Make the answer button touch target 4x the current size. Portal is a wonderful device for elderly users. Often those users have issues with vision. Increasing the answer button size would help tremendously. (just a note - on multiple occasions I've placed a portal in a care facility, and the staff is just amazed by the ease of use - just a little more on the accessibility side, and Portal could become dominate - I've bought 3 portals myself for others in this application)