EPOCS
EPOCS stands for Evoked Potential Operant Conditioning System. It is an experimental system for improving muscle control in people who have neuromuscular disorders - for example, to improve gait in people who have difficulty walking following an incomplete spinal-cord injury. It works by allowing a researcher or therapist to train a patient to increase or decrease the size of their reflex responses (for example, the knee-jerk reflex). The scientific principles behind this are explained in research papers published by Dr. Aiko Thompson, Dr. Jonathan Wolpaw and colleagues. Their 2013 paper in the Journal of Neuroscience demonstrates how the approach can improve walking in people with spinal-cord injuries. The system is described in our 2022 JoVE video article.
The software is based on BCI2000, a widely-used free software platform that allows biological signals to be measured and processed in real time for applications in research and in translational clinical neurotechnology. There is no dependency on proprietary third-party software beyond what's required to interface with the data-acquisition hardware (in other words. no Matlab, LabView or similar licenses are required). Technically-minded users may wish to take advantage of BCI2000's scripting system to extend the functionality of their EPOCS installation—for example, we have used this approach to customize EPOCS to record additional signal channels, make stimulation contingent on additional variables, open additional visualization windows, or coordinate with other applications over a network.
The hardware used with EPOCS consists of amplifiers that measure electrical signals from muscles, an input/output device (must be National Instruments DAQmx-compatible), and a stimulator that delivers a brief electrical pulse to elicit a reflex (specifically, a constant-current stimulator that can be triggered by a TTL pulse). The amplifier and stimulator both use electrodes that are stuck temporarily to the skin surface. It is also possible to configure the system to use a mechanical stimulator (for conditioning natural stretch reflexes) or a transcanial magnetic stimulator (for investigating the role of responses generated by the brain rather than reflexes from the spinal cord).
The software can also be used without hardware, for analysis of previous recordings. If you are a neuroscientist or clinical researcher who would like to use EPOCS in your lab, you can download it here, although we advise that you also contact us directly so that we can assess your needs and guide you in setting up your system by emailing Jeremy Hill (hill@neurotechcenter.org) and Cc Jonathan Carp (carp@neurotechcenter.org).