To curb hypertension among patients and to help health care systems attend to this widely misunderstood illness, scientists from the University of Freiburg developed a new implantable device that sends electric signals to the brain, offering new hope for patients who respond poorly to current treatments.

High blood pressure, or hypertension, occurs when arteries suddenly narrow down or there is a volume of blood passing through the blood vessel that is greater than normal. Sometimes, the heart pumps faster than it should.

"Our proof-of-concept interface has shown that it is possible to use the left vagal nerve to reduce blood pressure without any adverse side effects, which is important for a wide variety of potential treatments that could utilize nerve stimulation without actually penetrating the nerve," said Dennis Plachta, lead researcher of the study.

Figures from the American Heart Association revealed that one in every three American adults have high blood pressure. By 2030, the numbers will increase to 7.2 percent. Despite existing treatments, roughly 30 percent of the patients are found to respond inadequately to them.

The body has its own sensors that monitor the vessels to control any detected short-term fluctuations caused by increase in blood pressure. Called baroreceptors, they are found in the blood vessels of every vertebrate.

The device, which contains 24 individual electrodes integrated into a micro-machined cuff, works by identifying which fibers are exclusively in charge of blood pressure, avoiding the ones for heart rate, heart beat and ventilation among others, and then sends electric signals to the brain by tapping the vagal nerve.

The device was initially tested in five rats and, as luck would have it, successfully reduced the blood pressure by 40 per cent sans any side effects, not even a decline in heart rate nor in breathing, especially when the electrode were placed to in the closest proximity as possible to the baroreceptor fibers.

Moreover, the researchers discovered that the device could reduce blood pressure by almost 60 percent.

Since the device is tapping sensory nerves of the body, implanting it would be more effective, therefore requiring surgery. Plachta said the newly-developed device would not "be the first port of call for treatment" but rather a second option in case the patient performs poorly with any given medication.

Still, Plachta hopes that it could serve as a "treatment-on-demand" for patients with the use of an intelligent circuit, which could even function even when the patient is exercising.

The study came out in the Journal of Neural Engineering.

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