DETECTING OVULATION

摘要

Some non-invasive methods for determining hormone levels and the beginning and end of the fertile period of female mammals are known but they are either costly or unreliable. In the present invention a cyclic blood flow stimulus is applied to a subject and blood flow is measured by means of a plethysmograph 13. The plethysmograph is connected to a frequency analyser 14 and the output of the analyser is processed in a circuit 15 to determine the extent of entrainment of the stimulus frequency in blood flow, this being an indication of the level of certain hormones related to the fertility cycle.