HVPS & Interferential HVPS & Interferential StimulationStimulation

Adapted from Adapted from Therapeutic Therapeutic Modalities: Art & ScienceModalities: Art & Science, , Knight & Draper (2008) for Knight & Draper (2008) for

KIN 195KIN 195

Competencies for Competencies for Therapeutic ModalitiesTherapeutic Modalities

TM-C2TM-C2Explain the principles of physics, including basic Explain the principles of physics, including basic

concepts associated with the electromagnetic concepts associated with the electromagnetic and acoustic spectra (e.g., frequency, and acoustic spectra (e.g., frequency, wavelength) associated with therapeutic wavelength) associated with therapeutic modalities.modalities.

TM-C3TM-C3

Explain the terminology, principles, basic concepts, Explain the terminology, principles, basic concepts, and properties of electric currents as they relate and properties of electric currents as they relate to therapeutic modalities.to therapeutic modalities.

TM-C4TM-C4Describe contemporary pain-control theories.Describe contemporary pain-control theories.

Competencies for Competencies for Therapeutic Modalities, Therapeutic Modalities,

cont.cont.TM-C6TM-C6

Explain the body's physiological responses during Explain the body's physiological responses during and following the application of therapeutic and following the application of therapeutic modalities.modalities.

TM-C7TM-C7Describe the electrophysics, physical properties, Describe the electrophysics, physical properties,

biophysics, patient preparation and modality set-biophysics, patient preparation and modality set-up (parameters), indications, contraindications, up (parameters), indications, contraindications, and specific physiological effects associated with and specific physiological effects associated with commonly used therapeutic modalities.commonly used therapeutic modalities.

TM-C8TM-C8 Identify appropriate therapeutic modalities for the Identify appropriate therapeutic modalities for the treatment and rehabilitation of injuries and treatment and rehabilitation of injuries and illness.illness.

Law of DuBois Reymond:Law of DuBois Reymond:

• The The amplitudeamplitude of the individual stimulus of the individual stimulus must be high enough so that depolarization must be high enough so that depolarization of the membrane will occur.of the membrane will occur.

• The The rate of changerate of change of voltage must be of voltage must be sufficiently rapid so that accommodation sufficiently rapid so that accommodation does not occurdoes not occur

• The The durationduration of the individual stimulus must of the individual stimulus must be long enough so that the time course of be long enough so that the time course of the latent period (capacitance), action the latent period (capacitance), action potential, and recovery can take placepotential, and recovery can take place

For all modalities…For all modalities…• Know the effects, indications, Know the effects, indications,

contraindications, & precautionscontraindications, & precautions• Verify the modality is set up correctly Verify the modality is set up correctly

before treatment beginsbefore treatment begins• Prepare the patient psychologically & Prepare the patient psychologically &

physically for the treatmentphysically for the treatment• Begin treatment conservatively and ask Begin treatment conservatively and ask

for patient feedbackfor patient feedback• At the end of treatment, clean up the At the end of treatment, clean up the

modality and instruct the patient about modality and instruct the patient about next treatment and activity level until next treatment and activity level until thenthen

• Maintain the machines appropriatelyMaintain the machines appropriately

Review: Requirements for Review: Requirements for Ion Migration: Chemical Ion Migration: Chemical

EffectsEffects • Must have continuous monophasic DC Must have continuous monophasic DC

electron flow to cause ion migration. electron flow to cause ion migration. • Moving electrons against gradientMoving electrons against gradient

– Like pushing a car uphillLike pushing a car uphill– When you pause, it rolls back down.When you pause, it rolls back down.

• Why does a twin-pulse high-volt current Why does a twin-pulse high-volt current not produce a chemical effect? not produce a chemical effect?

Review: Pulse and Cycle Review: Pulse and Cycle Characteristics (cont.)Characteristics (cont.)

• Pulse named by Pulse named by number of phasesnumber of phases– MonophasicMonophasic

• One phaseOne phase• Current flows in one Current flows in one

direction only.direction only.

– BiphasicBiphasic• Two phasesTwo phases• Current flows in both Current flows in both

directions.directions.

– PolyphasicPolyphasic• Many phasesMany phases

Review: Current Timing Review: Current Timing & Modulation& Modulation

• Pulse width (pulse Pulse width (pulse duration)duration)

– Time required for each Time required for each pulse to complete its cyclepulse to complete its cycle

– Reported in microseconds Reported in microseconds or millisecondsor milliseconds

• Short pulse duration: Short pulse duration: <150 <150 µµsecsec

• Long pulse duration: Long pulse duration: >200 >200 µµsecsec

• Interpulse interval Interpulse interval – Time between successive Time between successive

pulsespulses

Commonly Used Wave Commonly Used Wave FormsForms (p. 142, cont.) (p. 142, cont.)• Twin pulse wave formTwin pulse wave form

– Monophasic, pulsed, twin spikedMonophasic, pulsed, twin spiked– Common wave form of high-volt muscle simulatorsCommon wave form of high-volt muscle simulators

– Has been called Has been called high-volt galvanichigh-volt galvanic and and pulsed direct pulsed direct currentcurrent

– However, not direct or galvanic currentHowever, not direct or galvanic current– Result of misunderstanding physiologyResult of misunderstanding physiology

High Voltage Pulsed High Voltage Pulsed Current Stimulation for Current Stimulation for

Wound HealingWound Healing•Electrical stimulation for the Electrical stimulation for the

purpose of repairing tissues purpose of repairing tissues includes management of open includes management of open wounds and edema reduction.wounds and edema reduction.

•Production of a twin-peak, Production of a twin-peak, monophasic, pulsed current driven monophasic, pulsed current driven by its characteristically high by its characteristically high electromotive force or voltageelectromotive force or voltage

•Positive or negative polarity Positive or negative polarity

HVPC Common HVPC Common TreatmentsTreatments

• Versatile and can perform several Versatile and can perform several functions:functions:

– Wound healing (only proven electrical Wound healing (only proven electrical modality proven to promote wound modality proven to promote wound healing)healing)

– Pain modulation (acute & chronic)Pain modulation (acute & chronic)– Muscle reeducation and spasm reductionMuscle reeducation and spasm reduction– Edema reduction (maybe)Edema reduction (maybe)

Characteristics of High-Volt Characteristics of High-Volt StimulatorStimulator

• Low volt stimulators generate <150 V Low volt stimulators generate <150 V • High volt stimulators generate >150 VHigh volt stimulators generate >150 V• HVPC uses between 150 and 500 V.HVPC uses between 150 and 500 V.• Low average current Low average current • Twin peak monophasic waveform Twin peak monophasic waveform

– Resembles a double spike with a fast rise Resembles a double spike with a fast rise followed by a fast decline followed by a fast decline

• Short pulse widths (100Short pulse widths (100––200 200 µµsec)sec)• Pulse rates of 1Pulse rates of 1––200 Hz200 Hz• Generally HVPS uses lower currentGenerally HVPS uses lower current

ReviewReview

• What is HVPS stand for? Why isn’t it What is HVPS stand for? Why isn’t it HVGS, according to Knight & Draper?HVGS, according to Knight & Draper?

• Describe the HVPS waveform.Describe the HVPS waveform.• Name the 4 common uses for HVPS.Name the 4 common uses for HVPS.• Does HVPS utilize high voltage or Does HVPS utilize high voltage or

high current to achieve outcomes?high current to achieve outcomes?• What is the voltage cutoff between What is the voltage cutoff between

high and low voltage stimulators?high and low voltage stimulators?

HVPC: Uses & HVPC: Uses & TechniquesTechniques

•Monophasic current used forMonophasic current used for– Wound managementWound management– Acute pain reductionAcute pain reduction– Reduction of edemaReduction of edema

•Bipolar TechniqueBipolar Technique– Bipolar used for muscle contraction Bipolar used for muscle contraction

or chronic pain (Note: HVPS is not or chronic pain (Note: HVPS is not as effective as NMES for muscle as effective as NMES for muscle contraction b/c of lower current in contraction b/c of lower current in HVPS)HVPS)

HVPC: AdvantagesHVPC: Advantages

1. Less resistance to the 1. Less resistance to the current by the skincurrent by the skin

2. Short phase duration 2. Short phase duration allows for moderately allows for moderately high-intensity muscle high-intensity muscle contraction with little contraction with little discomfortdiscomfort

– Other types of Other types of stimulators provide a stimulators provide a stronger contractionstronger contraction

3. 3. Highly variable in its Highly variable in its functionsfunctions

4. 4. Can be used for Can be used for – Wound healingWound healing– Pain modulationPain modulation

a. Sensory level (acute a. Sensory level (acute pain)pain)

b. Motor level b. Motor level (chronic pain)(chronic pain)

– Treating muscle Treating muscle weaknessweakness

– Edema reductionEdema reduction

HPVC: DisadvantagesHPVC: Disadvantages

DisadvantagesDisadvantages1.1. Cannot provide as strong of a Cannot provide as strong of a

contraction as NMEScontraction as NMES

2.2. Many aren’t portable.Many aren’t portable.

3.3. Sometimes trial and error are needed Sometimes trial and error are needed to determine electrode polarity for to determine electrode polarity for wound healing.wound healing.

4.4. Effects (muscle contraction) are not as Effects (muscle contraction) are not as strong as low-volt units.strong as low-volt units.

HPVC: Indications & HPVC: Indications & ContraindicationsContraindications

IndicationsIndications1.1. Wound lesions Wound lesions

(pressure sores, (pressure sores, scarring from scarring from incisions)incisions)

2.2. Edema control and Edema control and reductionreduction

3.3. Residual or chronic Residual or chronic muscle spasm muscle spasm (when low-volt unit (when low-volt unit unavailable)unavailable)

4.4. PainPain

ContraindicationsContraindications1.1. Do not use on Do not use on

patient with patient with pacemakerpacemaker

2.2. Do not use overDo not use overa.a. Heart or brainHeart or brain

b.b. Lumbar and Lumbar and abdominal area of abdominal area of pregnant womenpregnant women

c.c. Potential Potential malignanciesmalignancies

d.d. Anterior cervical Anterior cervical areaarea

HPVC PrecautionsHPVC Precautions

PrecautionsPrecautions1. Be cautious when using HVPC over 1. Be cautious when using HVPC over

an area with:an area with:a. Impaired sensationa. Impaired sensation

b. Extensive torn tissue (no use of bipolar)b. Extensive torn tissue (no use of bipolar)

c. Hemorrhagic areac. Hemorrhagic area

2. Patients with epilepsy should be 2. Patients with epilepsy should be monitored during treatment.monitored during treatment.

ReviewReview

• What are the monopolar and bipolar What are the monopolar and bipolar uses of HVPS?uses of HVPS?

• Name the 4 advantages of HVPS?Name the 4 advantages of HVPS?• Name the 4 disadvantages of HVPS?Name the 4 disadvantages of HVPS?• What are the 4 indications for HVPS?What are the 4 indications for HVPS?• What are the 5 contraindications for What are the 5 contraindications for

HVPS?HVPS?• What are the 4 precautions for HVPS?What are the 4 precautions for HVPS?

HVPC: Wound HVPC: Wound ManagementManagement

• How does HVPC stimulate wound repair?How does HVPC stimulate wound repair? – Body possesses bioelectric currents in the Body possesses bioelectric currents in the

vascular and interstitial tissues.vascular and interstitial tissues.– Blood vessel walls, insulating tissue Blood vessel walls, insulating tissue

matrix, interstitial fluid, and intravascular matrix, interstitial fluid, and intravascular plasma are capable of conducting plasma are capable of conducting bioelectricity.bioelectricity.

– When tissues are damaged, an electrical When tissues are damaged, an electrical potential is created between injured and potential is created between injured and noninjured tissues.noninjured tissues.

HVPC: Wound Management HVPC: Wound Management (cont.)(cont.)• Polarity may stimulate cellular activity when Polarity may stimulate cellular activity when

injured.injured.• Stimulating dStimulating déébridement of injured tissuesbridement of injured tissues• Tissue regeneration and remodelingTissue regeneration and remodeling• May speed up healing by promoting the natural May speed up healing by promoting the natural

healing processhealing process• May develop a difference in potential between May develop a difference in potential between

wound area and the surrounding healthy tissuewound area and the surrounding healthy tissue• Injury potential typically becomes positive 24Injury potential typically becomes positive 24––

48 hr after injury & negative 848 hr after injury & negative 8––9 days after 9 days after injury.injury.

• As the wound heals, the difference slowly As the wound heals, the difference slowly returns to baseline.returns to baseline.

– Can be used to enhance the natural process of tissue Can be used to enhance the natural process of tissue recovery and healingrecovery and healing

HVPC: Edema HVPC: Edema ManagementManagement

•Curbing edema formationCurbing edema formation– HVPC does not use DCHVPC does not use DC– Decreases the permeability of Decreases the permeability of

microvessels microvessels – Decreases the leaking of vessels, Decreases the leaking of vessels,

reducing the number of plasma proteins reducing the number of plasma proteins and amount of fluid that leave the and amount of fluid that leave the vessels to enter the interstitial spacesvessels to enter the interstitial spaces

HVPC: Edema Management HVPC: Edema Management (cont.)(cont.)

• Two protocols for curbing edema Two protocols for curbing edema Water immersionWater immersion

-Negative polarity -Negative polarity -120 pps -120 pps -90% of visible motor threshold-90% of visible motor threshold-30 min treatments every 4 hr-30 min treatments every 4 hr-Apply ASAP postinjury or as long as edema is still -Apply ASAP postinjury or as long as edema is still

formingforming

Resolution of edema once formedResolution of edema once formed-Can be employed in a muscle pumping action -Can be employed in a muscle pumping action to get rid of edemato get rid of edema-Intensity increased until strong muscle -Intensity increased until strong muscle contraction contraction -Setting of 1-Setting of 1––10 pps for muscle contraction10 pps for muscle contraction

HVPC: Pain ModulationHVPC: Pain Modulation

• Ineffective in reducing the pain of Ineffective in reducing the pain of delayed-onset muscle sorenessdelayed-onset muscle soreness

•Yet has been shown to help relieve Yet has been shown to help relieve pain caused by muscle spasmpain caused by muscle spasm

HVPC: Electrode HVPC: Electrode PolarityPolarity

• Negative polarityNegative polarity– IncreasesIncreases

• VascularityVascularity• Stimulation of Stimulation of

fibroblastic fibroblastic growthgrowth

• Collagen Collagen productionproduction

• Epidermal cell Epidermal cell migrationmigration

– Inhibits bacterial Inhibits bacterial growth growth

• Positive polarityPositive polarity – Increases Increases

macrophagesmacrophages– Promotes Promotes

epithelial growthepithelial growth

HVPC: Electrode Polarity HVPC: Electrode Polarity (cont.)(cont.)

•Most treatments begin with the Most treatments begin with the negative polaritynegative polarity– Encourages blood clots to dissolve Encourages blood clots to dissolve

and increases the inflammatory by and increases the inflammatory by productsproducts• Necrotic tissuesNecrotic tissues

•Positive polarity encourages clot Positive polarity encourages clot formation around the wound and formation around the wound and granulation tissue. granulation tissue.

REVIEW: Phases of the REVIEW: Phases of the Inflammatory ProcessInflammatory Process• Phase I: Acute Phase ( 2 subphases)Phase I: Acute Phase ( 2 subphases)

– Early (Acute): inflammatory response: lasts 2-4 Early (Acute): inflammatory response: lasts 2-4 days days

– Late (Sub-Acute): continue inflammatory phase Late (Sub-Acute): continue inflammatory phase which is usually complete in 2 weekswhich is usually complete in 2 weeks

• Phase 2: Tissue Formation (Proliferation)Phase 2: Tissue Formation (Proliferation)– Tissue rebuilding approximately 2-3 weeksTissue rebuilding approximately 2-3 weeks– This does not include chronic inflammationThis does not include chronic inflammation

• Phase 3: Remodeling PhasePhase 3: Remodeling Phase– Adapt to original tissue Adapt to original tissue – Continues for up to 1 year post injuryContinues for up to 1 year post injury

REVIEW: Phase II, REVIEW: Phase II, Stages of RegenerationStages of Regeneration

• Stage starts with periphery/outsideStage starts with periphery/outside• Re-eptheliaization is proliferation of Re-eptheliaization is proliferation of

peripheral epithelial tissue which then peripheral epithelial tissue which then migrates to the wound until the area is migrates to the wound until the area is covered.covered.

• Capillarization (Capillary buds Capillarization (Capillary buds proliferate and connect forming new proliferate and connect forming new capillaries which gives the red, capillaries which gives the red, granular appearance to the scar granular appearance to the scar (granular tissue)(granular tissue)

REVIEW: Chronic REVIEW: Chronic InflammationInflammation

• ComplicationsComplications– Granuloma: large mass of weaker scar Granuloma: large mass of weaker scar

tissue (usually due to large inflammation tissue (usually due to large inflammation and activity without regard to healing and activity without regard to healing time)time)

– Retardation of muscle fiber: with Retardation of muscle fiber: with excessive granuloma fibroblasts cannot excessive granuloma fibroblasts cannot reach damaged tissuereach damaged tissue

– Adhesions/contractures in tissueAdhesions/contractures in tissue– Keloid/hypotrophic scarsKeloid/hypotrophic scars

Application Parameters: Application Parameters: HVPCHVPC

• Frequency of applicationFrequency of application

As often as three per day if separated by 3–4 hr As often as three per day if separated by 3–4 hr

• When using the monopolar function, active When using the monopolar function, active electrode over the injury and dispersive over a electrode over the injury and dispersive over a large & remote sitelarge & remote site

• When using the bipolar function, place electrodes When using the bipolar function, place electrodes proximal & distal to the muscle bellyproximal & distal to the muscle belly

• Length of applicationLength of application

15 min if pulsed or patient is going to exercise post 15 min if pulsed or patient is going to exercise post treatmenttreatment

15 to 30 min if surge mode is used or patient is not going 15 to 30 min if surge mode is used or patient is not going to exercise post treatmentto exercise post treatment (longer tires out the (longer tires out the muscle)muscle)

ReviewReview• How does HVPS stimulate wound How does HVPS stimulate wound

repair (10 ways)?repair (10 ways)?• What are the 2 ways HVPS manage What are the 2 ways HVPS manage

edema? What are the 2 protocols?edema? What are the 2 protocols?• What are the 5 things negative polarity What are the 5 things negative polarity

in HVPS effects? What are the 2 things in HVPS effects? What are the 2 things positive polarity in HVPS effects?positive polarity in HVPS effects?

• What are the common pad placements, What are the common pad placements, duration and frequencies of treatment duration and frequencies of treatment w.r.t. HVPS?w.r.t. HVPS?

Interferential CurrentInterferential Current

• Interference or superimposition of two Interference or superimposition of two separate medium-frequency sinusoidal separate medium-frequency sinusoidal currents on one anothercurrents on one another

•Symmetrical, sinusoidal, medium Symmetrical, sinusoidal, medium frequency (2000frequency (2000––5000 Hz) AC5000 Hz) AC

•Invented in 1950; used in United States Invented in 1950; used in United States by 1980sby 1980s

•Fifth most frequently used physical Fifth most frequently used physical agentagent

Most Commonly Used Most Commonly Used Wave FormsWave Forms

DC: DC DC: DC

IF:IF: Polyphasic Polyphasic

HV: Twin pulseHV: Twin pulse

LVLV : Biphasic and polyphasic burst : Biphasic and polyphasic burst (Russian)(Russian)

TENS: BiphasicTENS: Biphasic

Commonly Used Wave Commonly Used Wave FormsForms (p. 142, cont.) (p. 142, cont.)

• Interferential wave formInterferential wave form– Symmetrical, sinusoidal, high frequency (2000Symmetrical, sinusoidal, high frequency (2000––5000 Hz) 5000 Hz)

ACAC

– Two channels, with different frequencies, used Two channels, with different frequencies, used simultaneouslysimultaneously

– Two currents cause a tissue current amplitude modulationTwo currents cause a tissue current amplitude modulation

Commonly Used Wave FormsCommonly Used Wave Forms (p. 142, cont.) (p. 142, cont.)

• Interferential wave form: current amplitude Interferential wave form: current amplitude modulationmodulationTwo identical currents

Two opposite currents

Two offset currents

Usually accomplished with two different frequency currents

• Basic principleBasic principle– Decrease tissue impedance (resistance) Decrease tissue impedance (resistance)

so simulation is less painfulso simulation is less painful• Impedance at 50Hz = ~3200 Impedance at 50Hz = ~3200 ΩΩ • Impedance at 4000 Hz = ~40 Impedance at 4000 Hz = ~40 ΩΩ• Current passes more easily through skinCurrent passes more easily through skin

• Advantages of vector patternAdvantages of vector pattern– Surface and deep stimulationSurface and deep stimulation– Targeted tissues for added benefitTargeted tissues for added benefit– Treatment of easily localized painTreatment of easily localized pain– Treatment of large areasTreatment of large areas– Treatment of poorly defined painTreatment of poorly defined pain

What Is IFC Therapy?What Is IFC Therapy?

How Does IFC work?How Does IFC work?

• Example: One channel runs at Example: One channel runs at 5000 Hz another at 5100 Hz5000 Hz another at 5100 Hz– Use a dynamic vector Use a dynamic vector (or scan for (or scan for

poorly defined pain)poorly defined pain)– Use target for easily localized painUse target for easily localized pain

– Treats most of the area bracketed by Treats most of the area bracketed by the electrodesthe electrodes (scan or dynamic vector)(scan or dynamic vector)

Is IFC Therapy Effective?Is IFC Therapy Effective?

• Those who have had success Those who have had success – Correctly position vectorCorrectly position vector– Use appropriate size and positioning Use appropriate size and positioning

of electrodesof electrodes– Use appropriate stimulation Use appropriate stimulation

parametersparameters– Persevere, if pain relief is not Persevere, if pain relief is not

immediately obtainedimmediately obtained

ReviewReview

• What is the basic principle of IFC?What is the basic principle of IFC?• What’s the advantage of the vector What’s the advantage of the vector

pattern?pattern?• What is the waveform of IFC?What is the waveform of IFC?• Why does IFC use 2 currents?Why does IFC use 2 currents?• What are 4 ways to increase the What are 4 ways to increase the

chances of effectiveness using IFC?chances of effectiveness using IFC?

IFC advantages & IFC advantages & disadvantagesdisadvantages

AdvantagesAdvantages1. More comfortable 1. More comfortable

than a TENS unitthan a TENS unita. Medium-frequency a. Medium-frequency

currents meet with currents meet with less skin resistance less skin resistance than low frequency than low frequency currents;currents; TENS uses TENS uses low frequency currentslow frequency currents

2. Stimulates tissues 2. Stimulates tissues deeper than a deeper than a

TENS unitTENS unit3. Larger coverage 3. Larger coverage

area than TENSarea than TENS

DisadvantagesDisadvantages1. Eliminates pain; 1. Eliminates pain;

doesn't deal with doesn't deal with cause of the paincause of the pain2. May mask more 2. May mask more

serious problemsserious problems3. Few portable 3. Few portable

units availableunits available4. Sometimes 4. Sometimes

becomes a becomes a panaceapanacea

IFC: Indications & IFC: Indications & ContraindicationsContraindications

IndicationsIndications1. Acute pain1. Acute pain

2. Chronic pain2. Chronic pain

3. Muscle spasm3. Muscle spasm

4. Pain that covers 4. Pain that covers a large areaa large area

ContraindicationsContraindications1. Do not use on a 1. Do not use on a

person who has:person who has:a. Implanted a. Implanted

pacemakerpacemaker

b. History of heart b. History of heart diseasedisease

2. Do not treat 2. Do not treat transthoracic areatransthoracic area

3. Discontinue if skin 3. Discontinue if skin irritation developsirritation develops

IFC: PrecautionsIFC: Precautions

PrecautionsPrecautions1. Be cautious when using IFC over:1. Be cautious when using IFC over:

a. Impaired sensationa. Impaired sensation

b. Skin lesions (cuts, abrasions, new skin, recent scar b. Skin lesions (cuts, abrasions, new skin, recent scar tissue, etc.)tissue, etc.)

2. Use caution when using IFC while 2. Use caution when using IFC while driving or operating heavy machinery.driving or operating heavy machinery.

3. A temporary decrease in pain does not 3. A temporary decrease in pain does not mean the cause of the pain has gone.mean the cause of the pain has gone.

Application Parameters: Application Parameters: IFCIFC

Adjust pulse rate settings for specific Adjust pulse rate settings for specific injuryinjury a. For acute paina. For acute pain

i. Use a high pulse rate of 80i. Use a high pulse rate of 80––200 pps200 ppsii. Pain relief is almost immediateii. Pain relief is almost immediateiii. Lasts only a few minutes to 1 hriii. Lasts only a few minutes to 1 hr

b. For chronic painb. For chronic pain i. Use a low pulse rate of 1i. Use a low pulse rate of 1––5 pps5 pps ii. Pain relief may take ½ hrii. Pain relief may take ½ hr iii. May last 6iii. May last 6––7 hr7 hr

Target or vectorTarget or vectora. Pain that is easily identifiable and pinpointeda. Pain that is easily identifiable and pinpointed

i. Use target or vector buttons to move spoti. Use target or vector buttons to move spot where current intersects to area directlywhere current intersects to area directly over painover pain

b. Pain that is hard to pinpointb. Pain that is hard to pinpointi. Use dynamic vectori. Use dynamic vector

Application Parameters: Application Parameters: IFC (cont.)IFC (cont.)

--Length of application: 20--Length of application: 20––30 min30 min

--Frequency of application: Once or --Frequency of application: Once or twice daily, as needed for paintwice daily, as needed for pain

--Duration of therapy: --Duration of therapy: Use until IFC is Use until IFC is no longer effective.no longer effective.

ReviewReview• What are the 3 advantages of IFC?What are the 3 advantages of IFC?• What are the 4 disadvantages of IFC?What are the 4 disadvantages of IFC?• What are the 4 indications for IFC?What are the 4 indications for IFC?• What are the 4 contraindications for IFC?What are the 4 contraindications for IFC?• What are the 4 precautions for IFC?What are the 4 precautions for IFC?• What’s the pps range to treat acute pain? What’s the pps range to treat acute pain?

Chronic pain?Chronic pain?• When should vector or target modes be When should vector or target modes be

used during IFC treatments?used during IFC treatments?• What are the length, frequency, and What are the length, frequency, and

duration of IFC treatments?duration of IFC treatments?