| 摘要 |
1. Amplifier for physiological signals, comprising : - a differential-type input amplification stage (10) having two inputs intended to be connected respectively to a first and a second electrodes, and two outputs, - a feed circut (70) for the input amplification stage (10), having a floating mass point and two outputs (A+, A-) which are at potentials situated to either side of the reference potential (MF) defined by the floating mass point, and two outputs (A+, A-) which are at potentials situated to either side of the reference potential (MF) defined by the floating mass point, - an intermediate amplification stage (20) having two differential inputs connected to the outputs of the input stage and an output connected to one of its inputs by a reverse feedback circuit to form a highpass filter in order to remove the continuous component of the collected signal, - an output amplification stage (40), and - a low-pass filter (50) connected in series with the output amplification stage (40) in order to remove the high-frequency components of the collected signal, said amplifier being characterised as follows : - the floating mass point (MF) of the feed circuit is fixed in relation to the common mode voltage defined from the input voltages of the input stage (10), - a phase-correcting circuit (30) is connected in series with the intermediate amplification stage (20) to correct the phase displacement introduced by the latter and not introduce any group propagation time variation, and - the low-pass filter (50) connected in series with the output amplification stage (40) is selected so as not to introduce any group propagation time variation. |
