Stereotypic Repetitive Hand Flapping Movement Detector Children with Autism

Subodh Ashok Bansode, Western Michigan University


The prevalence of Autism Spectrum Disorder (ASD) has increased at a significant rate in recent years, especially in developed nations such as the United States, Japan, and South Korea. Extensive research is being carried out to study the behavioral characteristics of the disease. Children affected with autism tend to exhibit a spectrum of symptoms depending on the severity of the disease. These behaviors are primarily repetitive, self-stimulatory, and stereotypic behaviors such as hand flapping (i.e., repeatedly shaking their hands), body rocking (i.e., swaying their body back and forth), drumming, walking around in a confined space, and walking with shortened steps on toes, etc. Some children with a high severity of autism exhibit abrupt and uncontrollable motions that may interrupt normal activity and be socially awkward. These behaviors may not cause immediate harm, but may hamper the learning abilities of children slowly and eventually. They may also lead to self-injurious behaviors and critical damage when harm is repeatedly inflicted in one location.

Parents who are concerned about the behavioral characteristics of autism often seek immediate treatment. They also seek the help of caregivers to look after their children. Correcting these restricted and repetitive behaviors at an early age helps children overcome them slowly. Although extensive research is being carried out in studying and categorizing the behavioral characteristics of the disease, there has not been a single technological device available in the market for aiding the autistic kids.

In this research project, a simple reminder system is proposed using wearable sensors to automatically detect significant hand flapping movements. The reminder system consists of a speaker encoded with the voice of mother, father, or any other custom designed voice. An algorithm was designed to trigger the audio device when the child showed significant hand flapping activity (i.e., hand flapping more than 10 times) within a given time frame. The time frame and the hand flapping count can be customized per severity of the child’s symptoms. The device was successfully tested in the laboratory by simulating the hand flapping movement shown by the child. It is hoped that this system provides a valuable service to parents and the child by alerting the child to autistic movements, preventing the habit from turning into self-injurious behavior, and taking away the burden from parents and caregivers.