Upload
huey
View
80
Download
0
Embed Size (px)
DESCRIPTION
Therapeutic Ultrasound. Chapter 8. Description. Acoustical energy (sound waves) above the range of human hearing Therapeutic range: 0.75 to 3.3 MHz Effects: Thermal Nonthermal (mechanical). Uses. Calcific bursitis Inflammatory conditions Joint contractures Pain Muscle spasm - PowerPoint PPT Presentation
Citation preview
Therapeutic Therapeutic UltrasoundUltrasound
Chapter 8Chapter 8
DescriptionDescription
Acoustical energy (sound waves) Acoustical energy (sound waves) above the range of human hearingabove the range of human hearing– Therapeutic range: 0.75 to 3.3 MHzTherapeutic range: 0.75 to 3.3 MHz
Effects:Effects:– ThermalThermal– Nonthermal (mechanical)Nonthermal (mechanical)
UsesUses
Calcific bursitisCalcific bursitis Inflammatory conditionsInflammatory conditions Joint contracturesJoint contractures PainPain Muscle spasmMuscle spasm Acute orthopedic injuries (low pulses, Acute orthopedic injuries (low pulses,
low intensity) low intensity)
Production of UltrasoundProduction of Ultrasound
An alternating current An alternating current is passed through a is passed through a crystalcrystal
The current causes the The current causes the crystal to vibratecrystal to vibrate– Electropiezo effectElectropiezo effect
Vibrating crystal Vibrating crystal produce high-produce high-frequency sound frequency sound waveswaves
Effective Radiating Area Effective Radiating Area (ERA)(ERA)
Area of the crystal that Area of the crystal that actually produces sound actually produces sound waveswaves– Produces more than 5% of Produces more than 5% of
the energy at 5 mm from the energy at 5 mm from the transducer facethe transducer face
ERA is always smaller than ERA is always smaller than the transducer facethe transducer face
Energy is concentrated Energy is concentrated near the centernear the center
ERA
Beam ProfileBeam Profile Multiple waves emerge Multiple waves emerge
from the headfrom the head Energy diverges as it Energy diverges as it
moves away from the moves away from the sourcesource
Energy is uniform close to Energy is uniform close to the headthe head– Near zone (Fresnel zone)Near zone (Fresnel zone)
Becomes less consistent Becomes less consistent farther away from the farther away from the headhead– Spatial peak intensitySpatial peak intensity Spatial Peak Intensity
Beam Nonuniformity Ratio Beam Nonuniformity Ratio (BNR)(BNR)
Describes the amount of variation Describes the amount of variation in the beamin the beam
Ratio between:Ratio between:– Spatial peak intensity (SPI)Spatial peak intensity (SPI)– Average intensity (SAI - metered Average intensity (SAI - metered
output)output)– BNR = SPI/SAIBNR = SPI/SAI
Perfect beam would have a BNR Perfect beam would have a BNR of 1:1of 1:1
Minimally acceptable BNR is 8:1Minimally acceptable BNR is 8:1 The actual peak output is equal The actual peak output is equal
to the SAI * the BNRto the SAI * the BNR– 10 W total output * 6:1 BNR10 W total output * 6:1 BNR– 60 watt SPI60 watt SPI
Spatial Peak Intensity
Spatial Average Intensity(Displayed on the unit)
Modes of ApplicationModes of Application
ContinuousContinuous Ultrasonic energy is constantly producedUltrasonic energy is constantly produced Can produce thermal effects based on:Can produce thermal effects based on:
– Output intensityOutput intensity– Treatment durationTreatment duration
PulsedPulsed Ultrasonic output is regularly interruptedUltrasonic output is regularly interrupted Produces nonthermal effectsProduces nonthermal effects
Pulsed OutputPulsed Output
Ultrasonic output is cycled Ultrasonic output is cycled “On” and “Off”“On” and “Off”– On = Pulse lengthOn = Pulse length– Off = Pulse intervalOff = Pulse interval
Expressed as a Expressed as a Duty Duty CycleCycle– ON/(ON+OFF) * 100ON/(ON+OFF) * 100– 20mSec/(20mSec+10mSec) 20mSec/(20mSec+10mSec)
* 100* 100– 20/30 * 10020/30 * 100– 67%67%
Continuous Output (100% Duty Cycle)
Pulsed Output (67% Duty Cycle)
Output FrequencyOutput Frequency
Measured in megahertz (MHz)Measured in megahertz (MHz)– 1 MHz = 1,000,000 waves per 1 MHz = 1,000,000 waves per
secondsecond Determines the depth of effectsDetermines the depth of effects 1 MHz Output1 MHz Output
– Penetrates 5 to 7 cmPenetrates 5 to 7 cm– Thermal effects last longerThermal effects last longer– More divergent beamMore divergent beam
3 MHz Output3 MHz Output– Penetrates 2 to 3 cmPenetrates 2 to 3 cm– Heats 3 times faster than 1 MHz Heats 3 times faster than 1 MHz
outputoutput– More collimated beamMore collimated beam
Power and IntensityPower and IntensitySpatial Average IntensitySpatial Average Intensity
Spatial Average Temporal Peak Spatial Average Temporal Peak IntensityIntensity
Spatial Average Temporal Average Spatial Average Temporal Average IntensityIntensity
Spatial Average Intensity Spatial Average Intensity (SAI)(SAI)
Describes the energy per unit of areaDescribes the energy per unit of area Total output (watts)/areaTotal output (watts)/area
– Watts/effective radiating area (cmWatts/effective radiating area (cm22))– W/cmW/cm22
15 watts being applied with a 10 cm15 watts being applied with a 10 cm22 ERA ERA – 15 Watts / 10 cm15 Watts / 10 cm22
– 1.5 W/cm1.5 W/cm22
Power Measures – Pulsed Power Measures – Pulsed OutputOutput
Spatial Average Temporal Spatial Average Temporal Peak Intensity (SATP)Peak Intensity (SATP)
The average energy The average energy delivered during the “On” delivered during the “On” time of the duty cycle.time of the duty cycle.
Spatial Average Temporal Spatial Average Temporal Average Intensity Average Intensity (SATA)(SATA)
Energy delivered over timeEnergy delivered over time– Spatial Average Intensity * Spatial Average Intensity *
Duty CycleDuty Cycle Meaningful only during Meaningful only during
pulsed outputpulsed output
Biophysical EffectsBiophysical Effects
ThermalThermal
Thermal EffectsThermal Effects Increased sensory nerve conduction velocityIncreased sensory nerve conduction velocity Increased motor nerve conduction velocityIncreased motor nerve conduction velocity Increased extensibility of collagen-rich Increased extensibility of collagen-rich Increased vascular permeability structuresIncreased vascular permeability structures Increased collagen depositionIncreased collagen deposition Increased blood flowIncreased blood flow Reduction of muscle spasmReduction of muscle spasm Increased macrophage activityIncreased macrophage activity Enhanced adhesion of leukocytes to damaged Enhanced adhesion of leukocytes to damaged
endothelial cellsendothelial cells
Heating ClassificationsHeating Classifications
IncreaseIncrease Used ForUsed For
MildMild 11°°CC Mild inflammationMild inflammationAccelerate metabolismAccelerate metabolism
ModerateModerate 22°° – 3 – 3°°CC Decreasing muscle Decreasing muscle spasmspasm
Decreasing painDecreasing painIncreasing blood flowIncreasing blood flowChronic inflammationChronic inflammation
VigorousVigorous 33°° – 4 – 4°°CC Tissue elongationTissue elongationScar tissue reductionScar tissue reduction
Heating RateHeating Rate
Heating rate and magnitude is based Heating rate and magnitude is based on:on:– Duty cycleDuty cycle– Output frequencyOutput frequency– IntensityIntensity– Target tissuesTarget tissues– Size of the treatment areaSize of the treatment area
Thermal EffectsThermal Effects Same as other heat modalitiesSame as other heat modalities
– Smaller volume of tissueSmaller volume of tissue– Shorter duration of effectsShorter duration of effects
Preheat the skin with a moist heat packPreheat the skin with a moist heat pack– Decreases the time to reach vigorous heatingDecreases the time to reach vigorous heating
Poorly vascularized, collagen-rich tissues Poorly vascularized, collagen-rich tissues are preferentially heatedare preferentially heated– Fascia, tendon, scar tissueFascia, tendon, scar tissue
Tissues containing an increased proportion Tissues containing an increased proportion of fluid do not heat as wellof fluid do not heat as well– Adipose tissue, articular fluidAdipose tissue, articular fluid
Biophysical EffectsBiophysical Effects
NonthermalNonthermal
Nonthermal EffectsNonthermal Effects Increased cell membrane Increased cell membrane
permeabilitypermeability Altered rates of diffusion Altered rates of diffusion
across the cell membraneacross the cell membrane
Increased vascular Increased vascular permeabilitypermeability
Secretion of cytokines Secretion of cytokines
Increased blood flowIncreased blood flow Increased fibroblastic Increased fibroblastic
activity activity Stimulation of Stimulation of
phagocytosis phagocytosis
Granulation tissue Granulation tissue productionproduction
Synthesis of proteinSynthesis of protein Synthesis of Synthesis of
collagencollagen Reduction of edemaReduction of edema Diffusion of ionsDiffusion of ions Tissue regenerationTissue regeneration Formation of Formation of
stronger deformable stronger deformable connective tissue connective tissue
Nonthermal ApplicationNonthermal Application
Pulsed outputPulsed output– 20 to 25% duty cycle20 to 25% duty cycle– Nonthermal output intensityNonthermal output intensity
Continuous outputContinuous output– 100% duty cycle100% duty cycle– Output intensity of less than 0.3 W/cmOutput intensity of less than 0.3 W/cm22
Acoustical StreamingAcoustical Streaming
Ultrasound causes interstitial Ultrasound causes interstitial fluids to flowfluids to flow
Fluids strike cell membranesFluids strike cell membranes Produce Produce eddy currentseddy currents Eddy currents displace ions Eddy currents displace ions
and moleculesand molecules Alter:Alter:
– Cell membrane permeabilityCell membrane permeability– Cellular functionCellular function
Effect on Injury Effect on Injury ResponseResponse
Cellular ResponseCellular Response
Acoustical streaming:Acoustical streaming:– Increases cell membrane permeabilityIncreases cell membrane permeability– Alters cell membrane diffusion rateAlters cell membrane diffusion rate– Increased histamine releaseIncreased histamine release– Mast cell degranulationMast cell degranulation– Increased rate of protein synthesisIncreased rate of protein synthesis
Thermal effects:Thermal effects:– Increased cell metabolismIncreased cell metabolism– Increased rate of inflammationIncreased rate of inflammation
InflammationInflammation
May lead to an earlier onset of May lead to an earlier onset of proliferationproliferation– Increased fibroblast proliferationIncreased fibroblast proliferation– Release of growth factors and plateletsRelease of growth factors and platelets
Increased macrophage activityIncreased macrophage activity Leukocytes bind to damaged Leukocytes bind to damaged
endothelial cellsendothelial cells Cell division is increasedCell division is increased
InflammationInflammation
Frequency SpecificityFrequency Specificity 1 MHz Output1 MHz Output
– Release of preformed fibroblastsRelease of preformed fibroblasts 3 MHz Output3 MHz Output
– Increased synthesis and secretion of Increased synthesis and secretion of fibroblast precursorsfibroblast precursors Increased in areas of high collagen Increased in areas of high collagen
concentrationconcentration
Blood and Fluid DynamicsBlood and Fluid Dynamics
May increase blood flow for 45 May increase blood flow for 45 minutesminutes– Thermal effectsThermal effects– Decreased vascular toneDecreased vascular tone– Histamine releaseHistamine release
Causes vasodilationCauses vasodilation
Moist heat application prior to Moist heat application prior to treatment decreases net increase in treatment decreases net increase in blood flowblood flow
Pain ControlPain Control
Direct Pain ReductionDirect Pain Reduction Increased nerve cell sodium permeabilityIncreased nerve cell sodium permeability Alters nerve functionAlters nerve function Increases pain thresholdIncreases pain thresholdIndirect Pain ReductionIndirect Pain Reduction Increased blood flowIncreased blood flow Increased capillary permeabilityIncreased capillary permeability Increased oxygen deliveryIncreased oxygen delivery Decreased muscle spasmDecreased muscle spasm
Muscle SpasmMuscle Spasm
Reduced secondary to:Reduced secondary to:– Decreased painDecreased pain– Altered nerve conduction velocityAltered nerve conduction velocity– Increased temperature (counterirritant Increased temperature (counterirritant
effect)effect)– Muscle relaxationMuscle relaxation
Tissue ElasticityTissue Elasticity
Ultrasound preferentially heats collagen-Ultrasound preferentially heats collagen-rich tissues (tendon, fascia, scar tissue)rich tissues (tendon, fascia, scar tissue)
Temperature must be increased 7.2Temperature must be increased 7.2°°FF Stretching window lasts approximately 3 Stretching window lasts approximately 3
minutes following the treatmentminutes following the treatment– Place tissues on stretch during applicationPlace tissues on stretch during application– Perform stretching/mobilization immediately Perform stretching/mobilization immediately
following the treatmentfollowing the treatment Multiple treatments are required to gain Multiple treatments are required to gain
lengthlength
Wound HealingWound Healing
Tendon HealingTendon Healing Continuous US application Continuous US application
may:may:– Increase tensile strengthIncrease tensile strength– Increase collagen depositionIncrease collagen deposition
Skin UlcersSkin Ulcers 3 MHz, low-intensity 3 MHz, low-intensity
pulsed output may assist pulsed output may assist the healing processthe healing process
Cover the wound with an Cover the wound with an occlusive dressingocclusive dressing
Electromagnetic FieldElectromagnetic Field
In vitro bone deformation produces In vitro bone deformation produces piezoelectric currents and streaming piezoelectric currents and streaming potentialspotentials
Electromagnetic (EM) devices are based Electromagnetic (EM) devices are based on Wolff’s Law that bone responds to on Wolff’s Law that bone responds to mechanical stress: Exogenous EM fields mechanical stress: Exogenous EM fields may simulate mechanical loading and may simulate mechanical loading and stimulate bone growth and repairstimulate bone growth and repair
Clinical efficacy very controversialClinical efficacy very controversial
Types of EM DevicesTypes of EM Devices
MicroamperesMicroamperes Direct electrical currentDirect electrical current Capacitively coupled electric fieldsCapacitively coupled electric fields Pulsed electromagnetic fields Pulsed electromagnetic fields
(PEMF)(PEMF)
PEMFPEMF
Approved by the FDA for the treatment of Approved by the FDA for the treatment of non-unionsnon-unions
Efficacy of bone stimulation appears to be Efficacy of bone stimulation appears to be frequency dependentfrequency dependent– Extremely low frequency (ELF) sinusoidal Extremely low frequency (ELF) sinusoidal
electric fields in the physiologic range are most electric fields in the physiologic range are most effective (15 to 30 Hz range)effective (15 to 30 Hz range)
– Specifically, PEMF signals in the 20 to 30 Hz Specifically, PEMF signals in the 20 to 30 Hz range appear more effective than those below range appear more effective than those below 10 Hz10 Hz
UltrasoundUltrasound
Low-intensity ultrasound is approved Low-intensity ultrasound is approved by the FDA for stimulating healing of by the FDA for stimulating healing of fresh fracturesfresh fractures
Modulates signal transduction, Modulates signal transduction, increases gene expression, increases increases gene expression, increases blood flow, enhances bone blood flow, enhances bone remodeling and increases callus remodeling and increases callus torsional strength in animal modelstorsional strength in animal models
UltrasoundUltrasound
Human clinical trials show a Human clinical trials show a decreased time of healing in fresh decreased time of healing in fresh fracturesfractures
Has also been shown to decrease the Has also been shown to decrease the healing time in smokers potentially healing time in smokers potentially reversing the ill effects of smokingreversing the ill effects of smoking
Fracture HealingFracture Healing Low-intensity pulsed Low-intensity pulsed
outputoutput Accelerates rate of fracture Accelerates rate of fracture
healing for:healing for:– Acute fracturesAcute fractures– Nonunion fracturesNonunion fractures– Stress fracturesStress fractures
Requires specialized unitRequires specialized unit Biophysical Effects:Biophysical Effects:
– Mechanical (sound) energy Mechanical (sound) energy strikes bonestrikes bone
– Microvibration of bone Microvibration of bone triggers growth triggers growth (osteogenesis)(osteogenesis)
PARAMETERSPARAMETERSFrequencyFrequency 1.5 MHz1.5 MHzERAERA 3.88 cm3.88 cm22
IntensityIntensity 30 mW/cm30 mW/cm22
Treatment DurationTreatment Duration 20 minutes20 minutesDailyDaily
ContraindicationsContraindications Acute conditions (thermal Acute conditions (thermal
mode)mode) Ischemic areasIschemic areas Areas of impaired Areas of impaired
circulationcirculation Over areas of deep vein Over areas of deep vein
thrombosisthrombosis Anesthetic areasAnesthetic areas Over cancerous tumors Over cancerous tumors Sites of active infection or Sites of active infection or
sepsissepsis Over the spinal cord or Over the spinal cord or
large nerve plexus in high large nerve plexus in high dosesdoses
Exposed penetrating metal Exposed penetrating metal (eg, external fixation (eg, external fixation devices) devices)
Around the eyes, heart, Around the eyes, heart, skull, or genitalsskull, or genitals
Over the thorax in the Over the thorax in the presence of an implanted presence of an implanted pacemakerpacemaker
Pregnancy when used over Pregnancy when used over the pelvic or lumbar areasthe pelvic or lumbar areas
Over a fracture site before Over a fracture site before healing is completehealing is complete
Stress fracture sites or Stress fracture sites or sites of osteoporosissites of osteoporosis
Over the pelvic or lumbar Over the pelvic or lumbar area in menstruating area in menstruating female patients female patients
Where are we going?Where are we going?
UltrsoundUltrsound Ultrasound uses:Ultrasound uses:
– Diagnostic (low intensity) Diagnostic (low intensity) FractureFracture
– Surgical (high intensity)Surgical (high intensity)
– TherapeuticTherapeutic
Therapeutic US widely used Therapeutic US widely used for deep heatfor deep heat
UltrasoundUltrasound
Primary clinical use:Primary clinical use:– Soft tissue repairSoft tissue repair
– Pain relief (analgesia)Pain relief (analgesia)
Effective Radiating Area Effective Radiating Area (ERA)(ERA)
Total area on surface of Total area on surface of transducer producing soundwavetransducer producing soundwave
Ideally ERA should match size of Ideally ERA should match size of transducertransducer
Treatment area should not Treatment area should not exceed 2-3 times ERAexceed 2-3 times ERA
Frequency of UltrasoundFrequency of Ultrasound Determined by number of times Determined by number of times
crystal deformed/sec.crystal deformed/sec. 2 most common utilized in U.S.2 most common utilized in U.S.
– 1.0 MHz1.0 MHz
– 3.0 MHz3.0 MHz
Determines depth of penetration, Determines depth of penetration, unlike ESunlike ES
Frequency of UltrasoundFrequency of Ultrasound Inverse relationship between frequency Inverse relationship between frequency
and depth of penetrationand depth of penetration Penetrating depths:Penetrating depths:
– 1.0 MHz: 2-5 cm1.0 MHz: 2-5 cm
– 3.0 MHz: 1-2 cm3.0 MHz: 1-2 cm Absorption rate increases with higher Absorption rate increases with higher
frequencyfrequency
Pulsed vs ContinuousPulsed vs Continuous
Most new generators produce Most new generators produce bothboth
Both produce thermal & Both produce thermal & nonthermal effectsnonthermal effects
Pulsed vs ContinuousPulsed vs Continuous Continuous:Continuous:
– Sound intensity remains the sameSound intensity remains the same– Commonly used for thermal effectsCommonly used for thermal effects
Pulsed vs ContinuousPulsed vs Continuous Pulsed:Pulsed:
– Intensity periodically interruptedIntensity periodically interrupted– Average intensity reduced over timeAverage intensity reduced over time
Physiological Effects Physiological Effects of Ultrasoundof Ultrasound
Thermal effectsThermal effects
Non-thermal effectsNon-thermal effects
– CavitationCavitation
– Acoustic microstreamingAcoustic microstreaming
Thermal EffectsThermal Effects
Clinical effects:Clinical effects:
– Increased extensibility of collagen Increased extensibility of collagen fibersfibers tendonstendons
joint capsulejoint capsule
– Decreased joint stiffnessDecreased joint stiffness
Thermal EffectsThermal Effects Clinical effects:Clinical effects:
– Reduction in muscle spasmReduction in muscle spasm
– Pain modulationPain modulation
– Increased blood flowIncreased blood flow
– Increased nerve conductionIncreased nerve conduction
Thermal EffectsThermal Effects Primary advantage of USPrimary advantage of US
– Selective heating of tissues high in Selective heating of tissues high in collagencollagen
– Non-thermal effects are occurringNon-thermal effects are occurring
Non-thermal (Mechanical) Non-thermal (Mechanical) EffectsEffects
Primary physiological Primary physiological effects are cavitation and effects are cavitation and acoustic microstreamingacoustic microstreaming
Cavitation:Cavitation:– Formation of gas-filled Formation of gas-filled
bubbles in tissue fluidsbubbles in tissue fluids– Expansion/compression of Expansion/compression of
bubbles either stable or bubbles either stable or unstableunstable
Non-thermal (Mechanical) Non-thermal (Mechanical) EffectsEffects
Acoustic microstreaming:Acoustic microstreaming:– Unidirectional movement of Unidirectional movement of
fluids along cell membrane fluids along cell membrane boundariesboundaries
– Produces high viscous Produces high viscous stressesstresses
– Alters membrane structure & Alters membrane structure & functionfunction
– Increased permeability to Increased permeability to ionic influxionic influx
Non-thermal (Mechanical) Non-thermal (Mechanical) EffectsEffects
Potential therapeutic effects from Potential therapeutic effects from cavitation & microstreamingcavitation & microstreaming
– Stim. of fibroblast activity increases Stim. of fibroblast activity increases protein synthesis & tissue repairprotein synthesis & tissue repair
– Increased blood flowIncreased blood flow
– bone healing & repair of non-union bone healing & repair of non-union fracturesfractures
UltrasoundUltrasound IndicationsIndications
– Increase deep tissue Increase deep tissue heatheat
– Decrease Decrease inflammationinflammation
– Decrease muscle Decrease muscle spasmsspasms
– Decrease painDecrease pain– Increase extensibility Increase extensibility
of collagen tissueof collagen tissue– Decrease pain of Decrease pain of
neuromasneuromas– Decrease joint Decrease joint
adhesionsadhesions– Treat myositis Treat myositis
ossificansossificans
ContraindicationsContraindications– HemorrhageHemorrhage– InfectionInfection– ThrombophlebitisThrombophlebitis– Suspected malignancySuspected malignancy– Impaired circulation or Impaired circulation or
sensationsensation– Stress fracture sitesStress fracture sites– Epiphyseal growth Epiphyseal growth
platesplates– Over the Eyes, Heart, Over the Eyes, Heart,
Spine, or genitalsSpine, or genitals
Treatment FrequencyTreatment Frequency
Ultrasound has cumulative effectsUltrasound has cumulative effects
· Daily for 10 days – low irritability and · Daily for 10 days – low irritability and scarscar
· 3-4 times/week – moderate irritability · 3-4 times/week – moderate irritability for 3-for 3- 4 weeks 4 weeks
· 2 times /week – high irritability 4-5 · 2 times /week – high irritability 4-5 weeksweeks
· If no change after 3-4 sessions, change · If no change after 3-4 sessions, change settings or discontinue. settings or discontinue.
· Stop after 10-15 treatments· Stop after 10-15 treatments
Sound Head MovementSound Head Movement
Never stay stationaryNever stay stationary Keep it moving, slow and gentle with Keep it moving, slow and gentle with
constant pressure.constant pressure. This will minimize the risk of creating This will minimize the risk of creating
unstable cavitation andunstable cavitation and Standing waves that is detrimental Standing waves that is detrimental
damaging to soft tissuedamaging to soft tissue 1 inch = 1 second1 inch = 1 second
Movement of the Movement of the TransducerTransducer
4 cm4 cm22/sec/sec Remaining stationary can cause problemsRemaining stationary can cause problems Moving too rapidly decreases the total Moving too rapidly decreases the total
amount of energy absorbed per unit areaamount of energy absorbed per unit area– May cause clinician to treat larger area and the May cause clinician to treat larger area and the
desired temps. May not be attaineddesired temps. May not be attained Slower strokes can be easier maintainedSlower strokes can be easier maintained If patient complains of pain or excessive If patient complains of pain or excessive
heat, then heat, then decrease intensitydecrease intensity but increase but increase timetime
Apply constant pressure – not too much & Apply constant pressure – not too much & not too littlenot too little
Coupling AgentsCoupling Agents Optimal agent – distilled HOptimal agent – distilled H220 0 (.2% reflection)(.2% reflection)
Modern units have a shut down Modern units have a shut down mechanism if sound head becomes too hot mechanism if sound head becomes too hot (Dynatron beeps; red lights on (Dynatron beeps; red lights on Chattanoogas)Chattanoogas)– Improperly coupled head causes Improperly coupled head causes temp. temp.
Types of agents:Types of agents:– DirectDirect
– HH220 immersion0 immersion
– BladderBladder Reduce amount of air bubblesReduce amount of air bubbles
Direct CouplingDirect Coupling
Effectiveness is Effectiveness is if body part is hair, if body part is hair, irregular shaped, or uncleanirregular shaped, or unclean
Must maintain firm, constant Must maintain firm, constant pressurepressure
Various gels utilized Various gels utilized
Water ImmersionWater Immersion Used for odd shaped partsUsed for odd shaped parts Place head approx. 1” away from partPlace head approx. 1” away from part Operator’s hand should not be Operator’s hand should not be
immersed No metal on part or immersed No metal on part or operator’s handoperator’s hand
Ceramic tub is recommendedCeramic tub is recommended If nondistilled HIf nondistilled H220 is used, intensity can 0 is used, intensity can
be be .5 w/cm .5 w/cm22 because of air & minerals because of air & minerals Don’t touch skin except to briefly sweep Don’t touch skin except to briefly sweep
skin when bubbles formskin when bubbles form
Bladder Bladder
HH220 filled balloon or plastic bag 0 filled balloon or plastic bag coated with coupling gelcoated with coupling gel
Use on irregular shape partUse on irregular shape part Place gel on skin, then place the Place gel on skin, then place the
bladder on the part, and then place bladder on the part, and then place gel on bladdergel on bladder
Make sure all air pockets are Make sure all air pockets are removed from bladderremoved from bladder
US SpecificsUS Specifics
BurningBurning Tissue DensityTissue Density Gel applicationGel application Burning the US head with no tissue Burning the US head with no tissue
contactcontact
PhonophoresisPhonophoresis
DescriptionDescription
Use of therapeutic ultrasound to Use of therapeutic ultrasound to assist in diffusion of medication assist in diffusion of medication through the skinthrough the skin
Increases the diameter of skin Increases the diameter of skin portals to allow the medication to portals to allow the medication to passpass– PoresPores– Hair folliclesHair follicles
Biophysical EffectsBiophysical Effects
Medication is introduced over a large Medication is introduced over a large areaarea– Relative to an injectionRelative to an injection
NoninvasiveNoninvasive Medication may not be filtered by the Medication may not be filtered by the
liverliver– Reducing metabolic elimination of the Reducing metabolic elimination of the
medicinemedicine
Transdermal ApplicationTransdermal Application
Medication must diffuse through:Medication must diffuse through:– Enzymatic barrier of the epidermisEnzymatic barrier of the epidermis– Stratum corneumStratum corneum
Rate-limiting barrier to absorptionRate-limiting barrier to absorption Medications must be able to diffuse across Medications must be able to diffuse across
this barrierthis barrier
Medication is stored in subcutaneous Medication is stored in subcutaneous tissues for some time before being tissues for some time before being diffused deeperdiffused deeper
Skin InfluencesSkin Influences
Medication uptake is improved when Medication uptake is improved when the skin is:the skin is:– Well hydratedWell hydrated– Has a high density of skin portalsHas a high density of skin portals– Highly vascularizedHighly vascularized– Relatively thinRelatively thin– ““Younger” skin tends to have better Younger” skin tends to have better
diffusion characteristics than “older” diffusion characteristics than “older” skin.skin.
Ultrasound Influences on Ultrasound Influences on DiffusionDiffusion
Thermal EffectsThermal Effects Increase kinetic energyIncrease kinetic energy Increase portal cross-sectionIncrease portal cross-section Increase circulationIncrease circulation Increase capillary permeabilityIncrease capillary permeabilityNonthermal EffectsNonthermal Effects Altered cell resting potentialAltered cell resting potential Increased cell membrane permeabilityIncreased cell membrane permeability Increased molecular permeabilityIncreased molecular permeability
Phonophoresis MedicationsPhonophoresis Medications
Either prescription or nonprescriptionEither prescription or nonprescription Low molecular size and weightLow molecular size and weight
– Most medications used can be applied Most medications used can be applied transdermally without ultrasoundtransdermally without ultrasound
Controlled medications require a Controlled medications require a prescription prescription for the patient being treatedfor the patient being treated
Medication is often mixed in an inert Medication is often mixed in an inert basebase– Base must be able to transmit ultrasonic Base must be able to transmit ultrasonic
energyenergy
Common MedicationsCommon Medications
TypeType IndicationsIndications ExampleExample
Corticosteroid Corticosteroid Inflammation Inflammation HydrocortisoneHydrocortisone
DexamethasoneDexamethasone
SalicylatesSalicylates InflammationInflammation
PainPain
AnestheticAnesthetic PainPain LidocaineLidocaine
Trigger pointsTrigger points
Application TipsApplication Tips
Moist heat pack prior to application:Moist heat pack prior to application:– Increase blood flowIncrease blood flow– Increase kinetic energyIncrease kinetic energy– Increase skin portalsIncrease skin portals
Following treatmentFollowing treatment– Leave medication on skinLeave medication on skin– Cover with an occlusive dressingCover with an occlusive dressing– Moist heat pack re-application Moist heat pack re-application maymay
assist in further absorptionassist in further absorption
Low-frequency US Low-frequency US PhonophoresisPhonophoresis
Parameters:Parameters:– 20 kHz output frequency20 kHz output frequency– 125 mW/cm125 mW/cm22
– Pulsed outputPulsed output Benefits:Benefits:
– Allows medications with a larger size Allows medications with a larger size and weight to diffuseand weight to diffuse
– More efficient medication deliveryMore efficient medication delivery