Xi’an Jiaotong University

Biomedical Engineering Research institute

Presented by : Mohammed Ygoub EsmailStudent Number:

4107037013

28. 12.2009

Low Electromagnetic Field Interact with the Excitable Cell

▪

Cells that produce electrical signals when stimulated are called Excitable Tissues. These are:

Nerve cellsMuscle cells

Electromedicine

or 

electromagnetic 

medicine  are 

the 

terms 

applied 

to 

such 

developments 

in 

the ELF, LF, RF, IR, visible or UV band. 

1913 early ECG recording

DuchenneElectrical stimulation of muscle

Victorian Energy Machines 

Using Induction Coils – Faradic Electric Current

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).

In heart math institute they found that heart has a very strong In heart math institute they found that heart has a very strong

electrical field which affects all surrounding people. Thereforeelectrical field which affects all surrounding people. Therefore human human can communicate with others only with his heart without talking.can communicate with others only with his heart without talking. !! !! Also they found a relation between number of heart pulses and thAlso they found a relation between number of heart pulses and the e transmitted waves from brain (Alfa waves). The more heart pulsestransmitted waves from brain (Alfa waves). The more heart pulses the the more transmitted waves from brain.more transmitted waves from brain.

The electrical field ofThe electrical field of

heartheart

HEARTHEART

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

information. information. 

Heart Heart …………Transmits information to brainTransmits information to brain

HeartHeart

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.

Personal Magnetic FieldThe Heart is most electrical organPushing blood through coiling AortaConducted by salty bloodProduction of Magnetic field

Cardiac Muscle Cells

Intercalated discs:interconnect cardiac muscle cellssecured by desmosomeslinked by gap 

junctionsconvey force of 

contraction propagate

action 

potentials

Characteristics of  Cardiac Muscle Cells1.

Small size

2.

Single, central nucleus3.

Branching interconnections between 

cells4.

Intercalated discs

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.

•

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.

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

•

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

Magnets

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.

Electric and Magnetic fields line

For each of the magnets draw each and write whether

 they will repel or attract each other

1

2

3

Attract

Repel

Repel

Al ZnAg

Cu

Au

Mg

Electromagnetism : Magnetic?

N

S

Fe

NiCo

Only Iron [Fe], Nickel [Ni] and Cobalt [Co] are.

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).

Before listing the requirements, a simple consideration about ELF fieldcharacteristic must be done…At ELF the electric and magnetic part of EM field can be consideredacting 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 dielectricproperties (conductivity and permittivity) of the body tissues.On the contrary, the magnetic field penetrate the body virtuallyunperturbed 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”

Basic concepts and definitions

LOOP: single circular or square wireCOIL: several turns of wire

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

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)

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.

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.

Cell membrane is not just a ‘skin’

–

it controls what comes in & what goesout The Phospho‐bilipid

molecules form an electromagnetic array

Biological Molecules

All matter vibrates at various frequencies (including our cells tissues organs)We have an energy bodyIt 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 piezoelectricsThey are liquid crystals and semi conductors

▪

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)

▪

TerminologyNormal, unpolarized, equlibriumNo difference in polarity, charge or concentrationPolarized:Differences in charge (+ or -) across membraneMembrane potential not 0 mVResting Membrane Potential:Membrane potential of the cell at restDepolarization:Membrane potential becomes less negative than

resting levelRepolarization:Membrane potential returning to resting levelHyperpolarization:Membrane potential more negative than resting

level

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

3 Steps of  Cardiac Action Potential1.

Rapid depolarization: 

–

voltage‐regulated sodium channels (fast channels) open

3 Steps of  Cardiac Action Potential2.

As sodium channels close:

–

voltage‐regulated calcium channels (slow  channels) open

–

balance Na+

ions pumped out–

hold membrane at 0 mV plateau

3 Steps of  Cardiac Action Potential3.

Repolarization: 

–

plateau continues–

slow calcium channels close

–

slow potassium channels open–

rapid repolarization

restores resting 

potential 

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 .

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.

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

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.

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.

Calcium Changes

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.

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. 

Membrane Voltage: IS THE INSIDE OF THE CELL  POSITIVE OR NEGATIVE? 

CELL

CELL HASHI [K+]AND LOW[Na+]

+

-

‐4O MILLIVOLTS

How 

calcium 

is 

released 

The 

membrane:  Most 

biological 

membranes 

are 

negatively 

charged, 

which 

makes 

them 

attract 

and  adsorb positive ions. 

MechanismPEMFs

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’.

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 .

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 DIRECTIONSSuccess 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.

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

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.

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”.

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.

PIERS 2010 Xi’anProgress In Electromagnetics Research Symposium

March 22–26, 2010Xi’an, CHINA

www.emacademy.orgwww.piers.org

For more information on PIERS, please  visit the following website address:

Biological Effects of Electromagnetic Fields Applicators for Medical and Industrial Applications 

of EM FieldEducation of Electromagnetic TheoryBiomedical Electromagnetic Instruments and 

Electromagnetic Condense Materials and ImagingPhysiological Effects of Static Magnetic FieldsEMC and EM protection