Besides calculating the blood oxygen levels of a person (SpO2), the oxygen monitor also displays his/her heart rate. The accuracy of this reading depends, first of all, of the type of pulse oximeter used: devices for clinical use are more dependable then simple models intended for home consumers. However, since the main feature of an oxygen monitor is the measurement of blood oxygenation, we should keep in mind that pulse rate monitoring is a secondary function (several studies indicate that in some cases pulse oximeters can offer inaccurate heart rate results, that’s why during serious medical interventions or critical situations the pulse rate should be double checked by using an additional method).
All types of pulse oximeters (fingertip, wrist, handheld or tabletop) have on their display two main parameters: SpO2 and PR (BPM). SpO2 means saturation of peripheral oxygen (or blood oxygen levels) and PR (BPM) means Pulse Rate (indicated in Beats per Minute).
What is the normal heart rate? The normal pulse rate of a healthy adult ranges from 60 to 80 BPM. In adolescence, the heart rate values can reach 120 BPM; small children’s heart rate oscillates between 80 and 150 BPM, while infants usually show results situated between 120 and 150 BPM.
When is the oximeter’s function of heart rate monitoring useful? The heart rate measurement provided by an oxygen monitor can be extremely helpful in various situations:
1. Hospital care. First of all, this function provides additional information about a patient’s condition in hospitals and other health care facilities, no matter if we talk about routine check-ups, emergency situations or monitoring a patient under anesthesia.
2. Personal use of cardiac patients. People suffering from cardio-vascular diseases (including arrhythmia) can also monitor their heart rate on a regular basis by using an oxygen monitor – usually the fingertip pulse oximeter is recommended for personal use.
3. Heart rate monitoring during running or other types of strenuous physical trainings. If you’re a professional athlete or you’re training regularly on your own, you can also use a blood oxygen monitor. The most suitable model for this purpose is the wrist pulse oximeter – a device made especially for runners and athletes. It can be wrapped around the wrist, offering constant monitoring of the oxygen levels and heart rate – important signs that can show if the person’s body is coping or not with the strenuous physical effort.
The gadget can be programmed to sound an alarm whenever the oxygen saturation goes below a certain limit (for example, 90% or 93% SpO2) or when the pulse rate is exceeding a certain number of BPM. This way, dangerous cases of hypoxia or heart failure can be prevented (especially if the person has the habit of pushing his/her body beyond the normal level of endurance during training). Thanks to this device, they will know when to take a break or stop the workout without jeopardizing their health. If the runner suffers from a minor respiratory or cardiac dysfunction, the use of a pulse oximeter is highly recommended. The oxygen monitor will also record the athlete’s oxygenation and heart rate parameters, which can be later analyzed and used as a reference point for future trainings.
Some models of blood oxygen monitors (especially more sophisticated types designed for medical use) also display the PI or Perfusion Index (a parameter which helps the specialists to get more accurate SpO2 readings). PI is a relative value that shows the pulse strength at the sensor site (site of monitoring). These assessments can range between 0.02% (an indicator of weak pulse strength) and 20% (a sign of a strong pulse). PI is calculated by evaluating the strength of the returning infrared signal.
Te Perfusion Index usually differs – each monitoring site will show its own values. This function can be useful for medical specialists in diagnosing and treating various health dysfunctions.
Even if it was created for obtaining easy, fast and reliable SpO2 readings, the oxygen monitor also offers its users additional features (such as heart rate monitoring) for a more complex assessment of one’s health condition at a given moment.