2. Abstract: To Functioning of the Sphygmomanometer has been
Observed in the laboratory .Modules present in it and also
working principle of it was studied.
Introduction: A Sphygmomanometer or blood pressure meter
is a device used to measure blood pressure composed of an
inflatable cuff to restrict blood flow, and a mercury or mechanical
manometer to measure the pressure. It is always used in
conjunction with a means to determine at what pressure blood
flow is just starting, and at what pressure it is unimpeded.They
measure systolic and diastolic pressure by oscillometric detection,
using apiezoelectric pressure sensor and electronic components
including a microprocessor.Manual sphygmomanometers require
a stethoscope for auscultation. They are used by trained
practitioners. It is possible to obtain a basic reading through
palpation alone, but this only yields the systolic pressure.
Tools /Equipment used:Screw Drivers of Appropriate sizes.
Experimental Procedure:Initiallythe working of the digital
sphygmomanometer has been tested and then the machine
was taken for dissection.With the help of the screw driver ,the
four screws at the bottom has been removed and the casing
was opened.The assembly of the component was pretty simple
and it consisted of a motor inside which compresses the air and
pumps it through another hole which can be then connected to
3. a tube. Power lines to the motor has been removed and
studied the functioning .
Discussion : The design of the Digital Sphygmomanometer is
not complex.it is used to measure systolic and diastolic
pressure of a person. There are three methods in
Sphygmomanometer 1)Palpatory Method 2)Auscullatory
Method 3)Oscillometric Method
Product Decomposition:
System Elements Task of system
elements
Sub function
Casing Protect it from
external
environment
Provide casing
Motor Convert electrical
energy into
mechanical energy
Drive the pump
Digital Display It displays values The values of systolic
and diastolic of a
person
Piston assembly To and fro motion
which takes in air
and pumps it to
hand cuff
Pressurizes the air
and pumps the same
4. Hand cuff Blows the air to
handcuff
Pressurize the hand
Product Architecture: Component Hierarchy
6. History: The circulation of blood within the body has
been a subject of study for many thousands of
years. In ancient times, the Chinese recognized the
fact that blood circulated through the blood vessels
and developed theories on how such systems
worked. Evidence also suggests that scholars in
India had developed some knowledge of the
circulatory system, with an emphasis on the pulse
and its dynamic nature.
A broader understanding of circulation and the
circulatory system was developed in the early 1600’s
by a doctor named William Harvey. He began
7. teaching about circulation in 1615 and later
published his work in 1628 entitled
ExercitatioAnatomica de MotuCordis et Sanguinis in
Animalibus (On the Movement of the Heart and
Blood in Animals). His work became a foundation for
the study of the circulatory system, and is still highly
regarded even to this day.
Once the correlation between heart rate and pulse
was discovered, it was possible to determine blood
volume and blood pressure. In 1733 Reverend
Stephen Hales recorded the first blood pressure
measurement on a horse. He did this by inserting a
long glass tube upright into an artery, observing the
increase in pressure as blood was forced up the
tube.
In 1881, the first sphygmomanometer was invented
by Samuel Siegfried Karl Ritter von Basch. It
consisted of a rubber bulb that was filled with water
to restrict blood flow in the artery. The bulb was then
connected to a mercury column, which would
translate the pressure required to completely
obscure the pulse into millimeters of mercury. In
1896, the device was further improved by Scipione
Riva-Rocci. Improvements included a cuff that could
be affixed around the arm to apply even pressure to
the limb that would become the standard design for
such devices going forward.
8. Modern blood pressure measurement was not
developed until 1905, when Dr. Nikolai Korotkoff
discovered the difference between systolic blood
pressure and diastolic blood pressure. These
pressures corresponded to the appearance, and
disappearance of, sounds within the arteries as
pressure was applied and then released. Known as
Korotkoff sounds, the use of systolic and diastolic
sounds is now standard in blood pressure
measurement.
Since that time, further advances have been made
to sphygmomanometers. Now available in a variety
of styles ranging from mercurial to aneroid and
electronic versions, blood pressure measurement
has become more accurate and widely accepted as
an important vital sign when diagnosing a patient.
Reference:
1. http://adctoday.com/learning-center/about-
sphygmomanometers/history-sphygmomanometer
2. http://en.wikipedia.org/wiki/Sphygmomanometer
