# A Novel Battery-Supplied AFE EEG Circuit Capable of Muscle Movement Artifact Suppression
## 5 Discussion
### Observed Limitations of the Proposed EEG Circuit Design
\begin{table}
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**Circuits** & **Case “1” [47]** & **Case “2” [48]** & **Case “3” [49]** & **Proposed Circuit EEG** & **Design Innovation** \\ \hline \multirow{4}{*}{Point of interest} & \multirow{2}{*}{\(\blacksquare\)} & Notch only at 50 Hz not 60 Hz or 60 Hz & \multirow{2}{*}{\(\blacksquare\)} & No notch at 50 Hz or 60 Hz & \multirow{2}{*}{\(\blacksquare\)} & \multirow{2}{*}{\(\blacksquare\)} & Notch either at 50 Hz or 60 Hz, depending on & \\  & & & & & 50 Hz not 60 Hz & & \\ \cline{1-1}  & & No test for strong muscle artifacts & \multirow{2}{*}{\(\blacksquare\)} & No test for strong muscle artifacts & \multirow{2}{*}{\(\blacksquare\)} & No test for strong muscle artifacts & \multirow{2}{*}{\(\blacksquare\)} & Sufficient muscle artifacts handling \\ \cline{1-1}  & & No ESD protection & \multirow{2}{*}{\(\blacksquare\)} & No ESD protection & \multirow{2}{*}{\(\blacksquare\)} & No ESD protection & \multirow{2}{*}{\(\blacksquare\)} & ESD protection \\ \cline{1-1}  & & Not tested for compliance with the safety standards for current & \multirow{2}{*}{\(\blacksquare\)} & Not tested for compliance with the safety standards for current & \multirow{2}{*}{\(\blacksquare\)} & Not tested for compliance with the safety standards for current & \multirow{2}{*}{\(\blacksquare\)} & Compliance with the safety standards for current \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline \hline \end{tabular}
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Table 3: Examination of case limitations and proposed design innovations. study. The present AFE was not simulated to determine if it is durable enough for use in everyday harsh weather conditions, including even a device that is waterproof. The current study has not entertained the possible hardware choices of more advanced methods for noise reduction, such as adaptive filtering, which may be necessary for effectively responding to environmental noise, particularly from highly interfering environments like hospitals or clinics. The latter could also be addressed by incorporating enhanced electromagnetic interference (EMI) shielding in the design stage of the printed circuit board (PCB). Also, the shielding of the cables, a topic that was not part of this study is of extreme importance when designing the interface between the AFE and the electrodes that acquire the brain signals of the potential users of an EEG or BCI that could potentially use the proposed circuit as an AFE. Additionally, the problems of data encryption or secure data transfer were not part of this study, yet both are paramount to securing the data of patients in medical applications. Nonetheless, this is a problem that is mostly addressed by the circuitry of the MCUs incorporated in the EEG circuits and not by the AFE design. Lastly, the design was not assessed for compliance with all the existing international regulatory norms in the domain of EEG but only with those related to safety and leakage currents. This can limit it from being considered for use in any medical environment, until more studies are conducted. Future Perspectives: Possible Updates and Real-World Applications of the Proposed EEG Circuit Design  
The proposed novel EEG AFE was designed with the goal of being able to be incorporated into multi-component EEG signal acquisition systems for neurofeedback training and BCI applications. It can ensure the collection of full-brain activity at the site, where the electrode of the single channel is applied, thus facilitating better control accuracy and more efficacious neurofeedback [59]. In a future study, adaptive filtering methods combined with commercially available ADCs and microcontrollers could allow the study of the real-time data collection capabilities of the proposed AFE, as part of a complete system.