You could try the Wacom graphics tablet. These tablets connect to the computer (both Mac and Windows) via a USB port. Anything you write on the tablet with a special 'pen' is transferred to the computer as text. They also allow you to create images such as drawings or, when you become really skilled in using them, almost any image your imagination (and artistic talent) allows. They can also be used instead of the mouse when you are busy drawing or writing.
They are fairly expensive, but the cheapest range from Wacom is the Bamboo and costs about €50 at Amazon, but this will last a lifetime. There are makes other than Wacom, but they do not have the same build quality and are slightly less versatile.