Clinical informaticians, also known as clinical informaticists, transform health care by analyzing, designing, implementing, and evaluating information and communication systems that enhance individual and population health outcomes, improve [patient] care, and strengthen the clinician-patient relationship.
An ellipse is defined by two points, each called a focus. (F1, F2 above). If you take any point on the ellipse, the sum of the distances to the focus points is constant. In the figure above, drag the point on the ellipse around and see that while the distances to the focus points vary, their sum is constant. The size of the ellipse is determined by the sum of these two distances.
A line segment can be viewed as a degenerate case of an ellipse in which the semiminor axis goes to zero, the foci go to the endpoints, and the eccentricity goes to one. A standard definition of an ellipse is the set of points for which the sum of a point's distances to two foci is a constant; if this constant equals the distance between the foci, the line segment is the result.