A Center Drive Frequency Differential EIT Method for Monitoring of Tumor Ablation.

Monitoring and evaluating tumor ablation is a critical step in the treatment process. However, the traditional medical imaging methods used in surgeries often have some drawbacks, such as poor real-time performance (CT/MRI), low imaging accuracy (ultrasound), and the presence of radiation risks (X-ray imaging). This paper proposes a Central Drive Frequency Difference Electrical Impedance Tomography (CD-FDEIT) approach. This method utilizes intra-body ablation electrodes along with body surface electrodes to record impedance data. By applying a sweeping excitation, it aims to measure the impedance changes in the tumor ablation area during the operation, convert them into visual real-time images, and thereby monitor the progress of the tumor ablation surgery and assist doctors in conducting the surgery and making clinical decisions. Simulation results indicate that this method effectively captures real-time alterations in ablated tissues. The measuring system primarily consists of current-delivering intra-body electrodes embedded in the surgical instrument, alongside non-invasive body surface sensor electrodes. Physical model tests reveal that the optimal measuring frequencies for the real and imaginary components are 10kHz and 1MHz, respectively. The relative error (RE), correlation coefficient (CC), and structural similarity index (SSIM) achieved by the CD-FDEIT method were 0.392, 0.889, and 0.788, respectively, compared with the traditional EIT method, they have been improved by 5.1%, 4.4%, and 12.2% respectively, suggesting improved accuracy in tracking the ablation status of tumors and offering practical reference for clinical monitoring.