Abstract: A probe adapted for insertion in living tissue for measuring oxygen partial pressure and temperature at a plurality of sites in living tissue is provided. A temperature sensitive resistor is positioned adjacent each of a plurality of oxygen sensors so that the oxygen partial pressure measured can be adjusted for tissue temperature. The probe substrate has thermal properties similar to living tissue and the resistors are formed of a material having a temperature sensitive resistance. Temperature at each temperature sensitive resistor is obtained by measuring resistance with a four point measurement and correlating the resistance to temperature.

Abstract: Thermal conductivity, thermal diffusivity and/or fluid perfusion within a medium such as cutaneous tissue is non-invasively measured by at least two heating and temperature sensor. One sensor is positioned in thermal communication with the medium and a second sensor is positioned thermal communication with the first sensor. Both sensor are heated (or cooled) so as to substantially prevent net heat flow between them. In this manner, net heat flow between the first sensor and the medium can be measured, which measurements allow determination of the thermal conductivity, thermal diffusivity and/or fluid perfusion within the medium.

Abstract: A method for determining the properties of a medium by activating temperature changing means to change the temperature of the medium from a first unperturbed temperature to a second different temperature during a first time period and permitting the temperature to relax to a final unperturbed temperature during a second time period. In a particular embodiment, for example, the intrinsic thermal conductivity and diffusivity of the medium are calculated during a selected portion of the first time period assuming an arbitrary value for the perfusion, and the perfusion of the medium is calculated during a selected portion of the second time period using the calculated intrinsic thermal conductivity and diffusivity. The calculated perfusion is then used to recalculate the intrinsic thermal conductivity and diffusivity during the selected portion of the first time period and the perfusion is then recalculated using such recalculated intrinsic thermal conductivity and diffusivity.