Functional Electrical Stimulation
    • Implantable stimulators for neuromuscular 
       control are the technologically most advanced 
       versions of functional electrical stimulators.
    • Their function is to generate contraction of 
       muscles, which cannot be controlled volitionally 
       because of the damage or dysfunction in the 
       neural paths of the central nervous system (CNS).
                         BME 312-BMI II-L5- ALİ IŞIN 2014
     • Their operation is based on the electrical nature of 
       conducting information within nerve fibers, from the 
       neuron cell body (soma),along the axon, where a 
       travelling action potential is the carrier of excitation.
     • While the action potential is naturally generated 
       chemically in the head of the axon, it may also be 
       generated artificially by depolarizing the neuron 
       membrane with an electrical pulse.
                            BME 312-BMI II-L5- ALİ IŞIN 2014
     • A train of electrical impulses with certain amplitude, 
       width, and repetition rate, applied to a muscle 
       innervating nerve (a motor neuron) will cause the 
       muscle to contract, very much like in natural 
       excitation. 
     • Similarly, a train of electrical pulses applied to the 
       muscular tissue close to the motor point will cause 
       muscle contraction by stimulating the muscle 
       through the neural structures at the motor point.
                            BME 312-BMI II-L5- ALİ IŞIN 2014
       The System for Delivering Stimulation 
                Pulses to Excitable Tissue
    • The system used to stimulate a nerve consists of 
      three components;
    1.A pulse generator to generate a train of pulses 
      capable of depolarizing the nerve
    2. A lead wire, the function of which is to deliver 
      the pulses to the stimulation site
    3. An electrode, which delivers the stimulation 
      pulses to the excitable tissue in a safe and 
      efficient manner.
                         BME 312-BMI II-L5- ALİ IŞIN 2014
    • In terms of location of these three components 
      of an electrical stimulator, stimulation 
      technology can be described in the following 
      terms:
    • Surface or transcutaneous stimulation, where 
      all three components are outside the body and 
      the electrodes are placed on the skin above or 
      near the motor point of the muscle to be 
      stimulated.
                        BME 312-BMI II-L5- ALİ IŞIN 2014