Real-time data acquisition and control system for the measurement of motor and neural data

Abstract

This paper outlines a powerful, yet flexible real-time data acquisition and control system for use in the triggering and measurement of both analog and digital events. Built using the LabVIEW development architecture (version 7.1) and freely available, this system provides precisely timed auditory and visual stimuli to a subject while recording analog data and timestamps of neural activity retrieved from a window discriminator. The system utilizes the most recent real-time (RT) technology in order to provide not only a guaranteed data acquisition rate of 1 kHz, but a much more difficult to achieve guaranteed system response time of 1 ms. The system interface is windows-based and easy to use, providing a host of configurable options for end-user customization.

Fig. 1

System overview. All time-critical processes are handled by the real-time system running a deterministic operating system. Non-time-critical tasks are managed by the host system running a general-purpose operating system (e.g., Windows). The two systems communicate over a TCP/IP connection established between them, resulting in a complete system that is deterministic, yet simple to use.

Fig. 2

State table editor. An integrated, easy-to-use state table editor allows the user to create and save an infinite number of possible trials for execution within the system.

Fig. 3

System parameter editors. Intuitive, point-and-click interfaces allow the user to customize system behavior quickly and easily. Many system parameters are available for modification, giving the user comprehensive control over his operating environment.

Fig. 4

Main panel. The main panel is the primary interface to the system, providing access to system parameters, control of trial execution and data storage, and reports on general system behavior.

Fig. 5

Trace/XY plots. The trace plot (above) presents temporal traces of analog data retrieved during execution of a single trial (note that the neural discharge data was simulated by manipulation of a frequency generator). The XY plot (below) displays system behavior (e.g., target color/placement, subject eye position, target windows, etc.) occurring in the spatial domain.

Fig. 6

Current parameters panel. While trials are executing on the system, the current parameters panel displays those specific values selected by the system to replace any variables defined within the current trial.