Catheter with obliquely-oriented coils

1. A medical probe, comprising:

an elongate body having a longitudinal axis and a central lumen about the longitudinal axis for a passage of solution, substances or objects therethrough; and

a plurality of magnetic field transducers, which are contained within the body, each magnetic field transducer having a respective magnetic field transducer axis that is oriented obliquely with respect to the longitudinal axis, wherein each magnetic field transducer is positioned along the respective magnetic field transducer axis so as not to interfere with the longitudinal axis and preserving an unobstructed lumen for the central lumen for the passage of solution, substances or objects therethrough and whereby the lumen does not pass through any of the magnetic field transducers.

2. The probe according to claim 1 , wherein the elongate body comprises an insertion tube for insertion into an organ of a patient.

3. The probe according to claim 1 , wherein the plurality of transducers comprises three transducers.

4. The probe according to claim 3 , wherein the transducers are substantially mutually orthogonal.

5. The probe according to claim 1 , wherein the transducers are positioned within the elongate body so that none of the transducers intersects the longitudinal axis.

6. The probe according to claim 1 , wherein the transducers are positioned at a distal end of the elongate body, and wherein the probe comprises leads connecting the transducers to a connector located at a proximal end of the elongate body.

7. The probe according to claim 1 , and comprising a cylinder-shaped fixture for holding the transducers within the elongate body, wherein the fixture has a central opening that is parallel with the longitudinal axis.

8. The probe according to claim 1 , wherein the field transducers comprise coils.

9. A medical position tracking system, comprising:

a medical probe, comprising:

an elongate body having a longitudinal axis and a central lumen about the longitudinal axis for a passage of solution, substances or objects therethrough; and

a plurality of magnetic field transducers, which are contained within the body, each magnetic field transducer having a respective magnetic field transducer axis that is oriented obliquely with respect to the longitudinal axis, wherein each magnetic field transducer is positioned along the respective magnetic field transducer axis so as not to interfere with the longitudinal axis and preserving an unobstructed lumen for the central lumen for the passage of solution, substances or objects therethrough and whereby the lumen does not pass through any of the magnetic field transducers; and

a position measurement subsystem, which is arranged to exchange one or more magnetic fields with the magnetic field transducers in the probe, and to compute a position of the probe responsively to the exchanged fields.

10. The system according to claim 9 , wherein the elongate body comprises an insertion tube for insertion into an organ of a patient.

11. The system according to claim 9 , wherein the plurality of transducers comprises three transducers.

12. The system according to claim 9 , wherein the transducers are substantially mutually orthogonal.

13. The system according to claim 9 , wherein the transducers are positioned within the elongate body so that none of the transducers intersects the longitudinal axis.

14. The system according to claim 9 , wherein the transducers are positioned at a distal end of the elongate body, wherein the probe comprises leads connecting the transducers to a connector located at a proximal end of the elongate body, and wherein the probe connects to the position measurement subsystem using the connector.

15. The system according to claim 9 , wherein the probe comprises a cylinder-shaped fixture for holding the transducers within the elongate body, and wherein the fixture has a central opening that is parallel with the longitudinal axis.

16. The system according to claim 9 , wherein the transducers comprise field detectors, which are positioned at a distal end of the elongate body and are operative to sense one or more magnetic fields generated by the position measurement subsystem in a vicinity of the distal end and to produce, responsively to the sensed fields, respective electrical signals that are indicative of the position of the distal end.

17. The system according to claim 9 , wherein the transducers comprise field generators, which are positioned at a distal end of the elongate body and are operative to generate one or more magnetic fields for sensing by the position measurement subsystem, such that the fields sensed by the position measurement subsystem are indicative of the position of the distal end.