US5997818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cassette for tonometric calibration
Assignee: Terumo Cardiovascular Systems Corp
•
Filing: 1997-02-27
•
Granted: 1999-12-07
•
Expires: 2017-02-27
Abstract
Abstract A cassette for tonometric calibration especially useful for systems that measure one or more blood parameters includes a cassette having an elongated fluid chamber. In one embodiment of the invention, the fluid chamber includes an expansion region that reduces the likelihood of bubble coalescence of the calibration gas. In another embodiment, inner wall sections of the chamber are provided with a hydrophilic surface. Optionally, a fitting is non-releasably coupled to a casing of the cassette and is movable between a first position for closing a calibration gas outlet port and a second position for venting the calibration gas outlet port. In another embodiment, the cassette includes an elongated sparging tube that extends in a direction generally parallel to the longitudinal axis of the chamber.
Inventors
- 👤 Thomas G. Hacker
- 👤 David J. Franta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:44
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/14551; A61B5/14557; G; G01; G01N; G01N21/00; G01N21/01; G01N21/03; G01N21/05
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
226 words
A cassette for tonometric calibration comprising: a casing having a chamber for receiving a quantity of calibration liquid, said chamber having a longitudinal axis extending in an upright direction, said chamber including a lower portion having a gas inlet port for connection to a source of calibration gas, an upper portion having a gas outlet port and a middle portion located between said lower portion and said upper portion; a gas filter assembly connected to said gas inlet port below said chamber for retaining liquid in said chamber for pretending liquid from leaking from solid chamber and for filtering calibration gas entering said chamber through said gas inlet port, wherein the calibration gas mixes with the calibration liquid in said lower section and said middle portion of said chamber; and at least one sensor connected to said casing adjacent said middle portion of said chamber for sensing the partial pressure of gas in said chamber, said chamber including an expansion region located between said middle portion and said upper portion, said expansion region having an area larger than the area of said middle portion in reference planes perpendicular to said longitudinal axis for facilitating the rupture of gas bubbles passing through the liquid, and wherein said middle portion includes wall sections having a hydrophilic surface for facilitating the passage of gas bubbles past said wall sections.
Claim 2
Dependent Claim
226 words
A cassette for tonometric calibration comprising: a casing having a chamber for receiving a quantity of calibration liquid, said chamber having a longitudinal axis extending in an upright direction, said chamber including a lower portion having a gas inlet port for connection to a source of calibration gas, an upper portion having a gas outlet port and a middle portion located between said lower portion and said upper portion; a gas filter assembly connected to said gas inlet port below said chamber for retaining liquid in said chamber for pretending liquid from leaking from solid chamber and for filtering calibration gas entering said chamber through said gas inlet port, wherein the calibration gas mixes with the calibration liquid in said lower section and said middle portion of said chamber; and at least one sensor connected to said casing adjacent said middle portion of said chamber for sensing the partial pressure of gas in said chamber, said chamber including an expansion region located between said middle portion and said upper portion, said expansion region having an area larger than the area of said middle portion in reference planes perpendicular to said longitudinal axis for facilitating the rupture of gas bubbles passing through the liquid, and wherein said middle portion includes wall sections having a hydrophilic surface for facilitating the passage of gas bubbles past said wall sections.
Claim 3
Dependent Claim
46 words
The cassette of claim 1 including a fitting coupled to said gas outlet port, said fitting being non-releasably connected to said casing, said fitting being movable between a first position for closing said gas outlet port and a second position for venting said gas outlet port.
Claim 4
Dependent Claim
13 words
The cassette of claim 1 wherein said middle portion has a hydrophilic surface.
Claim 5
Dependent Claim
14 words
The cassette of claim 3 wherein said hydrophilic surface comprises a coating of heparin.
Claim 6
Dependent Claim
16 words
The cassette of claim 1 including an elongated sparger tube connected to said gas inlet port.
Claim 7
Dependent Claim
11 words
The cassette of claim 5 wherein said sparger tube comprises polyetheresterketone.
Claim 8
Dependent Claim
23 words
The cassette of claim 5 wherein said sparger tube has a longitudinal axis that is collinear with said longitudinal axis of said chamber.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-12-06 | 2003-06-07 | 2003-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-06 | 2007-06-07 | 2007-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-06 | 2011-06-07 | 2011-12-07 | $7700.00 | Window Closed / Lapsed |