Magnetoelectric Surgical Tools for Minimally Invasive Surgery

• US 20110077663A1
• Filed: 09/24/2010
• Published: 03/31/2011
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: Virginia Commonwealth University
• Original Assignee: Virginia Commonwealth University
• Inventors: Clarke, Joshua, Atulasimha, Jayasimha, Sundaresan, Vishnu-Baba
• Granted Patent: US 8,602,034 B2
• Time in Patent Office: Days
• US Class Current: 606/130
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 2017/00402 Piezo electric actuators
• CPC Class Codes: A61B 2017/00411 actuated by application of energy from an energy source outside the body
• CPC Class Codes: A61B 2017/320791 with cutter extending outside the cutting window
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• CPC Class Codes: A61B 2034/2059 Mechanical position encoders
• CPC Class Codes: A61B 2034/2061 using shape-sensors, e.g. fiber shape sensors with Bragg gratings
• CPC Class Codes: A61B 2034/732 arranged around the patient, e.g. in a gantry
• CPC Class Codes: A61B 34/35 for telesurgery
• 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 34/76 Manipulators having means for providing feel, e.g. force or tactile feedback

Abstract

A magnetoelectric element of a surgical tool positioned in the body of a subject is controllably bent or elongated under the influence of an applied magnetic field. A piezoelectric layer in the magnetoelectric element provides output that can be used to determine the actual amount of bending or elongation of the magnetoelectric element, and this actual amount is compared to a theoretical amount of bending or elongation which would result from the applied magnetic field. Any differences between the actual and theoretical amounts provide feedback to the surgeon for performing the surgical procedure. Preferably, tactile feedback is provided to the surgeon.

Claims

1. A surgical tool, comprising:

a magnetoelectric member including at least one piezoelectric layer and at least one magnetostrictive layer, wherein said magnetoelectric member is insertable into a subject and is operable inside said subject to one or more of bend or elongate based on an applied magnetic field applied externally to said subject;

a controller which determines any difference between an actual position of said magnetoelectric member based on electrical output from said at least one piezoelectric layer and a theoretical position of said magnetoelectric member based on said applied magnetic field; and

a feedback member which provides feedback based on an amount of any difference determined by said controller.

2. The surgical tool of claim 1 further comprising a magnetized stabilizer connected to said magnetoelectric member which stabilizes said magnetoelectric member in said applied magnetic field.

3. The surgical tool of claim 1 wherein said feedback member includes a display for displaying one or more of an image, graph, or table which provides an indication of any difference determined by said controller.

4. The surgical tool of claim 1 wherein said feedback member provides tactile feedback based on any difference determined by said controller.

5. The surgical tool of claim 1, wherein said at least one magnetostrictive layer is selected from the group consisting of Galfenol (Iron Gallium), Terfenol-D (Terbium Dysprosium Iron), Cobalt Ferrite, Nickel Ferrite, Lithium Ferrite, Yttrium Iron Garnet, Copper Ferrite, Manganese Ferrite, LaCaMnO₃, LaSrMnO₃, SmFe₂, TbFe₂, Permendur (Iron Cobalt Vanadium), Ni2MnGa, Nickel, and Metglas.

6. The surgical tool of claim 1, wherein said at least one piezoelectric layer is selected from the group consisting of Lead Zirconate Titanate, Lead Magnesium Niobate-Lead Titanate, Polyvinylidine Fluoride, and Lead Zirconium Niobate-Lead Titanate. 10

7. A system for surgical operations, comprising:

a magnetic field generating device for generating an applied magnetic field external to a subject, where at least a portion of said applied magnetic field permeates said subject; and

a surgical tool comprising

a magnetoelectric member including at least one piezoelectric layer and at least one magnetostrictive layer, wherein said magnetoelectric member is insertable into said subject and is operable inside said subject to one or more of bend or elongate based on said applied magnetic field;

a controller which determines any difference between an actual position of said magnetoelectric member based on electrical output from said at least one piezoelectric layer and a theoretical position of said magnetoelectric member based on said applied magnetic field; and

a feedback member which provides feedback based on an amount of any difference determined by said controller.

8. The system of claim 7 wherein said feedback member includes a display for displaying one or more of an image, graph, or table which provides an indication of any difference determined by said controller.

9. The system of claim 7 wherein said feedback member provides tactile feedback based on any difference determined by said controller.

10. The system of claim 7 wherein said magnetic field generating device includes at least one electromagnet.

11. A surgical method, comprising the steps of:

inserting into a subject a surgical tool which includes at least one magnetoelectric member, wherein said at least one magnetoelectric member comprises at least one piezoelectric layer and at least one magnetostrictive layer;

applying a magnetic field to said subject sufficient to cause said magnetoelectric member to operate by one or more of bending or elongating based on said magnetic field;

sensing the bending or elongating of said magnetoelectric element based on output from said at least one magnetostrictive layer;

determining a difference between an actual position of said magnetoelectric member based on electrical output from said at least one piezoelectric layer and a theoretical position of said magnetoelectric member based on said applied magnetic field; and

providing feedback to a surgeon based on an amount of any difference determined in said determining step.

12. The method of claim 11 further comprising the step of using said feedback to adjust, change, or stop operation of said magnetoelectric member.

13. The method of claim 11 wherein said feedback includes tactile feedback.

14. The method of claim 11 wherein said feedback includes providing a visual display of an image, table or graph.

15. The method of claim 11 wherein said step of applying a magnetic field includes changing said magnetic field based on said feedback.

16. A method of operating the system for surgical operations, wherein said system for surgical operations comprises a magnetoelectric member including at least one piezoelectric layer and at least one magnetostrictive layer, wherein said magnetoelectric member is insertable into a subject and is maneuverable inside said subject under the influence of a magnetic field applied externally to said subject;

a magnetic field generating device for generating a magnetic field external to said subject;

a controller which determines any difference between an actual position of said magnetoelectric member based on electrical output from said at least one piezoelectric layer and theoretical position of said magnetoelectric member based on said applied magnetic field; and

a feedback member which provides feedback based on an amount of any difference determined by said controller, comprising steps of;

a) allowing said magnetoelectric member to controllably bend in the transverse direction and expand along its axial direction;

b) applying said magnetic field via said magnetic field generating device to induce strain in at least one magnetostrictive layer thereby straining at least one piezoelectric layer and causing at least one piezoelectric layer to generate electrical output;

c) using electrical output from at least one piezoelectric layer to obtain real-time values of physical parameters; and

d) Using the obtained values of physical parameters to produce feedback for the user via said feedback member.

17. The method of operating the system for surgical operations of claim 16, wherein the physical parameters include velocity, tip displacement, and mechanical work performed by the magnetoelectric member.

18. The method of operating the system for surgical operations of claim 16, wherein the magnetoelectric member is only allowed to bend in the transverse direction.

19. The method of operating the system for surgical operations of claim 16, wherein the magnetoelectric member is only allowed to expand along its axial direction.

20. The method of operating the system for surgical operations of claim 16, wherein the obtained values of physical parameters are compared with predicted values and the resulting deviation from the predicted values and obtained values is used to generate a resistive force on the remotely controlled tool operated by the surgeon.

21. The method of operating the system for surgical operations of claim 16, wherein a computer manipulates the magnetoelectric member upon receiving electrical output from at least one piezoelectric layer.

22. The method of operating the system for surgical operations of claim 16, wherein TCP/IP implementation is used to remotely manipulate the magnetoelectric member.

23. The method of operating the system for surgical operations of claim 16, wherein electrical output from at least one piezoelectric layer is recorded in the controller and processed to adjust the strength of the magnetic field and apply an electric field to at least one piezoelectric layer to precisely position the magnetoelectric member.