Method and Apparatus for Monitoring Surgical Traction

• US 20130072822A1
• Filed: 09/19/2011
• Published: 03/21/2013
• Est. Priority Date: 09/19/2011
• Status: Active Grant

• Current Assignee: Trimanus Medical, Inc.
• Original Assignee: Trimanus Medical, Inc.
• Inventors: Leckenby, Stephen Lewis, Browne, Gregory Vincent, Auchinleck, Geoffrey, Cameron, Kyle
• Granted Patent: US 8,986,228 B2
• Time in Patent Office: Days
• US Class Current: 600/595
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 5/0048 Detecting, measuring or recording by applying mechanical forces or stimuli A61B5/021, A61B5/4884 and A61B9/00 take precedence
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/704 Tables
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for

Abstract

Apparatus is described for measuring and displaying the magnitude of traction forces applied to a patient'"'"'s lower limbs during surgery, and for measuring the direction and magnitude of counter-traction forces applied to the patient'"'"'s body by the perineal post located at the patient'"'"'s groin to oppose traction forces applied to the patient'"'"'s lower limbs.

Claims

1. A method for indicating the force applied to a patient'"'"'s body while undergoing surgical traction, comprising the steps of:

a) applying traction to one or both of the patient'"'"'s legs;

b) providing a post between the patient'"'"'s legs in the vicinity of the groin to resist the traction force applied to the patient'"'"'s leg or legs;

c) measuring the force applied to said post by said surgical traction;

d) calculating the direction of the force applied to said post by said surgical traction; and

e) displaying the direction of said force.

2. The method according to claim 1 wherein step c) further comprises the step of measuring a bending moment applied to said post around a first axis substantially perpendicular to a longitudinal axis through said post.

3. The method according to claim 2 including the step of measuring a bending moment applied to said post around a second axis substantially perpendicular to said longitudinal axis.

4. The method according to claim 3 wherein the first axis is substantially perpendicular to the second axis.

5. The method according to claim 4 wherein step d) further comprises calculating a vector sum of said first and second bending moments.

6. The method according to claim 5 wherein said first and second axes are in a predetermined orientation relative to the patient'"'"'s anatomy and including the step of displaying the direction of the vector sum in relation to the patient'"'"'s anatomy.

7. The method according to claim 6 including the step of quantifying the magnitude of force applied to one or both legs.

8. The method according to claim 7 including displaying the magnitude of traction force applied to one or both legs.

9. The method according to claim 5 including the step of recording the magnitude and direction of the vector sum at regular intervals.

10. Apparatus for measuring and indicating the magnitude and direction of a traction force applied to the patient'"'"'s lower limb during surgery, comprising:

a perineal post having longitudinal axis and a first measuring element providing a first signal generated by a first bending moment in the post around a first axis substantially perpendicular to the longitudinal axis, and a second measuring element providing a second signal generated by a second bending moment in the post around a second axis substantially perpendicular to the longitudinal axis and substantially perpendicular to the first axis;

a load cell to measure the magnitude of a traction force applied to the patient and generate a signal correlating to said magnitude of traction force,

a controller configured for receiving said first and second signals from said first and second measuring elements, and for receiving the signal from said load cell, and for calculating the vector sum of said first and second bending moments; and

a display configured for displaying the vector sum.

11. Apparatus according to claim 10 wherein the display is further configured for displaying the magnitude of traction force.

12. Apparatus according to claim 10 wherein the controller includes a recorder for recording the vector sum and magnitude of force.

13. Apparatus according to claim 10 wherein the first and second axes are aligned in a predetermined relation to a mid-line through the patient'"'"'s body when the perineal post is located between the patient'"'"'s legs.

14. Apparatus according to claim 10 wherein the first and second signals are proportional to the first and second bending moments, respectively.

15. Apparatus for measuring and indicating the magnitude and direction of a traction force applied to the patient'"'"'s lower limb during surgery, wherein the patient is on a surgical table having a perineal post positioned in the patient'"'"'s groin area and a traction-applying apparatus is attached to one or both of the patient'"'"'s limbs, comprising:

means for measuring the direction of a traction force applied to the patient'"'"'s limb;

means for measuring the magnitude of the traction force applied to the patient'"'"'s limb; and

means for displaying the direction and magnitude of the traction force.

16. The apparatus of claim 15 wherein the means for measuring the direction of the traction force includes means for measuring first and second bending moments around the perineal post.

17. The apparatus of claim 16 wherein the means for measuring the first bending moment comprises a first pair of strain gages in the perineal post, and the means for measuring the second bending moment comprises a second pair of strain gages in the perineal post.

18. The apparatus according to claim 17 wherein the each strain gage in the first pair of strain gages is oriented on an opposite side of said perineal post to define a first axis therebetween.

19. The apparatus according to claim 18 wherein each strain in the second pair of strain gages is oriented on an opposite side said perineal post to define a second axis therebetween, the second axis substantially perpendicular to the first axis.

20. The apparatus according to claim 15 wherein the means for measuring the magnitude of a traction force applied to the patient is defined by a load cell interposed in the traction-applying apparatus.