Characteristics of wireless manipulation based on permanent magnet coupling, including anchoring distance, panning torque, and translational force, are assessed in this paper. The study focuses on a typical scenario where a slave robot embedded with a small permanent magnet can be remotely controlled within a constrained area by a master large permanent magnet placed outside the environment at a certain distance from it. The key parameters (force and torque) acting on the slave robot are quantified and evaluated. In this article, several combinations of permanent magnets with various dimensions and configurations are studied using finite element methods. Based on the obtained results, we create a lookup table for each parameter, serving as a guideline to help interested researchers choose suitable magnetic combinations for their applications.

This paper presents a long-range magnetic actuated and guided endoscope for uniport video-assisted thoracic surgery (VATS). In VATS, the incision is quite narrow and part of the chest wall may be very thick. So, the magnetic endoscope system is required to produce sufficient attractive force at a considerable distance with a compact dimension. In this paper, a magnetic endoscope system is developed to meet the aforementioned clinical demands. In the system, both the internal and external units consist of two cylindrical magnets at both ends and a semi-cylindrical magnet in the middle. Coupled with the magnetic field from the external unit, the internal endoscope can achieve anchoring, tilting, panning, and translating to provide the desired view for the surgeon. The rotation of the endoscope is dynamically modeled by combining magnetic theory and coordinate transformation. The prototype is made with a boundary box of 10×14×56 mm, which can be inserted through the narrow incision in VATS. In the experiment, the developed models of anchoring, tilting, and panning were verified. The magnet configuration in the system can achieve a static anchoring distance of 95 mm and exhibits enhancement in attractive force compared with other designs.

This paper presents a novel magnetic anchored and steered camera robot intended for minimally invasive surgery (MIS), particularly for single port access (SPA) surgery. The design aims to achieve both compactness and a planar pan/tilt workspace (instead of hemispheric) to lower robot footprint in vertical space. Robot comprises two 6mm×6mm diametrically magnetized internal permanent magnets (IPMs) fixed at either ends of a small cylindrical capsule, with camera module and a 45°mirror capped inside capsule. As such, camera view orientation can be steered in 2-DOF across range of 180° tilt and 360° panning, all within a planar workspace close to surface of anchor. Using only two small IPMs for all necessary functions (anchoring, translation along intra-abdominal surface, and steering) reduces bulk and length of robot. The robot is investigated first by finite element methods. Theoretical models for both tilting and panning were then built based on FEM results. The models are evaluated and verified by checking its predictions in benchtop experiments. Ex vivo evaluations was also utilized to prove feasibility of device in environment similar to human anatomy. Overall, the camera robot prototype is compact (4cm length; 7mm diameter), lightweight (3.6g), motor-free, and allow view orientation control (tilting and panning) in a planar workspace. Minimal footprint in vertical space is ideal for many MIS applications, where vertical space is extremely limited.

Minimally invasive surgery (MIS) has seen substantial development in recent decades. In MIS, particularly in laparoendoscopic single site (LESS) surgery, the surgical site is always crowded. One potential solution is the magnetic anchored and guidance system (MAGS), which liberates instruments from constraint of the accessing port. Current MAGS are all made by rigid components, which relies on articulated joints to maneuver inside the surgical cavity. Moreover, fabricating and assembling the MAGS are difficult due to the small size of the components. In this work, we present the design, modeling, fabrication and testing of a novel soft MAGS endoscope system. The system includes the external controller and the internal unit, which contains a soft body, two magnets and a replaceable wireless camera. It is compact, safe, lightweight and easy to make. Experimental results show that the system could offer stable maneuvering both in lab settings and in porcine model.