TRANSCRANIAL MAGNETIC STIMULATION BY ENHANCED MAGNETIC FIELD PERTURBATIONS
Described herein are devices, systems and methods to enhance the magnetic perturbation of a neuronal (e.g., brain) target during Transcranial Magnetic Stimulation (TMS), thereby enhancing the induced current in the target. In general, these devices, systems and methods enhance the magnetic perturbation (dB/dt) of the target by mechanically moving a TMS electromagnet (e.g. coil) at a frequency of greater than 1 kHz.
1 . A Transcranial Magnetic Stimulation system, the system comprising:
a magnet configured to be positioned around a subject's head;
a perturbing actuator connected to the magnet and configured to mechanically oscillate the magnet at a frequency of greater than 1 kHz; and
a controller configured to trigger activation of the magnet and mechanical oscillation of the magnet to delivery transcranial magnetic Stimulation to the subject.
2 . The device of claim 1 further comprising a support configured to hold the magnet in position relative to a subject's head.
3 . The device of claim 1 , wherein the perturbing actuator is configured to rotate the magnet on its central axis.
4 . The device of claim 1 , wherein the perturbing actuator is configured to move the magnet in and out on its central axis.
5 . The device of claim 1 , wherein the perturbing actuator is configured to move the magnet laterally on and off the central axis.
6 . The device of claim 1 , wherein the perturbing actuator is configured to move the magnet laterally partially on and off the central axis by moving the magnet about a fixed point on the central axis.
7 . The device of claim 1 further comprising a housing enclosing the magnet.
8 . The device of claim 1 further comprising a second magnet and a second perturbing actuator connected to the second magnet and configured to mechanically oscillate the second magnet at a frequency of greater than 1 kHz.
9 . The device of claim 1 wherein the magnet is part of an array of magnet and the perturbing actuator is configured to mechanically oscillate the array of magnet.
10 . The device of claim 1 , wherein the perturbing actuator comprises a voice coil.
11 . The device of claim 1 , wherein the perturbing actuator comprises a piezoelectric actuator.
12 . The device of claim 1 further comprising a coupling shaft connecting the perturbing actuator to the magnet.
13 . The device of claim 1 , wherein the perturbing actuator is configured to mechanically oscillate the magnet at a frequency of between about 2 kHz and about 10 kHz.
14 . A Transcranial Magnetic Stimulation system, the system comprising:
a TMS electromagnet;
a perturbing actuator connected to the TMS electromagnet comprising a voice coil, wherein the perturbing actuator is configured to mechanically oscillate the TMS electromagnet at a frequency of between about 1 kHz and 10 kHz; and
a controller configured to trigger activation of the TMS electromagnet and mechanical oscillation of the TMS electromagnet.
15 . A method of applying Transcranial Magnetic Stimulation (TMS) to a subject, the method comprising:
positioning a magnet toward a target brain region;
emitting a magnetic field from the magnet towards the target tissue; and
mechanically oscillating the magnet at a frequency of greater than 1 KHz so that magnetic field emitted by the magnet moves relative to the target tissue and electrically perturbs the target tissue.
16 . The method of claim 15 , further comprising synchronously emitting the magnetic field and mechanically oscillating the magnet.
17 . The method of claim 15 , wherein the step of positioning the magnet comprises fixing the position of the magnet relative to a subject's head.
18 . The method of claim 15 , wherein the step of mechanically oscillating the magnet comprises rotating the magnet on its central axis.
19 . The method of claim 15 , wherein the step of mechanically oscillating the magnet comprises moving the magnet in and out on its central axis.
20 . The method of claim 15 , wherein the step of mechanically oscillating the magnet comprises moving the magnet laterally on and off the central axis.
21 . The method of claim 15 , wherein the step of mechanically oscillating the magnet comprises moving the magnet laterally partially on and off the central axis by moving the magnet about a fixed point on the central axis.
22 . The method of claim 15 , wherein the step of mechanically oscillating the magnet comprises oscillating the magnet at a frequency of between about 2 KHz and about 10 kHz.
23 . The device of claim 1 , wherein the magnet is a TMS electromagnet.
24 . The device of claim 1 , wherein the magnet is a permanent magnet.
25 . The method of claim 15 , wherein the step of positioning a magnet comprises positioning a TMS electromagnet.
26 . The method of claim 15 , where in the step of positioning a magnet comprises positioning a permanent magnet.