Academic spinoff plans handheld optical imaging scanner

Optical imaging may soon enter the medical mainstream with a handheld device that developers say will help providers of emergency care quickly diagnose brain hematomas.

Engineers at InfraScan, a Drexel University spinoff, have created a miniature scanner that records the differential absorption and scattering of near-infrared (NIR) light transmitted into the brain.

"The skull is almost transparent to light at this wavelength," said Banu Onaral, Ph.D., director of Drexel University's School of Biomedical Engineering, Science, and Health Systems.

Normal brain tissue absorbs NIR light uniformly. Extravascular blood absorbs more light, however. These areas, which are hematomas, are depicted as dark areas on a PDA screen wirelessly connected to the handheld scanner.

InfraScan has moved past initial prototyping to a device compatible with clinical testing and, possibly within a year, mass production. Multicenter clinical trials, scheduled to start this spring, are expected to generate the data needed to support an FDA decision under a special category called a 510(k) review with clinical results. The company has chosen this path following discussions with officials.

"It is something in between a 510(k) and premarket approval," said Baruch Ben Dor, Ph.D., president and CEO of InfraScan. "It is an easier way through the FDA, but it requires some clinical data."

Ben Dor believes FDA clearance will be in hand by early 2007 if the company submits an application as planned by the end of this year. InfraScan will go first to India, where regulatory requirements are less restrictive and the market potentially very receptive.

"India has huge unmet needs, because there isn't the same kind of healthcare insurance and reimbursement as in many Western countries," he said.

InfraScanner might also appeal to the U.S. military, which has supported its early development through Department of Defense grants. Statistics from the Iraq conflict estimate that 30% of wounded or killed soldiers suffer head injuries. Brain hematomas develop in 40% of these injuries.

Eventually, Ben Dor sees the device finding its way to the U.S. market. The Centers for Disease Control and Prevention estimates that each year more than two million people in the U.S. require medical care for head injury, with more than 500,000 hospitalized with a diagnosis of traumatic brain injury. About 60,000 U.S. residents die annually as a result of head trauma.

Typically, emergency physicians and neurosurgeons use CT to diagnose moderate to severe traumatic brain injury. InfraScanner promises to allow such assessment at the accident site. The device might be used at sporting events or on the battlefield. It could also be used to assess head trauma affecting children, including infants, who require special care in limiting lifetime x-ray dose.

Tests of the basic technology on 305 subjects at Baylor College of Medicine determined the technology achieved 100% sensitivity for extracerebral (epidural and subdural) hematomas and 98% sensitivity for intracerebral hematomas. No false positives were observed for either. This basic technology has been adapted by engineers at Drexel into a miniaturized handheld device now being readied for testing.

"We have reengineered the modality and are moving it into a variety of clinical areas," Onaral said.

Initially, it will be used to assess suspected brain trauma. Patients with head injuries might be diagnosed at an accident site, in the ER to determine whether a CT scan is needed, or in physician offices after the patient is released from the hospital.

The technology might also be adapted for diagnosing neurologic diseases such as dementias, attention deficit/hyperactivity disease, or autism, according to Onaral. Further development and marketing of the device will be done using about a million dollars in financing obtained from Department of Defense and private grants and investments.