Pressure-sensing catheter system with compensation for atmospheric and configuration variations
OwnerAlbert E. Brooksinventor
Life of this patent
Estimating the term…
Abstract
A catheter incorporates a pair of flexible conduits which are structurally united over a major portion of their length where bending is likely to occur during use so they both undergo the same deformations. Each conduit contains an aqueous column that terminates at a meniscus. The meniscus interfaces directly with a column of a different liquid which is insoluble in and immiscible with the liquid in the aqueous column. One of the conduits is a pressure responsive conduit and the other is a stagnant conduit.
Claims9
A catheter for measuring pressures in internal regions, said catheter comprising a first stagnant conduit and a second pressure-responsive conduit, both of said conduits having a boundary wall, are flexible and have a lumen, said lumens having a proximal end and a distal end, said tubes being coextensive, parallel, united together, and having substantially identical cross-sections for a major portion of their length, a port through said boundary wall of said pressure responsive conduit into its respective lumen, a flexible impermeable membrane covering said port and transferring the pressure outside of the cathether to said port and thereby to its respective said lumen, the distal end of the lumen of said stagnant conduit being closed, an aqueous liquid column in both of said lumens extending from their distal ends, and an immiscible liquid column contiguous with each of said aqueous columns forming a meniscus interface therewith;
- and gas bias means communicable with said immiscible liquid columns at said proximal end of said lumens, whereby the location of said meniscuses and the relative location of both meniscuses provide an indication of the pressure in said region independent of bending distortions of the cathether.
In combination:
- a catheter for measuring pressures in internal regions, said catheter comprising a first stagnant conduit and a second pressure responsive conduit, both of said conduits having a boundary wall, are flexible and have a lumen, said lumens having a proximal end and a distal end, said tubes being coextensive, parallel, united together, and having substantially identical cross-sections for a major portion of their length, a port through said boundary wall of said pressure responsive conduit into its respective lumen, a flexible impermeable membrane covering said port and transferring the pressure outside of the catheter to said port and thereby to its respective said lumen, the distal end of the lumen of said stagnant conduit being closed, an aqueous liquid column in both of said lumens extending from their distal ends, and an immiscible liquid column contiguous with each of said aqueous columns forming a meniscus interface therewith;
- and gas bias means communicable with said immiscible liquid columns at said proximal end of said lumens, whereby the location of one of said meniscuses and the relative location of both meniscuses provide an indication of the pressure in said region independent of bending distortions of the catheter;
- sensor means for sensing the location of each meniscus;
- and
- means to determine the observed pressure as a function of the location of the meniscus in the pressure responsive conduit and of the difference in locations of the two meniscuses.
Dependencies are inferred from the claim text.