Wireless MRI‐Powered Reversible Orientation‐Locking Capsule Robot. Issue 13 (3rd May 2021)

• Record Type: Journal Article
• Authors: Erin, Onder; Boyvat, Mustafa; Lazovic, Jelena; Tiryaki, Mehmet Efe; Sitti, Metin
• Is Part Of: Advanced science. Volume 8:Issue 13(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-03
• Subjects: magnetic actuation -- magnetic resonance imaging -- medical robots -- millirobots -- minimally invasive medical devices; Science -- Periodicals; 505
• DOI: 10.1002/advs.202100463
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Magnetic resonance imaging (MRI) scanners do not provide only high‐resolution medical imaging but also magnetic robot actuation and tracking. However, the rotational motion capabilities of MRI‐powered wireless magnetic capsule‐type robots have been limited due to the very high axial magnetic field inside the MRI scanner. Medical functionalities of such robots also remain a challenge due to the miniature robot designs. Therefore, a wireless capsule‐type reversible orientation‐locking robot (REVOLBOT) is proposed that has decoupled translational motion and planar orientation change capability by locking and unlocking the rotation of a spherical ferrous bead inside the robot on demand. Such an on‐demand locking/unlocking mechanism is achieved by a phase‐changing wax material in which the ferrous bead is embedded inside. Controlled and on‐demand hyperthermia and drug delivery using wireless power transfer‐based Joule heating induced by external alternating magnetic fields are the additional features of this robot. The experimental feasibility of the REVOLBOT prototype with steerable navigation, medical function, and MRI tracking capabilities with an 1.33 Hz scan rate is demonstrated inside a preclinical 7T small‐animal MRI scanner. The proposed robot has the potential for future clinical use in teleoperated minimally invasive treatment procedures with hyperthermia and drug delivery capabilities while being wirelessly powered and monitored inside MRI scanners. Abstract : Rotation is coupled with translation for untethered magnetic resonance imaging (MRI)‐powered robots with a freely rotating magnet. To remove such a coupling issue, an orientation‐locking mechanism via a phase‐changing wax material is proposed. Wireless power transfer‐based heating is used to trigger the mechanism. This wireless heating also enables to trigger drug release and induce hyperthermia towards future potential therapeutic functionalities.