Fluoroscopic bone fragment tracking for surgical navigation in femur fracture reduction by incorporating optical tracking of hip joint rotation center.

A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation.

Architecture of authorization mechanism for medical data sharing on the grid.

Data security is becoming increasingly important as the Grid matures. The advances of the Grid have allowed scientists and researchers to build a data grid where they can share and exchange research-related data and information. In reality, however, these specialists do not benefit enough from this data grid. The reason is that the current Grid does not have sufficiently robust and flexible data security. We investigate a medical data-sharing environment where medical doctors and scientists can securely share clinical and medical research data. We show medical data sharing that takes advantage of PERMIS, or an RBAC-based authorization system that achieves XML element level access control. We also describe the lessons learnt in designing the environment as well as a comparison with other existing authorization mechanisms.

A parallel implementation of 2-D/3-D image registration for computer-assisted surgery.

Image registration is a technique usually used for aligning two different images taken at different times and/or from different viewing points. A key challenge for medical image registration is to minimise computation time with a small alignment error in order to realise computer-assisted surgery. In this paper, we present the design and implementation of a parallel two-dimensional/three-dimensional (2-D/3-D) image registration method for computer-assisted surgery. Our method exploits data parallelism and speculative parallelism, aiming at making computation time short enough to carry out registration tasks during surgery. Our experiments show that exploiting both parallelisms reduces computation time on a cluster of 64 PCs from a few tens of minutes to less than a few tens of seconds, a clinically compatible time.