Surgical navigation
AssigneeBritish Telecommunications public limited company
InventorsJohn Bladen, Alan Anderson
Life of this patent
Estimating the term…
Abstract
Methods and apparatus are provided for locating the position, preferably in three dimensions, of a sensor by generating magnetic fields which are detected at the sensor. The magnetic fields are generated from a plurality of locations and, in one embodiment of the invention, enable both the orientation and location of a single coil sensor to be determined. The present invention thus finds application in many areas where the use of prior art sensors comprising two or more mutually perpendicular coils is inappropriate.
Claims44
A method of determining a location and an orientation of an instrument relative to an anatomy, comprising:
- obtaining image data of the anatomy;
- displaying the obtained image data on a display device;
- moving the instrument relative to the anatomy;
- associating a sensor with the instrument;
- providing a plurality of field generators at known locations each including a plurality of field generating elements;
- energizing each of the plurality of field generating elements;
- a. measuring the respective field generated by each of the plurality of field generating elements with the sensor;
- b. calculating an estimate of a distance from a first field generator of the plurality of field generators to the sensor, based at least in part on the measurements of the field generated by each of the plurality of the field generating elements of the first field generator and an estimate of the orientation of the sensor;
- c. calculating an estimate of the location of the sensor utilizing the calculated estimate of the distance from the first field generator of the plurality of field generators to the sensor and the known location of the field generators;
- d. calculating a new estimate of the orientation of the sensor employing the calculated estimate of the location of the sensor and the measurements of-the field at the sensor;
- e. iteratively repeating portions (b) to (d) with portion (b) employing the new estimate of sensor orientation from the preceding portion (c) to improve the estimates of location and orientation of the sensor;
- determining a first location and a first orientation of the sensor based at least in part on portion e.);
- and
- displaying an icon representing the instrument on the display device based upon the determined first location and the first orientation of the sensor.
A method of determining a location and an orientation of afield generator relative to a plurality of field sensors each at a known location, each field sensor comprising a plurality of field sensor elements, the generator being energized and a measurement being made at a field sensor element of the field sensor of the respective field generated by the field generator, comprising:
- obtaining image data;
- displaying the obtained image data on a display device;
- moving an instrument relative to the anatomy;
- associating the field generator with the instrument;
- a. calculating an estimate of a distance from a first field sensor to the field generator based at least in part on a measurement of the field generated at each of the plurality of the field sensor elements of the first field sensor and an estimate of an orientation of the field generator;
- b. calculating an estimate of the location of the field generator utilizing the calculated estimate of distance and the known location of the field sensors;
- c. calculating a new estimate of an orientation of the field generator employing the calculated estimated location of the field generator from the measurements of the field at the first field sensor;
- d. iteratively repeating portions (a) to (c), wherein portion (a) employs the calculated new estimate of the field generator orientation from the preceding portion (c) to improve the calculated estimated location of the field generator and the calculated new estimate of an orientation of the field generator;
- and
- determining a location and an orientation of the portion of the instrument.
A method of determining a location and an orientation of an instrument within an anatomy, comprising:
- providing a first location member at a known location operable to comprise a first plurality of collocated elements;
- providing a second location member operable to comprise a second plurality of collocated elements;
- energizing at least one of the first location member, the second location member, or combinations thereof to create a field and sensing the field with the other of at least one of the first location member, the second location member, or combinations thereof
- measuring the field sensed by at least one of the first location member, the second location member, or combinations thereof;
- and
- determining the location and the orientation of at least one of the first location member, the second location member, or combinations thereof including:
- a. calculating an estimate of a distance between the first location member and the second location member based at least in part on a measurement of the generated field and an estimate of an orientation of at least one of the first location member, the second location member, or combinations thereof;
- b. calculating an estimate of the location of the second location member utilizing the calculated estimate of distance and the known location of the first location member;
- c. calculating a new estimate of an orientation of the second location member employing the calculated estimated location of the second location member and the measurements of the field with at least one of the first location member, the second location member, or combinations thereof;
- and
- d. iteratively repeating portions (a) to (c), wherein portion (a) employs the calculated new estimate of the second location member orientation from the preceding portion (c) to improve the calculated estimate of the location of the second location member and the calculated new estimate of an orientation of at least one of the first location member, the second location member, or combinations thereof.
Dependencies are inferred from the claim text.