Comparisons of Monosinusoidal with Bisinusoidal (Two-Wave) Analysis.

摘要

Body temperature rises slowly from a morning low to an early evening peak; starts to decline rapidly well before habitual bedtime, and continues to decline to a minimal value the next morning. Time interval between a trough and a peak of the body temperature curve is much longer than that between the peak and the next trough. When a single cosine wave of 24 hour/cycle is fitted to body temperature data, estimates of time-of-peak (TOP) and of time-of-trough (TOT) are usually poor and they are separated by many hours from peak and trough of raw data. Few methods can be used to improve estimation of TOP and TOT. One such improvement is based on the mathematical theory that any arbitrary repeating waveform can be reproduced completely as a sum of harmonic components found in that waveform. Rummel and his colleagues started their analysis by detailed harmonic analysis of data. Then, a computer program searched for the 'best' combination of the harmonics, which described the largest variance in the data with the fewest possible number of harmonics.