Low Electromagnetic Field Interact with the Excitable Cell

1. Xi’an Jiaotong University
Biomedical Engineering Research institute
Low Electromagnetic Field Interact
with the Excitable Cell
Presented by : Mohammed Ygoub Esmail
Student Number:
4107037013
28. 12.2009

2. Electromedicine or electromagnetic medicine
are the terms applied to such developments in
the ELF, LF, RF, IR, visible or UV band.
▪ Cells that produce electrical signals when
stimulated are called Excitable Tissues.
These are:
Nerve cells
Muscle cells

3. Duchenne
Electrical stimulation
of muscle
1913 early ECG recording

4. Victorian Energy Machines
Using Induction Coils – Faradic Electric Current

5. The role of the heart
It is known that the heart generates the
largest electrical and magnetic field of the
body. The fields of both the heart and the
brain contain signals in the biologically
important part of the energy spectrum
known as the ELF (extremely low frequency).

6. The electrical field of
heart
HEART
In heart math institute they found that heart has a very strong
electrical field which affects all surrounding people. Therefore human
can communicate with others only with his heart without talking. !!
Also they found a relation between number of heart pulses and the
transmitted waves from brain (Alfa waves). The more heart pulses the
more transmitted waves from brain.

7. Heart ……
Transmits information to brain
Heart
Today, researches confirm that heart with its organized
harmony controls the entire body as it considered to be a
method to linking all cells, when blood goes into each cell
then it feed these cells not only with oxygen but also with
information.

8. All magnets are surrounded by field lines
that by definition are called lines of force
and run from the North pole to the South
pole.
Where these are close together ,the field is
strong e.g. near to the poles.
So we also need to consider the area over
which these field lines act.
The Heart is most electrical organ
Personal Magnetic Field Pushing blood through coiling Aorta
Conducted by salty blood
Production of Magnetic field

9. Cardiac Muscle Cells
Intercalated discs:
interconnect
cardiac muscle cells
secured by
desmosomes
linked by gap
junctions
convey force of
contraction
propagate action
potentials

10. Characteristics of
Cardiac Muscle Cells
1. Small size
2. Single, central nucleus
3. Branching interconnections between
cells
4. Intercalated discs

11. Bioelectricity and Biomagnetism
• Bioelectricity is the study of electrical
phenomena generated by living
organisms and the effects of external
electromagnetic fields on the living body.
The electrical phenomena include
inherent properties of the cells, such as
membrane potential, action potential,
and propagation of the potentials.

12. • Bioelectromagnetics is a relatively new area of
science that deals with the interaction of
electromagnetic energy with biological
systems. Therefore, studies usually are carried
out jointly by researchers from both
biological/medical sciences and engineering/
physical sciences: expertise in both areas is
necessary.
Research on possible electromagnetic field effects on
biological systems originated primarily from different
‘sources’. One focus was an interest in basic
neurophysiological function: the nervous system is
fundamentally an electrical system. This area began with
Galvani and Volta in the early 19th century, when they
had their famous controversy about electrical
stimulation and contraction of the frog legs.

14. Electricity from magnetism
In 1831, Michael Faraday in England
demonstrated that moving a magnet near a coil
of wire induces a measurable current flow
through the wire. Faraday’s Law of Induction is
another basic law of electromagnetism.
The biological and medical significance of Faraday’s
Law of Induction is that moving or time‐varying
magnetic fields in the space around the body must
induce current flows within the tissues. This provides
a physical basis for a number of medical devices and
for various energy therapies

15. Magnets
• A magnet has 2 ends called poles
• They are known as North and South
– They line up with the Earth’s magnetic field
• Like poles repel and unlike poles attract

16. All magnets are surrounded by field lines that by
definition are called lines of force and run from
the North pole to the South pole.
Where these are close together ,the field is strong
e.g. near to the poles.
So we also need to consider the area over which
these field lines act. All magnets are surrounded
by field lines that by definition are called lines of
force and run from the North pole to the South
pole.
Where these are close together ,the field is strong
e.g. near to the poles.
So we also need to consider the area over which
these field lines act.

17. Electric and Magnetic fields line

18. For each of the magnets draw each and write whether
they will repel or attract each other
1
Attract
2
Repel
3
Repel

19. Electromagnetism : Magnetic?
Only Iron [Fe], Nickel [Ni] and Cobalt [Co] are.
S
Co Ni
N
Au Fe
Cu
Mg
Ag Al Zn

20. Magnetic flux density, being defined as the
amount of flux passing through a unit cross‐
section area, is often used in place of the
magnetic field. The unit of the magnetic flux
density is Wb/m or Tesla (T) which is equal to
10,000 Gauss (G).

21. Before listing the requirements, a simple consideration about ELF field
characteristic must be done…
At ELF the electric and magnetic part of EM field can be considered
acting in a separate manner.
An external electric field is greatly attenuated inside the body and
perpendicularly oriented to the surface. This is due to the dielectric
properties (conductivity and permittivity) of the body tissues.
On the contrary, the magnetic field penetrate the body virtually
unperturbed and induced electric fields and currents inside the tissues.
“the main objective of the bioeffects studies of ELF fields
is to investigate the effects related to the exposure to the
magnetic field, thus the exposure system has to be
essentially a system for generating magnetic fields”

22. Basic concepts and definitions
LOOP: single circular or square wire
COIL: several turns of wire

23. SET: several axial coils (usually from 2 to 5)
SYSTEM: One, two or three orthogonal sets
Scheme of two orthogonal sets of
two coils (multiwire) each, for the
generation of circularly polarized
magnetic field

24. Generation of low intensity magnetic field at ELF: one single coil
N: number of turns of the coil;
I: current which flows through it (A)
r: coil radius (m)

25. Basic requirements ‐ ELF exposure systems
Modify intensity and frequency values of
magnetic field generated in a wide range (0 – 100
Hz).
Large volumes of uniform magnetic field, related
to the size of the biological model.
Simultaneous generation of static and dynamic
magnetic fields.
Opportunity of varying magnetic field direction
and generating linearly and circularly polarized
fields.

26. Field strength:
An electromagnetic field consist of an
electrical, part and a magnetic part.
The electrical part is produced by a voltage
gradient and is measured in volts/metre.
The magnetic part is generated by any flow of
current and is measured in tesla.
• Both types of field give biological effects, but
the magnetic field is more damaging since it
penetrates living tissue more easily. Magnetic
fields as low as around one microtesla (a
millionth of a tesla) can produce biological
effects.

27. Biological Molecules
Cell membrane is not just a ‘skin’ – it controls what comes in & what goes
out The Phospho‐bilipid molecules form an electromagnetic array

28. All matter vibrates at various frequencies
(including our cells tissues organs)
We have an energy body
It is affected by electric pollution and geopathic stress and earth’s
fields
The protein molecules in our cells have subtle electromagnetic
fields
They work via piezoelectrics
They are liquid crystals and semi conductors

29. ▪ Electrical signals via movement of ions across
plasma membrane
Changes in membrane potential cause by
changes in ion movement across plasma
membrane
Changes in ion movement caused by changes
in permeability of the membrane
Changes in permeability cause by a triggering
event (stimulus)

30. ▪ Terminology
Normal, unpolarized, equlibrium
No difference in polarity, charge or concentration
Polarized:
Differences in charge (+ or -) across membrane
Membrane potential not 0 mV
Resting Membrane Potential:
Membrane potential of the cell at rest
Depolarization:
Membrane potential becomes less negative than
resting level
Repolarization:
Membrane potential returning to resting level
Hyperpolarization:
Membrane potential more negative than resting

31. What events take
place during an action potential
in cardiac muscle?

32. 3 Steps of
Cardiac Action Potential
1. Rapid depolarization:
– voltage‐regulated sodium channels (fast
channels) open

33. 3 Steps of
Cardiac Action Potential
2. As sodium channels close:
– voltage‐regulated calcium channels (slow
channels) open
– balance Na+ ions pumped out
– hold membrane at 0 mV plateau

34. 3 Steps of
Cardiac Action Potential
3. Repolarization:
– plateau continues
– slow calcium channels close
– slow potassium channels open
– rapid repolarization restores resting
potential

35. There are three well-understood methods by
which signals associated with a membrane
protein conformational changes are
propagated across the cell membrane :
1)opening and closing of ion channels and resultant
current flow;
2) changes in an intrinsic enzymatic activity of the
receptor; and .
3) changes in affinities of the receptor for
intracellular proteins, which might have enzyme
activity or be enzyme regulators .

36. ELECTROPHYSIOLOGICAL Ca SIGNALING
IN MYOCYTES
It is well known that on both sides of every cell
membrane, there are large numbers of free ions
(mainly Kþ, Naþ, Cl, Ca2þ, etc.), which control the cell
volume, play an important role in signal transduction
processes, and create an intense electric field that
exists between the two sides of all cell membranes
An oscillating, external electric or magnetic field will exert an oscillating force on every free
ion on both sides of the plasma membrane, as well as on the ions within channel proteins,
while they pass through them.

37. Intracellular and
Extracellular Calcium
• As slow calcium channels close:
– intracellular Ca2+ is absorbed by the SR
– or pumped out of cell
• Cardiac muscle tissue:
– very sensitive to extracellular Ca2+
concentrations

38. The hypothesis explains why only frequencies
from the low end of the spectrum give biological
effects and why pulses and square waves are more
effective than sine
waves.
Only if the frequency is low will the calcium ions
have time to be pulled clear of the membrane and
replaced by potassium ions before the field reverses and
drives them back. Pulses and square waves work best
because they give very rapid changes in voltage that
catapult the calcium ions well away from the membrane
and then allow more time for potassium to fill the vacated
sites. Sine waves are smoother, spend less time at
maximum voltage, and so allow less time for ion exchange.

39. Calcium Changes
Calcium is an important and ubiquitous inorganic ion that
serves as a messenger in numerous biochemical events
)Rasmussen and Barrett 1984 .(For example, it is involved in
muscle contraction, bone formation, cell attachment,
hormone release, synaptic transmission, maintaining
membrane potentials, function of ion channels, and cellular
regulation .It also serves as a second messenger in neural
function in which the concentration of calcium inside the cell
regulates a series of enzymatic events caused by kinases .
Thus, any exogenous agent that affects the flow of calcium
ions either into or out of the cell could potentially have a
major impact on biologic function.

40. Weak electromagnetic fields release calcium
from cell membranes
Weak fields were often more effective
than strong ones. The mechanism was
unknown at the time and it was thought
to be a trivial scientific curiosity, but as we
will see, it has huge significance for us all.

41. The signal: When an alternating electrical field from an
eddy current hits a membrane, it will tug the bound
positive ions away during the negative half‐cycle and
drive them back in the positive half‐cycle. If the field is
weak, strongly charged ions (such as calcium with its
double charge) will be preferentially dislodged. Potassium
(which has only one charge) will be less attracted by the
field and mostly stay in position. Also, the less affected
free potassium will tend to replace the lost calcium. In
this way, weak fields increase the proportion of potassium
ions bound to the membrane, and release the surplus
calcium into the surroundings. Potassium (which has only
one charge) will be less attracted by the field and mostly
stay in position. Also, the less affected free potassium will
tend to replace the lost calcium.

42. Membrane Voltage: IS THE INSIDE OF THE CELL
POSITIVE OR NEGATIVE?
‐4O MILLIVOLTS
CELL HAS
HI [K+]
AND LOW +
[Na+]
- CELL

44. How calcium is released The membrane:
Most biological membranes are negatively
charged, which makes them attract and
adsorb positive ions.

45. Mechanism
PEMFs initiate a cascade of reactions, leading
from the cell membrane to the cytoplasm to the
cell nucleus and the DNA, activating cellular
processes (Figure below).
Major effect of electromagnetic radiation is the
leakage of free calcium ions, either through the
cells’ external membranes or those surrounding
internal ‘calcium stores’.

47. The Ion Cyclotron Resonance Hypothesis
Ion cyclotron resonance (ICR) is one among a
number of possible mechanisms that have been
advanced to explain observed interactions
between weak low-frequency electromagnetic
fields and biological systems.
The properties of the applied fields used in ICR
The presence of a finite magnetostatic field,
Frequencies ranging from a few to several hundred hertz,
Magnetic intensities ranging from about 1 µT to 1 mT, and,
Orientation of the time-varying electromagnetic field to the
magnetostatic (DC)field .

48. Clinical magnetobiology.
Biomagnetism is the name given to the study of fields
emitted by living systems, and magnetobiology is the
study of the effects of magnetic fields on the body.
As an example of magnetobiology, medical researchers
have found that pulsing electromagnetic fields (PEMFs)
can “jump start” the healing process in a variety of tissues.
The most widely used example is the application of PEMFs
to stimulate the repair of fracture “nonunions.”
PROMISING DIRECTIONS
Success with PEMFs for bone healing led to research
on other tissues. It has been discovered that each tissue
responds to a particular frequency. Clinical methods are
being developed to use PEMFs to stimulate repair of
ligaments, nerves, capillaries, and skin.

49.  Recently research interest has shifted to
explore possible mechanisms for the
bone healing induced by magnetic field
exposure.
PEMF Pulsed Electromagnetic Field Therapy
Now used in hospitals when bone wont heal

50. This very simple conclusion can account for
virtually all of the known biological effects of
electromagnetic fields, including changes in metabolism,
the promotion of cancer, genetic damage, loss of fertility,
deleterious effects on brain function and the unpleasant
symptoms experienced by electro‐sensitive individuals.

51.  Was Found in USA in 1979 .
 The purpose of the Society, which now has world‐wide
membership, is to promote scientific study of the
interaction of electromagnetic energy (at frequencies
ranging from zero hertz through those of visible light)
and acoustic energy with biological systems.
 understanding fundamental mechanisms and efforts to
develop tools that can be applied by clinicians to
improve human health”.

52. Subjects of interest include:
‐ Response of living organisms to electric and
magnetic fields at frequencies from DC to visible light;
‐ Endogenous fields of biological systems;
‐ Mechanisms of interaction of electromagnetic (EM)
fields with biological systems;
‐ Absorption & distribution of EM energy in biological
models and living organisms;
‐ Diagnostic and therapeutic uses of electromagnetic
energy;
Commercial bioelectrochemical applications.

53. PIERS 2010 Xi’an
Progress In Electromagnetics Research Symposium
Biological Effects of Electromagnetic Fields
Applicators for Medical and Industrial Applications
of EM Field
Education of Electromagnetic Theory
Biomedical Electromagnetic Instruments and
Electromagnetic Condense Materials and Imaging
Physiological Effects of Static Magnetic Fields
EMC and EM protection
March 22–26, 2010
Xi’an, CHINA
For more information on PIERS, please
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