Simultaneous Acquisition of Signals and Images: Applications in Sports Medicine and Neurology

Abstract

In some medical applications, the simultaneous acquisition of signals corresponding to physiological parameters and video recording allows a more accurate analysis of the problem and a more complete diagnosis. In rehabilitation, the correlation between parameters of interest (angles, speed, power, EMG) and images of the patient's movements is important to devise an adequate training protocol. In neurology, some pathologies need to be investigated by a comparison of images and EEG signals. Nowadays, commonly used systems are made up of two different apparatuses: one for signals acquisition and one for video recording. They are separate pieces of equipment, and the integration between data and video is possible only to the detriment of information and the possibility to make quantitative analysis. This paper describes a new digital system for the concomitant acquisition of signals and video. It is a low cost instrumentation, PC based and easy-to-use. Data and video are recorded in standard formats and can be analyzed in a post-acquisition stage. The time resolution of the system is given by the video frame rate (25 fps), although an A/D conversion system allows frequencies up to 8000 Hz. The prototype was tested to verify synchronism between data and frames, and differences smaller than the resolution (40 ms) were found. The feasibility of the system was checked in two different applications: rehabilitation training with an isotonic Leg Extension and a daily EEG examination of one patient at the Neurological Institute of Bologna University. Both the applications gave good results in terms of time resolution, synchronism and user-friendliness.