Search results for "laser"

Rilievi laser scanner con tecniche di registrazione in situ: il sistema Topcon GLS2000 per il rilievo di siti archeologici

Il lavoro svolto presenta i risultati ottenuti durante una campagna di rilievi laser scanner in ambito archeologico effettuata utilizzando il sistema GLS2000 della Topcon. Le attività di rilievo sono state condotte per la documentazione e ricostruzione tridimensionale della Domus romana all’interno del Parco archeologico di Lilibeo a Marsala. Lo scopo del lavoro è stato quello di utilizzare e verificare le tecniche di registrazione in situ impiegando, in particolare, il metodo della poligonale.

Integration of terrestrial laser scanning and UAV-SFM technique to generate a detailed 3D textured model of a heritage building

2020

The digital twin is among the Top 10 of the strategic technological trends for the period 2007-2019, and it represents a powerful tool for the conservation and enhancement of cultural heritage. It reproduces with "precision" a physical asset, thus allowing to investigate its structure and to analyze the deformations that occur over the years. Various techniques have been introduced to obtain high-resolution 3D models. Among these, the Terrestrial Laser Scanner (TLS) is widely recognized as the gold standard to generate accurate 3D metric reconstructions. TLS allows acquiring a lot of data (point cloud) in a fast way, being not in physical contact with the objects of investigation. By integr…

Elaboración de modelos 3D de diferentes morfologías y escalas utilizando técnicas Structure-from-Motion y fotografías terrestres

2016

En este trabajo se evalúan los métodos de foto-reconstrucción automatizada basados en el uso conjunto de las técnicas Structure from Motion (SfM) y Multi-View Stereo (MVS) para medir, monitorizar y cuantificar la dinámica de tres formas geomorfológicas: i) el glaciar rocoso del Corral del Veleta (Granada, España), ii) un paisaje de cárcavas de tipo calanchi (Sicilia, Italia) y ii) cinco pequeñas cabeceras de cárcava (Cáceres, España). Se incluyen en este trabajo los resultados sobre la precisión, utilidad y aplicabilidad de estas técnicas. Para la cuantificación de la precisión se utilizan el error cuadrático medio (RMSE) de los puntos de control que se emplean en la georreferenciación y la…

The Latomiae of Syracuse: A Geotechnical Mapping Through Rock Reflectivity

2014

The archeological site of the Latomia del Paradiso (Syracuse) is endangered by severe instability phenomena due to the shape of walls and underground excava-tion related with the poor mechanical characteristics of the weathered and wet rock. The failure of huge blocks from the ceiling of the underground areas and the detaching of rock "flakes" from the walls surface make the geotechnical zon-ing particularly complex. the zoning is based on the characteristics of the rock wall surface that, in first approximation, can be distinguished in regularized sur-faces because of mining , and in irregular surfaces characterized by fracture prop-agation. The elaboration of reflectivity values obtained …

Posterior chamber phakic intraocular lenses after penetrating keratoplasty.

2009

Purpose To evaluate the efficacy, predictability, and safety of a phakic posterior chamber intraocular Collamer lens (ICL) after penetrating keratoplasty (PKP). Setting Fernandez-Vega Ophthalmological Institute, Oviedo, Spain. Methods A myopic or toric ICL was implanted after PKP in eyes unable to wear glasses or contact lenses and for which corneal laser surgery was contraindicated. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, and endothelial cell count were recorded preoperatively and 24 months postoperatively. Results Preoperatively, the 15 eyes had myopia from −2.00 to −17.00 diopters (D) or astigmatism from −1.50 to −7.00 D. …

Corneal thickness differences between type 2 diabetes and non-diabetes subjects during preoperative laser surgery examination

2016

Aims To evaluate the differences in corneal thickness between type 2 diabetes subjects with HbA1c under 7.0% and non-diabetes subjects during their preoperative laser surgery examinations. Methods The mean of five consecutive corneal thickness measurements at the central and mid-peripheral cornea was obtained by means of noncontact scanning-slit corneal topography (Orbscan Topography System II; Orbscan, Inc., Salt Lake City, UT, USA) in 35 myopic non-insulin dependent type 2 diabetes subjects (17 males and 18 females) and 48 healthy myopic controls (23 males and 25 females). Results The corneal thickness values at the central and mid-peripheral cornea were significantly higher in the diabet…

Soft palate preservation after tumor resection with transoral laser microsurgery

2012

Background: Management and preservation of the soft palate is dependent on clinical stage and tumor histology. However, available literature is scarce regarding the palate preservation with the use of laser CO 2 . Objectives : We report the results obtained after management with laser surgery and soft palate preservation in three patients with salivary gland neoplasms. Method: Three patients with minor salivary gland tumors were treated by means of transoral laser microsurgery. All tumors were assessed using magnetic resonance imaging. All tumors were >3 cm. Soft palate function was preserved and reconstruction was performed with primary closure. Patients began oral feeding the same day and…

Impact of resection margin status and revision transoral laser microsurgery in early glottic cancer: analysis of organ preservation and local disease…

2022

Abstract Introduction Transoral laser microsurgery represents the treatment of choice for early glottic cancer. Its use and effectiveness are mainly related to laryngeal exposure and deep extension of tumor. Histopathologic assessment of surgical margin presents a main issue about transoral laser microsurgery and complete oncological excision. Objective The aim was to analyze the impact of revision surgery on organ preservation and local disease control in patients with early glottic cancer treated by transoral laser microsurgery. Methods We carried out a retrospective study on a cohort of 153 patients with early glottic cancer (Tis, T1, T2) treated by transoral laser microsurgery. Resectio…

CO(2)-laser treatment of laryngeal amyloidosis.

2003

Four consecutive female patients (age: 14–47 years) with laryngeal amyloidosis, treated with endoscopic CO2-laser surgery, entered the study. All patients underwent periodic microlaryngoscopies following surgery to confirm the adequacy of the surgical resection. Recurrences or suspected lesions were resected and fibrin deposits were removed to prevent the formation of synechiae or healing adhesions. After two negative microlaryngoscopies, performed two months apart, the patients were followed-up approximately every six months over a period from six months to 18 years, with no evidence of recurrences. The endoscopic CO2-laser technique is highly effective in the treatment of localized laryng…

Yellow (577 nm) micropulse laser versus half-dose verteporfin photodynamic therapy in eyes with chronic central serous chorioretinopathy: results of …

2018

PurposeTo compare the functional and anatomical outcomes of eyes with chronic central serous chorioretinopathy treated with yellow micropulse (MP) laser versus half-dose verteporfin photodynamic therapy (PDT).MethodsThis is a multicentre, retrospective comparative study of 92 eyes treated with yellow MP laser (duty cycle of 5%, zero spacing between spots, spot size varied from 100 to 200 µm, power varied from 320 to 660 mW, and the pulse burst duration was 200 ms) and 67 eyes treated with PDT (half-dose verteporfin (3 mg/m2) infused over 10 min), followed by laser activation for 83 s. Spot sizes varied from 400 to 2000 µm.ResultsIn the MP group, at 12 months of follow-up, the mean best corr…