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Open Access Publications from the University of California

Electrical Engineering and Computer Science

There are 1574 publications in this collection, published between 1993 and 2024.
Electrical Engineering and Computer Science - Open Access Policy Deposits (1570)

Noninvasive Measurement of Ablation Crater Size and Thermal Injury after CO2 Laser in the Vocal Cord with Optical Coherence Tomography

Objective

To characterize tissue destruction after CO(2) laser-ablation of the vocal cords with the use of optical coherence tomography (OCT).

Study design and setting

OCT was used to image fresh porcine vocal cords after laser ablation. OCT and histology estimates of the ablation crater dimensions and the depth of thermal injury were obtained.

Results

The vocal cord substructures up to 2.29 mm in depth at 10 microm resolution, and the thermal disruption after laser ablation were identified by OCT. OCT and histology estimates of the lesion dimensions showed no significant differences. Crater depth is directly proportional to laser power, whereas crater width and the zone of thermal injury appear to be unrelated to laser power.

Conclusions

OCT may be used to accurately characterize the native states and the laser-induced thermal injury of laryngeal mucosa, within the inherent limitation in its depth of penetration. OCT may be a useful diagnostic and monitoring tool in an otolaryngology practice.

Effects of a fin edge close to a point caustic of a Gregorian antenna

The problem of edge diffraction close to a point caustic is analyzed in a typical dual-reflector Gregorian antenna in offset configuration. The diffraction phenomenon is produced by a perfectly conducting fin located between the feeder and the main reflector. This fin is sometimes used to reduce the coupling between the primary feed and the main reflector. For the sake of simplicity, the two-dimensional case is studied here, but the present technique can also be applied to practical three-dimensional configurations. © 1997 John Wiley & Sons, Inc.

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