From 1997 to 1999, we developed a spiral blood pump. The spiral pump consists of a brushless DC motor, the pump housing, a magnetic-fluid seal, bearings and a spiral impeller. The maximum diameter of the impeller is 2...From 1997 to 1999, we developed a spiral blood pump. The spiral pump consists of a brushless DC motor, the pump housing, a magnetic-fluid seal, bearings and a spiral impeller. The maximum diameter of the impeller is 21.8 mm and minimum is 9.8 mm, the cone angle of the impeller threads is 41.8 degrees. The housing has a maximum diameter of 30 mm. The pump was made from Titanium alloy, the total volume of pump housing and motor was 76 ml and its weight 220g. Methods used: The hydrodynamic performance of the spiral pump was examined from 8 000 to 10 000rpm rotation speeds in a closed circuit loop. This circuit consists of a reservoir, a clamp, two pressure transducers, an electric-magnetic flow rate transducer and glycerin-water solution. The damage test to blood was studied in a smaller circuit loop, that used fresh sheep blood and polyvinyl chloride bag instead of the glycerin-water solution and the reservoir. In this test, the damage of the spiral pump was compared with an axial flow blood pump. Furthermore the simulated condition was 5.0 L/ min flow rate and 100 mmHg pressure. Summarize Results: 1. The flow rate was 4.0 L/min against 120 mmHg pressure when pump rotated 10000 rpm. So the hydrodynamic performance of the spiral blood pump was enough to meet a patient’s need when the blood pump was used as a left ventricular assistant device. 2. The NIH results of three gaps were 0.074±0.022g/100L,0.086±.026g/100L and 0.111±0.034g/100L(n=40) respectively. The best hemolysis result was been at the gap of 0.14 mm. 3. The NIH result of the spiral pump with 0.40gap was 0.111±0.034g/100L, n=40; and the axial flow pump was 0.131±0.030g/100L, n=40 respectively; The mean fibrinogen decreases of two pumps between half of an hour were 4.281±2.098mg/100L and 9.625±5.630mg/100L(n=40). So we can conclude that the damage of the spiral pump to blood was less than the axial flow pump. (P<0.05).展开更多
The current research of hydrodynamic bearing in blood pump mainly focuses on the bearing structure design.Compared with the typical plane slider bearing and Rayleigh step bearing,spiral groove bearing has excellent pe...The current research of hydrodynamic bearing in blood pump mainly focuses on the bearing structure design.Compared with the typical plane slider bearing and Rayleigh step bearing,spiral groove bearing has excellent performance in load-carrying capacity.However,the load-carrying capacity would decrease significantly with increasing flow rate in conventional designs.In this paper,the special treatment is made to the upper spiral groove bearing to make sure that both the circulatory flowing and load-carrying capacity are high.Three-dimensional computational fluid dynamics(CFD) models in the space between rotor and shaft are developed by using FLUENT software.Effects of groove number,film height and groove depth on load-carrying capacity of the spiral groove bearings are investigated by orthogonal experiment design.The experimental results show that film height is the most remarkable factor to the load-carrying capacity.The variation tendency of load-carrying capacity reveals that the best combination of geometry is the one with groove number of 8,film height 0.03 mm and groove depth 0.08 mm.The velocity and pressure distributions in spiral groove bearings are also analyzed,and the analysis result shows that the distributions are in conformity with the design of the blood pump based on the principle of hydrodynamic bearing.The displacement of the rotor with the best combination parameters is tested by using laser displacement sensors,the testing result shows that the suspending performance is satisfactory both in axial and radial directions.This research proposes a bearing design method which has sufficient load-carrying capacity to support rotor as an effective passive hydrodynamic bearing.展开更多
基金The project was support by National Nine- Five Years Foundation
文摘From 1997 to 1999, we developed a spiral blood pump. The spiral pump consists of a brushless DC motor, the pump housing, a magnetic-fluid seal, bearings and a spiral impeller. The maximum diameter of the impeller is 21.8 mm and minimum is 9.8 mm, the cone angle of the impeller threads is 41.8 degrees. The housing has a maximum diameter of 30 mm. The pump was made from Titanium alloy, the total volume of pump housing and motor was 76 ml and its weight 220g. Methods used: The hydrodynamic performance of the spiral pump was examined from 8 000 to 10 000rpm rotation speeds in a closed circuit loop. This circuit consists of a reservoir, a clamp, two pressure transducers, an electric-magnetic flow rate transducer and glycerin-water solution. The damage test to blood was studied in a smaller circuit loop, that used fresh sheep blood and polyvinyl chloride bag instead of the glycerin-water solution and the reservoir. In this test, the damage of the spiral pump was compared with an axial flow blood pump. Furthermore the simulated condition was 5.0 L/ min flow rate and 100 mmHg pressure. Summarize Results: 1. The flow rate was 4.0 L/min against 120 mmHg pressure when pump rotated 10000 rpm. So the hydrodynamic performance of the spiral blood pump was enough to meet a patient’s need when the blood pump was used as a left ventricular assistant device. 2. The NIH results of three gaps were 0.074±0.022g/100L,0.086±.026g/100L and 0.111±0.034g/100L(n=40) respectively. The best hemolysis result was been at the gap of 0.14 mm. 3. The NIH result of the spiral pump with 0.40gap was 0.111±0.034g/100L, n=40; and the axial flow pump was 0.131±0.030g/100L, n=40 respectively; The mean fibrinogen decreases of two pumps between half of an hour were 4.281±2.098mg/100L and 9.625±5.630mg/100L(n=40). So we can conclude that the damage of the spiral pump to blood was less than the axial flow pump. (P<0.05).
基金supported by National Natural Science Foundation of China(Grant No.51275461)Zhejiang Provincial Natural Science Foundation of China(Grant No.Z1110189)+1 种基金National Hi-tech Research and Development Program of China(863 ProgramGrant No.2009AA045401)
文摘The current research of hydrodynamic bearing in blood pump mainly focuses on the bearing structure design.Compared with the typical plane slider bearing and Rayleigh step bearing,spiral groove bearing has excellent performance in load-carrying capacity.However,the load-carrying capacity would decrease significantly with increasing flow rate in conventional designs.In this paper,the special treatment is made to the upper spiral groove bearing to make sure that both the circulatory flowing and load-carrying capacity are high.Three-dimensional computational fluid dynamics(CFD) models in the space between rotor and shaft are developed by using FLUENT software.Effects of groove number,film height and groove depth on load-carrying capacity of the spiral groove bearings are investigated by orthogonal experiment design.The experimental results show that film height is the most remarkable factor to the load-carrying capacity.The variation tendency of load-carrying capacity reveals that the best combination of geometry is the one with groove number of 8,film height 0.03 mm and groove depth 0.08 mm.The velocity and pressure distributions in spiral groove bearings are also analyzed,and the analysis result shows that the distributions are in conformity with the design of the blood pump based on the principle of hydrodynamic bearing.The displacement of the rotor with the best combination parameters is tested by using laser displacement sensors,the testing result shows that the suspending performance is satisfactory both in axial and radial directions.This research proposes a bearing design method which has sufficient load-carrying capacity to support rotor as an effective passive hydrodynamic bearing.
