TINY BUBBLES: A PRIMER ON DOPPLER BUBBLE DETECTION

Authors
  1. Nishi, R.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
A considerable amount of interest in recent years has arisen in Doppler ultrasonic bubble detection and its application to decompression research and diving operations. As a result, there are some misunderstandings about the role of bubbles that can be detected by the Doppler instruments and the relationship between Doppler-detected bubbles and decompression sickness (DCS). The Doppler ultrasonic bubble detector is the simplest, most convenient and most practical method for observing bubbles in humans but it can only detect intravascular bubbles, i.e., bubbles moving through the circulatory system, and requires skilled personnel to use and interpret the bubble signals. An analysis of over 3200 man-dives shows that the risk of DCS is low when no bubbles or only a few are detected. However, for high bubble levels, there is a much higher risk of DCS. In the data set studied, 90% of the cases of DCS were associated with Grades 3 or 4 bubbles. It should be emphasized that intravascular bubbles are not believed to be the direct cause of the signs and symptoms in all cases of DCS. They are, however, an indicator of a high inert gas load in the body and, as a result, their presence reflects the risk of DCS. Dives which produce high levels of bubbles can be considered to have high "decompression stress". The primary use of Doppler is as a research tool for post-dive assessment of dive profiles. TRUNCATED
Report Number
DCIEM-92-62 — Reprint
Date of publication
01 Dec 1992
Number of Pages
8
Reprinted from
AquaCorps J, no 5, l993
DSTKIM No
93-04400
CANDIS No
134702
Format(s):
Hardcopy;Originator's fiche received by DSIS

Permanent link

Document 1 of 1

Date modified: