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Quick Overview of a Pulse Oximeter

Quick Overview of a Pulse Oximeter

What is a fingertip pulse oximeter?

A fingertip pulse oximeter is a small, portable and non-invasive device that indirectly monitors your blood oxygen saturation (SpO2) and pulse rate (heart rate).

How does a pulse oximeter work?

When the device is clipped onto your fingertip, it transmits two wavelengths of light through the finger to measure pulse rate and how much oxygen is in the blood. Once the oximeter finishes its assessment, it displays your current pulse rate in bpm (beats per minute) and your blood oxygen saturation level in %SpO2.  Below is a quick 2-minute explanation of an oximeter and how it can help from CBS 17 in North Carolina.


Measurement Principle

SpO2 stands for peripheral capillary oxygen saturation. Oxygen saturation is defined as the ratio of oxyhemoglobin (HbO2) to the total concentration of hemoglobin (i.e. Oxyhemoglobin + reduced hemoglobin) present in the blood. It is an important physiological parameter involved in respiration and circulation.

Oxygenated blood absorbs light preferentially at 905nm (near infrared light), whereas deoxygenated blood absorbs light preferentially at 660nm (red light). A pulse oximeter works by passing a beam of red and infrared light through a pulsating capillary bed and then measure the amount of red and infrared light emerging from the tissues via a sensor. The relative absorption of light by oxyhemoglobin (HbO) and deoxyhemoglobin is then calculated according to the Beer-Lambert's law and a quantitative measurement of the users’ oxyhemoglobin status i.e. Oxygen saturation level (SpO2) is derived.

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  • Beyond Med Shop

Comments 7

  • Gerry.

    What does Er 7 mean? Can’t find errr code is listed.
    Zacurate replied:

    I am sorry about the issues you are having with your pulse oximeter. Do you have nail polish? The Er 7 message usually appears when the user has nail polish. If this is not the case, please email us at with a copy of your purchase record and we will be more than happy to assist you with a replacement.

    Best regards, Sara Customer Service Beyond Med Shop 832-939-8290 Mon-Fri 9 am to 5 pm CST

    *Proud to be #295 Inc. 500 Fastest Growing Companies (1562% Growth) *

  • Blair Smith.
    Blair Smith

    Really interesting post!

  • Pooja Gupta .
    Pooja Gupta

    Your post is very informative …. now i know pulse oximeter more … Thankyou

  • viki cydell.
    viki cydell

    O2 levels can be critical in managing health care at home. Thank you for the offer.

  • Griselide  Albanez.
    Griselide Albanez

    I didn’t receive the pulse Oximeter and I am interested to receiving the Oximeter.

  • Martina Rodríguez .
    Martina Rodríguez

    I didn’t receive the pulse oximeter

  • Alliene G Parks.
    Alliene G Parks

    I am interested in receiving an Oximeter, I think it is a great way to assist in preventive health care.

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