HMS Medical Team


Alan Katz, MD, FUHM, FACEP, FAAEM
National Medical DirectorAlan A Katz, M.D. is the National Medical Director for Hyperbaric Medical Solutions (HMS), directing clinical operations, as well as education and research initiatives for all HMS locations. He has been a leader in the fields Hyperbaric Medicine and Emergency Medicine for over 30 years.

Gregory Alfred, MD, FAAEM, ABEM
Medical Director ‑ Fort Lauderdale
Gregory Alfred, MD, FAAEM, ABEM
Medical Director ‑ Fort LauderdaleDr. Alfred is the medical director for HMS Fort Lauderdale. He is board certified in emergency medicine and is also certified in hyperbaric medicine. He is an active member of the American Academy of Emergency Medicine, the Undersea and Hyperbaric Medical Society, and Hyperbaric Medicine International. Having grown up in the US Virgin Islands, Dr. Alfred's interest in hyperbaric medicine derives from his passion for scuba diving. Dr. Alfred received his undergraduate degree from Princeton and his medical degree from NYU-Mount Sinai School of Medicine. He completed his emergency medicine training at USC, where he also obtained his certification in hyperbaric medicine. Dr. Alfred was named outstanding resident of the year during his final year of residency. Along with practicing emergency medicine, Dr. Alfred has served as a clinician in one of the busiest in-patient hyperbaric departments in South Florida at Mercy Hospital since 2008. Dr. Alfred saw firsthand the amazing life-changing and neuro-restorative powers of HBOT while at the hospital, and has sought to expand the reach of the modality to the outpatient setting. Dr. Alfred is excited to join HMS's high-caliber team and to lead HMS's expansion into Florida.

Henry Prince, MD, FACOG
Chief Medical Officer
Henry Prince, MD, FACOG
Chief Medical OfficerDr. Henry Prince has led Hyperbaric Medical Solutions since its inception in 2011, forging important clinical relationships in the medical community and pioneering the practice’s effort to help patients experience optimal health using the incredible healing properties of HBOT. He has been practicing medicine on Long Island and the New York metropolitan area for over 30 years with extensive experience in the areas of obstetrics and gynecology, as well as HBOT. After graduating cum laude from Downstate Medical School, with Alpha Omega Alpha distinction, Dr. Prince completed his residency at North Shore University Hospital in Manhasset, New York. He is board certified in obstetrics and gynecology and accredited in HBOT. Dr. Prince is the President and Founder of Women’s Health Professionals, a large women’s health practice, a Mount Sinai affiliated physician, and an active member in both the American College of Obstetrics and Gynecology and the Undersea and Hyperbaric Medical Society.

Scott Sherr, MD
Director of Integrative Hyperbaric Medicine and Health Optimization
Scott Sherr, MD
Director of Integrative Hyperbaric Medicine and Health OptimizationDr. Scott Sherr is the director of Integrative Hyperbaric Medicine and Heath Optimization at Hyperbaric Medical Solutions. In this role, he facilitates protocol development, patient engagement, and outreach efforts.
Dr. Scott is also an independent provider of Integrative HBOT who runs a worldwide education, consulting, and advocacy telemedicine practice. He is of the few HBOT medical professionals in the country who develops personalized treatment plans for patients, which include:
- Cutting edge and dynamic HBOT protocols
- Health Optimization Medicine (HOMe) testing and balancing
- Adjunctive technologies
- Allied practitioner referral.

Rosemary Byrne, MSN, ANP-BC, ACHRN
Clinical Director - New England
Rosemary Byrne, MSN, ANP-BC, ACHRN
Clinical Director - New EnglandRosemary is a Boston College graduate who started her career as a registered nurse on Massachusetts General Hospital's gynecology/oncology surgical unit before becoming a board certified nurse practitioner. She obtained her master's degree from the MGH Institute of Health Professions in 2005 with certification as both an Adult and a Women's Health Nurse Practitioner. She has extensive experience in women's health and worked as a Nurse Practitioner for Planned Parenthood before joining Hyperbaric Oxygen Treatment Centers in 2009. She has been the Clinical Director of this site since then and is certified as an Advanced Certified Hyperbaric Registered Nurse. She was a clinical instructor and lecturer for the MGH Institute of Health Professions. Rosemary is passionate about education and the increased use and awareness of hyperbaric medicine. Recently Rosemary has completed the Program for Advanced Training in Hyperbaric Medicine is a Hyperbaric Advanced Practitioner.

Jodi Velocci, RPA‑C
Lead Physician Assistant
Jodi Velocci, RPA‑C
Lead Physician AssistantJodi Velocci is our Lead Physician Assistant. She comes from a background of Emergency Medicine, Orthopedics, Gastroenterology, and 15 years in Internal Medicine after graduating magna cum laude from the St. John’s University Physician Assistant Program in 1988. Jodi became certified in hyperbaric oxygen treatment in May 2015 while looking to be more integrative in her approach to healthcare. The most rewarding part of working in hyperbaric medicine at HMS, is that she is able to provide care to patients like she would her loved ones: with focus, dignity, and compassion.

Cydney Taylor, RPA‑C
Physician Assistant
Cydney Taylor, RPA‑C
Physician AssistantCydney started as a Physician Assistant in 1999 after completing her degree at the CUNY/Harlem Hospital Physician Assistant Program and CUNY/Hunter College School of Public Health. Cydney is passionate about using a holistic, integrative approach to health and wellness. Hyperbaric Oxygen Therapy compliments this passion and her professional interests in primary medicine, functional medicine, and public health.

Maryellen Bonito, PA-C
Physician Assistant
Maryellen Bonito, PA-C
Physician AssistantMaryellen attended Wagner College in Staten Island, NY, for both her undergraduate degree and Master's of Physician Assistant Studies. She graduated in 2013 and then entered a one-year Post-Graduate Emergency Medicine Physician Assistant Residency Program at NewYork-Presbyterian / Weill Cornell Medicine. Upon completion, she stayed on board at Weill Cornell Medicine / Lower Manhattan Hospital and spent the first nine years of her career as an Emergency Medicine Physician Assistant.
After years of taking a very "traditional" approach to patient care, Maryellen found herself developing a growing interest in complementary and alternative medicine. She began working part time at Hyperbaric Medical Solutions in 2021, in hopes of formally exploring another side of healthcare. She quickly grew to love the new concepts and approach and transitioned to working at HMS full time shortly thereafter. She currently serves as the lead clinician for the NYC office. She has found this shift in her career to be eye opening, exciting, and genuinely fulfilling.
Maryellen is proud to be a part of the regenerative medicine community and is thrilled to continually navigate this space as an HMS provider, where she has the opportunity to work alongside many well-respected and distinguished professionals. The HMS clinical group is comprised of individuals from various backgrounds who collectively offer an extensive level of expertise about hyperbarics, and beyond. Furthermore, everyone's dedication and enthusiasm have led to countless accomplishments and achievements over the years. Overall, she is honored to be a part of the impressive and inspiring team of clinicians at HMS.
Maryellen is looking forward to what is to come, in the world of regenerative medicine, and hyperbarics specifically. She is especially excited to be a part of this journey with HMS, as the organization continues to pave the path towards the future of this industry.

Linesary Cezaire, CNP
Certified Nurse Practitioner
Linesary Cezaire, CNP
Certified Nurse Practitioner
Kristin Thomson, PA-C
Physician Assistant
Kristin Thomson, PA-C
Physician AssistantKristin Thomson has been practicing medicine as a board-certified physician assistant since 2002. She received her medical training at Quinnipiac University and obtained her doctoral degree from Nova Southeastern University. In addition to practicing hyperbaric medicine, she has spent most of her clinical career in Emergency Medicine. Since 2008, Kristin has been an active participant in PA medical education at both the local and national level, where she has been awarded numerous leadership awards in PA education. She is a member of Pi Alpha National Honor Society, which recognizes PAs with significant academic achievement and honors them for their leadership, research, and professional service. In addition to her role at HMS, Kristin holds an academic faculty position at Stony Brook University in NY. Her scholarly work includes authoring medical education-related federal and local sponsored grants, being a member of the review board for the Internet Journal of Allied Health Sciences and Practice, and being active in academic policy workgroups that has been tasked to provide recommendations on competency-focused curriculums. Her research interests include investigational uses of hyperbaric medicine, regenerative medicine, and innovations related to medical education.