What is an oximeter and what is it used for?

In the past, a blood test is essential and inevitable in evaluating a person’s body status. Through taking a blood test, we can obtain most of our health index at one time. As we all know that a blood test is extremely intrusive and may be painful, it needs to be carried out by trained medical personnel and any improper tests can increase the risk of infection and transmission of various blood borne illnesses. It can be time-consuming as well, the collection, transportation and evaluation of blood requires at least a few hours to finish. But now non-invasive measurements are becoming more commonly used by people, they allow efficient and accurate tests with less health risks. Oximeter is one example of non-invasive measurement which helps monitor a person’s pulse and blood oxygen saturation. Under an improvement of the economy, technology and living standards, people are becoming more aware of their own body health. What’s more, the outbreak of covid-19 has proven that oximeters can help detect the disease even if patients do not show any symptoms. Therefore, some healthy individuals will also make use of oximeters to evaluate their health conditions to control and eliminate any possible health risks. Today, we will mainly focus on the function and implication of oximeters.

Oximeter is a non-invasive device which can monitor people’s health status through their pulse rate and blood oxygen saturation level. The device will send infrared light into the capillaries in patients’ fingers, toes or earlobes, the amount of light reflected is used to estimate the oxygen level in blood. Pulse, also equivalent to heart rate, measures the count of arterial pulses per minute. Oxygen saturation resembles the amount of oxygen-saturated hemoglobin relative to the total amount of hemoglobin. We all know that oxygen plays a critical role in human lives, it supports the normal function and drives the metabolism of our body tissues. As we breathe in, oxygen enters the lungs and diffuses into blood, hemoglobin in red blood cells carries oxygen and becomes oxyhemoglobin which brings oxygen to all around the body. When oxyhemoglobin arrives, it will split back to deoxyhemoglobin, so that the oxygen can enter the body tissues and the normal body functions can be maintained. Malfunctions in heart or lungs which affect the pulmonary and systemic circulation of blood throughout the body, lead to inadequate supply of oxygen in blood. By measuring the pulse rate, we can easily determine the frequency of our heartbeat as well as the condition of oxygen supply to blood and to the whole entire body.

Oximeter helps people to have a better understanding of their heart, lungs and body status, effectively detect any malfunctions and eliminate risks, but how can we evaluate the normality of the data that we obtain from the device? According to the World Health Organisation, a healthy person should have an oxygen saturation between 95% to 100%. When the blood oxygen saturation is 94% or lower, the patient will be diagnosed as hypoxic. Hypoxic may be caused by involuntary smoking, polluted air or high latitude environment; Abnormal respiratory and circulatory systems may cause chronic pulmonary disease and anemia which lead to hypoxic below-normal oxygen saturation level will lead to symptoms like headache, rapid heartbeat, chest pain and shortness of breath. An oxygen saturation of less than 90% is considered as a clinical emergency, the patient needs to be treated immediately otherwise it may lead to respiratory failure, damage in heart or brain tissues which could be life-threatening. Patients diagnosed with covid-19 have their lungs functions being damaged, even though they may not show any symptoms, oximeters are helpful in detecting the virus early. For resting pulse rate, normal individuals are around 60 to 100 times/minute , infants have a faster pulse rate which is about 110 to 120 times/minute while elderly’s pulse rate is much slower, around 55 to 75 times/minute. However, endurance athletes or someone who exercises often have a lower than normal resting pulse rate. It is because exercises strengthen their heart muscles, a greater amount of blood is pumped and more oxygen is supplied every time their hearts beat which results in fewer pulse rate. Some other factors may also affect the resting heartbeat like medication, temperature, emotion and caffeine, leading to the abnormality in pulse rate. When the resting pulse rate is lower than 60 beats/ minutes, the patient may suffer from weakness, dizziness, chest pain and fainting; When the resting pulse rate is too high, patients bear a higher risk of having stroke and heart failure, they may feel dizzy, fall unconscious and encounter cardiac arrest in extreme cases.

There are many oximeters selling in the market, each of them have different prices and functions. But how can we choose the right oximeter that best fits you and your family? We will further analyse the functions of oximeters in different price levels in the following passage.

References

1. World Health Organization (2011). Pulse Oximetry Training Manual. Retrieved from https://www.who.int/patientsafety/safesurgery/pulse_oximetry/who_ps_pulse_oxymetry_training_manual_en.pdf?ua=1

2. Pulse oximetry. (2017, June 13). Retrieved December 24, 2020, from https://www.who.int/patientsafety/safesurgery/pulse_oximetry/en/

3. 心跳紊亂乃心臟病徵兆. Retrieved from https://www.hkah.org.hk/tc/education/article/id/15/

4. 一文教你讀懂生命表徵: 標準值、異常狀況、量度方法 • Evercare. (2020, December 11). Retrieved December 24, 2020, from https://www.yourevercare.com/vital-signs-hong-kong/?lang=zh-hant

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