Long term ECG/EMG monitoring system

Due to the low costs of modern electronic components a versatile data acquisition unit (DAQ), as described in this paper is an efficient replacement for expensive long term electrocardiographic (ECG) and/or electromyographic (EMG) instruments. For general use it is necessary to generate a highly robust DAQ-system, which is very small in size (not larger than a credit card) and weight. As well a very low power consumption, for a long active operating time with standard types of battery cells, is required. The data memory is configurable with a maximum size of up to 16 megabytes (MB) (up to 32 MB in the near future). A local processor is required, which should be able to do real-time data compression and, depending on the application, analog signal path filtering and/or pre data calculations (e.g. validation). The analog signal path consists of an analog signal conditioning line with an instrumentation gain stage, a simple antialiasing filter structure and a free configurable analog to digital converter (ADC) with a maximum sampling rate of 25 kHz for one channel. First testing of this design has shown a wide range of replacement for bio-applications where intelligent sensors with long term capability are needed.