Ultrasonic transit-time system for arterial diameter measurement
Tóm tắt
An ultrasonic transit-time micrometer has been developed to measure pulsatile changes in arterial diameter with sufficient accuracy to verify haemodynamic theories. The instrument samples up to four distances at repetition frequencies above 1 kHz and is calibrated by a separate determination of the velocity of ultrasound in blood. New methods of transmitter pulse triggering and received pulse amplification and detection, and construction and testing of small arterial transducers, are described. The system will resolve distance changes smaller than 1 μm and will run continuously for long periods without temperature drift. Trials by measurement of the dynamic distension of a long water-filled rubber tube and comparison with the manometrically measured phase velocity showed that the technique yields results within the range of predicted values from pulsatile flow theory.
Tài liệu tham khảo
Aars, H. (1969) Relationship between blood pressure and diameter of ascending aorta in normal and hypertensive rabbits.Acta Physiol. Scand. 75, 397–405.
Aars, H. (1971) Diameter and elasticity of the ascending aorta during infusion of noradrenaline.83, 133–138.
Bergel, D. H. (1961) The dynamic elastic properties of the arterial wall.J. Physiol. 156, 458–469.
Bertram, C. D. (1974) Ultrasonic arterial diameter measurement.241, 85–87P.
Cheney, S. P., Lees, L., Gerhard, F. B. Jun. andKranz, P. R. (1973) Step excitation source for ultrasonic pulse transducers.Ultrasonics 11, 111–113.
Cox, R. H. (1969) Comparison of linearized wave propagation models for arterial blood flow analysis.J. Biomech. 2, 251–265.
Goldman, D. E. andRichards, J. R. (1954) Measurement of high-frequency sound velocity in mammalian soft tissues.J. Acoust. Soc. Amer. 26, 981–983.
Gow, B. S. (1966) An electrical caliper for measurement of pulsatile arterial diameter changesin vivo.J. Appl. Physiol. 21, 1122–1126.
Hokanson, D. E., Mozersky, D. J., Sumner, D. S. andStrandness, D. E. Jun. (1972) A phase-locked echo tracking system for recording arterial diameter changesin vivo.32, 728–733.
Hutchison, K. J. (1974) Effect of variation of transmural pressure on the frequency response of isolated segments of canine carotid arteries.Circulation Res. 35, 742–751.
Leraand, S. (1970) An ultrasonic technique forin vivo distance measurements. Proceedings of the 1st Nordic Meeting on Medical & Biological Engineering, 187–190.
Mallos, A. J. (1962) Electrical caliper for continuous measurement of relative displacement.J. Appl. Physiol. 17, 131–134.
McGough, G. A., Breazeale, D., Mullins, G. L. andGuntheroth, W. G. (1973) An ultrasonic displacement instrument with greater beam dispersal.Cardiovasc. Res. 7, 713–718.
Moritz, W. E. (1969) Transmission characteristics of distension, torsion, and axial waves in arteries. SUDAAR Report 373, Stanford University.
Murgo, J. P., Cox, R. H. andPeterson, L. H. (1971) Cantilever transducer for continuous measurement of arterial diameterin vivo.J. Appl. Physiol. 31, 948–953.
Myers, G. H., Thumin, A., Feldman, S., de Santis, G. andLupo, F. J. (1972) A miniature pulser-preamplifier for ultrasonic transducers.Ultrasonics 10, 87–89.
Redwood, M. (1963) A study of waveforms in the generation and detection of short ultrasonic pulses.Appl. Mat. Res. 2, 76–84.
Stinson, E. B., Rahmoeller, G. andTecklenberg, P. L. (1974) Measurement of internal left ventricular diameter by a tracking sonomicrometer.Cardiovasc. Res. 8, 283–289.
Womersley, J. R. (1955) Oscillatory motion of a viscous liquid in a thin-walled elastic tube—I: The linear approximation for long waves.Phil. Mag. 46, 199–221.
Womersley, J. R. (1957a) The mathematical analysis of the arterial circulation in a state of oscillatory motion. Wright Air Development Center, Technical Report WADC-TR56-614.
Womersley, J. R. (1957b) Oscillatory flow in arteries: the constraned elastic tube as a model of arterial flow and pulse transmission.Physics Med. Biol. 2, 178–187.