University Technologies International, Inc.

Cyril B Frank

Nigel G Shrive

Erich Damson

Sridhar Krishnan

Norman S Schachar

Fred Lhenen

Douglas B Bell

Rangaraj M Rangayyan

Roger W McPherson

Computer-assisted auscultation of knee joints by auditory display of vibroarthrographic signals emitted during active movement of the leg include audification and sonification. In audification, the vibroarthrographic signals are scaled in time and frequency using a time-frequency distribution to facilitate aural analysis. In sonification, the instantaneous mean frequency and envelope of the vibroarthrographic signals are derived and used to synthesize sounds that may facilitate more accurate diagnosis than the original signals by improving their aural quality.

Auditory display of knee joint vibration signals

A device and method for the measurement of stiffness of cartilage, specifically intended for arthroscopic use. An tissue softness probe is formed from a stiff shaft and flexible shaft, and strain gauges continuously measure the load in the stiff shaft and the deflection of the flexible shaft as they are displaced into cartilage. The stiff shaft and flexible shaft extend away from a probe body beside each other. The stiff shaft is semi-circular in section at one end with a flat side extending along the shaft at that end, and the flexible shaft is a flat shim that is attached to the flat side of the stiff shaft. Such a design advantageously allows the more or less parallel shafts to be inserted into a human body joint for displacement against cartilage, as for example during arthroscopic surgery. The stiff shaft terminates in a plunger extending at right angles to the stiff shaft, with the tip of the plunger lying, in the rest position, between a forked tip of the flexible shaft. In operation, as the plunger tip is displaced into cartilage, the flexible shaft gradually deflects providing a continuous read out from the strain gauge that is indicative of the relative displacement of the plunger tip as it is displaced into the cartilage. Both shafts are mounted to be enclosed within a retractable hollow cannula extending from the probe body.

Tissue softness probe

Growing community of inventors

Calgary, Canada

Cyril B Frank