Adults are aware of the fact that their heart rate can be monitored, and sometimes this is necessary. Most also know how to measure their pulse in the conventional way by finding it in various parts of the body. Less commonly known is the meaning of oximetry, which is the way to determine how much oxygen the blood contains. Equipment has been designed to measure oxygen levels, such as the wrist pulse oximeter.

When there is a worry that someone's oxygen levels could fall too low, oximeters will need to be used. Medical facilities are equipped with such appliances, and usually have them fitted in various sections, such as the intensive care and casualty areas. The oximeters that have been designed in the form of a wristwatch are more useful for persons who are not in a hospital environment.

Wristwatch oximeters are not cumbersome in any way, and have all the features of a hospital's unit. They have a memory of possibly up to eighty hours, which means that every reading can be stored. However, when the memory is full, the information must first be deleted or transferred before the device will work again. These wristwatch devices have been approved for usage by the FDA.

Persons who would like to monitor their heart rates and their oxygen levels at home, while they study or while they sleep, will find these devices ideal. Persons who would like to monitor their asthmatic condition may consider using them as well. Oximeters, including the wristwatch variety, have a non-invasive probe that produces red and infrared light. They are usually shined onto a finger, toe or earlobe.

The light that is shined onto the skin is mostly absorbed by tissue, but some is not, and it is this small amount of light that is used to show the level of oxygen in the blood, or the hemoglobin levels. An individual in good health will be expected to get a reading of between 95% and 98%. It will rarely be at 100%. However, for some people it could be normal that the percentage is anything down to 90% as well. Below this percentage, the patient may be having trouble breathing.

Oximeters give quite accurate readings, but there are certain things that cause unreliable readings. There must be a strong pulse rate in order for the device to work. Patients who have an irregular heartbeat will not be able to get an accurate reading. A patient will also struggle if they have a very weak heart rate.

Furthermore, the accuracy of the device is hindered by movement, as it affects the way the light is produced. The person being tested must remain still. The device works with light, and therefore the presence of other bright lights could affect its reliability. Since that oximeters can produce results that are inaccurate, several readings should always be taken.

Computer programs will need to be purchased along with the wrist pulse oximeter, but they are easy to find. The long battery life and the fact that they can be used even whilst wearing nail polish are additional advantages. They will also have a guarantee of quality.