Salley James, Muth Eric, Hoover Adam
IEEE J Biomed Health Inform. 2017 May;21(3):599-606. doi: 10.1109/JBHI.2016.2612580. Epub 2016 Sep 21.
This paper describes a study to test the accuracy of a method that tracks wrist motion during eating to detect and count bites. The purpose was to assess its accuracy across demographic (age, gender, and ethnicity) and bite (utensil, container, hand used, and food type) variables. Data were collected in a cafeteria under normal eating conditions. A total of 271 participants ate a single meal while wearing a watch-like device to track their wrist motion. A video was simultaneously recorded of each participant and subsequently reviewed to determine the ground truth times of bites. Bite times were operationally defined as the moment when food or beverage was placed into the mouth. Food and beverage choices were not scripted or restricted. Participants were seated in groups of 2-4 and were encouraged to eat naturally. A total of 24 088 bites of 374 different food and beverage items were consumed. Overall the method for automatically detecting bites had a sensitivity of 75% with a positive predictive value of 89%. A range of 62-86% sensitivity was found across demographic variables with slower eating rates trending toward higher sensitivity. Variations in sensitivity due to food type showed a modest correlation with the total wrist motion during the bite, possibly due to an increase in head-toward-plate motion and decrease in hand-toward-mouth motion for some food types. Overall, the findings provide the largest evidence to date that the method produces a reliable automated measure of intake during unrestricted eating.
本文描述了一项研究，旨在测试一种在进食过程中追踪手腕运动以检测和计数咬食次数的方法的准确性。目的是评估其在人口统计学（年龄、性别和种族）和咬食（餐具、容器、使用的手和食物类型）变量方面的准确性。数据是在自助餐厅正常进食条件下收集的。共有271名参与者在佩戴类似手表的设备以追踪其手腕运动时吃了一顿饭。同时记录了每位参与者的视频，随后进行查看以确定咬食的真实时间。咬食时间在操作上被定义为食物或饮料放入口中的时刻。食物和饮料的选择没有预先设定或限制。参与者以2至4人一组就座，并被鼓励自然进食。总共食用了374种不同食物和饮料的24088口。总体而言，自动检测咬食的方法灵敏度为75%，阳性预测值为89%。在人口统计学变量中，灵敏度范围为62%至86%，进食速度较慢的人群灵敏度往往较高。由于食物类型导致的灵敏度变化与咬食过程中手腕的总运动量呈适度相关，这可能是由于某些食物类型中头部向餐盘运动增加而手部向口部运动减少所致。总体而言，这些发现提供了迄今为止最大的证据，表明该方法在无限制进食期间能产生可靠的摄入量自动测量结果。
