A key step of constructing active appearance model is requiring a set of appropriate training shapes with well-defined correspondences.In this paper,we introduce a novel point correspondence method(FB-CPD),which can i...A key step of constructing active appearance model is requiring a set of appropriate training shapes with well-defined correspondences.In this paper,we introduce a novel point correspondence method(FB-CPD),which can improve the accuracy of coherent point drift(CPD) by using the information of image feature.The objective function of the proposed method is defined by both of geometric spatial information and image feature information,and the origin Gaussian mixture model in CPD is modified according to the image feature of points.FB-CPD is tested on the 3D prostate and liver point sets through the simulation experiments.The registration error can be reduced efficiently by FB-CPD.Moreover,the active appearance model constructed by FB-CPD can obtain fine segmentation in 3D CT prostate image.Compared with the original CPD,the overlap ratio of voxels was improved from 88.7% to 90.2% by FB-CPD.展开更多
The relationships among the proportions of the neon dual isotopes ratio, scale factor corrections (SFCs), light intensities, environmental magnetic field and magnetic zero drift are discussed in detail by numerical si...The relationships among the proportions of the neon dual isotopes ratio, scale factor corrections (SFCs), light intensities, environmental magnetic field and magnetic zero drift are discussed in detail by numerical simulations. The results show that the unification of the optimal operating point (OP) and the frequency stabilization operating point (FSP) is achievable by adjusting the proportions of neon dual isotopes accurately and tuning the cavity length with frequency stabilization system exactly. In that case, the left-rotation and right-rotation gyros can obtain the same SFC, which can decrease the magnetic sensitivity of the laser gyro efficiently. The Zeeman effect zero drift and the Faraday bias zero drift are both reduced by two orders of magnitude, while the magnetic shielding requirement of laser tube is decreased by 1-2 orders of magnitude.展开更多
Objective： To assess zero drift of intra- ventricular and subdural intracranial pressure （ICP） moni- toring systems. Methods： A prospective study was conducted in pa- tients who received Codman ICP monitoring in ...Objective： To assess zero drift of intra- ventricular and subdural intracranial pressure （ICP） moni- toring systems. Methods： A prospective study was conducted in pa- tients who received Codman ICP monitoring in the neuro- surgical department from January 2010 to December 2011. According to the location of sensors, the patients were ca- tegorized into two groups： intraventricular group and sub- dural group. Zero drift between the two groups and its as- sociation with the duration of ICP monitor were analyzed. Results： Totally, 22 patients undergoing intraven- tricular ICP monitoring and 27 receiving subdural ICP moni- toring were enrolled. There was no significant difference in duration of ICP monitoring, zero drift value and its absolute value between intraventricular and subdural groups （5.38 d± 2.58 d vs 4.58 d.±2.24 d, 0.77 mmHg±2.18 mmHg vs 1.03 mmHg±2.06mmHg, 1.68 mmHg~.l.55 mmHgvs 1.70mmHg.t_l.53 mmHg, respectively; all P〉0.05）. Absolute value of zero drift in both groups significantly rose with the increased duration of ICP monitoring （P〈0.05） while zero drift value did not. Moreover, daily absolute value in the intraventricular group was sig- nificantly smaller than that in the subdural group （0.27 mm Hg_＋ 0.32 mm Hg vs 0.29 mm Hg_-_＊0.18 mm Hg, P〈0.05）. Conclusion： This study demonstrates that absolute value of zero drift significantly correlates with duration of both intraventricular and subdural ICP monitoring. Due to the smaller daily absolute value, ICP values recorded from intraventficular system may be more reliable than those from subdural system.展开更多
基金National Basic Research Program of China(973 Program)grant number:2010CB732505+1 种基金National Natural Science Foundation of Chinagrant number:30900380
文摘A key step of constructing active appearance model is requiring a set of appropriate training shapes with well-defined correspondences.In this paper,we introduce a novel point correspondence method(FB-CPD),which can improve the accuracy of coherent point drift(CPD) by using the information of image feature.The objective function of the proposed method is defined by both of geometric spatial information and image feature information,and the origin Gaussian mixture model in CPD is modified according to the image feature of points.FB-CPD is tested on the 3D prostate and liver point sets through the simulation experiments.The registration error can be reduced efficiently by FB-CPD.Moreover,the active appearance model constructed by FB-CPD can obtain fine segmentation in 3D CT prostate image.Compared with the original CPD,the overlap ratio of voxels was improved from 88.7% to 90.2% by FB-CPD.
基金supported by the Science Foundation of Aeronautics of China (No.20090853014)
文摘The relationships among the proportions of the neon dual isotopes ratio, scale factor corrections (SFCs), light intensities, environmental magnetic field and magnetic zero drift are discussed in detail by numerical simulations. The results show that the unification of the optimal operating point (OP) and the frequency stabilization operating point (FSP) is achievable by adjusting the proportions of neon dual isotopes accurately and tuning the cavity length with frequency stabilization system exactly. In that case, the left-rotation and right-rotation gyros can obtain the same SFC, which can decrease the magnetic sensitivity of the laser gyro efficiently. The Zeeman effect zero drift and the Faraday bias zero drift are both reduced by two orders of magnitude, while the magnetic shielding requirement of laser tube is decreased by 1-2 orders of magnitude.
文摘Objective： To assess zero drift of intra- ventricular and subdural intracranial pressure （ICP） moni- toring systems. Methods： A prospective study was conducted in pa- tients who received Codman ICP monitoring in the neuro- surgical department from January 2010 to December 2011. According to the location of sensors, the patients were ca- tegorized into two groups： intraventricular group and sub- dural group. Zero drift between the two groups and its as- sociation with the duration of ICP monitor were analyzed. Results： Totally, 22 patients undergoing intraven- tricular ICP monitoring and 27 receiving subdural ICP moni- toring were enrolled. There was no significant difference in duration of ICP monitoring, zero drift value and its absolute value between intraventricular and subdural groups （5.38 d± 2.58 d vs 4.58 d.±2.24 d, 0.77 mmHg±2.18 mmHg vs 1.03 mmHg±2.06mmHg, 1.68 mmHg~.l.55 mmHgvs 1.70mmHg.t_l.53 mmHg, respectively; all P〉0.05）. Absolute value of zero drift in both groups significantly rose with the increased duration of ICP monitoring （P〈0.05） while zero drift value did not. Moreover, daily absolute value in the intraventricular group was sig- nificantly smaller than that in the subdural group （0.27 mm Hg_＋ 0.32 mm Hg vs 0.29 mm Hg_-_＊0.18 mm Hg, P〈0.05）. Conclusion： This study demonstrates that absolute value of zero drift significantly correlates with duration of both intraventricular and subdural ICP monitoring. Due to the smaller daily absolute value, ICP values recorded from intraventficular system may be more reliable than those from subdural system.
