**3.1.** A vector quantity represented by a directed
line segment

**3.2.** Vector addition

**3.3.** Vector dot product **A · B**

**3.4.** Vector cross product **A** x **B**

**3.5.** Graphical representation of a scalar field,
such as temperature

**3.6.** Graphical representation of a vector field,
such as air velocity between two plates

**3.7.** Force on a charge, q, due to the presence of
another charge, Q

**3.8.**
(a)** E**-field produced by one point
charge, Q, in space

**3.9.**
Field lines between infinite parallel
conducting plates

**3.10.**
(a) **E**-field lines when a small
metallic object is placed between the plates

**3.11.**
**B**-field produced by an infinitely
long, straight dc element out of the paper

**3.12.**
**B**-field produced by a circular
current loop

**3.13.**
Potential scalar fields (a) for a point
charge and (b) between infinite parallel conducting plates

**3.14.**
(a) Polarization of bound charges (b)
Orientation of permanent dipoles

**3.15.**
Charge Q inside a dielectric spherical shell

**3.16.**
Snapshots of a traveling wave at two
instants of time

**3.17.**
The variation of E at one point in space as
a function of time

**3.18.**
(a) A given periodic function versus time
(b) The square of the function versus time

**3.19.**
A spherical wave

**3.20.**
A planewave

**3.21.**
Cross-sectional views of the electric- and
magnetic-field lines in the TEM mode for coaxial cable and twin lead

**3.22.**
Schematic diagrams of two-conductor
transmission lines

**3.23.**
Total waves, incident plus reflected

**3.24.**
Top half of the envelope resulting from an
incident and reflected voltage wave

**3.25.**
Field variation of the TE_{10} mode in a rectangular waveguide

**3.26.** Some relative cutoff frequencies for a
waveguide with b = a/2, normalized to that of the
TE_{10} mode

**3.27.** A volume bounded by a closed surface

**3.28.** A planewave irradiating an absorber

**3.29.** Absorber placed between an incident
planewave and a conducting plane

**3.30.** Electric-field components at a boundary
between two materials

**3.31.** Planewave incident on a planar conductor

**3.32.** Total fields, incident plus scattered

**3.33.** Planewave obliquely incident on a planar
conductor

**3.34.** Planewave obliquely incident on a planar
dielectric

**3.35.** Average permittivity of the human body
(equivalent to two-thirds that of muscle tissue) as a
function of frequency

**3.36.** Skin depth versus frequency for a dielectric
half-space with permittivity equal to two-thirds that of
muscle

**3.37.** Polarization of the incident field with
respect to an irradiated object

**3.38.** Polarizations for objects that do not have
circular symmetry about the long axis

**3.39.** Calculated whole-body average SAR versus
frequency for models of an average man for three standard
polarizations

**3.40.** Calculated whole-body average SAR versus
frequency for models of a medium-sized rat, for three
standard polarizations

**3.41.** Short dipole used to sense the presence of
an electric field

**3.42.** Simple electric-field probe with a diode
detector

**3.43.** Loop antenna used as a pickup for measuring
magnetic field

**4.1.** Frequency dependence of the dielectric
constant of muscle tissue

**4.2.** Dielectric properties of muscle in the
impedance plane

**4.3.** Dielectric properties of barnacle muscle in
the microwave frequency range are presented in the complex
dielectric constant plane

**4.4.** Equivalent circuit for the -dispersion of a
cell suspension and corresponding plot in the complex
dielectric constant plane

**4.5.** Threshold field-strength values as a function
of particle size

**4.6.** Bridge circuit for measuring dielectric
properties of materials at frequencies below 100 MHz

**4.7.** Experimental setup for measuring
S-parameters, using an automatic network analyzer

**4.8.** Typical sample holders for measuring the
dielectric properties of biological substances at microwave
frequencies

**4.9.** Typical experimental setup for time-domain
measurement of complex permittivities

**4.10.** In vivo dielectric probes for measuring
dielectric properties of biological substances

**4.11.** Graphical illustration of the iterative
procedure for calculating complex permittivity parameters by
minimizing the difference between measured and calculated
values of the input impedance of the in vivo dielectric probe

**4.12.** Relative dielectric permittivity for muscle

**4.13.** Conductivity for muscle

**4.14.** Measured values of relative dielectric
constant of in vivo rat muscle and canine muscle compared to
reference data

**4.15.** Measured values of conductivity of in vivo
rat muscle and canine muscle compared to reference data

**4.16.** Measured values of relative dielectric
constant and conductivity of in vivo and in vitro canine
kidney cortex compared to reference data

**4.17.** Measured values of relative dielectric
constant and conductivity of in vivo canine fat tissue at
37° C

**4.18.** Measured values of relative dielectric
constant and conductivity of in vivo rat brain at 32° C

**4.19.** Measured values of relative dielectric
constant and conductivity of rat blood at 23° C

**4.20.** Relative permittivity of cat smooth muscle
in vivo

**4.21.** Relative permittivity of cat spleen in vivo

**4.22.** Average relative permittivity of two types
of cat muscle in vivo

**4.23.** Average relative permittivity of cat
internal organs in vivo

**4.24.** Relative permittivity of cat brain tissue

**4.25.** The real part of the dielectric constant and
conductivity of the canine skeletal muscle tissue at 37° C
as a function of frequency, in parallel orientation and
perpendicular orientation, averaged over five measurements on
different samples

**4.26.** The real part of the dielectric constant of
ocular tissues at 37° C

**4.27.** The imaginary part of the dielectric
constant of ocular tissues at 37° C

**4.28.** The conductivity of ocular tissues at 37°
C

**4.29.** The real part of the dielectric constant of
normal and tumor mouse tissue as a function of frequency

**4.30.** Conductivity of normal and tumor mouse
tissue as a function of frequency

**5.1.** Illustration of different techniques, with
their frequency limits, used for calculating SAR data for
models of an average man

**5.2.** Average SAR calculated by the empirical
formula compared with the curve obtained by other
calculations for a 70-kg man in E polarization

**5.3.** Calculated effect of a capacitive gap,
between man model and ground plane, on average SAR

**5.4.** Calculated effect of grounding resistance on
SAR of man model placed at a distance from ground plane

**5.5.** The volume fraction as a function of
frequency for a cylindrical model of an average man

**5.6.** The volume fraction as a function of
frequency for two spheres of muscle material

**5.7.** Calculated average SAR in a prolate
spheroidal model of an average man, as a function of
frequency for several values of permittivity

**5.8.** Relative absorption cross section in prolate
spheroidal models of an average man, a rabbit, and a
medium-sized rat--as a function of frequency for E
polarization

**5.9.** Comparison of relative scattering cross
section and relative absorption cross section in a prolate
spheroidal model of a medium rat--for planewave irradiation,
E polarization

**5.10.** Field components at a boundary between two
media having different complex permittivities

**5.11.** A lossy dielectric cylinder in a uniform
magnetic field

**5.12.** Qualitative evaluation of the internal
fields based on qualitative principles QPI and QP2

**5.13.** Average SAR in a prolate spheroidal model of
an average man as a function of normalized impedance for each
of three polarizations

**5.14.** Ratio of (SAR)_{e} to
(SAR)_{h} of a 0.07-m^{3} prolate spheroid for
each polarization as a function of the ratio of the major
axis to the minor axis of the spheroid at 27.12 MHz

**6.1.** Calculated planewave average SAR in an
ellipsoidal model of an average man, for the six standard
polarizations

**6.2.** Calculated planewave average SAR in
ellipsoidal models of different human-body types, EKH
polarization

**6.3.** Calculated planewave average SAR in a prolate
spheroidal model of an average man for three polarizations

**6.4.** Calculated planewave average SAR in a prolate
spheroidal model of an average ectomorphic (skinny) man for
three polarizations

**6.5.** Calculated planewave average SAR in a prolate
spheroidal model of an average endomorphic (fat) man for
three polarizations

**6.6.** Calculated planewave average SAR in a prolate
spheroidal model of an average woman for three polarizations

**6.7.** Calculated planewave average SAR in a prolate
spheroidal model of a large woman for three polarizations

**6.8.** Calculated planewave average SAR in a prolate
spheroidal model of a 5-year-old child for three
polarizations

**6.9.** Calculated planewave average SAR in a prolate
spheroidal model of a 1-year-old child for three
polarizations

**6.10.** Calculated planewave average SAR in a
prolate spheroidal model of a sitting rhesus monkey for three
polarizations

**6.11.** Calculated planewave average SAR in a
prolate spheroidal model of a squirrel monkey for three
polarizations

**6.12.** Calculated planewave average SAR in a
prolate spheroidal model of a Brittany spaniel for three
polarizations

**6.13.** Calculated planewave average SAR in a
prolate spheroidal model of a rabbit for three polarizations

**6.14.** Calculated planewave average SAR in a
prolate spheroidal model of a guinea pig for three
polarizations

**6.15.** Calculated planewave average SAR in a
prolate spheroidal model of a small rat for three
polarizations

**6.16.** Calculated planewave average SAR in a
prolate spheroidal model of a medium rat for three
polarizations

**6.17.** Calculated planewave average SAR in a
prolate spheroidal model of a large rat for three
polarizations

**6.18.** Calculated planewave average SAR in a
prolate spheroidal model of a medium mouse for three
polarizations

**6.19.** Calculated planewave average SAR in a
prolate spheroidal model of a quail egg for three
polarizations

**6.20.** Calculated planewave average SAR in
homogeneous and multilayered models of an average man for two
polarizations

**6.21.** Calculated planewave average SAR in
homogeneous and multilayered models of an average woman for
two polarizations

**6.22.** Calculated planewave average SAR in
homogeneous and multilayered models of a 10-year-old child
for two polarizations

**6.23.** Layering resonance frequency as a function
of skin and fat thickness for a skin-fat-muscle cylindrical
model of man, planewave H polarization

**6.24.** Layering resonance frequency as a function
of skin and fat thickness for a skin-fat-muscle cylindrical
model of man, planewave E polarization

**6.25.** Calculated planewave average SAR in a
prolate spheroidal model of an average man irradiated by a
circularly polarized wave, for two orientations

**6.26.** Calculated planewave average SAR in a
prolate spheroidal model of a sitting rhesus monkey
irradiated by a circularly polarized wave, for two
orientations

**6.27.** Calculated planewave average SAR in a
prolate spheroidal model of a medium rat irradiated by a
circularly polarized wave, for two orientations

**6.28.** Calculated planewave average SAR in a
prolate spheroidal model of an average man irradiated by an
elliptically polarized wave, for two orientations

**6.29.** Calculated planewave average SAR in a
prolate spheroidal model of a sitting rhesus monkey
irradiated by an elliptically polarized wave, for two
orientations

**6.30.** Calculated planewave average SAR in a
prolate spheroidal model of a medium rat irradiated by an
elliptically polarized wave, for two orientations

**6.31.** Calculated normalized average SAR as a
function of the electric dipole location for E polarization
in a prolate spheroidal model of an average man

**6.32.** Calculated average SAR (by long-wavelength
approximation) as a function of the electric dipole location
for K polarization at 27.12 MHz in a prolate spheroidal
model of an average man

**6.33.** Calculated average SAR (by long-wavelength
approximation) as a function of the electric dipole location
for H polarization at 27.12 MHz in a prolate spheroidal model
of an average man

**6.34.** Calculated average SAR (by long-wavelength
approximation) as a function of the electric dipole location
for E polarization at 100 MHz in a prolate spheroidal model
of a medium rat

**6.35.** Calculated average SAR (by long-wavelength
approximation) as a function of the electric dipole location
for K polarization at 100 MHz in a prolate spheroidal model of
a medium rat

**6.36.** Calculated average SAR (by long-wavelength
approximation) as a function of the electric dipole location
for H polarization at 100 MHz in a prolate spheroidal model
of a medium rat

**6.37.** Calculated normalized **E**-field of a
short electric dipole,as a function of y/ at z = 30 cm

**6.38.** Calculated normalized **H**-field of a
short electric dipole,as a function of y/ at z = 30 cm

**6.39.** Calculated variation of a as a function of
y/, at z =30 cm, for a short electric dipole

**6.40.** Calculated normalized field impedance of a
short electric dipole, as a function of y/ at z = 30 cm

**6.41.** Calculated average SAR in a prolate
spheroidal model of an average man irradiated by the near
fields of a short electric dipole, as a function of the
dipole-to-body spacing, d

**6.42.** Calculated average SAR in a prolate
spheroidal model of an average man irradiated by the near
fields of a small magnetic dipole, as a function of the
dipole-to-body spacing, d

**6.43.** The block model of man used by Chatterjee et
al. (1980a, 1980b, 1980c) in the planewave spectrum analysis

**6.44.** Incident-field E_{z} from a
27.12-MHz RF sealer, used by Chatterjee et al. (1980a, 1980b,
1980c) in the planewave angular-spectrum analysis

**6.45.** Average whole- and part-body SAR in the
block model of man placed in front of a half-cycle cosine
field, E_{z }; frequency = 27.12 MHz, E_{z }|_{ max} = 1 V/m

**6.46.** Average whole- and part-body SAR in the
block model of man placed in front of a half-cycle cosine
field, E_{z }; frequency = 77 MHz, E_{z }|_{ max} = 1 V/m

**6.47.** Whole- and part-body SAR at 77 MHz in the
block model of man as a function of an assumed linear
antisymmetric phase variation in the incident E_{z };
E_{z }|_{ max} = 1 V/m

**6.48.** Whole- and part-body SAR at 77 MHz in the
block model of man as a function of an assumed linear
symmetric phase variation in the incident E_{z }; E_{z }|_{ max} = 1 V/m

**6.49.** Whole- and part-body SAR at 350 MHz in the
block model of man as a function of an assumed linear
antisymmetric phase variation in the incident E_{z };
E_{z }|_{ max} = 1 V/m

**7.1.** A data sheet for RFR bioeffects research

**7.2.** Relative permittivity of simulated muscle
tissue versus frequency for three temperatures

**7.3.** Electrical conductivity of simulated muscle
tissue versus frequency for three temperatures

**7.4.** Schematic diagram illustrating the coordinate
system used in the scaling procedure

**7.5.** Electrical conductivity of phantom muscle as
a function of NaCl and TX-150 contents measured at 100 kHz
and 23° C

**7.6.** Electrical conductivity of saline solution as
a function of the aqueous sodium chloride concentration

**7.7.** Electrical conductivity of saline solution as
a function of the NaCl concentration at 25° C

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

**8.2B.** Comparison of measured and calculated SAR
values for an average man in free space, H and K
polarizations

**8.2.** Calculated and measured values of the average
SAR for a human prolate spheroidal phantom

**8.3.** Calculated and measured values of the average
SAR for a prolate spheroidal phantom of a sitting rhesus
monkey

**8.4.** Measured values of the average SAR for a
live, sitting rhesus monkey, for six standard polarizations

**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

**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

**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

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

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

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

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

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

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

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

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

**8.16.** Comparison of free-space absorption rates of
five human subjects with each other and with two standard
theories

**8.17.** Comparison of the grounded absorption rates
of five human subjects with each other and with two standard
theories

**8.18.** Frequency dependence of the average
absorption rates for five human subjects in the EKH and EHK,
orientations under both free-space and grounded conditions

**8.19.** Measured relative SARs in scaled saline
spheroidal models of man

**8.20.** Measured relative SARs in scaled saline
spheroidal models versus distance

**8.21.** Measured relative fields versus distance for
the thick monopole on a grounded plane. The values of E and H
are normalized with respect to their values at d/ = 0.6

**8.22.** Microwave absorption profiles for rhesus
monkey model

**8.23.** Profiles of electromagnetic absorption in
the sitting rhesus model at 225 MHz

**8.24.** Normalized microwave absorption profiles in
the man-sized model at 2.0 GHz

**8.25.** Rate of temperature rise from RFR exposure
in the face of a detached M. mulatta head; 1.2 GHz, CW, 70
mW/cm^{2}, far field

**8.26.** Rate of temperature rise from RFR exposure
at the right side of a detached M. mulatta head; 1.2 GHz, CW,
70mW/cm^{2}, far field

**8.27.** Rate of temperature rise from RFR exposure
at the back of a detached M. mulatta head; 1.2 GHz, CW, 70
mW/cm^{2}, far field

**8.28.** Rate of temperature rise from RFR exposure
to the back of an M. mulatta cadaver head (with body
attached); 1.2 GHz, W, 70 mW/cm ^{2}, in the far field

**8.29.** Temperature rise at 2.0 cm into the top of
the head of an M. mulatta exposed to 70 mW/cm^{2}, 1.2 CHz,
CW, RFR, in the far field

**8.30.** Temperature rise at 3.5 cm into the top of
the head of an M. mulatta exposed to 70 mW/cm ^{2}, 1.2 GHz,
CW, RFR, in the far field

**8.31.** Temperature rise at 3.5 cm into the back of
the head of an M. mulatta exposed to 70 mW/cm^{2}, 1.2 GHz,
CW, RFR, in the far field

**8.32.** Thermographic results of exposing a
4.3-cm-radius sphere to 144-MHz TM_{110}
electric field in a rectangular resonant cavity simulating a
25.6-cm-radius sphere exposed to 24.1 MHz

**8.33.** Thermographic results of exposing a
4.3-cm-radius sphere to 144-MHz TE_{102}
magnetic field in a rectangular resonant cavity simulating a
25.6-cm-radius sphere exposed to 24.1 MHz

**8.34.** Scale-model thermograms and calculated peak
SAR for 70kg, 5/1 prolate spheroid (a = 74.8 cm) exposed to
24.1-MHz electric field parallel to the major axis

**8.35.** Scale-model thermograms and calculated peak
SAR for 70kg, 5/1 prolate spheroid (a = 74.8 cm) exposed to
24.1- MHz magnetic field perpendicular to the major axis

**8.36.** Scale-model thermograms and measured
peak-SAR for 70kg, 1.74-m-height frontal-plane man model
exposed to 31.0-MHz electric field parallel to the long axis

**8.37.** Scale-model thermograms and measured peak
SAR for 70kg, 1.74-m-height frontal-plane man model exposed
to 31.0-MHz magnetic field perpendicular to the major axis

**8.38.** Scale-model thermograms and measured peak
SAR for 70kg, 1.74-m-height medial-plane man model exposed to
31.0-MHz magnetic field perpendicular to the median plane

**8.39.** Scale-model thermograms and measured peak
SAR for 70kg, 1.74-m-height medial-plane man model exposed to
31.0-MHz electric field parallel to the major axis

**8.40.** Computer-processed whole-body thermograms
expressing 2 SAR patterns for man with arms up, exposed to
1-mW/cm^{2 }450-MHz radiation with EHK polarization

**8.41.** Computer-processed whole-body thermograms
expressing SAR patterns for man with one arm extended,
exposed to 1-mW/cm ^{2 } 450-MHz radiation with KEH
polarization

**8.42.** Computer-processed upper-body thermograms
expressing SAR patterns for man with one arm extended,
exposed to 1-mW/cm ^{2 } 450-MHz radiation with KEH
polarization

**8.43.** Computer-processed midbody thermograms
expressing SAR patterns for man with one arm extended,
exposed to 1-mW/cm^{2 } 450-MHz radiation with KEH
polarization

**8.44.** Computer-processed lower-body thermograms
expressing SAR patterns for man with one arm extended,
exposed 1-mW/cm^{2 } 450-MHz radiation with KEH polarization

**8.45.** Computer-processed whole-body thermograms
expressing SAR patterns for man sitting (frontal plane),
exposed to 1-mW/cm^{2 } 450-MHz radiation with EKH polarization

**8.46.** Computer-processed whole-body thermograms
expressing SAR patterns for man sitting (sagittal plane
through leg), exposed to 1-mW/cm^{2 } 450-MHz radiation with
EHK polarization

**8.47.** SAR distribution along an average man-model
height for two cross sections; 1-mW/cm^{2 } incident-power
density on the surface of the model, frequency 350 MHz E||L back to front

**9.1.** Relationship between effective area and
short-circuit current for exposed human figure

**9.2.** Relative surface-current distribution in
grounded man exposed to VLF-MF fields

**9.3.** Relative surface-current distribution in man
exposed in free space to VLF-MF electric fields

**9.4.** Relative surface-current distribution in man
exposed to VLF-MF electric fields with feet insulated and
hand grounded

**9.5.** Comparison of theoretical and measured
short-circuit body current of grounded man exposed to VLF-MF
electric field that is parallel to body axis

**9.6.** Average values of the human body resistance
assumed for the calculations

**9.7.** Perception and let-go currents for finger
contact for a 50th percentile human as a function of
frequency assumed for the calculations

**9.8.** Unperturbed incident E-field required to
create threshold perception and let-go currents in a human
for conductive finger contact with various metallic
objects,as a function of frequency

**9.9.** Experimental arrangement for measuring
threshold currents for perception and let-go

**9.10.** Calculated current distributions as a
function of position in man exposed to 1-kV/m VLF-MF fields
with feet grounded

**9.11.** Calculated current density flowing through
one arm. The exposure condition is the same as that of Figure
9.10

**9.12.** Calculated current distribution as a
function of position in man exposed to 1-kV/m VLF-MF fields
in free space

**9.13.** Calculated current density flowing through
one arm. The exposure condition is the same as for Figure
9.12

**9.14.** Calculated current distributions as a
function of position in man exposed to 1-kV/m VLF-MF fields
with feet insulated but hands grounded

**9.15.** Calculated current density flowing through
one arm. Exposure condition is the same as for Figure 9.14

**9.16.** Calculated current distribution as a
function of position in man with hand contacting a large
object and with feet grounded. A 1-mA current is assumed to
be flowing through the arm, thorax, and legs of the subject
to ground, F = 60 Hz

**9.17.** Calculated current density flowing through
one arm. Exposure condition is same as for Figure 9.16

**9.18.** Real part, ', and imaginary part,
", of the dielectric constant for high-water-content tissue

**9.19.** Comparison of calculated average SAR
(obtained from VLF analysis) with average SAR (reported in
the first edition of this handbook) of average absorbed power
in an ellipsoidal model of an average man

**9.20.** Comparison of theoretical and experimentally
measured whole-body average SAR for realistic man models
exposed at various frequencies

**9.21.** Required restrictions of VLF-MF electric
field strength to prevent biological hazards related to
shock, RF burns, and SAR exceeding ANSI C95.1 criteria

**10.1.** A schematic diagram of the sources of body
heat (including radiofrequency radiation) and the important
energy flows between man and the environment

**10.2.** Thermoregulatory profile of a typical
endothermic organism to illustrate the dependence of
principal types of autonomic responses on environmental
temperature

**10.3.** Thermoregulatory profile of nude humans
equilibrated in a calorimeter to different ambient
temperatures

**10.4.** Logarithm of total metabolic heat production
plotted against logarithm of body mass

**10.5.** Variation of human resting metabolic rate,
with age and sex, expressed as power per unit surface area

**10.6.** Variation of human resting metabolic rate,
with age and sex, expressed as power per unit body mass

**10.7.** Calculated SAR_{60} values in an average man,
unclothed and quiet, irradiated by an electromagnetic
planewave with E polarization at resonance (about 70 MHz)

**11.1.** Calculated relative RFR absorption in
prolate spheroidal models of humans

**11.2.** Power densities that limit human whole-body
SAR to 0.4 W/kg compared to ANSI standard

**11.3.** Comparison of RPR safety guidelines based on
a threshold of 4 W/kg for adverse effects

**11.4.** Power densities that limit human whole-body
SAR to 0.4 W/kg for a 1.8-m, 70-kg person

**Go to List of Tables.**

Last modified: June 14, 1997

© October 1986, USAF School of Aerospace Medicine, Aerospace Medical Division (AFSC), Brooks Air Force Base, TX 78235-5301