\[\mathsf{\text {Regurgitant fraction}=\frac{\text{regurgitant volume}}{\text{forward stroke volume}}}\]

\[\mathsf{\text {Regurgitant fraction}= (\frac{\text{regurgitant volume}}{\text{forward stroke volume}}}\ )\times 100\]

RF = (RV / stroke )*100

\[\mathsf{\text {Intensity} (Watts/cm^2)=\frac{\text{Power (Watts)}}{\text{Beam Area }(cm)^2}}\]

\[\mathsf{\text {Doppler shift}=\frac{\text{2 x velocity of blood x incident frequency x cosine angle}}{\text{propagation speed}}}\]