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Technical study of real time eye-motion tracking system for radiotherapy of intra-ocular tumour
https://repo.qst.go.jp/records/60832
https://repo.qst.go.jp/records/608323cbacbb7-c9b3-4ec2-8dc3-8115ceaa6b59
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2005-02-03 | |||||
| タイトル | ||||||
| タイトル | Technical study of real time eye-motion tracking system for radiotherapy of intra-ocular tumour | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Minohara, Shinichi
× Minohara, Shinichi× 蓑原 伸一 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | To increase the accuracy and reproducibility of the patient eye-gaze and to decrease the error of dose distribution resulted from eye motion during irradiation we developed a system of real time eye-motion tracking for the particle radiotherapy of intra-ocular tumour. In almost facilities treating the intra-ocular tumors by particle beam, the patients must be capable to co-operate and to maintain to a fixed stare (gaze) at a particular angle during positioning and irradiation. An operator watches the eye motion in the monitor screen of CCD camera, and switch on the beam, or will manually switch off if patient breaks the gaze. The operator is required the instanuous interpretation to the eye motion, and this includes the time delay until beam-off with manual operation. In our developed system, the direction of the patient gaze is measured in real time using infrared video image. Two-dimensional coordinates of centres at the pupil and the Purkinje which is a reflection from the surface of cornea are determined by image processing at each field image of 16.7 milliseconds intervals. A set of these coordinates is applied to the geometrical eye model, and the angle of gaze in spatial coordinate is calculated. This estimated gaze direction is compared with previously set angle that is clinically admissible gaze motion. If the direction of gaze changes to outside of the admission or by the blink, the irradiation is automatically turned off thorough the gate signal (TTL) for beam extraction. In preliminary study using an artificial eye, our system detected the position variation of 0.2 mm, and in subjects study, detected the gaze variation of 1.8 degree that is almost equivalent to the variation of 0.4 mm on the eye surface. The total response time from the change of gaze to TTL-off was less than 67 milliseconds. This system will support the safety irradiation of ocular tumour. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 40th PTCOG | |||||
| 発表年月日 | ||||||
| 日付 | 2004-06-18 | |||||
| 日付タイプ | Issued | |||||
