Projects

BaroLoop Hypertension is a typical disease of civilization, a worldwide threat to patient’s health and a burden to health care systems. Even though most patients can rely on pharmaceutical therapy, some 30 % show refractory hypertension, which means that the given options are ineffective to robustly regulate down the blood pressure to normotensive values due to compliance or ineffectiveness of drugs. The human body possesses different regulatory loops to control the blood pressure. One of them is realized in the baroreflex, a negative feedback loop that reduces blood pressure almost instantaneously. This system has its origins in the baroreceptors of e.g. the aortic arch and transfers the pulsatile pressure information to the brainstem. If the pressure increases fast the braoreflex is triggered and the blood pressure decreases. Overriding the afferent signals from pressure receptors in the aortic arch and the carotid artery can trigger the so-called baroreflex regulation too. Technical solutions dealing with the stimulation of the pressure receptors or with the afferents of these receptors in the vagal nerve have been subject to research for many years, however, most of the approaches lack the option of feedback control and/or selective stimulation. Stimulations targeting the vagus nerve (VNS) are common practice for severe epilepsy therapy and are considered a safe implantation technology. However, the vagal nerve is the major communication path for many organs. If the whole vagus is subject to stimulation secondary effects cannot be avoided such as chest and throat pain, cough, voice alteration, nausea, vomiting and even arrhythmia. We develop an implant that is capable to detect the baroreceptice fibers of the vague nerve, and to stimulate it selectively free from side effects.