Abstract: A computer implemented medical method of calibrating a medical instrument is provided. The method calculates a position of the instrument tip model within the indentation model, associated with an estimated position of the instrument tip within the indentation and calibrates the medical instrument, thereby using the determined position of the instrument tip model. The position of any arbitrary medical instrument tip, such as an indentation of a calibration device, can be estimated. This is an improvement of accuracy in view of the generic approach of using the same reference point of the indentation of the calibration device for any arbitrary medical instrument tip. A virtual model of a shape of a medical instrument, such as the instrument tip, is matched onto a virtual model of a shape of a calibration device, such as an indentation of the calibration device.

Abstract: A method, performed by a computer, for measuring geometric length and offset differences of a subject element using landmarks obtained through, for example, analysis of medical data images. The method may include obtaining medical image data from a medical imaging device. The method includes measuring, by the computer, a first landmark vector between a femoral landmark and a second landmark at a first point in time from, for example, the medical data images. Further, the method includes measuring, by the computer, a second landmark vector between the femoral landmark and the second landmark at a second point in time which is later than the first point in time from, for example, the medical data images. Calculating an orthogonal projection of the first landmark vector into a sagittal plane and using the direction of the orthogonal projection of the first landmark vector into the sagittal plane as a length direction.

Abstract: A method, performed by a computer, for measuring geometric length and offset differences of a subject element using landmarks obtained through, for example, analysis of medical data images. The method may include obtaining medical image data from a medical imaging device. The method includes measuring, by the computer, a first landmark vector between a femoral landmark and a second landmark at a first point in time from, for example, the medical data images. Further, the method includes measuring, by the computer, a second landmark vector between the femoral landmark and the second landmark at a second point in time which is later than the first point in time from, for example, the medical data images. Calculating an orthogonal projection of the first landmark vector into a sagittal plane and using the direction of the orthogonal projection of the first landmark vector into the sagittal plane as a length direction.

Abstract: The present invention relates to a method for planning the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: —determining the geometric shape of the joint socket, in particular the acetabulum, and the geometric shape of the cup which is to be placed; —defining target areas where the cup has to abut the bony structure of the joint socket, in particular the acetabulum, in order for the cup to be sufficiently fixed; —determining actual areas of the cup which will abut the bony structure of the joint socket, in particular the acetabulum, when the cup is placed; —defining a requirement for the position and/or orientation of the cup on the basis of the position and/or size of the target areas and/or actual areas.

Abstract: A data processing method for determining the relative orientation of an object coordinate system of an anatomical object in a global co-ordinate system, comprising the steps of: acquiring a reference direction dataset representing a first reference direction of a line between a first anatomical landmark of a reference object and a second anatomical landmark of the reference object, and a second reference direction of a line between a third anatomical landmark of the reference object and a fourth anatomical landmark of the reference object, wherein the first and second reference directions are given in a reference coordinate system and the reference object corresponds to the anatomical object; acquiring an object direction dataset representing a first object direction of a line between the first anatomical landmark of the anatomical object and the second anatomical landmark of the anatomical object, and a second object direction of a line between the third anatomical landmark of the anatomical object and the f

Abstract: A data processing method, performed by a computer, for determining a leg length difference and a leg offset difference of a patient's leg including a femur connected to a pelvis, comprising the steps of: —determining a first landmark vector between a femoral landmark and a second landmark at a first point in time; —determining a second landmark vector between the femoral landmark and the second landmark at a second point in time which is later than the first point in time; —calculating an orthogonal projection of the first landmark vector into a sagittal plane and using the direction of the orthogonal projection of the first landmark vector into the sagittal plane as a leg length direction; —calculating a direction which is perpendicular to the sagittal plane and using this direction as a leg offset direction; and —calculating the leg length difference in the leg length direction and the leg offset difference in the leg offset direction from the first landmark vector and the second landmark vector.

Abstract: A data processing method for determining the relative orientation of an object coordinate system of an anatomical object in a global co-ordinate system, comprising the steps of: acquiring a reference direction dataset representing a first reference direction of a line between a first anatomical landmark of a reference object and a second anatomical landmark of the reference object, and a second reference direction of a line between a third anatomical landmark of the reference object and a fourth anatomical landmark of the reference object, wherein the first and second reference directions are given in a reference coordinate system and the reference object corresponds to the anatomical object; acquiring an object direction dataset representing a first object direction of a line between the first anatomical landmark of the anatomical object and the second anatomical landmark of the anatomical object, and a second object direction of a line between the third anatomical landmark of the anatomical object and the f

Abstract: The present invention relates to a method for planning the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: —determining the position of at least one point lying on the rim of the joint socket, in particular the position of at least two points lying in an anterior region of the acetabulum; —defining a requirement for the position and/or orientation of the cup on the basis of the determined positions of the at least one point. The present invention also relates to a method for optimizing the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: —defining at least one requirement for the position and/or orientation of the cup; —calculating an optimum position and/or orientation of the cup on the basis of all the defined requirements being fulfilled.

Abstract: The present invention relates to a method for planning the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: determining the geometric shape of the joint socket, particular the acetabulum, and the geometric shape of the cup which is to be placed; defining target areas where the cup has to abut the bony structure of the joint socket, in particular the acetabulum, in order for the cup to be sufficiently fixed; determining actual areas of the cup which will abut the bony structure of the joint socket, in particular the acetabulum, when the cup is placed; defining a requirement for the position and/or orientation of the cup on the basis of the position and/or size of the target areas and/or actual areas.

Abstract: The present invention relates to a method for planning the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: —determining the position of at least one point lying on the rim of the joint socket, in particular the position of at least two points lying in an anterior region of the acetabulum; —defining a requirement for the position and/or orientation of the cup on the basis of the determined positions of the at least one point. The present invention also relates to a method for optimising the positioning of a ball joint prosthesis, in particular a hip joint prosthesis, wherein the prosthesis includes a stem and a cup and the method comprises the following steps: —defining at least one requirement for the position and/or orientation of the cup; —calculating an optimum position and/or orientation of the cup on the basis of all the defined requirements being fulfilled.

Abstract: A data processing method for determining the position of a main plane of an anatomical body part, comprising the steps of: ·providing absolute auxiliary point data which describe the position of at least one actual auxiliary point of the body part relative to a marker device attached to the body part, the at least one actual auxiliary point being outside the main plane; ·providing relative point data which constrain the possible positions of the main plane relative to the at least one actual auxiliary point; ·providing absolute main point data which describe the position of one or two actual main points of the body part relative to the marker device attached to the body part, said one or two actual main points lying in the main plane and/or calculating the position of at least one virtual main point relative to the marker device, said at least one virtual main point being in the main plane and being calculated based on the absolute auxiliary point data and the relative point data; ·calculating a position of t

Abstract: Determining a three-dimensional model of a rim of an anatomical structure using two-dimensional images of the rim. The images are taken from different directions and each image can provide a different two-dimensional contour of the rim. Corresponding pairs of points are identified in the images and are used with a transformation matrix to calculate the three-dimensional model. The model may then be used to assist physicians in implantation procedures.