A 3D phantom for EIT printed in a single part

Electrical Impedance Tomography (EIT) is a medical imaging technology that uses electrical current to image the body. Imaging phantoms which act as a well-characterized reference objects are useful for the study of EIT and calibration of EIT devices. A proof of concept of a new type of 3D printed phantom for EIT was recently introduced, and this paper seeks to fully realize this concept by printing a phantom with three-dimensional geometry in a single part and demonstrating how it can be used for the study of EIT. The 3D printed phantoms are printed all-in-one, with internal regions of differing infill density which correspond to differing conductivity, the property imaged by EIT. Three prototype phantoms were printed, including one containing the 3D geometry of the surface of a pair of human lungs. A technique was demonstrated to calibrate an EIT device using measurements taken from a printed phantom, giving similar results to traditional calibration. Images of slices through the 3D phantoms were generated from physical measurements, and were comparable to simulations, giving evidence that the phantoms were sufficiently well characterized. Overall, this is an accessible and effective method for creating phantoms for EIT, and we encourage its wider adoption.