Open Access
September 2020 Optimal EMG placement for a robotic prosthesis controller with sequential, adaptive functional estimation (SAFE)
Jonathan Stallrich, Md Nazmul Islam, Ana-Maria Staicu, Dustin Crouch, Lizhi Pan, He Huang
Ann. Appl. Stat. 14(3): 1164-1181 (September 2020). DOI: 10.1214/20-AOAS1324


Robotic hand prostheses require a controller to decode muscle contraction information, such as electromyogram (EMG) signals, into the user’s desired hand movement. State-of-the-art decoders demand extensive training, require data from a large number of EMG sensors and are prone to poor predictions. Biomechanical models of a single movement degree-of-freedom tell us that relatively few muscles, and, hence, fewer EMG sensors are needed to predict movement. We propose a novel decoder based on a dynamic, functional linear model with velocity or acceleration as its response and the recent past EMG signals as functional covariates. The effect of each EMG signal varies with the recent position to account for biomechanical features of hand movement, increasing the predictive capability of a single EMG signal compared to existing decoders. The effects are estimated with a multistage, adaptive estimation procedure that we call Sequential Adaptive Functional Estimation (SAFE). Starting with 16 potential EMG sensors, our method correctly identifies the few EMG signals that are known to be important for an able-bodied subject. Furthermore, the estimated effects are interpretable and can significantly improve understanding and development of robotic hand prostheses.


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Jonathan Stallrich. Md Nazmul Islam. Ana-Maria Staicu. Dustin Crouch. Lizhi Pan. He Huang. "Optimal EMG placement for a robotic prosthesis controller with sequential, adaptive functional estimation (SAFE)." Ann. Appl. Stat. 14 (3) 1164 - 1181, September 2020.


Received: 1 April 2018; Revised: 1 September 2019; Published: September 2020
First available in Project Euclid: 18 September 2020

MathSciNet: MR4152128
Digital Object Identifier: 10.1214/20-AOAS1324

Keywords: adaptive group LASSO , correlated functional predictors , Electromyography signal , functional variable selection , sequential adaptive functional estimation , varying functional regression

Rights: Copyright © 2020 Institute of Mathematical Statistics

Vol.14 • No. 3 • September 2020
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