In the 1970s, engineer Sheldon Kaplan and his colleagues were tasked with creating an auto-injector pen to be used by US soldiers needing a nerve agent antidote.

The Pentagon called it the ComboPen but, in 1987, it was approved by the US Food and Drug Administration (FDA) as the EpiPen, for patients with allergies.

The device is carried by millions of people all over the world as it can quickly and easily deliver a shot of adrenaline to anyone at risk of death from anaphylactic shock.

Sheldon Kaplan died in 2009 and was inducted into the US National Inventors Hall of Fame in 2016.

Sheldon’s son Michael Kaplan and colleague Michael Mesa tell Vicky Farncombe the story behind the pen.