Accuracy enhancement in reflective pulse oximetry by considering wavelength-dependent pathlengths

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21730%2F22%3A00364570" target="_blank" >RIV/68407700:21730/22:00364570 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1088/1361-6579/ac890c" target="_blank" >https://doi.org/10.1088/1361-6579/ac890c</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6579/ac890c" target="_blank" >10.1088/1361-6579/ac890c</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Accuracy enhancement in reflective pulse oximetry by considering wavelength-dependent pathlengths

Popis výsledku v původním jazyce

Objective. Noninvasive measurement of oxygen saturation (SpO (2)) using transmissive photoplethysmography (tPPG) is clinically accepted and widely employed. However, reflective photoplethysmography (rPPG)-currently present in smartwatches-has not become equally accepted, partially because the pathlengths of the red and infrared PPGs are patient-dependent. Thus, even the most popular 'Ratio of Modulation' (R) method requires patient-dependent calibration to reduce the errors in the measurement of SpO (2) using rPPGs. Approach. In this paper, a correction factor or 'pathlength ratio' beta is introduced in an existing calibration-free algorithm that compensates the patient-dependent pathlength variations, and improved accuracy is obtained in the measurement of SpO (2) using rPPGs. The proposed pathlength ratio beta is derived through the analytical model of a rPPG signal. Using the new expression and data obtained from a human hypoxia study wherein arterial oxygen saturation values acquired through Blood Gas Analysis were employed as a reference, beta is determined. Main results. The results of the analysis show that a specific combination of the beta and the measurements on the pulsating part of the natural logarithm of the red and infrared PPG signals yields a reduced root-mean-square error (RMSE). It is shown that the average RMSE in measuring SpO (2) values reduces to 1 %. Significance. The human hypoxia study data used for this work, obtained in a previous study, covers SpO (2) values in the range from 70 % to 100 %, and thus shows that the pathlength ratio beta proposed here works well in the range of clinical interest. This work demonstrates that the calibration-free method applicable for transmission type PPGs can be extended to determine SpO (2) using reflective PPGs with the incorporation of the correction factor beta. Our algorithm significantly reduces the number of parameters needed for the estimation, while keeping the RMSE below the clinically accepted 2

Název v anglickém jazyce

Accuracy enhancement in reflective pulse oximetry by considering wavelength-dependent pathlengths

Popis výsledku anglicky

Objective. Noninvasive measurement of oxygen saturation (SpO (2)) using transmissive photoplethysmography (tPPG) is clinically accepted and widely employed. However, reflective photoplethysmography (rPPG)-currently present in smartwatches-has not become equally accepted, partially because the pathlengths of the red and infrared PPGs are patient-dependent. Thus, even the most popular 'Ratio of Modulation' (R) method requires patient-dependent calibration to reduce the errors in the measurement of SpO (2) using rPPGs. Approach. In this paper, a correction factor or 'pathlength ratio' beta is introduced in an existing calibration-free algorithm that compensates the patient-dependent pathlength variations, and improved accuracy is obtained in the measurement of SpO (2) using rPPGs. The proposed pathlength ratio beta is derived through the analytical model of a rPPG signal. Using the new expression and data obtained from a human hypoxia study wherein arterial oxygen saturation values acquired through Blood Gas Analysis were employed as a reference, beta is determined. Main results. The results of the analysis show that a specific combination of the beta and the measurements on the pulsating part of the natural logarithm of the red and infrared PPG signals yields a reduced root-mean-square error (RMSE). It is shown that the average RMSE in measuring SpO (2) values reduces to 1 %. Significance. The human hypoxia study data used for this work, obtained in a previous study, covers SpO (2) values in the range from 70 % to 100 %, and thus shows that the pathlength ratio beta proposed here works well in the range of clinical interest. This work demonstrates that the calibration-free method applicable for transmission type PPGs can be extended to determine SpO (2) using reflective PPGs with the incorporation of the correction factor beta. Our algorithm significantly reduces the number of parameters needed for the estimation, while keeping the RMSE below the clinically accepted 2

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10201 - Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physiological Measurement

ISSN

0967-3334

e-ISSN

1361-6579

Svazek periodika

43

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

20

Strana od-do

—

Kód UT WoS článku

000852492400001

EID výsledku v databázi Scopus

2-s2.0-85137164165