Multi-distance diffuse optical spectroscopy with a single optode via hypotrochoidal scanning

This work was inspired by the teacup rides common in amusement parks that send riders around in small circles while also traversing a larger circle. This pattern is called a hypotrochoid and has a number of unique properties: 1) A single actuator can drive an optical fiber along a hypotrochoidal path. 2) Two fibers on separate hypotrochoids will have a range of separations. 3) The center point between the two fibers will always be at a common location. These properties make it possible to assign depths to each measurement and produce a rough approximation of a 3D image when the probe is scanned over the surface of tissue.