1. transcutaneousElectrical Nerve Stimulator (TENS)

2. 1. AIM
TENS is a non invasive method of electrical stimulation through intact skin and primarily aims to provide a degree of pain relief by specifically exciting peripheral nerves .

3. 2.PHYSIOLOGICAL BACKGROUNDPAIN:
Pain is felt as a result of the brain's response to electrical (neural) and chemical (hormonal) changes in the body as a result of damage.

4. Signals from damage or injury are picked up by sensory receptors in nerve endings. The nerves then transmit the signal via the nerves to spinal cord and brain.

5. Mechanism of Pain:

6. Pain Relief:
Pain can be managed in the short term using analgesics, but long-term use can be detrimental to the patient's health.
Side effects of the long use of analgesics may affect on liver, kidney or stomach.
In many cases where pain is constant, a medical practitioner or physiotherapist may recommend the use of a TENS unit.

7. Why TENS?
When an electrical current is applied to a painful area,transmission of the perception of pain(small diameter fibre) to the brain is inhibited by the activity of the large diameter,closing the gate to the pain perception to the brain.

8. 3.DETAILED BLOCK DIAGRAM:

9. a.SENSOR:

10. b.CIRCUIT DIAGRAM:

11. 4.Future plan
Large range of resistances can be included by modifying the fuzzy table.
Fuzzy table can be made self learning.
Amplitude of current can be increased.

12. 5.ADVANTAGES: Improve cutaneous blood flow Wound healing
Fracture healing (non-united fracture).
To reduce both acute and chronic pain.
Labour pain.
Diabetic neuropathy.
Muscle streghth.

13. 5.DISADVANTAGES: Cannot be used for :
Someone suffering from epilepsy, siezure.
Someone with pacemaker.
Someone with undiagnosed pain.
Near operating diathermy device.
Using electrodes on infected(inflamed) skin.
On the eyes
Around head

14. Conclusion:
TENS administered with a strong intensity at an adequate frequency in the wound area can signifiacantly reduce analgesic consumption in the post operative pain.
It is non invasive,therapeutic device.
There is credible evidence that TENS reduces pain effectively.

15. Bibilography: Handbook of biomedical instrumentation-R.S.Khandpur.
McGill lecture notes for TENS.
Tens:Clinical Application and Related theory-Deidre Wash.
Electrotheraphy simplified-Nanda.
The Journey To pain relief-Phyllis Berger.