A new strategy for 3D imaging of residual limbs using ultrasound

An ultrasound system for imaging a residual limb is described. The system employs two scan modes using a linear array transducer: a vertical scan mode that is mainly for capturing the skin surface in a relatively short time, and a horizontal compound scan mode that is mainly for imaging the internal tissue structures. The accuracy of the system in geometric measurement is tested by scanning two objects: a cylindrical phantom and a limb model. For the cylindrical phantom, the diameter measured by a caliper is 113 mm. The diameter measured by the ultrasound method is 113.8±0.23, representing a relative error of less than 1%. For the limb model, the volume measured by the ultrasound method is compared with the volume measured by a more accurate hydrostatic weighing method. The relative error is found again less than 1%. In addition, result from scanning an amputee´s residual limb is presented. This study demonstrates the potential of the ultrasound imaging technique in prosthetic CAD/CAM applications