EC2021-Medical Electronics Notes for All Five Units

7/26/2019 EC2021-Medical Electronics Notes for All Five Units

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EC2021- Medical Electronics Study Materials for all 5 units

Prepared by A.Devasena., Asso. Prof., Dept/ECE Page 1

UNIT I

ELECTRO-PHYSIOLOGY AND BIO-POTENTIAL RECORDING

UNIT IPART A

1.1)Definea) Resting Potentialb)

Action Potential May/June 2009, Nov/Dec 20081.2)DefineConduction Velocity Apr/May 2008, Nov/Dec 2008, May/June 20071.3)State all or none law in respect of cell bio potential. Apr/May 2008

1.4)Name the electrodes used for recording EMG and ECG. Nov/Dec 20121.5)List the lead systems used in ECG recording. Apr/May 20101.6)What is PCG? May/June- 2012, Nov/Dec 20121.7)Compare the signal characteristics of ECG and PCG.Nov/Dec 20111.8)What is EOG? Nov/Dec 20111.9)Draw typical ECG waveform. Nov/Dec 2009, May/June 20071.10What are the peak amplitude and frequency response for ECG, EEG and EMG.1.11) Write down the Nernst equation ? (Nov/Dec 07 )

1.12) What is Phonocardiogram ? (Nov/Dec 07)1.1)What is the specific usage of a SIGNAL AVERAGER ? (May/ June 2006)

1.14)What is EARLY RECEPTOR POTENTIAL (ERP) ?(May/ June 2006)

1.15)Write down the Nernst Equation ? (APRIL/MAY 2005)

1.16)What are the factors that influence the flow of ions across the membrane ? (APR/MAY 2005)1.17).Draw an action potential waveform and label the amplitude and give the time scale for nerve cells

and heart muscle.( April /May 2004)

1.18). What is PCG ? What is its diagnostic use ? ( April /May 2004)

1.19)Mention the important bands of frequencies in EEG and their importance. ( Nov.Dec.2003)

1.20)What are the electrodes used for recording EMG ?( Nov.Dec.2003)

UNIT I-PART B

1.1)Discuss in detail the origin of bioelectric potentials with necessary diagrams. (Nov/Dec 07 )

1.2)Draw an Electrocardiogram, labeling the critical features. Include typical amplitudes andtime intervals for a normal person(Nov/Dec 07 )

1.3)With neat diagrams explain the 12 lead system in ECG measurement (Nov/Dec 07 )

1.4). Draw the waveform of the ACTION POTENTIAL and explain :

(i) Depolarization (ii) Repolarization


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(iii) Resting Potential (iv) Absolute Refractory period

(v) Relative Refractory Period (vi) Propagation Rate

(vii) all-or-nothing law and (viii) net height of the action. (May/ June 2006)

1.5)Draw the waveform of the ACTION POTENTIAL and describe Resting Potential ,

Depolarization, Repolarization, action potential, Absolute Refractory period and RelativeRefractory Period (APR/MAY 2005)

1.6)Write down Goldman Equation and write the constants indicate.(APR/MAY 2005)

1.7)Draw a typical single channel ECG machine and give justification for the inclusion of each circuitblock of the machine. ( Nov.Dec.2003)

1.8)Write about standard lead system for ECG recording. Also draw a typical ECG waveform and markthe various complexes of ECG and give their durations. ( April /May 2004)

1.9)Write briefly about the recording devices for EMG. ( April /May 2004)

1.10) Draw the equivalent circuit of a pair of electrodes in electrolytic contact with a human being to

measure bio-potential. Name the components. (4)1.11).Draw a typical 8 channel EEG machine and discuss about its function. (12)

UNIT I - ELECTRO-PHYSIOLOGY AND BIO-POTENTIAL RECORDING

TTHHEEOORRIIGGIINNOOFFBBIIOO--PPOOTTEENNTTIIAALLSS

1. Define

c) Resting Potential

d) Action Potential May/June 2009, Nov/Dec2008

Resting potential is defined as the electrical potential of an excitable cell relative to itssurroundings when not stimulated or involved in passage of an impulse. It ranges from -60mV to-100mVAction potential is defined as the change in electrical potential associated with the passage of animpulse along the membrane of a cell.


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22

11lnfC

fC

nF

RTE

2. DefineConduction Velocity Apr/May 2008, Nov/Dec 2008, May/June2007

Conduction velocity is defined as the rate at which an action potential moves down a fiber or ispropagated from cell to cell. It is also called as Nerve conduction rate.

3. Write down the Nernst equation of action potential.

An equation relating the potential across the membrane and the two concentrations of the ion iscalled Nernst equation.

Where,R gas constant(8.315 x 107 ergs/mole/degree Kelvin)T absolute Temperature, degrees Kelvinn valence of the ion (the number of electrons added or removed to ionize the atom)F Faraday constant (96,500 coulombs)C1,C2 two concentrations of the ion on the two sides of the membranef1, f2 respective activity coefficients of the ion on the two sides of the membrane

4. What is meant by sodium pump?

Sodium pump is an active process in which sodium ions are quickly transported to the outside ofthe cell and the cell again becomes polarized and assumes its resting potential.

5. State all or none law in respect of cell bio potential. Apr/May 2008

Regardless of the method by which a cell is excited or the intensity of the stimulus, the actionpotential is always the same for any given cell.

6. List the types of bioelectric potentials.Bio electric potential related to

Heart ElectroCardioGram (ECG)Brain ElectroEncephaloGram (EEG)Muscle ElectroMyoGram (EMG)Eye (Retina) ElectroRetinoGram (ERG)Eye (Cornea - Retina) ElectroOculoGram (EOG)


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7. Define electrode and list its types.

The devices that convert ionic potential into electronic potential are called as electrode.The types of electrode are

a)

Micro electrodeb) Depth and needle electrodec) Surface electrode

8. What are perfectly polarized and perfectly non polarized electrodes?

Electrodes in which no net transfer of charge occurs across the metal electrolyte interface iscalled perfectly polarized electrode.Electrodes in which unhindered exchange of charge occurs across the metal electrolyte interfaceis called perfectly non polarized electrode.

9. What are the types of electrodes used in bipolar measurement? May/June- 2012

The types of electrodes used in bipolar measurement are

a)

Limb electrodesb) Floating Electrodesc)

Skin electrodes10.Name the electrodes used for recording EMG and ECG . Nov/Dec-2012

Electrodes used for recording EMG area) Needle electrodesb)

Surface electrodesElectrodes used for recording ECG are

d) Limb electrodese)

Floating Electrodes

f)

Pregelled disposable electrodesg) Pasteless electrodes

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11.State the importance of biological amplifiers. Apr/May 2010

Bio signals such as ECG, EMG, EEG, EOG have low amplitude and low frequency. So,amplifier is used to boost the amplitude level of bio signals.

12.What are the requirements for bio-amplifiers?

Bio amplifiers must havea) High input impedance

b)

Isolation and protection circuitc)

High voltage gaind) Constant gain throughout required bandwidthe)

Low output impedancef)

High CMRR

EECCGG,,EEEEGG,,EEMMGG,,PPCCGG,,EEOOGGLLEEAADDSSYYSSTTEEMMSSAANNDDRREECCOORRDDIINNGGMMEETTHHOODDSS,,TTYYPPIICCAALL

WWAAVVEEFFOORRMMSSAANNDDSSIIGGNNAALLCCHHAARRAACCTTEERRIISSTTIICCSS..


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13.What are the basic components of biomedical systems?

The basic components area)

Patientb)

Transducer

c)

Signal processing equipmentd) Displaye) Control unitf)

Stimulus14.List the lead systems used in ECG recording. Apr/May 2010

The lead systems used in ECG recording area)

Bipolar Limb leads or Standard leadsb)

Augmented unipolar limb leadsc) Chest leads or precordial leads

15.What is evoked potential?

The external stimuli are detected by the sense organs which cause changes in the electricalactivity of the brain. Due to this, potential is developed in the brain as the response to externalstimului like light, sound etc. It is called as evoked potential.

16.What is PCG? May/June- 2012, Nov/Dec -2012

A Phonocardiogram or PCG is a graphic display of the sounds generated by the heart and pickedup by a microphone at the surface of the body. Frequency response required is 5 to 2000 Hz. Itis measured by special transducer or microphone.

17.Compare the signal characteristics of ECG and PCG. Nov/Dec-2011

ECG wave occurrence PCG wave occurrence

QRS Complex 1stheart sound

End of T wave 2n

heart soundBeginning of P wave 3r heart sound

18.What is EOG? Nov/Dec-2011Electrooculogram is the measure of the variations in the corneal retinal potential as affected bythe position and movement of eye. The EOG potentials are picked up by small surface electrodesplaced on the skin near the eye.


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19.State the importance of PCG signals. May/June 2009

The importance of PCG signals area)

Different types of heart sounds are measured.b)

Additional sounds are heard between normal heart sound due to vibration setupin the blood inside the heart by sudden closure of valves.

c)

The presence of higher frequencies (mumurs) in the phonocardiogram indicates apossible hear disorder such as Aortic stenosis, Mitral regurgitation, mitral stenosisetc.

20.Define latency as related to EMG. Nov/Dec 2008

Latency is defined as the elapsed time between the stimulating impulse and the muscle actionpotential. In other words it is the time delay between stimulus and response

21.Draw typical ECG waveform. Nov/Dec 2009, May/June 2007

Wave Amplitude (mV) Duration (sec)

P 0.25 0.120.22 (PR interval)

R 1.06 0.070.1T 0.10.5 0.050.15 (ST segment)

QRS Complex - 0.09

22.What are the important bands of frequencies in EEG and state their importance.

Nov/Dec 2004Waves Frequency (Hz) Observation

Delta() 0.54These wave occur in deep sleep in premature babies andin very serious organic brain disease.

Theta() 48These wave occurs during emotional stress in someadults particularly during disappointment and frustration


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Alpha() 813 They found in the normal persons when they are awakein a quiet, resting state. During sleep they disappear.

Beta() 13- 22 It is observed when the person is alert active, busy, oranxious thinking, active concentration

23.What are the peak amplitude and frequency response for ECG, EEG and EMG.

Bioelectric potential Function Peak

amplitude

Frequency

response

Observation

ElectroCardioGram(ECG)

Recordselectricalactivity of heart

0.1 to 4mV 0.05 to120 Hz

Used to measureheart rate,arrhythmia andabnormalities

ElectroEncephaloGram(EEG)

Recordselectrical

activity ofbrain

2 to 200V 0.1 to 100Hz

Used to analysisevoked potential,

certain patterns,frequencyresponse

ElectroMyoGram(EMG)

Recordsmusclepotential

50V to1mV

5 to 2000Hz

Used as indicatorof muscle actionfor measuringfatigue

UNIT II

BIO-CHEMICAL AND NON ELECTRICAL PARAMETER MEASUREMENTS

UNIT IIPART A

2.1) What are the typical values of blood pressure and pulse rate of an adult? (Nov/Dec.2012)2.2) What are systolic and diastolic pressures? ( Nov/Dec 2011)2.3) What is the reason for decrease of cardiac output?2.4) DefineCardiac Output.2.5) State the principle behind the indicator dilution method.2.6)What is residual volume? ( May /June 2007)2.7) What is electrophoresis? (April / May 2010)

2.8) What are the applications of flame photometer?( Nov/Dec2009)

2.9) How is auto analyzer useful in medical field? ( April /May 2010)2.10)What are korotkoff sounds? ( Nov/Dec 2008)

2.11) Name the four physical principles based on which blood flow meters are constructed?

(Nov/Dec 07 )

2.12) Define Mean Arterial Pressure ? (Nov/Dec 07)


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.1) What is a BRANCHO SPIROMETER ?(May/ June 2006)

2.14) Name two types of electronic temperature-sensing devices used in biomedical applications.

(May/ June 2006)

2.15) Write down the demerits of indirect method of blood pressure measurement . (APRIL/MAY 2005)

2.16) What are Cardiac output and phonocardiogram ?(APRIL/MAY 2005)2.17) What are the demerits of electromagnetic blood flow meter ? ( April /May 2004)

2.18) Name any two methods of respiration rate measurement . ( April /May 2004)

2.19) What is flame photometer? ( Nov.Dec.2003)

2.20) What is Cardiac output? Mention the methods of measurement of cardiac output.( Nov.Dec.2003)

2.21)What are the two methods of pulse measurement?

UNIT IIPART B

2.1) What is a coulter counter ? Explain its operation. Mention the drawbacks of the system.( Nov.Dec.2003)

2.2) Explain how the pH of blood is measured. ( Nov.Dec.2003)

.)Define the term Cardiac Output . How is cardiac output measured by dye dilution technique?

Explain. ( April /May 2004)

2.4).Describe , with neat diagrams, the operation of a blood cell counter working on the principle of

conductivity. list the drawbacks of the system. ( April /May 2004)

2.5) Give a pictorial representation of Long Volumes and capacities indicate and explain the following :

i)Tidal Volume (ii) Insipiratory reserve volume (iii) Expiratory Reserve Volume (iv) ResidualVolume (v) Vital Capacity (vi) Total Lung capacity (vii)Inspiratory capacity

(viii)Functional residual capacity.(APR/MAY 2005)

2.6) List out the physical principles based on which blood flow meters are working. (APR/MAY 2005)

2.7)Draw the block diagram of ultrasonic blood flow meters and explain the method of measuring the

velocity of blood flow. (APR/MAY 2005)

2.8) Compare DIRECT measurements and INDIRECT measurements of BLOOD

PRESSURE .(May/ June 2006)

2.9)Name the physical principles based on which the blood flow meters are used.

2.10)Write down the application of ELECTROPHORESIS and explain the BASIC principles

involved . (May/ June 2006)

2.11)Explain :

(i) ultrasonic Blood flow meter (Doppler type) (May/ June 2006)

(ii) Plethysmograph. (May/ June 2006)


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2.12) Draw the block diagram of ultrasonic blood flow meter. Explain the method ofmeasuring the velocity of blood flow using (i) transit time principle (ii) Doppler Effect

(Nov/Dec 07 )

2.13)Describe a procedure for the measurement of pH in blood . (Nov/Dec 07 )

2.14)Explain the principle and the working of Electrophoresis apparatus (Nov/Dec 07 )UNIT II - BIO-CHEMICAL AND NON ELECTRICAL PARAMETER

MEASUREMENTS

1. What are the typical values of blood pressure and pulse rate of an adult?

(Nov/Dec.2012)

Systolic (maximum) blood pressure in the normal adult is in the range of 95 to145 mmHg, with 120 mm Hg being average. Diastolic (lowest pressure between beats) bloodpressure ranges from60 to 90 mm Hg, 80 mm Hg being average.

2. What are systolic and diastolic pressures? ( Nov/Dec

2011)

The hearts pumping cycle is divided into two major parts systole and diastole. Systole isdefined as the period of contraction of the heart muscles specifically the ventricularmuscle at which time blood is pumped into the pulmonary artery and the aorta. Systolicpressure is 120 mm Hg(average value). Diastole is the period of dilation of the heartcavities as they fill with blood. Diastolic pressure is 80 mm Hg (average value).

3. What is the reason for decrease of cardiac output?

The reason for decrease of cardiac output may be due to low blood pressure, reducedtissue oxygenation, poor renal function, shock and acidosis.

4. DefineCardiac Output

Cardiac output is defined as the amount of blood delivered by the heart to the aorta perminute. In case of adults during each beat, the amount of blood pumped ranges from 70to 100 ml. for normal adults the cardiac output is about 4- 6 liters/ minute.

5. State the principle behind the indicator dilution method.

The indicator dilution method is based on the principle that a known amount of dye orradio isotope as an indicator is introduced with respect to time at the measurement site, sothe volume flow of blood can be estimated.

6. What is residual volume? ( May /June

2007)

Residual volume is the volume of gas remaining in the lungs at the end of maximum

expiration.7. DefineTidal Volume

Tidal volume is also called as normal depth volume of breathing or is the volume of gasinspired or expired during each normal quiet respiration cycle.

8. What is total lung capacity?

The total lung capacity is the amount of gas contained in the lungs at the end of maximalinspiration.


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9. DefineVital Capacity

The vital capacity (VC) is the maximum volume of gas that can be expelled from thelungs after a maximal inspiration.

10.What is electrophoresis? (April / May 2010)

Electrophoresis is a method for separating and analyzing macromolecular substances such asplasma proteins. The method is based on the fact that, the molecules carry electric charges andtherefore migrate in a electric field.

11.How is cardiac output is used?

Using implanted electromagnetic fine probe on the aorta, find the cardiac output per minutedirectly can be found by multiplying the stroke volume with the heart beat rate per minute.

12.What are the uses of gas analyzers?

Gas analyzers are used to determine the quantitative composition of inspired and expired gas toassess the lung function.

13.What are the uses of blood flow meters?Blood flow meters are used to monitor the blood flow in various blood vessels and to measurecardiac output.

14.What are the applications of flame photometer? (

Nov/Dec2009)

Flame photometer is used to analyze urine or blood in order to determine the concentration ofpotassium (K), sodium (Na), calcium (Ca) and lithium (Li).

15.What are blood cells?

The blood cells have important functions in our body. The red blood cell is used for the transportof oxygen and carbon dioxide. The white blood cells are part of the bodys defense against

infections and foreign substances. The platelet is involved in the clotting of blood.16.What is the purpose PO2electrode is used?PO2electrode is used to determine the oxygen tension in the blood. It is a piece of platinum wireembedded in an insulating glass holder with the end of wire exposed to the electrolyte into whichthe oxygen from the solution under measurement is allowed to diffuse through the membrane.

17.How is auto analyzer useful in medical field? ( April /May

2010)

Auto analyzer is used to measure blood chemistry and display that on a graphic recorder.18.What are korotkoff sounds? ( Nov/Dec

2008)

In the Blood pressure (BP) measurement, when the systolic pressure exceeds the cuff pressure,then the doctor can hear some crashing, snapping sounds through the stethoscope. These soundsare called as korotkoff sounds.

19.What is cardiac output? What are the methods of measurement of cardiac output?

( Nov/ Dec

2004).Cardiac output is the amount of blood delivered by the heart to the aorta per minute. For normaladult, the cardiac output is 4- 6 litres/min. The cardiac output is measured by using three


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methods. They are Ficks Method, Indicator dilation method, Measurement of cardiac output byimpedance change.

20. What are the two methods of pulse measurement?The methods used for measuring pulse are transmittance and reflectance methods.

UNIT II - BIO-CHEMICAL AND NON ELECTRICAL PARAMETERMEASUREMENTS


(Nov/Dec.2012)



2011)

The hearts pumping cycle is divided into two major parts systo le and diastole. Systole is

defined as the period of contraction of the heart muscles specifically the ventricularmuscle at which time blood is pumped into the pulmonary artery and the aorta. Systolicpressure is 120 mm Hg(average value). Diastole is the period of dilation of the heartcavities as they fill with blood. Diastolic pressure is 80 mm Hg (average value).




Cardiac output is defined as the amount of blood delivered by the heart to the aorta perminute. In case of adults during each beat, the amount of blood pumped ranges from 70

to 100 ml. for normal adults the cardiac output is about 4- 6 liters/ minute.5. State the principle behind the indicator dilution method.


6. What is residual volume? ( May /June

2007)

Residual volume is the volume of gas remaining in the lungs at the end of maximumexpiration.

7. DefineTidal VolumeTidal volume is also called as normal depth volume of breathing or is the volume of gasinspired or expired during each normal quiet respiration cycle.

8. What is total lung capacity?



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14.What are the applications of flame photometer? (

Nov/Dec2009)



The blood cells have important functions in our body. The red blood cell is used for the transportof oxygen and carbon dioxide. The white blood cells are part of the bodys defense against

infections and foreign substances. The platelet is involved in the clotting of blood.16.What is the purpose PO2electrode is used?PO2electrode is used to determine the oxygen tension in the blood. It is a piece of platinum wireembedded in an insulating glass holder with the end of wire exposed to the electrolyte into whichthe oxygen from the solution under measurement is allowed to diffuse through the membrane.

17.How is auto analyzer useful in medical field? ( April /May

2010)

Auto analyzer is used to measure blood chemistry and display that on a graphic recorder.18.What are korotkoff sounds? ( Nov/Dec

2008)



( Nov/ Dec

2004).Cardiac output is the amount of blood delivered by the heart to the aorta per minute. For normaladult, the cardiac output is 4- 6 litres/min. The cardiac output is measured by using three


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UNIT II - BIO-CHEMICAL AND NON ELECTRICAL PARAMETERMEASUREMENTS


(Nov/Dec.2012)



2011)

The hearts pumping cycle is divided into two major parts systole and diastole. Systole is

defined as the period of contraction of the heart muscles specifically the ventricularmuscle at which time blood is pumped into the pulmonary artery and the aorta. Systolicpressure is 120 mm Hg(average value). Diastole is the period of dilation of the heartcavities as they fill with blood. Diastolic pressure is 80 mm Hg (average value).




Cardiac output is defined as the amount of blood delivered by the heart to the aorta perminute. In case of adults during each beat, the amount of blood pumped ranges from 70

to 100 ml. for normal adults the cardiac output is about 4- 6 liters/ minute.5. State the principle behind the indicator dilution method.


6. What is residual volume? ( May /June 2007)

Residual volume is the volume of gas remaining in the lungs at the end of maximumexpiration.

7. DefineTidal Volume

Tidal volume is also called as normal depth volume of breathing or is the volume of gasinspired or expired during each normal quiet respiration cycle.8. What is total lung capacity?



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14.What are the applications of flame photometer? ( Nov/Dec2009)



The blood cells have important functions in our body. The red blood cell is used for the transportof oxygen and carbon dioxide. The white blood cells are part of the bodys defense againstinfections and foreign substances. The platelet is involved in the clotting of blood.

16.What is the purpose PO2electrode is used?

PO2electrode is used to determine the oxygen tension in the blood. It is a piece of platinum wireembedded in an insulating glass holder with the end of wire exposed to the electrolyte into whichthe oxygen from the solution under measurement is allowed to diffuse through the membrane.

17.How is auto analyzer useful in medical field? April /May 2010)

Auto analyzer is used to measure blood chemistry and display that on a graphic recorder.

18.What are korotkoff sounds? ( Nov/Dec 2008)



( Nov/ Dec 2004).

Cardiac output is the amount of blood delivered by the heart to the aorta per minute. For normaladult, the cardiac output is 4- 6 litres/min. The cardiac output is measured by using three


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UNIT IIIUNITIII ASSIST DEVICES AND BIOTELEMETRY

UNIT IIIPART A

3.1)Distinguish between Internal and External pacemakers. [M/J 2007], [N/D 2008]3.2)What are the batteries used for implantable pacemaker? [N/D 2012]3.3)What is meant by fibrillation? [M/J 2009][A/M 2010]3.4)Calculate the energy stored in 16F capacitor of a DC defibrillator that is charged to a

potential of 5000 Vdc.3.5)Draw the defibrillator output waveform and indicate the output energy level. [M/J 2012]3.6)Draw the block diagram of a Bio-Telemetry system.[N/D 2008]3.7)What are the advantages of biotelemetry system?[M/J 2007] [M/J 2009]3.8)Specify the frequencies used for biotelemetry.[N/D 2012]3.9)What is a radio-pill?[N/D 2009][A/M 2010][M/J 2012]3.10)What is principle of telestimulation?[A/M 2008]3.11)Classify Pacing modes. (Nov/Dec 07 )

3.12)What is Defibrillator ? State its use. (Nov/Dec 07 )

.1)Why should a patient susceptible to Ventricular fibrillation be watched continuously ?

(May/ June 2006)

3.14) Name three types of Exchangers used in HEMODIALYSIS system. (May/ June 2006)

3.15) Give two important features that demand internal pacemaker usage. (APRIL/MAY 2005)

3.16) Write down the advantage of (a) double modulation (b) Pulse Width Modulation in wirelesstelemetry system. (APRIL/MAY 2005).

3.17) List the parameters to be monitored during dialysis.( April /May 2004)

3.18) Define threshold of hearing.( April /May 2004).

3.19) List the parameters to be monitored when the heart lung machine is connected to a patient.

( Nov.Dec.2003)

3.20Name the different hearing losses. Which of these effects is being minimized by hearing aid.

( Nov.Dec.2003)

UNIT IIIPART B

3.1) With respect to the Defibrillator draw the following waveform :(Nov/Dec 07 )


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(1) DC fibrillator discharge waveform

(2) Dual peak monophasic defibrillator discharge waveform

(3) Truncated defibrillator discharge waveform .

3.2) Draw the basic circuit diagram of a capacitive discharge type of cardiac

defibrillator and explain the working principle (Nov/Dec 07 )

3.3)What is Bio Telemetry ? Explain the working of single channel ECG telemetry system.

(Nov/Dec 07 )

3.4) W.r.t. DEFIBRILLATOR draw the following waveforms : (May/ June 2006)

(1) DC fibrillator discharge waveform

(2) Dual peak monophasic defibrillator discharge waveform

(3) Truncated defibrillator discharge waveform

(4) Write the technical properties of Electrodes used in Defibrillator.

3.5) (i) What are the basic requirements to be taken care for any implantable circuit ?

(ii) W.r.t Dialyser Perforamance what are CLEARANCE, PRIMING

VOLUME, RESIDUAL BLOOD VOLUME , ULTRAFILTRATION RATE ?.

(May/ June 2006)

3.6 i) Draw the basic circuit diagram of a capacitive discharge type of cardiac defibrillator and explain

the working principle. (APR/MAY 2005)

ii) List out the advantages of Rectangular Wave Defibrillators. (APR/MAY 2005)3.7) Explain in detail about Pacing modes and pulse generators. (APR/MAY 2005)

3.8) What is Fibrillation ? With a neat diagram, discuss about the equipment used to correct this. What are

the precautions to be followed when such an equipment is used in the hospital? ( Nov.Dec.2003)

3.9) What is a Triggred type pacemaker ? Expalin .Also discuss about its merits and demerits compared to

other types of pacemakers. ( Nov.Dec.2003)

3.10). Write briefly about the power sources used for implantable tykpe of pacemaker . ( Nov.Dec.2003)

3.11).What is meant by Demand Pacemaker ? How is it different from other types of pacemakers ? State

the merits and demerits of this pacemaker..( April /May 2004)

3.12). How is atrial defibrillation arrested? Explain with neat diagrams of the setup used.

( April /May 2004)

3.13)What is meant by Demand Pacemaker ? How is it different from other types of pacemakers ? State

the merits and demerits of this pacemaker..( April /May 2004)


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3.14)How is atrial defibrillation arrested? Explain with neat diagrams of the setup used.

( April /May 2004)

UNITIII ASSIST DEVICES AND BIOTELEMETRY

CCAARRDDIIAACCPPAACCEEMMAAKKEERRSS

1 Give two important factors that demand internal pace makers usage. [A/M2005] The two important factors that demand internal pace makers usage are (i). Type and nature of the electrode used(ii). Nature of the cardiac problems.(iii). Mode of operation of the pacemaker system.

2 Distinguish between Internal and External pacemakers. [M/J 2007]

[N/D 2008]

S.No Internal Pacemakers External Pacemakers

1 The pacemaker is a surgicallyimplanted when if the skin near thechest or abdomen, with its outputs

leads is connected directly to the heartmuscle.

The pacemaker is placed outside thebody. It may be in the form of wristwatch or in the pocket, from that oneterminal will go in the heart through thevein

2 It requires open chest minor surgeryto place the pacemaker

It does not require open chest surgery

3 It is used for temporary heartregularity

It is used for permanent heart regularity

4 There is no safety for the pacemaker,particularly in case of child carryingthe pacemaker

There is 100% safety for circuit fromthe external disturbances.

3 Classify Pacing modes[N/D 2007]

Based on the modes of operation of the pacemakers, they can be classified into five types.They are:

i) Ventricular asynchronous pacemaker(fixed rate pacemaker)ii) Ventricular synchronous pacemaker.

iii) Ventri defibrillator inhibited pacemaker (demand pacemaker)iv) Atrial synchronous pacemaker.v) Atrial sequential ventricular inhibited pacemaker.

4 What are the batteries used for implantable pacemaker?[N/D 2012]

The batteries used for implantable pacemakers are(i).Mercury cell, (ii).Lithium cells, (iii). Nuclear cell


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DDCCDDEEFFIIBBRRIILLLLAATTOORR

5 What types of electrodes are used in a defibrillator? [A/M 2005]

The electrodes used in a defibrillator are

(i)Internal electrodes - Spoon shaped(ii)External electrodesPaddle shapped

6 What are the three types of exchangers used in HEMODIALYSIS system? [M/J

2005]

The three types of exchangers used in HEMODIALYSIS systems arei)Parallel Flow dialyzer,(ii).Coil Hemodialyser,(iii). Hollow Fiber Hemodialyser

7 What is meant by fibrillation?[M/J 2009][A/M 2010]

The condition at which this necessary synchronism is lost is known as fibrillation.During fibrillation the normal rhythmic contractions of either atria or the ventricles arereplaced by rapid irregular twitching of the muscular wall

8 Calculate the energy stored in 16F capacitor of a DC defibrillator that is charged

to a potential of 5000 Vdc.

Given Data:

C = 16FV= 5000E= (1/2) CV2

=(1/2) 16 10-6 25 106

=200 Joules

9 Draw the defibrillator output waveform and indicate the output energy level. [M/J

2012]

FFRREEQQUUEENNCCYYSSEELLEECCTTIIOONNAANNDDBBIIOO--TTEELLEEMMEETTRRYY

10 What is the modulation techniques used for biotelemetry? Mention the reason for

adopting that modulation scheme.[N/D 2004]

The two different modulation techniques used for biotelemetry are

i)Double Modulationii)Pulse Width ModulationThe reason for adopting such a scheme

i)Double modulation givesa) betterThe purpose behind this double modulation, it gives better interference free

performance in transmission, and this enables the reception of low frequency biologicalsignals. The sub modulators can be a FM (frequency modulation) system, or a PWM


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(pulse width modulation) system or a final modulator is practically always an FMsystem.

11 Draw the block diagram of a Bio-Telemetry system. [N/D 2008]

12 What are the advantages of biotelemetry system? [M/J 2007] [M/J 2009]

The advantages of biotelemetry systems are(i). It is used to record the biosignals over long periods and while the

Patient is engaged in his normal activities.(ii). The medical attendant or computer can easily diagonise the nature of

Disease by seeing the telemeter biosignals without attending patientRoom

(iii). Patient is not disturbed during recording.(iv). For recording on animals, particularly for research, the biotelemetry isgreatly used.

13 Specify the frequencies used for biotelemetry.[N/D 2012]

Wireless telemetry system uses modulating systems for transmitting biomedicalsignals. Two modulators are used here. A lower frequency sub-carrier is employed inaddition to very- high frequency (VHF). This transmits the signal from the transmitter.

RRAADDIIOO--PPIILLLLAANNDDTTEELLEE--SSTTIIMMUULLAATTIIOONN

14 What is a radio-pill? [N/D 2009][A/M 2010][M/J 2012]The radio pill is capable of measuring various parameters that are available in the

tract. With the help of radio pill type devices, it is possible for us to measure or sensetemperature, pH, enzyme activity, and oxygen tesion values. These measurements can bemade in associated with transducers. Pressure can be sensed by using variable inductance,temperature can be measured by using temperature-sensitive transducer.

15 What is principle of telestimulation? [A/M 2008]

Telestimulation is the measurement of biological signals over long distance.

UNIT IV

RADIOLOGICAL EQUIPMENTS

UNIT IV- PART A

4.1)State different types of radiation generated from radio isotopes. May/June 2012

Biologicalsignal(ECG,EEG) Transducer Transmisssionchannel

Amplifier &Filter(Conditioner)

Electrodes

Output unit(Video recorderTape recorder,C.R.O)


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4.2)What is meant by ionizing radiation? Nov/Dec 2012, Nov/Dec 2011

4.3)In what way X-ray equipments are useful for diagnostic purpose? Apr/May 2010

4.4)Distinguish between hard X-ray and soft X-ray. Nov/Dec 2009

4.5)What is angiography? Nov/Dec 2008

4.6)State few radio isotopes used for diagnostic purpose. Apr/May 2010, May/June 2009, Nov/Dec 20114.7)Differentiate between radiography and fluoroscopy. May/June 2007, Nov/Dec 2008

4.8)List out safety precaution to be taken while handling radio isotopes.

Nov/Dec 2009, Apr/May 2008

4.9)Name two equipments used in radiation therapy. May/June 2007

4.10)What is radiation therapy? Apr/May 2008

4.11) What is Angiography ? (Nov/Dec 07 )

4.12)State the principle by which body organs could be visualized by radioisotope

methods(Nov/Dec 07 )4.1)Define let go current level. (May/ June 2006)

4.14) What is the basic difference between coherent fiber bundles and non-coherent bundles?

(May/ June 2006)

4.15) Name the types of scanning modes used in modern instrumentation. (APRIL/MAY 2005)

4.16) What are the types of Lasers used for therapeutic purposes. (APRIL/MAY 2005)

4.17) Define Micro shock and Macro shock. ( April /May 2004)

4.18) What is the principle of Cryogenic technique? Give any two medical applications of the same.

( April /May 2004)

4.19)Mention the scheme of modulation techniques used for biotelemetry. Also mention the reason for

such scheme ( Nov.Dec.2003)

4.20)What is the frequency of operation of ultrasound diathermy ?What is the reason for this frequency

selection ? ( Nov.Dec.2003)

UNIT IV- PART B

4.1) Explain in detail an X-ray Image Intensifier with appropriate diagram (Nov/Dec 07 )

4.2)Discuss in detail the Scintillation detectors for gamma radiations with necessary diagrams

(Nov/Dec 07 )

4.3)With a neat block diagram explain the instrumentation system for radioisotope procedures.

(Nov/Dec 07 )

4.4)Write short notes on Fluroscopy. (Nov/Dec 07 )

4.5) Write down the salient features of Frequency Selection with respect to Biotelemetry.


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(May/ June 2006)

4.6) Draw the block diagram of a single channel telemetry system suitable for ECG

Transmission (May/ June 2006)

4.7) Write down the salient features of Microwave Diathermy .(May/ June 2006)

4.8) With the help of a suitable figure, explain Phrinic Nerve stimulator. (May/ June 2006)

4.9)List out the needs for Biotelemetry system.(APR/MAY 2005)

4.10)Draw the block diagram of a typical biotelemetry transmitter and a receiver. (APR/MAY 2005)

4.11)What are the advantages of Diathermy? (APR/MAY 2005)

4.12)Explain the Microwave Diathermy with a block diagram Representation. (APR/MAY 2005)

4.13)Write in detail about short wave diathermy. What are its applications. ?( Nov.Dec.2003)

4.14)What is a Radio Pill ?Describe briefly. ( Nov.Dec.2003)

4.15)Discuss about intensity duration curve What is its use.? ( Nov.Dec.2003)

UNIT IV -RADIOLOGICAL EQUIPMENTS

IIOONNIIZZIINNGGRRAADDIIAATTIIOONN

1. State the different types of radiation generated from radio isotopes. May/June

2012

Different types of radiation generated from radio isotopes arei. Alpha Emission

ii. Beta Emissioniii.

Gamma Emission2. What is meant by ionizing radiation? Nov/Dec 2012, Nov/Dec

2011The rays coming out from xrays or radioactive materials has the characteristics of ionizing thegases through which it travels. This is known as ionizing radiation.

3. What is the need for ionizing radiation? May/June 2009The ability of ionizing radiation to penetrate materials that are opaque to visible light is utilizedin numerous techniques in medical diagnosis. The ionizing effects of radiation are also used forthe treatment of certain diseases, such as cancer. It is used in imaging as an aid to diagnose or asa screening tool.

DDIIAAGGNNOOSSTTIICCXX--RRAAYYEEQQUUIIPPMMEENNTTSS

4. List the characteristics of X-ray. May/June

2012

Characteristics of X-ray arei. They travel in a straight line with the speed of light in vacuum.

ii.

They expose photographic films.iii.

They ionize gasesiv.

They penetrate matter.


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v. They cause emissions of electron from metalsvi. They are not deviated by electric or magnetic fields.

5. In what way X-ray equipments are useful for diagnostic purpose? (Apr/May 2010)

X-ray equipments are useful for diagnostic purpose such as,i.

For detecting fractures in bones.

ii.

In Angiography X-ray is mainly used, to study blockage in blood vessel.iii.

In fluoroscopy, it creates a moving x-ray image.iv. It is used to study the digestive and endocrine systems with the help of

contrast medium.6. Distinguish between hard X-ray and soft X-ray. Nov/Dec 2009

S. no Soft X-rays Hard X-rays

1 Low penetrating power High penetrating power2

They have long wavelength They have short wavelength3

Low frequency High frequency

4

Mainly used for diagnostic purpose, such

as detecting fractures and the presence offoreign matter like bullet in human body.

Mainly used for therapeutic purpose,

such as treating certain types of skindisease and cancer.

7. What is angiography? Nov/Dec 2008Angiography is a medical imaging technique in which an X ray picture is taken to visualize theinner opening of blood filled structures, including arteries, veins and the heart chambers. An X-ray contrast medium is injected into the blood vessel and an X-ray called an angiogram is taken.

UUSSEEOOFFRRAADDIIOOIISSOOTTOOPPEEIINNDDIIAAGGNNOOSSIISS

8. What is a betatron? What is its application? Nov/Dec 2012Betatron is a device which produces high energy X-ray beams and electron beams of varying

energies. It is a circular induction accelerator used for electron acceleration. The energyproduced by it is as high as 45 MeV.Applications of betatron are

i. It is used in treating tumors in trunk and pelvis.ii.

It is used in radio therapy for cancer treatment.9. List few radio isotopes used for diagnostic purpose.

Apr/May 2010, May/June 2009, Nov/Dec 2011

Radio isotopes used for diagnostic purpose arei.

Iodine - 123 : Used for diagnosis of thyroid functionii.

Bismuth - 213 : Used for targeted alpha therapy especially cancers

iii.

Cobalt : Used for external beam radio therapyiv.

Copper - 64 : Used for genetic disease

10.List out safety precaution to be taken while handling radio isotopes.

Nov/Dec 2009, Apr/May 2008

Safety precaution to be taken while handling radio isotopes arei.

Radioactive materials should be kept in thick walled lead containers so thatradiation cannot penetrate them.


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ii. Lead aprons and lead gloves should be worn.iii. All radioactive samples should be handled by a special remote control process

using robots.11. How radio isotopes are used for therapy? Apr/May 2011

Radio isotopes are used to identify the tumor location, detect any urinary tract obstruction, in

diagnosis of coronary heart disease and for giving external beam therapy.

RRAADDIIAATTIIOONNTTHHEERRAAPPYY

12.What is radiation therapy? Apr/May 2008Certain diseases and tumors can be treated by ionizing effect of x-rays. The use of radiation forthe treatment of disease is called as radiation therapy. In dermatology soft x-rays are used for thetreatment of skin diseases. Hard x-rays are used in treatment of deep seated tumors.

13.Name two equipments used in radiation therapy. May/June 2007

Equipments used in radiation therapy are

i.

Cobalt 60 machineii. Medical linear accelerator machine

14.Distinguish between radiography and fluoroscopy.May/June 2007, Nov/Dec 2008

S.No Radiography Fluroscopy

1

X-ray image is developed byphotosensitive film

X-ray image is developed byphotoelectric effect and fluoresence.

2Patient is not exposed to x-raysduring examination of the x-rayimage.

Patient is exposed to x-ray during theexamination of the x-ray image

3

The image can be obtained fordeveloping the film and theexamination cannot be made beforedeveloping the film

Immediately image can be seen andexqamination can be finished with ashort time.

4

Movement of organs cannot beobserved

Movement of organs can be observed

UNIT V

RECENT TRENDS IN MEDICAL INSTRUMENTATION

UNIT VPART A

5.1)DefineMicro Shock. [M/J 2007]5.2)What are the advantages of performing surgery using LASER?[A/M 2008][N/D 2009]5.3)DefineMacro Shock. [N/D 2009]5.4)What are the applications of laser in medicine?5.5)What is meant by diathermy?[A/M 2010]5.6)List the applications of Endoscope.


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5.7)What is the use of laparoscope?5.8)What is the purpose of using resuscitation unit?5.9)What are the two methods of shortwave diathermy?5.10)What are the devices used to protect against electrical hazards?5.11) Distinguish between Micro shock and macro shock . (Nov/Dec 07 )

5.12) What is Diathermy? List its types (Nov/Dec 07 )

5.1) Define let go current level. (May/ June 2006),[A/M 2008]

5.14). Draw the waveforms generated in a medical stimulator. ( April /May 2004)

5.15).What is a Radio pill ? ( April /May 2004)

5.14).What is the basic difference between coherent fiber bundles and non -coherent bundles

(May/ June 2006)

5.15) Name the types of scanning modes used in modern instrumentation. (APRIL/MAY 2005)

5.16) What are the types of Lasers used for therapeutic purposes . (APRIL/MAY 2005)

5.19.) What is medical thermography ? Mention its applications. ( Nov.Dec.2003)

5.20) Mention the types of Lasers used in medical field . ( Nov.Dec.2003).

UNIT VPART B

5.1)Discuss in detail the different applications of Lasers in medicine (Nov/Dec 07 )

5.2) Explain the physiological effects of current at 50Hz (Nov/Dec 07 )

5.3)With reference to Electrical safety explain (Nov/Dec 07 )

1)

Ground Fault Circuit Interpreter

2) Protection by low voltage

5.4) (a) Explain : . (May/ June 2006)

(i) Macro shock Hazards and

(ii) Micro shock Hazards

5.5) Write down the typical applications of bio-telemetry. (May/ June 2006)

5.6) Explain the basic concepts (including the modulation types )of radio transmission used inBio-telemetry.

5.7)With reference to Electrical safety explain : (APR/MAY 2005)

i) Physiological effects of electricity.

ii) Ventricular fibrillation

iii) Isolated power systems


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iv) Macro shock hazards.

5.8)List out the characteristics of different types of LASERS used in Biomedical field with particularreference to types of beam and the fields of applications. (APR/MAY 2005)

5.9) What is Cryogenic Technique ?How is it useful in the hospital ? Expalin. What are theprecautions to be followed during application ?( Nov.Dec.2003)

5.10) What are the methods by which the electrical safety of the patient in the hospital is ensured ?

Discuss in detail. ( Nov.Dec.2003)

5.11) Discuss about the applications of high frequency generator as a surgical knife. What are the

hazards associated with this. (April/ May 2004)

UNIT-V RECENT TRENDS IN MEDICAL INSTRUMENTATION

1. What is medical thermography? Mention its applications. [N/D 2004] [N/D 2005]

Thermography is the process of recording true thermal image of the surfaces of objects understudy. It displays images representing the thermal radiation of skin areas. Thermogram containboth qualitative and quantitative information relevant to the image itself and to temperature.Medical applications of thermography

i)Tumorsii) Inflammationiii) Diseases of peripheral vesselsiv) Orthopedic diseases

2. List the types of lasers used in medical field [N/D 2004]

The types of lasers used in medical fields arei). Pulsed Nd-YaG laserii). Continuous laser. Co2laseriii). Continuous wave organ ion laser

3. Define - Let-go current [M/J 2006] [A/M 2008]

Letgo current is the minimum current to produce muscular contraction.For menabout 16mAFor Womenabout 10.5 mA

4. DefineMicro Shock[M/J 2007]

A physiological response to a current alied to the surface of the heart that resultsin unnecessary stimulation like muscle contractions or tissue injury is called asmicroshock.

5. What are the advantages of performing surgery using LASER? [A/M 2008][N/D

2009]

The advantages of performing surgery using LASER arei)Highly sterile


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ii) Non-contact surgeryiii)Highly localized and preciseiv)prompt surgeryv)short period of surgical time

6. DefineMacro Shock [N/D 2009]

A physiological response to a current applied to the surface of the body thatproduces unwanted stimulation like tissue injury or muscle contractions is called asmacro shock.

7. What are the applications of laser in medicine?

Laser is used in ophthalmology (eye problem), Gynecology (fertility), Plastic surgery,skin cancer etc.

8. What is meant by diathermy? [A/M 2010]

Diathermy is the treatment process by which, cutting coagulation of tissues areobtained.

9. List the types of diathermy.

The types of diathermy arei)Short wave diathermy

ii)Microwave diathermyiii)Ultrasonic diathermyiv)Surgical diathermy

10.What are the types of thermography?

The types of thermography arei). Infrared thermography

ii) Liquid crystal thermographyiii). Microwave thermography

11.What are the different types of current that are used for medical applications?

The different types of current are Threshold current, pain current, let-go current, paralysiscurrent, fibrillation and defibrillation current.

12.Define - Endoscopes and mention some of its types.

Endoscope is a tubular optical instrument to inspect or view the body cavities which arenot visible to the naked eye normally.

Types of endoscopes are cardioscope, bronchoscope, laparoscope, otoscope, gastroscope

etc.

13.What are the devices used to protect against electrical hazards?

i).Ground fault interruptii). Isolation transformer


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14.What are the two methods of shortwave diathermy?

The two methods of shortwave diathermy arei)Capacitive methodii) Inductive method

15.What is the purpose of using resuscitation unit?Resuscitation unit is generally used in intensive care unit (ICU). In modern hospitals theresuscitation units are in the form of a mobile trolley.

16.List the applications of Endoscope.

Endoscopes are used in hospitals for examination, treatment of disease and surgery.

17. What is the use of laparoscope?

The laparoscope is used for analyzing abdominal related diseases and to performoperations in the abdominal region.


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Introduction

Introduction:

The human body is the most deeply studied and frequently portrayed object in thehistory. Despite its familiarity, it is instinctively absorbing and eternally fascinating.

The number of humans in the world is racing towards seven billion. More than 5babies are born every minute, while 150,000 people die daily. With the population increasing byalmost three humans per second. Each of these people lives, thinks, worries, and day dreamswith and within the most complex and marvelous of possessions- a human body. An enduringfeature of this body and its behavior is self-curiosity. We continually look inside ourselves inenormous and ever-increasing detail in order to comprehend the action within.

Levels of organization:

The body is viewed to be a series of integrated systems. Each system carries out onemajor role or task. In the cardiovascular system, for example the heart pumps blood throughvessels, to supply every body part with essential oxygen and nutrients. The systems are in turncomposed of main parts known as organs. The stomach, intestines and liver are the organs ofdigestive system. Moving through further levels in the hierarchy the organs consist of tissues andtissues made up of cells.

Cells are often called the microscopic building blocks of the body. However they areactive and dynamic, they continually grow and specialize function die and replenish themselvesby the millions every second. The whole body contains 200 different kinds. Science inincreasingly able to deliver deeper than cells to the organelles within them and onwards andinwards to the ultimate components of ordinary matter molecules and atoms.

Anatomy:

The study of the bodys structure and how it cells, tissues and organs are assembled isknown as human anatomy. In reality, the inside of the body is a crowded place. Tissues and

organs push and press against one another. There is no free space, and no stillness either. Bodyparts shift continually in relation to each other. We move about, breathe, pump blood shiftdigestive matter and eat. For example, swallowed food does not simply fall down inside thegullet {oesophagus}. The gullet is normally pressed flat by internal chest pressure so that foodmust be forced down into the stomach by waves of muscular contraction.


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Skeleton:

The skeleton is a mobile frame work made up of 201 bones, approximately half of whichare in the hands and feet. Although individual bones are rigid, the skeleton as a whole isremarkably flexible and allows the human body a huge range of movement. The Skelton servesas an anchorage for the skeletal muscles and as protective cage for the bodys internal organs.Female bones are usually smaller and higher than male bones, and the female pelvis is shallowerand has wider cavity.

Head:

In a new born body, the head accounts for one quarter of total body length, by adulthood,

the proportion has reduced to one eighth contained in the head are the bodys main sense organs,eyes, ears, olfactory nerves that defect smells, and the taste buds of the tongue. Signal from theseorgans pass to the bodys great coordination centre. The brain housed in the protective bony

dome of the skull. Hair on the head insulates against heat loss, and adult males also grow thickfacial hair. The face has three important openings two nostrils through which air passes and themouth which takes in the nourishment and helps from speech. Although all heads are basicallysimilar, differences in the size, shape and color of features produce an infinite variety ofappearances.

Body organs:

All the body organs except for the brain are enclosed within the trunk or torso(the bodyapart from the head and limbs). The trunk also contains two large cavities separated by amuscular sheet called the diaphragm. The upper cavity contains the stomach, intestines, liver andpancreas which all play a role in digesting the food. Also within the trunk are the kidneys andbleeder, which are part of the urinary system, and the reproductive organism which hold theseeds of new human life. Modern imaging techniques such as contrast X-rays and different typesof scans make it possible to see and study body organs without eh need to cut through theirprotective covering of skin, fat, muscle and bone

Bones and joints:

Bones form the bodys hard, strong skeletal framework. Each bone has a held compactexterior surrounding a spongy, lighter interior. The long bones of the arms and legs, such as thefemur (thick bone) hale a central cavity containing bone marrow,. Bones are composed chiefly ofcalcium, phosphorous and a fibrous substance known as collagen. Bones must at joints, whichare of several different types. For example, the hip is ball and socket joint that allows the femur awide range of movement, whereas finger joints are simple hinge joints that allow only bending


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and straightening. Joints are held in place by bands of tissue called ligaments. Movement of jointis facilitated b the smooth hyaline cartilage that covers the bone ends and by the synovialmembrane that lines and lubricates the joint.

Muscles:

There are three main types of muscles skeletal muscle (also called voluntary musclebecause it can be consciously controlled); smooth muscle (also called involuntary musclebecause it is not under voluntary control) and specialized muscle tissue of the heart. Humanshave more than 600 skeletal muscles which differ in size and shape according to the jobs they do.Skeletal muscles are attached directly or indirectly (via tendons) to bones and work in opposingpairs (one muscle in the pair contracts while the other relaxes) to produce body movements asdiverse as making threading a needle and an array of facial expression. Smooth muscles occur in

the wall of internal body organs and perform actions such as forcing food through the intestines,contracting the uterus (womb) In child birth and pumping blood through blood vessels someother muscle in the body.

Iris:

The muscle fibers contract and dilate (expand) to alter pupil size.Tongue:

Interacting layer of muscle allow great mobilityIleum:

Opposing muscle layers transport semi-digested food.

Movement of the forearm:

Controlled movement of the limbs relies on coordinated relaxation and contraction ofopposing muscles. To raise the forearm, the biceps (two-rooted muscle) contracts and shortenswhile the triceps (three-rooted muscle) relaxes, the reverse occurs when the forearm is lowered.

Muscles 2:

Muscles of facial expression:

A single expression is the result of movement of many muscles.

Hands:


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The human hand is an extremely versatile root, capable of delicate manipulation as wellas powerful gripping actions. The arrangement of its 27 small bones, moved by 37 skeletalmuscles that are connected to the bones by tendons, allows a wide range of movements. Outability to bring the tips of out thumbs and fingers together combined with the extra ordinarysensitivity of our fingertips due to their rich supply of nerve endings, makes out hands uniquelydextrous.

Feet:

The feet and toes are essential elements in body movement. They bear and propel theweight of the body during walking and running and also help to maintain balance during changesof body position. Each foot has 26 bones, more than 100 ligaments and 33 muscles some ofwhich are attached to the lower leg. The heel pad and the arch of the foot act as shock absorbers,providing and cushion against the joints that occur with every step.


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Physiological system2.1.Information ProcessingThe human body is alive with information. Being a complex, dynamic mechanism, its interactingand interdependent parts require control and co-ordination. This is done by passing information

between them. Two body systems are responsible for command-control and data management The nervous and the endocrine systems.Information processing involves inputs evaluation and decision making followed by

outputs. The body has inputs from the various senses such as sight and hearing. Its brain is CPU(Central Processing Unit) whose outputs control the physical action of muscles and chemicalresponses of glands. Both nerves and hormones are involved in data management.

2.1.1.Electrical and chemical pathwaysThe language of the nervous system is tiny electrical impulses. They are small and fast eachjust one-tenth of a volt in strength and lasting hardly one-thousandth of a second and numerous.Every second millions pass through the networks of long pale, string like pathways called

nerves. Informations from the senses flow to the brain as electrical impulse. Here it is shifted,analyzed and evaluated causing millions more signals to pass around and within the brainbetween numerous, complex areas. Decisions are reached and command messages are producedin the form of electrical impulses. The brains electrical output travels along motor nerves to themuscles to stimulate and co-ordinate their contraction for movements. Different informationcarriers-hormones-instruct the endocrine glands on the timing and quantity of secretion requiredfor the desired effect. More than 50 hormones circulate in the blood stream. The specificmolecular structure of each hormone stimulates only cells with suitable receptors on theirsurface, instructing the cells to carry out certain procedures. In general nerves work fast withinfraction of a second. Most hormones function over longer times within minutes, days or evenmonths. Long-lasting effects as in growth of hormones are continuously secreted over many

years, as individual dose would last only few days.

2.2.BodyClock Input

The body has built-in rhythms of activity. People in experimental timeless surroundings(of constant light, temperature food availability and other conditions) still tend to sleep, wake ,eat , become alert and move about in a roughly 24 hours style. A small part of the brain known asthe suprachiasmatic nucleus located just above the place where the visual or optic nerves meet, isthe body clock. It is continually adjusted by external cues such as light levels and temperaturefluctuations and our mental acknowledgement of clock times. In turn, it feeds information to

many brain parts that deal with cyclical activities such as hormone release, tissue repair, bodytemperature control, urine production and digestive matter. In this way, the natural rhythms ofthe body are co-ordinate.

2.2.1.The Importance of InputAs can be seen by the workings of the body clock, feeding information into the brains processingcenter relies on more than the five senses. The continuing environmental adjustment of the bodyclock is one example of more subtle and complex sensory input within the body, There are


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thousands of micro receptors that continually monitor variables, for example oxygen, wastecarbon dioxide and blood glucose. These data feed to automatic or subconscious parts of thebrain, which make decision that, do not register in the conscious mind. In this way a hugeamount of information processing occurs, of which we are hardly ever aware.

2.3.Nerves and Neurons

The brain has over 100 billion nerve cells or neurons, and the body contains millionsmore. Bundle of nerve fibers projecting from the neurons from body-wide networks of nerves.Neurons are highly specialized in their structure, function and the way they link together tocommunicate.

Like all other cells, typical neurons have a main cell body with a nucleus. But a neuronalso has a long wire. Process that read out to transmit messages to other neurons at junctioncalled synapse. These processes are of two kinds. Dendrites receive messages from other neuronsor from nerve-like cells in sense organs and conduct them towards the cell body of neurons.Axons convey messages away from the cell body to other neurons or to muscle or gland cells.Dendrite tend to be short and have many branches, while axons are usually longs and branchlessalong their length. Neurons in the brain and spinal cord are protected and nurtured by supporting

nerve cells known as glial cells.2.3.1.Types of Neurons

The shapes and sizes of the bodies of neuron cells vary greatly as do the type, numberand length of their projections. Neurons are classified according to the number of process thatextends from the cell body. Bipolar neurons are the original neuronal design in the embryo, butadulthood, they are found in only a few locations, such as the eyes ret ina and the olfactory nervein the nose. Most neurons in the brain and spinal cord are multipolar, unipolar neurons arepresent mainly in the sensory nerves of the peripheral nervous system.Unipolar Neuron: - A single short process, an axon extends from the cell body and splits intotow.Bipolar Neuron: - The cell body is located between two processes-an axon and a dendrite.Multipolar Neuron: -These have three or more processes several dendrites and one axon.2.4.ORIGIN OF BIOPOTENTIALS:

Nerve cells or neurons are excitable. When stimulated, they undergo chemical changesthat produce tiny traveling waves of electricity.- nerve signals or impulses. These pass to otherneurons, eliciting similar response from them.

Throughout the nervous system, information is conveyed as tiny electrical signals callednerve impulsesor action potentials. These impulses are the same all over the body about 100milli volts in strength and lasting just 1 millisecond. The information carried depends on theirposition in the nervous system, and their frequency from one impulse every few seconds toseveral hundreds per second. Typically when a neuron receives enough pulses from other

neurons it fires one of its own as wavelike movements of ions (electrically changed particles)impulses jump from one neuron to another at junctions known as synapses.

2.4.1.IMPULSE MOVEMENT WITHIN A NERVE CELL:The nerve impulse is based chiefly on movement of positively charged sodium and

potassium ions through the neurons cell membrane. Impulses travel at speeds between 1 and120 m/s. depending on the type of nerve. Movement is much faster in sheathed(myelinated),axons in which the action potential jumps along successively myelin-coatedsections from one node to the next.


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2.4.1.Nerve Impulse

Nerve cells or neurons are excitable. When stimulated they undergo chemical changes thatproduce tiny travelling waves of electricity nerve signals or impulses. These pass to otherneurons, exciting similar responses from them.

Throughout the nervous system, information is conveyed as tiny electrical signals callednerve impulses or action potentials. These impulses are the same all over the body about 100millivolts (0.1 volts) in strength and lasting just 1 millisecond. The information carried dependson their position in the nervous system and their frequency from one impulse every few secondsto several hundreds from other neurons it fires one of its own, as wave-like movements of ions(electricallychanged particles) .Impulses jump from one neuron to another at junctions knownas synapses.2.4.2.Crossing the gap between neuronsWhen and electrical impulse arrives at the junction (synapse) it triggers the release of chemicalscalled neurotransmitters. They cross the incredibly thin gap (synaptic cleft) between themembranes of presynaptic (sending) and postsynaptic neurons (receiving). They either trigger a

new impulse in the receiving neuron or actively inhibit in from firing.2.4.3.Resting PotentialWith no impulse, there are more positively charged ions, particularly sodium ions outside the cellmembrane and more negative ions inside. This produces an electrical resting potential of -70millivolts. The membrane is polarized, with the inside negative.2.4.4.DepolarizationDuring this phase (depolarization) positive sodium ions rush in through ion rush in through ionchannels in a patch of neuron membrane. The membrane is first depolarized then its polarity isreversed to become slightly positive, resulting in an action potential of +30 millivolts on theinside.

2.4.5.Repolarization

Positively charged potassium ions flow in the opposite direction, restoring the charge membraneand the next and so on. The impulse moves along the membrane as a wave of depolarization andrepolarization.

2.4.6.Excitement and InhibitionWhen neurotransmitters on their receptors sites they can either excite or inhibit the receivingcell. Both responses are equally valuable in relaying messages through the nervous systems. Toexcite a receiving cell, positive sodium ions flow into it, depolarizing the membrane in a similarway to a nerve impulse. The depolarizing effect spreads through the membrane for a fewmilliseconds, fading as it does so. If further signals enter the cell, they may become strong

enough to file a new nerve impulse. To inhibit the cell, negatively charged particles rush into thecell. The negative effect spreads through the cell membrane and prevents its excitement.2.4.6.1.Parts of Neurons: - Projection of neurons: collect nerve impulses from other neuronsor sensory nerve endings.2.4.6.2.Dendrites: - Main part of neuron, containing the nucleus and cell.2.4.6.3.Neuron fibril node:- Also called node of ranvier, portion of axon not covered bymyelin.


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2.4.6.4.Schwann cell: - Sheet-like cell that grows around a portion of axon (fiber) to formthe myelin sheath.2.4.6.5.Myelin Sheath: - Also called neurilemma or Schwann sheath; spiraling structure offatty myelin that helps to speed an impulse and prevent it fading or leaking.2.4.6.6.Axon: - Main nerve fiber of the neuron conveys impulses away from the cell body.

2.4.6.7..Neurotubule: - Specialized micro tube that works as a conveyerbelt to bring synaptic vesicles from the cell body to the axon terminal.2.4.6.8.Synaptic Knob: - Enlarged end of axon terminal.2.4.6.9Membrane Channel Protein: - Complex protein embedded in cell membrane; whenenough ions flood through the channel they cause a response in the receiving cell.2.4.6.9.Receptor: - Sits in membrane channel into which neurotransmitter molecules slot,altering the shape of the channel to admit charged ions.2.4.6.10.Synaptic Cleft: - Fluid-Filled gap between the sending and receiving neuron just 25nanometers wide.2.4.6.11.Microfilament: - Thinnest element of the flexible, supporting scaffolding found inmost cells.

Presynaptic Membrane: - Membrane of sending cells axon.Postsynaptic Membrane: - Membrane of receiving cells dendrite.

2.5.Respiratory system Respiratory systema pneumatic system- an air pump (diaphragm ) alternately creates negative and positive pressures in a sealed

chamber (thoriac cavity) and causes air to be sucked into and forced out of a pair of

elastic bags(lungs). The respiratory system supplies the oxygen needed by the body cells and carries off their

carbon dioxide waste. Inhaled air passes via the trachea (windpipe) through two narrower tubes, the bronchi to

the lungs.

chambers called alveoli Each lung comprises many fine, branching tubes called bronchioles that end in tiny

clustered


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Lungs -outside environment through a passage way comprising nasal cavities, pharynx,larynx, trachea, bronchi, and bronchioles.

Oxygen is taken into the blood from the incoming air and carbon dioxide is transferredfrom the blood to the air

Thus, the blood circulation forms link in the supply of oxygen to the tissues and in the

removal of gaseous waste products of metabolism. Gases cross the thin alveolar walls to and from a network of tiny blood vessels. Intrercostal (rib) muscles and the muscular diaphragm below the lungs operate the lungs

like bellows, drawing air in and forcing it out at regular intervals.

2.6.Urinary system

The urinary system filters waste products from the blood and removes them from thebody via a system of tubes.

Blood is filtered in the two kidneys which are fist-sized. Bean-shaped organs. The renal arteries carry blood to the kidneys.

The renal veins remove blood after filtering Each kidney contains about one million tiny units called nephrons. Each nephron is made up of tubule and a filtering unit called glomerulus, which consists

of a collection of tiny blood vessels surrounded by the hollow Bowmans capsule. The filtering process produces a watery fluid that leaves the kidney as urine. The urine is carried via two tubes called ureters to the bladder where it is stored until its

release from the body through another tube called urethra.

2.7.Nervous system The nervous system -control and communication network.

Rapid communications between various parts, the effective integrated activity of differentorgans and tissues and coordinated contraction of muscle are almost entirely dependentupon the nervous system.

The brain consists of three parts, namely the cerebrum, cerebellum, and the brain stem.2.7.1.cerebrum

The cerebrum consists of two hemispheres right and left.

Each hemisphere is sub divided into two lobes.

Frontal lobe and temporal lobe In the left hemisphere Parietal and occipital lobe in the right hemisphere. The outer layer of the brain is called the cerebral cortex. All sensory inputs from various parts of the body eventually reach the cortex.

Various areas are responsible for hearing, sight, touch and control of the voluntarymuscles of the body.

2.7.2.Cerebellum

The cerebellum acts as a physiological microcomputer which intercepts various sensoryand motor nerves to smooth out the muscle motions which could be otherwise jerky.

It also consists of two hemispheres which regulate the coordination of muscularmovements elicited by the cerebrum.

The cerebellum also enables a person to maintain his balance


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2.7.3.Brain stem

Brain stem- connects the spinal cord to the center of the brain just below the cerebralcortex.

Essential parts

medulla oblongata The pons Midbrain Diencephalonthalamus, hypothalamus.

2.7.4.spinal cord:

The spinal cord is a downward continuation of medulla oblongata The cord consists of white matter on the surface and gray matter inside. The cord containing motor and sensory fibres running between the brain and the body

and reflex action Billions of specialized cellsneurons are functionally active as signal transmitters

Fundamental property of neuron- is the ability to transmit electrical signals, callednerve impulses in response to the changes in their environment

2.7.4.5.Neuron

A typical neuron consists of a nucleated cell body and has several processes or branches. The size and distribution of these branches vary greatly at different sites in cells with

different functions, but two main kinds are the axon and the dendrite.

2.8.Endocrine system The endocrine system works by using harmones which are carried through circulatory

system. The harmones are generated in the endocrine glands. The principal endocrine gland is PITUTIARY which governs several other endocrine

glands.

The pitutiary is controlled by hypothalamus. The thyroid gland secretes thyroxin which increases the metabolism in the body.

The deficiency of thyroid gland secretes thyroxin which increases the metabolism ofthe body.

The adrenal gland secretes corticoids and they regulates the metabolism of glucose. A deficiency of insulin results in increase glucose in the blood which leads the

condition called diabetes.

2.9.Ear The ear is the organ of hearing and balance. The outer ear consists of a flap called the auricle or pinna and the auditory canal.

The main functional parts-the middle and inner ears are enclosed within the skull.

The middle ear consist of three tiny bones known as auditory ossicles and the eustachiantube, which links the ear to the back of the nose.


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The inner ear consist of the spiral-shaped cochlea and also the semicircular canals and thevestibule which are the organs of balance.

Sound waves entering the ear travel through the auditory canal to the tympanicmembrane (ear drum) where they are converted to vibrations that are transmitted via the

ossicles to the cochlea. Here the vibrations are converted by millions of microscopic hairs into electrical nerve

signal to be interpreted by the brain.

2.10.Eye The eye is the organ of sight. Two eyeballs, protected within bony sockets called orbits and on the outside by the

eyelids, eyebrows, and tear film are directly connected to the brain by the opticnerves.

Each eye is moved by six muscles.

Which are attached around the eyeball. Light rays entering the eye through the pupil are focused by the cornea and lens toform the image on the retina.

The retina contains millions of light-sensitive cells, called rods and cones whichconvert image into a pattern of nerve impulses These impulses are transmitted alongthe optic nerve to the brain.

Information from the two optic nerves is processed in the brain to produce a singlecoordinated image.

2.11.Body cells

Every one is made up of billions of cellsWhich are the structural units of the body.bones,

muscles, nerves, skin blood, and all other body tissues are formed from different types ofcells.Each cell has an outer layer (cell membrane) and contains fluidmaterial(cytoplasm)Within the cytoplasm many specialized structures calledorganelles.The most important is the nucleus which contains vital genetic material.Thestructure of DNA is like a spiral ladder.DNA contains genetic information and instructioncodes necessary for maintenance and continuation of life.In DNA we have four basicmaterials.

They are - adenine, guanine, thymine and cytocine.Nucleus is centrally located.It isseparated from surrounding fluids by cell membrane.Protoplasm is present in thecell.This protoplasm is composed by water, electrolytes, protein, lipids andcarbohydrates.

The principal fluid medium of the cell is water.Its concentration is about 70-85percent.Water serves as solvent for various chemicals to produce chemical reactions.Theinorganic chemicals for chemical reactions are provided by electrolytes.In the electrolyteswe have sodium ions, potassium ions, phosphate ions, sulphate ions, bicarbonate ions anda small quantity of proteins.Proteins- structural proteins, globular proteins.Lipids arecomposed of different types of phospho lipids and cholesterol.Carbohydrates play amajor role in the nutrition of the cell. They are stored in the cells in the form of glycogen

7/26/2019 EC2021-Medical Electronics Notes for All Fi

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EC2021-Medical Electronics Notes for All Five Units