Looking for NEET / JEE Coaching? Enquire Now

Know the three medical instruments related to the heart

Do you know which instruments are used for the diagnosis of heart diseases? In this article, you will learn about the structure and functioning of three medical instruments related to the heart, namely ECG, pacemaker and sphygmomanometer.


In medical science , different types of instruments are used for diagnosis of various disease. In this article, you will find the structure and functioning of three instruments which are related to the heart. These three instruments are :

  • Electrocardiogram (ECG)

  • Pacemaker

  • Sphygmomanometer

Electrocardiogram (ECG)

A graphic record of the electrical variations produced by the beating of the heart is called electro-cardiograph. These variations are due to the development of electrical negativity or impulses of excited muscles as compared with unexcited tissues. Impulses in the muscles are caused due to the cardiac cycle or relaxation and contraction in the heart. The contraction is known as systole while relaxation is called diastole. An instrument used to observe the working of the heart is called electrocardiogram. Electrocardiogram was discovered by Einthoven in 1906. Einthoven is known as the father of E.C.G. ECG is used for following two purposes:

  • To measure the heartbeat

  • To assess the situation of cardiac muscles

Einthoven used string galvanometer for obtaining the cardiograph. In new model E.C.G. instruments also, the galvanometer is the main part. It is connected with electric wires. While taking the ECG, these wires are attached to the wrists, the lower portion of legs and the machine is put on. Through wires, the electrical impulse generated by the cardiac cycle is transmitted to the galvanometer, the needle of which shows deflection accordingly. The galvanometer is attached to a recorder where the deflection caused due to fluctuations in electrical impulses in muscles is recorded. E.C.G. is formed by a series of ridges and furrows. Normal Pattern of ECG for a healthy person is given below:
(Image Curtsey: https://www.wikipedia.org/)

In this, P wave indicates the impulse of contraction generated by S.A. node. QRS wave indicates the spread of impulse of contraction from A.V. node to the wall of ventricles, whereas the T wave represents the relaxation of ventricles. Any abnormality in the working of the heart changes the wave pattern of ECG and can be interpreted by a trained physician to diagnose a particular disorder. The technique to detect the abnormalities of the heart with the help of ECG is called electrocardiography.


(Image Curtsey: https://www.wikipedia.org/)

The pacemaker is an instrument that sets the pace at which a phenomenon occurs. Often used along to indicate the natural cardiac pacemaker or an artificial cardiac pacemaker. An artificial pacemaker is used to pace the heart on a long-term basis when normal heart rate 72-80 drops to abnormally low levels like 30-40 due to disease or operation and threatens the life of the patient. A pacemaker consists of two parts viz, a pulse generator and an electrode. A pulse generator is a sealed box. Which contain lithium halide cells to produce power for over 10 years and an electronic circuit to regulate the rate pulse width of the electrical impulse. The pulse generator is placed under the chest below the collarbone. The electrode is a fine metallic spring inserted in a thin layer of biocompatible plastic which is connected on one end to the pulse generator while its special tip remains in contact with the interior of right ventricle whenever the pulse generator is exhausted it is replaced by new one. The necessary precautions for patients having pacemaker are as below:

  • Such patients should never be exposed to MRI tests. MRI test adversely affects the process of pulse generation.

  • He should not pass out through a metal detector or airport security.

  • Powerful radio waves, cell phone, radar, microwave oven and other electronic instruments also affect the functioning of the artificial pacemaker.


(Image Curtsey: https://www.wikipedia.org/)

Due to the continuous flow of blood, a pressure is exerted on the wall of blood vessels. This pressure is known as blood pressure (B.P.). The instrument used to measure B.P. is known as the sphygmomanometer. Sphygmomanometer was discovered by Scipione Riva Rocci in 1896. The instrument actually measures the atmospheric pressure which is equal to the pressure of blood in arteries. The instrument has a rubber pocket (cuff) in which air is pumped. It can be rapped over the arm. The pocket is connected with a rubber bulb through a tube. Another tube connects the pocket with a mercury column fixed with a meter scale which is movable. When the B.P. of a person is to be measured, the rubber pocket is rapped over the arm of the person so that it remains over the brachial artery. Air is now pumped into the pocket with the help of bulb. Due to increase in the air pressure the level of mercury in the column rises which can easily be seen on the meter scale. Pumping of air is continued till the pressure of mercury becomes higher than the person's B.P. Now the stethoscope is put over the brachial artery and heartbeat is observed. Due to high pressure in mercury column, the sound of the pulse is not heard. The air pressure in the apparatus is released slowly by opening the knob at the bulb. The pulse sound is regularly heard. With gradual decrease in air pressure, a situation prevails when the blood pressure and air pressure in mercury column become equal. In this situation, the sound of the heartbeat is clearly heard by ears. Ite denotes systolic pressure in arteries. With the further decrease in air pressure, the sound gradually becomes louder. But if the decrease in air pressure is continued, the sound of heartbeat diminishes slowly and ultimately hearing of sound stops. The pressure in mercury column at this point denotes the diastolic pressure of blood in arteries. If the systolic and diastolic pressure of a person is 120 and 80 mm, respectively, his / her blood pressure is represented as 120/80.


You thus now know all about the three medical instruments - ECG, pacemaker and sphygmomanometer - which are related to the heart.

Related Articles

What are the risks of high blood pressure?

Blood pressure is a killer disease all over the world. Blood pressure kills a person with in few hours, if the treatment is delayed. Some times, Due to blood pressure sudden heart attack leads to death. In this article, the causes, symptoms and risks of blood pressure are listed to create awareness about the killer disease.

The Electrical Properties Of Heart And The Regulation Of Heart Beat In Humans

In this article the electrical activities of the human heart have been described. The generation of impulse and the spread of depolarization among the various parts of heart have been described also. Control of heart beat due to the electrical activities of heart have been also written in brief. Arrhythmias and their common types are also described in this article. Heart block and its causes have been also described.

How To Control Low Blood Pressure?

Generally people don’t take hypertension (low pressure) seriously. They have many misconceptions also on this count in their . But when not treated well on time, low blood pressure can give invitations to several disorders. Hence it is necessary to keep the low blood pressure under the leash. This article tells you how blood pressure can be controlled.

Level Of Blood Pressure And Its Care

Blood pressure is one reveals the speed of the pumping/flowing of the blood to our heart. Normally we used to say,"I am having Blood Pressure". In the real sense, everybody has Blood Pressure, only because of the blood pressure we lives. But actually the problem arises when the pressure of blood is vary. Blood pressure should be normal and it should not fast or slow. If it is fast, the High BP and if it is slow, Low BP can be said. We can see about the variation of BP.

Heart And Coronary Arteries!

Heart manages the blood circulation for the entire body. This also could be said it works like a pump house. In order to work like a pump house, heart needs energy. To fulfil this need of energy of heart, there are two main coronary arteries of the radius of a pencil. We will know some more about how wondrously the heart and its coronary arteries function keeping us alive.

More articles: Sphegnomenometer Blood pressure ECG heart Medical


No responses found. Be the first to comment...

  • Do not include your name, "with regards" etc in the comment. Write detailed comment, relevant to the topic.
  • No HTML formatting and links to other web sites are allowed.
  • This is a strictly moderated site. Absolutely no spam allowed.
  • Name: