High magnetic field compatible interventional needle and integrated needle tracking system

Patent metadata

Field	Value
Publication number	US-9945915-B2
Application number	US-201013265387-A
Country	US
Kind code	B2
Filing date	Apr 13, 2010
Priority date	Apr 20, 2009
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

An elongate device, such as a catheter, for interventional MRI has one or more passive LC-circuits attached to its distal tip portion for position tracking. The LC-circuits includes an inductor winding and a three-dimensional “trench” capacitor. The LC-circuits are integrated in a piece of silicon. Optical fibers may be included in the device for optical probing of tissue surrounding the distal tip portion.

First claim

The invention claimed is:

1. A medical interventional device for intervention in a high magnetic field, the device comprising:
an elongate shaft with a tip portion; and
a plurality of passive inductor-capacitor (LC)-circuits positioned at the tip portion, wherein each of the plurality of passive LC-circuits comprises a resonator including an inductor and a capacitor integrated into an Si wafer, wherein the inductor is located on a portion of a surface of the Si wafer and the capacitor is located under the inductor below the portion of the surface of the Si wafer,
wherein each capacitor of the plurality of passive LC-circuits comprises a trench capacitor having a trench formed in the Si wafer and includes inner and outer conductors and a first dielectric between the inner and outer conductors, the outer conductor contacting the Si wafer and a first metal contact, and the inner conductor being located over the first dielectric and contacting a second metal contact,
wherein the first metal contact fills an exposed portion of the outer conductor not covered by the first dielectric and by a second dielectric formed over the first dielectric to contact the outer conductor, and the first metal contact is spaced away from the trench,
wherein the second metal contact fills an exposed portion of inner conductors of at least two trench capacitors not covered by the second dielectric formed over the first dielectric, the second metal contact is formed directly over trenches of the at least two trench capacitors and is isolated from the first metal contact, and
wherein the second metal contact contacts at least two inductor windings of the inductor.

2. The device as claimed in claim 1 , wherein each inductor of the plurality of passive LC-circuits includes an elongated spiral coil having a first dimension which is longer than a second dimension, each inductor having a main axis along the first dimension, and wherein one of the main axes of one of the elongated spiral coils is orientated parallel to a longitudinal axis of the elongate shaft.

3. The device as claimed in claim 1 , wherein each inductor of the plurality of passive LC-circuits includes an elongated spiral coil having a first dimension which is longer than a second dimension, each inductor having a main axis along the first dimension, and wherein one of the main axes of one of the elongated spiral coils is orientated radial to the elongate shaft.

4. The device as claimed in claim 1 , further comprising a sensing element.

5. The device as claimed in claim 4 , wherein the sensing element comprises at least two optical fibers, wherein one of the fibers is adapted to emit light and another one of the fibers is adapted to receive light reflected back into said fiber.

6. The device of claim 1 , wherein the tip portion including the plurality of passive LC-circuits is formed separately from the elongate shaft and affixed to the elongate shaft.

7. The device of claim 1 , wherein areas of the Si wafer including the capacitor have phosphorous doping and remaining areas of the Si wafer including not needed to form the capacitor includes an Argon implant.

8. A method of manufacturing a device for intervention in a high magnetic field, the method comprising the acts of:
forming a plurality of capacitors including trench capacitors having trenches formed in an Si wafer, inner and outer conductors and a first dielectric between the inner and outer conductors, the outer conductor contacting the Si wafer and a first metal contact, and the inner conductor contacting a second metal contact;
forming a second dielectric over the first dielectric;
removing a first part of the first dielectric and the second dielectric to expose a portion of the outer conductor not covered by the first dielectric and the second dielectric;
removing a second part of the second dielectric to expose a portion of inner conductors of at least two trench capacitors not covered by the second dielectric;
forming a plurality of inductors on a portion of a surface of the Si wafer, wherein the trench capacitors are located under the inductors below the portion of the surface of the Si wafer;
connecting the plurality of inductors to the plurality of capacitors so that a plurality of passive inductor-capacitor (LC)-circuits is formed, each of the plurality of passive LC-circuits including one of the plurality of capacitors and one of the plurality of inductors; and
fixing the plurality of passive LC-circuits at a tip portion of a shaft of the device, wherein the act of forming the plurality of capacitors includes acts of filling the first metal contact in the exposed portion of the outer conductor spaced away from the trenches to contact the outer conductor; and filling the second metal contact in the exposed portion of the inner conductors of the at least two trench capacitors directly over trenches of the at least two trench capacitors to contact the inner conductors, the second metal contact being isolated from the first metal contact,
wherein the second metal contact contacts at least two inductor windings of the inductor.

9. The method as claimed in claim 8 , further comprising the act of dicing the Si wafer.

10. The method as claimed in claim 9 , wherein the dicing act forms the tip portion of the device separate from the shaft, wherein the tip portion integrally includes the plurality of passive LC-circuits, and wherein the fixing act fixes the plurality of passive LC-circuits together with the tip portion to the shaft of the device.

11. The method as claimed in claim 9 , wherein the dicing act isolates the plurality of passive LC-circuits, and wherein the isolated plurality of passive LC-circuits is fixed at the shaft of the device.

12. The method as claimed in claim 8 , further comprising the act of coupling a sensing element to the shaft.

13. The method of claim 8 , wherein the act of forming a plurality of capacitors includes doping with phosphorous areas of the Si wafer including the plurality of capacitors and implanting with Argon remaining areas of the Si wafer not needed to form the plurality of capacitors.

Assignees

• Klee Mareike
• Winkel Axel
• Mills John Brean
• Dekker Ronald
• Hendriks Bernardus Hendrikus Wilhelmus
• Koninklijke Philips Nv

Inventors

• Klee Mareike
• Winkel Axel
• Mills John Brean
• Dekker Ronald
• Hendriks Bernardus Hendrikus Wilhelmus

Classifications

• G01R33/287 Primary

  involving active visualization of interventional instruments, e.g. using active tracking RF coils or coils for intentionally creating magnetic field inhomogeneities · CPC title

• G01R33/34007

  Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system · CPC title

• G01R33/34084

  implantable coils or coils being geometrically adaptable to the sample, e.g. flexible coils or coils comprising mutually movable parts · CPC title

• Y10T29/4902

  Electromagnet, transformer or inductor · CPC title