What is a Pulse Oximeter


Definition of Pulse Oximeter: A pulse oximeter is a device intended for the non-invasive measurement of arterial blood oxygen saturation and pulse rate. Oximeters are used medically by patients with asthma, emphysema, chronic obstructive pulmonary disease (COPD), chronic obstructive airway diseases (COAD), and other respiratory conditions. Pilots use pulse oximeters to help guard against hypoxia. This blood oxygen tester can also help athletes, such as mountain climbers and walkers, to improve their performance.

The main advantages of pulse oximeter over other testing methodologies are cost and speed. The most accurate way to obtain SpO2 reading is from a laboratory analysis of a blood sample. An oximeter only takes a few seconds to obtain a reading. The accuracy of a pulse oximeter (usually within 1-3%) is sufficient for most situations.

The finger tip pulse oximeter contains a dual light source and photo detectors. Typically it uses two LEDs (light-emitting diodes) generating red and infrared lights through a translucent part of the body. Bone, tissue, pigmentation, and venous vessels normally absorb a constant amount of light over time. Oxyhemoglobin and its deoxygenated form have significantly different absorption pattern. The arteriolar bed normally pulsates and absorbs variable amounts of light during systole and diastole, as blood volume increases and decreases. The ratio of light absorbed at systole and diastole is translated into an oxygen saturation measurement.

Understanding pulse oximetry principles is essential in order to have a good interpretation of the readings. In some situations insufficient blood perfusion and light blockage would cause errors. Low blood circulation can be caused by hypotension, hypothermia and other factors. Light blockage can be caused by nail polish and intravenous dyes. Read pulse oximeter readings for more information.

A more recent study has shown that the absorption changes can also be used to estimate blood volume of a patient.

Today there are many pulse oximeter manufacturers making different models of pulse oximeters. They mostly use the two-wavelength method; however each manufacturer has its own signal processing algorithms for deriving the oxygen saturation levels. With recent technological development, the accuracy has improved significantly especially during low perfusion and motion.

There are many places that have pulse oximeters for sale at very reasonable prices. Not long ago, buying a pulse oximeter could cause quite a bit of damage to your budget. We offer a wide selections of finger pulse oximeters here.