The diffusion and transfer of knowledge is central to the process of innovation and is of importance to both academics and industrialists. In this paper, we propose that academic articles and patent documents referring to a set of well-researched concepts may be used as a measure of this diffusion and transfer. Concepts are typically articulated as terms, and shared terms in specialist research papers and patent documents are proposed as a monitoring index for the transfer of academic knowledge to patented technology. The identification and statistical monitoring of changes in the use of terms, through the medium of texts, may provide innovative opportunities and reduce the extensive lead-time from invention to innovation. A text-based approach has been taken to research the changes in terminology that occurred in the development of Artificial Intelligence since 1936. Biological models of growth have been applied to model the diachronic changes, and the results show that the growth of term usage may be modelled by using logistic growth techniques.