OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive A...OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive Airway Pressure)ventilation on the upper airway of the patient through a household respiratory machine.However,if the ventilator mask is designed improperly,it might cause the residue and repeated inhalation of CO2,which will exert an adverse impact on the therapeutic effect.Present research numerically analyzed the CO2 transportation inside a commercial ventilator mask(Mirage SoftGel,ResMed,Australia)based on the reconstructed 3D numerical model of a volunteer's face and performed the improved design of the ventilator mask in terms of the CO2 residual concentration below the nostrils.The fluid dynamic analyses showed that at the end time of expiratory,the CO2 residual concentration below the nostrils is close to 4%.To improve the therapeutic effect,we changed the position of the exhaust holes and found that by moving the exhaust holes to the bottom of the ventilator mask,the CO2 residual concentration below the nostrils would be reduced to no more than 1%.This study established a near physiological computational model and provided a new method for the individualized design of the commercial ventilator mask.展开更多
A 3D laser scanning strategy based on cascaded deep neural network is proposed for the scanning system converted from 2D Lidar with a pitching motion device. The strategy is aimed at moving target detection and monito...A 3D laser scanning strategy based on cascaded deep neural network is proposed for the scanning system converted from 2D Lidar with a pitching motion device. The strategy is aimed at moving target detection and monitoring. Combining the device characteristics, the strategy first proposes a cascaded deep neural network, which inputs 2D point cloud, color image and pitching angle. The outputs are target distance and speed classification. And the cross-entropy loss function of network is modified by using focal loss and uniform distribution to improve the recognition accuracy. Then a pitching range and speed model are proposed to determine pitching motion parameters. Finally, the adaptive scanning is realized by integral separate speed PID. The experimental results show that the accuracies of the improved network target detection box, distance and speed classification are 90.17%, 96.87% and 96.97%, respectively. The average speed error of the improved PID is 0.4239°/s, and the average strategy execution time is 0.1521 s.The range and speed model can effectively reduce the collection of useless information and the deformation of the target point cloud. Conclusively, the experimental of overall scanning strategy show that it can improve target point cloud integrity and density while ensuring the capture of target.展开更多
基金We acknowledge the National Natural Science Foundation of China for supporting the project via the grant number 11472062 and 11002034.
文摘OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive Airway Pressure)ventilation on the upper airway of the patient through a household respiratory machine.However,if the ventilator mask is designed improperly,it might cause the residue and repeated inhalation of CO2,which will exert an adverse impact on the therapeutic effect.Present research numerically analyzed the CO2 transportation inside a commercial ventilator mask(Mirage SoftGel,ResMed,Australia)based on the reconstructed 3D numerical model of a volunteer's face and performed the improved design of the ventilator mask in terms of the CO2 residual concentration below the nostrils.The fluid dynamic analyses showed that at the end time of expiratory,the CO2 residual concentration below the nostrils is close to 4%.To improve the therapeutic effect,we changed the position of the exhaust holes and found that by moving the exhaust holes to the bottom of the ventilator mask,the CO2 residual concentration below the nostrils would be reduced to no more than 1%.This study established a near physiological computational model and provided a new method for the individualized design of the commercial ventilator mask.
基金funded by National Natural Science Foundation of China(Grant No. 51805146)the Fundamental Research Funds for the Central Universities (Grant No. B200202221)+1 种基金Jiangsu Key R&D Program (Grant Nos. BE2018004-1, BE2018004)College Students’ Innovative Entrepreneurial Training Plan Program (Grant No. 2020102941513)。
文摘A 3D laser scanning strategy based on cascaded deep neural network is proposed for the scanning system converted from 2D Lidar with a pitching motion device. The strategy is aimed at moving target detection and monitoring. Combining the device characteristics, the strategy first proposes a cascaded deep neural network, which inputs 2D point cloud, color image and pitching angle. The outputs are target distance and speed classification. And the cross-entropy loss function of network is modified by using focal loss and uniform distribution to improve the recognition accuracy. Then a pitching range and speed model are proposed to determine pitching motion parameters. Finally, the adaptive scanning is realized by integral separate speed PID. The experimental results show that the accuracies of the improved network target detection box, distance and speed classification are 90.17%, 96.87% and 96.97%, respectively. The average speed error of the improved PID is 0.4239°/s, and the average strategy execution time is 0.1521 s.The range and speed model can effectively reduce the collection of useless information and the deformation of the target point cloud. Conclusively, the experimental of overall scanning strategy show that it can improve target point cloud integrity and density while ensuring the capture of target.
