Ultrax: Real-time tongue tracking for speech therapy using ultrasound

点击翻译按钮获取中文摘要

Speech Sound Disorders (SSDs) are the most common communication impairment in childhood, affecting 6.5% of all UK children, or 2 children in every classroom. SSDs make it difficult for people to communicate with peers and integrate with society, yet the efficacy of interventions for most types of SSDs is weak. Speech, Language and Communication Disorders (SLCD) are a key UK government priority at present, with 2011 designated the national year of speech, language and communication . A recent government report (Bercow, 2008) highlighted the need for a programme of research to enhance the evidence base for children and young people with SLCD. Our programme of research aims to fulfill this need by developing technology which will aid the assessment, diagnosis and treatment of SSDs. Currently in Speech and Language Therapy, technological support is sparse. Technologies that do exist have been expensive to run or complicated to operate and hence not adopted in clinical practice. This project will develop technology (Ultrax) to turn ultrasound into a tongue imaging device specifically designed to provide real-time visual feedback of tongue movements. Most interventions for SSDs rely heavily on auditory skills; clients must listen to their own productions and modify them. However, with Ultrax people with SSDs will actually be able to see the movements of their own tongues and use this information to modify their speech. It is already possible to capture tongue movements by placing a standard medical ultrasound probe under the chin. Ultrasound has the potential to provide powerful information about atypical speech and to enable speakers to modify their own incorrect articulations. However, the image is grainy, information (especially about the tongue tip) is often lost and the image is difficult to interpret. We will improve this image by exploiting prior knowledge about the range of possible tongue shapes and movements in order to provide valuable constraints in tracking tongue contours in sequences of ultrasound images. We will apply a tongue model to this problem, making use of explicit sequence-based optimization for dynamic tracking and smoothing through time. We will use this technology to enhance the ultrasound images, transforming them into a dynamic, real-time 2D video of the tongue's movements which we hypothesize will be A) more easily understood by children B) extend the range of visible tongue shapes from only vowels and /r/ to include /t/,/k/,/ch/ and other consonants which are often targets for therapy Ultrax will be used to provide bio-feedback therapy for people with SSDs and to provide a means for objectively assessing progress by comparing tongue shapes before and after therapy. We will collect a large database of ultrasound and MRI images of tongue movements from 12 adults (ultrasound and MRI) and 90 primary school children (ultrasound) on which to base the model of tongue contours and to test its performance. At the same time, we will split the 90 children into 3 groups and record each group's response to one of 3 types of ultrasound display: 1. Raw, unenhanced, ultrasound 2. Unenhanced ultrasound with added anatomical context (e.g. the position of the teeth and roof of the mouth) 3. Fully enhanced ultrasound, developed in this project. The ability of the children to imitate tongue shapes and movements will be evaluated to determine whether they find the enhanced images easier to interpret than unenhanced images, leading to an improved ability use ultrasound for bio-visual feedback. We will trial ultrasound therapy with 9 children with SSDs (3 children for each type of display) enabling us to evaluate practical issues arising during therapy and pave the way for a future clinical trial. At the conclusion of our research project we will have developed the basis for a new visual-feedback tool (Ultrax) for Speech and Language Therapists to use in the diagnosis and treatment of SSDs.