20.500.12556/RUL-171255 Zaznavanje bioloških signalov z infrardečo spektroskopijo Detecting biological signals with infrared spectroscopy Diplomsko delo obravnava razvoj in validacijo nizkocenovnega sistema za zaznavanje bioloških signalov z uporabo funkcionalne bližnje infrardeče spektroskopije (fNIRS). fNIRS je neinvazivna optična metoda, ki omogoča spremljanje sprememb v oksigenaciji in perfuziji tkiv na osnovi absorpcije svetlobe pri specifičnih valovnih dolžinah. Namen naloge je bil razviti lasten, robusten in cenovno dostopen senzor, primeren za osnovne biomedicinske meritve, kot so zaznavanje srčnega utripa in odzivov na dihalne manipulacije. Razvit sistem temelji na uporabi dveh svetlobnih virov (660 nm in 940 nm), fotodetektorja ter dveh ločenih zvočnih kartic, ki služita kot vmesnika za generiranje in zajem signalov. Mehanska zasnova senzorja vključuje ohišje iz 3D-tiskanih komponent, kar omogoča stabilno in ponovljivo namestitev. Programska oprema, razvita v okolju LabVIEW, omogoča sinhrono generiranje modulacijskega signala, zajem podatkov in izvajanje lock-in demodulacije, s čimer se izboljša razmerje signal/šum in omogoči zaznavanje šibkih bioloških signalov. V eksperimentalnem delu sta bila izvedena dva ciljno usmerjena testa. Prvi test je bil namenjen validaciji delovanja naprave z zaznavanjem srčnega utripa in primerjavi z referenčno napravo. Drugi test je bil izveden z namenom preverjanja odzivnosti naprave na kontrolirane fiziološke spremembe, izzvane z zadrževanjem sape. Oba testa sta bila dopolnjena z elektrotehnično in biomedicinsko analizo pridobljenih signalov, kar je omogočilo večplastno interpretacijo rezultatov. Rezultati kažejo, da razviti fNIRS senzor zanesljivo zaznava spremembe v optični gostoti, ki sovpadajo s srčnim ciklom ter s hemodinamskimi odzivi med zadrževanjem sape. Zasnova naprave omogoča stabilno meritev tudi pri uporabi minimalnih komponent, kar potrjuje primernost za nadaljnji razvoj. Zaključki kažejo na uporabnost naprave v raziskovalne in izobraževalne namene, obenem pa ponujajo izhodišče za prihodnje nadgradnje, kot so večkanalni sistemi ali prenosne rešitve za domače spremljanje vitalnih funkcij. This thesis addresses the development and validation of a low-cost system for detecting biological signals using functional near-infrared spectroscopy (fNIRS). fNIRS is a non-invasive optical method that enables monitoring of changes in tissue oxygenation and perfusion based on light absorption at specific wavelengths. The aim of this work was to design a robust and affordable sensor suitable for basic biomedical measurements, such as detecting heart rate and responses to res- piratory manipulations. The developed system is based on two light sources (660 nm and 940 nm), a photodetector, and two separate sound cards serving as inter- faces for signal generation and acquisition. The mechanical design of the sensor features a 3D-printed housing, allowing stable and reproducible placement. The software, developed in the LabVIEW environment, enables synchronous generation of the modulation signal, data acquisition, and lock-in demodulation, thereby improving the signal-to-noise ratio and allowing the detection of weak biological signals. The experimental work consisted of two targeted tests. The first test aimed to validate the device’s operation by detecting heart rate and comparing the results with a reference device. The second test evaluated the device’s re- sponsiveness to controlled physiological changes induced by breath-holding. Both tests were complemented with electrical engineering and biomedical analyses of the acquired signals, enabling a multi-layered interpretation of the results. The results demonstrate that the developed fNIRS sensor reliably detects changes in optical density corresponding to the cardiac cycle and hemodynamic responses during breath-holding. The device design enables stable measurements even with minimal components, confirming its suitability for further development. The conclusions highlight the device’s potential for research and educational purposes, while also providing a basis for future upgrades, such as multi-channel systems or portable solutions for home monitoring of vital functions. fNIRS biološki signali infrardeča spektroskopija zvočna kartica lock-in demodulacija fNIRS biological signals infrared spectroscopy sound card lock-in demodulation true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-08-21 11:35:10 2025-08-21 11:35:18 2025-08-26 12:12:59 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 62983 246643715 Drenik_Martin_-_Zaznavanje_bioloskih_signalov_z_infrardeco_spektroskopijo.pdf Drenik_Martin_-_Zaznavanje_bioloskih_signalov_z_infrardeco_spektroskopijo.pdf 1 0C223A233328E14F4DCF9671B8F93B96 85a90a7db9c6a84639bff09e7d789c54c2331471355d39d7fa0dd83f6b2cb613 0befea49-7e72-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=214455 Fakulteta za elektrotehniko 0 0 0