Short wave diathermy uses electromagnetic waves between 107-108 Hz to induce heating in tissues. It has both thermal and non-thermal physiological effects and can be used to treat inflammatory conditions, infections, muscle injuries and more. The document describes the production of short wave diathermy through an oscillating circuit, and discusses methods of application including capacitor and cable techniques which create electric and magnetic fields. Precautions are outlined to avoid risks like burns. In summary, it provides an overview of short wave diathermy including its mechanisms, effects, indications and application methods.

1. SHORT
WAVE
DIATHERMY
P. KEERTHI PRIYA MPT NEURO,
ASSISTANT PROFESSOR

2. CONTENTS
INTRODUCTION
PRODUCTION
TECHNIQUE OF APPLICATION
PHYSIOLOGICAL EFFECTS
THERAPEUTIC EFFECTS
INDICATIONS
CONTRAINDICATIONS
PRECAUTIONS

3. DIATHERMY: MEANS THROUGH HEATING.
Based on frequency & wave length it’s divided into 3 types
SHORT WAVE
MICROWAVE
LONGWAVE
DEFINITION: Application of high frequency non ionizing electromagnetic energy
to generate heat in deep tissues.
Frequency: 107-108HZ
Wave Length: 30-3mts
USES :
Musculoskeletal
Neurological
INTRODUCTION
Therapeutically used: 27.12MHZ at 11mts
40.68MHZ at 7.5mts
13.56MHZ at 22mts Rarely used

4. PRODUCTION
PRODUCTION
PRINCIPLE
Discharging a condenser through
an inductance of low ohmic
resistance.
CONSTRUCTION
1. Machine circuit
2. Patient circuit

5. CONSTRUCTION PRODUCTION
MACHINE CIRCUIT
Transformer( step-up & step down)
Triode Valve
Oscillatory Circuit ( Condenser & induction)
PATIENT CIRCUIT
Condenser
Induction

7. PRODUCTION
WORKING
Circuit
primary coil of Step
up & step down
transformer
Induces EMF in
secondary coil (step
up 4000volts & step
down 20-25 volts
Current flows from
step down to filament
which causes
thermionic emission
Flow of current from
filament to anode
Anode to oscillator
coil CD , induces
EMF in AB which is
connected to grid
Grid becomes –ve ,
no flow of current
Self induced EMF ,
charging of
condenser
Discharge in direction
D to C, induced EMF
AB
Grid becomes neutral Flow of current
Induces EMF in
resonator coil EF
Flow of currentPatient circuit

8. PHYSIOLOGICAL EFFECTS
 Thermal Effects
 Non Thermal
Effects
Non Thermal Effects
 Increased microvasculature
perfusion
 Activation of fibroblast
 Increased macrophagic activity

9. PHYSIOLOGICAL EFFECTS
Direct Thermal Effects
 Increased metabolism
 Increased blood supply
 Effects on nerves
Indirect Thermal
Effects
 Muscle tissue
 General raise in temperature
 Fall in B.P
 Increased activity of sweat glands

10. THERAPEUTIC
EFFECTS
 Inflammation
 Bacterial infection
 Traumatic conditions
 Reduce healing time
 Relief of pain
 Effect on muscle tissue

11. Inflammation
Increased
blood flow
Increased
oxygen &
nutrient supply
Increased
WBC&
Antibodies
Increased
exudation of
fluid
Removal of
metabolites &
debris
Alteration of
cellular
diffusion
Improved
chondrocyte
proliferation
Increased
removal of
cellular debris
& metabolites

12. INDICATIONS
 Chronic inflammatory
conditions ( O.A & RA)
 Sprains
 Strains
 Hematoma
 Muscle & Tendon Tears
 Capsule Changes

13. INDICATIONS
 Boils
 Carbuncles
 Sinusitis
 Pelvic Conditions
 Infected Surgical Incision

14. CONTRAINDICATIONS
 Open Wounds
 Metal In Tissue
 Altered Skin Sensation
 Venous Thrombosis
 Arterial Disease
 Menstruation
 Pregnancy
 Tumours
 Exposure To Radiation
 Unconscious
 Children
 Mentally Retarted

15. DANGERS
 Burns
 Scalds
 Electric shock
 Over dosage
 Precipitation of gangrene
 Fainting
 Giddiness
 Dangers to other equipment
 Damage to hearing aids, pacemaker

16. METHOD OF APPLICATION
CONDENSOR/CAPACITOR METHOD
Creates strong electric field
Electrodes & patient tissue forms
capacitance
Depends on:
Size of electrode
Distance between electrodes
Tissue between electric field
CABLE METHOD
Creates strong magnetic field
Cable & patient tissue forms
inductance
EFFECT OF ELECTRICFIELD
Condenser: Rapid oscillation of electrons produce heat
Insulator: Distortion of molecules
Electrolyte : Rotation of dipolar
EFFECT OF ELECTRICFIELD ON BODY
Low Impedance: High dielectric constant
(Blood, Muscle)
High Impedance: Low dielectric constant
(Fat)

17. CAPACITOR METHOD
TYPES OF ELECTRODES
1. Pad
2. Plate
3. Disc
SIZE OF ELECTRODES
1. Different Size
2. Little Large
3. Smaller
4. Far Larger
Tuning :
Adjusting of variable condenser to equalise currents in
machine & patient circuit.

18. CAPACITOR METHOD
SPACING OF ELECTRODES
1. Small : Blood & muscle get heated up
2. Large : fat gets heated up
3. Narrow: superficial heating happens
4. Unequal
5. Wide: deep structures heated up
POSITION ELECTRODES
1. Coplanar
2. Contra planar
3. Mono planar
4. Cross fire

19. CABLE METHOD
Electric field: ends, used for high impedance
Magnetic field : centre used for low
impedance
Electrostatic field: capacitor method( low
impedance)
Method s
Helix
Grid

20. REFERENCES
 CLAYTONS ELECTROTHERAPY
 THERAPEUTIC FOR SPORTS MEDICINE AND ATHLETIC TRAINING MODALITIES BY W
I L L I A M E . P R E N T I C E
 ELECTROTHERAPY BY JEGMOHAN SING