Meet Our Staff
We are a group of research and healthcare professionals, striving for excellence in our research trials and dedicated to providing support for patients, their caregivers, and their families.
Portraits by Anne Philpot
Ralph W. Richter, MD, FACP, FAAN
President, Founder, Principal Investigator
In 1986, Dr. Richter established Tulsa Clinical Research LLC. As its founder and current president, his 50 years of experience are unparalleled. He also serves as Director of the Alzheimer's Disease Research Unit at St. John Medical Center and maintains a private practice in neurology and neuropsychiatry. Dr. Richter is Clinical Professor of Neurology and Psychiatry at the University of Oklahoma College of Medicine in Tulsa.
Brigitte Richter, Dipl. Pharm.
CEO, Rater, Medical Writer
Brigitte graduated from the University of Wuerzburg/Germany as research pharmacist and continued her post-graduate education at the University of Basel/Switzerland with special emphasis on the history of the development of anti-aging medications. She also trained to become a medical journalist, working for many years as editor-in-chief and publisher of medical journals in Europe. Her special interest in geriatric and neuro-psychiatric diseases facilitated her deep involvement in Alzheimer’s research. Over the last ten years, Brigitte has been actively involved in clinical research as executive manager, co-investigator, and clinical rater. She has authored or co-authored several well-received books.
Christy L. Lisenbee, BS, CCRC
Operations Manager, Certified Clinical Research Coordinator
Christy graduated with her Bachelor of Science in 2006 and has over 7 years experience as a clinical research coordinator. In 2009, she received her certification through the Association of Clinical Research Professionals (ACRP). She has worked on a variety of CNS phase I-IV clinical trials and recently has specialized in pediatric and adolescent trials.
Carmen H. Toegel, LpN, CCRC
Senior Certified Clinical Research Coordinator
Carmen has worked in clinical research with Dr. Richter since 1997 and was certified as a clinical research coordinator in 2001. She is also certified in Alzheimer’s clinical psychometric rating scales and truly enjoys working with the elderly. Carmen loves spending time with her two sons and two granddaughters, Addison and Makynna.
Sadie R. Fuller, BA, MS
A graduate of Texas Christian University, Sadie received her Bachelor’s degree in 1988 and Master's in 1990. She has served as the primary psychometrist at Tulsa Clinical Research since 1996. Sadie has worked on trials designed for patients with major depression, Alzheimer's, fibromyalgia, ADHD, autism, and Aspergers. She is also certified as an Alzheimer's Support Group Facilitator. Sadie is married and has two children, two cats and a dog.
Clinical Research Coordinator
Sarah graduated from CBM Education Center in Austin, TX with a certification in Medical Assistant, and later went on to obtain her phlebotomy certification through the American Association of Blood Bank. She has over 19 years Phase I-IV clinical trials experience in areas such as Allergy, Renal, Diabetic, psychiatric, Alzheimer, Gout and Cardiac research. Sarah enjoys spending time with her husband, three daughters and new grand baby.
L. Duwane Tillery, MA
Clinical Research Coordinator
Duwane graduated from Oklahoma College of Business and Technology in Tulsa, OK with a degree in Business Management and Nursing. Duwane has over 5 years clinical trials experience in allergy, depression, fibromyalgia, ED, and gout research.