The atraumatic detection of blood impurities such as charcoal particles has potential importance in the monitoring of extracorporeal blood flow for hemodialysis systems using carbon slurry in the dialisate and for blood detoxification using carbon columns. It is shown that existing clinical ultrasound Doppler systems can detect carbon particles whose diameter is comparable to that of an erythrocyte in concentrations as low as 1.5 times 10−6 g/ml in less than one second. It is shown that for particle detection in flow, Doppler systems are more sensitive than pulse echo systems of equivalent resolution by the ratio of the velocity of sound to that of the flow.
MorseP. M.IngardK. U., Theoretical Acoustics. Chapt. 8, p. 427, (McGraw-Hill, New York, NY, 1968).
3.
AhujaA. S., Effect of particle viscosity on propagation of sound in suspensions and emulsions, J. Acoust. Soc. Amer. 51, 182 (1972).
4.
SigelmannR. A.ReidJ. M., Analysis and measurements of ultrasound backscattering from an ensemble of scatterers excited by sine wave bursts, J. acoust. Soc. Amer. 53, 1351 (1973).
5.
ShungK. K.SigelmannR. A.ReidJ. M., The Scattering of Ultrasound by Red Blood Cells, in Ultrasonic Tissue CharacterizationLinzerI. M., ed., National Bureau of Standards Spec. Publ. 453, pp. 207–212, (U. S. Printing Office), Washington, DC, (1976).
6.
ShungK. K.SigelmannR. A.ReidJ. M., The angular dependence of the scattering of ultrasound by blood, IEEE Trans. on Biomed. Eng. BME, Vol. 24, July (1968).
7.
HillJ. B.TorresC. R., The B-D Hemodetoxifier: Particulate Release and It's Significance, in Artificial Kidney, Artificial Liver and Artificial Cells, ChangT. M., ed., pp. 199–207 (Plenum Publishing Corp., New York, NY), 1978).
8.
MoleL. A.HunterJ. L.DavenportJ. M., Scattering of sound by air bubbles in water, J. Acoust. Soc. Amer. 52, 837 (1972).
9.
SmithK. H.SpencerM. P., Doppler indices of decompression sickness: their evaluation and use, Aerospace Med., 41, 1396 (1970).
10.
SpencerM. P.ClarkH. F., Precordial Monitoring of Pulmonary Gas Embolism and Decompression Bubbles, Aerospace Med. 43, 762–767 (1972).
11.
GillisM. F.PetersonP. L.KaragianesM. T., In vivo detection of circulating gas emboli associated with decompression sickness using the Doppler flowmeter, Nature, 217, 965 (1968).
12.
Parks Elctronics Laboratory, Beaverton, Oregon 97005, Directional Doppler System Model 806-C.
