← Back to Patent Explorer
US4741345A Expired / Lapsed US ⏱️ 0.0 years remaining

Continuous flow tissue pressure measurement

Assignee: University of Michigan (System)
•
Filing: 1986-08-04
•
Granted: 1988-05-03
•
Expires: 2006-08-04
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract This invention provides a means of measuring tissue pressure in muscle compartments and other regions in humans and other animals. An appropriate length, for example, 6 to 12 inches of thin plastic tubing, typically less than 3 mm outside diameters, is prepared as a working part of the tissue pressure transducer. A portion of the plastic tubing including the thin wall section such as a bubble is inserted into the muscle tissue for which pressure measurement is desired to be made. A fluid is circulated through the tubing at a constant flow rate. When the internal pressure of the tubing is greater than the external pressure, the bubble expands and there is no increase in the flow resistance of the system. When the pressure on the outside exceeds the normal system operating pressure, the thin wall section or bubble contacts, resistance to flow increases, and the system pressure increases. This increase in system pressure is directly proportional to tissue pressure.

Inventors

  • 👤 Larry S. Matthews
  • 👤 Steven A. Goldstein

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 03:19
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/03

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 82 words
A catheter for use in measuring pressure in animal tissue which comprises a single long tubular member having only one lumen throughout and having a section having a wall more flexible than the rest: said long tubular member forms a U-shaped single flow channel open at each end and through which fluid may flow continuously, and said more flexible section is a part of said U-shaped flow channel and is near the bend of said U-shaped flow channel and is a bubble.
Claim 2
Dependent Claim 82 words
A catheter for use in measuring pressure in animal tissue which comprises a single long tubular member having only one lumen throughout and having a section having a wall more flexible than the rest: said long tubular member forms a U-shaped single flow channel open at each end and through which fluid may flow continuously, and said more flexible section is a part of said U-shaped flow channel and is near the bend of said U-shaped flow channel and is a bubble.
Claim 3
Dependent Claim 26 words
A catheter as defined in claim 1 in which said long tubular member has a non-perforated wall and such wall is impervious to animal tissue fluid.

References Cited (Backward Citations)

US2103371A Cited
US3483859A Cited
US4205691A Cited
US4214593A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-05-03 1991-11-02 1992-05-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-05-03 1995-11-02 1996-05-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-05-03 1999-11-02 2000-05-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag