Fibre=optic pressure sensor for lithotripsy - has bend in fibre=optic waveguide with material removed to form surface exposed to fluid for measurement of refractive index

摘要

The optical pressure sensor measures the pressure of a liquid bordering at a light outlet surface (5) of a fibre-optic wave guide (1), based on the reflectivity of light at the light outlet surface, dependent on the density of the liquid. The wave guide has a bend (2), and monochromatic light from a light source (7) is deflected over a wave guide section (3) to the light outlet surface (5). The light reflected at the light outlet surface arrives over another wave guide section (4) leading away from the bend (2) to the light receiver (8). The light outlet surface is formed, so that around outside of the bend, the wave guide material is removed fro a distance (a), which essentially does not reach over the middle of the wave guide diameter. USE/ADVANTAGE - For measuring acoustic pressure of shock waves in lithotripsy. High optical efficiency and wide bandwidth.