Bleeding simulation is an important visual effect. Real-time bleeding simulation is challenging because of the extensive computations required for blood-solid interactions. This study proposes a simulation method for surgical bleeding based on graphics-processing units (GPUs). The proposed method is derived from the smooth particle hydrodynamics (SPH) proposed by Müller et al. SPH uses the temperature item to generate particles with different speeds and simulate bloodstream. The multi-thread parallel technology compute unified device architecture (CUDA)

which is implemented on GPUs

is used to rapidly solve the control equation of the particle and the blood-solid interactions. Thus

this method allows real-time bleeding based on a uniformly spaced grid. The proposed method can simulate bleeding after a cut. It can also simulate blood flowing over complex obstacles in a surgical simulator. The method only takes 20 ms when the particle number is 9 000 and has 20.15 times faster computation than the central processing unit implementation. Thus

real-time bleeding simulation can be obtained with the method using a large particle number. The proposed method is flexible and capable of simulating real-time surgical bleeding.