Foetal Monitoring Instruments ( Biomedical Instrumentation ) MCQs – Biomedical Instrumentation MCQs
Latest Biomedical Instrumentation MCQs
By practicing these MCQs of Foetal Monitoring Instruments ( Biomedical Instrumentation ) MCQs – Latest Competitive MCQs , an individual for exams performs better than before. This post comprising of objective questions and answers related to “ Foetal Monitoring Instruments ( Biomedical Instrumentation ) Mcqs “. As wise people believe “Perfect Practice make a Man Perfect”. It is therefore practice these mcqs of Biomedical Instrumentation to approach the success. Tab this page to check ” Foetal Monitoring Instruments ( Biomedical Instrumentation )” for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others.
Biomedical Instrumentation MCQs – Foetal Monitoring Instruments ( Biomedical Instrumentation ) MCQs
The most occurred mcqs of Foetal Monitoring Instruments ( ) in past papers. Past papers of Foetal Monitoring Instruments ( Biomedical Instrumentation ) Mcqs. Past papers of Foetal Monitoring Instruments ( 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 Foetal Monitoring Instruments ( Biomedical Instrumentation ) Mcqs. The Important series of Foetal Monitoring Instruments ( Biomedical Instrumentation ) Mcqs are given below:
Cardiotocograph
1. Ambulatory monitoring of ECG is called ____________
a) Event Cardiography
b) Holter Cardiography
c) Real-Time Cardiography
d) Implantable Cardiography
Answer: b
Explanation: 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).
2. Which of the following type of systems are not available for ambulatory ECG monitoring?
a) Holter monitors
b) Event Recorders
c) Time Recorders
d) Implantable Loop Recorders
Answer: c
Explanation: Currently, the following four types of systems are available for ambulatory ECG monitoring: I) Holter Monitors II) Event Recorders III) Real-Time Continuous Cardiac Monitoring System IV) Implantable Loop Recorders.
3. The current state of Holter technology uses small recorders, which size is about _______
a) 75 x 20 x 90 cm
b) 75 x 95 x 20 cm
c) 75 x 20 x 95 mm
d) 75 x 95 x 20 mm
Answer: d
Explanation: The current state of Holter technology uses small recorders (size 75 x 95 x 20 mm; weight about 190 g) with flashcard technology to record and store data from 2 to 3 ECG leads attached to the patient’s chest and collected continuously over 24 to 48 hours.
4. Who provides an excellent review of ambulatory cardiac event recorders?
a) Handelsman
b) Benz
c) Alfonso
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.
5. The monitor automatically transmits recorded data transtelephonically to a central monitoring station for subsequent analysis when an arrhythmia is detected by an arrhythmia algorithm.
a) True
b) False
Answer: a
Explanation: In Real-Time Continuous Cardiac Monitoring Systems, the monitor is equipped with software that analyzes the rhythm data continuously and automatically. The monitor automatically transmits recorded data transtelephonically (by wireless network or land phone line) to a central monitoring station for subsequent analysis when an arrhythmia is detected by an arrhythmia algorithm.
6. In the data recording, the normal speed of sub miniature tape recorder is ___________
a) 3 cm/s
b) 2 cm/s
c) 3 mm/s
d) 2 mm/s
Answer: d
Explanation: In data recording, the core of the modern ambulatory monitoring system is a multichannel sub-miniature tape recorder running normally at a speed of 2 mm/s. At this speed, a C-120 entertainment cassette will run for 24 hours.
7. In data recorders, during replay, the tape is run at ________ to achieve rapid manual or automatic scanning of ambulatory records.
a) 80 times of recording speed
b) 70 times of recording speed
c) 60 times of recording speed
d) 50 times of recording speed
Answer: c
Explanation: In data recorders, during replay, the tape is run at 120 mm/s (60 times the recording speed) to achieve rapid manual or automatic scanning of ambulatory records. The tape recorders used for this purpose have some special features as compared to the usually available entertainment tape recorders.
8. Which of the following is not an arrhythmic condition?
a) Cardiographic beat
b) Bradycardia
c) Dropped beat
d) Ectopic beat
Answer: a
Explanation: The analyzer part in automatic scanning of ambulatory records look for four arrhythmic conditions. These are bradycardia, tachycardia, dropped beat and premature beat. A threshold control is associated with each of these and when the appropriate threshold is exceeded, an alarm condition is generated.
9. Which CPU has an overall system control responsibility?
a) Control
b) Acquisition
c) Control and timing
d) Acquisition and display
Answer: c
Explanation: The control and timing CPU has an overall system control responsibility. 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.
10. Full form of P-FCB is ________
a) Planar-Functional Circuit Board
b) Planar-Fashionable Circuit Branch
c) Planar-Functional Circuit Board
d) Planar-Fashionable Circuit Board
Answer: d
Explanation: The full form of F-PCB is Planar-Fashionable Circuit Board. Sometimes in Holter monitoring, the patient needs typically 6 to 10 wires worn around the body throughout the day. To overcome these problems, a wearable electrocardiogram acquisition system implemented with planar-fashionable circuit board (F-PCB)-based shirt is explained by Yoo.
Methods of Monitoring Foetal Heart Rate – 1
1. Which system may include lenses, mirrors, slits, diaphragm etc?
a) Radiant system
b) Optical system
c) Cardiac system
d) Photo system
Answer: b
Explanation: 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. 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.
2. What is the most common and convenient source of light?
a) Xenon-mercury arc
b) Hydrogen discharge lamp
c) Neon-xenon arc
d) Tungsten lamp
Answer: d
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.
3. In the radiation source, for work in the ultraviolet region, a _______ is used.
a) Tungsten lamp
b) Xenon-mercury arc
c) Deuterium discharge lamp
d) Hydrogen arc
Answer: c
Explanation: For work in the ultraviolet region, a hydrogen or deuterium discharge lamp is used. In these lamps, the envelope material of the lamp puts a limit on the smallest wavelength which can be transmitted.
4. What are the wavelengths of quartz and fused silica respectively in a hydrogen discharge lamp?
a) 200 nm, 185 nm
b) 200 nm, 145 nm
c) 185 nm, 200 nm
d) 145 nm, 200 nm
Answer: a
Explanation: In these lamps, the envelope material of the lamp puts a limit on the smallest wavelength which can be transmitted. For example, quartz is suitable only up to 200 nm and fused silica up to 185 nm. The radiation from the discharge lamps is concentrated into narrow wavelength regions of emission lines. Practically, there is no emission beyond 400 nm in these lamps.
5. Modern instruments use ________ light source in calorimeters and spectrophotmetry.
a) Xenon-mercury lamp
b) Tungsten-halogen lamp
c) Mercury arc
d) Deuterium discharge lamp
Answer: b
Explanation: Modern instruments use a tungsten-halogen light source, which has a higher intensity output than the normal tungsten lamp in the change over the region of 320–380 nm used in colorimetry and spectrophotometry. It also has a larger life and does not suffer from the blackening of the bulb glass envelope.
6. The absorption type optical filter usually consists of coloured glasses, gelatin etc. and solutions of the coloured substances.
a) True
b) False
Answer: a
Explanation: The absorption type optical filter usually consists of colour media: colour glasses, coloured films (gelatin, etc.), and solutions of the coloured substances. This type of filter has a wide spectral bandwidth, which may be 40 to 50 m in width at one-half the maximum transmittance.
7. Which of the following is the dielectric?
a) MgF3
b) ZnF2
c) ZnS
d) ZnF3
Answer: c
Explanation: Interference filters usually consist of two semi-transparent layers of silver, deposited on glass by evaporation in a vacuum and separated by a layer of dielectric (ZnS or MgF2). In this arrangement, the semi-transparent layers are held very close.
8. The transmittance of interference filters varies between ________ % with a spectral bandwidth of 10 to 15 nm.
a) 15 to 20 %
b) 20 to 60 %
c) 10 to 20 %
d) 15 to 60 %
Answer: d
Explanation: Interference filters allow a much narrower band of wavelengths to pass and are similar to monochromators in selectivity. They are simpler and less expensive. However, as the selectivity increases, the transmittance decreases. The transmittance of these filters varies between 15 to 60 percent with a spectral bandwidth of 10 to 15 nm.
9. The expression relating the wavelength of the radiation and the angle (q) at which it is reflected is given by _________
a) ml = 2d sin q, where l= lambda
b) m = 2d sin q
c) ml = d sin q, where l= lambda
d) m = d sin q
Answer: a
Explanation: The expression relating the wavelength of the radiation and the angle (q) at which it is reflected is given by
ml = 2d sin q, where l= lambda.
where d is the distance separating the grooves and is known as the grating constant and m is the order of interference.
When m = 1, the spectrum is known as first order and with m = 2, the spectrum is known as second order.
10. _______ are optical systems, which provide better isolation of spectral energy than the optical filters.
a) Spectromators
b) Monochromators
c) Tocochromators
d) Baromators
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.
Methods of Monitoring Foetal Heart Rate – 2
1. The energy must be reflected and returned through a single 30° prism, so that it passes through the prism in both directions is called __________
a) Cornu mounting
b) Mono mounting
c) Littrow mounting
d) Trio mounting
Answer: c
Explanation: Quartz shows the property of double refraction. Therefore, two pieces of quartz, one right-handed and one left handed are taken and cemented back-to-back in the construction of 60° prism (Cornu mounting), or the energy must be reflected and returned through a single 30° prism, so that it passes through the prism in both directions (Littrow mounting).
2. Most modern instruments now use a _______ as a dispersing element in the monochromator.
a) Prism monochromators
b) Holographic gratings
c) Diffraction gratings
d) Replica gratings
Answer: c
Explanation: Most modern instruments now use a diffraction grating as a dispersing element in the monochromator, as prisms in general have a poorer stray light performance and require complex precision cams to give a linear wavelength scale. Replica gratings can even be produced more cheaply than prisms and require only a simple sine bar mechanism for the wavelength scale.
3. A typical reflection grating may have 1200 grooves/mm, which means the grooves are spaced at about _______ intervals.
a) 800 nm
b) 600 nm
c) 860 nm
d) 680 nm
Answer: a
Explanation: A typical reflection grating may have 1200 grooves/mm, which means the grooves are spaced at about 800 nm intervals. The grating may have a width of 20 mm or more, giving a total of at least 24,000 grooves.
Patient Monitoring System MCQs
4. What is reproduced from a master holographic grating by moulding its grooves onto a resin surface or silica substrate?
a) Diffraction grating
b) Replica grating
c) Silicate glasses
d) Fused silica
Answer: b
Explanation: Holographic gratings used in commercial spectrophotometers are either original master gratings produced directly by an interferometer or are replica gratings. Replica gratings are reproduced from a master holographic grating by moulding its grooves onto a resin surface on a glass or silica substrate.
5. What is the utilization wavelength limit for quartz?
a) 300 nm
b) 350 nm
c) 180 nm
d) 210 nm
Answer: d
Explanation: Normally, the absorbance of any material should be less than 0.2 at the wavelength of use. Below 300 nm, quartz or fused silica is utilized. The limit for quartz is 210 nm.
6. Which material is used to reduce the reflections from glass surfaces?
a) Manganese Flouride
b) Magnesium oxide
c) Magnesium Flouride
d) Manganese oxide
Answer: c
Explanation: Reflections from glass surfaces are reduced by coating these with magnesium fluoride, which is one-quarter wavelength in optical thickness. With this, scattering effects are also greatly reduced.
7. With the use of _______ chromatic aberrations and other imperfections of the lenses are minimized.
a) Lenses
b) Mirrors
c) Slits
d) Diaphragm
Answer: b
Explanation: To minimize light losses, lenses are sometimes replaced by front-surfaced mirrors to focus or collimate light beam in absorption instruments. Mirrors are aluminized on their front surfaces. With the use of mirrors, chromatic aberrations and other imperfections of the lenses are minimized.
8. _______ are often used for splitting the beam.
a) Multilayer coated lenses
b) Silvered films
c) Silicate glasses
d) Half-silvered mirrors
Answer: d
Explanation: The two beams must retain the spectral properties of the incident beam. Half-silvered mirrors are often used for splitting the beam. However, they absorb some of the light in the thin metallic coating. Beam splitting can also be achieved by using a prismatic mirror or stack of thin horizontal glass plates, silvered on their edges and alternatively oriented to the incident beam.
9. The sample holder is generally inserted somewhere in the interval between the ______and _______
a) Silvered film and multi-layered coating
b) The light source and the detector
c) The light source and silvered film
d) Silvered film and the detector
Answer: b
Explanation: Gases may be contained in cells which are sealed or stoppered to make them air-tight. The sample holder is generally inserted somewhere in the interval between the light source and the detector. For the majority of analyses, a 10 mm path-length rectangular cell is usually satisfactory.
10. In sample holders, for such applications, a 50 cm path-length with about a ________ volume cell is employed.
a) 0.3 ml
b) 3 liters
c) 0.3 liters
d) 3 ml
Answer: c
Explanation: Studies of dilute or weakly-absorbing liquid samples, or of samples where trace components must be detected, require a cell with a long path-length. For such applications, a 50 cm path-length with about a 300 ml volume cell is employed.
Monitoring Labour Activity
1. Which section of the clinical laboratory deals with determinations of the number and characteristics of the constituents of the blood, particularly the blood cells?
a) Chemistry
b) Haematology
c) Microbiology
d) Sample collection
Answer: b
Explanation: There are three different areas within the clinical laboratory set up. These are:
• Chemistry section deals with the analysis of blood, urine, cerebrospinal fluid (CSF) and other fluids to determine the quantity of various important substances they contain. Most of the electronic instruments in the clinical laboratory are available in this section.
• Haematology section deals with the determinations of the number and characteristics of the constituents of the blood, particularly the blood cells.
• Microbiology section in which studies are performed on various body tissues and fluids to determine the presence of pathological micro-organisms.
2. What is the percentage of blood plasma and the blood cells respectively in blood volume?
a) 60, 40
b) 40, 60
c) 70, 30
d) 30, 70
Answer: a
Explanation: The liquid part of the blood—the blood plasma, and the formed elements—the blood cells are analyzed during a chemical examination. The blood plasma accounts for about 60% of the blood volume and the blood cells occupy the other 40%. The plasma is obtained by centrifuging a blood sample.
3. The plasma is a viscous, light yellow liquid, i.e. almost clear in the fasting stage.
a) True
b) False
Answer: a
Explanation: The plasma is obtained by centrifuging a blood sample. During centrifugation, the heavy blood cells get packed at the bottom of the centrifuge tube and the plasma can thus be separated. The plasma is a viscous, light yellow liquid, i.e. almost clear in the fasting stage.
4. Which of the following method is based on the absorption of electromagnetic radiation in the visible, ultraviolet and infrared ranges?
a) Cardiotocography
b) Ultrasonic therapy
c) Spectrophotometry
d) Diathermy
Answer: c
Explanation: Spectrophotometry is the most important of all the instrumental methods of analysis in clinical chemistry. This method is based on the absorption of electromagnetic radiation in the visible, ultraviolet and infrared ranges.
5. Which of the following waves have short wave-length?
a) Microwave
b) Radio wave
c) Gamma rays
d) IR waves
Answer: c
Explanation: Electromagnetic spectrum ranges from very short wavelengths (including gamma and X-rays) to very long wavelengths (including microwaves and broadcast radio waves). The range of wavelength of gamma rays and X-rays is 10-4 to 10 nm. The range of wavelengths of microwaves and radio-waves is 106 to 109 nm.
6. The method based on the absorption of radiation of a substance is known as?
a) Absorption photometry
b) Spectrophotometry
c) Absorption tocometry
d) Absorption spectrophotoscopy
Answer: d
Explanation: Electronic transitions correspond to the ultraviolet and visible regions, vibrational transitions to the near infrared and infrared regions and rotational transitions to the infrared and far-infrared regions. The method based on the absorption of radiation of a substance is known as Absorption Spectroscopy.
7. What is the range of visible light of electromagnetic spectrum?
a) 380 to 780 mm
b) 780 to 1080 nm
c) 380 to 780 nm
d) 380 to 1080 nm
Answer: c
Explanation: The region in the electromagnetic spectrum which is normally used in spectroscopic work is very limited. Visible light represents only a very small portion of the electromagnetic spectrum and generally covers a range from 380 to 780 nm. The ultraviolet region extends from 185 mm to the visible.
8. The ratio of the radiant power transmitted by a sample to the radiant power incident on the sample is known as ______
a) Absorbance
b) Transmittance
c) Optical density
d) Photometric concentration
Answer: b
Explanation: Let us suppose, Po is the incident radiant energy and P is the energy which is transmitted. The ratio of the radiant power transmitted by a sample to the radiant power incident on the sample is known as the transmittance.
Transmittance = P/Po
9. If absorbance is plotted graphically against concentration, the graph is _________
a) Parabola
b) Increasing
c) Straight line
d) Decreasing
Answer: c
Explanation: If absorbance is plotted graphically against concentration, a straight line is obtained. A graph derived from the transmittance data will not be a straight line unless transmittance (or percent transmission) is plotted on the log axis of a semi-log paper.
10. Which of the following is not a source of radiant energy?
a) Tungsten-mercury lamp
b) Tungsten lamp
c) Xenon-mercury arc
d) Deuterium discharge lamp
Answer: a
Explanation: Radiant just means energy that can move from one place to another without a medium to carry it. A source of radiant energy, which may be a tungsten lamp, a xenon-mercury arc, hydrogen or deuterium discharge lamp, etc.
Recording System
1. How are foetal heart sounds picked up from the maternal abdomen?
a) Piezoelectric device
b) Sensitive Microphone
c) Crystal microphone
d) Dynamic microphone
Answer: b
Explanation: Foetal heart sounds can be picked up from the maternal abdomen by a sensitive microphone. The heart sounds in the form of mechanical vibrations have to pass through tissue structure and the signals picked up are rather weak because of distance effects and the small size of foetal heart valves.
2. Crystal microphone is used for picking _______ signals.
a) cardiac
b) brain
c) phono
d) muscles
Answer: c
Explanation: To pick up the heart sounds, it is essential that the transducer is properly placed and its impedance carefully matched. A crystal microphone is used for picking up phono signals. The phono transducer signals are amplified by a low noise preamplifier and fed to a bandpass filter which rejects all frequencies outside the 70 to 110 Hz range.
3. Bandpass filter used in foetal phonocardiogram rejects all frequencies outside the ________ Hz range.
a) 0-40
b) 40-80
c) 70-110
d) 110-150
Answer: c
Explanation: To pick up the heart sounds, it is essential that the transducer be properly placed and its impedance carefully matched. A crystal microphone is used for picking up phono signals. The phono transducer signals are amplified by a low noise preamplifier and fed to a bandpass filter which rejects all frequencies outside the 70 to 110 Hz range.
4. The preamplifier is incorporated in the transducer housing to maximize interference signals being picked up.
a) True
b) False
Answer: b
Explanation: The preamplifier is incorporated in the transducer housing to minimize interference signals being picked up. Much of the random noise is eliminated during this process and the record on paper after this stage is called foetal phonocardiograph.
5. How many sounds are produced from the normal foetal heart action?
a) 1
b) 2
c) 3
d) 4
Answer: b
Explanation: From the normal foetal heart action, generally two sounds are produced corresponding to the contraction and relaxation of the heart muscles. These two bursts of heart sounds are mixed up with unwanted signals which may succeed in passing through the filters.
6. What is the fixed pulse width of the pulse after process of one-shot circuit?
a) 110 ms
b) 170 ms
c) 230 ms
d) 280 ms
Answer: c
Explanation: After peak detection, the processed pulses operate a one-shot circuit which gives a fixed pulse width of 230 ms. The output of one-shot triggers a variable pulse width multi-vibrator which adds and gives either 43 or 116 ms time depending on the heart rate. The pulse width at the output will be either 230 + 43 = 273 ms or 230 + 116 = 346 ms.
7. What is used to detect heart frequency in foetal phonocardiograph?
a) 230 ms one shot
b) 400 ms one shot
c) 20 ms one shot
d) 440 ms one shot
Answer: b
Explanation: To detect the heart frequency, the 400 ms one-shot is used. If the period duration is greater than 400 ms, the one-shot will deliver a pulse. The negative slope of this pulse is used to trigger the 20 ms one-shot. These 20 ms pulses are integrated by the integrator and the output of this integrator is compared with a fixed voltage -V.
8. If the period duration is lesser than 400 ms, the one-shot will deliver a pulse.
a) True
b) False
Answer: b
Explanation: False, to detect the heart frequency, the 400 ms one-shot is used. If the period duration is greater than 400 ms, the one-shot will deliver a pulse. The negative slope of this pulse is used to trigger the 20 ms one-shot. These 20 ms pulses are integrated by the integrator and the output of this integrator is compared with a fixed voltage -V.
9. What is used to delay the change in the time constant in foetal phonocardiograph?
a) Preamplifier
b) Notch Filter
c) Integrator
d) Band Pass Filter
Answer: c
Explanation: The integrator is used to delay the change in the time constant and to make sure that a change of on-time takes place only if several (3 to 4) heart beats with the longer period duration (below 150 bpm) are present.
10. No output pulse will occur when the period between two pulses is less than _____ ms.
a) 230
b) 20
c) 400
d) 440
Answer: c
Explanation: No output pulse will occur if the period between two pulses is less than 400 ms. The 20 ms pulses are, therefore, not generated and the integrator discharges slowly from the negative output voltage to a positive output voltage. If the output of the integrator (6) is less negative than-V, the output of the comparator (7) will become negative.
11. Ultrasound provides basically clearer signal than does phonocardiography.
a) True
b) False
Answer: b
Explanation: False, Phonocardiography provides a basically cleaner signal than does ultrasound, thus allowing a greater chance of detecting a smooth baseline FHR. Unfortunately, phonocardiography is more susceptible to artefacts introduced from ambient noise, patient movement or other intra-abdominal sounds.
12. Which of the following instrument makes use of the Doppler shift principle?
a) Abdominal Foetal Electrocardiogram
b) Foetal Phonocardiogram
c) Foetus blood flow detector
d) Foetal ECG with scalp electrode
Answer: c
Explanation: An important clinical instrument for obstetric applications which makes use of the Doppler shift principle is the foetus blood flow detector. The technique is extended to derive an integrated rate of the foetus heart from blood flow signals and to display it on a suitable display system.
13. Which technique is used to derive an integrated rate of the foetus heart from blood flow signals and to display it on a suitable display system?
a) Abdominal Foetal Electrocardiogram
b) Foetal Phonocardiogram
c) Ultrasound
d) Foetal ECG with scalp electrode
Answer: c
Explanation: An important clinical instrument for obstetric applications which makes use of the Doppler shift principle is the foetus blood flow detector. The ultrasound technique is extended to derive an integrated rate of the foetus heart from blood flow signals and to display it on a suitable display system.
14. What is ultrasonic frequency employed for obstetric studies?
a) 0.5 to 1 MHz
b) 1 to 1.5 MHz
c) 1.5 to 2 MHz
d) 2 to 2.5 MHz
Answer: d
Explanation: For obstetric studies, ultrasonic frequency of about 2 to 2.5 MHz is usually employed, whereas in the study of blood flow in arteries and superficial blood vessels frequencies around 5–10 MHz are preferred. The level of ultrasonic energy transmitted into the body is generally kept between 10–15 mW/cm2.
15. What is range of ultrasonic energy transmitted into the body?
a) 0-5 mW/cm2
b) 5-10 mW/cm2
c) 10-15 mW/cm2
d) 15-20 mW/cm2
Answer: c
Explanation: For obstetric studies, ultrasonic frequency of about 2 to 2.5 MHz is usually employed, whereas in the study of blood flow in arteries and superficial blood vessels frequencies around 5–10 MHz are preferred. The level of ultrasonic energy transmitted into the body is generally kept between 10–15 mW/cm2.