HybNetic: A Mobile Hybrid Magnetic Actuation System

Abstract

Magnetic actuation enables contactless control of medical microrobots and instruments and offers the potential for improved safety and effectiveness in robot-assisted minimally invasive surgery. While much research is being conducted on the development of surgical devices, there is a lack of external actuation systems that provide the necessary magnetic field shaping capability for in vivo control. Existing magnetic actuation systems often face trade-offs between field shaping capability and workspace size. In this work, we introduce HybNetic, a mobile hybrid magnetic actuation system that combines a single electromagnet with four independently rotatable permanent magnets mounted on a robotic arm. The C-shaped configuration of HybNetic has an opening of 520 mm, allowing positioning around the human torso. The mobility of the employed robotic arm extends the effective workspace to the length of a human body. We describe the design and field modeling and characterize the magnetic performance by comparing analytical model predictions and finite element simulations with experimental validations. Finally, we demonstrate the versatility of HybNetic by levitating a magnetic sphere and navigating a magnetic guidewire through a dimensionally accurate phantom of the abdominal aorta. The demonstrations highlight the potential of HybNetic as a magnetic actuation system with a workspace that is suitable for in vivo manipulation of macro- and micro-scale magnetic devices.