An Artificial EMG Generation Model Based on Signal-dependent Noise and Related Application to Motion Classification

The experimental data of measured and artificial EMG signals

Average absolute percentage error in average amplitude for each load weight.

<p>(a) Influence of the recording source of the preset parameters. (b) Comparison of each generation method. Error bars represent the standard deviations for all subjects.</p

Average classification rates of each method.

<p>(a) Muscle activation level of 40%MVC. (b) Muscle activation level of 80%MVC. Error bars in the results of Subjects A–D represent the standard deviations for all trials and those in the average of all subjects represent the standard deviations for all subjects.</p

Location of the electrodes.

<p>EMG signals were recorded using six electrodes (<i>L</i> = 6: Ch. 1: extensor carpi ulnaris; Ch. 2: flexor digitorum profundus; Ch. 3: extensor digitorum; Ch. 4: flexor carpi ulnaris; Ch. 5: triceps brachii; Ch. 6: biceps brachii) at a sampling frequency of 1000 Hz.</p

Overview of the proposed model.

<p>The model expresses an artificial EMG signal <i>z</i>_<i>t</i> at <i>t</i>, based on a process involving white Gaussian noise passed through a shaping filter <i>H</i> and variance . Variance is the value at <i>t</i> of a random variable <i>σ</i>² having a distribution determined by a commanded muscle force component of variance and signal-dependent noise <i>ε</i> according to the commanded muscle force .</p

Scene of the EMG recording.

<p>The subjects were seated with the right upper arm pointing downward, the right forearm bent forward to the horizontal, and the palm turned upward. EMG signals were recorded from a pair of electrodes attached to the biceps brachii while the subjects were weighted with a load on the right wrist and maintained the right elbow on a desk.</p

Examples of measured and artificial EMG signals for each load weight.

<p>(a) Measured EMG signals. (b) Artificial EMG signals generated from the measured EMG signals under each load weight based on the proposed model. (c) Artificial EMG signals generated from the measured EMG signals under a 1000 g load based on the proposed model with the variance modulation.</p

Screenshot of the EMG measurement system.

<p>The bar graph shows the muscle activation level of the agonist muscle.</p

Electrochemical Behavior of Phosphine-Substituted Ruthenium(II) Polypyridine Complexes with a Single Labile Ligand

A series of phosphine-substituted ruthenium polypyridine complexes, <i>cis­(P,Cl)</i>-[Ru­(trpy)­(Pqn)­Cl]­PF₆ (<i><b>cis</b></i><b>-Cl</b>), <i>trans­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF₆)₂ (<i><b>trans</b></i><b>-PN</b>), <i>cis­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF₆)₂ (<i><b>cis</b></i><b>-PN</b>), and [Ru­(trpy)­(dppbz)­(MeCN)]­(PF₆)₂ (<b>PP</b>), were synthesized and crystallographically characterized (trpy = 2,2′:6′,2″-terpyridine, Pqn = 8-(diphenylphosphanyl)­quinoline, and dppbz = 1,2-bis­(diphenylphosphanyl)­benzene). In electrochemical measurements for <i><b>cis</b></i><b>-PN</b> and <b>PP</b>, the reduction of <i><b>cis</b></i><b>-PN</b> resulted in the formation of <i><b>trans</b></i><b>-PN</b> via <i>cis</i>–<i>trans</i> isomerization and that of <b>PP</b> proceeded via a two-electron-transfer reaction. The mechanism of the electrochemical behaviors is discussed through consideration of five-coordinated species, [Ru­(trpy)­(Pqn)]^<i>n</i>+ or [Ru­(trpy)­(dppbz)]^<i>n</i>+ (<i>n</i> = 0–2), formed by liberation of a monodentate labile ligand

Electrochemical Behavior of Phosphine-Substituted Ruthenium(II) Polypyridine Complexes with a Single Labile Ligand

A series of phosphine-substituted ruthenium polypyridine complexes, <i>cis­(P,Cl)</i>-[Ru­(trpy)­(Pqn)­Cl]­PF₆ (<i><b>cis</b></i><b>-Cl</b>), <i>trans­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF₆)₂ (<i><b>trans</b></i><b>-PN</b>), <i>cis­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF₆)₂ (<i><b>cis</b></i><b>-PN</b>), and [Ru­(trpy)­(dppbz)­(MeCN)]­(PF₆)₂ (<b>PP</b>), were synthesized and crystallographically characterized (trpy = 2,2′:6′,2″-terpyridine, Pqn = 8-(diphenylphosphanyl)­quinoline, and dppbz = 1,2-bis­(diphenylphosphanyl)­benzene). In electrochemical measurements for <i><b>cis</b></i><b>-PN</b> and <b>PP</b>, the reduction of <i><b>cis</b></i><b>-PN</b> resulted in the formation of <i><b>trans</b></i><b>-PN</b> via <i>cis</i>–<i>trans</i> isomerization and that of <b>PP</b> proceeded via a two-electron-transfer reaction. The mechanism of the electrochemical behaviors is discussed through consideration of five-coordinated species, [Ru­(trpy)­(Pqn)]^<i>n</i>+ or [Ru­(trpy)­(dppbz)]^<i>n</i>+ (<i>n</i> = 0–2), formed by liberation of a monodentate labile ligand