When Captain Derek Herrera was shot by a sniper in Afghanistan his life was forever changed. Paralysed from the chest down, he left the military to embark on a new career in medical technology. He devoured the scientific literature to try to find solutions to the chronic disabilities he faced. One problem, neurogenic bladder dysfunction – an inability to control the bladder – mirrored the difficulties faced by millions of people with spinal injuries and other conditions such as Alzheimer’s and Parkinson’s disease. Cpt. Herrera set up a company, Spinal Singularity, and working with doctors, engineers and potential users, he has developed a new device, known as the Connected Catheter, which could significantly improve the lives of sufferers. In this interview with Peter Bowes, Cpt. Herrera describes the dramatic moment when his life was almost taken away; how he reinvented himself as an entrepreneur and built a company to change the way medical devices are developed.