CDS Invited Lecture: Sean Andersson, "Estimation and Control in Confocal Microscopy"
Friday, April 13, 2007
2168 A.V. Williams Building
301 405 6576
Control and Dynamical Systems Invited Lecture Series
Estimation and Control in Confocal Microscopy
Department of Aerospace and Mechanical Engineering
In recent years, single particle tracking techniques in optical microscopy have become an important tool in the study of single molecules. To date, most methods rely on wide-field microscopy with ultra-fast video cameras. In two dimensions, video-rate bandwidth with spatial resolution as high as 5 nanometers can be achieved. However, many biological systems are inherently three dimensional and the two-dimensional projection of the motion of the molecule is often inadequate to understand the associated dynamic phenomena. Efforts to track single particles in three spatial dimensions typically rely on imaging the sample at different axial positions and analyzing the resulting stack of images. This approach suffers from poor temporal resolution and has a limited range in the axial direction. These difficulties present an opportunity for systems and control theory to have an impact on the study of molecular systems. In this talk we discuss some of the challenges and the role that control theory can play. We will also present a novel estimator for determining, with sub-diffraction-limit resolution, the position of a single molecule. This estimator is based on the Bancroft algorithm, a closed-form solution to the localization problem in the global positioning system. The new algorithm, called fluoroBancroft, is computationally efficient and can therefore be used in a real-time closed-loop particle tracking system.
Sean B. Andersson is an Assistant Professor of Aerospace and Mechanical Engineering at Boston University. He received the B.S. degree in applied and engineering physics from Cornell University in 1994, the M.S. degree in mechanical engineering from Stanford University in 1995 and the Ph.D. degree in electrical engineering from the University of Maryland, College Park in 2003. From 1995-1996 he worked as a Project Engineer for AlliedSignal Aerospace (Torrance, CA) and from 1996-1998 as a Senior Controls Engineer for Aerovironment, Inc. (Monrovia, CA). From 2003-2006 he was a Lecturer in Applied Mathematics at Harvard University. Dr. Andersson's current research interests include control applications in scanning probe microscopy, robotics, and symbolic control.