an overview of ultrasound

1. AN OVERVIEW OF
ULTRASOUND
DONE BY
G.AAKARSH
19331A0340

2. WAVE
• A wave simply means to and fro motion a n
object.

3. TYPES OF WAVES
• Based on the direction of propagation and
displacement of wave particle
EXAMPLE: SOUND EXAMPLE: LIGHT

4. SOUND
• It is a vibrations that travel through the air or
another medium and can be heard when they reach
a person's or animal's ear.
• It requires a medium like air, water or solid to
travel
• Based on frequency sound is divide in the
following

5. ULTRASOUND
• A sound wave with frequency greater than 20,000Hz is
called ultrasound
• Humans (except infants) cannot hear this frequency
hence it has wide range of applications
• Certain animals like bats, etc use this for echolocation
and hunting.
• Due to its high frequency it has a higher penetrating
power which is a main advantage of it for using in
various testing.

6. ULTRASONICS IN MEDICAL FIELD
• Ultrasound has various applications in a variety of fields in
that medical field is one the most important one
• Ultrasound is used across all fields of medical industry in a
variety of ways
• Obstetrical sonography was originally developed in the late
1950s and 1960s by Sir Ian Donald and is commonly used
during pregnancy to check the development and presentation
of the fetus.
• It helps in the prevents any harmful complications during
pregnancy for both the mother and baby
• Echocardiography is an essential tool in cardiology, assisting
in evaluation of heart valve function

7. • Sonography (ultrasonography) is widely used in medicine. It is
possible to perform both diagnosis and therapeutic procedures,
using ultrasound to guide interventional procedures such as
biopsies or to drain collections of fluid, which can be both
diagnostic and therapeutic
• Compared to other medical imaging modalities, ultrasound has
several advantages like it provides images in real-time, is
portable, and can consequently be brought to the bedside. It is
substantially lower in cost than other imaging strategies and does
not use harmful ionizing radiation.

8. ULTRASONIC TESTING
• Ultrasonic testing is a type of nondestructive testing
commonly used to find flaws in materials and to measure
the thickness of objects.
• Ultrasound inspection of welded joints has been an
alternative to radiography for nondestructive testing since
the 1960s
• Ultrasonic inspection eliminates the use of ionizing
radiation, with safety and cost benefits
• In ultrasonic testing, an ultrasound transducer connected to
a diagnostic machine is passed over the object being
inspected

9. • There are two methods of receiving the ultrasound waveform:
reflection and attenuation
• In reflection (or pulse-echo) mode, the transducer performs
both the sending and the receiving of the pulsed waves as the
"sound" is reflected back to the device.
• Reflected ultrasound comes from an interface, such as the
back wall of the object or from an imperfection within the
object. The diagnostic machine displays these results in the
form of a signal with an amplitude representing the intensity
of the reflection and the distance, representing the arrival time
of the reflection
• In attenuation (or through-transmission) mode, a transmitter
sends ultrasound through one surface, and a separate receiver
detects the amount that has reached it on another surface after
traveling through the medium.

10. • Imperfections or other conditions in the space
between the transmitter and receiver reduce the
amount of sound transmitted, thus revealing their
presence
• This type of testing can be done manually and
automatically

11. PIEZOELECTRIC OSCILLATOR
• It is used in the production of ultrasound. It uses piezo
electric crystals like quartz for this purpose
• These crystals have a special property where in when there
are supplied electric in one direction they produce
mechanical movement. The vice versa is also possible.
• Using this property of the crystal as principal in this
oscillator varying frequency electric current is supplied to
the crystal to produce ultrasound with required high
frequency.
• The oscillator has 2 circuits one is oscillatory circuit while
the other is the vibrating circuit.
• A transistor is use to control the frequency of the primary
circuit.

12. Condition for Resonance:

13. MAGNETOSTRICTION OSCILLATOR
• It is another method used for the production of ultrasound
where in an ferromagnetic material like nickel, etc is used for
the purpose
• The principal of working of this oscillator is When a rod of
ferromagnetic material like nickel is magnetized.
Longitudinally, it undergoes a very small change in length.
• And by applying a varying frequency electric field we can get
a required frequency ultrasound.
• It has similar construction as piezo electric oscillator.

14. Condition for Resonance:
Frequency of the oscillator circuit = Frequency of the vibrating rod

15. THANK
YOU