Colorado State University Research Foundation

Kevin M Labus

Christian Matthew Puttlitz

Kirk C McGilvray

Jakob Wolynski

Hilmi Volkan Demir

Emre Unal

A loading device, a monitoring system, and a method thereof can measure stiffness of a structural member (SM) and monitor progress or property thereof over time. The loading device includes two types of displacement sensors, one type being an antenna. As the SM, which is in a magnetic or electromagnetic field and electromagnetically coupled to the antenna without contact, undergoes displacement under known loads, characteristics of the electromagnetic field coupling between the antenna and the SM change over time due to the displacement of the SM. The shift in the characteristics of the electromagnetic field coupling between the antenna and the SM can be used to determine the displacement of the SM. Based on the changes in the displacement over time, diagnosis of the SM being monitored over an evaluation period can be made. The loading device includes at least one movable frame to apply a preload to the SM.

Loading device for measuring stiffness of structural member over time, monitoring system, and method thereof

Multiple deflections of a structural member (SM) can be measured at multiple locations thereof, which deflections can be used to monitor changes in stiffness over time, using at least one antenna to measure the resonant frequencies at different harmonic frequency numbers of a predetermined radio frequency spectrum. One antenna can include a plurality of coils providing a first coil region that has a maximum sensitive to a first resonant frequency harmonic number and another antenna can include a plurality of coils providing a second coil region that has a maximum sensitivity to a second resonant frequency harmonic number that is different from the first predetermined resonant frequency harmonic number. Using different harmonic resonant frequency numbers, deflections at multiple regions of the SM can be determined concurrently using a plurality of antennae.

Method and system for measuring deflections of structural member at multiple locations using multiple antennae

Multiple deflections of a structural member (SM) can be measured at multiple locations thereof, which deflections can be used to monitor changes in stiffness over time, using an antenna to measure the resonant frequencies at different harmonic frequency numbers of a predetermined radio frequency spectrum. The antenna includes a plurality of coils providing at least a first coil region that has a maximum sensitive to a first resonant frequency harmonic number and a second coil region spaced from the first coil region and that has a maximum sensitivity to a second resonant frequency harmonic number that is different from the first predetermined resonant frequency harmonic number. Using different harmonic resonant frequency numbers, deflections at multiple regions of the SM can be determined concurrently using a single antenna.

Method and system for measuring deflections of structural member at multiple locations and antenna thereof

A loading device, a monitoring system, and a method thereof can measure stiffness of a structural member (SM), such as a bone, and monitor progress or property over time. The loading device includes two types of displacement sensors, one type being an antenna. As the SM, which is in a magnetic or electromagnetic field and electromagnetically coupled to the antenna without contact, undergoes displacement under known loads, characteristics of the electromagnetic field coupling between the antenna and the SM change over time due to the displacement of the SM. The shift in the characteristics of the electromagnetic field coupling between the antenna and the SM can be used to determine the displacement of the SM. Based on the changes in the displacement over time, diagnosis of the SM being monitored over an evaluation period can be made.

A monitoring method and system include an antenna disposed spaced from a structural member (SM), which itself can be the target object or attachable to a target object, without using any in-dwelling strain sensor. The antenna is arranged to not touch the SM in at least the no load condition. As the target object undergoes displacement and/or deformation, the SM undergoes displacement and/or deformation. The SM is juxtaposed, partially contained with, or fully contained within a magnetic or electromagnetic field and electromagnetically coupled to the emitting antenna. Characteristics of the electromagnetic field coupling between the antenna and the SM shift over time due to the displacement and/or deformation applied to the SM. The shift in the characteristics of the electromagnetic field coupling between the antenna and the SM over time can be used to determine the temporal change in deformation and/or displacement of the SM over time to enable diagnosis of the target structural object being monitored.

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Fort Collins, CO, United States of America

Kevin M Labus