Ultrasound
High frequency sound waves that are directed to produce beneficial physical effects as they are absorbed, reflected, and refracted. Waves are produced through this effect.
reverse piezoelectric effect
What are the Frequency for US? Which one penetrates deeper and how deep do they go?
1MHz- deeper up to 5cm
3MHz- more superficial 2-3cm- greater temperature change in shorter period of time
smaller surface area
Patient should feel warmth in 2-3 mins
low intensities for nonthermal
What is Diathermy? How does it work?
Shortwave or microwave electromagnetic energy to produce heat. Popularity varies.
waves move through tissue "accelerating electric charges produce electromagnetic waves of moving electric and magnetic field"
What are the 3 keys to safe delivery of a radiation-based agent
distance of radiation source
angle of incidence
appropriate power output
What is infrared? How deep can it penetrate?
Radiation with a lower frequency and longer wavelength than the red end of visible light
Generates heat in tissue proportional to the amount of time radiation that penetrates the tissue
IR-A- most common 770-1400nm
IR-B (1400-3000 nm)
IR C (3000- 1,000,000 nm)
if not laser may only penetrate 1-2 cm into skin
US Waves need a medium-dense medium (tissue) to move through. They are either compressed to increase density or rarefication to decrease density. The waves can then be 1. 2. or 3.
Absorbed- generating heat
Refracted- pass through dense tissue and change direction
Reflect- angle of application
US is more effective at heating dense tissue
What is Effective Radiating Area and Spatial Average Intensity? How do these concepts relate to treatment area?
ERA- area of the sound head sending US waves
treatment area should be no larger than 4x ERA- max efficacy at 2- thermal effects are diluted at larger
SAI- Power W/ERA (cm2)
Beam Nonuniformity Ratio- Spatial peak intensity- greatest in center of the beam
Spatial average intensity- over the whole head
How can Diathermy be delivered?
Shortwaves- only in US
Microwaves
can be pulsed or continuous
•Excite mitochondrial chromophores
•Increase ATP production
•Increase cellular repair and reproduction
•Increase mRNA production for pre-collagen
Increased neuronal sprouting (animal studies
How do you set up infrared? What will the patient feel? How long is the treatment time?
45-60 cm away from skin, perpendicular to treatment area
patient and therapist should be wearing IR-opaque googles
allow lamp to warm
patient will feel warm
15-30 mins
What are Indications for US?
(3 main ones)
Local inflammation and pain- carpal tunnel, muscle spams, arthritis, etc.
Soft tissue shortening- combined with other interventions
(small literature) soft tissue healing, wounds, scars, tissue remodeling
less evidence for non-thermal use
What is Duty Cycle? How is it expressed?
proportion of on time to total treatment time
Percentage or ratio
Mode: Pulsed vs Continous (thermal and deep heat)
20% 50% 100%
High collagen content absorbs US well
High water content not absorbed well
What are indications to diathermy?
Pain control
soft tissue healing
osteoarthritis
bone healing
control of edema (pulsed)
wound healing (pulsed)
What are indications for laser? precautions? contraindications?
indications- pain and inflammation associated with MSK conditions and open wounds
precautions- indirect eye exposure, impaired sensation or cognition, light sensitivity
contraindications- irradiation of eye, malignancy, hemorrhage, over thyroid or other glans, open growth plates, tattooed skin
Infrared indication? precautions? contraindications?
indications- superifical heat or laser is indicated
promising for venous wounds and improved in impaired sensation in neuropathy
precautions- all conditions for which superficial heat or laser has precautions
contraindications- all conditions for which superficial heat or laser is contraindicated
Precautions for US
Pulsed in active inflammation
regenerating nerves
skin disease
impaired sensation, cognition, communication
Adverse effects: burns and standing waves- if sound head is not moved
What is the treatment time for US?
5-15 minutes
What are contraindications to diathermy?
implanted nerve stimulators, including pacemakers
acute infection, inflammation
pacemaker
hemophilia
pregnancy
metal implants
malignancy
treatment over eyes or testes
thermal effects on internal organs
pain or temperature sensory deficits
What are the parameters for laser? For a continuous laser is W mean or peak power? For pulsed? What is the equation we use?
Wavelength
Power
time
Frequency
Energy
Radiating area
Energy density
continous- peak J=Wxt
pulsed- mean= peak x Hz x pulse duration
What is UV? How deep does it penetrate?
Radiation with higher frequency than blue/violent end of visible light?
3 bands
UVA (320-400)- fluroescence
UVB (290-320)- erythema
UVC (<290)- germicidal
penetrates several mm into skin- SUPERFICIAL
Contraindications for US
Tumor
Pregnancy
Breast implants
CNS tissue, eyes, heart, reproductive organs
Pacemaker
site of active bone growth
joint cement or plastic implant
metal implants
hemorrhagic conditions
continuous in acute injury
over spinal cord and regenerating/superficial nerve
decreased local circulation
recently irradiated tissue
How is US delivered?
Where should it be delivered?
How does the skin need to be prepped?
How fast should you move the head?
How much pressure should be applied?
What should the patient feel
Through a transducer head
Small areas
Apply gel
Not to fast not to slow
Firm pressure to sustain contact
Warmth is continuous or gentle pressure with few adverse effects?
What are precautions to diathermy?
treatment near electronic or magnetic equipment
obesity
pregnancy in therapist
menstruation in patient
skeletal immaturity
What is the patient experience for laser?
No overt sensation
may experience some warm
occasional short- term redness/tingling
How is UV delivered? What are indications? What are contraindications? What are precautions?
Delivery- 60-80cm away wearing UV googles 15,30, 45, or 60 secs to test exposure- minimal time it takes for the skin to get read is 8 hrs but takes 24 hrs to go away
Indications- psoriasis or other skin conditions and wound healing
Precautions- photosensitivity, recent tradition therapy, not until previous dose has disappeared
contraindications- irradiation of eyes, skin cancer, areas receiving radiation, pulmonary TB, cardiac, kidney, or liver disease, lupus, fever