A 0.5-V sub-mW wireless magnetic tracking transponder for radiation therapy

As the position of the tumor in a patient moves during radiation therapy, real-time knowledge of the position of the tumor is necessary in order to allow the maximum amount of radiation to be focused on the tumor and the minimum damage on the surrounding healthy tissues. A 0.5-V sub-mW wireless active transponder for a magnetic tracking system is designed in 130-nm CMOS technology to track the position of the tumor. The transponder consumes only 912 μW and an error of less than 5 mm is achieved with the tracking system.