Newswise — Christine Buffinton is a researcher with an ability to see to the heart of things — quite literally. Buffinton, an associate professor of mechanical engineering at Bucknell University, has been working with a state-of-the-art technique called confocal imaging, which uses focused light from a laser to see inside an object — in Buffinton's case, the embryonic heart of a chicken — allowing very detailed views of structures smaller than a cell.
More impressively, Buffinton, along with her colleagues, discovered innovative techniques that could one day lead to the development of computerized, 3-D models of the embryonic heart.
Working primarily with chicken eggs to study the embryonic heart, Buffinton has worked on this project for about 10 years. She said, "The overall goal has been to look at the effects of mechanical forces on the embryonic heart." She studied how forces change strength of the tissue and the shape of the chambers and vessels in the heart.
During the research, embryonic hearts are manipulated through microscopic surgery to create conditions of high blood pressure, low blood pressure, and normal blood pressure. Buffinton studied how the elastic properties of the heart tissue change depending on blood pressure. She also wanted "to look at the whole heart and see how shape changes depending on blood pressure."
In order to achieve the latter objective, Buffinton said, "We want to make a computerized 3-D model of the embryonic heart to match the various experimental conditions." From this model, researchers could study how the heart controls its levels of stress and strain.
The main obstacle to creating the 3-D model was that the heart samples, although just two millimeters wide, were too thick for the available techniques of confocal imaging. The laser light typically dies out after penetrating more than two-tenths of a millimeter.
Buffinton and colleagues figured out how to extend the depth of view of confocal imaging by changing the optical properties of the heart tissue so it was more "invisible" to the laser light. The light could then reach all the way across the heart and the researchers were able to "see" very detailed slices from the entire embryonic heart. The 500-600 optical slices from each heart are then combined with computer graphics software, resulting in a 3-D computer model of the heart. The models are later analyzed to obtain mechanical stress and strain in the heart.
Buffinton's research has many potential applications in the medical field. By studying embryonic hearts, Buffinton said one objective is "to learn what might trigger congenital heart disease and possible ways to correct it." The research in embryonic hearts might also help discover new ways to repair damaged hearts in adults.
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