Exam 2- US, Diathermy, Lasers/Light, CPM Flashcards
Ultrasound sound with Frequency > _____ Hz
20,000 Hz
Sound is a ____ _____ wave
Compression rarefaction
Sound waves enter body and are attenuated by:
Absorption, reflection, refraction
Attenuation is Tissue and Frequency specific: it increases with the ___ content of tissues and with the frequency of the US
Collagen
The ability to generate electricity in response to a mechanical force or to change shape in response to an electrical current
Piezoelectricity
Ultrasound generally heats smaller, ____ areas than superficial heating agents.
Deeper
The rate of tissue heating by ultrasound is proportional to the ____ _____ of the tissue at the applied US frequency
Absorption coefficient
When applying ultrasound to heat tissues, initial treatment parameters are set according to theoretical and research predictions, but the patient’s ____ of ____ is used to determine the final US intensity.
Patient’s report of warmth
Nonthermal effects of ultrasound are:
- Cavitation, microstreaming, and acoustic streaming
- Increased intercellular calcium
- Promotes cell function and tissue healing
Ultrasound with low average Intensity has been shown to increase intracellular ____ levels, and to increase skin and ____ _____ permeability.
Calcium levels
Cell membrane permeability
The application of ultrasound in conjunction with a topical drug preparation as the ultrasound transmission medium. The ultrasound is intended to enhance delivery of the drug through the skin, thereby delivering the drug for local or systemic effects.
Phonophoresis
The ratio of the spatial peak intensity to the spatial average Intensity
Beam nonuniformity ratio (BNR)
The steady, circular flow of cellular fluids induced by ultrasound. This flow is larger in scale than the flow caused by micro streaming and is thought to alter cellular activity by transporting material from one part of the ultrasound field to another
Acoustic streaming
The formation, growth, and pulsation of gas-filled bubbles caused by ultrasound. The bubbles oscillate in size throughout many cycles but do not burst
Stable cavitation
Microscale eddying that occurs near any small, vibrating object. It occurs around the gas bubbles set into oscillation by cavitation
Microstreaming
What is the primary indication for using continuous passive motion?
To improve range of motion that may have been impaired secondary to a surgical procedure. Although any joint may be indicated for CPM, most common is the knee.
When is CPM used most?
Usually right after surgery. Begin with small arc of motion and progress as indicated and tolerated. Sometimes ordered for home use with patient education
What is the best speed to set the CPM on?
Usually two cycles per minute is tolerated best
Therapeutic effects of CPM:
Decrease post-operative pain, improve the rate of recovery, increase range of motion, lessen the debilitating effects from immobilization, reduce edema by assisting venous and lymphatic return, and stimulate tissue healing
What is diathermy?
Application of short wave or microwave electromagnetic energy to produce heat and other physiological changes within tissues
How does diathermy heat tissues?
The increase in tissue temperature is determined in large part by the intensity of the electromagnetic field, the type of tissue, and distance from the patient
What is SWT?
Nonthermal shortwave therapy, which is NOT used for heating
Diathermy can heat more ___ than Hot packs and heats ___ areas than US
More deeply
Larger areas
What is the most common frequency used for SWD?
27.12 MHz
An Inductive diathermy applicator consists of a coil through which in alternating electrical current flows. The current produces a magnetic field ____ to the coil, which induces electrical ___ currents in tissues
Perpendicular to coil
Eddy currents
Capacitive plate diathermy applicators are made of metal encased in plastic housing or transmissive carbon rubber electrodes that are placed between felt pads. A high frequency alternating electrical current flows from one plate to the other through the patient, producing an electrical field in the flow of current in the body tissue between the plates. The patient becomes part of the ___ ____ connecting the two plates.
Patient becomes part of the electrical circuit connecting the two plates
Capacitive plate diathermy applicators produce ____ heat In the skin and superficial tissues, whereas ____ Applicators produce more heat in deeper structures.
More heat in skin/superficial tissues (capacitive)
Inductive,
More heat in deeper structures
What is used to deliver microwave diathermy (MWD)?
Magnetron