Lab 5 Heart Sound

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DEPARTMENT OF BIOMEDICAL ENGINEERING

FACULTY OF ENGINEERING

UNIVERSITY MALAYA

Lab 5 : HEARTS SOUNDS, PULSE RATE AND

BLOOD PRESSURE


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ObjectiveIn this experiment, the main objective is to describe some of the techniques used in the

assessment of the cardiovascular system. For example auscultation of normal heart sounds and

measurement of blood pressure are the two methods which can be used in the assessment of

the cardiovascular system.

IntroductionSounds of heart can be hear through stethoscope, thus it can used for the assessment of the

auscultation. There are 2 main components that build up a stethoscope, which are diaphragm

and bell. The diaphragm is used to hear sounds with high pitch whereas the bell is used to hear

low-pitched sounds.

The pulse rate of a person can be determined through the radial pulse. The normal pulse

rate of a person is around 60-100 per minutes. The blood pressure can be measured with the

help of mercury sphygmomanometer. The normal blood pressure of a normal person is

120/80mmHg. 120mmHg is refer to systolic blood pressure while 80 mmHg is refer to the

diastolic blood pressure.

Apparatus1. Mercury sphygmomanometer2. Digital stopwatch3. Stethoscope Deluxe

Procedure(a) Heart Sounds

1. For this procedure, students are encouraged to work in a pairs.2. By using a stethoscope, heart sound of a subject can be heard by placing the diaphragm

on the areas on auscultation.

3. The 1st heart sound (S1) and the 2nd heart sound (S2) can be heard. Their qualities arebeing compared and recorded in the result sheet.

4. During the process f auscultation, we can try to listen to the 3rd heart sound (S3) whichsometime it can be heard from normal people.

(b) Arterial Pulses1. The subject must be in sitting position for at least 5 minutes before advance to the step 2

in this part.

2. Radial pulse of the subject is being palpated at the wrist and counted for one minute.The number of pulses per minute is recorded in the result sheet.

3. After that, the subject is asked to stand up straight. The pulse of the subject isimmediately count again for one minute. The subject must be in up-straight standing

position during the counting process.


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4. The pulse rate of the subject when sitting and standing are being compared. Anydifferences are recorded into the result sheet for further comparison.

5. The subject later is asked to do some simple exercise for example running up and downstaircase. Subject need to do the exercise for about 2-3 minutes. After doing the exercise,

pulse rate of the subject are counted immediately. The results are recorded and once

again comparison needed to be done in order to identify any differences.

6. All the pulse rates are needed to count twice as to get the average result. In other words,the palpation processes need to be repeated.

(c)Arterial Blood PressureI. Palpation method

1. The subject is asked to rest in sitting position for at least 5 minute.2. Arm of the subject and the sphygmomanometer are being placed in the same

level as the heart of the subject. (Hand of the subject and the

sphygmomanometer can place on the table as can maintain theirs level with the

level of the hearts easily and can prevent the subject from too tiring maintaining

their hands level.)

3. The sphygmomanometer is firmly wrapped around the upper forearm such thatthe cuff (lower part) must be at least 2.5sm above the cubital fossa.

4. Then the radial pulse of the subject is located. The pressure of the cuff is slowlyincreases until the radial pulse is no longer palpable. After that, the pressure of

the cuff is further increased by another 20mmHg.

5. The pressure of the cuff is immediately but slowly and gradually release. Thepressure is released until the radial pulse can be palpate again.

6. The pressure value is determined immediately from the manometer column(mercury level) once the radial pulse are palpable. The result is being recorded

into the result sheet.

7. This pressure is known as the subjects SBP (Systolic Blood Pressure).8. The procedure is repeated as to obtain an average value of the subjects SBP. But

the process should be repeat after letting subject resting for several minutes.

II. Auscultation method1. The subject is asked to rest in sitting position for at least 5 minute.2. Arm of the subject and the sphygmomanometer are being placed in the same

level as the heart of the subject. (Hand of the subject and the

sphygmomanometer can place on the table as can maintain theirs level with the

level of the hearts easily and can prevent the subject from too tiring maintaining

their hands level.) The mercury meniscus should be ensured at readable eye

level.

3. The sphygmomanometer is firmly wrapped around the upper forearm such thatthe cuff (lower part) must be at least 2.5sm above the cubital fossa.

4. Then the radial pulse of the subject is located. The pressure of the cuff is slowlyincreases until the radial pulse is no longer palpable. After that, the pressure of

the cuff is further increased by another 20mmHg.


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5. The diaphragm of the stethoscope is gently placed on the cubital fossa overbrachial artery.

6. The pressure of the cuff is immediately but slowly and gradually release untiltapping sound is heard. The value of the manometer column at this point is

considered as the subjects SBP.

7. The pressure of the cuff is slowly released again and the differences in the pitchand the loudness of the sounds heard. The sound that is heard as the pressure

of the cuff is reduced is known as Korotkoff sounds.

8. When the Korotkoff sound become muffled and eventually inaudible, thepressure value of the manometer at that point is considered as the subjects

DBP (Diastolic Blood Pressure). The result is being recorded to the result sheet.

9. The procedure is being repeated after a gap of several minutes as to obtain theaverage values of the subjects SBP and DBP.

Result(a) Heart Sounds

Areas of auscultation

(valve)

S1 S2 Splitting S3 & S4

Aortic valve Softer Louder No splitting Not heard

Pulmonary Valve Softer Louder S2 splitting Not heard

Triscuspid valve Softer Louder S1 split Not heard

Mitral valve Softer Louder S1 split Not heard

(b) Arterial PulsesRest* Sit/Stand* Exercise*

Subject 1 2 Avg 1 2 Avg 1 2 Avg

1 72 74 73 77 77 77 104 94 99

2 68 70 69 74 72 73 90 90 90

*Pulse per minutes

(c) Blood PressurePalpation Auscultation

SBP(mmHg) SBP(mmHg) DBP(mmHg)

Subject 1 2 Avg 1 2 Avg 1 2 Avg

1 110 110 110 110 110 110 80 80 80

2 92 94 93 92 92 92 72 76 74

Discussion1. Explanation

(a) Comparison of the result obtained from a single subjecti. At part (a), the results obtained might not be the accurate answer as there are

many uncontrollable errors. This includes the listening ability of each person is

different and the ability to interpret the sound heard are differs.


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ii. At part (b), subjects pulse rate is gradually increased after doing some exercise.This is because after subjects do the exercise, the rate of respiration will

increase as the subjects need to slowly restable his/her breaths rate. Before

he/she manage to do so, their hearts will pump faster as it will increase the

respiration rate and thus increase the volume of oxygen inhaled. As a result,

pulse rate will increase too.

iii. At part (c) both the subject s blood pressure are in the normal range. Bloodpressure of a normal person is 120/80mmhg.

(b) Comparison with other group membersi. At part (b) and (c), the subject 2s pulse rate and blood pressure are lower than

subject 1. This may be because of subject 2 is a person whom always do

exercise.

ii. Athletes and those who exercise regurlary tend to have lower blood pressureand slower heart rate.

(c) The vibrations in the blood and the tissues when the valves close will cause heart tobeats and thus producing the heart sound. By using a stethoscope, the heart sound

can be listens clearly if and only if the diaphragm of the stethoscope is placed at the

right auscultation position. Through the auscultation, we can determine the

condition of the heart roughly.

(d) There are two heart sounds which is S1 and S2 for a normal person. The S1 is thesound produced when the atrioventricular valve is closed. While the S2 is the sound

produced when semilunar valves is close. Thus, there will be two sounds produced

periodically each time the heart beats which sound like lubb-dupp.

(e) After doing some simple exercises, the heart sound of a subject is louder and faster.This is because the subject needed more oxygen and thus increasing his/her

respiration rate. As the rate of the respiration increase, the demand of the oxygen

needed by the subject will be replenish. After a while, the rate of respiration will

slowly reduce to the normal level.

(f) Pulse rate of a normal person is around 60-100 beats per minute. Anyone withheartbeat which is more or less than the range should immediately refer to the

doctor.

(g) In this experiment, there are no S3 and S4 is heard. Therefore, we can conclude thatthe 2 subject are considered healthy.

(h) Normal blood pressure of a person is around 120/80mmHg. Since both of thesubject having the values around the normal range. Thus, there are considered to be

healthy.

(i) If person with high blood pressure they are known as hypertension while personwith low blood pressure will be known as hypotension. Hypertension will put the

person to risk for heart failure, strokes, heart attacks, arterial aneurysm and also

chronic renal failure. For person with hypotension, they will have risk of facing dizzy

or undergo faint or seizures. They also have a risk of organ failure as there is not

enough blood transfer to all organs.

2. ErrorsI. The comparison of S1 and S2 in part (a) might be a bit differences from the


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actual fact. This is because the difference between S1 and S2 is determined

through personally determination ability. Different people have different ability

to determine the differences thus there will be mistake during the experiment.

Besides that, during the auscultation process, we might exactly place the

diaphragm at the right position as shown in the figure below.

A- Aortic valveB- Pulmonary ValveC- Triscuspid ValveD- Mitral Valve

II. In part (b) where pulse rate of the subject need to be counted. Errors mightoccur as counting pulse rate without a device is not as accurate as the result we

obtain from digital blood pressure machine.

3. PrecautionsI. The level of the eyes must be perpendicular to the meniscus level of the

mercury when taking the readings as to eliminate parallax error.

II. The cuff of the sphygmomanometer must be wrapped at least 2.5cm above thecubital fossa. This is to make sure that the results obtain is more accurate.

III. During the moment where the pressure of the cuff is increased, the pressuremust be increased slowly and gentlely as to prevent applying too much pressure

onto the forearm of the subject as this will injured the forearm of the subject.IV. The procedure should be repeated after letting the subject to rest for at least 5

minutes to prevent the subject from exhausted and can obtain a more accurate

result.

V. When handling the mercury sphygmomanometer, we should be becareful asmercury is a highly toxic and corrosive element.


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ConclusionFrom the result, we can conclude that the two subjects are healthy as their heart sounds, pulse

rate and blood pressure are around the normal range. Although their readings are slightly lower

than the normal range, but still consider as healthy.

References1. Edith Applegate, The Anatomy and Physiology Learning System. 3rd Edition. Saunders Elsevier.

Canada. Page233-249. 2006.

2. Walker, H.K., Hall, W.D., Hurst, J.W., Clinical Methods: The History, Physical and LaboratoryExaminations. 3

rdEdition. Butterworth-Heinemann Ltd. 1990.

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Lab 5 Heart Sound