Abstract: Provided are methods of determining the cardiac contractility of a cardiovascular system, which methods comprise a step of utilizing values representing stroke volume, preload, and afterload to calculate the cardiac contractility. Most preferably, the calculation of cardiac contractility utilizes a mathematical relationship where the stroke volume is represented by the volume of a tetrahedron, the preload is represented by a length of the base of the base triangle of the tetrahedron, the afterload is represented by the height of the base triangle of the tetrahedron, and the cardiac contractility is represented by the height of the tetrahedron. Also provided are measurement systems for determining the cardiac contractility of a cardiovascular system that utilize such methods of determining cardiac contractility.

Abstract: A true childs shopping cart chair that has a seating part that by means of a cutout at its center front allows areas to extend outward beyond the shopping cart on which to place the legs as well as a part that fits into the cart on which to sit the child. A back and side support apparatus attaches to the sitting part to form an even more stable chair for a child. And the child's shopping cart chair can be attached to a base for use in automobiles.