Dan Root, M.D. *RETIRED IN FEB. 2025
Sleep Specialist
Dr. Root has been practicing medicine in Portland since his residency at OHSU in 1991. He is Board Certified in Sleep Medicine, and founded Oregon Sleep Associates (OSA) in 2005 in order to bring a more patient oriented approach to Sleep Medicine in Portland. In recognition of the success of OSA, he was awarded as one of Portland Monthly Magazine’s Top Doctors in Sleep Medicine for 2013.
He did his undergraduate work at Williams College where he received a Bachelor of the Arts in Political Science, and then went to Medical School and Fellowship training at Baylor College of Medicine. He is a member of the American Academy of Sleep Medicine, the Multnomah Medical Association, and the Oregon Medical Association.
He enjoys spending time with his family, cooking, cycling, supporting Canoe Island French Camp, and the Portland Timbers.
Matthew Keeslar, PA-C
Physician Associate
A former actor who successfully transitioned into a career as a certified Physician Assistant (PA-C) and medical instructor. Born in 1972, he is known for his roles in films like Waiting for Guffman, The Last Days of Disco, and Scream 3, as well as the sci-fi dramedy The Middleman.
After a decades-long career, Keeslar retired from acting in 2010 to pursue science. He graduated Phi Beta Kappa from Reed College with a biology degree in 2014, following initial coursework at Portland Community College. He went on to earn a Master of Physician Assistant Studies from Oregon Health & Science University (OHSU).
Now a practicing clinician in Oregon, Matt also served as an instructor at the OHSU School of Medicine. He has worked in urology and men's health, urgent care, and pediatrics.
Martha Gichia, FNP-C
Family Nurse Practitioner
Martha is board-certified with 17 years of clinical experience. She joined OSA in 2025 as a telehealth only provider.
She earned her master's degree as a family nurse practitioner at the University of Michigan-Flint in 2015 and is a proud fan of the University of Michigan.
Martha believes in a holistic and collaborative approach to patient care and strives to provide each patient with evidence-based information and support needed to achieve their ultimate individual health goals.
Martha believes good quality sleep is essential for health and emotional well-being.
Born and raised in Central Kenya, and currently residing in Michigan with family, Martha enjoys the outdoors, cooking, travelling and spending time with family and friends.