Closed-Loop Neuromodulation Technology for Baroreflex Blood Pressure Control

Blood pressure is a vital element to maintain circulation and eventually cellular respiration and metabolism. Blood pressure abnormalities are one of the most common diseases worldwide and their prevalence increases with age. For decades, basic and clinical investigations have shown that autonomic dysregulation/imbalance is involved in the development and progression of cardiovascular diseases. Arterial baroreflex is a powerful regulator of blood pressure and sympathetic nervous system. Closed-loop neuromodulation technology focusing on arterial baroreflex is challenging and might be promising to tackle the pathogenesis of blood pressure-related disorders, autonomic dysregulation, and eventually cardiovascular diseases. For more than a decade, we and associates have developed 'bionic' baroreflex systems. 'Bionic' means that the device is designed to replicate the dynamic characteristics of the native system to fully restore the function. The bionic baroreflex system basically consists of an artificial pressure sensor, a neurostimulator for autonomic nerves and a regulator that encodes blood pressure into neurostimulation. In the process of development toward clinical applicability, researchers have faced logical problems in designing the controller and practical problems of how to approach baroreflex activation. Closed-loop baroreflex systems utilizing sympathetic nerve trunk stimulation, spinal cord stimulation and noninvasive transcutaneous stimulation were proposed. Recently, the bionic baroreceptor was reported and proposed to be a potential therapy for heart failure. In this article, we introduce the closed-loop neuromodulation technology for baroreflex blood pressure control and discuss future direction of development of this technology.