Analysis of the Effect of Red LED and Infrared Flip Flop Frequency on SpO2 Measurement Accuracy

  • Moch Prastawa Assalim T P Department of Medical Electronics Engineering Technology, Poltekkes Kemenkes Surabaya
  • Dyah Titisari Department of Medical Electronics Engineering Technology, Poltekkes Kemenkes Surabaya
  • Wahyu Caesarendra Faculty of Integrated Technologies, Universiti Brunei Darussalam, Brunei Darussalam
  • Bagas Angger Prakoso Department of Medical Electronics Engineering Technology, Poltekkes Kemenkes Surabaya
Keywords: SpO2, Frequency, Infrared, Red Led


Oxygen saturation is a vital parameter for the early detection of advanced oxygen deficiency. Spo2 is a tool that measures the amount of oxygen in the blood non-invasively. This equipment consists of ophotodiodeiode as a sensor as well as red and infrared LEDs with a flip flop driver circuit that has a certain frequency. In this case, several research projects and equipment on the market have various flip flop frequencies. This research aims to find the best frequency setting value for red and infrared led drivers on SpO2 devices. In this research, a SpO2 that can be adjusted with a flip flop frequency of 400 Hz to 1400 Hz was designed. The SPO2 reading from the sensor is presented on the OLED LCD panel using Arduino Mega as a data processor from the driver frequency output controller. Frequency adjustment for sensor drivers is also at 400 Hz to 1400 Hz. This tool was further used to measure the frequency variation of the flip flop. The measurement results on the subject's finger were then compared with the results of the standard SpO2 tool to see the effect of the frequency value on the level of accuracy of the tool. The results of the comparison data processing showed that the largest error of 0.35% occurred in the SPO2 measurement using the 600 Hz sensor frequency driver, and the smallest error value of 0.07%, occurred in the use of the driver frequency at 1400Hz. These results can be used in the initial design of the production of SpO2 equipment, the higher the frequency, the more accurate it will be. This study only discusses the frequency, whereas the intensity parameters of the red and infrared LEDs also vary. In future research, it would be better to involve the LED light intensity parameter to determine its effect on the accuracy of the tool.


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S. Bagha and L. Shaw, “A Real-Time Analysis of PPG Signal for Measurement of SpO 2 and Pulse Rate,” Int. J. Comput. Appl., vol. 36, no. 11, pp. 45–50, 2015.

S. Hossain and K. Kim, “Comparison of Different Wavelengths for Estimating SpO2 Using Beer-Lambert Law and Photon Diffusion in PPG,” 2019 Int. Conf. Inf. Commun. Technol. Converg., no. 3, pp. 1377–1379, 2019.

C. Coli, G. M. Sari, and P. S. Rejeki, “Acute Moderate Intensity Exercise Decreases Oxygen Saturation In Obese Women,” Str. J. Ilm. Kesehat., vol. 9, no. 2, pp. 310–315, 2020, DOI: 10.30994/sjik.v9i2.302.

K. Kawai, T. Uchida, M. Mukai, M. Matsumoto, T. Itoh, and T. Oda, “Term Newborns with relatively low Tissue Oxygen Saturation Levels soon after Birth are predisposed to Neonatal Respiratory Disorders in Low-risk, Elective Cesarean Sections,” Int. J. Med. Sci., vol. 18, no. 11, pp. 2262–2268, 2021, DOI: 10.7150/ijms.53945.

C. Sun, E. Member, and I. Intr, “Low power M Microcontroller Solution for Measuring HBR Using single reflection SpO2 Sensor,” in International Conference on Consumer Electronics-Taiwan, 2015, pp. 82–83.

P. A. Sang-Soo Oak, “How to Design Peripheral Oxygen Saturation ( SpO 2 ) and Optical Heart Rate Monitoring ( OHRM ) Systems Using the” Appl. Rep., pp. 1–7, 2015.

J. G. Pak and K. H. Park, “Advanced Pulse Oximetry System for Remote Monitoring and Management,” J. Biomed. Biotechnol., vol. 2012, pp. 1–8, 2012, DOI: 10.1155/2012/930582.

E. Jahan, T. Barua, and U. Salma, “AN OVERVIEW ON HEART RATE MONITORING HEART RATE MONITORING AND PULSE OXIMETER SYSTEM,” Int. J. Latest Res. Sci. Technol., vol. 3, no. 5, pp. 148–152, 2020.

F. Welfare, “CLINICAL MANAGEMENT PROTOCOL : COVID-19,” Int. J. Gov. India Minist. Heal. Fam. Welf. Dir. Gen. Heal. Serv., vol. 1, no. 5, p. 81, 2020.

WHO, “Clinical management Clinical management Living guidance COVID-19,” J. World Heal. Organ., no. January, p. 22, 2021.

R. R. Adiputra, S. Hadiyoso, and Y. S. Hariyani, “Internet of Things : Low Cost and Wearable SpO2 Device for Health Monitoring,” Int. J. Electr. Comput. Eng., vol. 8, no. 2, pp. 939–945, 2018, DOI: 10.11591/ijece.v8i2.pp939-945.

M. G. et al Radwa Sameh, “Design and Implementation of an SPO2 Based Sensor for Heart Monitoring Using an Android Application,” J. Phys. Conf. Ser., vol. 1447, pp. 4–10, 2020, DOI: 10.1088/1742-6596/1447/1/012004.

J. Lapier and M. Chatellier, “CAN LOW COST FINGERTIP PULSE OXIMETERS BE USED TO MEASURE OXYGEN SATURATION AND HEART RATE DURING WALKING ?,” Int. J. Physiother. Res., vol. 4, no. 5, pp. 1689–1695, 2016, doi: 10.16965/ijpr.2016.166.

E. F. T. A. Eng. Ibrahim M. ALhyari, Eng. Mahdi A. Alabadi, Eng. Ghassan J. Hijazin, “SPO 2 Vital Sign : Definition, Ranges, and Measurements,” Int. J. Sci. Res. Publ., vol. 8, no. 7, pp. 287–289, 2018, doi: 10.29322/IJSRP.8.7.2018.p7945.

S. S. John and P. A. C. Raj, “Pulse Oximeter using PSoC,” J. Int. Teknol. Inov. dan Rekayasa Eksplor., vol. 2, no. 4, pp. 223–225, 2013.

L. C. Keat, A. B. Jambek, and U. Hashim, “A Study on Real-Time Pulse Sensor Interface with System-on-Chip Architecture,” in 3rd International Conference on Electronic Design (ICED), 2016, no. April 2018, pp. 1–6, DOI: 10.1109/ICED.2016.7804653.

R. C. R, K. P. Safeer, and P. Srividya, “Design and Development of Miniaturized Pulse Oximeter for Continuous Spo2 and HR Monitoring with Wireless Technology,” Int. J. New Technol. Res., vol. 1, no. 1, pp. 11–15, 2015.

M. R. M. and M. I. M. E A Suprayitno, “Measurement device for detecting oxygen saturation in blood, heart rate, and temperature of the human body,” J. Phys., no. doi:10.1088/1742-6596/1402/3/033110, pp. 1–6, 2019, DOI: 10.1088/1742-6596/1402/3/033110.

D. Yang, J. Zhu, and P. Zhu, “SpO2 and Heart Rate Measurement with Wearable Watch Based on PPG,” Int. J. Tongji Univ. Shanghai, China, vol. 4, no. 2, pp. 1–5, 2017.

F. International, C. Meeting, and B. Document, “Global Pulse Oximetry Project,” Int. J. Meet. Consult. Doc., vol. 20, no. October, p. 33, 2008.

J. Dn, M. Zakirulla, V. Sudhakar, and A. Meer, “Pulse Oximetry - Working Principles in Pulpal Vitality Testing,” Int. J. Heal. Sci. Res., vol. 2, no. August, pp. 118–123, 2012.

M. A. Zaltum, M. S. Ahmad, A. Joret, and M. M. Abdul, “Design and Development of a portable Pulse Oximetry System,” Int. J. Integr. Eng., pp. 37–44, 2015.

B. Anupama and K. Ravishankar, “Working mechanism and utility of pulse oximeter,” Int. J. Sport. Exerc. Heal. Res., vol. 2, no. 2, pp. 111–113, 2018.

M. M. Eid, “The Reliability of Oxygen Saturation Compared with Arterial Blood Gas Analysis in the Assessment of Respiratory Failure in Acute Asthma,” Int. J. Crit. Care Emerg. Med., vol. 6, no. 2, pp. 1–5, 2020, DOI: 10.23937/2474-3674/1510101.

WHO, “Technical and Regulatory Aspects of the Use of Pulse Oximeters in Monitoring COVID-19 Patients,” J. Pan Am. Heal. Organ., vol. 3, no. August, pp. 1–18, 2020.

How to Cite
M. P. Assalim T P, D. Titisari, W. Caesarendra, and B. A. Prakoso, “Analysis of the Effect of Red LED and Infrared Flip Flop Frequency on SpO2 Measurement Accuracy”,, vol. 4, no. 2, pp. 62-67, May 2022.
Research Article