06-06: Interferential Current

Question 1

Interferential Current (IFC)

Answer 1

• Combines 2 medium fequency alternating waveforms that are biphasic that interfere with each other in the tissue
• Reaches deeper tissue because of higher frequency and shorter pulse width

Question 2

TENS vs. IFC

Answer 2

• TENS is lower frequency; IFC is medium current
• Less accommodation with IFC than TENS
• IFC is 1) more comfortable, 2) reaches deeper tissue, 3) avoids accommodation

Question 3

Primary applications

Answer 3

• Pain Management

- Muscle Contraction

Question 4

Pain Management - Parameters

Answer 4

• Beat Frequency: 50-120 pps

- Pulse Width: 50-150 microsec

Question 5

Muscle Contraction - Parameters

Answer 5

• Beat Frequency: 20-50 pps

- Pulse Width: 100-200 microsec

Question 6

Vector Scan

Answer 6

• Automatic: allows interference of the 2 medium frequency waves to encompass a larger area
• Manual: allows PTA to more precisely pinpoint the treatment area

Question 7

Sweep

Answer 7

• Helps to avoid accommodation
• Off: Set Beat Frequency (one number)
• On: Set Beat High and Beat Low; machine will modulate the current between these 2 numbers

Question 8

Beat Frequency

Answer 8

Resultant frequency that is delivered to the tissue after the two medium frequency waves destructively interfere with each other

Question 9

Carrier Frequency

Answer 9

Lower of the two medium frequency waves that are generated by the the machine; other frequency wave is the sum of the carrier frequency and the beat frequency

Question 10

Indications for IFC

Answer 10

• Pain management
• Urinary Incontinence
• Edema Management
• Osteoarthritic pain
• Migraines

Question 11

Contraindications for IFC

Answer 11

• Malignancy
• All types of electronic implants
• 1st trimester of pregnancy
• Over pregnant uterus
• Over anterior transcervical area

Question 12

Delivery Methods (3)

Answer 12

• Bipolar (Pre-modulation)
• Quadripolar
• Quadripolar with automatic vector scan

Question 13

Bipolar delivery

Answer 13

• Allows IFC to be modulated prior to delivery of current (“Pre-modulated” or “Pre-Mod”)
• 2 electrodes connected to same channel with 2 medium sinusoidal currents
• Interference of 2 currents occurs in the machine and creates an amplitude modulation with a beat frequency that is delivered to tissue
• Ex: one current is 3,000 Hz (carrier frequency), second is 3,050 Hz; Beat frequency is 50 Hz

Question 14

Quadripolar delivery

Answer 14

• Interference of the currents, and thus moduation, occurs in tissue
• Electrodes #1 and #2 connected to one channel, #3 and #4 connected to another
• Electrode placement is criss-cross pattern surrounding treatment area, current forms a cloverleaf pattern
• Target area is in the center of the electrodes

Question 15

Quadripolar with Automatic Vector Scan Delivery

Answer 15

• Used when increasing the size of the current field
• Machine allows you to move current field around after the set up to focus field over the target area
• Field is circular rather than cloverleaf

Question 16

Documentation of IFC

Answer 16

• Bipolar (Pre-Mod) or Quadripolar (Interferential)
• Exact placement of electrodes
• Parameters
• Duration
• Beat Frequency, Carrier Frequency
• Vector Scan on or off
• Sweep on or off (If on, what is beat high, beat low)
• Position of patient