Vpliv tlačne povezovalne cevke na meritve gleženjskega indeksa

Pažon, Nejka (author), Kutin, Jože (mentor), Svete, Andrej (co-mentor)

Medicinska naprava za merjenje gleženjskega indeksa meri tlak v manšetah za merjenje krvnega tlaka, ki so s tlačnimi senzorji v ohišju naprave povezane s tlačnimi povezovalnimi cevkami. V magistrski nalogi smo izvedli eksperimentalno analizo razlike med tlačnima signaloma na vhodu in izhodu preskušane cevke, pri čemer smo spreminjali dolžino, premer in material preskušanih cevk ter osnovno frekvenco in amplitudo simuliranih tlačnih oscilacij. Tlačni merilni sistem smo tudi simulirali z implementacijo matematičnega modela v programski jezik Python in analizirali funkcijo amplitudnega razmerja med izhodnim in vhodnim tlačnim signalom v odvisnosti od frekvence signala pri različnih dolžinah, premerih, debelinah stene in materialih tlačne povezovalne cevke. Na podlagi rezultatov obeh analiz smo ugotovili, da v območju frekvenc srčnega utripa amplitudno razmerje občutno narašča le z daljšanjem tlačne povezovalne cevke, vendar pa naraščanje amplitudnega razmerja nima bistvenega vpliva na določanje gleženjskega indeksa.

• Language: Slovenian
• Keywords: gleženjski indeks, tlačne povezovalne cevke, merilniki krvnega tlaka, oscilometrična metoda, tlačni merilni sistemi, frekvenčni odziv, prenosna funkcija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [N. Pažon]
• Year: 2023
• Number of pages: XX, 62 str.
• PID: 20.500.12556/RUL-148987
• UDC: 531.787:612.14:681.2(043.2)
• COBISS.SI-ID: 166389507
• Publication date in RUL: 02.09.2023

Secondary language

• Language: English
• Title: The effect of pressure connecting tube on measurements of the ankle-brachial index

Abstract

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.

• Keywords: ankle-brachial index, pressure connecting tubes, blood pressure sensors, oscillometric method, pressure measurement system, frequency response, transfer function