EmergiCenter Physicians

Our physicians maintain board certification in their respective specialties, in addition to emergency medicine training, to provide patients with exemplary care. They strive to provide all medical services to our patients in a caring and compassionate manner.

Our Physicians

David J. Shingles, D.O.

Dr ShinglesDr. David Shingles is the founder and Medical Director of Cedar Crest EmergiCenter®. He has maintained a private family practice in the Lehigh Valley since 1977.  Dr. Shingles started his career as a pharmacist graduating from Union University, Albany College of Pharmacy in 1967.  He obtained his medical degree at the Philadelphia College of Osteopathic Medicine in 1975.

Dr. Shingles is board certified in Family Medicine and is a certified Medical Review Officer. He is a member of the American Osteopathic Association, Pennsylvania Osteopathic Medical Association, and American College of Family Physicians in Osteopathic Medicine and Surgery.  Dr. Shingles holds active staff affiliations with Lehigh Valley Hospital and St. Luke’s Hospital.  He is a clinical instructor for Pennsylvania College of Osteopathic Medicine and DeSales University.

Jonathan L. Shingles, D.O.

ShinglesDr. Jonathan Shingles earned his Bachelor of Science degree in Biology from Massachusetts Institute of Technology and is a 2000 graduate of the Philadelphia College of Osteopathic Medicine.  Dr. Shingles completed both his internship and residency in Emergency Medicine at St. Luke’s Hospital, Bethlehem, where he currently holds a position as Director of the Emergency Room.  Additionally, he received his MBA in Health Care Administration from St. Joseph’s University of Philadelphia.

Dr. Shingles certifications include; Advanced Life Support, Advanced Trauma Life Support, and Pediatric Advanced Life Support.  He maintains an active membership of the Pennsylvania Medical Association.

Joanne Steward, M.D.

Dr. Joanne Steward is a 1985 graduate of Temple University School of Medicine.  Additionally, Dr. Steward holds both a Master's Degree in Nutrition Science and a MBA from Drexel University.  Dr. Steward is an active member of the American Medical Association.

Dr. Steward has practiced family and internal medicine in the Lehigh Valley for many years prior to joining the staff of Cedar Crest EmergiCenter® in 1995.

William Barnhurst, D.O.

William Barnhurst, D.O.Dr. William Barnhurst earned a Bachelor of Science degree in Psychology from Temple University in 1965 and is also a graduate of the Philadelphia College of Osteopathic Medicine, Philadelphia, PA.

Dr. Barnhurst is board eligible in the field of emergency medicine and serves as the Medical Director of various ambulance corps in the Bucks County area.  He serves on numerous committee appointments which include; Trauma Committee, Industrial Medicine, and Paramedic Education.  Additionally, Dr. Barnhurst is a member of both the Medical Advisory and Emergency Health Council of Bucks County, PA.  Dr. Barnhurst brings over 35 years of Emergency Medicine knowledge and experience to Cedar Crest EmergiCenter®.

Mehran Armen, M.D.

Dr. ArmenDr. Mehran Armen is a graduate of Shahid Beheshti University of Medical Sciences, Tehran, Iran.  Dr. Armen completed his residency in Internal Medicine at Easton Hospital, Easton, PA, and is Board Certified in Internal Medicine.

Dr. Armen's certifications include; Advanced Life Support, Advanced Trauma Life Support, and Pediatric Advanced Life Support. He maintains an active membership with the American College of Physicians.



Dennis Schlener

Dennis Schlener, D.C. received his Bachelor’s degree from Moravian College, Bethlehem, PA and earned his Doctorate of Chiropractic degree in 1982 from Palmer College of Chiropractic in Davenport, Iowa.

He is a member of Pennsylvania Chiropractic Association and has been in private practice for over 30 years. Dr Schlener has been on staff at Cedar Crest Physical Therapy since 2004.



Aaron M. Smith, D.P.T.

Aaron M. Smith, DPT graduated summa cum laude as the valedictorian of the class of 2000 from Arcadia University with a degree in biology. He earned his clinical doctorate in physical therapy in 2003 after affiliations with Moss Rehab, Good Shepherd and the Hospital of the University of Pennsylvania.

Aaron specializes in orthopedic and sports medicine based rehabilitation and has been affiliated with Cedar Crest Physical Therapy since 2004.




Physicians On Duty


Cedar Crest EmergiCenter
7:00 a.m. - 10:00 p.m.
365 Days
(610) 435-3111

Airport Road EmergiCenter
Mon.-Fri. 7:00 a.m. - 9:00 p.m.
Weekends 8:00 a.m. - 6:00 p.m.
365 Days
(610) 264-5844

Cedar Crest Imaging
The Rose Professional Building
1125 S Cedar Crest Blvd.
Allentown, Pa 18103
Mon.-Fri. 9:00 a.m. - 6:00 p.m.