In a random number generator, a first converter converts a first analog noise signal into a random digital clock signal and a second converter samples a second analog noise signal asynchronous to the first analog noise signal in response to the random digital clock signal and generates a random digital number stream. In order to direct a portion of a light beam parallel to the axis of the hand towards the interior of the body, the head includes a plurality of reflectors distributed around the axis and formed by dihedron shaped hollows. After a workpiece is processed with the initial parameter configuration, the results are measured and a sensitivity matrix based upon the mathematical model of the processing chamber is used to select new parameters that correct for any deficiencies measured in the processing of the first workpiece. When the lid is opened, wet sheets can be taken out of the package. Also disclosed are methods for the preparation of the collagen films and their use as a vehicle for delivering a dose of therapeutic compound to a specific tissue site.