Have you considered voice activation? Touch pad?
I am very impressed with your device, and were I faced with the issue, your solution would be mine -- hands down, no doubt. However, the road to protecting and marketing any device is potentially fraught with substantial uncertainty, expense, and frustration. Not every great invention is entitled to patent protection.* (Patent lawyers sell their time and effort which may or may not result in the issuance of a patent. I quit trying to guess which inventions were patentable and which were not a long time and many dollars ago.) At best, obtaining a patent is an expensive proposition. If you have an existing relationship with a local attorney, begin with him or her as they can assist you in both controlling costs and protecting your interests.
Having traveled this path before, I will relate the following, although without any assurance of accuracy due to the lapse of time. (If you are determined to pursue a patent, educating yourself on all aspects of the subject will work to your benefit.) Obtaining the results of a patent search is one of the initial steps in the patent process -- a specialist is paid to search the patent records and identify all prior submissions touching upon your work. The product of the search enables/assists you and your lawyers in evaluating your chances of success.
The results of the patent search also assist in the development of certain written descriptions utilized throughout the patent process. For instance, consider the following from the patent issued for a Locking Safety Pin: "A purpose of the invention is to provide opposite spring wire reverse band portions connected by a straight portion and carrying a pointed pin portion which engages in a socket on one of the reverse bend portions, and to extend from the socket a spring lever provided with a hook which locks with the pointed pin portion in closed position." Next on the list of patent process essentials are patent drawings. Keep in mind that the process of securing a patent is only the beginning if you are knocked-off, because patent rights are not self-executing.
Whether to seek patent protection is often determined by the potential breadth of application of a particular device. What is the potential demand? Expansion of the application of an invention beyond the initial concept may be the critical factor ultimately dictating whether it is financially advisable to seek a patent. At this point, my advice is to return to the drawing table and expand the applicability of your invention as far as it will go, and then further.
*For Instance, the invention of a lead pencil with an attached eraser was ruled not patentable by the U. S. Supreme Court in the case of Reckendorfer v. Faber, 92 U.S. 357 (1875).
