DEVICE AND METHOD FOR MEASURING INTRACRANIAL PRESSURE

• US 3,669,094 A
• Filed: 07/06/1970
• Issued: 06/13/1972
• Est. Priority Date: 07/06/1970
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: William T. Heyer
• Inventors: Heyer, William T.
• Primary Examiner(s): Pace, Channing L.
• Application Number:
  US05/052,654
• Time in Patent Office: 708 Days
• Field of Search: 128/2,348,349B,349BV,350
• US Class Current: 600/561
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61M 2027/004 with at least a part of the circuit outside the body
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves

Abstract

A physiological drainage catheter and a method of using the same to provide a means for measuring intracranial pressure without substantially affecting the existing pressure by introduction of the measuring and drainage means.

Claims

1. A physiological drainage catheter for use in measuring fluid pressure in an enclosed body cavity, comprising an elongated drainage tube with a tip end, a central drainage passage extending along a central axis, a peripheral inner wall bounding said passage, a peripheral outer wall bounding said tube, an entry port passing througH the walls to the central passage, and a branch tube integrally formed with the drainage tube spaced from the entry port on the opposite side thereof from the tip end and having a branch passage therein in fluid communication with the drainage passage, said branch tube being adapted to be connected to a means for measuring pressure in said passages, said means terminating said branch passage, the outer surface of the tip and that portion of the outer wall which is intended to be inserted into the cavity enclosing a first volume which is substantially equal to a second volume defined by the entry port, branch passage, and the inner wall from the tip end to its junction with the branch passage, whereby the fluid which is displaced by insertion of the tube in the amount of the first volume can be received substantially totally in the region defined as the second volume, so that pressure in the cavity as measured in the branch passage will not have been changed substantially from the pressure in the cavity prior to insertion of the tube.

2. A physiological drainage catheter according to claim 1 in which the catheter is flexible.

3. In combination:

a physiological drainage catheter for use in measuring fluid pressure in an enclosed body cavity, comprising an elongated drainage tube with a tip, a central drainage passage extending along a central axis, a peripheral wall bounding said passage and having an inner diameter, a peripheral outer wall bounding said tube, an entry port passing through the walls to open into the drainage passage, and a branch tube integrally formed with the drainage tube and having a branch passage therein opening into the drainage passage at a point spaced from the entry port and on the opposite side thereof from the tip, and an insertion rod having an outer diameter substantially equal to the said inner diameter such that the rod is slidable therein, but makes a close fit with said peripheral wall so as to close said inlet port and said branch passage when opposed to their opening onto said peripheral wall, said branch tube being adapted to be connected to a means for measuring pressure in said passages, said means terminating said branch passage, the outer surface of the tip, and that portion of the outer wall which is intended to be inserted into the cavity enclosing a first volume which is substantially equal to a second volume defined by the entry port, branch passage, and the inner wall from the tip end to its junction with the branch passage, whereby the fluid which is displaced by insertion of the tube in the amount of the first volume can be received substantially totally in the region defined as the second volume, so that pressure in the cavity as measured in the branch passage will not have been changed substantially from the pressure in the cavity prior to insertion of the tube, whereby the catheter can be inserted into the body by means of an endwise axial force exerted on the tip by the rod, and the passages remain closed, and after the catheter is placed, the rod may be withdrawn to open and interconnect the inlet port and branch passage while closing the drainage passage on the side of the branch passage opposite from the tip so as to enable pressure in the cranium to be measured in the branch passage.

4. A combination according to claim 3 in which both tubes are flexible, whereby either may be pinched to shut off fluid flow therethrough.

5. A combination according to claim 4 in which the tubes are made of medical grade silicone rubber.

6. The method, utilizing a flexible drainage catheter having a tip, a peripheral inner wall defining a drainage passage extending along a central axis, a peripheral outer wall an inlet port passing through the walls and opening into said drainage passage, a branch tube integral with the drainage tube having a branch passage opening into the drainage passage through the peripheral wall at a location spaced from the entry port, and a rod making an axially sliding close fit with the peripheral wall so aS to close the inlet port and the branch passage when positioned contiguous to them, of inserting a physiological drainage catheter into an enclosed body cavity and measuring the fluid pressure in said cavity prior to draining the same, comprising the following steps in the order recited:

a. inserting the rod into the drainage passage so that it abuts the tip and is capable of exerting an endwise axial force thereon, b. inserting the catheter into a region to be drained by exerting said endwise axial force on the rod in order to press the tip through the body to a desired location in said cavity, c. leaving the catheter in place and withdrawing the rod until its end is on the side of the branch tube opposite from the tip, and d. measuring the fluid pressure in the branch tube.

7. A method according to claim 6 succeeded by the following additional step:

e. cutting the drainage tube between the branch tube and the tip and discarding the portion which is cut off.

8. The method according to claim 6, comprising admitting to the passages fluid in a volume substantially equal to the volume displaced by the outer boundary of that portion of the catheter which is inserted into the cavity.