A physical keyboard includes a plurality of multi-functional keys with a reduced column QWERTY key arrangement overlaid with a numeric phone key arrangement for use in both text entry and telephony. In some embodiments, the protrusion is generally cylindrical, while in other embodiments, the recessed portion is generally cylindrical. The first containing space hosts a circuit board and a driving unit, a standard CD-ROM drive with a panel on the front and the panel has a opening against the second containing space, a flash memory socket in the second containing space and its slot faces against the said opening of the panel. The device configuration is updated by updating the function status for at least one of the medical device functions in response to the allowable status for the medical device function. The invention may have various embodiments that can be to inflate the device, or the form and shape of the device. Also a differentiation output unit is provided to differentiate between a sensed voltage Vsig sensed at the sensor array by a sensing circuit and a sensed voltage Vdmy sensed at the canceling dummy block, thereby eliminating the influence of a variation in parasitic capacitance Cp, caused by a production tolerance.