Method of calibration for the representation of knee kinematics and harness for use therewith

• US 7,481,780 B2
• Filed: 12/11/2002
• Issued: 01/27/2009
• Est. Priority Date: 12/11/2001
• Status: Expired due to Fees

• Current Assignee: Centre hospitalier de l'Université de Montréal, Ecole de technologie superieure, Polyvalor, Socit En Commandite
• Original Assignee: Centre hospitalier de l'Université de Montréal, Ecole de technologie superieure, Polyvalor, Socit En Commandite
• Inventors: Parent, Gerald, St-Onge, Nancy, Anguelov, Borislav, Koller, Annick, Hagemeister, Nicola, El Maach, Ismail, Duval, Nicolas, Yahia, L'Hocine, De Guise, Jacques A.
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): HOEKSTRA, JEFFREY GERBEN
• Application Number:
  US10/497,170
• Publication Number:
  US 20050143676A1
• Time in Patent Office: 2,239 Days
• Field of Search: 600/595, 600/587, 600/594, 703/11, 606/102
• US Class Current: 600/595
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6828 Leg
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses

Abstract

A method for creating a frame of reference of a leg of a subject for subsequent 3-D kinematic analysis of the leg with non-invasive trackable references secured to the femur and the tibia of the leg. The method comprises the steps of: i) obtaining tibial and femoral axes with respect to the trackable references by tracking points and motions of the leg; ii) registering a known posture of the subject with respect to the trackable references; iii) obtaining a desired posture of the subject with respect to the trackable references as a function of the known posture by tracking a predetermined motion of the leg; and iv) setting a frame of reference to said tibial and femoral axes of the leg in the desired posture of the subject with respect to the trackable references.

Claims

1. A method for creating a frame of reference of a leg of a subject for subsequent 3-D kinematic analysis of the leg with non-invasive trackable references secured to the femur and the tibia of the leg, comprising the steps of:

i) obtaining tibial and femoral axes with respect to the trackable references by tracking points and motions of the leg, the femoral axis intersecting a femoral head center and a knee reference point, and the tibial axis intersecting said knee reference point and a tibial reference point;

ii) registering a known posture of the subject with respect to the trackable references, the known posture having the subject standing against a wall with the feet in a known position, such that a frontal plane of the subject is parallel to the wall and a sagittal plane of the subject incorporates a normal to the frontal plane and a vector intersecting the femoral head center and the tibial reference point;

iii) obtaining a desired posture of the subject with respect to the trackable references as a function of the known posture by tracking a predetermined motion of the leg, said predetermined motion of the leg including flexion/extension motions, the desired posture being obtained at a full extension with respect to said tibial and femoral axes, such that the frame of reference includes a tibial coordinate system originating from the knee reference point and having said tibial axis, a second tibial axis perpendicular to said tibial axis and lying in the sagittal plane and a third tibial axis perpendicular to said tibial axis and the second tibial axis, and a femoral coordinate system originating from the knee reference point and having said femoral axis, a second femoral axis perpendicular to said femoral axis and lying in the sagittal plane and a third femoral axis perpendicular to said femoral axis and the second femoral axis;

iv) setting a frame of reference to said tibial and femoral axis of the leg in the desired posture of the subject with respect to the trackable references;

v) tracking movement of the leg with respect to the frame of reference of the leg; and

vi) performing a 3-D kinematic analysis of the leg using said movement of the leg to establish a diagnosis.

2. The method according to claim 1, wherein the feet in the known position are positioned in a template.

3. The method according to claim 1, wherein the known position of the feet includes the foot of the referenced leg being position in elevation such that a predetermined angle between said femoral axis and tibial axis is obtained.