HuskySTEPS

B Nguyen, N Baicoianu, D Howell, KM Peters, KM Steele (2020) “Accuracy and repeatability of smartphone sensors for measuring shank-to-vertical angle” Prosthetics & Orthotics International

Dr. Steele HuskySTEPS, JournalArticle, Orthoses, UbiquitousRehabilitation , , , , , ,

Journal Article in Prosthetics & Orthotics International

Example of how the smartphone app was used for this research. The top images show a black smartphone attached with a running arm band to the side or front of the shank - the two positions tested in this research. The middle figure shows the placement of the reflective markers for 3D motion analysis to evaluate the accuracy of the smartphone measurements. Markers were placed on the lateral epicondyle of the knee, lateral maleolus of the ankle, tibial tuberosity, and the distal tibia. Blacklight was used to mark the position of each marker and hide the position from the clinicians. The bottom panel shows screenshots from the app. The first screen is used to align the device and has arrows at the top and bottom that remind the clinician which anatomical landmarks should be used to align the device while displaying the shank-to-vertical angle in real time. The second screenshot shows an example of the calculated shank-to-vertical angle while someone was walking. The average is shown with a bold black line, with all other trials shown in blue and excluded trials (e.g., when someone was stopping or turning) that deviated more than one standard deviation from other trials are shown in red. There is also text below the graph that provides summary measures, like shank-to-vertical angle in mid stand and cadence (steps/min). The results can be exported as a picture or sent via e-mail using the app.
A) Smartphone positioning on the front or side of the shank. B) Reflective markers on the the tibial tuberosity (TT) – distal tibia (DT) and lateral epicondyle (LE) – lateral malleolus (LM) were used to compare the accuracy of the smartphone to traditional motion capture. UV markings were used to keep placement of these markers constant while blinding clinicians. C) Sample screenshots of the mobile application, including the set-up screen and results automatically produced after a walking trial.

Background

Assessments of human movement are clinically important. However, accurate measurements are often unavailable due to the need for expensive equipment or intensive processing. For orthotists and therapists, shank-to-vertical angle (SVA) is one critical measure used to assess gait and guide prescriptions. Smartphone-based sensors may provide a widely-available platform to expand access to quantitative assessments.

Objectives

Assess accuracy and repeatability of smartphone-based measurement of SVA compared to marker-based 3D motion analysis.

Method

Four licensed clinicians (two physical therapists and two orthotists) measured SVA during gait with a smartphone attached to the anterior or lateral shank surface of unimpaired adults.  We compared SVA calculated from the smartphone’s inertial measurement unit to marker-based measurements. Each clinician completed three sessions/day on two days with each participant to assess repeatability.

Results

Average absolute differences in SVA measured with a smartphone versus marker-based 3D motion analysis during gait were 0.67 ± 0.25° and 4.89 ± 0.72°, with anterior or lateral smartphone positions, respectively. The inter- and intra-day repeatability of SVA were within 2° for both smartphone positions.

Conclusions

Smartphone sensors can be used to measure SVA with high accuracy and repeatability during unimpaired gait, providing a widely-available tool for quantitative gait assessments.

Try it out!

The app for monitoring shank-to-vertical angle is available for you to download and use on either Android or iOS smartphone. Please complete THIS SURVEY which will then send you an e-mail with instructions for installation and use. This app is not an FDA approved medical device and should be used appropriately.

US Patent Office Visit

Dr. Steele HuskySTEPS, Orthoses, Outreach, UbiquitousRehabilitation , , ,

Patent examiners spend their days critically evaluating the latest innovations, to determine if they are useful, novel, and non-obvious. When one of our students asked them what daily life is like as a patent examiner they responded, we basically write a 10-15 page report every 2-3 days.

Thankfully the patent office lets them escape from behind their computers a few times a year to meet with companies, research labs, and other entities. These visits help them see what is new and exciting in their specialty area.

We were lucky enough to host one of these teams this past week in the AMP Lab. Tim Stanis, a primary examiner from Art Unit 3786 that specializes in exoskeletons, orthoses, passive motion rehabilitation devices, and biomechanical technology led the visit. He was joined by nine other examiners.

One of the patent examiners in a red checkered shirt answers students questions. He is seated at a table with hands clasped in front of him.

Our lab demoed our latest creations in orthoses, biofeedback systems, and smartphone sensing. Patrick Aubin from the VA Hospital, Murray Maitland from Rehab Medicine, Chet Moritz from Electrical Engineering, and Tapo Bhattacharjee also shared their latest work.

We ended the session with a Q&A Panel for summer students to learn about career opportunities as a patent examiner and advice for new innovators. Most of the examiners had an undergraduate or master’s degree in engineering. They emphasized that working for the patent office is a great, flexible career path. As a patent examiner they are able to work remotely, have flexible hours, and enjoy other benefits such as having law school paid for.

Students listen attentively to the Q&A Panel. Some look bored, some look amused, and one is even taking notes, or maybe doodling!

For new innovators, they emphasized the importance of understanding the patent landscape. They recommended using Google Patents! Patents can seem intimidating. They recommended starting with the pictures and focusing on the claims. They also emphasized the importance of having a team. Translating technology requires team members with technical, business, and clinical backgrounds.

For our part, we were excited to meet real, live patent examiners. We appreciated seeing their faces and enjoyed sharing our work with them.

RehabWeek 2019 Recap

Dr. Steele HuskySTEPS, MotorControl, Presentation, UbiquitousRehabilitation , ,
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.

RehabWeek/ISPO Canada Best Student Poster: Brandon Nguyen!

Dr. Steele Abstract, Awards, HuskySTEPS, Orthoses, Presentation , , , , ,
Brandon Nguyen standing in front of his poster at RehabWeek wearing a dark blue shirt. His poster features images of the smartphone app and graphs.

Congrats to Brandon Nguyen who was awarded the Best Student Poster award by the International Society of Prosthetics & Orthotics Canada at RehabWeek in Toronto this past week! Brandon presented his work, “Accuracy and repeatability of using smartphone sensors for orthotic tuning.”

Check out his abstract and poster.

You can also download the HuskySTEPS app to try it out yourself.

The ISPO student award winners for 2019 rehab week, including four students with Brandon in the middle, and the two main conference award organizers.

This work, in collaboration with Nick Baicoianu and Darrin Howell, examined the accuracy of measuring shank-to-vertical angle during walking with a smartphone compared to traditional motion capture systems. Shank-to-vertical angle is a measure used by orthotists and therapists for AFO tuning and gait training. The short story – placing the smartphone on the front of the shank can measure shank-vertical-angle with errors less than two degrees compared to traditional motion capture systems, with high intra-rater and inter-rater repeatability across days.

Brandon dressed in his purple graduation regalia in front of the UW fountain

Brandon also recently finished his Doctorate of Physical Therapy (DPT) degree at the University of Washington – making him one of the rare engineer-therapists. In recognition of his efforts to combine academic scholarship with social awareness and concern, he was awarded the 2019 UW Graduate Medal.

Congratulations Brandon! We are so excited to see what you do next.