Basic study of charring detection at the laser catheter-tip using back scattering light measurement during therapeutic laser irradiation in blood.

Abstract

The purpose of this study is to investigate transient process of the charring at the laser catheter-tip in blood during therapeutic laser irradiation by the back scattering light measurement to detect precursor state of the charring. We took account of using photodynamic therapy for arrhythmia in blood through the laser catheter. We observed the influence of the red laser irradiation (λ=663 nm) upon the shape of red blood cells (RBCs). The RBCs aggregation, round formation, and hemolysis were took place sequentially before charring. With a model blood sandwiched between glass plates simulated as a catheter-tip boundary, we measured diffuse-reflected-light power and transmitted-light power simultaneously and continuously by a microscopic optics during the laser irradiation. We found that measured light power changes were originated with RBCs shape change induced by temperature rise due to the laser irradiation. A gentle peak following a slow descending was observed in the diffuse-reflected-light power history. This history might indicate the precursor state of the charring, in which the hemolysis might be considered to advance rapidly. We think that the measurement of diffuse-reflected-light power history might be able to detect precursor state of charring at the catheter-tip in blood.

• Authors: Mei Takahashi, Arisa Ito, Takuro Kajihara, Hiroki Matsuo, Tsunenori Arai
• Journal: Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference (Annu Int Conf IEEE Eng Med Biol Soc) Vol. 2010 Pg. 2759-61 ( 2010) ISSN: 2375-7477 [Print] United States
• PMID: 21096215 (Publication Type: Journal Article)

Chemical References

• Albumins
• Salts
• Glucose

Topics

• Albumins (metabolism)
• Animals
• Catheters
• Erythrocytes (cytology, radiation effects)
• Glucose (chemistry, metabolism)
• Hemolysis
• Lasers
• Light
• Optics and Photonics
• Photochemotherapy (instrumentation, methods)
• Rabbits
• Salts (chemistry)
• Scattering, Radiation
• Temperature
• Time Factors