Bio-signal Amplifier
The objective of this project is to develop a bio-signal amplifier for sensing physiological signals.
Block diagram of an amplifier (OpenXamp) for bio-signal amplification and filtering. The amplifier is built with commercially-off-the-shelf components and powered by a pair of batteries. A pre-amplifier section with high common-mode-rejection-ratio (CMRR) is used to differencially pick the bio-signal. If differential input is not required, the inverting input can be shorted with the input reference terminal. The signal is then band-passed filtered and amplified to the desired value by controlling the gain of the amplifier. One can directly use this analog signal or digitised by an analog-t-digital converter (ADC) and a a microcontroller (MCU). The digitised signal can be transfered to a computer via serial network (USB). Note that many MCU boards have built-in ADC and USB interfaces that can be used for the ditisation of the amplified bio-signal.
The design is offered as it is. Although it has been regorously tested with utmost care and to the best of my knowledge, I do not provide any warranty in any aspect.
- The design is intended stricktly for research and education purposes.
- The stimulator is not approved for human or animal use without receving prior approval from a local ethics committee such as Institutional Review Board.