A phantom with pulsating artificial vessels for non-invasive fetal pulse oximetry

Abstract

Arterial oxygen saturation of the fetus is an important parameter for monitoring its physical condition. During labor and delivery the transabdominal non-invasive fetal pulse oximetry could minimize the risk for mother and fetus, compared to other existing invasive examination methods. In this contribution, we developed a physical-like phantom to investigate new sensor circuits and algorithms of a non-invasive diagnostic method for fetal pulse oximetry. Hence, the developed artificial vascular system consists of two independent tube systems representing the maternal and fetal vessel system. The arterial blood pressure is reproduced with a pre-pressure and an artificial vascular system. Each pulse wave can be reproduced, by digital control of a proportional valve, adjustable viscoelastic elements, and resistances. The measurements are performed by pressure transducers, optical sensor units, and a coplanar capacitive sensor. Transmission and reflection measurements have shown that the fetal and maternal pulse waves can be reproduced qualitatively. The measured light represents the transabdominal modulated signal on an abdomen of a pregnant woman.

Nesa Days 2015, Conference Report

“…During labor and delivery, the transabdominal non-invasive fetal pulse oximetry [46] is a new method under research that may minimize the risk for mother and fetus. Compared to other existing invasive examination methods there is no risk of infection.…”

Functional and Metrological Issues in Arterial Simulators for Biomedical Testing Applications: A Review

“…Laqua et al, for example, realized an experimental set-up with a hydraulic system for the simulation of pulsating artificial vessels to study fetal pulse oximetry. In this context, they employed capacitive sensors as sensitive elements for the tube dilatation [16]. On the other hand, Lantos et al studied the deformation of a silicone elastomer tube by measuring the tube diameter using digital image processing after the acquisition of a set of photos through a CCD digital camera.…”

Development of Tubular Cardiovascular Phantom System for Pulse Transit Time Simulation

“…A phantom system is able to enhance understanding of the basic principles of a physiological system such as pulse wave propagation in a blood vessel [1] and PPG characteristics on different tissues properties [2]. A physical model of cardiovascular system has been widely developed mainly focused on a photoplethysmography (PPG) pulse waveform [3], [4] and to simulate pulse wave velocity (PWV) measurement [5], [6] leading to a pulse transit time (PTT) measurement system. A pulsatile waveform was generated either by a commercial pulsatile pump [7], [8] or custom motorised pump [9].…”

“…The system was designed based on Windkessel model in representing arterial compliance [4]. The amount of air and pressure inside a custom-made chamber was controlled to simulate the arterial compliance in a human system.…”