Portrait of Paul Yoo

Paul Yoo

Associate Professor

BASc (Toronto), MSc (Southern California), PhD (Case Western Reserve), PEng

Research Stream: Clinical Engineering

Laboratory Website:

Email: paul.yoo@utoronto.ca | Tel: 416 978-7326 | Office: Lassonde Mining Building (MB), 170 College Street, Room 321

Main Appointments

  • Institute of Biomaterials & Biomedical Engineering
  • Edward S. Rogers Sr. Department of Electrical & Computer Engineering
  • Chair, Biomedical Systems Engineering Major, Division of Engineering Science

Research Interests

A fundamental goal of neural engineering is to better understand the role of the nervous system—in both normal and pathological states — and thus develop clinically effective therapies based on electrical neuromodulation.

Examples include functional electrical stimulation in persons with spinal cord injury (e.g., reanimation of movement), hypoglossal nerve stimulation for obstructive sleep apnea, and sacral neuromodulation for urinary function.

Although, in some cases, serendipitous discoveries have lead to therapies in which the precise neural mechanism is not fully understood: deep brain stimulation, vagus nerve stimulation, and cortical stimulation.

Despite the different pathways to discovery, it is clear that these “neural prostheses” can make an immediate and profound impact on the quality of life for millions of people around the world.

Since my initial graduate work in studying the feasibility of selective hypoglossal nerve stimulation for obstructive sleep apnea, the scope of my research has expanded to investigating neural reflexes as a means of restoring bladder function in persons with spinal cord injury.

Through parallel studies conducted in both the laboratory and clinical settings, I have been able to both expand our understanding and also validate our findings regarding the anatomical innervation and the neurophysiology of the lower urinary tract.

More recently, my area of research has extended to corporate sponsored projects that seek to better understand the neural mechanisms of various emerging clinical therapies: vagus nerve stimulation for chronic heart failure, posterior tibial nerve stimulation for treating urinary symptoms, vagus nerve stimulation for obstructive sleep apnea, and investigation of proprietary stimulation waveforms aimed at selectively modulating peripheral nerves.

I will pursue three areas of study that will form the basis of my research program at the University of Toronto. The first two topics will extend my current interest in the areas of lower urinary tract dysfunction and obstructive sleep apnea, while the third topic will explore novel areas of research related to vagus nerve stimulation (e.g., epilepsy).

The complex nature of each problem will require a collaborative effort between clinicians and engineers, and most importantly, the training of graduate and post-doctoral students to become independent researchers at the forefront of neural engineering.

Stories & Media

Cover image of research gallery of 2019

Research Gallery 2019

  • The image shows the finite element (FE) solution for the electric field (heat map) and the current flow (arrows) resulting from the simulation of transcutaneous electrical stimulation (TES) in a 28 cm section of the lower leg (just below the knee to just above the ankle).
    These simulation allow us to gain a deeper understanding of the effects of transcutaneous electrical stimulation variables such as electrode shape and positioning, and stimulation magnitude on neural activation.