David B. Geselowitz, assistant professor in the School of Engineering and Applied Science at the University of Pennsylvania, died August 22 after a brief illness unrelated to COVID-19. He was 90.

Dr. Geselowitz was known for his contributions to the theory of the electrocardiogram and the development of the artificial heart. 

He was born in Philadelphia in 1930. He graduated from Central High School in Philadelphia and the University of Pennsylvania, where he received BS, MS, and PhD degrees in electrical engineering in 1951, 1954, and 1958, respectively. He was awarded the Atwater Kent Award as the top student in his undergraduate class.

Dr. Geselowitz’s doctoral dissertation dealt with theoretical approaches to the electrocardiogram with consideration of the relationship of ECG potentials on the skin to electric sources in the heart. A paper reporting this work became a Science Citation Classic on the basis of the number of references to it in subsequent literature. Other early work with Dr. Paul H. Langer, Jr. established the significance of small notches in the electrocardiogram. 

In 1951, after he earned his undergraduate degree, he joined Penn’s faculty as an assistant instructor in the Moore School of Electrical Engineering. He went on to become an instructor in 1955. After earning his PhD, Dr. Geselowitz became a professor research associate, then a few years later an assistant professor. Dr. Geselowitz became an associate professor in electrical engineering in medicine in 1965, and he founded Penn’s doctoral program in biomedical engineering. A paper by Dr. Geselowitz, “Multiple Representation for an Equivalent Cardiac Generator,” was chosen the best paper in the field by the professional group on Medical Electronics of the Institute of Radio Engineers (Almanac April 1961). 

In 1971, Dr. Geselowitz left Penn for Pennsylvania State University, where he established a graduate program in bioengineering. There, he served as a Distinguished Alumni Professor Emeritus of Bioengineering and a Professor Emeritus of Medicine. 

His major contributions were in theoretical electrocardiology. With his student Walter T. Miller, he developed the Miller-Geselowitz model, which relates cardiac sources to the electrocardiogram. The model accounted for the normal ECG as well as a number of abnormalities. He also developed the theory for magnetic fields generated by the heart and brain. This theory is used extensively by researchers in magnetocardiography and Magneto-encephalography. Another seminal paper developed a theory for impedance plethysmography which is the use of measurements of electrical resistance to visualize internal structures in the body. Dr. Geselowitz was also involved in the development of an artificial heart, a joint effort with the Colleges of Engineering and Medicine at Penn State. 

He served as a visiting professor at MIT, Duke, University of Oklahoma and University of New Mexico. He was also a Guggenheim Fellow. Dr. Geselowitz was a member of an advisory board established by Hubert Pipberger of the VA Hospital in Washington, D.C., who pioneered in the development of a computer program for interpretation of the electrocardiogram. Dr. Geselowitz also served on numerous panels of the national Institutes of Health and the National Science Foundation. He was the author of more than 150 papers and he co-edited one book, The Theoretical Basis of Electrocardiology. Dr. Geselowitz was a founding member and former director of the Biomedical Engineering Society. He helped found the International Society for Computerized Electrocardiography. He was a member of the North American Society of Pacing & Electrophysiology. He was one of the first three engineers elected a fellow of the American College of Cardiology. He was also a fellow of the Institute of Electrical and Electronic Engineers (IEEE) as well as the American Association for the Advancement of Science and a founding fellow of the American Institute for Medical and Biological Engineering. He was elected to the National Academy of Engineering in 1989. Dr. Geselowitz was awarded the Ragnar Granit Prize for contributions to bioelectromagnetism in 2005. 

Dr. Geselowitz was the editor of the IEEE Transactions on Biomedical Engineering from 1967 to 1972 and served on the editorial board of four other journals. He received the Career Achievement Award of the IEEE Engineering in Medicine and Biology Society in 1985.

He was actively involved in the development of standards for electrocardiographs and electric safety in medical instruments through the Committee on Electrocardiography of the American Heart Association and served at one point as the committee’s chairman. From 1983 to 1988, he served on the Cardiovascular Devices Panel of the Food and Drug Administration, which was responsible for approving medical devices for clinical use. 

As noted by the late Dr. Herman Schwan, who was known as the “founding father of biomedical engineering” and was a professor of electrical engineering and assistant professor of physics in medicine at Penn: “David was the best man I had met in electrocardiography work. The National Academy of Engineering recognized him for that work. He became a leader in the country in the field.”

Dr. Geselowitz is survived by his wife, Lola; sons, Daniel (Sandra Cohen), Michael (Emily Schneider), Ari (Bettina Welz); grandchildren, Samuel, Rezyl, Gabriela, Israel (EAS’14), Benjamin, Rye Welz Geselowitz, and Joshua; three great-grandchildren; and sister, Judy Gordon (C’52).