Quiz 2 Flashcards
what type of current does iontophoresis utilize
direct current utilizing coulmbs law
what type of medications are typically used in iontophoresis
antianalgesics and anti inflammatory
what are cations
positivly charged IONS
what is the cathode
negatively charged POLE
what are anions
negatively charged IONS
what are anodes
positively charged POLE
electrolytes
substance that when placed in water gives solution that can conduct electricity
hydrolysis
the breakdown of water into OH - and H+
pH more then 7
basic (more OH)
pH less then 7
acidic (more H+)
what does the pH measure
the potential for hydrogen
what does the anode repeal
positive ions
what does the cathode repeal
negative ions
what is the formula for current density
current amount (mA)/electrode surface area
what is the ionic profile for Ionphoresis
1) ions must be charged
2) small in size (<8000)
3) must be a solution (no creams)
cautions with DC - negative pole (cathode)
- alkaline reactions/burns
- depolarization
- proteolysis (tissue softening)
- bacteriostatic
cautions with DC- positive pole (red anode)
- acidic reaction
- hyperpolarization
- proteoscleriosis (tissue hardening)
- increase in healing
what is current amplitude influenced by
1) pt tolerance
2) polarity of the active electrode
3) size of the active electrode
4) duration of treatment
cathode current should not exceed
0.5 mA/cm2
anode current should not exceed
1 mA/cm2
what is buffering
substance that controls for changes in pH needed for iontophoresis
indications for iontophoresis
1) superficial locations
2) inflammation
3) scaring
4) Ca2+ deposits
5) myositis ossifications
6) antifungal, wound healing, infected wounds
7) trigger points
Contraindications for iontophoresis
1) cancer
2) pregnancy
3) pacemakers
4) implanted electrical devices
5) skin irritation from previous treatment
charge of corticosteriods/ dexamethasone
negative
charge of acetic acid
negative
charge of sodium chloride and Potassium iodine
negative; used to mobilize scar tissue
charge of lidocane
positive
charge of salcylate
negative used for inflammation
charge of lithium
positive; demineralizing in gout
charge of zinc oxide
positive; used for wound healing
charge of Hyperhidrosis
negative followed by positive; used for excessive sweating
what is the frequency of ultrasound
greater then 20,000 Hz
what is the piezoelectric effect
the ability for materals (crystals to generate an electric potential in reponse to applied mechanical stress
what is the converse piezoelectric effect
the production of stress and or strain when an electric field is applied
another name for the nearfield
Fresnel Zone
another name for the far field
Fraunhofer zone
absorption
conversion of the mechanical energy of an ultrasonic wave to heat.
what is absorption directly proportional to
frequency, higher for tissues with more collgan
reflection
return of energy (typically 35%) ; the higher the reflexion the higher the impedance
refraction
redirection of energy at interface; slight bending
attenuation
absorption+scattering(reflection and refraction)
what is attenuation directly proportional to
frequency
what type of tissue responds best to US
tissue with high content of collagen
repeated scattering
the idea that the deeper the object the less heat because of energy lost on the way secondary to scattering.
why is ultrasound not good for muscles
too much water content, decreased absorption coefficent, often too big and too deep
what is the average half life depth at 3 MHz
2.5 cm
what is the average half life depth at 1 MHz
4.0 cm
relationship between quality and depth of US
inversely related secondary to half life depth and repeated scattering
non thermal effects of US
1) cavitation
2) acoustic streaming
3) microstreaming
4) standing waves
cavitation
sonically generated activity of gas or vapor filled bubbles
acoustic streaming
the steady circular flow of cellular fluids induced by ultrasound
mircostreaming
takes place near any small vibrating object such as gas bubbles that are auscultating
standing wave
max and min intensities at fixed positions half a wavelength apart.
power
energy/time (watts)
intensity
power/area (W/cm2)
frequency
cycles/sec (Hz)
spatial average
average intensity/area of the transducer
spatial peak
peak intensity of US output/area of the transducer (center more then periphery)
ERA (effective radiating area)
area of the crystal from which US waves radiate
BNR (beam nonuniformity ratio)
the ratio of the set intensity to the max peak intensity (2:1 or 3:1 is usually most appropriate)
what is the temperature range for thermal effect of US
40-45 c for 5 mins
what are the healing effects of US on the body
1) increase metabolic waste
2) vasodilation
3) increase extensibility
4) decreased sensitivity of neuronal elements
what is the goal with US on wounds and ulcers
wound contraction and protein synthesis
what is the clinical setting for US on wounds
pulsed at low doses (3 MHz)
what is the goal of US on tendon healing
strengthening
US setting for tendon healing
0.5 -1 W/cm2
what is the goal for US on bone healing
piezoelectric effect osteogenic effects of non-thermal
US setting for bone healing
low dose first 2 weeks of healing
what are some things that will impact absorbtion
1) blood (cools the tissue)
2) increased temp at bone-tissue interface where reflection is the greatest
3) convection cooling
4) conduction heating
what are the settings for phonophoresis
increased frequency and pulsed
what are the contraindications/precausions for phonophoresis
prego and nursing
side effects for phonophoresis
1) thick skin
2) poor wound healing
3) vessel fragility
4) acne
5) alopecia
6) oral thrush
7) bone and muscle wasting
8) eye problems
what are the 3 ways to get through skin with phonophoresis
1) stratum corneum
2) trans follicular
3) through sweat gland
indication for hydrocortison (phonophoresis)
anti-inflam
indication for litocane/ xyclocaine (phonophoresis)
acute pain
indication for methyle and salicylate (phonophoresis)
chronic painful MS disorders
indication for zinc oxide and siloderm (phonophoresis)
open wounds
indication for Iodine (phonophoresis)
adhesion, calcification and adhesive capsulitis
what does it mean when the pt reports of feeling nothing with phono
frequency is too low
what does it mean when the pt reports of feeling a deep ache with phono
too high frequency
what does EMGBF measure
the function of the sarcolemma
usages for biofeedback
1) arthritis
2) LBP
3) post op
4) CVA and CP
5) pelvic floor dysfunction
what is the amplitude of the biofeedback indicuative of
the size and number of motor neuron units firing (more linear with an isometric contraction)
PT considerations/indications for EMGBF
1) good motivation
2) good cognition and orientation
3) at least a 1 MMT
4) adequate vision and hearing
sensitivity of EMG
the lower the settings the more sensitive (ex 0-1 is the lowest and most sensitive)
spacing for biofeedback
the closer the electrodes are to each other the more specific they are (1-2 cm is the most appropriate)
threshold detector
provides an on signal that is activated once a particular level of contraction or relaxation is reached
purpose of ground conduction
helps determine that the appropriate measure of activity to being recorded and minimizes cross talking
good conduction of EMGBF needs
1) gel for mediam
2) good skin prep
3) placed parallel to the muscle fibers
ABV
above threshold used to relax
BLE
below threshold used to contract
ALM/OFF
have to go above threshold and hold for at least 4 seconds for alarm to go off
LOCK/OFF
once triggered will have to reset the alarm (one and done)
