The wide acceptance and data deluge in medical imaging processing require faster and more efficient systems to be built.Due to the advances in heterogeneous architectures recently,there has been a resurgence in the fi...The wide acceptance and data deluge in medical imaging processing require faster and more efficient systems to be built.Due to the advances in heterogeneous architectures recently,there has been a resurgence in the first research aimed at FPGA-based as well as GPGPU-based accelerator design.This paper quantitatively analyzes the workload,computational intensity and memory performance of a single-particle 3D reconstruction application,called EMAN,and parallelizes it on CUDA GPGPU architectures and decouples the memory operations from the computing flow and orchestrates the thread-data mapping to reduce the overhead of off-chip memory operations.Then it exploits the trend towards FPGA-based accelerator design,which is achieved by offloading computingintensive kernels to dedicated hardware modules.Furthermore,a customized memory subsystem is also designed to facilitate the decoupling and optimization of computing dominated data access patterns.This paper evaluates the proposed accelerator design strategies by comparing it with a parallelized program on a 4-cores CPU.The CUDA version on a GTX480 shows a speedup of about 6 times.The performance of the stream architecture implemented on a Xilinx Virtex LX330 FPGA is justified by the reported speedup of 2.54 times.Meanwhile,measured in terms of power efficiency,the FPGA-based accelerator outperforms a 4-cores CPU and a GTX480 by 7.3 times and 3.4 times,respectively.展开更多
Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional C...Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The threedimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the threedimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction （total reduction, half reduction and non-reduction） were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws. Results： Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate. Conclusion： The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.展开更多
基金Supported by the National Basic Research Program of China(No.2012CB316502)the National High Technology Research and DevelopmentProgram of China(No.2009AA01A129)the National Natural Science Foundation of China(No.60921002)
文摘The wide acceptance and data deluge in medical imaging processing require faster and more efficient systems to be built.Due to the advances in heterogeneous architectures recently,there has been a resurgence in the first research aimed at FPGA-based as well as GPGPU-based accelerator design.This paper quantitatively analyzes the workload,computational intensity and memory performance of a single-particle 3D reconstruction application,called EMAN,and parallelizes it on CUDA GPGPU architectures and decouples the memory operations from the computing flow and orchestrates the thread-data mapping to reduce the overhead of off-chip memory operations.Then it exploits the trend towards FPGA-based accelerator design,which is achieved by offloading computingintensive kernels to dedicated hardware modules.Furthermore,a customized memory subsystem is also designed to facilitate the decoupling and optimization of computing dominated data access patterns.This paper evaluates the proposed accelerator design strategies by comparing it with a parallelized program on a 4-cores CPU.The CUDA version on a GTX480 shows a speedup of about 6 times.The performance of the stream architecture implemented on a Xilinx Virtex LX330 FPGA is justified by the reported speedup of 2.54 times.Meanwhile,measured in terms of power efficiency,the FPGA-based accelerator outperforms a 4-cores CPU and a GTX480 by 7.3 times and 3.4 times,respectively.
文摘Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The threedimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the threedimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction （total reduction, half reduction and non-reduction） were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws. Results： Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate. Conclusion： The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.
