@article {1969, title = {In the Fundamentals of Endovascular and Vascular Surgery model motion metrics reliably differentiate competency}, journal = {Journal of Vascular Surgery}, volume = {72}, number = {6}, year = {2020}, month = {12/2020}, pages = {2161-2165}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/JVS2020_Belvroy_et_al.pdf}, author = {Viony Belvroy and Barathwaj Murali and Malachi G. Sheahan and Marcia K. O{\textquoteright}Malley and Jean Bismuth} } @proceedings {1822, title = {Improving the retention of motor skills after reward-based reinforcement by incorporating haptic guidance and error augmentation}, year = {2016}, pages = {857-863}, abstract = {

There has been significant research aimed at leveraging programmable robotic devices to provide haptic assistance or augmentation to a human user so that new motor skills can be trained efficiently and retained long after training has concluded. The success of these approaches has been varied, and retention of skill is typically not significantly better for groups exposed to these controllers during training. These findings point to a need to incorporate a more complete understanding of human motor learning principles when designing haptic interactions with the trainee. Reward-based reinforcement has been studied for its role in improving retention of skills. Haptic guidance, which assists a user to complete a task, and error augmentation, which exaggerates error in order to enhance feedback to the user, have been shown to be beneficial for training depending on the task difficulty, subject ability, and task type. In this paper, we combine the presentation of reward-based reinforcement with these robotic controllers to evaluate their impact on retention of motor skill in a visual rotation task with tunable difficulty using either fixed or moving targets. We found that with the reward-based feedback paradigm, both haptic guidance and error augmentation led to better retention of the desired visuomotor offset during a simple task, while during a more complex task, only subjects trained with haptic guidance demonstrated performance superior to those trained without a controller.

}, isbn = {978-1-5090-3287-7}, issn = {978-1-5090-3287-7}, doi = {10.1109/BIOROB.2016.7523735}, url = {http://ieeexplore.ieee.org/abstract/document/7523735/}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/Losey_BioRob_Improving.pdf}, author = {Dylan P. Losey and Laura H. Blumenschein and Marcia K. O{\textquoteright}Malley} } @article {1723, title = {Interaction control capabilities of an MR-compatible compliant actuator for wrist sensorimotor protocols during fMRI}, journal = {IEEE/ASME Transactions on Mechatronics}, volume = {20}, number = {6}, year = {2015}, pages = {2678-2690}, abstract = {

This paper describes the mechatronic design and characterization of a novel MR-compatible actuation system designed for a parallel force-feedback exoskeleton for measurement and/or assistance of wrist pointing movements during functional neuroimaging. The developed actuator is based on the interposition of custom compliant elements in series between a non-backdrivable MR-compatible ultrasonic piezoelectric motor and the actuator output. The inclusion of physical compliance allows estimation of interaction force, enabling force-feedback control and stable rendering of a wide range of haptic environments during continuous scanning. Through accurate inner-loop

velocity compensation and force-feedback control, the actuator is capable of displaying both a low-impedance, subject-in-charge mode, and a high stiffness mode. These modes enable the execution of shared haptic protocols during continuous fMRI.\ 

The detailed experimental characterization of the actuation system is presented, including a backdrivability analysis, demonstrating an achievable impedance range of 22 dB, within a bandwidth of 4 Hz (for low stiffness). The stiffness control bandwidth depends on the specific value of stiffness: a bandwidth of 4 Hz is achieved at low stiffness (10\% of the physical springs stiffness), while 8 Hz is demonstrated at higher stiffness. Moreover, coupled stability is demonstrated also for stiffness values substantially (25\%) higher than the physical stiffness of the spring. Finally, compatibility tests conducted in a 3T scanner are presented, validating the potential of inclusion of the actuator in an exoskeleton system for support of wrist movements during continuous MR scanning, without significant reduction in image quality.

}, keywords = {compliant actuators., Force control, functional MRI (fMRI), MR-compatible robotics}, doi = {10.1109/TMECH.2015.2389222}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/MR-compatible_actuator_v3.pdf}, author = {Fabrizio Sergi and Andrew Erwin and Marcia K. O{\textquoteright}Malley} } @proceedings {1703, title = {Interaction control for rehabilitation robotics via a low-cost force sensing handle}, year = {2013}, address = {Palo Alto, CA}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/Erwin2013\%20-\%20RiceWrist-Grip.pdf}, author = {Andrew Erwin and Fabrizio Sergi and Vinay Chawda and Marcia K. O{\textquoteright}Malley} }