William Barsan, MD is a senior leader in SIREN, overseeing clinical trial recruitment, financial contracting, and investigator engagement. With over 40 years of experience in stroke and neurological emergency research, he has led major clinical trial networks, including NETT and SIREN. Dr. Barsan collaborates with national research networks and agencies to advance emergency care research and has extensive expertise in adaptive trial design. He is a Professor and former Chair of Emergency Medicine at the University of Michigan Medical School.