Real-Time Evaluation of the Mechanical Performance and Residual Life of a Notching Mold using Embedded PVDF Sensors and SVM Criteria.

The geometric tolerance of notching machines used in the fabrication of components for induction motor stators and rotators is less than 50 µm. The blunt edges of worn molds can cause the edge of the sheet metal to form a burr, which can seriously impede assembly and reduce the efficiency of the resulting motor. The overuse of molds without sufficient maintenance leads to wasted sheet material, whereas excessive maintenance shortens the life of the punch/die plate. Diagnosing the mechanical performance of die molds requires extensive experience and fine-grained sensor data. In this study, we embedded polyvinylidene fluoride (PVDF) films within the mechanical mold of a notching machine to obtain direct measurements of the reaction forces imposed by the punch. We also developed an automated diagnosis program based on a support vector machine (SVM) to characterize the performance of the mechanical mold. The proposed cyber-physical system (CPS) facilitated the real-time monitoring of machinery for preventative maintenance as well as the implementation of early warning alarms. The cloud server used to gather mold-related data also generated data logs for managers. The hyperplane of the CPS-PVDF was calibrated using a variety of parameters pertaining to the edge characteristics of punches. Stereo-microscopy analysis of the punched workpiece verified that the accuracy of the fault classification was 97.6%.

Physical processing for decellularized nerve xenograft in peripheral nerve regeneration.

In severe or complex cases of peripheral nerve injuries, autologous nerve grafts are the gold standard yielding promising results, but limited availability and donor site morbidity are some of its disadvantages. Although biological or synthetic substitutes are commonly used, clinical outcomes are inconsistent. Biomimetic alternatives derived from allogenic or xenogenic sources offer an attractive off-the-shelf supply, and the key to successful peripheral nerve regeneration focuses on an effective decellularization process. In addition to chemical and enzymatic decellularization protocols, physical processes might offer identical efficiency. In this comprehensive minireview, we summarize recent advances in the physical methods for decellularized nerve xenograft, focusing on the effects of cellular debris clearance and stability of the native architecture of a xenograft. Furthermore, we compare and summarize the advantages and disadvantages, indicating the future challenges and opportunities in developing multidisciplinary processes for decellularized nerve xenograft.

Long-term total hip arthroplasty rates in patients with acetabular and pelvic fractures after surgery: A population-based cohort study.

BACKGROUND/OBJECTIVE: Osteoarthritis typically develops after surgery for traumatic fractures of the acetabulum and may result in total hip arthroplasty (THA). We conducted a population-based retrospective study to investigate the incidence of THA after treatment of acetabular, pelvic, and combined acetabular and pelvic fractures with open reduction-internal fixation surgery compared with that in the control group. DESIGN: A retrospective population-based cohort study. SETTING: Data were gathered from the Taiwan National Health Insurance Research Database. PARTICIPANTS: We enrolled 3041 patients with acetabular fractures, 5618 with pelvic fractures, and 733 with combined pelvic and acetabular fractures between January 1, 1997, and December 31, 2013, totaling 9392 individuals. The control group comprised 664,349 individuals. Study participants were followed up for the occurrence of THA until death or the end of the study period. RESULTS: The THA rates after surgical intervention were 17.82%, 7.28%, and 18.01% in patients with acetabular, pelvic, and combined acetabular and pelvic fractures, respectively. Moreover, they were significantly higher for the acetabular fracture, pelvic fracture, and combined-fracture groups (adjusted hazard ratios [aHRs] = 58.42, 21.68, and 62.04, respectively) than for the control group (p < 0.0001) and significantly higher for the acetabular fracture and combined-fracture groups than for the pelvic fracture group (aHRs = 2.59 and 2.68, respectively; p < 0.0001). CONCLUSION: The incidence rates of THA after surgical intervention in the pelvic fracture, acetabular fracture, and combined-fracture groups were significantly higher than that of the control group.

Single-stage anterior debridement and fibular allograft implantation followed by posterior instrumentation for complicated infectious spondylitis: report of 20 cases and review of the literature.

Complicated infectious spondylitis is an infrequent infection with severe spinal destruction, and is indicated for combined anterior and posterior surgeries. Staged debridement and subsequent reconstruction is advocated in the literature. The purpose of this study is to evaluate the feasibility and clinical outcome of patients who underwent single-stage combined anterior debridement and fibular allograft implantation followed by supplemental posterior fixation for complicated infectious spondylitis. We retrospectively reviewed the medical records of 20 patients who underwent single-stage combined anterior and posterior surgeries for complicated infectious spondylitis from January 2005 to December 2010. Complicated infectious spondylitis was defined as at least 1 vertebral osteomyelitis with pathological fracture or severe bony destruction and adjacent discitis, based on imaging studies. The severity of the neurological status was evaluated using the Frankel scale. The clinical outcomes were assessed by careful physical examination and regular serological tests to determine the visual analog scale (VAS) score and Macnab criteria. Correction of the sagittal Cobb angle on radiography was also compared before and after surgery. The Wilcoxon signed-rank test was used to analyze patient surgical prognosis and radiological findings. All patients with complicated infectious spondylitis were successfully treated by single-stage combined anterior and posterior surgeries. No patients experienced neurologic deterioration. The average VAS score was 7.8 before surgery and significantly decreased to 2.1 at discharge. Three patients had excellent outcomes and 17 had good outcomes, based on Macnab criteria. The average length of the allograft for reconstruction was 64.0 mm. Kyphotic deformity improved in all patients, with an average correction angle of 13.4°. There was no implant breakage or allograft dislodgement during at least 36 months of follow-up. Single-stage anterior debridement and fibular allograft implantation followed by posterior pedicle screw instrumentation provide immediate stability, satisfactory alignment, and successful infection control. Fibular allograft implantation seems to be a good alternative for anterior reconstruction; it can proceed to bony incorporation and avoids donor site morbidity.