Biomedical Engineering and Bioengineering Commons^™

Characterization And Implementation Of Low Intensity Pulsed Ultrasound As A Tool To Apply Physical Load To Scaffolds And Bone Cells For Fracture Repair, Scott Frazee

Master's Theses

One current challenge in treating bone fractures is the effective treatment of non-unions and delayed unions. Low Intensity Pulsed Ultrasound (LIPUS) has been approved by the FDA to treat fresh fractures since 1994 and non-unions since 2000 and is an attractive treatment option because it is non-invasive. The mechanism by which it works, however, is not well understood; what is known is largely confined to the resultant changes in chemical output of cells. In this thesis several concepts and techniques were brought together to investigate the following hypothesis: LIPUS produces a measurable physical load that results in measurable deformation and …

High Power, Low Frequency Ultrasound: Meniscal Tissue Interaction And Ablation Characteristics, Brendan O'Daly, Edmund Morris, Graham Gavin, Conor Keane, John O Byrne, Garrett Mcguinness

Articles

Abstract—This study evaluates high power low frequency ultrasound transmitted via a flat vibrating probe tip as an alternative technology for meniscal debridement in the bovine knee. An experimental force controlled testing rig was constructed using a 20 kHz ultrasonic probe suspended vertically from a load cell. Effect of variation in amplitude of distal tip displacement (242–494 mm peak-peak) settings and force (2.5–4.5 N) on tissue removal rate (TRR) and penetration rate (PR) for 52 bovine meniscus samples was analyzed. Temperature elevation in residual meniscus was measured by embedded thermocouples and histologic analysis. As amplitude or force increases, there is a …

Perforation Of Arterial Tissue Using Kilohertz Frequency Ultrasound Delivered Via Wire Waveguides, Mark Wylie, Garrett Mcguinness, Graham Gavin

Conference Papers

An emerging technology proposes the use of low frequency-high power ultrasound transmitted via wire waveguides for the disruption and ablation of atherosclerotic lesions, more specifically advanced fibrous or calcified plaques such as chronic total occlusions (CTO). This energy delivery selectively ablates rigid diseased tissue by means of direct mechanical contact, cavitation and other forces generated by the intense dynamic pressure fields generated.

The first clinical device using this energy delivery was granted FDA approval in 2007 [1] for the ablation of CTOs and most research to date has focused on ablation and disruption of hard, fibrous or calcified tissues [2]. …

Ultrasound Echo Is Related To Stress And Strain In Tendon, Sarah Duenwald, Hirohito Kobayashi, Kayt E. Frisch, Roderic Lakes, Ray Vanderby Jr.

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

The mechanical behavior of tendons has been well studied in vitro. A noninvasive method to acquire mechanical data would be highly beneficial. Elastography has been a promising method of gathering in vivo tissue mechanical behavior, but it has inherent limitations. This study presents acoustoelasticity as an alternative ultrasound-based method of measuring tendon stress and strain by reporting a relationship between ultrasonic echo intensity (B-mode ultrasound image brightness) and mechanical behavior of tendon in vitro. Porcine digital flexor tendons were cyclically loaded in a mechanical testing system while an ultrasonic echo response was recorded. We report that echo intensity …