Microwave bone imaging: experimental evaluation of calcaneus bone phantom and imaging prototype

Microwave imaging (MWI) can be used as an alternate imaging modality for monitoring bone health. Evaluation and characterization of MWI prototype is a precursor step before in vivo investigation of bone dielectric properties. This paper presents experimental evaluation of a novel two layered simplified cylindrical shaped 3D printed human calcaneus bone phantom along with corresponding MWI prototype designed to image the bone phantom. The shape of the calcaneus bone was approximated with a cylinder. The external and internal layers represent cortical bone and trabecular bone respectively. Each layer of the phantom was filled with respective liquid tissue mimicking mixture (TMM). A MWI prototype was designed having six microstrip antennas in order to hold calcaneus bone phantom. The bone phantom was placed in the imaging prototype and scattered signals were measured at each antenna. Moreover, the performance of the system was explored by examining microwave measurement sensitivity. Based on the measured scattered signals the map of dielectric properties will be constructed by employing MWI algorithm and will be communicated in our future work. This two layered 3D printed human calcaneus bone phantom and imaging prototype can be used as a valuable test platform for pre-clinical assessment of calcaneus bone imaging for monitoring osteoporosis.