A method and system for creating a digital, virtual slide having optimum image quality characteristics. The compressible pacifier has a nipple with a radial base which is secured between a ring and a handle. The second bus interface is configured to communicate with a memory and to transfer the memory transactions of the CPU chipset to and from the memory. The space has a height corresponding to a step created by the higher and lower sections and is located between the specific zone and the edge section of the rear surface section of the base plate. In the end, employing the enzyme immobilization method to immobilize a urea enzyme onto ammonium ion-selective membrane, thus the fabrication of a potentiometric urea sensor is completed.