Chris B. Schaffer
Assistant Professor
Department of Biomedical Engineering
The Schaffer lab uses advanced optical techniques for in vivo studies of physiological processes in both normal and diseased states. The cell constitutes the basic unit of life, but many living systems depend on interactions that can only be studied in intact animals, such as the coupling between local blood flow and neural activity in the brain. Optical techniques provide one way to overcome the ensuing challenge of characterizing physiology with single cell resolution in intact biological systems. We exploit nonlinear interactions between femtosecond duration laser pulses and biological materials to provide a means to: 1. take three-dimensional images of fluorescently-labeled tissue with micrometer resolution as well as quantitatively measure physiological variables such as blood flow or neural activity, and 2. produce three-dimensionally localized damage to specifically targeted biological structures as a means to elucidate function and model disease.
A primary area of current interest in the Schaffer lab is the pathophysiology of small-scale stroke. Clots or leakages in small blood vessels in the brain are implicated in vascular dementia and Alzheimer's disease, and are thought to be responsible for small infarcts observed in MRI brain imaging, so called "silent strokes." In an effort to model and understand these diseases, we occlude individual cerebral microvessels in rat brain. These occlusions are produced by injuring the endothelial wall of the vessel through photochemical processes or through nonlinear absorption of femtosecond laser pulses, thereby triggering the natural clotting cascade. We can then study the changes in blood flow in the vascular network as well as changes in the activity and health of downstream neurons using two-photon excited fluorescence microscopy, a technique first demonstrated here at Cornell (Denk, Strickler, Webb, Science (1990)). A critical aspect of this work is the use of nonlinear optical techniques that allow individual vessels to be selectively clotted, and allow the resulting changes in blood flow and cell physiology to be imaged, all inside the optically scattering environment of the brain.
Chris Schaffer joined the Cornell faculty in 2006. His undergraduate research work was recognized in 1996 with the Apker Award from the American Physical Society, while his graduate research was recognized with the 2000 New Focus Student Award from the Optical Society of America. He serves as co-chair of the Commercial and Biomedical Applications of Ultrafast Lasers conference at SPIE's Photonics West and is the current chair of the Optical Society of America's Ultrafast Phenomena technical group.
Education
- Ph.D. 2001, Harvard University, Physics
- B.S. 1995, University of Florida, Physics
Awards
- 2009 Biomedical Engineering Teaching Award--ASEE Biomedical Engineering Division (BED)
