Pulmonology, critical care physician joins Franciscan Physician Network in Michigan City MICHIGAN CITY, Indiana – Pulmonary and critical care physician David Villafuerte Martinez, MD, is now part of the Franciscan Physician Network and is accepting new patients in Michigan City. Dr. Villafuerte Martinez is board-certified in pulmonary and critical care medicine. He attended medical school at Pontificia Universidad Católica del Ecuador in Ecuador and completed both his residency and fellowship at the