EPFL Engineers Build Low-Power LogSync Microchip for Psychiatric Brain Stimulation
A new implantable neural system-on-chip named LogSync extracts cross-regional brain synchrony biomarkers to trigger closed-loop psychiatric stimulation while consuming under 200 microwatts of power. Developed by researchers at the École Polytechnique Fédérale de Lausanne (EPFL) and detailed in the IEEE Journal of Solid-State Circuits, the device addresses a fundamental limitation in treating severe mood and anxiety disorders.
Why Brain Network Communication Matters for Psychiatric Illnesses
Most existing deep brain stimulation (DBS) systems operate in an open-loop manner, delivering electrical pulses according to predefined settings rather than reacting to shifting neural activity. Even adaptive closed-loop systems often rely on signals recorded from a single brain region. According to Mahsa Shoaran, head of the Integrated Neurotechnologies Lab in EPFL’s School of Engineering and Neuro-X Institute, psychiatric disorders arise from disruptions in communication between multiple brain regions rather than dysfunction in any isolated area. LogSync overcomes this barrier by analyzing network-level biomarkers across interacting brain structures.
How LogSync Processes Neural Signals on a Single Chip
The system records brain activity and extracts biomarkers describing signal synchrony and the strength of brain wave oscillations. A machine-learning algorithm then evaluates these network-level biomarkers to distinguish emotional and cognitive states, generating stimulation triggers when specific states appear. To fit within strict power limits, the EPFL team co-designed the hardware and algorithms together. The chip uses logarithmic computations to simplify complex operations required for real-time brain network analysis, keeping power consumption below 200 microwatts.
Human and Rat Trials Validate LogSync Technology
The research team evaluated LogSync using human brain recordings from previous psychiatric experiments, successfully distinguishing cognitive engagement and emotional arousal states from neural recordings alone. Additional experiments in rats at the University of Minnesota showed that the implant tracked ongoing oscillations and generated stimulation triggers at predefined phases of brain activity. The work forms part of a CHF 6.6 million grant from the US National Institute for Mental Health (NIMH). While initial validation focused on psychiatric care, the chip’s underlying technology applies broadly to adaptive DBS for movement disorders and closed-loop non-invasive stimulation, supported by EPFL spin-off Infera Neuro.
What Does LogSync Target and How Does It Work?
What specific psychiatric illnesses is LogSync designed to target?
LogSync is developed for severe psychiatric illnesses, particularly mood and anxiety disorders such as major depression, obsessive-compulsive disorder, and post-traumatic stress disorder.
How much power does the LogSync microchip consume?
The implantable system consumes under 200 microwatts of power, which is a fraction of the energy typically required by many implantable neural-interface systems.
Which institution led the development of LogSync?
The research was led by the Integrated Neurotechnologies Lab at the École Polytechnique Fédérale de Lausanne (EPFL), backed by funding from the US National Institute for Mental Health (NIMH).
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