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Electric current generated by ultrasonically induced Lorentz force in biological media

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Abstract

The ions of solutions exposed to the propagation of ultrasound in the presence of a magnetic field experience Lorentz force. Their movement gives rise to a local electric current density, which is proportional to the electric conductivity of the medium. In vitro assessment of this current is performed using simple models of biological media. A constant magnetic field of 0.35T and 500kHz pulsed ultrasound are used. The sensing electrodes are exposed to neither the pressure wave nor the magnetic field, thus ensuring that the signal is not due to any undesirable electrode effect. The experimental results confirm that the current is proportional to the electrical conductivity of the medium. The changes in the measured current against the width of the measurement chamber show that the electrodes only collect fraction of the current created within the medium. The magnitude of the measured current is 50nA in a saline solution of 0.5S/m conductivity. The technique enabled the determination of the conductivity of a porcine blood sample against haematocrit. It is concluded that this type of measurement has the potential to allow the electrical conductivity of a medium to be determined using ultrasound.

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Abbreviations

a :

distance of a fluid element from its equilibrium position (m)

B :

magnetic induction (T)

c :

celerity of ultrasound (m.s−1)

C :

molar concentration (mol.m−3)

C m :

membrane capacity (F.m−2)

dQ :

elementary charge (C)

dS :

surface element (m2)

dt :

time intervals (s)

d τ :

volume element (m3)

f :

ultrasound frequency (Hz)

F :

molar charge, 1 faraday (96487 C.mol−1)

i(t) :

electric current (A)

I :

magnitude of the instantaneous current (A)

j :

base of imaginary numbers

j y :

current density along axis Oy (A.m−2)

J :

magnitude of the instantaneous current density (A.m−2)

m :

ionic mass (kg)

M :

molar mass of a solvated ion (kg.mol−1)

n :

ionic charge

q :

electric charge (C)

q e :

electron charge (1.602 10–19 C)

r :

radius of a cell (m)

t :

time (s)

p :

instantaneous acoustic pressure (Pa)

P :

magnitude of the acoustic pressure (Pa)

u y ,u z :

instantaneous ionic speed along axes Oy, Oz, respectively (m.s−1)

U y ,U z :

magnitude of ionic speed along axes Oy, Oz, respectively (m.s−1)

v z :

instantaneous speed of a fluid element along axis Oz (m.s−1)

V z :

magnitude of the speed of a fluid element (m.s−1)

x, y, z :

Cartesian co-ordinates

μ:

ion mobility (m2.s−1. V−1)

σ:

mass density (kg.m−3)

σ:

electric conductivity (S.m−1)

σ1 :

electric conductivity of the interior of erythrocytes (S.m−1)

σp :

electric conductivity of plasma (S.m−1)

ϕ:

volume concentration of the particles in a suspension

Ψ:

phase angle (rd)

ω:

angular frequency (rd.s−1)

References

  • Cataldo, F. (1997): ‘Effects of ultrasound on the electrolytic conductivity of simple halide salts’,J Electroanal. Chem.,431, pp. 61–65

    Article  Google Scholar 

  • Cole, K. S. (1941): ‘Impedance of single cells’,Tabulae Biologice,19, pp. 24–27

    Google Scholar 

  • Cole, K. S. (1972): ‘Membrane capacity’ in ‘Membranes, ions and impulses’ (University of California Press, Los Angeles), Part 1, pp. 6–113

    Google Scholar 

  • Debye, P. (1933): ‘A method for the determination of the mass of electrolytic ions’,J. Chem. Phys.,1, pp. 13–16

    Article  Google Scholar 

  • Eyraud, C., Thomasset, A., Lille, R., andBerthe, D. (1967): ‘Caractérisation, par méthode électrique, d'un suspensoïde capacitif. Application à un milieu d'hématies de sang humain’,Acad. Sci. Paris,265, pp. 508–511

    Google Scholar 

  • Fox, F., Herzfeld, K. F., andRock, G. D. (1946): ‘The effect of ultrasonic waves on the conductivity of salt solutions’,Phys. Rev.,70, pp. 329–339

    Google Scholar 

  • Fry, W. (1968): ‘Electrical stimulation of brain localized without probes — Theoretical analysis of a proposed method’,J. Acoust. Soc. Am.,44, pp. 919–931

    Google Scholar 

  • Giriuniene, R., andGarska, E. (1997): ‘The influence of ultrasound on electrical conductivity of water’,Ultragarsas,2, pp. 25–27

    Google Scholar 

  • Jossinet, J., Lavandier, B., andCathignol, D. (1998): ‘The phenomenology of acousto-electric interaction signals in aqueous solutions of electrolytes’,Ultrason.,36, pp. 607–613

    Google Scholar 

  • Lavandier, B., Jossinet, J., andCathignol, D. (2000): ‘Quantitative assessment of ultrasound-induced resistance change in saline solution’,Med. Biol. Eng. Comput.,38, pp. 150–155

    Google Scholar 

  • Millner, R., andMüller, H. D. (1966): ‘Zum Debye-Effekt in Iönenlösungen’,Ann. Phys.,17, pp. 160–165

    Google Scholar 

  • Pauly, H. (1959): ‘Electrical conductance and dielectric constant of the interior of erythrocytes’,Nature,183, pp. 333–334

    Google Scholar 

  • Pethig, R. (1984): ‘Dielectric properties of biological materials: Biophysical and medical applications’,IEEE Trans. Electr. Insul.,EI-19, pp. 453–474

    Google Scholar 

  • Rabah, H., Prieur, G., Rouané, A., Kourtiche, D., Hedjiedj, A., andBarritault, L. (1994): ‘Interaction des champs électriques et acoustiques: approche mathématique et premiers résultats expérimentaux acoustiques: approche mathématique et premiers résultats expérimentaux pour une application éventuelle en stimulation transcutanée’,Innov. Tech. Biol. Méd.,15, pp. 49–59

    Google Scholar 

  • Rosenfeld, E. H. (1992): ‘Ultrasonic vibrational potentials in gels and preparations of biological tissue’,Ultrasound Med. Biol.,18, pp. 607–615

    Article  Google Scholar 

  • Roth, B. J., Basser, P. J., andWikswo, J. P. (1994): ‘A theoretical model for magneto-acoustic imaging of bioelectric currents’,IEEE Trans.,BME-41, pp. 723–728

    Google Scholar 

  • Towe, C., andIslam, M. R. (1998): ‘A magneto-acoustic method for the noninvasive measurement of bioelectric currents’,IEEE Trans.,BME-35, pp. 892–894

    Google Scholar 

  • Wells, P. N. T. (1977): ‘Longitudinal waves’ in ‘Biomedical ultrasonics’ (Academic Press, London), Chap. I, ‘Wave fundamentals’, pp. 3–25

    Google Scholar 

  • Wen, H., Shah, J., andBalaban, R. S. (1997): ‘An imaging method using the interaction between ultrasound and magnetic field’, Proc. IEEE Ultrasonics Symp., pp. 1407–1410

  • Wen, H., Shah, J., andBalaban, R. S. (1998): ‘Hall effect imaging’,IEEE Trans.,BME-45, pp. 119–124

    Google Scholar 

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Authors and Affiliations

  1. National Institute for Health and Medical Research, Lyon, France

    A. Montalibet, J. Jossinet, A. Matias & D. Cathignol

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  1. A. Montalibet
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  2. J. Jossinet
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  3. A. Matias
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  4. D. Cathignol
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Correspondence to A. Montalibet.

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Montalibet, A., Jossinet, J., Matias, A. et al. Electric current generated by ultrasonically induced Lorentz force in biological media. Med. Biol. Eng. Comput. 39, 15–20 (2001). https://doi.org/10.1007/BF02345261

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  • DOI: https://doi.org/10.1007/BF02345261

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