Maenhout Gertjan gertjan.maenhout@esat.kuleuven.be
The effect of dehydration on dielectric measurements of porcine liver as a function of time was investigated at different temperatures. Measurement data demonstrated that temperature not only has a direct effect on the measured dielectric properties but that it influences these properties in another manner as well, i.e. dehydration. During the experiment duration of 35 minutes, a significant relative change in the real as well as the imaginary part of the dielectric properties up to 9% has been established, which is significant with respect to multiple applications. Based on food process literature, the moisture content level of samples as a function of time can be predicted with respect to temperature and air velocity. In the case of high water content tissues like porcine liver in this work, the predicted trends by these equations are confirmed by the measurement data. From these equations, possible improvements are derived to stabilize the dielectric properties. These indicate that it is possible to extend the stability of the dielectric properties of the sample over time. In addition, this illustrates the relevance of clear documentation of sample storage between the time of excision and the measurement as well as the environmental conditions throughout the measurement.
The conducted experiments during this STSM were further continued in our group. The obtained results were presented during the MyWave meeting in Sibiu, Romania, and were published as a journal article in IEEE JERM. Following discussions regarding this work, the influence of contact pressure on dielectric measurements was investigated. These results were published in a special issue of Sensors (Measurements Techniques of Biological Tissues Dielectric Properties, Updated Data and Current Applications).
Maenhout, Gertjan, et al. “Effect of open-ended coaxial probe-to-tissue contact pressure on dielectric measurements.” Sensors 20.7 (2020): 2060.
