Dan Root, M.D.
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 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.


Kaanchan Gangal, M.D.
Sleep Specialist

Dr. Gangal is Board Certified in Neurology and Sleep Medicine.  She joined Oregon Sleep Associates to focus her practice on sleep medicine, seeing patients from 5 years old to geriatrics.  She brings a great knowledge base and personable style to her patient interactions.

Dr. Gangal graduated from the University of Virginia with a Bachelor of Arts in Cognitive Science and then completed medical school at Jefferson Medical College.  Her Neurology residency was completed at the University of Virginia, and she attended her sleep fellowship at the University of Michigan.  She is a member of the American Academy of Sleep Medicine, American Academy of Neurology, and Alpha Chi Sigma (National Professional Chemistry Fraternity).

Dr. Gangal enjoys working with the Junior League of Portland, traveling, reading, music promotion, French language, and writing.


Brook Ervin, N.P.
Nurse Practitioner

Brooke Ervin joined Oregon Sleep Associates in 2015. She is an adult nurse practitioner and assists Dr. Root and Dr. Gangal by providing follow-up and maintenance care for existing patients of OSA. She received her Bachelor of Science in Nursing from Villanova University in 1998 and completed her Master of Science in Nursing at Duke University in 2007. She is certified by the American Academy of Nurse Practitioners. She practiced in orthopedic and neurology fields prior to joining Oregon Sleep Associates.


Brooke and her family moved to Portland from Raleigh, NC, in 2014.  She enjoys spending time with her family and exploring the beautiful state of Oregon.


Jason Cowlishaw, RPSGT
Durable Medical Equipment Coordinator

Jason is a long-time member of Oregon Sleep Associates, starting with the practice in 2006. He is the clinic’s durable medical equipment (DME) coordinator and brings more than 15 years of experience in the DME field. He is registered with the Board of Registered Polysomnographic Technologists. He moved to Portland from Stayton, OR, in 2006.   

Jason enjoys his daily interactions with patients, which ultimately improves their quality of life. Outside of the office he likes watching sports, playing golf and basketball, cooking, and listening to music.


                                                                                                         Milyn Lefohn, CMA
                                                                                                         Practice Manager



Taylor Harrison, RPSGT
HST Office Administrator