Abstract
The present paper is concerned with realization of digital filter which has linear phase property suitable for filtering signals produced by human bodies. The signals from human bodies often suffer noises such as a slow fluctuation and line interference. The principle of the filter is relatively new using decimation (sampling rate decrease) and interpolation (sampling rate increase) effectively. This filter requires no multiplications and uses limited amount of memories to achieve economy.
The proposed filter effectively eliminates very low frequencies such as slow fluctuations around a reference level and 50Hz and its harmonics. The filter has been simply realized with a conventional microprocessor Z-80. Also presented will be a few experimental results of the realized digital filter to compare them with the results produced by a conventional analog filter.
