M Yamagami, KM Steele, SA Burden (2020) “Decoding Intent With Control Theory: Comparing Muscle Versus Manual Interface Performance”

Journal Article in ACM Conference on Human Factors in Computing Systems (CHI) 2020 Preceedings:

These results suggest that control theory modeling can provide a platform to successfully quantify device performance in the absence of errors arising from motor impairments

Split image of upper body of user holding rod and slider with computer screen

Photo (top and bottom) of a user using a slider (top) and muscles (bottom) to control a cursor on the screen.
(Top image) Side image of user. User rests their elbow and pinches the slider and moves the slider towards and away from their body to control the cursor.
(Bottom image) Side image of user. User is strapped to a rigid device holding a bar with hands supinated towards the ceiling, with the forearms at a 90 degree angle from the upper arms.
Electrodes are placed on the biceps and triceps and labelled. Arrows pointing up and down indicate that users move their arm up and down to control the cursor.

 

Background: Manual device interaction requires precise coordination which may be difficult for users with motor impairments. Muscle interfaces provide alternative interaction methods that may enhance performance, but have not yet been evaluated for simple (eg. mouse tracking) and complex (eg. driving) continuous tasks. Control theory enables us to probe continuous task performance by separating user input into intent and error correction to quantify how motor impairments impact device interaction

Aim:  Propose and extend an experimental and analytical method to guide future development of accessible interfaces like muscle interfaces using control theory

Method: We compared the effectiveness of a manual versus a muscle interface for eleven users without and three users with motor impairments performing continuous tasks.

Results: Both user groups preferred and performed better with the muscle versus the manual interface for the complex continuous task.

Interpretation: Results suggest muscle interfaces and algorithms that can detect and augment user intent may be especially useful for future design of interfaces for continuous tasks.

 

Momona also gave a phenomenal talk on this paper last week in the University of Washington’s ‘DUB Shorts’ series (video posted below). Nice job Momona!

Nicole Zaino wins the ESMAC Best Paper award

Congratulations to Nicole Zaino for being awarded the ESMAC (European Society of Movement Analysis for Adults and Children) Best Paper Award. Nicole received this award at the 2019 ESMAC conference in Amsterdam, September 23-28, 2019 where she gave her talk: “Spasticity reduction in children with cerebral palsy is not associated with reduced energy during walking.” For more information, visit ESMAC.

Woman in formal attire standing behind a black and purple podium in front of a large presentation screen

ESMAC 2019: Award Finalists

Congratulations to Nicole Zaino and our colleague Mike Schwartz at Gillette Children’s Specialty Healthcare for both being nominated as finalists for the Best Presentation Award at the upcoming ESMAC Conference in Amsterdam. Their abstracts are among the top 16 submissions to the conference and the final award will be determined based upon their presentations.

Logo for the 2019 ESMAC meeting overlaid on a classic Amsterdam scene, bikes lined up on a bridge over a canal with historic buildings in the background.

Nicole will be presenting her research:

Spasticity reduction in children with cerebral palsy is not associated with reduced energy during walking 

Selective dorsal rhizotomy reduces spasticity, but does it also reduce energy consumption during walking? In an analysis of over 300 children with cerebral palsy, Nicole demonstrated that although rhiztomy does reduce spasticity, it does not reduce energy consumption. These results provide further evidence that spasticity is not a main contributor to elevated energy among people with cerebral palsy. You can also learn more about this study from our recent submitted manuscript, available on bioRxiv.

Mike will be presenting his research:

The effects of walking speed and age on energy consumption in children with cerebral palsy and their typically developing peers

We know that walking energy is high among people with cerebral palsy, and that energy varies with speed and age. Using retrospective data of over 300 kids with cerebral palsy and 150 typically-developing peers, Mike used a statistical model to evaluate these speed and age effects. He found that energy decreases until 8-10 years of age for kids with CP, while it remains stable beyond age 5 for typically-developing peers. Kids with CP also have a greater elevation in energy with greater walking speeds. These results are important to help quantify and understand impacts of interventions, like surgery or assistive devices, which are often done during this time period when kids are still growing and developing.

They will both be presenting in the Optimizing Energy Cost session from 11:40-12:30 on Thursday, September 26th.

Best of luck to Nicole & Mike!

ISB 2019 Recap

Five members of our lab – Kat, Michael, Alyssa, Megan, & Nicole – attended ISB 2019 in Calgary, Canada. The International Society of Biomechanics promotes and supports international contacts amongst scientists, the dissemination of knowledge, and the activities of national organizations in the field of biomechanics.

Four individuals stand in hallway smiling at conference.

Our work at the conference included:

Kat Steele: ISB presentation on in-clinic EMG monitoring for muscle activity and movement in acute care in the initial days after stroke.
Michael Rosenberg: ISB poster showcasing how individuals’ kinematics and muscle activity change in response to ankle exoskeleton stiffness during acceleration from standing. ISB presentation on open-loop modeling of response to ankle exoskeleton torque during walking.
Alyssa Spomer: ISB poster highlighting how motor control is impacted when typically developing individuals emulate cerebral palsy gait patterns. ISB poster on understanding how individuals can alter motor control expression using visual biofeedback.
Megan Auger: ISB presentation on how muscle coordination strategies in typically developing children and children with cerebral palsy are not accurately captured using standard musculoskeletal modeling optimization algorithms in computer simulation.
Nicole Zaino: ISB presentation on spasticity reduction via rhizotomy in children with cerebral palsy and how there was no significant difference in the change in energy consumption when compared to a control group of children with cerebral palsy who had no rhizotomy.


TGCS 2019

Additionally, two members of our lab – Michael & Megan – attended TGCS 2019 in Canmore, Canada prior to ISB 2019. The Technical Group on Computer Simulation (TGCS) is a scientific and technical meeting for investigators and students in all areas of computer simulation in biomechanics. This group was a highly-focused subset of the ISB community, primarily focusing on forward simulation of unimpaired and pathological gait patterns, but also touching on multi-scale simulation, diving, cycling, and wheelchair use. 

A mountain view in Canmore, Canada with sharp jagged peaks and a bright blue lake.
Michael standing in the front of a room in between two screens giving a presentation.
Michael Rosenberg: TGCS presentation on Dynamic Mode Decomposition for modeling response to ankle exoskeletons during gait.

RehabWeek 2019 Recap

Modern meets colonial architecture at the huge Toronto Art Museum. An old colonial building sits in front of the modern, glass-fronted art museum.

Five members of our lab – Brandon, Christina, Nick, Michael, & Kat – attended RehabWeek 2019 in Toronto, Canada. This is a unique mega-conference where multiple conferences (ICORR, ACRM, ISPO, RESNA, etc) are hosted at the same time in the same location. Everyone attended common keynotes, poster sessions, and meals. In the morning and afternoon, each conference had their own scientific sessions.

While it was a bit overwhelming to figure out which sessions to attend, it was a great way to get a more diverse audience to provide feedback on your work. For future conferences, I would recommend that students just pick one conference (e.g., ICORR or RESNA) to attend and not bounce between sessions. This lets you more fully engage with a community, have long discussions, and identify common threads across presentations.

Our work at the conference included:

  • Michael Rosenberg: ISPO presented on how muscle coordination differs when you start to walk compared to steady-state walking. Synergies differ during the first step, but quickly converge to steady-state patterns and there was minimal effect of different AFO stiffnesses.
  • Christina Papazian: INERS poster demonstrating correlations between FIM scores and muscle activity in acute stroke care.
  • Brandon Nguyen: ISPO poster on the accuracy and repeatability of using a smartphone to monitor gait for AFO tuning – ISPO Best Student Poster Award
  • Nick Baicoianu: Developer’s Showcase for HuskySTEPS
  • Kat Steele: ISPO poster on synergy-based control of predictive simulations of walking.
Nick demonstrates HuskySTEPS at the Developer's Showcase.

I also served on the IEEE Women in Engineering panel at lunch on Thursday, which focused on new frontiers in technology that could increase accessibility and inclusion. A lot of the discussion focused on the potential of machine learning, wearable technology, and autonomous vehicles.

Flyer from the IEEE Women in Engineering panel with the moderator and four speaker pictures.

You can view our notes and take-aways from the conference in these slides.

We also got to visit with Naser Mehrabi, a former post-doc in the lab, who now works for General Motors. We took the train just north of downtown to visit with him, his wife, and their 9-week-old son. Not only did we get to enjoy some delicious Iranian food, but we also got to get lots of simulation questions answered.

The crew visits with Naser and his wife at their new home in Toronto.

The next RehabWeek will be 2021 in Rotterdam, Netherlands.