Skip to main content
. Author manuscript; available in PMC: 2010 Jul 1.
Published in final edited form as: Conf Proc IEEE Eng Med Biol Soc. 2009;2009:4194–4197. doi: 10.1109/IEMBS.2009.5334048

Figure 1. Alternating transillumination system.

Figure 1

The chopper modulates two laser beams to produce alternating illumination of either the epicardial or endocardial sides of the myocardial wall. The panel shows the phase when the beam from the left laser (dashed line) is blocked by the chopper, while the right beam (solid line) passes through. Before reaching the myocardium, each beam is expanded by a holographic lens and is directed towards the surface via a dichroic mirror (2). After passing through the dichroic mirrors (2) and long pass filters (3) located on both sides of the preparation, the emitted voltage-dependent fluorescent signals are recorded simultaneously with two fast CCD cameras (1). The synchronization diagram of the cameras and the chopper is shown on the right inset. “Trans” and “Reflect” indicate the cameras’ recording modes (reflection versus transillumination).