Tissue discrimination and applications in medical procedures

• US 20060224078A1
• Filed: 05/23/2006
• Published: 10/05/2006
• Est. Priority Date: 05/18/2000
• Status: Abandoned Application

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Foley, Kevin, Hoey, Michael, Stone, Corbett
• Application Number:
  US11/439,780
• Publication Number:
  US 20060224078A1
• Time in Patent Office: Days
• US Class Current: 600/546
• CPC Class Codes: A61B 17/7001 Screws or hooks combined with longitudinal elements which do not contact vertebrae A61B17/7058 takes precedence
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/4893 Nerves

Abstract

A system and method for discriminating tissue types, controlling the level of therapy to tissue, and determining the health or a known tissue by measuring the characteristics an electrical signal applied to conductive element located within or by the tissue. Additionally, the system and method may be used for determining whether the conductive tip of a pedicle probe or pedicle screw is located in one of cortical bone, cancellous bone, and cortical bone near a boundary with soft tissue, whether the conductive tip of a cannula is located adjacent to one of nerve tissue and annulus tissue, and whether the conductive tip of a cathode is located adjacent to one of nerve tissue and prostate gland tissue.

Claims

1. A system for determining pedicle integrity during spine surgery, comprising:

a controller for generating an electrical signal to be applied to tissue and for measuring the impedance of tissue to which the electrical signal is applied so as to determine pedicle integrity during spine surgery;

a probe having bi-polar electrodes configured to deliver said electrical signal generated by said controller to a portion of a pedicle during spine surgery; and

an output element in electrical communication with said controller adapted to convey information to a user regarding pedicle integrity based on the pedicle integrity determination by said controller.

2. The system of claim 1, wherein said electrical signal is generated by said controller in a digital form and converted to analog form prior to delivery by said probe.

3. The system of claim 2, further comprising a digital-to-analog converter adapted to convert said electrical signal generated by said controller from a digital form to an analog form.

4. The system of claim 1, wherein said probe is equipped with more than one pair of bi-polar electrodes.

5. The system of claim 1, wherein said controller is configured to determine pedicle integrity by monitoring the impedance of the tissue surrounding at least a portion of the probe to determine whether the probe is located in at least one of cortical bone of said pedicle, cancellous bone of said pedicle, and cortical bone near the boundary with soft tissue of said pedicle.

6. The system of claim 1, wherein said electrical signal has at least one of a fixed frequency and a sliding frequency.

7. A method for determining pedicle integrity during spine surgery, comprising the steps of:

(a) advancing a probe having bi-polar electrodes into a portion of a pedicle during spine surgery while delivering an electrical signal to said bi-polar electrodes of said probe; and

(b) measuring the impedance of the tissue adjacent to said probe during step (a) to determine pedicle integrity during spine surgery.

8. The method of claim 7, further comprising the step (c) of communicating to a user feedback regarding pedicle integrity determined in step (b).

9. The method of claim 7, wherein the delivery of said electrical signal and the measuring of tissue impedance is performed by a controller in electrical communication with said probe.

10. The method of claim 8, wherein the communication of feedback regarding pedicle integrity is performed by an output element.

11. An article of manufacture for use in determining pedicle integrity during spine surgery, the article of manufacture comprising a probe having bi-polar electrodes, said probe configured to allow a user to perform the steps:

(a) advancing said probe into a portion of a pedicle during spine surgery while delivering an electrical signal to said bi-polar electrodes of said probe; and

(b) measuring the impedance of the tissue adjacent to said probe during step (a) to determine pedicle integrity during spine surgery.

12. The article of manufacture of claim 11, wherein said probe is further configured to allow said user to perform the step (c) of examining feedback communicated to said user regarding pedicle integrity determined in step (b).

13. The method of claim 11, wherein the delivery of said electrical signal and the measuring of tissue impedance is performed by a controller in electrical communication with said probe.

14. The method of claim 12, wherein the communication of feedback regarding pedicle integrity is performed by an output element.