Systems and apparatus for monitoring internal temperature of a gradient coil
Systems, methods and apparatus are provided through which in some embodiments a thermal sensor of a magnetic coil of a magnetic resonance imaging system (MRI) is positioned, placed and/or mounted externally to the magnetic coil. The external placement of the thermal sensor does not require replacement of the entire magnetic coil, yielding less expensive replacement of a failed thermal sensor.
1. An apparatus for monitoring internal temperature of a gradient coil, the apparatus comprising:
a thermally conductive device having a first end and a second end, the first end positioned inside the gradient coil and the second end positioned outside the gradient coil; and
a thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil.
2. An apparatus according to claim 1 , wherein the first end of the thermally conductive device is positioned inside an end of the gradient coil in an axial direction.
3. An apparatus according to claim 1 , wherein the thermally conductive device comprises a copper material.
4. An apparatus according to claim 1 , wherein the thermally conductive device comprises advanced pyrolitic graphite.
5. An apparatus according to claim 1 , wherein the thermally conductive device comprises a copper-graphite composite.
6. An apparatus according to claim 1 , wherein the thermally conductive device comprises a heat pipe.
7. An apparatus according to claim 1 , further comprising a second thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil.
8. A system for monitoring internal temperature of a gradient coil, the system comprising:
at least one temperature monitoring apparatus comprising:
a thermally conductive device having a first end and a second end, the first end positioned inside the gradient coil and the second end positioned outside of the gradient coil; and
a thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil; and
a control computer coupled to the thermal sensor and configured to receive signals from the thermal sensor.
9. A system according to claim 8 , wherein the first end of the thermally conductive device is positioned inside an end of the gradient coil in an axial direction.
10. A system according to claim 8 , further comprising a plurality of temperature monitoring apparatus.
11. A system according to claim 10 , wherein the gradient coil is cylindrical and the end of the gradient coil has a circumference and each temperature monitoring apparatus is located at a position on the circumference of the end of the gradient coil.
12. A system according to claim 8 , wherein the control computer is further configured to determine if a temperature of the gradient coil exceeds a predetermined temperature.
13. A system according to claim 8 , wherein the temperature monitoring apparatus further comprises a second thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil.
14. A magnetic resonance imaging system comprising:
a gradient coil;
a plurality of thermal monitoring devices, each thermal monitoring device comprising:
a thermally conductive device having a first end and a second end, the first end positioned inside the gradient coil and the second end positioned outside of the gradient coil; and
a thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil; and
a control computer coupled to at least one of the plurality of thermal monitoring devices and configured to receive signals from the at least one thermal monitoring device.
15. A magnetic resonance imaging system according to claim 14 , wherein the first end of the thermally conductive device is positioned inside an end of the gradient coil in an axial direction.
16. A magnetic resonance imaging system according to claim 14 , wherein the gradient coil comprises an inner gradient coil assembly and an outer gradient coil assembly.
17. A magnetic resonance imaging system according to claim 16 , wherein at least one of the plurality of thermal monitoring devices is coupled to the inner gradient coil assembly.
18. A magnetic resonance imaging system according to claim 16 , wherein at least one of the plurality of thermal monitoring devices is coupled to the outer gradient coil assembly.
19. A magnetic resonance imaging system according to claim 14 , wherein at least one of the plurality of thermal monitoring devices further comprises a second thermal sensor thermally coupled to the second end of the thermally conductive device external to the gradient coil.
20. A magnetic resonance imaging system according to claim 14 , wherein the thermally conductive device comprises advanced pyrolitic graphite.