Arthroscopic indenter
AssigneeBoard of Regents, The University of Texas System
InventorsKyriacos Athanasiou, George Constantinides
Life of this patent
Estimating the term…
Abstract
An arthroscopic indenter for measuring creep deformation behavior, stress relaxation behavior and thickness of cartilage in vivo and in situ. A computer-based system measures deformation or force information upon cartilage and processes that information for closed-loop control of an indenter tip while also calculating intrinsic properties associated with the cartilage such as stiffness, compressibility and/or permeability.
Claims11
A computer controlled indenter to measure stress relaxation of cartilage overlying bone comprising:
- a loading shaft having a distal end for placement proximate to the cartilage;
- a system for aligning the loading shaft comprising:
- a frame which can be fixed in relationship to the bone;
- a protective sheath for said loading shaft movably attached to said frame;
- and
- means for detecting reflected light for determining alignment of said sheath;
- and
- means for aligning said sheath substantially perpendicular to said cartilage;
- an electromechanical actuator comprising a motor and adapted to axially move said loading shaft;
- a force transducer adapted to measure a force applied to the cartilage by said loading shaft;
- and
- a computer, operatively connected to said actuator and transducer, to calculate stress relaxation of the cartilage as a function over time of measured force required to maintain said distal end at a set displacement upon the cartilage.
A computer controlled indenter to measure the creep deformation of cartilage overlying bone comprising:
- a loading shaft having a distal end for placement proximate to the cartilage;
- a system for aligning the loading shaft comprising:
- a frame which can be fixed in relationship to the bone;
- a protective sheath movably attached to said frame;
- and
- means for detecting reflected light for determining alignment of said sheath;
- and
- means for aligning said sheath substantially perpendicular to said cartilage;
- an electromechanical actuator comprising a motor and adapted to axially move said loading shaft while maintaining constant force upon the cartilage;
- a positional detector adapted to measure the displacement of said shaft;
- and
- a computer, operatively coupled to said actuator and said positional detector, to calculate creep deformation of the cartilage as a function over time of measured displacement of said shaft at a constant force applied to said loading shaft.
Dependencies are inferred from the claim text.