Belson's Vascular Pathways prototype, inspired when he spent an entire shift working to insert an IV into a newborn, is a more practical design based on standard catheters. As with any needle, a medical professional using Vascular Pathways knows the vein has been reached when blood flashes back through the needle. She then slides forward a lever, which advances a guide wire safely out from inside the needle. The guide wire rolls into a curlicue before the catheter slides over it, preventing the catheter tip from hitting the vein's walls. Finally, the needle and guide wire are retracted, leaving the catheter in place. "It's going to make a big difference in saving a lot of what are now unavoidable re-sticks," says Jeff Stuart, medical director of the Washington Outpatient Surgery Center in Fremont, California.