Laser scanner measurement of central segment performance in isolated cardiac muscle preparations

A laser scanning system has been developed to facilitate the study of isolated cardiac muscle by excluding the possibly damaged tissue at the ends of the preparation. The laser scanner monitors the length of a central segment of the muscle that has been delineated by markers consisting of single loops of 8-0 silk suture. Focused laser light traverses the length of the muscle at 150 Hz. Scattered light is detected by a photodiode and the length of the central segment is calculated electronically. This system provides an accurate measure of central segment length in both resting and active muscle with no apparent damage to the preparation.