Biomedical Instrumentation Questions and Answers – Implantable Telemetry Systems

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This set of Biomedical Instrumentation Multiple Choice Questions & Answers (MCQs) focuses on “Implantable Telemetry Systems”.

1. ______________ is not a piezo-electric material.
a) quartz
b) rochelle salt
c) aluminium
d) barium titanate
View Answer

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.
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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
View Answer

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.

3. Mechanical deformation occurs in the piezo-electric material on applying electricity.
a) True
b) False
View Answer

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
View Answer

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
View Answer

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.
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6. Electricity is generated by a piezo-electric crystal on applying pressure to it.
a) True
b) False
View Answer

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
View Answer

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)
View Answer

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
View Answer

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.
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10. Which of the following parameter is measured by strain gauge?
a) temperature
b) displacement
c) height
d) pressure
View Answer

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.

Sanfoundry Global Education & Learning Series – Biomedical Instrumentation.

To practice all areas of Biomedical Instrumentation, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn