[abstract] PHOTODETECTOR FOR INTRAVASCULAR BUBBLES.

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[abstract] PHOTODETECTOR FOR INTRAVASCULAR BUBBLES.

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Title: [abstract] PHOTODETECTOR FOR INTRAVASCULAR BUBBLES.
Author: Butler, BD; Hills, BA
Abstract: A technique for intravascular bubble detection has been devised to quantify intravascular gas emboli in experimental animal preparations. The method employs a planar diffused photodetector-amplifier combination attached to a clean plexiglass viewing cuvette through which arterial or venous blood is circulated extracorporeally. Illumination is provided by fiber optics at either a 90 degree or 180 degree angle, depending upon bubble size and cuvette shape. Light reflected off the circulating bubble is picked up by the photodetector - a standard silicon diffused photodiode. When the reflected light from the bubble strikes the semiconductor junction, a contact is made to both sides of the junction and a current is generated - the "Photovoltaic Effect" When amplified, this current is fed into a standard chart recorder and a positive deflection noted. The system can be operated in two modes: to detect deflection of the incident beam, while through-transmission is preferred for larger bubbles. In vivo trials have shown that normal blood components do not reflect light at an intensity comparable to that of bubbles and therefore do not activate the detector. Microscopic observations through the viewing cuvette adjacent to the detector have verified corresponding current generations with bubble presence. This method has enabled bubbles of 75 um diameter to be detected with ease and has a limit in the range 50 um so it is ideal for monitoring gas emboli capable of arterial occlusion.
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held May 13-16, 1977. Holiday-Inn, Toronto, Ontario, Canada (http://www.uhms.org)
URI: http://archive.rubicon-foundation.org/4132
Date: 1977

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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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