Weeks 1-2 // Introduction & UTZ Physics Flashcards
the ability of a 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
the number of waves that pass a fixed point in unit time; also, the number of cycles or vibrations undergone during one unit of time by a body in periodic motion
frequency
distance from the crest of one wave to the crest of the next wave
wavelength
measures the number of wave cycles (or frequency) passing through a given point in a second
velocity
pattern of disturbance caused by the movement of energy travelling through a medium as it propagates away from the source of the sound
soundwave
refers to any reduction in the strength of a signal
attenuation
resistance to the propagation of ultrasound waves through tissues
acoustic impedance
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
he provides the first published work on medical ultrasonics in Austria in 1942 on transmission ultrasound investigation
Dr. Karl Theodore Dussik
his work in Glasgow in the mid 1950s did much to facilitate the development of practical technology and applications that led to the wider use of ultrasound in medical practice in the subsequence decades
Professor Ian Donald
he is an Italian physicist that uses soundwaves to determine the position of objects that first appeared in the 1794
Lazaro Spallanzani
he studied how bats managed to fly in total darkness and theorized that the nocturnal creatures were dependent on using sound to navigate
Lazaro Spallanzani
they determined that by applying electrical currents to quartz crystal they produce sound, more specifically, ultrasonic waves
Jacques and Pierre Curie
he is a russian physicist that was first to conceptualize using ultrasound for imaging techniques in 1928
Sy Sokolov
he was more interested in using the method to find imperfections in metallic structures than for saving lives through diagnostics
Sy Sokolov
he is an american scientist that was one of the first to use ultrasound imaging techniques
George Ludwig
his research is about gall stones, he turned ultrasound to detect the masses when they were embedded in soft tissue and his analysis in using these soundwaves on animal tissues helped the next scientist down the line
George Ludwig
he was the first to fused ultrasound with diagnostic medicine in 1956
Ian Donald
it is the device held close to the body
transducer
the reflected soundwaves are calculated by a computer and interpreted by a __________
the reflected soundwaves are calculated by a computer and interpreted by a SONOGRAM
the ____ makes sure that there are no air pockets between your skin and the transducer, such air pockets could block the soundwaves and prevent the ultrasound from imaging correctly
the GEL makes sure that there are no air pockets between your skin and the transducer, such air pockets could block the soundwaves and prevent the ultrasound from imaging correctly
ultrasound produces biological effects by two tissue interactions:
heating and cavitation
it is caused by the mechanical friction of the tissue moving during passing of the ultrasonic wave
heating
is the production and collapse of small bubbles in the inter and intracellular tissue fluid
cavitation
is the perimeter of a circle and is also expressed as unit of length
circumference
units of length
km
m
cm
units of area
square meter
square cm
unit of volume
cubic meter
square millimeter
unit of time
seconds
milliseconds
unit of speed
meter per seconds m/s
millimeters per microsecond
unit of powers
watts
unit of work
joule
unit of acoustic impendance
rayls
sonography comes from the latin word ____ and ______
sonography comes from the latin word SONUS and GRAPHIEN
sonus
sound
graphien
to write
it is medical imaging that uses non-ionizing high frequency soundwaves to generate image of a particular structure
sonography
first contact compound B-scanner which uses olive oil as a lubricant was developed
late 1950s
early utz equipment visual displays used _________ which produced bi-stable images
early utz equipment visual displays used OSCILLOSCOPES which produced bi-stable images
gray scale imaging was introduced
1970
real time scanning systems were introduced
mid 1970s
application of doppler technique were introduced
1980s
is a travelling variation in or more quantities such as pressure
wave
_______ are usually produced by something moving back and forth or vibrating
WAVE are usually produced by something moving back and forth or vibrating
two major categories of wave phenomena
mechanical wave
electromagnetic wave
can be transmitted and produced by matter in any form, can travel only through matter
mechanical wave
can travel either through matter or through empty space
electromagnetic wave
waves are divided into two basic types
longitudinal and trasnverse
motion of the particles in a medium is parallel to the direction of wave propagation
longitudinal
motion of the particles in a medium is perpendicular to the direction of wave propagation
transverse
it is a travelling variation of pressure and density
sound
regions of low pressure and density
rarefactions
regions of high pressure and density
compressions
distance between two consecutive identical positions in the wave
wavelength
unit of wavelength
mm
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)
is from the Latin word meaning below
infra
is from the Latin word meaning beyond
ultra
___________ frequency are absorbed more rapidly than lower lower frequencies
HIGHER FREQUENCY are absorbed more rapidly than lower lower frequencies
_________ _________ have shorter wavelength
HIGHER FREQUENCIES have shorter wavelength
_________ ________ can distinguish between reflectors that are closer together
SHORTER WAVELENGTHS can distinguish between reflectors that are closer together
____ ________ have better penetration
LOW FREQUNCIES have better penetration
________ _________ have better spatial resolution but limited penetration
HIGHER FREQUENCIES have better spatial resolution but limited penetration
the time it takes for one cycle to occue
period
ultrasound common unit:
microsecond
period and frequency is _______ proportional
period and frequency is INVERSERLY proportional
period _______ as frequency ________
period DECREASES as frequency INCREASES
refers to the relationship of one wave to another
phase
ultrasound waves whose wave fronts are at the same position
in phase
ultrasound waves whose wave fronts are out of position
out of phase
the interaction of two or more ultrasound beams having different frequency and/or phase
interference
two types of interference
constructive and destructive
it occurs when ultrasound waves of the same frequency are in phase, resulting in increased amplitude and it increases the intensity of the ultrasound beam
constructive interference
it occurs when ultrasound waves of the same frequency are out of phase, resulting in decreased amplitude and this interference contributes to ultrasound attenuation
destructive interference
are measurable quantities that vary within a medium as sound propagates through the medium
acoustic variables
acoustic being derived from greek word for _______
acoustic being derived from greek word for HEARING
4 acoustic variables
pressure
density
particle motion
temperature
amount of force in a given area
pressure
concentration of heat energy
temperature
concentration of matter
density
distance moved by the molecules in the medium
particle motion
it is the maximum variation that occurs in a acoustic variable that also measures of how far variable gets away from its normal, undisturbed value
amplitude
the rate at which work is done or the rate of flow of energy through a given area
power
power per unit area
intensity
speed at which sound moves through a medium
propagation speed
4 sound propagation properties
elasticity
density
bulk modulus
compressibility
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
mass per unit volume
density
reciprocal of compressibility
bulk modulus
stiffness of the medium
bulk modulus
resistance of a material to compression
sitffness
property of a substance which describes how particles of that substance behave when subjected to a soundwave
acoustic impedance
gives the proportion of energy reflected from an interface between two substances
intensity reflection coefficient
fraction of the incident intensity transmitted into the second medium
intensity transmission coefficient
difference in acoustic impedance between two substances
acoustic impedance mismatch
