ultrasonics apps

1. Ultrasonic
applications
omar salah
physics
dr : Mohamed hesham
By

2. 1
Ultrasonics is the application of ultrasound. Ultrasound can be
used for medical imaging, detection, measurement and
cleaning. At higher power levels, ultrasonics is useful for
changing the chemical properties of substances.
Ultrasound is an oscillating sound pressure wave with a
frequency greater than the upper limit of the human hearing
range. Ultrasound is thus not separated from 'normal' (audible)
sound by differences in physical properties, only by the fact that
humans cannot hear it. Although this limit varies from personto
person, it is approximately 20 kilohertz (20,000 hertz) in
healthy, young adults. Ultrasound devices operate with
frequencies from 20 kHz up to several gigahertz.
Ultrasound is used in many different fields. Ultrasonic devices
are used to detect objects and measure distances. Ultrasonic
imaging (sonography) is used in both veterinary medicine and
human medicine. In the nondestructive testing of products and
structures, ultrasound is used to detect invisible flaws.
Industrially, ultrasound is used for cleaning and for mixing, and
to accelerate chemical processes. Animals such as bats and
porpoises use ultrasound for locating prey and obstacles.[1]
As we said there are many applications for
ultrasonicwaves … we will mention some
of them
1-Imaging
The potential for ultrasonic imaging of OBJECTS, with a 3
GHZ sound wave producing resolution comparable to an
optical image, was recognized by Sokolov in 1939 but
techniques of the time produced relatively low-contrast images
with poorsensitivity.[20] Ultrasonic imaging uses frequencies of
2 megahertz and higher; the shorter wavelength allows

3. 2
resolution of small internal details in structures and tissues. The
power density is generally less than 1 watt per square
centimetre, to avoid heating and cavitation effects in the object
under examination. High and ultra high ultrasound waves are
used in acoustic microscopy, with frequencies up to 4 gigahertz.
Ultrasonic imaging applications include industrial non-
destructive testing, quality control and medical uses.
Imaging is an ultrasound-based diagnostic imaging
technique used for visualizing internal bodystructures
including tendons, muscles, joints, vessels and internal organs
for possible pathology or lesions. The practice of examining
pregnant women using ultrasound is called obstetric
sonography, and is widely used.
In physics, 'ultrasound' refers to sound waves with a frequency
too high for humans to hear. Ultrasound images (sonograms)
are made by sending a pulse of ultrasound into tissue using an
ultrasound transducer (probe). The sound reflects (echoes) from
parts of the tissue; these echoes are recorded and displayed as
an image to the operator.
Many different types of images can be formed using ultrasound.
The most well-known type is a B-mode image, which displays
the acoustic impedance of a two-dimensional cross-sectionof
tissue. Other types of image can display blood flow, motion of
tissue over time, the location of blood, the presence of specific
molecules, the stiffness of tissue, or the anatomy of a three-
dimensional region.
Compared to other prominent methods of medical imaging,
ultrasonography has several advantages. It provides images in
real-time (rather than after an acquisition or processing delay),
it is portable and can be brought to a sick patient's bedside, it is
substantially lower in cost, and it does not use harmful ionizing
radiation. Drawbacks of ultrasonography include various limits
on its field of view including difficulty imaging structures

4. 3
behind bone and air, and its relative dependence on a skilled
operator.
Video ex :
1-How does it work ?
https://www.youtube.com/watch?feature=player_embedded&v
=_TYsPBuNxW0
2- LIVe example on a prignet woman
http://vimeo.com/25105975#t=32
2-range finding (sonar
A common use of ultrasound is in underwater range finding;
this use is also called Sonar. An ultrasonic pulse is generated in
a particular direction. If there is an object in the path of this
pulse, part or all of the pulse will be reflected back to the
transmitter as an echo and can be detected through the receiver
path. By measuring the difference in time between the pulse
being transmitted and the echo being received, it is possible to
determine the distance.
The measured travel time of Sonar pulses in water is strongly
dependent on the temperature and the salinity of the water.
Ultrasonic ranging is also applied for measurement in air and
for short distances. For example hand-held ultrasonic
measuring tools can rapidly measure the layout of rooms.
Although range finding underwater is performed at both sub-
audible and audible frequencies for great distances (1 to several
kilometers), ultrasonic range finding is used when distances are
shorter and the accuracy of the distance measurement is desired
to be finer. Ultrasonic measurements may be limited through
barrier layers with large salinity, temperature or vortex

5. 4
differentials. Ranging in water varies from about hundreds to
thousands of meters, but can be performed with centimeters to
meters accuracy
Sonar(originally an acronym for SOund Navigation And
Ranging) is a technique that uses sound propagation (usually
underwater, as in submarine navigation) to navigate,
communicate with or detect objects on or under the surface of
the water, such as other vessels. Two types of technology share
the name "sonar": passive sonar is essentially listening for the
sound made by vessels; active sonar is emitting pulses of
sounds and listening for echoes. Sonar may be used as a means
of acoustic location and of measurement of the echo
characteristics of "targets" in the water. Acoustic location in air
was used before the introduction of radar. Sonar may also be
used in air for robotnavigation, and SODAR (an upward
looking in-air sonar) is used for atmospheric investigations. The
term sonar is also used for the equipment used to generate and
receive the sound. The acoustic frequencies used in sonar
systems vary from very low (infrasonic) to extremely high
(ultrasonic). The study of underwater sound is known as
underwater acoustics or hydroacoustics.
Video ex.
1-Sonar instructions :
http://youtu.be/i4GJapYeosg
2-sonar and the blind
http://youtu.be/W6Wb0Yy5uSs

6. 5
3-Ultrasound
Identification (USID)
Ultrasound Identification (USID) is a Real Time Locating
System (RTLS)or IndoorPositioning System (IPS) technology
used to automatically track and identify the location of objects
in real time using simple, inexpensive nodes (badges/tags)
attached to or embedded in objects and devices, which then
transmit an ultrasound signal to communicate their location to
microphone sensors.
Ultrasound Identification is a real-time locating system
(RTLS) or indoor positioning system (IPS) technology used to
automatically determine and identify the location of objects
with room accuracy.
The approachis using simple, inexpensive nodes (badges/tags)
attached to the surface of persons, objects and devices, which
then transmit an ultrasound signal to communicate their
locations to microphone sensors.
Because ultrasound signal wavelengths have short reach, they
are confined to lesser distant locations than with wireless
transmissions with higher susceptibility to multiple reflection,
multipath and through-the-wall multiple room responses. Hence
ultrasound-based RTLS is considered a more robust alternative
to passive radio-frequency identification (pRFID) and even to
active radio-frequency identification (aRFID) in complex
indoor environments (such as hospitals), where radio waves get
multiply transmitted and reflected, thereby compromising the
positioning accuracy. Generally the ultrasound signal does not
interfere with sensitive medical equipment.[1]

7. 6
A handicap of ultrasound nodes is the exposition of the sound
transducer at the surface, which prevents from hermetically
encapsulating the node. Vapour sterilisation is not offered with
these nodes.
Videos
1-ultrasound identification of PANCREAS scanning plain
http://youtu.be/Huwo5blUZsw
4-Non-destructive
testing
Ultrasonic testing is a type of nondestructive testing commonly
used to find flaws in materials and to measure the thickness of
objects. Frequencies of 2 to 10 MHz are common but for
special purposes other frequencies are used. Inspection may be
manual or automated and is an essential part of modern
manufacturing processes. Most metals can be inspected as well
as plastics and aerospacecomposites. Lower frequency
ultrasound (50–500 kHz) can also be used to inspect less dense
materials such as wood, concrete and cement.
Ultrasound inspection of welded joints has been an alternative
to radiography for non-destructive testing since the 1960s.
Ultrasonic inspection eliminates the use of ionizing radiation,
with safety and costbenefits. Ultrasound can also provide
additional information such as the depth of flaws in a welded
joint. Ultrasonic inspection has progressed from manual
methods to computerized systems that automate much of the
process. An ultrasonic test of a joint can identify the existence
of flaws, measure their size, and identify their location. Not all
welded materials are equally amenable to ultrasonic inspection;

8. 7
some materials have a large grain size that produces a high
level of background noise in measurements
testing techniques based in the propagation of ultrasonic waves
in the object or material tested. In most common UT
applications, very short ultrasonic pulse-waves with center
frequencies ranging from 0.1-15 MHz, and occasionally up to
50 MHz, are transmitted into materials to detect internal flaws
or to characterize materials. A common example is ultrasonic
thickness measurement, which tests the thickness of the test
object, for example, to monitor pipework corrosion.
Ultrasonic testing is often performed on steel and other metals
and alloys, though it can also be used on concrete, wood and
composites, albeit with less resolution. It is used in many
industries including steel and aluminium construction,
metallurgy, manufacturing, aerospace, automotive and other
transportation sector
videos
1-http://youtu.be/UM6XKvXWVFA
5-Motion sensors and
flow measurement
A common ultrasound application is an automatic dooropener,
where an ultrasonic sensordetects a person's approachand
opens the door. Ultrasonic sensors are also used to detect
intruders; the ultrasound can cover a wide area from a single
point. The flow in pipes or open channels can be measured by
ultrasonic flowmeters, which measure the average velocity of

9. 8
flowing liquid. In rheology, an acoustic rheometer relies on the
principle of ultrasound. In fluid mechanics, fluid flow can be
measured using an ultrasonic flow meter.
Videos
1-The Ultrasonic Flow Measuring Principle
http://youtu.be/Bx2RnrfLkQg?list=PLFD0722A576981F74
6-Non-contact sensor
An ultrasonic level or sensing system requires no contact with
the target. For many processes in the medical, pharmaceutical,
military and general industries this is an advantage over inline
sensors that may contaminate the liquids inside a vessel or tube
or that may be clogged by the product.
Both continuous wave and pulsed systems are used. The
principle behind a pulsed-ultrasonic technology is that the
transmit signal consists of short bursts of ultrasonic energy.
After each burst, the electronics looks for a return signal within
a small window of time corresponding to the time it takes for
the energy to pass through the vessel. Only a signal received
during this window will qualify for additional signal
processing.
A popular consumer application of ultrasonic ranging was the
Polaroid SX-70 camera which included a light-weight
transducer system to focus the camera automatically. Polaroid
later licenced this ultrasound technology and it became the
basis of a variety of ultrasonic products.
videos
Ultrasonic Distance Sensor

10. 9
http://youtu.be/XneX8EIL_qk
7-Acoustic microscopy
is the technique of using sound waves to visualize structures too
small to be resolved by the human eye. Frequencies up to
several gigahertz are used in acoustic microscopes. The
reflection and diffraction of sound waves from microscopic
structures can yield information not available with light.
Videos
1- Scanning acoustic microscopyofthyroid - Video abstract
http://youtu.be/ge_LqysqACQ
2- Scanning Acoustic Microscope
http://youtu.be/UmgG7fFA8d8
thank you 

11. 10