Patent ID: 7437644

Claim:
A closed system comprising: an internal device disposed interior of a boundary; an internal power source for powering the internal device; an external device separated from the internal device by and disposed exterior to the boundary, the external device being in telemetric communication with the internal device and generating an external RF energy source during telemetric communication with the internal device; a system clock for counting down a predetermined period of time; self-testing circuitry for verifying proper operation of at least one component of the internal device, the self-testing circuitry being automatically triggered upon the expiration of the predetermined period of time on the system clock; RF circuitry for detecting the presence and level of an external RF field received by the internal device; and a microprocessor for initiating the self-testing circuitry and resetting the system clock in the presence of a detected external RF field when the time remaining on the system clock is less than a predetermined reset time period.