Ultrasound by udenn
- 1. BY UDENNAKA IKECHUKWU .E. OBSTETRICS & GYANECOLOGY UNIT PHYSIOTHERAPY DEPARTMENT UNIVERSITY OF CALABAR TEACHING HOSPITAL
- 2. INTRODUCTION MECHANISM PHYSIOLOGICAL EFFECTS OF ULTRASOUND THERAPUEATIC USES OF ULTRASOUND TEST & TREATMENT METHODS DOSAGE OF ULTRASOUND CONTRAINDICATION PRECAUTION & DANGERS OF ULTRASOUND
- 3. Sound is defined as the periodic mechanical disturbance of an elastic medium such as air. Sound requires a medium for its transmission and cannot cross a vacuum. The human ear can hear up to a frequency of 20hz - 20khz Ultrasound refers to mechanical vibrations, which are essentially the same as sound waves but of a higher frequency above 20khz. Such waves are beyond human hearing and can therefore be called ultrasonic. Therapeutic frequencies range from 1MHz- 3MHz.
- 4. Therapeutic ultrasound is produced when high frequency current is imposed on materials with piezoelectric qualities to cause the piezoelectric effects. Ultrasound(US) is a deep heating modality
- 5. COMPONENNTS TREATMENT PARAMETERS TRANSMISSION/COUPLING MEDIUM PROPERTIES OF US
- 6. Therapeutic US is produced when high frequency current is imposed on materials with piezoelectric qualities to cause the piezoelectric effect. When electrical energy is applied on piezoelectric crystals they produce vibration and mechanical deformity of their molecular structure. This phenomenon is called piezoelectric effect. This principle is used for generation of ultrasound waves Piezoelectric crystals (e.g. Germanium, quartz, barium titanate, Lead- Zirconium-Tartarate etc.) convert mechanical energy into electrical energy.
- 7. The ultrasound machine consists of a electricity source, coaxial cable, main body (includes the knobs and buttons), user graphic interphase, treatment head/applicator/transducer/sound head.
- 9. These are determined with the following in mind: a) Type of condition and b) Depth and position of the lesion. The treatment parameters include: Mode Intensity Time Frequency
- 12. US waves are not transmitted by air. Coupling medium is used between the patients skin and the transducer. Couplants should also serve as lubricant to allow treatment head move smoothly over skin. Here are some coupling media and their transmission rate: Aqua sonic Gel 72.6% Glycerol Gel 67% Distilled Water 59% Liquid Paraffin 19% Petroleum Jelly 0% Air 0%
- 13. Reflection & Refraction: if the US beam encounters an interface between two media while being transmitted it may be reflected i.e. Deflected from its original path Care is taken not to leave air between the transducer head and patients skin. If US waves are reflected there are tendencies of damaging the piezoelectric crystals. There may also be refraction of the longitudinal waves at the bone interface. Which is accompanied by a change in speed and wavelength of the waves.
- 15. Attenuation: this is the gradual reduction of the intensity of the US beam after it has left the treatment head. Two main factors contribute to this: Absorption Scatter Absorption and scatter reduces the intensity and brings about half-life.
- 16. Thermal effect Mechanical effect Biological effect Chemical effect
- 17. US can be used in treatment of: Acute soft tissue injuries Scar tissues, keloid and contractures Chronic indurated oedema Pain relief Bone injuries Chronic strains/sprains Wound healing Inflammation of joint capsules, tendons, ligaments and bursa often associated with degenerative conditions like osteoarthritis, rheumatoid arthritis and repetitive stress injuries
- 18. Improves protein synthesis thus, increasing the rate of repair of damaged tissues. US helps to reduce pain, break unwanted calcification of soft tissues and restore function as well as increased extensibility of collagen fibers increasing range of motion.
- 19. Physiotherapist(PT) should test the ultrasound machine to ensure proper production of the US before treatment A water bath is used to reflect ultrasound beam up to the surface of the water The ultrasound Machine is turned on while the treatment head blows the water and ripples indicate production of US waves.
- 20. Direct contact or surface method Water bath or Under water method Water bag method
- 22. Phonophoresis: is the movement of drugs through the skin into the subcutaneous tissues under the influence of US The thermal and biological effects of ultrasound increases tissue permeability and these aid at driving the medication into the tissues. The type of ointment used depends on the physiological needs of the patient e.g salycilate. zinc. iodine. hydrocortisone etc
- 23. US can be used to treat both Acute and Chronic lesions. Acute lesions: a low dose intensity of 0.25-0.5w/cm2 can be used for 2-5mins at initial stages and if condition doesnt improve time can be increased or an intensity of 0.8w/cm2 for 5mins. Chronic lesions: can be treated with a pulsed or continuous mode. The maximum intensity of US which should be used is that which produces mildly perceptible warmth. Which usually occurs at 2w/cm2. A dose of 2w/cm2 for 8mins is usually considered. If treatment doesnt improve even at a gradually increased dose and time then US treatment should be discontinued.
- 24. Growing epiphysis Poor blood supply Pregnancy Cardiac disease Tumors Radiotherapy Acute sepsis and other infections Bony prominences Vascular conditions Metallic implants Anesthetic area or area with defective nervous sensation.
- 25. Burns Damage of equipment Unstable cavitation may occur Overdose may lead to exacerbation of symptoms Treatment area should be clean and dry before applying coupling gel Treatment time should be between 5-10mins never treat over 15mins regardless of the treatment area. Ultrasound should be discontinued if there is no improvement after a maximum of 8 sessions
- 26. Ultrasound intensity should be adjusted to patients tolerance After treatment the treatment head should be wiped off and placed in its bracket. Then clean the coupling medium off the patient. the intensity level turned down to zero so the intensity is not on when next the machine is turned on.