% norm_Kass.m
% function calculating time-varying elastance curve
% approximation as described by Stergiopulos et al., Am J Physiol 1996

function [fkass] = norm_Kass(tN)


fkass=28.38975+37.58583*sin(tN*2*pi/3.46+0.08367674)+21.02345*sin(2*tN*2*pi/3.46-1.486758);
fkass=fkass+7.665592*sin(3*2*pi*tN/3.46+2.865675)+4.809436*sin(4*2*pi*tN/3.46+0.1677238);
fkass=fkass+4.181973*sin(5*2*pi*tN/3.46+4.630239)+1.940692*sin(6*2*pi*tN/3.46+3.088379);
fkass=fkass+0.5870049*sin(7*2*pi*tN/3.46-0.3053668)+1.181256*sin(8*2*pi*tN/3.46+4.410703);
fkass=fkass+0.84039*sin(9*2*pi*tN/3.46+3.181538)+0.02259011*sin(10*2*pi*tN/3.46+1.242886);
fkass=fkass+0.3071458*sin(11*2*pi*tN/3.46+4.156753)+0.3226207*sin(12*2*pi*tN/3.46+2.946186);
fkass=fkass/100;