Abstract: A high input impedance circuit for a buffer amplifier of a hearing aid microphone includes a transistor coupled across an input of the buffer amplifier and providing a high impedance transconductance, and a control circuit operatively coupled with the transistor to control the effective value of the input impedance provided thereby.

Abstract: A system for a networking electronic game units, includes an arcade router coupled with one or more game units at each of a plurality of locations and coupled to a communications resource for supporting bi-directional exchange of information with the one or more game units. A first router is coupled with a first group of the communications resources for supporting bi-directional exchange of information with a first group of game units. A first server is coupled with the first router for controlling the bi-directional exchange of information so as to support interactive play by game units at different locations.

Abstract: An orthodontic abutment for attachment to a dental implant that is embedded living jawbone having overlying gingiva is set forth. The implant has a gingival surface exposed through the overlying gingiva. The orthodontic abutment is capable of receiving an orthodontic component. The orthodontic abutment comprises a generally cylindrical main body having a lower end for engaging the gingival surface of the implant and a supragingival end opposing the lower end for protruding above the overlying gingiva. The main body has an outer surface between the lower end and the supragingival end. The outer surface includes a roughened portion to which the orthodontic component is to be attached and a gingival portion for contacting the overlying gingiva. The gingival portion extends from the lower end for about 3 mm. The roughened portion typically extends 360° around a central axis of the main body and is preferably adjacent to the supragingival end.