Nosivi impulsni fotopletizmograf

undergraduate thesis

• Title (english): Wearable Pulse Photoplethysmograph
• Author: Fran Milković
• Mentor: Vedran Bilas (mentor)
• Committee member: Vedran Bilas (predsjednik povjerenstva)
• Committee member: Darko Vasić (član povjerenstva)
• Committee member: Dinko Oletić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2018-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Tržište nosivih uređaja je sve veće i u skladu s time rastu ulaganja u razvoj takvih uređaja. Kako bi se zadovoljili zahtjevi nosivih uređaja, poput jednostavnosti, ergonomičnosti i niske potrošnje, nužna je interdisciplinarna suradnja. Primjer tehnologije sve češće zastupljene u takvim uređajima je fotopletizmografija koja funkcionira na principu opažanja promjena u svjetlosti koja prolazi kroz tkivo ili se reflektira od njega. Fotopletizmograf u ovom radu sačinjen je od analognog kanala s dvije valne duljine (zelena svjetlost i IC zračenje) i dvaju ugradbenih sustava. Fotodiode imaju vršnu osjetljivost pri valnim duljinama 580nm i 900nm. Napon na izlazu kanala se iz područja 0-3V kvantizira u 10-bitne brojeve. Podaci se prenose radiokomunikacijom i UART serijskom vezom do prijenosnog računala na kojemu se prikazuju rezultati u obliku krivulje pulsa. Dva kanala omogućuju dobivanje informacija o zasićenosti kisikom. Za napajanje ugradbenog sustava koristi se solarna energija. Velika pažnja se pridaje minimiziranju potrošnje i dimenzija. Kad fotopletizmograf radi sa zelenim kanalom maksimalna potrošnja (pri radnom omjeru 1/2) je 98,07mW, a za IC kanal iznosi 90,42mW. Rješenje zadatka je funkcionalno, ali za postizanje razine rada koja se može uspoređivati s radom komercijalnih fotopletizmografa, nužne su izmjene.

Abstract (english)

The wearable devices market is growing and so are the investments into the development of such devices. In order to satisfy the demands on wearable devices, such as being simple, ergonomic and low-power, it is necessary for experts in various fields to work together. An example of technology increasingly used in such devices is photoplethysmography (PPG). It is based on detecting changes in light passing through or reflecting off tissue. The photoplethysmograph in this paper is consisted of an analog channel with two different wavelengths (green light and infrared (IR) radiation) and two embedded systems. The photodiodes have peak sensibility at wavelenghts of 580nm and 900nm. The voltage at the output of the analog channel in range of 0-3V is sampled and converted into 10-bit digital value. The collected data is transferred using radiocommunication and UART serial communication to a laptop in order to present the data in a more convenient form - a curve. Using two wavelengths lays the groundwork for getting information about oxygen saturation. Solar energy is harvested and used to power one of the embedded systems. A great deal of attention is paid to minimising the size and power consumption. When operating with the green channel, maximum power consumption (at duty cycle 1/2) is 98,07mW, while the maximum IR channel consumption is 90,42mW. The photoplethysmograph in this paper is fully functional, but in order to be comparable to commercially available photoplethysmographs, improvements are necessary.

• Keywords: fotopletizmografija; puls srca; nosivi uređaj; zelena svjetlost; infracrveno zračenje; solarno napajanje
• Keywords (english): photoplethysmography; pulse rate; wearable device; green light; infrared radiation; solar energy harvesting
• Language: croatian
• URN:NBN: urn:nbn:hr:168:355217
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-13 23:10:33