Abstract
Implantable brain computer interfaces have received a great deal of attention in recent years, with a number of high-profile companies from the US entering into the race to develop BCI technology for the masses. Despite numerous advances toward ubiquitous BCI technology, several practical scientific and engineering challenges remain. These include human grade technology for chronic interfacing with the brain, decoding the enormous amount of brain data that can be recorded with novel technology, and user-friendly software that does not require an expert to calibrate and use each day. We aim to meet those challenges by creating two hardware and software platform systems that holistically meet the needs for BCI technology from implantation through to user interface for novel interactions.
The first is a subcutaneously implanted chronic EEG system that will allow for recording of brain signals in daily life over months to years (https://www.wysscenter.ch/advances/epios-brain-monitoring). EPIOS comprises a set of thin electrode wires with up to 32 channels for broad head coverage inserted in a minimally invasive way beneath the scalp, and a miniature electronics implant behind the ear. The implant amplifies the recorded signals, performs analog-to-digital conversion and transmits the data via a wireless link to a receiver that is attached on the outside of the scalp. The signals are conveyed from the receiver to a wearable data processor via a cable and are uploaded and securely stored on a customized cloud-based platform once per day. The cloud platform allows remote access, retrieval and review of the data by clinicians and researchers. This technology will enable BCI applications outside of the lab.
As a first indication EPIOS will address the needs for chronic EEG monitoring in epilepsy patients. However, the same technology can be applied for the clinical management of various other neurological disorders such as tinnitus (e.g. via BCI based neurofeedback) or stroke. For the latter indication, there is a promising line of research suggesting significant gains of virtual-reality (VR) based rehabilitation on both motor and cognitive symptoms for individuals who have sustained stroke. VR could be combined with subcutaneous EEG monitoring to leverage the effects of plasticity-induced alterations in the brain that depend critically on the exact timing between attempted movement, detected in the EEG and virtual movement (experienced in the VR). Thus, one interesting future application could be subcutaneous EEG BCI VR for home-based stroke rehabilitation.
The second technology under development is a high-resolution BCI recording system that aims to restore communication and movement in people with paralysis (https://www.wysscenter.ch/advances/ability). The ABILITY system comprises microelectrode arrays with up to 128 channels and a fully implantable wireless amplifier. Data recorded at up to 30kS/s are streamed to a tablet computer running the NeuroKey software. NeuroKey is a modular data processing framework for BCI applications, allowing both fast iteration during research and development and transition to clinical applications due to verified and validated components. NeuroKey integrates data streams from other devices where needed and, through generic wireless interfaces such as Bluetooth LE, sends output to assistive devices or cloud services.
ABILITY enables information transmission from cortical neurons, 24/7. NeuroKey allows real-time processing of these data. Together, they provide researchers with more data, facilitating transition of existing BCI proof of concepts to useful products.
As important as the hardware and software platforms themselves is the consideration of user experience. In order to expand these technologies beyond medical applications in specific populations both the hardware and software must be acceptable and seamless in a person’s daily life. The only way to get to this point is to develop, research and iterate on these technology platforms to gain a better understanding of the human brain and ecosystem that will underly more targeted deployment for novel interactions.