Faculty of biomedical engineering saeed aghvami 1386 fall

Importance

 Understanding natural function of nerve and muscle  Clinical diagnosis, therapy, and rehabilitation  Electric and magnetic field stimulation

Number of variables

• geometry of the tissue being stimulated • Electrical characteristics • Location of the stimulus electrodes

Spherical cell stimulation

• In a spherical cell, the response to stimulus depend only on time

• S= strength of stimulation

Rheobase

(1) And (2) (1) (2) (3)

0 (1)

Symmetric

• Vm is non zero for all values of x • The effect of the stimulus varies with x.

•The magnitude of Vm increases as extracellular resistance increases • • Positive current at the origin leads to hyperpolarized as a measure of the distance from source

L

countinoued (1) (*) (2) (*)

For finite values of x At steady state

The Activating Function

Rest conditions

Subthreshold linear conditions

Initial stimulus

+30 Results

+118 +8

(1) , (2) (1) (3) (2)

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