I wanted to share a resource with you.  I recently purchased a book on Amazon called "Augmentative and Alternative Communication in Acute and Critical Care Settings".  (authors Richard R. Hurtig and Debora A. Downey)   It's a great resource book and comes with a CD too. 
Chapters include infomation on AAC, switch access, nurse call bell systems (always a concern for our ALS folks) and many pages of resource info.  I just wanted to pass this on. 
 
Alisa Brownlee, ATP
Clinical Manager, Assistive Technology Services
ALS (Lou Gehrig's Disease) Association National Office
 and Greater Philadelphia Chapter
Direct Phone: 215-631-1877