[Modular PC-based data acquisition and processing system for biological signals]

The data acquisition system described here is designed for biomedical research and permits the recording of up to eight biological signals simultaneously. A personal computer using the Windows 95 operating system is employed for data monitoring, data processing and analysis during experiments. The system has been designed for reliability, economy, flexibility and ease of handling, with the aim of achieving universal application. To avoid interface incompatibility, problems with transfer protocols and the data formats of commercially available products, analog signals are used for further processing. The individual input channels are electrically isolated from one another and the PC to avoid ground loops, and for reasons of safety. An isolated voltage supply is available for pre-amplifiers and bridges. A bandwidth of 0-5 kHz and the maximum sampling rate of 12.5 kHz suffice to pick up higher frequency signals such as EMG and ENG. The modular software and hardware concepts permit the use of almost any desktop or laptop PC as a central processing unit. The PC handless documentation, data acquisition, data analysis and the preparation of publications. If needed, further analytical functions can be added in modular form. Finally, the option of saving data in the ASCII format permits processing of results with such standard software packages as Excel, Access, Matlab and Origin.