Try Walking in My Shoes, Robot
Ultrasound imaging of muscle movements quickly adapts assistive exosuits to the needs of their wearers.
Exosuits may not exactly be something you come across in your everyday life just yet, but as technologies and methods continue to improve, that may begin to change. And that would be good news, because assistive exosuits can benefit a wide range of individuals, from those looking for a little boost on a rugged hike, to those with clinical disorders that can regain their ability to walk.
One challenge that is preventing widespread adoption of exosuit technology is the problem of calibration. Individuals all walk in different ways, which are influenced by factors such as sex, height, age, muscle strength, and the presence of neural or muscular disorders. Further, people walk at varying speeds and in environments with changing levels of inclination. A one-size-fits-all approach does not work for exosuits designed to assist walking.
Present approaches to the calibration problem typically require hours of manual or automatic tuning. This is a painful chore for anyone to complete, but for the elderly or clinical patients, it may not even be possible, effectively locking out those that need assistance the most. A group of researchers at Harvard University’s School of Engineering and Applied Sciences have recently published a new method that may circumvent this problem altogether.
The new approach uses ultrasound measurements of muscle dynamics to quickly generate an assistance profile tailored to an individual that is valid in a variety of real-world walking tasks. This profile can be created in a matter of seconds. That individualized information is then used to determine the optimal amount of assistive force that should be applied in parallel with normal muscle movements in a bilateral ankle exosuit.
When validating the technique, it was found that metabolic demand was reduced by as much as 15.9% when wearing the exosuit, indicating that a significant amount of assistance is being provided to the wearer. Benefits were observed across a wide range of walking speeds and inclines. The results compared favorably with previously published studies, which shows that nothing is being lost by introducing a rapid calibration process.
The team is currently working to enhance the system’s ability to make constant, real-time adjustments. They believe that their work will improve adoption of wearable robotics by making the technologies more comfortable and personalized.