In clinical practice a method for assessment of tissue vitality is a sought-after tool. We have developed a new sensor principle, which is able to register changes in tissue concentration of O2 and tissue flow. The technique is based on diffusion of inert gases and mass spectrometer detection of gaseous metabolites. It was hypothesized that the new sensor could register changes in vital parameters after induction and release of an ischaemic insult to muscular tissue. The sensor performance was evaluated in ten anaesthetized pigs subjected to local muscular ischaemia. Preliminary data from this study indicate the validity of registered hypoxia and reduction in tissue flow as a consequence of compromised blood supply. It was concluded that although precise calibration of the technique is not yet established, it holds promise as a technique that can be used to monitor changes in tissue vitality.