OBJECTIVE Intra-articular screws are used for internal fixation of osteochondral fragments after fracture or osteochondritis dissecans. This causes cartilage injury potentially leading to chondrocyte death. We have visualised/quantified the hole and zone of cell death (ZCD) in cartilage after drilling/insertion of various articular screws. METHOD Using an ex vivo bovine model with transmitted...

introduction: this study investigated the influence of erbium-doped yttrium aluminum garnet (er:yag) laser on microhardness, chemical composition and subsurface morphology of dentin cavity walls. methods: forty sound human premolars were selected and randomly assigned into four groups. class v cavities were prepared either with an er:yag laser (groups 1 and 2; 15 hz, 250 mj for enamel, 10 hz, 2...

Non-Gaussian beam profiles such as Bessel or annular beams enable novel approaches to modifying materials through laser-based processing. In this review paper, properties, generation methods and emerging applications for nonconventional beam shapes are discussed, including Bessel, annular, and vortex beams. These intensity profiles have important implications in a number of technologically rele...

We compared two methods of zona pellucida drilling. 213 embryos were biopsied with acid Tyrode. Each biopsy took 3 minutes and the entire procedure ~29 minutes. 5% of blastomeres lysed, 49% of embryos became blastocyst and 36% of patients became pregnant. 229 embryos were biopsied with laser. Each biopsy took 30 seconds and the entire procedure ~7 minutes. 2.5% of blastomeres lysed, 50.6% of em...

Laser direct-write (LDW) is an established technology for manufacturing electronic and optoelectronic appliances such as cellular telephones, digital cameras, and notebook-type personal computers. One of the most successful applications is laser drilling of via holes on printed circuit boards for the manufacture of cellular telephones. Other practical applications include marking, dicing, trimm...

When using ultrafast laser ablation in some orthopedic applications where precise cutting/drilling is required with minimal damage to collateral tissue, it is challenging to produce large-sized and deep holes using a tightly focused laser beam. The feasibility of producing deep, millimeter-size structures under different ablation strategies is investigated. X-ray computed microtomography was em...

Femtosecond laser drilling is used to produce a variablepressure fiber gas cell. Tightly focused laser pulses are used to produce micrometer-diameter radial channels in a hollow-core photonic band-gap fiber (HC-PBGF), and through these microchannels the core of the fiber is filled with a gas. The fiber cell is formed by fusion splicing and sealing the ends of the HC-PBGF to standard step-index ...

In this paper we propose a postprocessing technique for a spectrogram diffusion based harmonic/percussion decomposition algorithm. The proposed technique removes harmonic instrument leakages in the percussion enhanced outputs of the baseline algorithm. The technique uses median filtering and an adaptive detection of percussive segments in subbands followed by piecewise signal reconstruction usi...

The drilling of copper using a dual-pulse femtosecond laser with wavelength of 800 nm, pulse duration of 120 fs and a variable pulse separation time (0.1–150 ps) is investigated theoretically. A one-dimensional two-temperature model with temperature-dependent material properties is considered, including dynamic optical properties and the thermal-physical properties. Rapid phase change and phase...