Remote control of medical devices using real time location data

• US 8,024,024 B2
• Filed: 06/27/2008
• Issued: 09/20/2011
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: Stereotaxis, Inc.
• Original Assignee: Stereotaxis, Inc.
• Inventors: Blume, Walter M., Gasparakis, Charidimos E., Munger, Gareth T., Tunay, Ilker, Viswanathan, Raju R.
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US12/163,693
• Publication Number:
  US 20090177037A1
• Time in Patent Office: 1,180 Days
• Field of Search: 600/300, 600/325, 600/327, 600/332, 600/337, 600/407, 600/414, 600423-424, 600/426, 600462-471, 600/478, 600486-488, 600/505, 600508-509, 600117-118, 600/129, 604 21- 22, 606 14- 15, 606/21, 607/9, 607 17- 18, 607/29, 607/113, 607122-126
• US Class Current: 600/407
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61M 25/0105 Steering means as part of the catheter or advancing means; Markers for positioning systems for detection of markers A61B

Abstract

A method of determining the quality of contact between a remotely navigated medical device and a cyclically moving anatomical structure includes measuring movement of the device, and processing the measured movement of the device to determine the contact between the device and the moving anatomical structure.

Claims

1. A method of enhancing contact between a cyclically moving anatomical structure and a remotely navigated medical device, the method comprising determining a covariance matrix based upon the difference between the actual location and the mean location over the cyclical movement;

determining the eigenvectors of the covariance ellipsoid associated with the motion of the device tip;

identifying the eigenvector e_a of the covariance matrix that has the largest dot product with the surface normal vector n at the point of contact between the device and the anatomical surface; and

rotating the device about the eigenvector e_a to increase contact between the device and the anatomical surface.

2. The method of claim 1, where the remotely navigated device is magnetically actuated.

3. The method of claim 1, where the remotely navigated device is mechanically actuated.

4. The method of claim 1, where the remotely navigated device is electrostrictively actuated.

5. A method of determining contact stability of a remotely navigated medical device whose distal tip region is in contact with a cyclically moving anatomical structure, the method comprising:

recording the spatial motion of the distal tip of the medical device through sampling location data over a time period of at least two motion cycles;

determining the Fourier frequency spectrum of the spatial motion to identify at least one dominant frequency of the spatial motion; and

constructing a measure of contact stability of the medical device from analysis of the Fourier frequency spectrum.

6. The method according to claim 5 where the step of identifying at least one dominant frequency of the spatial motion includes identifying at least one sub-dominant peak in addition to the most dominant peak of the spatial motion.

7. The measure according to claim 6 where the most dominant peak and at least one sub-dominant peak in the Fourier frequency spectrum are used in constructing the measure of contact stability.

8. The method of claim 7, where the measure of the contact stability is a ratio of the most dominant peak to the sub-dominant peak.