A system and method are disclosed for securing binding updates in a wireless telecommunications system. The amount of power supplied to the implantable power unit for operating a pump, for example, can be varied in accordance with a cardiac cycle, so as to maintain the monitored condition in the power circuit within a desired range throughout the cardiac cycle. The cover is waterproof to prevent the core from absorbing liquid. To compensate, a correction factor is generated by minimizing the difference between the reference oscillator signal and a signal of known frequency, such as an external reference signal. The silicone rubber layer has a high heat conductivity and long-term temperature durability. The at least one trench and the at least one cavity form an electrical insulation structure between the region of the semiconductor substrate on which the photodiode is arranged and one or more adjacent regions of the semiconductor substrate.