Two-point electrical-fluorescence recording from heart with optical fibers.
Optical recordings from frog myocardium, stained with a voltage-sensitive dye, have been made through a fiber optic system that uses fiber couplers to provide two excitation/detection paths and to separate excitation light from the fluorescence signal. The excitation light, from a green He-Ne laser (543 nm), is focused into a 100 microns-core fiber then is split 1:1 to two other fibers. Each of these two fibers transmits part of the excitation light through a fiber coupler (1:15 transmittance ratio) to the heart preparation which is stained with the voltage-sensitive dye RH237. The returning red fluorescence is split at the same fiber coupler (15:1 transmittance ratio) and is directed to a photomultiplier tube through a longpass filter. With this two-point mapping method, differences in action potential shape and timing have been observed.
Krauthamer
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Food and Drug Administration, Center for Devices and Radiological Health, Rockville, MD 20857.
Davis
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Gan
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D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000379:methods*; D006321:Heart / Q000502:physiology*; D006329:Heart Conduction System / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000502:physiology; D055100:Optical Fibers; D011894:Rana pipiens