Interferential Current IFC Flashcards
(25 cards)
True or false
IFC is one of the WIDELY USED electrophysical agents by physical therapists
True
Definition of IFC
How is it produced
Low frequency, amplitude-modulated electrical current
(Less than 1000 cps)
Technical term: beat amplitude-modulated sinusoidal alternating current
It results from the interference caused by the crossing of two or three MEDIUM frequency (3000 - 5000 cps) alternating sine-wave currents with different carrier frequencies.
(Within 200 Hz difference between the two waves)
The currents intercept at the site of pathology to produce LOW frequency AC current
What is a beat?
What does it result from?
What is beat frequency + its range ?
Beat: a group of pulses or cycles separated by a time interval during which no electrical activity occurs (used for IFC)
Result from interference between two currents of different frequencies
Beat frequency: difference between the carrier frequency of the two circuits (1 - 200 beats per second)
Advantage of medium frequency current
Overcomes skin resistance and discomfort better than low frequency
Examples:
( 3200 Ω at 50 Hz)
( 40 Ω at 4000 Hz )
- so the higher the frequency = the less the skin resistance
Methods of delivery
Bipolar (premodulated) mode
Bipolar: 2 electrodes applied on target area
Premodulated: electronic interference occurs WITHIN THE DEVICE
(ONLY method that is modulated, meaning interference does not occur at the tissue)
Quadripolar (true interferential mode)
- electrodes
- shape
Quadripolar: 4 electrodes (2 pair of electrodes)
True interferential : interference occurs WITHIN soft tissues
Resultant current field = four-leaf clover shape
Quadripolar with automatic vector scan mode
What is a vector scan?
What are the advantages & disadvantages of vector scan ?
Similar to Quadripolar true interferential mode
BUT it covers MORE tissue area using a vector scan.
Vector scan:
- current in one circuit is allowed to vary (50-100%) of its maximum value
- current in the other circuit has fixed value
- field is rotated at an angle of 45 ° in each direction (nearly circular shape)
Advantage:
- equal distribution
- prevent nerve habituation
Disadvantage:
- effective time is not enough for target tissue due to distribution of current
(ONLY method that is DYNAMIC, the others are all STATIC)
Stereodynamic mode
- electrodes
- shape
- advantage
Three medium frequency allows for 3D interferential field
Total of 6 electrodes:
- 3 pairs of 2 electrodes
- 2 pairs of Y-shaped electrodes
Shape : six-petal flower
Advanatge: less adaptation and more effectiveness
Indications for IFC (hint: 10)
Pain
- acute pain
- post-operative pain
- chronic pain
Urinary and rectal incontinence
Muscle spasm
Trigger spots in myofascial syndrome
Osteoarthritis
Rheumatoid arthritis
Patellofemoral pain syndrome
Re-educate muscles
Delayed fracture union
Swelling or hematoma
Contraindications for IFC
Abdomen, pelvic, lumbar region of pregnant woman (induces labor + affect fetal development)
Anterior transcervical area (vagus/phrenic/carotid sinuses)
Venous thrombosis (embolism)
Arterial disease (embolism)
Malignancy (metastasis)
Impaired sensation
(More in picture)
Therapeutic uses (hint : 4)
- Increase local circulation
- vasodilation (parasympathetic activity + muscle contractions)
- used to treat circulatory disorders (ex: Raynaud’s disease) - Soft tissue healing
- fracture healing
- wound healing - Decrease incontinence
- re-educate pelvic floor muscles PFM and sphincters - Muscle stimulation:
- (1-10 Hz) = series of twitches
- (50 Hz) =- tetanic contractions
Theoretical mechanisms support the analgesic effects of IFC
What are these mechanisms?
- explain
- frequency
Gate control theory
- A-beta fiber activity will block the synaptic transmission of small A delta and C fibers = blocking pain
- Frequency: 90-100 Hz
Central biasing theory
- direct block of nociceptive activity by intense stimulation of small C fibers = stimulation of descending neurons
- Frequency: 90-100 Hz
Opiate control theory
- stimulate sensory nerves will lead to the release of enkephalin, B-endorphins = inhibits pain
(NOTE: enkephalin is an opiate-like chemical)
- Frequency: 10 Hz
Factors governing the success of IFC treatment
Considerations for application
Stimulator type
Electrode types
Another name for glove electrode ?
Frequency ?
Used for what?
Electrokinesy
50 Hz
Pain and muscle spasm
How are the electrodes attached/fixated to the treatment area?
Coupling media for IFC
Electro conductive gel
Water (wet sponges)
Suggested parameters for the following
Precautions when using IFC include
- greater the heat produced = higher the risk for irritation, damage, burn ( can be avoided with enough medium)
- avoid high currents
Dangers with IFC
Stimulator electronic interference
( at least 3 meters away from SWD)
Contact dermatitis
- prolonged electrode use
- conductive gel
- adhesive tape
Burns
- exposed metal electrode against skin
- high intensity
- insufficient moisture
- reduced/impaired sensation
- unreliable patient
Temporary bruising / hematoma
(Strong suction force)
Muscle damage
- repeated mechanical stress on same motor units
What do you warn the patient for IFC treatment
Expected feeling:
- mild pleasant tingling feeling
- should not feel heat or burning sensation
- should not be pinching sensation from electrode
- symptoms should not increase
- patient should call you if they need anything
- should not move or touch electrodes or equipment
