Breath-hold monitoring and visual feedback for radiotherapy using a charge-coupled device camera and a head-mounted display: System development and feasibility

Tadamasa Yoshitake, Katsumasa Nakamura, Yoshiyuki Shioyama, Satoshi Nomoto, Saiji Ohga, Takashi Toba, Takehiro Shiinoki, Shigeo Anai, Hiromi Terashima, Junji Kishimoto, Hiroshi Honda

Research output: Contribution to journalArticle

19 Citations (Scopus)


Purpose. The aim of this study was to present the technical aspects of the breath-hold technique with respiratory monitoring and visual feedback and to evaluate the feasibility of this system in healthy volunteers. Methods and materials. To monitor respiration, the vertical position of the fiducial marker placed on the patient's abdomen was tracked by a machine vision system with a charge-coupled device camera. A monocular head-mounted display was used to provide the patient with visual feedback about the breathing trace. Five healthy male volunteers were enrolled in this study. They held their breath at the end-inspiration and the end-expiration phases. They performed five repetitions of the same type of 15-s breath-holds with and without a head-mounted display, respectively. A standard deviation of five mean positions of the fiducial marker during a15-s breath-hold in each breath-hold type was used as the reproducibility value of breath-hold. Results. All five volunteers well tolerated the breath-hold maneuver. For the inspiration breath-hold, the standard deviations with and without visual feedback were 1.74 mm and 0.84 mm, respectively (P = 0.20). For the expiration breath-hold, the standard deviations with and without visual feedback were 0.63 mm and 0.96 mm, respectively (P = 0.025). Conclusion. Our newly developed system might help the patient achieve improved breath-hold reproducibility.

Original languageEnglish
Pages (from-to)50-55
Number of pages6
JournalRadiation Medicine - Medical Imaging and Radiation Oncology
Issue number1
Publication statusPublished - Jan 1 2008


All Science Journal Classification (ASJC) codes

  • Radiation
  • Radiology Nuclear Medicine and imaging
  • Oncology

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