Abstract

Isolated cardiac muscle cells exhibit phasic contractions when they are electrically stimulated and they maintain their distinct AûI band striation pattern, like a one-dimensional diffraction grating, during the contraction–relaxation cycle. This paper demonstrates the application of an on-line, hybrid digital–optical processor, with liquid crystal television (LCTV) serving as a spatial light modulator (SLM), to monitor the dynamics of contraction in real time. The processor, which is interfaced with a phase-contrast microscope, performs a Fourier transformation of the striated cell image optically and records the Fourier spectra digitally by means of a charge-coupled-device camera. A series of digitized images of the Fourier spectra, at intervals of 16.67 ms (noninterlaced frames), is captured during muscle contraction. The sarcomere length at each time point is calculated from centroidal positions of the firstorder diffraction spots. Experimental results demonstrate that LCTV has improved the contrast of striated cell images by 300%. These results suggest that the hybrid processor has a great potential for biomedical applications. Finally, the results obtained from normal and hypertensive heart cells (both with and without drug effects) will be presented.

© 1990 Optical Society of America