Experimental analysis of strain gauge sensor in detecting arterial blood flow stenosis

This study proposes a novel strain gauge sensor, to be used for arterial stenosis evaluation. The sensor is cost-effective, easy to apply on the skin and computationally simple to process the signal output and collect the result. The current study assesses the feasibility of strain gauge sensors in an experimental setting. The sensor is used in a closed flow circuit, reproducing the arterial blood flow and blood pressure. The artery is modelled after the radial artery in the upper wrist, using two major 4mm and 6mm internal diameters. The tissue surrounding the artery is modelled using a silicone enclosure with the same thickness as the artery diameter. The stenosis is introduced into the system from 30% to 100% in 5% intervals, and the sensor is placed 20 mm before the stenotic area. The measurements are captured using a data acquisition system by HBM and processed using signal processing libraries in Python. The signal output is presented as raw signal output, illustrating various parameters, such as maximum and minimum diameter, signal running average, etc., utilized in calculating the degree of stenosis. The result shows a positive nonlinear correlation between the degree of stenosis with 4mm data showing a 20% higher average signal peak compared to 6mm experiments.Clinical relevance- The degree of stenosis is calculated using a wrist elasticity model in combination with a hemodynamic Telegrapher model and presented in Pearson and Bland-Altman graphs, showing a plus 95% accuracy and 9% error range of the 95% of the results in calculations compared to actual stenosis present in the flow circuit. The strain gauge sensor demonstrates great viability in experimental setting to accurately predict the degree of arterial blood flow stenosis and a great choice for a continues self-monitoring device in cardiovascular patient groups.