FIBEROPTISK TRYKTRANSDUCER TIL MAALING AF FYSIOLOGISKE TRYK

In a fibre optic pressure transducer for measuring physiological pressure with a measuring catheter containing a fibre optic light conductor 4 and closed off with a pressure-sensitive light-reflecting membrane 7 at that end of the catheter intended to be fitted at the measuring site, in direct connection with the light conductor 4, between this and the membrane 7, an essentially cylindrical optical lens element 6 is fitted, which has a focal point situated on the end face facing the light conductor 4 and the refractive index of which has a continuous variation in the radial direction such that the quantity of light transmitted through the light conductor 4 is essentially emitted in a parallel pencil towards the membrane 7. With substantially lower tolerance requirements for the positioning of the membrane 7 relative to the light conductor 4 than with known pressure transducers of this type, a linear relationship between the pressure which is required to be measured and the ratio between reflected and incident light can herein be achieved with good approximation.