therapeutic ultra sound in physiotherapy
TRANSCRIPT
05/03/2023
1
BYODUENYI CHRISTIAN
PHYSIOTHERAPY DEPARTMENTBENUE STATE UNIVERSITY TEACHING
HOSPITAL(BSUTH), MAKURDI.
Therapeutic Ultrasound in Physiotherapy
05/03/2023
2
Introduction
Ultrasound is used in medicine for:DiagnosisDestruction of tissueTherapy
05/03/2023
3
Definition
Ultrasound is a mechanical vibration at any frequency above the audible sound range
Ultrasound therapy (UST) is the application of ultra frequency sound waves (1 – 3MHZ) to tissues in order to promote healing and reduce pain and swelling.
Therapeutic Us used in physiotherapy ranges from 0.5 to 5MHZ but most us machine are set at 1MHZ and/or 3MHZ
Classified as a deep heating modality
05/03/2023
4
Production of ultrasound
The inverse piezoelectric effect is used in production of ultrasonic sound waves.
Examples of piezoelectic materials are quartz,barium titanate and lead zirconate titanate (PZT).
Application of high frequency alternating current to the PZT crystal of the transducer transforms the electrical energy into vibratory sound wave (ultrasound)s
05/03/2023
5
Transmission of US wave
Through solid, liquid and gases in form of compression and separation of molecule
Normally cylindrical and longitudinal in fashion
Velocity higher in materials of high densityAir 340 m/s, water 1410m/s, muscle 1540m/s,
Bone 3500m/s.
05/03/2023
6
Properties of ultrasound beam
ReflectionRefraction AttenuationAbsorption Passing through the tissue US energy is
dissipated = attenuationHalf Value Distance = 4cm for 1MHZ and
2cm for 3MHZAcoustic Impedance(Z)
05/03/2023
7
Depth of penetration
1MHZ= deeper tissues at depth 3 to 5cm
3MHZ= superficial Tissues at depth 1 to 2cm
Depth of Penetration is inversely proportional to frequency
Near and Far Field Wave fonts from
different parts travel different distances causing interference between adjacent fonts
05/03/2023
8
Near and far field
The near field also known as the Fransel zone is the convergent region
The far field known as the fraunhofer zone is the divergent region
Length of Fresnel zone = r2 / λ where r=radius of transducer.
Therapeutic us utilizes the near field
Frequency of US and radius of transducer need to be considered for tissue depth above 6.5cm(shortest)
05/03/2023
9
Coupling media
Ultrasound waves are not transmitted by air, thus some couplant which does transmit them must be interposed
Unfortunately no couplant affords perfect transmission & only a percentage of the original intensity is transmitted to the patient.
Aquasonic gel 72.6% Glycerol 67 % Distilled water 59 % Petroleum jelly 0 % Air 0 %
05/03/2023
10
Characteristics of a coupling media
1. Acoustic impedance similar to tissue2. High transmissivity for US3. Low suceptibility to bubble formation4. Chemically inactive in nature5. A hypoallergic character6. High viscosity7. Cheap8. Relative sterility
05/03/2023
11
US beam parameters
Mode type : continuous and pulsed. Pulsed Mark Space(M:S) ratio: 1:1, 1:2, 1:4 etc.
Power: amount of acoustic energy per unit time (watts)
Intensity: power per unit area of the ultrasound head (watts/cm2). Space average intensity and time averaged/space average intensity(pulsed).
Frequency: number of compression-rarefaction cycles per unit of time, usually expressed in cycles per second (Hertz)
Effective radiating area (ERA): The area of the transducer from which the US energy radiates
Duty cycle: The proportion of total treatment the ultrasound was on
05/03/2023
12
Depth of penetration
Majority of the ultrasound generators used in physiotherapy are set at a frequency of 1MHZ and/or 3MHZ.The depth of penetration of ultrasound beam is inversely proportional to the frequency1MHZ ultrasound beam has a depth of penetration of 3-5cm and absorbed in deeper tissues3MHZ ultrasound beam with a depth of penetration of 1-2cm and is absorbed in the superficial tissues
05/03/2023
13
Treatment Protocols
Preparation of the MachinePreparation of the PatientSet up the treatmentTermination of treatmentDocumentation
05/03/2023
14
Protocols Preparation of the machine Position Inspect Be assured of functionality Bring all accessories closer:• Aquasonic gel• Cotton wool• Methylated spirit• Water in a bowl Preparation of the patient Inform your patient Remove metals Expose the Rx part Remove hair if necessary Wash or swab Inspect the Rx part Check for intact sensation Demand co-operation
Set-up up the Rx Secure pt.'s comfort and
stability of Rx part Plug dead, supply and
power on Select Rx programme Apply coupling media Ensure the transducer is in
contact with the coupling media on the skin
Start now Keeping asking how the
pt.'s feels
05/03/2023
15
protocols
Termination Return intensity to
zero Remove transducer Cut the mains supply Clean the skin and
the transducer Inspect
Documentation Date Machine Intensity Frequency Mode duration Coupulant Region Response of Rx`
05/03/2023
16
Application
Principles Rx surface parallel to the skin Even pressure maintained to
exclude air and balance irregularities in sonic field
Transducer moved continuously over the skin surface
Rate of movement must be slow enough to allow tissue to deform and fast enough to avoid hot spots
Pattern of movement- series of overlapping parallel strokes, circles or figure 8
Techniques of Application1. Direct contact2. Water bath: degased
water of comfortable temperature, transducer held 1cm parallel to the skin inside the water keeping
3. Water bag
05/03/2023
17
Dosage Factors to consider Receny of injury Depth of tissue Nature of the lesion Size of the area Attenuation Area of transducer Acute conditions Intensity: 0.25 or 0.5
watts/cm2 Time: 2-3minutes Failure to improve progress
to 0.8watts/cm2 or increase time to 4 0r 5minutes
Chronic conditions Start dose: 0.8watts/cm2
for 4minutes Failure to improve
progress to 1watts/cm2 for 4minutes, 1watts /cm2 for 6minutes, to 1.5watts/cm2 for 6minutes, 1.5watts/cm2 for 8minutes, 2watts/cm2 for 8minutes
Note: A dose of 2watts/cm2 for 8minutes is maximum permitted
05/03/2023
18
Physiological effects
Chemical ReactionsBiological ResponsesMechanical ResponsesThermal Effects
05/03/2023
19
Physiological effects
Chemical reactionUltrasound vibration stimulate tissue to enhance chemical reactions and processes and ensure circulation of necessary elements and radicals for recombination.
Biological responses Increase membrane
permeability which enhances transfer of fluid and nutrients to tissues
Acoustic Streaming: is unidirectional flow of tissue components which occurs particularly at the cell membrane. Streaming produce changes in the rate of protein synthesis and could thus have a role in the stimulation of repair.
05/03/2023
20
Physiological effects
Mechanical responses micro massage: cells are
alternately compressed and then pulled further apart. This increase mobility of intracellular fluids and thus helps to reduce oedema.
Tendon extensibility: ultrasound apparently increases the extensibility of tendons, muscles and scar tissues.
Thermal effects: as ultrasonic waves are absorbed they are converted to thermal energy (heat)
05/03/2023
21
Clinical application of US
Soft tissue injuries Oedema Varicose ulcers Pain control Chronic rheumatoid and arthritic conitions Tendon injuries Resorption of calcium deposits Bone fractures Carpal tunnel syndrome phonophoresis
05/03/2023
22
Contraindications
Vascular conditionsRadiotherapyTumoursPregnancyCardiac disease ImplantAnaesthetic areaAcute sepsis
05/03/2023
23
Time to Demonstrate
05/03/2023
24
Ask your Questions and make your contributions
05/03/2023
25
A Big Thank You