Accession Number : AD0787493

Title :   A Range-Gated Pulse-Echo Ultrasonic System for Detection of Bubbles in Decompression Sickness.

Descriptive Note : Medical research progress rept. no. 6,

Corporate Author : NAVAL MEDICAL RESEARCH INST BETHESDA MD

Personal Author(s) : Ulrich,Wesley D. ; Carey,William M.

Report Date : MAR 1974

Pagination or Media Count : 35

Abstract : A range-gated pulse-echo ultrasonic bubble detector was designed around a commercial neurological midline detector. The sensitivity of the system was tested with known numbers of glass beads suspended in water. The experimentally determined sensitivity of the device to single electrolytically produced gas bubbles was 79 - 16 log a. The clinical utility of the system for detecting decompression sickness was tested in 13 unanesthetized rabbits which had been subjected to air dives. Ten of the fourteen air dives (20 and 30 minutes at 100 PSIG with three minute linear decompression schedules) were lethal. Seven of the ten showed an ultrasonic decrease of ten or more db. Three were false negatives. Evaluation of the system for use in human beings showed that a substantial bubble population lying two to four centimeters below the skin should be necessary for detection. (Modified author abstract)

Descriptors :   *Hyperbaric conditions, *Decompression sickness, *Ultrasonics, *Medical equipment, Diving, Rabbits, Bubbles, Medical research, Laboratory animals, Stress(Physiology), Humans, Experimental data, Detectors

Subject Categories : Stress Physiology
      Medical Facilities, Equipment and Supplies

Distribution Statement : APPROVED FOR PUBLIC RELEASE