A method is described for increasing the likelihood of the occurrence of an arrhythmia in a heart, particularly a ventricular arrhythmia of the type leading to Sudden Cardiac Death. The handle can be moved into or out of an emplacing space, so as to prevent the inner casing from being dropped on a ground surface due to an excessive exertion of force upon pulling out the inner casing from the emplacement sink. The caliper housing has side walls extending generally in a plane parallel to a plane of the rotor and on opposite sides of the plane of the rotor which accommodate a piston. The cell is a granulocytemacrophage progenitor cell or a cell further differentiated therefrom, such as a mast cell or neutrophils. The disclosed devices and methods reduce, minimize, or eliminate the surface area limitation of known integrated microfluidic devices.