Device and method for preventing magnetic-resonance imaging induced damage
An electromagnetic shield has a first patterned or apertured layer having non-conductive materials and conductive material and a second patterned or apertured layer having non-conductive materials and conductive material. The conductive material may be a metal, a carbon composite, or a polymer composite. The non-conductive materials in the first patterned or apertured layer may be randomly located or located in a predetermined segmented pattern such that the non-conductive materials in the first patterned or apertured layer are located in a predetermined segmented pattern with respect to locations of the non-conductive materials in the second patterned or apertured layer.
1 . A device for amplifying an electrical signal of physiological significance in a magnetic-resonance imaging environment, comprising:
at least two electrodes with associated input leads for coupling to a patient;
an amplifier having a zero-signal reference terminal for detecting and amplifying the desired physiological signal; and
a filter, connected to said input leads and coupling said at least two electrodes to said amplifier, to attenuate any induced RF signal produced in the magnetic-resonance imaging environment and passing the lower frequency desired electrical physiological signal;
said filter including a shield enclosing said filter;
said shield enclosing said filter being patterned with non-conductive materials and conductive materials.
2 . The device as claimed in claim 1 , wherein said filter further includes a low pass filter connected to one of said input leads.
3 . The device as claimed in claim 1 , wherein said conductive material is a metal.
4 . The device as claimed in claim 1 , wherein said conductive material includes metal-coated carbon filaments.
5 . The device as claimed in claim 1 , wherein said conductive material is a polymer composite.
6 . The device as claimed in claim 1 , wherein said shield is constructed of two patterned sheaths, each patterned sheath having non-conductive materials and conductive materials.
7 . The device as claimed in claim 6 , wherein said conductive materials in one of said two patterned sheaths are randomly located.
8 . The device as claimed in claim 6 , wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern.
9 . The device as claimed in claim 1 , further comprising:
an input lead shield to shield said input leads.
10 . The device as claimed in claim 9 , wherein said input lead shield is patterned with non-conductive materials and conductive materials.
11 . The device as claimed in claim 10 , wherein said conductive material of said input lead shield is a metal.
12 . The device as claimed in claim 10 , wherein said conductive material of said input lead shield includes metal-coated carbon filaments.
13 . The device as claimed in claim 10 , wherein said conductive material of said input lead shield is a polymer composite.
14 . The device as claimed in claim 10 , wherein said input lead shield is constructed of two patterned sheaths, each patterned sheath having non-conductive materials and conductive materials.
15 . The device as claimed in claim 14 , wherein said conductive materials in one of said two patterned sheaths are randomly located.
16 . The device as claimed in claim 14 , wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern.
17 . The device as claimed in claim 14 , wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially parallel with an axis of said input leads.
18 . The device as claimed in claim 14 , wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially perpendicular with an axis of said input leads.
19 . The device as claimed in claim 17 , wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially perpendicular with an axis of said input leads.
20 . A device for amplifying an electrical signal of physiological significance in a magnetic-resonance imaging environment, comprising:
at least two electrodes with associated input leads for coupling to a patient;
an amplifier having a zero-signal reference terminal for detecting and amplifying the desired physiological signal; and
a filter, connected to said input leads and coupling said at least two electrodes to said amplifier, to attenuate any induced RF signal produced in the magnetic-resonance imaging environment and passing the lower frequency desired electrical physiological signal,
said filter including a shield enclosing said filter;
said shield being an apertured conductive material having a maximum aperture dimension of 0.01 millimeters to 10 millimeters.
21 . The device as claimed in claim 20 , wherein said filter further includes a low pass filter connected to one of said input leads.
22 . The device as claimed in claim 20 , wherein said conductive material is a metal.
23 . The device as claimed in claim 20 , wherein said conductive material includes metal-coated carbon filaments.
24 . The device as claimed in claim 20 , wherein said conductive material is a polymer composite.
25 . The device as claimed in claim 20 , wherein said conductive material comprises nanotubes.