A new QUS sensor measuring guided waves SOS and anisotropy using bidirectional transmission

Anisotropy of cortical bone is known to be associated with material properties and might thus be relevant for fracture risk assessment. We developed a sensor which is able to measure the velocity of guided waves in different directions simultaneously using bidirectional transmission along the long axis of the sensor and ± 37.5° angled to it. The method was tested on two anisotropic plates by scanning them during a full circle rotation in steps of 15° and compared with results from the commercial device Omnisense 7000 (Beam Med, Petah Tikva, Israel, developed by Sunlight Medical Ltd.). The profiles of the angle dependent SOS measured with both devices were equal in shape and differed less than 90 m/s. The devices' SOS repositioning precision was between 6.0 and 8.8 m/s. The accuracy error of a calculated anisotropy ratio was below 2%, its precision 1%. The results indicate that it is feasible to measure anisotropy using our sensor in one single position.