| 摘要 |
The invention contemplates dose-integrating instrumentation which relies upon continuously monitoring the illuminance level of a small sampling fraction of the total projected-light flux of the field-illuminating system of an operating microscope, the sampling being optionally within the projection system, or taken elsewhere. The sampled illuminance is in the form of an electrical signal which is continuously time-integrated to provide a continuous display of the dosage as it builds in the course of an operative procedure. Provision is made for the surgeon to preset what he chooses to be the safe upper limit of integrated exposure, beyond which he does not wish to go for fear of possible jeopardy to the retina of his patient, and the instrument continuously indicates the remaining time for him to complete his operation, should he continue at the current level of illumination. The instrument also provides a succession of different indications throughout the progress of the operation, as successive predetermined thresholds of building dosage (exposure) are reached.
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