Ultrasonic Bubble-Sizing Instrument

An ultrasonic instrument has been developed for measuring the sizes of bubbles in the human body. A primary example is that of bubbles associated with decompression sickness (the "bends"); these bubbles consist mostly of nitrogen and can occur in both blood vessels and extravascular tissues. The bubbles can lodge (embolize) in vessels in the lungs and elsewhere, causing any of a variety of pathological conditions. Gaseous emboli that cause decompression sickness pose a serious risk of injury to aviators, astronauts, divers, and other individuals who are exposed to varying environmental pressures. Gaseous emboli can also be serious complications of cardiopulmonary bypass operations, introduction of air during cardiotomy, and cavitation bubbles generated by replacement heart valves.