Blood Perfusion Measurements by the Analysis of the Heated Thermocouple Probe’s Temperature Transients

The Gibbs’ heated thermocouple technique for measuring a tissue’s thermal conductivity to infer the blood perfusion rate has been synthesized with a model of transient heal transport in perfused tissue. This procedure eliminates the necessity of probe calibration in surrogate tissue. The analytical predictions of the transient temperature behavior of a newly designed spherical probe were compared with experimental temperature transients to deduce thermal conductivities of and perfusion rates in gelatin and dog kidney. The principle heating modality was step heating. Consistent conductivity values for both the gelatin and the kidney were found. The calculated perfusion rates in the kidney were consistent but were higly dependent upon probe size and geometry, and the independently measured tissue’s thermal conductivity.