Bilirubin Calculi Crushing by Laser Irradiation at a Molecular Oscillating Region Wavelength Based on Infrared Absorption Spectrum Analysis Using a Free-Electron Laser: An Experimental Study

Watanabe, Manabu; Kajiwara, Hirohisa; Awazu, Kunio; Aizawa, Katsuo

doi:10.1007/s005950170097

Cited by 8 publications

(4 citation statements)

References 17 publications

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“…For example, selective treatments of arteriosclerosis and gallstones [1][2][3][4][5] , mass spectrometric analysis of proteins using laser desorption/ionization [6][7][8][9] , and infrared absorption spectroscopy 5,10,11 have been demonstrated with MIR tunable lasers such as free electron lasers (FELs) and solid-state lasers using differencefrequency generation (DFG) and optical parametric oscillators (OPOs). However, the application fields of the MIR tunable lasers have been restricted by their large size and high cost equipments.…”

Section: Introductionmentioning

confidence: 99%

Development of a mid-infrared tunable optical parametric oscillator pumped by a Q-switched Tm,Ho:YAG laser

Hazama

Yumoto

Ogawa

et al. 2011

Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications X

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A compact and high-energy pulsed mid-infrared laser using an optical parametric oscillator (OPO) has been developed using a diode-pumped and Q-switched Tm,Ho:YAG ceramic laser with a wavelength of 2.09 µm as a pump source. A singly-resonant OPO with a 20 mm long AgGaSe 2 crystal was used, and the crystal was set at an angle normal to the pump beam. The output idler pulse energy was up to about 200 µJ with the pump energy of about 6 mJ for both the type I and type II phase matching conditions. The wavelength of the idler pulses was 5.97 and 6.37 µm for type I and type II, respectively. The output characteristics predicted using a model calculation were in good agreement with the experimental results. It is suggested that the output idler pulse energy in the experiment is limited by the surface damage threshold of the AgGaSe 2 crystal. By increasing the pump beam diameter from 1 to 3 mm (3-fold) and the pump energy from 6 to 54 mJ (9-fold), the idler pulse energy of 1.8 mJ (= 200 µJ × 9) will be obtained without increasing the pump intensity and without saturation of the output idler pulse energy.

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Section: Introductionmentioning

confidence: 99%

Development of a mid-infrared tunable optical parametric oscillator pumped by a Q-switched Tm,Ho:YAG laser

Hazama

Yumoto

Ogawa

et al. 2011

Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications X

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“…So far, many applications using the selective absorption in the MIR wavelength region have been reported. For example, selective treatments of arteriosclerosis and gallstones [1][2][3][4], mass spectrometric analysis of proteins using laser desorption/ionization [5][6][7][8], and infrared absorption spectroscopy [9,10] have been demonstrated with MIR tunable lasers such as free electron lasers (FELs) and solid-state lasers using difference-frequency generation (DFG) and optical parametric oscillators (OPOs). However, the applicable fields of the MIR tunable lasers have been restricted by their large size and high cost equipments.…”

Section: Introductionmentioning

confidence: 99%

Mid-infrared tunable optical parametric oscillator pumped by a Q -switched Tm,Ho:YAG ceramic laser

et al. 2009

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Since resonant absorption of light caused by a variety of different molecular bond occurs in the mid-infrared (MIR) wavelength region, many applications using tunable MIR lasers have been reported. However, the applicable fields of the MIR tunable lasers have been restricted by their large size and high cost equipments. Therefore, we are developing a compact tunable MIR laser using an optical parametric oscillator (OPO). To obtain a long term stability and a high conversion efficiency, a diode-pumped and Q-switched Tm,Ho:YAG ceramic laser with a wavelength of 2.1 µm was adopted for the pump source. A maximum output energy of 40 mJ was obtained with the Tm,Ho:YAG ceramic laser at a pulse width of 150 ns and a repetition rate of 10 Hz. An experiment was performed using a singly-resonant OPO with a ZnGeP 2 crystal pumped by another OPO with a wavelength of 2.1 µm. A threshold pump fluence of 0.2 J/cm 2 and a slope efficiency of 60% were obtained at a signal and idler wavelengths of 3.3 and 5.6 µm, respectively. Using these results and a theoretical model calculation, the maximum output energy of MIR-OPO pumped with the Tm,Ho:YAG ceramic laser was estimated to be about 20 mJ.

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“…However, the accidental irradiation to surrounding normal tissues can lead to the damage to the normal tissue, and the recurrence rate of the stones are not negligible. Therefore, these laser lithotriptors have not widely been used in the clinical treatment [4].…”

Section: Introductionmentioning

confidence: 99%

Mid-Infrared Pulsed Laser Lithotripsy with a Tunable Laser Using Difference-Frequency Generation

Hazama¹,

Kutsumi²,

Awazu³

2013

OPJ

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A novel technique of lithotripsy was investigated with a mid-infrared tunable pulsed laser using difference-frequency generation (DFG). Human gallstone samples obtained from 24 patients were analyzed with their infrared absorption spectra. It was found that the principal components of the gallstones were different for the different patients and that the gallstone samples used in this research could be classified into four groups, i.e., mixed stones, calcium bilirubinate stones, cholesterol stones, and calcium carbonate stones. In addition, some gallstone samples had different compositions within the single stone. The mid-infrared laser tunable within a wavelength range of 5.5 - 10 μm was irradiated to the cholesterol stones at two different wavelengths of 6.83 and 6.03 μm, where the cholesterol stones had relatively strong and weak absorption peaks, respectively. As the result, the cholesterol stones were more efficiently ablated at the wavelength of 6.83 μm with the strong absorption peak. Therefore, it is suggested that the gallstones could be efficiently ablated by tuning the wavelength of the laser to the strong absorption peak of the gallstones. The higher efficiency of the ablation using the characteristic absorption peaks should lead to the safer treatment without damage to the surrounding normal tissues. In order to identify the composition of the gallstones in the patients, endoscopic and spectroscopic diagnosis using the DFG laser and an optical fiber probe made with two hollow optical fibers and a diamond attenuation total reflection prism should be useful. The absorption spectrum of the gallstones in the patients could be measured by measuring the energy of the DFG laser transmitted through the optical fiber probe and by scanning the wavelength of the DFG laser.

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Bilirubin Calculi Crushing by Laser Irradiation at a Molecular Oscillating Region Wavelength Based on Infrared Absorption Spectrum Analysis Using a Free-Electron Laser: An Experimental Study

Cited by 8 publications

References 17 publications

Development of a mid-infrared tunable optical parametric oscillator pumped by a Q-switched Tm,Ho:YAG laser

Development of a mid-infrared tunable optical parametric oscillator pumped by a Q-switched Tm,Ho:YAG laser

Mid-infrared tunable optical parametric oscillator pumped by a Q -switched Tm,Ho:YAG ceramic laser

Mid-Infrared Pulsed Laser Lithotripsy with a Tunable Laser Using Difference-Frequency Generation

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