07/02/2015 GMT

Lara Lewington looks at the differences in steps and calories burned while wearing different fitness trackers doing the same activities for a week. Neil Bowdler is in New York to demonstrate a miniature health monitor called the AcuPebble - the creators say it can predict epileptic fits and diagnose conditions like sleep apnea. Dan Simmons has an exclusive look at a prototype virtual reality system which could let you compete against sport stars in real time.