Southwest Research Institute

Electric Power Research Institute Incorporated

Omron Healthcare Company Ltd.

Keith Alan Bartels

Hegeon Kwun

Glenn M Light

Kevin S Honeyager

Harry H Peel, Iii

Adam C Cobb

Andrew H Stewart

Douglas R Earnest

Larry D Canady, Jr

Edward A Bloom

Richard Franklin Tennis

John J Hanley

K Arun Pandey

Bernard A Clairmont

Xin Chen

A method of in situ measurement of an acoustoelastic constant (L) of a railway rail, using an ultrasonic wedge sensor to measure a stress-free (unloaded) time-of-flight (t) in the vertical direction of the rail. Next, a vertical load of known load value is applied to the rail. While the vertical load is applied, the ultrasonic wedge sensor is used to measure a stressed time-of-flight value. The difference between the stress-free and the stressed time-of-flight is calculated to obtain a time-of-flight difference value (Δt). Based on the load value, the stress-free time-of-flight value, and the time-of-flight difference value, the acoustoelastic constant, L, may be calculated. The wedge sensor may be further used to measure the (stressed) horizontal time of flight, and a time-of-flight difference value in the horizontal direction may be used to measure longitudinal stress.

Reference-free load-modulated longitudinal rail stress measurement using ultrasonic LCR waves

Methods and systems for determining cardiovascular parameters of a patient. In an exemplary embodiment, the method includes placing a phonocardiogram sensor on a patient's body at a first distal location to the heart, and a blood-pressure waveform sensor at a second distal location to the heart. Then, a first set and a second set of waveforms is obtained from the phonocardiogram sensor and the blood-pressure waveform sensor, respectively. A signal processing or conditioning operation may optionally be performed using the first and second sets of waveforms. Then, a time delay between a dicrotic notch signal and an S2 signal is determined. A blood pressure pulse transit time value is calculated by adding S2D, representing a time delay between a patient's heart valve closure time and an arrival time of the S2 signal at the first distal location, to the time delay between a dicrotic notch signal and an S2 signal. Cardiovascular parameters are then determined using the determined blood pressure pulse transit time and at least one physical parameter representative of a arterial distance between a location of the aortic valve and a location of the blood-pressure waveform sensor.

Methods and systems for distal recording of phonocardiographic signals

In one embodiment the present invention provides a device for monitoring a cable, comprising an imaging device having a field of view; a target, distinguishable within the field of view of the imaging device, associated with a cable; and a computer processor connected to the imaging device for analyzing images of the target produced by the imaging device to determine a position of the cable. In another embodiment, the present invention provides a method for monitoring a cable, comprising calibrating a first image of a predetermined field of view showing a portion of a cable to be monitored; capturing a second image of the predetermined field of view; correlating the first image with the second image to determine a position of the portion of the cable within the second image; and reporting said position.

Apparatus and method for monitoring a cable

An uncalibrated sensor located at a first location relative to a physical phenomenon is calibrated using a calibrated sensor spaced away from the uncalibrated sensor at a second location relative to the physical phenomenon and a frequency-domain transfer function that relates the physical phenomenon at the second location to the output of the uncalibrated sensor.

Systems and methods for calibrating a distorted signal with another signal of known calibration

An improved method for defect detectability for the inspection of liquid filled pipes using magnetostrictive sensors. The improved method comprises first recognizing the liquid-induced changes in the dispersion properties of the second longitudinal wave mode, L(,). These liquid-induced changes include a severe dispersion at periodic branching frequencies that result in a pulse-like characteristic in the extended received signal. A trailing portion of a received signal component associated with a geometric irregularity, is shown to comprise the branching frequency components. The trailing portion of the extended signal may therefore be removed in order to improve defect detection. The removal process comprises one of three alternative methods. A first method includes creating a short duration pulse free of the frequency components that comprise the trailing signals, and applying the pulse to a magnetostrictive transmitter, thereby generating a longitudinal wave signal in the pipe wall free of the trailing signal frequency components. A second method comprises transmitting a broadband signal and processing the detected signal through a digital filter that eliminates those frequency components known to comprise the trailing signals. A third method involves using a signal whose bandwidth lies in the region between two adjacent branching frequencies in the dispersion curve. The result is a detected signal within which components representative of irregularities are less extended and therefore less likely to override subsequent defect components in the detected signal.

Method for inspecting liquid filled pipes using magnetostrictive sensors

An improved method for defect detection with systems using magnetostrictive sensor techniques. The improved method involves exciting the magnetostrictive sensor transmitter by using a relatively broadband signal instead of a narrow band signal typically employed in existing procedures in order to avoid signal dispersion effects. The signal detected by the magnetostrictive sensor receiver is amplified with an equally broadband signal amplifier. The amplified signal is transformed using a time-frequency transformation technique such as a short-time Fourier transform. Finally, the signal characteristics associated with defects and anomalies of interest are distinguished from extraneous signal components associated with known wave propagation characteristics. The process of distinguishing defects is accomplished by identifying patterns in the transformed data that are specifically oriented with respect to the frequency axis for the plotted signal data. These identified patterns correspond to signals from either defects or from known geometric features in the pipe such as welds or junctions. The method takes advantage of a priori knowledge of detected signal characteristics associated with other wave modes (such as flexural waves) and sensor excitation as well the effects caused by liquid induced dispersion.

Method for improving defect detectability with magnetostrictive sensors for piping inspection

The average wall thickness and the wall-thickness variation of a liquid-carrying pipe are determined. An elastic wave is generated and is measured after traveling a distance along the pipe. From the received wave, the average radius of the pipe, the average inside diameter of the pipe, and the inside diameter variation of the pipe are determined. From the average radius of the pipe and the average inside diameter of the pipe, the average wall thickness of the pipe is determined. From the variations in the average radius of the pipe and the inside diameter variation of the pipe, the wall-thickness variation of the pipe is determined. To determine the average inside diameter of the pipe, the invention relies upon the coupling between the elastic wave modes propagating in the wall of the pipe and the modes propagating in the liquid within the pipe.

Determining average wall thickness and wall-thickness variation of a

An apparatus and method for the non-contact measurement of tensile loading (or tension) in ferromagnetic materials, particularly wire ropes, cables, and strands. The magnetostrictive effect is used to measure wave propagation properties within such materials to determine load forces imposed on the tested material based upon a signature obtained for like materials under like conditions. The apparatus and method contemplate an active measurement application, wherein a transmitting sensor generates an mechanical pulse within a material through the magnetostrictive effect, and a receiving sensor detects reflected mechanical waves within the material by the inverse magnetostrictive effect. Unlike other sensing methods, utilizing the magnetostrictive effect in this way has the advantage of generating and detecting mechanical waves in the tested material without direct physical or acoustical contact. The apparatus and method of the present invention also anticipates the use of a long-term monitoring system that records acquired tensile load measurements for detection of possible structural anomalies and immediate activation of an alarm, or storage and retrieval/analysis at a later time.

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San Antonio, TX, United States of America

Keith Alan Bartels