AIM: To analyze whether wet-lab training(WLT) or surgical-simulator training(SST) is better for ophthalmology residents to master the chopping technique.METHODS: Sixty ophthalmology residents(in their second year) and...AIM: To analyze whether wet-lab training(WLT) or surgical-simulator training(SST) is better for ophthalmology residents to master the chopping technique.METHODS: Sixty ophthalmology residents(in their second year) and three cataract surgeons participated in the study. The residents were randomly separated into two groups, WLT group and SST group. The residents in WLT group were asked to perform 10 trials of chopping using pig eyes and scored by the surgeons, and then they performed and scored using simulator for one time. The residents in SST group underwent 10 trials of chopping using simulator, and the simulator scored each trail. Then, this group were asked to perform the chopping using pig eyes and scored by the surgeons. At last, we investigated the residents’ satisfaction about the training.RESULTS: The demographic characteristics had no significant differences between the two groups. Recorded by the simulator, the residents in SST group got significantly higher overall score(83.90±1.31) than WLT group(78.73±1.92, P=0.03). And the residents in SST group got less corner area injured, and they spend less time than WLT group(P<0.05). Moreover, the residents in WLT group used more ultrasonic energy value than SST group(P=0.03). However, scored by the surgeons, the residents in two groups got nearly the same overall score. The residents in WLT group performed better on the frequencies of posterior capsule torn and incisional stress(P=0.03, 0.008, respectively). In the survey, the residents in two groups held the same opinion that the training was helpful and they strongly recommended this training. And all of them enjoyed the training, and enjoyed being randomized in their own group. However, with respect to the realistic character, the residents thought that WLT was better than SST(P<0.001).CONCLUSION: Both of the Eyesi surgical-stimulator and the wet-lab improve the residents’ chopping ability and each has its own advantages. The combination of the two training ways could be considered to be a part of the training curriculum for new residents.展开更多
A onvel current chopping strategy for switched reluc-tance generator(SRG)-a full conducted current chopping(FCCC)scheme is presented,According to characteristics lf phase current wave of SRG generating operation,it ca...A onvel current chopping strategy for switched reluc-tance generator(SRG)-a full conducted current chopping(FCCC)scheme is presented,According to characteristics lf phase current wave of SRG generating operation,it can be generated under sensorless condition without an addi-tional circuit or a position signal algorithm.Simulational results show the feasibility of this scheme.Experimental results of a 6kW6/4configuration SRG show its simplic-ity and high reliability with little decrease in efficiency.Soit will be widely used.展开更多
A novel current chopping mode was used in a switched reluctance motor drive system to make full use of the characteristics of digital signal processor (DSP) TMS320F240. The necessity of this 180° phase-shift curr...A novel current chopping mode was used in a switched reluctance motor drive system to make full use of the characteristics of digital signal processor (DSP) TMS320F240. The necessity of this 180° phase-shift current control (PSCC) mode is introduced first and then the principle of PSCC covering both hardware requirement and software programming is described in detail. The analysis made indicated that with this mode, the chopping frequency in winding can reach 20 kHz with 10 kHz power switches and the control frequency can reach 40 kHz at the same time. Subsequently, based on the linear and nonlinear mathematical models of the switched reluctance motor (SRM), some simulation work has been done. The simulation results show that when this mode is applied to SRM drive (SRD) system, the current waveform becomes better. So the ripple of the torque is reduced simultaneously and the vibration and acoustic noise are reduced involuntarily. Stationary tests show that the acoustic noise is greatly diminished. Finally, some experiments were made using a 50 kW SRD system for electric vehicle (EV). Experimental results indicate that this mode can be implemented feasibly and it has a good action on the SRD system.展开更多
基金Supported by Natural Science Foundation Grant from Jiangxi Science and Technology Department (No.20192BAB205049)Young Talent Scholar Grant (No.2016KJXX-12)from Shaanxi Science and Technology Department, Teaching Reform Grant (No.JC2020-0309,No.JG20190330)。
文摘AIM: To analyze whether wet-lab training(WLT) or surgical-simulator training(SST) is better for ophthalmology residents to master the chopping technique.METHODS: Sixty ophthalmology residents(in their second year) and three cataract surgeons participated in the study. The residents were randomly separated into two groups, WLT group and SST group. The residents in WLT group were asked to perform 10 trials of chopping using pig eyes and scored by the surgeons, and then they performed and scored using simulator for one time. The residents in SST group underwent 10 trials of chopping using simulator, and the simulator scored each trail. Then, this group were asked to perform the chopping using pig eyes and scored by the surgeons. At last, we investigated the residents’ satisfaction about the training.RESULTS: The demographic characteristics had no significant differences between the two groups. Recorded by the simulator, the residents in SST group got significantly higher overall score(83.90±1.31) than WLT group(78.73±1.92, P=0.03). And the residents in SST group got less corner area injured, and they spend less time than WLT group(P<0.05). Moreover, the residents in WLT group used more ultrasonic energy value than SST group(P=0.03). However, scored by the surgeons, the residents in two groups got nearly the same overall score. The residents in WLT group performed better on the frequencies of posterior capsule torn and incisional stress(P=0.03, 0.008, respectively). In the survey, the residents in two groups held the same opinion that the training was helpful and they strongly recommended this training. And all of them enjoyed the training, and enjoyed being randomized in their own group. However, with respect to the realistic character, the residents thought that WLT was better than SST(P<0.001).CONCLUSION: Both of the Eyesi surgical-stimulator and the wet-lab improve the residents’ chopping ability and each has its own advantages. The combination of the two training ways could be considered to be a part of the training curriculum for new residents.
文摘A onvel current chopping strategy for switched reluc-tance generator(SRG)-a full conducted current chopping(FCCC)scheme is presented,According to characteristics lf phase current wave of SRG generating operation,it can be generated under sensorless condition without an addi-tional circuit or a position signal algorithm.Simulational results show the feasibility of this scheme.Experimental results of a 6kW6/4configuration SRG show its simplic-ity and high reliability with little decrease in efficiency.Soit will be widely used.
文摘A novel current chopping mode was used in a switched reluctance motor drive system to make full use of the characteristics of digital signal processor (DSP) TMS320F240. The necessity of this 180° phase-shift current control (PSCC) mode is introduced first and then the principle of PSCC covering both hardware requirement and software programming is described in detail. The analysis made indicated that with this mode, the chopping frequency in winding can reach 20 kHz with 10 kHz power switches and the control frequency can reach 40 kHz at the same time. Subsequently, based on the linear and nonlinear mathematical models of the switched reluctance motor (SRM), some simulation work has been done. The simulation results show that when this mode is applied to SRM drive (SRD) system, the current waveform becomes better. So the ripple of the torque is reduced simultaneously and the vibration and acoustic noise are reduced involuntarily. Stationary tests show that the acoustic noise is greatly diminished. Finally, some experiments were made using a 50 kW SRD system for electric vehicle (EV). Experimental results indicate that this mode can be implemented feasibly and it has a good action on the SRD system.
