This is a repository copy of Collaborative Magnetic Manipulation via Two Robotically Actuated Permanent Magnets.

Soft magnetic manipulators offer the prospect of improved surgical outcomes through their potential for miniaturization and inherently safe tissue interaction. However, independent actuation of multiple manipulators within the same confined workspace is limited by undesired simultaneous actuation and manipulator–manipulator interactions. Herein, for the first time, approaches for the independent magnetic actuation of two magnetic continuum manipulators within the same confined workspace are proposed. A novel modular magnetic soft robot segment design is proposed with modified geometry to provide preferential bending planes and high angles of deflection. This design is integrated into two dual‐segment magnetic manipulators which, when arranged in parallel, can deliver independent bending in two planes of motion. Two distinct independent control strategies are proposed, based on orthogonal manipulator magnetization profiles and local field gradient control, respectively. Each dual‐manipulator configuration is characterized over a sequence of applied magnetic fields and gradients, induced via a dual robotically controlled external permanent magnet system. Manipulator independence, bending range of motion, and twisting behaviors are evaluated as a function of control strategy and manipulator separation distance. To demonstrate the system's potential in clinical scenarios, a dual‐manipulator configuration is adapted to carry an endoscopic camera and optic fiber, respectively. The resultant bimanual system is deployed in the confined anatomy of a skull‐base phantom to simulate minimally invasive ablation of a pituitary adenoma. Independent motion of the camera and tool within the confined workspace demonstrate the potential for an independent magnetic tool manipulation for surgical applications.

Localization of magnetically actuated medical robots is essential for accurate actuation, closed loop control and delivery of functionality. Despite extensive progress in the use of magnetic field and inertial measurements for pose estimation, these have been either under single external permanent magnet actuation or coil systems. With the advent of new magnetic actuation systems comprised of multiple external permanent magnets for increased control and manipulability, new localization techniques are necessary to account for and leverage the additional magnetic field sources. In this letter, we introduce a novel magnetic localization technique in the Special Euclidean Group SE(3) for multiple external permanent magnetic field actuation and control systems. The method relies on a milli-meter scale three-dimensional accelerometer and a three-dimensional magnetic field sensor and is able to estimate the full 6 degree-of-freedom pose without any prior pose information. We demonstrated the localization system with two external permanent magnets and achieved localization errors of 8.5 ± 2.4 mm in position norm and 3.7 ± 3.6 • in orientation, across a cubic workspace with 20 cm length.

Lung cancer remains one of the most life-threatening diseases and is currently managed through invasive approaches such as surgery, chemo- or radiotherapy. In this work, we introduce a novel method for the targeted delivery of a therapeutic laser for the treatment of tumors in peripheral areas of the lungs. The approach uses a 2.4 mm diameter, ultra-soft, patient-specific magnetic catheter delivered from the end of a standard bronchoscope to reach the periphery of the lungs. Integrated shape sensing facilitates supervised autonomous full-shape control for precise navigation into the sub-segmental bronchi, and an embedded laser fiber allows for treatment via localized energy delivery. We report the complete navigation of eight primary lumina in the bronchi of an anatomically accurate phantom (developed from computed tomography (CT) data) and successful laser delivery for photothermal ablation. We further evaluate the approach in three diverse branches of excised cadaveric lungs, showing a mean improvement in navigation depth of 37% with less tissue displacement when compared to a standard semi-rigid catheter and navigation depth repeatability across all tests of <1 mm.

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