RFID Technology for Intraoperative Localisation of Small Colorectal Tumours: Electromagnetic Analysis and...

Area of Science:

• Biomedical Engineering
• Electromagnetics
• Surgical Oncology

Background:

• Conventional tumour marking in minimally invasive colorectal surgery faces challenges like marker migration and diffusion.
• Radio frequency identification (RFID) presents a radiation-free alternative using implantable passive transponders.
• Existing methods lack precision and carry risks of allergic reactions or tissue damage.

Purpose of the Study:

• To evaluate the feasibility of three RFID frequency bands (LF, HF, UHF) for intraoperative tumour localisation.
• To assess detection ranges and tissue attenuation for potential clinical translation.
• To identify the optimal RFID frequency band for developing a new surgical marking system.

Main Methods:

• Preclinical feasibility study using electromagnetic simulations and experimental validation.
• Evaluation of 134 kHz (LF), 13.56 MHz (HF), and 868 MHz (UHF) RFID bands.
• Measurement of transponder detection ranges in air and saline, considering angular variations.

Main Results:

• UHF offered the longest detection range in air (68.0 mm), but experienced significant tissue attenuation (74%).
• HF demonstrated a balance of detection range (20.7 mm in saline) and lower tissue attenuation (10%).
• LF and HF showed reduced range (64-70%) at orthogonal orientations, while UHF was more sensitive to orientation.

Conclusions:

• The 13.56 MHz HF band is the most suitable for clinical translation due to adequate penetration and miniaturisation potential.
• Further development is needed to address angular sensitivity using multi-axis antenna configurations.
• This study provides an electromagnetic basis for developing RFID-based surgical tumour marking systems.