Academic work
In July 2001, Popovic established The Rehabilitation Engineering Laboratory (REL) at the Lyndhurst Centre of TRI. [4] The laboratory supports multiple research groups, including the Popovic lab, under the supervision of 6 principal investigators. In 2004, he established the Neural Engineering and Therapeutics research team at TRI, which works on translation of rehabilitative research into advanced therapeutic tools. [5] Popovic led this team until 2017. In 2017, in partnership with Dr. Taufik Valiante, he established the Centre for Advancing Neurotechnological Innovation to Application (CRANIA) at UHN and UofT, which they jointly codirected until 2023. [1] In 2018, Popovic was appointed TRI's Director of Research, which he rebranded into the KITE Research Institute in 2019. [6] [7] In 2021, he founded the FabrIc-Based REsearch (FIBRE) platform and directed it until 2023. [1] In 2023, Popovic was appointed the Director of the Institute of Biomedical Engineering at UofT. [8]
Functional electrical stimulation
Functional electrical stimulation (FES) uses bursts of short electrical pulses to generate muscle contraction. Application of these electrical pulses to motor nerves results in generation of an action potential along the axon of that nerve towards its targeted muscle. [9] With electrodes placed on the skin over the muscle, individuals attempt to move their muscle by sending a signal with their brain to the muscle. The muscle is then stimulated by the system, causing a contraction which sends a signal from the muscle to the brain. Thus, a new neural pathway is formed, which improves recovery of voluntary movement. [10]
Popovic has led studies investigating the use of FES in the rehabilitation of muscular function for stroke victims with extremely limited arm and hand mobility in comparison with conventional therapy. One of the best-known publications is "Rehabilitation of Reaching and Grasping Function in Severe Hemiplegic Patients Using Functional Electrical Stimulation Therapy", conducted in 2008. Electrical impulses to activate muscles were used in combination with verbal cues, and over the course of the treatment period, less FES was necessary to achieve the desired movements. Patients using FES in the study showed significant improvement in object manipulation, palmar grip torque, and pinch grip pulling force when compared to those using only conventional therapy. [11]
Brain-machine interfaces
Popovic is involved in the development of various brain-machine interfaces (BMI) for use in humans, using implantable electrocorticographic (ECoG) and surface electroencephalographic (EEG) electrode. A neuroprosthesis study conducted using ECoG achieved high accuracy in producing intended grasp-and-release functionality in the hand. [12] Real-time asynchronous control of a remote-controlled car was achieved using a single EEG electrode to eliminate restrictions related to information transfer rates. [13] Work within this field tests the feasibility and functionality of using invasive and non-invasive physiological signals to improve implementation of FES as a rehabilitation method.
Compex Motion simulator
Popovic developed Compex Motion, a portable and programmable system used for transcutaneous FES, in collaboration with Swiss company Compex SA. The stimulator can be programmed to generate a variety of stimulation sequences, can be connected to other systems to increase channel capabilities, and can be controlled externally. The device can be used in the development of neuroprostheses, and muscle exercise systems. [14] This work provided the foundation for the use of FES in SCI rehabilitation.
