These exoskeleton prototypes are driven to address one question: "Can we use arms to aid legs?" This simple question has led to several exoskeleton concepts and design iterations over the years. The primary goal is to understand the neural coupling between arm and leg motions during walking and how to tap into that natural kinematic coupling to capture and transfer motion or force from arm movements to the leg joints. The target application is twofold: patients with moderate gait impairment or disability who rely on walking aids (such as canes, crutches, or walkers) and physical performance augmentation.

• G. R. Carbonell, R. Choudhury, E. Frankle, I. F. Kadhim, D. Fukuda and J. -H. Park, “Work-sharing of Upper and Lower Limbs (WULL) to Assist Ambulatory Movements,” 2022 9th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob), Seoul, Korea, Republic of, 2022, pp. 1-6, doi: 10.1109/BioRob52689.2022.9925403.

• J-H. Park, G. Carbonell, E. Frankle, “Appendage Work Sharing Apparatus”, US Patent  63/345,295, May 27, 2022

Resistance training is one of the common treatment modalities for various types of muscle impairment to regain muscle mass, strength, and tone. The most widely used tool is resistance bands that exert force on the body joints as elastic material stretches. The key difference of this variable resistance suit compared to resistance bands is providing speed-dependent (not proportional to elongation (stretching)), bi-directional, and adjustable resistance at a target joint using three rotary dampers connected in parallel. The effectiveness of this device has been validated which showed a significantly greater increase in muscle strength (>30%) compared to what can be achieved using existing resistance training tools. 

• Kadhim IF, Banarjee C, Fu J, Choudhury R, Mangum LC, Fukuda DH, Stout JR, Cramer JT, Park J-H*, Resistance Training Using VAriable Resistance Suit (VARS) Increased Isometric and Isokinetic Muscle Strength, IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 32, pp. 2835-2844, 2024, doi: 10.1109/TNSRE.2024.3435798

• J-H. Park, I. Kadhim, A. Alvial, G. Carbonell, S. Mohammadhosseini, “VARIABLE RESISTANCE EXERCISE APPAREL”, US Patent 63/343,302, May 19, 2022

• Kadhim, IF, Aracena Alvial, AA, Frankle, E, Rios Carbonell, G, Hosseini, SM, Fukuda, D, Stout, J, & Park, J*. “Variable Resistance Suit (VARS) for Enhancing Resistance Training.” Proceedings of the ASME 2022 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. Volume 7: 46th Mechanisms and Robotics Conference (MR). St. Louis, Missouri, USA. August 14–17, 2022. V007T07A055. ASME. https://doi.org/10.1115/DETC2022-91042

This project is to implement and validate myoelectric control on a bilateral cable-driven upper body exosuit. Using cables and pulleys integrated into brushless DC actuators with in-line tension sensor, the amount of tension in cables is controlled to modulate the assistive torque at shoulder and elbow joints. IMUs and EMG sensors are also integrated into wearable interface to facilitate joint torque estimation and human effort - these together can offer human-in-loop control of this wearable robot. 

• J. Fu, S. M. Hosseini, R. Simpson, A. Brooks, R. Huff and J. -H. Park, “A Bilateral Six Degree of Freedom Cable-driven Upper Body Exosuit,” 2022 IEEE International Conference on Mechatronics and Automation (ICMA), Guilin, Guangxi, China, 2022, pp. 617-623, doi: 10.1109/ICMA54519.2022.9856241. – “Best Student Paper Award”

• Fu, J., Choudhury, R., M. Hosseini, S., Simpson, R., Choudhury, R., Park, J., “Myoelectric Control Systems for Upper Limb Wearable Robots-A systematic review”, Sensors (Basel). 2022 Oct 24;22(21):8134. DOI: 10.3390/s22218134

• J. Fu, R. Choudhury and J. -H. Park*, “Deep Reinforcement Learning Based Upper Limb Neuromusculoskeletal Simulator for Modelling Human Motor Control,” 2023 IEEE International Conference on Systems, Man, and Cybernetics (SMC), Honolulu, Oahu, HI, USA, 2023, pp. 2789-2795, doi: 10.1109/SMC53992.2023.10394268

This project was funded by NSF to develop a robotic spine brace to improve clinical outcomes of bracing for correction of spine deformity (scoliosis, kyphosis). Two fully parallel mechanisms stacked together formed a total 12 degrees of freedom parallel robot mounted on a human torso to modulate 3D position and force applications at the desired location (level) of the torso.  

• J. Park, P. Stegall, D. Roye Jr., S. Agrawal, “Robotic Spine Exoskeleton (RoSE): Characterizing the Three-dimensional Stiffness of the Human Torso in Treatment of Spine Deformity,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, 26(5), pp. 1026-1035, 2018. DOI: 10.1109/TNSRE.2018.2821652

• R. Murray, C. Ophaswongse, J. Park and S. Agrawal, “Characterizing Torso Stiffness in Female Adolescents With and Without Scoliosis,” in IEEE Robotics and Automation Letters, vol. 5, no. 2, pp. 1634-1641, April 2020, DOI: 10.1109/LRA.2020.2969945

• S. Agrawal, J. Park, P. Stegall, “Spinal treatment device, methods, and systems,” US (US 2017/0042717 A1), European (EP3134038A4) and International (WO2015164814A3), Feb. 16, 2017

This project was funded by DARPA to develop an upper-body exosuit to help reduce shoulder and lower back pain associated with carrying a heavy rucksack. Our strategy was to create an external load pathway to transfer the load on the shoulders directly to the hips, bypassing the shoulders and spine. In addition, a slider mechanism was implemented at the waist level where the load from the backpack is applied, to which its vertical position could be modulated via cables attached to a brushless DC motor. The controller receives the real-time feedback on the vertical acceleration of the waist of the user during walking, estimates the dynamic (inertial) load induced during walking, and then applies force at the waist to compensate for it. This strategy was able to reduce the cost of transport and significantly reduce the load applied to the shoulders and spine.   

• J. Park, P. Stegall, H. Zhang, S. Agrawal, “Walking with a backpack using load distribution and dynamic load compensation reduces metabolic cost and adaptations to loads,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, 25(9), pp. 1419-1430, 2017. DOI: 10.1109/TNSRE.2016.2627057

• J. Park, P. Stegall, S. Agrawal, “Reducing Dynamic Loads from a Backpack during Load Carriage using an Upper Body Assistive Device,” Journal of Mechanisms and Robotics-Transactions of the ASME. 8(5), 051017, pp. 1-8, 2016. DOI: 10.1115/1.4032214

• J. Park, X. Jin, S. Agrawal, “Second Spine: Upper Body Assistive Device for Human Load Carriage,” Journal of Mechanisms and Robotics-Transactions of the ASME. 7(1), 011012, pp. 1-11, 2015 DOI: 10.1115/1.4029293