Intrabody navigation and imaging system for medical applications

• US 20020005719A1
• Filed: 06/13/2001
• Published: 01/17/2002
• Est. Priority Date: 08/02/1998
• Status: Abandoned Application

• Current Assignee: Super Dimension Ltd.
• Original Assignee: Super Dimension Ltd.
• Inventors: Gilboa, Pinhas, Blecher, Danny
• Application Number:
  US09/879,108
• Publication Number:
  US 20020005719A1
• Time in Patent Office: Days
• US Class Current: 324/309
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/4245 involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient

Abstract

A system and method for tracking the position and orientation of a probe such as a catheter whose transverse inner dimension may be at most about two millimeters. Three planar antennas that at least partly overlap are used to transmit electromagnetic radiation simultaneously, with the radiation transmitted by each antenna having its own spectrum. In the case of single-frequency spectra, the antennas are provided with mechanisms for decoupling them from each other. A receiver inside the probe includes sensors of the three components of the transmitted field, with sensors for at least two of the three components being pairs of sensors, such as coils, disposed symmetrically with respect to a common reference point. In one variant of the receiver, the coils are collinear and are wound about cores that are mounted in pairs of diametrically opposed apertures in the housing of the probe. In another variant of the receiver-catheter combination, the catheter is configured with an inner and outer sleeve connected at their ends by one or more flexible elements on which the coils are mounted. Each member of a pair of coils that sense the same component of the transmitted field is connected to a different input of a differential amplifier. The position and orientation of the receiver relative to the antennas are determined noniteratively, by setting up an overdetermined set of linear equations that relates the received signals to transmitter-receiver amplitudes, solving for the amplitudes and inferring the position coordinates and the orientation angles of the receiver relative to the transmitter from these amplitudes. For the purpose of navigating the probe within the body of a patient, the antennas are rigidly attached to an imaging device such as a fluoroscope, to provide a common frame of reference for both the acquired images of the patient and the measured position and orientation of the receiver. Alternatively, a second receiver is rigidly attached to the imaging device to provide the common frame of reference. In a third alternative, a third receiver is rigidly attached to the patient during imaging, and the mutual positions and orientations of the patient and the imaging device thus measured are used in subsequent navigation of the probe within the body of the patient. An imaging device that includes an electrically conductive surface is provided with a magnetically permeable compensator for minimizing distortion of the transmitted field. A scheme is provided for retrofitting an apparatus such as the receiver to a prior art catheter.

Claims

1. A system for navigating a probe inside a body, comprising:

(a) a receiver of electromagnetic radiation, inside the probe;

(b) a device for acquiring an image of the body; and

(c) a transmitter, of said electromagnetic radiation, including at least one antenna rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

2. The system of claim 1, wherein said system further comprises:

(d) a mechanism for displaying a representation of the probe superposed on at least a portion of said image.

3. The system of claim 1, wherein said image is selected from the group of modalities consisting of CT, MRI, ultrasound and fluoroscopy.

4. A system for navigating a probe inside a body, comprising:

(a) a first receiver of electromagnetic radiation, inside the probe;

(b) a device for acquiring an image of the body; and

(c) a second receiver, of said electromagnetic radiation, rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

5. The system of claim 4, further comprising:

(d) a transmitter of said electromagnetic radiation.

6. The system of claim 4, further comprising:

(d) a mechanism for displaying a representation of the probe superposed on at least a portion of said image.

7. The system of claim 4, wherein said image is selected from the group of modalities consisting of CT, MRI, ultrasound and fluoroscopy.

8. A method of navigating a probe inside a body, comprising the steps of:

(a) providing a device for acquiring an image of the body;

(b) simultaneously;

(i) acquiring said image of the body, and

(ii) determining a position and orientation of the probe with respect to said image; and

(c) displaying said image of the body with a representation of the probe superposed thereon according to said position and said orientation.

9. The method of claim 8, wherein said image is selected from the group of modalities consisting of CT, MRI, ultrasound and fluoroscopy.

10. The method of claim 8, wherein said determining of said position and said orientation is effected by steps including:

(A) transmitting electromagnetic radiation, using a transmitter;

(B) receiving said electromagnetic radiation, using a first receiver inside the probe, thereby producing signals corresponding to said electromagnetic radiation; and

(C) inferring said position and said orientation from said signals.

11. The method of claim 10, wherein said transmitter includes at least one antenna rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

12. The method of claim 10, wherein said determining of said position and said orientation is effected by steps including:

(D) receiving said electromagnetic radiation, using a second receiver rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

13. A method of navigating a probe inside a body, comprising the steps of:

(a) providing a device for acquiring an image of the body;

(b) simultaneously;

(i) acquiring said image of the body, and

(ii) determining a position and an orientation of the body with respect to said image;

(c) determining a position and an orientation of the probe with respect to the body; and

(d) displaying said image of the body with a representation of the probe superposed thereon according to both of said positions and both of said orientations.

14. The method of claim 13, wherein said image is selected from the group of modalities consisting of CT, MRI, ultrasound and fluoroscopy.

15. The method of claim 13, wherein said determining of said position and said orientation of the body with respect to said image is effected by steps including:

(A) transmitting electromagnetic radiation, using a transmitter;

(B) receiving said electromagnetic radiation, using a first receiver rigidly attached to the body, thereby producing signals corresponding to said electromagnetic radiation; and

(C) inferring said position and said orientation of the body with respect to said image from said signals.

16. The method of claim 15, wherein said transmitter includes at least one antenna rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

17. The method of claim 15, wherein said determining of said position and said orientation of the body with respect to said image is effected by steps including:

(D) receiving said electromagnetic radiation, using a second receiver rigidly attached to said device so as to define a frame of reference that is fixed with respect to said device.

18. The method of claim 13, wherein said determining of said position and said orientation of the probe with respect to the body is effected by steps including:

(i) transmitting electromagnetic radiation, using a transmitter;

(ii) receiving said electromagnetic radiation, using a first receiver rigidly attached to the body, thereby producing signals representative of a position and an orientation of the body with respect to said transmitter;

(iii) receiving said electromagnetic radiation, using a second receiver inside the probe, thereby producing signals representative of a position and an orientation of the probe with respect to said transmitter; and

(iv) inferring said position and said orientation of the probe with respect to the body from said position and said orientation of the body with respect to said transmitter and from said position and said orientation of the probe with respect to said transmitter.