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Ventricular assist devices or total artificial hearts can be used to save patients with heart failure when there are no donors available for heart transplantation. Blood pumps are integral parts of such devices, but traditional axial flow blood pumps have several shortcomings. In particular, they cause hemolysis and thrombosis due to the mechanical contact and wear of the bearings, and they cause blood stagnation due to the separation of the front and rear guide wheel hubs and the impeller hub. By contrast, the implantable axial flow, maglev blood pump has the characteristics of no mechanical contact, no lubrication, low temperature rise, low hemolysis, and less thrombosis. Extensive studies of axial flow, maglev blood pumps have shown that these pumps can function in laminar flow, transitional flow, and turbulent flow, and the working state and performance of such pumps are determined by their support mechanisms and flow channel. Computational fluid dynamics (CFD) is an effective tool for understanding the physical and mechanical characteristics of the blood pump by accurately and effectively revealing the internal flow field, pressure–flow curve, and shear force distribution of the blood pump. In this study, magnetic levitation supports were used to reduce damages to the blood and increase the service life of the blood pump, and a conical impeller hub was used to reduce the speed, volume, and power consumption of the blood pump, thereby facilitating implantation. CFD numerical simulation was then carried out to optimize the structural parameters of the conical axial maglev blood pump, predict the hemolysis performance of the blood pump, and match the flow channel and impeller structure. An extracorporeal circulation simulation platform was designed to test whether the hydraulic characteristics of the blood pump met the physiological requirements. The results showed that the total pressure distribution in the blood pump was reasonable after optimization, with a uniform pressure gradient, and the hemolysis performance was improved.

The positional accuracy of an optical-surgery navigation system is significantly affected by two factors. One is the acquisition synchronism of the two cameras in the system, and the other is the phase difference in image transmission acquired by these cameras. To further enhance image-acquisition synchronism, a field programmable gate array (FPGA)- based synchronous-acquisition method is introduced in this paper. The FPGA control circuit board is independently designed to equalize the length of all data lines, thereby reducing differences in image transmission. Two Complementary Metal Oxide Semiconductors (CMOS) image sensor chips of MT9V032 are also adopted to enable synchronous acquisition in passive acquisition mode. Moreover, the control of exposure time and frame number of MT9V032 under the passive acquisition mode is discussed. Finally, the proposed method is validated and the experimental results the two cameras show h