Single-camera mobile-vision coordinate measurement is one of the primary methods of 3D-coordinate vision measurement, and coded target plays an important role in this system. A multifunctional coded target and its rec...Single-camera mobile-vision coordinate measurement is one of the primary methods of 3D-coordinate vision measurement, and coded target plays an important role in this system. A multifunctional coded target and its recognition algorithm is developed, which can realize automatic match of feature points, calculation of camera initial exterior orientation and space scale factor constraint in measurement system. The uniqueness and scalability of coding are guaranteed by the rational arrangement of code bits. The recognition of coded targets is realized by cross-ratio invariance restriction, space coordinates transform of feature points based on spacial pose estimation algorithm, recognition of code bits and computation of coding values. The experiment results demonstrate the uniqueness of the coding form and the reliability of recognition.展开更多
Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior ...Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior wall fractures of the acetabulum hospitalized in our department from 2002 to 2006 were analyzed retrospectively in this study. The types of fractures, number of fragments, combined dislocations, and sciatic nerve function were documented before admission. All the fractures were treated with open reduction and internal fixation. Based on the fracture type and site, either screws alone or reconstructive plates were used. The patients were immobilized for an average of 12 weeks before partial weight bearing was permitted. After follow-up for 12-70 months （43.6 months on average）, modified Merle d＇Aubigne score was adopted to evaluate the outcomes of the operations. Results： The percentages of the excellent, good, fair and poor results were 48.4%, 41.9%, 6.5%, and 3.3%, respectively, with a good to excellent rate of 90.2%. Idiopathic sciatic nerve injury occurred in only one case. Conclusions： The sciatic nerve should be routinely exposed and protected during the surgery. The type of fixation should be based on the fracture type and site. Prolonged immobilization may be helpful in improving the final outcomes.展开更多
文摘Single-camera mobile-vision coordinate measurement is one of the primary methods of 3D-coordinate vision measurement, and coded target plays an important role in this system. A multifunctional coded target and its recognition algorithm is developed, which can realize automatic match of feature points, calculation of camera initial exterior orientation and space scale factor constraint in measurement system. The uniqueness and scalability of coding are guaranteed by the rational arrangement of code bits. The recognition of coded targets is realized by cross-ratio invariance restriction, space coordinates transform of feature points based on spacial pose estimation algorithm, recognition of code bits and computation of coding values. The experiment results demonstrate the uniqueness of the coding form and the reliability of recognition.
文摘Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior wall fractures of the acetabulum hospitalized in our department from 2002 to 2006 were analyzed retrospectively in this study. The types of fractures, number of fragments, combined dislocations, and sciatic nerve function were documented before admission. All the fractures were treated with open reduction and internal fixation. Based on the fracture type and site, either screws alone or reconstructive plates were used. The patients were immobilized for an average of 12 weeks before partial weight bearing was permitted. After follow-up for 12-70 months （43.6 months on average）, modified Merle d＇Aubigne score was adopted to evaluate the outcomes of the operations. Results： The percentages of the excellent, good, fair and poor results were 48.4%, 41.9%, 6.5%, and 3.3%, respectively, with a good to excellent rate of 90.2%. Idiopathic sciatic nerve injury occurred in only one case. Conclusions： The sciatic nerve should be routinely exposed and protected during the surgery. The type of fixation should be based on the fracture type and site. Prolonged immobilization may be helpful in improving the final outcomes.
