Abstract: A navigation, tracking and guiding system for the positioning of operatory instruments inside the body of a patient. The system includes a control unit, a viewer and detecting means for determining the spatial position of the viewer. The system further includes a sensor associated to an operatory instrument and insertable inside the internal portion of the body of the patient. The control unit is configured to project on the viewer an image of the state of the internal portion.

Abstract: The invention concerns a method for measuring the Brillouin shift distribution in optical fiber, comprising the launch of an optical pump signal from one end of the measurement fiber and an optical probe signal from the other end of the fiber, including: measuring frequency and phase components over a predeterminable number of frequency shifts between the optical carrier of the probe signal and the optical carrier of the pump signal and obtaining the corresponding transfer functions; and claborating the transfer functions in order to reconstruct the Brillouin shift distribution along the measurement fiber.

Abstract: The invention concerns a method for measuring the Brillouin shift distribution in optical fiber, comprising the launch of an optical pump signal from one end of the measurement fiber and an optical probe signal from the other end of the fiber, characterised in that it comprises the following steps: A. launching a pump signal with an intensity that is sum of a continuous component and a sinusoidal component at frequency f1, IPompa(z=0,t)=IPu0 (I+m1 cos(2?f1t+?)), and an optical probe signal with an intensity which is sum of a continuous component and a sinusoidal component at frequency f2, IProbe(z=L,t)=IPr0(1+m2 cos(2?f2t+?2)), said two frequencies f1 and f2 differing of a predefinable quantity fm such that: f1?f2=fm and fm<<f1, f2 L representing the total length of the measurement fiber, whilst ?1 and ?2 are two initial arbitrary phases, holding moreover the following relationship: m1, m2<<1; B.