rule of three


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rule of three

an arterial oxygen tension that is three times the value of the inspired oxygen concentration. It is regarded as an empiric guide to a temporarily acceptable minimal oxygenation or expression of clinical observation and has no scientific basis.
References in periodicals archive ?
The Rule of Three also can help us on an ILS by ensuring we're flying the correct glideslope.
The Rule of Three affords us an easy and quick check to ensure we're on the correct, three-degree glideslope: Using the example we just gave, if the three-degree glide-slope we're intercepting is approximately 2000 feet above the field elevation while we're approximately six miles from the threshold, we're good to go.
The Rule of Three can come in handy elsewhere on the ILS.
Because the math works both ways, we also can use the Rule of Three to help determine what our altitude on the ILS should be if we know the distance to the threshold.
Using gouges like the Rule of Three can simplify everything.
The Rule of Three is conveniently illustrated in this screen shot of an Avidyne Entegra primary flight display at right.
While the Rule of Three is not flawless, it is a powerful tool that can be used to further investigate sample integrity and/or instrument operation.
ORLANDO--The rule of threes that has been used to identify patients at risk of hereditary melanoma who may be candidates for genetic testing may be modified soon, according to Sancy Leachman, MD, PhD, professor and chair of the department of dermatology, Oregon Health & Science University, Portland.
In the interview, she discussed a soon-to-be-published literature review that builds upon the rule of threes and suggests a strategy for deciding which patients should be considered for genetic testing, and includes "a suggested list of genes" that should be used in these different subsets of patients.
Sancy Leachman discussing the rule of threes, go to edermatologynews.