Interferential current

Interferential current

1.) medium frequency currents penetrate deeper. IFC uses 3000-5000 hz

2.) uses slightly different frequency currents (2 channels = 4 electrodes), must apply electrode in crisscross pattern

3.) treatment frequency is produced by the interference of the 2 currents in the body

4.) treatment frequency based on type of pain

Constructive interference

when two sinusoidal waves that are exactly in phase combine, the waves supplement each other in constructive interference

Destructive interference

when two sinusoidal waves are exactly out of phase the result is cancellation of both waves

Heterodyne

combination of constructive and destructive interference resulting in a wave with a beat effect

True interferential

1.) electrodes are applied quadripolar → in a diagnonal or crisscross fashion, creates a cloverleaf patterned treatment area

2.) most intense where current cross, some units can use target to change intensity where patient feels max muscle stimulation

3.) Target: some machines have this feature, can reduce inaccuracy of therapy targeting the painful tissues

Premodulated current

1.) same as IF but interference occurs in machine, not body

2.) pain relief, good for small treatment areas → use 2 electrodes on either side of the pain

3.) allows for effective pain control with 2 electrodes

Bipolar electrode placement

1.) mix of two channels occurs in generator instead of tissues

2.) claim: does not penetrate tissues as deeply, but is more accurate

3.) good for one muscle or muscle group

Vector scan

1.) quadripolar electrode placement, uses True IF

2.) varies the amplitude between channels, cloverleaf pattern rotates

3.) larger treatment area

Stereodynamic

3 channels, 6 electrodes

3D interference pattern = 6 petal flower shape

Effects of IFC/indications

1.) pain reduction (acute and chronic)

2.) muscle strengthening / re-education: Esp. pelvic floor, secondary consideration, Russian stim is better

3.) slow bowel transit

Contraindications

1.) anterior cervical area

2.) through the chest

3.) through the head

4.) pacemakers and implantable cardioverter-defibrillator

5.) abdomen, pelvis, lumbar areas of pregnant women in their first trimester

6.) metal implants

7.) epilepsy

8.) areas of hemorrhage

9.) cancer

10.) confused and unreliable patients

11.) damaged skin

12.) unknown etiology

Risks

skin irritation

Parameter settings: Pain

1.) Beat frequency:

-Acute = high setting 80-150 (60-120)

-chronic = low 0-15

-subacute = 1-150

2.) treatment time = 15-20 minutes

3.) amplitude: patient comfort (tingling)

Parameter settings: strength

1.) amplitude → patient tolerance (40-70% of MVC)

2.) treatment (beat frequency): 40-60hz

3.) premodulated IFC with bipolar electrodes

4.) duty cycle = 10:50 (10 seconds on and 50 second off)

5.) use ramp time