THERAPUETIC ULTRASOUND

BYUDENNAKA IKECHUKWU .E.

OBSTETRICS & GYANECOLOGY UNIT

PHYSIOTHERAPY DEPARTMENT

UNIVERSITY OF CALABAR TEACHING HOSPITAL

INTRODUCTION MECHANISM PHYSIOLOGICAL EFFECTS OF ULTRASOUND

THERAPUEATIC USES OF ULTRASOUND

TEST & TREATMENT METHODS DOSAGE OF ULTRASOUND CONTRAINDICATION PRECAUTION & DANGERS OF ULTRASOUND

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.

INTRODUCTION

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

COMPONENNTS TREATMENT PARAMETERS TRANSMISSION/COUPLING MEDIUM PROPERTIES OF US

MECHANISM

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.

MECHANISM

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.

COMPONENTS OF AN US

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

TREATMENT PARAMETERS

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%

TREATMENT /COUPLING MEDIUM

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.

PROPERTIES OF ULTRASOUND

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.

PROPERTIES CONTD.

Thermal effect Mechanical effect Biological effect Chemical effect

PHYSIOLOGICAL EFFECTS OF US

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

THERAPUETIC USES OF US

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.

THERAPUETIC USES CONTD.

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.

TEST & TREATMENT METHODS

Direct contact or surface method

Water bath or Under water method

Water bag method

TREATMENT METHODS

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

Treatment methods contd.

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 doesn’t 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 doesn’t improve even at a gradually

increased dose and time then US treatment should be discontinued.

DOSAGE OF ULTRASOUND

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.

CONTRAINDICATIONS OF US

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

DANGERS AND PRECAUTIONS

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.

DANGERS AND PRECAUTIONS CONTD.

THANKS FOR LISTENING…