Sensors for detecting substances indicative of stroke, ischemia, infection or inflammation

• US 8,133,698 B2
• Filed: 01/16/2008
• Issued: 03/13/2012
• Est. Priority Date: 05/15/2000
• Status: Active Grant

• Current Assignee: James H. Silver
• Original Assignee: James H. Silver
• Inventors: Silver, James H.
• Primary Examiner(s): Foley, Shanon A
• Application Number:
  US12/015,347
• Publication Number:
  US 20080176271A1
• Time in Patent Office: 1,518 Days
• Field of Search: None
• US Class Current: 435/29
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/14528 invasively
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14557 specially adapted to extracorporeal circuits
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/4076 Diagnosing or monitoring particular conditions of the nervous system A61B5/4821, A61B5/4824 take precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/413 Monitoring transplanted tissue or organ, e.g. for possible rejection reactions after a transplant
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6862 Stents
• CPC Class Codes: A61B 5/6876 Blood vessel
• CPC Class Codes: A61B 5/6882 : Anchoring means
• CPC Class Codes: A61F 2/82 : Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2250/0001 : Means for transferring electromagnetic energy to implants
• CPC Class Codes: G01N 33/84 : involving inorganic compounds or pH
• CPC Class Codes: Y10T 436/177692 : Oxides of nitrogen

Abstract

A system is disclosed that extracts bodily fluid to a reaction chamber for monitoring a substance or property of the patient fluid. In one embodiment, a pump is used to advance the sample of bodily fluid through a filter to produce a filtrate. Another pump advances filtrate into the reaction chamber, while another pump advances reactant into the reaction chamber. A sensor in communication with the reaction chamber determines a concentration of nitric oxide or one of its metabolic products. Methods are also disclosed.

Claims

1. A method of measuring a level of one or more metabolic products of nitric oxide in bodily fluid, comprising the steps of:

directing a stream of bodily fluid through a filter to produce a filtrate;

directing the filtrate into a reaction chamber;

providing a reactant;

directing the reactant into the reaction chamber to react with the filtrate to produce a reaction product; and

measuring a concentration of one or more metabolic products of nitric oxide in the reaction product.

2. A method of claim 1, wherein the directing a stream of bodily fluid step is accomplished using a first pump.

3. A method of claim 1, wherein the directing the reactant step is accomplished using a second pump.

4. A method of claim 1, wherein the directing the filtrate step is accomplished using a third pump.

5. The method of claim 1, wherein the bodily fluid is blood.

6. The method of claim 1, wherein the bodily fluid is interstitial fluid.

7. The method of claim 1, wherein the bodily fluid is cerebrospinal fluid.

8. The method of claim 1, wherein the providing step further includes mixing an acid and iodide to produce the reactant.

9. The method of claim 1, wherein the reactant comprises Cr₂O₃.