Elektronski sistem za kalibracijo pulznega oksimetra

TOMŠIČ, JAKA (author), Žemva, Andrej (mentor)

Diplomska naloga nam prikaže enega izmed možnih načinov kalibracije pulznega oksimetra. Raziskali bomo možnost manipulacije svetlobe od izvora proti ponoru oksimetra. Opazujemo, kako se svetloba spreminja, ko prečka aktiven medij – prst. Uspešno zaključena kalibracija pomeni, da je signal, ki ga oddamo iz kalibratorja, podoben pravemu signalu na fotopletizmografu v sprejemnem delu oksimetra, ko nanj pade svetloba iz medija. S pravilno oblikovanim signalom, ter znanimi vrednostmi AC ter DC komponente signalov rdeče in infrardeče svetlobe, lahko ustvarimo tabelo ter iz te tabele izračunamo oksigenacijo krvi. Poleg oksigenacije lahko preverimo tudi natančnost meritve srčnega utripa, saj signal moduliramo tako frekvenčno kot amplitudno. Ves nadzor nad intenziteto svetlobe imamo preko računalnika v programu ArduinoIDE. Spoznamo, da je kalibracija možna, vendar je močno odvisna od karakteristik sprejemnega dela individualnega oksimetra.

• Language: Slovenian
• Keywords: oksimeter, pulzna oksimetrija, kalibracija, kalibrator, fotopletizmograf, moduliran LED signal, rdeča in infrardeča valovna dolžina, digitalni potenciometer
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2014
• PID: 20.500.12556/RUL-29480
• Publication date in RUL: 17.09.2014

Secondary language

• Language: English
• Title: Electronic system for calibration of pulse oximeter

Abstract

Reading through this thesis, you will be shown a few possible calibrations of pulse oximeter. We will focus on manipulation of the light source in a way in which the light coming out of calibrators output will create a signal that will replicate tissues response. It is crucial to pick the right output LED of the calibrator in order to satisfy the needs for an accurate calibration. Therefore LED should emit wavelengths in the bandwidth of the oximeters receiver. The calibrator is ready to be programmed to a certain amplitude and frequency to replace tissues response. We will be controlling the amplitude and the frequency of the calibrators LEDs via personal computer inside the ArduinoIDE program. In our results we can see that this kind of calibration is possible, but is highly dependent on oximeters receiver circuit. Each has a different response. Making experiments and putting results into a table should provide a stable calibration.

• Keywords: oximeter, pulse oximetry, calibration, calibrator, photoplethysmograph, light modulation, LED signal, red and infra-red wavelength, digital potentiometer