1. 1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION – 1099- 243
SHORTWAVE DIATHERMY
Dr/ Amal Mohamed Abd El Baky Chandrasekar Loganathan
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –

2. Lecture Outline
This lecture deals about the topic SWD in following sub- categories;
1. Basics principles & production of SWD
2. Indications & Contraindications of SWD
3. Physiological & Therapeutic effects of SWD
4. Methods of application / Treatment procedure – An overview of clinical application
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

3. Lecture Objective
At the end of this lecture, the students will be able to;
1. Recall the principles & production of SWD.
2. Compare & list down some of the indications, contraindications, precautions, physiological, therapeutic effects, advantages, disadvantages & dangers of SWD.
3. Safely & effectively to demonstrate the testing of machine, methods of application to various segments of the body as a treatment.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

4. SWD - INTRODUCTION
Application of High-Frequency Electromagnetic Energy
A deep-heating modality
Does Not stimulate MOTOR & SENSORY NERVES.
No Danger of CHEMICAL BURNS.
No Contraction of Muscles is produced
Wavelengths Too Short
Frequency
27.12 MHz at wavelength of 11 M
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

5. SWD - INTRODUCTION
Short-wave diathermy is used in medical therapy to produce local heating in tissue through the conversion of electromagnetic energy into thermal energy.
Dia means through and through
Thermo means temperature / heat.
Short wave diathermy (SWD), or radio frequency (RF), is used to penetrate deep into the body tissues to stimulate blood flow and to heat the treated area.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

6. SWD - INTRODUCTION
Diathermy is a modality that creates a deep heat from an electrical current.
It can go deeper than other modalities, such as hot packs. It heats larger areas than US.
Structures with high water content like blood, adipose tissue and muscle are selectively heated at depths of 2- 5cm.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

7. Possible Shortwave Diathermy Unit
A=Power Switch
B=Timer
C=Milliameter(monitors current from power supply not current entering patient-volume control)
D= Intensity(%max power to patient)
E=Tuning Control(tunes output from RFO)
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

8. Shortwave Diathermy Unit
Generates Both an Electrical and a Magnetic Field
Ratio Depends on Characteristics of Both The Generator and the Electrodes
SWD Units at MHz= Stronger Magnetic Field
SWD Units at MHz = Stronger Electrical Field
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

9. Generation / Production of High Frequency SWD
SWD have two main circuits;
The machine / Oscillator circuit which produce high frequency current.
The patient / Resonator circuit through inductors to transfer the electrical energy to the patient.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

10. The machine / Oscillator circuit
1- Main supply : connected AC mains that gives V and frequency 50 cycle /s
2- Transformer : step down transformer, step up transformer.
3- Triode valve : allow electron flow in one direction.
4- Grid leak resistance: it consists of a resistance coil
5- Oscillator: it consists of a stable condenser and an oscillator coil, give high magnitude, high frequency oscillator current.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

11. The Patient / Resonator circuit
a- Resonator coil
b- Variable condenser
c- Electrodes : pad electrodes, disc electrode, cable electrode, Monode & Diplode
d- Ammeter / Neon lamp
e- Tissue
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

12. Principle of Production of SWD
This type of high frequency current is obtained by DISCHARGING a CONDENSER through an INDUCTANCE of LOW OHMIC RESISTANCE.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

13. Biophysical and biochemical effects of SWD
Effects of an electrostatic field:
1- Free ions in the tissues give minimal movement (Vibration of Ions) due to high frequency leading to friction between ions and produce heat. + - + - - + - +
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

14. Biophysical and biochemical effects of SWD
2- The dipolar molecules (as water – will rotate to & fro - Swinging) move to the opposite charge on the condenser plates, charge change rapidly, friction between molecules leads to heat in the tissues.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

15. Biophysical and biochemical effects of SWD
3- The non-polar molecules (as fat – Insulator, undergo distortion of their electron cloud leading to back & forth movement) cause minimal friction and molecular movement producing little heat.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

16. SWD Physiological Events Summary
Electromagnetic Radiation
PSWD
CSWD
Electromagnetic Energy absorption
Increased molecular KE
cell ion-binding properties, protein synthesis, ATP production
Thermal Effect
Athermal Effect
Increased cell metabolism and function
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018
Enhanced soft-tissue healing

17. Physiological (Direct) Effects
An increase in the tissue temperature can produce number of physiological changes:
Direct effects
Indirect effects
1-Increase the metabolic activity, which lead to:
Encourage healing.
Increase metabolic rate.
Increase phagocytosis.
Increase CO2 release and O2 use.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

18. Physiological (Direct) Effects
2- Increase blood supply:
- Increase nutrient and O2 supply.
- Decrease metabolites.
-Decrease chemical pain mediators lead to decrease pain.
-Increase tissue fluid exchange which decrease edema.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

19. Physiological (Direct) Effects
3 - Stimulation of nerve lead to:
decrease pain through increase the conduction velocity
Decrease the conduction latency of motor and sensory nerve.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

20. Physiological (In-direct) Effects
Effects on the muscle tissue
Induce muscle relaxation
Increase the efficiency of muscle action
2. General rise in temperature.
3. Fall in blood pressure due to generalized vasodilatation that decrease the peripheral resistance
4. Increase activity of sweet glands due to reflex stimulation
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

21. Physiological (In-direct) Effects
5. Decrease viscosity: which decrease peripheral resistance synovial fluid which lead increase joint range "decrease joint stiffness".
6. Increase extensibility of collagen which facilitate stretching.
7. Assist in resolution of chronic inflammation.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

22. Types of Electrodes in SWD
Flexible pads: consist of metal electrode encased in rubber and produce an electrostatic field.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

23. Types of Electrodes in SWD
Space plates: consist of a rigid metal electrode encased in a Perspex cover  electrostatic field.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

24. Types of Electrodes in SWD
Coil: or cable electrode consists of a wire with plugs at either end electromagnetic field.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

25. Types of Electrodes in SWD
The monode: flat, rigid coil encased in Perspex cover electromagnetic field.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

26. Types of Electrodes in SWD
The diplode: or drum electrode, consists of a flat coil electrode encased in a Perspex cover with two wings electromagnetic field
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

27. SWD - Methods Capacitor field Method Inductive field Method
Selection of Appropriate methods Can Influence The Treatment
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

28. Capacitor (Condenser) Electrodes
The electrodes acts as CAPACITOR
The patient tissues & Insulating material acts as
DIELECTRIC MEDIUM.
Heat production by conversion of ELECTROMAGNETIC ENERGY
MECHANICAL (HEAT) ENERGY
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

29. Capacitor (Condenser) Electrodes
If the goal of treatment is to increase tissue extensibility & the limitation is primarily to capsular tightness, then capacitor field method of SWD is the more appropriate choice.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

30. Capacitor (Condenser) Electrodes
Create Stronger Electrical Field Than Magnetic Field
Ions Will Be Attracted Or Repelled Depending on the Charge of the Pole
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

31. Capacitor (Condenser) Electrodes
Electrical Field Is The Lines of Force Exerted on Charged Ions That Cause Movement From One Pole To Another
Center Has Higher Current Density Than Periphery
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

32. Capacitor (Condenser) Electrodes
Patient Is Between Electrodes and Becomes Part of Circuit
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

33. Capacitor (Condenser) Electrodes
The Tissue That Offers The Greatest Resistance To Current Flow Develops The Most Heat
Fat Tissue Resists Current Flow
Thus Fat Is Heated In An Electrical Field
Precaution: electrical field may overheat area with large fat content
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

34. Capacitor Electrodes (Air Space Plates)
Two Metal Plates Surrounded By Plastic Guard
Can Be Moved 3cm Within Guard
Produce High- Frequency Oscillating Current
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

35. Capacitor Electrodes (Air Space Plates)
Area To Be Treated Is Placed Between Electrodes Becoming Part of Circuit
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

36. Capacitor Electrodes (Air Space Plates)
Sensation Of Heat In Direct Proportion To Distance Of Electrode From Skin
Closer Plate Generates More Surface Heat
Parts Of Body Low In Subcutaneous Fat Best Treated
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

37. Capacitor Electrodes (Pad Electrodes)
Greater Electrical Field
Patient Part of Circuit
Must Have Uniform Contact (toweling)
Spacing Equal To Cross- sectional Diameter of Pads
Part To Be Treated Should Be Centered
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

38. Capacitor Electrodes (Pad Electrodes)
Increasing The Spacing Will Increase The Depth Of Penetration But Will Decrease The Current Density
Capacitive Method Good for Treating Superficial Soft Tissues
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

39. METHODS OF PLACEMENT OF ELECTRODES – CAPACITOR METHOD
COPLANAR METHOD
In this electrodes can be placed side by side on the same aspect of the part, provided that there is adequate distance between them.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

40. METHODS OF PLACEMENT OF ELECTRODES – CAPACITOR METHOD
CONTRAPLANAR METHOD
In this electrodes are placed on opposite sides of the treatment part. Most satisfactory method for deeply placed structures. E.g. - Joints
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

41. METHODS OF PLACEMENT OF ELECTRODES – CAPACITOR METHOD
CROSSFIRE
METHOD
In this first half of the treatment is given with the electrodes in one contra planar position & for the second half the electrodes are repositioned at right angles.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

42. METHODS OF PLACEMENT OF ELECTRODES – CAPACITOR METHOD
MONOPOLAR
METHOD
The active electrode is placed over the site of the lesion & the indifferent electrode is applied to some distant part of the body.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

43. Inductothermy Method
Creates A Stronger Magnetic Field Than Electrical Field
Using a long tubular flexible conductor covered in thick rubber called a Cable Or Coil, is Wrapped Circumferentially Around An Extremity Or Coiled Within Electrode
If the goal is to increase blood flow to aid healing of a muscle injury then Inductothermy can be chosen.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

44. Inductothermy Method
Passing Current Through A Coiled Cable Creates A Magnetic Field By Inducing Eddy Currents (small circular electrical fields) That Generate Heat
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

45. Inductothermy Method
Patient In A Magnetic Field Not Part Of A Circuit.
Greatest Current Flow Through Tissue With Least Resistance
Tissues react like a parallel circuit
Fat does not provide as much resistance to electromagnetic energy.
Tissue High In Electrolytic Content Respond Best To A Magnetic Field
Muscle and blood
Precaution: Not as much superficial sensation of heat with electromagnetic
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

46. Inductothermy Method Two Arrangements: Toweling Is Essential.
Pancake Coils
Wraparound Coils
Toweling Is Essential.
Pancake Coil Must Have 6” in Center. Then 5-10cm Spacing Between Turns
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

47. Factors influenced field distribution
C- Positioning of electrodes relative to tissues
B- Size of electrodes
A- Spacing of electrodes
electrodes not parallel to skin surface → superficial heating under closet part of electrode
different size electrodes →superficial heating under small electrode
Unequal spacing of electrodes → superficial heating under closer electrode
electrodes parallel to skin surface → more even heating
electrodes bigger than the body part → uniform field → more even heating
normal spacing electrodes "2-4 cm" → uniform field → more even heating
distance between electrodes less than combined skin electrode distances → field intensity is greatest in and near the air space
Electrodes smaller than the body part → superficial heating due to field spreading in tissues
Closely placed electrodes →superficial heating
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

48. FACTORS INFLUENCE FIELD DISTRIBUTION IN S.W.D
1- Spacing: allows the lines of force in the electrostatic field to diverge before entering the tissues.
This prevents concentration of heat in the super-facial tissues and ensures more heating through the part.
Spacing provided by:
1- Wrapping flexible pads in towel.
2-Flat felt spacing pads between pad electrode and skin.
3-Air when using space plates.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

49. FACTORS INFLUENCE FIELD DISTRIBUTION IN S.W.D
a- Normal spacing even field distribution.
b- Increased spacing deep field concentration.
c- Decreased spacing superficial concentration. a) c) b)
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

50. FACTORS INFLUENCE FIELD DISTRIBUTION IN S.W.D
It has been suggested that for most short wave sources at maximum output spacing of about 4 cm to the maximum that will give the greatest absolute heating of the deep tissues.
Conversely the minimum skin electrode distance is about 2 cm.
Note:
The spacing refers to the distance of the metal electrode, not the plastic cover, from the skin.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

51. FACTORS INFLUENCE FIELD DISTRIBUTION IN S.W.D
2.Electrode size: If the electrodes are too small than the diameter of treated part line of force will be concentrated superficially.
-If the electrodes are markedly larger the line of force will be lost in the air.
Electrode size:
-Ideally, the electrodes should be slight larger than the area treated.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

52. FACTORS INFLUENCE FIELD DISTRIBUTION IN S.W.D
3.Metal: metal causes the lines of force to concentrate on the metal
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

53. Heating With Continuous SWD
Patient Sensation Provides Basis For Recommendations Of Continuous SWD
Dose I (Lowest) - No Sensation of Heat
Dose II (Low) - Mild Heating Sensation
Dose III (Medium) - Moderate or Pleasant Heating Sensation
Dose IV (Heavy) -Vigorous Heating Within Pain Threshold
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

54. Duration of the treatment
Shorter duration is indicated in Sub-acute condition and when the target area is small(ear, wrist sinus).time is min .
Longer duration is indicated in chronic conditions and when the treated area is large ( low back, abdomen, posterior chest wall), the time allowed is or up to 30 min.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

55. Frequency of the treatment
It depends on the patient's reaction to therapy and the treatment should tack place daily if dosage per treatment is low and the effect of therapy not very long lasting.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

56. Indications of SWD Disorders of Musculoskeletal System;
( Sprain, Strain, Muscle & Tendon tear, Capsule lesion, Joint stiffness, Hematomas)
Sub acute & Chronic Inflammatory Conditions;
(Tenosynovitis, Bursitis, Synovitis, Sinusitis, Dysmenorrhoea, Fibrositis, Myositis)
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

57. Contraindications
Metal implants or metal jewelry (be aware of body piercings) – Concentration of the field.
Cardiac pacemakers – Interference with function
Ischemic areas – The inability of the circulation to disperse heat could result in high temperature – Burns.
Peripheral vascular disease - DVT
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

58. Contraindications
Perspiration and moist dressings: The water collects and concentrates the heat.
Tendency to hemorrhage, including menstruation – Increase vasodilatation, prolong hemorrhage.
Pregnancy – Miscarriage
Hyperpyrexia
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

59. Contraindications Sensory loss / Impaired thermal sensation
Cancer / Malignant tissues – Accelerate the rate of growth & Metastasis
Active T.B – Increase the rate of development of the infection.
Recent Radiotherapy – Skin sensation & Circulation may be decreased.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

60. Contraindications Dermatological Conditions – Will exacerbate
Severe Cardiac conditions – Greater demand of Cardiac output.
Areas of particular sensitivity:
Epiphysis plates in children
The genitals
Sites of infection
The abdomen with an implanted intrauterine device (IUD)
The eyes and face
Application through the skull
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

61. Therapeutic Effects of SWD
1- Pain relief:
Stimulation of Sensory heat receptors – Pain Gate Mechanism.
2-Muscle spasm:
Heating Secondary Afferent muscle spindle – Inhibitory influence to motor pool.
3- Inflammation: Assists in removal of cellular debris and toxins
Nonthermal: Alters diffusion rate across the cell membrane
Thermal: Increases intramuscular metabolism
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

62. Therapeutic Effects of SWD
4- Accelerate wound healing: by increase cutaneous circulation, Vasodilatation increases:
Blood flow
Capillary filtration
Capillary pressure
Oxygen perfusion
Increased fibroblastic activity and capillary growth
Effects occur deeper than other forms of heat.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

63. Therapeutic Effects of SWD
5- Infection: increase circulation and increase white blood cells and antibodies – Reinforcing body’s normal defense mechanism.
6- Fibrosis: increase extensibility of fibrous tissues such as tendons, joint capsule and scars. Alters collagen properties, allowing it to elongate.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

64. Dangers and Precautions in SWD
1- Burn
can be avoided by:
-Checking all contra-indications and area to be treated.
-Test of thermal skin sensation.
-Taking care during application over a bony prominence.
-Never apply S.W. over clothing.
-Making sure that the skin is dry.
-If you apply over two skin surfaces in contact, they must be separated by absorbent material towel.
-Making sure that the leads from the machine are not touching or within 25 mm electromagnetic field around the lead.
-Making sure that there is adequate spacing between the electrodes and the skin.
-Allowing 2 or 3 minutes on each intensity setting maximum heat.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

65. Dangers and Precautions in SWD
2- shock
can be avoided by:
-Not increasing intensity unless the leads and electrodes are connected to machine.
-Making sure that the machine is earthed.
-Not touching the machine.
-Making sure that there is no metal within the range of 300mm.
-If the patient is wearing a hearing aid switch it off.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

66. Dangers and Precautions in SWD
3.Synthetic Material
These do not absorb moisture as readily as normal materials
They ignite more easily
The material may absorb energy or concentrating the field.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

67. Dangers and Precautions in SWD
4. Obese Patients
Fat layers more readily heated
Absorbing 8 times that absorbed in muscle.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

68. Pulsed short wave diathermy(PSWD)
Modes of Application
Continuous short wave diathermy(CSWD)
Increases tissue temperature
Increased risk of burns
Pulsed short wave diathermy(PSWD)
May or may not increase temperature
Pulses allow for increased treatment intensity and duration
Not the same as “non-thermal”
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

69. Pulsed SWD (PSWD) It is also known as
Pulsed electromagnetic energy (PEME)
Pulsed electromagnetic field (PEMF)
The production of HFC for PSWD is exactly same as for CSWD.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

70. Variables that can be controlled by the therapist:
PSWD is the application of electromagnetic energy to patients in a short bursts to control pain, edema and promote wound , nerve, and fracture healing
Variables that can be controlled by the therapist:
Pulse repetition rate (PRR) Hz
Pulse duration (PD) us
Peak pulse power (PPP) W
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

71. Pulsed SWD
By incorporating a timing circuit, the output can be turned on & off allowing bursts of Oscillations.
Off-Time Longer Than On-Time
Low Mean Power Output
Uses Drum Electrode
Some machines give fixed – length pulses (65 or 400µsec)
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

72. Pulsed SWD
-Is short wave at the frequency of MHz, which is pulsed at a rate, selected by the therapist.
-The pulse frequency range is from 15 to 200 Hz.
-The maximum intensity is 1000 watts.
-The pulse duration is constant at 0.4 ms in square pulse.
-The advantage of pulsed S.W.D. is that a very high intensity of power can be administered with minimal effect.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

73. Pulsed SWD 1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION – 1099- 243
9/20/2018

74. PSWD Mean Power Calculations
Pulse Period (Pulse on + off time) =
Peak Pulse Power (W) / Pulse Rep Freq (Hz)
Percentage On Time =
Pulse Duration (msec) / Pulse Period (msec)
Mean Power =
Peak Pulse Power (W) / Percentage on Time
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

75. DOSAGE OF PSWD Acute conditions : Mean power of < 3 watts.
Sub-acute conditions : Mean power between 3 & 5 watts.
Chronic conditions : Mean power of > 5 watts.
At a mean power of > 12 watts more people can feel some heating effect.
Note: Thermal skin sensation test should be done when planning to use > 5 watts.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

76. PSWD - Physiological Effects
1-Increases the number & activity of cells in the injured region 2-Reabsorption of hematoma. 3-Reduces swelling & Inflammation 4-Increases rate of fibrin deposition & orientation 5-Increases collagen deposition & organization 6-Increase nerve growth & repair.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

77. None thermal Altered cell membrane function and cellular activity
Increase microvascular perfusion
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

78. 1- Increase microvascular perfusion
Application of PSWD for min at 600 Hz increase the local microvascular perfusion that increase oxygenation, nutrition and phagocytosis
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

79. Altered cell membrane function and cellular activity
Affect ion binding to the cell membrane which trigger some biological process as increase activity of macrophages
Accelerate cell growth and division
Increase cell activity
Stimulation of ATP and protein synthesis
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

80. Thermal effects
Increase in the tissue temperature has the same effect as in continuous SWD
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

81. Extensibility of tissues
Indications
Soft tissue injury
Control pain
Wound healing
Control edema
Nerve healing
Bone healing
Extensibility of tissues
Other applications
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

82. - PSWD allow healing of the injured ts Control pain
Soft tissue injury:
- PSWD allow healing of the injured ts
Control pain
- As in cases of neck and low back pain and postoperative pain
- This effects may due to modification of cell membrane function
Wound healing
As in cases of wound, ulcer, burn
PSWD increase rate of healing through increase collagen formation, WBC, phagocytosis, oxygenation and circulation
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

83. - PSWD improve edema resolution and decrease pain Nerve healing
Control edema
- PSWD improve edema resolution and decrease pain
Nerve healing
- PSWD has good effect in regeneration of peripheral nerve and spinal cord after injury
Bone healing
- Only detected in animal studies
Extensibility of tissues
- It enhance ts extensibility when applied before and during stretch
Other applications
- As in cases of ischemic skin flaps , and neuropathy
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

84. Contraindications
As in continuous SWD except the metal in ts, open wound and moist dressing
Pregnancy
Precancerous tissue Malignant tumor
Cardiac pacemaker TB
Hearing aids and electronic equipment
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

85. 1- Synthetic materials 2- Obese patients
PSWD - precautions
1- Synthetic materials 2- Obese patients
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

86. PSWD - Therapeutic Effects
1-Decrease of pain & Swelling – Tissue trauma. 2-Acceleration of Inflammatory & Healing Process 3-Relaxation of Muscle Spasm 4-Decreases the rate of hematoma formation 5-Superficial ulcers are treated successfully – Bed sores 6-Acceleration of bone growth
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

87. PSWD - Advantages
1-Effective in treatment of post traumatic & Infective conditions 2-Often used in conditions where continuous SWD is contraindicated.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

88. Application Capacitive Method= Inductive (drum) Method=
Place soft rubber electrodes parallel about 1-3 inches to the skin’s surface (spreads energy over area being treated and also to prevent hot spots). Don’t allow the cables to come in contact with patient (use a couple of layers to insulate the patient). Also, Do not allow the cables to touch together.
Inductive (drum) Method=
Heat sensation is delayed in machines that have a electro-static shielding that prevents the upper-skin fat tissue from heating. Start the treatment with an intensity level that is below the desired one and then increase later. Always keep drum in contact with patient at all times( to prevent damage to the drum). Frequently check the patient when using the drum applicator.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

89. Technique of Application
1- Shortwave machine with chosen electrodes and its test tube to ensure the machine is working. 2- Test tubes for skin test. 3- Cotton towels or felt pads for spacing. 4- Ensure that there are no contraindications for SW application. 5- Put the patient in a comfortable position and well support, allow the area to be treated to be completely uncovered.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

90. Technique of Application
6- Inspect the area to be treated.
7- Ensure there is no metal (jewellery or hairpin) within 300mm of treatment area.
8- Explain the procedure and feeling to the patient.
9- If using flexible pad electrodes, wrap them in several layers of towelling or place them between felt pads to ensure the required amount of spacing.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

91. Technique of Application
10- If using space electrodes adjust the distance according to the concentration needed. 11-Instruct the patient not to move during treatment and warn her/him from uncomfortable heat feeling. 12- If the machine has a patient safety switch instruct the patient to switch the machine off if he feel more heat.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

92. Technique of Application
13- Check the machine controls at the zero position, then switch the power on.
14- Switch the intensity on and wait 2-3 minutes on the minimum intensity and ask the patient about her/his feeling, then adjust the timer to the required treatment time.
15- After treatment time has finished, turn the intensity switch to zero and remove the electrodes.
16-Inspect the area after treatment and ask the patient to stay few minutes for rest and to regain to normal temperature.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

93. Technique of Application
1-Application using two flexible pads or space plates:
A- The electrodes should be slightly larger than the area treated and spaced from the skin by approximately 25 mm.
B- To concentrate heat on one aspect of the part the electrode should be unequal in size (smaller one placed over the area where concentration of heat is required).
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

94. Technique of Application
C- Coplanar application to treat structures on one aspect of the body.
The distance between adjacent ends (x) must be greater than the sum of skin electrode distance (A+B) otherwise the line of force will pass directly between electrodes rather than tissues.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

95. Technique of Application
D- Application using a coil electrode: 1- The coil wound evenly firmly heat superficial tissue. 2- Pancake application heat superficial tissues.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

96. Technique of Application
E- Application using diplode:
Adjust wings of diplode parallel to the skin of the treated area, electromagnetic field will produce.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

97. Technique of Application
F- Applications to two limbs:
Two flexible pads, two space plates or flexible pad with a space plate are used. It is essential to put a cotton towel between the two limbs to absorb any perspiration.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

98. Technique of Application
G- Cross-fire application:
For the treatment of sinuses, space plates positioned diagonally, after half of treatment time the positions are alternate. This ensures that all aspects of the sinus membrane are heated. Care must be taken to avoid direct placement over the eye.
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018

99. When Should Diathermy Be Used?
If The Skin Or Some Underlying Soft Tissue Is Tender And Will Not Tolerate Pressure
In Areas Where Subcutaneous Fat Is Thick And Deep Heating Is Required
Induction method
When The Treatment Goal Is To Increase Tissue Temperatures Over A Large Area
1435 – 1436H – 1ST SEMESTER - PHT 221 – SECTION –
9/20/2018