One embodiment of the present invention sets forth a technique for rendering a plurality of images from a graphics scene in one rendering pass. The frame body of the beach buggy is partitioned and formed with an uncovered accommodating space, and the article box with its opening facing upward is embedded in the accommodating space and concealed under the saddle of the beach buggy. Arrangements of the sending and receiving units are designed to allow emission of the laser light from the pointer only when the laser pointer is pointed toward the projection screen. The system also includes a current monitor to sense a magnitude of the output current. The energy level is varied during successive cardiac correlative changes in the filling time are assessed, and the energy level is set to a level that maximizes the ventricular filling time. The device has both an inlet and an outlet, which are both in fluid communication with the reagent chamber.