Patent ID: 8775877

Claim:
A method of checking the integrity of a dynamic link library (DLL) file called by an application being executed on a handheld medical device, the method comprising: loading a DLL from nonvolatile memory to volatile memory beginning at a fixed location in the volatile memory, the DLL including a first routine for performing a safety critical function of the handheld medical device and including a second routine for performing a cyclical redundancy check (CRC) for the DLL once the DLL is loaded to the volatile memory; selectively executing the first routine from the volatile memory to perform the safety critical function; selectively executing the second routine from the volatile memory to perform the CRC including: calculating a check value based on the DLL loaded to the volatile memory; comparing the check value with a predetermined check value set for the CRC; and generating an output indicating that an error is present when the check value is different than the predetermined check value.