Illumination Adaptation in a Multi-Wavelength Opto-Electronic Patch Sensor
| Autor: | Panagiotis Blanos, Yue Yu, Sijung Hu, Matthew Hayes, Samah Alharbi, David Mulvaney, Liangwen Yan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Computer science
Photodetector photoplethysmographic 02 engineering and technology lcsh:Chemical technology 01 natural sciences Biochemistry Signal Article Analytical Chemistry law.invention law adaptive algorithm 0202 electrical engineering electronic engineering information engineering Electronic engineering heart rate lcsh:TP1-1185 Electrical and Electronic Engineering Instrumentation Diode multi-wavelength opto-electronic patch sensor 020208 electrical & electronic engineering 010401 analytical chemistry Atomic and Molecular Physics and Optics 0104 chemical sciences Microcontroller Operational amplifier Voltage Light-emitting diode |
| Zdroj: | Sensors (Basel, Switzerland) Sensors, Vol 20, Iss 4734, p 4734 (2020) Sensors Volume 20 Issue 17 |
| ISSN: | 1424-8220 |
| Popis: | In capturing high-quality photoplethysmographic signals, it is crucial to ensure that appropriate illumination intensities are used. The purpose of the study was to deliver controlled illumination intensities for a multi-wavelength opto-electronic patch sensor that has four separate arrays each consisting of four light-emitting diodes (LEDs), the wavelength of the light generated by each array being different. The study achieved the following: (1) a linear constant current source LED driver incorporating series negative feedback using an integrated operational amplifier circuit (2) the fitting of a linear regression equation to provide rapid determination of the LEDs driver voltage and (3) an algorithm for the automatic adjustment of the output voltage to ensure suitable LED illumination. The data from a single centrally-located photo detector, which is capable of capturing all four channels of back-light in a time-multiplexed manner, were used to monitor heart rate and blood oxygen saturation. This paper provides circuitry for driving the LEDs and describes an adaptive algorithm implemented on a microcontroller unit that monitors the quality of the photo detector signals received in order to control each of the individual currents being supplied to the LED arrays. The study demonstrated that the operation of the new circuitry in its ability to adapt LED illumination to the strength of the signal received and the performance of the adaptive system was compared with that of a non-adaptive approach. |
| Databáze: | OpenAIRE |
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