Recent advances in neural prosthetics have provided patients with the ability to use signals derived from motor areas of the cerebral cortex to directly control an external device under visually guided closed-loop control. To attain a more natural form of prosthesis control, it is desirable to develop systems capable of providing real-time somatosensory feedback as well as visual feedback, akin to how we naturally process sensory information to control our limbs. To this end, a sophisticated data acquisition, control and feedback system was developed for neural
prosthetics and psychophysics research. The system deterministically collects and processes
high volume neural ensemble activity, limb kinematics, and eye movements while generating
visual stimuli in an immersive three-dimensional virtual reality (VR) environment. A vibrotactile
feedback device was also developed and incorporated into the system. It delivers real-time limb kinematics feedback in the form of continuous, graded vibratory stimulation. A flexible and intuitive user interface allows the researcher to design experimental paradigms and adjust parameters on the fly during experiments. A psychophysical study was conducted using this system to evaluate the potential use of vibrotactile feedback as a sensory substitution method to provide somatosensory feedback for neural prosthesis control. The study also aimed to provide insight into the mechanisms of multimodal sensory processing and sensory-motor control. Able-bodied human subjects performed a trajectory-following reach task in the VR environment under different visual and vibrotactile feedback conditions. The study showed that vibrotactile feedback is capable of enhancing motor performance, implying that subjects were able to integrate and effectively use this new 'proprioceptive-like' sensory modality. Subjects were also able to partially maintain task performance using vibrotactile feedback in the absence of visual feedback. Improved motor learning and motor skill consolidation were also observed after training in the VR environment with vibrotactile feedback. These results suggest that vibrotactile feedback may be a viable method for delivering somatosensory feedback for applications such as neural prosthesis control, motor rehabilitation, and enhanced human-computer interaction.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-07232009-133548 |
| Date | 25 September 2009 |
| Creators | Bacher, Daniel H |
| Contributors | Roberta Klatzky, George Stetten, Douglas Weber, Aaron Batista |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-07232009-133548/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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