Developing a Novel Hands-Free Interaction Technique Based on Nose and Teeth Movements for Using Mobile Devices

Human-mobile interaction is aimed at facilitating interaction with the smartphone devices. The conventional way to interact with mobile devices is through manual input where most of the applications are made assuming that the end user has full control over their hand movements. However, this assumption excludes people who are unable to use their hands or have suffered limb damage. In this paper, we proposed a nose and teeth based interaction system, which allows the users to control their mobile devices completely hands free. The proposed system uses the front facing camera of the smartphone to track the position of the nose for cursor control on the smartphone screen. The system detects teeth for performing the touch screen events such as tap, scroll, long press, and drag. Viola-Jones algorithm is used to detect the face and teeth based on the Haar features. After detecting the face, the nose position is calculated and tracked continuously using Lucas Kanade's method for optical flow estimation. All the touch screen events have been implemented in the system so that the user can execute all the operations of the smartphone. To evaluate the performance and the effect of (smartphone) device type on the execution time, the proposed system was installed in 3 smartphone devices and 7 trials for each device were performed by 3 different able-bodied elderly persons. The result shows a significant success rate for the detection of nose and teeth, and for the execution of the operations. The execution time of each operation slightly varies by 0.72s on average because of the configuration of the smartphones.