Meet The Leadership
GSI International
President & Chairman of the Board
Dr. Michael Marin
Founder of GSI, Dr Marin is also Surgeon-in-Chief at Mount Sinai Health System and Chairman of the Department of Surgery at the Icahn School of Medicine at Mount Sinai (USA). He has spearheaded the development of numerous minimally invasive arterial vascular diseases, has published over 325 communications in peer-reviewed journals, more than 70 book chapters, and has presented at more than 300 scientific meetings. His achievements garnered awards from the American Society of Gastronenterology, the Society for Vascular Surgery and the Peripheral Vascular Surgery Society.
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Dr Marin is a graduate of the Icahn School of Medicine at Mount Sinai, having completed an internship and residency at Columbia-Presbyterian Medical Center in New York and a fellowship in vascular surgery at Montefiore Medical Center/Albert Einstein College of Medicine.
Executive Director, Kyabirwa Surgical Centre
Anna Turumanya Kalumuna
With over 20 years of experience in health services management, including with the International Medical Group/International Hospital, Liberty Health Uganda, and ESKOM Uganda, Anna currently oversees strategic, operational and financial management of GSI's Kyabirwa Surgical Center, leading over 70 surgical and non-medical staff.
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Anna holds a BA in Mass Communication from Makerere University, a Master in Health Services Management from Clarke University, and a PG Diploma in Management Studies from Uganda Management Institute. Anna is currently pursuing a Doctorate in Strategic Leadership at Southeastern University (USA).
Chief Executive Officer
Sarah van Hellenberg Hubar-Fisher
Sarah is a leading strategist, impact investor, and medtech venture builder with 21 years of healthcare industry experience across global markets. She has been recognized by InspiringFifty as a TopFifty Deep Tech Winner (2021) and amongst the top Notable Female Angel Investors in the Netherlands (2023). She was awarded the first-ever Corporate Entrepreneur accolade by Corporate Entrepreneurs, LLC. (2010), and the Rising Star award by Global Corporate Venturing (2016),
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Sarah holds a Master’s of Business Administration in Entrepreneurship from Babson College in Wellesley (USA), an MA and a PG degree in Global Business from the University of Oxford in Oxford (UK).
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Head, External Affairs
Stéfanie Fréel
Stéfanie has over 13 years experience supporting public, private, multilateral, and non-governmental organizations in global health policy, research and advocacy efforts, including for the World Health Organization and the Canadian Ministry of Health. She also worked as the Director of a boutique strategy consulting firm where she build and led cross-industry and public-private partnerships, coalitions, and advocacy efforts.
Stéfanie holds an Honours Bachelor of Science in Psychology and a Master of Global Affairs from the University of Toronto (Canada). She is currently pursuing a PhD in Medicine at the Amsterdam University Medical Center (The Netherlands)
Board of Directors
We are grateful to our Board of Directors who make our work possible, year after year.
Jay Lieberman
Jay Lieberman has over 50 years of real estate experience and is the Chairman and CEO of Derfner Management, Inc., a real estate management company. As a member of the Department of Surgery Advisory Board in Mount Sinai, he supports the hospitals vision to excel in surgical leadership. Mr. Lieberman is actively committed to promoting the welfare of others in his continued philanthropic efforts. In addition to his role on GSI's Board, he is an Advsiory Board Member of the Department of Surgery at Mount SInai Health System and a trustee of The Derfner Foundation, which supports innovative science, education, and cultural purposes.
Dr. Jerome Waye, M.D.
Dr. Jerome Waye is a Professor Emeritus of Medicine and Surgery at the Icahn School of Medicine at Mount Sinai Health System. He devoted his entire medical career at Mount Sinai following graduation cum laude from Boston University School of Medicine which he attended after graduating from MIT. Dr. Waye developed techniques of colonoscopy used throughout the world, authored multiple textbooks and over 200 articles in medical journals, and has received several accolades both nationally and internationally. He was president of the American Society for Gastrointestinal Endoscopy and president of the American College of Gastroenterology, and was president of the World Endoscopy Organization. Currently in “retirement,” Dr. Waye remains active as a clinician and educator providing remote endoscopy instruction to the surgeons and clinicians of GSI's Kyabirwa Surgical Center in Uganda.
Andrea Lieberman
Currently living in Los Angeles, the acclaimed stylist, CFDA/ vogue Fashion Funds Finalist and designer Andrea Lieberman, was born and raised in New York City. After graduating from The Parsons School of Design with a degree in Fashion, Andrea began to make her mark in the Fashion industry. Not only has her work been featured in high profile magazines and editorials she is also recognized as an a-list celebrity stylist. Her travel to Paris and countries in East Africa, allowed Andrea to experience and engage deeply in different cultures. In 2009, she launched her own fashion brand A.L.C, a brand that focuses on timeless staple pieces for women. Andrea is also a founding member of the Female Founder Collective, whose mission is to promote and foster women-owned businesses.
Mark Yockey
Mark L. Yockey, CFA, is a managing director of Artisan Partners and a portfolio manager on the Global Equity team. In this role, he is a portfolio manager for the Artisan Non-U.S. Growth and Global Equity Strategies, including Artisan International and Global Equity Funds.
Prior to joining Artisan Partners in December 1995, Mr. Yockey was the portfolio manager of the United International Growth Fund and vice president of Waddell & Reed from January 1990 through December 1995. Before assuming responsibility for the United International Growth Fund, Mr. Yockey was an analyst for Waddell & Reed from 1986 through 1989, specializing in the worldwide health care industry and international special situations.
Earlier in his career, he was a health care analyst for the State of Michigan Retirement Fund for five years. Mr. Yockey holds a bachelor’s degree and a master’s degree in finance from Michigan State University. He completed one year of undergraduate work at the Université d’Aix-en-Provence in France. He also worked for the French bank, La Société Générale. He is fluent in French.
George George
George K. George is the founder of the award-winning architectural design firm GKG based in New York City. He earned a Bachelor of Architecture from the Regional Engineering College in Trichy, India, and a Master of Architecture from the University of Minnesota.
GKG is recognized for its global perspective—leveraging international talent and resources to create design solutions that are both innovative and environmentally conscious. The firm emphasizes reducing environmental impact while harnessing the power of technology to develop cutting-edge architectural concepts.
George's work has received numerous awards and citations from the American Institute of Architects (AIA). In 2022, GKG was honored with the AIA Healthcare Design Award, which “showcases the best of health care building design, health care planning, and health care design-oriented research,” for the Kyabirwa Surgical Center Ward, an extension of the original Kyabirwa Surgical Center
In addition, we thank our Board of Director Members Noel Grundwaldt and Richard Prince.
We also recognize our Board of Director Officers, Dr. Michael Marin, President and Chairman, Maurice Carper, Treasurer, and Dr. Jeanne Marin, Secretary, for their ongoing support.