Pulse oximeters are medical devices commonly used throughout the healthcare industry. A pulse oximeter (pulse ox) is a small, portable device that is used to non-invasively measure the oxygen saturation levels in the blood. The pulse oximeter will show the % oxygen saturation and the pulse rate of the user.
Pulse Oximeters are used by a wide variety of individuals for many different reasons.
You may have noticed that pulse oximeters are used throughout the community during visits to the doctor or dentist. These devices are easy-to-use and the perfect tool to “spot check” a pulse rate or oxygen saturation level.
Fingertip Pulse Oximeter: The fingertip pulse oximeter is most commonly used at home and outside of the clinic setting. These devices are gently clamped onto the fingertip and provide pulse rate and oxygen saturation readings. The fingertip pulse oximeter is small, portable, easy-to-use and provide immediate digitally displayed results.
Handheld Pulse Oximeter: The handheld pulse oximeter is most commonly recommended for use at a clinic. These devices come equipped with an adult fingertip sensor that is attached to a handheld display device. Pediatric or Neonatal sensors are also available for use with the handheld device. The handheld pulse oximeter is able to monitor pulse rate and oxygen saturation results, store results, download and print reports.
Wrist Pulse Oximeter: The wrist pulse oximeter uses the fingertip sensor but the display attaches to the wrist like a watch. This is a great unit to use for continuous monitoring while walking or for individuals who do not want to constantly carry around a fingertip oximeter. The wrist oximeter is able to store and download results and print reports.
Most fingertip pulse oximeters will have preset audio alarms.
SpO2 alarm will beep at the lower limit of 90%.
Pulse rate alarm will beep at the lower limit of 50 beats per minute and at the upper limit of 120 beats per minute.
The Wrist monitor and handheld devices do have adjustable alarms that the user may set.
The workings of a pulse oximeter are based on the latest processor chip technology, where accuracy is combined with portability. Once oxygen is breathed in the lungs, it enters the blood and attaches to hemoglobin as a means of transportation in the bloodstream. The oxygenated blood then circulates to various tissues in the human body. To understand the workings of a pulse oximeter, it is important to understand that oxygenated blood absorbs light at different levels compared to deoxygenated blood. Pulse oximeters utilize the light absorptive characteristics of hemoglobin and the varying pulsating nature of blood flow to measure oxygenation saturation levels.
Pulse oximeters consist of two (2) light emitting diodes and two (2) light collecting sensors, which are designed to measure the amount of red and infra-red light emerging from tissues traversed by the light rays. Oxygen-rich hemoglobin absorbs more of the infra-red light and the hemoglobin without oxygen absorbs more of the red light. Pulse oximeters calculate SPO2 and pulse rate based on the variations of the infra-red and red light absorption.
Based on Lamber-Beer Law, the light absorbance of a given substance is directly proportional with its density or concentration. When the light with certain wavelength emits on human tissue, the measured intensity of light after absorption, reflecting and attenuation in tissue can reflect the structure character of the tissue by which the light passes. Due to the fact that oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb) have different absorption characteristics, the spectrum range from red to infrared light (600nm~1000nm wavelength), by using these characteristics the SpO2 can be determined. SpO2 measured by the oximeter is the functional oxygen saturation – a percentage of the hemoglobin that can transport oxygen.
SpO2 is the saturation percentage of oxygen in the blood, so call O2 concentration in the blood; it is defined by the percentage of oxyhemoglobin of the arterial blood. SpO2 is an important physiological parameter to reflect the respiration function; it is calculated by the following method:
SpO2 = HbO2/(HbO2+ Hb) x 100%
HbO2 are the oxyhemoglobins (oxygenated hemoglobin) while Hb are those hemoglobins which release oxygen.
Pulse Oximeters Plus oximetry products including but not limited to fingertip pulse oximeter, hand held oximeters, sleep unit oximeters, and all accessories are not intended to replace a physician’s professional medical diagnosis or to cure any disease or ailment.