Our Team

The Princeton Longevity Center Staff Brings The Highest Levels Of Expertise To Your Care

All our physicians are American-trained and board-certified.

The Princeton Longevity Center’s staff’s knowledge and experience are unmatched by any other preventive medicine center in the region.


David A Fein, MD


Robert Singer, MD, FACC

Cardiologist - Princeton, NJ

Daniel Karlsberg, MD, FACC, FSCCT

Cardiologist - NEw York, ny

Sheila Chen, MD


Michael B. Schwartz, DO

Internal Medicine - Shelton, CT

Nathan Ruch, MD

Preventative Medicine - Princeton, NJ


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Donna Hayek, RD


Lori E. Skurbe, RDN, MPH, CDCES

Registered Dietitian - PRINCETON, NJ

Erin Botticelli, MS, RD, LDN

Registered Dietitian - Shelton, CT

Sandra Gollogly, RDN

Registered Dietitian - Fairfax, VA

Exercise Physiologists

Dr. Harry Pino

Exercise PhysiologIST - NEW YORK, NY

Louis Degnan M.S, CPT, NSCA TSAC-F


Alicia Sabatino, MS, ACSM-CEP


Ksenia Eldred, ACSM EP-C, BS


Abdollah Serajian, PhD, ACSM-EP


Matthew Harackiewicz, B.S., ACSM-EP


Technicians & Clinical Staff

Darlene Chuva, RT (R, CT)

Senior Ct Technologist - PRINCETON, NJ

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Demetri Kydonieus

Clinical Manager - PRINCETON, NJ

Nicole Grignoli RT (R, CT)


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Kristina DeGrandi

Clinical Coordinator - SHELTON, CT


Doug Cerminaro, MPA


Jillian Rhodes

Office Manager - PRINCETON, NJ

Milana Cantres


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Jennifer Sgrott


About David A Fein

Founder and Medical Director of the Princeton Longevity Center, Dr. David Fein has been a practicing physician with nearly 30 years of combined experience in Internal Medicine, Cardiovascular Diseases and Chronic Disease Prevention. He has traveled extensively to research the latest in medical advances, technology and wellness tools to incorporate into his nationally recognized preventive medicine center.

Dr. Fein is a Founding Member of the Society for Cardiovascular CT and remains one of the few Internists in the world that are Board Certified in Cardiac CT. He is an expert lecturer on topics such as Radiation Reduction Techniques and Coronary Artery Calcium Scoring in the clinical setting and has taught and certified hundreds of physicians to become proficient in the field of Cardiac CT.

He has also been invited nationally and internationally to speak at leading conferences on Preventive Medicine and lectures extensively on topics in preventive medicine, executive health, lifestyle management, and more. Additionally, Dr. Fein has been involved in developing health-related legislation in New Jersey.

A graduate of Franklin & Marshall College in Lancaster, PA, Dr. Fein received his medical degree from New York University School of Medicine and was elected to the Alpha Omega Alpha Medical Honor Society. Dr. Fein completed his residency training at Bellevue Hospital – New York University Medical Center and is Board Certified in Internal Medicine and Cardiac CT.

About Robert Singer

Dr. Singer is board certified by the American Board of Internal Medicine (ABIM) in both internal medicine and cardiovascular disease. Additionally, he holds board certification in Nuclear Cardiology.

Robert Singer graduated from the University of North Carolina at Chapel Hill, studied at Tel Aviv University – Sackler School of Medicine, and received his doctorate from SUNY Health Science Center at Brooklyn. He then completed residency in internal medicine at the Albert Einstein College of Medicine in Bronx, NY, followed by fellowship in cardiology at Hahnemann University Hospital in Philadelphia, PA.

Dr. Singer is a fellow of the American College of Cardiology and has nearly 30 years of experience as a clinical cardiologist with special interests in Nuclear Cardiology, Cardiac-Obstetrics, and Echocardiography.

During his career, Dr. Singer has served as Chair of the Department of Medicine, President of the Medical Staff and Lead physician at Virtua-West Jersey Health System. He has also served on many committees involving both the clinical and operational aspects of cardiology both in the office and hospital setting while maintaining a large clinical practice.

About Daniel Karlsberg

Dr. Karlsberg is board certified by the American Board of Internal Medicine (ABIM) in both internal medicine and cardiovascular disease. Additionally, he holds board certifications in comprehensive echocardiography, nuclear cardiology, and cardiovascular CT. He is currently on the clinical faculty at NYU Langone Health in the Department of Medicine & Division of Cardiology.

Daniel Karlsberg graduated from the University of California and received his doctorate with honors from Sackler School of Medicine, Tel Aviv University. He then completed residency in internal medicine at the University of Colorado, followed by fellowship in cardiology at California Pacific Medical Center in San Francisco.

Dr. Karlsberg is a fellow of the American College of Cardiology and an active member of the American Society of Preventive Cardiology. As a preventive medicine physician, he has a special interest in the early diagnosis and management of cardiovascular disease, complex lipid disorders, and advanced cardiovascular imaging. Throughout his medical training and career, Dr. Karlsberg has been deeply involved in cardiovascular CT research and currently advises and teaches with the Society of Cardiovascular Computed Tomography (SCCT). Dr. Karlsberg maintains ongoing clinical research with both the Cardiovascular Research Foundation and The Lundquist Institute & Harbor-UCLA Medical Center.

Dr. Karlsberg is deeply passionate and enthusiastic about the intersection of healthcare and technology to empower and educate for better outcomes. He is honored to be part of the team at Princeton Longevity Center as Associate Medical Director where he maintains a practice that strives to improve health via prevention, early detection, and exceptional follow up. His sole goal is to work with you to create optimal health and wellness that are tailored to your needs.

About Sheila Chen

Dr. Chen is board certified in Internal Medicine. She did her undergraduate training at MIT. She attended St. George’s University School of Medicine and completed her internship and residency at St. Barnabas Medical Center in Livingston, NJ. She has been in practice for over 10 years, and in addition to providing quality preventive care at Princeton Longevity Center, she is the founder of Dimensions Direct Primary Care.

Dr Chen’s focus is to provide quality care at all stages of life. In addition to her role in primary care, she also serves as medical director of Heartland Hospice in Northern Virginia.

For Dr. Chen, medicine is not only a career, but a passion. She believes in a personalized approach, and strives to be the kind of physician patients can feel comfortable talking to. She is committed to providing the highest quality of care and treatment to her patients, and places special emphasis on overall health and wellness, preventive care and patient education.

About Michael B. Schwartz

Dr. Schwartz received his BS in Cardiorespiratory science from The State University of New York/Stony Brook in 1986 and graduated from the New York College of Osteopathic Medicine in 1990. He completed his internship and residency in Internal Medicine at the Yale University School of Medicine/Norwalk Hospital Program in 1994. He is Board certified in Internal Medicine by the ABIM.

Dr. Schwartz has received the ‘Patient’s Choice Award’ every year since 2008 as well as the ‘Most Compassionate Doctor Award’ every year since 2010. Most recently, he was awarded the America’s Most Honored Doctors – Top 10%, and was named one of Fairfield County’s “Top Doctors” by Moffly Media both in 2022.

Dr. Schwartz emphasizes preventative care to insure that his patient’s health is the primary focus of a comprehensive health care program.

Dr. Schwartz is accomplished in sports medicine and acts as the Chief Ringside Physician for Professional Boxing and Mixed Martial Arts (MMA) for the State of Connecticut as well as at the Mohegan Sun Casino and at the Foxwoods Resort Casino. Dr. Schwartz has written many publications on fighter safety and has testified in front of congress to promote safety in these sports. In 2011, as a testimony to his commitment to improving the safety and health of the professional boxer, Dr. Schwartz was inducted into the Connecticut Boxing Hall of Fame.

About Nathan Ruch

Dr. Ruch brings more than 20 years of clinical experience to Princeton Longevity. He focuses his practice on the applied science of longevity and his passion is partnering with patients to help them achieve their goals and maximize healthspan.

A graduate of the Pennsylvania State University College of Medicine, Dr. Ruch completed his residency at the Case Western Reserve University, MetroHealth Medical Center, and Cleveland Clinic Foundation program in Ohio. He is board certified by the American Board of Emergency Medicine and has been elected a Fellow by the American College of Emergency Physicians.

Prior to joining Princeton Longevity, he was Chief Executive Officer and Chief Medical Officer for a national emergency medicine group. He lives in Bucks County with his wife and three children.

About Donna Hayek

Donna Hayek, RD brings over 20 years of experience as a registered dietitian to our Princeton office.

Prior to joining Princeton Longevity Center, Donna worked in various hospitals, long-term care facilities, gyms, and clinics. She received her BS in Food & Nutrition and Certificate in Sports Nutrition & Wellness from The College of St. Elizabeth in nearby Morristown, NJ. Donna is also certified as an Exercise Physiologist through the American College of Sports Medicine (ACSM.)

Throughout her career, Donna has worked with a wide range of patients, including pediatric, obstetric, adult, and elderly. In her spare time, she enjoys working out, shopping, and spending time with her puppy.

About Lori E. Skurbe

Lori has been a registered dietitian for over 20 years with an extensive background in weight management, diabetes education, metabolic disorders and wellness. Prior to joining PLC, Lori worked in community wellness, public health, and clinical nutrition.

She received her bachelor of science from Penn State University and her Master of Public Health from Rutgers University. Lori is passionate about helping people achieve maximum health through optimal nutrition.

About Erin Botticelli

Erin Botticelli is our Registered Dietitian in Shelton, CT. She is a graduate of Salem State University with a Bachelor of Science in Biology. After graduation, Erin was a published research assistant in the Neuroendocrine Lab at Massachusetts General Hospital, investigating the MEG-3 gene in Pituitary tumors. Erin also earned her Master of Science in Nutrition and Health Promotion from Simmons University where she completed their Sports Nutrition and Entrepreneurship certificate program. Erin completed her dietetic supervised practice hours at several locations in Boston and Virginia, including New England Baptist Hospital, and Virginia Commonwealth University Athletics.

Prior to joining PLC, Erin was Head Dietitian at a medical weight loss clinic in Foxboro, MA. Erin has extensive experience treating obesity and metabolic conditions through behavior change and lifestyle medicine. Currently, Erin also works in the private practice space with focuses on gut health, integrative weight loss and functional nutrition. Erin’s specific nutrition areas of interest include integrative obesity and metabolic health, and sustainable weight management.

Erin resides in New England, specifically the Massachusetts and New Hampshire areas. Outside of helping people with nutrition she enjoys yoga, oceanside walks, playing with her two cats, cooking and spending time with her family.

About Sandra Gollogly

Sandra Gollogly is a Registered Dietitian Nutritionist at Princeton Longevity Center’s Fairfax, Virginia office.

Sandra graduated from the State University of New York with a Bachelor of Science Degree in General Management & Clinical Dietetics. She also completed a dietetic internship from Perth Amboy Medical Center, in New Jersey with a Clinical and Management focus. In 2011, Sandra received her Certificate of Training in Adult Weight Management from the Commission on Dietetic Registration.

Sandra believes in the importance of empowering and motivating her clients to meet their health goals. She takes a holistic approach by recommending small tweaks, and shifts to food choices and routines. She partners with clients to identify strategies to overcome obstacles, with the ultimate goal of client health and happiness.

Most recently, Sandra has worked at a Rehabilitation and Health Care Center caring for residents and families with a wide range of health concerns such as diabetes, cardiac health, cancer, wound healing, and weight management. She has also provided outpatient and inpatient medical nutritional counseling, and wrote and taught a nutrition program curriculum for youth. Sandra has been affiliated with the Academy of Nutrition and Dietetics for over 25 years.

In the warm weather you can often find Sandra working in her vegetable garden and experimenting with new plant varieties. (Ask her about her trial run with brussel sprouts!) Year round you can find her hiking in Virginia, or entertaining family and friends! She loves to cook and modify recipes to be healthier; but she will never sacrifice taste!

About Harry Pino

Dr. Pino joins Princeton Longevity Center as the Manager for Exercise Physiology and is board certified in Exercise Physiology with the American Society of Exercise Physiology and the American College of Sports Medicine. As a graduate of Indiana and Pacific Western University with post graduate training at Florida Hospital, Dr. Pino is also the founder of the sports performance lab VO2max Medical, LLC and is an adjunct assistant clinical professor at Tufts University, School of Medicine.

Dr. Pino is regarded as one of the leading authorities on sports performance testing, health and fitness and healthy weight loss in the United States. He is has consulted for both the Puerto Rican and Japanese Olympic Team and is the immediate past president for the Massachusetts Association of Clinical Exercise Physiologists. Dr. Pino is a former Director of the Clinical Exercise Physiology Program at Tufts Medical Center and has also served as the Senior Clinical Exercise Physiologist for the Center for Musculoskeletal Care Sports Performance Center at NYU Medical Center Langone, as the Medical Director for the Center for Preventive Medicine in NYC, as a Consultant for Next Level Physio Sports Performance and Physical Therapy Center, as a Clinical Integration Director for Celebration Health at Florida Hospital, and as a member on the Board of Directors for the Greater New York American College of Sports Medicine Chapter.

In addition to these accomplishments, Dr. Pino’s work has been featured on The Today Show, Good Morning America, PBS, CBS and CNN and in a variety of print media including the New York Times, New York Times Magazine, LA Times, Wall Street Journal, Shape, Men’s Health and more. Dr. Pino contributes to Sirius XM Doctor Radio and lectures on topics including exercise prescription for sports performance and chronic diseases. He was named one of the 100 Most Influential People in Central Florida for his work at the Rippe Health Assessment at Celebration.

About Louis Degnan

Louis Degnan, M.S., is a National Strength & Conditioning Association Certified Personal Trainer and a National Strength & Conditioning Association Tactical Strength & Conditioning Facilitator

Prior to joining The Princeton Longevity Center, Louis was a Wellness Coordinator at a United Methodist Homes in his hometown of Wilkes-Barre, Pennsylvania. He also worked as a Personal Trainer, EKG/Telemetry Technician, and Physical Therapy Aide both during and upon completion of his graduate coursework.

Louis received his Bachelor’s from East Stroudsburg University and his Master’s Degree from Bloomsburg University, both in Exercise Science. With his education and experience, Louis’ career goal is to make himself and expert in preventive medicine throughout the lifespan. Louis has experience in working with adults of all ages and recreationally active populations in physical therapy clinics, hospitals, commercial gyms, and group settings.

In his spare time, Louis is a self-proclaimed “comic book nerd”. He attends various comic book conventions annually and passionately incorporates healthy lifestyle and fitness habits to look the super-hero part in costume.

About Alicia Sabatino

Alicia is an ACSM-certified Clinical Exercise Physiologist. She earned her Bachelor’s from East Stroudsburg University, and her Master’s in Clinical Exercise Physiology from Wake Forest University. During her graduate years, she taught undergraduate courses in both exercise science and biomechanics. She worked with older adults in a healthy exercise lifestyle program where she was a Silver Sneakers instructor. She also spent much of her time involved with multiple research studies (START and WE-CAN,) mainly focused on exercise and weight loss for patients with knee osteoarthritis. Her thesis work was a subset study looking at the differences in muscle activation using electromyography in patients with knee OA.

After moving on from WFU, Alicia moved back to her home state of New Jersey and transitioned to the clinical realm. She has worked in cardiopulmonary rehabilitation for many years and is certified in the Dean Ornish heart disease reversal program. She worked at both Hunterdon Medical Center and Virtua Health until she found her place at the Princeton Longevity Center. She is passionate about inspiring others to “move more, move often!” Fascinated by the human body’s ability to adapt to lifestyle change, she hopes to continue to guide others towards leading a healthy lifestyle for the long term.

Beyond her aspirations as a CEP Alicia loves to travel and hopes to see as much of the world as she can! She is a competitive sailor competing every summer on the Barnegat Bay and travels for various regattas. She also enjoys fishing and surfing! She loves the ocean so much she spent a year with her husband living and sailing abroad on their 42-ft sailboat!

About Ksenia Eldred

Ksenia Eldred is a certified exercise physiologist by the American College of Sport and Medicine (ACSM EP-C). Ksenia has a BS degree in Kinesiology from George Mason University, Fairfax, Virginia and is currently a graduate student, who is pursuing a MS in Exercise Physiology at GMU. She believes in the healing power of exercise. Staying fit and healthy means being able to move without any pain or limitations. It allows people to enjoy their lives fully, improve their longevity and minimize their risk of developing disease. A personalized exercise program and the combination of adequate fitness movements, the right amount of training load, and consistency of exercise performance leads to great fitness results. There is no one size fits all approach. Every exercise program is unique and specific to the client’s needs.

When Ksenia doesn’t work or study, she enjoys spending time with her family outdoors surrounded by nature’s beauty and harmony. Her philosophy is, “One gentle breath in and out, with 1 step behind and 10,000 more to go.”

About Abdollah Serajian

Abdollah earned his Bachelor’s degree in Exercise Sciences from Ferdowsi University of Iran. He went on to complete his Master’s in Exercise Physiology, followed by his PhD in Neuromuscular Exercise Physiology from Shahid Beheshti University of Iran. He is also a graduate of the Fencing Coaching Course from the International Fencing Federation (FIE) and the University of Budapest.
Motivated by his career as a fencer for the National Fencing Team of Iran, Abdollah chose to pursue education in Sport Sciences. His goal was to enhance athletic performance. He strongly advocates for the preventive benefits of exercise in disease management and improving overall quality of life. Abdollah has always been passionate about assisting others in enhancing their health through exercise.

While in Iran, he served as an Exercise Physiologist, aiding numerous individuals in reaching their fitness objectives. Additionally, he played a significant role as the Coach of the National Fencing Teams of Iran. Upon immigration, Abdollah continued his journey as an Exercise Physiologist at PLC. He also continued his involvement in fencing, leading as a Fencing Head Coach, and establishing his own fencing academy.

Beyond these accomplishments, Abdollah contributed his expertise as a lecturer in various Iranian colleges, covering subjects such as Exercise Physiology, Exercise Science, Conditioning, and other Exercise Science-related courses. Notably, he held the position of Head of the Talent Identification Committee at the Fencing Federation of Iran.

During his leisure time, Abdollah indulges in watching movies, cherishing moments with his family, and exploring the scenic beauty of Northern Virginia.

About Matt Harackiewic

Matthew Harackiewicz, B.S., is an ACSM Certified Exercise Physiologist, renowned for his remarkable contributions to improving the health and well-being of individuals. With an impressive background in personal training and strength and conditioning coaching, Matthew’s expertise has made a significant impact in the industry.

Prior to joining the Princeton Longevity Center, Matthew excelled as a Strength and Conditioning Coach at Future Fitness Pro in his hometown of Newington, CT, where he honed his skills and achieved remarkable results. His contributions were widely recognized during his time as a Personal Trainer at Anytime Fitness in Canton, CT.

Matthew’s extensive knowledge and proficiency stem from his Bachelor’s degree in Exercise Science from Central Connecticut State University. This comprehensive education, coupled with his wealth of experience, has fueled his unwavering passion for guiding individuals towards optimal health and longevity. He has achieved remarkable success in training both high school athletes and the general population, providing them with the tools and guidance to reach their highest potential.

Beyond his professional endeavors, Matthew finds joy in pursuing various activities. He showcases his talent on the golf course as an avid golfer, while also actively participating in men’s league softball. He cherishes every moment spent hiking alongside his beloved dog, Fawn. Furthermore, Matthew proudly supports the Boston sports scene, wholeheartedly cheering on his favorite teams, the New England Patriots and Boston Bruins.