title: Electromyogram whitening for improved classification accuracy in upper limb prosthesis control.
abstract: Time and frequency domain features of the surface electromyogram (EMG) signal acquired from multiple channels have frequently been investigated for use in controlling upper-limb prostheses. A common control method is EMG-based motion classification. We propose the use of EMG signal whitening as a preprocessing step in EMG-based motion classification. Whitening decorrelates the EMG signal and has been shown to be advantageous in other EMG applications including EMG amplitude estimation and EMG-force processing. In a study of ten intact subjects and five amputees with up to 11 motion classes and ten electrode channels, we found that the coefficient of variation of time domain features (mean absolute value, average signal length and normalized zero crossing rate) was significantly reduced due to whitening. When using these features along with autoregressive power spectrum coefficients, whitening added approximately five percentage points to classification accuracy when small window lengths were considered.
authors.forename: Lukai
authors.initials: L
authors.lastname: Liu
authors.forename: Pu
authors.initials: P
authors.lastname: Liu
authors.forename: Edward A
authors.initials: EA
authors.lastname: Clancy
authors.forename: Erik
authors.initials: E
authors.lastname: Scheme
authors.lastname: Englehart
mesh_terms: D000328:Adult; D000465:Algorithms; D000671:Amputation, Surgical / Q000534:rehabilitation*; D000673:Amputation, Traumatic / Q000534:rehabilitation*; D000674:Amputees; D001186:Artificial Limbs; D017076:Computer-Aided Design; D003627:Data Interpretation, Statistical; D004576:Electromyography / Q000145:classification* / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009068:Movement / Q000502:physiology; D011474:Prosthesis Design; D059629:Signal-To-Noise Ratio; D034941:Upper Extremity / Q000502:physiology*; D055815:Young Adult