Abstract: A model-based method is described which defines a rigid transformation between two co-ordinate systems that reduces the accuracy requirements on the quality of the data-set (including, but not restricted to, the error in the acquisition process, and the number and spread of the points) measured in one of the two co-ordinate systems by identifying a set of remote correspondences that are used to bind the convergence process. The method can be used in minimal-access orthopaedic surgery to improve the accuracy of limb registration. Specific instances include femoral registration, by estimating the functional center of the hip joint in both co-ordinate systems to be co-registered, and tibial registration, using the ankle center as a distant set of paired correspondences. Accuracy can be measured in a variety of ways, including, but not restricted to, evaluating the mis-alignment between the two co-registered objects.

Abstract: A steerable probe comprises a body and drive means arranged to drive the probe through a sample. The body comprises at least three body sections extending parallel to each other along the probe and each movable relative to the others along the probe. The drive means is arranged to move each of the body sections in turn relative to the others thereby to drive the probe through the sample.

Abstract: A mechanism which constrains the spatial location of a working or a focal point of a tool (103), has a manipulator (101) and a remote center mechanism (102) mounted thereon. The manipulator (101) provides at least one degree of freedom for positioning the remote center mechanism (102) which itself provides at least a further degree of freedom for positioning a tool holder suitable for holding the tool (103) which is to be constrained in operation with respect to a remote center point. The orientation of the tool holder is adjustable while still maintaining the position of the remote center point fixed with respect to the manipulator (101).

Abstract: A model-based method is described which defines a rigid transformation between two co-ordinate systems that reduces the accuracy requirements on the quality of the data-set (including, but not restricted to, the error in the acquisition process, and the number and spread of the points) measured in one of the two co-ordinate systems by identifying a set of remote correspondences that are used to bind the convergence process. The method can be used in minimal-access orthopaedic surgery to improve the accuracy of limb registration. Specific instances include femoral registration, by estimating the functional centre of the hip joint in both co-ordinate systems to be co-registered, and tibial registration, using the ankle centre as a distant set of paired correspondences. Accuracy can be measured in a variety of ways, including, but not restricted to, evaluating the mis-alignment between the two co-registered objects.

Abstract: A model-based method is described which defines a rigid transformation between two co-ordinate systems that reduces the accuracy requirements on the quality of the data-set (including, but not restricted to, the error in the acquisition process, and the number and spread of the points) measured in one of the two co-ordinate systems by identifying a set of remote correspondences that are used to bind the convergence process. The method can be used in minimal-access orthopaedic surgery to improve the accuracy of limb registration. Specific instances include femoral registration, by estimating the functional centre of the hip joint in both co-ordinate systems to be co-registered, and tibial registration, using the ankle centre as a distant set of paired correspondences. Accuracy can be measured in a variety of ways, including, but not restricted to, evaluating the mis-alignment between the two co-registered objects.

Abstract: A mechanism which constrains the spatial location of a working or a focal point of a tool (103), has a manipulator (101) and a remote centre mechanism (102) mounted thereon. The manipulator (101) provides at least one degree of freedom for positioning the remote centre mechanism (102) which itself provides at least a further degree of freedom for positioning a tool holder suitable for holding the tool (103) which is to be constrained in operation with respect to a remote centre point. The orientation of the tool holder is adjustable whilst still maintaining the position of the remote centre point fixed with respect to the manipulator (101).