Many of us keep our eyes very close to the small LCD screens on the Nintendo DS. This can be very straining on the eyes so this is where the Health Control Game Timer comes in. The Health Control Game Timer can be used to automatically shutdown the console after a designated amount of time. The time can be set to 30, 60, 90, or 120 minutes. The HCGT can also control volume of the device.
There is also a camera that tells you whether your face is too close to the console or not. The device costs 3,990 yen ($40). The device currently works for the Nintendo DS, no word on whether it will work for the DSi.