Mike kindly sent us a fantastic resource Universal_Principles_of_Assistive_Technology which he has adapted from Wendt, O., & Lloyd, L. L. (Eds.). (2011). Augmentative and Alternative Communications Perspectives Volume 4: Assistive Technology: Principles and Applications for Communication Disorders and Special Education. Bradford, GBR: Emerald Insight.
We have found it useful to summary of things we should all consider when working with assistive technology and have even displayed it in our office as a handy reminder!
Please keep checking our blog and website http://www.barnsleyhospital.nhs.uk/assistive-technology/ for further resources and ideas. We love to share!