Def/Formulas- Parameters Flashcards
Time it takes a wave to vibrate a single cycle; from the start of one cycle to the start of the next cycle
Period
of particular events that occur in a specific duration of time
Frequency
The bigness of a wave
Amplitude
Rate at which work is performed or rate of energy transfer; also bigness of wave
Power
Concentration of energy in a sound beam
Intensity
Distance or length of one complete cycle
Wavelength
Rate at which sound wave travels through a medium
Speed
The actual time from start of a pulse to the end of that pulse
Pulse duration
The time for the start of one pulse to the start of the next pulse
Pulse repetition period
Number of pulses that an ultrasound system transmits into the body each second
Pulse repetition frequency
Distance that a pulse occupies in a space from the start to the end of a pulse
Spatial pulse length
Percentage or fraction of time that the system transmits a pulse
Duty factor
Qualities of shallow imaging:
- less listening
- shorter PRP
- higher PRF
- higher duty factor
Qualities of Deep Imaging:
- more listening
- longer PRP
- lower PRF
- lower duty factor
Formula for intensity
W/cm^2
Power (W)
——————
Area (cm^2)
When amplitude is doubled, the intensity is____
Increased 4x
Formula for wavelength
1.54 mm or us
————————
Frequency (MHz)
Formula for speed
Frequency (Hz) x wavelength (m)
Two characteristics that affect speed and sound
Stiffness and density
What is the speed of sound traveling through soft tissue?
Avg= 1,540 m/s
Formula for pulse duration
of cycles x period (us)
OR
of cycles/ frequency (MHz)
Formula for SPL (spatial pulse length)
of cycles in each pulse x wavelength of each cycle (mm)
What is the relationship of pulse repetition period and pulse repetition frequency?
PRP and PRF are inversely related/ reciprocals
PRF= 1/PRP
PRP= 1/PRF
PRP x PRF = 1
Formula for duty factor
DF%= Pulse duration/ Pulse rep period (100)
