LabVIEW based Virtual Instrument for Simulation of Doppler Blood Flow Velocimetry of Umbilical Artery

Abstract

Doppler blood flow velocimetry has become a routine practice for fetal surveillance in high-risk pregnancies. Doppler assessment of various fetal vascular beds helps in determining the relationship between fetal circulation and associated fetal conditions like hypoxia, brain-sparing effect and growth restriction. The umbilical artery, uterine artery and middle cerebral artery are three most studied vascular beds for fetal surveillance. In our research we are focused only on the umbilical artery since, abnormal umbilical artery velocimetric findings is a direct indication of an elevated value of resistance to the blood flow in the placenta. To better understand this relationship we have constructed a mathematical model of feto-placental circulation. A LabVIEW-based virtual instrument is also designed to simulate the model. The simulated waveform is similar to Doppler blood flow velocimetry of umbilical artery. Doppler indices (resistive index, systolic-to-diastolic ratio, pulsatility index) derived from simulated waveform revealed consistent relationship with advancing gestation as shown by real-time Doppler blood flow velocimetry of umbilical artery. Abnormal values of Doppler indices indicate complicated fetal conditions like intra-uterine growth restriction (IUGR).