Non-intrusive and calibration free visual exploration analysis in children with autism spectrum disorder.

ABSTRACT: Assistive technology is a generic system that is used to increase, help or improve the functional capabilities of people with disability. Recently, its employment has generated innovative solutions also in the field of Autism Spectrum Disorder (ASD), where it is extremely challenging to obtain feedback or to extract meaningful data. In this work, a study about the possibility to understand the visual exploration in children with ASD is presented. In order to obtain an automatic evaluation, an algorithm for free gaze estimation is employed. The proposed gaze estimation method can work without constrains nor using additional hardware, IR light sources or other intrusive methods. Furthermore, no initial calibration is required. These relaxations of the constraints makes the technique particularly suitable to be used in the critical context of autism, where the child is certainly not inclined to employ invasive devices. In particular, the technique is used in a scenario where a closet containing specific toys, that are neatly disposed from the therapist, is opened to the child. After a brief environment exploration, the child will freely choose the desired toy that will be subsequently used during therapy. The video acquisition have been accomplished by a Microsoft Kinect sensor hidden into the closet in order to obtain both RGB and depth images, that can be processed by the estimation algorithm, therefore computing gaze tracking by intersection with data coming from the well-known initial disposition of toys. The system has been tested with children with ASD, allowing to understand their choices and preferences, letting to optimize the toy disposition for cognitive-behavioural therapy.