Researchers have created a device that uses electrical signals to reduce blood pressure.

The device has already successfully reduced blood pressure in rats by 40 percent without causing any known major side effects, an Institute of Physics news release reported.

The technology could give hope to patients who are not responding to today's treatments.

The device sends electrical signals to the brain; it consists of 24 electrodes that are built into a micro-machined cuff. The cuff would wrap around the vagal nerve, which runs from the brainstem to the abdomen. The nerve stimulates major organs such as the heart.

The device picks up signals from baroreceptor, which activates when the blood vessels stretch.

"Some baroreceptors are grouped together in concentrated areas in the aortic arch and report their information to the brainstem via [fibers] in the vagal nerve. These baroreceptors function to control short-term fluctuations in blood pressure," the news release reported.

The device could identify fibers that have an effect on blood pressure and refrain from targeting those that influence heart rate.

The research team tested a prototype of the device on five male rats; it delivered 40 pulses per second the "fibres of the baroreceptors in the vagal nerve," the news release reported.

The team found that blood pressure could be reduced by 60 percent of its original rate with a variety and stimulation and frequency combinations.

The researchers did not observe any major side effects. such as a decrease in heart of breathing rate.

"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," lead author of the research, Doctor Dennis Plachta, said in the news release.

"As the device will require surgery, it is not intended to be the first port of call for treatment and will come into play when patients, for whatever reasons, are resistant to medication. Nevertheless, the long-term goal is to provide 'treatment-on-demand' for the patient, whereby the implantable device uses an intelligent circuit to record the activity of the patient, for instance when they are doing exercise, and adjust the blood pressure accordingly," he said.