Alisa,
Does the patient have an iPhone only? We have a lot of success using a quadjoy with Samsung phones and tablets. It works just like a mouse to control the device. some of them have built in infrared so that they can control device. Here is a video demonstration of us using a quadjoy to control a samsung phone. Our patients who have voices, but no mobility find it easy and intuitive. It does not require much air pressure to sip. The patients can make calls, text, read and do pretty much anything.
Adina Bradshaw