Adaptive Dynamic Control for Magnetically Actuated Medical Robots

Abstract

In the present work we discuss a novel dynamic control approach for magnetically actuated robots, by proposing an adaptive control technique, robust towards parametric uncertainties and unknown bounded disturbances. The former generally arise due to partial knowledge of the robots' dynamic parameters, such as inertial factors, the latter are the outcome of unpredictable interaction with unstructured environments. In order to show the application of the proposed approach, we consider controlling the Magnetic Flexible Endoscope (MFE) which is composed of a soft-tethered Internal Permanent Magnet (IPM), actuated with a single External Permanent Magnet (EPM). We provide with experimental analysis to show the possibility of levitating the MFE-one of the most difficult tasks with this platform-in case of partial knowledge of the IPM's dynamics and no knowledge of the tether's behaviour. Experiments in an acrylic tube show a reduction of contact of the 32% compared to non-levitating techniques and 1.75 times faster task completion with respect to previously proposed levitating techniques. More realistic experiments, performed in a colon phantom, show that levitating the capsule achieves faster and smoother exploration and that the minimum time for completing the task is attained by the proposed approach.

Magnetic Actuation Methods in Bio/Soft Robotics

“…in 2012 [ 325 ] as a trade‐off between capsule and traditional colonoscopy combining the benefits of low‐invasive propulsion (through “front‐wheel” locomotion) with the multifunctional tether for treatment; was the capsule n.0 and the forerunner of a significant number of derived improvements, new implementations and allied magnetically guided endoscopic devices. Indeed, the system has been improved in the subsequent years, for instance, in terms of modelling, [ 326,327 ] tracking and localization, [ 328–330 ] and control, [ 331–333 ] toward autonomous locomotion strategies [ 334 ] and other applications. [ 335 ] In the recent years, a derived novel soft‐tethered magnetically guided colonoscope was designed within a European H2020 project, called “Endoscopic versatile robotic guidance, diagnosis and therapy of magnetic‐driven soft‐tethered endoluminal robots (Endoo project),” coordinated by Scuola Superiore Sant'Anna (Pisa, Italy).…”

Frontiers of Robotic Colonoscopy: A Comprehensive Review of Robotic Colonoscopes and Technologies

“…A proof-of-concept of the robotic colonoscope, presented by Valdastri et al in 2012, represents a trade-off between capsule and traditional colonoscopy combining the benefits of low-invasive propulsion (through “front-wheel” locomotion) with the multi-functional tether for treatment [ 109 ]. The system has been improved in the subsequent years in terms of modelling [ 110 , 111 ], localization [ 112 , 113 ] and control [ 114 , 115 , 116 ], towards autonomous locomotion [ 117 ] and other applications [ 118 ]. A novel derivative soft-tethered magnetically-driven colonoscope was designed within a European H2020 project, called “Endoscopic versatile robotic guidance, diagnosis and therapy of magnetic-driven soft-tethered endoluminal robots (Endoo project—2015–2019)”, coordinated by the Scuola Superiore Sant’Anna (Pisa, Italy) [ 119 ].…”

A Learnt Approach for the Design of Magnetically Actuated Shape Forming Soft Tentacle Robots

“…This limitation does not apply to magnetic actuation and, consequentially, the magnetic approach exhibits far greater potential for miniaturisation and therefore surgical application than rival methods. Magnetically actuated tip driven systems [9] [10] have been demonstrated to increase control and reduce trauma [11], [12] during the negotiation of anatomical convolutions. Recently a number of works [13], [14], [8] have demonstrated the efficacy and miniaturisation potential of such catheters.…”