Michael Rosenfield, D.O.
Dr. Rosenfield’s journey in medicine has been shaped by a deep commitment to bridging gaps in healthcare. His extensive training, coupled with decades of experience, have prepared him to support patients through life’s most challenging health concerns. By fostering a safe, inclusive environment, Dr. Rosenfield ensures that every patient feels seen, heard and cared for.
Dr. Rosenfield began his medical journey with a bachelor’s degree from the University of South Florida, followed by his doctoral degree of Osteopathic Medicine. He completed an OMM Fellowship at Nova Southeastern University in Fort Lauderdale, Florida. Prior to joining Hill Health, he served as a physician in Urgent Care and Occupational Medicine at Dignity Health and St. Mary’s Medical Center, where he built a reputation for delivering personalized care tailored to individual needs.
Outside of work, Dr. Rosenfield enjoys spending time with his two children and exploring his love for cooking, which led him to attend culinary school in the South of France.
“It was my first visit with Dr. Michael Rosenfield for establishing care, and I couldn’t be more impressed. He took the time to get to know me, listened carefully to my concerns, and explained everything clearly. I felt comfortable and confident in his care from the start.”
Schedule an appointment with Dr. Rosenfield today to experience personalized, compassionate care from a physician who is committed to improving lives, one patient at a time.
Gregg Pottorff, M.D.
Dr. Gregg Pottorff has been in orthopedic surgical practice for over 32 years. He is the Specialty Medical Director for Hill Physicians Medical Group in the Bay Region. In addition to being the President of Hill Physicians and the Chair of its Board, he is a chair or member of numerous administrative committees that help to maintain the recognized status of Hill Physicians as a medical organization of the highest quality.
Dr. Pottorff received his Bachelor of Arts in Physics and Economics from the University of California, Santa Cruz, in 1982 and earned his Medical Doctor degree in 1986 from Stanford University. He then stayed on to complete his orthopedic surgery residency at Stanford. Instead of going straight into practice, he then added an additional Fellowship in Sports Medicine from the Kerlan-Jobe Orthopedic Clinic in Los Angeles, helping to care for the Dodgers, Lakers, Rams, Kings, USC, Loyola, and other local LA area sports teams.
His specialty is now office-based orthopedics, and he will do his absolute best to help patients avoid surgery whenever possible. He loves playing tennis, hiking, and traveling with his family when he’s not with patients.
Justin Dumouchel, M.D.
Dr. Justin Dumouchel is a highly skilled and experienced pulmonary and critical care physician with 8 years of experience. He holds a Bachelor of Science degree in Biochemistry from Georgetown University, where he also completed a second major in History. After completing his Internal Medicine Residency at the University of Pittsburgh Medical Center, Dr. Dumouchel completed his Pulmonary and Critical Care Fellowship at the University of California San Diego.
He specializes in treating a range of respiratory issues, including asthma, acute and chronic lung disease, lung cancer screening, respiratory system testing, and pulmonary rehabilitation. Dr. Dumouchel’s dedication to healthcare is reflected in the numerous awards he has received, including Phi Beta Kappa, Alpha Omega Alpha (Medical School Honor Society), Phi Alpha Theta (History Honor Society), and Sigma Xi (Chemistry Honor Society). Prior to joining Hill Physicians as an outpatient pulmonary physician in 2021, Dr. Dumouchel worked at Alta Bates Summit in Berkeley and Oakland, and previously was part of a group outpatient practice for seven years.
He is passionate about his profession and believes in offering personalized care to each of his patients. When not working, Dr. Dumouchel enjoys hiking and water sports. He and his wife are fans of the Oakland Roots Sports Club, the local soccer team playing at Laney College Football Stadium.
Ryan J. Anderson, M.D.
Dr. Ryan Anderson MD completed his Critical Care and Pulmonary fellowship at Stanford University where he pursued a sub-fellowship in Pulmonary Hypertension at the Stanford Vera Moulton Wall Center for Pulmonary Vascular Disease.
He has privileges to perform right heart catheterizations for diagnosis of PH at Summit Medical Center, and he has experience in initiation and management of oral and inhaled pulmonary vasodilator thera¬pies for qualifying patients. Dr. Anderson can help to determine what cases require higher level therapy (i.e. subcutaneous and intravenous prostanoid therapy) or referrals.
Carene Parulan, R.N., M.S.
Carene became a valued member of Hill Health in 2022, leveraging her time here to gain extensive experience as a pulmonary nurse practitioner. She holds a master’s degree in nursing from California Baptist University, obtained her bachelor’s degree in nursing from the University of Santo Tomas, and is board-certified by the American Academy of Nurse Practitioners. With over 12 years of experience as a registered nurse in critical care settings, Carene has a wealth of knowledge in primary care.
Her approach to healthcare is patient-centered, ensuring she takes the time to listen to her patients’ concerns and collaborates with them to create personalized treatment plans that meet their needs and goals. Outside the clinic, Carene is an adventurer at heart. She loves spending quality time with her family, hiking through scenic trails, exploring diverse cultures through travel, experimenting with new recipes in the kitchen, and unwinding with a good movie.
David Louis, M.D.
For David Louis, MD, a family medicine practitioner, the best part about being a doctor is getting to work with patients every day. “I consider it a great honor and privilege when patients trust me with their care”.
Dr. Louis credits his patients as his main inspiration. “What has sustained me throughout the years is the amazing individual stories of my patients and their families — stories of courage, strength, grace, kindness and generosity. I have learned more from my patients than from medical school and residency training.”
Dr. Louis believes that trust, openness, cooperation, and kindness are the keys to the patient-doctor relationship. He has followed the same philosophy since graduating from medical school, which is “to respect my patients, learn what makes each patient unique, do the best I can, and ensure that everyone leaves my office feeling better than when they came in.
He enjoys hiking, watching good movies, spending time with family and pursuing creative outlets like singing and painting.
Languages: English, Cantonese
