Balldin U I, Borgström P
Aviat Space Environ Med. 1976 Feb;47(2):113-6.
Doppler ultrasound was used in five subjects to detect intracardial gas bubbles during decompressions to altitude. At a simulated altitude of 8,000 m, neither intracardial bubbles nor symptoms of decompression sickness occurred. At 9,000 m, bubbles were registered in two subjects, one of which had questionable bends. At 11,500 m, bubbles were registered in all but one subject and two had bends. The three subjects who had not gotten bends were exposed to an air-breathing period of 30 min or, in one case, even 45 min at 2 ATA, for extra nitrogen loading, followed by decompression to 11,500 m. These subjects had heavy showers of bubbles followed by bends. In all cases with decompression sickness during the decompressions to altitude, intracardial bubbles were registered prior to the appearance of symptoms. The technique may be used in studies of decompression sickness without provoking actual symptoms, thus making the studies safer.
在五名受试者身上使用多普勒超声在减压至高空过程中检测心内气泡。在模拟海拔8000米时，既未出现心内气泡，也未出现减压病症状。在9000米时，两名受试者检测到气泡，其中一名有可疑的减压病症状。在11500米时，除一名受试者外，其他受试者均检测到气泡，两名出现减压病症状。三名未出现减压病症状的受试者在2个绝对大气压下进行了30分钟甚至45分钟的呼吸空气时段，以增加氮负荷，然后减压至11500米。这些受试者出现大量气泡，随后出现减压病症状。在所有减压至高空过程中出现减压病症状的病例中，在症状出现之前均检测到心内气泡。该技术可用于减压病研究，而不会引发实际症状，从而使研究更安全。
