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Robotic teleoperators introduce novel electrome- chanical dynamics between the user and the environment. While considerable effort has focused on minimizing these dynamics, we lack a robust understanding of their impact on user task per- formance across the range of human motor control ability. Here, we utilize a 1-DoF teleoperator testbed with interchangeable mechanical and electromechanical couplings between the leader and follower to investigate to what extent, if any, the dynamics of the teleoperator influence performance in a visual-motor pursuit tracking task. We recruited N = 30 participants to perform the task at frequencies ranging from 0.55 - 2.35 Hz, with the testbed configured into Mechanical, Unilateral, and Bilateral configu- rations. Results demonstrate that tracking performance at the follower was similar across configurations. However, participants’ adjustment at the leader differed between Mechanical, Unilateral, and Bilateral configurations. In addition, participants applied different grip forces between the Mechanical and Unilateral configurations. Finally, participants’ ability to compensate for coupling dynamics diminished significantly as execution speed increased. Overall, these findings support the argument that humans are capable of incorporating teleoperator dynamics into their motor control scheme and producing compensatory control strategies to account for these dynamics; however, this compensation is significantly affected by the leader-follower coupling dynamics and the speed of task execution. 

Humans possess an innate ability to incorporate tools into our body schema to perform a myriad of tasks not possible with our natural limbs. Human-in-the-loop telerobotic systems (HiLTS) are tools that extend human manipulation capabilities to remote and virtual environments. Unlike most hand-held tools, however, HiLTS often possess complex electromechanical architectures that introduce non-trivial transmission dynamics between the robot’s leader and follower, which alter or obfuscate the environment’s dynamics. While considerable research has focused on negating or circumventing these dynamics, it is not well understood how capable human operators are at incorporating these transmission dynamics into their sensorimotor control scheme. To begin answering this question, we recruited N=12 participants to use a novel reconfigurable teleoperator with varying transmission dynamics to perform a visuo-haptic tracking task. Contrary to our original hypothesis, our findings demonstrate that humans can account for substantial differences in teleoperator transmission dynamics and produce the compensatory strategies necessary to adequately control the teleoperator. These findings suggest that advances in transparency algorithms and haptic feedback approaches must be coupled with control designs that leverage the unique capabilities of the human operator in the loop. 

Haptic illusions provide unique insights into how we model our bodies separate from our environment. Popular illusions like the rubber-hand illusion and mirror-box illusion have demonstrated that we can adapt the internal representations of our limbs in response to visuo-haptic conflicts. In this manuscript, we extend this knowledge by investigating to what extent, if any, we also augment our external representations of the environment and its action on our bodies in response to visuo-haptic conflicts. Utilizing a mirror and a robotic brushstroking platform, we create a novel illusory paradigm that presents a visuo-haptic conflict using congruent and incongruent tactile stimuli applied to participants' fingers. Overall, we observed that participants perceived an illusory tactile sensation on their visually occluded finger when seeing a visual stimulus that was inconsistent with the actual tactile stimulus provided. We also found residual effects of the illusion after the conflict was removed. These findings highlight how our need to maintain a coherent internal representation of our body extends to our model of our environment. 

Current commercially available robotic minimally invasive surgery (RMIS) platforms provide no haptic feedback of tool interactions with the surgical environment. As a consequence, novice robotic surgeons must rely exclusively on visual feedback to sense their physical interactions with the surgical environment. This technical limitation can make it challenging and time-consuming to train novice surgeons to proficiency in RMIS. Extensive prior research has demonstrated that incorporating haptic feedback is effective at improving surgical training task performance. However, few studies have investigated the utility of providing feedback of multiple modalities of haptic feedback simultaneously (multi-modality haptic feedback) in this context, and these studies have presented mixed results regarding its efficacy. Furthermore, the inability to generalize and compare these mixed results has limited our ability to understand why they can vary significantly between studies. Therefore, we have developed a generalized, modular multi-modality haptic feedback and data acquisition framework leveraging the real-time data acquisition and streaming capabilities of the Robot Operating System (ROS). In our preliminary study using this system, participants complete a peg transfer task using a da Vinci robot while receiving haptic feedback of applied forces, contact accelerations, or both via custom wrist-worn haptic devices. Results highlight the capability of our system in running systematic comparisons between various single and dual-modality haptic feedback approaches. 

The utility of telerobotic systems is driven in large part by the quality of feedback they provide to the operator. While the dynamic interaction between a robot and the environment can often be sensed or modeled, the dynamic coupling at the human-robot interface is often overlooked. Improving dexterous manipulation through telerobots will require careful consideration of human haptic perception as it relates to human exploration dynamics at the telerobotic interface. In this manuscript, we use exploration velocity as a means of controlling the operator's exploration dynamics, and present results from two stiffness discrimination experiments designed to investigate the effects of exploration velocity on stiffness perception. The results indicate that stiffness percepts vary differently for different exploration velocities on an individual level, however, no consistent trends were found across all participants. These results suggest that exploration dynamics can affect the quality of haptic interactions through telerobotic interfaces, and also reflect the need to study the underlying mechanisms that cause our perception to vary with our choice of exploration strategy.