Dorothy FarrarPulse oximeter (pulse oximetry)
A pulse oximeter is a medical measuring instrument. It is used in pulse oximetry.
What is a pulse oximeter?
A pulse oximeter or pulse oximeter is a small medical device used to measure the pulse and oxygen saturation within the capillary blood. The instrument is used in pulse oximetry or pulse oximetry. For this purpose, it can be attached like a clip to a finger of the person to be examined.
In pulse oximetry, arterial oxygen saturation is determined non-invasively by measuring the light absorption of hemoglobin (red blood pigment) within the circulating red blood cells (erythrocytes).
The first description of pulse oximetry took place in 1935 by K. Matthes. However, it was not until 1972 that bio-engineer Takuo Aoyagi from Japan was able to use the process. As part of a migraine research project in Germany, the method was also carried out for the first time in 1976 under the name photopletysmography.
Application and function
Pulse oximetry is one of the standard methods of medicine. It is an important part of basic monitoring in hospitals. The procedure is primarily used in anesthesia. But other medical departments also frequently resort to this form of pulse measurement.A pulse oximeter is used, which is worn by the patient on a finger or other easily accessible part of the body during the examination. The pulse oximeter consists mainly of a light source and a light sensor. Infrared light waves are emitted from the light source, which are able to penetrate the finger.
On the other hand, the light sensor is used to measure the light components at which absorption takes place. The absorption of light within the blood depends on the concentration of hemoglobin and its saturation with oxygen.
Pulse oximetry is considered a simple procedure that can be used anywhere. After just a few seconds, the first measured values are available, which enables reliable follow-up of circulatory and lung function.
In pulse oximetry, the fact is used that the blood pigment can have different colors, which depends on the respective condition. While saturated hamöglobin, which is loaded with oxygen, takes on a bright red coloration and absorbs red light, unsaturated hemoglobin has a dark red to bluish color. It primarily absorbs light in the infrared range. From the measured values recorded by the pulse oximeter, a computer can determine which light was recorded in which quantities of tissue and blood at the measuring site.
Pulse oximetry is used when taking drugs that affect the patient’s consciousness and breathing. This is mainly the case under anesthesia or when administering sedatives.
With the help of a pulse oximeter, the doctor also determines whether there is a lack of oxygen in an asthma attack or an acute lung disease such as pneumonia. Emergency services also have small portable devices that allow them to take measurements on site. Even in a sleep laboratory, the use of a pulse oximeter can be useful to diagnose obstructive sleep apnea syndrome (OSAS).
Special pulse oximeters are used to examine children suffering from heart defects. They are suitable for measuring low saturation ranges that are below 70 percent. Even mountaineers now rely on pulse oximeters. With their help, a drop in oxygen saturation can be detected, which makes a warning of altitude sickness possible.
What does the patient have to consider?
Special preparations in the run-up to pulse oximetry are not necessary for the patient. Thus, the procedure is one of the non-invasive methods that do not require any preparation for the persons examined. Only on the parts of the body where the pulse oximeter is attached, is it also necessary to pay attention to minor injuries. In this way, irritation or pain can be counteracted.
Even after the pulse oximetry, the patient does not need to take any special precautions. If an incorrect measurement occurs, the procedure must be carried out again.
process and implementation
Pulse oximetry is carried out using a pulse oximeter that is smaller than a packet of cigarettes. At the beginning of the measurement, the clip is attached to a finger , a Toe or an Earlobe . In babies, the device is sometimes attached to the Heel or Wrist . Pain is not to be feared for the patient while attaching the pulse oximeter. The measurement is completely bloodless.
In the finger or earlobe where the pulse oximeter is placed, there are various tissues and blood in Veins and Arterial that absorb light.
Of interest to pulse oximetry is the amount of light picked up by arterial blood. Tissues and venous blood are constantly in their place, which allows them to absorb a constant proportion of light from the light source, what medicine calls background absorption.
The arterial blood, on the other hand, is pulsed through the tissue due to the heartbeat. During the pulse rate, more arterial blood is present, which leads to a greater absorption of light. This process is called peak absorption.
A computer subtracts the background absorbance from the peak absorbance to determine the proportion of light absorbed by the pulsating arterial blood. The computer also compares the absorption at 660 and 940 nanometers. With this measurement data, he can calculate the proportion of unsaturated and saturated haemoglobin within the arterial blood.
The oxygen saturation is given in percent. A normal value is a saturation of 98 percent.
Self-service or health insurance – who will bear the costs?
Whether the health insurance covers the costs for a pulse oximeter depends on the medical indication. If a pulse oximeter is considered necessary as a medical treatment, the health insurance company can bear the costs for the device. For this purpose, the treating specialist or the specialist clinic must justify the medical measure. Health insurance companies reserve the right to loan patients a pulse oximeter only for the duration of the therapy.
Risks, dangers and complications
Complications or side effects are not to be expected from either pulse oximetry or the pulse oximeter. The pulse oximeter is attached using a clamping device. In rare cases, this can cause mechanical irritation.
In the worst case, the pressure can cause tissue to die. Therefore, it is recommended to repeatedly attach the pulse oximeter to different parts of the body.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.