Search results for "laser"
showing 10 items of 3161 documents
Intravitreal Plasmin Without Associated Vitrectomy as a Treatment for Refractory Diabetic Macular Edema
2009
To determine the effectiveness of a low-dose intravitreal injection of autologous plasmin enzyme (APE), without the performance of a vitrectomy, as a treatment for refractory diffuse diabetic macular edema (DDME).Prospective, comparative, interventional case series.Sixteen patients with bilateral DDME who had not responded to prior laser photocoagulation. All patients received an injection in 1 eye, while the other eye served as a control.Intravitreal 0.2 mL APE injection under topical anesthesia. The APE was obtained using a simplified method.Central macular thickness (CMT) at 1 and 6 months, determined by optical coherence tomography (OCT) and best corrected visual acuity (BCVA).All patie…
Prevention of hyperopic surprise after LASIK in patients with refractive multifocal intraocular lenses.
2011
Purpose. Three cases of patients who developed a similar hyperopic defect in refraction following laser in situ keratomileusis (LASIK) after multifocal intraocular lens (IOL) implantation are described. Methods. Ophthalmologic evaluation including refractive status, corrected and uncorrected visual acuity (both at far and near), and corneal topography in patients presenting similar hyperopic refractive surprise in one eye as a result of LASIK refinement of residual ametropia after refractive multifocal IOL implantation. Results. Laser in situ keratomileusis enhancement for residual ametropia of −1.00 to −1.50 D in patients with a prior implantation of refractive multifocal IOL resulted in a…
High-speed rotational angioplasty-induced echo contrast in vivo and in vitro optical analysis
1992
High-speed rotational angioplasty is being evaluated as an alternative interventional device for the endovascular treatment of chronic coronary occlusions. It has been postulated that this type of angioplasty device may produce particulate debris or cavitations that induce myocardial ischemia. To determine the clinical presence of myocardial ischemia during rotational angioplasty, echocardiographic monitoring for wall motion abnormalities was performed in 9 patients undergoing rotational atheroablation using the Auth Rotablator for 10-sec intervals at 150,000 and 170,000 rpm. No wall motion abnormalities were detected in 5 patients evaluated with transesophageal echocardiography or in 4 pat…
Management of retained bile duct stones: a prospective open trial comparing extracorporeal and intracorporeal lithotripsy.
1996
Abstract Background: Endoscopic management of common bile duct stones has become the approach of choice, especially in patients with high surgical risk. Problems are encountered if there are large stones or a duct stenosis. For these difficult stones, shock wave technology serves as an alternative to surgical intervention. Methods: A total of 125 patients with common bile duct stones in whom conventional endoscopic treatment had failed were selected and treated either by extracorporeal piezoelectric lithotripsy (ESWL, n=79) or intracorporeal electrohydraulic lithotripsy (EHL, n=46). The average age of our patients was 70 years. Results: In the ESWL group visualization of the stones by ultra…
Monochorionic twin pregnancy: screening, pathogenesis of complications and management in the era of microinvasive fetal surgery
2010
Objective The management of monochorionic (MC) twin pregnancies varies in different medical centers. This paper compares screening methods to predict the complications of the MC twin pregnancy and different treatment methods. Methods We performed a literature search without language restriction in Cochrane library and PubMed (1970-2009). Case series and cohort screening studies, pathogenesis and management of complications of MC pregnancy were included. Results Elevated risk for intrauterine fetal death (IUFD) and twin-to-twin transfusion syndrome (TTTS) can be detected sonographically. Monitoring of MC pregnancies at increased risk and regular training sessions for the operating team combi…
Image-Guided Thermal Ablation as an Alternative to Surgery for Papillary Thyroid Microcarcinoma: Preliminary Results of an Italian Experience
2021
PurposeTo report the results of our preliminary experience in treating patients with papillary thyroid microcarcinoma (PTMC) with image-guided thermal ablation, in particular estimating the feasibility, safety and short-term efficacyMaterials and MethodsFrom 2018 patients with cytologically proven PTMC < 10 mm were discussed in a multidisciplinary team and evaluated for feasibility of image-guided thermal ablation. In case of technical feasibility, the three possible alternatives (i.e., image-guided thermal ablation, surgery, and active surveillance) were discussed with patients. Patients who agreed to be treated with image guided thermal ablation underwent radiofrequency (RFA) or la…
Numerical study for a new methodology of flaws detection in train axles
2013
Train loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20 years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coup…
Analytical Study of the Thermal Induced Oscillations Known as Heartbeats
1998
Abstract A laser beam traveling horizontally at a short distance below the free surface of an absorbing solution exhibits various oscillatory states (periodic, quasiperiodic, and chaotic) which depend on both the buoyancy (Archimedes force) and the thermal coefficient of the surface tension (Marangoni effect). The beam oscillations have been called “heartbeats.” In this work, the heartbeats were produced by pumping 1-(2-pyridylazo)-2-naphthol (PAN) solutions in silicone oil with an Ar+continuous-wave laser beam. The relationships between PAN concentration and the other parameters that control the oscillatory behavior were studied. The frequency of the oscillations sensitively varied with sm…
Towards a real-time 3D shape reconstruction using a structured light system
2005
This paper deals with 3D shape reconstruction using a structured light system (SLS) which projects a matrix of laser rays onto the scene to be analyzed. The intrinsic problem of such a system is the correspondence problem solving, which in this particular case amounts to matching up the imaged spots and the originating laser rays. In this paper, we propose a method for automatically obtaining configurations of the system (COS) (i.e. the relative positions of the camera, laser projector, and measuring scene) that permit to achieve a direct and unambiguous correspondence. After, we propose a splitting cell algorithm, which efficiently performs a real-time correspondence procedure. Experimenta…
ELECTROCHEMICAL ANALYSIS ON FRICTION STIR WELDED AND LASER WELDED 6XXX ALUMINIUM ALLOYS T-JOINTS
2007
Friction Stir Welding (FSW) and Laser Welding (LW) can be successfully employed to weld aluminium alloys, in many cases overcoming the difficulties encountered with more conventional welding processes like MIG or TIG. The corrosion resistance of the welded joint remains, however, an important issue, especially in applications (like in aircrafts), where corrosion can induce structural failure: the weld region has often lower mechanical resistance in comparison with the parent material and a decrease in its corrosion resistance, especially when the corrosion damage can represent a potential crack initiation site, can be unacceptable in components design. In this work the corrosion resistance …