Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo...Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.展开更多
Objective:A novel portable and intelligent fluid resuscitation infuser is proposed in this paper. It satisfies the demands of long time use in harsh environment, such as traffic accident, natural disaster, battlefield...Objective:A novel portable and intelligent fluid resuscitation infuser is proposed in this paper. It satisfies the demands of long time use in harsh environment, such as traffic accident, natural disaster, battlefield, evacuation, pre-hospital emergency and so on. Methods:Miniature linear motor and liquid blood cartridge compose the pump body. It's based on the biological impedance method to measure and control, which resolve the disadvantage of traditional infuser device:large power dissipation, big size, AC power supply only and can't be use in field. The whole device weights 250 gram and sizes as two mobile phone together. Results:Model device experiment shows:six number 7 standard AAA size alkaline batteries will run the pump for approximately 8-10 h at 6 liters per hour; IV bag can be placed at any position of patient, even under the stretcher. Conclusion:It provides accurate and reliable intravenous infusion for first-aid treatment in展开更多
The present paper investigates the existence of chaos in a non-autonomous fractional-order micro-electromechanical resonator system（FOMEMRS）.Using the maximal Lyapunov exponent criterion,we show that the FOMEMRS exh...The present paper investigates the existence of chaos in a non-autonomous fractional-order micro-electromechanical resonator system（FOMEMRS）.Using the maximal Lyapunov exponent criterion,we show that the FOMEMRS exhibits chaos.Strange attractors of the system are plotted to validate its chaotic behavior.Afterward,a novel fractional finite-time controller is introduced to suppress the chaos of the FOMEMRS with model uncertainties and external disturbances in a given finite time.Using the latest version of the fractional Lyapunov theory,the finite time stability and robustness of the proposed scheme are proved.Finally,we present some computer simulations to illustrate the usefulness and applicability of the proposed method.展开更多
In this paper,we present the applications of Boundary Element Method(BEM) to simulate the electro-mechanical coupling responses of Micro-Electro-Mechanical systems(MEMS). The algorithm is programmed in our research gr...In this paper,we present the applications of Boundary Element Method(BEM) to simulate the electro-mechanical coupling responses of Micro-Electro-Mechanical systems(MEMS). The algorithm is programmed in our research group based on BEM modeling for electrostatics and elastostatics.Good agreement is shown while the simulation results of the pull-in voltages are compared with the theoretical/experimental ones for some examples.展开更多
According to the inland micro electro-mechanical system （MEMS） process technique level, a design platform of piezoresistive micro electro-mechanical accelerometer is given. This platform is much more adaptable to th...According to the inland micro electro-mechanical system （MEMS） process technique level, a design platform of piezoresistive micro electro-mechanical accelerometer is given. This platform is much more adaptable to the inland designer compared with the current MEMS CAD software. The design flow is presented in detail, and the key techique in the platform is analyzed amply. The structure design methodology is exemplified in the design of a piezoresistive accelerometer, and the accelerometer is the optimized structure for the given performance requirements. The accelerometer is now being manufactured.展开更多
A type of crank beam electro-thermal micro actuator was prescribed. Mechanical model of the actuator was established, and the static characteristic was analyzed.Comparing the theoretical analysis with experimental dat...A type of crank beam electro-thermal micro actuator was prescribed. Mechanical model of the actuator was established, and the static characteristic was analyzed.Comparing the theoretical analysis with experimental data, it is found that the thermodynamic character of material in micro actuator has a different variable regularity contrasted to that used in macro scale machines. It is the micro scale effect that results in the deviation between the simulating result and experimental results. The thermodynamic expression of polysilicon, which was fitted by means of the experimental data concerned, was used to modify the mechanical model. The modified model, in which the micro scale thermodynamic characteristic was considered, was more reasonable and could make the optimal design and control strategies analyzing the straight-line micro actuator more feasible.展开更多
In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock...In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application.展开更多
基金supported by the National Natural Science Foundation of China(No.32101153)the Fundamental Research Funds for the Central Universities(No.2021CX11018).
文摘Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.
基金Supported by the Second Batch of Projects of Army Medical Eleventh Five-Year Plan Research(08G084)Chongqing Key Scientific and Technological Projects(CSTC,2008AC5120)
文摘Objective:A novel portable and intelligent fluid resuscitation infuser is proposed in this paper. It satisfies the demands of long time use in harsh environment, such as traffic accident, natural disaster, battlefield, evacuation, pre-hospital emergency and so on. Methods:Miniature linear motor and liquid blood cartridge compose the pump body. It's based on the biological impedance method to measure and control, which resolve the disadvantage of traditional infuser device:large power dissipation, big size, AC power supply only and can't be use in field. The whole device weights 250 gram and sizes as two mobile phone together. Results:Model device experiment shows:six number 7 standard AAA size alkaline batteries will run the pump for approximately 8-10 h at 6 liters per hour; IV bag can be placed at any position of patient, even under the stretcher. Conclusion:It provides accurate and reliable intravenous infusion for first-aid treatment in
文摘The present paper investigates the existence of chaos in a non-autonomous fractional-order micro-electromechanical resonator system（FOMEMRS）.Using the maximal Lyapunov exponent criterion,we show that the FOMEMRS exhibits chaos.Strange attractors of the system are plotted to validate its chaotic behavior.Afterward,a novel fractional finite-time controller is introduced to suppress the chaos of the FOMEMRS with model uncertainties and external disturbances in a given finite time.Using the latest version of the fractional Lyapunov theory,the finite time stability and robustness of the proposed scheme are proved.Finally,we present some computer simulations to illustrate the usefulness and applicability of the proposed method.
基金The project supported by the 973 Program (G1999033108)the National Natural Science Foundation of China (10125211)
文摘In this paper,we present the applications of Boundary Element Method(BEM) to simulate the electro-mechanical coupling responses of Micro-Electro-Mechanical systems(MEMS). The algorithm is programmed in our research group based on BEM modeling for electrostatics and elastostatics.Good agreement is shown while the simulation results of the pull-in voltages are compared with the theoretical/experimental ones for some examples.
文摘According to the inland micro electro-mechanical system （MEMS） process technique level, a design platform of piezoresistive micro electro-mechanical accelerometer is given. This platform is much more adaptable to the inland designer compared with the current MEMS CAD software. The design flow is presented in detail, and the key techique in the platform is analyzed amply. The structure design methodology is exemplified in the design of a piezoresistive accelerometer, and the accelerometer is the optimized structure for the given performance requirements. The accelerometer is now being manufactured.
文摘A type of crank beam electro-thermal micro actuator was prescribed. Mechanical model of the actuator was established, and the static characteristic was analyzed.Comparing the theoretical analysis with experimental data, it is found that the thermodynamic character of material in micro actuator has a different variable regularity contrasted to that used in macro scale machines. It is the micro scale effect that results in the deviation between the simulating result and experimental results. The thermodynamic expression of polysilicon, which was fitted by means of the experimental data concerned, was used to modify the mechanical model. The modified model, in which the micro scale thermodynamic characteristic was considered, was more reasonable and could make the optimal design and control strategies analyzing the straight-line micro actuator more feasible.
基金The National Natural Science Foundation ofChina(No.60402003)The National High Technology Research and Development Pro-gram of China(863Program)(No.2002AA745120)
文摘In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application.
