Control strategies for high degree-of-freedom assistive devices using non-invasive body-machine interfaces: a survey and framework.

PURPOSE: Body-machine interfaces (BoMIs) provide individuals with movement impairments the ability to control assistive devices using signals from their body movements in a non-invasive and reliable way. However, high degree-of-freedom (DOF) assistive devices such as robotic manipulators require the user to control several device commands simultaneously and intuitively, which has resulted in limited adoption of these devices by the intended user population. In this review, we survey recent approaches for controlling high-DOF systems.

MATERIALS AND

METHODS

Based on a systematic literature search, we identified 25 articles that met our inclusion criteria. In each article, we specifically examined features of strategies related to two specific challenges: (i) simultaneously controlling a large number of DOFs, and (ii) making the interface more intuitive for the purpose of control.

RESULTS

We found that (i) a majority of studies simplified the control problem by using only a few DOF at a time, and (ii) most interfaces were pre-defined with little or no customisation to the individual's movement abilities. We also found that most studies were still at a proof-of-concept stage focusing mainly on unimpaired participants, small sample sizes, and short training durations.

CONCLUSION

Based on the results, we develop a high-level framework to classify these approaches that can serve as a basis for understanding current and future efforts in this domain. We also highlight factors that limit clinical relevance and translation and draw upon recent developments to provide recommendations for future research.