Sparse Damage Detection with Complex Group Lasso and Adaptive Complex Group Lasso.

Sparsity-based methods have recently come to the foreground of damage detection applications posing a robust and efficient alternative for traditional approaches. At the same time, low-frequency inspection is known to enable global monitoring with waves propagating over large distances. In this paper, a single sensor complex Group Lasso methodology for the problem of structural defect localization by means of compressive sensing and complex low-frequency response functions is presented. The complex Group Lasso methodology is evaluated on composite plates with induced scatterers. An adaptive setting of the methodology is also proposed to further enhance resolution. Results from both approaches are compared with a full-array, super-resolution MUSIC technique of the same signal model. Both algorithms are shown to demonstrate high and competitive performance.

Long-term outcome of scleral-fixated posterior chamber intraocular lens implantation with the knotless Z-suture technique.

PURPOSE: To assess the long-term results and complications of scleral-fixated posterior chamber intraocular lenses (PC IOLs) with the knotless Z-suture technique. SETTING: University Eye Hospital, Tübingen, Germany. DESIGN: Retrospective case series. METHODS: Records of consecutive patients who had implantation of scleral-fixated PC IOLs with the knotless Z-suture technique with a minimum follow-up of 3 years were reviewed. RESULTS: Sixty-six eyes of 62 patients were included. The mean preoperative corrected distance visual acuity (CDVA) was 0.71 logarithm of the minimum angle of resolution (logMAR) ± 0.58 (SD). The mean CDVA was 0.67 ± 0.54 logMAR (P = .257; n = 66) after 3 years, 0.73 ± 0.55 logMAR (P = .399; n = 60) after 5 years, 0.8 ± 0.68 logMAR (P = .348; n = 30) after 8 years, and 1.09 ± 0.76 logMAR (P = .069; n = 13) after 10 years. Failure because of suture breakage was observed in 11 eyes (16.7%) after a mean of 7.5 years. Kaplan-Meier time-to-event analysis showed a 40% failure probability after 10 years. Traumatic aphakia was the only risk factor for failure (odds ratio 4.1; 95% confidence interval, 1.0-18.3; P = .049). Complications included retinal detachment (15%), cystoid macular edema (9%), increased intraocular pressure requiring surgical intervention (7.6%), corneal edema (4.5%), and posterior iris-chafing syndrome with microhyphema (3%). CONCLUSIONS: Implantation of scleral-fixated PC IOLs using the knotless Z-suture was a safe technique resulting in good visual outcomes. The long-term success of the procedure was dependent on the material properties of the suture.