Physics Flashcards
the ability of certain materials to generate an electric charge in response to applied mechanical stress.
PIEZOELECTRIC EFFECT
the speed and the direction of motion of an object.
velocity
measures the number of wave cycles (or frequency) passing through a given point in a second.
velocity
the number of waves that pass a fixed point in unit time
frequency
the number of cycles or vibrations undergone during one unit of time by a body in periodic motion
frequency
distance from the “crest” (top) of one wave to the crest of the next wave
wavelength
peak of a wave
crest
λ is called the
lambda
pattern of disturbance caused by the movement of energy traveling through a medium as it propagates away from the source of the sound
sound wave
refers to any reduction in the strength of a signal
attenuation
echoes and vibrations are produced when sound waves are:
reflected or reflection
sound waves penetrate and produce
heat
used to describe the reflection and transmission of acoustic waves at interfaces of two materials with mismatched impedances
acoustic mismatch
the subjective perception of sound pressure
sound intensity notation
Italian physicist who used soundwaves to determine position of objects
LAZARO SPALLAZANI
who studied about bats who used sound to navigate?
LAZARO SPALLAZANI
when was sound waves as navigating tool discovered?
1794
who invented first machine that could generate soundwaves ?
JACQUES AND PIERRE CURIE
when did the french scientist discovered that the electrical currents to quartz crystal they produce sound, more specifically, ultrasonic waves?
1880
russian physicist who conceptualize using ultrasound for imaging techniques
SY SOKOLOV
When the physicist of russia used the method to find imperfections in metallic structures than for saving lives through diagnostics?
1928
who was the first to use ultrasound imaging techniques?
GEORGE LUDWIG
when was the sound waves first used as an imaging technique to detect gallstones and masses/
1949
Who discovered the transmission ultrasound investigation of the brain provides the first published work on medical ultrasonics?
DR. KARL THEODORE DUSSIK
when did dr. karl theodore dussik discovered the transmission ultrasound investigation of the brain ?
1942
Who first used ultrasound with diagnostic medicine?
IAN DONALD [haha bitch credit grabber]
who used the device was to determine the diameter of the head of a fetus?
IAN DONALD
When was the first use of the device was to determine the diameter of the head of a fetus discovered?
1956
hand geld device thatcontains special crystals that can create soundwaves when they are activated with an electrical field.
transducers
the soundwaves are received by a transducer because these waves are ______ by the body tissues?
reflected
what device interprets the soundwaves?
sonogram
where were soundwaves calculated and viewed?
computer
what device can generate an image based on the data?
sonogram
a medium that reduces the space(air) between the waves and the body.
gel
what should be avoided which could block the soundwaves and prevent the ultrasound from imaging correctly?
air pockets
caused by the mechanical friction of the tissue moving during passing of the ultrasonic wave
heating
production of bubbles
cavitation
helps examine retrograde organs (posteriorly positioned organs)
transrectal examitation
type of radiation used in utz
non-ionizing radiation — high frequency sound waves
perimeter of a circle
distance/circumference
unit of area
cm2, m2
units of length
km, m , cm
units of volume
m3, mm3
time unit
s, ms
speed units
m/s, mm/microsecond
power unit
watts
unit of work
joules
acoustic impedance unit
rayls
true or false: the greek word for sound is sonus
false
greek word for write
graphien
other terms of ultrasound
sonography
when was the patient being scanned in a water bath?
early 1950s
The first contact compound B-scanner which uses olive oil as a lubricant was developed. Single crystal transducer mounted on an articular arm
late 1950s
Gray scale imaging was introduced. Early ultrasound equipment visual displays used oscilloscopes which produced bi-stable (black and white) images.
1970
when were real time scanning systems were introduced.
mid 1970
when was the application of doppler techniques were introduced
1980
produced by something moving back and forth, or vibrating
waves
Can be transmitted and produced by matter in any form; solid, liquid, or gas.
MECHANICAL WAVE
Can travel either through matter or through empty space.
electromagnetic wave
longitudinal waves travels ______ to the direction of wave propagation
parallel
motion of the particles in a medium is parallel to the direction of wave propagation.
LONGITUDINAL WAVES
motion of the particles in a medium is perpendicular to the direction of wave propagation.
TRANSVERSE
transverse waves travels ______ to the direction of wave propagation
perpendicular
Regions of LOW pressure and density
rarefactions
compressions are regions that has _____ density and pressure
high
unit of wavelength
mm
distance between two (2) consecutive identical positions in the wave.
wavelength
the number of cycles per second performed by the particles in the medium in response to wave passing through it.
frequency
unit of frequency
hertz (Hz)
Hz formula
cycles/seconds
maximum frequency range of audible soundwaves
20,000Hz
Ultrasound in diagnostic medicine frequency range
20,000-3,000,000 Hz
latin word for below
infra
latin word for beyond
ultra
time it takes for one cycle to occur.
period
unit of period
µs/ microsecond
relationship of frequency and period
inversed
high frequency = __ absorption
high
high frequency = ___ penetration
low
high frequency = _____ spatial resolution
high
high frequency = ____period
short
low frequency = ____ wavelength
high
high wavelength = _____spatial resolution
low
low penetration = _____ wavelength
low
high penetration = _____ frequency
low
refers to the relationship of one wave to another
phase
Ultrasound waves whose wavefronts are at the SAME position
in phase
Ultrasound waves whose wavefronts differ from one to the other
out of phase
Occurs when ultrasound waves of the same frequency are in phase, resulting in increased amplitude. It increases the intensity of the ultrasound beam.
CONSTRUCTIVE INTERFERENCE
Occurs when ultrasound waves of the same frequency are out of phase, resulting in decreased amplitude. This Interference contributes to ultrasound attenuation.
destructive interference
measurable quantities that vary within a medium as sound propagates through the medium
acoustic variable
acoustic is greek word for
hearing
Amount of force in a given area
pressure
pressure unit
pascal (pounds per square inch (lbs/sq. in) and (N/m2))
Concentration of matter
density
density unity
Unit: kg/m3 or g/cm3
Concentration of heat energy
temperature
unit of temperature
celsius, Fahrenheit kelvin
distance moved by the molecules in the medium.
particle motion
unit of particle motion
nm
maximum variation that occurs in an acoustic variable
amplitude
measure of how far variable gets away from its normal, undisturbed value.
amplitude
height of wave
amplitude
The rate at which work is done or the rate of flow of energy through a given area.
power
unity of intensity
W/cm2
high intensity = ___ power
high
high area = ____ intensity
low
Speed at which sound moves through a medium
propagation speed
wavelength x frequency
propagation speed
unit of propagation speed
m/s or mm/µs
Refers to the ability of an object to return to its original shape and volume after a force is no longer acting on it.
elasticity
Indicates the fractional decrease in volume when pressure is applied to the material.
compressibility
Reciprocal of compressibility
bulk modulus
bulk modulus is also known as
stiffness
Resistance of a material to compression.
stiffness
which is the fastest type of matter to propagate sound
solid; because it is denser
same acoustic impedance of substances produce
total transmission of energy (100%0 and no reflections
Property of a substance, which describes how particles of that substance behave when subjected to a soundwave
acoustic impedance
what happens when substance with small difference in acoustic impedance
small amount of energy is reflected ( 1 to 5%) and majority is transmitted ( 95 - 99%)
In substance with bigger difference in acoustic impedance
large amount is refelected (40 - 90%) and small amount is transmitted (1 - 60%)
Gives the proportion of energy reflected from an interface between two substances
intensity reflection coefficient
intensity reflection coefficient formula
((secondary Z - primary Z)^2)/ (secondary Z - primary Z)^2)
Fraction of the incident intensity transmitted into the second medium
INTENSITY TRANSMISSION COEFFICIENT
INTENSITY TRANSMISSION COEFFICIENT formula
(4 x primary Z x Secondary Z)/ (sum of Zs)^2
percentage of energy reflected from soft tissues
1% or less
