[abstract] DECOMPRESSION BUBBLES AND DOPPLER: ENHANCEMENT OF BUBBLE GRADE ANALYSIS WITH DIGITIZED SIGNALS.

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[abstract] DECOMPRESSION BUBBLES AND DOPPLER: ENHANCEMENT OF BUBBLE GRADE ANALYSIS WITH DIGITIZED SIGNALS.

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Title: [abstract] DECOMPRESSION BUBBLES AND DOPPLER: ENHANCEMENT OF BUBBLE GRADE ANALYSIS WITH DIGITIZED SIGNALS.
Author: Butler, BD; Fife, C
Abstract: We have previously introduced a simple inexpensive sound digitizer for visualizing Doppler bubble recordings. This visual adjunct to audio bubble recordings can assist in resolving discrepancies in bubble grading that can occur even with experienced listeners. More recent upgrades have improved the utility of this device. Real-time or playback Doppler recordings can be visualized as original or reconstructed waveforms or as a graph of the frequencies of the recorded signal. A newer option is the spectrogram, which presents the bubble sounds as a map of the relative strength of the frequencies. Frequency patterns of bubble signals can be distinguished from similar sounds such as those caused by valve motion. By identifying background cardiac sound and valve motion sound frequency patterns, one can distinguish these patterns from those of bubbles. A second feature useful for Doppler bubble signal discrimination is the color sonogram which is a color scale map of the relative strengths of the frequencies. This function includes emphasis simulation of a high pass filter effect that allows for enhancement of the high frequency range, usually associated with bubbles, and reduction of the relative strength of the low frequency ranges. These functions assist in discriminating bubble signals from other sounds difficult to distinguish by audio interpretation alone. Examples of these functions and bubble sound discrimination are presented. Supported in part by NASA NAG 9-215.
Description: Abstract of the Undersea and Hyperbaric Medical Society Annual Scientific Meeting held June 19-23, 1991 at San Diego Princess Resort, San Diego, CA.
URI: http://archive.rubicon-foundation.org/7474
Date: 1991

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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