A sphygmomanometer, commonly referred to as a blood pressure meter, blood pressure gauge, or blood pressure monitor, is a device used to measure blood pressure. The words “sphygmomanometer” and “manometer” are derived from the Greek words “sphygmos” and “manometer,” respectively, which denote the instrument used to measure pressure or tension. In the year 1881, Samuel Siegfried Karl Ritter von Basch created this device. However, Scipione Riva-Rocci unveiled a more straightforward sphygmomanometer in 1896.
Sphygmomanometer Types
The three main kinds of sphygmomanometer are as follows:
Mercury sphygmomanometer
This blood pressure device is the most common and is regarded as the gold standard. It is made up of manually inflated cuffs that are connected to tubes that have been injected with mercury. The device has to be maintained upright and on a smooth surface in order to provide accurate readings. There are several concerns if the instrument is dropped accidently. This sphygmomanometer has the advantages of being long-lasting, simple to use, and not requiring calibration. It is prohibited in several nations because of its harmful components.
Aneroid Sphygmomanometer
Since this instrument is aneroid—which means “without fluid”—mercury is not used. It comprises a stethoscope attached to a cuff, which is then connected via tubing to a dial gauge. The gauge head contains a mechanical component that converts the pressure in the cuff to the gauge pressure. In order to prevent inaccurate readings, the device has to be calibrated. Depending on their intended application, there are more varieties of aneroid sphygmomanometers, including:
- Sphygmomanometer in a pocket
- Aneroid sphygmomanometer on a palm
- Clock-style sphygmomanometer made of aneroid
Automatic Digital
The most cutting-edge sphygmomanometer available now is the automatic digital model. The blood pressure is measured using an electronic sensor, and the results are shown on the digital monitor. The device monitors artery variations in order to estimate blood pressure. To prevent erroneous readings, they must be examined using a mercury sphygmomanometer.
Sphygmomanometer Components
An inflated balloon called a bladder is used to squeeze the arm and obstruct the artery. Bladders must meet certain size requirements in order to guarantee complete arterial compression.
Cuff: During the measurement, this is used to retain the bladder around the arm. The cuff has to be adequately built in terms of positioning and placement for reliable measurement.
Manometer: This instrument measures air pressure in millimeters of mercury (mmHg). An aneroid sphygmomanometer measures the air pressure that is applied to the cuff using a manometer that resembles a watch. The gauge uses a series of copper or beryllium to expand the diaphragm, and there are gears to translate the linear movement of the diaphragm into measurements in millimeters of mercury (mmHg).
This valve is used to manage the cuff’s deflation. In order to get an exact measurement, this is crucial.
Air is pumped into the cuff using a bulb.
What Is A Sphygmomanometer Used For?
The process for using a sphygmomanometer is as follows:
- The length of the blood pressure cuff bladder used for testing should be 80% of the upper arm’s circumference.
- The bottom border of the cuff should be one inch above the antecubital fossa when you wrap it around the upper arm.
- Below the border of the cuff, softly press the stethoscope’s bell over the brachial artery.
- At a moderate pace, let the air out of the cuff until it reaches 180 mmHg.
- Use a stethoscope to listen for the initial banging sound and keep an eye on the mercury gauge.
- The location of the patient and the size of the cuff should be noted, and this should be done for both the arms and the pressure.
- If the pressure is higher, the blood pressure should be taken again with brief intervals in between.
- The blood pressure should be checked immediately if it is higher than 180/120mmHg.