Localization of Gastrointestinal Marking Clip Using RFID. A Study in Canine Esophagus.

Abstract

Objective: To investigate the feasibility and accuracy of a newly-developed surgical marking system using gastrointestinal clip with radio-frequency identification (RFID) tag. Method: RFID is a technology for near field communication. The band, 13.56 MHz, is one of the open-bands for medical use and is suitable for the marking system in biological tissues because of its linear signal decay properties. The proposed system consists of four parts: (1) 13.56 MHz RFID reader and writer, (2) Gastrointestinal clip with RFID-tag, (3) Sensor antenna, (4) and Signal processing units with indicator. In the experiments using canine model, two or three clips were endoscopically applied in the esophagus of six dogs. During the subsequent operation, the clips were localized by the detection of RFID signal from the tag, and the detected sites were marked on adventitia by ablation. Longitudinal distance between the clips and the (metal) pin-needle which were pierced from ablated adventitia were measured with X-ray radiographs of the resected specimen. Result:All clips (14/14) were successfully detected and the detection time was 15.0 ± SD11.6 seconds. Longitudinal distance was 3.0 ± SD2.3 mm. Conclusions: Gastrointestinal clips with RFID-tag were localized by our system with substantial accuracy in the experimental setting using canine esophagus.