
Glenn E. Aldinger
MD, FACEP, FAAEM
CEO, IHC. Senior Vice-President MWOU Envision Physician Services
Full Bio »
With more than 35 years of leadership experience, Dr. Glenn Aldinger serves as Infinity HealthCare’s Chief Executive Officer and Chairman of the Board. A co-founder of the group, Dr. Aldinger has been instrumental in Infinity HealthCare’s development into the largest, employee-owned emergency medicine practice in Wisconsin and Illinois, growing from one hospital partnership, to currently more than 20. Dr. Aldinger led the expansion of Infinity HealthCare’s professional services to include Anesthesia, Pain Management, Imaging Services, Occupational Medicine, Hospitalist Services and Wound Care, Hyperbaric Medicine.
Board Certified as a Diplomate of the American Board of Emergency Medicine – where he served as an oral Board Examiner, he is a Fellow of the American College of Emergency Physicians and a Fellow of the American Academy of Emergency Medicine. Dr. Aldinger has been caring for patients since 1976. He received a Bachelor of Science from the University of Cincinnati and his medical degree from The Ohio State University College of Medicine. Dr. Aldinger completed a one-year surgical internship at Emory University and his residency training in Emergency Medicine at the University of Chicago Hospitals.
Dr. Aldinger has overseen the initiation of many of Infinity’s group practices serving in various practice and medical staff leadership positions and has for 30 years co-directed or directed the St. Francis Hospital EMS System. In addition to his responsibilities at Infinity HealthCare, Dr. Aldinger has for 3 decades been active – as an instructor in ACLS (Advanced Cardiac Life Support) serving as Affiliate and National Faculty for the American Heart Association. He is the Medical Director of McCormick Place and Navy Pier in Chicago. Dr. Aldinger contributes his time to several professional organizations. He is a State of Illinois governor – appointed member of the EMS Advisory Council where – he served as Chairman for 15 years and is a member of the State Trauma Advisory Board. Dr. Aldinger has engaged in many roles with the Illinois College of Emergency Physicians (ICEP) currently sitting on the Practice Management Committee as well as the Pre-Hospital Care Committee; in 2005 he was honored with ICEP’s Meritorious Service Award for his work in Trauma and EMS. Dr. Aldinger holds a faculty appointment as Clinical Associate Professor of Emergency Medicine at the University of Illinois, College of Medicine.
Bob Herdrich
MS, RN
Director of Operations
Full Bio »
With more than 35 years of leadership experience, Bob Herdrich serves as Infinity Healthcare’s Director of Operations. Joining the team in 2018, Mr. Herdrich plays a key role in forming and maintaining client relationships, understanding and improving business intelligence metrics, and negotiating contracts with client sites and systems.
Prior to joining Infinity Healthcare, Mr. Herdrich developed significant depth in the practice of hospital medicine through his employment with Cogent Healthcare. He was instrumental in growing Aurora Health Care’s hospital medicine, hospice and palliative care services. Being a registered nurse by trade, Mr. Herdrich has practiced as a nursing leader in Emergency Medicine and Urgent Care.
Mr. Herdrich graduated from the University of Wisconsin-Oshkosh with a Bachelor’s degree in Nursing and from the University of Wisconsin-Milwaukee with a Master’s degree in Nursing. He also has green belt certification in in Lean Continuous Improvement, and experience in TeleStroke.

Gary Zaid
MD, FACEP
Chief Medical Officer
Vice President of Risk and Quality Management
Full Bio »
Dr. Gary Zaid serves as Vice President of Risk and Quality Management for Infinity HealthCare. Since joining in 1985, Dr. Zaid has played an important role in Infinity HealthCare’s Emergency Medicine practice as well as an integral part in Infinity HealthCare’s risk management and performance improvement process. Dr. Zaid has extensive experience with development and implementation of quality performance and improvement initiatives. Working with the Wisconsin State Medical Society and Infinity’s malpractice carriers, Dr. Zaid had been instrumental in the development of the educational seminars and tools utilized for provider education purposes.
Dr. Zaid received a BS from Loyola University Chicago and his medical degree from Loyola University Stritch School of Medicine. He completed his residency training in Emergency Medicine at Harbor-UCLA Medical Center. Dr. Zaid holds medical licenses in Illinois, Wisconsin, California and Indiana. He is board certified as a Diplomate of the American Board of Emergency Medicine and is a Fellow of the American College of Emergency Medicine.
In addition to this leadership role with Infinity, Dr. Zaid holds various administrative positions at United Hospital System (UHS) in Kenosha, Wisconsin. These positions include: President of the Medical Staff; Chairman – Department of Emergency Medicine; and Medical Director of the Emergency Department at Kenosha Hospital and Medical Center Campus of UHS.
Manish H. Acharya
MD, FACEP
Director of Telemedicine/Innovation
Mark Waltz
Director of Information Technology
Donna O’Neil-Brunner
Comptroller
Melissa Vorpagel
Anesthesia Practice Director
Angela Enders
Director of Talent Acquisition/Residency Relations Coordinator
Lisa Harrison
Director of Revenue Cycle Management