The fundamental frequency of EIG events is determined directly, without first detecting the events themselves. Use is made of an analysis window containing more than one event (3-5). Techniques (1-8) are utilized which are somewhat similar to those utilized to detect, and estimate pitch in speech processing. The invention is based on two important biological discoveries. The first is that the EIG is generated by a functional pace maker. The second is that the EIG signal is quasi-periodic most of the time. The use of pitch detection algorithms is based on the essentially quasi-periodic nature of the EIG signal. Quasi-periodic means that the intervals between successive events are not exactly identical, but may vary slightly, that the amplitude and shape of successive events may also exhibit some variance.
Fundamental frequency estimation of Electro-Islet Graphy