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
Microwaves generate the most heat in tissues that have what?
High electrical conductivity
Microwave has ___ wavelength and ____ frequency
Shorter wl
Higher frequency
Metal and tissue with high water/electrolyte content [muscle/synovial fluid] have (high or low?) electrical conductivity?
High electrical conductivity
Fat, bone, and collagen with low water content have (high or low?) electrical conductivity?
Low electrical conductivity
Both continuous or pulsed SWD can heat tissues if intensity is high enough. What do the Watts need to be greater than?
> 38 W
The inverse square law applies to what type of applicator for diathermy?
Inductive coils
*Strength of magnetic field decreases in proportion to the square of the distance between the tissue and the applicator (inverse square law) but does not vary with tissue type. (Keep coil close to skin for maximum Intensity)
What are two non-thermal effects of diathermy?
Increased microvascular perfusion and altered cell membrane function and cellular activity
What are the two GENERAL contraindications for ALL diathermy?
- Implanted or transcutaneous stimulators including pacemakers
- Pregnancy
Contraindications for Thermal diathermy:
Metal Malignancy Eyes Testes Growing epiphyses
When performing diathermy, electronics should be kept at least - meters away (10-16 ft)
Therapist should stay how far away from continuous SWD?
SWT?
MWD?
3-5 meters away (electronics)
Therapist 1-2 m away (3-7 ft) for continuous SWD
30-50 cm (12-20 in) away from all SWT
Out of direct beam of MWD
[Light Parameters]
Longer wavelength penetrates ____
Deeper
Power = rate of energy flow
How is it written?
Power density =
P= mW
Power density= mW/cm2
Energy = Power x time _ = _ x _
Energy density= power per unit area
_/__2
*preferred clinical measurement
J = W x S
J/cm2
Effects of lasers and light:
- Promote ATP production by mitochondria
- Promote collagen production by fibroblasts
- Modulate inflammation
- Inhibit bacterial growth
Contraindications of Lasers and Light:
- Direct radiation of eyes (pt and clinician wear goggles)
- Malignancy
- within 4-6 months after radiotherapy
- Hemorrhage
- Thyroid or other endocrine glands
What three characteristics does laser light have?
It is monochromatic (meaning it is only a single wavelength), coherent, and directional
The frequency and wavelength of an electromagnetic wave are inversely related. This means that as the frequency increases, the wavelength
Decreases
EMR means?
Electromagnetic radiation
*Electric and magnetic fields that vary over time and are oriented perpendicular to each other
Laser stands for?
Light amplification by stimulated emission of radiation
What are diodes?
LEDs, SLDs, or laser diodes
Produce light in the visible or infrared range of the electromagnetic spectrum
SLD= supraluminous diode
The intensity of any type of electromagnetic radiation reaching the body is greatest win energy output is ___, the radiation source is ___ to patient, and the beam is ____ to the surface of the skin.
- Energy output is high
- Source is close to the patient
- Beam is perpendicular to surface of skin
Light with a ____ wavelength penetrates more deeply than light with a ____ wavelength
Longer goes deeper than shorter
Most laser diodes used for therapy have a power between:
5 and 500 mW
What class of lasers are used for therapy?
3B
(Ultraviolet radiation)
Erythema production primarily comes from UV_ and ____
UVB and PUVA
UV radiation is indicated for what condition?
Psoriasis
*Use PUVA (UVA + psoralen)
Inhibits cell division, inhibits dna synthesis, inhibits mitosis of hyperproliferating epidermal cells
What type of UV is best for wound healing?
UVC
No dose of UV radiation should be repeated until when?
Until the effects of the previous dose have disappeared
MED stands for:
Minimal Erythemal Dose
of UV radiation
When determining a patient’s MED of ultraviolet radiation the patient should observe the area for up to 4 days after exposure. The areas that shows mild reddening of the skin within _ hours that disappears within __ hours is treated as the MED
8 hrs
Disappears after 24 hrs
(Light Parameters)
Visible light : ~ ____-____ nm
Infrared light : > ___-_____ nm
~400-650 nm
> 650-1300 nm
Factors affecting the intensity of UV radiation reaching the patient skin:
Inverse square of the distance of the lamp from the patient, power output of the lamp, and cosine of the angle of incidence of the beam with the tissue
Contraindications of ultraviolet radiation:
Direct radiation of eyes, skin cancer, pulmonary disease, cardiac/kidney/liver disease, systemic lupus erythematosis, fever
When applying diathermy the increase in tissue temperature is determined in large part by the _____ of the magnetic field, distance from the patient, and the _____ of ____.
Intensity of magnetic field
Distance from patient
Type of tissue
Thermal effects of diathermy effect superficial and deep tissues vs. HP heats only outer few millimeters of tissue and US heats ____ but ____ areas.
US heats deep but small areas
The MED for patients receiving PUVA therapy should be determined [before or after?] the patient has taken psoralen orally or has bathed in psoralen
AFTER the pt. has taken psoralen
Skin disease characterized by bright red plaques with silvery scales, usually on the knees, elbows, and scalp and is associated with mild itching
Psoriasis
What is epidermal hyperplasia?
Thickening of the superficial layer of the skin
Does UVA, UVB or UVC produce the most skin erythema?
UVB
Because UV radiation does not produce ___, it is thought to produce physiological effects by ____ mechanisms.
Does not produce heat
Nonthermal mechanisms
The intensity of UV radiation reaching the skin is highest with a high power lamp positioned close to the patient with the radiation beam ____ to the skin surface.
Perpendicular
What type of UV radiation is bactericidal and used for wound healing?
UVC
Diathermy heats ___ tissues.
IR radiation heats ____ tissues.
*Advantage-doesn’t require direct contact with patient
Deep
Superficial
