Friday, August 9, 2013

How Overnight Pulse Oximeters Function

By Lela Perkins


Overnight pulse oximeters are medical devices used to noninvasively monitor oxygen saturation in the body of a patient. This equipment is used in a medical method called pulse oximetry. The equipment was invented by a German physician in the year 1935. Since that first invention, there have been many other physicians who have added components to the device with a bid to make it more effective.

Oximetry uses 2 tiny light emitting diodes, LEDs that face a photo-diode on the other surface through a translucent portion of the body. Earlobes, fingerprints, or feet if it is an infant in question can be utilized. One diodes is red and is made with wavelength of 660 nm. The other one is usually infrared with 940, 910, or 905 nm of wavelength. The velocity of absorption of the 2 wavelengths varies considerably between deoxygenated and its oxyhaemoglobin form.

Due to the variations in the absorption of the red and infrared wavelengths, the oxyhemoglobin and deoxyhemoglobin ratio can be calculated. At the wavelengths of 590 and 805 nm, the absorbance of deoxyhemoglobin and oxyhemoglobin is similar. Earlier equipment used these wavelengths to correct hemoglobin concentration.

The monitored signal changes over time with heart beats since arterial blood vessels constrict and expand with the heartbeat. By assessing the varying portion of the absorption spectrum alone, a monitor is capable of leaving out nail polishes or other tissues. By leaving out polish on fingernails and other tissues, monitors can capture absorption that is only caused by blood in arteries. It is therefore a vital requirement to identify a pulse in this practice, otherwise the exercise will fail.

The monitor that checks the level of oxygen in blood displays the content of hemoglobin in arteries in oxyhemoglobin configuration. For people who do not experience COPD and hypoxic drive problems, the normal acceptable range stands between ninety five to 99 percent. People with hypoxic problems expect values between 89 to ninety four percent. Carbon (II) oxide poisoning is shown by 100 percent of the reading.

Oximetry is different from other methods of monitoring the level of oxygen in blood because it is an indirect approach. The equipment can be integrated into multi-parameter patient monitoring systems. Most of them also indicate the pulse rate of an individual under monitoring. Overnight pulse oximeters are normally portable so that they can be carried into homes for home-based medication. They are small and operate on batteries.

These devices may be used in a broad range of environments and applications. They can be utilized in hospital wards, urgent care facilities, emergency units, intensive care units, and unpressurized aircrafts among several others. They are utilized to assess the efficiency and need of supplemental oxygen to patients. The gadget however cannot determine rate of oxygen metabolism in the human body. For this reason, they should be used together with carbon-dioxide monitoring gadgets.

Overnight pulse oximeters are vital for patients in critical medical conditions. They alert health staff of abnormalities in levels of oxygen in patients. Improvements in technology have rendered it possible to control them remotely for purposes of convenience.




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