Pulse Oximeter

Oxygen is the source of life on Earth. It is needed by every cell in our body at every moment of time. Its deficiency leads to serious health consequences: disruption of the brain, problems with memory and speech, diseases of internal organs. In severe cases, oxygen starvation leads to death. Pulse oximetry helps to determine the level of oxygen saturation. In this technique, devices are used – pulse oximeters, which quickly and accurately show the amount of this element in arterial blood. Such equipment makes it possible to prevent the development of hypoxia in time, improve the patient’s condition, and sometimes save his life.

The essence of pulse oximetry

We need oxygen for metabolism, without it the body will not be able to synthesize ATP – the main energy substance. When we inhale, air enters the lungs, from where it is transported through a network of capillaries throughout the body.

As a rule, ambient air consists of 78% nitrogen, 21% oxygen and 1% other mixtures. A healthy body can get enough oxygen from such air. But with environmental pollution, in industrial zones and large cities, the composition of the atmosphere does not change for the better, the proportion of carbon dioxide and nitrogen increases. As a result, people develop chronic oxygen starvation, constant fatigue, malformations of the cardiovascular system, drowsiness and lethargy.

Also, the body does not receive the right amount of O2 in diseases of the respiratory system, blood vessels and heart. The causes of these diseases can be malnutrition, snoring, sedentary lifestyle, bad habits. If left untreated, chronic lack of oxygen leads to more serious disorders, including death. Therefore, a section of pulse oximetry appeared in medicine, which is devoted to monitoring arterial blood O2 saturation. The average percentage of saturation is called the saturation index, normally it is 95-98%. At a decrease to 94%, the patient is prescribed treatment, at a rate below 91%, emergency medical care is required.

Pulse oximetry is necessary:

• with oxygen therapy;
• after operations;
• during anesthesia;
• for monitoring in chronic diseases (for the prevention of hypoxia);
• in neonatology for looking after premature newborns;
• in obstetrics and pediatrics.

Thanks to technological advances, today patients can measure their saturation on their own. To do this, you need to buy a portable pulse oximeter and learn how to use it.

How a pulse oximeter works

There are several types of pulse oximeters:

• stationary – overall equipment that is used in operating rooms, in the intensive care unit;
• belt – portable devices;
• wrist – used by athletes (heart rate monitor);
• Finger – can be used on an outpatient basis, as well as belt;
• sleep monitors – used when the respiratory system fails during sleep.

A pulse oximeter is a portable or stationary device for measuring the saturation index. It consists of a sensor and a monitor. The sensor is attached to the earlobe, finger or wing of the nose. The sensor has a source of infrared and red light, these sources provide two beams that pass through the tissue. Depending on how well hemoglobin is saturated with O2, the length of the light beam that it absorbs changes. The detector registers the light that remains unabsorbed.

The data is quickly processed and displayed on the monitor of the pulse oximeter. In addition to the level of saturation, the device shows the pulse. Some models record heart rate data in the form of a graph and give an alarm in case of hypoxia.

The most popular are portable devices that patients can use at home, because they are small in size and provide accurate data on blood oxygen saturation.

All pulse oximeters have memory, the results can be transferred to a computer. This is especially convenient for those who carry out measurement procedures at home, the obtained data can be brought to the doctor for control.

For newborns, a neonatal pulse oximeter is used. This is the same device as for adults, but with a cuff sensor, which is made of soft material, is attached to the foot and does not interfere with the child. For older children, the same sensors are used as adults, but smaller. There are also portable versions for children and adults, in which the sensor is built into the monitor, to receive data, you just need to put your finger in the connector and wait for the result.

When choosing your own pulse oximeter, be sure to consult a doctor (therapist, cardiologist). The doctor will tell you which type of apparatus is suitable (single-use or reusable), which pulse data can be considered normal, and in which case it is necessary to consult a doctor. After purchasing, you need to read the instructions.

Instructions for use

The pulse oximeter is easy to use at home, it is a simple and intuitive device. Its main advantage is that in order to obtain data, it is not necessary to take blood from a patient, for example, earlier this could only be done in the laboratory. Modern measuring devices do not require invasive interventions, which makes them more affordable. They are disposable or reusable, the latter being especially relevant for those patients undergoing oxygen therapy. So, a person independently controls the level of O2, and in case of poor results, he can consult a doctor.

Portable devices run on a pair of AA batteries, some are charged from the mains. You can measure the saturation index and heart rate with the help of relatives or on your own, and the device is also used for people in a severe and unconscious state. Important application rules:

1. Before use, you need to look at the charge level, which is reflected on the monitor. If the charge is too low, the data may be corrupted. It is also better to wipe the sensor from dust with a dry cloth.
2. After turning on the device, it will boot. You can put on the sensor after 1-2 minutes. Avoid strong light sources and electromagnetic radiation, as this will affect the final performance.
3. An important condition for correct data is immobility during the process. This does not apply to neonatal sensors. The pulse oximeter attaches to the ear (clothespin-shaped sensor), nose, or finger. For fingernails, it is imperative that the nail and finger are clean, without varnish, as this affects the result.
4. After connecting the device, you need to wait up to 25 seconds, during this time it is better not to move.
5. The monitor displays readings of the heartbeat and the level of O2 in the blood.

After that, you should not leave the device turned on, it must be turned off, folded and removed away from direct sunlight and moisture. We have considered a classic example of using the device, in addition to it, there is a technology for measuring saturation during sleep.

Sleep measurement

Night pulse oximetry is needed when you stop or have difficulty breathing at night. This picture is often found in diseases of the thyroid gland, obesity, hypertension, pathology of the lungs and heart. Against the background of such problems, a person suffers from respiratory failure in a dream, because of this, weakness, confusion, drowsiness, bad mood, and dizziness are felt in the morning. The danger lies in the fact that during sleep in such patients a fatal outcome may occur.

According to the symptoms described, the doctor suspects a lack of oxygen during sleep, and monitoring is needed to confirm suspicions.

Checking the degree of saturation of O2 at night occurs with the help of wrist devices, they are used in a hospital or at home. Such a device consists of a finger sensor and a wrist strap; the patient puts it on before going to bed. You do not need to turn on the device, it turns on by itself – 30 times a night. As a rule, the verification period lasts from 000 pm to 10 am.

Here, too, there are rules:

• the patient should sleep in comfortable conditions, the room temperature is 20-23 degrees;
• before going to bed it is forbidden to overeat, drink tea and coffee;
• you can not take sleeping pills;
• before starting the screening, you need to put a diary in front of the bed;
• the diary notes all the moments when the patient woke up: time, pain;
• In the morning, the sensor is removed, the time of getting up and feeling is recorded in the diary.

The pulse oximeter and diary are given to the attending doctor. For accurate conclusions, you will need to undergo an additional examination: ultrasound, tests, examination by a cardiologist or other specialists. Based on these studies, a diagnosis is determined and treatment is prescribed.

Results: norms and deviations

The norm of oxygen content for a healthy person is considered to be at least 95%, readings above 98% require rechecking. The pulse in adults is considered normal within 60-90 beats per minute. In newborns, this figure reaches 140 beats, with age, the heart rate slows down and in adolescence is compared with adults. Like any electronic device, a pulse oximeter can make mistakes.

For example, readings less than 90% with normal health indicate a malfunction of the device, it is better to check it for a charge. Also, data that constantly changes dramatically over large ranges cannot be considered correct. If the monitor is first 98%, and then 91%, the device is faulty.

If the monitor shows 94%, you need to urgently consult a doctor or call an ambulance if a visit to the doctor is not possible. Treatment always involves the treatment of the underlying disease, that is, the elimination of the problem that caused the lack of O2 in the body.

To quickly alleviate the condition and save the patient, oxygen therapy is used – a method of oxygen treatment. Most often, treatment is carried out through a mask or nasal cannula, through which useful gas enters.

This therapy can be done in a hospital or outpatient setting. Hospitals use masks, special cameras and tubes. The same can be done at home if there is an oxygen concentrator.

A concentrator is a small device that produces pure O2 molecules from the surrounding air. These molecules are additionally moistened so as not to overdry the airways. Optionally, you can connect it to a mask or cannula, some types of concentrators even make oxygen cocktails. Such portable equipment is recommended for people with chronic diseases, families with pregnant women and young children.

Where to buy it

Before buying, you should consult a doctor, you may not need such a device. There are situations when you need to measure the saturation level only a few times, in which case you can go through the procedure with a cardiologist or therapist. If you still need a pulse oximeter, you can buy it on the Internet and in large pharmacies. Of course, it is better to give preference to pharmacies, here you can get a guarantee for the product and make claims if they appear. The price of a device with a finger sensor will be 20-30 dollars. Luxury devices will cost $60-85, they have removable sensors, signal alerts, built-in memory, they can be used for the whole family. Neonatal costs $35 and up.

We learned that a pulse oximeter is a portable device for quickly measuring the oxygen content in the blood. Such a device helps to prevent the consequences of hypoxia in time, to check the effectiveness of treatment. Patients can independently check the indicators, based on the data obtained, doctors choose the tactics of therapy. It is convenient, fast and very important for health.