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Excimer Laser (excimer + laser)
Kinds of Excimer Laser Terms modified by Excimer Laser Selected AbstractsCombined Excimer Laser and Topical Tacrolimus for the Treatment of Vitiligo: A Pilot StudyDERMATOLOGIC SURGERY, Issue 2 2004Adam Z. Kawalek BA Background. Vitiligo is an acquired skin disorder that is characterized by well-defined, often symmetric white patches. Although current therapeutic modalities are directed toward increasing melanocyte melanin production, few treatment modalities address the immunologic nature of the disease. Objective. To determine whether excimer laser, a known therapeutic modality, in combination with tacrolimus, a topical immunomodulator, accelerate response time and/or improve the degree of response in patients with this disorder. Methods. Eight subjects diagnosed with vitiligo were recruited to participate in this institutional review board,approved double-blind, placebo-controlled study. Twenty-four symmetric vitiliginous patches (elbows, knees) from eight subjects received excimer laser treatment three times per week for 24 treatments or 10 weeks. Additionally, topical tacrolimus 0.1% ointment (Protopic) and placebo (Aquaphor) were applied to randomized patches (left or right) twice daily throughout the length of the trial. Vitiliginous patches were monitored with photographs at baseline, every 2 weeks, and 6 months after treatment. Biopsies were performed on subjects with significant results. Results. Twenty vitiliginous patches from six subjects qualified for evaluation. Fifty percent of patches treated with combination excimer laser and tacrolimus achieved a successful response (75% repigmentation) compared with 20% for the placebo group. Subjects who responded successfully repigmented faster (19%) with combination therapy compared with excimer laser alone. Additionally, three subjects experienced transient hyperpigmentation in lesions treated with combination therapy. Conclusion. Combining topical immunomodulators with known phototherapeutic modalities may represent a key advancement in the treatment of disease. [source] The Midas Touch: Surface Processing With the UV Excimer LaserLASER TECHNIK JOURNAL, Issue 1 2009Drive Disruptive Innovations, Open Up Growth Markets Very much like the ancient king Midas who as the legend tells was able to transform ordinary material into gold by the touch of his hand, today's excimer lasers are capable of transforming an unspecificmaterial layer into a high value, functional surface by their unique beam properties. Representing today's most cost-effective and dependable pulsed, ultraviolet (UV) laser technology, excimer lasers enable disruptive innovation in various growth industries as diverse as the markets for flat panel displays, automobiles, biomedical devices and alternative energies. It is the combination of two fundamental aspects, namely wavelength and output power, which determines the excimer laser's unique value adding potential in high tech industries which more than ever have to balance product size-efficiency and performance demands with process speed and production costs. This article will try to provide an insight into some key applications of the excimer laser. [source] Combined Excimer Laser and Topical Tacrolimus for the Treatment of Vitiligo: A Pilot StudyDERMATOLOGIC SURGERY, Issue 2 2004Adam Z. Kawalek BA Background. Vitiligo is an acquired skin disorder that is characterized by well-defined, often symmetric white patches. Although current therapeutic modalities are directed toward increasing melanocyte melanin production, few treatment modalities address the immunologic nature of the disease. Objective. To determine whether excimer laser, a known therapeutic modality, in combination with tacrolimus, a topical immunomodulator, accelerate response time and/or improve the degree of response in patients with this disorder. Methods. Eight subjects diagnosed with vitiligo were recruited to participate in this institutional review board,approved double-blind, placebo-controlled study. Twenty-four symmetric vitiliginous patches (elbows, knees) from eight subjects received excimer laser treatment three times per week for 24 treatments or 10 weeks. Additionally, topical tacrolimus 0.1% ointment (Protopic) and placebo (Aquaphor) were applied to randomized patches (left or right) twice daily throughout the length of the trial. Vitiliginous patches were monitored with photographs at baseline, every 2 weeks, and 6 months after treatment. Biopsies were performed on subjects with significant results. Results. Twenty vitiliginous patches from six subjects qualified for evaluation. Fifty percent of patches treated with combination excimer laser and tacrolimus achieved a successful response (75% repigmentation) compared with 20% for the placebo group. Subjects who responded successfully repigmented faster (19%) with combination therapy compared with excimer laser alone. Additionally, three subjects experienced transient hyperpigmentation in lesions treated with combination therapy. Conclusion. Combining topical immunomodulators with known phototherapeutic modalities may represent a key advancement in the treatment of disease. [source] A silica-based monolithic column in capillary HPLC and CEC coupled with ESI-MS or electrospray-atmospheric-pressure laser ionization-MSELECTROPHORESIS, Issue 21 2005Stefan Droste Abstract We describe the successful coupling of CEC and capillary HPLC with the recently developed atmospheric-pressure laser ionization (APLI) method. APLI is suitable for selectively and sensitively ionizing nonpolar aromatic compounds at ambient pressure for subsequent mass-selective detection. The polycyclic aromatic hydrocarbons used as analytes are first separated either by CEC on a silica-based monolithic column or by capillary HPLC. The eluent, along with a sheath flow, is volatilized by microelectrospray and then selectively ionized by excimer laser (KrF*) radiation via two-photon excitation. A QTOF-MS is used as mass-selective detector. This interface combination makes soft ionization of thermally labile nonpolar aromatic analytes possible. [source] Laser Ablation (193 nm), Purification and Determination of Very Low Concentrations of Solar Wind Nitrogen Implanted in Targets from the GENESIS SpacecraftGEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 2 2009Laurent Zimmermann azote; ablation laser; purification; spectrométrie de masse; mission GENESIS The GENESIS space mission recovered ions emitted by the Sun during a 27 month period. In order to extract, purify and determine the very low quantities of solar nitrogen implanted in the GENESIS targets, a new installation was developed and constructed at the CRPG (Nancy, France). It permitted the simultaneous determination of nitrogen and noble gases extracted from the target by laser ablation. The extraction procedure used a 193 nm excimer laser that allowed for surface contamination in the outer 5 nm to be removed, followed by a step that removed 50 nm of the target material, extracting the solar nitrogen and noble gases implanted in the target. Following purification using Ti and Zr getters for noble gases and a Cu-CuO oxidation cycle for N2, the extracted gases were analysed by static mode (pumps closed) mass spectrometry using electron multiplier and Faraday cup detectors. The nitrogen blanks from the purification section and the static line (30 minutes) were only 0.46 picomole and 0.47 picomole, respectively. La mission GENESIS a récupéré des ions émis par le soleil pendant une période de 27 mois. Afin d'extraire, purifier et analyser de très faibles quantités d'azote solaire implantés dans des cibles GENESIS, une nouvelle installation a été développée et construite au CRPG. Elle a permis l'analyse simultanée de l'azote et des gaz nobles extraits de la couche d'or par ablation. La procédure d'extraction a utilisé un laser Excimer 193 nm qui a permis une étape d'extraction à 5 nm pour éliminer la pollution à la surface, suivie d'une étape qui a extrait jusqu'à une profondeur de 50 nm l'azote et les gaz rares solaires implantés dans la cible. Après une purification à l'aide de getters Ti et Zr pour les gaz rares et un cycle d'oxydation Cu-CuO pour N2, les gaz extraits ont été analysés en mode statique (pompage fermé) par spectrométrie de masse à l'aide d'un multiplicateur d'électrons et d'une cage de Faraday. Les blancs d'azote provenant de la partie purification et de la ligne en statique (30 minutes) étaient de seulement 0.46 et 0.47 picomole, respectivement. [source] Laser desorption postionization for imaging MS of biological materialJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2010Artem Akhmetov Abstract Vacuum ultraviolet single photon ionization (VUV SPI) is a soft ionization technique that has the potential to address many of the limitations of matrix-assisted laser desorption/ionization (MALDI) for imaging MS. Laser desorption postionization (LDPI) uses VUV SPI for postionization and is experimentally analogous to a MALDI instrument with the addition of a pulsed VUV light source. This review discusses progress in LDPI-MS over the last decade, with an emphasis on imaging MS of bacterial biofilms, analytes whose high salt environment make them particularly resistant to imaging by MALDI-MS. This review first considers fundamental aspects of VUV SPI including ionization mechanisms, cross sections, quantum yields of ionization, dissociation and potential mass limits. The most common sources of pulsed VUV radiation are then described along with a newly constructed LDPI-MS instrument with imaging capabilities. Next, the detection and imaging of small molecules within intact biofilms is demonstrated by LDPI-MS using 7.87 eV (157.6 nm) VUV photons from a molecular fluorine excimer laser, followed by the use of aromatic tags for detection of selected species within the biofilm. The final section considers the future prospects for imaging intact biological samples by LDPI-MS. Copyright © 2010 John Wiley & Sons, Ltd. [source] Combination of 308-nm xenon chloride excimer laser and topical calcipotriol in vitiligoJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 4 2007SM Goldinger Abstract Background,, A large variety of therapeutic agents are being used for the treatment of vitiligo, but treatment remains a challenge. Recently, monochromatic phototherapies such as 311-nm narrowband ultraviolet B therapy and 308-nm xenon chloride excimer laser have been reported to be an effective and safe therapeutic option in children and adult patients with vitiligo. Single reports stipulate that the addition of topically applied calcipotriol to phototherapy increases its effectiveness. Objective, The purpose of the present pilot study was to determine if the addition of topical calcipotriol increases the efficacy of the 308-nm xenon chloride excimer in the treatment of vitiligo. Methods, Ten patients with vitiligo with essentially bilateral symmetrical lesions were enrolled in this prospective right/left comparative, single-blinded trial conducted over a 15-month period. All patients received 308-nm XeCl excimer laser therapy three times weekly. Calcipotriol ointment (Daivonex®) was applied to lesions on one side of the body twice daily. Results, After 24 treatments (8 weeks), nine patients were evaluated. Eight patients showed evidence of repigmentation on both body sides, with no significant difference between the body side treated with calcipotriol and excimer laser and the side treated with excimer laser alone. The mean repigmentation rate was 22.4% (1, 37%). Conclusion, The addition of calcipotriol ointment to 308-nm xenon chloride excimer laser phototherapy does not significantly enhance its efficacy. Small additive effects must be investigated in a larger trial. [source] The efficacy of excimer laser (308 nm) for vitiligo at different body sitesJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2006A Hofer Abstract Background, The treatment with XeCl-excimer laser generated 308-nm UVB radiation has shown promising results in patients with vitiligo. Objective, In this controlled, prospective trial we studied the primary efficacy (start and grade of repigmentation) and patient's satisfaction of XeCl-excimer laser for treatment of vitiligo patches at different body sites and re-evaluated the achieved repigmentation 12 months after the end of therapy. Methods, Twenty-five patients with generalized or localized vitiligo with a total of 85 lesions at different body sites were enrolled in this study. Vitiligo patches were treated with 308-nm XeCl-excimer laser 3 times a week for 6 to 10 weeks. The overall repigmentation grade of each treated lesion was evaluated once a week on a 5 point scale rating from 0 (no repigmentation), 1 (1,5%), 2 (6,25%), 3 (26,50%), 4 (51,75%), to 5 (76,100%). Results, Twenty-four patients completed the study. Within 6 to 10 weeks of treatment 67% of the patients (16/24) developed follicular repigmentation of at least one of their vitiligo lesions. Lesion repigmentation started after a mean of 13 treatments in lesions located on the face, trunk, arm, and/or leg (high-responder location), and after a mean of 22 treatments in lesions located on the elbow, wrist, dorsum of the hand, knee, and/or dorsum of the foot (low-responder location). Untreated control lesions and lesions located on the fingers did not achieve any repigmentation. After 10 weeks of treatment repigmentation of more than 75% was found in 25% (7/28) of lesions of the high-responder location group versus 2% (1/43) of lesions of the low-responder location group. In most cases, laser-induced repigmentation was persistent, as determined 12 months after the end of treatment. Conclusions, 308-nm excimer laser is an effective modality for the treatment of vitiligo. However, similar to other non-surgical treatment modalities, the therapeutic effect is mainly dependent on the location of vitiligo lesions. [source] The Midas Touch: Surface Processing With the UV Excimer LaserLASER TECHNIK JOURNAL, Issue 1 2009Drive Disruptive Innovations, Open Up Growth Markets Very much like the ancient king Midas who as the legend tells was able to transform ordinary material into gold by the touch of his hand, today's excimer lasers are capable of transforming an unspecificmaterial layer into a high value, functional surface by their unique beam properties. Representing today's most cost-effective and dependable pulsed, ultraviolet (UV) laser technology, excimer lasers enable disruptive innovation in various growth industries as diverse as the markets for flat panel displays, automobiles, biomedical devices and alternative energies. It is the combination of two fundamental aspects, namely wavelength and output power, which determines the excimer laser's unique value adding potential in high tech industries which more than ever have to balance product size-efficiency and performance demands with process speed and production costs. This article will try to provide an insight into some key applications of the excimer laser. [source] Utilization of excimer laser debulking for critical lesions unsuitable for standard renal angioplasty,LASERS IN SURGERY AND MEDICINE, Issue 9 2009On Topaz MD Abstract Background The energy emitted by ultraviolet laser is avidly absorbed in atherosclerotic plaques. Conceptually, it could be applied for debulking of selected atherosclerotic renal artery stenoses. We describe early experience with revascularization of critical renal artery lesions deemed unsuitable for standard renal angioplasty. Institutional Review Board permission to conduct the data analysis was obtained. Methods Among 130 percutaneous renal artery interventions with balloon angioplasty and adjunct stenting, there were 12 (9%) patients who underwent laser debulking prior to stenting. These patients presented with critical (95±3.5% stenoses) lesions (11 de novo, 1 stent restenosis) deemed unsuitable for standard renal angioplasty because of marked eccentricity and presence of thrombus. Indications for intervention included preservation of kidney function, treatment of uncontrolled hypertension, management of congestive heart failure, and treatment of unstable angina. Blood pressure and estimated glomerular filtration rate (eGFR) were measured pre- and 3 weeks post-intervention. Results A baseline angiographic stenosis of 95±3.5% was reduced to 50±13% with laser debulking. There were no laser-induced complications. Post-stenting the angiographic residual stenosis was 0%. The mean gradient across the lesions was reduced from baseline 85±40 to 0,mmHg. A normal post-intervention antegrade renal flow was observed in all patients. Baseline mean systolic BP of 178±20,mmHg decreased to 132±12,mmHg (P<0.0001) and mean diastolic pressure of 85±16,mmHg reduced to 71±9,mmHg (P,=,0.01). A pre-intervention mean eGFR of 47.7±19,ml/min/1.73,m2 increased to 56±20.4,ml/min/1.73,m2 (P,=,0.05) post-procedure. The interventions were not associated with major renal or cardiac adverse events. During follow-up one patient developed transient contrast-induced nephropathy. Conclusions Debulking of select renal artery stenoses with laser angioplasty followed by adjunct stenting is feasible. Further prospective, randomized studies will be required to explore the role of debulking and laser angioplasty in renal artery revascularization. Lasers Surg. Med. 41:622,627, 2009. © 2009 Wiley-Liss, Inc. [source] Treatment of alopecia areata with the 308-nm xenon chloride excimer laser: Case report of two successful treatments with the excimer laserLASERS IN SURGERY AND MEDICINE, Issue 2 2004Cuneyt Gundogan MD Abstract Background and Objectives Alopecia areata is a common disease of unknown etiology; it causes significant cosmetic and psycho-social distress for most of the people it affects. We report on an innovative form of treatment in two patients with typical alopecia areata on the capillitium. Study Design/Patients and Methods We successfully treated two patients whose alopecia areata had worsened progressively for 3 and 14 weeks. The treatment involved the use of a 308 nm xenon chloride excimer laser (dosage 300,2,300 mJ/cm2 per session). Results After 11 and 12 sessions within a 9-week and 11-week period, the entire affected focus showed homogenous and thick regrowth. No relapse was observed during the follow-up period of 5 and 18 months. Conclusions The use of the excimer laser is an effective, elegant, and safe means of treatment and has good tolerability. Analogous to topical treatment of alopecia areata, the immunosuppressive mechanism of the excimer laser can be interpreted as an induction of T-cell apoptosis. This new means of treatment has yet to be discussed in medical literature. Further studies with greater numbers are needed to assess its potential more precisely and evaluate the excimer laser in treating alopecia areata. Lasers Surg. Med. 34:86,90, 2004. © 2004 Wiley-Liss, Inc. [source] The design of single particle laser mass spectrometers,MASS SPECTROMETRY REVIEWS, Issue 2 2007Daniel M. MurphyArticle first published online: 16 OCT 200 Abstract This review explores some of the design choices made with single particle mass spectrometers. Different instruments have used various configurations of inlets, particle sizing techniques, ionization lasers, mass spectrometers, and other components. Systematic bias against non-spherical particles probably exceeds a factor of 2 for all instruments. An ionization laser tradeoff is the relatively poor beam quality and reliability of an excimer laser versus the longer wavelengths and slower response time of an Nd-YAG laser. Single particle instruments can make special demands on the speed and dynamic range of the mass spectrometers. This review explains some of the choices made for instruments that were developed for different types of measurements in the atmosphere. Some practical design notes are also given from the author's experience with each section of the instrument. Published 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:150,165, 2007 [source] Using scanning electron, confocal and optical microscopes to measure microscopic holes in traysPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2005Laura Bix Abstract Package integrity is of paramount importance to the medical device industry. As healthcare costs soar and integrity testers become more and more sensitive, concern with the question ,what hole size allows microbial penetration into device packages?' is re-ignited. However, producing a consistent and measurable defect in the microcosm presents challenges. Varying techniques are currently employed to produce these defects. Use of an excimer laser is one of the most precise and accurate techniques, and holes ,certified' to be a given size can be purchased at a significant cost. To verify the accuracy and precision of holes drilled with an excimer laser, researchers measured laser-drilled ,exit' and ,entry' holes in glycol-modified polyetheylene terephthalate (PETG) trays using scanning electron microscopy (SEM) and confocal microscopy. This data and the certification data provided by the laser driller were analysed using a mixed-model analysis of variance (ANOVA). Both the effect of measuring technique and hole side (entry vs. exit) were found to be significant. These significant differences have the potential to impact the question that the industry faces with regard to penetration threshold. This suggests that a shift in thinking is needed. Perhaps it would be better if the industry stops thinking about hole size and begins to think in terms of what researchers have referred to as the ,effective hole', which is defined as the volume of gas that will flow through a hole of defined size per unit time. Copyright © 2005 John Wiley & Sons, Ltd. [source] A comparative study of laser- and electric-field-induced effects on the crystallinity, surface morphology and plasmon resonance of indium and gold thin filmsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2010Prashant Kumar Abstract The effects of post-deposition treatment of In and Au thin films by excimer laser and electric field are reported. The films were subjected to an electric field in the range of 0.1,3.3,kV/cm and laser irradiation in the range from 0.01 to 0.1,J/cm2. The effect of this treatment on the morphology and crystallinity of indium and gold thin films (10,100,nm thickness) is investigated. Indium films exhibited a three-fold grain growth at an electric field of 3.3,kV/cm. Gold thin film, on the other hand, showed significant grain growth at a much lower field of 0.6,kV/cm. The as-deposited thin films of indium and gold were amorphous but turned nanocrystalline with average crystallite sizes of 57,nm at 3.33,kV/cm and 35,nm at 0.66,kV/cm, respectively. When indium thin films were laser irradiated, flat disc-shaped grains for as-deposited thin films were transformed to spherical grains at a laser fluence of 0.02,J/cm2 and cubical grains at 0.05,J/cm2. At 0.05,J/cm2, as-deposited amorphous indium and gold thin films turned nanocrystalline with crystallite sizes of 50,nm and 10,nm, respectively. Significantly, laser treatment causes the grain-size distribution to become narrower with a shift in mean size to larger values. Electric-field treatment on the other hand leads to a shifting of the mean grain size to larger values without affecting the distribution. [source] Study on the excimer laser annealed amorphous hydrogenated silicon carbon films deposited by PECVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3-4 2010G. Ambrosone Abstract Hydrogenated amorphous silicon carbon films of different carbon content were deposited by plasma enhanced chemical vapour deposition at low substrate temperature (200 °C) and were subjected to excimer laser annealing. X-ray diffraction spectra and field emission scanning electron microscopy images demonstrate that carbon content plays an important role in facilitating the crystallization process induced by the excimer laser treatment (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Some properties of very thin Bi2Te3 layers prepared by laser ablationPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2003R. Zeipl Abstract Thin layers of Bi2Te3 60,nm thickness were prepared by laser ablation in vacuum using KrF excimer laser. The energy of laser varied from 300 to 680,mJ and the laser energy density from 2 to 10,J,cm,2. The substrate temperature varied for different depositions in the interval of 20,500,°C. The influence of preparation conditions on Hall mobility, concentration of charge carriers and conductivity at room temperature is presented. Information about morphology and composition of prepared layers is given. [source] Comparison of the 308-nm excimer laser and a 308-nm excimer lamp with 311-nm narrowband ultraviolet B in the treatment of psoriasisBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2005K. Köllner Summary Background, Psoriasis is a chronic, genetically determined inflammatory disease, characterized by an immunomediated pathogenesis, which affects approximately 1,3% of the population. Various modalities have been used for psoriasis treatment, including ultraviolet (UV) radiation. Narrowband UVB (311 nm) phototherapy is a well-established, widely used and highly efficient treatment for psoriasis, but a big disadvantage is that large areas of unaffected skin are irradiated along with the psoriatic lesions. Objectives, This investigation evaluates a 308-nm excimer laser and a 308-nm excimer lamp in comparison with 311-nm narrowband UVB in the treatment of patch psoriasis by using two different dose-increase schemes. Materials and methods, Fifteen patients with plaque psoriasis were enrolled in the study (first regime). Three different psoriatic lesions were treated with the 308-nm excimer laser, the 308-nm excimer lamp or 311-nm narrowband UVB three times per week. UVB doses were increased slowly and stepwise (1, 1, 2, 2, 3, 3, ,multiple MEDs). Sixteen patients were enrolled in the second regime. Two plaques were treated with the 308-nm excimer laser or with the 308-nm lamp with an accelerated scheme (2, 2, 4, 4, 6, 6, ,multiple MEDs) three times per week. We increased the UVB doses every second treatment (first and second regime) during the whole treatment. If blistering occurred, the blistered plaque was not treated on the next scheduled treatment. At every third visit and 1, 2 and 4 months after the last treatment a Psoriasis Severity Index (PSI) score was assigned in both regimes. Results, Using Friedman analysis, the PSI scores did not show a statistically significant difference (P > 0·05) comparing 308-nm laser therapy, 308-nm lamp therapy and 311-nm narrowband therapy after 10 weeks in the first regime. The mean number of treatments to achieve clearance was 24. With the accelerated scheme, clearance could be achieved with fewer treatments and with half the cumulative dose of the first regime. Nevertheless, the side-effects such as blistering and crusting were also increased. Conclusions, Both 308-nm light sources can clear patch psoriasis in a similar manner to standard phototherapy, with the advantage of the ability to treat exclusively the affected skin and with a reduced cumulative dose, thus perhaps reducing the long-term risk of carcinogenicity. [source] Blunt atrial transseptal puncture using excimer laser in swine,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2007Abdalla A. Elagha MD Abstract Objectives: We describe a new approach that may enhance safety of atrial transseptal puncture using a commercially available laser catheter that is capable of perforation only when energized. We test this approach in swine. Background: Despite wide application, conventional needle transseptal puncture continues to risk inadvertent nontarget perforation and its consequences. Methods: We used a commercial excimer laser catheter (0.9-mm Clirpath, Spectranetics). Perforation force was compared in vitro with a conventional Brockenbrough needle. Eight swine underwent laser transseptal puncture under X-ray fluoroscopy steered using a variety of delivery catheters. Results: The 0.9-mm laser catheter traversed in vitro targets with reduced force compared with a Brockenbrough needle. In vitro, the laser catheter created holes that were 25,30% larger than the Brockenbrough needle. Laser puncture of the atrial septum was successful and accurate in all animals, evidenced by oximetry, pressure, angiography, and necropsy. The laser catheter was steered effectively using a modified Mullins introducer sheath and using two different deflectable guiding catheters. The mean procedure time was 15 ± 6 min, with an average 3.0 ± 0.8 sec of laser activation. There were no adverse sequelae after prolonged observation. Necropsy revealed discrete 0.9-mm holes in all septae. Conclusion: Laser puncture of the interatrial septum is feasible and safe in swine, using a blunt laser catheter that perforates tissues in a controlled fashion. © 2007 Wiley-Liss, Inc. [source] Laser-facilitated thrombectomy: A new therapeutic option for treatment of thrombus-laden coronary lesionsCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2002Johannes B. Dahm MD Abstract To overcome the adverse complications of balloon angioplasty in thrombus burden lesions (i.e., distal embolization, platelet activation, no-reflow phenomenon with persistent myocardial hypoxemia), mechanical removal of the thrombus or distal embolization protection devices is required. Pulsed ultraviolet excimer laser light at 308 nm can vaporize thrombus and suppress platelet aggregation. Clinical experience has already shown its efficacy in acute ischemic-thrombotic acute coronary syndromes. Unlike other thrombectomy devices, a 308 nm excimer laser can ablate thrombi as well as the underlying plaque, speed up thrombus clearing, and enhance thrombolytic and GP IIb/IIIa activity. It can also be employed in patients with contraindications for systemic thrombolytic agents or GP IIb/IIIa antagonists. Our report covers clinical data and technical aspects concerning three patients with acute myocardial infarction who presented with a large thrombus burden. After successful laser-transmitted vaporization of the thrombus mass in these patients, the remaining thrombus burden was evacuated, and normal antegrade coronary flow was successfully restored. This approach can be useful for selective patients with acute coronary syndromes. Cathet Cardiovasc Intervent 2002;56:365,372. © 2002 Wiley-Liss, Inc. [source] Treatment of post-keratoplasty astigmatism by topography supported customized laser ablationACTA OPHTHALMOLOGICA, Issue 4 2001Jesper Ø. Hjortdal ABSTRACT. Purpose: To evaluate the clinical and optical efficiency of topography modulated customized corneal ablations for irregular corneal astigmatism. Material & methods: Sixteen eyes of 16 patients with iatrogenic corneal astigmatism (post keratoplasty) were consecutively included. Based on preoperative corneal topographic measurements height deviations from a spherical corneal shape were calculated and transferred to a flying-spot excimer laser. Photo-refractive keratectomy of the topographic irregularities was then performed. Clinical and optical efficiency was evaluated by best corrected visual acuity and by computation of corneal wavefront aberrations before and up to one year after treatment. Wavefront aberrations were decomposed by Zernike polynomial analysis. Results: Before treatment the average best-corrected visual acuity was 0.23. Three and 12 months after PRK the average best-corrected visual acuity had increased to 0.37 (p<0.05) and 0.45 (p<0.05), respectively. Corneal wavefront aberrations (root-mean-square) were 3.35 before surgery and 1.88 (p<0.05) and 1.51 (p<0.05) at three and 12 months after treatment. Zernike polynomial decomposition of the wavefront aberrations revealed that regular corneal astigmatism was the most important aberration component before and after surgery. Regular astigmatism was significantly decreased by the procedure, whereas coma, spherical aberrations, and higher-order aberrations were not reduced significantly. Conclusion: Topography modulated photorefractive keratectomy of highly astigmatic corneal grafts can improve best corrected visual acuity and reduce corneal wavefront aberrations. Even in apparently irregular topographic astigmatism, regular astigmatic wavefront aberration may be the most important contributor to wavefront errors. [source] UV laser ablation and plasma treatment of wooden surfaces , a comparing investigationLASER PHYSICS LETTERS, Issue 8 2006N. Mertens Abstract Using UV short-wavelength laser irradiation, the layer of mechanically damaged cells on wooden surfaces can be removed. Four excimer lasers (157 nm, 193 nm, 248 nm, 308 nm) were used to compare the ablation of wooden surfaces by different UV wavelengths. The ablation depth was measured by using optical microscopy. LV-SEM was applied to determine the appearance and quality of the laser ablation. In addition to the ablation process the laser can be used also to influence the surface energy. As the same effect can be achieved by plasma treatment of wooden surfaces, both methods were compared. The comparison was made by means of the water droplet test. The plasma treatment was carried out at atmospheric pressure as a dielectric barrier discharge. Two types of wood were determined: beech and thermowood beech. Thermowood is a heat treated lumber product especially made for outdoor applications. It was examined, whether the thermal treatment of wood influences the characteristic changes of the laser ablation and the plasma treatment. With the researched wavelengths, homogeneous ablation is possible. The absorption time can be reduced both with laser ablation and plasma treatment, whereas plasma treatment causes a stronger effect. A combined treatment improves the effect additionally. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] The Midas Touch: Surface Processing With the UV Excimer LaserLASER TECHNIK JOURNAL, Issue 1 2009Drive Disruptive Innovations, Open Up Growth Markets Very much like the ancient king Midas who as the legend tells was able to transform ordinary material into gold by the touch of his hand, today's excimer lasers are capable of transforming an unspecificmaterial layer into a high value, functional surface by their unique beam properties. Representing today's most cost-effective and dependable pulsed, ultraviolet (UV) laser technology, excimer lasers enable disruptive innovation in various growth industries as diverse as the markets for flat panel displays, automobiles, biomedical devices and alternative energies. It is the combination of two fundamental aspects, namely wavelength and output power, which determines the excimer laser's unique value adding potential in high tech industries which more than ever have to balance product size-efficiency and performance demands with process speed and production costs. This article will try to provide an insight into some key applications of the excimer laser. [source] | |||||||||||||||||||