Hand pressure gauge: The needle pressure gauge is a spring-loaded device that uses air pressure to move the needle on the scale, each degree of which represents one millimeter of mercury. This type of pressure gauge is easier to carry than the mercury type and is cheaper. be How to use the sphygmomanometer: To measure blood pressure, we first tie the armband of the device 2-3 fingers above the elbow crease, after closing the air adjustment screw, we fill the armband with air with an air rubber pump, as a result, the mercury column (in a mercury device) or the graduated hand (in the hand device) starts to rise, we increase the pressure of the armband by the pump until the pulse stops. Then, we place the screen of the phone on the brachial artery in the area in front of the inner elbow crease and gradually and slowly reduce the air pressure of the armband by about 2 mmHg per second by opening the corresponding screw, and thus we measure the blood pressure. .