Let the line shine through: Lighting the way for complicated IV lines

A fiber optic tube like this could help make it much easier for doctors to place PICC lines and other catheters deep within the body.

The idea first came to Farhad Imam, MD, PhD, eight years ago as a trainee after a 30-hour shift.

Imam was helping care for a baby with particularly complex needs and who needed to have several IV lines inserted. The baby started having complications related to one of those lines, a deeply threaded one called a peripherally inserted central catheter, or PICC line, which had gone astray and had to be repositioned.

Walking out of the hospital at his shift’s end, Imam found himself wishing there were an easy way to visualize, in real time, the progress of lines that advance deep into the body through a child’s veins.

If only we could make these lines light up, he thought to himself….

PICC lines allow drugs to be injected into veins in the core of the body, close to the heart, so they’re evenly distributed. To put one in place, a doctor inserts it into an arm vein and gently pushes it all the way to the entrance of the heart.

Not surprisingly, it’s tricky work; nationally the misplacement rate for PICC lines on the first attempt can be up to 85 percent in children.

“You need a lot of precision to place a PICC line properly,” Imam, now a neonatologist with Boston Children’s Division of Newborn Medicine, explains. “In babies and small children your margin of error is millimeters. If you don’t do it right, you might have to readjust the line several times. This can add hours to the procedure time and raise the risk of damage to the veins, the surrounding tissues, or even the heart itself.”

The problem is that once the tip of the line goes in the vein, “You’re working blind,” Imam says. “You have to rely on feeling and measurements taken outside the body to know whether the line is traveling the correct path and reaching just to the entrance of the heart.

“We take X-rays to confirm placement,” he continues, “but it’s important to minimize the amount of radiation you give a child. Moreover, the fragile, critically ill babies we see in the NICU need procedures done as quickly and efficiently as possible.”

At a recent Innovators’ Forum (a series of monthly talks hosted by Boston Children’s Innovation Acceleration Program), Imam presented a solution he’s been working on for the last eight years: a bedside “real-time visualization” (or RTV) system consisting of an LED light source attached to a fiber optic tube that slips into the PICC line, lighting up the whole line.

“The light shines through the skin, giving you a lot of information about where the line is,” Imam explains. “You can tell if you’re advancing the tip of the line up the right path just by where the light is. By using two frequencies of light, the system tells you how deep in the body the line is: if the light is yellow, the line is close to the skin; if red, it’s deep within the body.

Farhad Imam, MD, PhD

“You can also tell when the tip reaches the superior vena cava, the vein the funnels all blood into the heart, because the high rate of blood flow in that vein makes the line’s tip flutter,” he continues. “That makes the light twinkle at the surface of the skin.”

Soon after his post-shift eureka moment, Imam talked to the hospital’s Technology and Innovation Development Office (TIDO): “I happened to walk past a poster encouraging anyone with an idea to come talk to TIDO about how to make it happen,” he recalls. A grant from TIDO helped Imam put a team together and launch a company dedicated to developing and commercializing the RTV system. The team has done extensive design and development work, thus far showing in small and large animals alike that the combination of LED light and optical fiber makes it possible to see PICC lines through at least two inches of tissue. He plans to ask to the Food and Drug Administration to clear the system for clinical trials in 2013.

While Imam’s system isn’t the only bedside solution for showing where a PICC line is and where it’s going, it’s certainly the cheapest. Other systems, like one that employs an EKG and a magnetic tube, can cost $50,000 and only allow for indirect detection of line placement. “This should be very inexpensive and would be the only system that lets a doctor directly visualize line placement within the body using their own eyes,” Imam says.