The repair of peripheral nerve injuries with autologous nerve remains the gold standard （Wang et al., 2005; Yao et al., 2010; Deal et al., 2012; Kriebel et al., 2014; Liu et al., 2014; Tamaki et al., 2014; Yu et al.,...The repair of peripheral nerve injuries with autologous nerve remains the gold standard （Wang et al., 2005; Yao et al., 2010; Deal et al., 2012; Kriebel et al., 2014; Liu et al., 2014; Tamaki et al., 2014; Yu et al., 2014; Zhu and Lou, 2014）. With advances in tissue engineering and biomaterials, tissue-engineered nerve conduits with various biomaterials and structures, such as collagen and chitosan nerve conduits, have already been used in the clinic as alternatives to autologous nerve in the repair of peripheral nerve injury （Wang et al., 2012; Svizenska et al., 2013; Eppenberger et al., 2014; Gu et al., 2014; Koudehi et al., 2014; MoyaDiaz et al., 2014; Novajra et al., 2014; Okamoto et al., 2014; Shea et al., 2014; Singh et al., 2014; Tamaki et al., 2014; Yu et al., 2014）. Therefore, new simple and effective methods展开更多
This work is aimed at developing an effective method for defect recognition in thermosonic imaging.The heat mechanism of thermosonic imaging is introduced,and the problem for defect recognition is discussed.For this p...This work is aimed at developing an effective method for defect recognition in thermosonic imaging.The heat mechanism of thermosonic imaging is introduced,and the problem for defect recognition is discussed.For this purpose,defect existing in the inner wall of a metal pipeline specimen and defects embedded in a carbon fiber reinforced plastic（CFRP） laminate are tested.The experimental data are processed by pulse phase thermography（PPT） method to show the phase images at different frequencies,and the characteristic of phase angle vs frequency curve of thermal anomalies and sound area is analyzed.A binary image,which is based on the characteristic value of defects,is obtained by a new recognition algorithm to show the defects.Results demonstrate good defect recognition performance for thermosonic imaging,and the reliability of this technique can be improved by the method.展开更多
The research aims at validating the ability of topological imaging to blind holes in isotropic plates using Lamb waves. Due to the defect is not symmetric around the mid- plane of the plate, the effect of Lamb mode co...The research aims at validating the ability of topological imaging to blind holes in isotropic plates using Lamb waves. Due to the defect is not symmetric around the mid- plane of the plate, the effect of Lamb mode conversion will have to be taken into account. The imaging method is based on two computations of ultrasonic fields, one forward and one adjoint, performed for the defect-free reference medium. The excited signal and scattered Lamb waves caused by the blind hole, are used as emitting sources to compute the forward problem and the adjoint problem, respectively. With the help of the finite element simulations, the natural refocusing process of the multimode Lamb waves at the defect location is visually demonstrated by the transient acoustic field snapshots at the different moments to strengthen the physical mechanism of the topological imaging method. The numerical results demonstrate that topological imaging has relatively stronger applicability to the blind hole in contrast to classical Delay And Sum （DAS） method and Time Reversal （TR） method. The topological imaging could handle complex Lamb wave signals containing mode conversions without the imaging quality being affected. The proposed imaging method presents a certain developing potential for detecting and imaging asymmetric defects in plate-like configurations using Lamb waves.展开更多
Congenital aortic arch anomalies occur most commonly in children. The disease can be classified into three types： ① obstructive congenital abnormalities, including coarctation of aorta （CoA） and interruption of ao...Congenital aortic arch anomalies occur most commonly in children. The disease can be classified into three types： ① obstructive congenital abnormalities, including coarctation of aorta （CoA） and interruption of aortic arch （IAA）; ② nonobstructive congenital abnormalities, including double aortic arch and others; ③ congenital shunt abnormalities, including different types of patent ductus arteriosus （PDA）. Management of patients with congenital aortic arch anomalies relies on imaging. Routine imaging modalities, such as conventional X-ray plain film and transthoracic echocardiography （TTE）, have been recently complemented by magnetic resonance imaging （MRI）.展开更多
基金supported by the National High Technology Research and Development Program of China,No.2012AA020502the National Natural Science Foundation of China,No.81171457 and 81371687the Priority of Academic Program Development of Jiangsu Higher Education Institutions
文摘The repair of peripheral nerve injuries with autologous nerve remains the gold standard （Wang et al., 2005; Yao et al., 2010; Deal et al., 2012; Kriebel et al., 2014; Liu et al., 2014; Tamaki et al., 2014; Yu et al., 2014; Zhu and Lou, 2014）. With advances in tissue engineering and biomaterials, tissue-engineered nerve conduits with various biomaterials and structures, such as collagen and chitosan nerve conduits, have already been used in the clinic as alternatives to autologous nerve in the repair of peripheral nerve injury （Wang et al., 2012; Svizenska et al., 2013; Eppenberger et al., 2014; Gu et al., 2014; Koudehi et al., 2014; MoyaDiaz et al., 2014; Novajra et al., 2014; Okamoto et al., 2014; Shea et al., 2014; Singh et al., 2014; Tamaki et al., 2014; Yu et al., 2014）. Therefore, new simple and effective methods
基金Joint Funds of the National Natural Science Foundationof China (61079020)
文摘This work is aimed at developing an effective method for defect recognition in thermosonic imaging.The heat mechanism of thermosonic imaging is introduced,and the problem for defect recognition is discussed.For this purpose,defect existing in the inner wall of a metal pipeline specimen and defects embedded in a carbon fiber reinforced plastic（CFRP） laminate are tested.The experimental data are processed by pulse phase thermography（PPT） method to show the phase images at different frequencies,and the characteristic of phase angle vs frequency curve of thermal anomalies and sound area is analyzed.A binary image,which is based on the characteristic value of defects,is obtained by a new recognition algorithm to show the defects.Results demonstrate good defect recognition performance for thermosonic imaging,and the reliability of this technique can be improved by the method.
基金supported by the National Natural Science Foundation of China(11474195,11274226,61171145)
文摘The research aims at validating the ability of topological imaging to blind holes in isotropic plates using Lamb waves. Due to the defect is not symmetric around the mid- plane of the plate, the effect of Lamb mode conversion will have to be taken into account. The imaging method is based on two computations of ultrasonic fields, one forward and one adjoint, performed for the defect-free reference medium. The excited signal and scattered Lamb waves caused by the blind hole, are used as emitting sources to compute the forward problem and the adjoint problem, respectively. With the help of the finite element simulations, the natural refocusing process of the multimode Lamb waves at the defect location is visually demonstrated by the transient acoustic field snapshots at the different moments to strengthen the physical mechanism of the topological imaging method. The numerical results demonstrate that topological imaging has relatively stronger applicability to the blind hole in contrast to classical Delay And Sum （DAS） method and Time Reversal （TR） method. The topological imaging could handle complex Lamb wave signals containing mode conversions without the imaging quality being affected. The proposed imaging method presents a certain developing potential for detecting and imaging asymmetric defects in plate-like configurations using Lamb waves.
文摘Congenital aortic arch anomalies occur most commonly in children. The disease can be classified into three types： ① obstructive congenital abnormalities, including coarctation of aorta （CoA） and interruption of aortic arch （IAA）; ② nonobstructive congenital abnormalities, including double aortic arch and others; ③ congenital shunt abnormalities, including different types of patent ductus arteriosus （PDA）. Management of patients with congenital aortic arch anomalies relies on imaging. Routine imaging modalities, such as conventional X-ray plain film and transthoracic echocardiography （TTE）, have been recently complemented by magnetic resonance imaging （MRI）.
