Formulas and Math Facts Flashcards
What is the equation for Velocity (estimated)?
Ve= deltaF * C / 2 * Fo * (Cos 0)
What is the equation for delta F?
delta F= 2 * Fo * (Cos O) / C
What is the BUC relationship?
SP
BUC | SA
What is the Duty Factor Relationship regarding temporal peaks and averages?
TA
DF | TP
What is the Intensity equation?
Intensity= amplitude 2 / 2 p V
what does p represent?
Density
What does V represent?
speed or velocity
What does C represent?
the propagation speed in of sound
not always in soft tissue
What is the propagation speed of sound in soft tissue?
1540 m/s
What PRF is required to avoid aliasing?
2 X the highest frequency shift
what is the relationship between PRP and PRF
They are reciprocals
PRP=1/PRF
PRF= 1/PRP
If your PRP is 0.5 seconds, what is your PRF?
If the Pulse repetition period is 1/2 second, the two pulses can occur in one second. The PRF is a frequency of repetition, so report it as 2Hz
how do you calculate Pulse Duration? (PD)
PD = (cpp) (period)
how do you calculate CPP (cycles per pulse)?
CPP = PD * F
What is the Duty Factor Relationship regarding PRP and PD?
PD
DF | PRP
(or DF = PD * PRF)
What is the equation to determine Quality Factor?
Fo
QF | B/W
What is the equation to derive the wave length of a frequency?
C / f
What is the equation to calculate IRC?
z2-z1
z2+z1 Squared x 100
or reflected intensity / incident intensity X 100
What is the equation to calculate ITC?
1 - IRC
What are the rules for oblique angles?
if:
V2 > V1, then t > i
V2 < V1, then t , i
rule of thumb: relate to the second medium:
if v2 bigger, angle t is bigger
if v2 smaller, angle t is smaller
which equation will you use to calculate IRC with intensity info and which with impedence info?
reflected / incident X 100 for intensities
z2-z1
z2+z1 squared X 100 for Impedences
which measurement parameter best predicts tissue heating?
SPTA
What is the upper limit of safe exposure to sound energy?
100mW/cm2, unfocused
which measurement parameter best predicts tissue cavitation?
SPTP
What is the attenuation equation?
attenuation = 0.5 X CM X MHz
What is the relationship for wavelength?
C
wavelength | F
