A method and an apparatus are provided for transmitting data by a transmitting apparatus in a communication system. Dielectric material is flowed over the silicon dioxide-comprising liner to fill remaining volume of the array isolation trenches and to form a dielectric liner over the silicon dioxide-comprising liner in at least some of the peripheral isolation trenches. The head structure is configured to be placed within the rectal cavity of a patient such that either a contact surface on the head structure or the fluid itself directly contacts a portion of the rectal mucosal membrane. The air sac is inflatable and deflatable for adjusting the hardness and the thickness of the computer wrist pad.