ShortwaveShortwave

DefinitionDefinition

Shortwave means the application of high Shortwave means the application of high frequency electrical energy to the body frequency electrical energy to the body tissues in order to bring physiological and tissues in order to bring physiological and therapeutic effects, these effects can be therapeutic effects, these effects can be achieved by thermal or non thermal achieved by thermal or non thermal effect.effect.

Shortwave is one of the diathermy family.Shortwave is one of the diathermy family.

Other modalities that can also heat the tissues Other modalities that can also heat the tissues are microwave and ultra sound.are microwave and ultra sound.

Shortwave, microwave and ultrasound can Shortwave, microwave and ultrasound can heat the tissues up to a very deep layer.heat the tissues up to a very deep layer.

The electromagnetic spectrum has a wild The electromagnetic spectrum has a wild range of shortwave.range of shortwave.

Shortwave Has Three Main Shortwave Has Three Main Frequencies:Frequencies:

27.12 MHz, wavelength 11 M (most common 27.12 MHz, wavelength 11 M (most common used one).used one).

13.56 MHz wavelength 22 M.13.56 MHz wavelength 22 M.

40.68 MHz 7.5 M.40.68 MHz 7.5 M.

Shortwave Diathermy MachineShortwave Diathermy Machine

Picture is on page 279 of Low and Reed book.Picture is on page 279 of Low and Reed book.

First we have the power supply. First we have the power supply.

Inside the machine there is a high frequency Inside the machine there is a high frequency generator + an amplifier + oscillator coil + resonator generator + an amplifier + oscillator coil + resonator coil + variable capacitor.coil + variable capacitor.

Outside the machine we have two electrodes + the Outside the machine we have two electrodes + the part being treated part being treated

There Are Two Circuits There Are Two Circuits Here:Here:

1)1) Machine circuit : composed of a high Machine circuit : composed of a high frequency generator, amplifier, oscillator frequency generator, amplifier, oscillator coil.coil.

2)2) Patient circuit: composed of a resonator Patient circuit: composed of a resonator coil, variable capacitor, electrodes and coil, variable capacitor, electrodes and the treated tissue. the treated tissue.

Shortwave produces both electric and Shortwave produces both electric and magnetic fields.magnetic fields.

The amount of electric field to magnetic The amount of electric field to magnetic field is dependent on:field is dependent on:

1)1) The characteristic of the machine itself The characteristic of the machine itself (dependent on the manufacturer).(dependent on the manufacturer).

2)2) The type of electrodes that we use.The type of electrodes that we use.

Shortwave Can Be Used in Two Shortwave Can Be Used in Two Modes:Modes:

1)1) Continuous (energy is emitted all the time).Continuous (energy is emitted all the time).

2)2) Pulsed (energy is emitted part of the time).Pulsed (energy is emitted part of the time).

When using the pulsed shortwave, there are certain When using the pulsed shortwave, there are certain parameters that we need to know:parameters that we need to know:

Pulse width: measured by micro seconds.Pulse width: measured by micro seconds.

Pulse frequency: how many pulses we have per second Pulse frequency: how many pulses we have per second measured by Hz or pulses per second (PPS)measured by Hz or pulses per second (PPS)

Peak power output: usually is a set value that is determined by Peak power output: usually is a set value that is determined by the manufacturer.the manufacturer.

Mean power output: is variable and is determined by factors Mean power output: is variable and is determined by factors such as the pulse width and the pulse frequency.such as the pulse width and the pulse frequency.

How could we produce energy into How could we produce energy into the body without causing heat the body without causing heat

productionproduction??

The off time with pulsed shortwave is longer than the The off time with pulsed shortwave is longer than the on time which allows the dissipation of heat.on time which allows the dissipation of heat.

The interpulse period gives time for the heat to The interpulse period gives time for the heat to dissipate.dissipate.

If the interpulse is short heat will develop, because If the interpulse is short heat will develop, because there is no time for the effect to dissipate within the there is no time for the effect to dissipate within the body.body.

Continuous shortwave is always thermal.Continuous shortwave is always thermal.

Pulsed shortwave can be thermal or non thermal.Pulsed shortwave can be thermal or non thermal.

High parameters usually gives thermal effect.High parameters usually gives thermal effect.

If we use long pulse duration, high pulse frequency, If we use long pulse duration, high pulse frequency, heat will develop.heat will develop.

The mean power is affected by the parameters chosen The mean power is affected by the parameters chosen and the time of treatment. and the time of treatment.

Pulsed shortwave can only be non thermal if Pulsed shortwave can only be non thermal if short pulses, low pulse repetition rate and short pulses, low pulse repetition rate and short treatment duration is being used.short treatment duration is being used.

Wrong Terminologies Used For Wrong Terminologies Used For Pulsed ShortwavePulsed Shortwave

1)1) Pulsed electromagnetic energy (PEME)Pulsed electromagnetic energy (PEME)2)2) Pulsed electromagnetic energy treatment Pulsed electromagnetic energy treatment

(PEMET)(PEMET)3)3) Pulsed electromagnetic field (PEMF)Pulsed electromagnetic field (PEMF)4)4) Pulsed electromagnetic therapy (PEMT)Pulsed electromagnetic therapy (PEMT)

Do Not Use Them!Do Not Use Them!

Recent attention has been paid to the Recent attention has been paid to the shortwave in the last 5-7 years.shortwave in the last 5-7 years.

More studies has been one to establish its More studies has been one to establish its efficiency.efficiency.

Equipments now are safer than before.Equipments now are safer than before.

User friendly.User friendly.

Advantages of ShortwaveAdvantages of Shortwave

The deep penetration, it goes deep to 5cm.The deep penetration, it goes deep to 5cm. You can use it while attending to another You can use it while attending to another

patient, which allows you to manage your time patient, which allows you to manage your time in the clinic.in the clinic.

It covers large areas.It covers large areas. It can heat the deeper tissue without heating It can heat the deeper tissue without heating

the superficial tissuethe superficial tissue It can be used with sensitive tissues because it It can be used with sensitive tissues because it

doesn’t need to be in contact with the treated doesn’t need to be in contact with the treated tissue.tissue.

Types of Electrodes:Types of Electrodes:

1)1) Flexible platesFlexible plates

2)2) Space electrodeSpace electrode

3)3) MonodeMonode

4)4) MinodMinod

5)5) DiplodeDiplode

6)6) CoilCoil

Minode and monode are called “drums”Minode and monode are called “drums”

Shortwave Can Be Applied In Two Shortwave Can Be Applied In Two WaysWays::

1)1) Capacitance (the electric field is more than the Capacitance (the electric field is more than the magnetic field) :magnetic field) :

Can be achieved by using two space plates together, Can be achieved by using two space plates together, or one space plate and a flexible ,or diplodes.or one space plate and a flexible ,or diplodes.

2)2) Inductance (the magnetic field is more than the Inductance (the magnetic field is more than the electric field) :electric field) :

Can be achieved by using the coil or the drums.Can be achieved by using the coil or the drums.

Effects of Shortwave on The Effects of Shortwave on The Molecules and Ions of TissuesMolecules and Ions of Tissues::

If it is charged If it is charged there will be vibration. there will be vibration.

If it is dipole If it is dipole it will rotate. it will rotate.

If it is not charged If it is not charged it won’t be affected. it won’t be affected.

Air Space ElectrodesAir Space Electrodes

They come in different sizes.They come in different sizes. Can be used in almost every part of the body, but Can be used in almost every part of the body, but

because they are rigid they will not fit every contour.because they are rigid they will not fit every contour. It can be put on either side of the limb, or can be It can be put on either side of the limb, or can be

used in the same side.used in the same side. If the electrodes are placed on the same side there If the electrodes are placed on the same side there

should be a distance between the electrodes, because should be a distance between the electrodes, because if there is no distance there would be a shock, so we if there is no distance there would be a shock, so we need to put a distance equal the diameter of the need to put a distance equal the diameter of the electrode.electrode.

Skin-electrode distance: is the distance Skin-electrode distance: is the distance between the electrode and the skin.between the electrode and the skin.

If we place to electrodes at the same distance If we place to electrodes at the same distance there will be even heating.there will be even heating.

If we placed one electrode closer to the skin If we placed one electrode closer to the skin than the other, the heating won’t be even, it than the other, the heating won’t be even, it will be more near the closer electrode.will be more near the closer electrode.

If we used a large electrode and a small one If we used a large electrode and a small one the heating will be more near the small.the heating will be more near the small.

Flexible ElectrodesFlexible Electrodes

When using them you should insure it is in full When using them you should insure it is in full contact.contact.

We have to rap it in towel that is 2 cm thick, less We have to rap it in towel that is 2 cm thick, less than that could cause a burn, more than that will than that could cause a burn, more than that will affect the amount of heating created in the body.affect the amount of heating created in the body.

Distance between the electrodes should be equal the Distance between the electrodes should be equal the diameter of the electrode, if it is less than that there diameter of the electrode, if it is less than that there will be a shock.will be a shock.

CoilCoil Usually used for limbsUsually used for limbs

Used in two ways: Used in two ways: 1)1) wrapped around the part being treated.wrapped around the part being treated.2)2) Pancake (usually used on the back).Pancake (usually used on the back).

When wrapping, the space between one turn and the When wrapping, the space between one turn and the other should be 5 to 10cm and it is insure by other should be 5 to 10cm and it is insure by felt felt spacersspacers (comes from the manufacturer). (comes from the manufacturer).

It is known to heat the deeper tissue without heating It is known to heat the deeper tissue without heating the superficial tissue.the superficial tissue.

Drum ElectrodesDrum Electrodes

It is known to heat the deeper tissue without heating It is known to heat the deeper tissue without heating the superficial tissue.the superficial tissue.

Penetration to 3cm.Penetration to 3cm. Make sure that the fat layer of the patient is not more Make sure that the fat layer of the patient is not more

than 2cm, because the penetration will be limited and than 2cm, because the penetration will be limited and the absorption of heat will accumulate in the fat layer the absorption of heat will accumulate in the fat layer which might cause a burn.which might cause a burn.

The tissues that are heated are blood vessels, muscles The tissues that are heated are blood vessels, muscles and sweat.and sweat.

Methods of Applying The ElectrodesMethods of Applying The Electrodes

1)1) Contraplanar electrodes are placed on opposite sides of the Contraplanar electrodes are placed on opposite sides of the part, to treat deeply placed structures.part, to treat deeply placed structures.

2)2) Coplanar: electrodes are placed on the same side of the part to Coplanar: electrodes are placed on the same side of the part to treat more superficial structures.treat more superficial structures.

3)3) Cross-fire: half the treatment is given with the electrodes in a Cross-fire: half the treatment is given with the electrodes in a diagonal way, the other half of the treatment is put on the diagonal way, the other half of the treatment is put on the opposite way. This method is usually used for sinuses and opposite way. This method is usually used for sinuses and body cavities such as the uterus. body cavities such as the uterus.

4)4) Longitudinal: one flexible electrode is used with a space Longitudinal: one flexible electrode is used with a space electrode. electrode.

Factors Influencing The FieldFactors Influencing The Field

Spacing between the electrodes.Spacing between the electrodes.

Electrode size.Electrode size.

The technique applied.The technique applied.

Metal (If the patient has a metal implants, or Metal (If the patient has a metal implants, or if the bed is metal).if the bed is metal).

Spacing The ElectrodesSpacing The Electrodes

When using flexible electrodes a 2cm thick towel When using flexible electrodes a 2cm thick towel ensures the spacing between the electrode and the ensures the spacing between the electrode and the body part.body part.

When using coil electrode “felt spacers” ensures the When using coil electrode “felt spacers” ensures the distance between the turns.distance between the turns.

When using space electrodes the space between the When using space electrodes the space between the electrode and the body part is 2-2.5cm.electrode and the body part is 2-2.5cm.

The SizeThe Size

If electrodes are smaller than the diameter of the part If electrodes are smaller than the diameter of the part treated there will be superficial heating.treated there will be superficial heating.

If the electrode is larger than the part being treated If the electrode is larger than the part being treated there will be wasted energy.there will be wasted energy.

When using unequal electrodes size concentrates the When using unequal electrodes size concentrates the field on the small electrode side.field on the small electrode side.

Spacing more than 2.5cm should be used on the Spacing more than 2.5cm should be used on the side where no concentration of the field is side where no concentration of the field is required.required.

When Choosing The Size of When Choosing The Size of Electrode We Should ConsiderElectrode We Should Consider::

1)1) The size of the area treated.The size of the area treated.

2)2) Location of the area to be treated.Location of the area to be treated.

3)3) The depth of the targeting tissue.The depth of the targeting tissue.

4)4) Treatment goals. Treatment goals.

5)5) The contraindications.The contraindications.

Modes of Heat Transfer In Modes of Heat Transfer In ShortwaveShortwave

1)1) Conduction (with the capacitance)Conduction (with the capacitance)

2)2) Conversion (with the inductance)Conversion (with the inductance)

Heat production depends on the amount of Heat production depends on the amount of resistance present inside the tissue.resistance present inside the tissue.

Physiological Effects of Shortwave Physiological Effects of Shortwave (Thermal)(Thermal)

Increase of tissue temperature by 1 degree Increase of tissue temperature by 1 degree increase metabolism (good for healing).increase metabolism (good for healing).

Increase of tissue temperature by 2-3 Increase of tissue temperature by 2-3 degreesdegrees effective for pain and muscle effective for pain and muscle spasm.spasm.

Increase of tissue temperature by 3-4 Increase of tissue temperature by 3-4 degreesdegrees good for tissue extensibility (when good for tissue extensibility (when we need to do stretching).we need to do stretching).

Patient’s FeelingPatient’s Feeling

Continuous (Thermal) shortwave Continuous (Thermal) shortwave Tell the Tell the patient that they will feel mild gentle warmth.patient that they will feel mild gentle warmth.

Pulsed, Non thermal shortwave Pulsed, Non thermal shortwave the patient the patient will feel nothing. will feel nothing.

Pulsed, Thermal shortwavePulsed, Thermal shortwave Tell the patient Tell the patient that they will feel mild gentle warmth.that they will feel mild gentle warmth.

Important RuleImportant Rule

Chronic cases Chronic cases you can treat it with thermal you can treat it with thermal or non thermal shortwave.or non thermal shortwave.

Acute Acute only use non thermal shortwave only use non thermal shortwave

ContraindicationsContraindications

Metal implantsMetal implants PregnancyPregnancy During mensesDuring menses Cardiac pacemakerCardiac pacemaker Radiation therapyRadiation therapy Malignant tissueMalignant tissue After analgesic therapyAfter analgesic therapy Blood pressure Blood pressure

abnormalitiesabnormalities

Vascular diseasesVascular diseases HemorrhageHemorrhage Fever Fever InflammationInflammation Wet dressing Wet dressing Tuberculoses Tuberculoses Impaired thermal Impaired thermal

sensationsensation

IndicationsIndications SprainSprain StrainStrain Muscle and tendon tearMuscle and tendon tear Capsule lesionCapsule lesion Degenerative joint diseaseDegenerative joint disease Joint stiffnessJoint stiffness HematomaHematoma SynovitisSynovitis BursitisBursitis AbscessAbscess

Effects of Thermal ShortwaveEffects of Thermal Shortwave

Increase blood flowIncrease blood flow Promote tissue healingPromote tissue healing Decrease inflammationDecrease inflammation Decrease painDecrease pain Increase tissue extensibilityIncrease tissue extensibility decrease muscle spasmdecrease muscle spasm Control infectionControl infection

Dosage with the shortwaveDosage with the shortwave

Includes:Includes:

1)1) Time of application.Time of application.

2)2) Parameters chosen (mode, frequency, type of Parameters chosen (mode, frequency, type of electrodes, etc…).electrodes, etc…).

3)3) How much do we apply the treatment.How much do we apply the treatment.

DurationDuration

Average of 15 minutes depending on the site Average of 15 minutes depending on the site of the area and the patient’s responseof the area and the patient’s response

Can increase to 30 minutes.Can increase to 30 minutes.

Longer treatment duration may result in Longer treatment duration may result in reflect vasoconstriction noticed clearly in the reflect vasoconstriction noticed clearly in the toes and fingers toes and fingers

When increasing the intensity wait 2-3 When increasing the intensity wait 2-3 minutes to allow the temperature to build in minutes to allow the temperature to build in the tissue before moving to the next stage.the tissue before moving to the next stage.

How To Set The Parameters When How To Set The Parameters When Using Pulsed ShortwaveUsing Pulsed Shortwave

If we want to set the pulsed shortwave:If we want to set the pulsed shortwave:

In acute conditions, the mean power output should be In acute conditions, the mean power output should be 3 and the treatment time is 10 minutes.3 and the treatment time is 10 minutes.

In sub acute, the mean power output should be 2-5 In sub acute, the mean power output should be 2-5 and the treatment time 10 to 15 minutes.and the treatment time 10 to 15 minutes.

In chronic conditions, the mean power output is from In chronic conditions, the mean power output is from 5-7 and the treatment can go up to 30 minutes. 5-7 and the treatment can go up to 30 minutes.

Mean power output = peak pulse power / Mean power output = peak pulse power / percentage of on timepercentage of on time

On time = pulse duration / pulse periodOn time = pulse duration / pulse period

Pulse period = peak pulse power / pulse repetition Pulse period = peak pulse power / pulse repetition raterate

When Using Thermal ShortwaveWhen Using Thermal Shortwave

1)1) Adjust the machine.Adjust the machine.

2)2) Ask the patient.Ask the patient.

3)3) If the temperature is too hotIf the temperature is too hot decrease it. decrease it.

4)4) The patient is not feeling heatThe patient is not feeling heat increase it. increase it.

5)5) Dosage with the continuous shortwave depending Dosage with the continuous shortwave depending on the thermal sensation reported from the patient.on the thermal sensation reported from the patient.

6)6) Use your clinical judgment in administering the Use your clinical judgment in administering the dosage .dosage .

Frequency of The treatmentFrequency of The treatment Daily or every other day.Daily or every other day.

Depends on the patient’s response.Depends on the patient’s response.

If the condition is very acute, daily treatment will If the condition is very acute, daily treatment will give better results.give better results.

Chronic condition, every other day treatment.Chronic condition, every other day treatment.

If it didn’t improve If it didn’t improve do it everyday. do it everyday.

I Wish You All The Best of Luck I Wish You All The Best of Luck