## 3 Results  
### Systematic Literature Review  
The results of the search in Scopus [74], Web of Science [75], and PubMed [76] databases, are summarised in Figure 2, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (drawn using an online flow diagram creator [96]). We found 1109 records in 3 databases (Scopus with 1081 results, Web of Science with 2 results, and PubMed with 26 results) as well as 4 other records from citations or prior unrelated searches. After removing 31 duplicate records and 1 record removed for other reasons, 1077 results were screened by title and abstract with 951 being excluded. Seven of the remaining 126 records could not be retrieved, and 90 were excluded due to being short papers, extended abstracts or workshops reports, that either had no evaluation data, a focus in unrelated (to SSD) areas (e.g., Cerebral Palsy, Autism, Aphasia, Deafness, Stuttering, or Visual Impairment), or addressed unrelated research goals, such as referencing simple toys, discussing speech and language therapy that was not technology-based. Three records from other sources (the grey boxes in Figure 2) were excluded for not being related to the present study, and two records were added to the review. Perhaps one of the most interesting results from the initial queries on scientific databases is the lack of studies in the area of this paper, evidencing the need for further  
Figure 2: PRISMA flow diagram. research, and to create a common framework that can serve as a bridge for a transdisciplinary approach by an interdisciplinary research team [97]. This is especially urgent in this area due to the very negative impact it can have on the present and future life of children with SSD. The _VOSviewer version 1.6.18_[98], a software tool developed to visualise bibliometric networks, was used in conjunction with Scopus' analytical tool to further investigate the data available from the relevant studies included in the literature review. Subjects ranged from Computer Science to Neuroscience, a diversity that produces an abundance of designations for the same area (shown in Figure 3), created by the authors or automatically generated by the publishers. Figure 3 was generated by Scopus analytical tool, based on the bibliography that were retrieved from the initial search of the literature review. The variety and richness of the keywords and different approaches interconnected to or with TUI and IoT devices, with speech disorders and speech and language therapy is plain to see in Figure 4. The co-occurrence of keywords shows not only the above-chance frequency in which two terms occur in different texts, but also the potential relations between those terms and other concepts [99]. The analysis in Figure 4 highlights possible areas for cooperation overlaps with other technologies or fields of research and current trends. Figure 5 shows the results of an analysis based on title and abstract fields only, while ignoring copyright statements and other common labels. There is a full count of the occurrences of a term, with a minimum of five occurrences in order to qualify for the analysis, with 60% of those terms selected (based on a relevance score). This resulted in 38 terms that were then manually refined to delete terms such as minute, research, paper, year, type. The end result shows that there is not a single disconnected term. Even those that were further away from the centre (three or four nodes away), and appeared less prominent, were connected. When addressing the challenge of providing an accountable at-home, post-session continuation of speech and language therapy, through use of exercises, games or toys, and supported by parents, this literature review provides a fresh perspective on what has been done and what seem to be the most recent trends in research. Figure 3: Percentage of documents by subject area.