Formulas

• Frequency 


  f(MHz)=c(mm/microseconds)/wavelength(mm)
• period


  T(microseconds)=1/f
• propagation speed 


  C=wavelength x frequency
• wavelength 


  wavelength(mm)= C/F
• power


  P=Amp^2
• intensity 


  I(mW/cm^2)=P(mW)/area(cm^2)
• pulse repetition period

  PRP(ms)=1/PRF(kHz)
• pulse duration 


  PD(microseconds)= period x number of cycles in pulse

  PD= number of cycles in pulse/frequency
• duty factor 


  duty factor= pulse duration(microseconds)/pulse repetition period
• spatial pulse length 


  SPL(mm)= wavelength x number of cycle in pulse
• bandwidth 


  Q factor= operating frequency/bandwidth
• attenuation coefficient 


  attenuation coefficient (dB/cm)= F/2
• total attenuation 


  total attenuation(dB)= attenuation coefficient x distance
• impedance 


  impedance(rayls)= density(kg/m^3) x c(m/s)
• intensity reflection coefficient 


  IRC= reflected intensity(mW/cm^2)/ incident intensity
• IRC with perp. incidence

  IRC=(z^2-z^1/z^2+z^1)^2 = Ir(W/cm^2)/Ii(W/cm^2)
• intensity transmission coefficient formulas

  ITC=1-IRC

  ITC + IRC = 100%

  ITC= transmitted intensity(W/cm^2)/ incident intensity(W/cm^2)

  ITC= It/Ii
• range 


  distance= (propagation speed x pulse round trip time)/2
• distance for soft tissue

  distance=0.777 x time
• PRP and imagining depth

  PRP= imaging depth x 13
• PRF and max imaging depth

  PRF= 77,000/imaging depth