| 摘要 |
An exposure control circuit captures an X-ray generator exposure time for a master exposure and replicates that time for subsequent exposures in a series. In one preferred circuit an read counter bank counts down clock pulses during the master exposure time, and then this count is held and is used by a write counter bank which counts up during subsequent exposures. A control circuit controls loading an enabling functions of the read and write counters. For the subsequent exposures, an output relay circuit terminates the X-ray generator exposure when the write counter bank reaches a predetermined count. This arrangement is used favorably with digital subtractive angiography (DSA).
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