Internal stimulation source near-field small target electrical impedance tomography methodology (ISEIT) in pulmonary...

Dynamic imaging of the surgical region during lung interventional procedures can provide clinicians with valuable real-time guidance, assisting them in making informed clinical decisions. However, conventional medical imaging methods have limitations, such as poor real-time capability (CT, MRI), radiation exposure risk (X-ray), limited imaging resolution (ultrasound), and restricted fields of view (endoscopy), making them unsuitable for effective intraoperative monitoring.

Evaluate the proposed Internal Stimulation Source Near-Field Small Target electrical impedance tomography (EIT) Methodology to verify its effectiveness.

Unlike conventional EIT methods relying on external stimulation, this approach employs the interventional probe tip as an embedded electrode to safely deliver excitation current directly into tissues, creating a local electric field. The position of the probe tip is at the center of the lesion or close to it. The potentials of the remaining electrodes are alternately measured to reconstruct images of lesions adjacent to the probe tip, thereby establishing an intraoperative imaging model for interventional procedures. The feasibility of this method was evaluated through sensitivity distribution analysis and image reconstruction simulations. An in vitro physical model platform was developed, and a 16+1 electrode internal EIT system was designed for experimental validation.

The simulation results show that ISEIT can accurately determine the target position in both single-target and multi-target scenarios. When the size of the lung nodules is less than 15 mm, the imaging quality of the traditional EIT method deteriorates, with the appearance of artifacts and position errors. However, the ISEIT method is basically unaffected by the images and still has stable imaging results and accuracy even for small target sizes. In different lesion area sizes, the imaging quality indicators of the ISEIT method are all superior to those of the traditional EIT method. Its internal source excitation feature enables it to have better robustness and anti-interference ability, verifying its boundary potential distribution characteristics and frequency response characteristics, as well as its ability to distinguish changes in the real part and imaginary part.

The results demonstrated the effectiveness of the internal stimulation-based EIT method. Compared with conventional EIT, this approach achieves superior imaging performance and image quality, providing surgeons with real-time functional monitoring capabilities during surgical interventions, thereby enhancing intraoperative imaging accuracy and supporting the advancement of intelligent surgical systems.