CHAPTER 14. HOW SPHYGMOMANOMETER WORKS.
You might be wondering what this complicated wordmeans. Well, in today's health freak world,
it is available in everyone's house. The sphygmomanometeris a medical term for blood
pressure monitoring machines, also commonly knownas BP monitor. Checking blood pressure
regularly is important because hypertension/ highblood pressure is a major cause of
life-threatening diseases. The heart has to work hardto pump the blood in the body when
pressure is high, which can cause strokes, kidneydiseases and even heart failure. So, it is
important to diagnose high blood pressure as earlyas possible so that it can be cured.
For the last many decades, if one had to check his/herblood pressure, then there was a need
for a trained medical practitioner to do so. The practitionerused an air-bladder cuff that is
manually inflated and a hearing device like a stethoscope.This method of measuring Blood
Pressure is known as the auscultatory method.
In this method, the air-bladder cuff shown above isfastened around the arm. It is then inflated
using the handheld air pump. While measuring the bloodpressure, two types of pressure are
measured systolic and diastolic. Systolic is the higherwhereas diastolic is the lower arterial
pressure, caused because of the heart pumping theblood in arteries.
Initially, the air cuff is inflated high above thesystolic pressure and stethoscope is used to hear
the blood flow turbulence. When the pressure of theair cuff is higher than systolic pressure, this
means that no blood flows through the arteries; henceno sound is heard through the
stethoscope. Gradually the air is released with thepressure valve that is attached to the
air-bladder cuff, which reduces the pressure. Whenthe pressure in the air cuff is equal to the
systolic pressure, the blood suddenly starts flowingin the arteries, and this causes blood