Arrangement and method for influencing and/or detecting magnetic particles in a region of action
An arrangement and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement comprises: —selection means for generating a magnetic selection field having a pattern in space of its magnetic field strength such that a first sub-zone having a low magnetic field strength and a second sub-zone having a higher magnetic field strength are formed in the region of action, —drive means for changing the position in space of the two sub-zones in the region of action by means of a magnetic drive field so that the magnetization of the magnetic particles changes locally, —receiving means for acquiring signals, which signals depend on the magnetization in the region of action, which magnetization is influenced by the change in the position in space of the first and second sub-zone, wherein the selection means and/or the drive means and/or the receiving means comprises at least partially a litz wire/stranded wire.
1. An arrangement ( 10 ) for influencing and/or detecting magnetic particles ( 100 ) in a region of action ( 300 ), which arrangement comprises:
selection means ( 210 ) for generating a magnetic selection field ( 211 ) having a pattern in space of its magnetic field strength such that a first sub-zone ( 301 ) having a low magnetic field strength and a second sub-zone ( 302 ) having a higher magnetic field strength are formed in the region of action ( 300 ),
drive means ( 220 ) for changing the position in space of the two sub-zones ( 301 , 302 ) in the region of action ( 300 ) by means of a magnetic drive field ( 221 ) so that the magnetization of the magnetic particles ( 100 ) changes locally,
receiving means ( 230 ) for detecting signals from the magnetic particles ( 100 ), which signals depend on the magnetization in the region of action ( 300 ), which magnetization is influenced by the change in the position in space of the first and second sub-zone ( 301 , 302 ),
wherein the selection means ( 210 ) and/or the drive means ( 220 ) and/or the receiving means ( 230 ) comprises at least partially a litz wire/stranded wire ( 250 ), and
wherein the signals detected from the magnetic particles ( 100 ) located in the sub-zone ( 301 ) are detected in another frequency band than a frequency band of the magnetic drive field ( 221 ).
2. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) comprises a plurality of individual wires ( 255 ), each individual wire being surrounded by an electrically high resistive material ( 256 ).
3. An arrangement ( 10 ) according to claim 2 , wherein the litz wire ( 250 ) comprises a plurality of first order litz wires ( 251 ) comprising a plurality of individual wires ( 255 ), wherein the litz wire ( 250 ) comprises a plurality of first order litz wires ( 251 ).
4. An arrangement( 10 ) according to claim 2 , wherein the litz wire ( 250 ) comprises a plurality of first order litz wires ( 251 ) and a plurality of second order litz wires ( 252 ), wherein the first order litz wires ( 251 ) comprise a plurality of individual wires ( 255 ), wherein the second order litz wires ( 252 ) comprise a plurality of first order litz wires ( 251 ), and wherein the litz wire ( 250 ) comprises a plurality of second order litz wires ( 252 ).
5. An arrangement ( 10 ) according to claim 1 , wherein the resistance of the receiving means ( 230 ) is dominated by thermal noise, especially generated by thermal noise in the region of action ( 300 ).
6. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) comprises at least partially a ferromagnetic material.
7. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) is at Least partially used for the selection means ( 210 ) and/or for the drive means ( 220 ) and wherein the litz wire ( 250 ) of the selections means ( 210 ) is at least partially penetrated by the magnetic drive field ( 221 ) of the drive means ( 220 ) and/or wherein the litz wire ( 250 ) of the drive means ( 220 ) is at least partially penetrated by the magnetic selection field ( 211 ) of the selection means ( 210 ).
8. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) is arranged such that the resistance in a given working frequency band and in a given electromagnetic field penetrating the litz wire ( 250 ) is substantially minimal.
9. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) has a ratio of the summed cross sectional area of the individual wires ( 255 ) relative to the cross sectional area of the litz wire ( 250 ) (filling factor) of about 0.30 to about 0.70 or wherein the litz wire ( 250 ) has a ratio of the summed cross sectional area of the individual wires ( 255 ) relative to the cross sectional area of the litz wire ( 250 ) (filling factor) of about 0.01 to about 0.20.
10. An arrangement ( 10 ) according to claim 1 , wherein the individual wires ( 255 ) of the litz wire ( 250 ) has a diameter of approximately 1 μm to approximately 50 μm.
11. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) is a compressed litz wire ( 250 ).
12. An arrangement ( 10 ) according to claim 1 , wherein the litz wire ( 250 ) comprises a multitude of thermoplastic resin wires.
13. An arrangement ( 10 ) according to claim 1 , wherein space between different litz wires ( 250 ) or space inside the litz wire ( 250 ) is used for one or a plurality of cooling channels.
14. An arrangement ( 10 ) according to claim 1 , wherein the selection means ( 210 ) and/or the drive means ( 220 ) and/or the receiving means ( 230 ) comprises an at least partially disk shaped coil ( 260 ).
15. A method for influencing and/or detecting magnetic particles ( 100 ) in a region of action ( 300 ), wherein the method comprises the steps of
generating a magnetic selection field ( 211 ) having a pattern in space of its magnetic field strength such that a first sub-zone ( 301 ) having a low magnetic field strength and a second sub-zone ( 302 ) having a higher magnetic field strength are formed in the region of action ( 300 ),
changing the position in space of the two sub-zones ( 301 , 302 ) in the region of action ( 300 ) by means of a magnetic drive field ( 221 ) so that the magnetization of the magnetic particles ( 100 ) changes locally,
detecting signals from the magnetic particles ( 100 ), which signals depend on the magnetization in the region of action ( 300 ), which magnetization is influenced by the change in the position in space of the first and second sub-zone ( 301 , 302 ),
wherein the generation of the magnetic selection field ( 211 ) and/or the change of the position in space of the two sub-zones ( 301 , 302 ) and/or the acquisition of the signals depending on the magnetization in the region of action ( 300 ) is performed at least partially by means of a litz wire/stranded wire ( 250 ), and
wherein the signals detected from the magnetic particles ( 100 ) located in the first sub-zone ( 301 ) are detected in another frequency band than a frequency band of the magnetic drive field ( 221 ).