The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and ...The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.展开更多
Objective To investigate the preliminary clinical outcome of the femur RetroButton combined with glaze allogenic cortical press-fit bolt fixation in ACL reconstruction.Methods A series of 10 patients suffered from ACL...Objective To investigate the preliminary clinical outcome of the femur RetroButton combined with glaze allogenic cortical press-fit bolt fixation in ACL reconstruction.Methods A series of 10 patients suffered from ACL ruptures展开更多
Summary： This study evaluated the clinical effect of impaction bone graft and distal press-fit fixation for the reconstruction of severe femoral bone defect in revision total hip arthroplasty. A total of 234 patients...Summary： This study evaluated the clinical effect of impaction bone graft and distal press-fit fixation for the reconstruction of severe femoral bone defect in revision total hip arthroplasty. A total of 234 patients （involving 236 hips） with Paprosky III and 1V femoral bone defects were treated with the revision total hip arthroplasty from June 1998 to Aug. 2006. Impaction bone graft technique was used for 112 hips, with allogeneic freeze-dried bone as bone graft and SP II as prosthesis. With 124 hips, modular distal press-fit fixation and tapered femoral stem （MP stem） were employed. After the operation, the subjects were followed up on regular basis and results were assessed by using the Harris Hip Score （HHS） and 12-item Short Form Health Survey （SF-12）. Radiolucence, subsidence and loosening were observed and complications, including infection, fracture, dislocation etc. were recorded. A 6-14-year follow-up showed that prostheses failed, due to infection, in 4 patients of impaction bone graft group and that 6 patients in the press-fit fixation group experienced prosthesis failure, with the survival rates for the two techniques being 96.43% and 95.16%, respectively. One-way ANOVA showed that prosthesis survival was significantly associated with surgery-related complications （P〈0.05） and was not related to the type of the bone defects （P〉0.05）. The rate of complications bore significant association with the type of bone defects in the two groups （P〈0.05）. Our study showed that the two revision methods could achieve satisfactory mid-term and long-term results for the reconstruction of severe bone defects. It is of great significance for attaining high prosthesis survival rate to select suitable operation on the basis of the type of bone defect. Careful operative manipulation and post-operative rehabilitation aimed at reducing complications are also important.展开更多
BACKGROUND In press-fit total hip arthroplasty(THA)ceramic-on-ceramic(CoC)bearings are a potential for overcoming the wear that is seen in ceramic-on-polyethylene(CoPE)bearings,and can lead to wear-induced osteolysis,...BACKGROUND In press-fit total hip arthroplasty(THA)ceramic-on-ceramic(CoC)bearings are a potential for overcoming the wear that is seen in ceramic-on-polyethylene(CoPE)bearings,and can lead to wear-induced osteolysis,resulting in loosening of the implant.However,CoC bearings show disadvantages as well,such as squeaking sounds and being more fragile,which can cause ceramic head or liner fracture.Because comparative long-term studies are limited,the objective of this study was to determine the long-term difference in wear,identify potential predictive factors for wear,investigate radiological findings such as osteolysis,and evaluate clinical functioning and complications between these bearings.AIM To determine 10-year differences in wear,predictive factors for wear,and investigate radiological findings and clinical functioning between CoC and CoPE.METHODS This observational prospective single-center cohort study with a 10-year followup includes a documented series of elective THAs.Primary outcome was wear measured by anteroposterior(AP)radiographs.Secondary outcomes were potential predictive factors for wear,complications during follow-up,Harris hip score(HHS),and radiological findings such as presence of radiolucency,osteolysis,atrophy,and hypertrophy around the cup.Due to the absence of wear in the CoC group,stratified analysis to identify risk factors for wear was only performed in the CoPE group by use of univariate linear regression analysis.HHS was expressed as a change from baseline and the association with bearing type was assessed by use of multivariate linear regression analysis,adjusted for potential confounders.RESULTS A total of 17 CoPE(63.0%)and 25 CoC(73.5%)cases were available for follow-up and showed a linear wear of respectively 0.130 mm/year(range 0.010;0.350)and 0.000 mm/year(range 0.000;0.005),which was significant(P<0.001)between both groups.Wear always occurred in the cranial direction.Cup inclination was the only predictive factor for polyethylene(PE)wear.No dislocations,ceramic head,or liner fractures were seen.The HHS showed a mean change from baseline of 37.1 points(SD 18.5)in the CoPE group and 43.9(SD 17.0)in the CoC group.This crude difference of 6.8(range-5.2;18.7)in favor of the CoC group was not significant(P=0.26)and was not significant when adjusted for age,gender,and diagnosis either(P=0.99).No significant differences in complications and radiological findings were seen between groups.CONCLUSION CoC bearing shows lower wear rates compared to CoPE at 10-year follow-up with cup inclination as a predictive factor for wear and no differences in complications,HHS,and radiological findings.展开更多
基金supported by the National Natural Science Foundation of China(No.52005378)the opening project fund of Materials Service Safety Assessment Facilities(No.MSAF-2021-107).
文摘The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.
文摘Objective To investigate the preliminary clinical outcome of the femur RetroButton combined with glaze allogenic cortical press-fit bolt fixation in ACL reconstruction.Methods A series of 10 patients suffered from ACL ruptures
基金supported by a grant from the National High Technology Research and Development Program of China(863 Program)(NO.2011AA030101)
文摘Summary： This study evaluated the clinical effect of impaction bone graft and distal press-fit fixation for the reconstruction of severe femoral bone defect in revision total hip arthroplasty. A total of 234 patients （involving 236 hips） with Paprosky III and 1V femoral bone defects were treated with the revision total hip arthroplasty from June 1998 to Aug. 2006. Impaction bone graft technique was used for 112 hips, with allogeneic freeze-dried bone as bone graft and SP II as prosthesis. With 124 hips, modular distal press-fit fixation and tapered femoral stem （MP stem） were employed. After the operation, the subjects were followed up on regular basis and results were assessed by using the Harris Hip Score （HHS） and 12-item Short Form Health Survey （SF-12）. Radiolucence, subsidence and loosening were observed and complications, including infection, fracture, dislocation etc. were recorded. A 6-14-year follow-up showed that prostheses failed, due to infection, in 4 patients of impaction bone graft group and that 6 patients in the press-fit fixation group experienced prosthesis failure, with the survival rates for the two techniques being 96.43% and 95.16%, respectively. One-way ANOVA showed that prosthesis survival was significantly associated with surgery-related complications （P〈0.05） and was not related to the type of the bone defects （P〉0.05）. The rate of complications bore significant association with the type of bone defects in the two groups （P〈0.05）. Our study showed that the two revision methods could achieve satisfactory mid-term and long-term results for the reconstruction of severe bone defects. It is of great significance for attaining high prosthesis survival rate to select suitable operation on the basis of the type of bone defect. Careful operative manipulation and post-operative rehabilitation aimed at reducing complications are also important.
文摘BACKGROUND In press-fit total hip arthroplasty(THA)ceramic-on-ceramic(CoC)bearings are a potential for overcoming the wear that is seen in ceramic-on-polyethylene(CoPE)bearings,and can lead to wear-induced osteolysis,resulting in loosening of the implant.However,CoC bearings show disadvantages as well,such as squeaking sounds and being more fragile,which can cause ceramic head or liner fracture.Because comparative long-term studies are limited,the objective of this study was to determine the long-term difference in wear,identify potential predictive factors for wear,investigate radiological findings such as osteolysis,and evaluate clinical functioning and complications between these bearings.AIM To determine 10-year differences in wear,predictive factors for wear,and investigate radiological findings and clinical functioning between CoC and CoPE.METHODS This observational prospective single-center cohort study with a 10-year followup includes a documented series of elective THAs.Primary outcome was wear measured by anteroposterior(AP)radiographs.Secondary outcomes were potential predictive factors for wear,complications during follow-up,Harris hip score(HHS),and radiological findings such as presence of radiolucency,osteolysis,atrophy,and hypertrophy around the cup.Due to the absence of wear in the CoC group,stratified analysis to identify risk factors for wear was only performed in the CoPE group by use of univariate linear regression analysis.HHS was expressed as a change from baseline and the association with bearing type was assessed by use of multivariate linear regression analysis,adjusted for potential confounders.RESULTS A total of 17 CoPE(63.0%)and 25 CoC(73.5%)cases were available for follow-up and showed a linear wear of respectively 0.130 mm/year(range 0.010;0.350)and 0.000 mm/year(range 0.000;0.005),which was significant(P<0.001)between both groups.Wear always occurred in the cranial direction.Cup inclination was the only predictive factor for polyethylene(PE)wear.No dislocations,ceramic head,or liner fractures were seen.The HHS showed a mean change from baseline of 37.1 points(SD 18.5)in the CoPE group and 43.9(SD 17.0)in the CoC group.This crude difference of 6.8(range-5.2;18.7)in favor of the CoC group was not significant(P=0.26)and was not significant when adjusted for age,gender,and diagnosis either(P=0.99).No significant differences in complications and radiological findings were seen between groups.CONCLUSION CoC bearing shows lower wear rates compared to CoPE at 10-year follow-up with cup inclination as a predictive factor for wear and no differences in complications,HHS,and radiological findings.
