title: Chronobiology principles and methods of studying biological rhythms.
abstract: In studying many diseases we meet with periodic phenomena. The appearance of some symptoms and the relevant remissions often have a cyclic pattern. The temporal structure of living organisms is at the root of these phenomena: the correct intermodulation, in terms of time, of the biological variables, realizes the conditions of well being. If the harmony between the biological rhythms is disturbed for some reason, the subjects find themselves in the state of proneness to disease or of overt disease. To evaluate this different situation it is necessary to follow the biological phenomena during the time and estimate, with correct statistical methods, the periodicity, the relevant parameters and the ratios. So research has to be completed with a sufficient number of measurements of pertinent variables and of the variables to be utilized as marker rhythms. For this purpose, autorhythmometry and automatic monitoring can help greatly. Evaluation of the parameters and ratios between the biological rhythms pertinent to the studied disease and marker rhythms constitute the ground on which the discussion and conclusions of the research have to be founded.
mesh_terms: D001831:Body Temperature; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010507:Periodicity