Sphygmomanometer Parts: Blood Pressure, Types, List, Accuracy, Working Principle, and Guidelines

Sphygmomanometer Parts Overview

A tool used in medicine to gauge blood pressure is called a sphygmomanometer. The force of the blood traveling through the blood arteries is used to calculate blood pressure. One of the most straightforward pieces of medical equipment is handled with accuracy and precision. In addition to blood pressure, it is useful for keeping an eye on heart rate and rhythm. Hearing heart and breathing sounds is also helpful. There are several varieties of sphygmomanometers in use now thanks to current innovation. Although their design and operation differ, they both measure blood pressure as their end result.

What is a Sphygmomanometer?

The Greek words "sphygmos" and "manometer," which both refer to instruments used to measure pressure via dimensional analysis, are the origins of the English word "sphygmomanometer." Samuel Siegfried Karl Ritter von Basch created it in 1881. It is the most fundamental tool used by clinicians and is often utilized each time a patient seeks a diagnosis. It comprises a rubber inflating cuff that is fastened to a mercury scale that has graduations on it. The steady buildup and release of pressure inside the rubber cuff is used to calculate the systolic and diastolic pressure.

What is Blood Pressure (BP)?

A condition when the blood exerts too much pressure on the arterial walls is called blood pressure. Blood pressure beyond 140/90 is often regarded as hypertension; blood pressure exceeding 180/120 is regarded as severe hypertension. If left untreated, it can eventually lead to illnesses including heart disease and stroke. Blood pressure can be lowered by eating a better diet with less sodium, exercising frequently, and taking medication. 

Types of Sphygmomanometer 

The three main types of sphygmomanometer are as follows-

Aneroid sphygmomanometer

Aneroid refers to something that is "without fluid," and this device does not utilize mercury. It comprises of 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-

Automatic Digital Sphygmomanometer

Based on changes in the arteries, it electronically monitors blood pressure. The cuff is directly attached to the gadget and just requires a button push to inflate and deflate. It contains a digital display that shows the blood pressure reading. These varieties may be carried from one location to another more readily because they don't contain any liquids.

Mercury sphygmomanometer

It is the sphygmomanometer that is most frequently used. It comprises a mercury-filled graduated tube that gauges the pressure put on the upper arm by the inflating rubber cuff's bladder. The equipment has to be kept on a level surface for accurate measurements. This kind has the benefit of having a long lifespan, but several nations have outlawed it since it contains mercury, a dangerous element.

List of Sphygmomanometer Parts

The following is a list of the parts of a sphygmomanometer-

Bladder

The arm is compressed to restrict the artery using an inflated bag. To guarantee complete artery compression, bladders must meet specific dimension requirements.

Cuff

During the measurement, a cuff around the arm holds the bladder in place. To obtain an accurate measurement, the cuff's location and position must be thoroughly thought out.

Manometer

mmHg (millimeters of mercury) is the unit used to measure air pressure via a manometer. The manometer of an aneroid sphygmomanometer, which resembles a watch, monitors the air pressure given to the cuff. The gauge expands the diaphragm using a series of copper or beryllium, and gears convert the diaphragm's linear movement into mmHg readings.

Valve

This deflation valve keeps the cuff in place by preventing inflation. For getting an exact measurement, this is essential.

Bulb

The bulb pumps air into the cuff.

A sphygmomanometer is made up of the pieces shown in the below image-

What is the Sphygmomanometer Accuracy?

The limits and possible causes of the mercury sphygmomanometer's inaccuracy are well known. Although real use may fall short of these conditions, it is generally acknowledged that the mercury device is a "gold standard" for measuring blood pressure when properly measured, used, and maintained. In widespread use, other techniques are also more accurate in the same situations. There are restrictions on several topic classes. Some personal-use gadgets, such as automated blood pressure monitors, are less precise.

Working Principle of Sphygmomanometer Parts

The fundamental idea underlying how a sphygmomanometer functions is that the pressure in the bladder and the pressure in the artery underneath the cuff are identical. Considering that the brachial artery is a significant blood vessel in the upper arm, blood pressure is typically checked there. The brachial artery is squeezed and blood flow is halted by inflating the cuff while it is wrapped around the patient's arm. Following this, the pressure is gradually released, and the rushing blood causes a vibration that may be detected with a stethoscope in the vascular tissue. As the artery no longer constricts, the sound disappears as the pressure falls even lower. These all involve two pressures, which are as follows-

1. Systolic Pressure: Pressure measured during contraction of the left ventricle.
2. Diastolic Pressure: The pressure the left ventricle experiences when it relaxes.

To determine blood pressure, the values of the systolic and diastolic pressures are tracked. Systolic over diastolic blood pressure is recorded as 120/80.

Guidelines for the use of Sphygmomanometer Parts

Below are some of the principles and regulations to follow while having blood pressure taken or to make sure a patient is safe-

1. Nothing to eat or drink for 30 minutes.
2. Prepare by having a bladder empty.
3. To prevent erroneous findings, make sure that your body is generally warm (not frigid).
4. Make sure you are calm and not agitated or tense.
5. During the process, silence is required.
6. The sleeves are lightly pulled up, the cuff resting on your exposed skin.
7. Sit for a few minutes in silence while supporting your back and sitting up straight on a chair before taking the measurement.
8. Uncrossed legs and flat feet on the floor in front of you.
9. Use the left arm as it is closest to the heart, but you may alternatively compare both sides. Place your left forearm and cuff at chest height on a table or other flat surface.
10. Make sure the cuff comfortably fits around your arm; it shouldn't be too loose or too tight to feel unpleasant or constricting.

Points to Remember

1. A sphygmomanometer is a device used in medicine to find and gauge blood pressure. 
2. Doctors use the sphygmomanometer to monitor the effects of drugs on their patients.
3. In addition to humans, measuring an animal's blood pressure has veterinary applications. 
4. Mercury Sphygmomanometers, aneroid Sphygmomanometers, and digital are the types of Sphygmomanometers.
5. Sphygmomanometers are instruments used in the study of medications and vaccines in medicine. 
6. The vital components of a sphygmomanometer are the bladder, cuff, manometer, valve, and bulb.