Christos Bergeles

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Artificial bacterial flagella (ABFs) consist of helical tails resembling natural flagella fabricated by the self-scrolling of helical nanobelts and soft-magnetic heads composed of Cr/Ni/Au stacked thin films. ABFs are controlled wirelessly using a low-strength rotating magnetic field. Self-propelled devices such as these are of interest for in vitro and in(More)
Concentric tube robots are catheter-sized continuum robots that are well suited for minimally invasive surgery inside confined body cavities. These robots are constructed from sets of precurved superelastic tubes and are capable of assuming complex 3-D curves. The family of 3-D curves that the robot can assume depends on the number, curvatures, lengths, and(More)
Concentric tube robots are continuum robots that can navigate natural pathways to reach locations deep inside the human body. Their operation is based on rotating and telescopically actuating concentric tubes to achieve robot tip pose control. During tube manipulation, the elastic energy stored in the robot structure may give rise to unstable robot(More)
Many current and proposed retinal procedures are at the limits of human performance and perception. Microrobots that can navigate the fluid in the interior of the eye have the potential to revolutionize the way the most difficult retinal procedures are conducted. Microrobots are typically envisioned as miniature mechatronic systems that utilize MEMS(More)
Concentric tube robots have shown promise for minimally invasive surgical (MIS) tasks that require navigation via tortuous anatomical paths. Despite extensive research on their kinematic and dynamic modelling, however, inaccuracies and deformations of their shape due to unknown loads and collisions with the anatomy make intraoperative shape sensing a(More)
Microrobots are promising tools for micromanipulation and minimally invasive interventions. Robust electromagnetic control of microrobots can be achieved through precisely modeled magnetic steering systems and accurate localization. Error-free modeling and position information, however, are not realistic assumptions, and microrobots need to be controlled(More)
The progress of wet age-related macular degeneration can now be controlled by intravitreal drug injection. This approach requires repeated injections, which could be avoided by delivering the drug to the retina. Intraocular implants are a promising solution for drug delivery near the retina. Currently, their accurate placement is challenging, and they can(More)
This paper presents a novel actuation technology for robotically assisted MRI-guided interventional procedures. In the proposed approach, the MRI scanner is used to deliver power, estimate actuator state and perform closed-loop control. The actuators themselves are compact, inexpensive and wireless. Using needle driving as an example application, actuation(More)
Dexterous manipulation of intraocular microrobotic devices has the potential to significantly augment ophthalmic surgeons' capabilities. Microrobots can be employed for targeted drug delivery and for procedures such as retinal-vein cannulation that require a high degree of dexterity. For precise externally generated magnetic control of microdevices, their(More)
Future retinal therapies will be partially automated in order to increase the positioning accuracy of surgical tools. Proposed untethered microrobotic approaches that achieve this increased accuracy require localization information for their control. Since the environment of the human eye is externally observable, images can be used to localize the(More)