Ms. Sayaka Ohmori Profile

Sayaka Ohmori

Grad Student at Keio Univ

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Publications (6)

Proceedings Article | 28 February 2007 Paper

The measurement of the phosphorescence and singlet oxygen fluorescence time-resolved waveforms of Photofrin(II) and Talaporfin sodium with pulsed excitation

Shiho Hakomori, Sayaka Ohmori, Kensuke Masuda, Kojiro Yamamoto, Tsunenori Arai

Proceedings Volume 6427, 642715 (2007) https://doi.org/10.1117/12.699857

KEYWORDS: Phosphorescence, Luminescence, Sodium, Photodynamic therapy, Oxygen, Photonics, Camera shutters, Excimer lasers, Dye lasers, Quantum efficiency

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Proceedings Article | 6 March 2006 Paper

Basic study on pulse-intensity-domain depth-controlled photodynamic therapy for transurethral prostate cancer

Sayaka Ohmori, Kensuke Masuda, Yuko Yamakawa, Tsunenori Arai

Proceedings Volume 6139, 61390T (2006) https://doi.org/10.1117/12.647768

KEYWORDS: Sodium, Photodynamic therapy, Prostate cancer, Oxygen, Luminescence, Tumors, Cancer, In vitro testing, Laser irradiation, Pulsed laser operation

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Proceedings Article | 25 April 2005 Paper

Novel laser-vascular welding to close catheter sheath hole after catheter intervention: welding against vascular model and fiber-based back scattering monitoring

Tsunenori Arai, Noriko Usami, Sayaka Ohmori

Proceedings Volume 5686, (2005) https://doi.org/10.1117/12.591360

KEYWORDS: Laser welding, Laser tissue interaction, Arteries, Backscatter, Light scattering, Laser scattering, Scattering, Collagen, Blood, Semiconductor lasers

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Proceedings Article | 8 April 2005 Paper

Basic study on therapeutic effect distribution formation along depth using high-intensity pulsed photodynamic therapy

Sayaka Ohmori, Kensuke Masuda, Tsunenori Arai

Proceedings Volume 5689, (2005) https://doi.org/10.1117/12.592890

KEYWORDS: Photodynamic therapy, Absorption, Oxygen, Laser irradiation, Absorbance, Laser beam diagnostics, Continuous wave operation, In vitro testing, Pulsed laser operation

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Proceedings Article | 1 July 2004 Paper

Direct photodynamic therapy for vulnerable plaque: investigation of light dosimetry for depth control

Sayaka Ohmori, Takeshi Yanagihara, Tsunenori Arai

Proceedings Volume 5319, (2004) https://doi.org/10.1117/12.528993

KEYWORDS: Photodynamic therapy, Oxygen, Cell death, Pulsed laser operation, In vitro testing, Energy efficiency, Natural surfaces, Tumors, Excimer lasers, Dye lasers

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Photodynamic therapy (PDT) mechanism with high-intensity pulsed laser excitation has not been well understood. We think complete understanding of this unknown effect in PDT leads perfect treated depth control at various lesions. To realize the depth controlled PDT for atheromatous plaque therapy with a fibrous cap intact and surrounding damage free, we studied PDT against murine macrophage-like cells in vitro with the second-generation chlorin photosensitizer manufactured by Photochemical Co. Ltd. (Okayama Japan). The relation between the excitation conditions (pulse energy density and repetition rate) and PDT photocytotoxicity was examined in vitro. The XeCl excimer laser pumped dye laser (wavelength: 669±3 nm, pulse duration: 7ns in FWHM) was used with the pulse energy density from 1.2 to 9.5 mJ/cm², and the pulse repetition rate from 5 to 80 Hz. Under higher pulse energy density condition, no significant PDT photocytotoxicity was obtained. We examined the photobleaching of the protein containing photosensitizer medium solution, which is considered to correlates with the generation of singlet oxygen. Under higher pulse energy condition, the photobleaching efficiency decrease was observed and the measured PDT effect decrease in terms of laser pulse energy density could be explained by the photobleaching. We measured the oxygen partial pressure in photosensitizer medium solution immediately after the laser exposure. The decrease of oxygen partial pressure, i.e., the amount of the oxygen consumption during the laser exposure was observed 46 mmHg under the excitation condition of the pulse energy density of 9.5 mJ/cm², the total fluence of 5 J/cm², the repetition rate of 80Hz, and correlated with the bleaching efficiency 87% under the same condition. We calculated cell death distribution in depth direction based on measured photocytotoxicity under various pulse energy densities. The possibility of depth controlled PDT for safety atheromatous plaque therapy was suggested by the PDT effect alteration depending on pulse energy density.

Proceedings Article | 12 September 2003 Paper

Diode laser vascular welding of swine aorta under scattering light monitoring

Sayaka Ohmori, Tsunenori Arai, Masanori Fujita, Noriko Usami, Makoto Kikuchi, Tadaaki Maehara

Proceedings Volume 4949, (2003) https://doi.org/10.1117/12.476396

KEYWORDS: Light scattering, Laser scattering, Laser welding, Scattering, Semiconductor lasers, Fiber lasers, Temperature metrology, Laser therapeutics, Blood circulation, Blood

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