Wireless Detecting Limb Blood Oxygen Saturation and Heart Rate based on Photoplethysmography

• Main Authors: Jhao-En Wei, 魏照恩
• Other Authors: Chiu-Ching Tuan
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/n2245z

碩士 === 國立臺北科技大學 === 電子工程系 === 106 === When the blood vessels are blocked, it will cause hypoxia of organ tissue or abnormal heart rate. Such as peripheral artery disease (PAD) symptom is limb hypoxia, myocardial Infarction (MI) may cause abnormal heart rate. However, it is difficultly conscious of tissue hypoxia and abnormal heart rate, when blood is unable to deliver oxygen to tissue cells. The situation causes the tissue turns into hypoxia and necrosis, limb may be amputated in the end. If the myocardial infarction, it will cause shock or sudden death. This study aims to measure the blood oxygen saturation (SpO2) and heart rate (HR) by photoplethysmography (PPG), providing the clinical doctors as treatment reference data. Photoplethysmography is applied to detect the intensity of light waveform through human’s capillary. The finger clip transmission light sensor only measure finger or toe, it can not measure arm or leg. This study is to measure the SpO2 of arm or leg by reflective PPG sensor. The SpO2 is percentage of hemoglobin (Hb) and oxyhemoglobin (HbO2), to be an evaluation index of the oxygen content of each part of the tissue. Heart rate is the number of heart beats per minute, to be an index of heart’s vessel state. Using a micro controller unit (MCU), SpO2 and HR algorithm and mobile application software, we constitute a mobile reflective SpO2 and HR detective device. Under the study limit, completed derivation of SpO2 formula parameter, SpO2 of left and right limbs, HR and SpO2 of pre-exercise and post-exercise experiments, the maximum error of SpO2 is 2%, HR is 6 bpm. The analysis difference of our system and commercial device by Wilcoxon sign rank, the p-value lager than 0.05, means no significant difference. Provide the clinical staff could evaluate the vascular suture and other hypoxia diseases, practice the prospect of mobile home care.