On-Line Measurement of Sarcomere Length from Diffraction Patterns in Muscle

Two different systems designed to extract sarcomere length and several other variables from the light diffraction pattern in muscle are described. One system utilizes a linear photodiode array to detect the intensity distribution of diffracted light from muscle. This system provides computed outputs of sarcomere length, first order width, and time rate of sarcomere length change according to two different algorithms. Another system utlizes a Schottky photo-position sensor and provides sarcomere length and integrated first order intensity. The accuracy (within 1%) and resolution (2 nm) of both systems are comparable. The former system offers better convenience of operation while the latter offers wider bandwidth (2.5 kHz vs. 100 kHz).