‘Sonic Flashlight’ Puts Ultrasound Images in Physician’s Line of Sight For Placement of Long-Term Catheters

A new device, called a “sonic flashlight,” offers a more efficient method of ultrasound guidance to place catheters in patients that will be used for repeated doses of chemotherapy or other treatments, a preliminary study shows.

Ultrasound can be used to help guide catheters, such as peripherally inserted central catheters, into place, said Wilson Chang, PhD, of the University of Pittsburgh and the lead author of the study. The difficulty occurs because the physician or nurse inserting the catheter has to look away from the patient to see the ultrasound monitor, he said. On the other hand, the sonic flashlight—which is an ultrasound probe with a two-inch monitor and a semi-transparent mirror—puts everything in front of the physician or nurse. The probe is placed on the area of the body where the catheter will be inserted. The monitor on the probe shows the ultrasound image, and the mirror makes the ultrasound images appear as if they are actually under the skin, said Dr. Chang.

The device was recently invented, and the study was undertaken to determine if physicians and nurses can easily learn how to use the device and if the device would make the catheter insertion process faster, said Dr. Chang. Sixteen medical students, with no ultrasound experience, performed 60 procedures on a vascular phantom (a body of material resembling body mass), and 14 IV nurses performed 18 procedures on the phantom. Both groups–experienced and inexperienced–were faster and more proficient with the sonic flashlight, compared to the standard ultrasound method, said Dr. Chang. The device has now been used on 15 patients, and “it has worked without a hitch,” according to Dr. Chang.

In 2003 at the University of Pittsburgh, between 10-15 patients per day had long-term catheters inserted under their skin, said Dr. Chang. It is a relatively common procedure, he said. “This device has the potential to increase patient safety, decrease the cost of this procedure and make it more comfortable for the patient because we could do it at the patient’s bedside with less training.” In addition, “the sonic flashlight might enable medical personnel to perform procedures under ultrasound guidance who are currently uncomfortable using ultrasound guidance,” he said.

The study will be presented on May 19 at the American Roentgen Ray Society Annual Meeting in New Orleans, LA.