Selection of tonometer
- Phase 1: Appearance of the first noise,
- Phase 2: Whisper Tone,
- Phase 3: clear and strong sound,
- Phase 4: Sound Attenuation,
- Phase 5: Disappearance of sound.
The value of systolic pressure corresponds to the first phase, and diastolic pressure to the fifth phase.
Measurement of blood pressure using electronic tonometers is based on the "oscillometric method". The basis of this method is the analysis of arterial oscillations. When the pressure in the cuff is higher than the systolic pressure in the artery, the oscillations that are a consequence of the impulse of the artery during the passage of blood can be intercepted. During the pumping of air in the cuff, a gradual decrease in pressure leads to an increase, and then to a decrease in the amplitude of these oscillations. Thus, the systolic pressure value corresponds to the beginning of the increase in the amplitude of these oscillations, and the diastolic pressure corresponds to the end of the decrease of these oscillations.
Choice of cuff and arm for measurement:
Tonometer cuffs are a very important element of measurement accuracy.
They should fit the shape of the arm: A tight cuff can lead to blood pressure readings that are too high, while a cuff that is too loose can lead to blood pressure readings that are too low.
When choosing the arm where blood pressure is measured, some pressure asymmetry is normal. Whatever the position of the consumer, and whatever the choice of hand, it is recommended to conduct the research always on the same hand and in the same position for further correct comparison of the results. Most often, the left hand is used.
Wrist or forearm tonometer?
Each tonometer has its advantages and disadvantages.
Tonometers on the forearm are more bulky and more difficult to put on. Their strict position at the level of the heart is excluded.
Regarding their reliability, both systems are equally reliable. The error in application depends on the individual characteristics of the subject.
For example, the arteries on the wrist are located quite superficially and, even in dense people, the wrist is quite thin. Therefore, it is recommended to use tonometers on the wrist for them.
If you have a choice, then buy a tonometer on the wrist, if you are mobile enough. And if you are going to use it at home, then choose a tonometer on the forearm.
Source: Dupont Medical.
Translated by Dr. Tuzani Khalid