Sphygmomanometer parts and how is it used

Sphygmomanometer parts and how is it used

A sphygmomanometer, typically known as a blood pressure monitor or blood pressure gauge, is a device used to measure blood pressure.

Blood pressure was first measured in 1733, and the first Sphygmomanometer was created in 1881 by Samuel Siegfried Karl Ritter Von Basch. In 1896, Scipione Riva-Rocci introduced a more simplified version of the Sphygmomanometer.

How does Sphygmomanometer work?

The Sphygmomanometer cuff is inflated to a level higher than the anticipated systolic pressure, and as the valve is opened, the cuff pressure drops.

Blood starts to flow past the cuff when the cuff pressure reaches the systolic arterial pressure, causing loud noises and blood flow turbulence.

These noises are audible by the use of a stethoscope, and the cuff pressure is noted.

The blood flow sound will persist until the cuff pressure drops below arterial diastolic pressure.

Types of Sphygmomanometers

With the technology we have today and the modernized society we live in, various sphygmomanometers have been produced and sold on the market. There are, however, three main categories, namely:

Mercury Sphygmomanometer

Mercury Sphygmomanometers consist of manually inflated cuffs connected to measuring devices through mercury-infused tubes. To acquire an accurate reading, it must be kept upright and on a flat surface. Handling this delicate device with care is necessary because the mercury has a significant likelihood of rupturing in the event of an accident drop, which might be dangerous and render the gadget worthless.

Mercury sphygmomanometers have some benefits, like being simple to operate and having a lifelong lifespan when used appropriately.

Aneroid Sphygmomanometer

Because it doesn’t contain any mercury, the Aneroid Sphygmomanometer is considered safer than the Mercury Sphygmomanometer. The recordings made by this instrument are comparable to those made by the Mercury Sphygmomanometer, except it has a stethoscope attached to a cuff that is further connected to a dual gauge by tubing.

The mechanical components in this gauge head transform the cuff pressure into a gauge-based measurement. To prevent inaccurate readings, the instrument needs to be recalibrated.

Depending on their intended application, Aneroid Sphygmomanometers come in various forms. They include;

  • Palm Aneroid Sphygmomanometer
  • Pocket Aneroid Sphygmomanometer
  • Clock-style Aneroid Sphygmomanometer

The main advantages of utilizing an aneroid sphygmomanometer are the device’s low cost and portability. It also needs to be calibrated and handled carefully to prevent inaccurate readings.

Automatic Digital Sphygmomanometer

Of the three, ADSs currently represent technological development’s pinnacle. A digital monitor displays the blood pressure reading from an electronic sensor used to measure it.

Inflatable cuffs are also included with digital sphygmomanometers; however, unlike the other two varieties, there is a difference in how blood pressure is measured.

Digital sphygmomanometers analyze and quantify artery variation. This gadget is practical and simple to use. Since they are automated, a person is not required to manipulate the cuff or pay attention to the blood flow noises in order to obtain a blood pressure reading. Digital types, however, are less precise.

Sphygmomanometer Parts and how it is used

The Sphygmomanometer parts include an inflatable rubber cuff that you wrap around your arm. A measuring gadget that displays cuff pressure. A cuff-inflating bulb and a pressure-releasing cable.

A stethoscope is also used with a sphygmomanometer to hear the sounds of blood flowing through the brachial artery. The Sphygmomanometer parts are:

  • Bladder: This inflated bag squeezes the arms and obstructs the arteries.
  • Cuff: During the measurement, the cuff retains the bladder around the arm.
  • Valve: This is a deflation valve that controls the cuff. It is critical for obtaining precise measurements.
  • Bulb: The bulb is used to pump the air into the cuff.
  • Manometer: The Manometer measures air pressure in millimeters of mercury (mmHg). The Manometer utilized in the Aneroid Sphygmomanometer features a watch-like mechanism that measures the air pressure delivered to the cuff. The gauge features a series of copper or beryllium gears to convert the diaphragm’s linear movement to mmHg reading.

How to use a Sphygmomanometer

  1. Use a blood pressure cuff the correct size before checking your blood pressure. At least 80% of the circumference of your upper arm should be the length of the cuffs.
  2. The cuff’s lower edge should be one inch above the Antecubital Fosse as you wrap it around the upper arm.
  3. The blood pressure cuff should be inflated to 180 mm Hg.
  4. Turn the valve slowly to release air, then watch the pressure drop.
  5. Look at the Mercury gauge while using the Stethoscope to listen.
  6. The systolic blood pressure can be determined based on the first sound you hear through a stethoscope.
  7. Continue to observe the pressure decrease; when the sound ceases, the pressure will have fallen to its diastolic level.
  8. You can record the pressure in both armsto note the differences. 
  9. Fully release the air press valve to deflate the cuff after completing the test. Then, remove the cuff from your arm.


The Sphygmomanometer is a device that’s used for measuring blood pressure. There are three main types: Automatic Digital, Aneroid, and Mercury Sphygmomanometer. This article contains information on what this device is used for, the Sphygmomanometer parts, and how it is used.

FAQs on Sphygmomanometer parts

What is Sphygmomanometer used for?

A sphygmomanometer, also known as a blood pressure cuff or blood pressure cuff, is the tool your doctor uses to measure your blood pressure. The cuff is put around your upper arm and then inflated to halt the blood flow through your artery.

What is the normal blood pressure range?

The recommended range for blood pressure is 90/60 mmHg to 120/80 mmHg. High blood pressure is 140/90 mmHg or greater, and Low blood pressure is considered 90/60 mmHg or lower.

What are the different parts of the Sphygmomanometer?

The different parts of the Sphygmomanometer include;
• Bladder
• Cuff
• Valve
• Bulb
• Manometer
These parts work hand in hand to enable your device to function correctly.

What is the difference between systolic and diastolic?

Two numbers are provided for blood pressure readings. The highest number represents the heart’s greatest rate of pressure production (systolic pressure). The amount of arterial pressure between beats is shown by the bottom number (diastolic pressure).

Where should I place the cuff?

Put the cuff an inch above the elbow on your naked upper arm. For the sensor to be positioned appropriately, make sure the tubing crosses your arm’s front center. Once it’s evenly taut around your arm, pull the cuff’s end.

Which arm is best for measuring blood pressure?

Taking your blood pressure from your left arm is recommended if you are right-handed. If your healthcare professional has informed you to do so, you may utilize the other arm.

Dr Sanam shakya

Dr. Sanam Shakya is a licensed MBBS doctor working as a medical officer under the emergency department in Karnali Province Hospital, Surkhet, Nepal.Dr. Shakya's interests are intensive trauma care, emergency medicine, and internal fixation surgeries. He spends a considerable amount of time inpatient''s healthcare.

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