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Microsystems, Electronics and Acoustics
ISSN 2523-4447 · e‑ISSN 2523-4455 Open Access · CC BY-SA 4.0
Vol. 31 · Issue 1 · 2026 May 1, 2026 Electronic Systems and Signals

WiFi-Based Control System for Active Lower Limb Orthosis: A Distributed Architecture Approach

AK
Anton Vasylovych Kotsiubailo Corresponding National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” Ukraine
OL
Dr.Sc.(Eng.), Prof. Oleksandr Mykolaiovych Lysenko National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” Ukraine
Pages355559.1-355559.6 PublishedMay 1, 2026 LicenseOpen Access
VOL 31 · ISS 1 · 2026 View issue

Abstract

This research presents the design, multi-threaded software implementation, and empirical evaluation of an active, electromyography (EMG)-driven upper-limb orthosis utilizing a distributed master-slave embedded control architecture. Engineered specifically to address the clinical challenges of severe upper-limb paresis—such as those resulting from brachial plexus trauma—the system bypasses traditional localized muscle control by acquiring voluntary surface EMG signals from the sternocleidomastoid (SCM) neck muscle, utilizing it as a stable proxy for motion intent. To ensure hard real-time deterministic execution and high-fidelity signal processing, the system is physically and logically decoupled into three operational layers. A dedicated analog front-end (AD8232) and an STM32F407 microcontroller handle localized biosignal conditioning and digitization. A Jetson Nano single-board computer operates as the supervisory node, executing a strictly governed finite state machine (FSM) to perform digital filtering, feature extraction, and motion classification. Finally, an ESP32 microcontroller paired with a BTS7960 high-current H-bridge manages real-time brushed DC motor actuation. Communication across these distinct hardware layers is achieved wirelessly via a TCP/IP protocol over Wi-Fi, eliminating cumbersome physical tethers and establishing a foundation for advanced Internet of Things (IoT) integration. Software execution relies on a multi-threaded, mutex-protected environment capable of achieving an average sample-to-result latency of 6.02 milliseconds. Real-time joint angle feedback is continuously provided by an AS5048A absolute magnetic encoder via an SPI interface, ensuring kinematic safety and rigid adherence to predefined anatomical limits. Experimental results validate the system's capacity for safe, highly responsive operation, demonstrating that complex classification algorithms and wireless distributed topologies can successfully meet the rigorous latency requirements of wearable rehabilitation robotics, though future iterations may necessitate the integration of brushless actuators to mitigate static friction and low-speed operational limitations.

Keywords

References

  1. R. A. R. C. Gopura, D. S. V. Bandara, K. Kiguchi, and G. K. I. Mann, “Developments in hardware systems of active upper-limb exoskeleton robots: A review,” Rob. Auton. Syst., vol. 75, pp. 203–220, Jan. 2016, doi: 10.1016/j.robot.2015.10.001.
  2. A. M. Dollar and H. Herr, “Lower Extremity Exoskeletons and Active Orthoses: Challenges and State-of-the-Art,” IEEE Trans. Robot., vol. 24, no. 1, pp. 144–158, Feb. 2008, doi: 10.1109/TRO.2008.915453.
  3. M. Asghari Oskoei and H. Hu, “Myoelectric control systems—A survey,” Biomed. Signal Process. Control, vol. 2, no. 4, pp. 275–294, Oct. 2007, doi: 10.1016/j.bspc.2007.07.009.
  4. K. Englehart and B. Hudgins, “A robust, real-time control scheme for multifunction myoelectric control,” IEEE Trans. Biomed. Eng., vol. 50, no. 7, pp. 848–854, Jul. 2003, doi: 10.1109/TBME.2003.813539.
  5. M. Barsotti et al., “A full upper limb robotic exoskeleton for reaching and grasping rehabilitation triggered by MI-BCI,” in 2015 IEEE International Conference on Rehabilitation Robotics (ICORR), IEEE, Aug. 2015, pp. 49–54. doi: 10.1109/ICORR.2015.7281174.
  6. J. R. Cram, G. S. Kasman, and J. Holtz, Introduction to surface electromyography. Aspen Publishers, 1998.
  7. A. V. Kotsiubailo et al., “Designing Minimalistic Powered Arm Orthosis for Brachial Plexus Injuries,” Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 96, pp. 50–61, Jun. 2024, doi: 10.20535/RADAP.2024.96.50-61.
  8. “AD8232 Single-Lead Heart Rate Monitor Front End (Datasheet),” 2012. Accessed: Mar. 25, 2026. [Online]. Available: https://www.analog.com/media/en/technical-documentation/data-sheets/ad8232.pdf
  9. A. Phinyomark, P. Phukpattaranont, and C. Limsakul, “Feature reduction and selection for EMG signal classification,” Expert Syst. Appl., vol. 39, no. 8, pp. 7420–7431, Jun. 2012, doi: 10.1016/j.eswa.2012.01.102.
  10. A. Wang, J. Dong, R. Teng, P. Liu, X. Yue, and X. Zhang, “A Hierarchical Distributed Control System Design for Lower Limb Rehabilitation Robot,” Technologies, vol. 13, no. 10, p. 462, Oct. 2025, doi: 10.3390/technologies13100462.
  11. H. Alemdar and C. Ersoy, “Wireless sensor networks for healthcare: A survey,” Comput. Networks, vol. 54, no. 15, pp. 2688–2710, Oct. 2010, doi: 10.1016/j.comnet.2010.05.003.
  12. “ESP32 Technical Reference Manual (Datasheet),” 2021. Accessed: Mar. 25, 2026. [Online]. Available: https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf
  13. “BTS7960 High Current Half Bridge (Datasheet),” 2011. Accessed: Mar. 25, 2026. [Online]. Available: https://www.infineon.com/dgdl/BTS7960_Datasheet.pdf?folderId=db3a304412b407950112b408e8c9
  14. “AS5048A/AS5048B 14-bit On-Axis Magnetic Rotary Position Sensor,” 2013. Accessed: Mar. 25, 2026. [Online]. Available: https://ams-osram.com/products/sensor-solutions/position-sensors/ams-as5048a-high-resolution-position-sensor
  15. N. Vitiello et al., “NEUROExos: A Powered Elbow Exoskeleton for Physical Rehabilitation,” IEEE Trans. Robot., vol. 29, no. 1, pp. 220–235, Feb. 2013, doi: 10.1109/TRO.2012.2211492.
  16. A. Williams, C++ concurrency in action : practical multithreading. Manning, 2012.
  17. “Jetson Nano Developer Kit User Guide,” 2019. Accessed: Mar. 25, 2026. [Online]. Available: https://developer.nvidia.com/embedded/jetson-nano-developer-kit
  18. K. W. Horch and D. Kipke, Neuroprosthetics : theory and practice. World Scientific Publishing Co. Pte. Ltd., 2017.

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