A jacket of biological compatible material has an internal volume dimensioned for an apex of the heart to be inserted into the volume and for the jacket to be slipped over the heart. Player authentication data is acquired via an interface provided by a gaming machine and the data is then placed on a cashless instrument so that it may later be read and authenticated. The sensor has an active area defined by the stripe height of the free layer. Step two requires coupling at least one support element to the underside surface of the flexible layer.