Limb volume determination by means of ultrasound

An ultrasonic method and device have been developed and evaluated for 3-D mapping of irregular surfaces. The device is used for limb volume determination, which is needed in the evaluation of physiological blood volume changes during manned space operations. Volume is calculated from several limb cross-sectional areas of known distances. First experiments on earth simulating physiological effects of microgravity have demonstrated clearly the system's ability to measure limb volume and volume changes. The axial resolution in distance measurement is approximately 0.4 mm. Absolute accuracy in cross-sectional area estimate is better than 0.5%. The time needed to measure one plane is about 10 s and a limb segment is scanned in about one min (4 planes). >