Robotically controlled catheter and method of its calibration

• US 8,407,023 B2
• Filed: 04/06/2012
• Issued: 03/26/2013
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Original Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Inventors: Hauck, John A.
• Primary Examiner(s): Le, John H
• Application Number:
  US13/441,249
• Publication Number:
  US 20120203485A1
• Time in Patent Office: 354 Days
• Field of Search: 702/75, 702/77, 702/85, 702/94, 702/95, 702/150, 702/151, 702/158, 702/163, 702/175, 702/176, 700/249, 700/260, 600/301, 600/374, 600/407, 600/424, 600/437, 600/449, 600/466, 600/509, 600/518, 600/547, 600/587, 604/95.01, 604/95.04, 604/117, 604/264, 604/500, 604/525, 604/528, 606/1, 606/28, 606/41, 607/101, 607/122, 607/125, 607/128, 128/899
• US Class Current: 702/95
• CPC Class Codes: A61B 1/0052 Constructional details of control elements, e.g. handles
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/00699 correcting for movement caused by respiration, e.g. by triggering
• CPC Class Codes: A61B 2017/00703 correcting for movement of heart, e.g. ECG-triggered
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2017/22075 with motorized advancing or retracting means
• CPC Class Codes: A61B 2017/3409 including needle or instrument drives
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2053 Tracking an applied voltage gradient
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 2034/742 Joysticks
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• 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 34/30 Surgical robots
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• 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
• CPC Class Codes: A61M 25/0133 : Tip steering devices

Abstract

A method of calibrating a robotic device, such as a cardiac catheter, includes oscillating the device on an actuation axis by applying an oscillation vector at an oscillation frequency. While oscillating, a location of the device is periodically measured to generate a plurality of location data points, which may express the location of the device relative to a plurality of measurement axes. The location data points are then processed using a signal processing algorithm, such as a Fourier transform algorithm, to derive a transfer function relating a position of the device to a movement vector for the actuation axis. The transfer function may be resolved into and expressed as a calibration vector for the actuation axis, which may include one or more components, including zero components, directed along each of the measurement axes. The process may be repeated for any actuation axes on which calibration is desired.

Claims

1. A method of calibrating a robotic surgical system including a medical device and at least one servo mechanism operable to move the medical device, comprising:

energizing the at least one servo mechanism to apply a first oscillation vector to the medical device;

while applying the first oscillation vector to the medical device, periodically measuring a location of at least one point on the medical device, thereby generating a first position signal for the medical device;

processing the first position signal to generate a first output signal, wherein the first output signal reflects movement of the medical device attributable to the application of the first oscillation vector to the medical device by the at least one servo mechanism; and

using the first output signal to generate a first transfer function that relates inputs to the at least one servo mechanism to resulting movements of the medical device.

2. The method according to claim 1, wherein application of the first oscillation vector causes the medical device to oscillate on a first actuation axis selected from the group consisting of a rotation axis, a translation axis, and a deflection axis.

3. The method according to claim 1, wherein application of the first oscillation vector causes the medical device to oscillate on a first actuation axis that combines movement on two or more axes selected from the group consisting of a rotation axis, a translation axis, and a deflection axis.

4. The method according to claim 1, wherein the processing step comprises applying a Fourier transform algorithm to the first position signal.

5. The method according to claim 1, wherein the processing step comprises applying a synchronous demodulation algorithm to the first position signal.

6. The method according to claim 1, wherein the processing step comprises applying a cross correlation algorithm to the first position signal.

7. The method according to claim 1, wherein the at least one servo mechanism comprises a plurality of servo mechanisms and wherein the step of energizing the at least one servo mechanism to apply a first oscillation vector to the medical device first oscillation vector comprises energizing only one of the plurality of servo mechanisms.

8. The method according to claim 1, wherein

the first oscillation vector has a first oscillation frequency;

the step of periodically measuring a location of at least one point on the medical device comprises measuring the location of at least one point on the medical device a first sampling rate; and

wherein the first sampling rate is an integer multiple of the first oscillation frequency.

9. A robotic surgical system, comprising:

a medical device;

at least one servo mechanism coupled to the medical device such that the at least one servo mechanism can actuate the medical device;

a controller operable to energize the at least one servo mechanism to actuate the medical device to oscillate on a first axis;

a positional feedback system to periodically measure a location of at least one point on the medical device as the medical device oscillates on the first axis, thereby generating a first position signal for the medical device;

a processor to process the first position signal into a transfer function that relates inputs by the at least one servo mechanism to movements of the medical device.

10. The robotic surgical system according to claim 9, wherein the at least one servo mechanism comprises a translation servo mechanism and a deflection servo mechanism.

11. The robotic surgical system according to claim 10, wherein the at least one servo mechanism further comprises a rotation servo mechanism.

12. The robotic surgical system according to claim 9, wherein the first axis is selected from the group consisting of a translation axis, a rotation axis, a deflection axis, and any combinations thereof.

13. The robotic surgical system according to claim 9, wherein the positional feedback system defines one or more measurement axes, and wherein the transfer function comprises a calibration vector including at least one component directed along each of the one or more measurement axes.

14. The robotic surgical system according to claim 9, wherein the transfer function relates inputs by the at least one servo mechanism to movements of the medical device on one or more of a translation axis, a rotation axis, and a deflection axis.

15. A non-transitory computer readable medium having stored thereon computer executable instructions that, if executed by a computing device in communication with at least one servo mechanism, cause the computing device to perform a method comprising:

energizing the at least one servo mechanism to apply a first oscillation vector to a device coupled thereto;

while applying the first oscillation vector to the device, periodically measuring a location of at least one point on the medical device, thereby generating a first position signal for the device;

processing the first position signal to generate a first output signal, wherein the first output signal reflects movement of the device attributable to the application of the first oscillation vector to the device by the at least one servo mechanism; and

using the first output signal to generate a first transfer function that relates inputs to the at least one servo mechanism to resulting movements of the device.

16. The non-transitory computer readable medium according to claim 15, wherein the step of energizing the at least one servo mechanism to apply a first oscillation vector to a device coupled thereto comprises energizing the at least one servo mechanism to apply a first oscillation vector that oscillates the device on a single axis selected from the group consisting of a translation axis, a rotation axis, and a deflection axis.

17. The non-transitory computer readable medium according to claim 15, wherein the step of energizing the at least one servo mechanism to apply a first oscillation vector to a device coupled thereto comprises energizing the at least one servo mechanism to apply a first oscillation vector that oscillates the device on an axis that has components directed along two or more axes selected from the group consisting of a translation axis, a rotation axis, and a deflection axis.

18. The non-transitory computer readable medium according to claim 15, wherein the step of energizing the at least one servo mechanism to apply a first oscillation vector to a device coupled thereto comprises energizing one, and only one, servo mechanism to apply a first oscillation vector to the device coupled thereto.