A computer implemented method for determining a stroke volume of an individual, comprising the steps of: - a) providing a first pulse contour stroke volume (PCSV _uncal) based on one or more characteristics of a measured arterial blood pressure waveform, determining at least one perfusion parameter (BioCal) descriptive for the perfusion through the fat free mass and the adipose mass of a body of the individual, and/or determining at least one fluid responsiveness parameter function f (FRP_norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting (S280, S350) the first pulse contour stroke volume (PCSV_uncal) based on at the least one of the perfusion parameter (BioCal) and/or the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV_imp), or - b) providing a conventionally derived pulse contour stroke volume (PCSV_conv), determining at least one fluid responsiveness parameter function f (FRP _norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting the conventionally derived pulse contour stroke volume (PCSV _conv) based on the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV _imp). - a) providing a first pulse contour stroke volume (PCSV _uncal) based on one or more characteristics of a measured arterial blood pressure waveform, determining at least one perfusion parameter (BioCal) descriptive for the perfusion through the fat free mass and the adipose mass of a body of the individual, and/or determining at least one fluid responsiveness parameter function f (FRP_norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting (S280, S350) the first pulse contour stroke volume (PCSV_uncal) based on at the least one of the perfusion parameter (BioCal) and/or the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV_imp), or determining at least one perfusion parameter (BioCal) descriptive for the perfusion through the fat free mass and the adipose mass of a body of the individual, and/or determining at least one fluid responsiveness parameter function f (FRP_norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting (S280, S350) the first pulse contour stroke volume (PCSV_uncal) based on at the least one of the perfusion parameter (BioCal) and/or the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV_imp), or - b) providing a conventionally derived pulse contour stroke volume (PCSV_conv), determining at least one fluid responsiveness parameter function f (FRP _norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting the conventionally derived pulse contour stroke volume (PCSV _conv) based on the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV _imp). determining at least one fluid responsiveness parameter function f (FRP _norm) depending on a fluid responsiveness parameter (FRP _norm) descriptive for a heart-lung interaction of the individual, and adjusting the conventionally derived pulse contour stroke volume (PCSV _conv) based on the fluid responsiveness parameter function f (FRP_norm) to provide a second pulse contour stroke volume (PCSV _imp).