The Court of Appeal has given a new definition of the number “1” in the case of Smith & Nephew Plc v Convatec Technologies Inc & Ors EWCA Civ 607.
ConvaTec owns a patent for silver and salt wound dressing solution “between 1% and 25% of the total volume of treatment”. Smith & Nephew has devised a competing product that contains 0.77% concentration, this it believed deviated from the ConvaTec patent.
In a previous judgement in 2013 the Judge ruled in Smith & Nephew’s favour. This was due to a mathematical formula known as the “significant figures rule”. This formula is a mathematical method of taking into account errors of measurement.
This Judgement stated that anything greater or equal to 0.95% and less than 25.5% was covered by the patent. Therefore Smith & Nephew were free to use their competing product without paying a licensing fee to ConvaTec.
The Judgement effectively held that the number “1” is anything greater or equal to 0.95 and less than 1.5. The question was asked how the number “1” can include a figure that is 0.05 less whilst also including a figure that is nearly ten times bigger.
The Court of Appeal has corrected this. The three Judges used the mathematical approach that we all learnt in school that is rounding. The mathematical approach of rounding involves rounding up or down to the nearest whole number where the numbers are decimal places.
It was held that the number “1” includes anything greater or equal to 0.5 and less than 1.5. This judgement therefore rules that Smith & Nephew’s “0.77” now falls within the ConvaTec patent.
Lord Justice Christopher Clark explained that, “A linguist may regard the word ‘one’ as meaning ‘one – no more and no less’. To those skilled in the art it may, however, in context, imply a range of values extending beyond the integer,”.
Philo of Alexandria (20 BC – AD 50) regarded the number “1” as God’s number and the basis for all numbers. However this judgment has regarded the number “1” as anything greater or equal to 0.5 and less than 1.5.