 Fluorescence imaging
of cardiac action potentials
Fluorescence from the heart surface
is elicited by a solid state, frequency doubled at a wavelength of 532 nm. Laser light is delivered to the heart using multiple 1-mm optical fibers or through a beem splitter and ground glass diffusers to create aa double beam illumination scheme. The emitting fluoresence is imaged with a high speed CCD camera through a color glass with a cutoff wavelength of 590 nm.
The faceplate of the camera is cooled with an ethylene-glycol coolant from a refrigerated waterbath to 15 degrees Celcius. The cooling of the camera reduces the dark current by fourfold to a digitized count of less than 100 per pixel for each frame.
Marc Lin
linsf@cshs.org
A bound pair of spiral waves
Wu, Bray, Ting & Lin
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