X-ray phototimer
US5084911A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1989 |
| Grant date | Jan 28, 1992 |
| Priority date | — |
| Expiry date | Jan 10, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05G1/46
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A phototimer for controlling x-ray exposure includes an array of x-ray sensors, and digital processing electronics for calculating x-ray exposure by selecting one or more signals from the x-ray sensors, and calculating the x-ray exposure from the selected signals. After calculating the x-ray exposure, the calculated exposure is employed to control the x-ray exposure either by displaying the calculated exposure to an operator who compares the calculated exposure with a desired exposure and repeats the exposure if necessary, or by automatically terminating the exposure by sending a control signal to the x-ray source. The improvement in the state of x-ray phototimer technology resides in the automatic selection of a subset of signals from a plurality of photosensors, thereby improving the reliability of the measurement. In prior art devices, the signals from a plurality of sensors were either selected manually by a switch, or all employed in a predetermined algorithm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.