Abstract: The invention relates to a method and a sensor for measurement of tissue perfusion. The sensor is provided with a reservoir (4) for a fluid or gaseous tracer and a tracer-permeable barrier (3), a sub-surface of which is in contact with the surrounding tissue and another sub-surface of which is in contact with a detection cavity (5) which is connected to a suitable apparatus for the measurement of tracer concentration in the detection cavity. The concentration of the tracer in the detection cavity is a measure of perfusion in the surrounding tissue. According to another embodiment of the invention it is also possible to carry out measurements of perfusion in the surface layers of the skin or of an organ.

Abstract: The invention relates to a method and a microsensor for measurement of transport coefficients like diffusivity or flow velocity. The microsensor has a reservoir provided with a mouth and a transducer. The transducer has a tip placed in the mouth, which can be provided with a membrane or insert. The reservoir contains one or more gases or one or more liquid-dissolved substances intended for the diffusion through the mouth into an area or field of a medium outside the mouth of the reservoir. The transducer measures the partial pressure of the gas or the concentration of the liquid-dissolved substance in the mouth, whereby transport coefficients of diffusivity or flow velocity are determined. Preferably, the gradient of the partial pressure or the concentration is determined.