Chronic electrocorticography (ECoG) studies will be necessary to understand how end-users of assistive brain-computer interface (BCI) technologies will control their devices on a long-term scale. A BCI platform consisting of a deep brain stimulator (DBS) and a cortical electrode strip, theoretically suitable for use over multi-year periods, is validated in a single human subject with essential tremor (ET). At the time of this writing, stable ECoG recordings have been demonstrated for four months after implantation. Additionally, the patient has performed a BCI cursor-control task with better-than-chance accuracy using both (1) an overt movement control scheme and (2) a motor imagery control scheme. These results validate the sensing-enabled DBS with cortical strip system as an exciting platform for chronic ECoG BCI experiments and as a scientific tool for long-term cortical recordings in different patient populations.

RELAY is a model of how a fault causes a failure on execution of some test datum. This process begins with introduction of an original state potential failure at a fault location and continues as the potential failure(s) transfers to output. Here we describe the second stage of this process, transfer of an incorrect intermediate state from a faulty statement to output.

RELAY is a model of faults and failures that defines failure conditions, which describe test data for which execution will guarantee that a fault originates erroneous behavior that also transfers through computations and information flow until a failure is revealed. This model of fault detection provides a framework within which other testing criteria's capabilities can be evaluated. Three test data selection criteria that detect faults in six fault classes are analyzed. This analysis shows that none of these criteria is capable of guaranteeing detection for these fault classes and points out two major weaknesses of these criteria. The first weakness is that the criteria do not consider the potential unsatisfiability of their rules. Each criterion includes rules that are sufficient to cause potential failures for some fault classes, yet when such rules are unsatisfiable, many faults may remain undetected. Their second weakness is failure to integrate their proposed rules.>