RT Journal Article
T1 A Simple front-end for pulse oximeters with a direct light-to-time-to-iigital interface circuit
A1 Hidalgo-López, José Antonio
K1 Electrónica
K1 Electrónica médica
K1 Electrónica - Aparatos e instrumentos
AB Pulse oximeters are electronic devices that pro-vide the values of two physiological parameters: heart rate(HR) and functional O2 saturation, SpO2. Acquiring this infor-mation requires a photodiode and a set of red and infraredlight-emitting diodes (LEDs) to generate two plethysmo-grams, which are digitally processed to find the HR and SpO2values. The circuits currently used to generate these plethys-mograms require multiple analog modules, such as voltagereferences, transimpedance amplifiers (TIAs), voltage ampli-fiers, and comparators. Analog-to-digital converters (ADCs)or switched integrators (SIs) are also needed to digitalize thesignals that provide the HR and SpO2 values when introducedin a digital processor (DP). This article proposes a new circuitthat eliminates the need for all these analog modules orconverters, replacing them with a single capacitor and tworesistors. The circuit is based on a light-to-time-to-digitalconversion performed using the DP, which does not requireany special characteristics to carry out this task. As a proofof concept, the new design has been implemented using afield-programmable gate array (FPGA) as the DP. The resultsshow plethysmograms with good detail regarding amplitudeand time, allowing the device to be used for clinical purposes. A comparison with two conventional commercial pulseoximeters shows that the new circuit provides similar HR and SpO2 values.
PB IEEE Xplore
YR 2023
FD 2023-11-21
LK https://hdl.handle.net/10630/28621
UL https://hdl.handle.net/10630/28621
LA eng
NO Hidalgo-López, J. A. "A Simple Front-End for Pulse Oximeters With a Direct Light-to-Time-to-Digital Interface Circuit," in IEEE Sensors Journal, vol. 24, no. 1, pp. 346-354, 1 Jan.1, 2024, doi: 10.1109/JSEN.2023.3333055.
NO Funding for open Access charge: Universidad de Málaga / CBUA
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026