Systems and methods of pH tissue monitoring

• US 6,600,941 B1
• Filed: 05/26/2000
• Issued: 07/29/2003
• Est. Priority Date: 05/28/1999
• Status: Expired due to Fees

• Current Assignee: Boston VA Research Institute
• Original Assignee: E-Monitors, Inc.
• Inventors: Khuri, Shukri F.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/580,809
• Time in Patent Office: 1,159 Days
• Field of Search: 600/345-350, 600/18, 607/17-23, 607/65-67
• US Class Current: 600/345
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/413 Monitoring transplanted tissue or organ, e.g. for possible rejection reactions after a transplant
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61M 1/3613 Reperfusion, e.g. of the coronary vessels, e.g. retroperfusion
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3664 for preparing cardioplegia solutions

Abstract

The invention relates to the use of pH measurements of tissue as a system for controlling diagnostic and/or surgical procedures. The invention also relates to an apparatus used to perform tissue pH measurements. Real time tissue pH measurements can be used as a method to determine ischemic segments of the tissue and provide the user with courses of conduct during and after a surgical procedure. When ischemia is found to be present in a tissue, a user can effect an optimal delivery of preservation fluids to the site of interest and/or effect a change in the conduct of the procedure to raise the pH of the site.

Claims

1. A tissue monitoring system comprising:

a pH electrode for insertion into tissue at a site; and

a fluid delivery system having a manifold connected to a fluid source to control fluid flow to a plurality of sites and having a valve, the system including a probe to be inserted at least at one of the plurality of sites.

2. The system of claim 1 wherein the pH electrode is adapted to contact tissue of a patient such that pH data of the tissue is monitored to determine if tissue pH deviates from a threshold level indicative of ischemia.

3. The system of claim 1 further comprising a data processor and a controller that is connected to the fluid delivery system.

4. The system of claim 3 wherein the controller controls the flow rate of a preservation solution delivered to a surgical site.

5. The system of claim 3 wherein the controller controls temperature of a preservation solution.

6. The system of claim 3 wherein the controller controls a site of delivery of a preservation solution.

7. The system of claim 1 further comprising a catheter which delivers the fluid.

8. The system of claim 1 further comprising a temperature sensor that measures temperature of the tissue.

9. The system of claim 1 wherein the delivery system applies coronary artery pressure on a proximal portion of an artery.

10. The system of claim 1 further comprising a balloon catheter.

11. The system of claim 1 further comprising a balloon of a retrograde coronary sinus catheter.

12. The system of claim 1 wherein the pH electrode is positioned relative to cardiac tissue of a patient with a percutaneous catheter.

13. The system of claim 1 wherein the pH electrode is delivered to a tissue site of a patient using a laparoscope.

14. The system of claim 1 wherein the pH electrode is positioned using an endoscope.

15. A tissue monitoring system comprising:

a pH electrode for insertion into tissue at a site;

a temperature sensor that measures temperature of the tissue;

a processor that determines tissue pH in response to a pH electrode measurement and a temperature measurement; and

a fluid delivery system having a manifold connected to a fluid source to control fluid delivery to a plurality of sites and having a probe to be inserted into at least one site.

16. The system of claim 15 wherein the pH electrode is adapted to contact tissue of a patient such that pH data of the tissue is monitored to determine if tissue pH deviates from a threshold level indicative of ischemia.

17. The system of claim 15 further comprising a controller that is connected to the fluid delivery system.

18. The system of claim 17 wherein the controller controls the flow rate of a preservation solution delivered to a surgical site.

19. The system of claim 17 wherein the controller controls temperature of a preservation solution..

20. The system of claim 17 wherein the controller controls a site of delivery of a preservation solution.

21. The system of claim 15 further comprising a catheter which delivers the fluid.

22. The system of claim 15 the delivery system applies coronary artery pressure on a proximal portion of an artery.

23. The system of claim 15 further comprising a balloon catheter.

24. The system of claim 15 further comprising a balloon of a retrograde coronary sinus catheter.

25. The system of claim 15 wherein the pH electrode is positioned relative to cardiac tissue of a patient with a percutaneous catheter.

26. The system of claim 15 wherein the pH electrode is delivered to a tissue site of a patient using a laparoscope.

27. The system of claim 15 wherein the pH electrode is positioned using an endoscope.