Classification of hand posture from electrocorticographic signals recorded during varying force conditions

Abstract

In the presented work, standard and high-density electrocorticographic (ECoG) electrodes were used to record cortical field potentials in three human subjects during a hand posture task requiring the application of specific levels of force during grasping. We show two-class classification accuracies of up to 80% are obtained when classifying between two-finger pinch and whole-hand grasp hand postures despite differences in applied force levels across trials. Furthermore, we show that a four-class classification accuracy of 50% is achieved when predicting both hand posture and force level during a two-force, two-hand-posture grasping task, with hand posture most reliably predicted during high-force trials. These results suggest that the application of force plays a significant role in ECoG signal modulation observed during motor tasks, emphasizing the potential for electrocorticography to serve as a source of control signals for dexterous neuroprosthetic devices.

Histological evaluation of a chronically-implanted electrocorticographic electrode grid in a non-human primate

“…This potentially mitigates some inflammatory burden on the brain. ECoG signals have been found to encode information about arm and hand movements (Leuthardt et al, 2004; Schalk et al, 2007; Crone et al, 1998; Miller et al, 2007; Pistohl et al, 2008; Wang et al, 2009; Kubánek et al, 2009; Ball et al, 2009; Miller et al, 2009; Chao et al, 2010; Acharya et al, 2010; Degenhart et al, 2011a; Shimoda et al, 2012; Chestek et al, 2013; Nakanishi et al, 2013), as well as auditory (Edwards et al, 2005; Trautner et al, 2006), visual (Lachaux et al, 2005), language (Crone et al, 2001; Mainy et al, 2007; Kellis et al, 2010; Wang et al; 2011, Pei et al, 2011), and attentional processes (Tallon-Baudry et al, 2005; Jung et al, 2008; Ray et al, 2008). Encouraged by these findings, researchers have begun to investigate ECoG as a potential source of control signals for BMI devices.…”

Collaborative Approach in the Development of High‐Performance Brain–Computer Interfaces for a Neuroprosthetic Arm: Translation from Animal Models to Human Control

“…In ECoG studies, initial human investigations, including real‐time BCI and neuroscience experiments, were conducted in patients being observed in an epilepsy monitoring unit (EMU) . ECoG during epilepsy monitoring has been used by a number of research groups to enable the development of software and training techniques with human participants .…”

“…This work guided development of subsequent human study protocols and IDE applications. Finally, the EMU study generated critical pilot data and initial funding from multiple agencies that made it possible for us to form and grow our clinical BCI research team with a demonstrated track record. The EMU research conducted in patients undergoing clinical brain mapping in itself has important scientific, engineering, and clinical value as exemplified by the ever‐increasing number of research groups and publications based on this study setting …”

“…In ECoG studies, initial human investigations, including real-time BCI and neuroscience experiments, were conducted in patients being observed in an epilepsy monitoring unit (EMU). [23][24][25] ECoG during epilepsy monitoring has been used by a number of research groups to enable the development of software and training techniques with human participants. [26][27][28][29][30][31] [1][2][3]12 studies in epilepsy patients, the next step in our BCI research pathway was to conduct a 28-day study of ECoG-based BCI in an individual with spinal cord injury.…”

“…The EMU research conducted in patients undergoing clinical brain mapping in itself has important scientific, engineering, and clinical value as exemplified by the ever-increasing number of research groups and publications based on this study setting. [23][24][25][26][27][28][29][30][31][34][35][36][37][38][39][40][41][42][43]…”