Quantification of Gastric Slow Wave Velocity Using Bipolar High-Resolution Recordings

Objective: Gastric bio-electrical slow waves are, in part, responsible for coordinating motility. High-resolution (HR) in vivo recordings can be used to capture the wavefront velocity of the propagating slow waves. A standard marking-and-grouping approach is typically employed along with manual review. Here, a bipolar velocity estimation (BVE) method was developed, which utilized local directional information to estimate the wavefront velocity in an efficient manner. Methods: Unipolar in vivo HR recordings were used to construct bipolar recordings in different directions. Then, the local directionality of the slow wave was extracted by calculating time delay information. The accuracy of the method was verified using synthetic data and then validated with in vivo HR pig experimental recordings. Results: Against ventilator noise amplitude of 0% - 70% of the average slow wave amplitude, the direction and speed error increased from 4.4 degrees and 0.9 mm/s to 8.6 degrees and 1.4 mm/s. For signals added with high-frequency noise with SNR of 60 dB - 12 dB, the error increased from 8.0 degrees and 1.0 mm/s to 9.8 degrees and 1.2 mm/s. With experimental data, the BVE algorithm resulted in 19.2 +/- 1.7 degrees of direction error and 2.0 +/- 0.2 mm/s of speed error, when compared to the standard marking-and-grouping method. Conclusion: Gastric slow wave wavefront velocities were estimated rapidly using the BVE algorithm with minimal errors. Significance: The BVE algorithm enables the ability to estimate wavefront velocities in HR recordings in an efficient manner.

Automated summary

In this study, a new bipolar velocity estimation method was developed to rapidly and efficiently estimate gastric slow wave wavefront velocities with minimal errors. This is of great significance for understanding and studying the coordination mechanism of gastrointestinal motility.