Endoscopic therapeutic device using focused ultrasonic small transducer

Akihiro Yasui, Yoichi Haga, Jiun Jie Chen, Hiroshi Iseki, Masayoshi Esashi, Hiroshi Wada

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


In this research, an ultrasonic probe (5.5 mm in diameter), which has a concave PZT transducer at its tip, was fabricated for ultrasonic treatments such as sonoporation and sonodynatnic therapy in the human body using a catheter and/or endoscope. Ultrasound has the potential to enhance cytotoxicity of drugs such as porphyrins, a process referred to as sonodynamic therapy, and also to deliver macromolecules such as plasmid DNA, a process referred to as sonoporation. The fabricated probe was then experimentally characterized by measuring the acoustic intensity distribution around the focal point, using a PVDF needle-type ultrasonic hydrophone. When the PZT transducer was driven by a 120 Volts peak-to-peak AC signal at 1.83 MHz, the ultrasound output was successfully focused at the focal point, with a peak intensity of 24.9 W/cm 2 (0.87 MPa). Using the fabricated probe, cultured Chinese Hamster Ovary (CHO) cells were exposed to ultrasound (1.83 MHz, continuous wave, peak acoustic pressure of 0.5 MPa) for 2 s in the presence of microbubbles MB-3 and Green Fluorescent Protein (GFP) plasmid DNA. As a result of sonication, the expression of GFP was observed in CHO cells.

Original languageEnglish
Pages (from-to)69-74+4
JournalIEEJ Transactions on Sensors and Micromachines
Issue number2
Publication statusPublished - 2007


  • Catheter
  • Concave PZT transducer
  • DDS
  • Endoscope
  • Focused ultrasound
  • Sonodynamic therapy
  • Sonoporation


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