Towards Accident Prevention: An Aspiration Risk Warning System for Older Adults During Meals

The aim of this study is to create a system to support cooperative prevention of accidents during mealtime among users of elderly care facilities. Experiments were conducted with 10 healthy adults to define abnormal postures during swallowing and extract responses to abnormal posture warnings by a communication robot. The participants were asked to tilt their bodies at 10° intervals from a comfortable posture and perform a food-intake test in the resulting posture. Based on observation of swallowing and feedback about posture from the participants, the angle at which each posture became dangerous was determined. As a result, abnormal posture thresholds were identified as leaning forward 30°, tilting left/right 30°, and chin tucking 20°. It was determined that the communication robot should not issue a warning in the event of repeated detection of abnormal posture. Moreover, it was considered that the warning alone is insufficient to prevent danger, and that the user and the people around them should be instructed on how to respond in the event of a warning. If the system is used in a care facility, the warning should be communicated to users and caregivers, facilitating cooperative accident prevention.