It's quite analog, or rather brute force, but I broke down the movements of the esophagus and stomach into detailed segments and recorded them as shape keys (though I only captured the stomach's movement in the video). When I animate the shape keys smoothly during playback, it should produce a natural-looking motion. This digestive tract model is intended for sale, and I designed it with ease of use and clarity in mind, whether in Blender or Unity.
video. 1
You can watch the videos from a link in the following link.
https://www.patreon.com/hulithi/membership