Neuroprosthesis Devices Based on Micro- and Nanosensors: A Systematic Review

Abstract

Background. A neuroprosthesis (NP) is a medical device that compensates and restores functionality of neural dysfunctions affected by different pathologies and conditions. To this end, an implantable NP (INP) must monitor and electrically stimulate neuronal small structures in the peripheral and central nervous system. Therefore, one of the most important parts of INPs are the sensors and electrodes since their size, resolution, and material are key for their design and performance. Currently, most of the studies focus only on the INP application but do not show the technical considerations of the sensors. Objective. This paper is a systematic literature review that summarizes and synthesizes implantable micro- and nanosensors/electrodes used in INPs for sensing and stimulating tissues. Data Sources. Articles and patents published in English were searched from electronic databases. No restrictions were made in terms of country or journal. Study Selection. All reports related to sensors/electrodes applied in INPs were included, focusing on micro- and nanotechnologies. Main Outcome Measures. Performance and potential profit. Results. There was a total of 153 selected articles from the 2010 to June 2020 period, of which 16 were about cardiac pacemakers, 15 cochlear implants, 13 retinal prosthesis, 31 deep brain stimulation, 6 bladder implants, and 18 implantable motor NPs. All those INPs are used for support or recovery of neural functions for hearing, seeing, pacing, and motor control, as well as bladder and bowel control. Micro- and nanosensors for signal stimulation and recording have four special requirements to meet: biocompatibility, long-term reliability, high selectivity, and low-energy consumption. Current and future considerations in sensor/electrode design should focus on improving efficiency and safety. This review is a first approximation for those who work on INP design; it offers an idea of the complexity on the matter and can guide them to specific references on the subject.