title: High-sensitive fluorescence endoscope using electrocardiograph-synchronized multiple exposure.
abstract: OBJECTIVE
  Fluorescence-based measurement of cardiac disease, using autofluorescent substances that already exist in the heart, has not been used for endoscopic surgery because the endoscopic lenses cannot transmit sufficient light. A highly sensitive fluorescence endoscope using an electrocardiograph (ECG)-synchronized multiple exposure (ESME) approach was developed that provides a bright fluorescent image.
  
  
  METHODS
  A system was developed consisting of an endoscope, an excitation light, an ECG amplifier, a trigger and delay unit, and a computer. This system is based on periodic motion of the heart. Since the shape of the heart can be photographed by ECG triggering in a similar manner, a bright image can be synthesized by accumulating multiple trigger-captured images. Laboratory and in vivo experiments were performed to confirm the effectiveness of ESME.
  
  
  RESULTS
  The experimental results revealed that the trigger unit generated the synchronization signals required to produce high-quality images of the heart depending on heart rate. The difference among trigger-captured images from the actual organ, which affects the quality of ESME images, was estimated at 0.65 mm from the calculated displacement of a marker on the heart. The results also revealed that a bright fluorescent image can be captured by ESME.
  
  
  CONCLUSIONS
  A highly sensitive fluorescence endoscope using ESME was developed and successfully tested. The experimental results indicated that the method enabled high-quality image acquisition in a very low illumination environment. This system is effective for the observation of faint fluorescence in the heart and is useful for the intraoperative examination of the heart status.
authors.affiliation: Graduate School of Engineering, The University of Tokyo, Engineering Building No 14, Room 722, Hongo 7-3-1, Bunkyo, Tokyo, Japan. take_and_o@bmpe.t.u-tokyo.ac.jp
authors.forename: Takehiro
authors.initials: T
authors.lastname: Ando
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Hongho
authors.initials: H
authors.lastname: Kim
authors.forename: Sanghyun
authors.initials: S
authors.lastname: Joung
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kobayashi
authors.forename: Hongen
authors.initials: H
authors.lastname: Liao
authors.forename: Shunei
authors.initials: S
authors.lastname: Kyo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakuma
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004562:Electrocardiography / Q000295:instrumentation*; D019723:Endoscopes; D004867:Equipment Design; D005260:Female; D005453:Fluorescence; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D013552:Swine
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