Autonomous navigation of a magnetic colonoscope using force sensing and a heuristic search algorithm

Area of Science:

• Robotics
• Medical Devices
• Control Systems

Background:

• Colonoscopy is a crucial diagnostic procedure, but traditional methods can be invasive and operator-dependent.
• Developing autonomous navigation systems can enhance safety, efficiency, and accessibility of colonoscopy.
• Magnetic-assisted colonoscopy offers a promising approach for minimally invasive procedures.

Purpose of the Study:

• To develop and evaluate a cost-effective autonomous navigation system for magnetic-assisted colonoscopy.
• To integrate force-based sensing for real-time safety monitoring and tracking.
• To implement and assess a heuristic path planning algorithm for efficient colonoscope navigation.

Main Methods:

• A magnetic-assisted colonoscopy system incorporating force-based sensors (load cells) and an actuator was developed.
• A proportional-integrator controller and a learning real-time A* (LRTA*) algorithm with a directional heuristic evaluation were employed for navigation.
• Experiments were conducted on a magnetic field navigator (MFN) platform using a realistic colonoscopy training model.

Main Results:

• The force sensing system provided accurate tracking with mean errors of 1.14 ± 0.59 mm (x-axis) and 1.61 ± 0.45 mm (y-axis) within a 15 cm detectable radius.
• The LRTA* algorithm demonstrated superior performance in path planning, completing navigation in an unknown synthetic colon map in 75 steps.
• Autonomous navigation in the colonoscopy training model averaged 15 min 38 s with an 83.33% intubation rate, all without operator intervention.

Conclusions:

• The integrated system of force-based sensing and LRTA* path planning enables effective autonomous navigation for magnetic-assisted colonoscopy.
• This approach enhances safety through real-time monitoring and improves efficiency with intelligent pathfinding.
• The developed system shows significant potential for cost-effective and automated colonoscopy procedures.