Galvanic currents

Galvanic CurrentsGalvanic Currents

Dr.Deepak Anap,Asso. Professor

COPT,PDVVPF

deepak.anap@hotmail.com

Galvanic Currents - Dr.Deepak

Objectives • History

• Introduction to DC

• Graphical Representation

• Interrupted DC

• Wave form Characteristics – Duration and Frequency

• IDC Waveforms

Galvanic Currents - Dr.Deepak

History

• Luigi Galvani ,an Italian Physiologist-on whose honor galvanic current is named.

• First to show that when electric current is passed through the legs of a frog, it twitched, way back in 1791.

Galvanic Currents - Dr.Deepak

Galvanic Currents - Dr.Deepak

Definition

• In DC, electrical current flows in one constant direction, as opposed to AC, in which the current constantly reverses direction.

• Ex of a device that provides DC : battery. • DC ultimately supplies power to nearly all

electronic devices (even if these devices require a component to convert AC current into DC current).

Galvanic Currents - Dr.Deepak

DC Vs AC

Galvanic Currents - Dr.Deepak

Galvanic Currents - Dr.Deepak

Modifications of DC

• Interruption – most usual modification of DC

• Interrupted DC

• Current flow commencing & ceasing at

regular intervals

Galvanic Currents - Dr.Deepak

Wave form Characteristics

• Duration

• Duration 100,300,600ms used for Treatment with IDC

Galvanic Currents - Dr.Deepak

Duration

• Frequency: No. of impulses/Sec• Depends on duration of Interval between the

impulses• Duration α 1/Frequency

Galvanic Currents - Dr.Deepak

Duration of interval

Galvanic Currents - Dr.Deepak

IDC waveforms

Galvanic Currents - Dr.Deepak

DC

Rectangular IDC

Current rises suddenly, constantly maintained for the duration of the stimulus then turned off abruptly

Triangular Pulses

• Traingular: has an equal phase of slow rise and then slow falling off in intensity

Galvanic Currents - Dr.Deepak

Trapezoidal Pulses

Current rises slowly, plateaus for a short period then gradually declines

Galvanic Currents - Dr.Deepak

Saw Tooth Pulses

current is gradually raised then turned off abruptly

Galvanic Currents - Dr.Deepak

Depolarised Wave Form

• Current of low intensity flows in reverse direction

• Chemical formation because of DC is reduced

Galvanic Currents - Dr.Deepak

Thank you