HMS Medical Team

Alan Katz, MD, FUHM, FACEP, FAAEM

National Medical Director

Alan A Katz, MD, FUHM, FACEP, FAEEM, has been a leader in medicine for over 30 years. He is double board-certified in both Hyperbaric and Emergency Medicine and is an elected Fellow of the Undersea and Hyperbaric Medical Society, the American College of Emergency Physicians, and the American Academy of Emergency Medicine. Currently, Dr. Katz practices Hyperbaric, Regenerative, and Metabolic Medicine.

He is the National Medical Director for Hyperbaric Medical Solutions (HMS), directing clinical operations, as well as education and research initiatives for all HMS locations.

A particular clinical interest of Dr. Katz is Longevity, Orthobiologics, and Integrative Oncology. Having completed a year long certification in the Metabolic Approach to Cancer under the tutelage of Dr Nasha Winters he is able to offer terrain based cancer care- often able to avoid the toxicities of chemotherapy and radiation.

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Gregory Alfred, MD, FAAEM, ABEM

Medical Director

Dr. Alfred is the medical director for HMS Florida. 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. 

Rosemary Byrne, MSN, ANP-BC, ACHRN

Clinical Director - New England

Rosemary 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. 

Rosemary has completed the Program for Advanced Training in Hyperbaric Medicine (PATH) and is deemed a Hyperbaric Advanced Practitioner by the Undersea Hyperbaric Medical Society (UHMS)

Henry Prince, MD, FACOG

Chief Medical Officer

Dr. 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.

Martin Peter Sayers, MD, FUHM

Hyperbaric Physician

Dr. Martin Peter Sayers is a dual-board certified Emergency Physician with a subspecialty in Undersea and Hyperbaric Medicine. Originally from Fort Lauderdale, Dr. Sayers’ interest in hyperbaric medicine and physiology arose from his experience with Scuba diving and freediving.

After completing medical school at The Ohio State University College of Medicine, Dr. Sayers completed Emergency Medicine residency at Jackson Memorial Hospital / University of Miami. From there, Dr. Sayers completed fellowship in Undersea and Hyperbaric Medicine at the Duke University F. G. Hall Center for Undersea Medicine and Environmental Physiology. While in fellowship, Dr. Sayers was involved with numerous dive medicine and environmental physiology research projects.

Dr. Sayers holds board certifications in both Emergency Medicine as well as Undersea and Hyperbaric Medicine, and practices clinical Emergency Medicine with Broward Health, as well as Hyperbaric Medicine at HCA Florida Mercy Hospital in Miami.

Scott Sherr, MD

Director of Integrative Hyperbaric Medicine

Dr. 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.

Integrative Hyperbaric Medicine with Dr. Scott Sherr

Maryellen Bonito, PA-C

Physician Assistant

Maryellen 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.  

Jodi Velocci, RPA‑C

Lead Physician Assistant

Jodi 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.

Cindy Yiu, PA-C

Physician Assistant

Cindy Yiu is a board-certified Physician Assistant, who has been practicing since 2014. Cindy received a Masters Degree in Physician Assistant Studies from Midwestern University, from which she completed a her residency in Emergency Medicine at New York Presbyterian Weill-Cornell, where she continues to work full-time. Cindy's interest in alternative medical therapies has brought her to extend her career into hyperbaric medicine.

 

 

Kate Yeadaker, APRN, FNP-BC

Nurse Practitioner

Kate Yeadaker, a seasoned Holistic Nurse Practitioner with over two decades in nursing, holds the Advanced Practice Registered Nurse (APRN) designation for the past nine years. Her diverse experience spans trauma, obstetrics, surgery, pediatrics, integrative/regenerative medicine, hyperbaric medicine, and psychedelic medicine.

A 2014 Georgetown University graduate, Kate has expertise in pre-operative medicine, holistic mental health, psychedelic medicine, functional medicine, and hyperbaric oxygen therapy. Her extensive post-master's studies cover nutrition, biochemistry, genomics, and functional medicine.

Passionate about uncovering root causes of illness, Kate approaches each patient holistically. Certified in energy healing for twenty years, she is a Qi-Gong practitioner, Reiki Master, and certified in Integrative Somatic Trauma therapy, IFS, and Ketamine therapy.

For the past four years, Kate has focused on ketamine therapy, advocating for psychedelics as a bridge between eastern and western philosophies. She is dedicated to raising awareness and dispelling stigmas around psychedelic use, helping individuals access their "medicine within.

Eddy Cabrera, APRN

Nurse Practitioner Eduardo Cabrera was born and raised in Miami, Florida. He started his career as an EMT/Paramedic, working in the Mercy Hospital Emergency Room and with ambulance services for National Health Transport. He continued his education at Miami Dade College, where he became a Registered Nurse. Eduardo was promoted to Charge Nurse at Mercy Hospital, where he served for approximately seven years while he pursued a Master's degree in nursing, becoming a Certified Acute Care Nurse Practitioner. While at Mercy Hospital, Eduardo met Dr. Gregory Alfred and learned about hyperbaric medicine and its benefits, in particular treating emergencies of divers' decompression sickness and patients with carbon monoxide poisoning. In 2023, Eduardo joined Hyperbaric Medical Solutions to work under Dr. Alfred and explore the wider reaches of hyperbaric oxygen therapy. Eduardo enjoys spending his free time outdoors, fishing, boating, or at the beach with his family.

Linesary Cezaire, CNP

Certified Nurse Practitioner

Elizabeth Celestin, NP

Nurse Practitioner Elizabeth Celestin is a board-certified Nurse Practitioner with extensive experience across emergency and trauma nursing, medical aesthetics, regenerative medicine, and hormone optimization. Before becoming an NP, Elizabeth spent over a decade as a registered nurse in high-acuity emergency and trauma settings, developing strong skills in acute patient care, critical decision-making, and patient advocacy. Today, Elizabeth brings this depth of clinical expertise to her work at HMS, where she provides evidence-based treatments that support healing, recovery, and overall wellness. Elizabeth is dedicated to delivering compassionate, personalized care that blends advanced technology with a holistic approach to help patients feel and function their best.