Probe for measuring viscoelastic properties of a medium of interest

A probe for measuring the viscoelastic properties of a medium, for example a human or animal biological tissue, such as a liver, said measurement consisting of:

• generating at least one low-frequency elastic wave in the medium,
• simultaneously with the generation of the low-frequency wave:
• emitting high-frequency ultrasonic waves, and
• receiving acoustic echoes due to the reflections of the ultrasonic waves in the medium, the probe including:
• a housing,
• a transducer array, mechanically integral with the housing, for emitting high-frequency ultrasonic waves and receiving acoustic echoes,
• at least one inertial vibration exciter for emitting said and at least one low-frequency elastic wave, said and at least one exciter including:
• a fixed part mechanically integral with the transducer array,
• a mobile part capable of moving freely relative to the fixed part to produce vibrations in order to generate the low-frequency elastic wave,
• at least one return spring extending between the fixed part and the mobile part,
• wherein the mass of the mobile part is comprised between 5 and 25% of the total weight of the probe, wherein the stiffness coefficient of said and at least one return spring is comprised between 300 kg·s2 and 50 000 kg·s2 so that the resonance frequency of the inertial vibration exciter is substantially equal to the frequency of the low-frequency elastic wave, wherein the probe further comprises a controller for applying an electrical excitation signal allowing to drive the movement of the mobile part relative to the fixed part, and wherein the mobile part includes at least one permanent magnet, each inertial vibration exciter including an additional inertial mass distributed around the permanent magnet.