An optoelectronic muscle contraction sensor for prosthetic hand application

Abstract

Surface electromyography (sEMG) is considered an established means for controlling prosthetic devices. sEMG suffers from serious issues such as electrical noise, motion artifact, complex acquisition circuitry, and high measuring costs because of which other techniques have gained attention. This work presents a new optoelectronic muscle (OM) sensor setup as an alternative to the EMG sensor for precise measurement of muscle activity. The sensor integrates a near-infrared light-emitting diode and phototransistor pair along with the suitable driver circuitry. The sensor measures skin surface displacement (that occurs during muscle contraction) by detecting backscattered infrared light from skeletal muscle tissue. With an appropriate signal processing scheme, the sensor was able to produce a 0–5 V output proportional to the muscular contraction. The developed sensor depicted decent static and dynamic features. In detecting muscle contractions from the forearm muscles of subjects, the sensor showed good similarity with the EMG sensor. In addition, the sensor displayed higher signal-to-noise ratio values and better signal stability than the EMG sensor. Furthermore, the OM sensor setup was utilized to control the rotation of the servomotor using an appropriate control scheme. Hence, the developed sensing system can measure muscle contraction information for controlling assistive devices.

Optical Myography-Based Sensing Methodology of Application of Random Loads to Muscles during Hand-Gripping Training

“…OMG is a myographic method based on optical information [ 37 ]. In particular, a near-infrared sensor is used to monitor the skeletal muscle activities [ 38 , 39 , 40 , 41 , 42 ] A near-infrared light is strongly scattered by biological tissue when it propagates through the tissues [ 43 ], which has a potential that the reflectance information includes relatively deeper muscle information. The reflectance of the near-infrared light changes due to muscle oxygenation activity involved by muscle deformation because hemoglobin and myoglobin absorb the near-infrared light [ 44 , 45 ].…”

Flexible and Stretchable Light-Emitting Diodes and Photodetectors for Human-Centric Optoelectronics

“…To overcome the mismatch present at the biotic-abiotic interface, tremendous research efforts have been devoted to developing functional devices that exhibit mechanical properties analogous to the target biological tissues. − Specifically, optoelectronic devices that mimic the mechanical properties of human tissues and organs have been extensively investigated, owing to the possibility of realizing versatile and practical applications. These include artificial vision systems, ,− HMIs, − soft prosthetics, − and biometric authentication systems. , Several optoelectronic devices with flexible and stretchable features have been readily demonstrated, showing excellent elastic properties and operational durability under mechanical deformation. − These optoelectronic devices engaged with users to consistently and precisely monitor their physiological conditions without imposing limitations based on the users’ location. The advancements in these devices were mainly achieved by the development of novel flexible and stretchable photoactive materials, along with device design and integration strategies.…”