We disclose the structure of a JFET device, the method of making the device and the operation of the device. A preferred material is small intestinal submucosa. The connector assembly comprises a first member configured to be engaged with the flow restricting apparatus at least partially about the outlet. The holding portion is provided with an opening which is releasably lashed by one end of one or more threads so as to make the opening leakproof. The circular outer wall of the seal member is tightly and hermetically held between an outer ring of the bearing and front end wall of the housing, so that the seal member is not displaced in the axial direction. Charge is trapped into a charge trapping region of the other reference cell so as to achieve a state equivalent to memory cell characteristics having a largest amount of current.