pt2 lesson 1

• Terminologies


  • Frequency
  • Intensity
  • Pulsed or Continuous
  • Absorption and Penetration
  • Reflection and Refraction
  • Beam Nonuniformity Ration (BNR)
  • Effective Radiating Area (ERA)
• Frequency


  The number of completed wave cycles that pass a fixed point in 1 second
• Frequency


  • 1MHz
  • 3MHz
• Intensity


  The average power distributed over the ERA of the transducer, expressed in W/cm²
• Pulsed ultrasound


  Produced by intermittently interrupting the supply of electrical energy to the ultrasound head, which causes the acoustical energy, or sound waves
• Continuous ultrasound


  An uninterrupted flow of sound waves
• Diathermy


  A term that literally means "to heat through" and involves the use of EM energy passing through and being absorbed by the body and then converted into heat
• Duty factor


  The percentage of "on" time of ultrasound output

  
• Types of diathermy applications

  • Diathermy with an electric field
  • Diathermy with a magnetic field
• The greater the frequency


  The lesser the penetration
• Reflection


  To bend or cast back (as light, heat, or sound)
• Indications for diathermy


  • Pain
  • Muscle guarding
  • Inflammation
  • Soft tissue tightness
  • Reflex heating
  • Pelvic inflammatory disease (PID)
  • Herpes zoster
• Refraction


  The bending of a wave portion that is transmitted across a boundary
• Precautions for diathermy


  • Remove contact lenses when applying SWD around the head, face, or eyes
  • The skin exposed to the treatment should be covered by at least 0.5 inch of toweling
  • Do not allow perspiration to collect in the treatment field
  • Thick adipose tissue in the treatment area
  • It is difficult to heat only localized areas
  • Never allow the skin to come into direct contact with the heating unit or cables
  • If the cable method is used, do not allow the cables to touch each other
  • If electrode pads are used, space them at least the distance of their diameter apart
  • A deep, aching sensation may be a symptom of overheating the tissues
  • Overheating of the patient's tissues may cause tissue damage without any immediate signs
  • The SWD energy scatters 2 to 3 feet from the source energy should be maintained to ensure the operator's safety
• Beam Nonuniformity Ratio (BNR)


  The ratio of the peak power to the average power in the ultrasound beam measured in any cross sectional plane
• Contraindications for diathermy


  • Remove all jewelry, clothing, coins, and other metallic items from the patient
  • For personal safety, the clinician should remove any rings, watches, bracelets, and clothing with metal zippers or grommets
  • There must be no metal within the immediate treatment area
  • Keep the patient out of reach of any metal objects (e.g., outlets, pipes)
• Acceptable BNRs for ultrasound devices in the United States are approximately 6:1 or lower
• Ultraviolet & Infrared wavelengths

  Wavelengths are measured in nanometers (nm), or billionths of a meter. The visible spectrum of wavelength occurs between 400 and 800 nm. Wavelengths from 180 to 400 nm represent UV nonvisible light and wavelengths from about 800 to 1,500 nm are considered IR.

  
• Effective Radiating Area (ERA)


  The radiating area of the ultrasound applicator
• Ultraviolet light


  • UV light has been used as a treatment modality for dermatological conditions, such as psoriasis and in the prepartion of wound beds for healing, or to kill harmful bacterial pathogens including methicillin-resistant Staphylococcus aureus (MRSA)
  • Types: UV A, UV B, UV C
• Effects of ultrasound


  • Thermal
  • Nonthermal
• Safety considerations for ultraviolet light

  • Patients who are photosensitive should not be treated with UV
  • Patients with pellagra, a niacin-deficiency dermatitis, should not receive UV
  • Patients who have dermatitis secondary to systemic lupus erythmatosus (SLE) should not receive UV
  • Patients with active tuberculosis should not receive UV
  • Patients with a fever or acute diabetes should not receive UV
  • Skin rarely exposed to light may respond more dramatically to UV
  • Some medications are photosensitizing and cause reactions to UV
  • Both the patient and the clinician should wear protective eye gear with UV
• Precautions


  • Open wounds
  • Impaired cognitive ability
  • Pregnancy
  • PVD
  • Advanced age
  • Previous experience with ultrasound
  • Over joint or metal implants
  • Pain with pressure
  • Lack of sensation
  • Over epiphyseal plates
  • Breast implants
• Infrared radiation


  Wherein various wavelengths of light are focused to the parts of the body that have injuries. A key characteristic of infrared light is that it has the ability to get below the skin layers and provide a much greater depth.
• Contraindications


  • Pregnancy
  • Abnormal growth (presumed malignant)
  • Metastasis
  • Lack of sensation
  • Thrombus
  • Pacemaker
  • Psoriasis
  • Joint cement
  • Plastic components
  • Over the eyes and reproductive organs
• Production of infrared radiation

  • Luminous infrared generators (lamp with tungsten filament)
  • Nonluminous infrared generator (electric current passed through coil of wire)
• Physiological effects of infrared radiation

  • Nerve stimulation
  • Vasodilation
  • Phagocytosis
  • Reflex heating
  • Pigmentation and erythema
  • Sweating
  • Blood pressure
• Indications for infrared radiation

  • Pain and muscle spasm
  • Edema
  • Tissue healing
  • Increases the sensory nerve conduction velocity
• Contraindications for infrared radiation

  • Impaired sensation
  • Impaired circulation
  • Dermatological conditions
  • Metal
  • Eyes
  • Age
  • Analgesic and narcotic drugs
  • Deep x-ray therapy
  • Topical creams and oils
  • Skin tumors
  • Acute infections
  • Blood pressure abnormalities
  • Severe cardiac conditions