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Three-dimensional transient simulation of CO_(2) laser tissue vaporization and experimental evaluation with a hydrogel phantom

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Journal of Innovative Optical Health Sciences 2022年第3期15卷 1-9页

作者： Kazuma Sudo Yu Shimojo Takahiro Nishimura kunio awazu Graduate School of Engineering Osaka University Yamadaoka 2-1SuitaOsaka 565-0871Japan Japan Society for the Promotion of Science Kojimachi 5-3-1ChiyodaTokyo 102-0083Japan Global Center for Medical Engineering and Informatics Yamadaoka 2-2 SuitaOsaka 565-0871Japan

A quantitative analysis method of CO_(2) laser treatments promotes laser treatment performance and rapid clinical application of novel treatment *** in silico clinical trial approach,which is based on computational simulation of light-tissue interactions using the mathematical model,can provide quantitative *** several simulation methods of laser tissue vaporization with CO_(2) laser treatments have been proposed,validations of the CO_(2) laser wavelength have been *** this study,we demonstrated a tissue vaporization simulation using a CO_(2) laser and performed the experimental validation using a hydrogel phantom with constant physical parameters to evaluate the simulation accuracy of the vaporization *** laser tissue vaporization simulation consists of the calculation of light transport,photothermal conversion,thermal diffusion,and phase change in the *** vaporization width,depth,and area with CO_(2) laser irradiation to a tissue model were *** simulated results differed from the actual vaporization width and depth by approximately 20%and 30%,respectively,because of the solubilization of the hydrogel ***,the simulation vaporization area for all light irradiation parameters,which is related to the vaporization amount,agreed well with the actual vaporization *** results suggest that the computational simulation can be used to evaluate the amount of tissue vaporization in the safety and effectiveness analysis of CO_(2) laser treatments.

关键词： Laser tissue vaporization in silico clinical trial hydrogel phantom CO_(2)laser

Coagulation and ablation of biological soft tissue byquantum cascade laser with peak wavelength of 5.7μm

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Journal of Innovative Optical Health Sciences 2014年第3期7卷 115-123页

作者： Keisuke Hashimura Katsunori Ishii Naota Akikusa Tadataka Edamura Harumasa Yoshida kunio awazu Medical Beam Physics Laboratory Division of Sustainable Energy and Environmental EngineeringGraduate School of Engineering Osaka UiniversityJapan Hamamatsu Photonics K.K.Japan Graduate School of Frontier Biosciences Osaka UniversityJapan The Center for Advanced Medical Engineering and Informatics Osaka University Japan

Molecules such as water,proteins and lipids that are contained in biological tissue absorb mid-infrared(MR)light,which allows such light to be used in laser surgical ***,amides and water exhibit strong absorption bands in the 5-7μm wavelength range,but at present there are no lasers in clinical use that can emit in this ***,the present study focused on thequantum cascade laser(QCL),which is a new type of semiconductor laser that can emit at MIRwavelengths and has recentiy achieved high output power.A high-power QCL with a peakwavelength of 5.7μm was evaluated for use as a laser scalpel for ablating biological soft *** interaction of the laser beam with chicken breast tissue was compared to a conventional CO_(2) laser,based on surface and cross-sectional *** QCL was found to have sufficient power to ablate soft tissue,and its coagulation,carbonization and ablation effects were similar to those forthe CO_(2) *** QCL also induced comparable photothermal effects because it acted as apseudo-continuous wave laser due to its low peak power.A QCL can therefore be used as an effective laser scalpel,and also offers the possibility of less invasive treatment by targeting specificabsorption bands in t he MIR region.

关键词： Quantum cascade laser mid-infrared wavelength CO,laser biological soft tissue laser-tissue interaction.

Artificial neural network-based determination of denoised optical properties in double integrating spheres measurement

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Journal of Innovative Optical Health Sciences 2023年第6期16卷 105-116页

作者： Yusaku Takai Takahiro Nishimura Yu Shimojo kunio awazu Graduate School of Engineering Osaka University Yamadaoka 2-1SuitaOsaka 565-0871Japan Global Center for Medical Engineering and Informatics Osaka University Yamadaoka 2-2SuitaOsaka 565-0871Japan

Accurate determination of the optical properties of biological tissues enables quantitative understanding of light propagation in these tissues for optical diagnosis and treatment *** absorption(μa)and scattering(μs)coe±cients of biological tissues are inversely analyzed from their diffuse re°ectance(R)and total transmittance(T),which are measured using a double integrating spheres(DIS)*** inversion algorithms,for example,inverse adding doubling method and inverse Monte Carlo method,are sensitive to noise signals during the DIS measurements,resulting in reduced accuracy during *** this study,we propose an arti ficial neural network(ANN)to estimateμa andμs at a target wavelength from the R and T spectra measured via the DIS to reduce noise in the optical *** models of the optical properties and Monte Carlo calculations that simulated the DIS measurements were used to generate spectral datasets comprisingμa,μs,R and *** noise signals were added to R and T,and the ANN model was then trained using the noise-added *** results showed that the trained ANN model reduced the effects of noise inμa andμs *** veri fication indicated noise-reduced estimation from the R and T values measured by the DIS with a small number of scans on average,resulting in measurement time *** results demonstrated the noise robustness of the proposed ANN-based method for optical properties determination and will contribute to shorter DIS measurement times,thus reducing changes in the optical properties due to desiccation of the samples.

关键词： Absorption coefficient scattering coe±cient bio-tissue tissue spectroscopy noise reduction.

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

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Optics and Photonics Journal 2013年第4期3卷 8-13页

作者： Hisanao Hazama Hiromu Kutsumi kunio awazu 1Graduate School of Engineering Osaka University Osaka Japan 2Graduate School of Frontier Biosciences Osaka University Osaka Japan 3The Center for Advanced Medical Engineering and Informatics Osaka University Osaka Japan Graduate School of Engineering Osaka University Osaka Japan Graduate School of Medicine Kobe University Kobe Japan

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.

关键词： Gallstone Lithotripsy Mid-Infrared Tunable Laser Difference-Frequency Generation

Observation of Atherosclerotic Plaque Phantoms through Saline or Blood Layers by Near-Infrared Hyperspectral Imaging

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Optics and Photonics Journal 2014年第10期4卷 271-279页

作者： Katsunori Ishii Akiko Kitayabu Ryo Nagao kunio awazu Medical Beam Physics Laboratory Graduate School of Engineering Osaka University Osaka Japan Graduate School of Frontier Biosciences Osaka University Osaka Japan The Center for Advanced Medical Engineering and Informatics Osaka University Osaka Japan

We observed atherosclerotic plaque phantoms using a novel near-infrared (NIR) hyperspectral imaging (HSI) technique. Data were obtained through saline or blood layers to simulate an angioscopic environment for the phantom. For the study, we developed a NIR-HSI system with an NIR supercontinuum light source and mercury-cadmium-telluride camera. Apparent spectral absorbance was obtained at wavelengths of 1150 - 2400 nm. Hyperspectral images of lipid were constructed using a spectral angle mapper algorithm. Bovine fat covered with saline or blood was observed using hyperspectral images at a wavelength around 1200 nm. Our results show that NIR-HSI is a promising angioscopic technique with the potential to identify lipid-rich plaques without clamping and saline injection.

关键词： Hyperspectral Imaging Near-Infrared Range Atherosclerotic Plaque Angioscopy

Evaluation of the Bending Loss of the Hollow Optical Fiber for Application of the Carbon Dioxide Laser to Endoscopic Therapy

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Optics and Photonics Journal 2013年第4期3卷 14-19页

作者： Daisuke Kusakari Hisanao Hazama Rinna Kawaguchi Katsunori Ishii kunio awazu 1Graduate School of Engineering Osaka University Osaka Japan 2Graduate School of Frontier Biosciences Osaka University Osaka Japan 3The Center for Advanced Medical Engineering and Informatics Osaka University Osaka Japan Graduate School of Engineering Osaka University Osaka Japan

Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollow optical fibers transmitting mid-infrared light have been developed, and the application of carbon dioxide laser to endoscopic therapy has become possible. However, it is expected that the irradiation effect is influenced by the change in the laser power at the tip of the hollow optical fiber due to the change in the transmittance by the bending loss. The purpose of this research is to quantitatively evaluate the change in the output power and therapeutic effect by bending the hollow optical fiber in a gastrointestinal endoscope. The change in the transmittance of the hollow optical fiber due to the insertion of the fiber into the endoscope and bending of the head of the endoscope was measured. Then, the relationship between the irradiated laser power and the incision depth for a porcine stomach was investigated. As the results, the most significant decrease in the transmittance of the hollow optical fiber was caused by the insertion of the fiber into the instrument channel of the endoscope, and bending of the head of the endoscope with the angle of 90° decreased the output laser power and incision depth by 10% and 25%, respectively. Therefore, it was confirmed that the bending loss of the hollow optical fiber due to the bending of the head of the endoscope had no significant influence on the endoscopic therapy using the carbon dioxide laser.

关键词： Hollow Optical Fiber Carbon Dioxide Laser Bending Loss Endoscopic Therapy

Highly Selective Photodynamic Therapy with a Short Drug-Light Interval Using a Cytotoxic Photosensitizer Porphyrus Envelope for Drug-Resistant Prostate Cancer Cells

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International Journal of Clinical Medicine 2018年第1期9卷 8-22页

作者： Youngsoon Hong Mizuho Inai Norihiro Honda Hisanao Hazama Manjusha A. Joshi Hiroyuki Nakamura Tomoyuki Nishikawa Yasufumi Kaneda kunio awazu Graduate School of Engineering Osaka University Osaka Japan Graduate School of Frontier Biosciences Osaka University Osaka Japan Institute of Academic Initiatives Osaka University Osaka Japan Institute of Innovative Research Tokyo Institute of Technology Kanagawa Japan Graduate School of Medicine Osaka University Osaka Japan Global Centre for Medical Engineering and Informatics Osaka University Osaka Japan

Background: Photodynamic therapy (PDT) is a less invasive cancer treatment using photochemical reactions induced by light irradiation to a photosensitizer (PS). Highly selective PDT with fast accumulation of the PS in target site might be a promising treatment option for drug-resistant prostate cancer facing high incidence rate of elderly men who have no effective treatment options and require a minimally invasive treatment. Hemagglutinating virus of Japan envelope (HVJ-E) allows selective and fast drug delivery to the drug-resistant prostate cancer cells via rapid cell membrane fusion. PS named porphyrus envelope (PE) has been developed by insertion of lipidated protoporphyrin IX (PpIX lipid) into HVJ-E. In this study, we investigated the optimal conditions for PE preparation and laser irradiation for highly selective PDT using PE with a short drug-light interval. Materials and Methods: Human hormon refractory prostate cancer cell line PC-3 and human normal prostate epithelial cell line PNT2 were cultured. PpIX lipid uptake and cytotoxicity of PDT in the cells incubated with PE for 10 min were evaluated by measuring fluorescence intensity and by using a cell counting reagent 24 h after PDT, respectively. Results: PpIX lipid uptake and cytotoxicity of PDT were increased with PpIX lipid concentration. Cytotoxicity of PDT using PE was more than 9 times as strong as that with PpIX lipid and PpIX induced by 5-aminolevulinic acid. Much stronger cytotoxicity was induced in PC-3 cells than PNT2 cells with the ratio of cell death rate for cancer to normal cells up to 4.64 ± 0.09. Conclusions: Fast PS delivery with HVJ-E allows highly selective PDT with a short drug-light interval. Therefore, PDT using PE has a potential to shorten treatment period and reduce side effects of PDT.

关键词： Photodynamic Therapy Hemagglutinating Virus of Japan Envelope Drug Delivery System Short Drug-Light Interval Drug-Resistant Prostate Cancer

Handedness found in a wild group of moor monkeys Macaca maurus in the Karaenta Nature Reserve, South Sulawesi,Indonesia

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Current Zoology 2010年第2期56卷 209-212页

作者： kunio WATANABE Primate Research Institute Kyoto University

Hand preference of wild moor monkeys Macaca maurus was investigated in food reaching situations at the Karaenta Nature Reserve, South Sulawesi, Indonesia. The frequency picking up sweet-corn grains to take into the mouth by either hand of monkeys was counted directly at the feeding ground where sweet-corn grains were scattered for monkeys. Among the 20 monkeys examined, 8 were right-handed, 8 were left-handed, and 4 were ambilateral. The results indicated the prevailed hand preference on individual level but not either trends of left- or right-hand preference on population level. The trend toward a higher proportion of left-handed monkeys found in Japanese and rhesus monkeys was not found. Some other characteristics found in moor monkeys are discussed in comparison with those previous findings in Japanese and Tibetan macaques in order to evaluate variations within the genus Macaca

关键词： Moor macaque Macaca maurus Handedness Laterality Sulawesi

Early development of peer dominance relationships in a captive group of Japanese macaques Macaca fuscata

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Current Zoology 2010年第2期56卷 190-197页

作者： RIZALDI kunio WATANABE Primate Research Institute Kyoto University Department of Biology Faculty of Sciences Andalas University

We studied early development of peer dominance relationships in a captive group of Japanese macaques Macaca fuscata fuscata at the Primate Research Institute of Kyoto University. This study aims to give detailed descriptions on characteristic patterns of maternal rank acquisition from infant to juvenile. Focal subjects were 22 young monkeys belonging to three cohorts born in 2002, 2003 and 2005. Data were collected with a total 2130 sessions of 30-minute continuous recording of focal subjects combined with all occurrence-sampling methods. The onset of aggressive behavior varied per cohort and was delayed in cohorts with fewer close-aged associates. More than 60% of dyadic combinations in agonistic interactions between peers were unidirectional throughout the study period. Although some bidirectional interactions could have involved unstable relationships between particular individuals, most of the bidirectional interactions included a few continuous series of alternating one-sided interactions. A linear order could be found among peers from the first appearance of aggressive behavior, and nearly 90% of those dyads were concordant with that of their mother＇s rank order. Young males were responsible for most of the dominance relations that would not be predicted based on their mother＇s rank. These results suggest that infant monkeys may recognize their own social status relative to their opponent＇s before onset of aggressive behavior and adjust themselves into the matrilineal rank system accordingly.

关键词： Aggressive behavior Dominance relationship Early development Japanese macaque