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Sample records for noncontact holmium yag

  1. Holmium:YAG laser coronary angioplasty in acute myocardial infarction

    Science.gov (United States)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Patients who sustain complicated acute myocardial infarction in whom thrombolytic agents either fail or are contraindicated often need mechanical revascularization other than PTCA. In 24 patients with acute infarction complicated by continuous chest pain and ischemia who either received lytics or with contraindication to lytics, a holmium:YAG laser (Eclipse Surgical Technologies, Palo Alto, CA) was utilized for thrombolysis and plaque ablation. Clinical success was achieved in 23/24 patients, with 23 patients (94%) surviving the acute infarction. Holmium:YAG laser is very effective and safe in thrombolysis and revascularization in this complicated clinical setting.

  2. Use of the holmium:YAG laser in urology

    Science.gov (United States)

    Mattioli, Stefano

    1997-12-01

    The Holmium-YAG is a versatile laser with multiple soft- tissue applications including tissue incision and vaporization, and pulsed-laser applications such as lithotripsy. At 2140 nanometers, the wavelength is highly absorbed by tissue water. Further, like CO2 laser, the Holmium produces immediate tissue vaporization while minimizing deep thermal damage to surrounding tissues. It is an excellent instrument for endopyelotomy, internal urethrotomy, bladder neck incisions and it can be used to resect the prostate. The Holmium creates an acute TUR defect which gives immediate results like the TURP. More than 50 patients were treated from Jan. 1996 to Jan. 1997 for obstructive symptoms due to benign prostatic hyperplasia, bladder neck stricture, urethral stenosis, and superficial bladder tumors.

  3. Intracorporeal lithotripsy with the holmium:YAG laser

    Science.gov (United States)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    A variety of devices are currently available for intracorporeal stone fragmentation. Recently a new wavelength of laser, the Holmium:YAG, has demonstrated a variety of potential urologic applications including ablation of soft tissue lesions as well as stone fragmentation. This laser has a wavelength of 2100 nm and operates in a pulsed mode. Energy is delivered through a 400 um quartz end-firing fiber. In this presentation we review our clinical experience with the Holmium:YAG laser for the treatment of renal and ureteral calculi. Over a 23 month period, 63 patients underwent 67 procedures. Seven procedures consisted of percutaneous nephrolithotripsy for large or staghorn renal calculi. Sixty procedures were performed for ureteral stones. Procedures for proximal ureteral stones (6) employed a retrograde approach using flexible ureteroscopes (8.5 or 9.8). Stones in the mid ureter (12) and distal ureter (42) were approached transurethrally using a 6.9 rigid ureteroscope. Complete stone fragmentation without the need for additional procedures was achieved in 82% of cases. Treatment failures included 1 stone migration into the renal pelvis during laser activation, 6 patients who had incomplete fragmentation and 3 patients in which laser malfunction precluded complete fragmentation. Stone analysis available in 23 patients revealed calcium oxalate monohydrate (15), calcium oxalate dihydrate (2), cystine (2), uric acid (3) and calcium phosphate (1). A single complication of ureteral perforation occurred when the laser was fired without direct visual guidance. Radiographic follow-up at an average of 16 weeks is available in 22 patients and has identified 2 patients with ureteral strictures that are not believed to be related to laser lithotripsy. In summary, we have found the Holmium:YAG laser to be a reliable and versatile device for intracorporeal lithotripsy. Its safety and efficacy make it a suitable alternative for performing intracorporeal lithotripsy of urinary

  4. Holmium:YAG laser angioplasty: treatment of acute myocardial infarction

    Science.gov (United States)

    Topaz, On

    1993-06-01

    We report our clinical experience with a group of 14 patients who presented with acute myocardial infarction. A holmium:YAG laser was applied to the infarct-related artery. This laser emits 250 - 600 mJ per pulse, with a pulse length of 250 microseconds and repetition rate of 5 Hz. Potential benefits of acute thrombolysis by lasers include the absence of systemic lytic state; a shortened thrombus clearing time relative to using thrombolytics; safe removal of the intracoronary thrombus and facilitation of adjunct balloon angioplasty. Potential clinical difficulties include targeting the obstructive clot and plaque, creation of debris and distal emboli and laser-tissue damage. It is conceivable that holmium:YAG laser can be a successful thrombolytic device as its wave length (2.1 microns) coincides with strong water absorption peaks. Since it is common to find an atherosclerotic plaque located under or distal to the thrombotic occlusion, this laser can also be applied for plaque ablation, and the patient presenting with acute myocardial infarction can clearly benefit from the combined function of this laser system.

  5. Holmium:YAG laser in dentistry: photoconditioning of dentinal surfaces

    Science.gov (United States)

    Holt, Raleigh A.; Nordquist, Robert E.

    1994-09-01

    This in vitro study was undertaken to determine energy levels necessary to produce tubule closure and surface smoothing on dentinal surfaces of human teeth and their resultant temperature increases within the pulpal canals with the Holmium:YAG laser. An optimal working spot size and even absorption pattern were produced by defocusing the laser beam and evaluated by images produced on light exposed and developed photographic paper. The surface effects on dentin were examined by scanning electron microscopy. A thermocouple was positioned in the canals of fresh dissected dog jaws and attached to a recorder which produced a graph of the temperature changes. The in vitro research model for intrapulpal temperatures changes was verified by comparing premortem and postmortem temperature readings. The same protocol was used to evaluate temperature changes in fresh human extracted teeth. In vivo histological studies were conducted to evaluate the effects of HO:YAG laser energy on pulpal tissues. The results of these studies indicate the HO:YAG laser at a wavelength of 2.12 microns can be safely and effectively used for photoconditioning of the dentinal surfaces of teeth in clinical conditions.

  6. Ablation of skin tissue by holmium:YAG laser

    Science.gov (United States)

    Chen, Wei R.; Holt, Andrew; Nordquist, Robert E.

    1994-08-01

    Surface epithelial damage by Ho:YAG laser and recovery were studied using histology and electron microscopy. Rabbit skin was irradiated with fluence varying from 55 J/cm2 to 680 J/cm2. Laser damage was determined by histological measurement of three major injury indicators: surface lesion width, depth of photocoagulation, and depth of thermal damage. When the fluence increased, the surface lesion widened and the photocoagulation zone extended deeper into the dermis. The thermally damaged zone (60 degree(s)C muscle and nerve tissues appeared to remain intact under most of our irradiance except at 500 J/cm2 and greater. Thermally injured tissues began recovery within a short period and eventually returned to normal; electron microscopic findings indicated that severe swelling occurred in the individual collagen fibrils, but they were not disrupted and usually recovered to appear normal. A layer of new epithelium started growing underneath the photocoagulated zone around day 3. After 7 days, most photocoagulated tissue was partially, in some cases completely, separated from the skin by the new epithelium. The damage and recovery parameters established should aid in the clinical use of Holmium laser in treating lesions, benign or malignant, in hollow tubular organs and on surface epithelia.

  7. Laser-assisted hair transplantation: histologic comparison between holmium:YAG and CO2 lasers

    Science.gov (United States)

    Chu, Eugene A.; Rabinov, C. Rose; Wong, Brian J.; Krugman, Mark E.

    1999-06-01

    The histological effects of flash-scanned CO2 (λ=10.6μm) and pulsed Holmium:YAG (Ho:YAG, λ=2.12μm) lasers were evaluated in human scalp following the creation of hair transplant recipient channels. Ho:YAG laser irradiation created larger zones of thermal injury adjacent to the laser channels than irradiation with the CO2 laser device. When the two lasers created recipient sites of nearly equal depth, the Holmium:YAG laser caused a larger region of lateral thermal damage (589.30μm) than the CO2 laser (118.07μm). In addition, Holmium:YAG irradiated specimens exhibited fractures or discontinuities beyond the region of clear thermal injury. This shearing effect is consistent with the photoacoustic mechanism of ablation associated with pulsed mid-IR laser irradiation. In contrast, channels created with the CO2 exhibited minimal epithelial disruption and significantly less lateral thermal damage. While the Holmium:YAG laser is a useful tool for ablation soft tissue with minimal char in select applications (sinus surgery, arthroscopic surgery), this study suggests that the use of the CO2 laser for the creation of transplantation recipient channels result in significantly less lateral thermal injury for the laser parameters employed.

  8. Treatment of Special Renal Colic with Ureteroscope and Holmium YAG Laser

    Institute of Scientific and Technical Information of China (English)

    沈明顺; 刘军

    2002-01-01

    Objective To investigate the method of emergent relief of special renal colicand treatment of ureter diseases causing renal colic. Methods By analyzing 63 cases of special re-nal colic treated with ureteroscope and Holmium YAG laser. Results 61 cases of renal colic were re-lieved in a short period of time and the ariginal ureter diseases causing renal colic were cured. Conclu-sion Special renal colic could be treated with ureteroscope and Holmium YAG laser in a quick and ef-fective manner.

  9. Holmium:YAG laser-assisted otolaryngologic surgery: Lahey Clinic experience

    Science.gov (United States)

    Shapshay, Stanley M.; Rebeiz, Elie E.; Pankratov, Michail M.

    1993-07-01

    The Holmium:YAG laser was used to assist in 36 rhinologic procedures including surgery for chronic sinus disease, chronic dacryocystitis, recurrent choanal stenosis, and a sphenoid sinus mucocele. There were no laser related complications. The laser permitted controlled ablation of bone and soft tissue in all cases with satisfactory results. The Ho:YAG laser can be used in otolaryngology to assist in cases where surgical access is difficult or when controlled, precise bone and soft tissue ablation is necessary.

  10. Soft-tissue applications of the holmium:YAG laser in urology

    Science.gov (United States)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    The ideal surgical laser for the treatment of soft tissue pathology should possess both ablative and hemostatic abilities. As well, for use in urologic conditions the laser must also be suitable for endoscopic use. The Holmium:YAG laser possesses these qualities and in preliminary clinical use has demonstrated a variety of potential urologic applications. In this study we review our initial experience with the Holmium:YAG laser over a 18 month period. A total of 51 patients underwent 53 procedures for a variety of soft tissue conditions including: bladder tumor ablation (25), incision of ureteral stricture (15), incision of urethral stricture (6), treatment of ureteropelvic junction obstruction (3), incision of bladder neck contracture (2), and ablation of a ureteral tumor (2). Satisfactory hemostasis was achieved in all cases. Procedures were considered successful (no further intervention being required to treat the condition) in 81% of the cases. Two patients with dense bladder neck contractures required electroincision under the same anesthetic for completion of the procedure. A single complication, that of urinary extravasation following incision of a urethral stricture resolved with conservative management. In summary, the Holmium:YAG laser has demonstrated safety and proficiency in the treatment of a variety of urologic soft tissue conditions.

  11. Noncontact Er:YAG laser ablation: clinical evaluation.

    Science.gov (United States)

    Dostálová, T; Jelínková, H; Kucerová, H; Krejsa, O; Hamal, K; Kubelka, J; Procházka, S

    1998-10-01

    The aim of this study is to evaluate the quality of laser ablation in comparison with the classical drilling preparation. For the experiment, the Er:YAG laser drilling machine was used. The system had a laser head, water cooler, and power supply with automatic control. Spot size of 300-350 microns was used for the preparation. Repetition rate of 1-4 Hz, and pulse energies of 100-400 mJ with water spray were chosen. Cavity shape in comparison with classical drill, time of preparation, and influence of cavity shape on filling materials retention in accordance with the U.S. Public Health Service System were used. The evaluation criteria for noncontact Er:YAG ablation were done. The cavity shape is irregular, but spot surface has larger area and microretentive appearance. Caries of enamel and dentin were treated with a noncontact preparation. It was possible to remove the old insufficient fillings, except for amalgam or metal alloys. The average number of pulses was 111.22 (SE 67.57). Vibrations of microexplosions during preparation were felt by patients on 14 cavities; however, nobody felt unpleasant pain. The qualities of filling materials in laser cavities were very stable; however, cavo surface margin discoloration of 82-86% of Alfa rating could be a problem. Changes of the color and anatomic form of the tooth were observed in 4-8%. In comparison with the classical treatment, it could be said that the retention and quality of filling materials is the same or very similar.

  12. PNEUMATIC LITHOTRIPSY VERSUS HOLMIUM:YAG LASER LITHOTRIPSY I N THE MANAGEMENT OF URETERAL STONES

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    Sebastiano Cimino

    2013-04-01

    Full Text Available Background: Pneumatic lithotripsy (PL and Holmium:YAG laser lithotripsy (LL are two valid mini-invasive approaches in the treatment of urologic stones disease. The aim of this study was to compare stone free rates between these two treatment options. Material and methods: From January 2010 to January 2011, 120 consecutive patients with single and primary ureteral stones were prospectively enrolled in this prospective study. The study was single-blinded and none of the patients knew which approach for stone fragmentation would be used. Results: The ureteral stone-free rate (SFRs in the PL group was 80.7% and 86.1 % in the LL group (p=0.002. The mean operating time was 60 (± 25 minutes in the LL group and 61 (± 21 minutes in the PL group, without significant differences (p=0.68. Multivariate logistic analysis revealed that stone location was not significantly predictive of SFRs (p=0.47. None of the patients had blood transfusions and no other severe complications appeared in either group. Conclusions: In our study LL was significantly associated with a stone 80.7% in the PL group and 86.1% in the LL group (p<0.05. Also, Holmium:YAG laser lithotripsy was demonstrated to be the more efficacious endoscopic procedure for the treatment of ureteral stones, allowing stones to be successfully fragmented, with few complications.

  13. Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

    Science.gov (United States)

    Watterson, James D.; Girvan, Andrew R.; Beiko, Darren T.; Nott, Linda; Wollin, Timothy A.; Razvi, Hassan A.; Denstedt, John D.

    2003-06-01

    Objectives: Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy (PCN). Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. The purpose of this study was to review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Methods: A retrospective analysis was conducted at 2 tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and 2 encrusted ureteral stents were treated. Mean gestational age at presentation was 22 weeks. Mean stone size was 8.1 mm. Stones were located in the proximal ureter/ureteropelvic junction (UPJ) (3), mid ureter (1), and distal ureter (6). Results: Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetrical or urological complications were encountered. Conclusions: Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

  14. Operation of the nose using Nd-YAG and holmium laser

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    Kukwa, Andrzej; Tulibacki, Marek P.; Zajac, Andrzej; Dudziec, Katarzyna

    2000-06-01

    During more than 5 years Nd:YAG and Holmium laser has been used in our ENT Department for the treatment of varies pathological changes. Most of our cases were previously treated many times because of recurrences of the nasal polyps. As a rule the treatment was given in one to three sessions. Each patient was very closely monitored. The time period between the session was 2-4 weeks. The consequent application of laser was dependent on healing process. All adults' patients were treated in local anesthesia using 1,5 percent of Cocaine and 10 percent Xylocaine applied in a spray; no other anesthetics were needed, although in some patients 10 mg Valium was administered before first session of laser application. We do not observe a severe bleeding needed sponge or a nose package. Among advantages we have to concentrate on two: the recurrences of nasal polyps are definitely much rare and patient may appear at work at the same day.

  15. Bouveret's syndrome complicated by distal gallstone ileus after laser lithotropsy using Holmium: YAG laser

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    Rodgers John B

    2002-06-01

    Full Text Available Abstract Background Bouveret's syndrome is an unusual presentation of duodenal obstruction caused by the passage of a large gallstone through a cholecystoduodenal fistula. Endoscopic therapy has been used as first-line treatment, especially in patients with high surgical risk. Case presentation We report a 67-year-old woman who underwent an endoscopic attempt to fragment and retrieve a duodenal stone using a Holmium: Yttrium-Aluminum-Garnet Laser (Ho:YAG which resulted in small bowel obstruction. The patient successfully underwent enterolithotomy without cholecystectomy or closure of the fistula. Conclusion We conclude that, distal gallstone obstruction, due to migration of partially fragmented stones, can occur as a possible complication of laser lithotripsy treatment of Bouveret's syndrome and might require urgent enterolithotomy.

  16. Evaluation of pneumatic versus holmium:YAG laser lithotripsy for impacted ureteral stones.

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    Binbay, Murat; Tepeler, Abdulkadir; Singh, Avinash; Akman, Tolga; Tekinaslan, Erdem; Sarilar, Omer; Baykal, Murat; Muslumanoglu, Ahmet Yaser

    2011-12-01

    We prospectively analyzed and compared the effectiveness and complications of pneumatic lithotripter with a holmium:yttrium-aluminum-garnet (Ho:YAG) laser for the ureterorenoscopic management of impacted ureteral stones. From January 2006 to January 2008, we performed retrograde endoscopic treatment in 288 patients with ureteral stones in our clinic. The patients with impacted stones were randomized into two groups according to the lithotripter used to fragment the stone: pneumatic (n = 40) and laser (n = 40). The preoperative, operative, and post-operative follow-up findings were analyzed and compared. The average stone size was similar in both groups (118.8 ± 58.3 mm(2) vs. 110.7 ± 54.4 mm(2)). The calculi were located in the distal ureter in most of the patients in both groups (65% in pneumatic group and 52.5% in laser group). The operation time was significantly diminished in the laser group (P = 0.001). The stone-free rates after a single ureteroscopic procedure were 80 and 97.5% in the pneumatic and laser groups, respectively (P = 0.03). Auxiliary treatments were needed in seven patients in the pneumatic group, while only one patient in the laser group (P = 0.05) needed this treatment. After the additional procedures, a 100% success rate was achieved in both groups. The rate of double J stent insertion was significantly higher in the pneumatic group (P = 0.01). In the pneumatic group, four cases of stone up-migration and one case of post-operative stricture were seen, whereas only one case of stone up-migration was noted in the laser group. Our comparative study has shown that the use of Ho:YAG as an intracorporeal lithotripter during ureteroscopic management of impacted ureteral stones is highly efficient with high success rates, regardless of the stone location.

  17. Transurethral lithotripsy with holmium-YAG laser of a large exogenous prostatic calculus.

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    Hasegawa, Masanori; Ohara, Rei; Kanao, Kent; Nakajima, Yosuke

    2011-04-01

    Prostatic calculi are classified into two types, endogenous and exogenous calculi, based on their origin. Endogenous calculi are commonly observed in elderly men; however, exogenous prostatic calculi are extremely rare. We report here the case of a 51-year-old man who suffered incontinence and pollakiuria with a giant exogenous prostatic calculus almost completely replacing the prostatic tissue. X-rays and computed tomography demonstrated a large calculus of 65 × 58 mm in the small pelvic cavity. The patient underwent a transurethral lithotripsy with a holmium-YAG laser and a total of 85 g of disintegrated stones was retrieved and chemical stone analysis revealed the presence of magnesium ammonium phosphate. The incontinence improved and the voiding volume increased dramatically, and no stone recurrence in the prostatic fossa occurred at the 2 years follow-up. The etiology of this stone formation seemed to be based on some exogenous pathways combined with urinary stasis and chronic urinary infection due to compression fracture of the lumbar vertebra.

  18. Restenosis of the coronary stenotic lesions treated by holmium:YAG laser coronary angioplasty

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    Miyazaki, Shunichi; Nonogi, Hiroshi; Goto, Yoichi; Itoh, Akira; Ozono, Keizaburo; Daikoku, Satoshi; Haze, Kazuo

    1994-07-01

    Clinical efficacy of newly developed Holmium YAG laser coronary angioplasty (HLCA) was assessed for 30 patients with angina. There were 12 near left main trunk (LMT) lesions and 4 aorto- ostial lesions. Adjunctive balloon angioplasty was performed for 25 of 30 lesions. Delivered energy ranged from 1.5 to 2.5 watts/pulse and the total exposure time ranged from 6 to 55 seconds. External diameter of laser catheter was 1.5 mm for 13 lesions, 1.4 mm for 17 lesions, and 1.7 mm for 5 lesions. Laser success, defined as 20% reduction of stenotic ratio, was obtained in 21 of 30 (70%) and overall procedural success rate was 93%. There were 3 cases with acute coronary occlusions relieved by adjunctive balloon angioplasty and one coronary perforation without manifestation of cardiac tamponade. There were no large coronary dissection which involved more than 5 mm of the coronary artery. Follow up coronary angiography after 3 months showed restenosis in 14 of 27 patients (52%). Percent stenosis after lasering (56%) was similar to that at 3 months after (62%). HLCA is acutely effective treatment for lesions near LMT, because of low incidence of large coronary dissection. However, angiographical restenosis rate is high at 3 months after HLCA. This may be attributed to the relatively large residual stenosis after the procedure and vessel injury caused by shock wave.

  19. Er:YAG and CTH:YAG laser radiation: contact versus non-contact enamel ablation and sonic-activated bulk composite placement

    Science.gov (United States)

    Buckova, M.; Kasparova, M.; Dostalova, T.; Jelinkova, H.; Sulc, J.; Nemec, M.; Fibrich, M.; Bradna, P.; Miyagi, M.

    2013-05-01

    Laser radiation can be used for effective caries removal and cavity preparation without significant thermal effects, collateral damage of tooth structure, or patient discomfort. The aim of this study was to compare the quality of tissue after contact or non-contact Er:YAG and CTH:YAG laser radiation ablation. The second goal was to increase the sealing ability of hard dental tissues using sonic-activated bulk filling material with change in viscosity during processing. The artificial caries was prepared in intact teeth to simulate a demineralized surface and then the Er:YAG or CTH:YAG laser radiation was applied. The enamel artificial caries was gently removed by the laser radiation and sonic-activated composite fillings were inserted. A stereomicroscope and then a scanning electron microscope were used to evaluate the enamel surface. Er:YAG contact mode ablation in enamel was quick and precise; the cavity was smooth with a keyhole shaped prism and rod relief arrangement without a smear layer. The sonic-activated filling material was consistently regularly distributed; no cracks or microleakage in the enamel were observed. CTH:YAG irradiation was able to clean but not ablate the enamel surface; in contact and also in non-contact mode there was evidence of melting and fusing of the enamel.

  20. Mini-percutaneous nephrolithotomy with high-power holmium YAG laser in pediatric patients with staghorn and complex calculi.

    Science.gov (United States)

    Bujons, Anna; Millán, Félix; Centeno, Clara; Emiliani, Esteban; Sánchez Martín, Francisco; Angerri, Oriol; Caffaratti, Jorge; Villavicencio, Humberto

    2016-08-01

    Shock wave lithotripsy (SWL) is the treatment of choice for most cases of renal lithiasis in children. Some cases, however, are refractory to SWL and may be associated with anatomic and metabolic changes or a large stone burden. In these circumstances, mini-percutaneous nephrolithotomy (mini-PCNL) is an option. The aim was to assess the safety and efficacy of high-power holmium YAG (Ho:YAG) laser in mini-PCNL for staghorn calculi. The clinical records relating to 35 mini-PCNLs (Table) performed between January 2008 and December 2012 in 33 patients (27 boys and 6 girls; mean age 7 years, range 2-18 years) were retrospectively reviewed. Twenty-two (66.7%) of the patients had undergone a previous SWL (28.6% three sessions). The mini-PCNL puncture technique used involved fluoroscopic guidance with the C arm at 0-90° in the supine position. An 18F tract was used. Stone fragmentation was performed with a high-power Ho:YAG laser (Lumenis 100 W). Ten of the mini-PCNLs (28.6%) were right sided, and 25 were left sided (71.4%). Stones were located in the lower calyceal group in 64% of patients and in the renal pelvis in 50%. The mean stone size was 4.46 cm(2) (range 3-13.20 cm(2)). The number of stones varied between one and 20, and 83.3% were radiopaque. The laser was set at 70 W (range 50-100 W) (3.5 J/pulse with a frequency of 20 pulses/s). The mean surgical time was 150 min. In 78% of patients, complete stone clearance was achieved, and the overall stone-free rate rose to 85% when residual stones were treated with either SWL or retrograde intrarenal surgery. No perioperative complications were seen. There are few reports in the literature concerning the use of a high-power laser for treatment of complex stones and the few that do exist relate to adults have similar results, showing it to be highly effective and safe, with low morbidity. Some limitations of the present study must be acknowledged. It was retrospective and a relatively small number of patients were

  1. Photothermal ablation is the primary mechanism in holmium:YAG laser lithotripsy of urinary calculi

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    Glickman, Randolph D.; Teichman, Joel M. H.; Corbin, Nicole S.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Welch, Ashley J.

    1999-09-01

    Because of the >= 250 microsecond(s) pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Previous work has shown that stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures. Moreover, lithotripsy proceeds fastest with desiccated stones in air (data based on laser ablation of calcium oxalate monohydrate stones), indicating that direct absorption of the laser radiation by the stone material is required for the most efficient ablation. Lowering the initial temperature of calculi reduces the stone mass-loss following 20 J of delivered laser energy: 2.2 +/- 1.1 mg vs 5.2 +/- 1.6 mg for calcium oxalate monohydrate (COM) stones (-80 vs 23 degree(s)C), and 0.8 +/- 0.4 mg vs 2.2 +/- 1.1 mg for cystine stones (-80 vs 23 degree(s)C), p cystine; Ca2O7P2 from calcium hydrogen phosphate dihydrate, and cyanide and alloxan from uric acid. All of these observations are most consistent with a photothermal breakdown process induced by Ho:YAG laser lithotripsy.

  2. Endoluminal non-contact soft tissue ablation using fiber-based Er:YAG laser delivery

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    Kundrat, Dennis; Fuchs, Alexander; Schoob, Andreas; Kahrs, Lüder A.; Ortmaier, Tobias

    2016-03-01

    The introduction of Er:YAG lasers for soft and hard tissue ablation has proven promising results over the last decades due to strong absorption at 2.94 μm wavelength by water molecules. An extension to endoluminal applications demands laser delivery without mirror arms due to dimensional constraints. Therefore, fiber-based solutions are advanced to provide exible access while keeping space requirements to a minimum. Conventional fiber-based treatments aim at laser-tissue interactions in contact mode. However, this procedure is associated with disadvantages such as advancing decrease in power delivery due to particle coverage of the fiber tip, tissue carbonization, and obstructed observation of the ablation progress. The objective of this work is to overcome aforementioned limitations with a customized fiber-based module for non-contact robot-assisted endoluminal surgery and its associated experimental evaluation. Up to the authors knowledge, this approach has not been presented in the context of laser surgery at 2.94 μm wavelength. The preliminary system design is composed of a 3D Er:YAG laser processing unit enabling automatic laser to fiber coupling, a GeO2 solid core fiber, and a customized module combining collimation and focusing unit (focal length of 20 mm, outer diameter of 8 mm). The performance is evaluated with studies on tissue substitutes (agar-agar) as well as porcine samples that are analysed by optical coherence tomography measurements. Cuts (depths up to 3mm) with minimal carbonization have been achieved under adequate moistening and sample movement (1.5mms-1). Furthermore, an early cadaver study is presented. Future work aims at module miniaturization and integration into an endoluminal robot for scanning and focus adaptation.

  3. Combined electrohydraulic and holmium: YAG laser ureteroscopic nephrolithotripsy of large (>2 cm) renal calculi.

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    Mariani, Albert J

    2008-10-01

    Percutaneous nephrolithotripsy (PCL) is a standard treatment for renal calculi >2 cm. Modern flexible ureteroscopes and accessories employing the complementary effects of electrohydraulic lithotripsy (EHL) and Ho:YAG laser lithotrites can treat these renal calculi in a minimally invasive fashion with similar or superior results. To assess the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of >2 cm renal calculi in the community setting. Fifty nine patients with 63 renal calculi ranging from 20 to 97 mm (mean 44 mm) in length and 175 to 3300 mm2 (mean 728 mm2) area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (BMI > 30) was present in 54% and 19% were morbidly obese (BMI > 40). An infectious etiology was present in 49% and hard stone components in 89%. All patients presented with hematuria, pain, and/or recurrent urinary tract infection (UTI). Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly EHL. Laser drilling was employed (n = 6) to weaken very hard stones prior to EHL. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation. All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 60/63 (95%) with a mean of 1.7 nephrolithotripsy stages and 0.38 secondary or ancillary procedures. Outpatient management was sufficient for 121/131 (92%) of the procedures. Operative time averaged 46 min/stage and 79 min/calculus. Complications included endotoxic shock (3), fever (5), ureteral fragments requiring treatment (11), delayed extubation (2), delayed pneumonia (1), and urinary retention (1). Staged ureteroscopic nephrolithotripsy of large renal calculi is feasible with low morbidity and stone clearance rates that compare favorably with PCL. It

  4. Combined electrohydraulic and holmium: YAG laser ureteroscopic nephrolithotripsy of large (>2 cm renal calculi

    Directory of Open Access Journals (Sweden)

    Albert J Mariani

    2008-01-01

    Full Text Available Percutaneous nephrolithotripsy (PCL is a standard treatment for renal calculi> 2 cm. Modern flexible ureteroscopes and accessories employing the complementary effects of electrohydraulic lithotripsy (EHL and Ho:YAG laser lithotrites can treat these renal calculi in a minimally invasive fashion with similar or superior results. Objective: To assess the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of> 2 cm renal calculi in the community setting. Materials and Methods: Fifty nine patients with 63 renal calculi ranging from 20 to 97 mm (mean 44 mm in length and 175 to 3300 mm2 (mean 728 mm2 area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (BMI > 30 was present in 54% and 19% were morbidly obese (BMI > 40. An infectious etiology was present in 49% and hard stone components in 89%. All patients presented with hematuria, pain, and/or recurrent urinary tract infection (UTI. Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly EHL. Laser drilling was employed (n = 6 to weaken very hard stones prior to EHL. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation. Results: All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 60/63 (95% with a mean of 1.7 nephrolithotripsy stages and 0.38 secondary or ancillary procedures. Outpatient management was sufficient for 121/131 (92% of the procedures. Operative time averaged 46 min/stage and 79 min/calculus. Complications included endotoxic shock (3, fever (5, ureteral fragments requiring treatment (11, delayed extubation (2, delayed pneumonia (1, and urinary retention (1. Conclusion: Staged ureteroscopic nephrolithotripsy of large renal calculi is feasible with low morbidity

  5. Combined electrohydraulic and holmium:YAG laser ureteroscopic nephrolithotripsy of large (greater than 4 cm) renal calculi.

    Science.gov (United States)

    Mariani, Albert J

    2007-01-01

    Percutaneous nephrolithotripsy is standard treatment for renal calculi larger than 2 cm. Modern flexible ureteroscopes and accessories using the complimentary effects of electrohydraulic lithotripsy and holmium:YAG laser lithotrites can treat large (greater than 4 cm) branched renal calculi in a minimally invasive fashion with similar or superior results. This report is an assessment of the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of large (greater than 4 cm) branched renal calculi in the community setting. A total of 16 patients with 17 branched renal calculi ranging from 41 to 97 mm (mean 65) in length and 560 to 2,425 mm2 (mean 1,169) in area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (body mass index greater than 30) was present in 81% and 38% were morbidly obese (body mass index greater than 40). An infectious etiology was present in 81% and hard stone components were present in 94%. All patients presented with hematuria, pain and/or recurrent urinary tract infection. Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly electrohydraulic lithotripsy. Laser drilling was used (in 4) to weaken hard stones before electrohydraulic lithotripsy. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation. All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 15 of 17 renal units (88%) with a mean of 2.4 stages and 36 of 40 (90%) procedures performed on an outpatient basis. Operative time averaged 49 minutes per stage and 115 minutes per calculus. There were 3 patients admitted for fever and 1 patient (90 years old) admitted for pneumonia 3 days postoperatively. There were also 3 patients with calculi larger than 75 mm who required

  6. Optimized evaluation of a pulsed 2.09 microns holmium:YAG laser impact on the rat brain and 3 D-histomorphometry of the collateral damage.

    Science.gov (United States)

    Ludwig, H C; Bauer, C; Fuhrberg, P; Teichmann, H H; Birbilis, T; Markakis, E

    1998-12-01

    Since more than 20 years CO2 and Nd:YAG lasers are established in the microsurgery of the nervous system. CO2 lasers can be used handheld, but may be focused on the target area by mirror optics and sideports of the operating microscope's micromanipulator. Nd:YAG lasers have the disadvantage of deep penetration into the brain and provocation of a large collateral damage. The need is for a fibre conducted solid system for surgery in delicate areas as for brain stem surgery. Fibre conduction of near infrared lasers allows better exposure of the target area compared to hollow wave guides or mirror equipment. Fibres can be tapered and modified according to the purpose. The holmium:YAG (Ho:YAG) laser has acquired interest by introducing the system into microsurgery of parenchymal tissue. They have not been proven yet sufficiently for neurosurgical tasks. The effort to minimalize the collateral tissue damage has to be maximalized in the surgery of nervous tissue and functional low redundant brain stem or spinal cord tissue. Volumetric data may be more precise in comparison to depth and width data of the laser lesion even when the different levels of the tissue interaction have to be analyzed for estimation of the real side effects in nervous tissue. We have used 50-800 ml delivered Ho:YAG single pulses in cortical areas of Sprague-Dawley rats and investigated the different lesion zones by volumetric data. The functional lesion zone was detected and measured by immunohistological staining of the heat shock protein HSP 72. For further reduction of the focus area, we have used tapered 400 to 200 microns fibres.

  7. Low-power holmium:YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique.

    Science.gov (United States)

    Atak, Mustafa; Tokgöz, Hüsnü; Akduman, Bülent; Erol, Bülent; Dönmez, Ibrahim; Hancı, Volkan; Türksoy, Ozlem; Mungan, Necmettin Aydın

    2011-11-01

    In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200-1,400 mJ; 8-12 Hz) at 12 o'clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o'clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher's exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 ± 8.04 minutes) when compared with cold-knife group (23.8 ± 5.47 minutes) (plaser group when compared with cold-knife group (p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique. Copyright © 2011. Published by Elsevier B.V.

  8. Inductively coupled plasma-emission spectroscopy and atomic absorption for the use of elemental analysis of a root canal after lasing with a holmium:YAG laser.

    Science.gov (United States)

    Deutsch, Allan S; Cohen, Brett I; Musikant, Barry Lee

    2003-06-01

    It has been reported in the literature that after lasing dentin the dentin surface has a glassy or globular appearance. Many authors believe this to be recrystallized hydroxyapatite. The purpose of this elemental analysis was to see if any of the silica fiber optic was melted and deposited as these globular structures on the canal wall. Two teeth were used. One was hand-instrumented with files and used as the control, the other was lased with a holmium:YAG laser. A 245-micro low OH- fiber was used with a power setting of 0.75 W, 5 Hz, 94.2 J, and 1134 V to lase the root. The roots were microanalyzed for oxygen, phosphorus, silicon, nitrogen, hydrogen, calcium, and carbon. The percentages for all elements tested were the same for both teeth. Therefore, there was no silicon deposited onto the canal wall of the tooth that was lased. It is concluded that the low OH- silica fiber optic was not melted and deposited onto the dentinal canal wall.

  9. A basic study of the interstitial laser prostatectomy using pulsed holmium: yttrium-aluminium-garnet (Ho:YAG) laser

    Energy Technology Data Exchange (ETDEWEB)

    Daidoh, Yuichiro [National Defenese Medical Coll., Tokorozawa, Saitama (Japan)

    1996-03-01

    The efficacy of interstitial laser irradiation with a pulsed Ho:YAG laser ({lambda}: 2.1 {mu}m) was evaluated in the normal canine prostate. Pathological studies were performed up to 6 months after interstitial laser irradiation in 26 mongrel dogs. Two dogs without irradiation were as controls (control group). Prostate glands of the other 24 dogs were irradiated interstitially with a Ho:YAG laser. Four prostates were irradiated with 150-175 J/cm{sup 2} in fluence (low-fluence group) and 19 were irradiated with 500-600 J/cm{sup 2} in fluence (high-fluence group). Prostates glands were excised immediately, 1, 2, 3, or 6 months after irradiation and examined histologically. To investigate the influence of interstitial irradiation with a Ho:YAG laser on smooth muscle and/or on the adrenergic activity of the prostate, we also measured changes in intraluminal pressure of the prostatic urethra upon administration of epinephrine (10 {mu}g/kg) in 6 dogs before and after irradiation. In only the high-fluence group, smooth muscles and small vessels surrounded the ablated hole were destroyed, but the thickness of the thermal coagulation layer was only approximately 0.2 mm. These findings suggested that damage to the small vessels and smooth muscle may have been caused by laser-induced stress waves rather than by a thermal effect. In the high-fluence group, huge cavities were created in the laser-irradiated prostate gland 1 or 2 months after irradiation, prostatic volume was reduced, the cavities collapsed and prostatic volume was reduced by up to 50% at 6 months post-procedure. The prostatic urethra expanded following the reduction in volume. The maximal intraluminal change in pressure of the prostatic urethra decreased significantly after laser irradiation. Results indicate that interstitial irradiation of the prostate with a Ho:YAG laser with high-fluence may relieve the anatomical and functional obstruction of the prostatic urethra in benign prostatic hyperplasia. (H.O.).

  10. Efeito do Hólmio YAG laser (Ho: YAG sobre o tendão patelar de ratos após 12 e 24 semanas de seguimento The effects of Holmium YAG laser (Ho:YAG on the patellar tendon of rats after 12 and 24 weeks of follow up

    Directory of Open Access Journals (Sweden)

    Waldo Lino Júnior

    2005-01-01

    , com neoformação vascular evidente. No grupo de 24 semanas as fibras de colágeno se apresentavam com disposição regular e paralela ao longo eixo do tendão.The authors have studied the effects of the Holmium: Yttrium Aluminum Grenade (Ho:YAG laser on tendon sizes (proximal and distal length and width and on the cellularity and arrangement of collagen fibers in 20 Wistar variety, male, white, adult rats (Rattus Novergicus. The animals have been divided in two groups, according to the follow-up time (12 and 24 weeks and pursuant to the for form of laser application (continuous or two-point. A Holmium laser (pulsed, solid state, 2.1 micron waves, 40 watts, OmniTip 30º tip apparatus was used. After the animals were sacrificed, the proximal and distal length and width of the operated size of such rats were compared to those of the non-operated size be means of non-parametric testing (considering p=0,05. The length in the operated size was significantly bigger for both follow-up groups, when compared to the length of the non-operated size, however there was no significant difference in such measures in function of the type of laser application. In the same manner, the width, both in the proximal and distal regions, was significantly bigger in the operated size in both follow-up groups, without showing any significant difference whatsoever in function of the type of application. When the measures in both follow-up groups were compared, distal length and width showed a trend to become bigger after 24 weeks, while width in the proximal region was significantly bigger in this group. As for the subjective microscopic evaluation, both in longitudinal and cross sections, it was possible to observe and increase in the number of fibroblasts, mainly in the 12-week group. The average fibroblast concentration in the tendon with 24-week follow-up was group deemed to be intermediate between the 12-week group and non-operated tendon. The conjunctive tissue was exuberant in the region

  11. Treatment of ureteral obstruction by holmium: YAG laser endoureterotomy: a report of 18 cases%输尿管镜钬激光内切开术治疗输尿管梗阻

    Institute of Scientific and Technical Information of China (English)

    付宜鸣; 倪少滨; 陈起引; 赵忠山; 任明华; 麻立; 焦治兴

    2009-01-01

    Objective To investigate the clinical value and safety of holmium: YAG laser endoureterotomy in the treatment of ureteral obstruction. Methods Holmium: YAG laser endoureterotomy, with the laser optic fiber 550 μm in diameter and the output power of 3.5 Watt, via ureteroscopy, was performed on 18 patients ureteral obstruction, 8 males and 10 females, aged 52.1 (34 -67), 11 with the stricture in the upper segment (complete obstruction in 4 cases), 5 in the middle segment, and 2 in lower segment ; and 6 cases complicated with ureteral calculus. Postoperatively, an orthopedic ureteral stent ( a 6-Fr double-J ureteral stent with a movable 5 cm length 9-Fr orthopedic cannula) was remained indwelling for 3 -6 months. Follow-up was conducted for 10.7 (2-14) months. Results The operative duration was 32 (25 -70 ) minutes. One patient underwent failed endoureterntomy and was turned to percutaneous nephroscopy. Success was achieved in 16 patients. The glomerular filtration rate (GFR) of these affected kidneys increased from 16.4 ± 6.9 ml/min ante-operatively to 24.9 ± 8.2 ml/min (P<0.01) postoperatively. One kidney was resected because of non-function, with GFR of 2 ml/min and intractable pyelitis. No recurrence of ureteral stricture was observed. Conclusion Holmium: YAG laser endoureterotomy with insertion of orthopedic ureteral stent is an efficient and safe treatment for ureteral strictures with minimal invasion, less complications and easy recovery. This operation should be performed with a thorough preparation and severely restricted indication.%目的 探讨输尿管镜钬激光内切开术治疗输尿管狭窄的疗效及安全性.方法 回顾性分析18例采用输尿管镜钬激光治疗的输尿管梗阻患者的临床资料.输尿管狭窄位于上段11例(其中完全闭锁4例)、中段5例、下段2例,输尿管狭窄合并结石6例,采用输尿管镜钬激光(550 μm激光光纤,输出功率35 W)内切开术治疗,术后留置矫形输尿管支架,3~6

  12. Spectral performance of monolithic holmium and thulium lasers

    Science.gov (United States)

    Storm, Mark E.

    1991-01-01

    Fabry-Perot resonators have been used to demonstrate single-mode lasing of holmium and neodymium YAG. The previous demonstration in the holmium laser required TE cooling the crystal to -15 C in order to achieve threshold. The present study extends that result, demonstrating +25 C operation in a 1-mm thick plano/plano resonator. The experimental configuration of lasing both the holmium and thulium lasers used a 500-mW diode laser which was collimated, circularized, and focused into a beam radius of 60 microns. The single-frequency lasing spectrum of the holmium laser is shown. By adjusting the mirror reflectivity, the ability to control the laser's wavelength is demonstrated. This laser operated with 11 mW of optical power, a 57-percent slope efficiency, and 120-mW threshold vs absorbed diode power laser for the 60-micron beam radius. The thulium laser operated very efficiently at room temperature, but on seven longitudinal modes. The Tm:TAG laser exhibits typical characteristics of spatial hole burning not seen in the Ho:Tm:YAG for flat/flat resonators.

  13. Effects of Nursing Intervention on Quality of Life of Patient with Ureteral Stones Underwent Holmium: YAG Laser Ureteroscopic Lithotripsy%护理干预对输尿管镜钬激光碎石术患者生活质量的影响

    Institute of Scientific and Technical Information of China (English)

    钱彦; 瞿青云; 沈敏; 张涛; 吴宗林

    2012-01-01

    目的:探讨护理干预对输尿管镜钬激光碎石术患者生活质量的影响.方法:采取前瞻性随机对照的方法,从2008年5月到2010年12月,共有123例接受榆尿管镜钬激光碎石术的输尿管结石患者被随机分成对照组和护理干预组.使用世界卫生组织生存质量测定量表简表评价输尿管镜钬激光碎石术对患者生活质量的影响.结果:非护理干预组和护理干预组的世界卫生组织生存质量测定量表简表的生活质量评分手术后比手术前有明显改善(P<0.05).输尿管镜钬激光碎石术后,护理干预组患者的生活质量优于非护理干预组.结论:护理干预能明显改善输尿管镜钬激光碎石术患者的生活质量.%Objective: To investigate the effects of nursing intervention on quality of life of patient with ureteral stones underwent holmium: YAG laser ureteroscopic lithotripsy. Methods: From May in 2008 to December in 2010, a total of 123 consecutive patients admitted from a waiting list for surgery for ureteral stones were prospectively randomized to either nursing intervention or non-nursing intervention. Pre-and postoperative WHOQOL-BREF outcome data were obtained. Results; The WHOQOL-BREF in non-nursing intervention and nursing intervention group had significantly improved at post-operation compared to pre-operation. There was significant difference on WHOQOL-BREF scores in two groups at post-operation. Conclusions: Nursing intervention can improve the quality of life of patients with ureteral stones underwent holmium: YAG laser ureteroscopic lithotripsy. Improving the nursing after the procedure makes good prognosis.

  14. Holmium microparticles for intratumoral radioablation

    NARCIS (Netherlands)

    Bult, W.

    2010-01-01

    The aim of this dissertation is to describe the preparation and characterization of a holmium-loaded radioablation device: holmium acetylacetonate microspheres (HoAcAcMS). This device is to be injected directly into unresectable, chemorefractory, solid tumors, a technique referred to as (interstitia

  15. 输尿管硬镜下钬激光碎石取石术治疗输尿管上段结石112例%Study on treatment of upper ureteral calculi using rigid ureteroscope and holmium:YAG laser lithotripsy (report of 112 cases)

    Institute of Scientific and Technical Information of China (English)

    徐汉新; 吴兆春; 黄海

    2014-01-01

    Objective To investigate clinical effect and safety of holmium: YAG laser lithotripsy under ureteroscopy for managing upper ureteral calculi. Methods The clinical data of 112 cases of ureter calculi treated by ureteroscope with Holmium laser lithotripsy were retrospectively analyzed. Among these patients, 63 were male, and 49 were female. The age of the patients varied between 18~87 years with a mean age of 46.7 years. The largest diameter of the largest stone was 0.7~2.2 cm (1.2±0.5 cm). There are 5 cases of bilateral upper ureteral calculi, and the total number of left upper ureteral calculi was 61, and the right side was 46. There were 26 cases affiliated with ureteral polypus, and 31 cases with ESWL treatment history preoperative. All the cases had different degrees of hydronephrosis. Results The overall successful operation rate for all level of ureteral stones in single procedure was 88.4% (99/112). The operation time ranged 15~80 min (33.6 ±16.8 min), and the postoperative hospital stay was 3~14 d (4.7 ±2.1 d). No complications occurred such as severe hematouria, ureteral perforation, ureteral avulsion and ureteral stone street in this post cohort operation. There were three cases with urinary tract infection and suffered fever. Urosepsis occurred in one case , and cured by timely anti-infection treatment. Conclusion Rigid ureterorenoscopy using Ho:YAG laser lithotripsy for upper ureteral calculi can be an effective and safely performed technique.%目的:探讨输尿管硬镜下钬激光碎石取石术治疗输尿管上段结石的临床效果及安全性。方法应用输尿管硬镜下钬激光碎石取石术治疗112例输尿管上段结石患者。男63例,女49例,年龄18~87岁(46.7±13.6岁),左侧61例,右侧46例,双侧5例。结石长径0.7~2.2 cm (1.2±0.5 cm)。26例合并输尿管息肉,31例曾行体外冲击波碎石术,所有患侧肾脏均合并不同程度肾积水。结果手术成功率88.4

  16. Efficacy and safety of retrograde flexible ureteroscopic lithotripsy with holmium:YAG laser in the treatment of renal stones%逆行软性输尿管镜下钬激光碎石术治疗肾结石的有效性与安全性分析

    Institute of Scientific and Technical Information of China (English)

    曾国华; 李佳胜; 赵志健; 刘陈黎; 刘旸; 曾滔; 刘永达; 陈文忠; 吴文起

    2015-01-01

    Objective To evaluate the efficacy and safety of retrograde flexible ureteroscopic lithotripsy ( RFUL) with holmium:YAG laser for the treatment of renal stones with a large series.Methods The data of 466 patients who underwent RFUL with holmium:YAG laser for the treatment of kidney stones between January 2013 and December 2013 were collected.The maximum diameter of stone was 23 ±16 mm.The stone free rate, complications, retreatment rate were evaluated.Results Out of the 466 patients, the mean operative time and postoperative hospital stay were 33.5 ±18.8 min and 2.3 ±2.0 d.The stone free rate was 67.6% ( 315/466 ) after single procedure, which increased to 69.5% ( 324/466 ) via re-treatments after 3 months.The retreatment rate was 4.3%(20/466), with a total of 493 RFUL procedures performed and 1.06 times per patient.There were 67 (14.4%) cases undergoing complications.Five cases had false passage of ureter orifice causing slight ureteral wall injuries.Steinstrasse occurred in 9 cases, ureteral perforation in 3 cases and perirenal hematoma in 1 case.Overall postoperative fever rate was 10.7%(50/466) with urosepsis in 16 cases (3.4%).When the stone size was≤10, 11-20, 21-30, 31-40, and >40 mm, the stone free rates after a single procedure were 97.0% ( 65/67 ) , 84.2% ( 160/190 ) , 63.1%(70/111), 29.2%(14/48), 12.0%(6/50) (P<0.001), and the postoperative fever rates were 1.5%(1/67), 9.5%(18/190), 13.5% (15/111), 14.6% (7/48), 18.0% (9/50), respectively. The postoperative fever rates were 19.3%(27/140) and 7.1%(23/326) (P<0.001) in the patient with positive and negative preoperative urine leukocyte, and 22.0% ( 22/100 ) and 7.7% ( 28/366 ) ( P <0.001) in patients with positive and negative preoperative urine culture.Conclusions RFUL with holmium:YAG laser is a safe and effective treatment for kidney stones.The postoperative fever rate would increase and stone free rate would reduce with the increased stone size.%目的:评价逆行软性输尿管镜下钬激

  17. Holmium radioembolization : Efficacy and safety

    NARCIS (Netherlands)

    Prince, J.F.

    2016-01-01

    This thesis describes the application of holmium-166 (166Ho) microspheres for radioembolization of hepatic malignancies. In radioembolization, a scout dose of technetium-99m macroaggregated albumin (99mTc-MAA) is injected in the hepatic artery first, as a scout dose, to screen for any of two contrai

  18. Ureteropyeloscopy and homium: YAG laser lithotripsy for treatment of ureteral calculi (report of 356 cases)

    Science.gov (United States)

    Wu, Zhong; Din, Qiang; Jiang, Hao-wen; Zen, Jing-cun; Yu, Jiang; Zhang, Yuanfang

    2005-07-01

    Objective: To evaluate the efficacy and safety of holmium YAG laser lithotripsy for the treatment of ureteral calculi. Methods: A total of 356 patients underwent ureteropyeloscopic lithotripsy using holmium YAG laser with a semirigid uretesopyeloscope, 93 upper, 135 middle, and 128 lower ureteral stones were treated. Results: The overall successful fragmentation rate for all ureteral stones in a single session achieved 98% (349/356). The successful fragmentation rate stratified by stone location was 95% 88/93 in the upper ureter, 99% (134/135) in the mid ureter , and 99%(127/128) in the distal ureter. 12 cases with bilateral ureteral stones which caused acute renal failure and anuria were treated rapidly and effectively by the holmium YAG laser lithotripsy. No complications such as perforation and severe trauma were encountered during the operations. 2 weeks 17months (with an average of 6.8 month ) follow up postoperatively revealed that the overall stone-free rate was 98%(343/349) and no ureteral stenosis was found. Conclusions Holmium YAG laser lithotripsy is a highly effective, minimally invasive and safe therapy for ureteral calculi. It is indicated as a first choice of treatment for patients with ureteral calculi, especially for the ones with mid- lower levels of ureteral calculi.

  19. THC:YAG, Ultrasonic, And Electrohydraulic Gallstone Lithotriptors

    Science.gov (United States)

    Johnson, Jeffrey P.; Oz, Mehmet C.; Treat, Michael R.; Chuck, Roy S. H.; Trokel, Stephen L.

    1989-09-01

    There is considerable interest in methods of dealing with gallstones that would be less invasive than traditional gallbladder surgery. Our group has been especially interested in percutaneous endoscopic or transcatheter methods for performing biliary lithotripsy. We performed an in vitro comparison of three methods for lithotripsy, the thulium-holmium-chromium:YAG laser (THC:YAG), the ultrasonic lithotriptor (UL) and the electrohydraulic lithotriptor (EHL). We concluded that no one modality is clearly superior to the others, but rather that these methods are complementary with each modality having a preferred role.

  20. Stone Retropulsion with Ho: YAG and Tm: YAG Lasers: A Clinical Practice-Oriented Experimental Study.

    Science.gov (United States)

    Kamal, Wissam; Kallidonis, Panagiotis; Koukiou, Georgia; Amanatides, Lefteris; Panagopoulos, Vasileios; Ntasiotis, Pantelis; Liatsikos, Evangelos

    2016-11-01

    To compare the retropulsion of stones with the use of holmium: yttrium aluminum garnet (Ho: YAG) laser and thulium: yttrium aluminum garnet (Tm: YAG) laser in settings that could be used in clinical practice. The experimental configuration included a glass tube set in a water bath filled with physiologic saline. Plaster of Paris stones were inserted in the tube. Tm: YAG and Ho: YAG laser systems were used along with a high-speed slow-motion camera. The lasers were activated with different settings. The displacement of the stone was measured according to a custom-made algorithm. Ho: YAG: the retropulsion of stones was the lowest with the energy setting of 0.5 J and the frequency of 20 Hz with long pulse duration. The highest retropulsion was observed in the case of 3 J, 5 Hz, and short pulse. Tm: YAG: the retropulsion of stones was the lowest with the energy setting of 1 J and the frequency of 10 Hz with either long or short pulse duration. Practically, there was no retropulsion at all. The highest retropulsion was observed in the case of 8 J, 5 Hz, and short pulse. Ho: YAG laser has a linear increase in stone retropulsion with increased pulse energy. On the other hand, the retropulsion rate was kept to the minimum with Tm: YAG as much as the energy level of 8 J. The activation of lasers with short pulse resulted in further displacement of the stone. Lower frequency with the same power setting seemed to result in further stone retropulsion. Higher power with the same frequency setting resulted in further displacement of the stone.

  1. Magnetic structure of holmium-yttrium superlattices

    DEFF Research Database (Denmark)

    Jehan, D.A.; McMorrow, D.F.; Cowley, R.A.;

    1993-01-01

    that the superlattices have high crystallographic integrity: the structural coherence length parallel to the growth direction is typically almost-equal-to 2000 angstrom, while the interfaces between the two elements are well defined and extend over approximately four lattice planes. The magnetic structures were......We present the results of a study of the chemical and magnetic structures of a series of holmium-yttrium superlattices and a 5000 angstrom film of holmium, all grown by molecular-beam epitaxy. By combining the results of high-resolution x-ray diffraction with detailed modeling, we show...... determined using neutron-scattering techniques. The moments on the Ho3+ ions in the superlattices form a basal-plane helix. From an analysis of the superlattice structure factors of the primary magnetic satellites, we are able to determine separately the contributions made by the holmium and yttrium...

  2. Prospective analysis of a complete retrograde ureteroscopic technique with holmium laser stent cutting for management of encrusted ureteral stents.

    Science.gov (United States)

    Thomas, Alexandre; Cloutier, Jonathan; Villa, Luca; Letendre, Julien; Ploumidis, Achilles; Traxer, Olivier

    2017-03-14

    To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The Holmium-YAG laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intra-renal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery or a combination of these techniques. The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Holmium-YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly non-obstructive pyelonephritis (10%). The most significant predictor of this life threatened complication was the presence of struvite stones with the encrusted stent (p=0,018). Contrariwise, operative time, BMI, gender and encrustation rate were not associated with postoperative pyelonephritis. Cystine stone disease or pregnancy both led to faster stent encrustation. Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Holmium-YAG laser is essential to perform the encrustation removal and sectioning of the stent.

  3. Safety and efficacy of pneumatic lithotripters versus holmium laser in management of ureteral calculi: a randomized clinical trial.

    Science.gov (United States)

    Razzaghi, Mohammad Reza; Razi, Abdollah; Mazloomfard, Mohammad Mohsen; Golmohammadi Taklimi, Amin; Valipour, Reza; Razzaghi, Zahra

    2013-01-01

    To compare efficacy and safety of holmium:YAG laser and pneumatic lithotripter in the management of ureteral stones. One hundred and twelve patients with 1 to 2 cm ureteral calculi were selected for pneumatic or holmium:YAG laser transurethral ureterolithotripsy (56 patients in each group). Ultrasonography and plain abdominal x-ray were performed for all the patients before the operation. The pneumatic lithoclast was Swiss LithoClast, while in laser lithotripsy, holmium:YAG laser frequency was used, which was usually set between 5 and 10 Hz at a power of 10 to 15 Watt. Intravenous urography was performed for all the patients at 3 months to assess functional status and to delineate the ureteral anatomy. The mean patients' age and stones' size were the same in both groups, and there were no statistical differences. Mean duration of lithotripsy was 13.7 ± 12.6 minutes in laser group and 7.9 ± 4.2 minutes in pneumatic lithotripsy group. Immediate stone-free rate was 100% and 82.1% in the laser and pneumatic groups, respectively (P = .001). Stone pushing back occurred only in 10 (17.9%) patients in pneumatic group. In terms of complications, such as perforation, mucosal injury, and bleeding, there were no differences between the two groups. No intravenous pyelography related complication was seen at 3-month follow-up. Laser lithotripsy is a superior approach for the management of upper ureteral stones of 1 to 2 cm in size due to its higher rate of stone clearance.

  4. Holmium laser lithotripsy of bladder calculi

    Science.gov (United States)

    Beaghler, Marc A.; Poon, Michael W.

    1998-07-01

    Although the overall incidence of bladder calculi has been decreasing, it is still a significant disease affecting adults and children. Prior treatment options have included open cystolitholapaxy, blind lithotripsy, extracorporeal shock wave lithotripsy, and visual lithotripsy with ultrasonic or electrohydraulic probes. The holmium laser has been found to be extremely effective in the treatment of upper tract calculi. This technology has also been applied to the treatment of bladder calculi. We report our experience with the holmium laser in the treatment of bladder calculi. Twenty- five patients over a year and a half had their bladder calculi treated with the Holmium laser. This study was retrospective in nature. Patient demographics, stone burden, and intraoperative and post-operative complications were noted. The mean stone burden was 31 mm with a range of 10 to 60 mm. Preoperative diagnosis was made with either an ultrasound, plain film of the abdomen or intravenous pyelogram. Cystoscopy was then performed to confirm the presence and determine the size of the stone. The patients were then taken to the operating room and given a regional or general anesthetic. A rigid cystoscope was placed into the bladder and the bladder stone was then vaporized using the holmium laser. Remaining fragments were washed out. Adjunctive procedures were performed on 10 patients. These included transurethral resection of the prostate, transurethral incision of the prostate, optic internal urethrotomy, and incision of ureteroceles. No major complications occurred and all patients were rendered stone free. We conclude that the Holmium laser is an effective and safe modality for the treatment of bladder calculi. It was able to vaporize all bladder calculi and provides a single modality of treating other associated genitourinary pathology.

  5. Holmium laser for multifunctional use in urology

    Science.gov (United States)

    Watson, Graham M.; Shroff, Sunil; Thomas, Robert; Kellett, Michael

    1994-05-01

    The holmium laser pulsed at 350 microsecond cuts tissue and fragments calculi. It has been assessed for minimally invasive urological intervention. It is useful for partly excising and partly coagulating tumors, incising strictures and the obstructed PUJ. It partly drill and partly fragments urinary calculi however hard. Other lasers are more effective at any one particular application, but this laser is a useful compromise as a multifunctional device.

  6. Spherulitic crystallization of holmium tartrates in silica gels

    Energy Technology Data Exchange (ETDEWEB)

    Want, Basharat [University of Kashmir, Department of Physics, Srinagar (India)

    2011-09-15

    Spherulites of holmium tartrate trihydrate and holmium nitro-tartrate monohydrate have been grown in silica gel medium by making holmium nitrate to react with tartaric acid at high supersaturations. The mechanism of spherulitic growth of holmium tartrates is discussed. The spherulitic crystallization is shown to be due to heterogeneous nucleation. In the early stages of growth an amorphous spherical mass gets nucleated inside the gel. Crystal fibers diverge radially from the surface of the spherical mass giving rise to a spherical polycrystalline holmium tartrate. Thermal stability of the two types of spherulites grown in the silica gel shows that the holmium tartrate trihydrate is more stable than holmium nitro-tartrate monohydrate. The surface morphology and internal structure of the spherulites of holmium tartrates have been studied by using scanning electron microscopy. The results on growth kinetics are given by studying the variation of radius of spherulites as a function of time. A non-linear time-size relations under several conditions of growth have been observed, which suggests a non-uniform solute concentration at the crystal surface. (orig.)

  7. High- vs low-power holmium laser lithotripsy: a prospective, randomized study in patients undergoing multitract minipercutaneous nephrolithotomy.

    Science.gov (United States)

    Chen, Shushang; Zhu, Lingfeng; Yang, Shunliang; Wu, Weizhen; Liao, Lianming; Tan, Jianming

    2012-02-01

    To determine the efficacy and safety of high-power holmium: yttrium aluminum-garnet (Ho:YAG) laser lithotripsy for multitract modified minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of patients with large staghorn renal calculi. A randomized, prospective study was conducted. Two-hundred seventy-three consecutive patients (291 renal units) with large staghorn renal calculi were randomized to undergo multitract MPCNL with 30-W low-power or 70-W high-power Ho:YAG laser lithotripsy. Both groups were compared in terms of perioperative findings and postoperative outcomes, including procedure time, stone-free rate, length of hospital stay, transfusion rates, renal function recovery, and other complications. The average patient age was 49.2 years (range 22-73) and mean stone size was 5.54±0.7 cm. The 2 groups had some comparable perioperative findings and outcome, including tracts required per operated renal unit (n), blood loss, postoperative fever, postoperative hospital stay, stone-free rate, and improvement of operated renal function. The operation time in the high-power group was significantly shorter than that in the low-power group (129.20±17.2 vs 105.18±14.2, Ppower Ho:YAG laser lithotripsy can greatly decrease the operative time without increasing the intraoperative complications or delaying postoperative renal function recovery when compared with low-power Ho:YAG laser lithotripsy. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Nd:YAG laser treatment of herpes and aphthous ulcers: a preliminary study

    Science.gov (United States)

    Parkins, Frederick M.; O'Toole, Thomas J.; Yancey, John M.

    2000-06-01

    Previously herpes labialis and recurrent aphthous ulcers have not been successfully treated. A preliminary study with a pulsed Nd:YAG laser evaluated the results with a protocol of four minute non-contact exposures for both types of lesions. Most patients experienced relief of symptoms. The progress of herpes lesion was halted and aphthous lesions became desensitized.

  9. Three-dimensional topographic scanning electron microscope and Raman spectroscopic analyses of the irradiation effect on teeth by Nd:YAG, Er: YAG, and CO(2) lasers.

    Science.gov (United States)

    Yamada, Magda K; Uo, Motohiro; Ohkawa, Shoji; Akasaka, Tsukasa; Watari, Fumio

    2004-10-15

    A three-dimensional analyzer installed in a scanning electron microscope was used to evaluate the morphology and surface roughness using noncontact profilometry. Observations were carried out on the enamel and dentin surface irradiated by three different lasers: Nd:YAG (wavelength 1.06 microm), Er:YAG (2.94 microm), and CO(2) (10.6 microm). Spectroscopic analysis was done by Raman spectroscopy for nonirradiated and laser-irradiated surfaces. The lasers were applied perpendicularly to vertically sectioned and polished human extracted caries-free molars. The tooth was sectioned at each cavity for cross-section analysis after laser irradiation. Irradiation by Nd:YAG and CO(2) lasers of the enamel surface showed an opaque white color, different from dentin where the surface turned black. The Er:YAG laser induced no changes in color of the dentin. Numerous cracks associated with thermal stress were observed in the CO(2) laser-irradiated dentin. Noncontact surface profile analysis of Er:YAG laser-irradiated enamel and dentin showed the deepest cavities, and direct cross-sectional observations of them showed similar cavity outlines. The CO(2) laser-irradiated dentin had the least surface roughness. Raman spectroscopic analysis showed that fluorescence from the laser-irradiated tooth was generally greater than from nonirradiated teeth. Bands in dentin attributed to organic collagen matrix were lost after Nd:YAG and CO(2) laser irradiation, and a broad peak due to amorphous carbon appeared. The Er:YAG laser-irradiated dentin showed no sign of a carbon band and had more suitable results for dental ablation. Noncontact surface profile analysis was effective to evaluate the structural change in the tooth in the microarea of study after laser irradiation.

  10. The use of holmium-yttrium aluminum garnet laser as pit and fissure cleaner

    Directory of Open Access Journals (Sweden)

    Armasastra Bahar

    2009-09-01

    Full Text Available Background: The prevention and management of pit and fissure caries has become relatively more important in recent times. There is a need for an effective preventive measure against pit and fissure caries. Purpose: The purpose of this study was to investigate the effect of laser beam as a cleaning method of pits and fissures. Methods: Ho-YAG laser which has a wavelength of 2.1 µm was used in this experiment. The specimens were extracted human teeth. The effect of three cleaning methods was examined comparatively by scoring the cleaned area of fissure, namely laser irradiation with Ho-YAG laser, chemico-mechanical with combination of 10% NaOCl and ultrasonic scaler and mechanical with ultrasonic scaler. Vertico-bucco-lingual serial ground sections of each tooth were observed under light microscopy. Scoring the depth of cleaned area was performed by comparing the depth of fissure. result: Progressive result was obtained on the cleaning effect of three methods laser irradiation methods which was the most effective compared to other methods but statistically was not significant. Cleaned area of laser irradiation method was 48.91%, chemico-mechanical method was 41.77% and mechanical method was 36.78%. Conclusion: Holmium -yttrium aluminum garner laser is a relatively new method for pit and fissure cleaning even though the effectivity is not yet maximal. More research is needed to maximize the use of this laser.

  11. Picosecond holmium fibre laser pumped at 1125 \\ {\\text{nm}}

    Science.gov (United States)

    Kamynin, V. A.; Filatova, S. A.; Zhluktova, I. V.; Tsvetkov, V. B.

    2016-12-01

    We report a passively mode-locked, all-fibre holmium laser based on nonlinear polarisation rotation. As a pump source use is made of an 1125-{\\text{nm}} ytterbium-doped fibre laser. The pulse repetition rate of the holmium laser is 7.5 {\\text{MHz}}, and the pulse duration does not exceed 52 {\\text{ps}} at wavelengths of 2065 and 2080 {\\text{nm}}. The average laser output power reaches 5 {\\text{mW}}.

  12. Holmium laser enucleation of the prostate hyperplasia: technical aspects

    Directory of Open Access Journals (Sweden)

    P. V. Glybochko

    2015-01-01

    Full Text Available Holmium laser enucleation of the prostate (HoLEP was first described by doctor P.J. Gilling et al. from New Zealand in 1996. The operation involves anatomical dissection of the prostatic tissue off the surgical capsule using a high-powered holmium laser followed by intravesical morsellation. The objective of this article is to explain the techniques for HoLEP.

  13. Holmium nanoparticles : preparation and in vitro characterization of a new device for radioablation of solid malignancies

    NARCIS (Netherlands)

    Bult, Wouter; Varkevisser, Rosanne; Soulimani, Fouad; Seevinck, Peter R; de Leeuw, Hendrik; Bakker, Chris J G; Luijten, Peter R; van Het Schip, Alfred D; Hennink, Wim E; Nijsen, J Frank W

    2010-01-01

    PURPOSE: The present study introduces the preparation and in vitro characterization of a nanoparticle device comprising holmium acetylacetonate for radioablation of unresectable solid malignancies. METHODS: HoAcAc nanoparticles were prepared by dissolving holmium acetylacetonate in chloroform, follo

  14. Electrochemical formation of holmium-cobalt alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The electrochemical formation processes of holmium-cobalt alloys on cobalt cathode in molten HoC13-KC1 wereinvestigated by cyclic voltammetry and open current potential-time curve after potentiostatic electrolysis. The structure ofHo-Co alloys' films deposited on cobalt electrode by potentiostatic electrolysis was characterized by X-ray diffraction. Thestandard Gibbs free energies of formation for the intermetallic compounds of Ho and Co were determined. The diffusioncoefficient and diffusion activation energy of Ho atom in the alloy phase were calculated to be 10-10-10-11 cm2/s and 96.0kJ/mol, respectively, from the current-time curve at potential step.

  15. Magnetodielectric coupling in multiferroic holmium iron garnets

    Science.gov (United States)

    Malar Selvi, M.; Chakraborty, Deepannita; Venkateswaran, C.

    2017-02-01

    Single phase magneto-electric multiferroics require a large magnetic or electric field for producing magneto-electric (ME) and magnetodielectric (MD) effects. For utilizing these effects in devices investigations on the room temperature and low field MD studies are necessary. Recently, efforts have been largely devoted to the investigation of rare earth iron garnets. In the physical method, the preparation of rare earth iron garnet requires high sintering temperature and processing time. To solve these problems, ball milling assisted microwave sintering technique is used to prepare nanocrystalline holmium iron garnets (Ho3Fe5O12). Magnetic and dielectric properties of the prepared sample are investigated. These properties get enhanced in nanocrystalline form when compared to the bulk. The MD coupling of the prepared sample is evident from the anomaly in the temperature dependent dielectric constant plot and the ME coupling susceptibility is derived from the room temperature MD measurements.

  16. Magneto-Optical Trapping of Holmium Atoms

    CERN Document Server

    Miao, J; Stratis, G; Saffman, M

    2014-01-01

    We demonstrate sub-Doppler laser cooling and magneto-optical trapping of the rare earth element Holmium. Atoms are loaded from an atomic beam source and captured in six-beam $\\sigma_+ - \\sigma_-$ molasses using a strong $J=15/2 \\leftrightarrow J=17/2$ cycling transition at $\\lambda=410.5~\\rm nm$. Due to the small difference in hyperfine splittings and Land\\'e $g$-factors in the lower and upper levels of the cooling transition the MOT is self-repumped without additional repump light, and deep sub-Doppler cooling is achieved with the magnetic trap turned on. We measure the leakage out of the cycling transition to metastable states and find a branching ratio $\\sim 10^{-5}$ which is adequate for state resolved measurements on hyperfine encoded qubits.

  17. Mid-infrared ZGP optical parametric oscillator directly pumped by a lamp-pumped, Q-switched Cr,Tm,Ho:YAG laser

    NARCIS (Netherlands)

    Nieuwenhuis, Ab F.; Lee, Chris J.; Slot, van der Peter J.M.; Gross, Petra; Boller, Klaus-Jochen; Powers, Peter E.

    2007-01-01

    We generate mid-infrared pulsed light tunable between 5.6 μm and 6.6 μm using an optical parametric oscillator (OPO) directly pumped by a Cr,Tm,Ho:YAG, Q -switched laser operating at 2.1 μm. The Holmium laser uses a RTP Q -switch to produce pulses shorter than 100 ns and energies of up to 42 mJ in a

  18. Mid-Infrared ZGP optical parametric oscillator directly pumped by a lamp-pumped, Q-switched Cr,Tm,Ho:YAG laser

    NARCIS (Netherlands)

    Nieuwenhuis, Albert F.; Lee, Christopher James; van der Slot, Petrus J.M.; Gross, P.; Boller, Klaus J.; Powers, Peter E.

    2007-01-01

    We generate mid-infrared pulsed light tunable between 5.6 μm and 6.6 μm using an optical parametric oscillator (OPO) directly pumped by a Cr,Tm,Ho:YAG, Q -switched laser operating at 2.1 μm. The Holmium laser uses a RTP Q -switch to produce pulses shorter than 100 ns and energies of up to 42 mJ in a

  19. Non-contact ECG monitoring

    Science.gov (United States)

    Smirnov, Alexey S.; Erlikh, Vadim V.; Kodkin, Vladimir L.; Keller, Andrei V.; Epishev, Vitaly V.

    2016-03-01

    The research is dedicated to non-contact methods of electrocardiography. The authors describe the routine of experimental procedure and suggest the approach to solving the problems which arise at indirect signal recording. The paper presents the results of experiments conducted by the authors, covers the flow charts of ECG recorders and reviews the drawbacks of filtering methods used in foreign equivalents.

  20. Microspheres with Ultrahigh Holmium Content for Radioablation of Malignancies

    NARCIS (Netherlands)

    Bult, W.; Seevinck, P.R.; Krijger, G.C.; Visser, T.; Kroon-Batenburg, L.M.J.; Bakker, C.J.G.; Hennink, W.E.; Van het Schip, A.D.; Nijsen, J.F.W.

    Purpose The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  1. Microspheres with ultrahigh holmium content for radioablation of malignancies

    NARCIS (Netherlands)

    Bult, W; Seevinck, P R; Krijger, G C; Visser, T; Kroon-Batenburg, L M J; Bakker, C J G; Hennink, W E; van het Schip, A D; Nijsen, J F W

    2009-01-01

    PURPOSE: The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  2. Using transurethral Ho:YAG-laser resection to treat urethral stricture and bladder neck contracture

    Science.gov (United States)

    Bo, Juanjie; Dai, Shengguo; Huang, Xuyuan; Zhu, Jing; Zhang, Huiguo; Shi, Hongmin

    2005-07-01

    Objective: Ho:YAG laser had been used to treat the common diseases of urinary system such as bladder cancer and benign prostatic hyperplasia in our hospital. This study is to assess the efficacy and safety of transurethral Ho:YAG-laser resection to treat the urethral stricture and bladder neck contracture. Methods: From May 1997 to August 2004, 26 cases of urethral stricture and 33 cases of bladder neck contracture were treated by transurethral Ho:YAG-laser resection. These patients were followed up at regular intervals after operation. The uroflow rate of these patients was detected before and one-month after operation. The blood loss and the energy consumption of holmium-laser during the operation as well as the complications and curative effect after operation were observed. Results: The therapeutic effects were considered successful, with less bleeding and no severe complications. The Qmax of one month postoperation increased obviously than that of preoperation. Of the 59 cases, restenosis appeared in 11 cases (19%) with the symptoms of dysuria and weak urinary stream in 3-24 months respectively. Conclusions: The Ho:YAG-laser demonstrated good effect to treat the obstructive diseases of lower urinary tract such as urethral stricture and bladder neck contracture. It was safe, minimal invasive and easy to operate.

  3. PREFACE: Non-contact AFM Non-contact AFM

    Science.gov (United States)

    Giessibl, Franz J.; Morita, Seizo

    2012-02-01

    This special issue is focussed on high resolution non-contact atomic force microscopy (AFM). Non-contact atomic force microscopy was established approximately 15 years ago as a tool to image conducting and insulating surfaces with atomic resolution. Since 1998, an annual international conference has taken place, and although the proceedings of these conferences are a useful source of information, several key developments warrant devoting a special issue to this subject. In the theoretic field, the possibility of supplementing established techniques such as scanning tunneling microscopy (STM) and Kelvin probe microscopy with atomically resolved force micrsoscopy poses many challenges in the calculation of contrast and contrast reversal. The surface science of insulators, self-assembled monolayers and adsorbates on insulators is a fruitful field for the application of non-contact AFM: several articles in this issue are devoted to these subjects. Atomic imaging and manipulation have been pioneered using STM, but because AFM allows the measurement of forces, AFM has had a profound impact in this field as well. Three-dimensional force spectroscopy has allowed many important insights into surface science. In this issue a combined 3D tunneling and force microscopy is introduced. Non-contact AFM typically uses frequency modulation to measure force gradients and was initially used mainly in a vacuum. As can be seen in this issue, frequency modulation is now also used in ambient conditions, allowing better spatial and force resolution. We thank all of the contributors for their time and efforts in making this special issue possible. We are also very grateful to the staff of IOP Publishing for handling the administrative aspects and for steering the refereeing process. Non-contact AFM contents Relation between the chemical force and the tunnelling current in atomic point contacts: a simple model Pavel Jelínek, Martin Ondrácek and Fernando Flores Theoretical simulation of

  4. SEM evaluation of the morphological changes in hard dental tissues prepared by Er: YAG laser and rotary instruments

    Directory of Open Access Journals (Sweden)

    Tomov Georgi

    2010-09-01

    Full Text Available Effective ablation of dental hard tissues by means of the erbium:yttrium-aluminum garnet (Er: YAG laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the morphological changes in hard dental tissues after Er: YAG laser caries treatment. In the present study the morphological changes in hard dental tissues after Er: YAG laser caries ablation in vitro was compared with that of conventional mechanical treatment. Thirty extracted human teeth with caries were used. Ten tooth was treated with the Er: YAG laser, and the other was treated with a conventional steel and diamond burs. Laser treatment was performed by means of a non-contact irradiation modes with cooling water spray, with a new Er: YAG laser (LiteTouch. Conventional bur treatment was conducted by means of a low-speed micromotor and air turbine with water cooling. Scanning electron microscope (SEM observations were performed for each treatment. The Er: YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the burtreatment. In addition, a lower degree of vibration was noted with the Er: YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin and enamel surfaces with potential benefits for adhesive restorations. Our results show that the Er: YAG laser is promising as a new technical modality for caries treatment

  5. Adhesion of composite luting cement to Er:YAG-laser-treated dentin.

    Science.gov (United States)

    Carrieri, Teresa C D; de Freitas, Patricia M; Navarro, Ricardo S; Eduardo, Carlos de P; Mori, Matsuyoshi

    2007-09-01

    Although some studies claim to the increase of composite resin adhesion to Er:YAG-laser-treated dentin, there are still no reports on the adhesion of composite resin cements to the irradiated surface. This in vitro study evaluated the tensile bond strength (TBS) of a composite resin cement to dentin treated with the Er:YAG laser. Sixty human dentin samples were divided into four groups (n = 15): G1 (Control)-no treatment; G2-Er:YAG laser 60 mJ, 2 Hz, with water cooling, non-contact (19 J/cm(2)); G3-Er:YAG laser 60 mJ, 10 Hz, 50/10 fiber, contact, without water cooling (40 J/cm(2)); G4-Er:YAG laser 60 mJ, 10 Hz, 50/10 fiber, contact, with water cooling (40 J/cm(2)). After the surface treatment, each sample was submitted to bonding procedures. The analysis of variance (ANOVA) and Tukey tests revealed no statistical significant difference on TBS values for groups G1 (13.73 +/- 3.05 MPa), G2 (12.60 +/- 2.09 MPa) and G4 (11.17 +/- 4.04 MPa). G4 was not statistically different from G3 (8.64 +/- 2.06 MPa). Er:YAG laser irradiation with different settings can constitute an alternative tool to the use of composite resin-luting cements.

  6. Noncontacting Optical Measurement And Inspection Systems

    Science.gov (United States)

    Asher, Jeffrey A.; Jackson, Robert L.

    1986-10-01

    Product inspection continues to play a growing role in the improvement of quality and reduction of scrap. Recent emphasis on precision measurements and in-process inspection have been a driving force for the development of noncontacting sensors. Noncontacting sensors can provide long term, unattended use due to the lack of sensor wear. Further, in applications where, sensor contact can damage or geometrically change the part to be measured or inspected, noncontacting sensors are the only technical approach available. MTI is involved in the development and sale of noncontacting sensors and custom inspection systems. This paper will review the recent advances in noncontacting sensor development. Machine vision and fiber optics sensor systems are finding a wide variety of industrial inspection applications. This paper will provide detailed examples of several state-of-the-art applications for these noncontacting sensors.

  7. High Efficient Continuous-Wave Ho: YAG Laser Pumped by a Diode-pumped Tm: YLF Laser at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    DUAN Xiao-Ming; YAO Bao-Quan; ZHANG Yun-Jun; SONG Cheng-Wei; GAO Jing; JU You-Lun; WANG Yue-Zhu

    2008-01-01

    We present a high efficient continuous wave Ho:YAG laser pumped by a diode-pumped Tm:YLF laser with a Fabry-Perot etalon tuning at 1.91 μm. The maximum output power reaches 7.2 W when the absorbed pump power is 10.8 W.The slope efficiency (relative to the absorbed power) is 74.1%,and the Tm:YLF to Ho:YAG optical conversion efficiency of 60%,then the diode-to-Holmium optical conversion efficiency achieved is 21.0%.The wavelength is 2090 nm when the transmission of output coupler is larger than 20%.The beam quality factor is M2 ~ 1.15 measured by the travelling knife-edge method.

  8. Infrared emission from holmium doped gallium lanthanum sulphide glass

    Science.gov (United States)

    Schweizer, T.; Samson, B. N.; Hector, J. R.; Brocklesby, W. S.; Hewak, D. W.; Payne, D. N.

    1999-08-01

    Infrared emission at 1.2, 1.25, 1.67, 2.0, 2.2, 2.9, 3.9, and 4.9 μm is measured in holmium (Ho 3+) doped gallium lanthanum sulphide (GLS) glass. Branching ratios, radiative quantum efficiencies, and emission cross-sections are calculated from lifetime, absorption, and emission measurements using Judd-Ofelt analysis and the Füchtbauer-Ladenburg equation. The fluorescence band at 3.9 μm coincides with an atmospheric transmission window and the fluorescence band at 4.9 μm overlaps with the fundamental absorption of carbon monoxide, making the glass a potential fibre laser source for remote sensing and gas sensing applications. This is the first time this latter transition has been reported in any holmium doped host.

  9. Effect of Fluoride Varnish Combined with Er:YAG Laser on the Permeability of Eroded Dentin: An In Situ Study

    OpenAIRE

    Nemezio,Mariana Alencar; Carvalho,Sandra Chiga; Scatolin, Renata Siqueira; Colucci,Vivian; Galo, Rodrigo; Corona, Silmara Aparecida Milori

    2015-01-01

    This study evaluated the combined effect of fluoride varnish and Er:YAG laser on the permeability of eroded bovine root dentin. After initial erosive challenge followed by a remineralization period, the specimens were divided in two groups according to the treatment - fluoride varnish and non-fluoride varnish - and were subdivided according to the irradiation protocol: Er:YAG laser (100 mJ, 3 Hz, 12.8 J/cm2per pulse, non-contact and defocus mode) and non-irradiated. After a lead-in period, 7 ...

  10. Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(l-lactic acid) microspheres in healthy pigs

    NARCIS (Netherlands)

    Vente, M.A.D.; Nijsen, J.F.W.; De Wit, T.C.; Seppenwoolde, J.H.; Krijger, G.C.; Seevinck, P.R.; Huisman, A.; Zonneneberg, B.A.; Van den Ingh, T.S.G.A.M.; Van het Schip, A.D.

    2008-01-01

    Purpose The aim of this study is to evaluate the toxicity of holmium-166 poly(l-lactic acid) microspheres administered into the hepatic artery in pigs. Methods Healthy pigs (20–30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres (165HoMS; n = 5) or with holmium-166-l

  11. Tape casting fabrication and properties of planar waveguide YAG/Yb:YAG/YAG transparent ceramics

    Science.gov (United States)

    Zhao, Yu; Liu, Qiang; Ge, Lin; Wang, Chao; Li, Wenxue; Yang, Chao; Wang, Juntao; Yuan, Lei; Xie, Tengfei; Kou, Huamin; Pan, Yubai; Gao, Qingsong; Bo, Yong; Peng, Qinjun; Xu, Zuyan; Li, Jiang

    2017-07-01

    Highly transparent YAG/10at.%Yb:YAG/YAG planar waveguide ceramics were fabricated by the non-aqueous tape casting and solid-state reactive sintering technology. The tapes are relatively homogeneous and the green body shows a dense structure without distinct interfaces after the treatment of debinding and cold isostatic pressing. YAG/10at.%Yb:YAG/YAG ceramics with almost full dense structure were obtained by vacuum-sintering at 1760 °C for 30 h. For the mirror-polished sample with the thickness of 3.5 mm, the In-line transmittance was measured to be 83.6% at the visual wavelength of 400 nm. The diffusion distance of the Yb3+ ions was about 215 μm along the thickness direction of the ceramics. In the lasing experiments, the YAG/10at.%Yb:YAG/YAG planar waveguide ceramics were end-pumped by a 976 nm semiconductor diode laser and enabled efficient continuous-wave lasers, which resulted in a maximum output power of 1.6 W and a slope efficiency of 34.4% at 1030 nm.

  12. Acupoint Massage in Relieving Pain after Ureteroscopic Holmium Laser Lithotripsy

    Institute of Scientific and Technical Information of China (English)

    Xia Wei-qin

    2014-01-01

    Objective: To observe the effect of acupoint massage in relieving pain after ureteroscopic holmium laser lithotripsy. Methods: Ninety-two patients undergone ureteroscopic holmium laser lithotripsy were enrolled and randomized into a treatment group and a control group, 46 in each group. Patients in the control group were given regular nursing care, while patients in the treatment group were intervened by acupoint massage in addition to the regular nursing care. The pain was evaluated by visual analogue scale (VAS) at 6 h, 12 h, and 24 h after operation, and compared between the two groups. Results:There was no significant difference in comparing the VAS score at 6 h after operation between the two groups (P>0.05). The VAS scores in the treatment group at 12 h and 24 h after operation were significantly lower than those in the control group (both P Conclusion: Acupoint massage can effectively relieve the pain after ureteroscopic holmium laser lithotripsy, reduce the use of analgesics, and promote the recovery.

  13. Nd:YAG laser therapy for rectal and vaginal venous malformations.

    Science.gov (United States)

    Gurien, Lori A; Jackson, Richard J; Kiser, Michelle M; Richter, Gresham T

    2017-08-01

    Limited therapeutic options exist for rectal and vaginal venous malformations (VM). We describe our center's experience using Nd:YAG laser for targeted ablation of abnormal veins to treat mucosally involved pelvic VM. Records of patients undergoing non-contact Nd:YAG laser therapy of pelvic VM at a tertiary children's hospital were reviewed. Symptoms, operative findings and details, complications, and outcomes were evaluated. Nine patients (age 0-24) underwent Nd:YAG laser therapy of rectal and/or vaginal VM. Rectal bleeding was present in all patients and vaginal bleeding in all females (n = 5). 5/7 patients had extensive pelvic involvement on MRI. Typical settings were 30 (rectum) and 20-25 W (vagina), with 0.5-1.0 s pulse duration. Patients underwent the same-day discharge. Treatment intervals ranged from 14 to 180 (average = 56) weeks, with 6.1-year mean follow-up. Five patients experienced symptom relief with a single treatment. Serial treatments managed recurrent bleeding successfully in all patients, with complete resolution of vaginal lesions in 40% of cases. No complications occurred. Nd:YAG laser treatment of rectal and vaginal VM results in substantial improvement and symptom control, with low complication risk. Given the high morbidity of surgical resection, Nd:YAG laser treatment of pelvic VM should be considered as first line therapy.

  14. Microspheres with an ultra high holmium content for brachytherapy of malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Raphael A.; Myamoto, Douglas M.; Souza, Jaime R.; Nascimento, Nanci; Azevedo, Mariangela de Burgos M. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia; Martinelli, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The overall objective of this work is to develop biodegradable microspheres intended for internal radiation therapy which provides an improved treatment for hepatic carcinomas. The most studied brachytherapy system employing microspheres made of holmium-biopolymer system is composed by poly(L-lactic acid) (PLLA) and holmium acetylacetonate (HoAcAc). The importance of the holmium high content in the microspheres can be interpreted as follow from a therapeutic standpoint, to achieve an effective use of microspheres loaded with HoAcAc, a high content of holmium is required to yield enough radioactivity with a relatively low amount of microspheres.The usual amounts of holmium that are incorporated in the microspheres composed by poly(L-lactic acid) and HoAcAc are 17.0 {+-} 0.5% (w/w) of holmium, which corresponds to a loading of about 50% of HoAcAc. Different approaches have been investigated to increase that value. One updated approach towards this direction is the production of microspheres with ultrahigh holmium as matrix using HoAcAc crystals as the sole starting material without the use of biopolymer. Likewise, in the search of microspheres with increased holmium content , it has been demonstrated that by changing the HoAcAc crystal structure by its recrystallization from crystal phase to the amorphous there is lost of acetylacetonate and water molecules causing the increasing of the holmium content. Microspheres were prepared by solvent evaporation, using holmium acetylacetonate (HoAcAc) crystals as the sole ingredient. Microspheres were characterized by using light and scanning electron microscopy, infrared and Raman spectroscopy, differential scanning calorimetry, X-rays diffraction, and confocal laser scanning microscopy. (author)

  15. Non-contact temperature measurement

    Science.gov (United States)

    Nordine, Paul C.; Krishnan, Shankar; Weber, J. K. R.; Schiffman, Robert A.

    Three methods for noncontact temperature measurement are presented. Ideal gas thermometry is realized by using laser-induced fluorescence to measure the concentration of mercury atoms in a Hg-Ar mixture in the vicinity of hot specimens. Emission polarimetry is investigated by measuring the spatially resolved intensities of polarized light from a hot tungsten sphere. Laser polarimetry is used to measure the optical properties, emissivity, and, in combination with optical pyrometry, the temperature of electromagnetically levitated liquid aluminum. The precision of temperature measurements based on the ideal gas law is + or - 2.6 percent at 1500-2000 K. The polarized emission technique is found to have the capability to determine optical properties and/or spectral emissivities of specimens over a wide range of wavelengths with quite simple instruments.

  16. Synthesis and Characterization of Holmium-Doped Iron Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Maarten Bloemen

    2014-02-01

    Full Text Available Rare earth atoms exhibit several interesting properties, for example, large magnetic moments and luminescence. Introducing these atoms into a different matrix can lead to a material that shows multiple interesting effects. Holmium atoms were incorporated into an iron oxide nanoparticle and the concentration of the dopant atom was changed in order to determine its influence on the host crystal. Its magnetic and magneto-optical properties were investigated by vibrating sample magnetometry and Faraday rotation measurements. The luminescent characteristics of the material, in solution and incorporated in a polymer thin film, were probed by fluorescence experiments.

  17. Efficacy and Safety of 120-W Thulium:Yttrium-Aluminum-Garnet Vapoenucleation of Prostates Compared with Holmium Laser Enucleation of Prostates for Benign Prostatic Hyperplasia

    Institute of Scientific and Technical Information of China (English)

    Kai Hong; Yu-Qing Liu; Jian Lu; Chun-Lei Xiao; Yi Huang; Lu-Lin Ma

    2015-01-01

    Background:This study compared the efficacy and safety between 120-W thulium:yttrium-aluminum-garnet (Tm:YAG) vapoenucleation of prostates (ThuVEP) and holmium laser enucleation of prostates (HoLEP) for patients with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).Methods:A retrospective analysis of 88 consecutive patients with symptomatic BPH was carried out,who underwent either 120-W ThuVEP or HoLEP nonrandomly.Patient demographics and peri-operative and 12-month follow-up data were analyzed with the International Prostate Symptom Score (IPSS),quality of life (QoL) score,maximum flow rate (Qmax),postvoid residual urine volume (PVR),and rates of peri-operative and late complications.Results:The patients in each group showed no significant difference in preoperative parameters.Compared with the HoLEP group,patients in the 120-W ThuVEP group required significantly shorter time for laser enucleation (58.3 ± 12.8 min vs.70.5 ± 22.3 min,P =0.003),and resulted in a significant superiority in laser efficiency (resected prostate weight/laser enucleation time) for 120-W Tm:YAG lasercompared to holmium:YAG laser (0.69 ± 0.18 vs.0.61 ± 0.19,P =0.048).During 1,6,and 12 months of follow-ups,the procedures did not demonstrate a significant difference in IPSS,QoL score,Qmax,or PVR (P > 0.05).Mean peri-operative decrease of hemoglobin in the HoLEP group was similar to the ThuVEP group (17.1 ± 12.0 g/L vs.15.2 ± 10.1 g/L,P =0.415).Early and late incidences of complications were low and did not differ significantly between the two groups of 120-W ThuVEP and HoLEP patients (P > 0.05).Conclusions:120-W ThuVEP and HoLEP are potent,safe and efficient modalities of minimally invasive surgeries for patients with LUTS due to BPH.Compared with HoLEP,120-W ThuVEP offers advantages of reduction of laser enucleation time and improvement of laser efficiency.

  18. Dielectric and thermal behaviour of holmium tartrate trihydrate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Want, B.; Ahmad, F. [Department of Physics, University of Kashmir, Srinagar (India); Kotru, P.N. [Department of Physics and Electronics, University of Jammu (India)

    2007-08-15

    Measurements on dielectric constant of holmium tartrate trihydrate crystals at frequencies of the applied a.c. in the range 1 kHz to 1 MHz and at temperature in the range 30 C to 330 C are reported. The dielectric constant {epsilon}' increases with temperature at all frequencies, attains a peak near 250 C, and then decreases as the temperature goes beyond 250 C. The anomalous dielectric behaviour at near about 250 C is attributed to be as a result of crystallographic/polymorphic phase transition brought about in the material. The results on the dielectric behaviour of the material are supplemented by results of thermal analysis viz., TG and DTA. Thermogravimetric and differential thermal analytic techniques have been used to study thermal behaviour of the material. It is shown that the material is thermally stable up to 220 C beyond which it decomposes through three stages till the formation of holmium oxide at 1200 C. The non-isothermal kinetic parameters e.g., activation energy and the frequency factor have been evaluated for first two stages of thermal decomposition by using the integral method of Coats and Redfern. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Coagulation of a giant hemangioma in glans penis with holmium laser

    Institute of Scientific and Technical Information of China (English)

    Emin Aydur; Bulent Erol; Lutfi Tahmaz; Hasan Cem Irkilata; Cenker Eken; Ahmet Fuat Peker

    2008-01-01

    A 21-year-old man presented with an enlarged giant hemangioma on glans penis which also causes an erectile dysfunction (ED) that partially responded to the intracavernous injection stimulation test. Although the findings in magnetic resonance imaging (MRI) indicated a glandular hemangioma, penile colored Doppler ultrasound revealed an invaded cavernausal hemangioma to the glans. Surgical excision was avoided according to the broad extension of the gland lesion. Holmium laser coagulation was applied to the lesion due to the cosmetically concerns. However, the cosmetic results after holmium laser application was not impressive as expected without an improvement in intracavernous injection stimulation test. In conclusion, holmium laser application should not be used to the heman- giomas of glans penis related to the corpus cavernosum, but further studies are needed to reveal the effects of holmium laser application in small hemangiomas restricted to the glans penis.

  20. X-ray and neutron scattering studies of magnetic critical fluctuations in holmium

    Energy Technology Data Exchange (ETDEWEB)

    Thurston, T.R.; Helgesen, G.; Gibbs, D.; Shirane, G. [Brookhaven National Lab., Upton, NY (United States); Hill, J.P. [Brookhaven National Lab., Upton, NY (United States)]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Gaulin, B.D. [Brookhaven National Lab., Upton, NY (United States)]|[McMaster Univ., Hamilton, ON (Canada). Dept. of Physics

    1993-04-01

    We describe measurements of the magnetic critical fluctuations of holmium by x-ray scattering techniques. The x-ray results are compared to those obtained in neutron scattering experiments performed on the same sample.

  1. X-ray and neutron scattering studies of magnetic critical fluctuations in holmium

    Energy Technology Data Exchange (ETDEWEB)

    Thurston, T.R.; Helgesen, G.; Gibbs, D.; Shirane, G. (Brookhaven National Lab., Upton, NY (United States)); Hill, J.P. (Brookhaven National Lab., Upton, NY (United States) Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics); Gaulin, B.D. (Brookhaven National Lab., Upton, NY (United States) McMaster Univ., Hamilton, ON (Canada). Dept. of Physics)

    1993-01-01

    We describe measurements of the magnetic critical fluctuations of holmium by x-ray scattering techniques. The x-ray results are compared to those obtained in neutron scattering experiments performed on the same sample.

  2. Effect of Fluoride Varnish Combined with Er:YAG Laser on the Permeability of Eroded Dentin: An In Situ Study.

    Science.gov (United States)

    Nemezio, Mariana Alencar; Carvalho, Sandra Chiga; Scatolin, Renata Siqueira; Colucci, Vivian; Galo, Rodrigo; Corona, Silmara Aparecida Milori

    2015-01-01

    This study evaluated the combined effect of fluoride varnish and Er:YAG laser on the permeability of eroded bovine root dentin. After initial erosive challenge followed by a remineralization period, the specimens were divided in two groups according to the treatment - fluoride varnish and non-fluoride varnish - and were subdivided according to the irradiation protocol: Er:YAG laser (100 mJ, 3 Hz, 12.8 J/cm2per pulse, non-contact and defocus mode) and non-irradiated. After a lead-in period, 7 volunteers wore a palatal device containing 4 specimens that were subjected to erosive challenges. At the first experimental phase, 4 volunteers used specimens treated with fluoride varnish and fluoride varnish+Er:YAG laser and 3 volunteers used specimens treated with non-fluoride varnish and non-fluoride varnish+Er:YAG laser. After a washout period, volunteers were crossed to treatments, characterizing a 2x2 crossover experiment. At the end of the experimental phase, the quantitative response variable was obtained by permeability analysis and the qualitative response by scanning electron microscopy (SEM). Two-way ANOVA and Tukey-Kramer's test revealed that specimens treated with fluoride varnish+Er:YAG laser showed the lowest permeability and a significant difference was found between this group and the others. When varnish (fluoride/non-fluoride) was applied in the absence of Er:YAG laser, higher permeability was found when compared to the laser-treated groups. SEM evaluations showed partially or completely obliterated dentinal tubules when specimens were treated with fluoride varnish+Er:YAG laser. It may be concluded that Er:YAG laser was able to control the permeability of eroded root dentin and the combination with fluoride varnish increased laser action.

  3. Wound healing after irradiation of bone tissues by Er:YAG laser

    Science.gov (United States)

    Watanabe, Hisashi; Yoshino, Toshiaki; Aoki, Akira; Ishikawa, Isao

    1997-05-01

    Clinical applications of Er:YAG laser are now developing in periodontics and restorative dentistry. To date, there have been few studies indicating safety criteria for intraoral usage of the Er:YAG laser. The present study examined the effects of the Er:YAG laser on bone tissues, supposing mis- irradiation in the oral cavity during dental application, especially periodontal surgery. The experiments were performed using the newly-developed Er:YAG laser apparatus equipped with a contact probe. In experiment 1, 10 pulses of laser irradiation were administered to the parietal bone of a rat at 50, 150 and 300 mJ/pulse with and without water irrigation, changing the irradiation distance to 0, 5, 10 and 20 mm, respectively. As a control, electric knife was employed. Macroscopic and SEM observations of the wound surface were performed. In experiment 2, laser irradiation in a straight line was performed at 150 mJ/pulse, 1- pps and 0,5, 10 mm irradiation distance without water irrigation. Wound healing was observed histologically at 0, 3, 7, 14 and 28 days after laser irradiation and compared with that of the control. Non-contact irradiation by Er:YAG laser did not cause severe damage to the parietal bone tissue under water irrigation. Contact irradiation induced a limited wound, however, new bone formation was observed 28 days after laser irradiation, while osseous defect with thermal degenerative tissue remained at the control site. In conclusion, irradiation with an Er:YAG laser would not cause severe damage to surrounding bone tissues in the oral cavity when used within the usual power settings for dental treatment. Furthermore, this laser may be applicable for osseous surgery because of its high ablation efficiency and good wound healing after irradiation.

  4. Er:YAG laser ablation: 5-11 years prospective study

    Science.gov (United States)

    Dostalova, Tatjana; Jelinkova, Helena; Nemec, Michal; Sulc, Jan; Miyagi, Mitsunobu

    2005-03-01

    The Er:YAG laser at 2940 nm has been proposed for use in dental cavity preparation and removal of carious enamel and dentin. The purpose of the present study was to determine the effect of the Er:YAG laser ablation in treating dental caries after a period from 5 to 11 years. For this study, 133 cavities were chosen, and for their reparation of it the three restorative materials were used. Baseline examination was made in the following intervals: one week, 1 year, and from 5 to 11 years after cavity preparation and placement of filling material. Clinical assessments were carried out in accordance with the US Public Health Service System. The follow-up included: the marginal ridge, marginal adaptation, anatomic form, caries, color match, cavo surface margin discoloration, surface smoothness, and postoperative sensitivity. Er:YAG laser ablation is an excellent method for treating frontal teeth, i.e., incisors, canines, premolars, and initial occlusal caries of molars. However, visual control of non-contact therapy is necessary. Er:YAG laser ablation is safe, and it strongly reduces pain. The laser treatment markedly decreases the unpleasant sound and vibration.

  5. Evaluation of holmium laser for transurethral deroofing of severe and multiloculated prostatic abscesses

    OpenAIRE

    Lee, Chan Ho; Ku, Ja Yoon; Park, Young Joo; Lee, Jeong Zoo; Shin, Dong Gil

    2015-01-01

    Purpose Our objective was to evaluate the use of a holmium laser for transurethral deroofing of a prostatic abscess in patients with severe and multiloculated prostatic abscesses. Materials and Methods From January 2011 to April 2014, eight patients who were diagnosed with prostatic abscesses and who underwent transurethral holmium laser deroofing at Pusan National University Hospital were retrospectively reviewed. Results Multiloculated or multifocal abscess cavities were found on the preope...

  6. Determination of neodymium, holmium and erbium in mixed rare earths by norfloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Wang Nai-Xing; Jiang Wei; Ren Yuezhen; Si Zhikun; Qiu Xunxing [Department of Chemistry, Shandong University, Jinan (China); Wang Lei [Department of Pharmacy, Shandong Medical University, Jinan (China); Du Gaoying; Qi Ping [Shandong Analysis and Test Center, Jinan (China)

    1998-08-01

    Norfloxacin (NFX) is proposed as reagent for the derivative spectrophotometric determination of neodymium, holmium and erbium in mixed rare earths. The absorption spectra of 4f electron transitions of the systems of neodymium, holmium and erbium complexes with norfloxacin in presence of cetylpyridinium chloride were studied by normal and derivative spectra. The absorption bands found normally at 575 nm for neodymium, 450 nm for holmium and 523 nm for erbium were enhanced markedly. Using the second derivative spectrum, Beer`s Law is obeyed from 5.0 x 10{sup -5} {proportional_to} 2.5 x 10{sup -4} mol dm{sup -3} for neodymium, holmium and erbium. The relative standard deviations are 1.0, 1.4 and 1.1% for 6.9 x 10{sup -5} mol dm{sup -3} of neodymium, 6.1 x 10{sup -5} mol dm{sup -3} of holmium and 6.0 x 10{sup -5} mol dm{sup -3} of erbium, respectively. A method for the direct determination of neodymium, holmium and erbium in mixtures of rare earth elements with good accuracy and selectivity, is described. (orig.) With 4 figs., 2 tabs., 11 refs.

  7. Standardization of noncontact 3D measurement

    Science.gov (United States)

    Takatsuji, Toshiyuki; Osawa, Sonko; Sato, Osamu

    2008-08-01

    As the global R&D competition is intensified, more speedy measurement instruments are required both in laboratories and production process. In machinery areas, while contact type coordinate measuring machines (CMM) have been widely used, noncontact type CMMs are growing its market share which are capable of measuring enormous number of points at once. Nevertheless, since no industrial standard concerning an accuracy test of noncontact CMMs exists, each manufacturer writes the accuracy of their product according to their own rules, and this situation gives confusion to customers. The working group ISO/TC 213/WG 10 is trying to make a new ISO standard which stipulates an accuracy test of noncontact CMMs. The concept and the situation of discussion of this new standard will be explained. In National Metrology Institute of Japan (NMIJ), we are collecting measurement data which serves as a technical background of the standards together with a consortium formed by users and manufactures. This activity will also be presented.

  8. Erbium: YAG laser lithotripsy mechanism.

    Science.gov (United States)

    Chan, Kin Foong; Lee, Ho; Teichman, Joel M H; Kamerer, Angela; McGuff, H Stan; Vargas, Gracie; Welch, Ashley J

    2002-08-01

    We tested the hypothesis that the mechanism of long pulse erbium:YAG laser lithotripsy is photothermal. Human urinary calculi were placed in deionized water and irradiated with erbium:YAG laser energy delivered through a sapphire optical fiber. Erbium:YAG bubble dynamics were visualized with Schlieren flash photography and correlated to acoustic emissions measured by a polyvinylidene fluoride needle hydrophone. The sapphire fiber was placed either parallel or perpendicular to the calculus surface to assess the contribution of acoustic transients to fragmentation. Stones were irradiated using desiccated stone irradiated in air, hydrated stone irradiated in air and hydrated stone irradiated in water. Ablation crater sizes were compared. Uric acid stones were irradiated in water and the water was assayed for cyanide. During the early phase of vapor bubble expansion, acoustic transients had minimal effects on calculus fragmentation. Fragmentation occurred due to direct absorption of laser energy transmitted to the calculus through the vapor channel between the sapphire fiber tip and calculus. The forward axial expansion of the bubble occurred more rapidly than the radial expansion. A parallel oriented fiber on the calculus surface produced no fragmentation but generated larger amplitude acoustic transients compared to perpendicular orientation. In perpendicular orientation the erbium:YAG laser did not generate any collapse acoustic waves but fragmentation occurred. Crater width was greatest for desiccated stones irradiated in air (p <0.03). Cyanide production increased as erbium:YAG irradiation of uric acid calculi increased, (r2 = 0.98). The erbium:YAG laser fragments stones through a photothermal mechanism.

  9. Holmium laser enucleation of the prostate: patient selection and perspectives

    Science.gov (United States)

    Marien, Tracy; Kadihasanoglu, Mustafa; Miller, Nicole L

    2016-01-01

    Background Multiple endoscopic surgical options exist to treat benign prostatic hyperplasia (BPH), including holmium laser enucleation of the prostate (HoLEP). HoLEP alleviates obstructive prostatic tissue via enucleation, both bluntly with a resectoscope and by cutting tissue with the holmium laser, and removal of adenoma via morcellation. This article reviews patient selection for HoLEP in order to optimize outcomes, costs, and patient satisfaction. Methods A literature review of all studies on HoLEP was conducted. Studies that focused on outcomes in regard to patient and procedural factors were closely reviewed and discussed. Results Various studies found that men with large or small prostates, on antithrombotic therapy, in urinary retention, with bladder hypocontractility, with prostate cancer, undergoing retreatment for BPH, or in need of concomitant surgery for bladder stones and other pathologies do well with HoLEP, as demonstrated by excellent functional and symptomatic outcomes as well as low complication rates. There is a 74–78% rate of retrograde ejaculation following HoLEP. Techniques to preserve ejaculatory function following enucleative techniques have not been able to demonstrate a significant improvement. Conclusion Patient selection for HoLEP can include most men with bothersome BPH who have evidence of bladder outlet obstruction and are healthy enough to undergo surgery. The ability to safely perform concomitant surgery with HoLEP benefits the patient by sparing them an additional anesthetic and also decreases costs. Patients should be made aware of the risk of retrograde ejaculation following HoLEP and counseled on treatment alternatives if maintaining ejaculatory function is desired. PMID:27800470

  10. Ceramic planar waveguide laser of non-aqueous tape casting fabricated YAG/Yb:YAG/YAG.

    Science.gov (United States)

    Wang, Chao; Li, Wenxue; Yang, Chao; Bai, Dongbi; Li, Jiang; Ge, Lin; Pan, Yubai; Zeng, Heping

    2016-08-18

    Ceramic YAG/Yb:YAG/YAG planar waveguide lasers were realized on continuous-wave and mode-locked operations. The straight waveguide, fabricated by non-aqueous tape casting and solid state reactive sintering, enabled highly efficient diode-pumped waveguide continuous-wave laser with the slope efficiency of 66% and average output power of more than 3 W. The influence of the waveguide structure on the wavelength tunability was also experimentally investiccgated with a dispersive prism. Passively mode-locked operation of the ceramic waveguide laser was achieved by using a semiconductor saturable absorber mirror (SESAM), output 2.95 ps pulses with maximum power of 385 mW at the central wavelength of 1030 nm.

  11. Synthesis and microstructure analysis of composite Nd: YAG/YAG transparent ceramics

    Institute of Scientific and Technical Information of China (English)

    Benxue Jiang; Tongde Huang; Yusong Wu; Wenbin Liu; Yubai Pan

    2009-01-01

    Transparent Nd:YAG/YAG composite ceramics are synthesized by solid-state reaction method using highpurity Y2O3,Al2O3,and Nd2O3 powders as raw materials.The mixed powder compacts are sintered at 1780 ℃ for 10 h under vacuum and annealed at 1450 ℃ for 20 h in air.The Nd:YAG/YAG ceramics exhibit a pore free structure with an average grain size of about 30 μm.The microstructure of the Nd:YAG/YAG composite transparent ceramics is studied and there is no interface between Nd:YAG and YAG ceramics.The Nd ion distribution in one grain is also studied,which shows that there is no segregation of Nd ions as in Nd:YAG crystals.

  12. Histological and SEM analysis of root cementum following irradiation with Er:YAG and CO2 lasers.

    Science.gov (United States)

    Almehdi, Aslam; Aoki, Akira; Ichinose, Shizuko; Taniguchi, Yoichi; Sasaki, Katia M; Ejiri, Kenichiro; Sawabe, Masanori; Chui, Chanthoeun; Katagiri, Sayaka; Izumi, Yuichi

    2013-01-01

    Recently, the Er:YAG and CO(2) lasers have been applied in periodontal therapy. However, the characteristics of laser-irradiated root cementum have not been fully analyzed. The aim of this study was to precisely analyze the alterations of root cementum treated with the Er:YAG and the CO(2) lasers, using non-decalcified thin histological sections. Eleven cementum plates were prepared from extracted human teeth. Pulsed Er:YAG laser contact irradiation was performed in a line at 40 mJ/pulse (14.2 J/cm(2)/pulse) and 25 Hz (1.0 W) under water spray. Continuous CO(2) laser irradiation was performed in non-contact mode at 1.0 W, and ultrasonic instrumentation was performed as a control. The treated samples were subjected to stereomicroscopy, scanning electron microscopy (SEM), light microscopy and SEM energy dispersive X-ray spectroscopy (SEM-EDS). The Er:YAG laser-treated cementum showed minimal alteration with a whitish, slightly ablated surface, whereas CO(2) laser treatment resulted in distinct carbonization. SEM analysis revealed characteristic micro-irregularities of the Er:YAG-lased surface and the melted, resolidified appearance surrounded by major and microcracks of the CO(2)-lased surface. Histological analysis revealed minimal thermal alteration and structural degradation of the Er:YAG laser-irradiated cementum with an affected layer of approximately 20-μm thickness, which partially consisted of two distinct affected layers. The CO(2)-lased cementum revealed multiple affected layers showing different structures/staining with approximately 140 μm thickness. Er:YAG laser irradiation used with water cooling resulted in minimal cementum ablation and thermal changes with a characteristic microstructure of the superficial layer. In contrast, CO(2) laser irradiation produced severely affected distinct multiple layers accompanied by melting and carbonization.

  13. Impact of pulse duration on Ho:YAG laser lithotripsy: fragmentation and dusting performance.

    Science.gov (United States)

    Bader, Markus J; Pongratz, Thomas; Khoder, Wael; Stief, Christian G; Herrmann, Thomas; Nagele, Udo; Sroka, Ronald

    2015-04-01

    In vitro investigations of Ho:YAG laser-induced stone fragmentation were performed to identify potential impacts of different pulse durations on stone fragmentation characteristics. A Ho:YAG laser system (Swiss LaserClast, EMS S.A., Nyon, Switzerland) with selectable long or short pulse mode was tested with regard to its fragmentation and laser hardware compatibility properties. The pulse duration is depending on the specific laser parameters. Fragmentation tests (hand-held, hands-free, single-pulse-induced crater) on artificial BEGO stones were performed under reproducible experimental conditions (fibre sizes: 365 and 200 µm; laser settings: 10 W through combinations of 0.5, 1, 2 J/pulse and 20, 10, 5 Hz, respectively). Differences in fragmentation rates between the two pulse duration regimes were detected with statistical significance for defined settings. Hand-held and motivated Ho:YAG laser-assisted fragmentation of BEGO stones showed no significant difference between short pulse mode and long pulse mode, neither in fragmentation rates nor in number of fragments and fragment sizes. Similarly, the results of the hands-free fragmentation tests (with and without anti-repulsion device) showed no statistical differences between long pulse and short pulse modes. The study showed that fragmentation rates for long and short pulse durations at identical power settings remain at a comparable level. Longer holmium laser pulse duration reduces stone pushback. Therefore, longer laser pulses may result in better clinical outcome of laser lithotripsy and more convenient handling during clinical use without compromising fragmentation effectiveness.

  14. Management of impacted proximal ureteral stone: Extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy

    Directory of Open Access Journals (Sweden)

    Mostafa Khalil

    2013-01-01

    Conclusion: Both procedures can be used effectively and safely as a primary treatment for impacted stone in the proximal ureter; however, the URSL has a significantly higher initial stone-free rate and lower re-treatment rate.

  15. Chitosan microspheres loaded with holmium-165 produced by spray dryer for liver cancer therapy: preliminary experiments

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Douglas Massao; Pires, Geovanna; Lira, Raphael A. de; Melo, Vitor H.S.; Nascimento, Nanci; Azevedo, Mariangela de Burgos M. de, E-mail: douglas.miyamoto@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia

    2011-07-01

    Chitosan is a biopolymer of 2-deoxy-2-amino-D-glucose that is obtained by deacetylation of chitin. It's biocompatible, biodegradable, non toxic and has antitumor activity. Chitosan has many applications, such as their microparticles that can be used to treat prostate cancer, rheumatoid arthritis, and for liver tumor brachytherapy treatment. Our group is developing different biodegradable polymer-based microspheres loaded with holmium-165 for this purpose. The Chitosan microspheres were produced loaded with holmium (III) chloride, and not loaded with it, by Mini Spray Dryer procedure. The microspheres were evaluated by scanning electron microscopy, energy dispersive spectroscopy (EDS), confocal laser scanning microscopy, thermogravimetric analysis, particle size, and X-ray diffraction. The EDS analysis confirmed the holmium chloride presence into the prepared chitosan microparticles. (author)

  16. Effect of silver nanoparticles on the dielectric properties of holmium doped silica glass

    Energy Technology Data Exchange (ETDEWEB)

    Rejikumar, P.R.; Jyothy, P.V. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 686560 (India); Mathew, Siby [Department of Physics, S.H. College, Thevara, Cochin, Kerala 682013 (India); Thomas, Vinoy [Department of Physics, Christian College, Chengannur, Kerala 689122 (India); Unnikrishnan, N.V., E-mail: nvu50@yahoo.co.i [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 686560 (India)

    2010-03-15

    The effect of silver nanoparticle co-doping on the dielectric properties of holmium doped silica glasses was studied. Silver nanoparticles of size between 20 and 22 nm were produced by the sol-gel technique. One of the samples showed an icosahedral morphology of the nanocrystal formed, along with spherical morphology. It was found that the tuning of the dielectric constant values could be accomplished by co-doping. The sample, with 1 wt% of Ho, had low dielectric constant values within the range 100 Hz-3 MHz due to the formation of quasi-molecular structures of holmium. This effect was evaded to some extent with silver co-doping as a result of the interdispersion of holmium complexes. Also it was found that the co-doping produced a higher dielectric loss which was calculated from the tan delta-log f graph. The Cole-Cole parameters and the Jonscher power law parameters were also calculated and are presented.

  17. Holmium-166 therapy of malignant and benign diseases

    Energy Technology Data Exchange (ETDEWEB)

    Park, C.H. [Ajou Univ. School of Medicine, Suwon (Korea)

    1999-07-01

    Holmium-166 (Ho-166), one of the lanthanide radionuclides and produced upon neutron irradiation of naturally abundant Ho-165, is an almost ideal radionuclide for therapeutic purposes. The reasons for this are: (1) it is a strong beta emitter (Emax = 1.86 MeV) with maximum range in soft-tissue of 8.4 mm, (2) it has a short physical half-life of 26.9 hours, (3) it emits a gamma photon (81 keV, 5.4%) that can be used for external imaging of post-therapy monitoring purpose. Clinical trials of Ho-166 therapy for various malignancies and benign conditions are under way in Korea, {sup 166}Ho(NO{sub 3}) solution is applied into the balloon following percutaneous transfemoral coronary angioplasty (PTCA) in an attempt to inhibit neointimal hyperplasia incident to ballooning injury. Chitosan obtained by deacetylation of naturally abundant chitin is complexed with Ho-166 by mixing acidic chitosan solution at a room temperature with higher than 99% labelling yield. The Ho-166 complex is stable in vitro and vivo. Another benign condition, rheumatoid joint disease, is treated by local administration of the agent into the knee joint for radionuclide synovectomy. Malignant conditions being treated with Ho-166-CHICO (chitosan complex) include cystic brain tumours, malignant ascites and pleural effusion, hepatocellular carcinomas, recurrent melanoma and recurrent rectal carcinomas. Our clinical experience with Ho-166 or Ho-166-CHICO therapy is presented. (orig.)

  18. Synthesis, Characterization and Thermal Diffusivity of Holmium and Praseodymium Zirconates

    Directory of Open Access Journals (Sweden)

    Stopyra M.

    2016-06-01

    Full Text Available A2B2O7 oxides with pyrochlore or defected fluorite structure are among the most promising candidates for insulation layer material in thermal barrier coatings. The present paper presents the procedure of synthesis of holmium zirconate Ho2Zr2O7 and praseodymium zirconate Pr2Zr2O7 via Polymerized-Complex Method (PCM. Thermal analysis of precursor revealed that after calcination at relatively low temperature (700°C fine-crystalline, single-phase material is obtained. Thermal diffusivity was measured in temperature range 25-200°C, Ho2Zr2O7 exhibits lower thermal diffusivity than Pr2Zr2O7. Additionally, PrHoZr2O7 was synthesized. The powder in as-calcined condition is single-phase, but during the sintering decomposition of solid solution took place and Ho-rich phase precipitated. This material exhibited the best insulating properties among the tested ones.

  19. Development of Holmium 166-chitosan complex as a radiopharmaceutical agent for liver cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jei Man; Nam, Soon Chul; Park, Sun Joo; Moon, Eun Yi; Lee, Won Yong; Shin, Dong Hyuk; Cho, Eun Hee [Korea Atomic Energy Research Instisute, Taejon (Korea, Republic of)

    1997-09-01

    Effective therapeutic methods for cancer disease should be developed because the frequency of cancer disease is being increased rapidly. But there is no effective therapeutic method for treating these disease until now. The purpose of this research is to gain the clinical approval of Holmium{sup 166}-Chitosan complex as a radiopharmaceutical agent for liver cancer. We finished the preclinical test of Holmium{sup 166}-Chitosan complex and got the approval for clinical trial of this agent. 12 refs., 11 tabs., 9 figs. (author)

  20. Scintillation properties of YAG:Yb crystals

    CERN Document Server

    Antonini, P; Carugno, Giovanni; Iannuzzi, D

    2001-01-01

    We report on measurements of the light yield, emission spectrum, and time response of YAG:Yb crystals. The temperature dependence of light yield was investigated. Data show that YAG:Yb crystals are good scintillators, suitable for applications to neutrino detection and spectroscopy.

  1. Clinical, radiographic, and histopathologic evaluation of Nd:YAG laser pulpotomy on human primary teeth.

    Science.gov (United States)

    Odabaş, Mesut Enes; Bodur, Haluk; Bariş, Emre; Demir, Cem

    2007-04-01

    The purpose of this study was to compare clinical, radiographic, and histopathologic effects of Nd:YAG laser pulpotomy to formocresol pulpotomy on human primary teeth. Patients with at least two vital primary molar teeth that required pulpotomy, because of pulpal exposure to caries, were selected for this study. After hemorrhage control, complete hemostasis into the canal orifice was achieved by exposure to Nd:YAG laser (1064 nm) and an He-Ne laser (the aiming beam of the Nd:YAG laser) in noncontact mode at 2 W, 20 Hz, 100 mJ, or was achieved by applying 1:5 dilution of formocresol. Forty-two teeth in two groups were to be followed up clinically and radiographic at 1, 3, 6, 9, and 12 months. Eighteen teeth planned for serial extractions were selected for histopathologic study. The teeth were extracted at 7 and 60 days. The teeth in the laser group had a clinical success rate of 85.71% and a radiographic success rate 71.42% at 12 months. The teeth in the formocresol group had a clinical and radiographic success rate of 90.47% at 12 months. There were no statistically significant differences between laser and formocresol group with regard to both clinical and radiographic success rates. There was a statistically significant difference between 7- and 60-day laser groups with regard to inflammatory cell response criteria. Dentin bridge was absent in all samples. No stained bacteria were observed in any of these samples. In conclusion, Nd:YAG laser may be considered as an alternative to formocresol for pulpotomies in primary teeth.

  2. Transurethral Cystolithotripsy of Large Bladder Stones by Holmium Laser as a Day Care Procedure

    Science.gov (United States)

    Naorem, Salinita; Faridi, M.S.; Akoijam, Kaku Singh; Sinam, Rajendra Singh

    2016-01-01

    Introduction Bladder stones constitute around 5% of bladder stones in the developed countries. Holmium laser lithotripsy has revolutionised the treatment of urinary lithiasis. Aim The aim of this study was to report the outcome of transurethral cystolithotripsy with Holmium Laser under Local Anaesthesia (LA) as a day care procedure in patients with bladder stones. Materials and Methods Patients with bladder stone greater than 1.5cm attending urology Outpatient Department underwent transurethral cystolithotripsy with Holmium Laser under LA as day care procedure. The results were analysed on aspects of peri-operative pain, completion of procedure, stone clearance, hospital stay, complications and patient compliance. Results A total of 85 patients with bladder stone ≥1.5cm underwent transurethral cystolithotripsy LA. The mean age of the patient was 52±7 years. There were 80 males. The mean size of stone was 3±1.2cm. Mean operation time was 40±10 minutes. Complete stone clearance was achieved in all the patients. None of the patients required hospital stay following the procedure. Conclusion Transurethral holmium laser lithotripsy is an effective and safe procedure for large bladder stones. This procedure can be easily performed as a day care procedure. PMID:28208921

  3. Successful Treatment of Stent Knot in the Proximal Ureter Using Ureteroscopy and Holmium Laser

    Directory of Open Access Journals (Sweden)

    Masters M. Richards

    2011-01-01

    Full Text Available Knotted ureteral stent is rare yet tedious complication that might represent a treatment challenge to the endourologist. Only twelve cases of knotted stent have been reported. Different management options have been reported, including simple traction, ureteroscopy, percutaneous removal, and open surgery. In this paper, we present the successful untying of the knot using ureteroscopy with holmium laser.

  4. Radioactive Holmium Acetylacetonate Microspheres for Interstitial Microbrachytherapy: An In Vitro and In Vivo Stability Study

    NARCIS (Netherlands)

    Bult, W.; De Leeuw, H.; Steinebach, O.M.; Van der Bom, M.J.; Wolterbeek, H.T.; Heeren, R.M.A.; Bakker, C.J.G.; Van het Schip, A.D.; Hennink, W.E.; Nijsen, F.W.

    2011-01-01

    Purpose The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. Methods

  5. Radioactive holmium acetylacetonate microspheres for interstitial microbrachytherapy : an in vitro and in vivo stability study

    NARCIS (Netherlands)

    Bult, Wouter; de Leeuw, Hendrik; Steinebach, Olav M; van der Bom, Martijn J; Wolterbeek, Hubert Th; Heeren, Ron M A; Bakker, Chris J G; van Het Schip, Alfred D; Hennink, Wim E; Nijsen, J Frank W

    2012-01-01

    PURPOSE: The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. METHODS: HoA

  6. Preclinical studies on holmium-166 poly(L-lactic acid) microspheres for hepatic arterial radioembolization

    NARCIS (Netherlands)

    Vente, M.A.D.

    2009-01-01

    Hepatic arterial radioembolization with radioactive holmium-166 loaded poly(L-lactic acid) microspheres (166Ho-PLLA-MS) constitutes the subject of this thesis. This technique represents a potential treatment option for patients with unresectable liver malignancies. 166Ho-PLLA-MS are believed to be a

  7. Holmium laser fulguration of superficial urothelial carcinoma of the pendulous urethra

    Directory of Open Access Journals (Sweden)

    Michael A Liss

    2012-01-01

    Full Text Available Urothelial carcinoma may occur anywhere in the urinary tract including the pendulous urethra. To prevent urethral stricture after resection and monopolor fulguration we describe the use of the holmium laser to fulgurate recurrent pTa UC from the urethra. The surgical approach was staged and provided excellent long term results for management of superficial UC.

  8. Noncontact atomic force microscopy v.3

    CERN Document Server

    Morita, Seizo; Meyer, Ernst

    2015-01-01

    This book presents the latest developments in noncontact atomic force microscopy. It deals with the following outstanding functions and applications that have been obtained with atomic resolution after the publication of volume 2: (1) Pauli repulsive force imaging of molecular structure, (2) Applications of force spectroscopy and force mapping with atomic resolution, (3) Applications of tuning forks, (4) Applications of atomic/molecular manipulation, (5) Applications of magnetic exchange force microscopy, (6) Applications of atomic and molecular imaging in liquids, (7) Applications of combine

  9. Self-acting geometry for noncontact seals

    Science.gov (United States)

    Allen, G. P.

    1981-01-01

    Performance ot two self acting seal designs for a liquid oxygen (LOX) turbopump was predicted over ranges of pressure differential and speed. Predictions were compared with test results. Performance of a radial face seal for LOX was predicted up to 448 N/cu cm and 147 m/sec. Performance of a segmented circumferential seal for helium was predicted up to 69 N/cu cm and 189 m/sec. Results confirmed predictions of noncontact operation. Qualitative agreement between test and analysis was found. The LOX face seal evidently operated with mostly liquid in the self acting geometry and mostly gas across the dam.

  10. Laser lithotripsy with the Ho:YAG laser: fragmentation process revealed by time-resolved imaging

    Science.gov (United States)

    Schmidlin, Franz R.; Beghuin, Didier; Delacretaz, Guy P.; Venzi, Giordano; Jichlinski, Patrice; Rink, Klaus; Leisinger, Hans-Juerg; Graber, Peter

    1998-07-01

    Improvements of endoscopic techniques have renewed the interest of urologists in laser lithotripsy in recent years. Laser energy can be easily transmitted through flexible fibers thereby enabling different surgical procedures such as cutting, coagulating and lithotripsy. The Ho:YAG laser offers multiple medical applications in Urology, among them stone fragmentation. However, the present knowledge of its fragmentation mechanism is incomplete. The objective was therefore to analyze the fragmentation process and to discuss the clinical implications related to the underlying fragmentation mechanism. The stone fragmentation process during Ho:YAG laser lithotripsy was observed by time resolved flash video imaging. Possible acoustic transient occurrence was simultaneously monitored with a PVDF-needle hydrophone. Fragmentation was performed on artificial and cystine kidney stones in water. We observed that though the fragmentation process is accompanied with the formation of a cavitation bubble, cavitation has only a minimal effect on stone fragmentation. Fragment ejection is mainly due to direct laser stone heating leading to vaporization of organic stone constituents and interstitial water. The minimal effect of the cavitation bubble is confirmed by acoustic transients measurements, which reveal weak pressure transients. Stone fragmentation with the Holmium laser is the result of vaporization of interstitial (stone) water and organic stone constituents. It is not due to the acoustic effects of a cavitation bubble or plasma formation. The fragmentation process is strongly related with heat production thereby harboring the risk of undesired thermal damage. Therefore, a solid comprehension of the fragmentation process is needed when using the different clinically available laser types of lithotripsy.

  11. Non-contact temperature measurement requirements for electronic materials processing

    Science.gov (United States)

    Lehoczky, S. L.; Szofran, F. R.

    1988-01-01

    The requirements for non-contact temperature measurement capabilities for electronic materials processing in space are assessed. Non-contact methods are probably incapable of sufficient accuracy for the actual absolute measurement of temperatures in most such applications but would be useful for imaging in some applications.

  12. Laser properties of yag: Nd, Cr, Ce

    Science.gov (United States)

    Kvapil, J.; Kvapil, Jos; Perner, B.; Kubelka, J.; Mánek, B.; Kubeček, V.

    1984-06-01

    Transient absorption of a long lifetime (≧ 20 s) of YAG: Nd is typical of pure material. It is the main reason of thermal deformation of the laser rods accompanied with power decreases at higher CW input. It may be prevented by an admixture of Fe, Ti or Cr. Using a small admixture (≦ 10-3 wt.%) of Ti or Cr the energy transfer among Nd ions and the gain coefficient may be increased. Cr in a higher concentration absorbs the pumping light and serves as earlier described coactivator (sensitizer) only. Fe impurity fully prevents any increase of the gain of YAG: Nd containing Ti or Cr and causes slow but irreversible degradation of the active parameters. Ce favourably modifies properties of YAG: Nd, Cr. YAG: Nd, Cr, Ce free of iron impurity is advisable active material for powerfull CW lasers.

  13. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y. [Department of Physics, University of Miami, Coral Gables, Florida 33146 (United States); Alves, E.; Rocha, J. [Centre for Nuclear Physics, University of Lisbon and IST-ID (Portugal); Bagliani, D.; Biasotti, M.; Gatti, F. [Department of Physics, University of Genova and INFN Genova (Italy); Gomes, M. Ribeiro [Centre for Nuclear Physics, University of Lisbon (Portugal)

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  14. Calcium phosphate holmium-166 ceramic to addition in bone cement: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Donanzam, Blanda A.; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade do Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Dalmazio, Ilza; Valente, Eduardo S., E-mail: id@cdtn.b, E-mail: valente@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Spine metastases are a common and painful complication of cancer. The treatment often consists of bone cement injection (vertebroplasty or kyphoplasty) within vertebral body for vertebrae stabilization, followed by external beam radiation therapy. Recently, researchers introduced the concept of radioactive bone cement for spine tumors therapy. Then, investigations about bioactive and radioactive materials became interesting. In this study, we present the synthesis of calcium phosphate incorporated holmium (CaP-Ho) via sol-gel technique, and its characterization by XRD, FT-IR, NA and SEM. Results showed a multiphasic bioceramic composed mainly of hydroxyapatite, {beta}-tricalcium phosphate, holmium phosphate and traces of calcium pyrophosphate. Furthermore, the nuclide Ho-166 was the major radioisotope produced. Despite that, the radioactive bioceramic CaP-{sup 166}Ho must be investigated in clinical trials to assure its efficacy and safety on spine tumors treatment (author)

  15. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de [Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Viergever, Max A. [Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96–106.21 ml were improved from 32%–63% (SPECT-DSW) and 50%–80

  16. [Thermographic assessment of thermal effects of Er:YAG laser in periodontal surgery].

    Science.gov (United States)

    Zmuda, Stanisław; Ignatowicz, Elzbieta; Stankiewicz, Justyna; Marczyńiska-Stolarek, Magdalena; Dabrowski, Mirosław

    2006-02-01

    An assessment of thermal effect of Er:YAG laser (KEYII, KaVo) on oral soft tissues in select procedures. Experimental researches were carried out on Wistar rats. To measure the temperature changes the thermal imaging camera (ThermaCAM SC3000, FLIR Systems) was used. There has been a significant increase of temperature observed on the end of optical fibre: the mean temperature ranged from 270 to 360 degrees C (at laser energy of 100 mJ and repetition rate of 25 Hz) and from 230 to 290 degrees C (300 mJ, 15 Hz). On the surface of oral mucosa thermal changes at the time of laser frenulectomy was analysed along the line of incision. The temperature above 50 degrees C was recorded on the length of 2 mm (at 100 mJ) and 3 mm (at 300 mJ). The temperature maintained on this level for about 0.4 s. On the surface of tongue during lingual mucosa excision the temperature above 40 degrees C was observed on the length of 1.6 mm (80 mJ, 2 Hz) or 2.5 mm (160 mJ, 2 Hz). The rate of cooling for both cases was lower than 0.5 s. To prevent undesirable thermal side effects from an Er:YAG laser optical fibre should be moved very fluently in non-contact mode.

  17. Densification behavior, doping profile and planar waveguide laser performance of the tape casting YAG/Nd:YAG/YAG ceramics

    Science.gov (United States)

    Ge, Lin; Li, Jiang; Qu, Haiyun; Wang, Juntao; Liu, Jiao; Dai, Jiawei; Zhou, Zhiwei; Liu, Binglong; Kou, Huamin; Shi, Yun; Wang, Zheng; Pan, Yubai; Gao, Qingsong; Guo, Jingkun

    2016-10-01

    The sintering behavior and doping concentration profile of the planar waveguide YAG/Nd:YAG/YAG ceramics by the tape casting and solid-state reaction method were investigated on the basis of densification trajectory, microstructure evolution, and Nd3+ ions diffusion. The porosity of the green body by tape casting and cold isostatic pressing is about 38.6%. And the green bodies were consolidated from 1100 °C to 1800 °C for 0.5-20 h to study the densification and the doping diffusion behaviors. At the temperature higher than 1500 °C, pure YAG phase is formed, followed by the densification and grain growth process. With the increase of temperature, two sintering stages occur, corresponding to remarkable densification and significant grain growth, respectively. The mechanism controlling densification at 1550 °C is grain boundary diffusion. The diffusion of Nd3+ ions is more sensitive to temperature than the sintering time, and the minimum temperature required for the obvious diffusion of Nd3+ ions is higher than 1700 °C. Finally, planar waveguide YAG/1.5 at.%Nd:YAG/YAG transparent ceramics with in-line transmittance of 84.8% at 1064 nm were obtained by vacuum-sintering at 1780 °C for 30 h. The fluorescence lifetime of 4F3/2 state of Nd3+ in the specimen is about 259 μs. The prepared ceramic waveguide was tested in a laser amplifier and the laser pulse was amplificated from 87 mJ to 238 mJ, with the pump energy of 680 mJ.

  18. The Efficacy of Percutaneous Nephrolithotomy Using Pneumatic Lithotripsy vs. the Holmium Laser: a Randomized Study.

    Science.gov (United States)

    Liu, Chaoying; Zhou, Houyong; Jia, Weisheng; Hu, Hua; Zhang, Heng; Li, Longkun

    2017-08-01

    The objective of the study is to compare the efficacy of percutaneous nephrolithotomy using holmium laser vs pneumatic lithotripsy. From August 2010 to March 2014, 200 patients with double kidney and single kidney stones without previous operations or other diseases were randomized into two groups according to the type of lithotripter used: pneumatic (n = 100) and laser (n = 100). The preoperative, intraoperative, and post-operative follow-up findings were analyzed and compared. The average stone size was similar in both the pneumatic and holmium laser lithotripsy groups (202.8 ± 52.6 mm(2) vs. 200.3 ± 50.8 mm(2)). No significant difference was found between the operation time for the two groups (55.9 ± 16.5 min vs. 62.4 ± 17.6 min). The concentrations of creatinine in both groups increased 2-24 h after the operation and decreased to a normal level 1-4 days after the operation in both groups. Renal diuretic scan revealed that the peak and the renal index were both abnormal after the operation but became normal 4 days after the operation in both groups. No significant difference of creatinine concentration or the diuresis renogram was observed between the two groups. However, two cases in the holmium laser group had almost lost the renal function of the operated kidney 1 year later. Both pneumatic and holmium laser lithotripsy can be associated with acute renal injury in some patients after the operation without any significant difference. However, some infrequent severe renal function damage in laser lithotripsy should be noted.

  19. Safety of holmium laser prostatectomy in patients with cardiac pacemaker implant

    Directory of Open Access Journals (Sweden)

    Narmada P Gupta

    2006-01-01

    Full Text Available Objectives: The use of the standard monopolar electrocautery is associated with significant risks of implant malfunction in patients on a cardiac pacemaker. It is also associated with a risk of adverse cardiac events due to blood loss and fluid absorption. The properties of the holmium laser prevent the occurrence of these adverse events. We report the successful use of this technology in resecting the gland in patients on a permanent cardiac pacemaker implant. MATERIALS AND Methods: Six patients with permanent cardiac pacemaker implant were treated with holmium laser resection of prostate over a period of two years. Treated patients had bothersome prostatic symptoms and failed to respond to medical therapy. All patients were operated under spinal anesthesia using a high power VersaPulse ® PowerSuiteTM Holmium laser source. Normal saline was used as irrigant. Intravesical tissue morcellator was also used to remove the larger fragments in two of the patients. Results : Median patient age was 60 years (range 56-73 and median prostate volume was 40cc (range 20-48cc. None of the patient required blood transfusion or had significant hyponatremia or Transurethral resection syndrome. No patients had any pacemaker malfunction or hemodynamic instability during the procedure or in immediate postoperative period. Improvement in maximum urine flow rate was observed from an average of 7 ml/sec in preoperative period to 22 ml/sec postoperatively at 3 month followup. Conclusions: Holmium laser prostatectomy offers the ideal modality of surgery in patients on a cardiac pacemaker. It helps to avoid additional preparation and minimizes the risk of device malfunction and adverse post operative events.

  20. Effects of the holmium laser on the human cornea: a preliminary study

    Science.gov (United States)

    Mueller, Linda J.; Tassignon, Marie J.; Trau, Rene; Pels, Liesbeth; Vrensen, Gijs F.

    1996-12-01

    Treatment of peripheral post-mortem human corneas with the Holmium laser in a ring pattern resulted in opaque spots. One pair of treated eyes was immediately processed for light and electron microscopy and three other treated eyes were preserved for 4 days in medium in order to compare direct and short-term effects of the Holmium laser. Cross as well as frontal light microscopical sections of all eyes revealed interconnecting bands between the spots. At the ultrastructural level the anterior corneal tissue within these spots was characterized by coagulation of cells and collagen and shoed either a dramatic distorting effect on the epithelium in the eyes processed immediately or a single layer of flattened multi-nucleolated epithelial cells having more than one nucleolus per nucleus in the eyes stored in medium. Furthermore, the spots showed disturbed Bowman's layer, destroyed keratocytes and collagen fibrils which were either coagulated or organized chaotically. The interconnecting bands contained alternating normal and coagulated collagen fibers. The rest of the cornea outside the spots had a normal appearance. In corneas stored in medium, both keratocytes and epithelial cells over the entire cornea exhibited accumulations of cytoplasmic fibrils and glycogen particles. These phenomena were not observed in non-preserved corneas, suggesting that the differences are due to preservation and not due to the laser treatment. It is concluded that morphological changes occur mainly in the treated peripheral cornea whereas the central untreated cornea remains unaffected,indicating that the Holmium laser is a reliable instrument to treat hypermetropic patients.

  1. Stone/tissue differentiation for Holmium laser lithotripsy using autofluorescence: Clinical proof of concept study.

    Science.gov (United States)

    Lange, Birgit; Jocham, Dieter; Brinkmann, Ralf; Cordes, Jens

    2017-04-01

    Holmium laser lithotripsy is the gold standard for intracorporeal fragmentation of urinary calculi. Usually, a visible beam is superimposed on the IR treatment laser as an aiming beam to guide the surgeon. In vitro tests showed that this aiming beam (532 nm, power proof of concept study with eight patients. For this, a modulated excitation/detection scheme (lock-in technique) was implemented. A frequency-doubled, diode-pumped solid-state laser module (532 nm, modulation frequency 66 Hz, average power 0.3 mW) was coupled via a dichroic mirror with the Holmium lithotripsy laser into the treatment fiber. The fluorescence signal entering the treatment fiber was detected via another dichroic mirror with a photodiode and a lock-in amplifier. In most instances (94%), the calculus of a patient gave a signal which was at least twice the maximum signal of ureteral tissue. The results of our proof of concept study indicate that measuring the fluorescence signal of a green aiming beam could be used to implement a feedback loop for Holmium laser lithotripsy. Preventing the laser being fired on tissue, this would increase the safety of the procedure. Lasers Surg. Med. 49:361-365, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography.

    Science.gov (United States)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

    2016-05-20

    We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.

  3. Real-time ultrasonography as a monitoring technique for interstitial Nd:YAG laser treatment of voluminous hemangiomas and vascular malformations

    Science.gov (United States)

    Werner, Jochen A.; Gottschlich, Stefan; Lippert, Burkard M.; Folz, Benedikt J.

    1998-01-01

    Voluminous vascular anomalies of the head and neck region are still treated with conventional surgery although Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser therapy is an effective treatment method. One hundred thirty give patients with voluminous hemangiomas and vascular malformations were treated with interstitial Nd:YAG laser therapy, partly complemented by a non-contact mode Nd:YAG laser light application. The vascular tumors had a diameter of more than 3 cm in two or all three dimensions. Treatment was carried out under ultrasound and manual control. Nearly 60% of the patients showed a complete clinical regression of the vascular tumor, a third of the patients had a partial regression and were satisfied with the treatment outcome. Four patients were treated unsuccessfully with the laser and three of them subsequently underwent conventional surgery. Only 10 patients showed cosmetic and functional deficits. These results on the interstitial Nd:YAG laser therapy of voluminous hemangiomas and vascular malformations in a large patient group demonstrated the high effectiveness of this novel and innovative therapy modality.

  4. Preparation and Characterization of Yb - doped YAG Ceramics

    OpenAIRE

    2011-01-01

    Rare-earth doped yttrium aluminum garnet (YAG) ceramics are among the most widely produced transparent ceramics for laser applications. Yb:YAG ceramics are an interesting IR laser material [1], which allows significantly higher doping compared to the generally more used Nd:YAG [2,3]. This work presents the preparation of polycrystalline Yb:YAG ceramics with dopant concentration from 0 up to 20 at.% via solid state reactive sintering. Samples were prepared via cold isostatic pressing of spray ...

  5. Noncontact vibration measurements using magnetoresistive sensing elements

    Science.gov (United States)

    Tomassini, R.; Rossi, G.

    2016-06-01

    Contactless instrumentations is more and more used in turbomachinery testing thanks to the non-intrusive character and the possibility to monitor all the components of the machine at the same time. Performances of blade tip timing (BTT) measurement systems, used for noncontact turbine blade vibration measurements, in terms of uncertainty and resolution are strongly affected by sensor characteristics and processing methods. The sensors used for BTT generate pulses, used for precise measurements of turbine blades time of arrival. Nowadays proximity sensors used in this application are based on optical, capacitive, eddy current and microwave measuring principle. Pressure sensors has been also tried. This paper summarizes the results achieved using a novel instrumentation based on the magnetoresistive sensing elements. The characterization of the novel probe has been already published. The measurement system was validated in test benches and in a real jet-engine comparing different sensor technologies. The whole instrumentation was improved. The work presented in this paper focuses on the current developments. In particular, attention is given to the data processing software and new sensor configurations.

  6. Noncontact blood perfusion mapping in clinical applications

    Science.gov (United States)

    Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

    2016-04-01

    Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

  7. [Noncontact and noninvasive microwave biological measurements].

    Science.gov (United States)

    Misawa, T; Kutsumi, Y; Tada, H; Kim, S S; Nakai, T; Miyabo, S; Hamada, T; Arai, I; Suzuki, T

    1990-01-01

    Without contact probes, the signals of small human body surface movements were obtained with microwave Doppler sensors using a two-phase interferometric method. The signals were then compared with mechanocardiographic records routinely obtained by contact transducers. Furthermore, this system was applied to patients wearing clothes. The study subjects consisted of 20 cardiac patients and 10 normal controls. 1. The microwave signals obtained in the cervical and precordial regions were similar to those of the mechanocardiographic recordings, such as the carotid pulse and jugular venous pulse tracings and the apexcardiogram. There was a significant correlation between left ventricular ejection time (LVET) obtained by microwave Doppler sensors and that by the carotid pulse tracing (r = 0.95). 2. The signals of the microwave Doppler sensor were obtained from the patients wearing clothes. The heart beat components were distinguished from respiratory motion and patients' movements using band-pass filters. These results suggest that this method is capable of evaluating cardiac function noninvasively and thus has a distinct advantage in the field of non-contact measurements.

  8. Laser properties of YAG:Nd, Ti

    Science.gov (United States)

    Kvapil, J.; Kvapil, J.; Kubelka, K. J.; Perner, B.

    1982-07-01

    YAG:Nd containing about 0.001 wt percent Ti showed slightly increased losses at 1.064 micron but a substantially increased gain coefficient if compared with a material containing no Ti. The increased losses may be attributed to the increased absorption near 1.064 nm and the increased gain to the better energy coupling among Nd(3+) ions occupying nonequivalent sites due to the presence of Ti(3+) ions. YAG:Nd, Ti may be used as a high performance pulsed laser.

  9. YAG laser welding with surface activating flux

    Institute of Scientific and Technical Information of China (English)

    樊丁; 张瑞华; 田中学; 中田一博; 牛尾诚夫

    2003-01-01

    YAG laser welding with surface activating flux has been investigated, and the influencing factors and mechanism are discussed. The results show that both surface activating flux and surface active element S have fantastic effects on the YAG laser weld shape, that is to obviously increase the weld penetration and D/W ratio in various welding conditions. The mechanism is thought to be the change of weld pool surface tension temperature coefficient, thus, the change of fluid flow pattern in weld pool due to the flux.

  10. Pre-pumped passively Q-switched Nd:YAG/Cr:YAG microchip laser

    Institute of Scientific and Technical Information of China (English)

    Xinning Tian(田信宁); Ping Yan(闫平); Qiang Liu(柳强); Mali Gong(巩马理); Yun Liao(廖云)

    2004-01-01

    A pre-pumped passively Q-switched Nd:YAG/Cr:YAG microchip laser is demonstrated with a peak power of 7.5 kW at pulse repetition rate of serveral kilohertzs. The full-width at half-maximum(FWHM)is 734 ps, and the pulse energy is 5.5 μJ with a fundamental spatial mode. In this system, the pre-pumped microchip laser of Nd:YAG/Cr:YAG wafer which is bonded through the thermal-bonding technique has achieved a time jitter value of 12 μs and a Q-switched amplitude instability of 1.26%(15)through the pre-pumped modulation technique.

  11. Microchip laser based on Yb:YAG/V:YAG monolith crystal

    Science.gov (United States)

    Nejezchleb, Karel; Šulc, Jan; Jelínková, Helena; Škoda, Václav

    2016-03-01

    V:YAG crystal was investigated as a passive Q-switch of longitudinally diode-pumped microchip laser, emitting radiation at wavelength 1030.5 nm. This laser was based on diffusion bonded monolith crystal (diameter 3 mm) which combines in one piece an active laser part (Yb:YAG crystal, 10 at.% Yb/Y, 3 mm long) and saturable absorber (V:YAG crystal, 2 mm long, initial transmission 86 % @ 1031 nm). The microchip resonator consisted of dielectric mirrors directly deposited on the monolith surfaces (pump mirror HT @ 968 nm and HR @ 1031 nm on Yb:YAG part, output coupler with reflection 55 % @ 1031 nm on the V:YAG part). For longitudinal CW pumping of Yb:YAG part, a fibre coupled (core diameter 100 μm, NA = 0.22, emission @ 968 nm) laser diode was used. The laser threshold was 3.8W. The laser slope efficiency for output mean in respect to incident pumping was 16 %. The linearly polarized generated transversal intensity beam profile was close to the fundamental Gaussian mode. The generated pulse length, stable and mostly independent on pumping power, was equal to 1.3 ns (FWHM). The single pulse energy was increasing with the pumping power and for the maximum pumping 9.7W it was 78 μJ which corresponds to the pulse peak-power 56 kW. The maximum Yb:YAG/V:YAG microchip laser mean output power of 1W was reached without observable thermal roll-over. The corresponding Q-switched pulses repetition rate was 13.1 kHz.

  12. Optimization of dosimetry and safety using the holmium laser for urology

    Science.gov (United States)

    van Swol, Christiaan F. P.; Verdaasdonck, Rudolf M.; Zeijlemaker, Bram Y. W.; Grimbergen, Matthijs C. M.; Boon, Tom A.

    1998-07-01

    The holmium laser has become accepted as a versatile instrument for urological applications, such as prostate resection, urethrotomy, tumor coagulation and lithotripsy. Presently, more powerful lasers have become available generating pulses up to 4 J at 80 W. The necessity of these high power systems in urology is ambiguous. In this study, the dosimetry as to efficacy and especially safety was investigated for various applications. The holmium laser ((lambda) equals 2.1 micrometer) emits its energy in 350 microsecond pulses which instantly turn water into vapor. Using high-speed photography explosive vapor bubbles with diameters over 10 mm were captured. The mechanical force of these bubbles, effectively fragments stones but may dilate and rupture a small lumen like the ureter. After implosion of the bubble, the energy of vaporization turns into heat. Depending on pulse energy and pulse repetition rate, tissue can be thermally affected up to 5 mm. For soft tissue applications, e.g., urethrotomy, prostatectomy or tumor coagulation, pulse energies of 0.5 - 1.5 J were applied at a high repetition rate (20 - 40 Hz) to provide sufficient coagulative and hemostatic effects. At higher pulse energies, the fiber tip was vibrating vigorously and the tissue was ripped to pieces decreasing hemostasis and visibility. For hard tissue applications, bursts of 0.5 J pulses at 5 Hz, proved to be sufficient to fragment all types of stones (including cystine) in the ureter and the bladder without mechanical or thermal damage to surrounding tissue. At higher settings, targeting the stone was less controlled and effective due to 'jumping' of the fiber tip with resulting mechanical and thermal trauma to the surrounding tissue. The holmium laser can be used effectively to coagulate and cut soft tissue and fragment stones at relatively low energy and power settings, thus minimizing the risk of complications.

  13. Holmium-lipiodol-alginate microspheres for fluoroscopy-guided embolotherapy and multimodality imaging.

    Science.gov (United States)

    Oerlemans, Chris; Seevinck, Peter R; Smits, Maarten L; Hennink, Wim E; Bakker, Chris J G; van den Bosch, Maurice A A J; Nijsen, J Frank W

    2015-03-30

    Embolotherapy is a minimally invasive transcatheter technique aiming at reduction or complete obstruction of the blood flow by infusion of micro-sized particles in order to induce tumor regression. A major drawback of the current commercially available and clinically used microspheres is that they cannot be detected in vivo with medical imaging techniques, impeding intra- and post-procedural feedback. It can be expected that real-time monitoring of microsphere infusion and post-procedural imaging will result in better predictability and higher efficacy of the treatment. In this study, a novel microsphere formulation has been developed that can be visualized with fluoroscopy, X-ray computed tomography (CT) and magnetic resonance imaging (MRI). The microspheres were prepared with the JetCutter technique and consist of alginate (matrix-forming polymer), holmium (cross-linking and MRI contrast agent), lipiodol (radiopaque contrast agent) and Pluronic F-68 (surfactant). The mean size (±SEM) of the hydrated holmium-lipiodol-alginate microspheres (Ho-lip-ams) was 570±12 μm with a holmium content of 0.38±0.01% (w/w). Stability studies showed that the microspheres remained intact during incubation for two weeks in fetal calf serum (FCS) at 37 °C. The inclusion of lipiodol in the microspheres rendered excellent visualization capabilities for fluoroscopy and CT, whereas the holmium ions, which keep the alginate network together, also allow MR imaging. In this study it was shown that single sphere detection was possible by fluoroscopy, CT and MRI. The Ho-lip-ams were visualized in real-time, during infusion in a porcine kidney using fluoroscopy, and post-procedural, the deposition of the microspheres was examined with fluoroscopy, (cone beam rotational) CT and MRI. The different imaging modalities showed similar deposition patterns of the microspheres within the organ. The combination of intra-procedural visualization, multimodality imaging for patient follow-up and the

  14. Endoscopic removal of a proximal urethral stent using a holmium laser: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Francisco Botelho

    2012-01-01

    Full Text Available Urethral stents were initially developed for the management of urethral strictures and obstructive voiding disorders in select patients. Urethral stent complications are common and may require stent explantation, which is often quite challenging. We present our experience with endoscopic removal of an encrusted UroLume proximal urethral stent in a 72-year-old male using a holmium laser. The literature on various management options and outcomes for urethral stent removal is reviewed. Endoscopic removal of proximal urethral stents is feasible and safe and should be considered as the primary treatment option in patients requiring stent extraction.

  15. Noncontacting thermoelectric detection of material imperfections in metals

    Energy Technology Data Exchange (ETDEWEB)

    Peter B. Nagy; Adnan H. Nayfeh; Waseem I. Faidi; Hector Carreon; Balachander Lakshminaraya; Feng Yu; Bassam Abu-Nabah

    2005-06-17

    This project was aimed at developing a new noncontacting thermoelectric method for nondestructive detection of material imperfections in metals. The method is based on magnetic sensing of local thermoelectric currents around imperfections when a temperature gradient is established throughout a conducting specimen by external heating and cooling. The surrounding intact material serves as the reference electrode therefore the detection sensitivity could be very high if a sufficiently sensitive magnetometer is used in the measurements. This self-referencing, noncontacting, nondestructive inspection technique offers the following distinct advantages over conventional methods: high sensitivity to subtle variations in material properties, unique insensitivity to the size, shape, and other geometrical features of the specimen, noncontacting nature with a substantial stand-off distance, and the ability to probe relatively deep into the material. The potential applications of this method cover a very wide range from detection metallic inclusions and segregations, inhomogeneities, and tight cracks to characterization of hardening, embrittlement, fatigue, texture, and residual stresses.

  16. Mechanical impedance measurement and damage detection using noncontact laser ultrasound.

    Science.gov (United States)

    Lee, Hyeonseok; Lim, Hyeong Uk; Hong, Jung-Wuk; Sohn, Hoon

    2014-06-01

    This Letter proposes a mechanical impedance (MI) measurement technique using noncontact laser ultrasound. The ultrasound is generated by shooting a pulse laser beam onto a target structure, and its response is measured using a laser vibrometer. Once ultrasound propagation converges to structural vibration, MI is formed over the entire structure. Because noncontact lasers are utilized, this technique is applicable in harsh environments, free of electromagnetic interference, and able to perform wide-range scanning. The formation of MI and its feasibility for damage detection are verified through thermo-mechanical finite element analysis and lab-scale experiments.

  17. CO2, Er: YAG and Nd:YAG lasers in endodontic surgery

    Directory of Open Access Journals (Sweden)

    Daniel Humberto Pozza

    2009-12-01

    Full Text Available OBJECTIVES: CO2, Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1% Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software® of 108 endodontically treated human permanent canines. MATERIAL AND METHODS: Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity preparation with ultrasound and filled with MTA; B: 90-degree apicoectomy with bur, root-end cavity prepared with ultrasound and filled with MTA, and treatment of apical surface with CO2 laser (1 W, CW/CW; C: 90-degree apicoectomy with bur, and treatment of apical surface with Nd:YAG laser (150 mJ, 10 Hz; D: 90-degree apicoectomy with bur, and treatment of apical surface with CO2 laser,(1 W, CW/CW; E: apicoectomy with Er:YAG laser (400 mJ, 10 Hz, root-end cavity prepared with ultrasound and filled with MTA; F: apicoectomy with Er:YAG laser (400 mJ, 10 Hz and treatment of apical surface with Nd:YAG laser (150 mJ, 10Hz; G: apicoectomy with CO2 laser (5W, CW/SP, root-end cavity prepared with ultrasound and filled with MTA; H: irradiation of apical end with CO2 laser (1 W, CW/CW; I: irradiation of apical end with Nd:YAG laser (150 mJ, 10 Hz. RESULTS: Dye penetration was found in all specimens at different rates, the lowest penetration occurring in groups C (16.20%, B (17.24% and F (17.84%. CONCLUSIONS: Groups B, C and F represent the best technical sequences to perform endodontic surgery.

  18. CO2, ER:YAG AND ND:YAG LASERS IN ENDODONTIC SURGERY

    Science.gov (United States)

    Pozza, Daniel Humberto; Fregapani, Patrícia Wehmeyer; Xavier, Cristina Braga; Weber, João Batista Blessmann; de Oliveira, Marília Gerhardt

    2009-01-01

    Objectives: CO2, Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1% Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software®) of 108 endodontically treated human permanent canines. Material and methods: Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity preparation with ultrasound and filled with MTA; B: 90-degree apicoectomy with bur, root-end cavity prepared with ultrasound and filled with MTA, and treatment of apical surface with CO2 laser (1 W, CW/CW); C: 90-degree apicoectomy with bur, and treatment of apical surface with Nd:YAG laser (150 mJ, 10 Hz); D: 90-degree apicoectomy with bur, and treatment of apical surface with CO2 laser (1 W, CW/CW); E: apicoectomy with Er:YAG laser (400 mJ, 10 Hz), root-end cavity prepared with ultrasound and filled with MTA; F: apicoectomy with Er:YAG laser (400 mJ, 10 Hz) and treatment of apical surface with Nd:YAG laser (150 mJ, 10Hz); G: apicoectomy with CO2 laser (5W, CW/SP), root-end cavity prepared with ultrasound and filled with MTA; H: irradiation of apical end with CO2 laser (1 W, CW/CW); I: irradiation of apical end with Nd:YAG laser (150 mJ, 10 Hz). Results: Dye penetration was found in all specimens at different rates, the lowest penetration occurring in groups C (16.20%), B (17.24%) and F (17.84%). Conclusions: Groups B, C and F represent the best technical sequences to perform endodontic surgery. PMID:20027433

  19. CO(2), Er: YAG and Nd:YAG lasers in endodontic surgery.

    Science.gov (United States)

    Pozza, Daniel Humberto; Fregapani, Patrícia Wehmeyer; Xavier, Cristina Braga; Weber, João Batista Blessmann; Oliveira, Marília Gerhardt de

    2009-01-01

    CO(2), Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1% Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software) of 108 endodontically treated human permanent canines. Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity preparation with ultrasound and filled with MTA; B: 90-degree apicoectomy with bur, root-end cavity prepared with ultrasound and filled with MTA, and treatment of apical surface with CO(2) laser (1 W, CW/CW); C: 90-degree apicoectomy with bur, and treatment of apical surface with Nd:YAG laser (150 mJ, 10 Hz); D: 90-degree apicoectomy with bur, and treatment of apical surface with CO(2) laser,(1 W, CW/CW); E: apicoectomy with Er:YAG laser (400 mJ, 10 Hz), root-end cavity prepared with ultrasound and filled with MTA; F: apicoectomy with Er:YAG laser (400 mJ, 10 Hz) and treatment of apical surface with Nd:YAG laser (150 mJ, 10Hz); G: apicoectomy with CO(2) laser (5W, CW/SP), root-end cavity prepared with ultrasound and filled with MTA; H: irradiation of apical end with CO(2) laser (1 W, CW/CW); I: irradiation of apical end with Nd:YAG laser (150 mJ, 10 Hz). Dye penetration was found in all specimens at different rates, the lowest penetration occurring in groups C (16.20%), B (17.24%) and F (17.84%). Groups B, C and F represent the best technical sequences to perform endodontic surgery.

  20. Holmium-166 radioembolization for the treatment of patients with liver metastases : design of the phase I HEPAR trial

    NARCIS (Netherlands)

    Smits, Maarten L J; Nijsen, Johannes F W; van den Bosch, Maurice A A J; Lam, Marnix G E H; Vente, Maarten A D; Huijbregts, Julia E; van het Schip, Alfred D; Elschot, Mattijs; Bult, Wouter; de Jong, Hugo W A M; Meulenhoff, Pieter C W; Zonnenberg, Bernard A

    2010-01-01

    BACKGROUND: Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alt

  1. Intratumoral administration of Holmium-166 Acetylacetonate Microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer

    NARCIS (Netherlands)

    Bult, W.; Kroeze, S.G.C.; Elschot, M.; Seevinck, P.R.; Beekman, F.J.; De Jong, H.W.A.M.; Uges, D.R.A.; Kosterink, J.G.W.; Luijten, P.R.; Hennink, W.E.; et al.

    2013-01-01

    The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microsp

  2. Crystal structure and infrared spectrum of thallium holmium polyphosphate, TIHo(PO3)4

    Institute of Scientific and Technical Information of China (English)

    Karima Horchani-Naifer; Jaouher Amami; Mokhtar Ferid

    2008-01-01

    Crystals of thallium-holmium polyphosphate TIHo(PO3)4 were grown by flux method technique and characterized by single crystal X-ray diffraction. Structure of TIHo(PO3)4 was solved for the first time, and it crystallized in the monoclinic P21/n space group with the following unit-cell dimensions: a=1.02225(3) nm, b=0.88536(2) nm, c=1.09541(4) nm, β=105.888(1)°, V=0.95354(5) nm3 and Z=4. The crystal structure was solved from 2174 independent reflections with final R1(F2)=0.0442 and Rw(F<2)=0.0861 refined with 164 parameters. The atomic arrangement could be described as a long chain polyphosphate organization. Holmium atoms had eighffold coordination. The structure of T1Ho(PO3)4 consisted of HoO8 polyhedra sharing oxygen atoms with phosphoric group PO4. Infrared spectrum was investigated at room temperature in the frequencies range, 350-4000 cm-1, showing some characteristic vibration bands of infinite chain structure of PO4 tetrahedra linked by bridging oxygen.

  3. Thermochemical Study of Coordination of Holmium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

    Institute of Scientific and Technical Information of China (English)

    ZHAO Feng-qi; CHEN San-ping; JIAO Bao-juan; REN Yi-xia; GAO Sheng-li; SHI Qi-zhen

    2004-01-01

    The complex of holmium chloride hydrate with diethylammonium diethyldithiocarbamate(D-DDC) was synthesized via mixing their solutions in absolute alcohol under a dry N2 atmosphere. The elemental and chemical analyses show that the complex has the general formula Et2NH2[Ho(S2CNEt2)4]. It was also characterized by IR spectroscopy. The enthalpies of the dissolution of holmium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reactions of the formation of Et2NH2[Ho(S2CNEt2)4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters(the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters(the apparent activation energy, the pre-exponential constant and the reaction order) of the liquid-phase reaction of the complex formation were obtained. The enthalpy change of the solid-phase complex formation reaction at 298.15 K was calculated by means of a thermochemical cycle.

  4. Microstructure and hysteresis curves of samarium-holmium-iron garnet synthesized by coprecipitation

    Directory of Open Access Journals (Sweden)

    Caffarena Valeska da Rocha

    2003-01-01

    Full Text Available An investigation was made into the synthesis and magnetic properties of Sm(3-xHo xFe5O12 (samarium-holmium-iron garnet ferrite, as yet absent from the literature. The material in question was synthesized by co-precipitation, starting from hydrated chlorides of rare-earth elements and ferrous sulfate, and the mixed hydroxide co-precipitate was calcined at 1000 °C. Using PVA as a binder, rectangular cross section-shaped compacts were produced by means of steel-die pressing, drying and sintering from 1200 to 1450 °C. The main conclusions of this study were that the coercive force decreases as the sintering temperature increases, and that the effect of substituting holmium for samarium in SmIG is entirely different from that provided by replacing yttrium by gadolinium in YIG, which is the most important result of this work. An in-depth investigation will be necessary to determine the correlation between microstructure/magnetic properties and ceramic processing variables.

  5. MRI-based biodistribution assessment of holmium-166 poly(L-lactic acid) microspheres after radioembolisation

    Energy Technology Data Exchange (ETDEWEB)

    Maat, Gerrit H. van de; Seevinck, Peter R.; Leeuw, Hendrik de; Viergever, Max A. [University Medical Center Utrecht, Image Sciences Institute, Q S.459, PO Box 85500, Utrecht (Netherlands); Elschot, Mattijs; Smits, Maarten L.J.; Schip, Alfred D. van het; Vente, Maarten A.D.; Zonnenberg, Bernard A.; Jong, Hugo W.A.M. de; Lam, Marnix G.E.H.; Bosch, Maurice A.A.J. van den; Nijsen, Johannes F.W.; Bakker, Chris J.G. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands)

    2013-03-15

    To demonstrate the feasibility of MRI-based assessment of the intrahepatic Ho-PLLA-MS biodistribution after radioembolisation in order to estimate the absorbed radiation dose. Fifteen patients were treated with holmium-166 ({sup 166}Ho) poly(L-lactic acid)-loaded microspheres (Ho-PLLA-MS, mean 484 mg; range 408-593 mg) in a phase I study. Multi-echo gradient-echo MR images were acquired from which R{sub 2} {sup *} maps were constructed. The amount of Ho-PLLA-MS in the liver was determined by using the relaxivity r{sub 2} {sup *} of the Ho-PLLA-MS and compared with the administered amount. Quantitative single photon emission computed tomography (SPECT) was used for comparison with MRI regarding the whole liver absorbed radiation dose. R{sub 2} {sup *} maps visualised the deposition of Ho-PLLA-MS with great detail. The mean total amount of Ho-PLLA-MS detected in the liver based on MRI was 431 mg (range 236-666 mg) or 89 {+-} 19 % of the delivered amount (correlation coefficient r = 0.7; P < 0.01). A good correlation was found between the whole liver mean absorbed radiation dose as assessed by MRI and SPECT (correlation coefficient r = 0.927; P < 0.001). MRI-based dosimetry for holmium-166 radioembolisation is feasible. Biodistribution is visualised with great detail and quantitative measurements are possible. (orig.)

  6. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System

    Directory of Open Access Journals (Sweden)

    Inbok Lee

    2016-12-01

    Full Text Available This paper proposes a non-contact nondestructive evaluation (NDE technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS, with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

  7. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System.

    Science.gov (United States)

    Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

    2016-12-16

    This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

  8. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  9. Material removal model for non-contact chemical mechanical polishing

    Institute of Scientific and Technical Information of China (English)

    ZHANG JianQun; ZHANG ChaoHui

    2008-01-01

    Material removal mechanism under non-contact condition between the pad and the wafer in the chemical mechanical polishing (CMP) process is investigated. Based on the assumption that almost all effective material removals take place due to the active abrasives which cut material through the plowing effects. A novel model is developed to predict the material removal rate (MRR) under non-contact condition between the pad and the wafer in CMP. Validated by the experimental data, the model is proved to be able to predict the change of MRR under non-contact condition. Numerical simulation of the model shows: the relative velocity u between the pad and the wafer and fluid viscosity η are the most important factors which impact MRR under non-contact condition; load changes of wafer also affects the MRR, but the effect is not as obvious as the relative velocity and fluid viscosity;when the radius of abrasive is not less than 50nm, the impact of MRR alone with the changes in the size of the abrasive can be ignored.

  10. Continuous control systems for non-contact ECG

    Science.gov (United States)

    Kodkin, Vladimir L.; Yakovleva, Galina V.; Smirnov, Alexey S.

    2017-03-01

    South Ural State University is still conducting the research work dedicated to innovations in biomedicine. Development of system for continuous control and diagnosis of the functional state in large groups of people is based on studies of non-contact ECG recording reported by the authors at the SPIE conference in 2016. The next stage of studies has been performed this year.

  11. A noncontact temperature measurement method in polymerase chain reaction reactors

    Science.gov (United States)

    Sochivko, D. G.; Varlamov, D. A.; Fedorov, A. A.; Kurochkin, V. E.

    2016-04-01

    A new noncontact method for measuring temperatures of liquids, which is based on the fluorescent probes, is proposed. The method is intended for measuring temperatures of reaction media in reactors of devices for polymerase chain reactions in real time and can be used for determining dynamic temperature parameters.

  12. High-resolution noncontact atomic force microscopy.

    Science.gov (United States)

    Pérez, Rubén; García, Ricardo; Schwarz, Udo

    2009-07-01

    Progress in nanoscience and nanotechnology requires tools that enable the imaging and manipulation of matter at the atomic and molecular scale. During the last two decades or so, scanning probe-based techniques have proven to be particularly versatile in this regard. Among the various probe-based approaches, atomic force microscopy (AFM) stands out in many ways, including the total number of citations and the breadth of possible applications, ranging from materials characterization to nanofabrication and biological studies. However, while nanometer scale operation in different environments became routine, atomic resolution imaging remained elusive for a long time. The reason for this initial deficiency was that contact with the sample blunts atomically sharp tips, which are mandatory for successful atomic resolution imaging. This problem was overcome in the mid-1990s with the introduction of noncontact atomic force microscopy (NC-AFM), which represents a version of AFM where the cantilever is oscillated close to the sample surface without actually 'touching' it. This allows the preservation of the atomic sharpness of the tip while interaction-induced changes in the cantilever's resonance frequency are used to quantify the tip-sample distance. Since then, progress has been steady and includes the development of commercial instruments as well as the addition of many new capabilities beyond imaging, such as the identification and manipulation of individual atoms. A series of annual international conferences, starting in Osaka in 1998, have contributed significantly to this outstanding performance. The program of the most recent conference from this series, held in Madrid on 15-19 September 2008, reflects the maturity of this field, with an increasing number of groups developing strong activities that involve novel approaches and applications covering areas well beyond the original vacuum-based imaging. In this special issue of Nanotechnology we present a selection of

  13. Properties of Yb:YAG scintillators

    CERN Document Server

    Antonini, P; Bressi, G; Carugno, Giovanni; Santilli, P

    2002-01-01

    Relative light yield (LY) dependence on temperature for Yb:YAG crystals containing from 10% to 100% of Yb dopant is studied for gamma and alpha excitations. The maximum LY is achieved at 120 KYAG. Linearity of the light output is checked. alpha/gamma ratio is found to be 0.42+-0.02. Pulse shapes induced by gamma and alpha particles and cosmic rays are investigated by analyzing a set of single events recorded. Gamma events are fast tau<4 ns), while other kinds of radiation give rise to more complicated and longer profiles, allowing particle discrimination. Dependence of scintillation properties on concentration of Yb and purity is discussed.

  14. End-Pumped Tm:YAG Ceramic Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiao-Jin; XU Jian-Qiu; ZHANG Wen-Xin; JIANG Sen-Xue; PAN Yu-Bai

    2009-01-01

    Lasers from a Tm:YAG ceramic aare reported for the first time to our best knowledge. The Tm:YAG ceramic slab is end-pumped by a laser diode with central wavelength 792nm. At room temperature, the maximum continuous-wave output power is 4.5 W, and the sloping efficiency is obtained to be 20.5%. The laser spectrum of the Tm: YAG ceramic is centered at 2015 nm.

  15. Cryogenic Yb:YAG thin-disk laser

    Science.gov (United States)

    Vretenar, N.; Carson, T.; Lucas, T.; Newell, T.; Latham, W. P.; Peterson, P.; Bostanci, H.; Lindauer, J. J.; Saarloos, B. A.; Rini, D. P.

    2011-11-01

    At cryogenic temperatures, Yb:YAG behaves as a 4-level laser. Its absorption and emission cross-sections increase, and its thermal conductivity improves. Yb:YAG thin disk laser performance at room and cryogenic (80°K) temperatures will be presented. The Yb:YAG gain media is cooled using either a pressurized R134A refrigerant system or by a two-phase liquid nitrogen spray boiler. Interchangeable mounting caps allow the same Yb:YAG media to be switched between the two systems. This allows direct comparison of lasing, amplified spontaneous emission, and temperature performance between 20°C and -200°C.

  16. Laser-diode pumped Nd:YAG lasers; Laser diode reiki Nd:YAG lasear

    Energy Technology Data Exchange (ETDEWEB)

    Yuasa, H.; Akiyama, Y.; Nakayama, M. [Toshiba Corp., Tokyo (Japan)

    2000-04-01

    Laser-diode pumped Nd:YAG lasers are expected to be applied to laser processing fields such as welding, cutting, drilling, and marking due to their potential for high efficiency and compactness. We are designing and developing laser-diode pumped Nd:YAG lasers using numerical analysis simulation techniques such as ray tracing and thermal analysis. We have succeeded in achieving a laser power of more than 3 kW with 20% efficiency, which is the best ever obtained. In addition, we have developed a laser-diode pumped green laser by second harmonic generation, for precision machining on silicon wafers. (author)

  17. Improvement of thermal management in the composite Yb:YAG/YAG thin-disk laser

    Science.gov (United States)

    Kuznetsov, I. I.; Mukhin, I. B.; Palashov, O. V.

    2016-04-01

    To improve the thermal management in the composite Yb:YAG/YAG thin-disk laser a new design of laser head is developed. Thermal-induced phase distortions, small signal gain and lasing in the upgraded laser head are investigated and compared with previously published results. A substantial decrease of the thermal lens optical power and phase aberrations and increase of the laser slope efficiency are observed. A continuous-wave laser with 440 W average power and 44% slope efficiency is constructed.

  18. Investigations of YAG:Er(3+),Yb(3+) and YAG:Co(2+) Crystals for Laser Applications

    Science.gov (United States)

    2001-01-01

    doped YAG crystals are given. Erbium and ytterbium doped YAG single crystals were obtained by the Czochralski method . The spectral properties and laser...relaxation time of 290 Rts14 2. CRYSTAL GROWTH The crystals were obtained by the Czochralski method , using iridium crucibles of external dimensions...YAG:Co 2+ single crystal grown by Czochralski method is presented. In all obtained crystals the core area of the characteristic threefold symmetry was

  19. High-efficiency lasing and spectroscopy of domestic 1%Nd:YAG and 1%Ho:YAG ceramics

    Science.gov (United States)

    Vatnik, S. M.; Vedin, I. A.; Kurbatov, P. F.; Osipov, V. V.; Luk'yashin, K. E.; Maksimov, R. N.; Solomonov, V. I.

    2017-01-01

    We report on spectroscopy and high-efficiency lasing of YAG ceramics synthesized at the Institute of Electrophysics, Ural Branch, Russian Academy of Sciences. The best slope efficiency is to be 36% for 1%Nd:YAG ceramics and 40% for 1%Ho:YAG ceramics, in the latter case the emission was centred at 2090 nm. Internal losses in the samples of domestic ceramics were estimated.

  20. Apical sealing quality of in vitro apicectomy procedures after using both Er:YAG and Nd:YAG.

    Science.gov (United States)

    Leonardi, Denise Piotto; Sivieri-Araujo, Gustavo; Zielak, Joao Cesar; Baratto-Filho, Flares; Moriyama, Lilian Tan; Berbert, Fabio Luiz Camargo Villela

    2010-10-01

    The aim of this study was to evaluate the apical sealing of dentinal tubules after root-end surface cutting by using Er:YAG and Nd:YAG lasers. After root-canal instrumentation and filling, apices of 50 extracted maxillary canine human teeth were resected by Er:YAG with 400 mJ, 10 Hz, for 30 sec. The samples were randomly assigned to five groups (n = 10): (GI) treated without root-end cavity, but with Nd:YAG (1.0 W, 10 Hz, 20 sec) for dentinal tubules sealing; (GII) treated with root-end cavity without the use of Nd:YAG; (GIII) treated with root-end cavity and Nd:YAG application; (GIV) treated with root-end cavity made by Er:YAG with no focus and without Nd:YAG application; and (GV) treated without root-end cavity and without Nd:YAG application. The root-end cavities were performed by using Er:YAG at 300 mJ, 10 Hz, for 20 sec. Subsequently, all teeth were waterproofed and immersed in 2% methylene blue for 48 h in a vacuum environment. The samples were longitudinally sectioned, and microleakage was measured. ANOVA and the Fisher LSD test showed that GIV was less susceptible to microleakage than were the other groups (p < 0.05). Interestingly, the use of the Er:YAG with no focus showed superior dentinal tubule sealing in comparison with the other groups, even with or without root-end cavity and Nd:YAG application.

  1. 340 W average power output of diode-pumped composite ceramic YAG/Nd:YAG disk laser

    Science.gov (United States)

    Jia, Kai; Jiang, Yong; Yang, Feng; Deng, Bo; Hou, Tianjin; Guo, Jiawei; Chen, Dezhang; Wang, Hongyuan; Yang, Chuang; Peng, Chun

    2016-11-01

    We report on a diode-pumped composite ceramic disk laser in this paper. The composite ceramic YAG/Nd:YAG disk consists of 4 mm thick pure YAG and 2 mm thick Nd:YAG with 1.0 at.% doping concentration. The slope efficiency of the composite ceramic disk laser is 36.6% corresponding to the maximum optical-optical efficiency of 29.2%. Furthermore, 340 W average power output was achieved at the absorbed pump power of 1290 W.

  2. The possibility of clinical application of the solid state lasers: Nd:YAG, Ho:YAG, and Er:YAG in otolaryngology - head and neck surgery

    Science.gov (United States)

    Tomaszewska, M.; Kukwa, A.; Tulibacki, M.; Wójtowicz, P.; Olędzka, I.; Jeżewska, E.

    2007-02-01

    The purpose of this study was to summarize our experiences in clinical application of Nd:YAG, Ho:YAG and Er:YAG in otolaryngology- head and neck surgery. Choosing the laser type and parameters for the particular procedures was based on our previous research on tissue effects of those lasers. During the period of 1993-2006 we performed 3988 surgical procedures with the Nd:YAG laser. Over 87% of those were made for the nasal cavity pathologies as polyps, hyperplasia of inferior nasal turbinate, granulation tissue, postoperative adhesions, vascular malformations, under the local anesthesia conditions. In our experience Nd:YAG laser gives the possibility of good clinical control and low risk of side effects for disorders of high recurrence and frequent interventions necessity, as nasal polyps or respiratory papillomatosis. Nd:YAG assisted uvulopalatoplasty gives an interesting alternative for surgical procedures for snoring and slight/mild OSA-recognized patients. Due to its good hemostatic properties, it is a perfect tool for removal of the chemodectoma from meddle ear. During the period of 1995-2006 we performed 229 surgical procedures with the Ho:YAG laser, mostly for larynx pathologies (adhesion and scar tissue removal). In our experience Ho:YAG laser can serve as a precise laser knife for both soft and bony tissue. The ER:YAG laser still remain under clinical trial. Since 2001 year we performed 24 procedures of removing stone deposits from salivary glands. We believe it may become a promising method to cope with sialolithiasis which allows for glandule function preservation. All of the laser types mentioned above, can be easily coupled with endoscopes, what makes them available for all of the head and necklocalized disorders.

  3. Cleaning of carbon layer from the gold films using a pulsed Nd:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Amol [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Choubey, Ambar [Solid State Laser Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Modi, Mohammed H., E-mail: modimh@rrcat.gov.in [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Upadhyaya, B.N.; Oak, S.M. [Solid State Laser Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Lodha, G.S.; Deb, S.K. [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

    2013-10-15

    Hydrocarbon cracking and carbon contamination of optical elements in soft X-ray spectrometers and synchrotron radiation beamlines is a severe problem. Carbon contamination seriously affects the optics performance. In the present work, an Nd:YAG laser providing 2 mJ of pulse energy and 100 ns of pulse duration has been used for carbon cleaning experiments. The laser cleaning is a non-contact, accurate, efficient and safe process. A surface area of 48 cm{sup 2} having ∼20 nm thick carbon layer on gold surface has been removed with six number of laser passes and with 80% laser spot overlapping without any change in surface roughness of the underneath gold film. Effect of laser beam on gold film after carbon removal has been analyzed using X-ray photoelectron spectroscopy, soft X-ray reflectivity techniques. Atomic force microscopy was used to analyze surface morphology before and after laser cleaning process. Power spectral density function was calculated over large frequency range of 10{sup −1} to 10{sup −4} nm{sup −1} to understand topographic data.

  4. Cleaning of carbon layer from the gold films using a pulsed Nd:YAG laser

    Science.gov (United States)

    Singh, Amol; Choubey, Ambar; Modi, Mohammed H.; Upadhyaya, B. N.; Oak, S. M.; Lodha, G. S.; Deb, S. K.

    2013-10-01

    Hydrocarbon cracking and carbon contamination of optical elements in soft X-ray spectrometers and synchrotron radiation beamlines is a severe problem. Carbon contamination seriously affects the optics performance. In the present work, an Nd:YAG laser providing 2 mJ of pulse energy and 100 ns of pulse duration has been used for carbon cleaning experiments. The laser cleaning is a non-contact, accurate, efficient and safe process. A surface area of 48 cm2 having ∼20 nm thick carbon layer on gold surface has been removed with six number of laser passes and with 80% laser spot overlapping without any change in surface roughness of the underneath gold film. Effect of laser beam on gold film after carbon removal has been analyzed using X-ray photoelectron spectroscopy, soft X-ray reflectivity techniques. Atomic force microscopy was used to analyze surface morphology before and after laser cleaning process. Power spectral density function was calculated over large frequency range of 10-1 to 10-4 nm-1 to understand topographic data.

  5. High power operation of cladding pumped holmium-doped silica fibre lasers.

    Science.gov (United States)

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency.

  6. Application of 2-um wavelength holmium lasers for treatment of skin diseases

    Science.gov (United States)

    Shcherbakov, Ivan A.; Klimov, Igor V.; Tsvetkov, Vladimir B.; Nerobeev, Alexander I.; Sadovnikova, Lija B.; Eliseenko, Vladimir I.

    1994-09-01

    Theoretical and experimental analysis of the efficiency of application of 2 micrometers pulsed holmium laser for cosmetic and plastic surgery and dermatology is carried out. Preliminary experiments were carried out on rats. Solid state 2 micrometers pulsed laser was allowed to operate in free running mode with pulse energy up to 1.5 J and pulse repetition rate up to 5 Hz. To deliver emission to the object a flexible quartz fiber without further focusing of 2.5 m in length and 400 micrometers of the core diameter was used. The effect of the different power density emission on the skin was studied. The second stage was the study of the influence of 2 micrometers emission on human skin. The results of the removal of hemangioma, papilloma, telangiectasia, nevus, nevus acantholytic, xanthelasma palpebral, verruca, chloasma, pigmental spots, tattoos, etc. are presented. Precision, simplicity, efficiency, and the high cosmetic effect of these operations is noted.

  7. Synthesis and characterization of holmium oxide doped cadmium lead borate glasses

    Science.gov (United States)

    Alemi, A. A.; Sedghi, H.; Mirmohseni, A. R.; Golsanamlu, V.

    Holmium doped cadmium lead borate glasses were prepared from melting in appropriate proportions of a mixture of CdO, PbO2, H3BO3 and (1-2 mol %) Ho2O3 in the temperature range of 800-850 °C. The density of glass samples was measured using Archimedes Principle. The infrared spectra of the glasses in the range of 400-4000 cm-1 showed their structure systematically. No boroxol ring formation was observed in the structure of these glasses, but the conversion of 3-fold to 4-fold coordination of boron atoms in the structure of glasses was observed. The glass transition studies were done through differential scanning calorimetry. The optical analysis is done by using the Judd-Ofelt theory.

  8. Outcomes of flexible ureteroscopic lithotripsy with holmium laser for upper urinary tract calculi

    Directory of Open Access Journals (Sweden)

    Marcello Cocuzza

    2008-03-01

    Full Text Available OBJECTIVE: To assess the perioperative and financial outcomes of flexible ureteroscopic lithotripsy with holmium laser for upper tract calculi in 44 patients. MATERIALS AND METHODS: Between February 2004 and September 2006, 44 patients treated for upper tract stone with flexible ureteroscopic lithotripsy were evaluated. Renal stones were associated with collecting system obstruction in 15 (34% patients, failed extracorporeal shock-wave lithotripsy (SWL occurred in 14 (32% patients, unilateral multiple stones in 18 (41% patients, and multiple bilateral stones in 3 (7%. In 29 (66% patients, the stone was located in the inferior calyx. Perioperative and financial outcomes were also evaluated. RESULTS: 50 procedures were performed in 44 patients. The mean stone burden on preoperative CT scan was 11.5 ± 5.8 mm. The mean operative time was 61.3 ± 29.4 min. The stone free rate was 93.1% after one procedure and 97.7% after a second procedure, with overall complication rate of 8%. Therapeutic success occurred in 92% and 93% of patients with lower pole stones and SWL failure, respectively. Treatment failure of a single session was associated with presence of a stone size larger than 15 mm (p = 0.007, but not associated with inferior calyx location (p = 0.09. Surgical disposables were responsible for 78% of overall costs. CONCLUSION: Flexible ureteroscopy using holmium laser is a safe and effective option for the treatment of upper urinary tract calculi. In addition, it can be considered an attractive option as salvage therapy after SWL failure or kidney calculi associated with ureteral stones. Stone size larger than 15 mm is associated with single session treatment failure.

  9. Holmium laser assisted ′anatomical′ enucleation of adenoma of benign hyperplasia of prostate

    Directory of Open Access Journals (Sweden)

    Shivadeo S Bapat

    2006-01-01

    Full Text Available Aims: To present our technique of Holmium Laser assisted "ANATOMICAL" enucleation of the benign prostatic adenoma (HoLEP in 219 patients. Procedure is based on the principle of digital enucleation of the adenoma from its surgical capsule, but performed entirely by perurethral endoscopic technique assisted by Holmium Laser. Materials and Methods: From March 2001 to November 2004, 219 patients under went HoLEP. After the initial cuts from bladder neck to verumontanum at 5 and 7 o′clock position, capsule is identified. The beak of the resectoscope sheath was inserted in the plane between the capsule and the adenoma and the adenoma was physically pushed away towards the urethra from the capsule. Laser was used to coagulate the bleeders, to cut the mucosal attachments and tough stromal tissue. Procedure was repeated for median and two lateral lobes. There was minimal bleeding and fluid absorption. Complications were few. Results: In 206 cases successful enucleation of the adenoma was carried out. First 13 cases formed part of the learning curve and were completed by standard transurethral resection of prostate (TURP. IPSS score dropped from average of 23 to 8 and peak flow improved from 20. No patient had postoperative urinary incontinence or stricture. Conclusions: HoLEP is an effective alternative to TURP. Ultimate end results replicate the end results of open enucleation of BPH without its morbidity and have all the advantages of endoscopic surgery. It offers distinct advantages over standard TURP as the incidence of blood transfusion and fluid absorption are greatly minimized.

  10. Simulation of non-contact tonometer - Ocular response analyzer

    Directory of Open Access Journals (Sweden)

    M. Arsalan Khan

    2016-04-01

    Simultaneous explosion of ophthalmic knowledge and medical instrument, being made in the 19th century, has led to the invention of tonometers of varied designs and principles, and Non-Contact Tonometers (NCTs are among them. Glodmann Applanation Tonometer (GAT is considered the ‘gold standard’ in measuring IOP; however, IOP measurement using GAT is now known to be affected by various factors like corneal thickness, curvature and material properties as demonstrated by Khan [1]. Due to inaccuracies in measuring IOP by GAT, this ‘gold standard’ has been challenged. Therefore, the present research aims to develop a multi-parametric correction equation to determine the True Intraocular Pressure (IOPT using Non-Contact Tonometer and the current article focuses on evaluating the influence of individual parameters on IOP by NCT.

  11. Non-Contact Measurement Using A Laser Scanning Probe

    Science.gov (United States)

    Modjarrad, Amir

    1989-03-01

    Traditional high accuracy touch-trigger probing can now be complemented by high speed, non-contact, profile scanning to give another "dimension" to the three-dimensional Co-ordinate Measuring Machines (CMMs). Some of the features of a specially developed laser scanning probe together with the trade-offs involved in the design of inspection systems that use triangulation are examined. Applications of such a laser probe on CMMs are numerous since high speed scanning allows inspection of many different components and surfaces. For example, car body panels, tyre moulds, aircraft wing skins, turbine blades, wax and clay models, plastics, etc. Other applications include in-process surveillance in manufacturing and food processing, robotics vision and many others. Some of these applications are discussed and practical examples, case studies and experimental results are given with particular reference to use on CMMs. In conclusion, future developments and market trends in high speed non-contact measurement are discussed.

  12. Preamplifiers for non-contact capacitive biopotential measurements*

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F.

    2014-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF - typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF. PMID:24109979

  13. Preamplifiers for non-contact capacitive biopotential measurements.

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F

    2013-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35 um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF--typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF.

  14. Non-contact intracellular binding of chloroplasts in vivo

    Science.gov (United States)

    Li, Yuchao; Xin, Hongbao; Liu, Xiaoshuai; Li, Baojun

    2015-06-01

    Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner.

  15. Role of iron ions in YAG and YAP

    Energy Technology Data Exchange (ETDEWEB)

    Kvapil, J.; Kvapil, J.; Kubelka, J. (Monokrystaly, Turnov (Czechoslovakia)); Autrata, R. (Ceskoslovenska Akademie Ved, Brno. Ustav Pristrovoje Techniky)

    1983-01-01

    Spectroscopic properties of YAG doped with Fe were compared. YAG:Fe crystals grown under reducing atmosphere showed strong colouration whereas similar colouration in YAP:Fe was found after oxygen treatment. Nd/sup 3 +/ luminescence was effectively quenched by Fe ions in YAP, whereas Ce/sup 3 +/ luminescence was quenched by Fe ions in both the materials.

  16. Flash-lamp-pumped picosecond Nd:YAG regenerative amplifier

    Institute of Scientific and Technical Information of China (English)

    Bingyuan Zhang; Gang Li; Meng Chen; Guoju Wang; Yonggang Wang; Xiaoyu Ma

    2005-01-01

    @@ A flash-lamp-pumped Nd:YAG regenerative amplifier has been developed at 1.06 μm, seeded with 10-ps pulses from a diode-end-pumped and mode-locked Nd:YAG oscillator with homemade semiconductor saturable absorber mirror(SESAM).

  17. Computational unit for non-contact photonic system

    Science.gov (United States)

    Kochetov, Alexander V.; Skrylev, Pavel A.

    2005-06-01

    Requirements to the unified computational unit for non-contact photonic system have been formulated. Estimation of central processing unit performance and required memory size are calculated. Specialized microcontroller optimal to use as central processing unit has been selected. Memory chip types are determinated for system. The computational unit consists of central processing unit based on selected microcontroller, NVRAM memory, receiving circuit, SDRAM memory, control and power circuits. It functions, as performing unit that calculates required parameters ofrail track.

  18. Noncontacting measurement technologies for space propulsion condition monitoring

    Science.gov (United States)

    Randall, M. R.; Barkhoudarian, S.; Collins, J. J.; Schwartzbart, A.

    1987-01-01

    This paper describes four noncontacting measurement technologies that can be used in a turbopump condition monitoring system. The isotope wear analyzer, fiberoptic deflectometer, brushless torque-meter, and fiberoptic pyrometer can be used to monitor component wear, bearing degradation, instantaneous shaft torque, and turbine blade cracking, respectively. A complete turbopump condition monitoring system including these four technologies could predict remaining component life, thus reducing engine operating costs and increasing reliability.

  19. Non-contacting "snubber bearing" for passive magnetic bearing systems

    Energy Technology Data Exchange (ETDEWEB)

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  20. YAG Laser Treatment of Tinea Pedis

    OpenAIRE

    Ueda, Masahiro; KAGAWA, Kiichiro

    1985-01-01

    A clinical experiment on the treatment of tinea pedis infections (common as an athlete’s foot) was conducted using a pulsed Nd-YAG laser with an output energy of 0.5 joule/pulse and duration of 1 millisecond. The experiment was supported by 13 volunteers for skin samples used in this experiment. The treatment was performed with the following irradiation condition; an energy density of 400 joule/cm2 at a skin sample surface, a spot diameter of the laser beam on the surface of 0.4 mm and a re...

  1. Ion beam luminescence of Nd:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Khanlary, M. [Science and Technology, Pevensey Building, University of Sussex, Brighton BN1 9QH (United Kingdom); Department of Physics, Imam Khomeini International University, Qazvin, Iran (Iran, Islamic Republic of); Hole, D.E. [Science and Technology, Pevensey Building, University of Sussex, Brighton BN1 9QH (United Kingdom); Townsend, P.D. [Science and Technology, Pevensey Building, University of Sussex, Brighton BN1 9QH (United Kingdom)]. E-mail: p.d.townsend@sussex.ac.uk

    2005-01-01

    Luminescence recorded during ion beam implantation of Nd:YAG has proved valuable in sensing structural and local crystal field changes caused by waveguide fabrication in this laser material. The relative line intensities from Nd are sensitive to excitation rate and so the spectra differ strongly between H{sup +} and H2+ excitation, with further changes in the examples using He{sup +} and N{sup +} ions. The overall intensities are reduced at lower temperatures, as well as showing variations in relative line patterns. Some suggestions of component lines and weak broad bands are offered in terms of trace rare earth and other impurities.

  2. Cryogenic Yb: YAG Thin-Disk Laser

    Science.gov (United States)

    2016-09-09

    Spitzberg, "Cryogenic Yb3+-Doped Solid-State Lasers," IEEE Journ. of Sel. Topics in Quant. Elect., 13(3), 448-459 (2007). [3] S. Tokita, J. Kawanaka, M...Europe ( IEEE ,2005) ,CTu3 (2005). [4] D. C. Brown, J. M. Singley, E. Yager, J. W. Kuper, B. J. Lotito, L. L. Bennett, "Innovative high-power CW...Y. Sun, and R. W. Equall, "Yb:YAG Absorption at Ambient and Cryogenic Temperatures," IEEE Journ. Sel. Topics Quant. Elect. 11(3), 604-612 (2005

  3. Motion-compensated non-contact detection of heart rate

    Science.gov (United States)

    Yang, Lei; Liu, Ming; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua

    2015-12-01

    A new non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. This poses a great challenge to compensate the motion artifacts during measurements. In order to circumvent this problem, we have proposed the amplitude spectrum and phase spectrum adaptive filter. Comparing with the time-domain adaptive filter and independent component analysis, the amplitude spectrum and phase spectrum adaptive filter can suppress the interference caused by the two circuit differences and effectively compensate the motion artifacts. To make the device is much compact and portable, a photoelectric probe is designed. The measurement distance is from several centimeters up to several meters. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor.

  4. Measuring elastic constants using non-contact ultrasonic techniques

    Science.gov (United States)

    Edwards, R. S.; Perry, R.; Cleanthous, D.; Backhouse, D. J.; Moore, I. J.; Clough, A. R.; Stone, D. I.

    2012-05-01

    The use of ultrasound for measuring elastic constants and phase transitions is well established. Standard measurements use piezoelectric transducers requiring couplant and contact with the sample. Recently, non-destructive testing (NDT) has seen an increase in the use of non-contact ultrasonic techniques, for example electromagnetic acoustic transducers (EMATs) and laser ultrasound, due to their many benefits. For measurements of single crystals over a range of temperatures non-contact techniques could also bring many benefits. These techniques do not require couplant, and hence do not suffer from breaking of the bond between transducer and sample during thermal cycling, and will potentially lead to a simpler and more adaptable measurement system with lower risk of sample damage. We present recent work adapting EMAT advances from NDT to measurements of single crystals at cryogenic temperatures and illustrate this with measurements of magnetic phase transitions in Gd64Sc36 using both contact and non-contact transducers. We discuss the measurement techniques implemented to overcome noise problems, and a digital pulse-echo-overlap technique, using data analysis in the frequency domain to measure the velocity.

  5. Combustion synthesis of YAG:Ce and related phosphors

    Science.gov (United States)

    Gupta, K. V. K.; Muley, A.; Yadav, P.; Joshi, C. P.; Moharil, S. V.

    2011-11-01

    YAG:Ce is an important phosphor having applications in various fields ranging from solid state lighting to scintillation detectors. YAG phosphors doped with activators are mainly synthesized by solid state reaction techniques that require high sintering temperatures (above 1500°C) to eliminate YAM and YAP phases. Though several soft chemical routes have been explored for synthesis of YAG, most of these methods are complex and phase pure materials are not obtained in one step, but prolonged annealing at temperatures around 1000°C or above become necessary. One step combustion synthesis of YAG:Ce3+ and related phosphors carried out at 500°C furnace temperature is reported here. Activation with Ce3+ could be achieved during the synthesis without taking recourse to any post-combustion thermal treatment. LEDs prepared from the combustion synthesized YAG:Ce3+, exhibited properties comparable to those produced from the commercial phosphor.

  6. Molecular dynamics simulation of thermodynamic properties of YAG

    Institute of Scientific and Technical Information of China (English)

    Chen Jun; Chen Dong-Quan; Zhang Jing-Lin

    2007-01-01

    In this paper we study the thermodynamic properties of Y3Al5O12 (YAG) by using molecular dynamic method combined with two- and three-body potentials. The dependences of melting process, elastic constant and diffusion coefficient on temperature of crystal YAG are simulated and compared with the experimental results. Our results show that anion O has the biggest self-diffusivity and cation Y has the smallest self-diffusivity in a crystal YAG. The calculated diffusion activation energies of ions O, Al and Y are 282.55, 439.46, 469.71k J/mol, respectively. Comparing with experimental creep activation energy of YAG confirms that cation Y can restrict the diffusional creep rate of crystal YAG.

  7. Influence of ureter mirror holmium laser lithotripsy on blood rheology and oxidative stress in patients with upper ureteral calculi

    Institute of Scientific and Technical Information of China (English)

    Guo-Dong Chen; Jian Dong; Jun Ding; Guo-Bo Li; Chen-Xi Zhou

    2016-01-01

    Objective:To explore the influence of ureter mirror holmium laser lithotripsy on blood rheology and oxidative stress in patients with upper ureteral calculi.Methods:A total of 113 cases patients who underwent surgical treatment of ureter mirror holmium laser lithotripsy were divided into observation group (n=76) and the control group (n=37) according to different therapeutic methods. Patients in the observation group were treated by ureteroscopy holmium laser lithotripsy treatment and patients in control group were treated by open surgery treatment. Venous blood was collected ro test the blood rheology and oxidative stress indicators respectively in the preoperative and postoperative 1 d, 7 d after treatment.Results:The postoperative backlog of red blood cells increased performance first decreased after treatment in two groups, the plasma viscosity and whole blood viscosity, high shear viscosity of whole blood were increased after the stable trend, the postoperative hematocritg, plasma viscosity, whole blood viscosity, high shear viscosity of whole blood were significantly lower than the control group in the observation group 1 d and 7 d after operation; The postoperative Cor, MDA in two groups showed a rising trend, SOD showed a decreasing trend, the difference was statistically significant; MDA in observation group 1 d and 7 d after operation was significantly lower than the control group, SOD was significantly higher than control group in the same point in time.Conclusions:Patients with upper ureteral calculi treated by surgical treatment may cause abnormal blood rheology and oxidative stress. And compared with open surgery, ureteroscopy holmium laser lithotripsy is of smaller side effect, and is beneficial for postoperative recovery.

  8. Ureteroscopy and holmium laser lithotripsy: Is this procedure safe in pregnant women with ureteral stones at different locations?

    Directory of Open Access Journals (Sweden)

    Senol Adanur

    2014-06-01

    Full Text Available Objectives: The aim of this study was to assess the safety and effectiveness of ureteroscopy and Holmium: Yttrium-Aluminum-Garnet lithotripsy for the treatment of ureteral stones with different localizations in symptomatic pregnant women. Methods: A retrospective analysis was performed on 19 pregnant patients referred to our center between January 2005 and December 2012 with symptomatic hydronephrosis requiring surgical intervention. 7.5 F and 9.5 F semirigid ureterorenoscopy with Holmium laser lithotripsy was used for treatment in all patients. Complications were stratified according to modified Clavien criteria. Results: The mean age of patients was 25.4 (18-41 years, and the mean gestation duration was 24.8 (7-33 weeks. Six cases (31.5% had a history of stone. Solitary kidney secondary to previous nephrectomy was observed in 2 patients and 1 patient had a hypoplastic kidney. Abdominal ultrasonography was used as the main diagnostic tool. Mean stone size was 9.2 mm (6-13. The location of the stones was the lower, middle, and upper ureter in 8 (42.1%, 5 (26.3% and 6 (31.5% cases, respectively. All stones were fragmented with Holmium laser lithotripsy. Of the 19 patients, 11 (57.8% required doublr J stent insertion peroperatively. Intraoperative urological and obstetric complications were not observed. Postoperatively two complications were noted. According to Clavien criteria a complication was level 1, and the other was level 2. Conclusions: For treatment of pregnant women with symptomatic ureteral stones in every location, Holmium laser lithotripsy with a semirigid ureteroscopy can be used as judicious treatment. This approach is effective and safe with an acceptable complication rate.

  9. Scaling and passively Q-switch operation of a Nd:YAG laser pumped laterally through a YAG prism

    Science.gov (United States)

    Dascalu, T.; Salamu, G.; Sandu, O.; Dinca, M.; Pavel, N.

    2015-04-01

    We report on scaling of a laser configuration in which a YAG prism is used to couple the pump beam from a fiber-coupled diode laser directly into a Nd:YAG medium. Several resonator geometries have been investigated. In free generation regime laser pulses at 1.06 μm with energy of 22.1 mJ for the pump energy of 44.6 mJ were obtained from a 10.0 mm long, 1.0-at% Nd:YAG single crystal that had the high-reflectivity mirror coated directly on one of the laser crystal surface. The slope efficiency was 0.51. A similar uncoated Nd:YAG crystal placed in a plane-plane resonator delivered laser pulses with 17.8 mJ energy under the pump with 45.4 mJ energy, at 0.40 slope efficiency. Further, a passively Q-switched Nd:YAG/Cr4+:YAG composite ceramic laser pumped through a YAG prism has been built. Using a Cr4+:YAG saturable absorber of 0.85 initial transmission the device delivered laser pulses with 0.29 mJ energy and 11 ns duration. The output performances are compared to those obtained in a classical end-pumping scheme.

  10. Combined effect of fluoride varnish to Er:YAG or Nd:YAG laser on permeability of eroded root dentine.

    Science.gov (United States)

    Chiga, Sandra; Toro, Carmen Victoria Torres; Lepri, Taísa Penazzo; Turssi, Cecília Petroso; Colucci, Vivian; Corona, Silmara Aparecida Milori

    2016-04-01

    This study evaluated the combined effect of fluoride varnish to Er:YAG or Nd:YAG laser on permeability of eroded root dentine. Sixty slabs of bovine root dentine (2×2×2mm) were eroded with citric acid 0.3% (pH 3.2) during 2h and then kept in artificial saliva during 24h. Specimens were randomly assigned in 6 groups (n=10), to receive the following treatments: fluoride varnish; fluoride varnish+Er:YAG laser; fluoride varnish+Nd:YAG laser; non-fluoride varnish; non-fluoride varnish+Er:YAG laser; non-fluoride varnish+Nd:YAG laser. The Er:YAG (100mJ, 3Hz) and Nd:YAG (70mJ, 15Hz) were applied for 10s. Specimens were subjected to further erosive challenges with citric acid 0.3% 4×/day, during 1min, for 5 days, remaining in artificial saliva between cycles. Dentin permeability was then assessed. Two-way ANOVA demonstrated no significant interaction between laser and varnish (p=0.858). No effect was also detected for the main factor varnish (p=0.768), while permeability of eroded root dentin was significantly lower when such substrate was laser-irradiated, no matter the laser source (pfluoride varnish application. Copyright © 2016. Published by Elsevier Ltd.

  11. Use of radars to monitor stream discharge by noncontact methods

    Science.gov (United States)

    Costa, J.E.; Cheng, R.T.; Haeni, F.P.; Melcher, N.; Spicer, K.R.; Hayes, E.; Plant, W.; Hayes, K.; Teague, C.; Barrick, D.

    2006-01-01

    Conventional measurements of river flows are costly, time-consuming, and frequently dangerous. This report evaluates the use of a continuous wave microwave radar, a monostatic UHF Doppler radar, a pulsed Doppler microwave radar, and a ground-penetrating radar to measure river flows continuously over long periods and without touching the water with any instruments. The experiments duplicate the flow records from conventional stream gauging stations on the San Joaquin River in California and the Cowlitz River in Washington. The purpose of the experiments was to directly measure the parameters necessary to compute flow: surface velocity (converted to mean velocity) and cross-sectional area, thereby avoiding the uncertainty, complexity, and cost of maintaining rating curves. River channel cross sections were measured by ground-penetrating radar suspended above the river. River surface water velocity was obtained by Bragg scattering of microwave and UHF Doppler radars, and the surface velocity data were converted to mean velocity on the basis of detailed velocity profiles measured by current meters and hydroacoustic instruments. Experiments using these radars to acquire a continuous record of flow were conducted for 4 weeks on the San Joaquin River and for 16 weeks on the Cowlitz River. At the San Joaquin River the radar noncontact measurements produced discharges more than 20% higher than the other independent measurements in the early part of the experiment. After the first 3 days, the noncontact radar discharge measurements were within 5% of the rating values. On the Cowlitz River at Castle Rock, correlation coefficients between the USGS stream gauging station rating curve discharge and discharge computed from three different Doppler radar systems and GPR data over the 16 week experiment were 0.883, 0.969, and 0.992. Noncontact radar results were within a few percent of discharge values obtained by gauging station, current meter, and hydroacoustic methods. Time

  12. Comparison of trauma extent between transurethral plasmakinetic resection of the prostate and holmium laser enucleation treatment of BPH

    Institute of Scientific and Technical Information of China (English)

    Ying-Shu Zhen

    2016-01-01

    Objective:To study the trauma extent of transurethral plasmakinetic resection of the prostate and holmium laser enucleation treatment of BPH. Methods:A total of 134 cases of patients with benign prostatic hyperplasia were selected for study and randomly divided into PKRP group who received transurethral plasmakinetic resection of the prostate and HoLEP group who received transurethral holmium laser enucleation of the prostate, and serum prostate-specific antigen, cortin and medulla hormone as well as thyroid hormone content were detected. Results:1 d after operation, serum t-PSA and f-PSA content of both groups were higher than those before operation and serum t-PSA and f-PSA content of HoLEP group were lower than those of PKRP group, serum ACTH, COR, FC, CBG, NE, E and rT3 content of HoLEP group were significantly lower than those of PKRP group, FT3, TT3, FT4 and TT4 content were significantly higher than those of PKRP group, and TSH content was without significant difference;6 months after operation, serum t-PSA and f-PSA content of both groups were lower than those before operation and serum t-PSA and f-PSA content of HoLEP group were not different from those of PKRP group. Conclusion:Both transurethral plasmakinetic resection of the prostate and holmium laser enucleation can effectively remove hyperplastic prostate tissue, and the surgical trauma of HoLEP is less.

  13. Feasibility of Endovascular Radiation Therapy Using Holmium-166 Filled Balloon Catheter in a Swine Hemodialysis Fistula Model: Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong Yun; Lee, Kwang Hun; Lee, Do Yun [Dept. of Radiology, Research Institute of Radiological Science, Yensei University College of Medicine, Seoul (Korea, Republic of); Kim, Myoung Soo [Dept. of Radiology, Yensei University College of Medicine, Seoul (Korea, Republic of); Kang, Byung Chul [Dept. of Radiology, Internal Medicine, EwhaWoman' s University School of Medicine, Seoul (Korea, Republic of); Kim, Seung Jung [Dept. of Internal Medicine, EwhaWoman' s University School of Medicine, Seoul (Korea, Republic of)

    2011-08-15

    To describe how to make a swine hemodialysis fistula model and report our initial experience to test the feasibility of endovascular radiation therapy with Holmium-166 filled balloon catheters. The surgical formation of arterio-venous fistula (AVF) was performed by end-to-side anastomosis of the bilateral jugular vein and carotid artery of 6 pigs. After 4 weeks, angiograms were taken and endovascular radiation was delivered to the venous side of AVF with Holmium-166 filled balloon catheters. Pigs were sacrificed 4 weeks after the radiation and AVFs were harvested for histological examination. All animals survived without any morbidity during the experimental periods. The formation of fistula on the sides of necks was successful in 11 of the 12 pigs (92%). One AVF failed from the small jugular vein. On angiograms, 4 of the 11 AVFs showed total occlusion or significant stenosis and therefore, endovascular radiation could not be performed. Of 7 eligible AVFs, five underwent successful endovascular radiation and two AVFs did not undergo radiation for the control. Upon histologic analysis, one non-radiated AVF showed total occlusion and others showed intimal thickening from the neointimal hyperplasia. Formation of the swine carotid artery-jugular vein hemodialysis fistula model was successful. Endovascular radiation using a Holmium-166 filled balloon catheter was safe and feasible.

  14. Diode pumped Nd:YAG laser development

    Science.gov (United States)

    Reno, C. W.; Herzog, D. G.

    1976-01-01

    A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work.

  15. The growth of Nd: YAG single crystals

    Directory of Open Access Journals (Sweden)

    ANDREJA VALCIC

    2002-04-01

    Full Text Available Y3Al5O12 doped with 0.8 % wt. Nd (Nd:YAG single crystals were grown by the Czochralski technique under an argon atmosphere. The conditions for growing the Nd: YAG single crystals were calculated by using a combination of Reynolds and Grashof numbers. The critical crystal diameter and the critical rate of rotation were calculated from the hydrodynamics of the melt. The crystal diameter Dc = 1.5 cm remained constant during the crystal growth, while the critical rate of rotation changed from wc = 38 rpm after necking to wc = 13 rpm at the end of the crystal. The value of the rate of crystal growth was experimentally found to be 0.8–1.0 mm/h. According to our previous experiments, it was confirmed that 20 min exposure to conc. H3PO4 at 603 K was suitable for chemical polishing. Also, one-hour exposure to conc. H3PO4 at 493 K was found to be suitable for etching. The lattice parameter a = 1.201 (1 nm was determined by X-ray powder diffraction. The obtained results are discussed and compared with published data.

  16. Ablation of porcine ligamentum flavum with Ho:YAG, q-switched Ho:YAG, and quadrupled Nd:YAG lasers.

    Science.gov (United States)

    Johnson, Matt R; Codd, Patrick J; Hill, Westin M; Boettcher, Tara

    2015-12-01

    Ligamentum flavum (LF) is a tough, rubbery connective tissue providing a portion of the ligamentous stability to the spinal column, and in its hypertrophied state forms a significant compressive pathology in degenerative spinal stenosis. The interaction of lasers and this biological tissue have not been thoroughly studied. Technological advances improving endoscopic surgical access to the spinal canal makes selective removal of LF using small, flexible tools such as laser-coupled fiber optics increasingly attractive for treatment of debilitating spinal stenosis. Testing was performed to assess the effect of Ho:YAG, Q-switched Ho:YAG, and frequency quadrupled Nd:YAG lasers on samples of porcine LF. The objective was to evaluate the suitability of these lasers for surgical removal of LF. LF was resected from porcine spine within 2 hours of sacrifice and stored in saline until immediately prior to laser irradiation, which occurred within an additional 2 hours. The optical absorbance of a sample was measured over the spectral band from 190 to 2,360 nm both before and after dehydration. For the experiments using the Ho:YAG (λ = 2,080 nm, tp  = 140 µs, FWHM) and Q-Switched Ho:YAG (λ = 2,080 nm, tp  = 260 ns, FWHM) lasers, energy was delivered to the LF through a laser-fiber optic with 600 µm core and NA = 0.39. For the experiment using the frequency quadrupled Nd:YAG laser (λ = 266 nm, tp  = 5 ns FWHM), rather than applying the laser energy through a laser-fiber, the energy was focused through an aperture and lens directly onto the LF. Five experiments were conducted to evaluate the effect of the given lasers on LF. First, using the Ho:YAG laser, the single-pulse laser-hole depth versus laser fluence was measured with the laser-fiber in direct contact with the LF (1 g force) and with a standoff distance of 1 mm between the laser-fiber face and the LF. Second, with the LF remaining in situ and the spine bisected

  17. The evaluation of tissue mass loss in the incision line of prostate with benign hyperplasia performed using holmium laser and cutting electrode.

    Science.gov (United States)

    Szewczyk, Mariusz; Jesionek-Kupnicka, Dorota; Lipiński, Marek Ireneusz; Lipinski, Piotr; Różański, Waldemar

    2014-01-01

    The aim of this study is to compare the changes in the incision line of prostatic adenoma using a monopolar cutting electrode and holmium laser, as well as the assessment of associated tissue mass and volume loss of benign prostatic hyperplasia (BPH). The material used in this study consisted of 74 preparations of prostatic adenoma obtained via open retropubic adenomectomy, with an average volume of 120.7 ml. The material obtained cut in vitro before fixation in formaldehyde. One lobe was cut using holmium laser, the other using a monopolar cutting electrode. After the incision was made, tissue mass and volume loss were evaluated. Thermocoagulation changes in the incision line were examinedunder light microscope. In the case of the holmium laser incision, the average tissue mass loss was 1.73 g, tissue volume loss 3.57 ml and the depth of thermocoagulation was 1.17 mm. When the monopolar cutting electrode was used average tissue mass loss was 0.807 g, tissue volume loss 2.48 ml and the depth of thermocoagulation was 0.19 mm. Where holmium laser was used, it was observed that the layer of tissue with thermocoagulation changes was deeper than in the case of the monopolar cutting electrode. Moreover, it was noticed that holmium laser caused bigger tissue mass and volume loss than the cutting electrode.

  18. Method of preparation and structural properties of transparent YAG nanoceramics

    Science.gov (United States)

    Fedyk, Robert; Hreniak, Dariusz; Łojkowski, Witold; Stręk, Wiesław; Matysiak, Hubert; Grzanka, Ewa; Gierlotka, Stanisław; Mazur, Piotr

    2007-06-01

    Transparent Nd:YAG nanoceramics composed of nanosized grains were fabricated by high-pressure low temperature sintering technique (HPLT). Structural and morphological studies of the sintered pellets were carried out using X-ray powder diffraction and Transmission Electron Microscopy. The hardness of nanoceramics, extinction coefficient and transmittance spectra were measured and analyzed. The initial grain size of the YAG powder was 30 nm and no grain growth has taken place during the consolidation process. The density of the obtained nanoceramics was close to the theoretical density of YAG.

  19. Solvothermal synthesis of spherical YAG powders via different precipitants

    Energy Technology Data Exchange (ETDEWEB)

    Wu Zuogui [Department of Materials Science and Engineering, Shandong Institute of Light Industry, Jinan, Shandong 250353 (China); Zhang Xudong [Department of Materials Science and Engineering, Shandong Institute of Light Industry, Jinan, Shandong 250353 (China)], E-mail: wuzuogui11550@163.com; He Wen; Du Yuanwei; Jia Naitao; Liu Pengcheng; Bu Fanqing [Department of Materials Science and Engineering, Shandong Institute of Light Industry, Jinan, Shandong 250353 (China)

    2009-03-20

    Yttrium aluminum garnet (YAG) powders were synthesized by a solvothermal method under mild conditions with inexpensive aluminum and yttrium nitrates as the starting materials, and the ethylenediamine (EDA) solution as the solvent. Hydroxide precursors were synthesized by two different precipitating processes, in which urea or ammonium hydrogen carbonate was used as precipitant. The formation of YAG particle was investigated by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The TEM results showed that spherical YAG powders were successfully synthesized when ammonium hydrogen carbonate was used as precipitant.

  20. Lasing and thermal characteristics of Yb:YAG/YAG composite with atomic diffusion bonding

    Science.gov (United States)

    Sankar Nagisetty, Siva; Severova, Patricie; Miura, Taisuke; Smrž, Martin; Kon, Hitoe; Uomoto, Miyuki; Shimatsu, Takehito; Kawasaki, Masato; Higashiguchi, Takeshi; Endo, Akira; Mocek, Tomáš

    2017-01-01

    We demonstrated the laser performance of an Yb:YAG/YAG composite ceramic laser medium mounted on an aluminium heatsink via atomic diffusion bonding (ADB) technique using nanocrystalline metal films at room temperature in air. The surface temperature rise of the ADB bonded laser medium was linear with 57 °C lower than that of the commercially available soldered Yb:YAG thin disk at the pump power of 280 W. Moreover, the ADB disk was pumped 1.5 times higher (7.3 kW cm-2) than the typical damage threshold of the soldered disk without any sign of damage. The undoped capping may be effective for the suppression of ASE heating; however, according to the in situ OPD measurement it induces strong thermal lensing. The CW laser output power of 177 W was obtained at the pump power of 450 W with the optical-to-optical efficiency of 40% using V-shape cavity.

  1. Report on Non-Contact DC Electric Field Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Miles, R; Bond, T; Meyer, G

    2009-06-16

    This document reports on methods used to measure DC electrostatic fields in the range of 100 to 4000 V/m using a non-contact method. The project for which this report is written requires this capability. Non-contact measurements of DC fields is complicated by the effect of the accumulation of random space-charges near the sensors which interfere with the measurement of the field-of-interest and consequently, many forms of field measurements are either limited to AC measurements or use oscillating devices to create pseudo-AC fields. The intent of this document is to report on methods discussed in the literature for non-contact measurement of DC fields. Electric field meters report either the electric field expressed in volts per distance or the voltage measured with respect to a ground reference. Common commercial applications for measuring static (DC) electric fields include measurement of surface charge on materials near electronic equipment to prevent arcing which can destroy sensitive electronic components, measurement of the potential for lightning to strike buildings or other exposed assets, measurement of the electric fields under power lines to investigate potential health risks from exposure to EM fields and measurement of fields emanating from the brain for brain diagnostic purposes. Companies that make electric field sensors include Trek (Medina, NY), MKS Instruments, Boltek, Campbell Systems, Mission Instruments, Monroe Electronics, AlphaLab, Inc. and others. In addition to commercial vendors, there are research activities continuing in the MEMS and optical arenas to make compact devices using the principles applied to the larger commercial sensors.

  2. Pulsed Nd-YAG laser in endodontics

    Science.gov (United States)

    Ragot-Roy, Brigitte; Severin, Claude; Maquin, Michel

    1994-12-01

    The purpose of this study was to establish an operative method in endodontics. The effect of a pulsed Nd:YAG laser on root canal dentin has been examined with a scanning electron microscope. Our first experimentation was to observe the impacts carried out perpendicularly to root canal surface with a 200 micrometers fiber optic in the presence of dye. Secondarily, the optical fiber was used as an endodontic instrument with black dye. The irradiation was performed after root canal preparation (15/100 file or 40/100 file) or directly into the canal. Adverse effects are observed. The results show that laser irradiation on root canal dentin surfaces induces a nonhomogeneous modified dentin layer, melted and resolidified dentin closed partially dentinal tubules. The removal of debris is not efficient enough. The laser treatment seems to be indicated only for endodontic and periapical spaces sterilization after conventional root canal preparation.

  3. Crystallography of Alumina-YAG-Eutectic

    Science.gov (United States)

    Farmer, Serene C.; Sayir, Ali; Dickerson, Robert M.; Matson, Lawrence E.

    2000-01-01

    Multiple descriptions of the alumina-YAG eutectic crystallography appear in the ceramic literature. The orientation between two phases in a eutectic system has direct impact on residual stress, morphology, microstructural stability, and high temperature mechanical properties. A study to demonstrate that the different crystallographic relationships can be correlated with different growth constraints was undertaken. Fibers produced by Laser-Heated Float Zone (LHFZ) and Edge-defined Film-fed Growth (EFG) were examined. A map of the orientation relationship between Al2O3 and Y3Al5O12 and their relationship to the fiber growth axis as a function of pull rate are presented. Regions in which a single orientation predominates are identified.

  4. Demining with Nd:YAG laser

    Science.gov (United States)

    Rothacher, Thomas; Lüthy, Willy; Weber, Heinz P.

    2004-04-01

    Laser neutralization of antipersonnel (AP) mines offers the enormous advantage to work from a safe distance. In this article the interaction of Nd:YAG laser radiation and four different types of blast AP mines is investigated. For this purpose, a very compact laser system for mine neutralization is developed. The incident power on the mine surfaces is varied from 20 to 70 W. Neutralization of all mines is achieved from a safe distance up to 50 m. The mines burn and finally detonate after an irradiation time of a few minutes. Detonation of the irradiated burning mines is considerably weaker compared to fully functional mines. Therefore, expected damage in the surrounding area is significantly reduced.

  5. Algorithm describing pressure distribution of non-contact TNT explosion

    Directory of Open Access Journals (Sweden)

    Radosław Kiciński

    2014-12-01

    Full Text Available [b]Abstract[/b]. The aim of this study is to develop a computational algorithm, describing the shock wave pressure distribution in the space induced by non-contact TNT explosion. The procedure describes pressure distribution on a damp surface of the hull. Simulations have been carried out using Abaqus/CAE. The study also shows the pressure waveform descriptions provided by various authors and presents them in charts. The formulated conclusions convince efficiency of the algorithm application.[b]Keywords:[/b] Underwater explosion, shock wave, CAE, TNT, Kobben class submarine

  6. Microwave non-contact imaging of subcutaneous human body tissues

    Science.gov (United States)

    Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-01-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated. PMID:26609415

  7. Effects of noncontact cleaners on transparent solar materials

    Energy Technology Data Exchange (ETDEWEB)

    Hampton, H.L.; Lind, M.A.

    1979-04-01

    A brief study has been undertaken to evaluate the performance of noncontact cleaning agents for use on solar collectors. Several techniques are used to compare cleansing agents which have been recommended by their respective manufacturers for cleaning solar mirrors. Wetting and residue buildup properties are evaluated for over 50 of these commercially available cleaners. The wetting properties of each cleaner are evaluated by measuring the growth of the contact area of a constant volume drop as a function of time. Losses due to residue buildup are solar weighted and considered equally with the wetting parameters and cost figures to construct a figure of merit for cleaner comparison.

  8. Non-Contact Detection of Breathing Using a Microwave Sensor

    Science.gov (United States)

    Dei, Devis; Grazzini, Gilberto; Luzi, Guido; Pieraccini, Massimiliano; Atzeni, Carlo; Boncinelli, Sergio; Camiciottoli, Gianna; Castellani, Walter; Marsili, Massimo; Dico, Juri Lo

    2009-01-01

    In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume) has been found. PMID:22574033

  9. Non-Contact Detection of Breathing Using a Microwave Sensor

    Directory of Open Access Journals (Sweden)

    Massimo Marsili

    2009-04-01

    Full Text Available In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume has been found.

  10. Non-Contact Cardiac Activity Monitoring using Pulsed Laser Vibrometer

    Directory of Open Access Journals (Sweden)

    Chen Chia WANG

    2014-01-01

    Full Text Available We demonstrate experimentally the detection of detailed human cardiac mechanical activity in a remote, non-contacting, and non-ionizing manner using a pulsed laser vibrometer. The highly sensitive pulsed laser vibrometer allows the detection of the temporally-phased mechanical events occurring in individual cardiac cycles even from the surface of clothing-covered extremities of the subjects. Fine structures of the detected cardiac traces are identified with their meanings assigned and corroborated using accelerometer and electrocardiogram measurements obtained concurrently with the pulsed laser vibrometer studies.

  11. Noncontact monitoring of cardiorespiratory activity by electromagnetic coupling.

    Science.gov (United States)

    Teichmann, Daniel; Foussier, Jérôme; Jia, Jing; Leonhardt, Steffen; Walter, Marian

    2013-08-01

    In this paper, the method of noncontact monitoring of cardiorespiratory activity by electromagnetic coupling with human tissue is investigated. Two measurement modalities were joined: an inductive coupling sensor based on magnetic eddy current induction and a capacitive coupling sensor based on displacement current induction. The system's sensitivity to electric tissue properties and its dependence on motion are analyzed theoretically as well as experimentally for the inductive and capacitive coupling path. The potential of both coupling methods to assess respiration and pulse without contact and a minimum of thoracic wall motion was verified by laboratory experiments. The demonstrator was embedded in a chair to enable recording from the back part of the thorax.

  12. Microwave non-contact imaging of subcutaneous human body tissues.

    Science.gov (United States)

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  13. Crystal structure and luminescent properties of nanocrystalline YAG and YAG:Nd synthesized by sol-gel method

    Science.gov (United States)

    Zhydachevskii, Ya.; Syvorotka, I. I.; Vasylechko, L.; Sugak, D.; Borshchyshyn, I. D.; Luchechko, A. P.; Vakhula, Ya. I.; Ubizskii, S. B.; Vakiv, M. M.; Suchocki, A.

    2012-10-01

    The work describes results of synthesis of undoped and Nd-doped YAG nanopowders by sol-gel method using different complexing agents (ethylene glycol and citric acid) and characterization of the material by X-ray powder diffraction, scanning electron microscopy, photoluminescence and thermoluminescence techniques. Utilization of citrate sol-gel procedure using yttrium and aluminum nitrate nonahydrates as starting substances allowed to obtain highly stoichiometric and non-defected YAG and YAG:Nd nanocrystalline samples with good luminescence performance and low radiation storage efficiency.

  14. Sequence of oral bacterial co-adhesion and non-contact brushing

    NARCIS (Netherlands)

    van der Mei, H. C.; Rustema-Abbing, M.; Bruinsma, G. M.; Gottenbos, B.; Busscher, H. J.

    Non-contact plaque removal offers advantages in interproximal spaces, fissures, and pockets. It requires the generation of strong fluid flows and the inclusion of air bubbles to become effective. A pair of co-adhering streptococci and actinomyces has been used previously to demonstrate non-contact

  15. Energy transfer, volumetric expansion, and removal of oral biofilms by non-contact brushing

    NARCIS (Netherlands)

    Busscher, H. J.; Jager, D.; Finger, G.; Schaefer, N.; van der Mei, H. C.

    2010-01-01

    Non-contact removal of oral biofilms offers advantages beyond the reach of bristles, but it is unknown how energy transfer for removal from brush-to-biofilm occurs. In the present study we evaluated non-contact, oral biofilm removal by oscillating-rotating and sonic toothbrushes, and their acoustic

  16. Er:YAG laser radiation etching of enamel

    Science.gov (United States)

    Dostalova, Tatjana; Jelinkova, Helena; Krejsa, Otakar; Hamal, Karel; Kubelka, Jiri; Prochazka, Stanislav

    1996-12-01

    This study compares the effects of acid treatment and Er:YAG laser radiation on the enamel. The permanent human molars were used. Oval cavities in the buccal surface were prepared and the edges of cavities were irradiated by Er:YAG radiation. The energy of laser was 105 mJ and repetition rate 1 Hz. The radiation was focused by CaF2 lens and the sample was placed in the focus. Ten samples were etched by 35 percent phosphoric acid during 60 s. Than cavities were filled with composite resin following manufacturers directions. By laser etching the structure enamel in section was rougher. The optimal connection between the enamel and composite resin was achieved in 75 percent by acid etching and in 79.2 percent by Er:YAG laser etching. Er:YAG laser etching could be alternative method for etching of enamel.

  17. Optical properties of epitaxial YAG:Yb films

    Science.gov (United States)

    Ubizskii, S. B.; Matkovskii, A. O.; Melnyk, S. S.; Syvorotka, I. M.; Müller, V.; Peters, V.; Petermann, K.; Beyertt, A.; Giesen, A.

    2004-03-01

    This work deals with the investigation of the optical properties of epitaxial YAG:Yb films and their suitability as gain media for thin disk lasers. Epitaxial films of YAG:Yb were grown by the liquid phase epitaxy method in air on the (111)-oriented YAG substrates. The thickness of the grown layers was from 30 to 260 m. The melt composition was varied to obtain the desired doping level from 10 to 15% and to optimize the optical properties. The best epitaxial films were colourless and had an Yb3+ luminescence lifetime of more than 950 s, which is very close to the intrinsic lifetime of the Yb ions in the bulk YAG single crystals. These films were tested in a thin disk laser setup with 24 absorption passes of the 940 nm pumping beam. The maximum output power at 1.03 m wavelength in CW operation reached more than 60 W and the optical efficiency was close to 30%.

  18. Growth and characterization of YAG:Cr4+epitaxial films

    Science.gov (United States)

    Ubizskii, Sergii B.; Syvorotka, Igor M.; Melnyk, Sergii S.; Matkovskii, Andrej O.; Kopczynski, Krzysztof; Mierczyk, Zygmunt; Frukacz, Zygmunt

    1999-03-01

    Epitaxial films with thickness of 10 - 250 micrometers of yttrium aluminum garnet (YAG) doped with Cr were grown by liquid phase epitaxy technique on YAG:Nd substrates. Co-doping with Mg2+ is used to force the Cr4+ valent state formation. Dependence of absorption spectra of obtained films on melt-solution composition, growth conditions and thermal treatment in reducing and oxidizing atmospheres is studied. A very intensive absorption band in UV region with maximum at 275 nm was found both in co-doped and YAG:Mg2+ epifilms caused probably by oxygen vacancies compensating the excess charge of Mg2+. Its intensity correlates with Cr4+ content in the film in that way: it decreases with Cr4+ entering in the film. The absorption being characteristic for YAG:Cr4+ crystals is found in co-doped films grown at higher temperatures (1000 - 1100 degree(s)C). The processes occurring during annealing are discussed.

  19. Effect of Additive on Microstructure of Transparent YAG Ceramics

    Institute of Scientific and Technical Information of China (English)

    Sun Xudong; Wen Lei; Xiu Zhimeng; Huo Di; Li Xiaodong; Chi-Tay Tsai

    2005-01-01

    Transparent YAG (yttrium aluminum garnet) ceramics were fabricated by solid-state reaction method. Effect of additive (tetraethyl orthosilicate, TEOS) on microstructure of YAG ceramics was investigated. If the addition of TEOS is more than 3% (mass fraction), large amount of liquid phase can be yielded at grain boundaries, resulting in the formation of second phase particles at grain boundaries. If the addition is less than 0.05% (mass fraction), pores are entrapped in the grains. The suitable amount is 0.5% (mass fraction). A fully transparent YAG ceramic was fabricated by vacuum sintering at 1700 ℃ for 5 h. Optical transmittance of the YAG ceramic is 63% in the visible light wavelengths and 70% in the infrared wavelengths.

  20. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    2010-01-01

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  1. The bactericidal effect of a Genius Nd: YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; van der Reijden, W.A.; van Winkelhoff, A.J.; van der Weijden, G.A.

    2010-01-01

    Purpose: To evaluate the ‘in vitro’ bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. Methods: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  2. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    2010-01-01

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  3. 600-W lamp pumped CW Nd:YAG laser

    Institute of Scientific and Technical Information of China (English)

    Qiang Li(李强); Zhimin Wang(王志敏); Zhiyong Wang(王智勇); Zhensheng Yu(于振声); Hong Lei(雷訇); Jiang Guo(郭江); Gang Li(李港); Tiechuan Zuo(左铁钏)

    2003-01-01

    A lamp pumped CW Nd:YAG laser is presented in this paper for the requirement of industrial application.The main factors, which affect output power and beam quality of high power solid-state laser module, are theoretically analyzed. Total electro-optics efficiency of lamp pumped Nd:YAG crystal as high as 4.0% is obtained, and output power is higher than 647 W with beam parameter product 22 mm.mrad.

  4. Ho:YAG Single Crystal Fiber: Fabrication and Optical Characterization

    Science.gov (United States)

    2014-06-16

    diameter variations, two feedback systems are employed. First, a standard proportional-integral-derivative ( PID ) controller provides feedback from...broad emission band from 2050 – 2150 nm, and previous papers confirm the wavelength tuning capability of Ho:YAG solid state lasers [23]. Ho:YAG SCF... tuned across the spectral band, then the gain was measured and plotted as markers in Fig. 4 for the 10.5 cm piece, along with the measured emission

  5. Holmium laser enucleation of the prostate and retropubic prostatic adenomectomy: morbidity analysis and anesthesia considerations.

    Science.gov (United States)

    Soto-Mesa, D; Amorín-Díaz, M; Pérez-Arviza, L; Fernández-Pello Montes, S; Martín-Huéscar, A

    2015-11-01

    Holmium laser enucleation of the prostate (HoLEP) is an alternative to prostatic adenomectomy for the surgical treatment of benign prostatic hypertrophy. We analyzed our learning curve for this technique, and we compared it in a secondary manner with prostatic adenomectomy. A retrospective comparative study was conducted that included the first 100 cases of HoLEP performed in our center and the latest 50 cases of retropubic adenomectomy. We collected data on the patients, the surgery, the anesthesia, the perioperative variables, the anesthesia complications and the postoperative variables, with a 6-month follow-up. We analyzed the learning curve without mentors for HoLEP and compared the characteristics of HoLEP in 2 separate phases (learning and stabilization phases) with the latest retropubic prostatic adenomectomies performed. Intradural anesthesia was the most common technique. The transfusion needs, length of stay (PLocal anesthesia is a good choice for the anesthesia technique. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. A comparative study of donor formation in dysprosium, holmium, and erbium implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Emtsev, V.V.; Emtsev, V.V. Jr.; Poloskin, D.S.; Shek, E.I.; Sobolev, N.A. [Division of Solid State Electronics, Ioffe Physicotechnical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)

    1998-12-01

    Formation of donor centers in Czochralski grown silicon doped with dysprosium, holmium, and erbium is discussed. Donor states of three kinds are introduced in the implanted layers after annealing at T=700C. Shallow donor states with ionization energies between 20 and 40 meV are attributed to oxygen -related thermal donors. Other donor centers in the energy range of E{sub C}-(60...70) meV and E{sub C}-(100...120) meV appear to be dependent on dopants. After a 900C anneal strong changes in the donor formation are observed only in silicon doped with erbium. Instead of donors at E{sub C}-(118{+-}5) meV, new donor centres at E{sub C}-(145{+-}5) meV are formed. Reportedly, the latter ones are involved in the excitation process of the Er{sup 3+} ions with a characteristic luminescence line at {approx}1.54 {mu}m. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Microspheres of polyester loaded with Holmium-165: effect of gamma irradiation on the polymeric structure

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Mariangela de Burgos M. de; Pires, Geovanna; Lira, Rafael A. de; Geraldes, Adriana N.; Nascimento, Nanci; Melo, Vitor Hugo Soares de, E-mail: mbmazevedo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Kodama, Yasko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

    2011-07-01

    Biodegradable polymers containing radioactive isotopes have potential applications as delivery vehicles of beta radiation to the cancer tumors by brachytherapy. 166-Ho is an example of such radioisotope emitting high-energy beta particles, and also its gamma rays allow nuclear imaging in everywhere is applied. Among the biodegradable polymers, different types of poly(lactide) have been investigated in our laboratory, and poly(L-lactide) (PLLA) was used as substrate to prepare microparticles loaded with holmium acetylacetonate HoAcAc (PLLA-HoAcAc-MP). The aim of this study was to evaluate the stability of these microparticles to gamma radiation. The PLLA-HoAcAc-MP were irradiated in a nuclear reactor IEA-R1 at IPEN/CNEN-SP, and their stability studied out with gamma radiation of 25, 50 and 100 kGy doses. MP were characterized before and after irradiation by differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and con focal laser scanning microscopy (CLSM). Preliminary results showed that gamma radiation did not damage morphologically the prepared PLLA-HoAcAc-MP in the dose range studied, and this procedure may be an important tool for knowing the stabilities of the polymers studied as MP for possible application in brachytherapy. (author)

  8. Day-Case Holmium Laser Enucleation of the Prostate: Prospective Evaluation of 90 Consecutive Cases.

    Science.gov (United States)

    Comat, Vincent; Marquette, Thibault; Sutter, Willy; Bernhard, Jean-Christophe; Pasticier, Gilles; Capon, Gregoire; Bensadoun, Henri; Ferrière, Jean-Marie; Robert, Gregoire

    2017-09-28

    To prospectively assess the feasibility and safety of holmium laser enucleation of the prostate (HoLEP) as day-case surgery for the treatment of benign prostatic hyperplasia. A prospective observational study was conducted by a single surgeon between June 2012 and October 2015. Except for patients ineligible for day-case surgery due to unstable cardiovascular disease, all patients with lower urinary tract symptoms presumably due to benign prostatic hyperplasia were consecutively included. HoLEP procedures were performed at 8AM, and patients were discharged before 8PM. The urinary catheter was removed at home the following morning. The monitoring of complications related with surgery included systematic assessment of perioperative complications, phone call within 48 hours after surgery, and follow-up visits after 1 and 3 months. Intent-to-treat univariate and multivariate analysis was performed to identify risk factors for day-case surgery failure. Ninety among 211 HoLEP performed by the surgeon were selected for day-case surgery (43%). Hospital stay was Day-case surgery failure rate (including prolonged hospitalization and readmissions within 48 hours) was 20.0% (18/90). The overall complication rate was 36.7%, with a Clavien III complication rate of only 3.3%. Monocentric design and limited number of patients are the main limitations of this work. This prospective evaluation shows that day-case HoLEP may be performed by a trained surgeon with an appropriate patient selection.

  9. Holmium-doped ZBLAN fiber lasers at 1.2 μm

    Science.gov (United States)

    Zhu, X.; Zong, J.; Norwood, R. A.; Chavez-Person, A.; Peyghambarian, N.; Prasad, N.

    2012-02-01

    Holmium (Ho3+)-doped ZBLAN glasses have been investigated for the purpose of achieving efficient fiber lasers at 1.2 μm. Because of the long lifetime of the upper laser level and the small phonon energy in Ho3+-doped ZBLAN glasses, strong fluorescence at 1.2 μm that usually cannot be observed in Ho-doped silica glass has been measured. Fluorescence of 1 mol%, 3 mol%, and 6 mol% Ho3+-doped ZBLAN glasses are reported. The effect of cerium and terbium ions on the emission of Ho3+-doped ZBLAN glass has also been studied. Obstacles to achieving an efficient Ho3+-doped ZBLAN laser are analyzed and discussed. In studies of a commercial Ho3+-doped ZBLAN fiber laser, it was found that the 3 μm four-energy-level laser can easily overwhelm the 1.2 μm laser, which is a three-energy-level system having the same upper laser level with the 3 μm laser. In order to effectively suppress the competiting 3 μm transition, advanced Ho3+-doped ZBLAN fiber has been designed and fabricated for 1.2 μm fiber lasers. Fiber lasers at 1.2 μm using the new Ho3+-doped ZBLAN fiber have been developed. Our experiments demonstrate that the new Ho3+-doped ZBLAN fiber is an efficient gain medium for lasers at 1.2 μm.

  10. Pressure potential and stability analysis in an acoustical noncontact transportation

    Science.gov (United States)

    Li, J.; Liu, C. J.; Zhang, W. J.

    2017-01-01

    Near field acoustic traveling wave is one of the most popular principles in noncontact manipulations and transportations. The stability behavior is a key factor in the industrial applications of acoustical noncontact transportation. We present here an in-depth analysis of the transportation stability of a planar object levitated in near field acoustic traveling waves. To more accurately describe the pressure distributions on the radiation surface, a 3D nonlinear traveling wave model is presented. A closed form solution is derived based on the pressure potential to quantitatively calculate the restoring forces and moments under small disturbances. The physical explanations of the effects of fluid inertia and the effects of non-uniform pressure distributions are provided in detail. It is found that a vibration rail with tapered cross section provides more stable transportation than a rail with rectangular cross section. The present study sheds light on the issue of quantitative evaluation of stability in acoustic traveling waves and proposes three main factors that influence the stability: (a) vibration shape, (b) pressure distribution and (c) restoring force/moment. It helps to provide a better understanding of the physics behind the near field acoustic transportation and provide useful design and optimization tools for industrial applications.

  11. Non-Contact Heart Rate Monitoring Using Lab Color Space.

    Science.gov (United States)

    Rahman, Hamidur; Ahmed, Mobyen Uddin; Begum, Shahina

    2016-01-01

    Research progressing during the last decade focuses more on non-contact based systems to monitor Heart Rate (HR) which are simple, low-cost and comfortable to use. Most of the non-contact based systems are using RGB videos which is suitable for lab environment. However, it needs to progress considerably before they can be applied in real life applications. As luminance (light) has significance contribution on RGB videos HR monitoring using RGB videos are not efficient enough in real life applications in outdoor environment. This paper presents a HR monitoring method using Lab color facial video captured by a webcam of a laptop computer. Lab color space is device independent and HR can be extracted through facial skin color variation caused by blood circulation considering variable environmental light. Here, three different signal processing methods i.e., Fast Fourier Transform (FFT), Independent Component Analysis (ICA) and Principal Component Analysis (PCA) have been applied on the color channels in video recordings and blood volume pulse (BVP) has been extracted from the facial regions. In this study, HR is subsequently quantified and compare with a reference measurement. The result shows that high degrees of accuracy have been achieved compared to the reference measurements. Thus, this technology has significant potential for advancing personal health care, telemedicine and many real life applications such as driver monitoring.

  12. Non-Contact Conductivity Measurement for Automated Sample Processing Systems

    Science.gov (United States)

    Beegle, Luther W.; Kirby, James P.

    2012-01-01

    A new method has been developed for monitoring and control of automated sample processing and preparation especially focusing on desalting of samples before analytical analysis (described in more detail in Automated Desalting Apparatus, (NPO-45428), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 44). The use of non-contact conductivity probes, one at the inlet and one at the outlet of the solid phase sample preparation media, allows monitoring of the process, and acts as a trigger for the start of the next step in the sequence (see figure). At each step of the muti-step process, the system is flushed with low-conductivity water, which sets the system back to an overall low-conductivity state. This measurement then triggers the next stage of sample processing protocols, and greatly minimizes use of consumables. In the case of amino acid sample preparation for desalting, the conductivity measurement will define three key conditions for the sample preparation process. First, when the system is neutralized (low conductivity, by washing with excess de-ionized water); second, when the system is acidified, by washing with a strong acid (high conductivity); and third, when the system is at a basic condition of high pH (high conductivity). Taken together, this non-contact conductivity measurement for monitoring sample preparation will not only facilitate automation of the sample preparation and processing, but will also act as a way to optimize the operational time and use of consumables

  13. Non-contact biomedical photoacoustic and ultrasound imaging.

    Science.gov (United States)

    Rousseau, Guy; Gauthier, Bruno; Blouin, Alain; Monchalin, Jean-Pierre

    2012-06-01

    The detection of ultrasound in photoacoustic tomography (PAT) usually relies on ultrasonic transducers in contact with the biological tissue through a coupling medium. This is a major drawback for important potential applications such as surgery. Here we report the use of a remote optical method, derived from industrial laser-ultrasonics, to detect ultrasound in tissues. This approach enables non-contact PAT (NCPAT) without exceeding laser exposure safety limits. The sensitivity of the method is based on the use of suitably shaped detection laser pulses and a confocal Fabry-Perot interferometer in differential configuration. Reliable image reconstruction is obtained by measuring remotely the surface profile of the tissue with an optical coherence tomography system. The proposed method also allows non-contact ultrasound imaging (US) by applying a second reconstruction algorithm to the data acquired for NCPAT. Endogenous and exogenous inclusions exhibiting optical and acoustic contrasts were detected ex vivo in chicken breast and calf brain specimens. Inclusions down to 0.3 mm in size were detected at depths exceeding 1 cm. The method could expand the scope of photoacoustic and US to in-vivo biomedical applications where contact is impractical.

  14. Non-contact electromagnetic exciter design with linear control method

    Science.gov (United States)

    Wang, Lin; Xiong, Xianzhi; Xu, Hua

    2017-01-01

    A non-contact type force actuator is necessary for studying the dynamic performance of a high-speed spindle system owing to its high-speed operating conditions. A non-contact electromagnetic exciter is designed for identifying the dynamic coefficients of journal bearings in high-speed grinding spindles. A linear force control method is developed based on PID controller. The influence of amplitude and frequency of current, misalignment and rotational speed on magnetic field and excitation force is investigated based on two-dimensional finite element analysis. The electromagnetic excitation force is measured with the auxiliary coils and calibrated by load cells. The design is validated by the experimental results. Theoretical and experimental investigations show that the proposed design can accurately generate linear excitation force with sufficiently large amplitude and higher signal to noise ratio. Moreover, the fluctuations in force amplitude are reduced to a greater extent with the designed linear control method even when the air gap changes due to the rotor vibration at high-speed conditions. Besides, it is possible to apply various types of excitations: constant, synchronous, and non-synchronous excitation forces based on the proposed linear control method. This exciter can be used as linear-force exciting and controlling system for dynamic performance study of different high-speed rotor-bearing systems.

  15. Characterization of noncontact piezoelectric transducer with conically shaped piezoelement

    Science.gov (United States)

    Williams, James H., Jr.; Ochi, Simeon C. U.

    1988-01-01

    The characterization of a dynamic surface displacement transducer (IQI Model 501) by a noncontact method is presented. The transducer is designed for ultrasonic as well as acoustic emission measurements and, according to the manufacturer, its characteristic features include a flat frequency response range which is from 50 to 1000 kHz and a quality factor Q of less than unity. The characterization is based on the behavior of the transducer as a receiver and involves exciting the transducer directly by transient pulse input stress signals of quasi-electrostatic origin and observing its response in a digital storage oscilloscope. Theoretical models for studying the response of the transducer to pulse input stress signals and for generating pulse stress signals are presented. The characteristic features of the transducer which include the central frequency f sub o, quality factor Q, and flat frequency response range are obtained by this noncontact characterization technique and they compare favorably with those obtained by a tone burst method which are also presented.

  16. Non-contact biomedical photoacoustic and ultrasound imaging

    Science.gov (United States)

    Rousseau, Guy; Gauthier, Bruno; Blouin, Alain; Monchalin, Jean-Pierre

    2012-06-01

    The detection of ultrasound in photoacoustic tomography (PAT) usually relies on ultrasonic transducers in contact with the biological tissue through a coupling medium. This is a major drawback for important potential applications such as surgery. Here we report the use of a remote optical method, derived from industrial laser-ultrasonics, to detect ultrasound in tissues. This approach enables non-contact PAT (NCPAT) without exceeding laser exposure safety limits. The sensitivity of the method is based on the use of suitably shaped detection laser pulses and a confocal Fabry-Perot interferometer in differential configuration. Reliable image reconstruction is obtained by measuring remotely the surface profile of the tissue with an optical coherence tomography system. The proposed method also allows non-contact ultrasound imaging (US) by applying a second reconstruction algorithm to the data acquired for NCPAT. Endogenous and exogenous inclusions exhibiting optical and acoustic contrasts were detected ex vivo in chicken breast and calf brain specimens. Inclusions down to 0.3 mm in size were detected at depths exceeding 1 cm. The method could expand the scope of photoacoustic and US to in-vivo biomedical applications where contact is impractical.

  17. Microwave sensor design for noncontact process monitoring at elevated temperature

    Science.gov (United States)

    Yadam, Yugandhara Rao; Arunachalam, Kavitha

    2016-02-01

    In this work we present a microwave sensor for noncontact monitoring of liquid level at high temperatures. The sensor is a high gain, directional conical lensed horn antenna with narrow beam width (BW) designed for operation over 10 GHz - 15 GHz. Sensor design and optimization was carried out using 3D finite element method based electromagnetic (EM) simulation software HFSS®. A rectangular to circular waveguide feed was designed to convert TE10 to TE11 mode for wave propagation in the conical horn. Swept frequency simulations were carried out to optimize antenna flare angle and length to achieve better than -10 dB return loss (S11), standing wave ratio (SWR) less than 2.0, 20° half power BW (HPBW) and 15 dB gain over 10 GHz - 15 GHz. The sensor was fabricated using Aluminum and was characterized in an anechoic test box using a vector network analyzer (E5071C, Agilent Technologies, USA). Experimental results of noncontact level detection are presented for boiling water in a metal canister.

  18. Dry-contact and noncontact biopotential electrodes: methodological review.

    Science.gov (United States)

    Chi, Yu Mike; Jung, Tzyy-Ping; Cauwenberghs, Gert

    2010-01-01

    Recent demand and interest in wireless, mobile-based healthcare has driven significant interest towards developing alternative biopotential electrodes for patient physiological monitoring. The conventional wet adhesive Ag/AgCl electrodes used almost universally in clinical applications today provide an excellent signal but are cumbersome and irritating for mobile use. While electrodes that operate without gels, adhesives and even skin contact have been known for many decades, they have yet to achieve any acceptance for medical use. In addition, detailed knowledge and comparisons between different electrodes are not well known in the literature. In this paper, we explore the use of dry/noncontact electrodes for clinical use by first explaining the electrical models for dry, insulated and noncontact electrodes and show the performance limits, along with measured data. The theory and data show that the common practice of minimizing electrode resistance may not always be necessary and actually lead to increased noise depending on coupling capacitance. Theoretical analysis is followed by an extensive review of the latest dry electrode developments in the literature. The paper concludes with highlighting some of the novel systems that dry electrode technology has enabled for cardiac and neural monitoring followed by a discussion of the current challenges and a roadmap going forward.

  19. NON-CONTACT MEASUREMENT OF SCULPTURED SURFACE OF ROTATION

    Institute of Scientific and Technical Information of China (English)

    Zhang Guoxiong; Liu Shugui; Qiu Zurong; Yu Fusheng; Na Yonglin; Leng Changlin

    2004-01-01

    A method for measuring the sculptured surface of rotation by using coordinate measuring machine (CMM) and rotary table is proposed. The measurement is realized during the continuous rotation of the workpiece mounted on the rotary table while the probe moves along the generatrix of the surface step by step. This method possesses lots of advantages such as simplicity of probe motion, high reliability and efficiency. Some key techniques including calibration of the effective radius of the probing system, determination of the position of axis of rotation, auto-centering of the workpiece, data processing algorithm, are discussed. Approaches for determining the coordinates on measured surface, establishing workpiece coordinate system and surface fitting are presented in detail. The method can be used with contact or non-contact probes. Some fragile ceramic and plaster parts are measured by using the system consisting of a CMM, rotary table, motorized head and non-contact laser triangulation probe. The measuring uncertainty is about 0.02 mm which meets the general requirement in most cases.

  20. Theory of noncontact friction for atom-surface interactions

    CERN Document Server

    Jentschura, U D; DeKieviet, M

    2016-01-01

    The noncontact (van der Waals) friction is an interesting physical effect which has been the subject of controversial scientific discussion. The "direct" friction term due to the thermal fluctuations of the electromagnetic field leads to a friction force proportional to 1/Z^5 where Z is the atom-wall distance). The "backaction" friction term takes into account the feedback of thermal fluctuations of the atomic dipole moment onto the motion of the atom and scales as 1/Z^8. We investigate noncontact friction effects for the interactions of hydrogen, ground-state helium and metastable helium atoms with alpha-quartz (SiO_2), gold (Au) and calcium difluorite (CaF_2). We find that the backaction term dominates over the direct term induced by the thermal electromagnetic fluctuations inside the material, over wide distance ranges. The friction coefficients obtained for gold are smaller than those for SiO_2 and CaF_2 by several orders of magnitude.

  1. A non-contact fiber Bragg grating vibration sensor.

    Science.gov (United States)

    Li, Tianliang; Tan, Yuegang; Wei, Li; Zhou, Zude; Zheng, Kai; Guo, Yongxing

    2014-01-01

    A non-contact vibration sensor based on fiber Bragg grating (FBG) sensing has been proposed and studied in this paper. The principle of the sensor as well as simulation and experimental analyses are introduced. When the distance between the movable head and the measured shaft changed, the diaphragm deformed under magnetic coupling of the permanent magnet on the measured magnetic shaft. As a result, the center wavelength of the FBG connected to the diaphragm changed, based on which the vibration displacement of the rotating shaft could be obtained. Experimental results show that the resonant frequency of the sensor is about 1500 Hz and the working band ranges within 0-1300 Hz, which is consistent with the simulation analysis result; the sensitivity is -1.694 pm/μm and the linearity is 2.92% within a range of 2-2.4 mm. It can be used to conduct non-contact measurement on the vibration of the rotating shaft system.

  2. Deicing with Nd:YAG and CO2 lasers

    Science.gov (United States)

    Qi, Lijun; Zhu, Xiao; Zhu, Changhong; Guo, Fei; Zhu, Guangzhi; Gu, Shanqiang

    2010-11-01

    A model of deicing with Nd:YAG and CO2 lasers for simulation using ANSYS software is presented. Experiments with a 300-W, 1-ms, 60-Hz Nd:YAG laser and a 500- to 2000-W cw CO2 laser are reported. The Nd:YAG laser is considered as a volume thermal source, and the CO2 laser as a plane thermal source. The model and the simulation results can describe both Nd:YAG and CO2 laser deicing well. The results of the simulation and experiments suggest that the melting rates for the two lasers are almost equal at the same laser power density. So are the melting efficiencies. The hard and transparent ice irradiated by the Nd:YAG laser becomes opaque and loose, because the thermal stress is distributed in the body of the ice, while the ice irradiated by the CO2 laser is still transparent and hard, because thermal stress hardly occurs. So the laser with characteristics of high output power and large ice absorbing length can be selected for the power line laser deicing system, and Nd:YAG laser is more appropriate for power-line deicing than CO2 laser.

  3. Passive mode locking of a Nd:YAG laser with co-doped Nd, Cr:YAG as saturable absorber

    Institute of Scientific and Technical Information of China (English)

    Yang Lin(杨林); Feng Bao-Hua(冯宝华); Zhang Zhi-Guo(张治国); Gaebler Volker; Liu Bai-Ning(刘百宁); Eichler Hans

    2003-01-01

    We demonstrate the characteristics of relatively low saturation intensity using co-doped Nd, Cr:YAG as saturable absorber for passively mode locking the Nd:YAG laser. The difference of the saturation intensity between Q-switched and mode-locked operation in co-doped Nd, Cr:YAG was only one to two orders of magnitude, while Cr:YAG was generally reported at a difference of five orders of magnitude. More than 80% mode locking modulation depth was achieved at an incident pump power of 4.4W, corresponding to an intracavity intensity of 6 × 104W/cma2, using a 68cm long plano-concave cavity.

  4. Clinical application of the Nd-YAG and Ho-YAG lasers in otolaryngology: head and neck surgery

    Science.gov (United States)

    Kukwa, Andrzej; Tulibacki, Marek P.; Dudziec, Katarzyna; Wojtowicz, Piotr

    1997-10-01

    The authors present their clinical experience regarding the possibilities of application of Nd:YAG and Ho:YAG lasers for the treatment of disorders in the area of the upper respiratory tract sinuses and ears. This technique makes it possible to perform a number of procedures in local anesthesia which considerably improves the economic effectiveness of the treatment. In case of the Nd:YAG laser they have also utilized the effect of deep coagulation of the soft tissues, whereas the Ho:YAG laser energy was applied for the surgery of bone tissue. The surgeries performed using laser beam enabled very good effect of treatment. They are competitive compared wit the methods used by traditional surgery.

  5. The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin.

    Science.gov (United States)

    Nahas, Paul; Zeinoun, Toni; Majzoub, Zeina; Corbani, Karim; Nammour, Samir

    2016-01-01

    Objective. To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods. Sixty freshly extracted human third molars were randomly divided into five groups (n = 12). In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100 µs; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min), and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ). Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS) was applied and fractured surfaces were examined using scanning electron microscopy. Results. SBS values showed significant differences in 60 mJ (P flowable resin composite when it is used at the appropriate low level of energy density.

  6. Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(l-lactic acid) microspheres in healthy pigs

    Energy Technology Data Exchange (ETDEWEB)

    Vente, M.A.D.; Nijsen, J.F.W.; Wit, T.C. de; Schip, A.D. van het [University Medical Center Utrecht, Department of Nuclear Medicine, P.O. Box 85500, Utrecht (Netherlands); Seppenwoolde, J.H.; Seevinck, P.R. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Krijger, G.C. [Delft University of Technology, Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft (Netherlands); Huisman, A. [University Medical Center Utrecht, Department of Clinical Chemistry and Haematology, Utrecht (Netherlands); Zonnenberg, B.A. [University Medical Center Utrecht, Department of Internal Medicine, Utrecht (Netherlands); Ingh, T.S.G.A.M. van den [TCCI Consultancy B.V., P.O. Box 85032, Utrecht (Netherlands)

    2008-07-15

    The aim of this study is to evaluate the toxicity of holmium-166 poly(l-lactic acid) microspheres administered into the hepatic artery in pigs. Healthy pigs (20-30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres ({sup 165}HoMS; n = 5) or with holmium-166-loaded microspheres ({sup 166}HoMS; n = 13). The microspheres' biodistribution was assessed by single-photon emission computed tomography and/or MRI. The animals were monitored clinically, biochemically, and ({sup 166}HoMS group only) hematologically over a period of 1 month ({sup 165}HoMS group) or over 1 or 2 months ({sup 166}HoMS group). Finally, a pathological examination was undertaken. After microsphere administration, some animals exhibited a slightly diminished level of consciousness and a dip in appetite, both of which were transient. Four lethal adverse events occurred in the {sup 166}HoMS group due either to incorrect administration or comorbidity: inadvertent delivery of microspheres into the gastric wall (n = 2), preexisting gastric ulceration (n = 1), and endocarditis (n = 1). AST levels were transitorily elevated post-{sup 166}HoMS administration. In the other blood parameters, no abnormalities were observed. Nuclear scans were acquired from all animals from the {sup 166}HoMS group, and MRI scans were performed if available. In pigs from the {sup 166}HoMS group, atrophy of one or more liver lobes was frequently observed. The actual radioactivity distribution was assessed through ex vivo {sup 166m}Ho measurements. It can be concluded that the toxicity profile of HoMS is low. In pigs, hepatic arterial embolization with {sup 166}HoMS in amounts corresponding with liver-absorbed doses of over 100 Gy, if correctly administered, is not associated with clinically relevant side effects. This result offers a good perspective for upcoming patient trials. (orig.)

  7. Intratumoral administration of holmium-166 acetylacetonate microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer.

    Directory of Open Access Journals (Sweden)

    Wouter Bult

    Full Text Available PURPOSE: The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres ((166HoAcAcMS. This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. METHODS: (166HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice. Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. RESULTS: (166HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in (166HoAcAcMS treated mice (0.10±0.01 cm(3 vs. 4.15±0.3 cm(3 for control tumors. Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of (166HoAcAcMS in the kidney. CONCLUSIONS: Intratumorally administered (166HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities.

  8. Chemical decomposition of urinary stones during holmium-laser lithotripsy: II. Evidence for photothermal breakdown

    Science.gov (United States)

    Glickman, Randolph D.; Teichman, Joel M. H.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Pfefer, T. Joshua; Welch, Ashley J.

    1999-06-01

    Because of the greater than or equal to 250 microsecond pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures (cf. part I). The mass- loss of desiccated calcium oxalate monohydrate (COM) stones exposed to 150 J from the Ho:YAG laser in air was 40 plus or minus 12 mg (mean plus or minus 1 s.d.); for hydrated stones in air was 25 plus or minus 9 mg; and for hydrated stones in water was 17 plus or minus 3 mg, p less than .001. These differences indicate that direct absorption of the laser radiation by the stone is required for the most efficient ablation. Lowering the initial temperature of COM or cystine stones also reduced the stone mass-loss following 20 J of delivered laser energy: 2.2 plus or minus 1.1 mg vs 5.2 plus or minus 1.6 mg for COM stones (-80 vs 23 degrees Celsius), and 0.8 plus or minus 0.4 mg vs 2.2 plus or minus 1.1 mg for cystine stones (-80 vs 23 degrees Celsius), p less than or equal to .05. Finally, chemical analysis of the laser-induced stone fragments revealed the presence of thermal breakdown products: CaCO3 from COM; free sulfur and cysteine from cystine; Ca2O7P2 from calcium hydorgen phosphate dihydrate, and cyanide from uric acid.

  9. The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin

    Directory of Open Access Journals (Sweden)

    Paul Nahas

    2016-01-01

    Full Text Available Objective. To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods. Sixty freshly extracted human third molars were randomly divided into five groups (n=12. In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100 µs; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min, and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ. Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS was applied and fractured surfaces were examined using scanning electron microscopy. Results. SBS values showed significant differences in 60 mJ (P<0.05 compared to other groups. Morphological evaluation revealed tags or plugs in dentinal tubules, especially when 60 mJ and 80 mJ were used. All four groups tended to leave more residues on the dentin surface, than the control group. Conclusion. Er:YAG dentin irradiation may enhance SBS of the self-adhering flowable resin composite when it is used at the appropriate low level of energy density.

  10. The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin

    Science.gov (United States)

    Corbani, Karim

    2016-01-01

    Objective. To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods. Sixty freshly extracted human third molars were randomly divided into five groups (n = 12). In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100 µs; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min), and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ). Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS) was applied and fractured surfaces were examined using scanning electron microscopy. Results. SBS values showed significant differences in 60 mJ (P < 0.05) compared to other groups. Morphological evaluation revealed tags or plugs in dentinal tubules, especially when 60 mJ and 80 mJ were used. All four groups tended to leave more residues on the dentin surface, than the control group. Conclusion. Er:YAG dentin irradiation may enhance SBS of the self-adhering flowable resin composite when it is used at the appropriate low level of energy density. PMID:27830151

  11. Nd:YAG Laser Posterior Capsulotomy and Visual Outcome

    Directory of Open Access Journals (Sweden)

    Khaleda Nazneen Bari

    2013-05-01

    Full Text Available Background: Neodymium-doped yttrium aluminum garnet (Nd:YAG laser capsulotomy is a relatively noninvasive procedure that is used in the treatment of posterior capsular opacification (PCO. PCO is caused by proliferation of lens epithelial cells which causes fibrotic changes and wrinkling of the posterior capsule and results in decreased vision, glare, and other symptoms similar to that of the original cataract.Objective: To find out the visual outcome after performing Nd:YAG laser capsulotomy for PCO.Materials and method: A prospective clinical trial was carried out in National Institute of Ophthalmology (NIO, Dhaka, Bangladesh from January 2010 to June 2011 on purposively selected 70 adult subjects of both sexes who developed PCO within 2 months to more than 2 years after extracapsular cataract extraction with posterior chamber intra ocular lens implant. After thorough pre laser assessment Nd:YAG laser capsulotomy was carried out with Zeis VISULAS YAG II through Zeiss slit lamp under topical anesthesia. Data were recorded and expressed as proportion.Results: Out of the 70 subjects 40 were male and 30 were female. The average time interval of cataract surgery and Nd: YAG laser capsulotomy was 23 months. Capsular fibrosis (57.04% was the predominant type of PCO. The pre laser visual acuity (VA of more than 61.06% of eyes was 6/36 or below while 41.12% had VA hand movements to finger count. After Nd:YAG laser capsulotomy VA of 6/18 or better was achieved in 63.9% of eyes while 9.94% recovered to 6/9 and 11.36% achieved 6/6. None of these eyes showed further deterioration in VA.Conclusion: Nd:YAG laser capsulotomy for PCO is safe, effective and a rewarding procedure for improvement of vision.

  12. Sulcular debridement with pulsed Nd:YAG

    Science.gov (United States)

    Harris, David M.; Gregg, Robert H., II; McCarthy, Delwin K.; Colby, Leigh E.; Tilt, Lloyd V.

    2002-06-01

    We present data supporting the efficacy of the procedure, laser sulcular debridement (laser curettage), as an important component in the treatment of inflammatory periodontal disease. Laser Assisted New Attachment Procedure (LANAP) is a detailed protocol for the private practice treatment of gum disease that incorporates use of the PerioLase pulsed Nd:YAG Dental Laser for laser curettage. Laser curettage is the removal of diseased or inflamed soft tissue from the periodontal pocket with a surgical dental laser. The clinical trial conducted at The University of Texas HSC at San Antonio, Texas, evaluated laser curettage as an adjunct to scaling and root planing. They measured traditional periodontal clinical indices and used a questionnaire to evaluate patient comfort and acceptance. The Texas data (N=10 patients) are compared with pocket depth changes following LANAP. LANAP data were obtained from a retrospective review of patient records at three private practices (N=65). No significant differences in post treatment probe depth changes were found among the four centers indicating that the procedure produced consistent, favorable outcomes, and that results from controlled scientific clinical trials can be replicated in private practices. Reduction in pocket depths following laser treatment compare well with results obtained with scalpel surgery. The use of the laser offers additional benefits. We also present quantitative evidence from digitized radiographs of increased bone density in affected areas following LANAP.

  13. Specific heat of holmium and YNi{sub 2}B{sub 2}C. Criticalbehaviour and superconducting properties; Spezifische Waerme von Holmium und YNi{sub 2}B{sub 2}C. Kritisches Verhalten und supraleitende Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Bekkali, Abdelhakim

    2010-01-04

    Object of the thesis is the study of the specific heat of holmium and YNi{sub 2}B{sub 2}C in the temperature ranges from 50 to 200 KI respectively from 380 mK to 20 K in magnetic fields up to 9 T. In the present thesis the criticalbehaviour of YNi{sub 2}B{sub 2}C and properties of the superconducting state of tne non-magnetic rare-earth nickel borocarbide YNi{sub 2}B{sub 2}C are studied by means of a self-developed measurement apparatur of the specific heat using the quasi-adiabatic heating-pulse method as well as of holmium by means of the relaxation method. In this thesis reliable statements about the critical exponents on monocrystalline holmium could be made. The study on holmium proves that the critical behaviour of the specific heats cannot be described in the framework of the predictions of the chiral universality classes. By means of measurements of the specific heat in this thesis could be confirmed that YNi{sub 2}B{sub 2}C is a multiband superconductor. The positive curvature of the boundary line below T{sub c} in the phase diagram yields a first hint to the many-band character of YNI{sub 2}B{sub 2}C. In the zero-field the electronic specific heat in the superconducting state c{sub es}(T) can be not explained in the framework of the pure BCS theory. At low temperatures a residual contribution by normally conducting electrons could be detected, which hints to a not completely opened energy gap. A possible explanation would be that a band (or several bands) with low charge-carrier concentration not contribute to the superconductivity. This result agrees with de Haas-van Alphen measurements on isostructural superconducting LuNi{sub 2}B{sub 2}C monocrystals, which suggest the many-band character of the superconductivity as well as a vanishing energy gap in one band. The fluctuation behaviour of the specific heat of YNi{sub 2}B{sub 2}C in the neighbourhood of the superconducting-normally conducting transition agrees well with that of the 3D-XY model. [German

  14. Numerical analysis of the non-contacting gas face seals

    Science.gov (United States)

    Blasiak, S.

    2017-08-01

    The non-contacting gas face seals are used in high-performance devices where the main requirements are safety and reliability. Compliance with these requirements is made possible by careful research and analysis of physical processes related to, inter alia, fluid flow through the radial gap and ring oscillations susceptible to being housed in the enclosure under the influence of rotor kinematic forces. Elaborating and developing mathematical models describing these phenomena allows for more and more accurate analysis results. The paper presents results of studies on stationary ring oscillations made of different types of materials. The presented results of the research allow to determine which of the materials used causes the greatest amplitude of the vibration of the system fluid film-working rings.

  15. Biomedical Monitoring By A Novel Noncontact Radio Frequency Technology Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    The area of Space Health and Medicine is one of the NASA's Space Technology Grand Challenges. Space is an extreme environment which is not conducive to human life. The extraterrestrial environment can result in the deconditioning of various human physiological systems and thus require easy to use physiological monitoring technologies in order to better monitor space crews for appropriate health management and successful space missions and space operations. Furthermore, the Space Technology Roadmap's Technology Area Breakdown Structure calls for improvements in research to support human health and performance (Technology Area 06). To address these needs, this project investigated a potential noncontact and noninvasive radio frequency-based technique of monitoring central hemodynamic function in human research subjects in response to orthostatic stress.

  16. Non-contact feature detection using ultrasonic Lamb waves

    Science.gov (United States)

    Sinha, Dipen N [Los Alamos, NM

    2011-06-28

    Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

  17. A non-contacting instrument for direct stress mapping

    Science.gov (United States)

    Oliver, David E.

    An instrument called SPATE (stress pattern analysis by measurement of thermal emission) developed for noncontact measurements of stress in structures and components under cyclic load or vibration is described. The method is based on the phenomenon called the thermoelastic or Kelvin effect, whereby cyclic changes in the volume or pressure in a material produce cyclic temperature changes that are proportional to stress. The temperature changes measured by SPATE are totally reversible and are independent of heating due to material hysteresis damping. Two instrument was used to test structural materials including steels, aluminum alloys, a magnesium alloy, titanium, Nimonic 90, copper, brass, silicon nitride, Hylox 961, plexiglass, epoxy, polyester, rubber, Kevlar, wood, brick, concrete, 'live' bone, glass, boron, and various composites. The results of SPATE test on a stage-one turbine blade (tested at 9224 Hz) and a notched aluminum plate loaded in tension at 20 Hz are presented together with a diagram of the SPATE equipment.

  18. Modeling noncontact atomic force microscopy resolution on corrugated surfaces

    Directory of Open Access Journals (Sweden)

    Kristen M. Burson

    2012-03-01

    Full Text Available Key developments in NC-AFM have generally involved atomically flat crystalline surfaces. However, many surfaces of technological interest are not atomically flat. We discuss the experimental difficulties in obtaining high-resolution images of rough surfaces, with amorphous SiO2 as a specific case. We develop a quasi-1-D minimal model for noncontact atomic force microscopy, based on van der Waals interactions between a spherical tip and the surface, explicitly accounting for the corrugated substrate (modeled as a sinusoid. The model results show an attenuation of the topographic contours by ~30% for tip distances within 5 Å of the surface. Results also indicate a deviation from the Hamaker force law for a sphere interacting with a flat surface.

  19. Development of monolith Nd:YAG /Cr+4:YAG passively Q-switched microchip laser

    Science.gov (United States)

    Izhnin, Ihor; Vakiv, Mykola; Izhnin, Aleksandr; Syvorotka, Igor; Ubizskii, Sergii; Syvorotka, Ihor, Jr.

    2005-09-01

    The main features of passively Q-switched microchip lasers development are considered. The active medium of laser is an epitaxial structure combining an epitaxial layer of saturable absorber Cr4+:Y3Al5O12 (Cr:YAG) grown on substrate of generating crystal Nd:YAG by liquid phase epitaxy. The modulator layer has an initial optical absorption of 36 cm-1 at wavelength of lasing (1064 nm). The epitaxial layer grown on unworking side was mechanically removed and this substrate side was optically polished. The other one was processed precisely to needed thickness. The cavity's mirrors were deposited by electron beam technique directly on each side of the structure to form a rugged, monolithic resonator. Diode laser Model ATC-C4000 with lasing wavelength 808 nm provided the CW end pumping. The output pulses parameters were investigated by means of test bench consisting of photoelectric transducer FEK-15 and Digital Phosphor Oscilloscope TDS 5052B. The obtained laser parameter are as follows: pulse width (FWHM) about 1.3 ns, repetition rate 5.5 kHz, average output power about 10 mW, pulse energy 1.0 μJ, pick power 1.2 kW. The possible solutions for laser parameter improving and optimization are discussed.

  20. Factors affecting de novo urinary retention after Holmium laser enucleation of the prostate.

    Directory of Open Access Journals (Sweden)

    Sung Han Kim

    Full Text Available OBJECTIVE: Patients can experience urinary retention (UR after Holmium laser enucleation of the prostate (HoLEP that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP. MATERIALS AND METHODS: 336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37 and the non-urinary retention (non-UR; n = 299 groups. RESULTS: The mean age of patients was 68.3 (±6.5 years and the mean operative time was 75.3 (±37.4 min. Thirty seven patients (11.0% experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7 days after UR. With regard to the causes of UR, 24 (7.1% and 13 (3.9% patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p0.05. CONCLUSIONS: De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP.

  1. An international evaluation of holmium oxide solution reference materials for wavelength calibration in molecular absorption spectrophotometry.

    Science.gov (United States)

    Travis, John C; Zwinkels, Joanne C; Mercader, Flora; Ruíz, Arquímedes; Early, Edward A; Smith, Melody V; Noël, Mario; Maley, Marissa; Kramer, Gary W; Eckerle, Kenneth L; Duewer, David L

    2002-07-15

    Commercial spectrophotometers typically use absorption-based wavelength calibration reference materials to provide wavelength accuracy for their applications. Low-mass fractions of holmium oxide (Ho2O3) in dilute acidic aqueous solution and in glass matrixes have been favored for use as wavelength calibration materials on the basis of spectral coverage and absorption band shape. Both aqueous and glass Ho2O3 reference materials are available commercially and through various National Metrology Institutes (NMIs). Three NMIs of the North American Cooperation in Metrology (NORAMET) have evaluated the performance of Ho3-(aq)-based Certified Reference Materials (CRMs) under "routine" operating conditions using commercial instrumentation. The study was not intended to intercompare national wavelength scales but to demonstrate comparability of wavelength measurements among the participants and between two versions of the CRMs. It was also designed to acquire data from a variety of spectrophotometers for use in a NIST study of wavelength assignment algorithms and to provide a basis for a possible reassessment of NIST-certified Ho3+(aq) band locations. The resulting data show a substantial level of agreement among laboratories, instruments, CRM preparations, and peak-location algorithms. At the same time, it is demonstrated that the wavelength comparability of the five participating instruments can actually be improved by calibrating all of the instruments to the consensus Ho3+(aq) band locations. This finding supports the value of absorption-based wavelength standards for calibrating absorption spectrophotometers. Coupled with the demonstrated robustness of the band position values with respect to preparation and measurement conditions, it also supports the concept of extending the present approach to additional NMIs in order to certify properly prepared dilute acidic Ho2O3 solution as an intrinsic wavelength standard.

  2. Studies on therapeutic method of liver cancer(hapatocellular carcinome)by Holmium-166 radionuclide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Tae; Yoo, H. S.; Kim, M. J.; Han, K. H.; Park, C. I. [Yonsei University Medical College, Seoul (Korea, Republic of)

    1997-07-01

    As the study of radioactive nuclide, Holmium-166 in the treatment of liver cancer(hepatocellular carcinoma), this study was performed under the base of animal experimental. Using dog liver, percutaneous injection of Ho-166 MAA or chitosan with premade dose was done under the ultrasound guidance. Continuously the same procedure as previous one was performed in the skin hapatoma, which was developed by the injection of hepatocellular carcinoma cell in the nude mouse, In case of injected normal liver of dog, imaging study including ultrasound, CT and MRI was done in order to evaluate effect of Ho-166 and pathologic reaction. The result showed well defined nectosis of normal liver as well as skin hepatoma. The area of nectosis is dependent on the dose of injected Ho-166. Generally, pathologic reaction is tissue coagulation nectosis, Ho-166 particles, fibrosis and hemorrhage. In the clinical study, 50 patients with hapatoma was selected for this study under the agreement of patient. Under ultrasound guidance percutaneous injection of Ho-166 Maa or chitosan to tumor was performed and follow-up study was extended from 6 to 12 month. The result showed that 64% of patient were completely treated. Overall, the effect of treatment could be obtained in 41 patient (82%) among 50 hepatoma patient. Conclusively Ho-166 is thought to be a compromising agent in the treatment of hepatocellular carcinoma and one of therapeutic modality, if it is established internally and world-wide. In the future, the popular percutaneous ethanol injection method will be replaced to this method. 19 refs., 1 tabs., 14 figs. (author)

  3. Noncontact depth-resolved micro-scale corneal elastography

    Science.gov (United States)

    Wang, Shang; Larin, Kirill V.

    2015-03-01

    Noninvasive high-resolution depth-resolved measurement of corneal biomechanics is of great clinical significance for improving the diagnosis and optimizing the treatment of various degenerated ocular diseases. Here, we report a micro-scale optical coherence elastography (OCE) method that enables noncontact assessment of the depthwise elasticity distribution in the cornea. The OCE system combines a focused air-puff device with phase-sensitive optical coherence tomography (OCT). Low-pressure short-duration air stream is used to load the cornea with the localized displacement at micron level. The phase-resolved OCT detection with nano-scale sensitivity probes the induced corneal deformation at various locations within a scanning line, providing the ultra-fast imaging of the corneal lamb wave propagation. With spectral analysis, the amplitude spectra and the phase spectra are available for the estimation of the frequency range of the lamb wave and the quantification of the wave propagation, respectively. Curved propagation paths following the top and bottom corneal boundaries are selected inside the cornea for measuring the phase velocity of the lamb wave at the major frequency components over the whole depths. Our pilot experiments on ex vivo rabbit eyes indicate the distinct stiffness of different layers in the cornea, including the epithelium, the anterior stroma, the posterior stroma, and the innermost region, which demonstrates the feasibility of this micro-scale OCE method for noncontact depth-resolved corneal elastography. Also, the quantification of the lamb wave dispersion in the cornea could lead to the measurement of the elastic modulus, suggesting the potential of this method for quantitative monitoring of the corneal biomechanics.

  4. Low-power noncontact photoacoustic microscope for bioimaging applications

    Science.gov (United States)

    Sathiyamoorthy, Krishnan; Strohm, Eric M.; Kolios, Michael C.

    2017-04-01

    An inexpensive noncontact photoacoustic (PA) imaging system using a low-power continuous wave laser and a kilohertz-range microphone has been developed. The system operates in both optical and PA imaging modes and is designed to be compatible with conventional optical microscopes. Aqueous coupling fluids are not required for the detection of the PA signals; air is used as the coupling medium. The main component of the PA system is a custom designed PA imaging sensor that consists of an air-filled sample chamber and a resonator chamber that isolates a standard kilohertz frequency microphone from the input laser. A sample to be examined is placed on the glass substrate inside the chamber. A laser focused to a small spot by a 40× objective onto the substrate enables generation of PA signals from the sample. Raster scanning the laser over the sample with micrometer-sized steps enables high-resolution PA images to be generated. A lateral resolution of 1.37 μm was achieved in this proof of concept study, which can be further improved using a higher numerical aperture objective. The application of the system was investigated on a red blood cell, with a noise-equivalent detection sensitivity of 43,887 hemoglobin molecules (72.88×10-21 mol or 72.88 zeptomol). The minimum pressure detectable limit of the system was 19.1 μPa. This inexpensive, compact noncontact PA sensor is easily integrated with existing commercial optical microscopes, enabling optical and PA imaging of the same sample. Applications include forensic measurements, blood coagulation tests, and monitoring the penetration of drugs into human membrane.

  5. Noncontact laser sensing technology for structural health monitoring and nondestructive testing (presentation video)

    Science.gov (United States)

    Sohn, Hoon

    2014-03-01

    Noncontact sensing techniques is gaining prominence for structural health monitoring (SHM) and nondestructive testing (NDT) due to (1) their noncontact and nonintrusive natures, (2) their spatial resolution much higher than conventional discrete sensors can achieve, (3) their less dependency on baseline data obtained from the pristine condition of a target structure (reference-free diagnosis), (4) cost and labor reduction in sensor installation and maintenance. In this talk, a suite of noncontact sensing techniques particularly based on laser technology will be presented for SHM and NDT of aircraft, wind turbine blades, high-speed trains, nuclear power plants, bridges, automobile manufacturing facilities and semiconductors.

  6. Simultaneous drift, microsaccades, and ocular microtremor measurement from a single noncontact far-field optical sensor

    Science.gov (United States)

    Ryle, James P.; Vohnsen, Brian; Sheridan, John T.

    2015-02-01

    We report on the combined far-field measurement of the three involuntary eye movements, drift, microsaccades, and ocular microtremor (OMT), using a noncontact far-field optical method. We review the significance of the smallest and least measured, and thus least understood, of the three, OMT. Using modern digital imaging techniques, we perform detailed analysis, present experimental results, and examine the extracted parameters using a noncontact far-field sensor. For the first time, in vivo noncontact measurements of all three fixational in-plane movements of the human eye are reported, which simultaneously provide both the horizontal (left-right) and vertical (up-down) displacement results.

  7. Er:YAG laser debonding of porcelain veneers

    Science.gov (United States)

    Buu, Natalie; Morford, Cynthia; Finzen, Frederick; Sharma, Arun; Rechmann, Peter

    2010-02-01

    The removal of porcelain veneers using Er:YAG lasers has not been previously described in the scientific literature. This study was designed to systematically investigate the efficacy of an Er:YAG laser on veneer debonding without damaging the underlying tooth structure, as well as preserving a new or misplaced veneer. Initially, Fourier Transform Infrared Spectroscopy (FTIR) was used on flat porcelain veneer samples (IPS Empress Esthetic; Ivoclar Vivadent, Amherst, NY) to assess which infrared laser wavelengths are transmitted through the veneer. Additionally, FTIR spectra from a veneer bonding cement (RelyX Veneer Cement A1; 3M ESPE, St. Paul, MN) were obtained. While the veneer material showed no characteristic water absorption bands in the FTIR, the bonding cement has a broad H2O/OH absorption band coinciding with the ER:YAG laser emission wavelength. Consequently Er:YAG laser energy transmission through different veneer thicknesses was measured. The porcelain veneers transmitted 11 - 18 % of the incident Er:YAG laser energy depending on their thicknesses (Er:YAG laser: LiteTouch by Syneron; wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 μs at 133 mJ/pulse; straight sapphire tip 1,100 μm diameter; Syneron, Yokneam, Israel). Initial signs of cement ablation occurred at approximately 1.8 - 4.0 J/cm2. This can be achieved by irradiating through the veneer with the fiber tip positioned at a distance of 3-6 mm from the veneer surface, and operating the Er:YAG laser with 133 mJ output energy. All eleven veneers bonded on extracted anterior incisor teeth were easily removed using the Er:YAG laser. The removal occurred without damaging underlying tooth structure as verified by light microscopic investigation (Incident Light Microscope Olympus B 50, Micropublisher RTV 3.3 MP, Image Pro software, Olympus). The debonding mainly occurred at the cement/veneer interface. When the samples were stored in saline solution for 5 days and/or an air-waterspray was

  8. Oberservation of long term effect of transurethral noncontact laser ablation of the prostate%经尿道激光切除前列腺远期疗效观察

    Institute of Scientific and Technical Information of China (English)

    薛建; 马立萍; 王俊生; 庄红雨

    2001-01-01

    Objective To evaluation the long term effect of transurethral noncontact laser ablation of the prostate.Methods Two hundred and fifty-eight cases of benign prostatic hypertrophy (BPH) were treated by transurethral noncontact laser (Nd:YAG) ablation with the power fixed at 60W and lighted 60 second for each point.Results The patients were followed up in an average period of 3.2 years.The subjuctive and objective effects of the treatment were about 80% respectively.Conclusions Transurethral noncontact laser ablation of the prostate is effective in the treatment of BPH patients.It has the benefit of less bleeding and less suffering.%目的 评价激光治疗前列腺增生症患者的远期疗效。方法 应用Nd:YAG激光仪,对258例前列腺增生症患者进行经尿道非接触式激光治疗并随访。功率60W,每点照射60秒,一般照射4~24点。结果 治疗后平均随访3.2年,258例患者主、客观总有效率均在80%左右。结论 经尿道非接触式激光切除前列腺手术具有出血少及对病人打击小的特点,更适于年老体弱患者,是治疗前列腺增生症患者的有效方法之一。

  9. Clinical application of erbium:YAG laser in periodontology.

    Science.gov (United States)

    Ishikawa, Isao; Aoki, Akira; Takasaki, Aristeo Atsushi

    2008-01-01

    Various lasers have been introduced for the treatment of oral diseases and their applications in dental clinics have become a topic of much interest among practitioners. Technological advances and improvements have increased the choices of the available laser systems for oral use. Among them, a recently developed erbium-doped:yttrium aluminum garnet (Er:YAG) laser system possesses suitable characteristics for oral soft and hard tissue ablation. Due to its high absorption in water, an effective ablation with a very thin surface interaction occurs on the irradiated tissues without any major thermal damage to the irradiated and surrounding tissues. In the field of periodontics, the application of Er:YAG laser for periodontal hard tissue has begun with studies from Japanese and German researchers. Several in vitro and clinical studies have already demonstrated an effective application of the Er:YAG laser for calculus removal and decontamination of the diseased root surface in periodontal non-surgical and surgical procedures. However, further studies are required to better understand the various effects of Er:YAG laser irradiation on biological tissues for its safe and effective application during periodontal and implant therapy. Randomized controlled clinical trials and more basic studies have to be encouraged and performed to confirm the status of Er:YAG laser treatment as an adjunct or alternative to conventional mechanical periodontal therapy. In this paper, the advantages and current clinical applications of this laser in periodontics and implant dentistry are summarized based on current scientific evidence.

  10. 2.05 µm holmium-doped all-fiber laser diode-pumped at 1.125 µm

    Science.gov (United States)

    Kir'yanov, A. V.; Barmenkov, Y. O.; Villegas Garcia, I.

    2017-08-01

    We report a holmium-doped all-fiber laser oscillating at ~2.05 µm in continuous wave at direct in-core pumping by a 1.125 µm laser diode. Two types of home-made holmium-doped alumino-germano-silicate fiber (HDF), differentiated in the Ho3+ doping level, were fabricated to implement the laser, for revealing the effect of Ho3+ concentration upon the laser output. Firstly, the fibers were characterized thoroughly from the material and optical viewpoints. Then, laser action with both HDFs was assessed using the simplest Fabry-Perot cavity, assembled by a couple of spectrally adjusted fiber Bragg gratings, also made-in-house. In the best case, when using the lower-doped HDF of proper length (1.4 m), low threshold (~370 mW) and moderate slope efficiency (~13%) of ~2.05 µm lasing were obtained at 1.125 µm diode pumping. Long-term stability, high brightness, low noise, and purely CW operation are shown to be the laser’s attractive features. Yet, when utilizing the heavier-doped HDF, laser output is revealed to be overall worse, with a possible reason being the deteriorating Ho3+ concentration-related effects.

  11. Electrochemical formation of holmium-copper alloys on copper cathode in molten KCl-HoCl3

    Institute of Scientific and Technical Information of China (English)

    SU Yu-zhi; YANG Qi-qin; LIU Guan-kun

    2006-01-01

    Cyclic voltammetry, open circuit potential-time curve after potentiostatic electrolysis and potential step chronoamperometry were used to investigate the electrochemical formation processes of holmium-copper alloys on copper cathode in molten HoCl3-KCl. Intermetallic compounds HoCu5, HoCu4, HoCu2 and HoCu are formed in sequence and then the metallic Ho is deposited when Ho3+ is reduced on copper electrode in molten KCl-HoCl3 at 1 066 K. The first charge-transfer reaction is reversible. The structure of holmium-copper alloy film deposited on copper electrode by potentiostatic electrolysis was characterized by X-ray diffraction. The standard free energies of formation for the intermetallic compounds HoCu5, HoCu4, HoCu2 and HoCu are -95.5, -92.6, -73.8 and -44.0 kJ/mol, respectively. The diffusion coefficient and diffusion activation energy of Ho atom in the alloy are estimated to be 10-10-10-11 cm2/s and 75.35 kJ/mol, respectively, from the chronoamperometry data.

  12. Predictors of Clinical Outcomes of Flexible Ureterorenoscopy with Holmium Laser for Renal Stone Greater than 2 cm

    Directory of Open Access Journals (Sweden)

    Saeed M. Al-Qahtani

    2012-01-01

    Full Text Available Objective. To evaluate the clinical outcome of flexible ureterorenoscopy (F-URS with holmium laser in managing renal stone greater than 2 cm. Patients and Methods. Records of 120 patients (123 renal units with renal stone greater than 2 cm who underwent F-URS with holmium laser iwere evaluated. The mean stone size was 26.3 mm. Patient and stone characteristics, perioperative outcomes and complications were evaluated. The outcome was determined at 4 weeks on plain radiograph (KUB and Non-contrast CT scan (NCCT. Follow-up visit was up to 6 months to evaluate the clinical outcome and patients symptoms. Results. Stone burden was an independent predictor of FURS results. After first session of treatment, success rate was obtained in 72 renal units (58.5%. On the other hand, significant residual fragment was encountered in 51 renal units (41.5%. This was improved with “staged-therapy” to 87% and 96.7% after second and third session of treatment, respectively. Complications were recorded. They were managed in proper manner accordingly. Conclusion. This is an attractive, safe and effective technique. It is an ideal option for low volume complex stone with average burdens of 2 to 3 cm. Patient should be informed and consented about staged-therapy.

  13. Pump beam waist-dependent pulse energy generation in Nd:YAG/Cr4+:YAG passively Q-switched microchip laser

    Science.gov (United States)

    Li, Chao-yu; Dong, Jun

    2016-08-01

    The incident pump beam waist-dependent pulse energy generation in Nd:YAG/Cr4+:YAG composite crystal passively Q-switched microchip laser has been investigated experimentally and theoretically by moving the Nd:YAG/Cr4+:YAG composite crystal along the pump beam direction. Highest pulse energy of 0.4 mJ has been generated when the Nd:YAG/Cr4+:YAG composite crystal is moved about 6 mm away from the focused pump beam waist. Laser pulses with pulse width of 1.7 ns and peak power of over 235 kW have been achieved. The theoretically calculated effective laser beam area at different positions of Nd:YAG/Cr4+:YAG composite crystal along the pump beam direction is in good agreement with the experimental results. The highest peak power can be generated by adjusting the pump beam waist incident on the Nd:YAG/Cr4+:YAG composite crystal to optimize the effective laser beam area in passively Q-switched microchip laser.

  14. Sintering of transparent Nd:YAG ceramics in oxygen atmosphere

    Institute of Scientific and Technical Information of China (English)

    HUANG Yihua; JIANG Dongliang; ZHANG Jingxian; LIN Qingling; HUANG Zhengren

    2013-01-01

    Yttrium aluminum garnet (YAG) transparent ceramics were fabricated by sintering at oxygen atmosphere.Tetraethyl orthosilicate (TEOS) was added as the sintering additive to control the grain growth and densification.Pores were eliminated clearly at temperature lower than 1700 ℃,while grain size was around 3 μm.The in-line transmittance was 80% at 1064 nm when samples vere sintered at 1710 ℃.The effect of TEOS was studied in oxygen atmosphere sintering for Nd:YAG transparent ceramics.At higher temperature like 1710 ℃,the grain growth mechanism was solute drag,while at 1630 and 1550 ℃ the grain growth was controlled by liquid phase sintering mechanism.And 0.5 wt.% TEOS was the best adding content for Nd:YAG sintered in oxygen atmosphere.

  15. Growth of single-crystal YAG fiber optics.

    Science.gov (United States)

    Nie, Craig D; Bera, Subhabrata; Harrington, James A

    2016-07-11

    Single-crystal YAG (Y3Al5O12) fibers have been grown by the laser heated pedestal growth technique with losses as low as 0.3 dB/m at 1.06 μm. These YAG fibers are as long as about 60 cm with diameters around 330 μm. The early fibers were grown from unoriented YAG seed fibers and these fibers exhibited facet steps or ridges on the surface of the fiber. However, recently we have grown fibers using an oriented seed to grow step-free fibers. Scattering losses made on the fibers indicate that the scattering losses are equal to about 30% of the total loss.

  16. Electrically Tunable Nd:YAG waveguide laser based on Graphene

    Science.gov (United States)

    Ma, Linan; Tan, Yang; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

    2016-11-01

    We demonstrate a tunable hybrid Graphene-Nd:YAG cladding waveguide laser exploiting the electro-optic and the Joule heating effects of Graphene. A cladding Nd:YAG waveguide was fabricated by the ion irradiation. The multi-layer graphene were transferred onto the waveguide surface as the saturable absorber to get the Q-switched pulsed laser oscillation in the waveguide. Composing with appropriate electrodes, graphene based capacitance and heater were formed on the surface of the Nd:YAG waveguide. Through electrical control of graphene, the state of the hybrid waveguide laser was turned on or off. And the laser operation of the hybrid waveguide was electrically tuned between the continuous wave laser and the nanosecond pulsed laser.

  17. A Coprecipitation Coating Synthesis of SiC/YAG Composites

    Institute of Scientific and Technical Information of China (English)

    Ning ZHANG; Hongqiang RU; Xudong SUN; Qingkui CAI

    2004-01-01

    The α-SiC in 0.5 μm size powders were coated with Al2O3 and Y2O3 by a coprecipitation coating (CPC) method for fabrication of SiC/YAG composites. The same powder preparation was carried out by conventional mechanical mixing (MM) method for comparison. Two kinds of SiC/YAG composites were manufactured by pressureless sintering using the different powders, named CPC composite and MM composite thereafter respectively. It is shown that the CPC composite has the advantages of homogeneous distribution of YAG phase and of being sintered to high density at a low temperature, 100℃ lower than that of MM composite. The strength (573 Mpa) and hardness (23.3 Gpa) of the CPC composite are significantly higher than those (323 Mpa and 13.5 Gpa) of the MM composite, respectively.

  18. Can YAG screen accept LEReC bunch train?

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy S.; Thieberger, P.; Miller, T.

    2016-05-18

    LEReC RF diagnostic beamline is supposed to accept 250 us long pulse trains of 1.6 MeV – 2.6 MeV (kinetic energy) electrons. This beamline is equipped with YAG profile monitor. Since we are interested in observing only the last macro bunch in the train, one of the possibilities is to install a fast kicker and a dedicated dump upstream of the YAG screen (and related diagnostics equipment). This approach is expensive and challenging from engineering point of view. Another possibility is to send the whole pulse train to the YAG screen and to use a fast gated camera (such as Imperex B0610 with trigger jitter under 60ns) to observe the image from the last pulse only. In this paper we study the feasibility of the last approach.

  19. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  20. INNOVATIVE NON-CONTACT METROLOGY SOLUTIONS FOR LARGE OPTICAL TELESCOPES Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has unique non-contact precision metrology requirements for dimensionally inspecting the global position and orientation of large and highly-polished...

  1. ChemCam-like Spectrometer for Non-Contact Measurements of Key Isotopes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project addresses the need for a non-contact instrument capable of measuring the isotopic ratios O-18/O-16 and D/H from water ice and other solid materials...

  2. Noncontact, Low Frequency Ultrasound as an Effective Therapy against Pseudomonas aeruginosa-infected Biofilm Wounds

    Science.gov (United States)

    2013-03-01

    effective. Previous studies have shown physical effects on cells and their surrounding matrix due to ultrasound energy, termed cavitation and...Noncontact, low-frequency ultrasound as an effective therapy against Pseudomonas aeruginosa–infected biofilm wounds Akhil K. Seth, MD1; Khang T...devices may potentially improve healing, but with no evidence of efficacy against biofilms. This study evaluates noncontact, low-frequency ultrasound

  3. Transient absorption and laser output of YAG : Nd

    Science.gov (United States)

    Kvapil, Jiří; Kvapil, Jos; Kubelka, J.; Kubeček, V.

    1981-06-01

    YAG : Nd grown under 98% Ar 2% H2 protective atmosphere free of nitrogen or hydrocarbons showed after UV irradiation broad absorption peaked at ˜1·9×104 cm-1 which disappeared relatively slowly at room temperature. It was more intensive in oxygen treated samples than in those annealed in hydrogsn. Transient absorption suppresses laser output by the increase of absorption at 0·94×104 cm-1 (1064 nm) and, particularly in CW mode, by the anomalous rod deformation. YAG : Nd containing Fe ions (≲2·10-4 wt%) showed no transient absorption.

  4. CW Yb:YAG LASER FOR PORTABLE MEASURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. M. Ivashko

    2014-01-01

    Full Text Available The theoretical and experimental results of longitudinally continuous-wave diode-pumped Yb:Y3Al5O12 (YAG laser performance for compact field-condition measuring systems were demonstrated. Optimization of laser setup in terms of operation condition in the range of -40 ˚С – +65 ˚С without active thermal stabilization was carried out. Using Yb (10 ат.%:YAG crystal with the length of 3 mm the maximal output power more than 2 W was obtained in the whole of temperature range.

  5. Experimental 511 W Composite Nd:YAG Ceramic Laser

    Institute of Scientific and Technical Information of China (English)

    LI Hai-Feng; XU De-Gang; YANG Yang; WANG Yu-Ye; ZHOU Rui; ZHANG Tie-Li; ZHAO Xin; WANG Peng; YAO Jian-Quan

    2005-01-01

    @@ We demonstrate a 511 W laser diode pumped composite Nd:YAG ceramic laser. The optical pumping system is consisted of five laser diode stacked arrays arranged in a pentagonal shape around the ceramic rod whose size is φ6.35×144mm. When the pumping power is 1600W, the cw laser output up to 511 W at 1064nm can be obtained with a linear plano-plano cavity, and the optical-to-optical efficiency is 31.9%. To our knowledge, this is the highest value of laser output by using a newly invented composite Nd:YAG ceramic rod as the gain medium.

  6. Absorption of some powder materials to YAG laser

    Institute of Scientific and Technical Information of China (English)

    SHAOT.M.; LINX.C.; ZHOUM.

    2001-01-01

    Laser powder alloying is widely used for tribological applications. As one of the key pa-rameters , absorptivity of powder materials to laser plays an important role in the processing. Themeasurement of laser absorptivity is essential for absorptivity research. In present work, lumpedmethod based on heat transfer is established for laser absorptivity measurement. The absorptivityof some powder materials as Cu, Fe, Al, NiO, Al2O3, ZrO2, SiC, to YAG laser, are investigated.The results show that the absorptivity of powder materials to YAG laser is generally larger thanthat of bulk materials.

  7. Flow visualization of a non-contact transport device by Coanda effect

    Science.gov (United States)

    Iki, Norihiko; Abe, Hiroyuki; Okada, Takashi

    2014-08-01

    AIST proposes new technology of non-contact transport device utilizing Coanda effect. A proposed non-contact transport device has a cylindrical body and circular slit for air. The air flow around non-contact device is turbulent and its flow pattern depends on the injection condition. Therefore we tried visualization of the air flow around non -contact device as the first step of PIV measurement. Several tracer particles were tried such as TiO2 particles, water droplets, potatoes starch, rice starch, corn starch. Hot-wire anemometer is employed to velocity measurement. TiO2 particles deposit inside of a slit and clogging of a slit occurs frequently. Potato starch particles do not clog a slit but they are too heavy to trace slow flow area. Water droplets by ultrasonic atomization also deposit inside of slit but they are useful to visualize flow pattern around a non-contact transport device by being supplied from circumference. Coanda effect of proposed non-contact transport device was confirmed and injected air flow pattern switches by a work. Air flow around non-contact trance port device is turbulent and its velocity range is wide. Therefore flow measurement by tracer part icle has traceability issue. Suitable tracer and exposure condition depends on target area.

  8. Safety and Efficacy of Pneumatic Lithotripters Versus Holmium Laser on Multiple Ureteral Calculi.

    Science.gov (United States)

    Ercil, Hakan; Alma, Ergun; Bas, Okan; Unal, Umut; Sener, Nevzat Can; Vuruskan, Ediz; Senturk, Aykut Buğra; Gurbuz, Zafer Gokhan

    2016-11-01

    Different energy sources can be used for ureteroscopic stone fragmentation, such as pneumatic, ultrasonic, laser or electrohydraulic. The aim of this study was to compare the efficacy and safety of pneumatic lithotripters versus Ho: YAG laser in the treatment of multiple stones in the distal ureter. A retrospective evaluation was done using the data of patients to whom ureteroscopic lithotripsy (URL) was applied for ureter stones in our clinic. From these patients, those with multiple unilateral distal ureter stones were identified, then these patients were separated into 2 groups according to the type of lithotriptor used in stone fragmentation as laser lithotripsy (Group 1) and pneumatic lithotripsy (Group 2). Statistically, the two groups were similar in respect of the number of stones, stone burden and the number of double J stents applied intra-operatively. The mean operating time was similar in the 2 groups as 53.47 (±17.3) minutes in Group 1 and 50.59 (±15.3) minutes in Group 2. On postoperative day 1 after the URL, the stone free rate (SFR) of Group 1 (78.7%) was found to be significantly high compared to the SFR of Group 2 (63.6%), while at postoperative month 1, the SFR of both groups was found to be similar. Binary logistic regression was applied to determine the effect of related independent variables on the 1st month SFR. In this model, age and stone burden were affecting variables. Compared to the pneumatic lithotripter, the Ho: YAG laser seems to have advantages of a higher SFR in the early postoperative period, eventhough there are statistically similar success rates and complication rates.

  9. Noncontact optical measurement of lens capsule thickness ex vivo

    Science.gov (United States)

    Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

    2004-07-01

    Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

  10. Single-frequency, single-polarization holmium-doped ZBLAN fiber laser

    Science.gov (United States)

    Zhu, X.; Zong, J.; Miller, A.; Wiersma, K.; Norwood, R. A.; Prasad, N. S.; Chavez-Pirson, A.; Peyghambarian, N.

    2013-02-01

    We present the performance of a single frequency, single-polarization holmium (Ho3+)-doped ZBLAN (ZrF4-BaF2-LaF3- AlF3-NaF) fiber laser at 1200 nm. This distributed Bragg reflector (DBR) fiber laser was developed by splicing a 22 mm long highly Ho3+-doped ZBLAN fiber to a pair of silica fiber Bragg gratings (FBG). The successful fusion splicing of silica fiber to ZBLAN fiber, with their very different melting temperatures, was accomplished by using NP Photonics proprietary splicing technique. The 3 mol% Ho3+-doped ZBLAN fiber had a core diameter of 6.5 μm and a cladding diameter of 125 μm. The threshold of this laser was seen to be about 260 mW, and when the pump power was 520 mW, the output power was about 10 mW. The efficiency of the 1200 nm single-frequency fiber laser, i.e. the ratio of the output power to the launched pump power, was about 3.8%. The linewidth of the 1200 nm single-frequency fiber laser was estimated to be about 100 kHz by comparing the measured frequency noise of the 1200 nm single-frequency fiber laser with that of 1 μm NP Photonics single-frequency fiber lasers whose linewidths have been measured to be in the 1- 10 kHz range. The relative intensity noise of this DBR all-fiber laser was measured to be 19 dB. Due to its low phonon energy and long radiative lifetimes, rare-earth-doped ZBLAN allows various transitions that are typically terminated in silica glass, resulting in ultraviolet, visible, and infrared rare-earth doped ZBLAN lasers. Therefore, our results highlight the exciting prospect that the accessible wavelength range of single-frequency DBR fiber lasers can be expanded significantly by using rare-earth-doped ZBLAN fibers.

  11. Structural and magnetic properties of holmium substituted cobalt ferrites synthesized by chemical co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Irshad; Islam, M.U.; Ishaque, M.; Khan, Hasan M. [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan); Naeem Ashiq, Muhammad, E-mail: naeemashiqqau@yahoo.com [Department of Chemistry, Bahauddin Zakariya University, Multan (Pakistan); Rana, M.U. [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan)

    2012-11-15

    CoHo{sub x}Fe{sub 2-x}O{sub 4} ferrites (x=0.00-0.1) were prepared by the co-precipitation technique and the effect of holmium substitution on the magnetic properties was investigated. X-ray diffraction reveals that the substituted samples show a second phase of HoFeO{sub 3} along with the spinel phase. The magnetic properties such as the saturation magnetization (M{sub s}), coercivity (H{sub c}) and remanence (M{sub r}) are obtained from the hysteresis loops. It is observed that the M{sub s} decreases while H{sub c} increases with Ho{sup 3+} substitution. The decrease of saturation magnetization is attributed to the weakening of exchange interactions. The coercivity increases with increase of the Ho{sup 3+} concentration, which is attributed to the presence of an ultra-thin layer at the grain boundaries that impedes the domain wall motion. Low field AC susceptibility was also measured over the temperature range 300-600 K at the frequency of 200 Hz. It decreases with the increase of temperature following the Curie-Weiss law up to the Curie temperature. Above the Curie temperature it shows paramagnetic behavior. The increase in coercivity suggests that the material can be used for applications in perpendicular recording media. - Highlights: Black-Right-Pointing-Pointer CoHo{sub x}Fe{sub 2-x}O{sub 4} ferrites (x=0.00, 0.04, 0.06, 0.08, 1.0) were prepared by the simple and economic co-precipitation technique. Black-Right-Pointing-Pointer X-ray diffraction reveals that the samples are biphasic except for the undoped sample. Black-Right-Pointing-Pointer Decrease in saturation magnetization is attributed to the weakening of the exchange interactions. Black-Right-Pointing-Pointer Coercivity increases with increase of the Ho{sup 3+} concentration. Black-Right-Pointing-Pointer Increase in coercivity suggests that the materials can be used for applications in perpendicular recording media.

  12. Fabrication of transparent YAG ceramics by traditional solid-state-reaction method

    Institute of Scientific and Technical Information of China (English)

    LI Chang-qing; ZUO Hong-bo; ZHANG Ming-fu; HAN Jie-cai; MENG Song-he

    2007-01-01

    Transparent polycrystalline YAG ceramics were fabricated by solid-state reaction method using commercial ultrafine yttria and α-Al2O3 powders. The starting materials were milled and calcined at 1 400 ℃, and sintered into transparent YAG ceramics at 1 750 ℃ in the vacuum for 4 h. Neither the starting materials as-milled or those calcined into YAG phase at 1 500 ℃ can be sintered into transparent ceramics. Wide grain boundaries emerge in the YAG ceramics sintered at 1 850 ℃ for 4 h, at the edge of which YAG phases decompose into perovskite YAlO3(YAP) and α-Al2O3.

  13. Highly efficient Nd: YAG ceramic CW laser with 59.8% slope-efficiency

    Institute of Scientific and Technical Information of China (English)

    Yunfeng Qi; Qihong Lou; Haixia Ma; Jingxing Dong

    2005-01-01

    @@ In this paper, a highly efficient Ti:sapphire end-pumped 1 at.-% Nd:YAG ceramic laser that is comparable in efficiency with Nd:YAG single crystal lasers has been developed. Optical absorption and emission spectra for Nd:YAG ceramics have been measured. With 673-mW pumping, 295-mW laser output at 1064 nm has been obtained. The laser threshold is only 13 mW. Deducted the transmitted light, the corresponding optical-to-optical conversion efficiency is 58.4%. The lasing characteristics of Nd:YAG ceramic are nearly equal to those of Nd:YAG single crystal.

  14. Comparison of spectroscopic properties of Yb:YAP and Yb:YAG crystals

    Institute of Scientific and Technical Information of China (English)

    Xiaoming He; Guangjun Zhao; Xiaodong Xu; Xionghui Zeng; Jun Xu

    2007-01-01

    The Yb:YAG and Yb:YAP crystals have been grown by Czochralski method. The absorption spectra and the fluorescence spectra of Yb:YAG and Yb:YAP crystals have been investigated. It is shown that the Yb:YAG crystal has better laser properties and smaller threshold power than Yb:YAP crystal. In addition, the absorption cross-section of the Yb:YAP crystal is 2.16 times of that of the Yb:YAG crystal,so laser diode pumped Yb:YAG lasing can be easily realized. Because YAP single crystal is anisotropic, it is provided with polarization characteristics.

  15. Outcomes of transurethral resection and holmium laser enucleation in more than 60 g of prostate: A prospective randomized study

    Science.gov (United States)

    Jhanwar, Ankur; Sinha, Rahul J.; Bansal, Ankur; Prakash, Gaurav; Singh, Kawaljit; Singh, Vishwajeet

    2017-01-01

    Aim: Transurethral resection of prostate (TURP) is considered a gold standard surgical procedure. The management of benign prostatic hyperplasia (BPH) has undergone tremendous change in recent years and shifted from open to minimal invasive procedure. With the advancement in technology and skills of surgeons, lasers have been used more liberally, particularly holmium laser. Holmium laser enucleation of prostate (HoLEP) is seen as close rival of TURP. The objective if this study is to observe long- and short-term outcomes of transurethral resection and holmium laser enucleation in the prostate of more than 60 g. Materials and Methods: This prospective randomized study includes 164 patients. Inclusion criteria were age prostatic size >60 g, gross hematuria secondary to BPH, recurrent urinary tract infection, acute urinary retention, postvoid residual >150 ml, and Schafer Grade II or more. BPH associated with neurogenic bladder, stricture urethra, and carcinoma prostate were excluded from the study. Group 1 comprises patients who underwent TURP and Group 2 comprises who underwent HoLEP. Follow-up was done at 1, 3, 6, 12, and 24 months after the surgery. Results: Data of 144 patients were analyzed. The mean age of patients in TURP and HoLEP group was 66.78 ± 7.81 and 67.70 ± 7.44 years, respectively (P = 0.47), mean prostatic volume was 74.5 ± 12.56 and 75.6 ± 12.84 g, respectively (P = 0.60), operative time was 73.10 ± 10.49 and 89.56 ± 13.81 min, respectively (P = 0.0001). Mean resected tissue was 44.80 ± 9.87 and 48.49 ± 10.87, respectively (P = 0.03). The sexual function did not changed significantly in postoperative follow-up. Conclusion: HoLEP is associated with less blood loss, lower transfusion rates, and a shorter hospital stay. The disadvantage of HoLEP is longer operative time and postoperative dysuria. PMID:28216929

  16. Evaluation of dermal fillers with noncontact optical coherence elastography

    Science.gov (United States)

    Singh, Manmohan; Wang, Shang; Yee, Richard W.; Han, Zhaolong; Aglyamov, Salavat R.; Larin, Kirill V.

    2017-02-01

    Over 2 million dermal filler procedures are performed each year in the USA alone, and this figure is only expected to increase as the aging population continues to grow. Dermal filler treatments can last from a few months to years depending on the type of filler and its placement. Although adverse reactions are rare, they can be quite severe due to ischemic events and filler migration. Previously, techniques such as ultrasound or magnetic resonance imaging have been used to evaluate the filler injections. However, these techniques are not practical for real-time filler injection guidance due to limitations such as the physical presence of the transducer. In this work, we propose the use of optical coherence tomography (OCT) for image-guided dermal filler injections due to the high spatial and temporal resolution of OCT. In addition, we utilize a noncontact optical coherence elastography (OCE) technique, to evaluate the efficacy of the dermal filler injection. A grid of air-pulse OCE measurements was taken, and the dynamic response of the skin to the air-pulse was translated to the Young's modulus and shear viscosity. Our results show that OCT was able to visualize the dermal filler injection process, and that OCE was able to localize the dermal filler injection sites. Combined with functional techniques such as optical microangiography, and recent advanced in OCT hardware, OCT may be able to provide real-time injection guidance in 3D by visualizing blood vessels to prevent ischemic events.

  17. A Novel Multidirectional, Non-Contact Strain-Sensing Nanocomposite

    Science.gov (United States)

    Withey, Paul; Vemuru, Srivishnu; Bachilo, Sergei; Nagarajaiah, Satish; Weisman, R. Bruce

    2013-03-01

    Single-walled carbon nanotubes (SWCNTs) have been successfully dispersed in a polymeric host resulting in the development of a novel strain-sensitive nanocomposite material with promise for scalability. Dubbed ``strain paint'' this new material when coated onto a surface becomes a smart-skin sensor that can detect strain through load transfer from the polymeric host to embedded SWCNTs. Strain is easily measured in a non-contact manner via laser excitation and detection of the unique near-infrared (NIR) fluorescence spectrum of semiconducting SWCNTs. When strained, each (n , m) SWCNT type exhibits a predictable shift in its NIR fluorescence peak. SWCNTs with high intensity are easily detected in the bulk fluorescence spectrum of raw, unsorted SWCNTs embedded in the polymer. Thin films of the polymer/SWCNT nanocomposite were spin-coated onto substrates, strains typically up to 1% were applied, and strain magnitudes were determined by resistive strain gauges bonded to the coating and substrate. Spectral shifts reveal a linear response to strain with little hysteresis. Two SWCNT types exhibiting opposite spectral shifts with strain were used to improve sensitivity. Strain along any direction is determined simply by adjusting the polarization of the excitation laser.

  18. Dual Modality Noncontact Photoacoustic and Spectral Domain OCT Imaging.

    Science.gov (United States)

    Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Hochreiner, Armin; Hollinger, Philipp; Berer, Thomas

    2016-01-01

    We developed a multimodal imaging system, combining noncontact photoacoustic imaging and optical coherence tomography (OCT). Photoacoustic signals are recorded without contact to the specimens' surface by using an interferometric technique. The interferometer is realized within a fiber-optic network using a fiber laser at 1550 nm as source. The fiber-optic network allows the integration of a fiber-based OCT system operating at a wavelength region around 1310 nm. Light from the fiber laser and the OCT source are multiplexed into one fiber using wavelength-division multiplexing. The same focusing optics is used for both modalities. Back-reflected light from the sample is demultiplexed and guided to the respective imaging systems. As the same optical components are used for OCT and photoacoustic imaging, the obtained images are co-registered intrinsically in lateral direction. Three-dimensional imaging is implemented by hybrid galvanometer and mechanical scanning. To allow fast B-scan measurements, scanning of the interrogation beam along one dimension is executed by a galvanometer scanner. Slow-axis scanning, perpendicular to the fast axis, is performed utilizing a linear translational stage. We demonstrate two-dimensional and three-dimensional imaging on agarose phantoms.

  19. High magnetic field ohmically decoupled non-contact technology

    Science.gov (United States)

    Wilgen, John [Oak Ridge, TN; Kisner, Roger [Knoxville, TN; Ludtka, Gerard [Oak Ridge, TN; Ludtka, Gail [Oak Ridge, TN; Jaramillo, Roger [Knoxville, TN

    2009-05-19

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  20. A Novel Noncontact Ultrasonic Levitating Bearing Excited by Piezoelectric Ceramics

    Directory of Open Access Journals (Sweden)

    He Li

    2016-10-01

    Full Text Available A novel ultrasonic levitating bearing excited by three piezoelectric transducers is presented in this work. The transducers are circumferentially equispaced in a housing, with their center lines going through the rotation center of a spindle. This noncontact bearing has the ability to self-align and carry radical and axial loads simultaneously. A finite element model of the bearing is built in ANSYS, and modal analysis and harmonious response analysis are conducted to investigate its characteristics and driving parameters. Based on nonlinear acoustic theory and a thermodynamic theory of ideal gas, the radical and lateral load-carrying models are built to predict the bearing’s carrying capacity. In order to validate the bearing’s levitation force, a test system is established and levitating experiments are conducted. The experimental data match well with the theoretical results. The experiments reveal that the maximum radical and axial levitating loads of the proposed bearing are about 15 N and 6 N, respectively, when the piezoelectric transducers operate at a working frequency of 16.11 kHz and a voltage of 150 Vp-p.

  1. Noncontact manipulation of microflow by photothermal control of viscous force

    Energy Technology Data Exchange (ETDEWEB)

    Motosuke, Masahiro, E-mail: mot@rs.kagu.tus.ac.j [Department of Mechanical Engineering, Tokyo University of Science, 1-14-6 Kudankita, Chiyoda-ku, Tokyo (Japan); Shimakawa, Jun; Akutsu, Dai; Honami, Shinji [Department of Mechanical Engineering, Tokyo University of Science, 1-14-6 Kudankita, Chiyoda-ku, Tokyo (Japan)

    2010-12-15

    In this paper, we investigate a potential of local control of the viscous force in a microfluidic device for a noncontact microflow manipulation method. Photothermal effect and temperature dependence of the liquid viscosity play a key role to induce an inhomogeneous viscosity distribution in the flow field in a microchannel. Absorption of focused laser beam generates the local change in the viscosity of liquid corresponding to the temperature change. The velocity and temperature fields are measured by the micron-resolution particle image velocimetry and laser-induced fluorescence, respectively. Measurement results indicate that the local reduction of the fluid viscosity due to the temperature rise can cause the change of the flow structure in the microchannel. At the focused area of heating laser beam, namely high temperature area, the flow velocity was increased. The accompanying fluid behavior around the heated region was also recognized. In addition, the agreement between the experimental results and numerical simulation clarifies that the primary factor for the change of the microflow structure is the locally controlled viscous force.

  2. Automatic noncontact 3-dimensional gauging via sensor fusion

    Science.gov (United States)

    Buckley, Shawn; Tavormina, Joseph J.

    1993-09-01

    Manufacturers are now driving toward the increased use of automation and the goal of zero-defects. As quality is improved and defect rates approach the popularized " Six-Sigma" level (customarily 3. 4 defects per million) manual or sampled measurementtechniques limit the achievementof product quality and manufacturing cost objectives. New automated inspection and gaging technology is required for process verification and control. To be competitive in the current manufacturing environment new gaging technology must be integrated into the manufacturing process to provide on-line feedback. The co-authors are founders of CogniSense a technology company dedicated to industrial inspection and gaging applications which use non-contact sensing techniques. CogniSense is currently applying its technology in the precision metalforming and other manufacturing industries to perform automatic dimensional measurement and provide real time information used to control and fine-tune the manufacturing process. A variety of sensors are used to detect the characteristics of parts on-line as they are produced. Data from multiple sensors is " fused" and analyzed by a dedicated microcomputer which evaluates the sensory signature and calculates critical dimensions from the sensor input to determine whether parts are within the acceptable tolerance range. Pattern recognition algorithms are used to automatically select the sensors which provide the most important information about critical part characteristics and dimensions. These algorithms operate by observing the changes in sensor output as critical features of the part are varied. The decision-making algorithms

  3. A standing wave-type noncontact linear ultrasonic motor.

    Science.gov (United States)

    Hu, J; Li, G; Chan, H L; Choy, C L

    2001-05-01

    In this study, a novel standing wave-type noncontact linear ultrasonic motor is proposed and analyzed. This linear ultrasonic motor uses a properly controlled ultrasonic standing wave to levitate and drive a slider. A prototype of the motor was constructed by using a wedge-shaped aluminum stator, which was placed horizontally and driven by a multilayer PZT vibrator. The levitation and motion of the slider were observed. Assuming that the driving force was generated by the turbulent acoustic streaming in the boundary air layer next to the bottom surface of the slider, a theoretical model was developed. The calculated characteristics of this motor were found to agree quite well with the experimental results. Based on the experimental and theoretical results, guidelines for increasing the displacement and speed of the slider were obtained. It was found that increasing the stator vibration displacement, or decreasing the gradient of the stator vibration velocity and the weight per unit area of the slider, led to an increase of the slider displacement. It was also found that increasing the amplitude and gradient of the stator vibration velocity, or decreasing the weight per unit area of the slider and the driving frequency, gave rise to an increase of the slider speed. There exists an optimum roughness of the bottom surface of the slider at which the slider speed has a maximum.

  4. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    Directory of Open Access Journals (Sweden)

    Ruzairi Abdul Rahim

    2012-09-01

    Full Text Available This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA. The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments and a nominal frequency range (0–80 Hz, with 10 Hz per step increments. The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

  5. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    Science.gov (United States)

    Chee, Pei Song; Arsat, Rashidah; Adam, Tijjani; Hashim, Uda; Rahim, Ruzairi Abdul; Leow, Pei Ling

    2012-01-01

    This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB) as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA). The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments) and a nominal frequency range (0–80 Hz, with 10 Hz per step increments). The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

  6. Coating of SiC Powder with Nano YAG Phase

    Institute of Scientific and Technical Information of China (English)

    Zhang Ning; Cai Qingkui; Ru Hongqiang; Li Ying; Qiu Guanming; Sun Xudong

    2005-01-01

    SiC-YAG(Y3Al5O12) ceramic composite powders were prepared by co-precipitation coating method. Mechanism of co-precipitation coating of SiC powders with Y3+ and Al3+ precursors was investigated. If the concentration of [OH-] ion in the solution is controlled within the range between critical values for heterogeneous nucleation and homogeneous nucleation, Y3+ and Al3+ precipitation precursors can be coated on the surface of SiC particles. Y3+ and Al3+ precipitation precursors transform into YAG phase after calcining at 1000 ℃ without the formation of YAM and YAP phases. The formation temperature of YAG phase is about 600 ℃ lower than that of conventional powder mixing method. The effect of pH value of the solution and precipitant titration rate on coating quality of SiC-YAG composite powders was also studied. The results show that co-precipitation coating can be realized at a final pH of 9 and a precipitant titration rate of 5 ml·min-1.

  7. Dichroic mirror for diode pumped YAG:Nd-laser

    DEFF Research Database (Denmark)

    Dinca, Andreea; Skettrup, Torben; Lupei, V.

    1996-01-01

    The paper describes the design and realization of a dichroic mirror for a diode pumped YAG:Nd laser. The mirror is deposed on an optical glass substrate and works in optical contact with the laser crystal. The design was performed by admittance matching of the basic stack with the adjacent media...

  8. Er:YAG and adhesion in conservative dentistry : clinical overview

    OpenAIRE

    Fornaini, Carlo

    2013-01-01

    The notion of utilizing laser technology in conservative dentistry was proposed in 1990 by Hibst and Keller, who introduced the possibility of using an Er:YAG laser as alternative to conventional instruments such as the turbine and micro-motor. In subsequent years a continuing effort has been made by clinicians, researchers and commercial companies to improve the technology.

  9. Optical properties of epitaxial YAG:Yb films

    Energy Technology Data Exchange (ETDEWEB)

    Ubizskii, S.B. [Institute for Telecommunication, Radioelectronics and Electronic Engineering, Lviv Polytechnic National University, 12, Bandera St., Lviv, 79013 (Ukraine); Matkovskii, A.O. [Institute for Telecommunication, Radioelectronics and Electronic Engineering, Lviv Polytechnic National University, 12, Bandera St., Lviv, 79013 (Ukraine); Institute of Physics, University Rzezsow, 16 Rejtana St., Rzeszow, 35310 (Poland); Melnyk, S.S.; Syvorotka, I.M. [R and D Institute for Materials, Scientific Research Company ' ' Carat' ' , 202, Stryjska St., Lviv, 79031 (Ukraine); Mueller, V.; Peters, V.; Petermann, K. [Institut fuer Laser-Physik, Universitaet Hamburg, Jungiusstrasse 9a, 20355 Hamburg (Germany); Beyertt, A.; Giesen, A. [Institut fuer Strahlwerkzeuge, Universitaet Stuttgart, Pfaffenwaldring 43, 70569 Stuttgart (Germany)

    2004-03-01

    This work deals with the investigation of the optical properties of epitaxial YAG:Yb films and their suitability as gain media for thin disk lasers. Epitaxial films of YAG:Yb were grown by the liquid phase epitaxy method in air on the (111)-oriented YAG substrates. The thickness of the grown layers was from 30 to 260 {mu}m. The melt composition was varied to obtain the desired doping level from 10 to 15% and to optimize the optical properties. The best epitaxial films were colourless and had an Yb{sup 3+} luminescence lifetime of more than 950 {mu}s, which is very close to the intrinsic lifetime of the Yb ions in the bulk YAG single crystals. These films were tested in a thin disk laser setup with 24 absorption passes of the 940 nm pumping beam. The maximum output power at 1.03 {mu}m wavelength in CW operation reached more than 60 W and the optical efficiency was close to 30%. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Hyperfine-interaction-driven suppression of quantum tunneling at zero field in a holmium(III) single-ion magnet

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan-Cong; Liu, Jun-Liang; Chen, Xiao-Ming; Tong, Ming-Liang [Key Lab. of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen Univ., Guangzhou (China); Wernsdorfer, Wolfgang [Institut Neel, CNRS and Universite Joseph Fournier, Grenoble (France); Institute of Nanotechnology, Karlsruhe Institute of Technology (Germany); Physikalisches Institut, Karlsruhe Institute of Technology (Germany); Liu, Dan; Chibotaru, Liviu F. [Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven (Belgium)

    2017-04-24

    An extremely rare non-Kramers holmium(III) single-ion magnet (SIM) is reported to be stabilized in the pentagonal-bipyramidal geometry by a phosphine oxide with a high energy barrier of 237(4) cm{sup -1}. The suppression of the quantum tunneling of magnetization (QTM) at zero field and the hyperfine structures originating from field-induced QTMs can be observed even from the field-dependent alternating-current magnetic susceptibility in addition to single-crystal hysteresis loops. These dramatic dynamics were attributed to the combination of the favorable crystal-field environment and the hyperfine interactions arising from {sup 165}Ho (I=7/2) with a natural abundance of 100 %. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Neutron diffraction and electrical transport studies on the incommensurate magnetic phase transition in holmium at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Sarah [University of Alabama, Birmingham; Uhoya, Walter [University of Alabama, Birmingham; Tsoi, Georgiy [University of Alabama, Birmingham; Wenger, Lowell E [University of Alabama, Birmingham; Vohra, Yogesh [University of Alabama, Birmingham; Chesnut, Gary Neal [University of Alabama, Birmingham; Weir, S. T. [Lawrence Livermore National Laboratory (LLNL); Tulk, Christopher A [ORNL; Moreira Dos Santos, Antonio F [ORNL

    2012-01-01

    Neutron diffraction and electrical transport measurements have been made on the heavy rare earth metal holmium at high pressures and low temperatures in order to elucidate its transition from a paramagnetic (PM) to a helical antiferromagnetic (AFM) ordered phase as a function of pressure. The electrical resistance measurements show a change in the resistance slope as the temperature is lowered through the antiferromagnetic Neel temperature. The temperature of this antiferromagnetic transition decreases from approximately 122 K at ambient pressure at a rate of -4.9 K GPa(-1) up to a pressure of 9 GPa, whereupon the PM-to-AFM transition vanishes for higher pressures. Neutron diffraction measurements as a function of pressure at 89 and 110 K confirm the incommensurate nature of the phase transition associated with the antiferromagnetic ordering of the magnetic moments in a helical arrangement and that the ordering occurs at similar pressures as determined from the resistance results for these temperatures.

  12. Holmium-doped 2.1 μm waveguide chip laser with an output power > 1 W.

    Science.gov (United States)

    Lancaster, D G; Stevens, V J; Michaud-Belleau, V; Gross, S; Fuerbach, A; Monro, T M

    2015-12-14

    We demonstrate the increasing applicability of compact ultra-fast laser inscribed glass guided-wave lasers and report the highest-power glass waveguide laser with over 1.1 W of output power in monolithic operation in the short-infrared near 2070 nm achieved (51% incident slope efficiency). The holmium doped ZBLAN chip laser is in-band pumped by a 1945 nm thulium fiber laser. When operated in an extended-cavity configuration, over 1 W of output power is realized in a linearly polarized beam. Broad and continuous tunability of the extended-cavity laser is demonstrated from 2004 nm to 2099 nm. Considering its excellent beam quality of M² = 1.08, this laser shows potential as a flexible master oscillator for single frequency and mode-locking applications.

  13. FT-Raman spectroscopic characterization of enamel surfaces irradiated with Nd:YAG and Er:YAG lasers

    Science.gov (United States)

    Shahabi, Sima; Fekrazad, Reza; Johari, Maryam; Chiniforoush, Nasim; Rezaei, Yashar

    2016-01-01

    Background. Despite recent advances in dental caries prevention, caries is common and remains a serious health problem. Laser irradiation is one of the most common methods in preventive measures in recent years. Raman spectroscopy technique is utilized to study the microcrystalline structure of dental enamel. In this study, FT-Raman spectroscopy was used to evaluate chemical changes in enamel structure irradiated with Nd:YAG and Er:YAG lasers. Methods. We used 15 freshly-extracted, non-carious, human molars that were treated as follows: No treatment was carried out in group A (control group); Group B was irradiated with Er:YAG laser for 10 seconds under air and water spray; and Group C was irradiated with Nd:YAG laser for 10 seconds under air and water spray. After treatment, the samples were analyzed by FT-Raman spectroscopy. Results. The carbonate content evaluation with regard to the integrated area under the curve (1065/960 cm–1) exhibited a significant reduction in its ratio in groups B and C. The organic content (2935/960 cm-1) area exhibited a significant decrease after laser irradiation in group B and C. Conclusion. The results showed that the mineral and organic matrices of enamel structure were affected by laser irradiation; therefore, it might be a suitable method for caries prevention. PMID:28096945

  14. Er:YAG and Nd:YAG laser in treatment of patients with contraindications of conventional dental and maxillofacial surgery

    Science.gov (United States)

    Smucler, Roman; Mazanek, Jiri

    2000-03-01

    In clinical praxis we must treat patients with some relative or absolute contraindications every day. Need of hospitalization, antibiotics, hemostyptics and complex examinations makes dentoalveolar and maxillofacial surgery in those cases quite expensive. Combination of Nd:YAG and Er:YAG laser gives us new possibilities. We can help some untreatable patients or transfer care from hospital to dental office. We have been trying to solve contraindications for laser therapy five years. In the center of our work are disorders of blood coagulation, immunity and metabolism. Nd:YAG laser is very useful in coagulation and vaporization of dental gum hypertrophies, benign and malign tumors in case of chronic anticoagulation therapy and immunosupress / in combination for example- after heart transplantation /. Special chapter is the care of patients with disseminated tumors. Er:YAG laser large solve big lesions because of minimal invasivity of course but for small benign tumors are recidives is ideal. Better and quicker healing make new standard of patients' cooperation. Generally fashionable and more comfortable laser treatment minimize need of general anesthesia. After five years we use complex laser therapy in our routine. Aim of our new work is to find ideal combination of cutting lasers to minimize classical complications of laser surgery / carbonization, long and secondary healing /.

  15. FT-Raman spectroscopic characterization of enamel surfaces irradiated with Nd:YAG and Er:YAG lasers

    Directory of Open Access Journals (Sweden)

    Sima Shahabi

    2016-12-01

    Full Text Available Background. Despite recent advances in dental caries prevention, caries is common and remains a serious health problem. Laser irradiation is one of the most common methods in preventive measures in recent years. Raman spectroscopy technique is utilized to study the microcrystalline structure of dental enamel. In this study, FT-Raman spectroscopy was used to evaluate chemical changes in enamel structure irradiated with Nd:YAG and Er:YAG lasers. Methods. We used 15 freshly-extracted, non-carious, human molars that were treated as follows: No treatment was carried out in group A (control group; Group B was irradiated with Er:YAG laser for 10 seconds under air and water spray; and Group C was irradiated with Nd:YAG laser for 10 seconds under air and water spray. After treatment, the samples were analyzed by FT-Raman spectroscopy. Results. The carbonate content evaluation with regard to the integrated area under the curve (1065/960 cm–1 exhibited a significant reduction in its ratio in groups B and C. The organic content (2935/960 cm-1 area exhibited a significant decrease after laser irradiation in group B and C. Conclusion. The results showed that the mineral and organic matrices of enamel structure were affected by laser irradiation; therefore, it might be a suitable method for caries prevention.

  16. 输尿管软镜下钬激光碎石术治疗上尿路结石——附126例报告%Treatment of Upper Urinary Calculi with Holmium Laser Lithotriptor under Flexible Ureteroscope (Appended with Report of 126 Cases)

    Institute of Scientific and Technical Information of China (English)

    周振宇; 何朝晖; 杨江根; 曾国华

    2013-01-01

    Objective To evaluate the clinical effect of holmium laser with flexible ureteroscope on upper urinary calculi.Methods All 126 patients of upper urinary calculi were treated with Holmium laser lithotriptor under flexible ureteroscope in our hospital.Of them,75 patients had calculi in the right side and 51 patients in the left side.The calculi were in the kidney for 64 patients,in the upper ureteral for 33 patients,and both in the upper ureteral and kidney for 29 patients.The diameter of the calculi ranged 0.6-2.0 cm,mean 1.33 cm.After ureter dilation and placement of ureteral access sheath,the stone were fragmented and removed with 200μm Ho ∶ YAG laser fiber,energy 0.8-1.0 J,frequency 5-10 Hz.Results The successful rate of stone fragmentation after single session was 92.86% (117/126).Mean operation time was 48 min(23-71 min).Six patients had low fever after the operation.Neither ureteral perforation nor pyonephrosis was observed.Conclusions The therapy of Holmium laser lithotriptor under flexible ureteroscope is safe and effective for upper urinary calculi,especially for upper ureteral,pelvis,middle calyx and upper calyx stones.%目的 探讨输尿管软镜下钬激光碎石术治疗上尿路结石的疗效.方法 上尿路结石患者126例,其中右侧结石75例,左侧结石51例.输尿管上段结石33例,输尿管上段合并肾结石29例,肾结石64例.结石大小0.6 ~2.0 cm,平均1.33 cm.经输尿管硬镜扩张后留置输尿管扩张鞘寻找结石,采用输尿管软镜下钬激光碎石术治疗,光纤直径200μm,能量0.8~1.0J,频率5~10Hz.结果 单次碎石成功117例(占92.86%),手术时间25~ 75 min,平均48 min.术后6例出现低热,无脓肾、输尿管穿孔等并发症.结论 输尿管软镜下钬激光碎石术治疗上尿路结石安全有效,尤其适用于输尿管上段、肾盂、肾中盏及肾上盏结石.

  17. Tissue damage by laser radiation: an in vitro comparison between Tm:YAG and Ho:YAG laser on a porcine kidney model.

    Science.gov (United States)

    Huusmann, Stephan; Wolters, Mathias; Kramer, Mario W; Bach, Thorsten; Teichmann, Heinrich-Otto; Eing, Andreas; Bardosi, Sebastian; Herrmann, Thomas R W

    2016-01-01

    The understanding of tissue damage by laser radiation is very important for the safety in the application of surgical lasers. The objective of this study is to evaluate cutting, vaporization and coagulation properties of the 2 µm Tm:YAG laser (LISA Laser Products OHG, GER) in comparison to the 2.1 µm Ho:YAG laser (Coherent Medical Group, USA) at different laser power settings in an in vitro model of freshly harvested porcine kidneys. Laser radiation of both laser generators was delivered by using a laser fiber with an optical core diameter of 550 µm (RigiFib, LISA Laser GER). Freshly harvested porcine kidneys were used as tissue model. Experiments were either performed in ambient air or in aqueous saline. The Tm:YAG laser was adjusted to 5 W for low and 120 W for the high power setting. The Ho:YAG laser was adjusted to 0.5 J and 10 Hz (5 W average power) for low power setting and to 2.0 J and 40 Hz (80 W average power) for high power setting, accordingly. The specimens of the cutting experiments were fixed in 4 % formalin, embedded in paraffin and stained with Toluidin blue. The laser damage zone was measured under microscope as the main evaluation criteria. Laser damage zone consists of an outer coagulation zone plus a further necrotic zone. In the ambient air experiments the laser damage zone for the low power setting was 745 ± 119 µm for the Tm:YAG and 614 ± 187 µm for the Ho:YAG laser. On the high power setting, the damage zone was 760 ± 167 µm for Tm:YAG and 715 ± 142 µm for Ho:YAG. The incision depth in ambient air on the low power setting was 346 ± 199 µm for Tm:YAG, 118 ± 119 µm for Ho:YAG. On the high power setting incision depth was 5083 ± 144 µm (Tm:YAG) and 1126 ± 383 µm (Ho:YAG) respectively. In the saline solution experiments, the laser damage zone was 550 ± 137 µm (Tm:YAG) versus 447 ± 65 µm (Ho:YAG), on the low power setting and 653 ± 137 µm (Tm:YAG) versus 677 ± 134 µm (Ho:YAG

  18. Non-contact Laser-based Human Respiration Rate Measurement

    Science.gov (United States)

    Scalise, L.; Marchionni, P.; Ercoli, I.

    2011-08-01

    At present the majority of the instrumentation, used in clinical environments, to measure human respiration rate are based on invasive and contact devices. The gold standard instrument is considered the spirometer which is largely used; it needs a direct contact and requires a collaboration by the patient. Laser Doppler Vibrometer (LDVi) is an optical, non-contact measurement system for the assessment of a surface velocity and displacement. LDVi has already been used for the measurement of the cardiac activity and for the measurement of the chest-wall displacements. The aims of this work are to select the best measurement point on the thoracic surface for LDVi monitoring of the respiration rate (RR) and to compare measured data with the RR valued provided by the spirometer. The measurement system is composed by a LDV system and a data acquisition board installed on a PC. Tests were made on 10 different point of the thorax for each patient. Patients population was composed by 33 subjects (17 male and 16 female). The optimal measurement point was chosen considering the maximum peak-to-peak value of the displacement measured by LDV. Before extracting RR we have used a special wavelet decomposition for better selection of the expiration peaks. A standard spirometer was used for the validation of the data. From tests it results that the optimal measurement point, namely is located on the inferior part of the thoracic region (left, front side). From our tests we have obtained a close correlation between the RR values measured by the spirometer and those measured by the proposed method: a difference of 14±211 ms on the RR value is reported for the entire population of 33 subjects. Our method allows a no-contact measurement of lungs activity (respiration period), reducing the electric and biological risks. Moreover it allows to measure in critical environment like in RMN or in burned skin where is difficult or impossible to apply electrodes.

  19. Non-contact luminescence lifetime cryothermometry for macromolecular crystallography.

    Science.gov (United States)

    Mykhaylyk, V B; Wagner, A; Kraus, H

    2017-05-01

    Temperature is a very important parameter when aiming to minimize radiation damage to biological samples during experiments that utilize intense ionizing radiation. A novel technique for remote, non-contact, in situ monitoring of the protein crystal temperature has been developed for the new I23 beamline at the Diamond Light Source, a facility dedicated to macromolecular crystallography (MX) with long-wavelength X-rays. The temperature is derived from the temperature-dependent decay time constant of luminescence from a minuscule scintillation sensor (luminescence lifetime thermometry is presented, the features of the detection method and the choice of temperature sensor are discussed, and it is demonstrated how the temperature monitoring system was integrated within the viewing system of the endstation used for the visualization of protein crystals. The thermometry system was characterized using a Bi4Ge3O12 crystal scintillator that exhibits good responsivity of the decay time constant as a function of temperature over a wide range (8-270 K). The scintillation sensor was calibrated and the uncertainty of the temperature measurements over the primary operation temperature range of the beamline (30-150 K) was assessed to be ±1.6 K. It has been shown that the temperature of the sample holder, measured using the luminescence sensor, agrees well with the expected value. The technique was applied to characterize the thermal performance of different sample mounts that have been used in MX experiments at the I23 beamline. The thickness of the mount is shown to have the greatest impact upon the temperature distribution across the sample mount. Altogether, these tests and findings demonstrate the usefulness of the thermometry system in highlighting the challenges that remain to be addressed for the in-vacuum MX experiment to become a reliable and indispensable tool for structural biology.

  20. Laser-SQUID microscope for noncontact evaluation of solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, Y., E-mail: nakatani@sup.ee.es.osaka-u.ac.jp [Osaka University, 1-3, Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Hayashi, T. [Sendai National College of Technology, 4-16-1, Ayashityuou, Aoba-ku, Sendai, Miyagi 989-3128 (Japan); Itozaki, H. [Osaka University, 1-3, Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2011-11-15

    A polycrystalline solar cell was investigated by the laser-SQUID microscope without contact to the surface of the solar cell. The laser-SQUID microscope image of the solar cell was similar to the laser-beam-induced current image. The laser-SQUID microscope images varied when the needle and the SQUID were shifted in the x- and y-directions from the center of a laser spot. The laser-SQUID microscopy has the possibility of estimation of the photocurrent direction. A polycrystalline solar cell with several grains was investigated by the laser-SQUID (Superconducting QUantum Interference Device) microscope. The laser-SQUID microscopy detects the magnetic field generated by a photo-induced current. This technique enables nondestructive and noncontact evaluation of semiconductor samples. A needle made of high permeability material was used to transmit the magnetic field near the sample to the SQUID. The needle and the SQUID were shifted in the x- and y-directions from the center of a laser spot. The laser-SQUID microscope images varied with needle position. This indicated the possibility of current estimation using a laser-SQUID microscope. In this study the sample was also evaluated using Laser Beam Induced Current (LBIC) which is widely used for evaluation of the conversion efficiency distribution of solar cells. The laser-SQUID microscope image was compared with the LBIC image and was found to be similar. This result showed that laser-SQUID microscopy can be used for the electrical evaluation of solar cells without contact, and furthermore has the possibility of estimation of the photocurrent direction.

  1. Development of an electromagnetic acoustic transducer (EMAT) for the noncontact excitation of guided ultrasonic waves

    Science.gov (United States)

    Fromme, P.

    2015-03-01

    Fatigue damage can develop in aerospace structures at locations of stress concentration, such as fasteners. For the safe operation of the aircraft fatigue cracks need to be detected before reaching a critical length. Guided ultrasonic waves offer an efficient method for the detection and characterization of such defects in large aerospace structures. Noncontact excitation of guided waves was achieved using electromagnetic acoustic transducers (EMAT). The transducer development for the specific excitation of the A0 Lamb wave mode is explained. The radial and angular dependency of the excited guided wave pulses at different frequencies were measured using a noncontact laser interferometer. Based on the induced eddy currents in the plate a theoretical model was developed and reasonably good agreement with the measured transducer performance was achieved. The developed transducers were employed for defect detection in aluminum components using fully noncontact guided wave measurements. Excitation of the A0 Lamb wave mode was achieved using the developed EMAT transducer and the guided wave propagation and scattering was measured using a noncontact laser interferometer. These results provide the basis for the defect characterization in aerospace structures using noncontact guided wave sensors.

  2. High energy high repetition rate compact picosecond Holmium YLF laser for mid-IR OPCPA pumping

    Science.gov (United States)

    Sanchez, Daniel; Biegert, Jens; Matras, Guillaume; Simon-Boisson, Christophe

    2017-02-01

    Holmium YLF laser developed in order to be used as the puming laser for the first mid-IR optical parametric chirped pulse amplifier (OPCPA) operating at a center wavelength of 7 μm with output parameters suitable already for strong-field experiments. It is also the first demonstration of an Optical Parametric Chirped Pulse Amplifier (OPCPA) using a 2 μm laser pump source which enables the use of nonoxide nonlinear crystals with typically limited transparency at 1 mm wavelength. This new OPCPA system is alloptically synchronized and generates 0.2 mJ energy, CEP stable optical pulses. The pulses are currently compressed to sub-8 optical cycles but support a sub-4 cycle pulse duration. The discrepancy in compression is due to uncompensated higher order phase from the grating compressor which will be addressed in the future.

  3. Evaluation in vitro of effects of Er:YAG and Nd:YAG lasers irradiation on root canal wall, by stereoscopy, scanning electron micrography and thermographic camera; Avaliacao in vitro dos efeitos da irradiacao laser de Er:YAG e Nd:YAG na parede dentinaria do canal radicular, sob observacao do estereoscopio, da micrografia eletronica e da camera termografica

    Energy Technology Data Exchange (ETDEWEB)

    Goya, Claudia

    2001-07-01

    This study was carried out to evaluate in vitro the effects of Nd:YAG laser and Er:YAG laser irradiation in the root canal wall by SEM, evaluating the apical leakage and the temperature changes during the laser irradiation. Seventy four extracted human teeth were used, they were instrumented and divided into seven groups of 10 teeth each. The teeth were evaluated through stereoscopy, by SEM, and with the thermographic camera. The Nd:YAG laser irradiation parameters were 100 mJ/p, 15 Hz, and Er:YAG laser were 160 mJ/p and 10 Hz, the irradiation was 4 times at 2 mm/sec speed, with 20 sec interval. The apical leakage was not observed in the teeth irradiated by Nd:YAG laser alone or in association with Er:YAG laser. However in the teeth irradiated only by the Er:YAG laser we observed a little leakage. By SEM observation the Nd:YAG laser irradiation showed melting and recrystallization in the dentin surface closing dentinal tubules, and in the samples irradiated by Er:Y AG laser a clean surface, opened dentinal tubules, and the combination by two lasers, showed melting covering some dentinal tubules The thermographic study found the temperature increase was not more than 6 deg C. This study showed the safety parameters applications of Er:YAG laser in association with Nd:YAG laser in root canal treatment, in order to not cause thermal damages to the periodontal tissues. (author)

  4. Effect of dental surface treatment with Nd:YAG and Er:YAG lasers on bond strength of resin composite to recently bleached enamel.

    Science.gov (United States)

    Rocha Gomes Torres, Carlos; Caneppele, Taciana Marco Ferraz; Del Moral de Lazari, Regina; Ribeiro, Carolina Ferraz; Borges, Alessandra Buhler

    2012-07-01

    The aim of this work is to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached enamel. In this study, 120 bovine incisors were distributed into two groups: group C: without bleaching treatment; group B: bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: subgroup N: without laser treatment; subgroup Nd: irradiation with Nd:YAG laser; subgroup Er: irradiation with Er:YAG laser. The adhesive system (Adper Single Bond 2) was then applied and composite buildups were constructed with Filtek Supreme composite. The teeth were sectioned to obtain enamel-resin sticks (1 × 1 mm) and submitted to microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. The bond strength values in the bleached control group (5.57 MPa) presented a significant difference in comparison to the group bleached and irradiated with Er:YAG laser (13.18 MPa) or Nd:YAG (25.67 MPa). The non-bleached control group presented mean values of 30.92 MPa, with statistical difference of all the others groups. The use of Nd:YAG and Er:YAG lasers on bleached specimens was able to improve the bond strengths of them.

  5. Temperature rise during Er:YAG cavity preparation of primary enamel.

    Science.gov (United States)

    Contente, Marta Maria Martins Giamatei; de Lima, Fabrício Augusto; Galo, Rodrigo; Pécora, Jesus Djalma; Bachmann, Luciano; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

    2012-01-01

    This study aimed to assess in vitro thermal alterations taking place during the Er:YAG laser cavity preparation of primary tooth enamel at different energies and pulse repetition rates. Forty healthy human primary molars were bisected in a mesio-distal direction, thus providing 80 fragments. Two small orifices were made on the dentin surface to which type K thermocouples were attached. The fragments were individually fixed with wax in a cylindrical Plexiglass® abutment and randomly assigned to eight groups, according to the laser parameters (n = 10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz and G8 - 300 mJ/ 6 Hz. An area of 4 mm(2) was delimited. Cavities were done (2 mm long × 2 mm wide × 1 mm thick) using non-contact (12 mm) and focused mode. Temperature values were registered from the start of laser irradiation until the end of cavity preparation. Data were analyzed by one-way ANOVA and Tukey test (p ≤ 0.05). Groups G1, G2, G6, and G7 were statistically similar and furnished the lowest mean values of temperature rise. The set 250 mJ/10 and 15 Hz yielded the highest temperature values. The sets 250 and 300 mJ and 6 Hz provided temperatures with mean values below the acceptable critical value, suggesting that these parameters ablate the primary tooth enamel. Moreover, the temperature elevation was directly related to the increase in the employed pulse repetition rates. In addition, there was no direct correlation between temperature rise and energy density. Therefore, it is important to use a lower pulse frequency, such as 300 mJ and 6 Hz, during cavity preparation in pediatric patients.

  6. Bonding Strength of Ceromer with Direct Laser Sintered, Ni-Cr-Based, and ZrO2 Metal Infrastructures After Er:YAG, Nd:YAG, and Ho:YAG Laser Surface Treatments-A Comparative In Vitro Study.

    Science.gov (United States)

    Gorler, Oguzhan; Ozdemir, Ali Kemal

    2016-08-01

    Laser modalities instead of conventional surface treatment techniques have been suggested to obtain an adequate micromechanical bonding between dental super- and infrastructures. The present study was undertaken to assess the effect of surface treatment with Ho:YAG, Er:YAG, and Nd:YAG laser modalities on the shear bond strength (SBS) of ceromer to different types of metal infrastructures in in vitro settings. The study specimens consisted of 40 direct laser sintered (DLS), 40 Ni-Cr-based, and 40 zirconium oxide (ZrO2) infrastructures. In each infrastructure group, the specimens were divided randomly into five treatment modalities (n = 8): no treatment (controls), sandblasting, Er:YAG, Nd:YAG, and Ho:YAG lasers. The DLS, Ni-Cr-based, and ZrO2 infrastructures were prepared in the final dimensions of 7 mm in diameter and 3 mm in thickness in line with the ISO 11405 standard. Ceromer as superstructure was applied to all the infrastructures after their surface treatments according to the selected treatment modality. SBS test was performed to test the effectiveness of surface treatments. A stereomicroscope was used to determine the changes in the surface morphology of specimens. Among the laser modalities and sandblasting, Ho:YAG laser caused the most important increase in the DLS and Ni-Cr-based infrastructures but sandblasting caused the most important increase in the ZrO2 infrastructure. In all the infrastructures, Nd:YAG laser has the least effectiveness, and Er:YAG laser makes an intermediate success. The stereomicroscopy images presented that the applications of laser surface treatments altered the surface in all the infrastructures. Overall, in current experimental settings, Ho:YAG, Nd:YAG, and Er:YAG lasers, in order of strength, are effective in improving the bonding of ceromer to all the infrastructures. Ho:YAG laser is more effective in the DLS and Ni-Cr-based infrastructures, but sandblasting is more effective in the ZrO2 infrastructure. The studied

  7. Outcome analysis of holmium laser and pneumatic lithotripsy in the endoscopic management of lower ureteric calculus in pediatric patients: a prospective study

    Directory of Open Access Journals (Sweden)

    Ankur Jhanwar

    Full Text Available ABSTRACT Objective: To analyse outcomes of holmium laser and pneumatic lithotripsy in treatment of lower ureteric calculus in pediatric patients. Materials and methods: Prospective study conducted between August 2013 and July 2015. Inclusion criteria were lower ureteric calculus with stone size ≤1.5cms. Exclusion criteria were other than lower ureteric calculus, stone size ≥1.5cms, congenital renal anomalies, previous ureteral stone surgery. Patients were divided into two groups. Group A underwent pneumatic and group B underwent laser lithotripsy procedure. Patient's baseline demographic and peri-operative data were recorded and analysed. Post operatively X-ray/ultrasound KUB (Kidney, ureter and bladder was performed to assess stone free status. Results: A total of 76 patients who met the inclusion criteria to ureteroscopic intracorporeal lithotripsy were included. Group A and B included 38 patients in each. Mean age was 12.5±2.49 in Group A and 11.97±2.74 years in Group B respectively (p=0.38. Overall success rate was 94.73% in Group A and 100% in Group B, respectively (p=0.87. Conclusion: Holmium Laser lithotripsy is as efficacious as pneumatic lithotripsy and can be used safely for the endoscopic management of lower ureteric calculus in pediatric patients. However, holmium laser requires more expertise and it is a costly alternative.

  8. Transurethral treatment of bladder leukoplakia with holmium-laser%经尿道钬激光治疗膀胱黏膜白斑

    Institute of Scientific and Technical Information of China (English)

    张占学; 岳霄; 苗晓林; 高敏; 张杏梅; 李杰

    2010-01-01

    目的 探讨经尿道钬激光治疗膀胱黏膜白斑的疗效.方法 105例膀胱黏膜白斑患者采用经尿道钬激光治疗.结果 105例均手术成功,无膀胱穿孔及术后继发出血等并发症,随访1~5年,治愈100例,复发5例,无癌变发生.结论 经尿道钬激光治疗黏膜白斑疗效显著,值得推广使用.%Objective To study the efficacy of transurethral treatment of bladder leukoplakia with holmium-laser. Methods A group of 105 cases with the bladder leukoplakia were treated by US Trimydyne Holmium-laser. Results All cases were successfully conducted, there was no bladder perforation and second hemorrhage, Follow-up was 1-5 years, Relapse occurred in 5 cases, no tumers occurred. Conclusion Holmium-laser has good effect on transurethral treatment of bladder leukoplakia and should be widely spread.

  9. Experimental study of noncontact ultrasonic motor with non-symmetrical electrode

    Institute of Scientific and Technical Information of China (English)

    Yang Bin; Liu Jing-Quan; Chen Di; Zhou Wei-Min; Cai Bing-Chu

    2006-01-01

    We have proposed a novel noncontact ultrasonic motor based on non-symmetrical electrode driving. The configuration of this electrode and the fabrication process of rotors are presented. Its vibration characteristics are computed and analysed by using the finite element method and studied experimentally. Good agreement between them is obtained. Moreover, it is also shown that this noncontact ultrasonic motor is operated in antisymmetric radial vibration mode of B21 mode. The maximum revolution speed for three-blade and six-blade rotors are 5100 and 3700r/min at an input voltage of 20V, respectively. Also, the noncontact high-speed revolution of the rotors can be realized by the parts of Ⅰ, Ⅲ of the electrode or Ⅱ, Ⅳ of the electrode. The levitation distance between the stator and rotor is about 140/μm according to the theoretical calculation and the experimental measurement.

  10. Economic evaluation of noncontact normothermic wound therapy for treatment of pressure ulcers.

    Science.gov (United States)

    Macario, Alex

    2002-06-01

    New adjunctive treatments for pressure ulcers have become available to complement standard care. The economic benefits of new advanced wound care treatments like noncontact normothermic wound therapy are related to: the costs of adequately providing standard care treatment, the baseline probability of healing a pressure ulcer to closure with standard care, the relative improvement in healing rates with the advanced wound care treatment and the acquisition cost of the advanced treatment. Healing data from preliminary clinical trials suggest that pressure ulcer healing in long-term care patients is accelerated two-fold with noncontact normothermic wound therapy. At this healing rate, noncontact normothermic wound therapy for stage III and IV pressure ulcer is an economically attractive intervention. Additional well-controlled clinical trials are necessary.

  11. Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review

    Directory of Open Access Journals (Sweden)

    Changzhan Gu

    2016-07-01

    Full Text Available Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends.

  12. A Contact and Non-Contact Hybrid Profilometer with Large Range

    Institute of Scientific and Technical Information of China (English)

    YUN Jianping; YANG Xudong; XIE Tiebang; CHANG Suping

    2007-01-01

    A novel hybrid instrument of contact and non-contact measurement with large range is developed, and both measurement systems are based on a Linnik interference microscope and on white-light interference measuring techniques. The ambiguity presented in conventional monochromatic interferometers is not present in the contact and non-contact measurement, and they have a virtually unlimited unambiguous range. For the contact measurement, the vertical measuring range is ±5 mm with a resolution of 1 nm and the horizontal measuring range is ±25 mm in x-range and y-range with a resolution of 1.25 μm; for the non-contact measurement, the vertical measuring range is ±5 mm with a resolution of 1 nm and the horizontal resolution better than 0.5 μm.

  13. Multimodal non-contact photoacoustic and OCT imaging with galvanometer scanning

    Science.gov (United States)

    Berer, Thomas; Hochreiner, Armin; Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Buchsbaum, Andreas

    2015-03-01

    In this paper we present multimodal non-contact photoacoustic and optical coherence tomography (OCT) imaging using a galvanometer scanner. Photoacoustic signals are acquired without contact on the surface of a specimen using an interferometric technique. The interferometer is realized in a fiber-optic network using a fiber laser at 1550 nm as source. In the same fiber-optic network a spectral-domain OCT system is realized, using a broadband light source at 1300 nm. Light from the fiber laser and the OCT source are multiplexed into the same fiber and the same objective is used for both imaging modalities. Fast non-contact photoacoustic and OCT imaging is demonstrated by scanning the detection spot utilizing a galvanometer scanner. Multimodal photoacoustic and OCT imaging is shown on agarose phantoms. As the same fiber network and optical components are used for non-contact photoacoustic and OCT imaging the obtained images are co-registered intrinsically.

  14. Non-contact optoacoustic imaging with focused air-coupled transducers

    Energy Technology Data Exchange (ETDEWEB)

    Deán-Ben, X. Luís [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); Pang, Genny A.; Razansky, Daniel, E-mail: dr@tum.de [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); School of Medicine, Technische Universität München (TUM), Munich (Germany); Montero de Espinosa, Francisco [CSIC, Institute of Physics and Communication Technologies, Madrid (Spain)

    2015-08-03

    Non-contact optoacoustic imaging employing raster-scanning of a spherically focused air-coupled ultrasound transducer is showcased herein. Optoacoustic excitation with laser fluence within the maximal permissible human exposure limits in the visible and near-infrared spectra is applied to objects with characteristic dimensions smaller than 1 mm and absorption properties representative of the whole blood at near-infrared wavelengths, and these signals are shown to be detectable without contact to the sample using an air-coupled transducer with reasonable signal averaging. Optoacoustic images of vessel-mimicking tubes embedded in an agar phantom captured with this non-contact sensing technique are also showcased. These initial results indicate that an air-coupled ultrasound detection approach can be suitable for non-contact biomedical imaging with optoacoustics.

  15. Cutting of nonmetallic materials using Nd:YAG laser beam

    Institute of Scientific and Technical Information of China (English)

    Bashir Ahmed Tahir; Rashid Ahmed; M. G. B. Ashiq; Afaq Ahmed; M. A. Saeed

    2012-01-01

    This study deals with Nd:YAG laser cutting nonmetallic materials,which is one of the most important and popular industrial applications of laser.The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed.For approximate cutting depth,a theoretical study is conducted in terms of material property and cutting speed.Results show a nonlinear relation between the cutting depth and input energy.There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s.An extra energy is utilized in the deep cutting.It is inferred that as the laser power increases,cutting depth increases.The experimental outcomes are in good agreement with theoretical results.This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting,scribing,trimming,engraving,and marking nonmetallic materials.

  16. Amplification of complex fields in Nd:YAG amplifiers

    Science.gov (United States)

    Chen, Xudong; Chang, Chengcheng; Pu, Jixiong

    2017-04-01

    High energy nanosecond vortex beams and cylindrically polarized beams are generated in Nd:YAG amplifiers. Vortex seed beams and cylindrically polarized seed beams are converted from a conventional Nd:YAG laser by spiral phase plate and polarization converter, respectively. Maximum output energy of optical vortex up to 995 mJ and cylindrically polarized beams up to 772 mJ have been achieved at 10 Hz in a 10-ns pulse, respectively. The amplification efficiency, the beam quality and pulse width of the amplification output are studied. Both the topological charge of the vortex seed beams and polarization state of cylindrically polarized beams are confirmed to be conserved during the amplification. The generation of high energy vortex beams and cylindrically polarized beams would be beneficial to laser material processing.

  17. Development behavior of liquid plasma produced by YAG laser

    CERN Document Server

    Yamada, J; Yamada, Jun; Tsuda, Norio

    2004-01-01

    The laser induced plasma in liquid hasn't been studied enough. In liquid, the laser induced plasma may be able to resolve the hazardous material called the environment material. Then, the plasma produced in liquid by the laser light is studied and the plasma development is observed by a streak camera. The ultra pure water or the ultra pure water with a melted NaCl is used as a test liquid. The liquid plasma is produced by the fundamental wave of YAG laser. When NaCl concentration is varied, the plasma development behavior is obserbed by streak camera. The liquid plasma develops backward. The plasma is produced from many seeds and It consists of a group of plasmas. However, the liquid plasma produced by second harmonic wave of YAG laser develops as a single plasma. The development mechanism is investigated from the growth rate of backward plasma. The backward plasma develops by breakdown wave and radiation supported shock wave.

  18. Hollow polycarbonate fiber for Er:YAG laser light delivery.

    Science.gov (United States)

    Nakazawa, Masayuki; Shi, Yi-Wei; Matsuura, Yuji; Iwai, Katsumasa; Miyagi, Mitsunobu

    2006-05-15

    We developed hollow fibers with polycarbonate (PC) capillaries for use as a supporting tube. The PC capillaries were prepared by using a glass-drawing technique. Hollow PC fibers are safer and more flexible than hollow glass fibers because no fragments are released when the fibers are broken in various applications. Inner coating layers of silver and cyclic olefin polymer (COP) enhanced the reflection rate at the Er:YAG laser light wavelength. Using these fibers, we attained low loss for Er:YAG laser light transmission. By adjusting the drawing temperature in the fabrication of the PC capillaries, we created a smooth inner surface and uniform PC capillaries. We also demonstrated low-loss properties for visible pilot beams.

  19. Synthesis and characterization of yttrium aluminium garnet (YAG powders

    Directory of Open Access Journals (Sweden)

    Magdalena Zarzecka-Napierala

    2007-12-01

    Full Text Available In this paper synthesis and characterization of YAG powders, prepared by a process based on complexing properties of citric acid, was reported. Influence of citric acid estrification induced by 2-propanol or ethylene glycol on the system homogeneity was investigated. These reagents were introduced to aqueous solution of yttrium and aluminium nitrates. A variety of powders from Al2O3-Y2O3 system with different phase composition were obtained by altering the citrate to nitrate ratio. Evolution of the powders phase composition vs. temperature was investigated using DTA/TG, XRD, and FT-IR methods. The most interesting results were observed in case of the citric acid–propanol–relative nitrates system. The mole ratio of these reagents equal to 1:2.5:2.5 (nitrates (Al,Y:citric acid:2-propanol allowed to synthesize pure YAG phase powders at temperature as low as 950°C.

  20. Effects of Er:YAG laser irradiation on human cartilage

    Science.gov (United States)

    Glinkowski, Wojciech; Brzozowska, Malgorzata; Ciszek, Bogdan; Rowinski, Jan; Strek, Wieslaw

    1996-03-01

    Irradiation of the hyaline or fibrous cartilage excised from the body of a human cadaver with Er:YAG laser beam, single pulse with a dose of 1 J, produces a crater with a depth of approximately 500 micrometers and a diameter varying from 5 to 300 micrometers. Histological examination has revealed that the laser-made craters were surrounded by a thin rim (2-10 micrometer) of charred and coagulated tissue. No damage was observed in the cartilage surrounding the rim. The presence of sharp demarcation between the tissue areas ablated by laser energy and the undamaged areas argues for the potential usefulness of the Er:YAG laser in surgery of cartilages.

  1. Pulsed Tm:YAG laser ablation of knee joint tissues

    Science.gov (United States)

    Shi, Wei-Qiang; Vari, Sandor G.; Duffy, J. T.; Miller, J. M.; Weiss, Andrew B.; Fishbein, Michael C.; Grundfest, Warren S.

    1992-06-01

    We investigated the effect of a free-running 2.01 micron pulsed Tm:YAG laser on bovine knee joint tissues. Ablation rates of fresh fibrocartilage, hyaline cartilage, and bone were measured in saline as a function of laser fluence (160 - 640 J/cm2) and fiber core size (400 and 600 microns). All tissues could be effectively ablated and the ablation rate increased linearly with the increasing fluence. Use of fibers of different core sizes, while maintaining constant energy fluence, did not result in significant difference in ablation rate. Histology analyses of the ablated tissue samples reveal average Tm:YAG radiation induced thermal damage (denatunalization) zones ranging between 130 and 540 microns, depending on the laser parameters and the tissue type.

  2. Investigation of bulk laser damage in transparent YAG ceramics controlled with microstructural refinement

    Science.gov (United States)

    Kamimura, T.; Kawaguchi, Y.; Arii, T.; Shirai, W.; Mikami, T.; Okamoto, T.; Aung, Yan Lin; Ikesue, A.

    2008-10-01

    We have investigated a relationship among the bulk laser-induced damage threshold (LIDT) and YAG ceramics with various structural defects. The correlation of scattering defect density and laser damage resistance was clearly observed. A high-quality YAG ceramic having a low-scattering density showed a higher LIDT than that of a low-quality YAG ceramic. Laser damage threshold (LIDT) of high-quality YAG ceramic was almost the same as that of a single crystal. In addition, the high-quality Nd:YAG ceramics with low-defect density showed an excellent oscillation efficiency which was comparable to that of a single crystal. Thus, high-quality YAG ceramic with low-defect density is more reliable as a material which is highly resistant to laser damage.

  3. Cryogenic Tm: YAG Laser in the Near Infrared

    Science.gov (United States)

    2015-05-29

    REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < Cryogenic Tm:YAG Laser in the Near Infrared* Tso Yee Fan...therefore limits operation. However, operation at cryogenic temperature depopulates the lower laser level, reduces laser threshold, increases...efficiency, and greatly mitigates thermo-optic effects in crystalline host materials [21]-[23]. Here, we have used cryogenic cooling to enable laser

  4. Neodymium YAG Lasers. Citations from the NTIS data base

    Science.gov (United States)

    Carrigan, B.

    1980-07-01

    Federally funded research reports on lasing of neodymium doped yttrium aluminum garnet are cited. Studies on design, fabrication, quantum efficiency, light pulses, stabilization, and testing are covered. Optical pumping, mode locking, frequency conversion, and modulation of these lasers are discussed. Laser applications such as optical communication, range finding, and tracking are included. Safety hazards and radiation damage related to neodymium YAG lasers are also covered. This updated bibliography contains 181 citations, 15 of which are new entries to the previous edition.

  5. Diode-pumped 1123-nm Nd:YAG laser

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Guo(郭晓萍); Meng Chen(陈檬); Gang Li(李港); Bingyuan zhang(张炳元); Jiandong Yang(杨建东); Zhigang Zhang(张志刚); Yonggang Wang(王勇刚)

    2004-01-01

    We demonstrated a diode-pumped Nd:YAG laser with a plano-concave resonator. When the pump power is 1.57 W, the output power of 1123-nm laser is 132 mW at the temperature of 20 ℃, and the power change is less than 2% in an hour. A periodically poled LiNbOa (PPLN) was used as outer cavity frequency-doubling crystal and 561-nm laser was observed.

  6. Experimental study of thermal lensing of Nd:YAG laser

    Institute of Scientific and Technical Information of China (English)

    HU Shao-yun; ZHONG Ming; ZUO Yan; FAN Hong-ying

    2006-01-01

    A wavefront method of measuring the thermal lensing of solid-state lasers is proposed.This method is easy to implement and has a high spatial resolution for diagnosing thermal lensing.By this method,the thermal lensing of Nd:YAG laser is studied in detail.And this work provides a means for studying the thermal effects of laser medium and many instructional parameters for optimizing the design of the laser cavity.

  7. The Effects of Er:YAG, Nd:YAG, and Ho:YAG Laser Surface Treatments to Acrylic Resin Denture Bases on the Tensile Bond Strength of Silicone-Based Resilient Liners.

    Science.gov (United States)

    Gorler, Oguzhan; Dogan, Derya Ozdemir; Ulgey, Melih; Goze, Aysegul; Hubbezoğlu, Ihsan; Zan, Recai; Ozdemir, Ali Kemal

    2015-08-01

    The present study was to assess the effect of surface treatments of Er:YAG, Nd:YAG, and Ho:YAG lasers on the tensile bond strength of a silicone-based resilient liner to an acrylic denture in an in vitro setting. Experimental dumbbell-shaped specimens (75 mm) were produced by combining two acrylate pieces fabricated from heat-polymerized acrylic resin (36 mm) with 3 mm of Molloplast(®)-B filling between them. The specimens (n=200) were randomly divided in half for thermocycling, and each 100 specimen set was randomized into five groups (n=20) with different surface treatments: control (no surface treatment), sandblasting, Er:YAG laser, Nd:YAG laser, and Ho:YAG laser. A tensile bond strength test was performed. The effect of the laser surface treatments was examined with scanning electron microscopy. Only the Er:YAG laser increased the tensile bond strength compared with the other treatments. The other laser groups showed lower bond strengths. The Ho:YAG laser resulted in considerably reduced tensile bond strength. The scanning electron microscopy images showed that applying laser surface treatments modified the surface of the denture base resin. There was not an overall improvement with the use of the studied laser modalities in the adhesion quality of resilient denture liner to acrylic resin, although Er:YAG laser showed a potential to improve their adhesion. These laser modalities need to be subjected to further studies to determine optimal setup for use in prosthodontics.

  8. Noncontact photoacoustic imaging by using a modified optical-fiber Michelson interferometer

    Science.gov (United States)

    Lu, Jiao; Gao, Yingzhe; Ma, Zhenhe; Wang, Bo; Wang, Yi

    2016-03-01

    We demonstrate a noncontact photoacoustic imaging (PAI) system in which an optical interferometer is used for ultrasound detection. The system is based on a modified optical-fiber Michelson interferometer that measures the surface displacement caused by photoacoustic pressure. A synchronization method is utilized to keep its high sensitivity to reduce the influence of ambient vibrations. The system is experimentally verified by imaging of a phantom. The experimental results indicate that the proposed system can be used for noncontact PAI with high resolution and high bandwidth.

  9. Optical non-contact floating object tracking using an open-source library

    DEFF Research Database (Denmark)

    2013-01-01

    In this paper, an optical non-contact low budget method for tracking the position of multi-object is presented for marine/off-shore laboratory applications. Particular focus is given at the wave energy field and the analysis of floating wave energy converters dynamics. The measurement of the posi......In this paper, an optical non-contact low budget method for tracking the position of multi-object is presented for marine/off-shore laboratory applications. Particular focus is given at the wave energy field and the analysis of floating wave energy converters dynamics. The measurement...

  10. Emerging blue-UV luminescence in cerium doped YAG nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Shirmane, Liana [Institute of Solid State Physics, University of Latvia, Riga (Lithuania); Pankratov, Vladimir [Research Center of Molecular Materials, University of Oulu (Finland)

    2016-06-15

    Time-resolved luminescence properties of Ce{sup 3+} doped Y{sub 3}Al{sub 5}O{sub 12} (YAG) nanocrystals have been studied by means of vacuum-ultraviolet excitation spectroscopy. It was discovered that additionally to the regular Ce{sup 3+} yellow-green emission which is well-known luminescence in YAG, new emission covering a broad spectral range from 2.7 eV to 3.5 eV was revealed in the luminescence spectra for all YAG:Ce nanocrystals studied. This blue-UV emission has fast decay time about 7 ns as well as intensive well-resolved excitation band peaking at 5.9 eV and, in contrast to green Ce{sup 3+} emission, practically is not excited at higher energies. The origin of the blue-UV emission is tentatively suggested and discussed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Bactericidal effect of Nd:YAG laser irradiation in endodontics

    Science.gov (United States)

    Aun, Carlos E.; Barberini, Alexandre F.; Camargo, Selma C. C.; Silva Kfouri, Luciana; Lorenzetti Simionato, Maria R.

    1999-05-01

    The success of endodontic therapy is based on the elimination of bacterial colonization from the endodontic system and periapical tissues. Recent studies have been showing the bactericidal effect of laser in root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canals from upper central incisor. For the experiment 12 teeth were selected, respect at the apical third, sterilized, and 10 μm Streptococcus sanguis liquid culture were inoculated in the root canals. The laser test groups were irradiated with Nd:YAG laser at standard setting of 15Hz, 100mj and 1,5 W for 10, 20 and 30 seconds each in slow helicoidal movements from the apex to the top using a 300 micrometers fiber. After the procedure the specimens were placed in Tryptic Soy Agar, the number of colony forming units was evaluated. The experiment showed a significant reduction on viability of Streptococcus sanguis at the respective time of 20 and 30 seconds.

  12. Temperature variation during apicectomy with Er:YAG laser.

    Science.gov (United States)

    Bodrumlu, Emre; Keskiner, Ilker; Sumer, Mahmut; Sumer, A Pinar; Telcıoglu, N Tuba

    2012-08-01

    The purpose of this in vitro study was to evaluate the generated temperature of the Er:YAG laser, with three different pulse durations for apicectomy, compared with tungsten bur and surgical saw. Apicectomy is an endodontic surgery performed to remove the root apex and curette adjacent periapical tissue because of lesions of the apical area that are not healing properly. Sixty single-rooted extracted human teeth were resected by three cutting methods: tungsten bur, surgical saw, and Er:YAG laser irradiation with three different pulse durations; pulse duration 50 μs, pulse duration 100 μs, and pulse duration 300 μs. Teflon-insulated, type K thermocouples were used to measure temperature changes during the apicectomy process. Data were analyzed using the general linear models procedure of the SPSS statistical software program. Although there was no statistically significant difference for the mean values of temperature changes at 1 mm away to the cutting site of teeth, there was statistically significant difference among groups for the mean values of temperature changes at 3 mm away to the cutting site of teeth. Additionally, there was statistically significant difference among groups for the total time required for apicectomy. The laser irradiation with pulse duration 50 μs appears to have the lowest temperature rise and the shortest time required for apicectomy of the three pulse durations. However, Er:YAG laser for apicectomy in all pulse durations could be used safely for resection in endodontics in the presence of sufficient water.

  13. Accidental macular hole following Neodymium:YAG posterior capsulotomy

    Directory of Open Access Journals (Sweden)

    Munteanu Mihnea

    2014-01-01

    Full Text Available Introduction. Posterior capsular opacification (PCO is the commonest complication of cataract surgery, occurring in up to one-third of patients in a period of five years. The treatment of choice is the Neodymium:YAG laser posterior capsulotomy. This treatment can be associated with several complications, some of them severe. A rare complication of this procedure is the accidental induced macular hole. Case Outline. A 54-year-old female patient was referred to our Department because of a severe loss of vision and a central scotoma at the right eye. The patient underwent a Nd:YAG posterior capsulotomy 2 days ago, for a PCO. The fundus examination at presentation revealed a round retinal defect in the macular region, a massive inferior preretinal hemorrhage and a mild vitreous hamorrhage. A 6-months follow-up of the case, including retinography and fluorescein angiography, is presented. Conclusion. Although the Nd:YAG laser capsulotomy is a safe, noninvasive, and effective outpatient procedure to improve vision hindered by PCO, it must be recognized that it carries a low but definite risk of serious complications. Physicians and patients should be aware of these rare but severe complications regarding this otherwise safe procedure. Fortunately, most of the complications related to this procedure are transient and can be managed by proper medication.

  14. Amalgam Surface Treatment by Different Output Powers of Er:YAG Laser:SEM Evaluation.

    Science.gov (United States)

    Hosseini, Mohammad Hashem; Hassanpour, Mehdi; Etemadi, Ardavan; Ranjbar Omrani, Ladan; Darvishpour, Hojat; Chiniforush, Nasim

    2015-01-01

    The purpose of this study was to evaluate amalgam surfaces treated by different output powers of erbium-doped yttrium aluminum garnet (Er:YAG) laser by scanning electron microscope (SEM). Twenty-one amalgam blocks (8 mm × 8 mm, 3 mm thickness) were prepared by condensing silver amalgam (into putty impression material. After keeping them for 24 hours in distilled water, they were divided into 7 groups as follow: G1: Er:YAG laser (1 W, 50 mJ), G2: Er:YAG laser (2 W, 100 mJ), G3: Er:YAG laser (3 W, 150 mJ), G4: Sandblast, G5: Sandblast + Er:YAG laser (1 W, 50 mJ), G6: Sandblast +Er:YAG laser (2 W, 100 mJ) and G7: Sandblast +Er:YAG laser (3 W, 150 mJ). Then after preparation of all samples, they were examined by SEM. The SEM results of amalgam surfaces treated by different output powers of Er:YAG laser showed some pitting areas with non-homogenous irregularities Conclusion: It seems that the application of sandblasting accompanied by Er:YAG laser irradiation can provide proper surface for bonding of orthodontic brackets.

  15. Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial

    Directory of Open Access Journals (Sweden)

    de Jong Hugo WAM

    2010-06-01

    Full Text Available Abstract Background Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid microspheres ( 166Ho-PLLA-MS have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases. Methods The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively. The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution. Discussion This will be the first clinical study on 166Ho-RE. Based on

  16. Application of the NANOMEFOS non-contact measurement machine in asphere and freeform optics production

    NARCIS (Netherlands)

    Henselmans, R.; Gubbels, G.P.H.; Drunen, C. van

    2010-01-01

    The NANOMEFOS machine is capable of fast, non-contact and universal measurement of aspheres and freeforms, up to ø500 mm with a measurement uncertainty below 30 nm (2σ). It is now being applied in asphere and freeform production at TNO.

  17. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions...

  18. Antimicrobial penetration in a dual-species oral biofilm after noncontact brushing : an in vitro study

    NARCIS (Netherlands)

    He, Y.; Peterson, B. W.; Ren, Y.; van der Mei, H. C.; Busscher, H. J.

    2014-01-01

    Oral biofilm is inevitably left behind, even after powered brushing. As a special feature, powered brushing removes biofilm in a noncontact mode. When the brushing distance becomes too large, biofilm is left behind. We hypothesize that biofilm left behind after brushing has different viscoelastic pr

  19. NONCONTACT MEASUREMENT OF ULTRASONIC VELOCITY IN LIQUID USING PULSED PHOTOACOUSTIC TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    王钦华; 黄孟才

    1993-01-01

    Based on the theory of the pulsed photoacoustic signal in liquid generated by a pulsed laser, a novel, optically noncontact, fast and accurate method for temperature-dependent ultrasonic velocities for ethanol and water has been demonstrated. The experiment results are in good agreemerit with literature values.

  20. A High Revolution Speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

    Institute of Scientific and Technical Information of China (English)

    YANG Bin; LIU Jing-Quan; CHEN Di; CAI Bing-Chu

    2005-01-01

    @@ A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque.

  1. Atomic Steps with tuning-fork-based noncontact atomic force microscopy

    NARCIS (Netherlands)

    Rensen, W.H.J.; Hulst, van N.F.; Ruiter, A.G.T.; West, P.E.

    1999-01-01

    Tuning forks as tip-sample distance detectors are a promising and versatile alternative to conventional cantilevers with optical beam deflection in noncontact atomic force microscopy (AFM). Both theory and experiments are presented to make a comparison between conventional and tuning-fork-based AFM.

  2. Electric force microscopy of semiconductors: Theory of cantilever frequency fluctuations and noncontact friction

    Energy Technology Data Exchange (ETDEWEB)

    Lekkala, Swapna; Marohn, John A.; Loring, Roger F., E-mail: roger.loring@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 (United States)

    2013-11-14

    An electric force microscope employs a charged atomic force microscope probe in vacuum to measure fluctuating electric forces above the sample surface generated by dynamics of molecules and charge carriers. We present a theoretical description of two observables in electric force microscopy of a semiconductor: the spectral density of cantilever frequency fluctuations (jitter), which are associated with low-frequency dynamics in the sample, and the coefficient of noncontact friction, induced by higher-frequency motions. The treatment is classical-mechanical, based on linear response theory and classical electrodynamics of diffusing charges in a dielectric continuum. Calculations of frequency jitter explain the absence of contributions from carrier dynamics to previous measurements of an organic field effect transistor. Calculations of noncontact friction predict decreasing friction with increasing carrier density through the suppression of carrier density fluctuations by intercarrier Coulomb interactions. The predicted carrier density dependence of the friction coefficient is consistent with measurements of the dopant density dependence of noncontact friction over Si. Our calculations predict that in contrast to the measurement of cantilever frequency jitter, a noncontact friction measurement over an organic semiconductor could show appreciable contributions from charge carriers.

  3. Quantification of tip-broadening in non-contact atomic force microscopy with carbon nanotube tips

    DEFF Research Database (Denmark)

    Meinander, Kristoffer; Jensen, Thomas N.; Simonsen, Soren B.

    2012-01-01

    Carbon nanotube terminated atomic force microscopy (AFM) probes have been used for the imaging of 5 nm wide surface supported Pt nanoclusters by non-contact (dynamic mode) AFM in an ultra-high vacuum. The results are compared to AFM measurements done with conventional Si-tips, as well...

  4. Noncontact excitation of guided waves (A0 mode) using an electromagnetic acoustic transducer (EMAT)

    Science.gov (United States)

    Fromme, Paul

    2016-02-01

    Fatigue damage can develop in aircraft structures at locations of stress concentration, such as fasteners, and has to be detected before reaching a critical size to ensure safe aircraft operation. Guided ultrasonic waves offer an efficient method for the detection and characterization of such defects in large aerospace structures. Electromagnetic acoustic transducers (EMAT) for the noncontact excitation of guided ultrasonic waves were developed. The transducer development for the specific excitation of the A0 Lamb wave mode with an out-of-plane Lorentz force is explained. The achieved radial and angular dependency of the excited guided wave pulses were measured using a noncontact laser interferometer. Based on the induced eddy currents in the plate a theoretical model was developed. The application of the developed transducers for defect detection in aluminum components using fully noncontact guided wave measurements was demonstrated. Excitation of the A0 Lamb wave mode was achieved using the developed EMAT transducer and the guided wave propagation and scattering was measured using a noncontact laser interferometer.

  5. A Calibration-Free, Noncontact, Disposable Liquid Dispensing Cartridge Featuring an Online Process Control.

    Science.gov (United States)

    Bammesberger, Stefan Borja; Malki, Imad; Ernst, Andreas; Zengerle, Roland; Koltay, Peter

    2014-08-01

    We present a noncontact liquid dispenser that uses a disposable cartridge for the calibration-free dosage of diverse biochemical reagents from the nanoliter to the microliter range. The dispensing system combines the advantages of a positive displacement syringe pump (responsible for defining the aliquot's volume with high accuracy) with a highly dynamic noncontact dispenser (providing kinetic energy to detach the liquid from the tip). The disposable, noncontact dispensing cartridge system renders elaborate washing procedures of tips obsolete. A noncontact sensor monitors the dispensing process to enable an online process control. To further increase confidence and reliability for particularly critical biomedical applications, an optional closed-loop control prevents malfunctions. The dispensing performance was characterized experimentally in the range of 0.25 to 10.0 µL using liquids of different rheological properties (viscosity 1.03-16.98 mPas, surface tension 30.49-70.83 mN/m) without adjusting or calibrating the actuation parameters. The precision ranged between a coefficient of variation of 0.5% and 5.3%, and the accuracy was below ±10%. The presented technology has the potential to contribute significantly to the improvement of biochemical liquid handling for laboratory automation in terms of usability, miniaturization, cost reduction, and safety.

  6. Simultaneous epicardial and noncontact endocardial mapping of the canine right atrium: simulation and experiment.

    Science.gov (United States)

    Sabouri, Sepideh; Matene, Elhacene; Vinet, Alain; Richer, Louis-Philippe; Cardinal, René; Armour, J Andrew; Pagé, Pierre; Kus, Teresa; Jacquemet, Vincent

    2014-01-01

    Epicardial high-density electrical mapping is a well-established experimental instrument to monitor in vivo the activity of the atria in response to modulations of the autonomic nervous system in sinus rhythm. In regions that are not accessible by epicardial mapping, noncontact endocardial mapping performed through a balloon catheter may provide a more comprehensive description of atrial activity. We developed a computer model of the canine right atrium to compare epicardial and noncontact endocardial mapping. The model was derived from an experiment in which electroanatomical reconstruction, epicardial mapping (103 electrodes), noncontact endocardial mapping (2048 virtual electrodes computed from a 64-channel balloon catheter), and direct-contact endocardial catheter recordings were simultaneously performed in a dog. The recording system was simulated in the computer model. For simulations and experiments (after atrio-ventricular node suppression), activation maps were computed during sinus rhythm. Repolarization was assessed by measuring the area under the atrial T wave (ATa), a marker of repolarization gradients. Results showed an epicardial-endocardial correlation coefficients of 0.80 and 0.63 (two dog experiments) and 0.96 (simulation) between activation times, and a correlation coefficients of 0.57 and 0.46 (two dog experiments) and 0.92 (simulation) between ATa values. Despite distance (balloon-atrial wall) and dimension reduction (64 electrodes), some information about atrial repolarization remained present in noncontact signals.

  7. Simultaneous epicardial and noncontact endocardial mapping of the canine right atrium: simulation and experiment.

    Directory of Open Access Journals (Sweden)

    Sepideh Sabouri

    Full Text Available Epicardial high-density electrical mapping is a well-established experimental instrument to monitor in vivo the activity of the atria in response to modulations of the autonomic nervous system in sinus rhythm. In regions that are not accessible by epicardial mapping, noncontact endocardial mapping performed through a balloon catheter may provide a more comprehensive description of atrial activity. We developed a computer model of the canine right atrium to compare epicardial and noncontact endocardial mapping. The model was derived from an experiment in which electroanatomical reconstruction, epicardial mapping (103 electrodes, noncontact endocardial mapping (2048 virtual electrodes computed from a 64-channel balloon catheter, and direct-contact endocardial catheter recordings were simultaneously performed in a dog. The recording system was simulated in the computer model. For simulations and experiments (after atrio-ventricular node suppression, activation maps were computed during sinus rhythm. Repolarization was assessed by measuring the area under the atrial T wave (ATa, a marker of repolarization gradients. Results showed an epicardial-endocardial correlation coefficients of 0.80 and 0.63 (two dog experiments and 0.96 (simulation between activation times, and a correlation coefficients of 0.57 and 0.46 (two dog experiments and 0.92 (simulation between ATa values. Despite distance (balloon-atrial wall and dimension reduction (64 electrodes, some information about atrial repolarization remained present in noncontact signals.

  8. Noncontact remineralization of incipient lesions treated with a 5% sodium fluoride varnish in vitro.

    Science.gov (United States)

    Karlinsey, Robert L; Mackey, Allen C; Dodge, Lauren E; Schwandt, Craig S

    2014-01-01

    Fluoride varnishes are appealing topical fluoride preparations that may provide anticaries benefits. The purpose of this in vitro study was to assess the noncontact remineralization effects of a commercial 5% sodium fluoride varnish on white spot lesions (WSLs). Three-millimeter diameter enamel cores were extracted from bovine teeth, mounted in acrylic rods, ground and polished, and initially demineralized to create WSLs. Specimens were evaluated for surface microhardness and divided (N=6) into two groups (water control or noncontact 5% sodium fluoride white varnish with tricalcium phosphate, where one 0.50 ml unit dose was applied to acrylic rods instead of directly on WSLs). Groups were cycled in a three-day regimen consisting of two rounds of one-hour treatments and one-hour static immersions in demineralization solution. Between these events, WSLs were immersed in artificial saliva. Remineralization was evaluated using surface and cross-sectional microhardness and high-resolution scanning electron microscopy (SEM). The noncontact varnish treatment produced significantly greater percent surface microhardness recoveries (Pvarnish. Noncontact application of a commercial 5% sodium fluoride varnish reduced white spot lesion porosity and produced significant acid-resistant white spot lesion remineralization.

  9. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury

    DEFF Research Database (Denmark)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars Louis

    2016-01-01

    BACKGROUND: Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular phenome...

  10. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate.

    Directory of Open Access Journals (Sweden)

    Keisuke Saito

    Full Text Available In order to investigate how holmium laser enucleation of the prostate (HoLEP improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53-88 underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS, IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS, uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2. The median IPSS improved significantly from 20 (range: 6-35 to 3 (0-22 (p < 0.001; Wilcoxon signed-rank test, as did the storage symptoms score, which decreased from 13 (2-20 to 3 (1-8 (p < 0.001. Median bladder blood flow increased at the trigone from 9.57 ± 0.83 ml/sec to 17.60 ± 1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms.

  11. Targeting of liver tumour in rats by selective delivery of holmium-166 loaded microspheres: a biodistribution study

    Energy Technology Data Exchange (ETDEWEB)

    Nijsen, F.; Rook, D.; Zonnenberg, B.; Klerk, J. de; Rijk, P. van; Schip, F. van het [Dept. of Nuclear Medicine, University Medical Center, Utrecht (Netherlands); Brandt, C. [Animal Inst., Utrecht Univ. (Netherlands); Meijer, R. [Dept. of Radiology, Univ. Medical Center, Utrecht (Netherlands); Dullens, H. [Dept. of Pathology, Univ. Medical Center, Utrecht (Netherlands); Hennink, W. [Dept. of Pharmaceutics, Utrecht Univ. (Netherlands)

    2001-06-01

    Intra-arterial administration of beta-emitting particles that become trapped in the vascular bed of a tumour and remain there while delivering high doses, represents a unique approach in the treatment of both primary and metastatic liver tumours. Studies on selective internal radiation therapy of colorectal liver metastases using yttrium-90 glass microspheres have shown encouraging results. This study describes the biodistribution of 40-{mu}m poly lactic acid microspheres loaded with radioactive holmium-166, after intra-arterial administration into the hepatic artery of rats with implanted liver tumours. Radioactivity measurements showed >95% retention of injected activity in the liver and its resident tumour. The average activity detected in other tissues was {<=}0.1%ID/g, with incidental exceptions in the lungs and stomach. Very little {sup 166}Ho activity was detected in kidneys (<0.1%ID/g), thereby indicating the stability of the microspheres in vivo. Tumour targeting was very effective, with a mean tumour to liver ratio of 6.1{+-}2.9 for rats with tumour (n=15) versus 0.7{+-}0.5 for control rats (n=6; P<0.001). These ratios were not significantly affected by the use of adrenaline. Histological analysis showed that five times as many large (>10) and medium-sized (4-9) clusters of microspheres were present within tumour and peritumoural tissue, compared with normal liver. Single microspheres were equally dispersed throughout the tumour, as well as normal liver parenchyma. (orig.)

  12. Preparation of Terbium Sesquisulfide and Holmium Sesquisulfide by Sulfurization of Their Oxide Powders Using CS2 Gas

    Institute of Scientific and Technical Information of China (English)

    Yuan Haibin; Michihiro Ohta; Shinji Hirai; Toshiyuki Nishimura; Kazuyoshi Shimakage

    2004-01-01

    The formation behaviors of terbium sesquisulfide(Tb2S3)and holmium sesquisulfide(Ho2S3)synthesized via the sulfurization of their oxide powders using CS2 gas in the range of temperature 673 to 1323 K were investigated. In the sulfurization of Tb4O7 powder, Tb2O3 and Tb2O2S were formed in the initial stage of reaction, and α-Tb2S3 was finally formed at higher temperature. For long sulfurization time of 8 h, single-phase α-Tb2S3 could be synthesized at 1323 K. In the sulfurization of Ho2O3 powder using CS2 gas, only Ho2O2S was formed as an intermediate product. At a sulfurization temperature above 873 K, Ho2O2S was formed in the initial stage of reaction, and single-phase δ-Ho2S3 was formed at 1323 K for 8 h instead of Ho2O2S. Furthermore, the influence of the addition of carbon black to the sulfurization of Ho2O3 powder using CS2 gas was investigated, and the result implied that the reactions were accelerated slightly by the addition of carbon black.

  13. Holmium laser enucleation of the prostate (HoLEP) for small, large and giant prostatic hyperplasia: tips and tricks.

    Science.gov (United States)

    Glybochko, Petr V; Rapoport, Leonid M; Enikeev, Mikhail E; Enikeev, Dmitry V

    2017-08-01

    Holmium laser enucleation of the prostate (HoLEP) allows to treat extremely large prostates (>200 cm3). The aim of the study was to compare the efficiency of HoLEP for prostates of different sizes. Four hundred and fifty-nine patients were divided into three groups: group 1 included 278 patients (200 cm3). The duration of enucleation in group 1 was 56.5 ± 10.7 min; in group 2 was 96.4 ± 24.9 min; in group 3 was 120.9 ± 35 min. The duration of morcellation in group 1 was 37.5 ± 7.3 min; in group 2 was 63.3 ± 11.2 min; in group 3 was 84.0 ± 25.6 min. The enucleation efficiency in group 3 (1.70 g/min) was higher (p0.05) in International Prostate Symptom Score, Qmax, quality of life and postvoid residual volume for 1, 3, 6, 12 and 18 months after surgery. HoLEP is a safe, highly efficacious and a size-independent procedure.

  14. All solid-state diode pumped Nd:YAG MOPA with stimulated Brillouin phase conjugate mirror

    NARCIS (Netherlands)

    Offerhaus, H.L.; Godfried, H.P.; Witteman, W.J.

    1996-01-01

    At the Nederlands Centrum voor Laser Research (NCLR) a 1 kHz diode-pumped Nd:YAG Master Oscillator Power Amplifier (MOPA) chain with a Stimulated Brillouin Scattering (SBS) Phase Conjugate mirror is designed and operated. A small Brewster angle Nd:YAG slab (2 by 2 by 20 mm) is side pumped with 200 μ

  15. Nd:YAG Lasers Treating of Carious Lesion and Root Canal In Vitro

    Directory of Open Access Journals (Sweden)

    Danqing Xia

    2012-01-01

    Full Text Available Dental caries is a transmissible bacterial disease process, with cavities at the end, and caused by acids from bacterial metabolism. The essence of dental treatment is to clean and disinfect bacterial contamination from the tooth. In this work, we tried to demonstrate the cleaning and disinfecting effects of Nd:YAG laser irradiation on dental carious lesion and root canal in vitro. Acousto-optic Q-switched quasicontinuous and Cr3+:YAG crystal Q-switched pulse Nd:YAG lasers were employed to treat caries lesion and the root canal, respectively. Results showed that acousto-optic Q-switched quasicontinuous Nd:YAG laser irradiation and Cr3+:YAG crystal Q-switched pulse Nd:YAG laser irradiation could rapidly clean decayed material and bacterial contamination from dental carious lesion and the narrow tail end of root canal with minimally invasive in vitro, respectively. It was concluded that acousto-optic Q-switched quasicontinuous laser irradiation may be a rapid and effective alternative caries treatment, and Cr3+:YAG crystal Q-switched pulse Nd:YAG laser irradiation may be an effective method for canal cleaning and disinfecting during root canal therapy.

  16. Effect of Nd:YAG laser capsulotomy on refraction in multifocal apodized diffractive pseudophakia.

    NARCIS (Netherlands)

    Vrijman, V.; Linden, J.W.M. van der; Nieuwendaal, C.P.; Meulen, I.J. van der; Mourits, M.P.; Lapid-Gortzak, R.

    2012-01-01

    PURPOSE: To evaluate the effect on refraction of neodymium:YAG (Nd:YAG) laser posterior capsulotomy for posterior capsule opacification (PCO), and to evaluate the correlation between automated and subjective refraction in multifocal apodized diffractive pseudophakia. METHODS: A retrospective study

  17. Histological and TEM examination of early stages of bone healing after Er:YAG laser irradiation.

    Science.gov (United States)

    Pourzarandian, Amir; Watanabe, Hisashi; Aoki, Akira; Ichinose, Shizuko; Sasaki, Katia M; Nitta, Hiroshi; Ishikawa, Isao

    2004-08-01

    The aim of this study was to analyze the early healing process of bone tissue irradiated by Er:YAG laser and compare it with that treated by mechanical drilling and CO(2) laser. Er:YAG laser has a great potential for cutting hard tissues as it is capable of ablation with less thermal damage. Twenty-four male Wistar rats were used for this study. The calvarial bone of rats was exposed and straight grooves were prepared by Er:YAG laser, mechanical bur and continuous wave CO(2) laser. Four rats each were sacrificed at six time points: 10 min, 6 and 24 h and 3, 7, and 14 days post-surgery. Sections were prepared for light and transmission electron microscopic (TEM) observations. Compared to mechanical bur and CO(2) groups, the inflammatory cell infiltration adjacent to the irradiated bone surface, fibroblastic reaction, and revascularization were more pronounced in the Er:YAG laser-irradiated tissues. A cell-rich granulation tissue with fibroblasts and osteoblasts was predominant in 7-day specimens of Er:YAG laser group. Histopathological analysis of 14-day specimens in the Er:YAG group also revealed significantly greater new bone formation, compared with the mechanical bur and CO(2) laser groups. Initial bone healing following Er:YAG laser irradiation occurred faster than that after mechanical bur and CO(2) laser. Er:YAG laser treatment may be advantageous for wound healing of bone tissue, presumably by providing a favorable surface for cell attachment.

  18. Er:YAG crystal temperature influence on laser output characteristics

    Science.gov (United States)

    Němec, Michal; Å ulc, Jan; Hubka, Zbyněk.; Hlinomaz, Kryštof; Jelínková, Helena

    2017-02-01

    The main goal of this work was to investigate the influence of the temperature of the Er:YAG active medium on laser properties in eye-safe spectral region for three various pump wavelengths. The tested Er:YAG sample doped by 0.5% of Er3+ ions had a cylindrical shape with 25mm in length and 5mm in diameter. The absorption spectrum of the Er:YAG active medium in the range from 1400nm up to 1700nm for temperatures 80K and 300K was measured. The crystal was placed inside the vacuum chamber of a liquid nitrogen cooled cryostat. The temperature was controlled within the 80 - 340K temperature range. Three pump sources generating at 1535, 1452, and 1467nm were applied. The first one was flash lamp pumped Er:glass laser (repetition rate 0.5 Hz, pulse duration 1 ms, pulse energy 148 mJ). The further two sources were fiber coupled laser diodes (repetition rate 10 Hz, pulse duration 10 ms, maximum pulse energies 106mJ and 195 mJ). The semi-hemispherical laser resonator consisted of a pump curved mirror and output plan coupler with a reflectivity of 90% @ 1645 nm. The laser output characteristics were investigated in dependence on temperature of active medium for three laser pumping systems. The output energy has an optimum in dependence on active medium temperature and pump wavelengths. The maximal generated laser energies were 16.2mJ (90 K), 28.7mJ (120 K), and 33.2mJ (220 K), for pump wavelengths 1452 nm, 1467 nm, and 1535 nm, respectively.

  19. Vitreous humor rheology after Nd:YAG laser photo disruption.

    Science.gov (United States)

    Abdelkawi, Salwa A; Abdel-Salam, Ahmed M; Ghoniem, Dina F; Ghaly, Sally K

    2014-03-01

    This work aimed to consider the hazardous side effect of eye floaters treatment with Q-switched Nd:YAG laser on the protein and viscoelastic properties of the vitreous humor, and evaluate the protective role of vitamin C against laser photo disruption. Five groups of New Zealand rabbits were divided as follows: control group for (n = 3) without any treatment, the second group (n = 9) treated with Q-switched Nd:YAG laser energy of 5 mJ × 100 pulse delivered to the anterior, middle, and posterior vitreous, respectively (n = 3 for each). The third group (n = 9) received a daily dose of 25 mg/kg body weight vitamin C for 2 weeks, and then treated with laser as the previous group. The fourth group (n = 9) treated with 10 mJ 9 50 pulse delivered to the anterior, middle, and posterior vitreous, respectively (n = 3 rabbits each). The fifth group (n = 9) received a daily dose of 25 mg/kg body weight vitamin C for 2 weeks, and then treated with laser as the previous group. After 2 weeks of laser treatment, the protein content, refractive index (RI), and the rheological properties of vitreous humor, such as consistency, shear stress, and viscosity, were determined. The results showed that, the anterior vitreous group exposed to of 5 mJ × 100 pulse and/or supplemented with vitamin C, showed no obvious change. Furthermore, all other treated groups especially for mid-vitreous and posterior vitreous humor showed increase in the protein content, RI and the viscosity of vitreous humor. The flow index remained below unity indicating the non-Newtonian behavior of the vitreous humor. Application of Q-switched Nd:YAG laser should be restricted to the anterior vitreous humor to prevent the deleterious effect of laser on the gel state of the vitreous humor.

  20. Transmission of Er:YAG laser through different dental ceramics.

    Science.gov (United States)

    Sari, Tugrul; Tuncel, Ilkin; Usumez, Aslihan; Gutknecht, Norbert

    2014-01-01

    The aim of this study was to determine the erbium-doped yttrium aluminum garnet (Er:YAG) laser transmission ratio through different dental ceramics with different thicknesses. Laser debonding procedure of adhesively luted all-ceramic restorations is based on the transmission of laser energy through the ceramic and the ablation of resin cement, because of the transmitted laser energy. Five different dental ceramics were evaluated in this study: sintered zirconium-oxide core ceramic, monolithic zirconium-oxide ceramic, feldspathic ceramic, leucite-reinforced glass ceramic, and lithium disilicate-reinforced glass ceramic. Two ceramic discs with different thicknesses (0.5 and 1 mm) were fabricated for each group. Ceramic discs were placed between the sensor membrane of the laser power meter and the tip of the contact handpiece of an Er:YAG laser device with the aid of a custom- made acrylic holder. The transmission ratio of Er:YAG laser energy (500 mJ, 2 Hz, 1 W, 1000 μs) through different ceramic discs was measured with the power meter. Ten measurements were made for each group and the results were analyzed with two way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. The highest transmission ratio was determined for lithium disilicate-reinforced ceramic with 0.5 mm thickness (88%) and the lowest was determined for feldspathic ceramic with 1 mm thickness (44%). The differences among the different ceramics and between the different thicknesses were significant (pCeramic type and thickness should be taken into consideration to adjust the laser irradiation parameters during laser debonding of adhesively luted all-ceramic restorations.

  1. Influence of the Ce:YAG Amount on Structure and Optical Properties of Ce:YAG-PMMA Composites for White LED

    Science.gov (United States)

    Armetta, Francesco; Sibeko, Motshabi A.; Luyt, Adriaan S.; Chillura Martino, Delia F.; Spinella, Alberto; Saladino, Maria Luisa

    2016-09-01

    Ce:YAG-poly(methyl methacrylate) (PMMA) composites were prepared by using a melt compounding method, adding several amounts of Ce:YAG in the range 0.1-5 wt. %. The optical properties of the obtained composites and of the composites combined with a blue LED were measured to investigate the effect of the amount of Ce:YAG on the resulting emitted light in view of possible application in white LED manufacture. An increase in Ce:YAG amount caused an increase in the emission and a shift of 15 nm, influencing the white LED performance. The structure and morphology of the composites were studied. The results show that the interaction between the two components, observed by using solid state NMR experiments, are the responsible for the observed shift.

  2. Ignition of an automobile engine by high-peak power Nd:YAG/Cr⁴⁺:YAG laser-spark devices.

    Science.gov (United States)

    Pavel, Nicolaie; Dascalu, Traian; Salamu, Gabriela; Dinca, Mihai; Boicea, Niculae; Birtas, Adrian

    2015-12-28

    Laser sparks that were built with high-peak power passively Q-switched Nd:YAG/Cr(4+):YAG lasers have been used to operate a Renault automobile engine. The design of such a laser spark igniter is discussed. The Nd:YAG/Cr(4+):YAG laser delivered pulses with energy of 4 mJ and 0.8-ns duration, corresponding to pulse peak power of 5 MW. The coefficients of variability of maximum pressure (COV(Pmax)) and of indicated mean effective pressure (COV(IMEP)) and specific emissions like hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NO(x)) and carbon dioxide (CO2) were measured at various engine speeds and high loads. Improved engine stability in terms of COV(Pmax) and COV(Pmax) and decreased emissions of CO and HC were obtained for the engine that was run by laser sparks in comparison with classical ignition by electrical spark plugs.

  3. Neodymium YAG lasers pumped by light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Bilak, V.I.; Goldobin, I.S.; Zverev, G.M.; Kuratev, I.I.; Pashkov, V.A.; Stel' makh, M.F.; Tsvetkov, Y.V.; Solov' eva, N.M.

    1981-11-01

    The results are presented of theoretical and experimental investigations of room-temperature YAG:Nd lasers pumped by light-emitting diodes. The lasing characteristics of a laser operated at the 1.06 and 1.32 ..mu.. wavelengths were investigated in the cw and pulsed regimes and dependences of its parameters on the temperature, pulse repetition frequency, and other factors were studied. In the pulsed regime the laser efficiency was 0.2% and in the cw regime the radiation power reached 50 and 17 mW at the 1.06 and 1.32 ..mu.. wavelengths, respectively.

  4. Cooperative emission in ion implanted Yb:YAG waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

    2011-01-01

    In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

  5. Tapered diode laser pumped 946 nm Nd:YAG laser

    DEFF Research Database (Denmark)

    Cheng, Haynes Pak Hay; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2009-01-01

    We successfully implemented a 946 nm Nd:YAG laser based on a 808 nm tapered diode pump laser. The tapered diode is developed at the Ferdinand-Braun-Institute fur Hochstfrequenztechnik in Germany. Figure 2 shows the experimental setup and results of each pump source coupled into a 1.5 mm crystal...... laser, we show that tapered diode laser pumping potentially increase the power of 946 nm lasers by a factor of two and reduce the threshold by a factor of three....

  6. Effect of transscleral neodymium: YAG cyclophotocoagulation on intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Blomquist, P.H.; Gross, R.L.; Koch, D.D. (Baylor College of Medicine, Houston, TX (USA))

    1990-03-01

    A neodymium: YAG laser operating in the thermal mode was used to irradiate isolated intraocular lenses (IOLs) and to perform transscleral cyclophotocoagulation on pseudophakic autopsy eyes to investigate the potential damage to IOL haptics such irradiation may cause. In the isolated IOLs, 70 mJ of energy deformed and partially melted both polymethylmethacrylate (PMMA) and polypropylene haptics. One of the capsular-fixated PC-IOL haptics in an autopsy eye partially melted when irradiated with the maximum energy level (8.8 J), with the aiming beam focused 1 mm posterior to the limbus and maximal posterior focus offset.

  7. Dual-polarization mode-locked Nd:YAG laser.

    Science.gov (United States)

    Thévenin, J; Vallet, M; Brunel, M

    2012-07-15

    A mode-locked solid-state laser containing a birefringent element is shown to emit synchronously two frequency combs associated to the two polarization eigenstates of the cavity. An analytical model predicts the polarization evolution of the pulse train, which is determined by the adjustable intracavity birefringence. Experiments realized with a Nd:YAG laser passively mode locked by a semiconductor saturable absorber mirror are in perfect agreement with the model. Locking between the two combs arises for particular values of their frequency difference, e.g., half the repetition rate, and the pulse train polarization sequence is then governed by the relative overall phase offset of the two combs.

  8. Neodymium YAG laser for treatment of oral cavernous hemangiomas

    Science.gov (United States)

    Bradley, Paul F.

    1999-02-01

    Oral cavernous haemangiomas are common lesions which may require treatment due to episodes of bleeding when bitten or deformity particularly when involving the lips and/or cheeks. Surgery can be hazardous due to haemorrhage while cryosurgery tends to be tedious for large lesions and be accompanied by major oedema. Sclerosants produce hard bulky masses. Embolization is seldom helpful due to lack of arterial feeders. The Nd:YAG laser is proving a useful modality in the oro-facial region and appeared worth investigating for these lesions in a laboratory animal model, by thermography and in the clinical situation.

  9. Treatment of rosacea with long-pulsed Nd: YAG laser

    Directory of Open Access Journals (Sweden)

    Ekin Meşe Say

    2013-03-01

    Full Text Available Background and Design: Rosacea is a chronic inflammatory disorder of the face. There is no curative treatment for the disease. Facial flushing and vascular lesions due to rosacea may significantly affect a patient’s quality of life. Topical and oral antibiotics are not effective for treating rosacea. Currently, laser treatment of vascular lesions has been reported in the literature. We aimed to investigate the efficacy of long-pulse 1064-nm neodymium: YAG (Nd: YAG laser in the treatment of vascular lesions (erythema and telangiectasia in rosacea patients. Materials and Methods: Thirty-nine patients (29 women, 10 men with erythematotelangiectatic rosacea (ETR were recruited into the study. Severity of the disease (ETR-score: 0-3 was assessed for all patients. We used long-pulsed Nd: YAG laser for vascular lesions at 3-4 weeks intervals. The face was divided into seven anatomic regions for evaluation. Assessment was made by comparing pretreatment and posttreatment photographs by using ETR-scores. For evaluating patient satisfaction, a scale of 0 to 3 was used. Results: The patients were divided into three groups according to the ETR scores [ETR-1 (n=12, ETR-2 (n=9, ETR-3 (n=18]. Following an average of 3.95 (2-8 sessions laser treatments, the clinical improvement was statistically significant in all groups (p<0.05. The mean reduction of ETR-score was 91.70% in patients with ETR-1 and. the clinical improvement was to be decreased in severe forms of ETR. The most common sites for the lesions were the malar region, ala nasi and the nasal dorsum, respectively. The lesions on the ala nasi were more recalcitrant to the treatment than those on the other areas. Regarding to physician assessment of treatment’s success, 97% of the patients was associated with moderate and excellent improvement. According to physicians’ assessment, excellent improvement was noticed in 43.58% and, 61.5% of patients reported a high degree of satisfaction with this

  10. Studies on Nd∶YAG Single-pass Amplifiers for High-power Q-switched Laser System

    Institute of Scientific and Technical Information of China (English)

    CAO Sansong(曹三松); ZHANG Xiangyang(张向阳); HUANG Yanlin(黄燕琳); LI Guangrong(李光荣); SU Xinzhi(苏心智)

    2002-01-01

    The output of Nd∶YAG single-pass laser amplifiers is studied analytically and experimentally. Methods of analysis for single-pass Nd∶YAG laser amplifier are presented. A flashlamp-pumped Q-switched Nd∶YAG oscillator/amplifier laser system has been developed with the average output power of 121.5 W.

  11. Microstructural characteristics of Nd:YAG powders leading to transparent ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaolin; LIU Duo; LIU Hong; WANG Jiyang; QIN Haiming; SANG Yuanhua

    2011-01-01

    We reported on the successful synthesis of the Nd:YAG (Nd:Y3Al5O12) nano-powders by using urea as the precipitant with the microwave assisted homogeneous precipitation (MAHP) method. The different microstructural characteristics of the Nd:YAG nano-powders were affected by the concentrations of (Y3++Nd3+) and Al3+ ([Y3++Nd3+]=0.06 mol/L, [Al3+]=0.1 mol/L), aging time (6 d) and aging condition (in vessel). The optimum microstructural characteristics of the high quality Nd:YAG nano-powders leading to transparent Nd:YAG ceramics including the pure YAG phase, the smallest crystallite size, a uniform crystallite size distribution, less density defects, uniform micro-components and the proper molar ratio of (Y3++Nd3+) and Al3+ (0.6148) were discussed.

  12. One Step Combustion Synthesis Of YAG:Ce Phosphor For Solid State Lighting

    Science.gov (United States)

    Yadav, Pooja; Gupta, K. Vijay Kumar; Muley, Aarti; Joshi, C. P.; Moharil, S. V.

    2011-10-01

    YAG:Ce is an important phosphor having applications in various fields ranging from solid state lighting to scintillation detectors. YAG phosphors doped with activators are mainly synthesized by solid state reaction techniques that require high sintering temperatures (above 1500°C) to eliminate YAM and YAP phases. Though several soft chemical routes have been explored for synthesis of YAG, most of these methods are complex and phase pure materials are not obtained in one step, but prolonged annealing at temperatures around 1000 C or above becomes necessary. One step combustion synthesis of YAG:Ce3+ and related phosphors carried out at 500 C furnace temperature is reported here. Activation with Ce3+ could be achieved during the synthesis without taking recourse to any post-combustion thermal treatment. LEDs prepared from the combustion synthesized YAG:Ce3+, exhibited properties comparable to those produced from the commercial phosphor.

  13. Analysis of the thermal effects in diode-pumped Tm:YAG ceramic slab lasers

    Science.gov (United States)

    Cheng, Xiaojin; Shang, Jianhua; Jiang, Benxue

    2017-03-01

    Tm:YAG ceramics with a quasi-three-level system are sensitive to temperature. The optical and thermodynamic properties of Tm:YAG ceramics can change with changing temperature, and this affects the output power stability and beam quality of lasers. Thus temperature control is a key and difficult problem for Tm:YAG lasers, especially for high power laser output. In combination with slab structure and grad-doping techniques for composite ceramics, the temperature distributions of Tm:YAG ceramics are analyzed. It is found that the temperature difference of a rationally designed grad-doping Tm:YAG ceramic can be reduced significantly with the same absorption pump power, which results in higher output power and beam quality.

  14. Stability of a Laser-diode-pumped Cr4+∶YAG Passively Q-switched Nd3+∶YAG Laser

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xingyu; ZHAO Shengzhi; WANG Qingpu; ZHANG Qidi; B. Ozygus; M. Weber

    2000-01-01

    In this paper, the stability of a laser-diode-pumped Cr4+∶YAG passively Nd3+∶YAG Q-switched laser and the influence of the transversal mode structure on the stability are investigated. With the laser operating in TEM00 mode, the pulse energy fluctuation and the repetition rate fluctuation as functions of the repetition rate are measured, and semi-quantitatively and qualitatively analyzed, respectively.

  15. Thulium fiber laser damage to Nitinol stone baskets

    Science.gov (United States)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-02-01

    Our laboratory is studying the experimental Thulium fiber laser (TFL) as an alternative lithotripter to clinical gold standard Holmium:YAG laser. Safety studies characterizing undesirable Holmium laser-induced damage to Nitinol stone baskets have been previously reported. Similarly, this study characterizes TFL induced stone basket damage. A TFL beam with pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rates of 50-500 Hz was delivered through 100-μm-core optical fibers, to a standard 1.9-Fr Nitinol stone basket wire. Stone basket damage was graded as a function of pulse rate, number of pulses, and working distance. Nitinol wire damage decreased with working distance and was non-existent at distances greater than 1.0 mm. In contact mode, 500 pulses delivered at pulse rates >= 200 Hz (Nitinol wires. The Thulium fiber laser, operated in low pulse energy and high pulse rate mode, may provide a greater safety margin than standard Holmium laser for lithotripsy, as evidenced by shorter non-contact working distances for stone basket damage than previously reported with Holmium laser.

  16. Effect of Raykeen holmium laser electric resection and conventional electric resection on malignant degree and immune function of non-invasive bladder cancer

    Institute of Scientific and Technical Information of China (English)

    Liang-Suo Zhang

    2016-01-01

    Objective:To analyze the effect of Raykeen holmium laser electric resection and conventional electric resection on the malignant degree and immune function of non-invasive bladder cancer. Methods:A total of 96 cases of patients with non-invasive bladder cancer were included for study and divided into observation group 46 cases who received Raykeen holmium laser electric resection treatment and control group 50 cases who received conventional electric resection treatment. Differences in postoperative illness-related indexes, serum adhesion molecule levels, urinary sediment miRNA and immune function-related indexes were compared between two groups.Results:Serum DKK-3 and Endostatin values of observation group after treatment were higher than those of control group while CIP2A, DKK-1 and sFasL values were lower than those of control group; serum CD44v6, E-cadherin and hepaCAM values of observation group after treatment were higher than those of control group while EpCAM, sVCAM-1 and sICAM-1 values were lower than those of control group; urinary sediment miR-129, miR-125b, miR-720, miR-191 and miR-107 expression levels of observation group after treatment were lower than those of control group; serum IgG, IgA, IgM, C3, C4, CD4+ and CD4+/CD8+ values of observation group after treatment were higher than those of control group while CD8+ value was lower than that of control group.Conclusions:Raykeen holmium laser electric resection treatment of patients with non-invasive bladder cancer can effectively reduce the malignant degree of tumor and improve body’s immune function, and it has positive clinical significance.

  17. Optic coherence tomography measurement of choroidal and retinal thicknesses after uncomplicated YAG laser capsulotomy

    Directory of Open Access Journals (Sweden)

    İsa Yuvacı

    2015-12-01

    Full Text Available ABSTRACT Purpose: Optic coherence tomography (OCT evaluation of the choroid, retina, and retinal nerve fiber layer after uncomplicated yttrium-aluminum-garnet (YAG laser capsulotomy. Methods: OCT analysis of retinal and choroidal structures was performed in 28 eyes of 28 patients following routine examinations before and 24 h, 72 h, 2 weeks, 4 weeks, and 12 weeks after YAG laser capsulotomy. Data were analyzed using the SPSS software. Results: Data collected before YAG capsulotomy and at the above mentioned follow-up visits are summarized as follows. Mean central subfoveal choroidal thickness before YAG capsulotomy was 275.85 ± 74.78 µm; it was 278.46 ± 83.46 µm, 283.39 ± 82.84 µm, 280.00 ± 77.16 µm, 278.37 ± 76.95 µm, and 278.67 ± 76.20 µm after YAG capsulotomy, respectively. Central macular thickness was 272.14 ± 25.76 µm before YAG capsulotomy; it was 266.53 ± 26.47 µm, 269.14 ± 27.20 µm, 272.17 ± 26.97 µm, 270.91 ± 26.79 µm, and 273 ± 26.63 µm after YAG capsulotomy, respectively. Mean retinal nerve fiber layer thickness before YAG was 99.89 ± 7.61 µm; it was 98.50 ± 8.62 µm, 98.14 ± 8.69 µm, 99.60 ± 8.39 µm, 99.60 ± 8.39 µm, and 99.60 ± 8.35 µm after YAG capsulotomy, respectively. No observed change was statistically significant. No significant changes were observed with regard to mean intraocular pressure. Conclusions: After YAG laser capsulotomy, no statistically significant changes were found in choroidal, retinal, and optical nerve fiber layer thicknesses, although slight thickness changes in these structures were observed, particularly during the first days.

  18. Impact of holmium fibre laser radiation (λ = 2.1 μm) on the spinal cord dura mater and adipose tissue

    Science.gov (United States)

    Filatova, S. A.; Kamynin, V. A.; Ryabova, A. V.; Loshchenov, V. B.; Zelenkov, P. V.; Zolotovskii, I. O.; Tsvetkov, V. B.; Kurkov, A. S.

    2015-08-01

    The impact of holmium fibre laser radiation on the samples of biologic tissues (dura mater of spinal cord and adipose tissue with interlayers of muscle) is studied. The experimental results are evaluated by the size of carbonisation and coagulation necrosis zones. The experiment shows that in the case of irradiation of the spinal cord dura mater samples the size of carbonisation and coagulation necrosis zones is insignificant. In the adipose tissue the carbonisation zone is also insignificant, but the region of cellular structure disturbance is large. In the muscle tissue the situation is opposite. The cw laser operation provides clinically acceptable degree of destruction in tissue samples with a minimal carbonisation zone.

  19. Photoacoustic eigen-spectrum from light-absorbing microspheres and its application in noncontact elasticity evaluation

    Science.gov (United States)

    Gao, Xiaoxiang; Tao, Chao; Liu, Xiaojun; Wang, Xueding

    2017-01-01

    Noncontact evaluation of elastic properties of a microstructure is still a challenge in turbid media. In this Letter, we present the observation of a phenomenon—the photoacoustic eigen-spectrum from light-absorbing objects. Analysis and experiments demonstrate that the eigen-vibration information of a microstructure is imprinted in its photoacoustic coda waves after it is exposed to a laser pulse illumination. The spectral lines in the time-frequency map of photoacoustic coda waves correspond to the eigen-frequencies of the light-absorber. This phenomenon provides a physical basis for noncontact evaluation of elastic properties of a microstructure in turbid media. Elastic parameters can be accurately inversed from the measured photoacoustic eigen-spectrum.

  20. Non-Contact Translation-Rotation Sensor Using Combined Effects of Magnetostriction and Piezoelectricity

    Directory of Open Access Journals (Sweden)

    Guang Meng

    2012-10-01

    Full Text Available Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  1. Atomic-scale non-contact AFM studies of alumina supported nanoparticles

    DEFF Research Database (Denmark)

    Jensen, Thomas Nørregaard; Meinander, Kristoffer; Simonsen, Søren Bredmose

    ATOMIC-SCALE NON-CONTACT ATOMIC FORCE STUDIES OF ALUMINA SUPPORTED NANOPARTICLES Thomas N. Jensen, Kristoffer Meinander, Flemming Besenbacher and Jeppe V. Lauritsen Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus C, Denmark Heterogeneous catalysis plays a crucial role...... at the nanometre scale [1]. When operated in the so-called non-contact mode (nc-AFM), this technique yields genuine atomic resolution and offers a unique tool for atomic-scale studies of clean surfaces, as well as, nanoparticles and thin films on these surfaces irrespective of the substrate being electrically...... conducting or non-conducting [2]. We use nc-AFM to study the growth, shape and size of nanoparticles on spinel and alumina surfaces. In addition to this, we have grown a transition alumina thin film on a spinel surface in order to characterize such a film as well as studying the catalytic properties...

  2. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus.

    Science.gov (United States)

    Hansen, Birgitte; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis.

  3. Non-contact translation-rotation sensor using combined effects of magnetostriction and piezoelectricity.

    Science.gov (United States)

    Yang, Bintang; Liu, Qingwei; Zhang, Ting; Cao, Yudong; Feng, Zhiqiang; Meng, Guang

    2012-10-15

    Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  4. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions......, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  5. Study of noncontact air-puff applanation tonometry IOP measurement on irregularly-shaped corneas

    Science.gov (United States)

    Wang, Wai W.; Wang, Kuo-Jen; Tsai, Che-Liang; Wang, I.-Jong

    2017-04-01

    Abnormal corneas with corneal tissue defects like ulceration, melting, laceration, thinning scar, keratoconus etc., poses special challenges for ophthalmologist to measure intraocular pressure (IOP) correctly using air-puff noncontact applanation tonometry. Here, we propose an novel model, Abnormal Applanation IOP Model (AAIOP), to simulate IOP in these abnormal corneas on an air-puff noncontact applanation tonometry system, and the simulated IOP results are correctly fit in those of IOP measured database on human eyes of 91,024 patients (174,666 eyes)1). Our simulated IOP indicates that every 10 μm of central corneal thickness change results in 0.36 mmHg of IOP change. Using our simulation model, the IOP on abnormal eyes with irregularly-shaped corneas can be correctly expected and reported.

  6. Non-contact transmittance photoplethysmographic imaging (PPGI) for long-distance cardiovascular monitoring

    CERN Document Server

    Amelard, Robert; Kazemzadeh, Farnoud; Pfisterer, Kaylen J; Lin, Bill S; Wong, Alexander; Clausi, David A

    2015-01-01

    Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restrict their use to at-rest short-term monitoring using single-point measurements. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, of which many are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level using ambient correction via temporally coded illumination (TCI) and signal processing for PPGI signal extraction. Experimental results show that the processing steps yield a substantially more pulsatile PPGI si...

  7. Contact and non-contact ultrasonic measurement in the food industry: a review

    Science.gov (United States)

    Taufiq Mohd Khairi, Mohd; Ibrahim, Sallehuddin; Yunus, Mohd Amri Md; Faramarzi, Mahdi

    2016-01-01

    The monitoring of the food manufacturing process is vital since it determines the safety and quality level of foods which directly affect the consumers’ health. Companies which produce high quality products will gain trust from consumers. This factor helps the companies to make profits. The use of efficient and appropriate sensors for the monitoring process can also reduce cost. The food assessing process based on an ultrasonic sensor has attracted the attention of the food industry due to its excellent capabilities in several applications. The utilization of low or high frequencies for the ultrasonic transducer has provided an enormous benefit for analysing, modifying and guaranteeing the quality of food. The contact and non-contact ultrasonic modes for measurement also contributed significantly to the food processing. This paper presents a review of the application of the contact and non-contact mode of ultrasonic measurement focusing on safety and quality control areas. The results from previous researches are shown and elaborated.

  8. Non-contact tunable damping of a cantilever beam structure embedded with photo-rheological fluids

    Science.gov (United States)

    Cho, Min-Young; Kim, Ji-Sik; Choi, Seung-Bok; Kim, Gi-Woo

    2016-02-01

    This research presents an introduction to non-contact tunable damping using a new class of photo-rheological fluids (PRFs) whose rheological behavior can be changed by using ultraviolet (UV) light. When the PRF is irradiated by UV light, its viscosity decreases; the viscosity recovers to its initial value when UV light is switched off, implying that the viscosity of PRF is reversible and tunable. We demonstrate that UV light can be used to induce the changes in the viscosity of PRFs, and that the proposed method can be successfully applied to realize non-contact tunable damping of vibrating structures. The additional advantages of PRF include no deposition associated with the single-phase solution of PRF and no electro-magnetic interference shielding.

  9. Noncontact photoacoustic imaging achieved by using a low-coherence interferometer as the acoustic detector.

    Science.gov (United States)

    Wang, Yi; Li, Chunhui; Wang, Ruikang K

    2011-10-15

    We report on a noncontact photoacoustic imaging (PAI) technique in which a low-coherence interferometer [(LCI), optical coherence tomography (OCT) hardware] is utilized as the acoustic detector. A synchronization approach is used to lock the LCI system at its highly sensitive region for photoacoustic detection. The technique is experimentally verified by the imaging of a scattering phantom embedded with hairs and the blood vessels within a mouse ear in vitro. The system's axial and lateral resolutions are evaluated at 60 and 30 μm, respectively. The experimental results indicate that PAI in a noncontact detection mode is possible with high resolution and high bandwidth. The proposed approach lends itself to a natural integration of PAI with OCT, rather than a combination of two separate and independent systems.

  10. Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing

    Science.gov (United States)

    Orloff, Nathan D.; Long, Christian J.; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas P.; McMichael, Robert D.; Pasquali, Matteo; Stranick, Stephan J.; Alexander Liddle, J.

    2015-11-01

    Advances in roll-to-roll processing of graphene and carbon nanotubes have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible and wearable electronics, woven fabrics, and wires. These applications often require specific electrical properties, and hence precise control over material micro- and nanostructure. While such control can be achieved, in principle, by closed-loop processing methods, there are relatively few noncontact and nondestructive options for quantifying the electrical properties of materials on a moving web at the speed required in modern nanomanufacturing. Here, we demonstrate a noncontact microwave method for measuring the dielectric constant and conductivity (or geometry for samples of known dielectric properties) of materials in a millisecond. Such measurement times are compatible with current and future industrial needs, enabling real-time materials characterization and in-line control of processing variables without disrupting production.

  11. In vitro fragmentation efficiency of holmium: yttrium-aluminum-garnet (YAG) laser lithotripsy--a comprehensive study encompassing different frequencies, pulse energies, total power levels and laser fibre diameters.

    Science.gov (United States)

    Kronenberg, Peter; Traxer, Olivier

    2014-08-01

    To assess the fragmentation (ablation) efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibres, in particular to compare high- with low-frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. An automated laser fragmentation testing system was developed. The unmoving laser fibres fired at the surface of an artificial stone while the stone was moved past at a constant velocity, thus creating a fissure. The lithotripter settings were 0.2-1.2 J pulse energies, 5-40 Hz frequencies, 4-20 W power levels, and 200 and 550 μm core laser fibres. Fissure width, depth, and volume were analysed and comparisons between laser settings, fibres and ablation rates were made. Low frequency-high pulse energy (LoFr-HiPE) settings were (up to six times) more ablative than high frequency-low pulse energy (HiFr-LoPE) at the same power levels (P fragmentation volume, fissure width, and fissure depth (all P fragmentation measurements. Laser fibre diameter did not affect fragmentation volume (P = 0.81), except at very low pulse energies (0.2 J), where the large fibre was less efficient (P = 0.015). At the same total power level, LoFr-HiPE lithotripsy was most efficient. Pulse energy was the key variable that drove fragmentation efficiency. Attention must be paid to prevent the formation of time-consuming bulky debris and adapt the lithotripter settings to one's needs. As fibre diameter did not affect fragmentation efficiency, small fibres are preferable due to better scope irrigation and manoeuvrability. © 2013 The Authors. BJU International © 2013 BJU International.

  12. Holmium Laser Enucleation of the Prostate versus Laparoscopic Transcapsular Prostatectomy: Perioperative Results and Three-Month Follow-Up.

    Science.gov (United States)

    Baldini, Arnaud; Fassi-Fehri, Hakim; Duarte, Ricardo C; Crouzet, Sebastien; Ecochard, René; Abid, Nadia; Martin, Xavier; Badet, Lionel; Colombel, Marc

    2017-07-01

    Symptomatic benign prostatic hypertrophy greater than 70 cc used to be treated by invasive procedures. Holmium laser enucleation of prostate (HoLEP) and laparoscopic transcapsular prostatectomy (LTP) are two techniques whose efficacy has been demonstrated compared to standard onesmore invasive standard procedures. The objective was to evaluate and compare perioperative results from these two techniques for the treatment of benign prostatic hypertrophy greater than 70 cc. This was a non-randomized retrospective study comparing the HoLEP technique with LTP. From January 2012 to January 2015, 39 patients had HoLEP and 28 had LTP. Perioperative outcomes, complications, and functional results at 3 months were compared. A chi-2 squared test and Student's t test were used for statistical analysis. In multivariate analysis, there was a statistically significant difference in favor of HoLEP for the duration of catheterization (1.9 vs. 3.7 days; p = 0.004) and the average length of stay (2.8 vs. 4.0 days, p = 0.010). There was a trend towards a greater decrease in postoperative hemoglobin levels in LTP (138 vs. 218 g/l; p = 0.082), which was statistically significant in univariate analysis (p = 0.033). Other endpoints were not significant, particularly the enucleated prostate volume compared to the total prostate volume (61.8 vs. 68.4%; p = 0.319) and postoperative complications. There was no increased morbidity for LTP compared to the HoLEP technique. However, the HoLEP technique appeared to be a less invasive technique, reducing the duration of catheterization, blood loss, and the average length of stay while maintaining good efficacy for the enucleated prostate volume.

  13. Enucleation ratio efficacy might be a better predictor to assess learning curve of holmium laser enucleation of the prostate

    Directory of Open Access Journals (Sweden)

    Chang Wook Jeong

    2012-06-01

    Full Text Available PURPOSE: To appraise the evaluation methods for learning curve and to analyze the non-mentor-aided learning curve and early complications following the holmium laser enucleation of the prostate. MATERIALS AND METHODS:One-hundred and forty (n=140 consecutive patients who underwent HoLEP from July 2008 to July 2010 by a single surgeon (SJO were enrolled. Perioperative clinical variables, including enucleation time, morcellation time, enucleation ratio (enucleation weight/transitional zone volume, enucleation efficacy (enucleated weight/enucleation time, enucleation ratio efficacy (enucleation ratio/enucleation time, and early complication rate were analyzed. RESULTS: Mean prostate volume was 62.7 mL (range 21-162 and preoperative International Prostate Symptom Score (IPSS was 19.0 (4-35. Mean enucleation time and morcellation time were 49.9±23.8 (S.D. min and 11.0±9.7 min, respectively. Median duration of postoperative indwelling catheter was 1 (1-7 day and median hospital stay was 1 (1-6 day. There were a total of 31 surgery-related complications in 27 patients (19.3%, and all were manageable. There was an increasing trend of enucleation efficacy in the first 50 cases. However, enucleation efficacy was linearly correlated with the prostate size (correlation coefficients, R=0.701, p<0.001. But, enucleation ratio efficacy could eliminate the confounding effect of the prostate size (R=-0.101, p=0.233. The plateau of enucleation ratio efficacy was reached around the twenty-fifth case. CONCLUSIONS: Our results demonstrated that the operative learning curve plateau is reached after about 25 cases. We propose that a more appropriate parameter for estimating the operative learning curve is enucleation ratio efficacy, rather than enucleation efficacy.

  14. Effect of Er:YAG laser energy on the morphology of enamel/adhesive system interface

    Science.gov (United States)

    Delfino, Carina Sinclér; Souza-Zaroni, Wanessa Christine; Corona, Silmara Aparecida Milori; Pécora, Jesus Djalma; Palma-Dibb, Regina Guenka

    2006-10-01

    The aim of this study was to evaluate in vitro the influence of Er:YAG laser energy variation to cavity preparation on the morphology of enamel/adhesive system interface, using SEM. Eighteen molars were used and the buccal surfaces were flattened without dentine exposure. The specimens were randomly assigned to two groups, according to the adhesive system (conventional total-etching or self-etching), and each group was divided into three subgroups (bur carbide in turbine of high rotation, Er:YAG laser 250 mJ/4 Hz and Er:YAG laser 300 mJ/4 Hz) containing six teeth each. The enamel/adhesive system interface was serially sectioned and prepared for SEM. The Er:YAG laser, in general, produced a more irregular adhesive interface than the control group. For Er:YAG laser 250 mJ there was formation of a more regular hybrid layer with good tag formation, mainly in the total-etching system. However, Er:YAG laser 300 mJ showed a more irregular interface with amorphous enamel and fused areas, for both adhesive systems. It was concluded that cavity preparation with Er:YAG laser influenced on the morphology of enamel/adhesive system interface and the tissual alterations were more evident when the energy was increased.

  15. Laser Erbium: YAG no tratamento de nevos melanocíticos Erbium: YAG laser in treatment of acquired melanocytic nevi

    Directory of Open Access Journals (Sweden)

    Mauricio Martins

    2008-12-01

    Full Text Available FUNDAMENTOS - Os nevos melanocíticos adquiridos são observados em grande parte da população e o resultado da sua excisão, dependendo da localização, extensão e fatores inerentes ao paciente, pode ser insatisfatório. OBJETIVO - Avaliar o uso do laser Erbium: YAG no tratamento de nevos melanocíticos adquiridos MÉTODOS - Foram selecionados nove pacientes, seis homens e três mulheres, brancos, com idade entre 20 e 60 anos e desejo de remover um nevo melanocítico composto no tronco. Metade do nevo foi tratada com laser, e a outra metade foi utilizada como controle. Após um mês da aplicação, foram avaliados a cicatrização, o resultado estético e a persistência de células névicas e melanina. RESULTADOS - Houve rápida cicatrização e ótimo resultado estético, no entanto, o exame histopatológico demonstrou a permanência de células névicas e melanina em sete e em nove das amostras examinadas, respectivamente. CONCLUSÃO - A utilização do laser Erbium:YAG, com os parâmetros utilizados neste estudo, não foi capaz de destruir completamente as células névicas melanocíticas e a melanina, não sendo, portanto, recomendada para o tratamento dessas lesões, dada a possibilidade de transformação maligna futura.BACKGROUND- Acquired melanocytic nevi are commonly found and the result of their excision may not be satisfactory depending on their location, extension and factors associated to the patient. OBJECTIVE - To evaluate the use of Erbium:YAG laser in treatment of acquired melanocytic nevi. METHOD - Nine white-skinned patients were selected, six men and three women with aged 20-60 years. All desired to remove one compound acquired melanocytic nevus on the trunk. Half of the nevi was treated with Erbium YAG laser while the remaining were used as control. One month after application, healing, aesthetic results and persistence of melanocytic cells and melanin were evaluated. RESULTS - All patients presented fast healing and

  16. Risk factors and prevention strategies of non-contact anterior cruciate ligament injuries.

    Science.gov (United States)

    Laible, Catherine; Sherman, Orrin H

    2014-01-01

    In recent years, the number of women playing sports has increased significantly. The passage of Title IX in 1972 had a significant effect in encouraging female participation in sports. This increase in women's sports participation also led to a rise in noncontact anterior cruciate ligament (ACL) injuries. As ACL injuries in young female athletes have be- come a public health issue, much research has been done on risk factors and prevention strategies.

  17. Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

    Institute of Scientific and Technical Information of China (English)

    于永新; 张恒; 王宗超; 常以哲

    2010-01-01

    A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

  18. NON-CONTACT MEASUREMENT SYSTEM OF FREEFORM SURFACE AND NURBS RECONSTRUCTION OF MEASUREMENT POINTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the development of the non-contact measurement system of free-form surface, NURBS reconstruc-tion of measurement points of freeform surface is effectively realized by modifying the objective function and recursiveprocedure and calculating the optimum number of control points. The reconstruction precision is evaluated through Ja-cobi's transformation method. The feasibility of the measurement system and effectiveness of the reconstruction algo-rithm above are proved by experiment.

  19. Non-contact laser speckle sensor for measuring one- and two-dimensional angular displacement

    DEFF Research Database (Denmark)

    Rose, Bjarke; Imam, H.; Hanson, Steen Grüner

    1998-01-01

    A novel method for measurement of angular displacement in one or two dimensions for arbitrarily shaped objects is presented. The method is based on Fourier transforming the scattered field from a single laser beam that illuminates the target. The angular distribution of the light field at the tar...... interest. Furthermore, it is shown that robust, non-contact optical systems for industrial applications can be produced....

  20. Non-contacting gas lubricated face seals for high p x v-values

    Science.gov (United States)

    Glienicke, J.; Launert, A.; Schums, H.; Kohring, B.

    1994-07-01

    The authors discuss recently developed mathematical fundamentals concerning the calculation of noncontacting gas lubricated face seals. They carried out extensive experiments using three different designs at pressures up to 10 MPa and sliding velocities up to 110 m/s. A comparison between the experimental results and the calculations indicates that a stable operation without wear can be ensured in all cases, provided that the materials and geometrical parameters of the seal have been properly chosen.

  1. Modeling leukocyte-leukocyte non-contact interactions in a lymph node.

    Directory of Open Access Journals (Sweden)

    Nicola Gritti

    Full Text Available The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (~25% increase upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

  2. Noncontact AFM Imaging of Atomic Defects on the Rutile TiO2 (110) Surface

    DEFF Research Database (Denmark)

    Lauritsen, Jeppe Vang

    2015-01-01

    The atomic force microscope (AFM) operated in the noncontact mode (nc-AFM) offers a unique tool for real space, atomic-scale characterisation of point defects and molecules on surfaces, irrespective of the substrate being electrically conducting or non-conducting. The nc-AFM has therefore in rece...... on the rutile TiO2(110) surface. The present Chapter continues the review of nc-AFM initiated in Chap. 7 by Barth....

  3. Noncontact atomic force microscopy in liquid environment with quartz tuning fork and carbon nanotube probe

    DEFF Research Database (Denmark)

    Kageshima, M.; Jensenius, Henriette; Dienwiebel, M.

    2002-01-01

    A force sensor for noncontact atomic force microscopy in liquid environment was developed by combining a multiwalled carbon nanotube (MWNT) probe with a quartz tuning fork. Solvation shells of octamethylcyclotetrasiloxane surface were detected both in the frequency shift and dissipation. Due...... to the high aspect ratio of the CNT probe, the long-range background force was barely detectable in the solvation region. (C) 2002 Elsevier Science B.V. All rights reserved....

  4. Effect of Er:YAG laser on enamel demineralization around restorations.

    Science.gov (United States)

    Colucci, Vivian; de Souza Gabriel, Aline Evangelista; Scatolin, Renata Siqueira; Serra, Mônica Campos; Corona, Silmara Aparecida Milori

    2015-05-01

    This study evaluates in situ the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser parameters on the development of caries-like lesions adjacent to dental restorations. One hundred fifty bovine enamel slabs were randomly allocated among 15 volunteers. The specimens were subdivided into ten groups: nine experimental groups prepared with Er:YAG laser (300 mJ output, frequency of 2, 4 or 6 Hz, water flow rate of 2.0, 5.0, or 8.0 mL/min) and one control group (high-speed handpiece). The prepared cavity was restored with a composite resin, and the slabs were mounted on palatal appliance to be installed in the volunteers to the cariogenic challenge. After this, the specimens were sectioned to the longitudinal microhardness measurements. Data were submitted to Friedman and Wilcoxon paired tests. All groups prepared with Er:YAG laser demonstrated microhardness values higher than those prepared with high-speed handpiece, which showed the lowest microhardness values (24.86). The group prepared with Er:YAG laser (2 Hz-2.0 mL/min) showed the highest microhardness values (152.43), followed by those prepared with Er:YAG laser (2 Hz-5.0 mL/min) (133.08) and Er:YAG laser (2 Hz-8.0 mL/min) (91.61), respectively. The groups Er:YAG laser with 4 and 6 Hz of frequency and water flow rates of 2.0, 5.0, and 8.0 mL/min showed microhardness values lower than the groups cited above and showed statistical similarity among them. The Er:YAG laser parameters employed to cavity preparation influenced the acid resistance of the irradiated substrate, and the Er:YAG laser was capable to control the development of caries-like lesions around composite resin restorations.

  5. An investigation of highly accurate and precise robotic hole measurements using non-contact devices

    Directory of Open Access Journals (Sweden)

    Usman Zahid

    2016-01-01

    Full Text Available Industrial robots arms are widely used in manufacturing industry because of their support for automation. However, in metrology, robots have had limited application due to their insufficient accuracy. Even using error compensation and calibration methods, robots are not effective for micrometre (μm level metrology. Non-contact measurement devices can potentially enable the use of robots for highly accurate metrology. However, the use of such devices on robots has not been investigated. The research work reported in this paper explores the use of different non-contact measurement devices on an industrial robot. The aim is to experimentally investigate the effects of robot movements on the accuracy and precision of measurements. The focus has been on assessing the ability to accurately measure various geometric and surface parameters of holes despite the inherent inaccuracies of industrial robot. This involves the measurement of diameter, roundness and surface roughness. The study also includes scanning of holes for measuring internal features such as start and end point of a taper. Two different non-contact measurement devices based on different technologies are investigated. Furthermore, effects of eccentricity, vibrations and thermal variations are also assessed. The research contributes towards the use of robots for highly accurate and precise robotic metrology.

  6. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee, E-mail: symolloi@uci.edu

    2015-04-11

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm{sup 3} Lithium Niobate (LiNbO{sub 3}) pyroelectric crystal maintained in a 3–12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  7. A model undergraduate research institute for study of emerging non-contact measurement technologies and techniques

    Science.gov (United States)

    Dvonch, Curt; Smith, Christopher; Bourne, Stefanie; Blandino, Joseph R.; Miles, Jonathan J.

    2006-04-01

    The Infrared Development and Thermal Structures Laboratory (IDTSL) is an undergraduate research laboratory in the College of Integrated Science and Technology (CISAT) at James Madison University (JMU) in Harrisonburg, Virginia. During the 1997-98 academic year, Dr. Jonathan Miles established the IDTSL at JMU with the support of a collaborative research grant from the NASA Langley Research Center and with additional support from the College of Integrated Science and Technology at JMU. The IDTSL supports research and development efforts that feature non-contact thermal and mechanical measurements and advance the state of the art. These efforts all entail undergraduate participation intended to significantly enrich their technical education. The IDTSL is funded by major government organizations and the private sector and provides a unique opportunity to undergraduates who wish to participate in projects that push the boundaries of non-contact measurement technologies, and provides a model for effective hands-on, project oriented, student-centered learning that reinforces concepts and skills introduced within the Integrated Science and Technology (ISAT) curriculum. The lab also provides access to advanced topics and emerging measurement technologies; fosters development of teaming and communication skills in an interdisciplinary environment; and avails undergraduates of professional activities including writing papers, presentation at conferences, and participation in summer internships. This paper provides an overview of the Infrared Development and Thermal Structures Laboratory, its functionality, its record of achievements, and the important contribution it has made to the field of non-contact measurement and undergraduate education.

  8. Simulation Test System of Non-Contact D-dot Voltage Transformer

    Science.gov (United States)

    Yang, Jie; Wang, Jingang; Luo, Ruixi; Gao, Can; Songnong, Li; Kongjun, Zhou

    2016-04-01

    The development trend of future voltage transformer in smart grid is non-contact measurement, miniaturization and intellectualization. This paper proposes one simulation test system of non-contact D-dot transformer for voltage measurement. This simulation test system consists of D-dot transformer, signal processing circuit and ground PC port. D-dot transformer realizes the indirect voltage measurement by measuring the change rate of electric displacement vector, a non-contact means (He et al. 2004, Principles and experiments of voltage transformer based on self-integrating D-dot probe. Proc CSEE 2014;15:2445-51). Specific to the characteristics of D-dot transformer signals, signal processing circuits with strong resistance to interference and distortion-free amplified sensor output signal are designed. WIFI wireless network is used to transmit the voltage detection to LabVIEW-based ground collection port and LabVIEW technology is adopted for signal reception, data processing and analysis and other functions. Finally, a test platform is established to simulate the performance of the whole test system of single-phase voltage transformer. Test results indicate that this voltage transformer has sound real-time performance, high accuracy and fast response speed and the simulation test system is stable and reliable and can be a new prototype of voltage transformers.

  9. OLAM: A wearable, non-contact sensor for continuous heart-rate and activity monitoring.

    Science.gov (United States)

    Albright, Ryan K; Goska, Benjamin J; Hagen, Tory M; Chi, Mike Y; Cauwenberghs, G; Chiang, Patrick Y

    2011-01-01

    A wearable, multi-modal sensor is presented that can non-invasively monitor a patient's activity level and heart function concurrently for more than a week. The 4 in(2) sensor incorporates both a non-contact heartrate sensor and a 5-axis inertial measurement unit (IMU), allowing simultaneous heart, respiration, and movement monitoring without requiring physical contact with the skin [1]. Hence, this Oregon State University Life and Activity Monitor (OLAM) provides the unique opportunity to combine motion data with heart-rate information, enabling assessment of actual physical activity beyond conventional movement sensors. OLAM also provides a unique platform for non-contact sensing, enabling the filtering of movement artifacts generated by the non-contact capacitive interface, using the IMU data as a movement noise channel. Intended to be used in clinical trials for weeks at a time with no physician intervention, the OLAM allows continuous non-invasive monitoring of patients, providing the opportunity for long-term observation into a patient's physical activity and subtle longitudinal changes.

  10. Three-dimensional flow contrast imaging of deep tissue using noncontact diffuse correlation tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yu; Huang, Chong; Irwin, Daniel; He, Lian; Shang, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States)

    2014-03-24

    This study extended our recently developed noncontact diffuse correlation spectroscopy flowmetry system into noncontact diffuse correlation tomography (ncDCT) for three-dimensional (3-D) flow imaging of deep tissue. A linear array of 15 photodetectors and two laser sources connected to a mobile lens-focusing system enabled automatic and noncontact scanning of flow in a region of interest. These boundary measurements were combined with a finite element framework for DCT image reconstruction implemented into an existing software package. This technique was tested in computer simulations and using a tissue-like phantom with anomaly flow contrast design. The cylindrical tube-shaped anomaly was clearly reconstructed in both simulation and phantom. Recovered and assigned flow contrast changes in anomaly were found to be highly correlated: regression slope = 1.00, R{sup 2} = 1.00, and p < 10{sup −5} in simulation and regression slope ≥ 0.97, R{sup 2} ≥ 0.96, and p < 10{sup −3} in phantom. These results exhibit promise of our ncDCT technique for 3-D imaging of deep tissue blood flow heterogeneities.

  11. Non-Contact Stiffness Measurement of a Suspended Single Walled Carbon Nanotube Device

    Science.gov (United States)

    Zheng, Yun; Su, Chanmin; Getty, Stephanie

    2010-01-01

    A new nanoscale electric field sensor was developed for studying triboelectric charging in terrestrial and Martian dust devils. This sensor is capable to measure the large electric fields for large dust devils without saturation. However, to quantify the electric charges and the field strength it is critical to calibrate the mechanical stiffness of the sensor devices. We performed a technical feasibility study of the Nano E-field Sensor stiffness by a non-contact stiffness measurement method. The measurement is based on laser Doppler vibrometer measurement of the thermal noise due to energy flunctuations in the devices. The experiment method provides a novel approach to acquire data that is essential in analyzing the quantitative performance of the E-field Nano Sensor. To carry out the non-contact stiffness measurement, we fabricated a new Single-Walled Carbon Nanotube (SWCNT) E-field sensor with different SWCNTs suspension conditions. The power spectra of the thermal induced displacement in the nano E-field sensor were measured at the accuracy of picometer. The power spectra were then used to derive the mechanical stiffness of the sensors. Effect of suspension conditions on stiffness and sensor sensitivty was discussed. After combined deformation and resistivity measurement, we can compare with our laboratory testing and field testing results. This new non-contact measurement technology can also help to explore to other nano and MEMS devices in the future.

  12. A Noncontact Picolitor Droplet Handling by Photothermal Control of Interfacial Flow.

    Science.gov (United States)

    Muto, Masakazu; Yamamoto, Makoto; Motosuke, Masahiro

    2016-01-01

    We present a noncontact handling of droplets in a microfluidic platform by the Marangoni convection, interfacial tension driven flow, generated by a light-induced local temperature gradient in the surrounding liquid of the droplet. Droplets flowing in a microchannel experience a force due to the interfacial tension gradient when approaching the heated area. This method provides noncontact, selective and flexible manipulation for droplets flowing in microchannel network. In this study, an O/W emulsion system with oleic acid for the dispersed phase and a buffer solution for the continuous one was used. Trajectory control and trapping for droplets with 5 - 65 pL in volume was achieved by patterned laser irradiation. Also, we quantitatively evaluated the driving force exerted on droplets by measuring the fluidic temperature distribution around the droplet. From the balance of the drag force and the photo-induced Marangoni force, the driving force was determined using the measured temperature gradient of the droplet. From the results, the applicability of noncontact droplet manipulation using the photothermal Marangoni effect by continuous-phase heating has been demonstrated.

  13. Assessment of human respiration patterns via noncontact sensing using Doppler multi-radar system.

    Science.gov (United States)

    Gu, Changzhan; Li, Changzhi

    2015-03-16

    Human respiratory patterns at chest and abdomen are associated with both physical and emotional states. Accurate measurement of the respiratory patterns provides an approach to assess and analyze the physical and emotional states of the subject persons. Not many research efforts have been made to wirelessly assess different respiration patterns, largely due to the inaccuracy of the conventional continuous-wave radar sensor to track the original signal pattern of slow respiratory movements. This paper presents the accurate assessment of different respiratory patterns based on noncontact Doppler radar sensing. This paper evaluates the feasibility of accurately monitoring different human respiration patterns via noncontact radar sensing. A 2.4 GHz DC coupled multi-radar system was used for accurate measurement of the complete respiration patterns without any signal distortion. Experiments were carried out in the lab environment to measure the different respiration patterns when the subject person performed natural breathing, chest breathing and diaphragmatic breathing. The experimental results showed that accurate assessment of different respiration patterns is feasible using the proposed noncontact radar sensing technique.

  14. Fully Noncontact Wave Propagation Imaging in an Immersed Metallic Plate with a Crack

    Directory of Open Access Journals (Sweden)

    Jung-Ryul Lee

    2014-01-01

    Full Text Available This study presents a noncontact sensing technique with ultrasonic wave propagation imaging algorithm, for damage visualization of liquid-immersed structures. An aluminum plate specimen (400 mm × 400 mm × 3 mm with a 12 mm slit was immersed in water and in glycerin. A 532 nm Q-switched continuous wave laser is used at an energy level of 1.2 mJ to scan an area of 100 mm × 100 mm. A laser Doppler vibrometer is used as a noncontact ultrasonic sensor, which measures guided wave displacement at a fixed point. The tests are performed with two different cases of specimen: without water and filled with water and with glycerin. Lamb wave dispersion curves for the respective cases are calculated, to investigate the velocity-frequency relationship of each wave mode. Experimental propagation velocities of Lamb waves for different cases are compared with the theoretical dispersion curves. This study shows that the dispersion and attenuation of the Lamb wave is affected by the surrounding liquid, and the comparative experimental results are presented to verify it. In addition, it is demonstrated that the developed fully noncontact ultrasonic propagation imaging system is capable of damage sizing in submerged structures.

  15. Development of SCARA-Type Haptic Device for Electrostatic Non-Contact Handling System

    Science.gov (United States)

    West, Ewoud Van; Yamamoto, Akio; Burns, Benjamin; Higuchi, Toshiro

    This paper describes the development of a SCARA-type haptic device, which will be used to assist a human operator in non-contact object handling of silicon wafers using electrostatic levitation. The device has three degrees of freedom, of which only one (vertical) is actively controlled. By utilizing the admittance control paradigm, a high vertical stiffness and a high output force can be achieved. These properties are necessary for the intended application of non-contact object handling to prevent instabilities (induced by the human motion) of the electrostatic levitation system. As the nominal air gap between object and electrostatic levitator is in the order of 350 micrometer, with an allowable position error of about 150 micrometer, instability can easily occur if there is no haptic assistance, especially in the picking up or placing process. The developed SCARA-type haptic device has a mechanical stiffness of 51 N/mm for the vertical direction when it is in the weakest posture, which is sufficient for the non-contact handling task. The design and performance of the haptic device for the active vertical degree of freedom are described in this paper.

  16. Intracameral air following pneumatic noncontact tonometry in a recently post–perforating keratoplasty patient

    Directory of Open Access Journals (Sweden)

    Vámosi P

    2014-04-01

    Full Text Available Péter VámosiDepartment of Ophthalmology, Péterfy Sándor Hospital, Budapest, Department of Ophthalmology, Medical and Health Science Centre, University of Debrecen, Debrecen, HungaryPurpose: The purpose of this report is to highlight the potential risk of noncontact tonometry after routine uncomplicated penetrating keratoplasty (PK.Case report: After uncomplicated PK for keratoconus, routine noncontact tonometry was performed on the second postoperative day. In spite of the adequately closed wound and the tight suture, temporary wound dehiscence occurred, and two-thirds of the anterior chamber was occupied by air. The running suture remained intact, and the Seidel test was negative. One week postoperatively, the patient’s corrected distance visual acuity was 0.4 (0.4 logMAR, and the air bubble had absorbed.Conclusion: This is the first report to conclude that noncontact tonometry may not be sufficiently safe in the early postoperative period in normal PK cases. To prevent possible wound opening, we suggest the use of other tonometry methods during the first several months after PK.Keywords: wound dehiscence, penetrating keratoplasty

  17. Non-contact SQUID-NDT method using a ferrite core for carbon-fibre composites

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Yoshimi [Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo 169-8555 (Japan); Kasai, Naoko [Nanoelectronics Research Institute, AIST, Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takashima, Hiroshi [Nanoelectronics Research Institute, AIST, Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Ishiyama, Atsushi [Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo 169-8555 (Japan)

    2002-12-01

    Carbon-fibre composites (CFCs), such as carbon-fibre-reinforced plastic (CFRP), are promising composite materials for aerospace structures. However, there is no reliable non-contact NDT method for the detection of deep-lying cracks in thick CFCs at the present time. In this study a non-contact eddy-current-based SQUID-NDT method for thick CFCs was developed. Because CFC is conductively low (electrically), and the target CFC is thick, an induction coil with a U-shaped ferrite core was employed to generate a strong induction field while supplying a low frequency current to the coil. This method was applied to 20 mm thick CFRP specimens with hidden slots at various depths. All signal responses due to the slots located at 5 mm up to 17.5 mm in depth were successfully detected while supplying 150 mA at 300 Hz. The peak amplitude of the response obtained by the method was the same as, or larger than, that of previous results on the same specimens by the current injection method. It shows that the developed method can efficiently induce a large eddy current in the conductively low specimen. It is concluded that this method has the potential to be applicable to the non-contact NDT on very thick CFCs.

  18. Multiresolution Approach for Noncontact Measurements of Arterial Pulse Using Thermal Imaging

    Science.gov (United States)

    Chekmenev, Sergey Y.; Farag, Aly A.; Miller, William M.; Essock, Edward A.; Bhatnagar, Aruni

    This chapter presents a novel computer vision methodology for noncontact and nonintrusive measurements of arterial pulse. This is the only investigation that links the knowledge of human physiology and anatomy, advances in thermal infrared (IR) imaging and computer vision to produce noncontact and nonintrusive measurements of the arterial pulse in both time and frequency domains. The proposed approach has a physical and physiological basis and as such is of a fundamental nature. A thermal IR camera was used to capture the heat pattern from superficial arteries, and a blood vessel model was proposed to describe the pulsatile nature of the blood flow. A multiresolution wavelet-based signal analysis approach was applied to extract the arterial pulse waveform, which lends itself to various physiological measurements. We validated our results using a traditional contact vital signs monitor as a ground truth. Eight people of different age, race and gender have been tested in our study consistent with Health Insurance Portability and Accountability Act (HIPAA) regulations and internal review board approval. The resultant arterial pulse waveforms exactly matched the ground truth oximetry readings. The essence of our approach is the automatic detection of region of measurement (ROM) of the arterial pulse, from which the arterial pulse waveform is extracted. To the best of our knowledge, the correspondence between noncontact thermal IR imaging-based measurements of the arterial pulse in the time domain and traditional contact approaches has never been reported in the literature.

  19. Non-Contact Plant Growth Measurement Method and System Based on Ubiquitous Sensor Network Technologies

    Directory of Open Access Journals (Sweden)

    Intae Ryoo

    2011-04-01

    Full Text Available This paper proposes a non-contact plant growth measurement system using infrared sensors based on the ubiquitous sensor network (USN technology. The proposed system measures plant growth parameters such as the stem radius of plants using real-time non-contact methods, and generates diameter, cross-sectional area and thickening form of plant stems using this measured data. Non-contact sensors have been used not to cause any damage to plants during measurement of the growth parameters. Once the growth parameters are measured, they are transmitted to a remote server using the sensor network technology and analyzed in the application program server. The analyzed data are then provided for administrators and a group of interested users. The proposed plant growth measurement system has been designed and implemented using fixed-type and rotary-type infrared sensor based measurement methods and devices. Finally, the system performance is compared and verified with the measurement data that have been obtained by practical field experiments.

  20. High-energy nanosecond radially polarized beam output from Nd:YAG amplifiers

    Science.gov (United States)

    Chang, Chengcheng; Chen, Xudong; Pu, Jixiong

    2017-04-01

    Radially polarized laser beam amplification up to the 772 mJ using flash-lamp-pumped Nd:YAG amplifiers was demonstrated. In the experiments, a nanosecond radially polarized seed beam was converted from a conventional Q-switched Nd:YAG laser output with a polarization converter and then amplified with two Nd:YAG amplifier stages. A maximum amplification output energy up to 772 mJ was achieved at 10 Hz with a 10-ns pulse, corresponding to an amplification factor of 323%. Excellent conservation of polarization was also obtained during the amplification.

  1. Laser dyes excited by high PRR Nd:YAG laser second-harmonic radiation

    Science.gov (United States)

    Soldatov, A. N.; Donin, V. I.; Jakovin, D. V.; Reimer, I. V.

    2008-01-01

    The lasing characteristics of red-emitting dyes in ethanol excited by Nd:YAG laser second-harmonic radiation are examined. The Nd:YAG laser was pumped by a diode matrix. The pump pulse repetition rates (PRRs) were 2.5 - 10 kHz and the pulse duration was 60 - 300 ns. The following dyes were evaluated: oxazine 17, DCM, DCM sp, and pyridine 1. The conversion efficiency for oxazine was 25 % without wavelength selection and 15 % with wavelength selection over the tuning range from 630 to 700 nm. The Nd:YAG and dye laser designs used are described elsewhere [1,2].

  2. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    OpenAIRE

    Masoumeh Hasani Tabatabaei; Sara Shirmohammadi; Esmaeil Yasini; Mansoureh Mirzaei; Sakineh Arami; Hamid Kermanshah; Ladan Ranjbar Omrani; Azar Alimi; Nasim Chiniforush; Afrooz Nakhostin; Mahdi Abbasi

    2015-01-01

    Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser.Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative...

  3. Preserving a diffraction-limited beam in Ho:YAG laser using coherent polarization locking.

    Science.gov (United States)

    Tan, L H; Chua, C F; Phua, P B

    2012-11-15

    We overcome several thermal issues present in Ho:YAG lasers by distributing the gain over a larger volume and achieve a diffraction-limited beam using coherent polarization locking. Increased single-pass absorption, suppression of output power saturation, and improvement in beam quality were shown using the coherent polarization locking technique as compared to a conventional Ho:YAG laser cavity with the same pump and cavity configuration. Ten watts of CW Ho:YAG laser power was generated with >96% coherent combining efficiency.

  4. Morphological assessment of dentine and cementum following apicectomy with Zekrya burs and Er:YAG laser associated with direct and indirect Nd:YAG laser irradiation.

    Science.gov (United States)

    de Moura, Abilio Albuquerque Maranhão; Moura-Netto, Cacio; Barletta, Fernando Branco; Vieira-Júnior, Nilson Dias; Eduardo, Carlos de Paula

    2010-04-01

    This study aimed to assess the apical surface morphology of maxillary central incisors resected 3.0 mm from the tooth apex using Zekrya burs or Er:YAG laser, with or without subsequent direct Nd:YAG laser irradiation (apical and buccal surfaces) and indirect irradiation (palatal surface). Forty maxillary central incisors were instrumented and obturated. The roots were divided into 4 groups according to the root resection method (Zekrya bur or Er:YAG laser - 1.8 W, 450 mJ, 4 Hz, 113 J/cm(2)) and further surface treatment (none or Nd:YAG laser - 2.0 W, 100 mJ, 20 Hz, 124 J/cm(2)). The teeth were prepared for SEM analysis. Scores ranging from 1 to 4 were attributed to cut quality and morphological changes. The data were analyzed by the Kruskal-Wallis test and by Dunn's test. SEM images showed irregular surfaces on the apical portions resected with Zekrya burs, with smear layer and grooves in the resected dentine and slight gutta-percha displacement and plasticization. On the other hand, apicectomies carried out with Er:YAG laser showed morphological changes compatible with ablated dentine, with rough surfaces and craters. In spite of the presence of plasticized gutta-percha, with the presence of bubbles, an irregular adaptation of the filling material to the root walls was also observed. Direct Nd:YAG laser irradiation of the apical and buccal surfaces of the resected roots resulted in areas of resolidification and fusion in the dentine and cementum, with a vitrified aspect; indirect Nd:YAG laser irradiation of the palatal surfaces yielded a lower number of changes in the cementum, with irregular resolidification areas. There were no differences in terms of cut quality between the use of burs and Er:YAG laser or between the 2 surfaces (apical and buccal) treated with Nd:YAG laser with direct irradiation. However, morphological changes were significantly less frequent on surfaces submitted to indirect irradiation (palatal) when compared with those directly irradiated

  5. Ho:YAG laser arthroscopy of the knee

    Science.gov (United States)

    Sisto, Domenick J.; Blazina, Martin E.; Hirsh, Linda C.

    1994-09-01

    The HO:YAG laser is a near-contact laser with a capacity to ablate or cut tissues. The ablation function allows the surgeon to remove meniscal tissue, lyse and resect adhesions, melt loose bodies, and dissolve inflamed synovium. The cutting function of the laser is utilized to perform a lateral release or resect torn menisci. The laser can also be utilized to drill holes in Grade IV chondromalacic lesions to initiate a healing response. The laser has been embraced by orthopaedic surgeons because of its shape and versatility. The tip is only 2 mm wide and can be delivered into the tight posterior compartments of the knee with no damaging contact with the articular surfaces. The laser coagulates as it works and bleeding is minimized. The laser can function both as a cutting and ablating tool. The laser can also drill holes into subchondral bone to, hopefully, initiate a healing response.

  6. Clinical evaluation of Er:YAG laser caries treatment

    Science.gov (United States)

    Dostalova, Tatjana; Jelinkova, Helena; Kucerova, Hana; Krejsa, Otakar; Hamal, Karel; Kubelka, Jiri; Prochazka, Stanislav

    1997-05-01

    To prepare the enamel, the energy used was mainly 345 mJ and repetition rate 2 Hz, for dentine the optimal energy of Er:YAG drilling machine was 200 mJ and repetition rate from 1 to 2 Hz, depending on cavity depth. Subject of treatment were caries of enamel and dentine and it was possible to remove the old insufficient fillings. The average number of pulses was 111.22, ranging from 16 to 489. During preparation, vibrations of microexplosions were felt by 8 patients, however, neither pain or unpleasant sensations were experienced. The filling materials used were composite resins and glassionomer cements. Their clinical evaluation 6 months post insertion was similar to that of the classical drilling system.

  7. Numerical simulation of a battlefield Nd:YAG laser

    Science.gov (United States)

    Henriksson, Markus; Sjoqvist, Lars; Uhrwing, Thomas

    2005-11-01

    A numeric model has been developed to identify the critical components and parameters in improving the output beam quality of a flashlamp pumped Q-switched Nd:YAG laser with a folded Porro-prism resonator and polarization output coupling. The heating of the laser material and accompanying thermo-optical effects are calculated using the finite element partial differential equations package FEMLAB allowing arbitrary geometries and time distributions. The laser gain and the cavity are modeled with the physical optics simulation code GLAD including effects such as gain profile, thermal lensing and stress-induced birefringence, the Pockels cell rise-time and component aberrations. The model is intended to optimize the pumping process of an OPO providing radiation to be used for ranging, imaging or optical countermeasures.

  8. Q-switched Nd:YAG optical vortex lasers.

    Science.gov (United States)

    Kim, D J; Kim, J W; Clarkson, W A

    2013-12-02

    Q-switched operation of a high-quality Nd:YAG optical vortex laser with the first order Laguerre-Gaussian mode and well-determined helical wavefronts using a fiber-based pump beam conditioning scheme is reported. A simple two-mirror resonator incorporating an acousto-optic Q-switch was employed, along with an etalon and a Brewster plate to enforce the particular helicity of the output. The laser yielded Q-switched pulses with ~250 μJ pulse energy and ~33 ns pulse duration (FWHM) at a 0.1 kHz repetition rate for 5.1 W of absorbed pump power. The handedness of the helical wavefronts was preserved regardless of the repetition rates. The prospects of further power scaling and improved laser performance are discussed.

  9. LED pumped Nd:YAG laser development program

    Science.gov (United States)

    Farmer, G. I.; Kiang, Y. C.; Lynch, R. J.

    1973-01-01

    The results of a development program for light emitting diode (LED) pumped Nd:YAG lasers are described. An index matching method to increase the coupling efficiency of the laser is described. A solid glass half-cylinder of 5.0 by 5.6 centimeters was used for index matching and also as a pumping cavity reflector. The laser rods were 1.5 by 56 millimeters with dielectric coatings on both end surfaces. The interfaces between the diode array, glass cylinder, and laser rod were filled with viscous fluid of refractive index n = 1.55. Experiments performed with both the glass cylinder and a gold coated stainless steel reflector of the same dimensions under the same operating conditions indicate that the index matching cylinder gave 159 to 200 percent improvement of coupling efficiency over the metal reflector at various operating temperatures.

  10. Er:YAG laser for endodontics: efficiency and safety

    Science.gov (United States)

    Hibst, Raimund; Stock, Karl; Gall, Robert; Keller, Ulrich

    1997-12-01

    Recently it has been shown that bacterias can be sterilized by Er:YAG laser irradiation. By optical fiber transmission the bactericidal effect can also be used in endodontics. In order to explore potential laser parameters, we further investigated sterilization of caries and measured temperatures in models simulating endodontic treatment. It was found out that the bactericidal effect is cumulative, with single pulses being active. This offers to choose all laser parameters except pulse energy (radiant exposure) from technical, practical or safety considerations. For clinical studies the following parameter set is proposed for efficient and safe application (teeth with a root wall thickness > 1 mm, and prepared up to ISO 50): pulse energy: 50 mJ, repetition rate: 15 Hz, fiber withdrawal velocity: 2 mm/s. With these settings 4 passes must be performed to accumulate the total dose for sterilization.

  11. Random Laser Action in Nd:YAG Crystal Powder

    Directory of Open Access Journals (Sweden)

    Jon Azkargorta

    2016-05-01

    Full Text Available This work explores the room temperature random stimulated emission at 1.064 μm of a Nd:YAG crystal powder (Neodymium-doped yttrium aluminum garnet in a very simple pump configuration with no assistance from an internal mirror. The laser threshold energy as a function of pump beam area and pump wavelength has been measured, as well as the temporal dynamics of emission pulses. The absolute energy of stimulated emission and the absolute laser slope efficiency have been measured by using a method proposed by the authors. The results show a surprising high efficiency that takes the low Nd3+ ion concentration of the crystal powder into account.

  12. SEM investigation of Er:YAG laser apical preparation

    Science.gov (United States)

    Bǎlǎbuc, Cosmin; Todea, Carmen; Locovei, Cosmin; RǎduÅ£ǎ, Aurel

    2016-03-01

    Endodontic surgery involves the incision and flap elevation, the access to the root tip, its resection, the cavity retrograde preparation and filling it with biocompatible material that provides a good seal of the apex[1]. Apicoectomy is compulsory in endodontic surgery. The final stage involves the root retropreparation and the carrying out of the retrograde obturation. In order to perform the retrograde preparation the endodontist can use various tools such as lowspeed conventional handpieces, sonic and ultrasonic equipment. The ideal depth of the preparation should be 3 mm, exceeding this value may affect the long-term success of the obturation [2]. Resection at the depth of 3 mm reduces apical ramifications by 98% and lateral root canals by 93%. The ultrasonic retropreparation has numerous advantages compared to the dental drill. Firstly, the cavity will be in the axis of the tooth which implies a minimum destruction of the root canal morphology. The preparations are precise, and the cutting pattern is perpendicular to the long axis of the root, the advantage being the reduction in the number of dentinal tubules exposed at the resected area [3]. Therefore, the retrograde filling is the procedure when an inert and non-toxic material is compacted in the apically created cavity.[4,5]. The Er:YAG laser is the most common wavelength indicated for dental hard tissue preparation. Its natural selectivity offers a significant advantage compared to the conventional hard tissue preparation [6-9].The purpose of this in vitro study was to investigate the quality of Er:YAG laser apical third preparation using Scanning Electron Microscopy (SEM), in comparison with the conventional ultrasonic method.

  13. High-average-power diode-pumped Yb: YAG lasers

    Energy Technology Data Exchange (ETDEWEB)

    Avizonis, P V; Beach, R; Bibeau, C M; Emanuel, M A; Harris, D G; Honea, E C; Monroe, R S; Payne, S A; Skidmore, J A; Sutton, S B

    1999-10-01

    A scaleable diode end-pumping technology for high-average-power slab and rod lasers has been under development for the past several years at Lawrence Livermore National Laboratory (LLNL). This technology has particular application to high average power Yb:YAG lasers that utilize a rod configured gain element. Previously, this rod configured approach has achieved average output powers in a single 5 cm long by 2 mm diameter Yb:YAG rod of 430 W cw and 280 W q-switched. High beam quality (M{sup 2} = 2.4) q-switched operation has also been demonstrated at over 180 W of average output power. More recently, using a dual rod configuration consisting of two, 5 cm long by 2 mm diameter laser rods with birefringence compensation, we have achieved 1080 W of cw output with an M{sup 2} value of 13.5 at an optical-to-optical conversion efficiency of 27.5%. With the same dual rod laser operated in a q-switched mode, we have also demonstrated 532 W of average power with an M{sup 2} < 2.5 at 17% optical-to-optical conversion efficiency. These q-switched results were obtained at a 10 kHz repetition rate and resulted in 77 nsec pulse durations. These improved levels of operational performance have been achieved as a result of technology advancements made in several areas that will be covered in this manuscript. These enhancements to our architecture include: (1) Hollow lens ducts that enable the use of advanced cavity architectures permitting birefringence compensation and the ability to run in large aperture-filling near-diffraction-limited modes. (2) Compound laser rods with flanged-nonabsorbing-endcaps fabricated by diffusion bonding. (3) Techniques for suppressing amplified spontaneous emission (ASE) and parasitics in the polished barrel rods.

  14. High power CW diode-side-pumped Nd:YAG rod laser

    Institute of Scientific and Technical Information of China (English)

    Hailin Wang(王海林); Weiling Huang(黄维玲); Zhuoyou Zhou(周卓尤); Hongbing Cao(曹红兵)

    2003-01-01

    We report on the characterization of a diode-side-pumped Nd:YAG rod laser operating at high CW output power. A four-fold pump configuration is designed and the pump light is directly coupled into the Nd:YAG rod without the help of any cylindrical lenses. The distribution of pump light in the Nd:YAG rod has been calculated by using ray tracing program. The thermal lens effect of the Nd:YAG rod has been experimentally measured. A maximum output power of 800 W at 1064 nm in multimode operation is obtained for a pump power of 2400 W with 33% optical-optical efficiency. At the same time, the maximum beam parameter product of 25 mm.mrad is achieved.

  15. Up Conversion Measurements in Er:YAG; Comparison with 1.6 Micrometer Laser Performance

    Science.gov (United States)

    Barnes, Norman P.; Walsh, Brian M.; Amzajerdian, Farzin; Reichle, Donald J.; Busch, George E.; Carrion, William A.

    2011-01-01

    Up conversion significantly affects Er:YAG lasers. Measurements performed here for low Er concentration are significantly different than reported high Er concentration. The results obtained here are used to predict laser performance and are compared with experimental results.

  16. Erbium:YAG laser as a method of deepithelization in corrective and reductive breast surgery.

    Science.gov (United States)

    Trelles, Mario A; Pardo, Lourdes; Chamorro, Juan José; Bonanad, Enrique; Allones, Inés; Buil, Carmen; Luna, Ricardo

    2005-08-01

    Deepithelization of the breast in breast ptosis surgery is important, being associated with risks which could affect the clinical outcome. The role of Er:YAG laser deepithelization was investigated. A total of 12 bilateral mammoplasties were performed, randomly assigned to 2 groups, one of experienced and one of less-experienced surgeons. Results were compared between the 2 groups of surgeons for scalpel deepithelization on one breast and the Er:YAG laser on the contralateral breast. No complications; less edema, pain, and erythema; and quicker wound healing were observed in the laser-deepithelized breasts, with a shorter operation time even for the less-experienced surgeons. The authors do not suggest that the Er:YAG laser should replace the scalpel in the hands of the expert surgeon for breast deepithelization in breast ptosis surgery, but the results of the study suggest that Er:YAG laser ablation is a safe, precise, effective and complication-free method.

  17. Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis

    Science.gov (United States)

    2012-01-01

    This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film. PMID:23151219

  18. Coherent polarization locking: an approach to mitigating optical damage in a pulsed Ho:YAG laser.

    Science.gov (United States)

    Tan, L H; Chua, C F; Phua, P B

    2013-04-01

    Intracavity optical damage is mitigated in a pulsed Ho:YAG laser cavity using the coherent polarization locking (CPL) technique. By splitting the available pump power into two individual Ho:YAG laser rods, we passively coherently locked two orthogonal polarization lasers with 9.13 mJ output pulse energies and 14 ns pulsewidths, and operating at 800 Hz repetition rate. A conventional Ho:YAG laser cavity with the same pump and cavity configuration results in severe optical damage when operating at <2 kHz repetition rate, thus limiting the output pulse energies to <5 mJ. We also demonstrated, to the best of our knowledge, the first pulsed operation within the entire CPL Ho:YAG laser cavity by Q-switching in one of the polarization arms, producing nanosecond pulses with no sign of pulse instability.

  19. Application of Stereology on Neodymium-Doped Yttrium Aluminum Garnet (Nd: YAG) Transparent Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nd: YAG precursor powders were synthesized by homogeneous precipitation, and Nd: YAG transparent ceramics were prepared by vacuum sintering at 1700 ℃ for 5 h. The ceramic materials were characterized by light transmittance and field emission gun-environment scanning microscope. Using statistics and stereology theory, study was carried out on the quantitative relationships between light transmittance and stereological parameters in three-dimensional Euclidean space. It is found that the transmittance of Nd:YAG with 1 mm in thickness is about 45% and 58% in visible and near-infrared wavelength, respectively. The transmittance linearly increases with increasing equivalent sphere diameter and reaches the theoretical value of single crystal when the equivalent sphere diameter is 20μm. The transmittance decreases with the increasing of mean specific area per unit volume of grain and discrete grains, and the transmittance decreases with increasing mean free distance of grains in Nd:YAG ceramics.

  20. High energy single frequency Yb:YAG crystalline fiber waveguide master oscillator power amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective is to demonstrate the concept of Yb:YAG crystalline fiber MOPA laser and investigation the technical feasibility toward 50 mJ single frequency...

  1. Nd: YAG Laser Treatment for Keloids and Hypertrophic Scars: An Analysis of 102 Cases

    Directory of Open Access Journals (Sweden)

    Sachiko Koike, MD

    2014-12-01

    Conclusions: Hypertrophic scars responded significantly better to 1064 nm Nd:YAG laser treatment than keloids. However, keloid recurrence occurred when there was remaining redness and induration, even if only a small part of the scar was affected.

  2. A Continuous-Wave Diode-Side-Pumped Tm:YAG Laser with Output 51 W

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Fu; CUI DaFu; XU Zu-Yan; XU Yi-Ting; LI Cheng-Ming; ZONG Nan; XU Jia-Lin; CUI Qian-Jin; LU Yuan-Fu; BO Yong; PENG Qin-Jun

    2008-01-01

    A compact diode-side-pumped Tm:YAG laser is presented, which can output 51 W of cw power at 2.02μm. The Tm:YAG rod is side pumped by nine diode arrays with the central wavelength of 783nm and the with bandwidth of about 2.5 nm at 25℃. To decrease the thermal effect on the both ends and dissipate the heat effectively, one composite Tm:YAG rod with the undoped YAG end caps and the screw threads on the side surface of the rod is used as the laser crystal. The maximum optical-to-optical conversion efficiency of the 2.02-μm laser output is 14.2%, with a slope efficiency of 26.8%.

  3. Analysis on the effect of urethra caruncle treated by Ho:YAG laser

    Science.gov (United States)

    Zhang, Mei-Jue; Zhu, Jing; Shi, Hong-Min

    2005-07-01

    Objective: To observe the effect of Ho:YAG laser in treatment of urethra cauncle. Methods: The patients suffering from urethra cauncle were treated by Ho:YAG laser, the energy of per pulse is 0.5J. The frequency of pulse is 5~15Hz, and the average power of the laser is 2.5~7.5W. Results: Among the patients 188 cases of urethra cauncle were only cured for one time, twice for12 cases. No stricture on the peristome of urethra or urethrovaginal fistula was observed. Conclusions: The technique of treatment of urethra cauncle with Ho:YAG laser is an effect and safe therapeutics with the merit of excellent homeostasis, improved visualization, minimal thermal damage to surrounding tissue, shorter period of recovery and easy to operate. It is better than CO2 laser and Nd:YAG laser.

  4. Luminescence and scintillation properties of YAG:Ce single crystal and optical ceramics

    CERN Document Server

    Mihóková, E; Mareš, J A; Beitlerová, A; Vedda, A; Nejezchleb, K; Blažek, K; D’Ambrosio, C

    2007-01-01

    We use various techniques to study optical and scintillation properties of Ce-doped yttrium aluminum garnet, Y3Al5O12 (YAG:Ce), in the form of a high-quality industrial single crystal. This was compared to optical ceramics prepared from YAG:Ce nanopowders. We present experimental data in the areas of optical absorption, radioluminescence, scintillation decay, photoelectron yield, thermally stimulated luminescence and radiation-induced absorption. The results point to an interesting feature—the absence of antisite (YAl, i.e. Y at the Al site) defects in optical ceramics. The scintillation decay of the ceramics is faster than that of the single crystal, but its photoelectron yield (measured with 1 μs integration time) is about 30–40% lower. Apart from the photoelectron yield value the YAG:Ce optical ceramic is fully comparable to a high quality industrial YAG:Ce single crystal and can become a competitive scintillator material.

  5. Welding of Thermomechanically Rolled Steel by Yb:YAG Disk Laser / Spawanie Stali Walcowanej Termomechanicznie Laserem Dyskowym Yb:YAG

    Directory of Open Access Journals (Sweden)

    Lisiecki A.

    2015-12-01

    Full Text Available Autogenous laser welding of 5.0 mm thick butt joints of thermomechanically rolled steel S700MC was investigated. The Yb:YAG disk laser TruDisk 3302 emitted at 1.03 μm was used for the trials of autogenous welding. The effect of laser welding parameters and thus thermal conditions of welding on weld shape, microstructure of weld metal and heat affected zone (HAZ, tensile strength, bending angle, impact toughness and microhardness profile was determined. Studies have shown that it is advantageous to provide a high welding speed and low heat input. High cooling rate of weld metal and HAZ leads to the formation of a favorable structure characterized by a large proportion of fine-grained acicular ferrite and provides high mechanical properties of butt joints.

  6. Influence of Gamma-Ray Irradiation on Absorption and Fluorescent Spectra of Nd:YAG and Yb:YAG Laser Crystals

    Institute of Scientific and Technical Information of China (English)

    SUN Dun-Lu; ZHANG Qing-Li; XIAO Jing-Zhong; LUO Jian-Qiao; JIANG Hai-He; YIN Shao-Tang

    2008-01-01

    We investigate the influence of gamma-ray irradiation on the absorption and fluorescent spectra of Nd3+ : Y3Al5O12 (Nd:YAG) and Yb3+ :Y3Al5O12 (Yb:YAG) crystals grown by the Czochralski method. Two additional absorption (AA) bands induced by gamma-ray irradiation appear at 255nm and 340nm. The former is eontributed due to Fe3+ impurity, the latter is due to Fe2+ ions and F-type colour centres. The intensity of the excitation and emission spectra as well as the fluorescent lifetime of Nd:YAG crystal decrease after the irradiation of 100 Mrad gamma-ray. In contrast, the same dose irradiation does not impair the fluorescent properties of Yb: YA G crystal. These results indicate that Yb: YA G crystal possesses the advantage over Nd: YA G crystal that has better reliability for applications in harsh radiant environment.

  7. The growth of Ho:YAG single crystals by Czochralski method and investigating the formed cores

    Energy Technology Data Exchange (ETDEWEB)

    Hasani Barbaran, J., E-mail: jhasani@aeoi.org.ir; Ghani Aragi, M. R.; Javaheri, I.; Baharvand, B.; Tabasi, M.; Layegh Ahan, R.; Jangjo, E. [NSTRI, Laser and Optics Research School (Iran, Islamic Republic of)

    2015-12-15

    Ho:YAG single crystals were grown by Czochralski technique, and investigated by the X-ray diffraction (XRD) and optical methods. The crystals were cut and polished in order to observe and analyze their cores. It was found that the deviation of the cores formed in the Czochralski grown Ho:YAG single crystals are resulted from non-symmetrical status of thermal insulation around the Iridium crucible.

  8. Nd: YAG laser therapy of rectosigmoid bleeding due to radiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Leuchter, R.S.; Petrilli, E.S.; Dwyer, R.M.; Hacker, N.F.; Castaldo, T.W.; Lagasse, L.D.

    1982-06-01

    The Nd:YAG laser was used to treat a patient bleeding from the rectosigmoid as a result of radiation injury related to therapy for cervical carcinoma. Successful laser therapy was performed after a diverting colostomy failed to control persistent bleeding. Further surgical procedures were not required. Characteristics of Nd:YAG laser as compared with those of the carbon dioxide and argon lasers are considered.

  9. Continuous-wave operation of a room-temperature Tm: YAP-pumped Ho: YAG laser

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report a continuous-wave (CW) 2.1-μm Ho:YAG laser operating at room temperature pumped by a diode-pumped 1.94-?m Tm:YAP laser.The maximum output power of 1.5 W is obtained from Ho:YAG laser,corresponding to Tm-to-Ho slope efficiency of 17.9% and diode-to-He conversion efficiency of 5.6%.

  10. Er:YAG laser for the surgical treatment of the carpal tunnel syndrome

    Science.gov (United States)

    Russ, Detlef; Ebinger, Thomas; Illich, Wolfgang; Steiner, Rudolf W.

    2003-10-01

    We developed a new surgical procedure to improve the recurrence rate using an Er:YAG laser as dissection tool for the carpal ligament with the objective to ablate a small amount of the carpal ligament and to denaturate its ends. The Er:YAG Laser was transmitted to the applicator via a GeO fiber. With this system we proceeded 10 carpal ligament dissections without any complications in the follow-up period. All patients were free of pain and recurrence.

  11. Q-switched pulse laser generation from double-cladding Nd:YAG ceramics waveguides.

    Science.gov (United States)

    Tan, Yang; Luan, Qingfang; Liu, Fengqin; Chen, Feng; Vázquez de Aldana, Javier Rodríguez

    2013-08-12

    This work reports on the Q-switched pulsed laser generation from double-cladding Nd:YAG ceramic waveguides. Double-cladding waveguides with different combination of diameters were inscribed into a sample of Nd:YAG ceramic. With an additional semiconductor saturable absorber, stable pulsed laser emission at the wavelength of 1064 nm was achieved with pulses of 21 ns temporal duration and ~14 μJ pulse energy at a repetition rate of 3.65 MHz.

  12. Monostatic Doppler lidar using an Nd:YAG laser for wind-velocity measurement

    Science.gov (United States)

    Bersenev, V. I.; Kaptsov, L. N.; Priezzhev, A. V.

    1987-10-01

    A monostatic Doppler lidar using a CW Nd:YAG laser has been developed for measurements of wind velocity. A series of atmospheric measurements using this lidar was carried out. At medium turbulence levels, the limiting lidar range is 200 m. As compared with a CO2 Doppler lidar, the Nd:YAG lidar has a better spatial resolution, is more convenient to use, and does not require a cooled photodetector.

  13. Analysis of apical sealing of canals irradiated with Er: YAG and Nd: YAG lasers and filled with AH Plus®

    Directory of Open Access Journals (Sweden)

    Celso Luis Caldeira

    2013-03-01

    Full Text Available Introduction: Laser technology is gaining increasing importance in dental practice and also in the field of Endodontics with its ability to promote disinfection and experimentally in the preparation of root canal. The action of different types of lasers results in changes representing the increase in permeability of dentinal tissue (Er: YAG or sometimes by a decrease in melting and recrystallization of dentin (Nd: YAG. Objective: this study assessed through apical dye leakage, the influence of irradiation with two types of laser, regarding to the quality of apical sealing of endodontic fillings. Material and methods: Thirty-six single-rooted teeth were used after being prepared with the ProFile system up to size #40 instrument and then divided into four experimental and two control groups. The technique used previously to the filling was as follows: G1 – not irradiated; G2 – irradiated with Er: YAG; G3 – irradiated with Nd: YAG and G4 – irradiated with Er: YAG followed by Nd: YAG. After external waterproofing and dry, the specimens were filled with a cold vertical condensation technique, using AH Plus sealer, and immediately immersed into 0.5% methylene blue solution for subsequent cleavage. The linear values of apical marginal leakage were obtained with the aid of an optical microscope connected to a computer using the Image Lab® software. Results: Data analysis showed the non-existence of statistically significant (p = 0.05 differences between different groups. Conclusion: It was concluded that the laser does not have influence on the apical sealing.

  14. Combined application of Er:YAG and Nd:YAG lasers in treatment of chronic periodontitis. A split-mouth, single-blind, randomized controlled trial.

    Science.gov (United States)

    Sağlam, M; Köseoğlu, S; Taşdemir, I; Erbak Yılmaz, H; Savran, L; Sütçü, R

    2017-10-01

    The aim of the present study was to compare the effectiveness of combined Er:YAG and Nd:YAG laser therapy to that of scaling and root planing with hand instruments in non-surgical treatment of chronic periodontitis. Twenty-five systemically healthy patients with chronic periodontitis were selected for this study. The quadrants were randomly allocated in a split-mouth design to either combined Er:YAG (160 mJ/pulse, 10 Hz) and Nd:YAG laser (100 mJ/pulse, 20 Hz) therapy (test group) or scaling and root planing alone (control group). At baseline, 1 month and 3 months after treatment, plaque index, gingival index, probing depth, clinical attachment level and bleeding on probing (%), were recorded and gingival crevicular fluid and subgingival plaque samples were taken. The gingival crevicular fluid levels of interleukin-1β and tumor necrosis factor-α were analyzed by enzyme-linked immunosorbent assay. Quantitative analysis of red complex bacteria was performed using quantitative real-time polymerase chain reaction. The clinical parameters had significantly improved for both groups after treatment. There were statistically significant differences in probing depth and clinical attachment level between the test and control groups only for deep pockets (≥7 mm) (Pnd microbiological parameters at any time points (P>.05). The present study suggests that a combined course of Er:YAG and Nd:YAG laser therapy may be beneficial particularly in inaccessible areas such as deep pockets on a short-term basis. Further, well-designed studies are required to assess the effectiveness of the combination of these lasers. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Combination of CO2 and Q-switched Nd:YAG lasers is more effective than Q-switched Nd:YAG laser alone for eyebrow tattoo removal.

    Science.gov (United States)

    Radmanesh, Mohammad; Rafiei, Zohreh

    2015-04-01

    The eyebrow tattoo removal using Q-switched lasers is usually prolonged. Other modalities may be required to enhance the efficacy and shorten the treatment course. To compare the efficacy of Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser alone versus combination of Q-switched Nd:YAG and Ultrapulse CO2 lasers for eyebrow tattoo removal after a single session. After local anesthesia, the right eyebrow of 20 patients was treated with Ultrapulse CO2 laser with the parameters of 4 J/cm(2) and 3.2 J/cm(2) for the first and the second passes. Both eyebrows were then treated with 1064-nm and 532-nm Q-switched Nd:YAG laser. The spot size and pulse duration were 3 mm and 5 nanoseconds for both wavelengths, and the fluence was 7 J/cm(2) for 1064 nm and 3 J/cm (2) for 532 nm. The side treated with combination of Q-switched Nd:YAG and CO2 lasers improved 75-100% in 6 of 20 patients versus only 1 of 20 in the side treated with Q-switched Nd:YAG alone. Similarly, the right side in 13 of 20 patients showed more than 50% improvement with combination therapy versus the left side (the monotherapy side), where only 6 of 20 cases showed more than 50% improvement. The Mann-Whitney test was 2.85 for the right side and 1.95 for the left side (P value = 0.007). Using Ultra pulse CO2 laser enhances the efficacy of Q-switched Nd:YAG laser in eyebrow tattoo removal.

  16. Long-term sexual outcomes after holmium laser enucleation of the prostate: which patients could benefit the most?

    Science.gov (United States)

    Capogrosso, P; Ventimiglia, E; Ferrari, M; Serino, A; Boeri, L; Capitanio, U; Briganti, A; Damiano, R; Montorsi, F; Salonia, A

    2016-09-01

    Assess rate and predictors of erectile function (EF) outcomes at long-term follow-up (FU) after holmium laser enucleation of the prostate (HoLEP). Cross-sectional analyses were performed on 135 patients with a mean FU of 12 years post HoLEP. Patients completed both a baseline and a FU International Index of Erectile Function (IIEF)-EF domain and the International Prostatic Symptoms Score (IPSS). Postoperative EF outcomes, including rate and predictors of EF improvement considering minimal clinically important differences (MCIDs) criteria, were assessed. Logistic regression models tested the association between predictors and EF. At a mean (median) FU of 152.1 (163) months, patients showed a significant decrease in the IIEF-EF score P<0.01) and significant IPSS improvement (P<0.01). Overall, 50 (37%) patients worsened by at least one IIEF-EF category. Conversel, 23 (17%) patients reported an improvement in postoperative IIEF-EF score; 75 (55.6%) and 10 (7.4%) patients maintained and eventually improved their IIEF-EF category, respectively. Patients reporting a decrease in the postoperative IIEF-EF score were significantly older (P=0.03) and showed a significantly longer mean FU (P<0.01) than those reporting postoperative improvements of IIEF-EF. Nine (6.7%) patients showed significant EF improvement according to MCIDs criteria. Both higher IPSS scores (odds ratio (OR): 1.12; P=0.02) and lower IIEF-EF (OR: 0.88; P<0.01) at baseline, emerged as independent predictors of postoperative EF improvement. HoLEP was associated with a decrease in EF and a persistent amelioration of BPH-related urinary symptoms at long-term FU. Almost one third of patients worsened by at least one IIEF-EF category. However, a clinically meaningful EF improvement was observed in roughly 7% of the individuals. Patients with more severe preoperative urinary symptoms and ED benefited more from HoLEP in terms of EF.

  17. Holmium laser enucleation versus simple prostatectomy for treating large prostates: Results of a systematic review and meta-analysis

    Science.gov (United States)

    Jones, Patrick; Alzweri, Laith; Rai, Bhavan Prasad; Somani, Bhaskar K.; Bates, Chris; Aboumarzouk, Omar M.

    2015-01-01

    Objective To compare and evaluate the safety and efficacy of holmium laser enucleation of the prostate (HoLEP) and simple prostatectomy for large prostate burdens, as discussion and debate continue about the optimal surgical intervention for this common pathology. Materials and methods A systematic search was conducted for studies comparing HoLEP with simple prostatectomy [open (OP), robot-assisted, laparoscopic] using a sensitive strategy and in accordance with Cochrane collaboration guidelines. Primary parameters of interest were objective measurements including maximum urinary flow rate (Qmax) and post-void residual urine volume (PVR), and subjective outcomes including International Prostate Symptom Score (IPSS) and quality of life (QoL). Secondary outcomes of interest included volume of tissue retrieved, catheterisation time, hospital stay, blood loss and serum sodium decrease. Data on baseline characteristics and complications were also collected. Where possible, comparable data were combined and meta-analysis was conducted. Results In all, 310 articles were identified and after screening abstracts (114) and full manuscripts (14), three randomised studies (263 patients) were included, which met our pre-defined inclusion criteria. All these compared HoLEP with OP. The mean transrectal ultrasonography (TRUS) volume was 113.9 mL in the HoLEP group and 119.4 mL in the OP group. There was no statistically significant difference in Qmax, PVR, IPSS and QoL at 12 and 24 months between the two interventions. OP was associated with a significantly shorter operative time (P = 0.01) and greater tissue retrieved (P < 0.001). However, with HoLEP there was significantly less blood loss (P < 0.001), patients had a shorter hospital stay (P = 0.03), and were catheterised for significantly fewer hours (P = 0.01). There were no significant differences in the total number of complications recorded amongst HoLEP and OP (P = 0.80). Conclusion The results of the meta

  18. Comparative study between Fortify and Nd:YAG laser used for marginal sealing in composite restorations

    Science.gov (United States)

    Navarro, Ricardo S.; Esteves, Grazia V.; Oliveira, Wilson T., Jr.; Matos, Adriana B.; Turbino, Mirian L.; Youssef, Michel N.; Matson, Edmir

    1999-05-01

    The aim of this study was to evaluate microleakage of composite restorations submitted to marginal treatment. Class V preparations with walls located in enamel were performed at buccal and lingual surfaces of eighteen recently extracted, non-carious human premolars. Cavities were restored with composite resins and adhesive system. Samples were stored in distilled water for 48h and polished with Sof-Lex discs. Teeth were randomly divide in six groups: G1 - Control; G2 - marginal treatment with surface sealant; G3 - Nd:YAG 25 Hz, 80mJ, 2W; G4 - Nd:YAG 20Hz, 100mJ, 2W; G5 - Nd:YAG 30Hz, 60mJ, 1.8W; G6 - Nd:YAG 30Hz, 40mJ, 1.2W. Contact fiberoptic (300μm) pulsed (1.064 μm) Nd:YAG laser was used for 30sec, under air cooling. Teeth were impermeabilized, immersed in a dye (Rhodamine B) for 4h at 37°, and sectioned. Specimens were evaluated under light microscopy and evaluated with scores. Results were analyzed with Kruskal- Wallis test (p=0.05) and showed that there were significant differences between marginal treatments; there were no significant differences beaten groups 1, 2, 4 and 3, 5, 6; lower values of microleakage were at groups 3, 5, 6. Nd:YAG laser showed marginal sealing ability and decreased microleakage of composite resins restorations.

  19. Low temperature synthesis of monodispersed YAG:Eu crystallites by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Mengmeng [Shanghai Institute of Ceramics, Chinese Academy of Sciences, No. 1295 Dingxi Road, Shanghai, 200050 (China); University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 (China); Zhang, Zhijun, E-mail: zhangzhijun@shu.edu.cn [School of Materials Science and Engineering, Shanghai University, No. 99 Shangda Road, Shanghai, 200072 (China); Zhao, Jingtai, E-mail: jtzhao@shu.edu.cn [School of Materials Science and Engineering, Shanghai University, No. 99 Shangda Road, Shanghai, 200072 (China); Zhang, Jiazhi [Shanghai Institute of Ceramics, Chinese Academy of Sciences, No. 1295 Dingxi Road, Shanghai, 200050 (China); University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 (China); Liu, Zhiwei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, No. 1295 Dingxi Road, Shanghai, 200050 (China)

    2015-10-25

    Single phase europium doped yttrium aluminum garnet (YAG:Eu) crystallites with good dispersity were successfully synthesized by a facile hydrothermal method at 300 °C for 24 h. The influences of the molar ratio of (Y + Eu) to Al (denoted by Ln/Al) in the raw material on the phase, morphology, crystallinity, local environment of Eu ions and photoluminescence properties were investigated. It was found that the monodispersed single phase YAG:Eu crystallites with terminating faces of {110} can be obtained when Ln/Al is 3:4. Eu ions in all the samples are trivalent regardless of Ln/Al, while the local environment of Eu ions is more symmetric when Ln/Al is 3:4. Moreover, the YAG:Eu crystallites obtained when Ln/Al is 3:4 exhibit improved crystallinity, which contributes to the enhanced luminescence intensity. - Highlights: • Single phase YAG:Eu was synthesized by the hydrothermal method at 300 °C. • The YAG:Eu crystallites are monodispersed and exhibit improved crystallinity. • The YAG:Eu crystallites exhibit improved luminescence intensity. • XAFS and VUV were used to investigate the local structure of Eu.

  20. Er:YAG laser irradiation to control the progression of enamel erosion: an in situ study.

    Science.gov (United States)

    Scatolin, R S; Colucci, V; Lepri, T P; Alexandria, A K; Maia, L C; Galo, R; Borsatto, M C; Corona, S A M

    2015-07-01

    This in situ study evaluated the effect of Er:YAG laser irradiation in controlling the progression of enamel erosion-like lesions. Fifty-six enamel slabs (330 KHN ± 10 %) with one fourth of the surface covered with resin composite (control area) were submitted to initial erosion-like lesion formation with citric acid. The slabs were divided into two groups: irradiated with Er:YAG laser and non-irradiated. Fourteen volunteers used an intraoral palatal appliance containing two slabs, in two phases of 5 days each. During the intraoral phase, in a crossed-over design, half of the volunteers immersed the appliance in citric acid while the other half used deionized water, both for 5 min, three times per day. Enamel wear was determined by an optical 3D profilometer. ANOVA revealed that when deionized water was used as immersion solution during the intraoral phase, lower values of wear were showed when compared with the groups that were eroded with citric acid, whether irradiated or non-irradiated with Er:YAG laser. When erosion with citric acid was performed, Er:YAG laser was not able to reduce enamel wear. Small changes on enamel surface were observed when it was irradiated with Er:YAG laser. It may be concluded that Er:YAG laser irradiation did not reduce the progression of erosive lesions on enamel submitted to in situ erosion with citric acid.

  1. Low-temperature solution synthesis and characterization of Ce-doped YAG nanoparticles

    Institute of Scientific and Technical Information of China (English)

    吉成; 冀立宇; 连刘超; 沈丽明; 张晓艳; 王一峰

    2015-01-01

    Monophasic Ce3+-doped yttrium aluminum garnet (Ce:YAG) nanoparticles with high crystallinity and tunable grain size ranging from ~19–30 nm were prepared by a modified co-precipitation process with a follow-up calcination treatment. For the syn-thesis, aluminum, yttrium, and cerium nitrates were used as starting materials, ammonium sulfate as dispersant, and a combination of ammonium bicarbonate and ammonia as precipitating agent. Influence of precipitation temperature, the pH value of precipitant solu-tions, aging period, calcination conditions, and Ce-doping level were investigated for controlling the purity, particle size, and photo-luminescence performance of the Ce:YAG nanoparticles. High-purity YAG nanoparticles were prepared at pH=10.50–11.00 and cal-cination temperatures of 850–1100 ºC with a calcination time of 3 h. With increasing Ce3+ concentration, the peak in the emission spectra of the obtained nanopowders shifted from 529 nm for the 0.67 wt.%-Ce:YAG to 544 nm for the 3.4 wt.%-Ce:YAG, while the strongest photoluminescence intensity was observed for the 1.3 wt.%-Ce:YAG nanoparticles.

  2. About the luminescence properties of YAG:Nd, Ce and YAG:Nd single crystals and their relation to laser properties

    Science.gov (United States)

    Mares, Jiri A.; Kubelka, Jiri; Kvapil, Jiri

    1986-09-01

    Laser excited luminescence studies of various YAG:Nd, Ce and YAG:Nd (with an excess of yttrium) single crystals together with a testing of laser properties of rods made from the same crystals have been investigated in this paper. It was observed that laser pulse energies increase with increasing halfwidths of the luminescence spectral bands. This dependence and other observations indicate that local structure changes or Nd(3+) nonequivalent centers are present in the studied crystals. Various mechanisms leading to the formation of Nd(3+) nonequivalent centers are discussed and it seems that the more probable mechanism is oxygen segregation and diffusion.

  3. Continuous-wave and Q-switched performance of an Yb:YAG/YAG composite thin disk ceramic laser pumped with 970-nm laser diode

    Institute of Scientific and Technical Information of China (English)

    Hong Cai; Jun Zhou; Hongming Zhao; Yunfeng Qi; Qihong Lou; Jingxing Dong; Yunrong Wei

    2008-01-01

    Using front face-pumped compact active mirror laser (CAMIL) structure, we have demonstrated an Yb:YAG/YAG composite ceramic disk laser with pumping wavelength at 970 nm. The laser has been operated in both continuous-wave (CW) and Q-switching modes. Under CW operation, laser output power of 1.05 W with 2% transmission output coupler was achieved at the wavelength of 1031 nm. Qswitched laser output was gotten by using an acousto-optic Q-switch. The repetition rate ranged from 1 to 30 kHz and the pulse width varied from 166 to 700 ns.

  4. Numerical Modelling of QCW-Pumped Passively Q-Switched Nd:YAG Lasers with Cr4+:YAG as Saturable Absorber

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-Ye; XU De-Gang; XIONG Jing-Ping; WANG Zhuo; WANG Peng; YAO Jian-Quan

    2008-01-01

    @@ Passively Q-switched quasi-continuous-wave (QCW) diode-pumped Nd:YAG laser with Cr4+:YAG as saturable absorber is numerically investigated by solving the coupled rate equations. The threshold pump rate for passively Q-switched QCW-pumped laser is derived. The effects of the pump rate and pump-pulse duration on the laser operation characteristics are studied theoretically. The pump power range can be estimated according to the number of output pulses. The numerical simulation results are in good agreement with the experimental results.

  5. Continuous-wave yellow laser generation at 578 nm by intracavity sum-frequency mixing of thin disk Yb:YAG laser and Nd:YAG laser

    Science.gov (United States)

    Ma, Gangfei; Yang, Jianming; Tan, Huiming; Tian, Yubing; Yao, Wenming; Ju, Qiaojun; Zhang, Long; Chen, Jiansheng; Wu, Xiaodong; Gao, Jing

    2017-07-01

    We report a continuous-wave yellow laser at 578 nm obtained by doubly resonant intracavity sum-frequency mixing of thin disk Yb:YAG laser and Nd:YAG laser with a LBO nonlinear crystal. Single-wavelength laser operation at 578 nm by using a silica etalon as a wavelength selector and dual-wavelength operation at 578 nm and 582 nm are obtained with maximum output powers of 100 mW and 136 mW, respectively. The single wavelength operating power stability value in 30 min was 4.7%, which was improved ∼21.6%, compared with that of dual-wavelength operation.

  6. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    Science.gov (United States)

    2011-01-01

    Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors. PMID:22243660

  7. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    Directory of Open Access Journals (Sweden)

    Abbas Abbas K

    2011-10-01

    Full Text Available Abstract Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI detection and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU. The promising results suggest to include this technology into advanced NICU monitors.

  8. Noncontact interface trap determination of SiO2-4H-SiC structures

    Science.gov (United States)

    Oborina, E. I.; Hoff, A. M.

    2010-01-01

    A sequence of noncontact corona-Kelvin metrology is introduced that enables the determination and monitoring of interface properties in dielectric/wide band gap semiconductor structures. The technique involves the incremental application of precise and measured quantities of corona charge, QC, onto the dielectric surface followed by determination of the contact potential difference, VCPD, as the material structure response. The V-Q characteristics obtained are used to extract the surface barrier, VSB, response related to the applied corona charge. The described approach differs from the common noncontact method applied in the case of dielectric/silicon structures where for each quanta of applied charge the value of surface barrier voltage, VSB, is obtained. Materials with wide band gaps and high concentrations of deep levels, as suggested for silicon carbide, do not permit quick determination of VSB by modulation of the band bending in the semiconductor with light. Light exposure in the case of SiC results in a long recovery time required to approach the nominal value of the preillumination VCPD value. The metrology approach presented determines an intersection of the VCPD-QC characteristic obtained in the dark with the Vox-QC characteristic representing the dielectric response. The specific VSB-QC dependence surrounding the reference VFB value is obtained from this approach and enables the noncontact determination of the dielectric interface trap density and its spectrum. Application of the modified metrology method to thermal oxide on n-type 4H-SiC demonstrates the modification of the Dit distribution by Fowler-Nordheim stress. In addition, an ability to quantify and separate trapped charge components is shown.

  9. An ultrasonically levitated noncontact stage using traveling vibrations on precision ceramic guide rails.

    Science.gov (United States)

    Koyama, Daisuke; Ide, Takeshi; Friend, James R; Nakamura, Kentaro; Ueha, Sadayuki

    2007-03-01

    This paper presents a noncontact sliding table design and measurements of its performance via ultrasonic levitation. A slider placed atop two vibrating guide rails is levitated by an acoustic radiation force emitted from the rails. A flexural traveling wave propagating along the guide rails allows noncontact transportation of the slider. Permitting a transport mechanism that reduces abrasion and dust generation with an inexpensive and simple structure. The profile of the sliding table was designed using the finite-element analysis (FEA) for high levitation and transportation efficiency. The prototype sliding table was made of alumina ceramic (Al2O3) to increase machining accuracy and rigidity using a structure composed of a pair of guide rails with a triangular cross section and piezoelectric transducers. Two types of transducers were used: bolt-clamped Langevin transducers and bimorph transducers. A 40-mm long slider was designed to fit atop the two rail guides. Flexural standing waves and torsional standing waves were observed along the guide rails at resonance, and the levitation of the slider was obtained using the flexural mode even while the levitation distance was less than 10 microm. The levitation distance of the slider was measured while increasing the slider's weight. The levitation pressure, rigidity, and vertical displacement amplitude of the levitating slider thus were measured to be 6.7 kN/m2, 3.0 kN/microm/m2, and less than 1 microm, respectively. Noncontact transport of the slider was achieved using phased drive of the two transducers at either end of the vibrating guide rail. By controlling the phase difference, the slider transportation direction could be switched, and a maximum thrust of 13 mN was obtained.

  10. "Non-Contact Ultrasonic Treatment of Metals in a Magnetic Field"

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard Michael [ORNL; Wilgen, John B [ORNL; Kisner, Roger A [ORNL; Jaramillo, Roger A [ORNL; Ludtka, Gail Mackiewicz- [ORNL

    2007-01-01

    A concept has been originated for non-contact ultrasonic treatment of metals based on the use of an induction coil located in a high-field superconducting magnet. An advantage of using a high magnetic field environment (> 9 T) is that this allows the induced surface current in the sample to be decreased proportionately. As a result, the incidental induction heating associated with the use of the EMAT (Electromagnetic Acoustical Transducer) is greatly reduced, which improves the energy efficiency of the EMAT approach. The method can be coupled with high-field magnetic processing, but can also be used where only ultrasonic treatment is beneficial. In the proof-of-principle experiments, a high-field EMAT was used for non-contact ultrasonic processing of aluminum samples during solidification. The magnetic field for the EMAT was supplied by a high-field (20 Tesla) resistive magnet, and the current was provided by an induction coil. This resulted in a highly efficient EMAT that delivered 0.5 MPa (~5 atmospheres) of acoustic drive to the surface of the sample while coupling less than 100 watts of incidental induction heating. The exceptionally high energy efficiency of the electromagnetic transducer is due to the use of the high magnetic field, which reduces the current needed to achieve the same acoustic pressure. In these initial experiments, aluminum samples of A356 alloy were heated to the liquid state and allowed to solidify at a controlled cooling rate while subjected to the non-contact ultrasonic stimulation (0.5 MPa @ 165 kHz) provided by an induction coil located within the 200 mm (~8-inch) bore of a 20-T Bitter resistive magnet.

  11. Fos expression at the cerebellum following non-contact arousal and mating behavior in male rats

    Science.gov (United States)

    Manzo, Jorge; Miquel, Marta; Toledo, Rebeca; Mayor-Mar, Justo Abraham; Garcia, Luis I.; Aranda-Abreu, Gonzalo E.; Caba, Mario; Hernandez, Maria Elena

    2010-01-01

    The cerebellum is considered a center underlying fine movements, cognition, memory and sexual responses. The latter feature led us to correlate sexual arousal and copulation in male rats with neural activity at the cerebellar cortex. Two behavioral paradigms were used in this investigation: the stimulation of males by distant receptive females (non-contact sexual stimulation), and the execution of up to three consecutive ejaculations. The vermis area of the cerebellum was removed following behavioral experiments, cut into sagittal sections, and analyzed with Fos immunohistochemistry to determine neuronal activation. At the mid-vermis region (sections from the midline to 0.1 mm laterally), non-contact stimulation significantly increased the activity of granule neurons. The number of activated cells increased in every lobule, but lobules 1 and 6 to 9 showed the greatest increment. In sexual behavior tests, males reaching one ejaculation had a high number of activated neurons similar to those counted after non-contact stimulation. However, two or three consecutive ejaculations showed a smaller number of Fos-ir cells. In contrast to the mid-vermis region, sections farthest from the midline (0.1 to 0.9 mm laterally) revealed that only lobule 7 expressed activated neurons. These data suggest that a well-delineated group of granule neurons have a sexual biphasic response at the cerebellar vermis, and that Fos in them is under an active degradation mechanism. Thus, they participate as a neural substrate for male rat sexual responses with an activation-deactivation process corresponding with the sensory stimulation and motor performance occurring during copulation. PMID:17936859

  12. Non-contact metrology of aspheric surfaces based on MWLI technology

    Science.gov (United States)

    Berger, G.; Petter, J.

    2013-09-01

    A non-contact optical scanning metrology solution measuring aspheric surfaces is presented, which is based on multi wavelength interferometry (MWLI). The technology yields high density 3D data in short measurement times (including set up time) and provides high, reproducible form measurement accuracy. It measures any asphere without restrictions in terms of spherical departures. In addition, measurement of a large variety of special optics is enabled, such as annular lenses, segmented optics, optics with diffractive steps, ground optics, optics made of opaque and transparent materials, and small and thin optics (e.g. smart phone lenses). The measurement instrument can be used under production conditions.

  13. A non-contact mine pressure evaluation method by electromagnetic radiation

    Science.gov (United States)

    Wang, Enyuan; He, Xueqiu; Liu, Xiaofei; Li, Zhonghui; Wang, Chao; Xiao, Dong

    2011-10-01

    An electromagnetic radiation evaluation method for the relative stress state of coal bed under stress was proposed in this paper. The stress distribution of mine roadway or working face, as well as high stress zone or stress gradient zone, was analyzed by the method. The main advantages of the technique are its characteristics of non-contact, orientability, and regional monitoring. Correlation analysis of electromagnetic radiation with relative stress was carried out in coal mines and tunnels. The results indicate that the electromagnetic radiation technology has a wide application prospect in the evaluation of mine pressure.

  14. Pulsed photothermal radiometry for noncontact spectroscopy, material testing and inspection measurement

    Science.gov (United States)

    Tam, A. C.

    1984-08-01

    Photothermal Radiometry (PTR) is a sensitive technique for noncontact spectroscopy and inspection. Its principle is the following: a modulated beam of photons (or other particles) produces temperature transients in a sample; the corresponding transients in the infrared thermal radiation emitted from the sample are analyzed. This can provide absolute absorption coefficients, as well as information on thermal diffusivity, layered structure, and dimensions. Variations of PTR are possible with continuously-modulated or pulsed excitation, and with transmission or back-scattering detection. These variations are reviewed. The recent technique of pulsed PTR with backscattering detection is described in more detail, and some important single-ended remote sensing applications are discussed.

  15. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury.

    Science.gov (United States)

    Viswanath, Y K; Rogers, I M

    1999-09-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein bypass graft. Similar injury in association with Aikido has not been described in the English literature previously. Various martial art injuries are briefly discussed and safety recommendations made.

  16. Terahertz paintmeter for noncontact monitoring of thickness and drying progress in paint film

    Science.gov (United States)

    Yasui, Takeshi; Yasuda, Takashi; Sawanaka, Ken-Ichi; Araki, Tsutomu

    2005-11-01

    We propose a paintmeter for noncontact and remote monitoring of the thickness and drying progress of a paint film based on the time-of-flight measurement of the echo signal of a terahertz (THz) electromagnetic pulse. The proposed method is effectively applied to two-dimensional mapping of the painting thickness distribution for single-layer and multilayer paint films. Furthermore, adequate parameters for the drying progress are extracted from the THz pulse-echo signal and effectively applied to monitor the wet-to-dry transformation. The THz paintmeter can be a powerful tool for quality control of the paint film on the in-process monitoring of car body painting.

  17. Non-contact 3D fingerprint scanner using structured light illumination

    Science.gov (United States)

    Troy, Mike; Hassebrook, Laurence; Yalla, Veeraganesh; Daley, Raymond

    2011-03-01

    As crime prevention and national security remain a top priority, requirements for the use of fingerprints for identification continue to grow. While the size of fingerprint databases continues to expand, new technologies that can improve accuracy and ultimately matching performance will become more critical to maintain the effectiveness of the systems. FlashScan3D has developed non-contact, fingerprint scanners based on the principles of Structured Light Illumination (SLI) that capture 3Dimensional data of fingerprints quickly, accurately and independently of an operator. FlashScan3D will present findings from various research projects performed for the US Army and the Department of Homeland Security.

  18. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography

    Directory of Open Access Journals (Sweden)

    Buj C.

    2015-09-01

    Full Text Available A very fast innovative holographic off-axis non-contact detection method for Photoacoustic Tomography (PAT is introduced. It overcomes the main problems of most state-of-the-art photoacoustic imaging approaches that are long acquisition times and the requirement of acoustic contact. In order to increase the acquisition speed significantly, the surface displacements of the object, caused by the photoacoustic pressure waves, are measured interferometrically in two dimensions. Phase alterations in the observed speckle field are used to identify changes in the object’s topography. A sampling rate of up to 80 MHz is feasible, which reduces the occurrence of motion artefacts.

  19. Phenomenally High Transduction Air/gas Transducers for Practical Non-Contact Ultrasonic Applications

    Science.gov (United States)

    Bhardwaj, Mahesh C.

    2009-03-01

    Based on novel acoustic impedance matching layers and high coupling piezoelectric materials this paper describes exceptionally high air/gas transduction ultrasonic transducers. By providing applications oriented performance of these transducers we also usher in the era of much desired Non-Contact Ultrasound (NCU) testing and analysis of a wide range of materials including early stage formation of materials such as uncured composite prepregs, green ceramics and powder metals, plastics, elastomers, porous, hygroscopic, chemically bonded and other materials. Besides quality control, ultimately NCU offers timely opportunities for cost-effective materials production, energy savings, and environment protection.

  20. Noncontact atomization of droplets using an aerial ultrasonic source with two vibrating plates

    Science.gov (United States)

    Endo, Arisa; Yanagimoto, Miduki; Asami, Takuya; Miura, Hikaru

    2015-07-01

    For use in mass spectrometry, we investigated the noncontact atomization of droplets using a rectangular transverse vibrating plate ultrasonic source. To determine the atomization properties of the ultrasonic source, we examined the sound pressure distribution of the standing wave acoustic field formed and observed the behavior of the atomized particles in the acoustic field. We determined the relationship between sound pressure and the conditions and location where atomization occurs with the variations in droplet surface tension and viscosity using three different compounds: water, ethanol, and glycerin. Furthermore, we clarifies the distribution of particle diameters in atomized water.