The following is a summary of the “System and approach to detecting gastric slow wave and environmental noise suppression based on the optically pumped magnetometer,” published in the December 2023 issue of Gastroenterology by Liang et al.
Gastric slow waves (SWs) are a crucial metric for evaluating gastric functional disorders. Compared to surface electrogastrography, using magnetic signals for SW recording promises higher signal quality. Their investigation focused on optically pumped magnetometers (OPM) using the spin exchange relaxation-free method. These OPMs exhibit weak magnetic detection abilities similar to superconducting quantum interference devices (SQUIDs) but without liquid helium cooling. However, the challenge arises from the unavoidable interference of low-frequency environmental drift, obscuring the distinctive SW features and complicating gastric magnetic signal detection.
To address this issue, the researchers developed an OPM Magnetogastrography (OPM-MGG) system. Their approach involved an adaptive filtering framework, environmental drift suppression, and a non-stationary signal decomposition method to isolate SW signals. Controlled human experiments validated their system’s ability to successfully extract SW signals within the 2–4 cycles per minute frequency range. These extracted SW signals exhibited consistent power and time–frequency characteristics in line with existing reported results.
Their study validates the viability of two critical aspects: firstly, employing the OPM-MGG system for capturing SW signals, and secondly, the efficacy of their devised processing strategies in identifying ultralow-frequency SW signals. Ultimately, the OPM-MGG system and the signal extraction methodologies developed herein hold promise in furnishing wearable technology for bioweak magnetic field measurements. This innovation offers novel prospects for research and clinical applications, potentially transforming the landscape of biomedicine by enabling non-invasive and wearable tools for monitoring gastric functions.
Source: sciencedirect.com/science/article/abs/pii/S0208521623000633
