EP0386218B1
Expired / Lapsed
EP
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Remote sensing tonometric catheter apparatus and method
Assignee: Instrumentarium Oyj
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Filing: 1989-08-24
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Granted: 1996-01-10
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Expires: 2009-08-24
Abstract
Abstract A remote sensing tonometric catheter apparatus (20) and method for sampling of a fluid or gas property of interest in a hollow internal organ. The tonometric catheter (20) assists in early detection of the problems of stress ulceration and/or intestinal ischemia. The tonometric catheter (20) has one or more sampling chambers (40) for introduction into a hollow internal organ or an area adjacent thereto. The tonometric catheter (20) has an electric sensor (42) for developing a signal indicative of the condition of the organ. Electric sensor (42) is in communication with the sampling chamber (40). The sensor (42) has a conductor (56) coupled therewith for conveying the signal to a location outside the organ such that the condition of the organ may be remotely determined. Preferably, the wall (36) of the sampling chamber (40) is freely permeable to the gas or fluid to be measured by the sensor (42), but is poorly permeable to other gases or fluids which may interfere with the sensor (42). The method is accomplished by introducing the catheter into the organ such that the sampling chamber is disposed at a portion of the wall of the organ. The sampling chamber is left in position at the wall of the organ for a time sufficient to allow the fluid or gas of interest to diffuse into the sampling chamber. The concentration of the fluid or gas of interest is analyzed. The pH of the wall of the organ may be calculated based on the concentration of the fluid or gas property of interest.
Inventors
- 👤 Richard G. Fiddian-Green
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 10:32
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/14542; A61B5/14539; A61B5/1455; A61B5/1459; A61B5/1468; A61B5/1473; A61B5/42; A61B5/4222; A61B5/4255; A61B5/68; A61B5/6846; A61B5/6847; A61B5/6852; A61B5/6853
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
405 words
A tonometric catheter apparatus (20) for remotely determining a fluid or gas property indicative of the condition of a hollow internal organ of a human or other mammal in vivo as defined by said fluid or gas property comprising: (a) an elongated tonometric catheter tube (22) having a lumen (68) extending longitudinally therethrough, said tube (22) being composed of a first elastomeric material that is substantially impermeable to one or more fluids or gases of interest, said fluids of interest including oxygen gases and carbon dioxide gases; (b) at least one walled sampling chamber (40) on said catheter tube (22) in fluid communication with the interior of said lumen (68), said walled sampling chamber (40) being defined by a balloon member generally surrounding a portion of said tube (22) and sealingly interconnected therewith, said balloon member being adapted to form an interior space between said balloon member and said catheter tube (22), the wall (36) of said balloon member being composed of a second material that is freely and selectively permeable to said one or more fluids or gases of interest, said second material being substantially impermeable to other fluids or gases, with said tube (22) extending to a position outside of the body of the human or other mammal, and with said lumen (68) providing fluid communication between said sampling chamber and the outside of the body of the human or other mammal; (c) sensor means (42) for sensing the level of at least one of said fluids or gases of interest present within said sampling chamber (40); characterised in that: said sensor means (42) is disposed within said sampling chamber (40); said apparatus further comprises calibration means for introducing a calibration fluid into said sampling chamber through said lumen in order to calibrate or recalibrate said sensor means; and a portion of said balloon member may be selectively positioned substantially adjacent to a wall portion of the internal organ in order to allow said one or more fluids or gases of interest from the tissue of the wall portion of the internal organ to permeate into said sampling chamber (40), the sensor means (42) being adapted to sense the level of at least one of the fluids or gases of interest from the tissue of the wall portion of the internal organ, and the calibration means being operable whilst said balloon member is substantially adjacent to the wall portion of the internal organ.
Claim 2
Dependent Claim
198 words
An apparatus (20) according to claim 1 for determining the pH of a hollow internal organ of a human or other mammal, characterised in that: said tube (22) is composed of a first elastomeric material that is substantially impermeable to a fluid or gas indicative of pH; said wall (36) of said balloon member is composed of a second material that is freely and selectively permeable to said fluid or gas indicative of pH; a non-temperature sensor (42) is disposed on said tonometric catheter tube (22) in communication with said sampling chamber (40) for introduction into said organ with said tonometric catheter, said sensor (42) comprising means responsive to a fluid or gas property indicative of pH and means for developing an electromagnetic signal indicative of said fluid or gas property; a means is provided responsive to said signal for generating a pH signal indicative of the pH of said organ; and said position of said balloon member substantially adjacent to said wall portion of said hollow internal organ is such to allow said fluid or gas indicative of pH from the tissue of the wall portion of the internal organ to permeate into said sampling chamber (40).
Claim 3
Dependent Claim
263 words
An apparatus (20) according to claim 1 for determining the condition of a hollow internal organ of a human or other mammal as defined by the fluid pressure and the blood pH indicative of the condition of the hollow internal organ, characterised in that: said tube (22) is composed of a first elastomeric material that is substantially impermeable to a fluid or gas indicative of the fluid pressure of the hollow internal organ; said wall (36) of said balloon member is composed of a second material that is freely and selectively permeable to said fluid or gas indicative of the fluid pressure of the hollow internal organ; a non-temperature sensor (42) is disposed on said tonometric catheter tube (22) in communication with said sampling chamber (40) for developing a first electromagnetic signal indicative of said fluid pressure condition of said hollow internal organ; a means (174) is provided for developing a second electromagnetic signal indicative of said blood pH of said hollow internal organ; a means (170,176,172) is provided receptive of said first and second signals for generating a third signal indicative of the condition of said hollow internal organ; a means (178) is provided responsive to said third signal and located outside said organ for reporting said condition of said hollow internal organ; and said position of said balloon member substantially adjacent to a wall portion of said hollow internal organ is such to allow said fluid or gas indicative of the fluid pressure from the tissue of the wall portion of the internal organ to permeate into said sampling chamber (40).
Claim 4
Dependent Claim
28 words
An apparatus according to claim 1 or claim 2 or claim 3, characterised in that it additionally comprises a temperature sensor in communication with said sampling chamber (40).
Claim 5
Dependent Claim
24 words
An apparatus according to claim 1 or claim 2 or claim 3, characterised in that said sensor (42) comprises a chemically sensitive electronic transducer.
Claim 6
Dependent Claim
26 words
An apparatus according to claim 1 or claim 2 or claim 3, characterised in that said sensor (42) comprises a chemically sensitive field effect transistor transducer.
Claim 7
Dependent Claim
28 words
An apparatus according to claim 2, characterised in that said electromagnetic signal is an electrical signal conveyed by wire (56) to said means for generating a pH signal.
Claim 8
Dependent Claim
30 words
An apparatus according to claim 3, characterised in that said first electromagnetic signal is an electrical signal conveyed by wire (56) to said means (172) for generating said third signal.
Claim 9
Dependent Claim
27 words
An apparatus according to claim 3, characterised in that said means (178) for reporting said condition includes analog circuit means for producing a report of said condition.
Claim 10
Dependent Claim
27 words
An apparatus according to claim 3, characterised in that said means (178) for reporting said condition includes digital circuit means for producing a report of said condition.
Claim 11
Dependent Claim
31 words
An apparatus according to claim 3, characterised in that said tonometric catheter (20) additionally comprises a second electronic sensor for determining the temperature of the sampling area adjacent said first sensor.
Claim 12
Dependent Claim
18 words
An apparatus according to claim 3, characterised in that the fluid or gas property of interest is pCO₂.
Claim 13
Dependent Claim
18 words
An apparatus according to claim 3, characterised in that the fluid or gas property of interest is pO₂.
Claim 14
Independent Claim
21 words
An apparatus according to any preceding claim characterised in that at least a portion of the tonometric catheter (20) comprises α-hydro-Ω-hydroxypoly-(oxytetramethylene).
References Cited (Backward Citations)
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