Radiofrequency Radiation
Dosimetry Handbook

(Fourth Edition)

Chapter 8. Experimental Dosimetric Data

Experimental data from the literature on the average SAR, SAR distributions, and the temperature-rise distributions on some test animals, human subjects, and phantom models, along with some calculated data, are shown in Figures 8.1-8.47 and Tables 8.1-8.4. References are given in the figure captions and table headings.

Of particular interest is the comparison between measured and calculated values of average SAR. Figures 8.1A and 8.1B show a summary of measured values reported in the literature compared with calculations of average SAR in a block model of an average man. The data lead to the following observations:
  1. Values measured in figurines by Gandhi et al. (1977) are very close to calculated values for frequencies up to about 600 MHz.
  2. Values measured in figurines by Guy et al. (1984) are about a factor of 2 higher than calculated values for frequencies up to about resonance, and above resonance are about equal to calculated values
  3. Values measured in human subjects by Hill (1984), just below resonance in a large TEM cell, are higher than values measured by others in figurines. Also, the values Guy et al. (1984) measured in human subjects, using VLF techniques, are higher than those they measured in figurines. All these human-subject data are a factor of 2-4 higher than calculated values.
  4. The value at 27.12 MHz calculated in the 1132-cell inhomogeneous block model (DeFord et al., 1983) is about 2 times larger than that calculated in the 180-cell homogeneous block model and about the same as that measured in figurines by Guy et al. (1984).
  5. In surmnary, one set of measured data agrees reasonably well with calculated values; three other sets of measured data and DeFord's calculated datum are all higher than the other calculated values by a factor of 2-4.

Figure 8.1 A.
Comparison of measured (experimental) and calculated (theoretical) SAR values for an average man in free space, E polarization.

Figure 8.1 B.
Comparison of measured and calculated SAR values for average man in free space, H and K polarizations. The figure is basically that of Guy et al. (© 1984 IEEE), showing their measurements on scaled figurines compared with the theoretical curve (180-cell block model) and two VLF measurements on human subjects. An approximate average of measured values on human subjects by Hill has been added, also a single value in a 1132-cell inhomogeneous block model of man as calculated by DeFord et al.

A possible explanation of the higher values lies in the very nonuniform distribution of SAR within the body, as explored extensively with thermographic techniques by Guy et al. (1976b, 1984) and illustrated by Figures 8.32 to 8.46. Measured local SAR values are as much as 13 times greater than average SAR values at 450 MHz. In particular the legs, which are relatively thinner and longer than the main trunk of the body, absorb significantly more than the average (see Figures 8.36, 8.46); the reason is explained qualitatively in Section 5.1.5. Since using pulse functions with the moment method to calculate local SAR in block models has been unsatisfactory (Massoudi et al., 1984), average-SAR calculation by the same method may not adequately include the higher local absorption in the legs, thus resulting in lower values of average SAR. Calculated average SARs in prolate spheroidal models, which are very close to those calculated in the block model, also would not account for higher absorption in the legs. Thus the calculated average SARs in both block and spheroidal models might be low because the calculations do not adequately include locally high SAR values. More calculated and measured values are needed to clarify the results.

Figure 8.2.
Calculated and measured values of the average SAR for a human prolate spheroidal phantom; a = 0.875 m, b = 0.138 m, V = 0.07 m³ (Allen et al., 1975).

Figure 8.3.
Calculated and measured values of the average SAR for prolate spheroidal phantom of a sitting rhesus monkey; a = 0.2 m, b = 6.46 cm, V = 3.5 x 10 -3m3 (Allen et al., 1975).

Figure 8.4.
Measured values of the average SAR for a live, sitting rhesus monkey, for six standard polarizations (Allen et al., 1976).

Figure 8.5.
Measured values of the average SAR for saline-filled ellipsoidal phantoms, for six standard polarizations; a = 20 cm, b = 7.92 cm, c = 5.28 cm, = 0.64 S/m (Allen et al., 1976).

Figure 8.6.
Measured values of the average SAR for saline-filled ellipsoidal phantoms, for six standard polarizations; a = 20 cm, b = 7.92 cm, c = 5.28 cm, = 0.54 S/m (Allen et al., 1976).

Figure 8.7.
Measured values of the average SAR for saline-filled ellipsoidal phantoms, for six standard polarizations; a = 20 cm, b = 7.92 cm, c = 5.28 cm, = 0.36 S/m (Allen et al., 1976).

Figure 8.8.
Calculated and measured values of the average SAR for models of an average man, E polarization.

Figure 8.9.
Calculated and measured values of the average SAR for a 96-g rat, K polarization.

Figure 8.10.
Calculated and measured values of the average SAR for a 158-g rat, K polarization.

Figure 8.11.
Calculated and measured values of the average SAR for a 261-g rat, K polarization.

Figure 8.12.
Calculated and measured values of the average SAR for a 390-g rat, K polarization.

Figure 8.13.
Calculated and measured values of the average SAR for models of a rat, H polarization.

Figure 8.14.
Calculated and measured values of the average SAR for models of a rat, K polarization.

Figure 8.15.
Calculated and measured values of the average SAR for models of a rat, E polarization.

Figure 8.16.
Comparison of free-space absorption rates of five human subjects with each other and with two standard theories (Hill, 1984).

Figure 8.17.
Comparison of the grounded absorption rates of five human subjects with each other and with two standard theories (Hill, 1984).

Figure 8.18.
The frequency dependence of the average absorption rates for five human subjects in the EKH and EHK orientations under both free-space and grounded conditions (Hill, 1984).

Figure 8.19.
Measured relative SARs in scaled saline spheroidal models of man. To emphasize the differences in the absorption characteristics, the values are normalized with respect to their far-field value at d/ = 0.5. T is the temperature rise in the saline solution after exposure for time t (Iskander et al., 1981).

Figure 8.20
Measured relative SARs in scaled saline spheroidal models versus distance. SAR values for the different models are normalized with respect to their planewave value. T is the temperature rise in the saline solution after exposure for time t (Iskander et al., 1981).

Figure 8.21.
Measured relative fields versus distance for the thick monopole on a ground plane. The values of E and H are normalized with respect to their values at d/ = 0.6 (Iskander et al., 1981).

Figure 8.22
Microwave absorption profiles for rhesus monkey model. Irradiation frequency was 1.29 GHz. Vertical bars represent ± in the calculated value of the SAR (Olsen et al., 1980).

Figure 8.23
Profiles of electromagnetic absorption in the sitting rhesus model at 225 MHz. Vertical bars represent ±1 SD (N=3) in calculated mean SAR (Olsen and Griner, 1982).

Figure 8.24.
Normalized microwave absorption profiles in man-size model at 2.0 Ghz. Vertical bars represent ±1 SD of the mean SAR. Minimum N, 3; average N, 5 (Olsen, 1982).

Figures 8.25 and 8.26.
Rate of temperature rise from RFR exposure in the face of detached M. mulatta head; 1.2 GHz, CW, 70 mW/cm² far field Burr and Krupp, 1980).

Figure 8.26.
Rate of temperature rise from RFR exposure at the right side of a detached M. mulatta head; 1.2 GHz, 70 mW/cm² CW, far field (Burr and Krupp, 1980).

Figures 8.27 and 8.28.
Rate of temperature rise from RFR exposure at the back of detached M. mulatta head; 1.2 GHz, CW, 70 mW/cm² , far field (Burr and Krupp, 1980).

Figure 8.28.
Rate of temperature rise from RFR exposure to the back of an M. mulatta cadaver head (with body attached); 1.2 GHz, CW, 70 mW/cm², far field.Temperature rise shown for animal's body oriented parallel with the E- and H-fields (Burr and Krupp, 1980).

Figures 8.29 and 8.30.
Temperature rise (at 2.0 cm into the top of the head) of an M. mulatta exposed to 70 mW/cm², 1.2 GHz, CW, RFR, in the far field (Burr and Krupp, 1980).

Figure 8.30.
Temperature rise (at 3.5 cm into the top of the head) of an M. mulatta exposed to 70 mW/cm², 1.2 GHz, CW, RFR in the far field (Burr and Krupp, 1980).

Figure 8.31.
Temperature rise (at 3.5 cin into the back of the head) of an M. mulatta exposed to 70 mW/cm², 1.2 GHz, CW, RFR, in the far field (Burr and Krupp, 1980).

Figure 8.32.
Thermographic results of exposing a 4.3-cm-radius sphere to 144-MHz TM110 electric field in a rectangular resonant cavity simulating a 25.6-cm-radius sphere exposed to 24.1 MHz: vertical divergence = 2°C, horizontal divergence = 2 cm (Guy et al., 1976b) ( © 1976 IEEE)

Figure 8.33.
Thermographic results of exposing a 4.3-cm-radius sphere to 144-MHz TE102 magnetic field in a rectangular resonant cavity simulating a 25.6-cm-radius sphere exposed to 24.1 MHz: vertical divergence = 2°C, horizontal divergence = 2 cm (Guy et al., 1976b) ( © 1976 IEEE)

Figure 8.34.
Scale-model thermograms and calculated peak SAR for 70-kg, 5/1 prolate spheroid (a = 74.8 cm) exposed to 24.1-MHz electric field parallel to major axis: vertical divergence 2ºC, horizontal divergence = 2.65 cm (Guy et al., 1976b) ( © 1976 IEEE).

Figure 8.35.
Scale-model thermograms and calculated peak SAR for 70-kg, 5/1 prolate spheroid (a = 74.8 cm) exposed to 24.1-MHz magnetic field parallel to major axis: vertical divergence 2ºC, horizontal divergence = 2.65 cm (Guy et al., 1976b) ( © 1976 IEEE)

Figure 8.36.
Scale-model thermograms and measured peak SAR for 70-kg, 1.74-m-height frontal-plane man model exposed to 31.0-MHz electric field parallel to the long axis: vertical divergence = 2ºC, horizontal divergence = 4 cm (Guy et al., 1976b) ( © 1976 IEEE).

Figure 8.36. (Continued)

Figure 8.37.
Scale-model thermograms and measured peak SAR for 70-kg, 1.74-m-height frontal-plane man model exposed to 31.0-MHz magnetic field perpendicular to the major axis: vertical divergence = 2ºC, horizontal divergence = 4 cm (Guy et al., 1976b) (© 1976 IEEE).

Figure 8.37. (Continued)

Figure 8.38.
Scale-model thermograms and measured peak SAR for 70-kg, 1.74-m-height medial-plane man model exposed to 31.0-MHz magnetic field perpendicular to the median plane: vertical divergence = 2ºC, horizontal divergence = 2.65 cm (Guy et al., 1976b) ( © 1976 IEEE)

Figure 8.38. (Continued)

Figure 8.39.
Scale-model thermograms and measured peak SAR for 70-kg, 1.74-m-height medial-plane man model exposed to 31.0-MHz electric field parallel to the major axis: vertical divergence = 2º C, horizontal divergence = 2.65 cm (Guy et al., 1976b) (© 1976 IEEE).

Figure 8.40.
Computer-processed whole-body thermograms expressing SAR patterns for man with arms up, exposed to 1-mW/cm² 450 MHz radiation with EHK polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.41.
Computer-processed whole-body thermograms expressing SAR patterns for man with one arm extended, exposed to 1-mW/cm² 450 MHz radiation with KEH polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.42.
Computer-processed upper-body thermograms expressing SAR patterns for man with one arm extended, exposed to 1-mW/cm² 450 MHz radiation with KEH polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.43.
Computer-processed midbody thermograms expressing SAR patterns for man with one arm extended, exposed to 1-mW/cm² 450 MHz radiation with KEH polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.44.
Computer-processed lower-body thermograms expressing SAR patterns for man with one arm extended, exposed to 1-mW/cm² 450 MHz radiation with KEH polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.45.
Computer-processed whole-body thermograms expressing SAR patterns for man sitting (frontal plane), exposed to 1-mW/cm² 450 MHz radiation with EKH polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.46.
Computer-processed whole-body thermograms expressing SAR patterns for man sitting (sagittal plane through leg), exposed to 1-mW/cm² 450 MHz radiation with EHK polarization (Guy et al., 1984) (© 1984 IEEE).

Figure 8.47.
SAR distribution along an average man-model height for two cross sections; 1-mW/cm² incident-power density on the surface of the model, frequency 350 MHz E||L, K back to front (Krazewski et al., 1984) (© 1984 IEEE).

Table 8.1.
Measured And Calculated Values Of Average SAR For Mice (Allen and Hurt, 1977)

Table 8.2.
Measured And Calculated Values Of Average SAR For Prolate Spheroidal Models Of Man And Test Animals (Guy et al., 1978)

Table 8.3.
Whole-Body Average SAR For Saline-Filled Figurines Under Near-Field Exposure Conditions. Experimental Frequency = Simulated Frequency x (Height Of Man/Height Of Figurine) (Chatterjee et al., 1982b)

Table 8.4.
Internal Electric Field In The Abdominal Region Of Phantom Figurines As A Fraction Of The Maximum Incident Electric Field (Just In Front of the Figurine) For Near-Field Exposure Conditions (Chatterjee et al., 1982b)

Go to Chapter 9.

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Last modified: June 14, 1997
October 1986, USAF School of Aerospace Medicine, Aerospace Medical Division (AFSC), Brooks Air Force Base, TX 78235-5301