HIV Svietlahorsk
An unusual application of a mathematical theorem could help identify the point of recovery for patients.Reuters

A medical researcher at the University of Warwick has applied the 2,500-year-old Pythagoras theorem to find out when a patient has turned a corner in recovery.

Using data from a set of curves first developed during World War II for enemy craft detection, the team of Dr Rob Froud from Warwick Medical School at the University of Warwick and Gary Abel from the University of Cambridge were able to determine the point of recovery for patients.

While epidemiologists have been picking the top-left corner of the curve for studying chronic conditions, the team realised the Pythagoras theorem based on the sum of squares of a right angled triangle was the best way to go about it.

Dr Froud says: "We set about exploring the implications of this and how it might change conclusions in research. We conducted several experiments using real trial data and it seems using Pythagoras' theorem makes a material difference."

They were able identify the point at which a patient has improved with more consistency and accuracy than other methods commonly used.

The paper is published in PLOS ONE.