Dynamic monitoring of forearm muscles using one-dimensional sonomyography system

Abstract

Abstract-We introduce a method, known as one-dimensional sonomyography (1-D SMG), that uses A-mode ultrasound signals to detect dynamic thickness changes in skeletal muscle during contraction. We custom-designed a 1-D SMG system to collect synchronized A-mode ultrasound, joint angle, and surface electromyography (EMG) signals of forearm muscles during wrist extension. We extracted the 1-D SMG signal from the ultrasound signal by automatically tracking the corresponding echoes, which we then used to calculate muscle thickness changes. We tested the right forearm muscles of nine nondisabled young subjects while they performed wrist extensions at 15.0, 22.5, and 30.0 cycles/min and their largest wrist extension angle ranged from 80° to 90°. We found that the muscle deformation and EMG root mean square signals correlated linearly with wrist extension angle. The ratio of deformation to wrist angle was significantly different among the subjects (p < 0.001) but not among the trials of different extension rates for each subject (p = 0.9). The results demonstrate that 1-D SMG can be reliably performed and that it has the potential for skeletal muscle assessment and prosthesis control.

Feasibility of controlling prosthetic hand using sonomyography signal in real time: Preliminary study

“…We studied the relationship between the thickness deformation SMG of the forearm extensor and wrist angle during wrist extensionflexion. We discovered qualitatively similar profiles between the SMG and the wrist angle, suggesting a high degree of correlation [7,[20][21][22]. Furthermore, we found that SMG profiles from amputees performing hypothetical wrist extension-flexion were similar to those from nondisabled subjects [20].…”

“…In previous studies, we have proposed that the thickness deformation SMG of extensor carpi radialis muscle was closely correlated with wrist extension-flexion [7,20,23]. This close relationship is the basis for SMGbased prosthetic control.…”

“…For example, it is believed that considerable attention is required to control EMG-based prostheses, often resulting in fatigue [4][5]. It is also difficult for SEMG to detect the activities of deep muscles because the deep muscle EMG may be attenuated and/or mixed with the superficial muscle EMG at the skin surface [4,[6][7]. Furthermore, the lack of proprioceptive feedback is one of the major disadvantages for SEMG-based control [2,[3][4][5].…”

“…Therefore, muscle structure could potentially be used to control a prosthetic hand. Ultrasonography can accurately and reliably detect the structural changes of skeletal muscle, such as muscle thickness [7,[15][16], muscle fiber pennation angle [15][16], muscle fascicle length [15,17], and crosssectional area [18] during isometric and dynamic contractions. The relationships between EMG activities and changes in muscle structure extracted from ultrasound images have also been reported [7,[15][16]19], resulting in a characterization of the muscle properties from both electrophysiology and structural morphology.…”

“…In previous studies, we used the term sonomyography (SMG) to describe the structural and morphological changes of skeletal muscle extracted from ultrasound images [7,[20][21][22] and showed that the SMG signal is different from the sound signal generated by muscle contraction, which is commonly called MMG. We studied the relationship between the thickness deformation SMG of the forearm extensor and wrist angle during wrist extensionflexion.…”