The JMD (Jake Monitoring Device)
This is the JMD or "Jake Monitoring Device", a hand-held PDA which Dr. Diane Hughes uses to monitor Jake's vitals and nanite activity. Whether she is at Ft. Meade or off-site, Diane usually carries it on her person (in her labcoat pocket or purse), and has auditory "beep" warnings depending on the data it displays. Its screen has been known to freeze.
In Get Foley, it was revealed that there is more than one JMD device.
The JMD prop is a Sony Clié PED-NX70V handheld device, programmed with screens of data on Jake's nanites, depending on what the episode requires.