The difference between automatic and semi-automatic blood pressure monitors lies in the way air is pumped into and released from the cuff.

An automatic blood pressure monitor fully automates the process of measuring blood pressure. When using such a device, you just need to put the cuff on your arm and press a button. The monitor automatically inflates the cuff to the required level and then deflates it automatically after the measurement is completed. Many modern automatic blood pressure monitors are equipped with an "artificial intelligence" function, which accurately determines the required pressure, optimizing the process of inflation and deflation.

In a semi-automatic blood pressure monitor, part of the process is done manually. The user needs to manually inflate the cuff using a rubber bulb. After reaching the required pressure level, the measurement is performed automatically, but deflating the air from the cuff must be done manually through a special valve. This approach requires more effort and control from the user, but semi-automatic monitors are usually less expensive than automatic ones.

Thus, automatic blood pressure monitors offer greater comfort and ease of use, while semi-automatic ones require more active user involvement in the measurement process.

The main disadvantages of measuring blood pressure with a mechanical tonometer are related to several factors. Firstly, the accuracy of the measurements depends on the individual characteristics of the person conducting the procedure. Good vision, hearing, and coordination of movements ("hands – vision – hearing") are required. People with impairments in vision, hearing, or motor skills may experience difficulties using a mechanical tonometer.

The mechanical tonometer is also sensitive to external conditions such as noise in the room. External sounds can interfere with correctly hearing the heart tones through the stethoscope, affecting measurement accuracy. The accuracy also depends on the correct positioning of the stethoscope head relative to the artery. Incorrect positioning can lead to distorted results.

Additionally, the mechanical tonometer requires direct contact of the cuff and stethoscope head with the patient's skin, which can cause discomfort and increase the risk of infections with insufficient hygiene.

Another significant drawback is the technical complexity of using the device. Improper handling can lead to erroneous blood pressure readings. Accurate measurement requires special training, without which there is a high risk of incorrect procedure and interpretation of the results.