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Elf on the excitable cell

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Low Electromagnetic Field Interact with the Excitable Cell …

Low Electromagnetic Field Interact with the Excitable Cell

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  • 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.
  • 13. 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
  • 14. 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
  • 15. 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.
  • 16. Electric and Magnetic fields line
  • 17. For each of the magnets draw each and write whether  they will repel or attract each other 1 Attract 2 Repel 3 Repel
  • 18. Electromagnetism : Magnetic? Only Iron [Fe], Nickel [Ni] and Cobalt [Co] are. S Co Ni N Au Fe Cu Mg Ag Al Zn
  • 19. 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).
  • 20. 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”
  • 21. Basic concepts and definitions LOOP: single circular or square wire COIL: several turns of wire
  • 22. 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
  • 23. 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)
  • 24. 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.
  • 25. 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.
  • 26. 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
  • 27. 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
  • 28. ▪ 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)
  • 29. ▪ 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
  • 30. What events take  place during an action potential  in cardiac muscle?
  • 31. 3 Steps of  Cardiac Action Potential 1. Rapid depolarization:  – voltage‐regulated sodium channels (fast channels) open
  • 32. 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
  • 33. 3 Steps of  Cardiac Action Potential 3. Repolarization:  – plateau continues – slow calcium channels close – slow potassium channels open – rapid repolarization restores resting  potential 
  • 34. 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 .
  • 35. 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.
  • 36. 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
  • 37. 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.
  • 38. 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.
  • 39. 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.
  • 40. 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. 
  • 41. Membrane Voltage: IS THE INSIDE OF THE CELL  POSITIVE OR NEGATIVE?  ‐4O MILLIVOLTS CELL HAS HI [K+] AND LOW + [Na+] - CELL
  • 42. How  calcium  is  released  The  membrane:  Most  biological  membranes  are  negatively  charged,  which  makes  them  attract  and  adsorb positive ions. 
  • 43. 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’.
  • 44. 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 .
  • 45. 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.
  • 46.  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
  • 47. 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.
  • 48.  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”.
  • 49. 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.
  • 50. 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  visit the following website address: www.emacademy.org www.piers.org