US4691709A
Expired / Lapsed
US
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Apparatus for measuring velocity of blood flow in a blood vessel
Assignee: Cordis Corp
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Filing: 1986-09-25
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Granted: 1987-09-08
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Expires: 2006-09-25
Abstract
Abstract Apparatus is provided for measuring the velocity of blood in a blood vessel in a body as well as for measuring static pressure at one or more sites within the blood vessel. The apparatus employs an elongated optical fiber member carried within a tubular catheter having a proximal end and a distal end with the latter adapted to be inserted within a blood vessel so that the blood flowing therein is parallel to the catheter. A first pressure transducer is carried by the catheter adjacent the distal end thereof and responds to static pressure acting transversely of the catheter for modulating the intensity of any light passing through the optical fiber inversely proportional to the magnitude of the transversely acting static pressure. A second pressure transducer is carried by the catheter at the distal end thereof and responds to total pressure including both static and kinetic pressure, acting parallel to the catheter, and which modulates the intensity of any light passing through the optical fiber proportional to the magnitude of the total pressure. This permits the velocity of blood flowing in the blood vessel to be determined as a function of the difference between the total pressure and the transversely acting static pressure.
Inventors
- 👤 Donald M. Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:54
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0091; G01L9/0097; A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/0215; A61B5/02154; A61B5/02158; A61B5/026; A61B5/0261; G01L11/00; G01L11/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
203 words
Apparatus for use in a device for measuring the velocity of blood flowing in a blood vessel in a body, comprising: an elongated tubular catheter having a proximal end and a distal end with the latter adapted to be inserted into a blood vessel such that said blood flows parallel to said catheter; an elongated optical fiber member carried within said catheter and having a proximal end and a distal end and extending throughout essentially the length of said catheter; first pressure transducer means carried by said catheter adjacent the distal end thereof and responsive to static pressure acting transversely of said catheter for modulating the intensity of any light passing through said optical fiber inversely proportional to the magnitude of said transversely acting static pressure; and second pressure transducer means carried by said catheter at the distal end thereof and responsive to total pressure, including static pressure and kinetic pressure, acting parallel to said catheter, for modulating the intensity of any light passing through said optical fiber proportional to the magnitude of said total pressure, whereby the velocity of blood in said vessel can be determined as a function of the difference between said total pressure and said transversely acting static pressure.
Claim 2
Dependent Claim
203 words
Apparatus for use in a device for measuring the velocity of blood flowing in a blood vessel in a body, comprising: an elongated tubular catheter having a proximal end and a distal end with the latter adapted to be inserted into a blood vessel such that said blood flows parallel to said catheter; an elongated optical fiber member carried within said catheter and having a proximal end and a distal end and extending throughout essentially the length of said catheter; first pressure transducer means carried by said catheter adjacent the distal end thereof and responsive to static pressure acting transversely of said catheter for modulating the intensity of any light passing through said optical fiber inversely proportional to the magnitude of said transversely acting static pressure; and second pressure transducer means carried by said catheter at the distal end thereof and responsive to total pressure, including static pressure and kinetic pressure, acting parallel to said catheter, for modulating the intensity of any light passing through said optical fiber proportional to the magnitude of said total pressure, whereby the velocity of blood in said vessel can be determined as a function of the difference between said total pressure and said transversely acting static pressure.
Claim 3
Dependent Claim
35 words
Apparatus as set forth in claim 1 including means for providing an output indication of said velocity of blood as a function of the difference between said total pressure and said transversely acting static pressure.
Claim 4
Dependent Claim
70 words
Apparatus as set forth in claim 1 wherein said first transducer means and said second transducer means are respectively constructed in such a manner that each acts to vary the intensity of light passing through said optical fiber in respectively opposing manners so that any variation in the intensity of light returning to the proximal end is due mainly to variations in kinetic pressure and, hence, to velocity of blood.
Claim 5
Dependent Claim
66 words
Apparatus as set forth in claim 1 wherein said second pressure transducer means includes elastic mirror means located forwardly of the distal end of said optical fiber member for reflecting any light received from said optical fiber member back into said optical fiber member proportional to said total pressure so that the reflected light directed to the proximal end thereof is indicative of said total pressure.
Claim 6
Dependent Claim
66 words
Apparatus as set forth in claim 4 wherein said elastic mirror means has a light reflective convex surface facing the distal end of said optical fiber member and serves to make variable surface area contact therewith in dependence upon the magnitude of said total pressure so that the amount of light returned toward the proximal end of said optical fiber member varies with said total pressure.
Claim 7
Dependent Claim
135 words
Apparatus as set forth in claim 5 wherein said elongated optical fiber member has a light transmitting core coaxially surrounded by cladding means essentially throughout its length with said core being uncladded for at least a portion of its length proximal to the distal end thereof and said first pressure transducer means includes a flexible transducer member having a pitted surface facing said uncladded core portion making surface area contact therewith such that the contacting surface area varies with pressure applied to said transducer member acting transversely thereof, said transducer member being constructed of material exhibiting a greater index of refraction than that of said cladding means so that the intensity of any light passing through said core proximate to said transducer means is modulated inversely in its intensity as a function of said pressure.
Claim 8
Dependent Claim
62 words
Apparatus as set forth in claim 6 further including means for supplying light into the proximal end of said optical fiber member and detecting means for receiving light exiting from the proximal end, said detecting means including means for providing an output indication of blood velocity as a function of the difference between said total pressure and said transversely acting static pressure.
Claim 9
Dependent Claim
66 words
Apparatus as set forth in claim 7 wherein said detecting means includes means for providing a first output indication representative of said total pressure and second means for providing an output indication representative of said transversely acting static pressure and third means for providing an output indication of blood velocity as a function of the difference between said total pressure and said transversely acting static pressure.
Claim 10
Dependent Claim
35 words
Apparatus as set forth in claim 8 wherein said third means includes means providing said blood velocity indication dependent on the squareroot of the difference between said total pressure and said transversely acting static pressure.
Claim 11
Dependent Claim
74 words
Apparatus as set forth in claim 7 including filter means interposed between the distal end of said optical fiber member and said elastic mirror means for passing light beyond wavelength W and reflecting light at shorter wavelengths back into the proximal end of said optical fiber means so that the light reflected back into the proximal end of said optical fiber means from said elastic mirror is of a wavelength greater than wavelength W.
Claim 12
Dependent Claim
74 words
Apparatus as set forth in claim 4 including a plurality of said first pressure transducer means carried by said catheter at spaced apart locations along its length adjacent the distal end thereof for simultaneously measuring static blood pressure acting transversely of said catheter at different sites within said blood vessel whereby said apparatus serves to simultaneously measure static blood pressure at multiple sites while also measuring the velocity of blood within said blood vessel.
Claim 13
Dependent Claim
38 words
Apparatus as set forth in claim 11 wherein each of said plurality of said first pressure transducer means includes light wavelength dependent means for modulating light at a particular wavelength different from that at said other transducer means.
Claim 14
Dependent Claim
35 words
Apparatus as set forth in claim 12 wherein each said first transducer means includes a transducer filter means for passing light within one wavelength range less than wavelength W while reflecting light of other wavelengths.
Claim 15
Dependent Claim
74 words
Apparatus as set forth in claim 13 wherein said second pressure transducer means includes light filter means interposed between the distal end of said optical fiber member and said elastic mirror means for passing light greater than wavelength W while reflecting light of shorter wavelengths so that variations in said total pressure will cause light greater than wavelength W to be varied in its intensity in proportion to the magnitude of said total pressure.
References Cited (Backward Citations)
US3273447A
Cited
US3822695A
Cited
US4201222A
Cited
US4210029A
Cited
US4487206A
Cited
WO1985003855A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-07 | 1991-03-09 | 1991-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-07 | 1995-03-09 | 1995-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-07 | 1999-03-09 | 1999-09-08 | $7700.00 | Window Closed / Lapsed |