Abstract: 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 (t0) 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 (?t). 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Methods and systems for determining physiological parameters from body sounds obtained from a person's ear. In various exemplary embodiment, the system includes an earplug housing; a sensing element disposed within a portion of the earplug housing; an acoustic shield coupled to the earplug housing, the acoustic shield reducing or eliminating extracorporeal sounds; and a preamplification circuit electrically coupled to the sensing element. In various exemplary embodiments, the system is operable to determine motion and/or vibration of the external acoustic meatus or the tympanic membrane of the ear due to internally generated body sounds.

Abstract: 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.

Abstract: 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(0,2). 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.

Abstract: 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.

Abstract: An improvement is provided for an embossing machine of the type having a rotating dual die character wheel assembly. The die character wheels are mounted independently from their outer surfaces within the embossing machine so that a completely unobstructed region exists between the character wheels. This allows a workpiece to be marked to pass unimpeded through the region so that the entire workpiece is capable of being marked. Pinion gears are provided at the outer periphery of the character wheels which engage ring gears mounted on the character wheels whereby the character wheels are rotated simultaneously.

Abstract: 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.