Figure 2: An electronic simulation test to form triangular wave from 10 Hz wave cluster. The 10Hz wave group was passed through an integral circuit, of which time constant was 7 sec, i.e. the 10 Hz signals were delayed for 7 sec in the integral circuit. The outputof the circuit was triangular curves similar to FHR acceleration. It will be concluded that the mid-brain center reacts fetal movement burst changing it to triangular acceleration.