Ao Technology Ag

Brainlab Ag

Universitât Bern

University of Bern

Guoyan Zheng

Xuan Zhang

Thomas Feilkas

Lutz-Peter Nolte

Xiao Dong

Steffen Schumann

An acetabular component alignment device for total hip arthroplasty comprises a calibration component allowing for aligning a main instrument axis () of the acetabular component depending on a set of two patient specific calibration parameters relating to rotational offsets of the acetabular component, whereas the device is constructed in such a way that calibration parameters may be chosen such that a second parameter of the set of calibration parameters is adjustable independently from a first parameter of the set of calibration parameters by rotating the acetabular component around the main instrument axis () of the acetabular component. A method for obtaining patient specific calibration parameters for alignment of an acetabular component in total hip arthroplasty, comprises the steps of determining patient specific morphology information relating to a geometry of the patient's pelvis; and processing the patient specific morphology information for obtaining a set of two patient specific calibration parameters relating to rotational offsets of the acetabular component. The calibration parameters are chosen such that a second parameter of the set of calibration parameters may be adjusted independently from a first parameter of the set of calibration parameters by rotating the acetabular component around a main instrument axis of the acetabular component.

Methods and devices for patient-specific acetabular component alignment in total hip arthroplasty

The invention relates to a method for detecting a phantom, comprising the steps of: arranging a phantom with respect to an object, acquiring at least one image of said object by means of an x-ray apparatus, such that the image contains projections of the object and projections of at least three first calibration fiducials of the phantom, detecting the projections of the at least three first calibration fiducials in said at least one image, and establishing a correspondence between the 2D image coordinates of said projections of the at least three first calibration fiducials and the 3D coordinates of said at least three first calibration fiducials in a local coordinate system of the phantom for computing the projection matrix at least up to a scale factor.

Image distortion correction and robust phantom detection

A method for computer assisted localization of the distal locking holes () of an implanted intramedullary nail () having a nail axis () and a first and second distal locking hole () by A) acquiring one single image IM of the distal end section () of said intramedullary nail by means of an X-ray device () whose optical axis () is oriented essentially perpendicular to the nail axis () but irrespective to the orientation of the distal locking holes (); and B) calculating the position of the first and second hole axis () of the first and second distal locking hole () with respect to a three-dimensional coordinate system A-COS () of the implanted intramedullary nail ().

Method and device for computer assisted distal locking of intramedullary nails

A method and a device for computer assisted distal locking of intramedullary nails comprising the steps of: A) establishing a virtual geometric representation of an intramedullary nail (); B) acquiring a first medical image () using a radioscopic unit () with its focal line () adjusted at an angle between 0&#xb0; and 30&#xb0; to the axis () of the at least one distal locking hole (); C) acquiring a second medical image using a radioscopic unit () with its focal line () adjusted at an angle between 60&#xb0; and 90&#xb0; to the axis (); D) computing the position of the longitudinal axis () of the distal part () of the intramedullary nail () using said first and second medical image and said virtual geometric representation by means of a computer (); E) computing the position of the axis () of the at least one distal locking hole () using said first and second medical image (); F) transferring information related to the positions of the distal part () and the at least one distal locking hole () from a central processing unit of the computer () to an external guide means () for drilling a hole in a bone ().

A method for generating a three-dimensional model of a structure based on at least one two-dimensional image of the structure includes obtaining a general three-dimensional model of the structure; determining at least one image feature from the at least one two-dimensional image; determining an orientation of the general three-dimensional model of the structure relative to the at least one two-dimensional image of the structure so that at least one image feature of a two-dimensional projection of the three-dimensional model match or at least approximate the at least one two-dimensional image feature; and after determining the orientation of the general three-dimensional model, morphing a form or shape of the general three-dimensional model to fit the at least one two-dimensional image.

Growing community of inventors

Bern, Switzerland

Guoyan Zheng