  Brain-computer interface (BCI) technology is an interdisciplinary field that
allows individuals to connect with the external world. The performance of BCI
systems relies predominantly on the advancements of signal acquisition
technology. This paper aims to present a comprehensive overview of signal
acquisition technologies in BCI by examining research articles published in the
past decade. Our review incorporates both clinician and engineer perspectives
and presents a surgery-detection two-dimensional panorama of signal acquisition
technologies in BCI. We classify the technologies into nine distinct
categories, providing representative examples and emphasizing the significant
challenges associated with each modality. Our review provides researchers and
practitioners with a macroscopic understanding of BCI signal acquisition
technologies and discuss the field's major issues today. Future development in
BCI signal acquisition technology should prioritize the integration of diverse
disciplines and perspectives. Striking a balance among signal quality, trauma,
biocompatibility, and other relevant factors is crucial. This will promote the
advancement of BCI technology, enhancing its efficiency, safety, and
reliability, and ultimately contributing to a promising future for humanity.
