Pulse oximetery helps to record two important pieces of information about patients. These two pieces of data are the rate at which the heart beats and the percentage of blood oxygen saturation. This method is considered non-invasive because no kind of penetration is done to the body. Patients who are under CPAP therapy for apnea can use a recording pulse oximeter to determine how effective the efficiency is.

Research has indicated that at night time when apnea activities are happening, blood oxygen level reduces. Such drops in oxygen level can be recorded over time and then used to compare with previous recordings hence helping in determining if therapy is helping or not. Oximeters with recording capabilities have several features that make them worth having. For instance, heart rates and blood oxygen concentration levels are able to be determined on the spot.

Ability to check the 2 aspects on the spot is useful in determining things like effect of height and changes in air pressure on normal brain functions. When exercising or involved in strenuous activities, one may want to know their heart rates and oxygen concentration in blood. These devices have certain features that a buyer should check out for before settling for any specific product.

The display should be the first factor to consider when making a purchase. Ordinary devices based on LED displays display heart rates and saturation of O2 in blood as the only pieces of information. Complex devices however, display more data on a better screen. Most common additional data displayed includes pulse waveform, various menus, pulse meter, perfusion index, and battery level indicator. Depending on the make of product, the menus open various functions.

All good devices include the alarm function. Alarms are vital because they warn users when threshold values are exceeded or have fallen below. Normally the threshold values can be determined by the user themselves. Users therefore get warned when blood oxygen saturation or heart rate falls or exceeds a certain level. The alarm also warns users when the battery is empty or below a certain percentage.

These products come with two main types of batteries to choose from. The first type is the rechargeable lithium ion battery and the second one is the standard alkaline battery. The rechargeable type as suggested in the name can be recharged and reused when they run low. This way, they can last for several years unlike the alkaline types which when they wear out cannot be recharged. Some models of products can use both types of batteries. So it is upon the user to try that possibility out.

One must never ignore comfort in the device. The user should be comfortable with how tightly the device fits on the area of attachment. Clip-based devices that are attached to the finger should be comfortable even after being used for hours especially at night. One can switch the fingers if discomfort is felt.

After checking that all the important factors are well, one may check for extra functions like Bluetooth or wireless capabilities. A device that can wirelessly transmit real time values to the computer running the software is better off. Such capabilities are important to third parties like caregivers.