Sphygmomanometer is an instrument with which you can measure your blood pressure. It provides you an indirect method to keep a proper tab on the flow and pressure of your blood. It is the most commonly used equipment to meter blood pressure. A sphygmomanometer functions by inflating a cuff made of rubber. This inflated cuff is then placed around the arm of the patient till the blood flow stops in that area.
In simple terms blood pressure is described as the systemic arterial blood pressure. This pressure is exerted by the blood at right angles to the blood vessels. If you ever had a chat with your doctor, he would have told you that apart from flowing in a stream, your blood flows in the form of regular spurts. The continuous pressure of your blood is dependent on the elasticity of your arteries. Such a pressure is known as diastolic pressure. With each heartbeat there occurs an increased pressure, which is termed as systolic pressure.
Now after understanding the systolic and diastolic pressures, it will be easy for you to comprehend the functioning of a sphygmomanometer. The instrument consists of a rubber bag known as cuff. In it’s interior is attached a mercury pressure gauge. The mercury gauge and the cuff are connected via rubber tube. A rubber pump is also attached to both these parts, which is used to inflate the cuff. The functioning of this equipment follows a very simple principle.
As the pressure of the cuff becomes equal to the pressure in the artery, the pulse disappears. This can be felt by keeping a stethoscope on the brachial artery. The pressure measurements can be easily seen on the mercury gauge. This is what you call a systolic pressure. Now as you loosen the air pump, the cuff starts to deflate and eventually the mercury in the glass gauge begins to fall. With this the stethoscopic sound gets muffled and then disappears. This is what is termed as diastolic pressure.
The measurement of blood pressure with the help of sphygmomanometer is termed as the Korotkoff’s method.
As with any other equipment there are certain things that you should keep in mind while measuring your blood pressure using a sphygmomanometer. They are :
1.The most important part of a sphygmomanometer is the cuff. Make sure that the cuff is free of any leaks.
2.Besides this the cuff should be of a tangible size, according to the arm. Ideally it should be covering a third portion of your upper arm.
3.The mercury used in the glass tunnel should be free from impurities.
4.Before measuring the blood pressure make sure the mercury is stationed at a zero mark.
5.While you are inflating the cuff, see to it that the mercury rises smoothly in the tunnel and immediately stops as you stop pumping air in the cuff.
Follow these simple guidelines and you will get accurate measurement of your blood pressure.
