Toward a Meso-Scale SMA-Actuated MRI-Compatible Neurosurgical Robot

Abstract

Brain tumors are the most feared complications of cancer. Their treatment is challenging due to the lack of good imaging modality and the inability to remove the complete tumor. Facilitating tumor removal by accessing regions outside the “line-of-sight” will require a highly dexterous and MRI compatible robot. We present our work towards the development of a MRI-compatible neurosurgical robot. We used two antagonistic shape memory alloy (SMA) wires as actuators for each joint. Due to the size limitation of the device, we rely on temperature feedback to control the joint motion of the robot. We have developed a theoretical model based on Tanaka’s model to characterize the joint motion with the change in SMA wire temperature. The results demonstrated that the SMA wire temperature can be used reliably to predict the motion of the robot. We then used a PWM scheme and switching circuit to control the temperature of multiple SMA wires. Experimental results showed that we can actuate the robot reliably and observe joint motion in a gelatin medium. MR images also showed that the robot is fully MRI-compatible and creates no significant image distortion.

From Passive Tool Holders to Microsurgeons: Safer, Smaller, Smarter Surgical Robots

“…Exemplary surgical robots for different applications. "Ophthalmic microrobot": c ETH Zurich; "Steady-hand robot": adapted from [34], c SAGE publications; "Hyperredundant robot", c Carnegie Mellon; "MRI-compatible SMA robot": reprinted with IEEE permission from [35]; "Concentric tube robots" (top): c Vanderbilt University; "MRI-steerable bacteria": reprinted with IEEE permission from [36]; "Anubis": c Karl Storz GmbH; "Active capsule": c Scuola Superiore San't Anna; "MASCE": reprinted with IEEE permission from [37]; "da Vinci": c 2013 Intuitive Surgical Inc; "i-Snake": reprinted with Springer permission from [38]; "IREP": c Vanderbilt University; "Concentric tube robots" (bottom): c Boston Children's Hospital; "Magellan": c Hansen Medical Inc.; "Heartlander": reprinted with IEEE permission from [39]. Representation of systems inspired by [25] by Nelson et al spine-mountable [45], [46], and by expanding their application area to cover kidney, prostate and lung procedures [47].…”

Robotic-assisted real-time MRI-guided TAVR: from system deployment to in vivo experiment in swine model

“…Magnetic resonance (MR)-compatible robotic systems have been developed for various medical interventions, from prostate brachytherapy to neurosurgery [12][13][14][15][16][17][18][19][20]. Among all MR-compatible systems, two general-purpose devices have been designed for use with a standard closed-bore scanner [21,22].…”

A Passive Parallel Master–Slave Mechanism for Magnetic Resonance Imaging-Guided Interventions

“…[22], but with two moving platforms connected for passive master-slave manipulation. Due to its elongated workspace, this type of design may also be suitable for MRI-guided neurosurgery, yet at reduced cost and complexity compared to fully robotic approaches [30,31]. Extended parallel mechanisms for MRIguided interventions can enable access to other parts of the body which are difficult to reach due to the constraints of the scanner bore, such as the liver or breast.…”