Field concentrating antennas for magnetic position sensors
View Patent ↗A medical device is configured for diagnosis or treatment of a tissue within a body. The medical device comprises an elongate member and a position sensor. The elongate member is configured to be received within the body, and has a lumen extending between a proximal end and a distal end. The position sensor is disposed within the lumen proximate the distal end of the deformable member. The position sensor comprises a coil wound to form a central passage and configured to generate a current flow when subject to a magnetic field, and a high-permeability antenna having at least a portion disposed outside the central passage to concentrate the magnetic field into the coil and increase the current flow.
1 . A medical device configured for diagnosis or treatment of a tissue within a patient, the medical device comprising the following:
an elongate member configured to be received within the patient, the elongate member having a lumen extending between a proximal end and a distal end; and
a position sensor disposed within the lumen proximate the distal end of a deformable member, the position sensor comprising:
a coil wound to form a central passage and configured to generate a current flow when subject to a magnetic field; and
a core including a body passing through the central passage and having at least a portion disposed outside the central passage, the core comprising a mass of high magnetic permeability material configured to concentrate the magnetic field into the coil and increase the current flow.
2 . The medical device of claim 1 , wherein the core has an axial length longer than that of the coil.
3 . The medical device of claim 2 , wherein the body of the core is circumferentially curved in a direction of windings of the coil.
4 . The medical device of claim 1 , further including a high-permeability antenna disposed outside the central passage and configured to further increase the current flow into the coil by concentrating the magnetic field into the coil.
5 . The medical device of claim 4 , wherein the antenna has an outer diameter greater than that of the coil.
6 . The medical device of claim 1 , wherein the antenna includes:
a first mass of high magnetic permeability material disposed axially adjacent the coil; and
a second mass of high magnetic permeability material disposed axially adjacent the coil opposite the first mass.
7 . The medical device of claim 6 , wherein the first mass is in contact with the core outside of the central passage.
8 . The medical device of claim 6 , wherein the first mass is axially spaced from the coil.
9 . A medical device configured for diagnosis or treatment of a tissue within a patient, the medical device comprising the following:
an elongate member configured to be received within the patient, the elongate member having a lumen extending between a proximal end and a distal end; and
a position sensor disposed within the lumen proximate the distal end of the elongate member, the position sensor comprising:
a body defining an internal lumen;
a wire winding supported by the body; and
a magnetic flux antenna disposed within the body, the antenna including:
a first mass of high magnetic permeability material located externally to the wire winding and positioned proximate to the wire winding, and
a core of high magnetic permeability material disposed within the wire winding.
10 . The sensor assembly of claim 9 , wherein the antenna further includes a second mass of high magnetic permeability material located externally to the wire winding and positioned proximate to the wire winding in a location opposite the first mass relative to the core.
11 . The sensor assembly of claim 9 , wherein the antenna has a permeability greater than that of the wire winding.
12 . The sensor assembly of claim 9 , wherein the first mass has a diameter greater than the wire winding.
13 . The sensor assembly of claim 9 , further comprising:
a conductor electrically coupling the wire winding and the magnetic flux antenna; and
a shield surrounding the wire winding and the conductor.
14 . A medical device comprising:
an elongate sheath defining a lumen;
a position sensor disposed within the lumen, the position sensor including a coil wound to form a central passage;
an electrode exposed to an exterior of the elongate sheath; and
a magnetic antenna comprising a core of high magnetic permeability material, the core being disposed within the central passage of the coil and further extending beyond the central passage of the coil.
15 . The medical device of claim 14 , wherein an axial length of the magnetic antenna is greater than the coil.
16 . The medical device of claim 15 , wherein the magnetic antenna has a permeability greater than that of air.
17 . The medical device of claim 16 , wherein the magnetic antenna is configured to increase the current flow into the coil by concentrating the magnetic field into the coil.
18 . The medical device of claim 14 , wherein the magnetic antenna comprises a thin strip of material extending circumferentially about and generally parallel to a central axis of the coil.