Term
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Definition
| rate that work is performed, or rate of energy transfer |
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Term
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Definition
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Term
| sound source and attenuation |
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Definition
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Term
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Definition
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Term
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Definition
| If amplitude increases, power ______. |
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Term
| power = intensity = amplitude^2 |
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Definition
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Term
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Definition
| length a single wave occupies |
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Term
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Definition
| typical value of wavelength |
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Term
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Definition
| wavelength is determined by: |
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Term
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Definition
| Is wavelength adjustable? |
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Term
wavelength = propagation speed/frequency
λ = c/f
λ = 1.54mm/µs / frequency(MHz) |
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Definition
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Term
frequency decreases
penetration increases
resolution decreases |
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Definition
| When wavelength goes increases, frequency _______, penetration ________, and resolution _________. |
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Term
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Definition
| percentage/fraction of time that the system transmits a pulse |
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Term
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Definition
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Term
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Definition
| typical values of duty factor |
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Term
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Definition
| duty factor is determined by: |
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Term
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Definition
| Is duty factor adjustable? |
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Term
| duty factor(%) = pulse durations / PRP x 100 |
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Definition
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Term
depth decreases
PRF increases
PRP decreases |
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Definition
| If duty factor increases, depth _____, PRF _______, and PRP ________. |
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Term
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Definition
| the difference between average and maximum value of an acoustic variable |
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Term
pressure (Pa)
density (g/cm^3)
distance |
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Definition
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Term
|
Definition
| typical values of amplitude |
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Term
| sound source and attenuation |
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Definition
| amplitude is determined by: |
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Term
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Definition
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Term
| amplitude^2 = power = intensity |
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Definition
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Term
|
Definition
| number of cycles per second |
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Term
|
Definition
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Term
|
Definition
| frequency is determined by: |
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Term
|
Definition
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Term
|
Definition
| typical values of frequency |
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Term
penetration decreases
resolution increases |
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Definition
| If frequency increases, penetration ______ and resolution _______. |
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Term
f = 1/P
frequency x period = 1 |
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Definition
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Term
|
Definition
| time from beginning to end of a pulse; 'on' time only |
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Term
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Definition
| typical value for pulse duration |
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Term
|
Definition
| pulse duration is determined by: |
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Term
|
Definition
| Is pulse duration adjustable? |
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Term
duration(µs) = #cycles x period(µs)
duration(µs) = #cycles / frequency(MHz) |
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Definition
| equations for pulse duration |
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Term
period increases
frequency decreases
number of cycles increases
accuracy decreases |
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Definition
| If pulse duration increases, period ______, frequency ________, #cycles ________, accuracy _________. |
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Term
| pulse repetition period (PRP) |
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Definition
| time from the start of one pulse to the start of the next, including 'on' and 'off' time |
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Term
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Definition
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Term
| sound source and imaging depth |
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
depth increases
PRF decreases |
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Definition
| If PRP increases _________, depth _______ and PRF ________. |
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Term
|
Definition
| concentration of energy in a sound beam |
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Term
|
Definition
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Term
| sound source and attenuation |
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Definition
| intensity is determined by: |
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Term
|
Definition
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Term
| intensity = power(W) / beam area(cm^2) |
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Definition
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Term
amplitude increases
power increases |
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Definition
| If intensity increases, amplitude ______ and power ________. |
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Term
| pulse repetition frequency (PRF) |
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Definition
| number of pulses in one second |
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Term
|
Definition
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Term
| sound source and imaging depth |
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Definition
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Term
|
Definition
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|
Term
PRP decreases
depth decreases |
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Definition
| If PRF increases, PRP _______ and depth ______. |
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Term
|
Definition
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Term
| spatial pulse length(SPL) |
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Definition
| length or distance a pulse occupies in space, from the start to the end of a pulse |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
|
|
Term
| SPL(mm) = #cycles x λ(mm) |
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Definition
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Term
#cycles in pulse increases
wavelength increases
frequency decreases
resolution decreases |
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Definition
| When SPL increases, #cycles _____, wavelength _____, frequency _______, and resolution ________. |
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Term
|
Definition
| the length of time it takes to complete one cycle |
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Term
|
Definition
| typical values for period |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
|
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Term
|
Definition
| distance a soundwave travels through a medium in one second |
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Term
|
Definition
| propagation speed is determined by: |
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Term
propagation speed = frequency x wavelength
c = f(Hz) x λ(m) |
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Definition
| equation for propagation speed |
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Term
stiffness increases
density decreases
compressibility decreases
elasticity decreases
bulk modulus increases |
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Definition
| If propagation speed increases, stiffness ______, density _______, compressibility ______, elasticity _______, and bulk modulus ________. |
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Term
amplitude
power
intensity
PRP
PRF
duty factor |
|
Definition
| Which parameters are adjustable? |
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Term
period
frequency
amplitude
power
intensity
pulse duration
PRP
PRF
duty factor |
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Definition
| Which parameters are determined by sound source only? |
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Term
SPL
wavelength
propagation speed |
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Definition
| Which parameters are determined by the medium? |
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Term
|
Definition
| peaks and troughs of two waves occur simultaneously and interfere constructively |
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Term
|
Definition
| A sound wave is identified when there are rhythmical oscillations within these variables: |
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Term
|
Definition
| peaks and troughs of two waves occur at different times, interfering destructively |
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Term
|
Definition
| when two waves overlap each other at the same instant at the same location, creating a new single wave; can be constructive or destructive |
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Term
|
Definition
| propagation speed through brain |
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Term
|
Definition
| propagation speed through metals |
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Term
|
Definition
| propagation speed through tendon |
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Term
|
Definition
| propagation speed through muscle |
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Term
|
Definition
| propagation speed through liver and kidney |
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Term
|
Definition
| propagation speed through fat |
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Term
|
Definition
| propagation speed through bone |
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Term
|
Definition
| propagation speed through lung |
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Term
|
Definition
| propagation speed through air |
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Term
|
Definition
| propagation speed through water |
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Term
|
Definition
| propagation speed through soft tissue |
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Term
|
Definition
| physics term used to describe the type of energy used to produce a sonographic image |
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Term
ultrasound > 20,000Hz
audible sound 20-20,000 HZ
infrasound < 20 Hz |
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Definition
| What is the frequency range for ultrasound? For audible sound? For infrasound? |
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Term
|
Definition
| a coordinated disturbance moving at a fixed speed through a medium |
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Term
|
Definition
| Is sound a longitudinal or transverse wave? |
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Term
| acoustic propagation properties |
|
Definition
| the effects of the biologic tissue upon the sound wave |
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Term
|
Definition
| the effects of the sound wave upon the biologic tissue through which it passes |
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Term
|
Definition
| the difference between the maximum and minimum values of an acoustic variable |
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