Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divide...Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divided into two展开更多
For the autonomous guided vehicle (AGV) used mainly in unfixed work fields, a machine vision method was proposed for the navigation system, in which a series of navigation-signs are placed along the travel route. The ...For the autonomous guided vehicle (AGV) used mainly in unfixed work fields, a machine vision method was proposed for the navigation system, in which a series of navigation-signs are placed along the travel route. The navigation system detects and recognizes these signs, and accordingly informs the travel control system. In order for the navigation to have balanced ability of 1) covering a large area and 2) recognizing details of the sign, the proposed vision method was designed to be a hybrid one, using both the stereo vision and the traditional 2D template matching. The former implemented a coarse recognition function for above 1), and the later implemented a fine recognition function for above 2). The results from the coarse recognition were used in the fine recognition for the gaze control to input suitable 2D image of the signs. Experiments on a prototype system show the feasibility of the proposed hybrid method in achieving the objective specifications for a typical AGV.展开更多
For the purpose of positioning in various scenes, including indoors, on open road, and side street buildings, a low-cost personal navigation unit is put forward. The unit consists of a low-cost MEMS(micro-electro-mech...For the purpose of positioning in various scenes, including indoors, on open road, and side street buildings, a low-cost personal navigation unit is put forward. The unit consists of a low-cost MEMS(micro-electro-mechanical system) accelerometer, a gyroscope, a magnetometer and a GPS(global positioning system) chip, and it is capable of switching modes between indoor and outdoor situations seamlessly. The outdoor mode is MIMU(MEMS-inertial measurement unit)/GPS/magnetometer integrated mode and the indoor mode is MIMU/magnetometer integrated mode. The outdoor algorithm uses the extended Kalman filter to fuse data and provide optimum parameters. The indoor algorithm is dead reckoning, which uses vertical and forward accelerations to judge steps and uses a magnetometer to define heading. The two-axis acceleration data is used to calculate the adaptive threshold and estimate the confidence value of the steps, and when the confidence of both two axes data meet the conditions, the steps can be detected in the adaptive time windows. The detection precision is more than 95%. An experiment was conducted in complex situations. The experiment participant wearing the unit walked about 1 600 m in the experiment. The results show that the positioning error is less than 0.2% of the total route distance.展开更多
目的(1)探究锂基生物玻璃水凝胶,赋予介孔生物玻璃材料促成骨、促血管生成和抑制脂肪生成等多重生物医学功能。(2)利用3D打印技术制作导航模板,精确定位股骨头坏死病灶区域和清除病灶,将锂基生物玻璃水凝胶精确注入,观察其修复股骨头坏...目的(1)探究锂基生物玻璃水凝胶,赋予介孔生物玻璃材料促成骨、促血管生成和抑制脂肪生成等多重生物医学功能。(2)利用3D打印技术制作导航模板,精确定位股骨头坏死病灶区域和清除病灶,将锂基生物玻璃水凝胶精确注入,观察其修复股骨头坏死的作用。方法利用明胶和甲基丙烯酸酐制备了甲基丙烯酰化明胶(gelatin methacryloyl,GelMA)及锂基生物玻璃水凝胶(GelMA and Li-mesoporous bioglass,GM/M-Li)。扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)对材料进行表征分析;同时,通过细胞活/死染色、细胞增殖实验(cell counting kit-8,CCK-8)及细胞形态观察评估材料的生物相容性;另外,使用免疫荧光染色、碱性磷酸酯酶染色、茜素红染色、成血管实验、油红O染色评估材料的成骨分化能力、成血管能力和抑制脂肪生成的能力。体内成功建立了兔股骨头坏死模型,利用3D导航模板联合髓芯减压术将坏死骨去除后填充GM/M-Li水凝胶。通过苏木素伊红(hematoxylin eosin,HE)染色、油红O染色、免疫组化染色验证其成骨、成血管和抑制脂肪生成能力。结果SEM结果显示GM/M-Li水凝胶材料为三维多孔的结构;TEM结果表明,M-Li材料为纳米级别;离子释放实验证明了GM/M-Li水凝胶中的锂元素,同时具有缓释作用;细胞活/死染色、CCK-8证明了GM/M-Li水凝胶材料具有良好的生物相容性;体外成骨、成血管、抑制脂肪生成实验证实,材料中锂离子的释放有利于骨髓间充质干细胞的成骨分化、人脐静脉血管内皮细胞的小管形成,抑制了脂肪前体细胞的脂肪形成。体内HE染色和免疫荧光验证了GM/M-Li水凝胶有效促进了骨组织、血管再生;通过油红O染色验证了GM/M-Li水凝胶的抑制脂肪能力。结论利用3D打印技术制作导航模板,将GM/M-Li精确注入股骨头坏死病灶区域和清除病灶。因GM/M-Li水凝胶具有良好的生物相容性,其可通过调节骨髓间充质干细胞成骨方向分化,促进股骨头坏死中骨缺损的重建,同时促进了血管的生成,减少脂肪细胞的浸润。展开更多
文摘Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divided into two
文摘For the autonomous guided vehicle (AGV) used mainly in unfixed work fields, a machine vision method was proposed for the navigation system, in which a series of navigation-signs are placed along the travel route. The navigation system detects and recognizes these signs, and accordingly informs the travel control system. In order for the navigation to have balanced ability of 1) covering a large area and 2) recognizing details of the sign, the proposed vision method was designed to be a hybrid one, using both the stereo vision and the traditional 2D template matching. The former implemented a coarse recognition function for above 1), and the later implemented a fine recognition function for above 2). The results from the coarse recognition were used in the fine recognition for the gaze control to input suitable 2D image of the signs. Experiments on a prototype system show the feasibility of the proposed hybrid method in achieving the objective specifications for a typical AGV.
基金The National Natural Science Foundation of China(No.61773113)International Special Projects for Scientific and Technological Cooperation(No.2014DFR80750)the National Key Research and Development Program of China(No.2016YFC0303006,2017YFC0601601)
文摘For the purpose of positioning in various scenes, including indoors, on open road, and side street buildings, a low-cost personal navigation unit is put forward. The unit consists of a low-cost MEMS(micro-electro-mechanical system) accelerometer, a gyroscope, a magnetometer and a GPS(global positioning system) chip, and it is capable of switching modes between indoor and outdoor situations seamlessly. The outdoor mode is MIMU(MEMS-inertial measurement unit)/GPS/magnetometer integrated mode and the indoor mode is MIMU/magnetometer integrated mode. The outdoor algorithm uses the extended Kalman filter to fuse data and provide optimum parameters. The indoor algorithm is dead reckoning, which uses vertical and forward accelerations to judge steps and uses a magnetometer to define heading. The two-axis acceleration data is used to calculate the adaptive threshold and estimate the confidence value of the steps, and when the confidence of both two axes data meet the conditions, the steps can be detected in the adaptive time windows. The detection precision is more than 95%. An experiment was conducted in complex situations. The experiment participant wearing the unit walked about 1 600 m in the experiment. The results show that the positioning error is less than 0.2% of the total route distance.
文摘目的(1)探究锂基生物玻璃水凝胶,赋予介孔生物玻璃材料促成骨、促血管生成和抑制脂肪生成等多重生物医学功能。(2)利用3D打印技术制作导航模板,精确定位股骨头坏死病灶区域和清除病灶,将锂基生物玻璃水凝胶精确注入,观察其修复股骨头坏死的作用。方法利用明胶和甲基丙烯酸酐制备了甲基丙烯酰化明胶(gelatin methacryloyl,GelMA)及锂基生物玻璃水凝胶(GelMA and Li-mesoporous bioglass,GM/M-Li)。扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)对材料进行表征分析;同时,通过细胞活/死染色、细胞增殖实验(cell counting kit-8,CCK-8)及细胞形态观察评估材料的生物相容性;另外,使用免疫荧光染色、碱性磷酸酯酶染色、茜素红染色、成血管实验、油红O染色评估材料的成骨分化能力、成血管能力和抑制脂肪生成的能力。体内成功建立了兔股骨头坏死模型,利用3D导航模板联合髓芯减压术将坏死骨去除后填充GM/M-Li水凝胶。通过苏木素伊红(hematoxylin eosin,HE)染色、油红O染色、免疫组化染色验证其成骨、成血管和抑制脂肪生成能力。结果SEM结果显示GM/M-Li水凝胶材料为三维多孔的结构;TEM结果表明,M-Li材料为纳米级别;离子释放实验证明了GM/M-Li水凝胶中的锂元素,同时具有缓释作用;细胞活/死染色、CCK-8证明了GM/M-Li水凝胶材料具有良好的生物相容性;体外成骨、成血管、抑制脂肪生成实验证实,材料中锂离子的释放有利于骨髓间充质干细胞的成骨分化、人脐静脉血管内皮细胞的小管形成,抑制了脂肪前体细胞的脂肪形成。体内HE染色和免疫荧光验证了GM/M-Li水凝胶有效促进了骨组织、血管再生;通过油红O染色验证了GM/M-Li水凝胶的抑制脂肪能力。结论利用3D打印技术制作导航模板,将GM/M-Li精确注入股骨头坏死病灶区域和清除病灶。因GM/M-Li水凝胶具有良好的生物相容性,其可通过调节骨髓间充质干细胞成骨方向分化,促进股骨头坏死中骨缺损的重建,同时促进了血管的生成,减少脂肪细胞的浸润。
