Frequency-Dependent Absorption of Electromagnetic Energy in Biological Tissue

The frequency-dependent absorption of electromagnetic energy in biological tissue is illustrated by use of the Debye equations, model calculations for different irradiation conditions, and measured electrical properties (conductivity and permittivity) of different tissues. Four separate irradiation conditions are treated for calculating the power absorbed. in a given tissue when it forms a flat interface or is surrounded by another tissue. The calculations show that the greatest differential absorption occurs at frequencies between the dominant relaxation frequencies in the two tissues. From rat mammary gland tumor data, the calculations show an optimum frequency range of about 100-500 MHz for microwave hyperthermia treatment of at least these types of tumor.

[1]  C. Cone.  Electroosmotic interactions accompanying mitosis initation in sarcoma cells in vitro. , 1969, Transactions of the New York Academy of Sciences.

[2]  S. P. Spragg,et al.  Dielectric and Electronic Properties of Biological Materials , 1980 .

[3]  K. Foster,et al.  The UHF and microwave dielectric properties of normal and tumour tissues: variation in dielectric properties with tissue water content. , 1980, Physics in medicine and biology.

[4]  R. Damadian.  Tumor Detection by Nuclear Magnetic Resonance , 1971, Science.

[5]  C. Cone.  SECTION OF BIOLOGICAL AND MEDICAL SCIENCES: ELECTROOSMOTIC INTERACTIONS ACCOMPANYING MITOSIS INITIATION IN SARCOMA CELLS IN VITRO* , 1969 .

[6]  K. Foster,et al.  Dielectric properties of tumor and normal tissues at radio through microwave frequencies. , 1981, The Journal of microwave power.

[7]  Balitsky Kp,et al.  RESTING POTENTIAL OF MALIGNANT TUMOUR CELLS. , 1964 .

[8]  D. Schaefer,et al.  Microwave power absorption differences between normal and malignant tissue. , 1980, International journal of radiation oncology, biology, physics.

[9]  S. Schelkunoff.  Electromagnetic fields , 1963 .

[10]  S. Tokuoka,et al.  The membrane potential of the human cancer and related cells. I. , 1957, Gan.

[11]  K. Foster,et al.  Microwave dielectric properties of tissue. Some comments on the rotational mobility of tissue water. , 1977, Biophysical journal.

[12]  H. Schwan.  Electrical properties of tissue and cell suspensions. , 1957, Advances in biological and medical physics.

[13]  William T. Joines,et al.  Broadening of the RF Power-Density Window for Calcium-ion Efflux from Brain Tissue , 1981, IEEE Transactions on Biomedical Engineering.