Journal: PNAS Nexus

Article Title: Customizable, reconfigurable, and anatomically coordinated large-area, high-density electromyography from drawn-on-skin electrode arrays

doi: 10.1093/pnasnexus/pgac291

Figure Lengend Snippet: High-density DoS MEA usage for muscle activity assessments. (A) High-density DoS MEA on the flexor muscle group of a subject, inset shows the orientation of the layout (“A to D” for rows and “1 to 8” for columns, scale bar = 1 cm) for motor unit propagation mapping and innervation zone localization (scale bar = 2 cm). (B) Propagation map of a single row of the high-density DoS MEA. The change in the inflection of the wave in the third trace from the bottom (indicated by the red star) denotes the innervation zone, and the red arrows indicate the characteristic “V” pattern indicating propagation of the MUAP in different directions from the innervation zone. (C) Complete propagation maps for the entire DoS MEA and innervation zone band indicated by the red stars connected with dotted lines. (D) Setup for DoS MEA and conventional FPC grid comparison of EMG measurement during seated resistance band bicep curls. The labeling of the rows is used to calculate average EMG signals across each of the rows of the respective MEAs for signal quality examination. (E) Signal-to-noise ratios of averaged EMG signals from each row of the DoS MEA and FPC grid during 30 min of exercise.

Article Snippet: The sensing capability of the high-density DoS MEAs was validated by measuring their impedance characteristics, and they were compared with multiple types of the existing bioelectronics (stretchable Au mesh-based MEA and intrinsically stretchable PEDOT: PSS MEA) and the conventional technology, referred to herein as the flexible printed circuit (FPC) grid (Twente Medical Systems TMSi, Enschede Netherlands).

Techniques: Activity Assay, Comparison, Labeling

Journal: PNAS Nexus

Article Title: Customizable, reconfigurable, and anatomically coordinated large-area, high-density electromyography from drawn-on-skin electrode arrays

doi: 10.1093/pnasnexus/pgac291

Figure Lengend Snippet: Subject-customized DoS MEAs for finger gesture classification and prosthetic hand control. (A) Custom stencils of linear eight-electrode arrays placed as four rows (to form a 4 × 8 array) around the varying circumferences (indicated by the four labeled positions) of the forearm of a subject (scale bar = 2 cm). (B) Camera image of a completed and customized DoS MEA over the flexor and extensor groups for flexion and extension-based finger gesture classification (scale bar = 2 cm). (C) V rms feature maps of different gestures on lateral views of the forearm. (D) The confusion matrix from a linear discriminant analysis (LDA) classifier after offline analysis of EMG data obtained with two FPC grids having 128 channels. These grids only covered a portion of the circumference of the forearm. The numbers on the axes correspond to the labels in the feature maps above. (E) Confusion matrix from a LDA classifier after offline analysis of EMG data obtained with DoS MEAs having 32 channels. The DoS MEAs covered the entire circumference of the forearm. The numbers on the axes correspond to the labels in the feature maps above. (F) Near real-time control of a prosthetic hand by a human subject wearing the customized DoS MEA to mimic ring, little flexion (left, scale bar = 5 cm); thumb, index, middle flexion (middle, scale bar = 5 cm); and hand closed (right, scale bar = 5 cm).

Article Snippet: The sensing capability of the high-density DoS MEAs was validated by measuring their impedance characteristics, and they were compared with multiple types of the existing bioelectronics (stretchable Au mesh-based MEA and intrinsically stretchable PEDOT: PSS MEA) and the conventional technology, referred to herein as the flexible printed circuit (FPC) grid (Twente Medical Systems TMSi, Enschede Netherlands).

Techniques: Control, Labeling