Sphygmomanometer Date of Experiment: 17-02-2014

Submission Date: 21-02-2014

Team – 4

Chaitanya Kumar D(ED11B045)

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 a piezoelectric 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: Initially the 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

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

Hand cuff Blows the air to handcuff

Pressurize the hand

Product Architecture: Component Hierarchy

Function Structure:

Geometric layout:

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 teaching about circulation in 1615 and later published his work in 1628 entitled Exercitatio Anatomica de Motu Cordis 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.

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