LIPSS-based functional surfaces produced by multi-beam nanostructuring with 2601 beams and real-time thermal processes measurement.

A unique combination of the ultrashort high-energy pulsed laser system with exceptional beam quality and a novel Diffractive Optical Element (DOE) enables simultaneous production of 2601 spots organized in the square-shaped 1 × 1 mm matrix in less than 0.01 ms. By adjusting the laser and processing parameters each spot can contain Laser Induced Periodic Surface Structures (LIPSS, ripples), including high-spatial frequency LIPSS (HFSL) and low-spatial frequency LIPSS (LSFL). DOE placed before galvanometric scanner allows easy integration and stitching of the pattern over larger areas. In addition, the LIPSS formation was monitored for the first time using fast infrared radiometry for verification of real-time quality control possibilities. During the LIPSS fabrication, solidification plateaus were observed after each laser pulse, which enables process control by monitoring heat accumulation or plateau length using a new signal derivation approach. Analysis of solidification plateaus after each laser pulse enabled dynamic calibration of the measurement. Heat accumulation temperatures from 200 to 1000 °C were observed from measurement and compared to the theoretical model. The temperature measurements revealed interesting changes in the physics of the laser ablation process. Moreover, the highest throughput on the area of 40 × 40 mm reached 1910 cm2/min, which is the highest demonstrated throughput of LIPSS nanostructuring, to the best of our knowledge. Thus, showing great potential for the efficient production of LIPSS-based functional surfaces which can be used to improve surface mechanical, biological or optical properties.

Experimental investigation of a time-power transformation method for flash-pulse thermographic testing.

The paper deals with flash-pulse thermography, which is one of the most used thermographic inspection methods. The method is based on flash excitation of an inspected object and an analysis of its thermal response recorded by an infrared camera. This paper deals with a time-power transformation method (P-function) for an evaluation of the flash-pulse thermography measurement. The method is based on a transformation of the measured thermal response using a power function of time. An adaptation of the method is introduced, and an experimental investigation of the method is presented. The method and the evaluation procedure are described. A flash-pulse inspection of an experimental sample is performed, and the results of the inspection obtained by the P-function method and by a fast Fourier transform evaluation are compared using a contrast-to-noise ratio ranking. Advantages of the P-function method resulting from its numerical outputs for an estimation of the depth of defects are described. An influence of noise reduction and data preprocessing is discussed.

Comparison of the long-term effectiveness of physiotherapy programs with low-level laser therapy and pulsed magnetic field in patients with carpal tunnel syndrome.

PURPOSE: The aim of the study was to compare the long term effects of low - level laser therapy (LLLT) and pulsed magnetic field (PMF) in the rehabilitation of patients with carpal tunnel syndrome (CTS). METHODS: The study included 38 patients with idiopathic CTS, confirmed by electroneurographic (ENG) examination. All patients were randomly assigned to 2 groups: group L (18 patients) treated with LLLT and group M (20 patients) with PMF therapy. Clinical assessment, including day and night pain, the presence of paresthesia, functional tests (Phalen, Tinel, armband tests) and pain severity according to the Visual Analogue Scale (VAS) was conducted before treatment, after the first series of 10 sessions, after a two-week break, after the second series of 10 sessions and six months after the last series. RESULTS: After LLLT a significant reduction of day and night pain was observed at each stage of treatment and 6 months after the last series (p<0.05). However, in group M, a significant reduction of both day and night pain was demonstrated only after the second series (p<0.05). A reduction of the incidence of Phalen's symptoms were noticed in both groups, however, only in group L the improvement was significant (p<0.05). In groups L and M a significant reduction of pain intensity was observed at every stage of treatment (p<0.05). CONCLUSIONS: Although after LLL as well as PMF therapy clinical improvement was observed, the most significant differences were registered after the second series and persisted for up to 6 months in both groups.

Morphological changes of the vocal fold mucosa in hyperfunctional dysphonia diagnosed by psychoacoustic and videostroboscopic methods.

PURPOSE: The aim of the study was to provide a morphological assessment of the laryngeal mucosa in patients with hyperfunctional dysphonia diagnosed by psychoacoustic and videostroboscopic methods. MATERIAL AND METHODS: Forty patients with voice quality disorders of hyperfunctional dysphonia were recruited for participation in the study. The diagnosis of dysphonia was based on the Voice Rating Scale GRBAS, and endoscopic and stroboscopic assessment of the vocal folds. Acoustic assessment was carried out using following parameters: fundamental frequency, Jitter, Shimmer, Noise to Harmonic Rate and Yanagihara (YG) scale. In order to evaluate the morphology of the vocal fold mucosa transmission electron microscopy was performed using postoperative material obtained from the larynx. Results of clinical and morphological analysis were compared with the reference group. The morphological material was obtained from patients with hypopharyngeal cancer without pathological changes of the vocal folds. RESULTS: The psychoacoustic assessment using the perceptual GRBAS scale enables the appropriate diagnostics of hyperfunctional dysphonia, which was confirmed by evaluation of acoustic parameters and YG scale analysis. In 40 patients with voice quality disorders causing by hyperfunctional dysphonia, in morphological assessment of the laryngeal mucosa, 4 (10%) patients demonstrated the presence of oedema and signs of intensive dysphonia in psychoacoustic and stroboscopic examination. CONCLUSIONS: Oedema of the laryngeal mucosa confirmed by stroboscopic and ultramorphological examination may coexist with hyperfunctional dysphonia. The presence of the laryngeal oedema in patients with hyperfunctional dysphonia has the negative impact on voice quality in psychoacoustic assessment with the use of the GRBAS and YG scales.