Diagnostic Imaging Online
March 27, 2004

Report from SIR: New ultrasound display makes body translucent

A new handheld ultrasound device merges the patient, image, instrument, and operator?s hands into the same field-of-view without using a head-mounted display.

The Sonic Flashlight uses a mirror to reflect real-time ultrasound images into the body, making the body part in question appear translucent.

Accessing vessels and fluid collections is made more intuitive, especially to the novice user, said Wilson Chang, an M.D./Ph.D. student at the University Of Pittsburgh. Chang spoke on Saturday at the Society of Interventional Radiology meeting in Phoenix.

Viewing the image directly within the body eliminates the displaced sense of hand-eye coordination that occurs when the operator must look away from the patient to view the ultrasound monitor.

The Sonic Flashlight may make it easier to accurately place vascular access catheters, drainage catheters, and biopsy needles, Chang said.

Researchers have been developing the Sonic Flashlight for three years. The current version consists of a Terason 10-MHz scanner that is modified by attachment to the transducer of a small flat-panel display and a 20 x 50 x 1-mm half-silvered mirror.

The study population consisted of 20 individuals with little to no ultrasound experience. They used a 21-gauge needle to pierce the lumen of a vascular access phantom, and the time from touching the transducer to piercing the lumen was recorded.

This procedure was repeated using the Site-Rite, a small battery-powered ultrasound scanner designed primarily to assist physicians in accessing arteries and veins.

Significantly faster times were recorded using the Sonic Flashlight for guidance as compared with the Site-Rite (5.17 sec vs. 6.54 sec, p = 0.013).

"The results of this study suggest that learning to use the Sonic Flashlight for guidance is significantly easier than conventional ultrasound," Chang said.

Several subjects stated that the product made more sense or was more intuitive.

-- By C.P. Kaiser