Engineering to enhance human mobility, play, and exploration
Congratulations, Claire, on finishing your undergraduate capstone and for providing a fantastic culminating presentation!
For her senior capstone, Claire was challenged with creating a web-based application clinicians could use to compute and translate muscle synergies into the clinic. Her mentors and fellow collaborators were Ben Shuman, Nick Baicoianu, and Dr. Kat Steele. In June, Claire will head to Boston, MA to begin her position at Delsys.
On May 18th, Claire Mitchell, Karley Benoff, and Makoto Eyre presented their research at the Mary Gates Undergraduate Research Symposium. These three students worked on year-long projects and showcased their hard work during a campus-wide poster session.
Claire’s research focused on creating a website and server framework for clinicians and researchers across the country to use for calculating muscle synergies for motor control analysis. Muscle synergies are an incredibly complex and computationally expensive analysis of electromyography data but provide quantification of motor control and assist in therapy prescription for movement disorders.
Karley and Mako’s research focused on designing and testing a 3D-printed elbow-driven orthosis for individuals with limited hand function. They drew inspiration from upper-extremity prosthetic devices and evaluated a voluntary close and voluntary open mechanism to assist an individual’s dominant limb.
Great work Karley, Mako, and Claire!
Journal article in Sensors:
In collaboration with University of Texas – Austin, we evaluated a new flexible, gold-based epidermal electrode for sensing muscle activity.
Background: Commercially available electrodes can only provide quality surface electromyography (sEMG) measurements for a limited duration due to user discomfort and signal degradation, but in many applications, collecting sEMG data for a full day or longer is desirable to enhance clinical care. Few studies for long-term sEMG have assessed signal quality of electrodes using clinically relevant tests. The goal of this research was to evaluate flexible, gold-based epidermal sensor system (ESS) electrodes for long-term sEMG recordings.
Methods: We collected sEMG and impedance data from eight subjects from ESS and standard clinical electrodes on upper extremity muscles during maximum voluntary isometric contraction tests, dynamic range of motion tests, the Jebsen Taylor Hand Function Test, and the Box & Block Test. Four additional subjects were recruited to test the stability of ESS signals over four days.
Results: Signals from the ESS and traditional electrodes were strongly correlated across tasks. Measures of signal quality, such as signal-to-noise ratio and signal-to-motion ratio, were also similar for both electrodes.
Conclusions: Over the four-day trial, no significant decrease in signal quality was observed in the ESS electrodes, suggesting that thin, flexible electrodes may provide a robust tool that does not inhibit movement or irritate the skin for long-term measurements of muscle activity in rehabilitation and other applications.
Brianna Goodwin, a Master’s student in our lab, presented her collaborative 
abstract on monitoring Constraint-Induced Movement Therapy (CIMT), a therapy for children with hemiplegic cerebral palsy (CP), at the Seattle Children’s Hospital (SCH) Grand Rounds this past week. The Grand Rounds are a time to present research, new ideas, and translational science to medical personnel of varied background.
To read Brianna’s abstract in full, download her PDF here: SCH Grand Rounds, CIMT abstract
Journal article in PLOSOne: In collaboration with the University of Washington Prosthetics and Orthotics Division, a user-centered design approach was used to improve the design and wearability of a passive, wrist-driven orthosis. To read the article in full, click HERE. To access the open-source print files, click HERE.
Background: Assistive technology, such as wrist-driven orthoses (WDOs), can be used by individuals with spinal cord injury to improve hand function. A lack of innovation and challenges in obtaining WDOs have limited their use. These orthoses can be heavy and uncomfortable for users and also time-consuming for orthotists to fabricate.
Purpose/Methods: The goal of this research was to design a WDO with user (N = 3) and orthotist (N = 6) feedback to improve the accessibility, customizability, and function of WDOs by harnessing advancements in 3D-printing.
Results: The 3D-printed WDO reduced hands-on assembly time to approximately 1.5 hours and the material costs to $15 compared to current fabrication methods. Varying improvements in users’ hand function were observed during functional tests, such as the Jebsen Taylor Hand Function Test. For example, one participant’s ability on the small object task improved by 29 seconds with the WDO, while another participant took 25 seconds longer to complete this task with the WDO. Two users had a significant increase in grasp strength with the WDO (13–122% increase), while the other participant was able to perform a pinching grasp for the first time.
The WDO designs are available open-source to increase accessibility and encourage future innovation.