Competitive Biomedical Instrumentation MCQs – Biomedical Telemetry ( Biomedical Instrumentation ) MCQs
Latest Biomedical Instrumentation MCQs
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Biomedical Instrumentation MCQs – Biomedical Telemetry ( Biomedical Instrumentation ) MCQs
The most occurred mcqs of Biomedical Telemetry ( ) in past papers. Past papers of Biomedical Telemetry ( Biomedical Instrumentation ) Mcqs. Past papers of Biomedical Telemetry ( Biomedical Instrumentation ) Mcqs . Mcqs are the necessary part of any competitive / job related exams. The Mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Biomedical Telemetry ( Biomedical Instrumentation ) Mcqs. The Important series of Biomedical Telemetry ( Biomedical Instrumentation ) Mcqs are given below:
Biotelemetry
1. Leucocytes are in the shape of ________
a) sphere
b) cube
c) hollow
d) cuboid
Answer: a
Explanation: Leucocytes are in the shape of a sphere. Leucocytes have a nucleus. They live for seven to fourteen days and there is a rapid turn over, with constant destruction and replacement. There are normally 5000–10,000 white cells per cubic mm of blood but their number varies during the day.
2. What should be the frequency response of the amplifiers that are used for the amplification purpose of the input signal in medical devices?
a) high frequency response
b) low frequency response
c) frequency response has no role to play in it
d) average frequency response
Answer: b
Explanation: The response should be down to less than one hertz which is a very frequent requirement. The bioelectric signals in medical science contain components of extremely low frequency. Thus the amplifiers must also have a low frequency response.
3. Leucocytes are not responsible for the formation of the defence mechanism of the body that fights against infection.
a) True
b) False
Answer: b
Explanation: It is False. Leucocytes form the defence mechanism of the body against infection. The number and proportion of these types of leucocytes may vary widely in response to various disease conditions. They are of two main types: the neutrophils and the lymphocytes. Neutrophils ingest bacteria and lymphocytes are concerned with immunological response.
4. To achieve the ______________ required for medical applications, the amplifier must have large values of coupling capacitance.
a) random frequency response
b) high frequency response
c) average frequency response
d) low frequency response
Answer: d
Explanation: In all RC-coupled amplifiers, low frequency response is limited by the reluctance of the coupling capacitors. The response should be down to less than one hertz which is a very frequent requirement. To achieve the low frequency response required for medical applications, the amplifier must have large values of coupling capacitance.
5. Neutrophils are bigger than the red cells.
a) True
b) False
Answer: a
Explanation: It is True. Neutrophils are nearly twice as big as the red cells.Lymphocytes are of the same size as the red cells but contain a large density staining nucleus and no granules. Neutrophils contain both a nucleus divided into several lobes and granules in their protoplasm.
6. High pass filter amplifies frequency _____________
a) above certain value
b) below certain value
c) above and below certain value
d) at certain value
Answer: a
Explanation: High pass filter amplifies signal above a certain frequency. Band pass filter amplifies frequencies with in a certain band. Band stop filter amplifies all the frequencies except those in a certain band. Low pass filter amplifies signals below a certain frequency.
7. Mean Platelet Volume is the ratio of the ___________ and is expressed in femolitres.
a) integrated platelet volume to the platelet count
b) integrated platelet volume to the WBC count
c) integrated RBC volume to the platelet count
d) integrated platelet volume to the RBC count
Answer: a
Explanation: Mean Platelet Volume (MPV) is the ratio of the integrated platelet volume to the platelet count and is expressed in femolitres. Platelet Distribution Width is related to the size range covered by those platelets lying between the sixteenth and eighty fourth percentile. Red Cell Distribution Width is a numerical expression of the width of the size distribution of red cells.
8. Unit of Mean Platelet Volume is expressed in?
a) millilitres
b) femolitres
c) picolitres
d) decilitres
Answer: c
Explanation: Unit of Mean Platelet Volume is expressed in femolitres. 1f/l = 10–15 . 1 litre of blood contains 0.45 litres of red cells. Mean Platelet Volume (MPV) is the ratio of the integrated platelet volume to the platelet count and is expressed in femolitres.
9. Low pass filter amplifies signals below a certain frequency.
a) True
b) False
Answer: a
Explanation: It is true. Low pass filter amplifies signals below a certain frequency. Band stop filter amplifies all the frequencies except those in a certain band. High pass filter amplifies signal above a certain frequency. Band pass filter amplifies frequencies within a certain band.
10. _______ is the percentage of the total specimen volume occupied by the platelets.
a) Mean Platelet Volume
b) Plateletcrit
c) Red Cell Distribution Width
d) Platelet Distribution Width
Answer: b
Explanation: Plateletcrit is the percentage of the total specimen volume occupied by the platelets. Red Cell Distribution Width is a numerical expression of the width of the size distribution of red cells. Mean Platelet Volume is the ratio of the integrated platelet volume to the platelet count and is expressed in femolitres.
11. Modern instrument use ________ for intravascular oximetry?
a) photodiode
b) red and infrared LED’s
c) optical fibre
d) phototransistor
Answer: c
Explanation: For intravascular oximetry, modern instruments make use of optical fibres to guide the light signal inside the vessel and the reflected light from the red blood cells back to the light detector.
12. Optical fiber sensors are immune to electromagnetic disturbances.
a) True
b) False
Answer: a
Explanation: It is True. Optical fiber sensors are electrically passive and consequently immune to electromagnetic disturbances. They can be miniaturized and are most suitable for telemetry applications. They are geometrically flexible and corrosion resistant.
13. Currently available oximeters utilize __________ wavelengths.
a) Equal to 2
b) Cannot be determined
c) Less than 2
d) More than 2
Answer: d
Explanation: Currently available fiber-optic oximeters utilize more than two wavelengths to adjust for haematocrit variation. For estimating SO2, usually the reflectance at two wavelengths, one in the red and the other in the near infrared regions, are used.
14. Mix venous saturation is measured by __________
a) Ear Oximeter
b) Intravascular Oximeter
c) Skin Reflectance Oximeter
d) Pulse Oximeter
Answer: b
Explanation: Mixed venous saturation varies in reflecting the changes of oxygen saturation, cardiac output, haematocrit or haemoglobin content and oxygen consumption. Intravasacular oximeters are normally used to measure mixed venous saturation, from which the status of the circulatory system can be deduced.
15. Which of the following is correct expression for RDW index?
a) [(20th – 80th) Percentile Volume / (20th – 80th) Percentile Volume] X 100 X K
b) [(20th – 80th) Percentile Volume / (20th + 80th) Percentile Volume] X 100 X K
c) [(20th + 80th) Percentile Volume / (20th – 80th) Percentile Volume] X 100 X K
d) [(20th + 80th) Percentile Volume / (20th + 80th) Percentile Volume] X 100 X K
Answer: b
Explanation: The total erythrocyte count is scanned by a continuously variable thresholding circuit. The RDW index is expressed by the following equation [(20th – 80th) Percentile Volume / (20th + 80th) Percentile Volume ] X 100 X K. It is a numerical expression of the width of the size distribution of red cells. It is derived by analog computation. The upper threshold is moved progressively lower from a level equivalent to 360 femolitres until 20 per cent of all erythrocytes present have a size above a certain value.
Single Channel Telemetry System
1. ___________ system may include lenses, mirrors, slits, diaphragm etc.
a) Photo system
b) Radiant system
c) Cardiac system
d) Optical system
Answer: d
Explanation: A detecting system for the measurement of unabsorbed radiant energy, which could be the human eye, a barrier-layer cell, phototube or photo-multiplier tube. An optical system for producing a parallel beam of filtered light for passage through an absorption cell (cuvette). The system may include lenses, mirrors, slits, diaphragm, etc.
2. __________ is not the property of instrumentational amplifier.
a) Extremely high input impedance
b) Very low CMRR
c) Low bias and offset currents
d) High slew rate
Answer: b
Explanation: Instrumentational amplifiers have very high CMRR. The instrumentation amplifier offers the following advantages for its applications in the biomedical field. Some of them are like extremely high input impedance, low bias and offset currents, high slew rate.
3. Which of the following feedback type is employed with DC amplifiers?
a) negative
b) can be any positive or negative doesn’t matter
c) depends on the application
d) positive
Answer: a
Explanation: DC amplifiers are generally of the negative feedback type. They are used for medium gain applications down to about 1 mV signal levels for full scale. They are not practical for very low level applications because of dc drift and poor common-mode rejection capabilities.
4. The CMRR is expressed in _____________
a) V/s
b) dB/ms
c) dB/s
d) dB
Answer: d
Explanation: The ability of the amplifier to reject common voltages on its two input leads is known as common-mode rejection. It is specified as the ratio of common-mode input to differential input to elicit the same response. CMRR is an important specification referred to the differential amplifier and is normally expressed as decibels.
5. An oscillator and a capacitance coupled amplifier are present in a carrier amplifier.
a) True
b) False
Answer: a
Explanation: It is True. The transducers, which require ac excitation, are those whose impedance is not purely resistive. The carrier amplifier consists of an oscillator and a capacitance coupled amplifier. The oscillator is used to energize the transducer with an alternating carrier voltage.
6. Reduction in electromagnetic coupling is achieved by _____
a) shielding
b) common grounding
c) multiple grounding
d) wire twisting
Answer: c
Explanation: Electromagnetic coupling is reduced by shielding, wire twisting and proper grounding which provide a balanced signal pair with satisfactory noise rejection characteristics. Having multiple grounds in a single circuit increases the electromagnetic coupling effect by producing ground loop which may generate so much noise that it may completely obscure the useful signal.
7. ________________ is employed with resistive transducers which require an external source of excitation?
a) dc bridge amplifier
b) ac coupled amplifier
c) carrier amplifier
d) differential amplifier
Answer: a
Explanation: Essentially, the amplifier comprises a stable dc excitation source, a bridge balance and calibration unit, a high gain differential dc amplifier and a dc output amplifier. DC bridge amplifiers are employed with resistive transducers which require an external source of excitation. They can be used as conventional dc high gain amplifiers and offer operating simplicity and high frequency response.
8. From the options given below select the one which is not a type of isolation amplifier?
a) transformer type isolation amplifiers
b) resistive coupled isolation amplifiers
c) optically isolated isolation amplifiers
d) capacitively coupled isolation amplifiers
Answer: b
Explanation: Opto-coupled amplifier uses a minimum number of components and is cost effective, followed by the transformer coupled amplifier. The capacitor coupled amplifier is the most expensive. There is nothing such as the resistive coupled isolation amplifiers. All the other three types are in common use, though the transformer isolation amplifier is more popular.
9. The isolation includes common supply voltage sources and common grounds on each side of the isolation barrier.
a) True
b) False
Answer: b
Explanation: It is False. Three methods are used in the design of isolation amplifiers: (i) transformer isolation (ii) optical isolation (iii) capacitive isolation. Isolation amplifiers are commonly used for providing protection against leakage currents. The isolation includes different supply voltage sources and different grounds on each side of the isolation barrier.
10. Which of the following amplifier is commonly used for providing protection against leakage currents?
a) Isolation amplifiers
b) Instrumentational amplifiers
c) Inverting amplifiers
d) Differential amplifiers
Answer: a
Explanation: Isolation amplifiers are commonly used for providing protection against leakage currents. They break the ohmic continuity of electric signals between the input and output of the amplifier. The isolation includes different supply voltage sources and different grounds on each side of the isolation barrier.
Multi-Channel Wireless Telemetry System
1. _________ instrument is used for recording the electrical activity of the muscles.
a) ECG
b) EMG
c) PCG
d) EEG
Answer: b
Explanation: Electromyograph is an instrument used for recording the electrical activity of the muscles to determine whether the muscle is contracting or not; or for displaying on the CRO and loudspeaker the action potentials spontaneously present in a muscle or those induced by voluntary contractions as a means of detecting the nature and location of motor unit lesions; or for recording the electrical activity evoked in a muscle by the stimulation of its nerve.
2. EMG cannot be recorded by using surface electrodes.
a) True
b) False
Answer: b
Explanation: It is False. EMG is usually recorded by using surface electrodes because the surface electrodes may be disposable, adhesive types or the ones which can be used repeatedly.
3. Which of the following signal is used to myoelectric prosthetic devices?
a) EEG
b) EMG
c) ECG
d) VCG
Answer: b
Explanation: EMG measurements are also important for the myoelectric control of prosthetic devices (artificial limbs). This is the most demanding requirement from an EMG since on it depends on the working of the prosthetic device. This use involves picking up EMG signals from the muscles at the terminated nerve endings of the remaining limb and using the signals to activate a mechanical arm.
4. _________ is the most common and convenient source of light.
a) Neon-xenon arc
b) Xenon-mercury arc
c) Tungsten lamp
d) Hydrogen discharge lamp
Answer: c
Explanation: The most common and convenient source of light is the tungsten lamp. This lamp consists of a tungsten filament enclosed in a glass envelope. It is cheap, intense and reliable. A major portion of the energy emitted by a tungsten lamp is in the visible region and only about 15 to 20% is in the infrared region.
5. Which of the following factor determines the amplitude of EMG signal?
a) Respiration
b) Ventricular Volume
c) Blood Resistivity
d) Position of electrode
Answer: d
Explanation: The amplitude of the EMG signals depends upon various factors, e.g. the type and placement of electrodes used and the degree of muscular exertions. The needle electrode in contact with a single muscle fibre will pick up spike type voltages whereas a surface electrode picks up many overlapping spikes and therefore produces an average voltage effect.
6. EMG signals range from ______________
a) 0.1 to 0.5 mV
b) 0.050 to 0.1 mV
c) 0.5 to 1 mV
d) 0.025 to 0.050 mV
Answer: a
Explanation: A typical EMG signal ranges from 0.1 to 0.5 mV. They may contain frequency components extending up to 10 kHz.Such high frequency signals cannot be recorded on the conventional pen recorders and therefore, they are usually displayed on the CRT screen.
7. Modern day calorimeters and spectrophotmetry instruments use ________ light source.
a) Tungsten-halogen lamp
b) Xenon-mercury lamp
c) Deuterium discharge lamp
d) Mercury arc
Answer: d
Explanation: Modern instruments use a tungsten-halogen light source, which has a higher intensity output than the normal tungsten lamp in the change over a region of 320–380 nm used in colorimetry and spectrophotometry. It also has a larger life and does not suffer from blackening of the bulb glass envelope.
8. Which of the following from the options is included in the system to facilitate playback and study of EMG sound waveforms at a later convenient time?
a) Tape Recorder
b) Preamplifier
c) Oscilloscope
d) Ground Electrode
Answer: a
Explanation: The waveform can also be photographed from the CRT screen by using a synchronized camera. The tape recorder is included in the system to facilitate playback and study of the EMG sound waveforms at a later convenient time.
9. ____________ is necessary for providing a common reference for measurement?
a) active electrode
b) ground electrode
c) tape recorder
d) oscilloscope
Answer: b
Explanation: A ground electrode is necessary for providing a common reference for measurement. The signal can then be amplified and displayed on the screen of a cathode ray tube. It is also applied to an audio amplifier connected to a loudspeaker. These electrodes pick up the potentials produced by the contracting muscle fibres.
10. Which among the following are optical systems, which provide better isolation of spectral energy than the pptical filters.
a) Spectromators
b) Monochromators
c) Baromators
d) Tocochromators
Answer: b
Explanation: Monochromators are optical systems, which provide better isolation of spectral energy than the optical filters, and are therefore preferred where it is required to isolate narrow bands of radiant energy. Monochromators usually incorporate a small glass of quartz prism or a diffraction grating system as the dispersing media.
11. _______________ is not an arrhythmic condition.
a) Cardiographic beat
b) Bradycardia
c) Ectopic beat
d) Dropped beat
Answer: a
Explanation: These are bradycardia, tachycardia, dropped beat and premature beat. The analyzer part in automatic scanning of ambulatory records looks for four arrhythmic conditions. A threshold control is associated with each of these and when the appropriate threshold is exceeded, an alarm condition is generated.
12. CMRR of preamplifier upto 5 Khz should be _____________
a) 10 dB
b) greater than 90 dB
c) less than 90 dB
d) 30 dB
Answer: b
Explanation: The common-mode rejection should be greater than 90 dB up to 5 kHz. The main amplifier has controls for gain adjustment from 5 mV/div to 10 mV/div for selecting the sensitivity most appropriate to the incoming signal from the patient. A calibrating square wave signal of 100 mV (peak-to-peak) at a frequency of 100 Hz is usually available.
13. Holter Cardiography is ambulatory monitoring of ECG signal.
a) True
b) False
Answer: a
Explanation: Modern EMG machines are PC based available both in a console as well as laptop models as they provide full colour waveform display, automatic cursors for marking and making measurements and a keyboard for access to convenient and important test controls. Ambulatory monitoring of ECG is called ‘Holter Cardiography’, after Dr. Norman Holter who introduced this concept in 1962. A Holter monitor is a type of ambulatory electrocardiography device, a portable device for cardiac monitoring (the monitoring of the electrical activity of the cardiovascular system) for at least 24 hours (often for two weeks at a time).
14. _____________ provides an excellent review of ambulatory cardiac event recorders.
a) Alfonso
b) Benz
c) Handelsman
d) Friesen
Answer: b
Explanation: An excellent review of ambulatory cardiac event recorders is provided by Benz in 1999. The major advantage of these devices compared with a traditional Holter monitor is that they are small, allow ECG monitoring for longer time periods, and can provide nearly real time data analysis when the patient transmits a recording in proximity to the symptomatic event.
15. ________ CPU has overall system control responsibility.
a) Control
b) Acquisition
c) Control and timing
d) Acquisition and display
Answer: c
Explanation: It also handles individuals functions such as keyboard and direct writer interface, tape deck control, timing data processing, and arrhythmia count totalizing via a high speed interrupt system. The control and timing CPU has an overall system control responsibility.
Multi-Patient Telemetry
1. _____________ instrument is used for recording the electrical activity of the brain.
a) ECG
b) PCG
c) EEG
d) EMG
Answer: c
Explanation: EEG, describing the general function of the brain activity, is the superimposed wave of neuron potentials operating in a non-synchronized manner in the physical sense. Electroencephalograph is an instrument for recording the electrical activity of the brain, by suitably placing surface electrodes on the scalp.
2. EEG electrodes are smaller in size than ECG electrodes.
a) True
b) False
Answer: a
Explanation: EEG electrodes are smaller in size than ECG electrodes. Several types of electrodes may be used to record EEG. These include: Peel and Stick electrodes, Silver plated cup electrodes and Needle electrodes.
3. Which of the following is the superimposed wave of neuron potentials operating in a non-synchronized manner in a physical sense?
a) EEG
b) ECG
c) VCG
d) PCG
Answer: a
Explanation: Electroencephalograph is an instrument for recording the electrical activity of the brain, by suitably placing surface electrodes on the scalp. EEG, describing the general function of the brain activity, is the superimposed wave of neuron potentials operating in a non-synchronized manner in the physical sense.
4. ______________ material is used to improve electrical contact in electrodes with the skin.
a) Silver Tungsten
b) Copper Tungsten
c) Electrode jelly
d) Silver Graphite
Answer: c
Explanation: If the electrodes are intended to be used under the skin of the scalp, needle electrodes are used. Electrode jelly or paste is used to improve the electrical contact. They offer the advantage of reducing movement artefacts.
5. Which among the following electrode gives high skin impedance as compared to ECG?
a) VCG
b) EEG
c) EMG
d) PCG
Answer: b
Explanation: EEG electrodes give high skin contact impedance as compared to ECG electrodes. Good electrode impedance should be generally below 5 kilohms. Impedance between a pair of electrodes must also be balanced or the difference between them should be less than 2 kilohms.
6. Which of the following component is generally designed to have a very high value of input impedance to take care of high electrode impedance?
a) Montages
b) Filters
c) Electrodes
d) Preamplifiers
Answer: c
Explanation: EEG preamplifiers are generally designed to have a very high value of input impedance to take care of high electrode impedance. Good electrode impedance should be generally below 5 kilohms. Impedance between a pair of electrodes must also be balanced or the difference between them should be less than 2 kilohms.
7. What is the recording called in which voltage difference between an active electrode on scalp with respect to reference electrode at ear lobe or any other part of the body is recorded?
a) Unipolar
b) Bipolar
c) Monopolar
d) Nonpolar
Answer: c
Explanation: This type of recording is called ‘monopolar’ recording. EEG may be recorded by picking up the voltage difference between an active electrode on the scalp with respect to a reference electrode on the ear lobe or any other part of the body.
8. Which of the following is employed for a bipolar recording done?
a) Uni Channel EEG
b) Omni channel EEG
c) Non Channel EEG
d) Multi channel EEG
Answer: d
Explanation: Such recordings are done with multi-channel electroencephalographs. ‘bipolar’ recording is more popular wherein the voltage difference between two scalp electrodes is recorded.
9. EEG signals picked up by surface electrodes are usually larger as compared to ECG.
a) True
b) False
Answer: b
Explanation: They may be several hundred microvolts, but 50 microvolts peak-to-peak is the most typical. Yes, EEG signals picked up by the surface electrodes are usually small as compared with the ECG signals.
10. A pattern of electrodes on the head and the channels they are connected to is called a montage. Montages are always ___________
a) inverse
b) random
c) symmetrical
d) asymmetrical
Answer: c
Explanation: Montages are always symmetrical. A pattern of electrodes on the head and the channels they are connected to is called a montage. The reference electrode is generally placed on a nonactive site such as the forehead or earlobe.
11. Reference electrode for recording EEG is placed on __________
a) forehead
b) cervical
c) nasal
d) facial
Answer: a
Explanation: The reference electrode is generally placed on a nonactive site such as the forehead or earlobe. A pattern of electrodes on the head and the channels they are connected to is called a montage. Montages are always symmetrical.
12. The typical value of calibration signal is ________
a) 10 uV/cm
b) 70 uV/cm
c) 50 uV/cm
d) 30 uV/cm
Answer: c
Explanation: A typical value of the calibration signal is 50 uV/cm. A calibrating signal is used for controlling and documenting the sensitivity of the amplifier channels. This supplies a voltage step of adequate amplitude to the input of the channels.
13. Preamplifiers used in electroencephalograph have low gain and high noise characteristics for EEG.
a) True
b) False
Answer: b
Explanation: It is False. Preamplifier used in electroencephalographs must have high gain and low noise characteristics because the EEG potentials are small in amplitude. In addition, the amplifier must have a very high common-mode rejection to minimize stray interference signals from power lines and other electrical equipments.
14. At what frequency is the notch filter in EEG machines sharply tuned to eliminate mains frequency interference?
a) 60
b) 90
c) 10
d) 70
Answer: a
Explanation: EEG machines have a notch filter sharply tuned at 60 Hz so as to eliminate mains frequency interference. The use of notch filters should preferably be restricted to exceptional circumstances when all other methods of eliminating interference have been found to be ineffective. These however have the undesirable property of ‘ringing’ i.e. they produce a damped oscillatory response to a square wave calibration waveform or a muscle potential.
15. ______________ is typical frequency range of standard EEG machines.
a) 70 to 140 Hz
b) 0.1 to 70 Hz
c) 0.05 to 0.1 Hz
d) 0.025 to 0.05 Hz
Answer: b
Explanation: The typical frequency range of standard EEG machines is from 0.1 Hz to 70 Hz, though newer machines allow the detection and filtering of frequencies up to several hundred Hertz. This may be of importance in some intracranial recordings.
Implantable Telemetry Systems
1. ______________ is not a piezo-electric material.
a) quartz
b) rochelle salt
c) aluminium
d) barium titanate
Answer: a
Explanation: Quartz is the most stable natural crystal with high mechanical and thermal stability and has volume resistivity higher than 10^4 ohm-cm and small internal electric loss. Barium titanate ceramic is a ferroelectric crystal and has small voltage output. Aluminium is not a piezo-electric material.
2. Which of the following is the correction option in relation to piezo-electricity?
a) sound electricity
b) pressure electricity
c) temperature electricity
d) photo electricity
Answer: b
Explanation: Piezo-electricity is pressure electricity. The piezo electric effect is a property of natural crystalline substance to develop electric potential along a crystallographic axis in response to the movement of charge as a result of mechanical deformation.
Arrhythmia And Ambulatory Monitoring Instruments MCQs
3. Mechanical deformation occurs in the piezo-electric material on applying electricity.
a) True
b) False
Answer: a
Explanation: It is True. The piezo electric effect is a property of a natural crystalline substance to develop electric potential along a crystallographic axis in response to the movement of charge as a result of mechanical deformation. On applying electricity to the piezo-electric material mechanical deformation occurs in the material.
4. ________________ material employed for making diaphragm to measure pressure.
a) zirconate titanate
b) barium titanate
c) tourmaline
d) phosphor bronze
Answer: d
Explanation: The motion of the diaphragm is measured in terms of electric signals. Tourmaline, barium titanate and zirconate titanate are piezo electric materials. Phosphor bronze is used to make diaphragm to measure pressure.
5. Which of the following is the principle behind strain gauge?
a) variable contact area
b) variable inductance
c) variable capacitance
d) variable resistance
Answer: d
Explanation: The principle behind strain gaude is the variable resistance. A linear relation exists between the deformation and electrical resistance of a suitable selected gauge over a specified range. The transducer is based upon the changed in resistance of a wire produced due to small mechanical displacement.
6. Electricity is generated by a piezo-electric crystal on applying pressure to it.
a) True
b) False
Answer: a
Explanation: It is True. On applying pressure to piezo-electric crystal, electricity is generated. The piezo electric effect is a property of a natural crystalline substance to develop electric potential along a crystallographic axis in response to the movement of charge as a result of mechanical deformation. Thus, piezo-electricity is pressure electricity.
7. ________________ is used to describe the figure of merit which determines the overall behaviour of the wire under stress.
a) gauge resistance
b) elastic factor
c) gauge factor
d) elastic modulus
Answer: c
Explanation: Gauge factor gives information on the expected resistance change or output signal at maximum permissible elongation. The gauge factor determines to a large extent the sensitivity of the wire when it is made into a practical strain gauge. The figure of merit which describes the overall behaviour of the wire under stress is determined from the gauge factor of the wire.
8. Which of the following is the correct definition for Gauge factor?
a) (incremental change in resistance due to strain/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length)
b) (resistance of an unstretched wire/incremental change in resistance due to stress)*(unstretched length of wire/incremental change in length)
c) (incremental change in resistance due to stress/resistance of an unstretched wire)*(incremental change in length/unstretched length of wire)
d) (incremental change in resistance due to stress/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length)
Answer: d
Explanation: Gauge factor is defined as (incremental change in resistance due to stress/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length). Gauge factor gives information on the expected resistance change or output signal at maximum permissible elongation. The gauge factor determines to a large extent the sensitivity of the wire when it is made into a practical strain gauge.
9. Which lead method is employed to compensate for temperature variation in the leads?
a) three
b) eight
c) six
d) two
Answer: c
Explanation: The third lead is in series with the power supply and is therefore independent of bridge balance. Compensation for temperature variation in the leads can be provided by using three lead methods. In this method, two of the leads are in the adjacent legs of the bridge which cancels their resistance changes and does not disturb the bridge balance.
10. Which of the following parameter is measured by strain gauge?
a) temperature
b) displacement
c) height
d) pressure
Answer: d
Explanation: Strain gauge is used to measure pressure. There are two types of strain gauges. Bounded strain gauge and unbounded strain gauge. Its working principle is a change in resistance. Mostly used to measure the arterial and venous blood pressure in the body.
Biotelemetry Application on Wimax Networks
1. ________________ records the electrical activity of heart.
a) ECG(Electrocardiograph)
b) PCG(Phonocardiograph)
c) VCG(Vectorcardiograph)
d) EEG
Answer: a
Explanation: Electrical signals from the heart characteristically precede the normal mechanical function and monitoring of these signals has great clinical significance.The electrocardiograph (ECG) is an instrument, which records the electrical activity of the heart.
2. Which of the following material used in limb surface electrode?
a) german silver
b) platinum
c) gold
d) copper
Answer: a
Explanation: The most common type of electrode most routinely used for recording ECG are rectangular or circular surface limb electrodes. They are applied to the surface of the body with electrode jelly. The material used in them are German silver, nickel silver or nickel plated steel.
3. Which of the following reason is responsible for the Welsh cup electrodes to record the electrical signal of the heart?
a) low contact impedance
b) zero contact impedance
c) high contact impedance
d) negligible contact impedance
Answer: c
Explanation: It has a high contact impedance as only the rim of the electrode is in contact with the skin. Welsh cup electrodes or suction electrodes is a metallic cup shaped electrode which is used for recording ECG from various positions from the chest. It is commonly used to record the unipolar chest leads.
4. Among the following, which has CMRR is of an order of 100-120 dB?
a) VCG
b) ECG
c) PCG
d) EEG
Answer: b
Explanation: CMRR of the order of 100–120 dB with 5 kW unbalance in the leads is a desirable feature of ECG machines. In addition to this, under specially adverse circumstances, it becomes necessary to include a notch filter tuned to 50 Hz to reject hum due to power mains.
5. In floating electrodes metal electrode make direct contact with the skin.
a) True
b) False
Answer: b
Explanation: The electrode consists of a light weighted metalled screen or plate held away from the subject by a flat washer which is connected to the skin. In floating electrode the metal electrode does not make direct contact with the skin. Floating electrodes can be recharged, i.e. the jelly in the electrodes can be replenished if desired.
6. __________ is considered to be the primary pacemaker of the heart.
a) bundle of his
b) sino-atrial node
c) purkinje fibres
d) atrio-ventricular node
Answer: b
Explanation: Located in the top right atrium near the entry of the vena cava, are a group of cells known as the sion-atrial node (SA node) that initiates the heart activity. Because of this is also considered as the primary pacemaker of the heart. The SA node is 25 to 30 mm in length and 2 to 5 mm in thickness.
7. Which is the correct location of Atrio ventricular node?
a) upper part of the heart wall between the two atrial
b) lower part of the heart wall above the two atrial
c) upper part of the heart wall above the two atrial
d) lower part of the heart wall between the two atrial
Answer: d
Explanation: The AV node delays the spread of excitation for about 0.12s, due to the presence of a fibrous barrier of non-excitable cells that effectively prevent its propagation from continuing beyond the limits of stria. The AV node is located in the lower part of the wall between the two atria.
8. Which of the following option is correct regarding the Buffer Amplifier?
a) low impedance signals to high impedance signals
b) high impedance signals to low impedance signals
c) ac impedance signals to dc impedance signals
d) dc impedance signals to ac impedance signals
Answer: b
Explanation: A buffer amplifies is essentially an impedance converter, that converts high impedance signals to low impedance signals. Noise is typically generated from motion artefacts and power line interference. A common solution used to suppress noise in dry electrode signals is a buffer amplifier.
9. Preamplifier is used ________
a) For Amplification
b) For Stabilizing effect
c) For Modifying effects
d) For Reducing effect
Answer: b
Explanation: The preamplifier is usually a three or four stage differential amplifier having a sufficiently large negative current feedback, from the end stage to the first stage, which gives a stabilizing effect.
10. ______________ is a wireless ECG acquiring system.
a) limb electrodes
b) smart pad
c) pasteless electrodes
d) pregelled disposable electrodes
Answer: b
Explanation: The system automatically selects three electrodes from an array of Cu/Ni fabric based electrodes patterned on a thin pad on which the patient lies. The smart pad is a system that displays a patients electrocardiogram signals without adhesive pads, wires or active intervention from a clinician. The selected electrodes are used to provide a differential 3 lead measurement of the patient’s ECG, which is then transmitted wirelessly and displayed on a laptop computer.
11. What is made horizontally on electrocardiogram?
a) time measurements and heart rate measurements
b) only heart Rate Measurements
c) only time Measurements
d) not fixed and can be any thing
Answer: a
Explanation: Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals.
12. _____________ is paper recording speed for routine work.
a) 10 mm/s
b) 20 mm/s
c) 25 mm/s
d) 15 mm/s
Answer: b
Explanation: Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals.
13._______________ is measured on the vertical axis of electrocardiogram.
a) Time Measurements and Heart Rate Measurements
b) Amplitude Measurements
c) Time Measurements
d) Heart Rate Measurements
Answer: c
Explanation: Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Amplitude measurements are made vertically in millivolts. The sensitivity of an electrocardiograph is typically set at 10 mm/mV.
14. Which of the following option is correct regarding the sensitivity of an electrocardiograph?
a) 10 mm/mV
b) 15 mm/mV
c) 20 mm/mV
d) 25 mm/mV
Answer: a
Explanation: Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Amplitude measurements are made vertically in millivolts. The sensitivity of an electrocardiograph is typically set at 10 mm/mV.
Transmission of Analog Physiological Signals Over Telephone
1. What is the principle behind Doppler velocimetry working?
a) amplitude measurement of fiber optic sensor
b) frequency measurement of fiber optic sensor
c) time shift measurement of fiber optic sensor
d) phase measurement of fiber optic sensor
Answer: b
Explanation: Doppler velocimetry works on the principle of frequency measurement of fiber optic sensor. The moving red blood cells scatter the light and produce a Doppler frequency shift because of their movement. In this method, light from a laser, normally helium/neon, is sent via a fibre onto the skin surface.
2. Which of the following is the principle behind Fluoroptic temperature sensors working?
a) optical fiber
b) thermistor
c) thermocouple
d) rtd
Answer: a
Explanation: They contain a rare earth phosphor which is illuminated by a white light along a short length of large core optical fibre. Fluoroptic temperature sensors work on the principle of optical fiber sensors. The light excites the phosphor which emits a number of lines. By using filters, two of these lines at 540 and 630 nm are selected, and the ratio of their intensities is a single valued function of the temperature of the phosphor.
3. Monopolar needle electrode has a coating of______________ material over the stainless steel wires which are bare only at the tips.
a) carbon
b) calcium
c) teflon
d) sodium
Answer: c
Explanation: The wire is bare only at the tip. The monopolar needle electrode consists of a teflon coated stainless steel wire. It is found that after the needle has been used a number of times, the teflon coating will recede, increasing the tip area. The needle should be discarded when this happens.
4. Which of the following sensor is used for Endoscopic imaging?
a) thermal sensors
b) optic fiber sensors
c) chemical sensors
d) pressure sensors
Answer: b
Explanation: Optical fibre sensors are non-electrical and hence are free from electrical interference usually associated with electronically based sensors. Optic sensors are used for endoscopic imaging. They are suitable for telemetry applications as the bulk of the instrumentation can be at a reasonable distance from the patient.
5. Which of the following component converts biochemical events into measurable signals?
a) amplifier
b) opamp
c) rectifier
d) transducer
Answer: d
Explanation: Transducers convert biochemical events into measurable signals. They provide the means for detecting the biochemical changes inside the body. Particularly biosensors are employed for this purpose.
6. Which of the following is used to determine the biological response of the biosensor?
a) artificial membrane
b) chemical membrane
c) physio-chemical membrane
d) biocatalytic membrane
Answer: d
Explanation: The biocatalytic membrane accomplishes the conversion of reactant to product. The product of the reaction diffuses to the transducer. The biological response of the biosensor is determined by biocatalytic membrane. This then causes the electrical response.
7. What is the working principle behind Home blood glucose sensor?
a) electro-physiological
b) electrochemical
c) chemical
d) physio-chemical
Answer: b
Explanation: Home blood glucose detection sensor works on the principle of electrochemical. The biosensor in this instrument relies upon enzymes that recognize and catalyze reactions of glucose with the generation of redox – active species that are detected electrochemically.
8. ____________ is a wireless ECG acquiring system.
a) pregelled disposable electrodes
b) smart pad
c) pasteless electrodes
d) limb electrodes
Answer: b
Explanation: Smart pad is a system that displays patients electrocardiogram signals without adhesive pads, wires or active intervention from a clinician. The selected electrodes are used to provide a differential 3 lead measurement of the patient’s ECG, which is then transmitted wirelessly and displayed on a laptop computer. The system automatically selects three electrodes from an array of Cu/Ni fabric based electrodes patterned on a thin pad on which the patient lies.
9. Home blood glucose measurement devices measure the glucose level through an invasive method.
a) True
b) False
Answer: a
Explanation: There is a small needle at the tip of the machine that pierces the skin to take a blood sample. Home blood glucose measurement devices measure the glucose level through invasive method. This blood is then undergoes electrochemical reactions and the glucose level is determined.
10. Blood glucose level measurement device uses a biosensor works on the principle of _____________
a) electromechanical
b) electrochemical
c) electrothermal
d) electroresistive
Answer: b
Explanation: The biosensor in this instrument relies upon enzymes that recognise and catalyze reactions of glucose with the generation of redox – active species that are detected electrochemically. Home blood glucose detection sensor works on the principle of electrochemical.