## 1. To conclude

This textbook aims to acquaint students and those interested in the field of use of technology in medicine with the elementary principles of operation of devices and tools based on the use of various wave phenomena.

In addition to the basic principles, this publication lists and explains some simple applications encountered in the field of biomedicine. However, modern science and technology provide many new sophisticated technical tools that go beyond the scope of this textbook. These are mainly devices of radiology and nuclear medicine. These are also applications of wave processes but in conjunction with sophisticated computational methods that require a more detailed explanation. These are mainly acoustic and optical imaging methods, USG, thermography, tomographic imaging methods, such as CT, MRI, PET, SPECT, and other methodologies, which use radioactive radiation in therapy and diagnostics. The description of these advanced methods will be the content of the prepared book - Technical means of biomedical engineering.

The present textbook uses basic knowledge of mathematics and physics. Special medical applications are going out of the personal experience of authors and current books and journals. Part of the information and most of the documentary images are from publicly available and freely usable Internet sources.

## List of used symbols

A

voltage transmission (−)

A

complex voltage transmission (−)

b

oscillation damping coefficient (s^{−1})

B

magnetic induction (T)

c

phase velocity (m∙s^{−1}), speed of light (m∙s^{−1})

*0*c

speed of light in free space (* c*0 = 299,792,458 m∙s

^{−1}exactly)

C

capacitance (F)

D

electric displacement (C∙m^{−2})

e

elementary charge (* e* = 1,602,177 × 10

^{−19}C)

electron-volt unit (1 eV = 1,602,177 × 10^{−19} J)

e

_{EM}

electromagnetic field energy density (J∙m^{−3})

E

energy (J, eV), e.g., * E*p potential,

*k kinetic*E

E

illuminance (lx)

E

electric field strength (V∙m^{−1})

f

frequency (Hz), focal length (m)

*L*f

Larmor frequency (Hz)

F

force vector (N)

g

gravity acceleration (m∙s^{−2})

h

Planck’s constant (* h* = 6,626,070 × 10–34 J∙s)

H

loudness level (Ph – phon, dB)

H

magnetic field strength (A∙m^{−1})

i

electric current (A)

I

phasor of electric current (A)

I

rms value of electric current (A), luminous intensity (cd)

I

power density of wave (radiation) (W∙m^{−2}), * I*dB intensity level (dB)

imaginary unit (j = √−1)

J

current density (A∙m^{−2})

k

complex wave number (m^{−1})

l

length (m)

L

inductance (H), luminance (cd∙m^{−2})

L

angular momentum (N∙m∙s)

m

mass (kg)

m

magnetic dipole moment (N∙m∙T^{−1})

M

torque (N∙m)

n

refractive index (−)

p

pressure (Pa), power density (W∙m^{−3})

p

_{a}

acoustic pressure (Pa)

p

linear momentum (kg∙m∙s^{−1})

P

power (W), active power (W)

Q

electric charge (C), quality factor (−), reactive power (Var)

r

radius (m), distance (m)

r

wave reflection factor (−)

r

position vector (m)

R

electrical resistance (Ω)

S

apparent power (VA), area (m^{2})

S

complex power of the alternating current (VA)

t

time (s)

t

wave transition factor (−)

T

period (s), thermodynamic temperature (K)

u

voltage (V), acoustic displacement (m)

U

rms value of electric voltage (V)

U

voltage phasor (V)

v

velocity vector (m∙s^{−1})

V

volume (m^{3})

W

work (J)

x

_{m}

amplitude of oscillations (m)

x

coordinate (m), axis designation, displacement in the * x*- axis direction

y

coordinate (m), axis designation

z

coordinate (m), axis designation

Z

impedance, wave impedance (Ω)

Z

complex impedance (Ω)

α

wavenumber (m^{−1}), angle (rad),

β

wave attenuation coefficient (m^{−1}), angle (rad)

δ

effective wave propagation length (m), wave penetration depth (m)

γ

conductivity (S∙m^{−1}), gyromagnetic ratio (s^{−1}∙T^{−1})

ε

electric permittivity (F∙m^{−1}), strain (−)

ε

_{0}

electric permittivity of free space (_{0} = 8,854,187 × 10^{−12} F∙m^{−1})

ε

_{r}

relative permittivity (−)

λ

wavelength (m)

φ

plane angle (rad), phase shift (rad)

ρ

bulk density (kg∙m^{−3}), electric charge density (C∙m^{−3})

μ

magnetic permeability (H∙m^{−1})

μ

_{0}

permeability of free space (_{0} = 4π × 10^{−7} H∙m^{−1})

μ

_{r}

relative permeability (−)

Poynting vector (W∙m^{−2})

τ

time constant (s)

τ

mechanical stress in shear (Pa)

σ

mechanical tensile stress (Pa)

Φ

magnetic flux (Wb), luminous flux (lm)

_{e}

radiation flux density (W∙m^{−2})

ω

angular frequency (s^{−1}), angular velocity (rad∙s^{−1})

ω

_{L}

Larmor angular frequency (s^{−1})

Ω

angular frequency of forced oscillations (s^{−1}), solid angle (sr)

designation of the first derivative by time

designation of the second derivative by time

a, A

designation of a scalar quantity

a, A

designation of a vector quantity

a, A

designation of a complex quantity

## Abbreviations

detection chip (Charge-Coupled Device)

detection chip (Complementary Metal Oxide Semiconductor)

subtractive colour composition (Cyan-Magenta-Yellow-Black)

Carbon Nano Tubes

Computed Tomography

electromagnetic

magnetic resonance signal (Free Induction Decay)

Infra-Red

Light Amplification by Stimulated Emission of Radiation

Liquid Crystals Display

Light Emitting Diode

Magnetic Resonance

Magnetic Resonance Imaging

Magnetic Resonance Spectroscopy

Micro-Waves

Photo-Acoustic Microscopy

Positron Emission Tomography

additive colour composition (Red-Green-Blue)

Radiofrequency, Radio-Waves

Single Photon Emission Tomography

Ultrasonography

Ultra-Violet

Ultra-High Frequency

Very Short Waves

wireless connection (Wireless Fidelity)

Visible Light

X-rays (Roentgen radiation)

gamma radiation

two-, three-dimensional