Respiratory sinus arrhythmia in growth restricted fetuses with normal Doppler hemodynamic indices.

Background: The autonomic behavior of growth-restricted fetuses at different evolving hemodynamic stages has not been fully elicited.

Aim: To analyze the respiratory sinus arrhythmia (RSA) of growth-restricted fetuses that despite this severe condition show normal Doppler hemodynamics.

Subjects: 10 growth-restricted fetuses (FGR group) with normal arterial pulsatility indices (umbilical, uterine, middle cerebral, ductus venosus and aortic isthmus), and 10 healthy fetuses (Control group), 32-37weeks of gestation.

Implementation of a real-time algorithm for maternal and fetal heart rate monitoring in a digital signal controller platform.

An LMS-based algorithm to monitor fetal and maternal heart rate in real time was implemented and evaluated on a development platform. Hardware has three modules: dsPIC30F digital signal controller, a low-noise analog front end and a storage stage. They were evaluated using on-chip debugging tools and a patient simulator.