Understanding the Mechanism of TMSweb_admin
The nerve cells in our body are surrounded by a membrane that maintains the difference in electrical potential of -70mV between their surrounding and their interior.
When current is locally induced, it decreases this potential difference by some millivolts all along the length of the cell membrane and initiates a depolarization wave that propagates along the nerve fiber length.
This is referred as a nerve impulse.
This nerve impulse can also be generated by electrode insertion into/near the nerve and can be stimulated by providing current through the skin or electrically.
Both of these methods are either invasive or cause discomfort due to stimulation of pain receptors in the skin.
However, Faraday’s discovery revealed a proper way to achieve the same results but rather non-invasively. It was about painlessly inducing a current by the use of the magnetic field, applied externally.
This is exactly what TMS is about!
The equipment that generates sufficient magnetic field comprises of the power source. It charges the single large capacitor which feeds a coil located on the body surface and above the nerves to be enthused. When the capacitor discharges into the coil it generates a magnetic field pulse that eventually sets up nerve current, creating a nerve impulse.
Nowadays the therapy devices can deliver around 30+ pulses each second. It also has complex circuit topography to allow energy from the basic pulse to be slightly recaptured, decreasing the additional energy essential to produce next pulse.
It requires actual engineering to generate the needed field. The main challenges arise due to the involved parameters size. The peak magnetic fields of around 4 Tesla are required to pass current in the tissues, depending on the coil. This, in turn, needs peak currents of several thousand amps in the coil.
While this is a complex mechanism, only a professional psychiatrist is qualified enough to perform the TMS treatment. Remember the best results of this therapy depend on the experience and expertise of the professional performing the job.