3 Parameters Amplitude: 0 to 500 mA Voltage: 0 to 500V Current: MonophasicAmplitude: 0 to 500 mAVoltage: 0 to 500VPulse Frequency: 1 to 120 ppsPulse Duration: 13 to 100 µsecPhase Duration: 20 to 45 µsecAdjustable ParametersDuty cycleElectrode alternating rateElectrode balanceIntensityPolarityProbe electrodeSurge/Ramp
4 TheoryShort-duration, high amplitude (voltage) pulses can produce comfortable, moderate contractions.Short phase duration targets sensory nerves and motor nervesWave form is modified to decrease total current to improve comfortEach electrode has a known polarityMay cause galvanic (ion) changesShort phase duration and long interpulse interval probably negates any effect
5 Uses Reeducation of peripheral nerves Delay denervation and disuse atrophy by stimulating muscle contractionsReduction of post-traumatic edemaIncrease in local blood circulation (unsubstantiated)Restoring range of motion:Reduction of muscle spasmInhibition of spasticityReeducation of partially denervated muscleFacilitation of voluntary motor function
6 Effects Neuromuscular Stimulation Pain Control Moderate to strong muscle contractionsLess torque production than NMESPain ControlSensory-level (short-term)Motor-levelAcute pain: Positive electrode over painful siteChronic pain: Negative electrode over site
7 Effects Edema Control Edema Reduction Negative electrode may prevent the formation of edemaCauses the gaps between endothelial cells to close, preventing leakageEdema ReductionMotor-level stimulation “milks” the venous and lymphatic vessels.
8 Effects Blood Flow Wound Healing Associated with frequency and intensity of muscle contractionWound HealingElectrode polarity kills or repels different microbesAssists healing and inhibits bacteria growthDirect current techniques are more effective than HVPS
9 Notes and PrecautionsMotor-level stimulation can cause unwanted tension on the muscle fibers, the tendons, or the bony insertion.Muscle fatigue can occur if the duty cycle is too high.Intense or prolonged stimulation may result in muscle spasm and/or muscle soreness.Improper use can cause electrode burns or irritation.
11 Parameters Adjustable Parameters Total current flow 0 to 100 mA Current: BiphasicTotal current flow 0 to 100 mAPulse frequency 1 to 150 ppsPulse duration 10 to 500 µsecPhase duration 5 to 250 µsecAdjustable ParametersIntensityMode (output modulation)Pulse durationPulse frequency
12 TheoryAdjustable phase durations specifically target sensory, motor, and pain fibersPhase duration is matched with pulse frequency to produce specific effectsBiphasic form prevents net residual charge
13 Uses Control of acute or chronic pain Management of postsurgical pain Reduction of post-traumatic acute pain
14 Effects High – Frequency TENS (Sensory Level) Short phase duration (< 100 µsec)High pulse frequency (60 to 100+ pps)Sensory-level outputActivates spinal gateLong-term treatmentOutput must be modulated to reduce accommodation
15 Effects Low – Frequency TENS (Motor level) Long phase duration (150 to 250 µsec)Low pulse frequency (2 to 4 pps)Motor-level outputPituitary gland releases:ACTHβ-lipotropinCauses the release of β-endorphinBinds to the A-beta and C fiber receptor sitesBlocks the transmission of pain
16 Effects Brief – Intense TENS (Noxious level) Long phase duration (300 to 1,000 µsec)High pulse frequency (> 100 pps)Noxious-level outputVery short treatment durationCreates a negative feedback loop in the CNSTheoretically “short circuits” the pain carrying loopOpiates inhibit the release of Substance PBlocks or reduces pain transmission
17 Notes and Precautions Do not use to treat pain of unknown origin TENS is a symptomatic treatmentImproper use can result in electrode burns or skin irritation.Intense or prolonged stimulation may result in muscle spasm and/or muscle soreness.Intake of 200 mg or more of caffeine may reduce the effectiveness of TENSNarcotics decrease the effectiveness of TENS
19 Parameters Current: Alternating Adjustable Parameters Intensity Beat frequency – Analogous to the number of cycles or pulses per secondBurst duty cycle – Bursts separated by periods of no stimulation (interburst interval)Interburst interval – Duration of time between burstsPremodulation (e.g., Russian Stimulation)RampSweep – Variation in the beat frequency; Set with a low value and a high valueVector/Scan – Variation in current intensityCurrent: AlternatingTwo alternating currents form a single interference current. Premodulated output is based on a single alternating current.Current: 1 to 100 mACurrent flow (RMS) 0 to 50 mAVoltage: 0 to 200 VCarrier Frequency: Fixed at 2500 to 5000 HzBeat Frequency: 0 to 299 HzSweep Frequency: 10 to 500 µsec
20 Theory High-frequency waves easily overcome skin resistance Carrier WaveInterference Wave=High-frequency waves easily overcome skin resistanceThe two waves are slightly out of frequencyThey cancel each other out and produce a frequency of 1 to 299 Hz in the tissuesResults in a comfortable stimulation capable of depolarizing sensory and motor nervesVariable Wave
25 Parameters Total current: 0 to 200 mA Adjustable Parameters Intensity Current: Biphasic, PremodulatedTotal current: 0 to 200 mAPulse frequency: 1 to 200 ppsPhase duration: 20 to 300 µsecIntrapulse interval: Appx. 100 µsecAdjustable ParametersIntensityPulses per secondDuty cycleReciprocal rateRamp
26 Theory Current type varies by manufacturer Tends to have long phase durationBiphasic and alternating current decreases possibility of electrode irritation
27 Uses Maintaining range of motion Muscle reeducation Prevention of joint contracturesPrevention of disuse atrophyIncreasing local blood flowDecreasing muscle spasm
28 Effects Can produce substantial muscular tension Capable of increasing strengthUsed when limb is immobilizedAlso slows the onset of atrophyDuty cycle is required to prevent fatigue
29 Notes and PrecautionsImproper use may result in electrode burns or skin irritationIntense or prolonged stimulation may result in muscle spasm and/or muscle soreness.An electrically induced contraction can generate too much tension within the muscleUse caution:Musculotendinous lesions, the tension from the contraction may injure the muscle or tendon fibersCases where the muscle’s bony attachment is not secure
31 Parameters Total current: Up to 5 mA Voltage: 80 V Current: DirectTotal current: Up to 5 mAVoltage: 80 VDosage: 0 to 80 mA/minAdjustable Parameters:Dosage:AmperageDurationPolarity
32 TheoryThe charges associated with a DC can “drive” medications into the tissueMedication must have an electrical chargeNegative charges driven from the cathode Attracted towards the anodeAnd vice-versaRequires specialized electrodes to hold the medication
33 Dose-Oriented Treatments Medications are delivered in mA/MinMilliamp MinutesFunction of the amount of current times the duration of the treatment:5 mA applied for 20 minutes5mA * 20 min = 100 mA/Min4 mA applied for 25 minutes4mA * 25 minutes = 100 mA/MinDose-oriented treatments provide the basis for the Ionotopatch™ which delivers the medication using a low current applied for an extended time.
34 Uses Delivers medication to the tissues to treat: Acute inflammation Chronic inflammationArthritisMyositis ossificansMyofascial pain syndromesDelivering local anesthetics before injection or other minor invasive proceduresHyperhidrosis
35 Sample Medications Medication Pathology Concentration Dosage Polarity Acetic acid Myositis ossificans 2% 80 mA/Min NegativeDexamethason Inflammation 4mg Decadron 41 mA/Min Negative and lidocaine Pain control 4% Xylocaine 40 mA/Min PositiveLidocaine and Pain control 4% Lidocaine 30 mA/Min Positive epinephrine mL/1:50, mA/Min PositiveDexamethasone Inflammation 2cc 4mg/mL 41 mA/Min NegativeRefer to the prescription for the exact treatment parameters.Each electrode size has a maximum treatment amperage. Consult the packaging information included with the electrodes.
36 Notes and PrecautionsControlled medications require a physician’s prescription:Each patient requires his/her own prescriptionFollow any notes or instructions provided by the pharmacist.State practice acts may further regulate the delivery of iontophoresis.The exact medication dosage delivered is unknown.Erythema under the electrodes is commonToo intense of a treatment dose can result in electrode burnsDo not reuse electrodesMedications remain, contaminating the electrode
38 ParametersCurrent: Monophasic. (Polarity reverses)Total current flow: 1 to 999 µA (Peak current) 25 to 600 µA (RMS)Pulse frequency: 0.1 to 1000 HzPulse duration: 0.5 to 5000 µsecPhase duration: 0.5 to 5000 µsecAdjustable Parameters:IntensityPolarity/alternating polarityRampThreshold – Ohm Meter
39 TheorySmall, subsensory pulses can affect the function of healing tissuesInjured tissues have a reversal of their normal electrical charges (“injury potential”)MET attempts to normalize the electrical potentialActivation of ATP and increased ATP levelsThe efficacy of MET has not been substantiated.
40 Uses* Acute and chronic pain Acute and chronic inflammation Reduction of edemaSprainsStrainsContusionsTemporomandibular joint dysfunctionCarpal tunnel syndromeSuperficial wound healingScar tissueNeuropathies* Efficacy has not been established
41 Notes and PrecautionsIf the patient is dehydrated, nausea, dizziness, and/or headaches may result.Electrical “shocks” may be reported by the patient when MET is applied to scar tissue.Caused by decreased electrical resistance.