The medical device for measuring the ankle-brachial index measures the pressure in blood pressure cuffs, which are connected to the pressure sensors placed inside the housing by pressure connecting tubes. In this thesis, we performed an experimental analysis of the difference between pressure signals at the inlet and outlet of the tested tube, by changing the length, diameter and material of the tested tube and the base frequency and the amplitude of simulated pressure oscillations. We also simulated the pressure measurement system by implementing a mathematical model in Python programming language, then we analysed the amplitude ratio between the output and input pressure signal as a function of frequency at different lengths, diameters, wall thicknesses and materials of the pressure connecting tube. Based on the results of both analyses we concluded that within the heart rate frequency range the amplitude ratio increases significantly only by increasing the length of the pressure connecting tube, but the increasing ratio does not significantly affect the ankle-brachial index value.
|
