US5271408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrodynamic system for blood flow measurement
Assignee: BOZIDAR FEREK-PETRIC SOVINEC 17
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Filing: 1992-03-23
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Granted: 1993-12-21
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Expires: 2012-03-23
Abstract
Abstract A device for measuring blood flow in the vicinity of a catheter implanted within the vascular vessel or the heart uses hydrodynamic principles. The device has two transducers mounted at the exterior surface of the catheter spaced from each other. One of the transducers has a protrusion in the form of a hydrofoil profile, and the other transducer presents a substantially flat surface at the exterior of the catheter. The transducer having the hydrofoil profile generates a signal due to the quasi-static pressure acting on the transducer as well as due to the drag force acting on the transducer caused by the blood flow. The other transducer generates a signal solely due to the quasi-static pressure. The transducers can either be connected with opposite polarity, or their respective signals can be subtracted in a differential amplifier, so that a signal proportional to the axial flow velocity is obtained.
Inventors
- 👤 Branko Breyer
- 👤 Bozidar Ferek-Petric
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:09
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/06; A61B8/12; A61B8/44; A61B8/4444; A61B8/445
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
132 words
A hydrodynamic system for blood flow velocity measurement comprising: a catheter adapted for long-term in vivo implantation in a blood flow; first and second passive transducer means carried on said catheter at a side of said catheter and spaced from each other and interactable with said blood flow for respectively generating signal components corresponding to static pressure of said blood flow at each passive transducer means; hydrofoil profile means mounted on only one of said passive transducer means and interactable with said blood flow for causing said one of said passive transducer means to generate a further signal component proportional to the velocity of said blood; and electrically conductive means connected to said first and second passive transducer means for conducting said signal components and said further signal component through said catheter.
Claim 2
Dependent Claim
132 words
A hydrodynamic system for blood flow velocity measurement comprising: a catheter adapted for long-term in vivo implantation in a blood flow; first and second passive transducer means carried on said catheter at a side of said catheter and spaced from each other and interactable with said blood flow for respectively generating signal components corresponding to static pressure of said blood flow at each passive transducer means; hydrofoil profile means mounted on only one of said passive transducer means and interactable with said blood flow for causing said one of said passive transducer means to generate a further signal component proportional to the velocity of said blood; and electrically conductive means connected to said first and second passive transducer means for conducting said signal components and said further signal component through said catheter.
Claim 3
Dependent Claim
23 words
A hydrodynamic system as claimed in claim 1 wherein each of said passive transducer means consists of a plurality of piezoelectric transducer segments.
Claim 4
Dependent Claim
17 words
A hydrodynamic system as claimed in claim 2 wherein said segments are symmetrically arranged around said catheter.
Claim 5
Dependent Claim
35 words
A hydrodynamic system as claimed in claim 1 wherein said hydrofoil profile means is mounted at an exterior of said one of said passive transducer means and projects beyond an exterior surface of said catheter.
Claim 6
Dependent Claim
40 words
A hydrodynamic system as claimed in claim 1 wherein each of said first and second passive transducer means has a polarity, and wherein said electrically conductive means is connected to said first and second passive transducer means with opposite polarity.
Claim 7
Dependent Claim
49 words
A hydrodynamic system as claimed in claim 1 further comprising means connected to said electrically conductive means for forming a difference between said signal component and said further signal component from said one of said passive transducer means and the signal component from the other of said transducer means.
Claim 8
Dependent Claim
27 words
A hydrodynamic system as claimed in claim 1 further comprising reinforcing means attached to said catheter to which said first and second passive transducer means are mounted.
References Cited (Backward Citations)
US4237729A
Cited
US4697595A
Cited
US4706681A
Cited
US4771787A
Cited
US4691709A
Cited
US4790323A
Cited
US4757821A
Cited
US4783994A
Cited
US5069679A
Cited
US5099686A
Cited
EP0474957A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-12-20 | 1997-06-21 | 1997-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-20 | 2001-06-21 | 2001-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-20 | 2005-06-21 | 2005-12-21 | $7700.00 | Window Closed / Lapsed |