A simulator (10, 1000, 3000) comprising: a physical surrogate for a portion of a simulated human patient, the surrogate having a surface feature of a portion of a human body; a camera system aimed at the surrogate to generate an input video feed; a processor having a program operatively connected to the camera system, wherein the program is programmed to create a simulation of an interaction between at least one object and the simulated patient, the program being programmed to receive the input video feed in real time and to generate an output video feed that comprises at least a visual rendering in real time; and a display operatively connected to the processor and configured to display the output video feed so that the visual rendering is viewable along a line of sight toward a corresponding position of the visual rendering relative to the surrogate; characterised in that the program is further programmed to, in real time: determine, based at least in part on the input video feed, a location of the surrogate and the at least one object, detect an interaction between the at least one object and the surrogate based at least in part on the determined location of the surrogate and the at least one object, generate a simulated hemodynamic consequence of the detected interaction between the at least one object and the surrogate based on a computational model of a human body's hemodynamic system, generate a simulated location and appearance of the simulated hemodynamic consequence on the simulated human patient, identify a portion of the simulated hemodynamic consequence that is not obstructed from a user's view according to the simulation, generate the visual rendering, wherein the visual rendering is of the portion of the appearance of the simulated hemodynamic consequence, and determine, from the simulated location of the simulated hemodynamic consequence, the corresponding position of the visual rendering relative to the surrogate. a physical surrogate for a portion of a simulated human patient, the surrogate having a surface feature of a portion of a human body; a camera system aimed at the surrogate to generate an input video feed; a processor having a program operatively connected to the camera system, wherein the program is programmed to create a simulation of an interaction between at least one object and the simulated patient, the program being programmed to receive the input video feed in real time and to generate an output video feed that comprises at least a visual rendering in real time; and a display operatively connected to the processor and configured to display the output video feed so that the visual rendering is viewable along a line of sight toward a corresponding position of the visual rendering relative to the surrogate; characterised in that the program is further programmed to, in real time: determine, based at least in part on the input video feed, a location of the surrogate and the at least one object, detect an interaction between the at least one object and the surrogate based at least in part on the determined location of the surrogate and the at least one object, generate a simulated hemodynamic consequence of the detected interaction between the at least one object and the surrogate based on a computational model of a human body's hemodynamic system, generate a simulated location and appearance of the simulated hemodynamic consequence on the simulated human patient, identify a portion of the simulated hemodynamic consequence that is not obstructed from a user's view according to the simulation, generate the visual rendering, wherein the visual rendering is of the portion of the appearance of the simulated hemodynamic consequence, and determine, from the simulated location of the simulated hemodynamic consequence, the corresponding position of the visual rendering relative to the surrogate. determine, based at least in part on the input video feed, a location of the surrogate and the at least one object, detect an interaction between the at least one object and the surrogate based at least in part on the determined location of the surrogate and the at least one object, generate a simulated hemodynamic consequence of the detected interaction between the at least one object and the surrogate based on a computational model of a human body's hemodynamic system, generate a simulated location and appearance of the simulated hemodynamic consequence on the simulated human patient, identify a portion of the simulated hemodynamic consequence that is not obstructed from a user's view according to the simulation, generate the visual rendering, wherein the visual rendering is of the portion of the appearance of the simulated hemodynamic consequence, and determine, from the simulated location of the simulated hemodynamic consequence, the corresponding position of the visual rendering relative to the surrogate.