Pulse Oximeter Essay

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Abstract— Optical Pulse Oximetry is feasibly the greatest advance in patient monitoring. Pulse Oximetry enables oxygenation, an important physiological variable that is poorly detected by clinical means, to be monitored continuously and easily. Hypoxemia is commonly found in all aspects of medical practice and is a major cause of organ abnormality and death. It should be widely available and used routinely in clinical practice both in primary care and in hospital.
This paper will design a non-invasive optical pulse oximeter using the Arduino. The pulse oximeter consists of a sensor and an Arduino microcontroller. The (Photo Transistor) sensor is used for the pulse wave 's detection, and the Arduino microcontroller is designed to analyze
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The emitters and photo detector are placed so as to face each other through tissue about 5-10 mm in thickness. The diodes are switched turn on and turn off in rapid sequence so that each measurement set include an estimate of transmission of infrared light, red light and ambient illumination. The ratio of red to infrared light is determined and the corresponding oxyhemoglobin saturation is found from an empirically determined table. The individual measurements are made each second and fed into an algorithm in an Arduino, where they are accepted or rejected and then weighted using formulas. The displayed value is an average value based on the previous 3-6 seconds of recording and updated about every 0 5-1 second. …show more content…
The traditional sign is cyanosis, which is defined as a concentration of more than 5 g/100 ml of reduced hemoglobin in capillary blood and depends on arterial oxygenation, skin perfusion, and hemoglobin content. In human body the presence of central cyanosis, a blue coloration of the tongue and mucous membranes is thought to be a more reliable indicator of hypoxemia as these tissues are less likely to be poorly per fused.
This definition translates to an oxyhemoglobin saturation of about 75% with normal perfusion, which is clinically important hypoxemia. For detecting hypoxemia the ability depends on the experience and eyesight of the observer, the colour balance of the ambient lighting, and the skin pigmentation of the subject. The places where hypoxemia may be expected (operating theatres, accident departments, endoscopy suites) should have lighting with blue coloration ("northern daylight") to facilitate detection. In several studies-the earliest was by Comroe and Bothelo in 1947 '-have shown that even under ideal conditions skilled observers cannot detect hypoxemia until the oxyhemoglobin saturation is fewer than 80%. The pulse oximeter thus extends our clinical senses rather than replacing

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