Tracking of Human microscopic parasites in Matlab Algorithm: Mass-Spring System
Schistosoma move by expanding and contracting their bodies, making a fixed-mesh system difficult to use for tracking. Instead, this algorithm uses a modified mass-spring system to automatically match the changing dimensions of the parasite's body. After calculation of edge points on the image of the schistosome, the mass-spring system moves existing edge nodes to these points and calculates appropriate locations of the rest of the skeleton.
A mass-spring system is generally defined as two nodes connected by an elastic spring. Each node has mass, position, velocity, acceleration, and force, and each spring has stiffness, natural resting length, and a damping value. Hooke's Law is used to calculate the force applied to each node based on these variables, and new positions are calculated. In this system, each node correlates with a point on the parasite, with mesh lines matching the springs connecting each node in a grid array.