The Effect Of Focused Ultrasound On Altering The Diameter Class Of Nerve Fibers Contributing To A Compound Evoked Potential, Analyzed Using A Perturbative Decomposition Technique.

Peripheral neuropathies are disorders that involve the damage of peripheral nerve fibers, affecting the ability of different parts of the body to communicate. A differentiating factor in diagnosis between various clinical conditions can be which size class of nerve fibers are affected. A nerve conduction velocity test can be used to assess the viability of the nerve but is a single-parameter test and gives no information about the population characteristics of the remaining active fibers. A method developed and previously reported by Szlavik (2016) utilizes a mathematical perturbed decomposition to determine the normalized frequency of each size class of fiber contributing to a compound action potential. In this study, the effects of focused ultrasound and anesthetics on the profile of active fiber diameters are analyzed using the Szlavik method and compared against another method used to estimate the sizes in the fiber population. The sciatic nerves of rats were subjected to focused ultrasound, focused ultrasound and bupivacaine, or focused ultrasound and ropivacaine and stimulated. The resulting compound action potential was recorded and decomposed, using the perturbation method and the action potential amplitude to assess fiber size involved in each potential. The range and variability of results confound the ability to draw decisive conclusions about application of this model this data and the effect of focused ultrasound. This study did show that a perturbative decomposition method for analyzing compound evoked potentials is feasible for vast amounts of data and identified sources of variability to be accounted for and the mathematical functions necessary in further trials

Vacuum Compatibility of 3D-Printed Materials

The fabrication fidelity and vacuum properties are tested for currently available 3D-printed materials including polyamide, glass, acrylic, and sterling silver. The silver was the only material found to be suitable to ultrahigh vacuum environments due to outgassing and sublimation observed in other materials.Comment: 3 pages, 2 figures, preprin