The effect of scanning strategy on intraoral scanner’s accuracy.

Background The purpose of the present study was to examine the impact of scanning strategy on trueness and precision of the impression acquired from an intraoral scanner. Materials and methods Fifteen complete-arch, mandibular, post orthodontic treatment casts were scanned with a laboratory scanner (Identica SE 3D, Medit) as the gold standard, and with an intraoral scanner (i500 Medit) following 3 different paths of the scanning head over the arch (scanning strategies A, B, C). The hand scans were performed twice by one examiner and repeated by a second examiner, resulting in 180 triangular mesh surfaces (digital casts). The meshes were superimposed on the gold standards using the Viewbox 4 software. The closest distances between the meshes were computed and trueness and precision were evaluated using a General Linear Model. Results Scanning strategy A was statistically significantly better (p < 0.05) and differed from B and C, which were similar. A positive correlation was found among examiner and strategy. Conclusions The accuracy of complete-arch impressions is affected by the scanning strategy. The manufacturer’s recommended strategy was statistically significantly better (p < 0.05). Average accuracy below 50 µm, which is clinically acceptable in most orthodontic procedures, was achieved with all the examined scanning strategies.

Anti-Reflection Nanostructures on Tempered Glass by Dynamic Beam Shaping

Reflectivity and surface topography of tempered glass were modified without any thermal damage to the surroundings by utilizing 1.7 ps ultrashort pulsed laser on its fundamental wavelength of 1030 nm. To speed up the fabrication, a dynamic beam shaping unit combined with a galvanometer scanning head was applied to divide the initial laser beam into a matrix of beamlets with adjustable beamlets number and separation distance. By tuning the laser and processing parameters, reflected intensity can be reduced up to 75% while maintaining 90% of transparency thus showing great potential for display functionalization of mobile phones or laptops.

Radiation Mapping and Laser Profiling Using a Robotic Manipulator

The use of a robotic arm manipulator as a platform for coincident radiation mapping and laser profiling of radioactive sources on a flat surface is investigated in this work. A combined scanning head, integrating a micro-gamma spectrometer and Time of Flight (ToF) sensor were moved in a raster scan pattern across the surface, autonomously undertaken by the robot arm over a 600 × 260 mm survey area. A series of radioactive sources of different emission intensities were scanned in different configurations to test the accuracy and sensitivity of the system. We demonstrate that in each test configuration the system was able to generate a centimeter accurate 3D model complete with an overlaid radiation map detailing the emitted radiation intensity and the corrected surface dose rate.

On-Line Measurement of Wood Surface Smoothness

The latest progress in the field of optics and microelectronics resulted in the development of new generation vision systems capable of scanning surface topography with very high sampling frequencies. The blue color of illuminating light as well as novel systems for controlling ultra-thin laser line thickness allows the measurement of the porous surface of wood with a triangulation method. Three alternative sensors were tested here in order to verify their suitability for the determination of surface topography in the industrial environment. The scanning head was installed at the exit zone of the four-side profiling moulder and was set to scrutinize the wood surface shape line-by-line, immediately after profiling. The sensor was also tested for automatic detection of surface defects appearing on the elements after sanding, wetting and painting with various finishing products. The set of pilot test results is presented, together with an original algorithm for real-time surface defects detection.

Time-Resolved Imaging of VLSI Circuits Using a Single-Point Single-Photon Detector and a Scanning Head

In this paper, we present the first prototype of a Scanning Time-Resolved Emission (STRE) system consisting of a high-sensitivity, low-noise, and low-jitter single-point Superconducting Single-Photon Detector (SSPD) combined with a specialized scanning head of a Laser Scanning Microscope (LSM). This idea was first proposed in late 2006 [1] but required the right combination of detector, customization, and collaboration with a tool vendor to get to fruition. It should be understood that this is still a prototype system under development and significant improvements in acquisition time, resolutions, and performance are expected in the near future. In this paper, we will also present the first preliminary results acquired using a test chip fabricated in 32 nm SOI.

Treatment of rhinophyma using a copper vapor laser

Background.Rhinophyma is considered to be the most severe stage of rosacea, associated with the proliferation of the nose skin epithelium, hyperproduction of the sebaceous glands and telangiectasia.The treatment of rhinophyma remains a difficult task. One of the problems associated with rhinophyma is thickened and lumpy skin, penetrated with telangiectasias. The use of laser radiation in the treatment of rhinophyma seems to be promising, since this method allows blood vessels to be selectively heated.For the first time, we describe the treatment of rhinophyma using a copper vapour laser (CVL) equipped with a computerized scanner.Patient description.A 63-year-old male with Fitzpatrick skin type II was treated using an CVL (‘Yakhroma-med' model, RaS P. N. Lebedev Physical Institute). The clinical manifestations of the disease were typical of the phymatous or hypertrophic rhinophyma type, including significant thickening of the tissues and an uneven roughness of the skin surface. The treatment was carried out using a radiation wavelength of 578 nm, exposure duration of 0.2 s and energy exposure (fluence) of 15-30 J/cm2. Operational parameters used for the CVL in the scanner mode were the average power of 0.6-1.2 W and the focusing size of the light spot on the skin of 0.6 mm. The hexagonal mode of the scanning head was used with a maximum size of 12 mm and 1 mm distance between the centres of the laser spots. The treatment resulted in the restoration of the natural nose shape without redness. No side effects were noted.Conclusion:CVL radiation provided a selective photodisruption of the vessels with increased diameter.Due to the remodelling of the vasculature, the described method showed excellent results in the treatment of rhinophyma without side effects.