Exoskeleton Training Contributes to Assistance

How much time is required before a person can strap on an exoskeleton device and begin using it effectively? A team from Stanford University has conducted a study in an attempt to answer this exact question. Their findings? On average, it takes a new exoskeleton user two hours to familiarize themselves with a wearable robot, with three important details:

• The above-mentioned two hours of familiarization time is an average. Some users continued to become more adept at using an exoskeleton efficiently, many slowed their improvement, and some even regressed. The data suggests that not all people will react the same way to using a wearable device, but on average, there are some trends.
• The study did not investigate long-term adaptation to exoskeleton use in a range of weeks or months. It is more than possible that further performance improvements will occur with additional training time.
• The study is based on an ankle exoskeleton powered by the Humotech Simulator. It is not a definitive answer for a minimum adaptation time needed for all exo technology for new users.

The full research paper is titled: How adaptation, training, and customization contribute to benefits from exoskeleton assistance and was penned by Katherine Poggensee and Steven Collins. It was published in Science Robotics in Sept 2021. The experimental results showed that first-time exoskeleton users had an immediate reduction in metabolic cost after donning a powered exoskeleton. However, the benefit of the exo nearly tripled with more training of, on average, 109 minutes.

Note that 109 minutes is significantly longer than most exoskeleton lab studies, which usually allow between 0 to 6 minutes of familiarization with the device. This paper suggests that exoskeletons are more related to a motorcycle, bicycle, or pogo stick than a screwdriver or a toaster. Some familiarization time for the nervous system to get used to a wearable is required to begin reaping a greater reward from using the device.

How much should users know about an exoskeleton?

For decades the mantra has been that exoskeleton devices need to understand the user and their intention. But how much should the users know and understand exoskeleton devices? We need a shift in thinking. The exoskeleton needs to predict the user’s intent, but the user also has to spend time and effort to understand what the exoskeleton is doing – presented Roveda Loris during ExoBerlin ExoTech 2021.

There is precedent for systems to require training and certification. In California, a motorcycle safety course is highly recommended for new riders and it takes two entire days to complete. The course covers elements of understanding how a motorcycle works such as the sound it makes when air enters the engine, when to accelerate to offload the front suspension, or even how to stop safely (for older models without ABS breaks). The course even covers how to think when riding a motorcycle, calculate routes, and avoid obstacles. The same is true for full-face respirators, which require a maintenance program, training, a recurring fit test, and a lung capacity test. In other words, there is a precedence of motorized devices and wearables to require a minimum amount of training and familiarization prior to use.

Reference:

Exoskeleton research demonstrates the importance of training, Stanford University, September 29, 2021, https://www.sciencedaily.com/releases/2021/09/210929142712.htm