Electrotherapy (Infrared) Flashcards
What is electrotherapy ?
Electrotherapy is the use of electrical energy as a medical treatment.
Using electricity to reduce pain,improve circulation , repair tissues and strengthen muscles , leading to improvement in physical functioning..
What is thermotherapy?
Also called heat therapy uses physical agents to induce superficial or deep heat to increase soft tissue extensibility, reduce pain , improve circulation , and accelerate healing.
Types of superficial heating modalities
- Hydrocollator pack
- Infrared radiation
- Paraffin wax bath
What is temperature?
The measure of the average amount of kinetic energy possessed by each individual molecule of a body.
Mention (6) Physical effect of heat?
# Expansion # Change of state # acceleration of chemical reaction # production of electromagnetic waves (IR, white lights ) # reduction of viscosity of fluids #Thermionic emission
(8) PHYSIOLOGICAL EFFECT OF HEAT
depends upon several factors
Including :
- Extent of tempt rise
- Rate at which energy is being added to the tissue.
- Volume of tissue exposed
- Composition of the absorbing tissue
- Capacity of the tissue to dissipate heat.
- Thermal conductivity of skin and tissue.
- Size of the tissue exposed
- Duration of tissue tempt elevation or reduction..
Short note on infrared ?
Slightly more than half of the energy from the sun that arrives in earth is in the form of IRR
*IRR are EM waves
Wavelength of 750nm to 400000nm
*It lies between visible lights and microwaves.
* It has higher frequency but lower wavelength than microwave
*It has lower frequency and longer wavelength than visible lights.
Classification of infrared
*Near or short (IRA)
Have a wavelength between 770nm to 1500nm
*Far or Long (IRB)
Have a wavelength between 1500nm to 12000nm
*IRC
Have a wavelength of 3000nm to 1mm (not used in therapy)
WIEN’S LAW
States that the wavelength of maximum production of a radiation is inversely proportional to the absolute temperature of the source.
Types of infrared lamp
- Non luminous generator.
* Luminous generator.
About Non- luminous generator
- also known as low temperature generators
- Produces only infra red rays of wavelength 750nm to 1500nm
#they are usually produced from heated elements of which there are 3 basic types: 1.coil of wire wound round a cylinder of insulating material.
- coil and insulator in an encasement of same insulating material
- U-shaped steel tube enclosing a spiral wire.
About luminous generator
- Also know as high temperature generators
- Emits visible rays , UV rays , and infra red rays of wavelength of 350nm to 4000nm
- Similar to lamps used for House lightening
*Are in form of incandescent bulb Consists of : -A wire filament enclosed in a bulb -May contain inert gas at low pressure. -filament made of tungsten or carbon.
Accessories of Luminous generator
Localizer: facilitate the different sizes
Filter: absorbs visible rays and UV rays..
Variable Resistance: adjusts the output of rays
Production of IRR(4)
- produced as a result of molecular motion within heated material
- Increase in tempt above absolute zero results in the rotation and vibration of molecules within the material.
- The wavelength of the IR is dependent on the temperature of the material
- The higher the temperature the higher the frequency the shorter the wavelength.
Absorption of radiation
depends on: (3) and explain
*The frequency or wavelength:
Wavelength longer than 3000nm is absorbed by the moisture present in the skin.
-Both long and short wavelength are absorbed by moisture present in the skin, thus reducing the absorption of heat.
- 11% of luminous or short IRR is absorbed by the glass of the bulb
33% are reflected by the skin , 56% is absorbed of the rays and 36% is absorbed in the epidermis, 10% goes deeper into the dermis and the remaining is scattered in the epidermis.
The long IRR 36% is reflected, 20% is absorbed in superficial epidermis ,16% reaches the deep epidermis ,
19% penetrate up to dermis , 11 % is absorbed by the glass of the bulb.
- The angle of incidence from the source :
According to Lambert’s cosine law , the angle of incident determines the amount of radiation absorption.
Absorption at 90° of incident is maximum due to zero reflection
For every 15° increase in angle of incidence there is 3% decrease in absorption.
*Distance of the source:
Obeys inverse square law
The intensity of the radiating energy is inversely proportional to the square of the distance between the source and the surface being radiated.
Absorption of radiation also depends on
- Thermal conductivity of the tissue
- Specific heat of the tissue
- Density of the tissue
- Circulation of the tissue
Pattern of absorption and penetration
is variable according to :
- Skin structure
- Vascularity
- Pigmentation of the skin
- Wavelength of the radiation
Mechanism of heating (5)
- Conduction: two surfaces directly touching one another
- Convection: circulation between two mediums of different tempt.
- Conversion: Non- thermal energy becomes thermal.
- Evaporation: transfer of energy that causes liquid to gas state
5: Radiation : direct transfer of energy without a medium for transfer.
Physiological effect of IRR (8)
- Increased metabolic rate
- Circulation of body fluid
- Pigmentation
- Sedative effect
- Increased temperature
- Increased B.P
- Muscle relaxation
- Increased sweat gland activity.
Therapeutic Effects (8)
- Encourages healing
- Controls infection
- Sedative effect
- Increase range of motion
- As precursor for other treatments
- Reduction muscle spasm.
Indications and therapeutic uses
Of IRR
Relief pain Sedative effect Counter irritation Muscle relaxation Muscle relaxation before exercise Circulation (metabolites reduction) Increase in blood supply Wound healing Cold limb Inflammatory conditions Elimination of waste products (sweat) Recent injuries
Contraindications of IRR (6)
- Impaired thermal sensation
- Skin tumours
- Patient whose level of
- consciousness is lowered by drug or disease
- Acute skin lesions(dermititis , eczema)
- Severe cardiac conditions
- Patient whose blood pressure is defective
- Over pregnant uterus
- Over Metal implant
Dangers when Using IRR (5)
- Burns ( defective sensation, impaired circulation, absence of PT, intensity)
- Skin irritation
- Low BP
- Dehydration
- Eye damage
Techniques of application of IRR
6 steps
Step 1: Apparatus should be in working other..
Stp 2: if luminous is chosen the apparatus should be pre heated for at least 5 min before heating.
If non luminous preheated 15min before treatment commences.
Step 3: preparation of patients
- position of patient should be comfortable and adequate.
- part to be treated exposed and others covered.
- the nature of effect of treatment should be explained to patient.
- examine the skin to be treated and conduct thermal sensation test.
- protect the eyes of the patient
- remove all metal objects like ring and safety pins.
Step 4 : arrangement of lamp and patient
- arrange the lamp so that the rays strike the skin at right angles.
- Never position the lamp over patient
- distance from the patient to the lamp should 50cm to 70 cm (lamps of 750-1000w)
Step 5 : set the timer
-For acute conditions duration should be 10-15 min and for chronic conditions it should be 30min.
Step 6: At the end of treatment
-cover the area exposed with a dry towel
-remove the lamp to a safe location
Inspect the area exposed for erythema produced.
Ask the patient how he or she is feeling now.
Ask the patient to dress up.
Type of IRR generator used for treating Acute inflammation,/recent injuries??
non luminous generator
Type of generator used for treating chronic / lesion counter irritant
Luminous generator
