neel IFT.pptx

Ppt of ITF

1. Interferential Current Therapy Dr N.K. Choudhary Assistant Professor

2. SET INDUCTION

3. SPECIFIC LEARNING OBJECTIVES Introduction Principle Sweep Parameters Techniques and applications/electrodes Physiological effects Indications & Contraindications Precautions Summary References

4. CONTENTS Definition Main clinical applications History Indications & contraindications Amplitude modulated frequency Precautions Static interference Dynamic interference Triangular Rectangular Trapezoidal Frequency Dosage Bipolar Quadripolar Vector

5. DEFINITION Developed by Dr. Hans Nemec of Vienna, Austria in the early 1950’s. It may be described as the transcutaneous application of two alternating medium frequency electrical currents, which are slightly out of phase causing amplitude modulation at low frequency for therapeutic purposes

6. PRINCIPLE The main principle of IFT is that when two medium frequency alternating currents of slightly different frequency are passed through the tissues where the current intersect to produce a low frequency current. The interference produced by the two currents in the tissue varies in amplitude is called BEAT FREQUENCY or AMPLITUDE MODULATED FREQUENCY The current is delivered through two sets of electrode via two separate channel in the same stimulator

7. Amplitude Modulated Frequency (AMF) The AMF or beat frequency is the effective component of IFT, it mimics the low freq current and creates differential stimulation of nerve. Low AMF, elicits a beating or taping sensation, while higher AMF elicits a tingling sensation.

8. STATIC INTERFERENCE :  If the two medium frequencies remain constant, the beat frequency will also be constant When a constant beat frequency is selected for eg 10 Hz, 50Hz or 100Hz…or any frequency between 1 to 250Hz is called as constant mode or static mode or static interference system. It may lead to gradually diminishing response due to habituation of this particular current

9. DYNAMIC INTERFERENCE An arrangement that allows the beat frequency to change automatically and regularly in the given time period is called frequency modulation or sweep or swing or dynamic Interference system . Here there is moving of the area of interference current in a to and fro manner through 45 °.

10. Thus the machine could be set to sweep Eg: between 20 to 80Hz over a period of 6secs and back over next 6 secs. This pattern and timing of the modulation is adjustable and sometimes called as spectrum. This dynamic system helps to prevent nerve accomadation.

11. Types of sweep pattern Triangular sweep pattern Rectangular Sweep Pattern Trapezoidal Sweep Pattern

12. PARAMETERS FREQUENCY DOSAGE

13. FREQUENCY High AMF: 1) Frequency ranges from 100Hz-150Hz 2)Useful for relief of acute and chronic pain Low AMF : 1)Frequency below 50Hz 2)Useful for sub acute pain

14. DOSAGE Intensity of Current: It should be gradually increased till patient feels comfortable tingling sensation

15. Treatment Duration 10 – 15 mins of treatment not exceeding 20 mins to one area.

16. SWEEP The principle of using the sweep is that the machine is set to automatically vary the effective stimulation frequency using either pre-set or user set sweep ranges. Such sweep prevents accommodation of nerves

17. METHOD OF APPLICATION Bipolar Application Quadripolar Application Vector or scanning mode

18. Quadripolar Application Interferential current is produced by applying two medium frequency currents via 4 electrodes. Electrodes are used in two pairs.(color coded) Each pair should be placed diagonally It produces modulated current in a clover leaf pattern.

19. Vector or scanning mode Specific area of the tissue at any depth can be treated in patients with diffuse area of pathology and when the arrangement of the lesion within the static interference field is doubtful, The vector principal which produces a scanning movement of the field, so that all the field are subjected to have maximal interferential effect

20. Suction Vs Plate electrode IFT is often applied via electrodes that are held in place using the intermittent suction unit. Alternately flat carbon electrodes may be used. Suction has claimed to stimulate cutaneous nerves and vasodilatation.

21. PHYSIOLOGICAL EFFECTS

22. This depends upon: Magnitude of current Type of mode used i.e. Rhythmic or constant The frequency range used Accuracy of electrode positioning

23. Main clinical applications are : Pain relief Muscle stimulation Increased local blood flow Reduction of edema

24. Pain Relief Pain relief is achieved by stimulation of AB fibers by using short duration pulses of frequency 100 Hz. (pain gate theory) While 15Hz is applied to stimulate the small diameter c and Ad fibres via descending pain supression pathway.

25. MUSCLE STIMULATION For patients who can not generate useful voluntary contraction, IFT may be beneficial. Most effective motor nerve stimulation range is between 10-25Hz When employing IFT it is possible to continue to stimulate the muscle beyond its point of fatigue. It helps in reducing oedema

26. Increase circulation Deep tissue penetration stimulates parasympathetic nerve fibers for increased blood flow It improves circulation of blood and helps wash away the chemicals that stimulate the nociceptive nerve endings and thus help to reduce pain too.

27. OEDEMA Local muscle contraction combined with its local vascular changes encourages the reabsorbtion of tissue fluid.

28. Indications Pain and muscle spasm Oedema relief Stress Incontinence

29. Interferential Precautions • If there is abnormal skin sensation, electrodes should be positioned in a site other than this area to ensure effective stimulation • Patients who have (marked) abnormal circulation • For patients who have febrile conditions, the outcome of the first treatment should be monitored

30. • Patients who have epilepsy, advanced cardiovascular conditions or cardiac arrhythmias should be treated at the discretion of the physiotherapist in consultation with the appropriate medical practitioner • Treatment which involves placement of electrodes over the anterior chest wall

31. Summary History of IFT Amplitude or beat frequency Interferences( static and dynamic) Types of sweep Parameters Techniques Effects Precautions

32. References 1 .Textbook of electrotherapy Jagmohan Singh 2. Electrotherapy evidence-based practice by Sheila kitchen 3. https://www.slideshare.net/.../interferential-current-or-therapy-for-physiotherapy- stude  

33. THANK YOU