Week 7 Flashcards
Name 4 EPAs
Thermal
Non-thermal
Electrical stimulation
Othes
Thermal EPAs (7)
Hydrocollator (Hot) packs Cryotherapy (Ice/cold/immersion) Continuous Therapeutic Ultrasound Shortwave Diathermy Microwave Diathermy Infrared Wax Bath
Non thermal EPAs (8)
Pulsed ultrasound Low intensity pulsed ultrasound (LIPUS)) Pulsed laser therapy Pulsed shortwave therapy Pulsed electromagnetic fields Magnetic therapies Mircrocurrent therapies shock wave therapy
Electrical Stimulation EPAs (6)
Interferential therapy (IFT)
Transcutaneous Electrical Nerve stimulation (NMES)
Functional Electrical Stimulation (FES)
Microcurrent Therapy (MCT)
Transcranial Direct-Current Stimulation (tDCS)
Other EPAs (4)
Biofeedback (no stimulation)
Electromyograph - Biofeedback
Ultrasound Imaging
Ultraviolet light
pages to review
10,11.12, 25,26,33
Generation of US
An ultrasound wave is generated when an electric field is applied to an array of piezoelectric crystals located on the transducer surface. Electrical stimulation causes mechanical distortion of the crystals resulting in vibration and production of sound waves (i.e. mechanical energy)
Generation of US Part 2
The conversion of electrical to mechanical (sound) energy is called converse piezoelectric effect (Gabriel Lippman 1881)
Frequency dependant on crystalline disc and current applied
Characteristics of Traditional US (3)
High frequency modality (1- 3MHz)
Thermal and non thermal effects
European, Antipodean North American approaches
Characteristics of Long Wave US (4)
Newer modality
45 kHz
Longer wavelength - penetrates more deeply (several metres)
promoted for same uses as traditional high frequency US
What is a transducer
A device that produces sound waves that bounce off body tissues and make echoes. The transducer also receives the echoes and sends them to a computer that uses them to create a picture called a sonogram
What is ERA
Effective radiating arm
What is the power of US measured in
Watts
What is the intensity of US measured in
Wcm^-2
p20
What is the Beam Non-uniformity Ratio (BNR)
Describes the consistency (or uniformity) of the US output ratio
What does the BNR range from
10:1-2:1
Lower = better
What is the Duty Cycle (Pulsed Ratio)
describes the proportion of time the current is actually flowing
e.g. 5s on 10s off - duty cycle is 33% (1:2)
typically 1;1 or 1;4
each pulse lasts about 2ms