A circuit and method for signal amplification is provided. A user session is initiated with a client device. The damping or support materials can modify the force and displacement characteristics of the switch, thereby allowing a user experience to be customized. The nephroprotective effect is common to compounds of different chemical nature and solubility and is specific for the kidney, causing no interference with the effects of nephrotoxic drugs having their targets in other organs. The control center assigns an account number for that identification code and provides the DHC card linked to that account number to the reliable source to give to that user.