A medical system intended for penetrating an anatomical structure (2, 3) of a patient, the anatomical structure (2, 3) having tissues presenting different capacities for conducting electric current, said medical system comprising: - a body suitable for penetrating the anatomical structure (2,3), the body having an outer surface, - at least one first electrode having a first contact surface arranged on the outer surface of the body so as to come into contact with the tissues of the anatomical structure (2, 3), - at least one second electrode having a second contact surface arranged on the outer surface of the body so as to come into contact with the tissues of the anatomical structure (2, 3) at a distance from the first contact surface, - an electric generator suitable for applying an electric current between the first and second contact surfaces, - a processing device suitable for determining an electrical characteristic representative of the capacity of the tissue of the anatomical structure (2, 3) between the first and second contact surfaces to conduct the electric current, and for emitting a warning signal corresponding to the determined electrical characteristic, the warning signal having at least one parameter that varies as a function of the determined electrical characteristic, wherein the warning signal is intermittent and has a warning cadence according to which user-perceptible warning sections (Sa) are emitted successively with a time interval (Si) between two successive warning sections (Sa), wherein the processing device is adapted to detect a variation of the electrical characteristic and to vary said at least one variable parameter of the warning signal after a time delay following the variation of the electrical characteristic has elapsed, the medical system being characterized in that the time delay is equal to a portion of a warning period corresponding to the warning cadence and comprising one warning section (Sa) and one time interval (Si), and in that at least one variable parameter of the warning signal comprises the warning cadence, the processing device being adapted to modify the warning cadence after the time delay has elapsed, the warning section (Sa) of each warning period having a same duration and the time interval of each warning period varying as a function of the warning cadence. - a body suitable for penetrating the anatomical structure (2,3), the body having an outer surface, - at least one first electrode having a first contact surface arranged on the outer surface of the body so as to come into contact with the tissues of the anatomical structure (2, 3), - at least one second electrode having a second contact surface arranged on the outer surface of the body so as to come into contact with the tissues of the anatomical structure (2, 3) at a distance from the first contact surface, - an electric generator suitable for applying an electric current between the first and second contact surfaces, - a processing device suitable for determining an electrical characteristic representative of the capacity of the tissue of the anatomical structure (2, 3) between the first and second contact surfaces to conduct the electric current, and for emitting a warning signal corresponding to the determined electrical characteristic, the warning signal having at least one parameter that varies as a function of the determined electrical characteristic, wherein the warning signal is intermittent and has a warning cadence according to which user-perceptible warning sections (Sa) are emitted successively with a time interval (Si) between two successive warning sections (Sa), wherein the processing device is adapted to detect a variation of the electrical characteristic and to vary said at least one variable parameter of the warning signal after a time delay following the variation of the electrical characteristic has elapsed, the medical system being characterized in that the time delay is equal to a portion of a warning period corresponding to the warning cadence and comprising one warning section (Sa) and one time interval (Si), and in that at least one variable parameter of the warning signal comprises the warning cadence, the processing device being adapted to modify the warning cadence after the time delay has elapsed, the warning section (Sa) of each warning period having a same duration and the time interval of each warning period varying as a function of the warning cadence.