Heads up on new devices

Recognizing that some tools used to assess patients aren’t ideal for all situations, and some are simply too risky, two Pitt Med professors and their teams are developing technologies to offer alternatives. Although these are separate initiatives, both approaches happen to look to the forehead to collect this important information.
Illustrated by
Frank Harris

Light work

The risks that come with invasively measuring intracranial pressure can be catastrophic enough that it’s ruled out for many patients who would benefit from the information, like some who’ve had a head injury.

Michael McDowell, an MD assistant professor of neurological surgery, and his collaborator Jana Kainerstorfer, a PhD at Carnegie Mellon University, have an alternative. They’re developing a device no bigger than a credit card that attaches to the patient’s forehead, without a procedure or incision, by either a headband or adhesive.

Once it’s secured, near-infrared light passes heatlessly and painlessly through the skin and skull to reach blood vessels in the brain. The light is then temporarily absorbed by hemoglobin within the blood cells. The hemoglobin releases the light, which then makes its way back to the device. The operator calculates the distance the blood cell traveled in the time between absorbing and releasing the light. Fluctuations in blood flow correspond with changes in intracranial pressure.

A preliminary study of 15 children at UPMC Children’s Hospital of Pittsburgh found that the device’s results closely matched those of the more invasive method. McDowell hopes that “by the end of 2023, we will have a large-scale observational trial in adults and children at a multicenter level.”

By making intracranial brain pressure measurement faster and safer, the device may also help physicians discover new, useful applications for brain pressure monitoring.


Losing contact

The key to simpler vital sign measurement may already be in your pocket. Michael Pinsky, an MD professor of critical care medicine, and his team have developed a noncontact pulse oximeter app compatible with any Android smartphone. Unlike the standard finger-clip style device for blood oxygen saturation, the app uses a smartphone camera to provide the same information.

Every time your heart beats, the color of your skin changes slightly, getting a little redder. The app detects such changes in a tiny area of a patient’s forehead to determine pulse rate. Other changes in light density indicate the patient’s respiratory rate. In tests, the app has returned these measurements accurately regardless of the person’s skin pigmentation. Based on an analysis of the pulse and respiration data, the app determines blood oxygen saturation.

If the FDA approves the technology, it could be used to assess the vitals of unconscious victims in disaster scenarios, give health information to previously unreachable communities and even allow patients to collect measurements in the waiting room before an appointment—reducing the chances of exposing medical staff to infections.

Says Pinsky, “My critical care professional colleagues around the world have called it a game-changer.”