SHORTWAV

E

DIATHERM

Y

Def.: SWD is a modality that produces deep heating via conversion of electromagnetic energy to thermal energy.The pattern of heat produced depend on:ᴥFreq. used. ᴥ type of SWD unit. ᴥwater content of the tissues. Shortwave diathermy current freq. 10 – 100 MHz(The shortest radiofrequency wave is used in therapeutic diathermy.)

the commonly used in medical work having freq. of 27.12 MHz with wavelength of 11 meters

Modalities: ether continuous or pulsed (PSWD).o PSWD: application of series of short pulses of SWD so that short periods of SWD interrupted by gaps

where there is no SWD. The pt. receives lower dose of SWD energy if compared with continuous SWD applied of the same time. The tissues will receive lower thermal load.

o SWD: produce both deep and sup. Tissue heating, under certain controlled conditions it’s applied for 20 min at the max tolerable dose.

SWD produced by an oscillating electric current of extremely high frequency.

Therapeutic effect: 1. Increase blood flow.2. Help resolution of inflammation.3. accelerate wound healing.4. ↗ extensibility of deep collagen tissues. 5. ↘ joint stiffness.6. Relief deep mus. Pain & spasm. ( via muscle spindle & Golgi

tendon organ stimulation)

Clinical indications:1. Resent burns.2. Recent injuries.3. Plastic surgery.4. Postoperative 5. Post laminectomy pain.6. Sinusitis 7. TMJ disorders.8. Bell’s palsy.9. Sub deltoid bursitis ass. With calcification.10. Chronic arthritis11. Degenerative complaints.12. PID (pelvic infla. Dis.)13. ↘pain ass. With herpes zoster.

Exp. Of SWD application in various cond.:Soft tissues healing: SWD ++ earlier maturation of collagen fibers. raped regeneration of damaged ms. fibers. PSWD more raped activity in collagen formation. enhance rate of skin healing.Resolution of haematoma: enhance rapid resolution.Recent ankle injuries PSWD more effective improve: pain, swelling, disability.Pain: relief pain ass. With various cond. E.g.: back pain. PSWD relief pain ass. With acute injuries.Nerve regeneration: PSWD accelerate recovery of nerve conduction.O.A: SWD & PSWD forming part of physiotherapeutic modalities used in OA ttt.

contraindications:1) Implanted pacemaker.2) Metal in the tissues or ext. fixators.3) Impaired thermal sensation.4) Over pregnant uterus & intrauterine devises.5) Hemorrhagic areas ( menses ).6) Ischemic tissues.7) Recent thrombosis.8) Mlg. Tumors ↗proliferation.9) Active TB.10) Pt. pyrexia.11) Areas of skin affected by courses of x-ray.12) Uncooperative pt.

T (x)

Temp ↗

Application of SWD:pt. is connected to the electrode circuit of the high freq. Generator by:

A) capacitive applicator

or

B) inductive coil

A) capacitive applicator: 2 diff. types of electrodes for applying the capacitive method:

Flexible metal plate malleable electrodes

Rigid metal discs disc electrode (more commonly used method.

Uses the patient’s tissues as a part of the circuitThe tissues’ electrical resistance produces heatSelectively heats skinMuscle is heated via conduction from the adiposeAlso referred to as “condenser field diathermy”

capacitive applicator .. ContThe pt. is placed between 2 metal condenser plates. Achieve higher temperature in water-poor tissues, (like: sub. Cut. Adipose tissue, lig, tendons, joint capsule, Bone.) Guid lines for electrode selection & placement:1. Electrode should be of equal size 2. Electrode should be slightly larger than the body part

electric field is less uniform at the edge of the plate.3. Electrode should be equidistant & at right angles to the

skin surface.Electrodes arrangement4. contraplanar application ( transverse): an electrode is

placed on either side of the limb.5. Coplanar application: both electrodes are placed on

the same side of the limb.6. Longitudinal application: one electrode is placed at

each end of the limb.

B) Inductive applicationBased on ( electromagnetic induction)Use induction coils that apply a magnetic field to induce circular electrical field in the tissue.They achieve higher temperature in water-rich tissues. (Like: ms. Skin. Blood ..etc.) Current flowing within the coil

produces a rotating magnetic fieldWhich produces eddy currents in the tissuesEddy currents cause friction that produce heat

Inductive application… cont.

Induction SWD method using magnetic induction to produce small eddy current in the tissues which ↗↗ tissue temp.2 diff. applicators are used in this method:1) most commonly used an

inductive coil applicator 2) Wrapping insulated cable around

the limb to be ttt.

Dose determination using thermal sensationPt. pain perception used to monitor heat intensity that is being produced. (inaccurate method )

Therapist must be aware of the potential risk of causing tissue damage & ensure that the max dose that a pt. receives cause only a mild sensation of warmth. Towels are sometime placed to spacing & absorb sweet, which is highly conductive and could result in potentially sever focal heating.Typical ttt time is 20 to 30 minutesAcute cond. Should be ttt with low dose PSWDAnd chronic conditions should be ttt with high dose SWD.

TTT proceduresPrepare the pt.:1. Exclude any C.I.2. Examine thermal & pain sensitivity of the pt.3. Ensure removal of any metal object (ring jewelry ..) from the ttt area.4. Ensure removal of any hearing aid. Contact lenses.5. Removal of all bandages & clothes from the ttt area.6. Ensure dryness of skin.7. Ask the pt. to report immediately any abnormal sensation felt during ttt.8. Ensure that the gonads aren’t subjected to irradiation.

TTT procedures … contPrepare the machine:1. Ensure correct connection of cables.2. Ensure that cables & applicators aren’t placed

on metal surfaces.3. Ensure appropriate alignment of the applicator

for max energy transfer.4. Ensure that cables aren’t close to untreated

tissues.5. Ensure that pt. support isn’t metallic & all metal

objects are kept at least 3ms. Away from the applicators & cables.

Correct wrong

TTT procedures … cont.Once the unit activated the operator should:1.Remain at least 1m from the cables 2.Ensure that the pt. maintain correct

position.3.Ensure that the pt. not left alone during

ttt unless supplied with reliable cut-off switch.

4.Ensure the pt. not touch the machine.5.Ensure that no other person is in the

vicinity of the machine.

Dangers of SWD.1) Burns.2) Scalads.3) Faintness due to ↘ BP.4) Ppt. of gangrene if area of ↘blood supply5) Sparking if one electrodes touched while application of current6) Electric shock.7) Over dose … ↗ pain.