second radiations (111, 121) being partially absorbed by said first compound (34),
• measurement, by measurement means (21, 22), of said fluorescence radiations (112, 122) induced by said first and second radiations (111, 121), and
• determination, from said first measurement, of the content of said first compound (34) in said tissue (30).
• characterized in that said method comprises moreover at least one compensation of a measurement saturation due to too high an absorption of said measurement radiation (111) by said first compound (34), said compensation comprising a choice, for said measurement radiation, of a wavelength corresponding to a lower absorption in the absorption spectrum of the first compound (34).