## 5 Conclusions  
This work presents a system for acquiring EEG, sEMG, and ECG biopotentials. The electronic characteristics of the proposed system--specifically in its amplification, filtering, and compensation blocks--make it simple, efficient, and suitable for various biopotential applications.  
The nonparametric Wilcoxon test was used to evaluate differences between samples obtained with the proposed and literature-reported configurations, with a significance level of \(\alpha\)=0.05. A \(p\)-value of 0.546 indicated no significant difference between the data, confirming the feasibility of the proposed configuration. Additionally, the Bland-Altman method was used to compare the signals and determine any deviations between configurations, further validating the proposed configuration by showing that most values lie within the 95% confidence interval on the Bland-Altman plot.  
The system can be scalable, allowing for an increased electrode count and adjustable filtering stages, depending on the study requirements. The 10-bit ADC resolution reduces computational load, supporting migration to a dedicated system. The system's resolution can be increased or decreased based on study requirements. Its open architecture enables the partial or complete modification of the MATLAB-based software, allowing for potential migration to other programming languages such as C++ V17, Visual Basic.NET V16.9, or Python V3.10.7. Additionally, the hardware can be modified at the amplification, filtering, and ADC resolution levels, thanks to the modular design of the system. This flexibility supports the replacement of the PC with an embedded card, FPGA, or compact systems like the Hummingboard-I4, Raspberry Pi, or NVidia Jetson. The proposed system has a low cost (USD 50) compared to commercial systems, which range from USD 700 to USD 1700.  
Future work will address current system limitations, including developing classification interfaces for EEG, ECG, and sEMG biopotentials with digital filtering, generating control signals using power electronics, increasing the number of electrodes via software for enhanced robustness, proposing a multiplexing configuration to allow for the software selection of specific filter bands, and migrating the system to an integrated board to create a portable device for medical diagnostics and applications for individuals with physical and motor limitations. Future developments also include an interface for applying various biopotential-processing and digital-filtering techniques.  
Conceptualization, G.T.-T., F.J.G.-F. and A.J.R.-S.; methodology, G.T.-T., F.J.G.-F., G.U.-S., B.R.-A., G.U.-C., A.J.R.-S. and E.V.-L.; software, G.T.-T., F.J.G.-F. and A.J.R.-S.; validation, G.T.-T., F.J.G.-F., [PERSON]-S., [PERSON]-A., [PERSON]-C., [PERSON]-S. and E.V.-L.; formal analysis, [PERSON]-T. and [PERSON]-F.; investigation, [PERSON]-T., [PERSON]-F., [PERSON]-S., [PERSON]-A., [PERSON]-C., [PERSON]-S. and E.V.-L.; resources, [PERSON]-T., [PERSON]-F., [PERSON]-S., [PERSON]-A., [PERSON]-C., [PERSON]-S. and E.V.-L.; data curation, [PERSON]-T., [PERSON]-F., [PERSON]-S., [PERSON]-A., [PERSON]-C., [PERSON] and [PERSON]; writing--original draft preparation, [PERSON] and [PERSON]; writing--review and editing, [PERSON] and [PERSON]; visualization, [PERSON]-[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON]; supervision, [PERSON]. All authors have read and agreed to the published version of the manuscript.  
This work is supported by Instituto Politecnico Nacional de Mexico (IPN) and Consejo Nacional de Humanidades, Ciencia y Tecnologia (Conahcyt), project 240820.  
Not applicable.  
The data will be available from the authors upon request.  
The authors declare no conflicts of interest.