There is disclosed a circuit and method for demultiplexing in a receiver a digital data stream including at least two types of data, so as to retain only those parts of the digital data stream required by the receiver. The first and second fastening elements each have a contact face, which is formed in a concave manner in the first fastening element and in a mirror-inverted, convex manner in the second fastening element,. These improvements provide the attending personnel with information needed to determine whether the MRI should be suspended in response to induced tachyarrhythmias or other adverse conditions within the patient. In the present invention, the separation distance \u201cd\u201d is adjustable. The controller includes a user interface that allows a user to control at least one of the following available functions: desired amplifier gain value; amplifier output power value; ASE noise compensation. The device has an epitaxially grown fill material in an etched source region and an etched drain region.