Abstract: A wrist-worn device monitors movements of a user with a flexible circuit member. The flexible circuit member is fault tolerant. It may contain extra and/or redundant traces as well as the ability to store data on RAM if the flash memory fails or if some or all trace connections between the processor and flash memory fail. Data stored on the RAM may or may not contain less fidelity. Lower fidelity data may be used to alleviate issues arising if the RAM has less storage capacity than the flash memory.