How is "downtime" defined for our CT?
Canon (ex Toshiba) guarantees that the machine downtime does not exceed 2% per year. This is checked by calculating the ratio of yearly down-hours and yearly operating hours (2500 hrs/year, see TrueBeam). Nominal daily working hours are from 7:00 - 17:00. Typically, there is currently no patient after 14:00. In such a case, if the CT is down for a full day, we only record 7 hours (7:00 - 14:00).
| Date | Hours | Reason for Downtime |
|---|---|---|
| 20.06.2011 | 7.5 | |
| 21.06.2011 | 10.0 | |
| 22.06.2011 | 5.0 | |
| 2011 | 22.5 | 0.9% |
| 29.11.2012 | 4.5 | Tube replacement (scan counter old tube: 75000). |
| 30.11.2012 | 7.0 | Tube replacement (cont'd). |
| 2012 | 11.5 | 0.5% |
| 17.01.2013 | 1.0 | Ring artefacts. Suspecting defective detector readout converter PWB. |
| 18.01.2013 | 1.5 | Ring artefacts again. |
| 25.01.2013 | 2.5 | Ring artefacts. Suspecting defective detector. |
| 28.01.2013 | 5.5 | Ring artefacts. Waiting for new detector. |
| 29.01.2013 | 7.0 | Installation of new detector. |
| 25.04.2013 | 7.0 | Reference detector failure. |
| 26.04.2013 | 7.0 | Installation of new reference detector. Still artefacts on images. |
| 29.04.2013 | 7.0 | Installation of new detector. |
| 2013 | 38.5 | 1.5% |
| 2014 | 0.0 | 0.0% |
| 03.08.2015 | 7.0 | Oil cooler replacement. |
| 01.12.2015 | 7.0 | Tube replacement (scan counter old tube: 130000). |
| 2015 | 14.0 | 0.6% |
| 2016 | 0.0 | 0.0% |
| 2017 | 0.0 | 0.0% |
| 2018 | 0.0 | 0.0% |
| 24.01.2019 | 1.0 | DICOM worklist doesn't work (device not connected or powered on). Checked cables, pinged w3454100, OK. |
| 07.08.2019 | 3.0 | Warm-up not possible. "X-Ray condition prohibited. Change scan condition". Replaced oil cooler. |
| 2019 | 4.0 | 0.2% |
| 14.04.2020 | 0.5 | 09:00: No couch movement. EM-off, rescued pat. After reboot, Vertical OK, horiz. not OK. Reboot again. OK. |
| 20.04.2020 | 0.75 | 08:45: No longitudinal movement. Gantry OFF/ON, no change. Reboot, OK. |
| 20.04.2020 | 0.42 | 11:42: No longitudinal movement. EM-off, rescued patient. Canon replaces touch guard in Gantry. |
| 22.04.2020 | 1.5 | 12:30: No longitudinal movement. EM-off, rescued patient. Canon replaces drive assembly in couch. |
| 2020 | 3.2 | 0.1% |
| 18.05.2021 | 0.17 | 07:26: "Over kV" during warmup. Phantom test scan. Notified Canon. |
| 01.06.2021 | 0.16 | 09:16: "Over kV" during warmup. Phantom test scan. Notified Canon. |
| 02.06.2021 | 0.17 | 10:11: "Over kV" during warmup. Phantom test scan. Notified Canon. |
| 08.06.2021 | 0.17 | 12:09: "Over kV" during warmup. Notified Physics. |
| 09.06.2021 | 0.16 | 06:57: "Over kV" during warmup. Notified Physics & Canon. |
| 22.06.2021 | 0.5 | 09:20: "Over kV" during patient scan. Scheduled tube replacement for tomorrow. |
| 23.06.2021 | 7.0 | Tube replacement. Still "Over kV". Troubleshooting. |
| 24.06.2021 | 7.0 | Waiting for parts. |
| 25.06.2021 | 7.0 | Troubleshooting cont'd. |
| 2021 | 22.33 | 0.9% |
| 06.07.2022 | 0.33 | The data transfer system in the gantry is abnormal. Reboot system. OK. |
| 2022 | 0.33 | 0.0% |
| 24.03.2023 | 2.0 | Error in XC. Troubleshooting. |
| 31.03.2023 | 2.0 | Error in XC. Troubleshooting. Ordered generator. |
| 2023 | 4.0 |
