HLS-based FPGA Acceleration of Light Propagation Simulation in Turbid Media

Several clinical applications rely on understanding light transport in heterogeneous biological tissues. Researchers usually resort to Monte-Carlo (MC) simulations to model the problem accurately. However, MC simulations require acceleration for better turnaround time, and this motivates the use of Field-Programmable Gate Arrays (FPGAs) to accelerate the algorithm. Nevertheless, the long cycle of developing and verifying FPGA designs makes it challenging to model realistic tissues accurately and smoothly. To this end, we present a complete and highly-optimized MC simulator for light propagation in 3D voxel-based biological tissue representations with floating-point operations using High-Level Synthesis (HLS). We provide practical guidelines in utilizing HLS to create efficient structures that help achieve the desired throughput. We also show where future work is needed to improve HLS. We use Vivado to implement the design on a Xilinx Kintex Ultrascale FPGA running at 150 MHz. With a design time of 1.5 months, experimental results show a 3x speedup against the fastest software simulator published to date.