Am I loosing nerves? I've been loosing the ability to use devices with captive touch screens. It's gotten to the point that I've had to start using a cap active stylus. From what I understand of the technology this means I'm loosing the ability for my nerves to generate a sensible charge. Is this possible?
Today’s touch screens work on the principle of capacitance. A capacitor is a device that holds electric charge and when you touch the device with a material that acts as a conductor some of the charge will transfer to this conductor. The human body, because it is made up of a large amount of water filled with ions (such as sodium), can act as a conductor of electric charge. When someone touches a touchscreen they pull some of the electric charge away from the device; because the amount of charge in the device is known, changes in this charge can be detected and used to drive the device.
(See http://www.computerworld.com/article/2491831/computer-hardware/how-it-works--the-technology-of-touch-screens for an excellent description of the technology.)
In multiple sclerosis, over time there can be some loss of nerve fibers (called eurodegeneration), which likely contributes to the changes in body function experienced by those with MS. However, because the skin is covering the body’s tissues (approximately 4 mm in the hand), separating the nerves and other structures from the environment, it is unlikely that loss of nerve fibers would contribute to the charge that your body holds. Instead, one potential culprit that may explain the difficulties that you are experiencing is the composition of your skin. There have been some reports that some people (including those who don’t have MS) of having difficulties with touchscreens; people in the technology world have started calling this “zombie fingers”.
Some have suggested that dry skin or calluses can get in the way of the electric charge being transferred between the device and your finger. In our lab where we can measure the resistance of people’s skin to transfer of electric charge, we have anecdotally discovered differences in resistance that appear to be related to the composition of the skin itself. Unfortunately, I have been unable to find a solution for this problem and it appears that most people who experience this problem resort to using a stylus, as you have done. One other possibility may be that there can be some charge transferred between other fingers that may come very close to or are contacting the screen itself while you are using your finger on the screen.
-Stephanie Jones, PhD, is an MS researcher at the University of Massachusetts Amherst currently conducting a study on the relationship between skin sensation and balance in people with MS.
From HealthCare Journey: If anyone reading this lives within 50 miles of Amherst, MA (free transportation to/from the study is provided) be sure to read about the study Stephanie and her team are conducting here...SENSATION AND BALANCE STUDY