Robert Jarvik, the inventor of the first successful permanent artificial heart has had a change of heart. He tells IEEE Spectrum that diseased hearts should only rarely be replaced with mechanical ones. Instead, most just need some help pumping until they can recover. He has developed a new pump to do just that, and it's barely a tenth the weight of competing products. He expects such heart-assist devices to become as commonplace as pacemakers.

Jarvik's company, New York City-based Jarvik Heart Inc., is now gearing up for a U.S. Food and Drug Administration trial of its ventricular-assist device, the Jarvik 2000 Flowmaker. Implanted in one of the two ventricles of the heart—compartments that pump blood out of the heart—a ventricular-assist device helps a patient's natural heart pump blood. In the United States they are used as temporary implants until a donor heart can be found, although they've been used as permanent implants in Europe. In fact, the first person to get the Jarvik 2000 implant, now the longest-surviving patient supported by any type of artificial heart, will have had the implant five years in June. More important for patients, the Jarvik 2000 is light as a feather compared with competitors. It's the size of a C battery and weighs just 90 grams, as opposed to its rivals, which weigh at least 1000 grams. Spectrum's Prachi Patel Predd recently spoke with Jarvik about his new device and about the state of artificial heart technology in the United States.

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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
Blue

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.


8 channels


64 channels

Since optogenetic therapies are just beginning to be tested in clinical trials, there’s still some uncertainty about how best to make the technique work in humans. We’re still thinking about how to get the viral vector to deliver the necessary genes to the correct neurons in the cochlea. The viral vector we’ve used in experiments thus far, an adeno-associated virus, is a harmless virus that has already been approved for use in several gene therapies, and we’re using some genetic tricks and local administration to target cochlear neurons specifically. We’ve already begun gathering data about the stability of the optogenetically altered cells and whether they’ll need repeated injections of the channelrhodopsin genes to stay responsive to light.

Our roadmap to clinical trials is very ambitious. We’re working now to finalize and freeze the design of the device, and we have ongoing preclinical studies in animals to check for phototoxicity and prove the efficacy of the basic idea. We aim to begin our first-in-human study in 2026, in which we’ll find the safest dose for the gene therapy. We hope to launch a large phase 3 clinical trial in 2028 to collect data that we’ll use in submitting the device for regulatory approval, which we could win in the early 2030s.

We foresee a future in which beams of light can bring rich soundscapes to people with profound hearing loss or deafness. We hope that the optical cochlear implant will enable them to pick out voices in a busy meeting, appreciate the subtleties of their favorite songs, and take in the full spectrum of sound—from trilling birdsongs to booming bass notes. We think this technology has the potential to illuminate their auditory worlds.

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