Analysis system and method for determining joint equilibrium position

Abstract

A method includes obtaining rotational data and translational data for a joint. The rotational and translational data is indicative of rotational and translational movement of the joint during rotational and translational joint testing, respectively. The rotational and translational joint testing is implemented by a robotic testing apparatus. Respective zero torque points are determined for the rotational and translational movement based on the rotational data and the translational data. The respective zero torque points are combined for the rotational and translational movement to determine an equilibrium position for the joint. A biomechanical characteristic of the joint is ascertained based on an analysis of the equilibrium position.

What is claimed is: 
     
         1 . A method of evaluating a joint of a patient, the method comprising the steps of:
 obtaining, by a processor, rotational data and translational data captured via a robotic testing apparatus for the joint, the rotational and translational data being indicative of rotational and translational movement of the joint during rotational and translational joint testing, respectively, the rotational and translational joint testing being implemented by the robotic testing apparatus, the robotic testing apparatus comprising first and second motors for the rotational and translational movement, respectively;   determining, by the processor, an equilibrium position for the joint based on the rotational data and the translational data; and   ascertaining, by the processor, a biomechanical characteristic of the joint based on an analysis of the equilibrium position to provide an assessment of joint condition.   
     
     
         2 . The method of  claim 1 , wherein determining the equilibrium position comprises computing the equilibrium position as a function of the rotational data and the translational data. 
     
     
         3 . The method of  claim 1 , wherein determining the equilibrium position comprises determining, by the processor, respective neutral positions for the rotational and translational movement using endpoints for each of the rotational and translational movement. 
     
     
         4 . The method of  claim 1 , wherein determining the equilibrium position comprises determining, by the processor, respective neutral positions for the rotational and translational movement using a peak positive position and a peak negative position for each of the rotational and translational movement. 
     
     
         5 . The method of  claim 1 , wherein determining the equilibrium position comprises determining, by the processor, respective neutral positions for the rotational and translational movement using a peak positive torque and a peak negative torque for each of the rotational and translational movement. 
     
     
         6 . The method of  claim 1 , wherein ascertaining the biomechanical characteristic comprises comparing the equilibrium position with preset equilibrium position data. 
     
     
         7 . The method of  claim 1 , wherein ascertaining the biomechanical characteristic comprises comparing the equilibrium position with a boundary differentiating between normal joints and abnormal joints. 
     
     
         8 . The method of  claim 1 , further comprising adjusting a starting position for further rotational or translational joint testing based on the equilibrium position. 
     
     
         9 . The method of  claim 1 , further comprising adjusting a load-deformation curve for the rotational or translational movement based on the equilibrium position. 
     
     
         10 . The method of  claim 1 , further comprising:
 compiling a profile for the joint, the profile including the equilibrium position, the biomechanical characteristic, or both the equilibrium position and the biomechanical characteristic;   accessing a data store in which profile data for abnormal joints is stored; and   comparing the profile with the profile data.   
     
     
         11 . The method of  claim 1 , wherein obtaining the rotational and translational data comprises measuring torque with first and second torque transducers of the robotic testing apparatus during the rotational and translation joint testing, respectively. 
     
     
         12 . A method of evaluating a joint of a patient, the method comprising the steps of:
 obtaining, by a processor, rotational data and translational data captured via a robotic testing apparatus for the joint, the rotational and translational data being indicative of rotational and translational movement of the joint during rotational and translational joint testing, respectively, the rotational and translational joint testing being implemented by the robotic testing apparatus, the robotic testing apparatus comprising first and second motors for the rotational and translational movement, respectively;   determining, by the processor, respective neutral positions for the rotational and translational movement based on the rotational data and the translational data;   combining, by the processor, the respective neutral positions for the rotational and translational movement to determine an equilibrium position for the joint; and   ascertaining, by the processor, a biomechanical characteristic of the joint based on an analysis of the equilibrium position to provide an assessment of joint condition.   
     
     
         13 . The method of  claim 12 , wherein determining the respective neutral positions for the rotational and translational movement uses endpoints for each of the rotational and translational movement. 
     
     
         14 . The method of  claim 12 , wherein ascertaining the biomechanical characteristic comprises comparing the equilibrium position with preset equilibrium position data. 
     
     
         15 . The method of  claim 12 , further comprising adjusting a load-deformation curve for the rotational or translational movement based on the equilibrium position. 
     
     
         16 . The method of  claim 12 , further comprising:
 compiling a profile for the joint, the profile including the equilibrium position, the biomechanical characteristic, or both the equilibrium position and the biomechanical characteristic;   accessing a data store in which profile data for abnormal joints is stored; and   comparing the profile with the profile data.   
     
     
         17 . A method of evaluating a knee of a patient, the method comprising the steps of:
 obtaining, by a processor, varus-valgus rotational data, tibial rotational data, and anterior-posterior translational data captured via a robotic testing apparatus for the knee, the varus-valgus rotational data, the tibial rotational data, and the anterior-posterior translational data being indicative of varus-valgus rotation, external-internal rotation, and anterior-posterior translation of the knee, during joint testing implemented via first through third motors of the robotic testing apparatus, respectively;   determining, by the processor, respective neutral positions for the varus-valgus rotation, the external-internal rotation, and the anterior-posterior translation based on the varus-valgus rotational data, the tibial rotational data, and the anterior-posterior translational data, respectively;   combining, by the processor, the respective neutral positions for the varus-valgus rotation, the external-internal rotation, and the anterior-posterior translation to determine an equilibrium position for the joint; and   ascertaining, by the processor, a biomechanical characteristic of the joint based on an analysis of the equilibrium position to provide an assessment of joint condition.   
     
     
         18 . The method of  claim 17 , wherein determining the respective neutral positions for the varus-valgus rotation, the external-internal rotation, and the anterior-posterior translation uses endpoints for each of the varus-valgus rotation, the external-internal rotation, and the anterior-posterior translation. 
     
     
         19 . The method of  claim 17 , wherein ascertaining the biomechanical characteristic comprises comparing the equilibrium position with preset equilibrium position data. 
     
     
         20 . The method of  claim 17 , further comprising:
 compiling a profile for the knee, the profile including the equilibrium position, the biomechanical characteristic, or both the equilibrium position and the biomechanical characteristic;   accessing a data store in which profile data for abnormal knees is stored; and   comparing the profile with the profile data.