Design and development of magnetic flexible endoscope for upper gastrointestinal examination

Magnetic continuum robot (CR) represents a subtype of CRs, which could realize non-contact manipulation through external magnetic field. Their appearance alongside advancements in robotic technology has significantly improved procedures such as flexible endoscopy examinations, microscopic surgeries, and active catheter operations, providing new ideas and approaches for endoscope examination. By using magnetic field, observation and navigation at different positions are achieved by controlling the bending of the flexible endoscope tip through magnetic torque. In this study a design and fabrication approach for miniaturized magnetic flexible endoscope (diameter of 4 mm) was proposed hoping to achieve the functionality of upper gastrointestinal endoscopy. Experimental validation on a 3D electromagnetic platform underscores the flexibility and steerability of the magnetic flexible endoscope, with a mean-square error of 16.52° for maximum bending angle. Additionally, integrating simulation results based on minimum potential energy principle of magnetic potential energy and elastic potential energy has demonstrated precise deformation forecasting, compared with experimental results. The results also indicated that the maximum deflection angle of the magnetic flexible endoscope can reach 164.97°. Magnetic fields in different directions are obtained by varying the current of the power sources. The magnetic flexible endoscope can achieve trajectory motion within a 2D plane along predefined paths. The functionality of the magnetic flexible endoscope has been demonstrated by in vitro model and ex vivo porcine stomach experiments, which showed that magnetic flexible endoscope can bend and deform within the model to observe different positions and even realize the retroflexion capabilities of existing endoscopes. These findings provide a foundation for further development of miniaturized magnetic flexible endoscopic manipulation devices, aiming to improve treatment efficacy and optimize patient treatment experiences.