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The GammaSafe memory token from Datakey Electronics Inc, Savage, MN, is a non-volatile, reprogrammable, portable memory that withstands gamma sterilization without losing data. It can hold up to four kilobits of rewritable memory and is accessed via an SPI bus. It is functionally similar to an SPI EEPROM. But traditional, nonvolatile memories, such as EEPROMs can lose data or fail when exposed to gamma rays. Gamma radiation can leave some plastics brittle and weak. By using the right combination of materials, engineers at Datakey Electronics ensured the memory token can operate reliably, withstanding up to 45kGy (4.5Mrad) of gamma radiation with no data loss. (Medical devices sterilized using gamma radiation typically receive a dose of 25 to 35kGy.)

To keep costs down on the memory, which is intended to be used with single-use/ limited-use medical devices, it features a single-sided PCB with contacts on just one side of the token. And to make sure the token gets inserted in the proper orientation, both the token and its mating receptacle have matching keying features.

There are two options available for the memory device. A prelooped tether gives medical OEMs an easy way to attach the memory to their disposable device. A sterilization indicator within a recessed window changes from yellow to red when exposed to a dosage of 10kGy or more of gamma radiation.

The GammaSafe memory token lets medical device manufacturers easily add anti-counterfeit and limit-use capabilities to their disposable devices, even if their devices contain no active electronics. The memory token sells for less than $2 at typical OEM production quantities.