Microwave sensors in medical environments play a significant role due to the contact-less\nand non-invasive sensing mechanism to determine dielectric properties of tissue. In this work,\na theranostic sensor based on Split Ring Resonators (SRRs) is presented that provides two operation\nmodes to detect and treat tumor cells, exemplary in the liver. For the detection mode, resonance\nfrequency changes due to abnormalities are evaluated, and in the treatment mode, microwave\nablation is performed. The planar sensor structure can be integrated into a needle like a surgery\ntool that evokes challenges concerning size limitations and biocompatibility. To meet the size\nrequirements and provide a reasonable operating frequency, properties of oval shaped SRRs are\ninvestigated. By elongating the radius of the SRR in one direction, the resonance frequency can\nbe decreased significantly compared to circular SRR by a factor of two below 12 GHz. In order\nto validate the detection and treatment characteristics of the sensor, full wave simulations and\nmeasurements are examined. Clear resonance shifts are detected for loading the sensor structures\nwith phantoms mimicking healthy and malignant tissue. For treatment mode evaluation, ex vivo beef\nliver tissue was ablated leading to a lesion zone 1.2 cm Ã?â?? 1 cmÃ?â?? 0.3 cm with a three minute exposure\nof maximum 2.1 W.
Loading....