Ultrasound Therapy 2022-2023 PDF

ULTRASOUND (US) ELECTROPHYSICAL AGENT Degree of Physiotherapy San Pablo-CEU University 2022-2023 OUTCOME 1. Definition and classification 2. Production 3. Biophysical properties. 4. Therapeutical effects 5. Modalities 6. Application 2 DEFINITION • Ultrasound (US) is sound traveling through a me...

ULTRASOUND (US) ELECTROPHYSICAL AGENT Degree of Physiotherapy San Pablo-CEU University 2022-2023 OUTCOME 1. Definition and classification 2. Production 3. Biophysical properties. 4. Therapeutical effects 5. Modalities 6. Application 2 DEFINITION • Ultrasound (US) is sound traveling through a medium at frequencies above the upper-limit frequency of human audibility (20 kHz). INFRASOUND: < 20 Hz. AUDIBLE SOUND: 20- 20.000 Hz. ULTRASOUND: > 20.000 Hz. 1-3 MHz. 1-10 MHz 3 THERAPEUTIC US • Use of this mechanical acoustic energy for treating a variety of soft tissues pathologies including bone fractures and dermal wounds. • Conventional Ultrasound (CUS): 1-3 MHz • Low-intensity Pulsed Ultrasound (LIPUS): 1,5 MHz • Non-contact low-frequency ultrasound (NCLFUS): 40 KHz 4 US PRODUCTION AND WAVE FORMATION • Ultrasound therapy is a physical agent based on the application of mechanical energy produced by sound waves of frequencies betweem 1-3 MHz. – PIEZOELECTRIC PHENOMENON – REVERSE PIEZOELECTRIC EFFECT 5 PRODUCCIÓN DEL US • PIEZOELECTRIC PHENOMENON: some solid materials (artificial quartz, crystals, ceramics can be electrically charged on their surfaces when they are subjected to mechanical stress. • Bone and collagen have this effect. The deformation of the crystal results in a potential difference!!!!!. 6 US PRODUCTION AND WAVE FORMATION • 7 REVERSE PIEZOELECTRIC EFFECT: the application of a high-frequency alternating electrical current is applied on the surfaces of such piezoelectric materials (TRANSDUCER), a mechanical deformation follows in the form of oscillations of the material. BIOPHYSICAL PROPERTIES • US FREQUENCY (DEPTH OF THE LESION): • 1 MHz: Deeper tissues (longer wavelength) • 3 MHz: Superficial tissues (shorter wavelength) • Multifrequency Transducers. • US TRANSMISSION VELOCITY: • DENSITY. • ELASTICITY 8 US TRANSMISSION VELOCITY Medium Velocity (m/s) Aluminium 12890 m/s Bone 3500 m/s Cartilage 1750 m/s Muscle 1580 m/s Heart 1575 m/s Subcutaneous Fat 1215 m/s Air 343 m/s 9 BIOPHYSICAL PROPERTIES • US AQUOSTIC IMPEDANCE • Related to reflection. • Z = v 10 US REFLECTION • The greater the Z the greater the reflection • Importance of the conducting gel • Important between soft tissues and bone • Continuos movement of the transducer • Avoiding interferences in the near field. • Avoiding interferences due to reflection. 11 US REFLECTION Interface Reflection (%) Aluminium- Air 100 Skin-Air 99,9 Aluminium-Coupling media 60 Muscle-bone 41-34,5 Skin-Fat 0,90 Fat-Muscle 0,80-1,08 Muscle-Blood 0,74 Us head-Coupling media Almost zero 12 REFRACTION • Non- perpendicular incidence of sonic waves • Change of direction of the wave between 2 mediums 13 BIOPHYSICAL PROPERTIES • US ATENUATTION • Weaking of the US as its propagates through a medium. • Tissues rich is structural proteins. • Directly proportional to the US frequency and the absorption • It results from the combined effect of absorption and scattering. 14 ATTENUATTION Attenuation Coefficient Medium 1 MHz 3 MHz Blood 0,028 0,084 Nervous Tissue 0,2 0,6 Fat 0,14 0,42 Skin 0,62 1,86 Muscle 0,76 2,28 Tendon 1,12 3,36 Cartilage 1,16 3,48 Bone 3,22 Air 2,76 8,28 15 US ABSORPTION AND DEPTH PENETRATION Absorption: Conversion of US in other energies. INVERSELY PROPORTIONALS Penetration (mm) Medium 1 MHz 3 MHz Bone 2,1 Skin 11,1 4 Cartilage 6 2 Air 2,5 0,8 Tendon 6,2 2 Muscle 9 3 16 US DEPTH • Tissues Depth at which half of the US intensity is maintained. • 3 MHz: 2 cm (1-3 cm) • 1 MHz: 4 cm (2-6 cm) 17 TECNICAL CHARACTERISTICS • EFFECTIVE RADIATION AREA • ULTRASOUND BEAM PROJECTION 18 EFFECTIVE RADIATING AREA (ERA) • Measured in cm2. • Area of the transducer from which ultrasound energy radiates. • 10% Smaller that the soundhead applicator faceplate surface (transducer is embedded in the applicator). 19 ULTRASONIC BEAM PROJECTION • FRESNEL ZONE – Near field. – Less divergent/more focused. – Heterogeneous – Therapeutic zone • FRAUNHOFER ZONE – Far field. – Divergent. – Homogeneous 20 BEAM NONUNIFORMITY RATIO (BNR) • US delivered at the transducer faceplate is irregular or nonuniform (intensity is greater at the center: larger spikes than at the edges: lower spikes) of the transducer. • Ratio between the peak intensity (highest spike at the center) and the average intensity of all other spikes (edges). 21 BEAM NONUNIFORMITY RATIO (BNR) • BNR: 2-8. • Determined by the intrinsic properties of the transducer. • The better the piezoelectric quality, the more uniform the beam intensity across its ERA, and the lower the BNR. • The lower the BNR, the lower the hot spots in the near field. The lower the value the better the result in the crystal 22 DELIVERY MODE • CONTINUOUS MODE • PULSED MODE Intensity: 3 Intensity for continuous: 2 • UNINTERRUPTED FLOW OF ACOUSTIC ENERGY DURING THE TOTAL TREATMENT DURATION. • PERIODIC INTERRUPTION OF ACOUSTIC ENERGY (ON-OFF). • PULSE PRECUENCY. • CONSTANT FREQUENCY VIBRATION. • MECHANICAL EFFECT PREDOMINANT. • THERMAL EFFECT PREDOMINANT 23 US PHYSIOLOGICAL EFFECTS see notes in other ppt THERMAL EFFECTS • Continuous vibration. US: MECHANICAL EFFECTS Heat and • Thermal energy by molecular vibration (friction). • The US energy absorbed by the soft tissue and converted into heat depends on the frequency, intensity, mode of application, duration of application and the proportion of collagen in the tissue. • Pulsed US: vibration heat: controlled • Thermal energy from movement of liquids/molecules. • Consequences: • Stable cavitation • Unstable cavitation the higher the collagen the better the application ? 24 CAVITATION • Formation, in fluids or solids, of empty spaces or cavities resulting from the formation of microbubbles (hollows) • Contract (compression) • Expand (rarefaction) can happen in new vessels after tissue healing we need to control amount of intensity bc those bubbles increase intensity take into consideration in an area with gases (in belly for ex) 25 CAVITATION • STABLE CAVITATION • UNSTABLE CAVITATION • High intensity. • High intensity. • New vessels. • Implosion of microbubbles: high temperature • Organic liquids with dissolved gasses. • Bubbles begin to pulsate producing microstreaming. • US devices do not have frequency and intensity to produce it!!! • Due to nonthermal/mechanic effect. shockwave therapy aim: create high amount of intensity (bc we wanna break tenderness, cavications in tendons...) therapeutic US no pb except we deal with area with gazes 26 MECHANICAL/NON THERMAL EFFECTS • Increase blood flow. • Increase cell metabolism • Increase collagen synthesis. • Increase protein synthesis. • Increase collagen extensibility. • Enhance tissue healing. 27 US TREATMENT PARAMETERS • MODE OF DELIVERY heat than – CONTINUOUS: CHRONIC CONDITIONS (thermal) more mechanical effects – PULSED: ACUTE CONDITIONS (mechanical) (Use of mechanical higher than heat effects Duty Cycle or DC) similar to galvanic component so it's also percentage but applied to US • DEPTH: US FREQUENCY – 1 MHz : 4 cm – 3 MHz : 2 cm • TREATMENT SURFACE: ERA big era (5cm2) for big areas or small era (1cm2) for small areas like metacarpal joints the part of the transducer dirctly in contact with the skin 28 ULTRASOUND DOSIMETRY the higher the duty cycle the higher the thermal effects • DUTY CYCLE: – US PULSE DURATION US/ US PERIOD(%) • PULSE RATIO: – ON-OFF RELATION – 1:1 RATIO IS THE SAME THAN 50% DUTY CYCLE – MORE THERMAL EFFECT CLOSED TO 100% 100% is the obly one continuous if the percentage is lower than 100%: pulsed if PD = ID -> ratio is 1:1 same as having a duty cycle of 50% bc the current is passing only 50% of the time ID = 2xPD -> 1:2 ratio 29 US MODE PULSE RATIO DUTY CYCLE (DC) Continuous 1:0 100 % Pulsed 1:0,25 80 % 1:1 50 % 1+1= 2 2x 50= 100 1+2= 3 3x33= 99 it's fine the lower value the lower the thermal effects 1:2 33 % 1:3 25 % 1:4 20 % 1:9 10 % 1:19 5% for a very acute condition with swelling we would use more 5 or 10% the higher the value the more it is for chronic conditions 30 US INDICATIONS 31 • DEGENERATIVE AND RHEUMATIC DISORDERS • CONTRACTURES • TENOSYNOVITIS. • CAPSULAR AND LIGAMENTOUS FIBROSIS • SCAR TISSUES • FRACTURES. US PRECAUTIONS always try to use pulsed US bc depending on duty cycle we can have more or less thermal effects but control the dose in this case • Over recent fractures. • Over growing epiphyseal plates. • Osteosynthesis or metallic implants. • In areas with acute inflammation. • Cavities with air. • Breast implants. • With patients who haved received radiotherapy bc skin is altered, can get burned area of cage thoracique blablala 32 US CONTRAINDICATIONS • Over spinal cord after • laminectomy. when you remove jsp quoi sur • la colone Over recent wounds or hemorrhagic area. bc we could increase VD Over infected lesion. • Over eyes and ear. • Over keloid scars. • Over malignant area. • Over a pacemaker. • Over heart area. • Over gonads. • Over ischemic area. • • Over area of thrombosis. Over plastic and cementing implants • bc we can increase metabolism bc maybe vessels are not ready to receive heat Over the pelvic, lumbar, abdominal areas of women menstruating or pregnant. if person agrees you can apply during menstruation but warn the girl more blood will come 33 ULTRASOUND: BEFORE STARTING • • PUT SOME WATER DROPS OVER THE TRANSDUCER: LOOKS LIKE BOILING. IDEAL COUPLING MEDIA (GEL): only way to see if ulstrasound is working the higher the value th eless the effect less frequency = more effect the best gel: with no bubble, no color, that absorb not fast – Acoustic impedance similar to the piezoelectric transducer. – A low coefficient of US energy absorption. – Viscous proporties: good lubricant without melting. – No bubbles. – Non-irritating – Transparent 34 TRANSDUCER COUPLING • Soundhead parallel to surface. faceplate the skin • More than 15º angulations may outside and colides with other heat coming so higher peak of heat produce REFLECTION goes and can burn 35 REGARDING THE MOVEMENT • STATIONARY TECHNIQUE • Keep the soundhead stationary over the targeted tissue during the treatment session. (Pulsed ultrasound!!!!) • DYNAMIC TECHNIQUE – Continuous, slow, overlapping, circular or longitudinal movement of the soundhead over the targeted tissue during the treatment session. • SEMISTATIONARY TECHNIQUE – Combination between stationary and dynamic technique. dynamic technique little circle stationary technique little circles but without removing the transducer us calculation: continuous, gel, high intensity -> count seconds until pain (Pulsed ultrasound!!!!) 37 METHODS OF APPLICATION • REGARDING MOVEMENT: • REGARDING CONTACT: • STATIONARY TECHNIQUE. • DIRECT CONTACT. • DYNAMIC TECHNIQUE. • WATER IMMERSION. • SEMISTATIONARY. • CUSHION CONTACT a ballon filled with water in areas where it is difficult to adapt the transducer • REGARDING ADDITIONAL METHODS: • PHONOPHORESIS. • COMBINED THERAPY: US+ ELECTRICAL CURRENT 36 cf regarding contact slide either gel REGARDING THE ADDITIONAL TECHNIQUE or plastic gloves for PT if not receive US in our hand joints less than 3cm container must be plastic or ceramic if not it will reflect water must be boiled before to avoid cavitation (formation of bubble) but then wait for the temperature to be normala again usually for elbow (irregular so more reflection), area with allodynia (you cannot touch bc of pain) or in hands/ feet more intensity in water • PHONOPHORESIS or gel apply ballon gel ultrasond over ballon • Ultrasound plus a drug medium as the US conduction medium. • COMBINED THERAPY can use it for diagnosis (to search for motor point...) or ttmt • Combination of US + electrical current (IF, DF, BYPHASIC) acting as cathode if deeper: IF and 1MH for us superficial: 3MH for us and tens 38 COMBINED THERAPY • TRANSDUCER= CATHODE. • DYNAMIC TECHNIQUE: use VC. • • • • – DIAGNOSTIC US + low-frequency or medium frequency currents. MTP, painful points, Head areas, dolorosos, dermatomes. Areas with hyperesthesia show redness. Can be: – THERAPEUTIC • Electrical Currents: – Diadynamic. – Byphasic (TENS) – Interferential. 39 COMBINED THERAPY • • DIAGNOSTIC: – (-) US; (+) ELECTRODE. – 0,2-0,5 W/cm2. – TENS, IF bipolar, DF. – CONTINUOUS-VC. to find refer areas – More sensitivity points irradiated to the targered area(referred pain) THERAPEUTIC: – (-) US; (+) ELECTRODE. – 0,5 W /cm2 – PULSED or CONTINUOUS. – SEMISTATIONARY – Short time, till point sensitivity decreases. very low intensity 40 INDICATIONS • PAINFUL AREAS • CONTRACTURES. • ACUTE INFLAMMED AREAS • MYOFASCIAL TRIGGER POINTS. CONTRAINDICATIONS • ELECTROTHERAPY GENERAL CONTRAINDICATIONS • ULTRASOUND CONTRAINDICATIONS. 41 Low-intensity Pulsed Ultrasound (LIPUS) • Based on mechanical effects (low-intensity). • Target tissue is the bone: highest US absoption coefficient. • US application generates the piezoelectric effect in bone (property to convert mechanical into electrical current) • 20 minutes per treatment. 42 Noncontact low –frequency ultrasound (MIST system) • Low-frequency US energy to atomize saline water and deliver it as mist to the wound to clean and debride devitalized tissues covering the wound. freq very very low 43 SPECTRUM OF THERAPEUTIC US she won't ask for specific values just remember lowest freq Characteristics CUS LIPUS NCLFUS conventional US Frequency Low (LF) Mid (MF) High (HF) LF,MF, HF 1-3 MHz MF 1,5 MHz LF 40 kHz Intensity Low (LI) High (HI) LI/HI 0-3 W/cm2 LI 0,03 W/cm2 LI 0,5 W/cm2 Delivery Mode Continuous (C) Pulsed (P) C/P P P Effect Mechanical (M) Thermal (T) M/T M M 44 SPECTRUM OF THERAPEUTIC US Characteristics CUS LIPUS NCLFUS D/S S D Application Technique Stationary (S) Dynamic (D) Application method Contact (C) C/NC Noncontact NC) C NC Coupling Agent Gel (G) Water (W) G W Indications G/W Muscle, tendon, Bone fracture ligaments Dermal wounds 45