Compositions and methods are provided for producing a medical device such as a stent, a stent graft, a synthetic vascular graft, heart valves, coated with a biocompatible matrix which incorporates antibodies, antibody fragments, or small molecules, which recognize, bind to andor interact with a progenitor cell surface antigen to immobilize the cells at the surface of the device. The frame includes an array orthogonal rigid interstices defining a plurality of similar sized rectangular openings or window and the cloths are also bonded to the interstices for the purpose of maintaining the length to width ratio of the openings in the cloths defined by the warp and weft wires thereof. Additives that have been found to work include salts, such as lithium chloride and zinc chloride and bases, such as sodium hydroxide and lithium hydroxide. The read signal is integrated to generate a ramp signal, wherein a position error signal is generated from the ramp signal.