A plate for a compressible elastomeric spring is formed from a predetermined material and has each of a first substantially flat surface, an opposed second substantially flat surface, a predetermined thickness and a predetermined shape. A printing unit is located below the paper feeding unit. A heat sink is thermally coupled to the first substrate and an electrical cooling circuit is thermally coupled to the second substrate. The front ends of the first and second clip members are used to clip the positivenegative electrode of the car battery. In this way, the method enables quantitative evaluation of the hardness of body tissue of a region to be diagnosed.