Closed-Loop Wearable Device Network of Intrinsically-Controlled, Bilateral Coordinated Functional Electrical...

Area of Science:

• Neuroscience
• Rehabilitation Engineering
• Biomedical Devices

Background:

• Functional electrical stimulation (FES) aids stroke rehabilitation but lacks precision.
• Limitations include timing, adaptivity, and symmetry issues, reducing clinical efficacy.
• Foot drop is a common challenge for stroke survivors, impacting mobility.

Purpose of the Study:

• To develop and evaluate a closed-loop wearable device network of intrinsically controlled functional electrical stimulation (CI-FES) system.
• To utilize personal surface myoelectricity for adaptive and precise FES.
• To enhance walking ability and promote recovery in stroke patients.

Main Methods:

• Developed a CI-FES system using surface myoelectricity as a switch and intensity regulator.
• Integrated inertial measurement units for closed-loop control.
• Assessed improvements in ankle joint angle, oxyhemoglobin concentration (fNIRS), and functional movement scales.

Main Results:

• CI-FES significantly improved patients' walking ability, indicated by changes in ankle joint angle mean and variance.
• Functional near-infrared spectroscopy showed positive changes in oxyhemoglobin concentration.
• Long-term testing revealed decreased machine learning classification discriminability between patients and healthy individuals (100% to 92.5%), suggesting recovery.

Conclusions:

• The CI-FES system offers precise, adaptive, and symmetrical stimulation for stroke rehabilitation.
• The system demonstrates significant potential for improving gait and promoting neurological recovery in stroke survivors.
• CI-FES is crucial for contralateral-hemiplegic stroke recovery and advances closed-loop stimulation systems.