Swimming metrics

  • Activity: Represents the brush stroke (see Brush stroke metric) normalized by the time taken to perform the two strokes.
  • Asymmetry: Evaluates how balanced the swim posture is per stroke by reporting on whether the animal bends more toward one side or the other.
  • Attenuation: Measures how well the depth of a wave is maintained as it propagates along the body.
  • Body wave number: Refers to the number of waves transiting through the animal's body at a point in time. This metric provides an estimate of the "waviness" of the body posture.
  • Brush stroke: Refers to the area "painted" by the animal's body in a single complete stroke.
  • Dynamic amplitude (stretch): Calculates the maximum curvature differences between the two most extreme curvature points at any part of an animal during a given stroke. This metric provides an estimate of the type of body bend (deep or flat) and of the intensity of the "stretching" effort in a stroke.
  • Reverse swim: Measures the amount of time (%) spent by the animal swimming in reverse, initiating a body wave from the tail that propagates toward the head.
  • Self-contact distance (curling): Measures the relative amount of time (%) that an animal spends bent around so much that it overlaps with itself.
  • Swimming speed: Refers to the traveling swimming speed of an animal measured over a two-stroke interval.
  • Wave initiation rate: Refers to the number of body waves initiated from either the head or the tail per minute.

 

Reference

These metrics are based on the metrics described in CeleST: Computer Vision Software for Quantitative Analysis of C. elegans Swim Behavior Reveals Novel Features of Locomotion (Restif , Ibáñez-Ventoso , Vora et al., 2014).