SURGICAL ORIENTATION DEVICE AND METHOD

• US 20090318836A1
• Filed: 02/11/2009
• Published: 12/24/2009
• Est. Priority Date: 06/09/2003
• Status: Abandoned Application

• Current Assignee: Orthalign, Inc.
• Original Assignee: Orthalign, Inc.
• Inventors: Russial, Joseph F., Stone, A. Curt
• Application Number:
  US12/369,693
• Publication Number:
  US 20090318836A1
• Time in Patent Office: Days
• US Class Current: 600/595
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61B 17/1778 for the shoulder
• CPC Class Codes: A61B 2017/00115 with audible or visual output with imaging means A61B90/37, A61B34/20
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• 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 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/4609 of acetabular cups
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/4632 using computer-controlled surgery, e.g. robotic surgery
• CPC Class Codes: A61F 2002/4668 for measuring angles
• CPC Class Codes: A61F 2002/4687 Mechanical guides for implantation instruments
• CPC Class Codes: A61F 2250/0006 for adjusting angular orientation

Abstract

A device for detecting and measuring a change in angular position with respect to a reference plane is useful in surgical procedures for orienting various instruments, prosthesis, and implants with respect to anatomical landmarks. One embodiment of the device uses three orthogonal rate sensors, along with integrators and averagers, to determine angular position changes using rate of change information. A display provides position changes from a reference position. Various alignment guides are useful with surgical instruments to obtain a reference plane.

Claims

1. A method of determining angular position change comprising:

a. sensing the presence or absence of motion of a rate sensor;

b. sensing a rate of change of angular position with respect to a reference using the rate sensor to provide an output that is a rate signal proportional to the rate of change of angular position of the rate sensor;

c. averaging the output of the rate sensor in the absence of motion of the rate sensor to provide an average signal representative of the output of the rate sensor in the absence of motion of the rate sensor;

d. integrating the rate signal when motion is sensed to provide an integral signal indicative of a relative angular position experienced by the rate sensor; and

e. presenting the difference between the integral signal and the average signal as indicative of the change of position of the rate sensor.

2. The method of claim 1 wherein the integral signal is zeroed before step d.

3. The method of claim 2 wherein the difference is presented as an absolute position change occurring after zeroing the integral signal.

4. The method of claim 1 wherein step e. further comprises presenting the difference in a visually perceptible format.

5. The method of claim 1 wherein step e. further comprises presenting the difference in an electronic format.

6. The method of claim 1 further comprising an additional step:

a0. automatically zeroing the integral signal upon initial startup.

7. The method of claim 1 further comprising an additional step:

f. continuing to integrate the rate signal for a predetermined period of time after motion stops.

8. The method of claim 1 further comprising an additional step:

b1. detecting the presence of motion by determining when there is more than a predetermined difference between the output of the rate sensor and the average signal.

9. The method of claim 8 wherein step b1 further comprises detecting the absence of motion by determining when there is less than the predetermined difference between the output of the rate sensor and the average signal.

10. The method of claim 1 further comprising the additional step of:

g. detecting an error condition when the integral signal exceeds a predetermined maximum value.

11. The method of claim 1 wherein step a. includes providing an indication of the direction of motion detected.

12. The method of claim 1 wherein step d. includes providing an indication of the direction of motion detected.

13. The method of claim 1 wherein each of the steps are performed for each of three mutually orthogonal dimensions.