Advances in closed-loop deep brain stimulation devices

Background: millions of patients around the world are affected by neurological and psychiatric disorders. deep brain stimulation (dbs) is a device-based therapy that could have fewer side-effects and higher efficiencies in drug-resistant patients compared to other therapeutic options such as pharmacological approaches. thus far,several efforts have been made to incorporate a feedback loop into dbs devices to make them operate in a closed-loop manner.methods: this paper presents a comprehensive investigation into the existing research-based and commercial closed-loop dbs devices. it describes a brief history of closed-loop dbs techniques,biomarkers and algorithms used for closing the feedback loop,components of the current research-based and commercial closed-loop dbs devices,and advancements and challenges in this field of research. this review also includes a comparison of the closed-loop dbs devices and provides the future directions of this area of research.results: although we are in the early stages of the closed-loop dbs approach,there have been fruitful efforts in design and development of closed-loop dbs devices. to date,only one commercial closed-loop dbs device has been manufactured. however,this system does not have an intelligent and patient dependent control algorithm. a closed-loop dbs device requires a control algorithm to learn and optimize the stimulation parameters according to the brain clinical state.conclusions: the promising clinical effects of open-loop dbs have been demonstrated,indicating dbs as a pioneer technology and treatment option to serve neurological patients. however,like other commercial devices,dbs needs to be automated and modernized.