In accordance with the principles of the present invention, unwanted calls may be prevented. The membrane prevents blood clots in the atrial appendage from escaping therefrom and entering the blood stream which can result in a blocked blood vessel, leading to strokes and heart attacks. The methods and systems analyze and use the data to calculate and define a continuous BREP object which accurately represents the original polygonal object. A configuration device is provided, by which presettable display fields can be set for the measured parameters on the display unit. Embodiments can include sensors and controllers to automate the switching, as well as energy harvesting elements to increase battery life.