Optical device measures amounts of drugs within IV

For electrical and computer engineering professor Brian Cunningham and his team of graduate student researchers, the future of health care can be found within a two-inch piece of plastic.

This small piece of plastic, called a photonic nanodome, can measure the kinds and concentrations of drugs within an IV line in real-time and more accurately than other devices in its class.

The device, created by Cunningham and his team at the University’s Micro and Nanotechnology Laboratory, is comprised of a centimeter-wide, gold sheet covered in nanometer sized “domes”, which work in conjunction with IV tubes and a laser light detector. The detector identifies the concentrations of drugs in a patient’s system, eliminating medical errors that are commonly associated with IV treatment, Cunningham said.

“We are interested in helping to improve the safety of drug delivery in hospitals,” Cunningham said. “Getting an incorrect dose, an incorrect medication or an incompatible combination of drugs is one of the most common ways to be harmed or killed in the hospital.”

Cunningham provided an example of when this device would be most useful: for patients in intensive care units.

“People in the intensive care unit might be receiving ten different things all at the same time, “ he said. “That is also how different drugs get into the system … For many of those things, there can be toxic effects if two drugs that are not compatible with each other go together or if the dose is too high or too low.”

The drug-detecting process begins when the drugs being given to the patient pass through the IV tubing and into the device. Next, a laser, which provides a high concentration of electrons, stimulates a strong electric field between the nanodomes’ small gold bumps on the surface plasmon. When the drugs wander through that small interdome space they give off light.

This kind of testing allowed Cunningham and Hsin-Yu Wu, a former graduate student in Engineering and first author of the research, to detect the Raman signatures, or specific light reflections, of drugs within an IV tube.

“We use the strong electrical field to enhance the Raman signature, and this is how we detect the very low concentration of the drug,” Wu said. “We can detect even the smallest molecule in the interdome region.”

Apart from the strong electrical field that will allow medical staff to quickly identify drug concentrations, Wu and Cunningham agree that the device’s pricetag is one of its most important assets. The device, which is made from plastic and attaches easily to standard IV tubing, would cost less than one dollar.

“There are other devices that can use that light scattering, but the challenge is making these devices that are disposable,” Cunningham said. “Ours is the first that can be made out of plastic in a pretty inexpensive way.”

This project was funded by the National Science Foundation and by Baxter, a Chicago company that produces drug infusion pumps and IV tubes that were used in the research.

The team officially released its first paper on the device last year, but Wu recently extended the paper to include more information on the replication, design and characterization of the sensors, as well as a more detailed description of the drugs that the device will identify, Wu said.

The device can currently identify a wide variety of drugs commonly found in IV treatments, including morphine, dopamine and heparin. However, with additional research, Cunningham said, this technology could potentially be applied to dialysis tubing and biomedical tubing, helping small sensors in urinary catheters monitor kidney health and check for infections.

“It’s a long way still before a research idea like this becomes a product and begins to be used in a hospital,” Cunningham said. “But with an ability like this to detect medication errors before it results in a problem for the patient, we would save thousands of lives every year.”

Many hospitals already employ a system of human and technology checks to make sure patients receive the right treatment, but Linda Fred, pharmacy director at Carle Foundation Hospital, sees benefit in the extra layer of protection that the device would provide.

“Here at Carle, we utilize a number of technologies and human checks to help ensure that the right medication is administered to the right patient and the right dose,” Fred said. “The availability to electronically validate a drug concentration at the bedside would give one more layer of checks.”

Cunningham and Meng Zhang, a graduate student, will present the team’s findings at the Frontier in Optics Conference held in Orlando, Fla. from Oct. 6-10. Although Zhang was not a part of the team that worked on the device, she was chosen to speak on behalf of Wu, Cunningham said.

“It is definitely a great pleasure and honor to present Prof. Cunningham’s work to the entire optics community during the Frontiers in Optics Conference,” Zhang said. “The novelty of the work lies in its power to identify medications in the tubing of intravenous delivery system in real time.”

MaryCate can be reached at [email protected]