A Comparison of Finger and Wrist Motion Tracking to Detect Bites during Food Consumption

This paper evaluates the use of a sensor mounted on a finger to detect bites during food consumption. Previous works have demonstrated the capability to detect bites by tracking wrist motion. The key motion is the roll of the wrist that occurs between picking up food and delivering it to the mouth. We hypothesize that the roll axes of the wrist, hand, and finger are congruent, and that therefore the roll motion measured at the wrist can be similarly measured at the finger. We collected data for 10 meals of subjects wearing sensors on both the wrist and finger. Results indicate that the bite counting algorithm obtains similar accuracy at both locations. The practical implication is that an eating activity monitor could be embedded in the form of a ring worn on the finger, and that this form factor could work as well as a watch-like device.