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Microwave Stethoscope Lets Physicians Peer Into the Lungs

A stick-on sensor can measure vital signs and lung fluid

4 min read
Microwave Stethoscope Lets Physicians Peer Into the Lungs
Heart-Failure Helper: A microwave transceiver (center) can do what other sensors can’t: measure the accumulation of water in a patient’s lungs.
Photo: Hawaii Center for Advanced Communications/The University of Hawaii

When a person’s heart is failing, water begins to build up in the lungs, making it increasingly difficult to breathe. The sensation, patients say, is like drowning.

Deciding whether it’s safe for that patient to go home can depend on whether the water level goes back down. But today the options for measuring lung water are cumbersome, such as taking chest X-rays, inserting a tube into the lung, doing blood tests, or even weighing the patient over time to quantify the decrease. The most hands-off method requires measuring the impedance of electricity passing through the patient’s body with a bulky vest, but this method can fail if the patient shifts position.

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Restoring Hearing With Beams of Light

Gene therapy and optoelectronics could radically upgrade hearing for millions of people

13 min read
A computer graphic shows a gray structure that’s curled like a snail’s shell. A big purple line runs through it. Many clusters of smaller red lines are scattered throughout the curled structure.

Human hearing depends on the cochlea, a snail-shaped structure in the inner ear. A new kind of cochlear implant for people with disabling hearing loss would use beams of light to stimulate the cochlear nerve.

Lakshay Khurana and Daniel Keppeler

There’s a popular misconception that cochlear implants restore natural hearing. In fact, these marvels of engineering give people a new kind of “electric hearing” that they must learn how to use.

Natural hearing results from vibrations hitting tiny structures called hair cells within the cochlea in the inner ear. A cochlear implant bypasses the damaged or dysfunctional parts of the ear and uses electrodes to directly stimulate the cochlear nerve, which sends signals to the brain. When my hearing-impaired patients have their cochlear implants turned on for the first time, they often report that voices sound flat and robotic and that background noises blur together and drown out voices. Although users can have many sessions with technicians to “tune” and adjust their implants’ settings to make sounds more pleasant and helpful, there’s a limit to what can be achieved with today’s technology.

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