Closed Loop Controller System (image) Brigham and Women's Hospital Share Print E-Mail Caption This is a representation of the drug delivery system. Serving as the acoustic indicator of drug delivery dosage, the microbubble emission signal y(t) is used to find the expected controller output u(f) which is fed back to help control ultrasound transducer transmission. Credit Tao Sun, Brigham and Women's Hospital Usage Restrictions Reporters may freely use this image in their coverage of this paper with credit to Tao Sun and citation of the full journal reference (Sun T et al. 'Closed-loop control of targeted ultrasound drug delivery across the blood-brain/tumor barriers in a rat glioma model' Proceedings of the National Academy of Sciences) doi:10.1073/pnas.1713328114 Share Print E-Mail 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.