Prototype Expandable Bileaflet Heart Valve (IMAGE) Boston Children's Hospital Caption This view from above demonstrates the valve retaining its essential shape at various states of diametric expansion (from 1x to 1.8x). The prototype was created by Sophie C. Hofferberth in the lab of Pedro J. del Nido, M.D., at Boston Children's Hospital. Credit Sophie C. Hofferberth, Boston Children's Hospital Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.