Patent US4971068A successfully refreshed from Google Patents.
US4971068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blood vessel locating needle assembly with thermochromic indicator
Assignee: ICU Medical Sales Inc
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Filing: 1989-07-07
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Granted: 1990-11-20
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Expires: 2009-07-07
Abstract
Abstract The penetration of a vein or the like by a fluid collecting or dispensing needle is rapidly confirmed by the transfer of thermal energy from fluid entering the needle bore upon such penetration to a temperature responsive medium in intimate contact with the exterior of the needle. The temperature responsive medium may comprise thermochromic liquid crystals which signal a change in temperature from ambient temperature by changing color.
Inventors
- 👤 Carl R. Sahi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:47
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/42; A61M5/427; A61B; A61B5/00; A61B5/15; A61B5/150007; A61B5/150015; A61B5/15003; A61B5/150374; A61B5/150381; A61B5/150389; A61B5/150473; A61B5/150496; A61B5/150763; A61B5/150786; A61B5/153; A61B5/154; A61B5/1545; G; G01; G01K; G01K11/00; G01K11/12; G01K11/16; G01K11/165; A61B5/150206; A61B5/150221; Y; Y10; Y10S; Y10S604/00; Y10S604/90
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A method of detecting the penetration of liquid into the bore of a cannula comprising the steps of: establishing a heat transfer relationship between the cannula and a thermochromic crystalline material, the thermochromic crystalline material undergoing a change in color in response to an increase in its temperature; and visually observing the crystalline material to determine if the material has changed color in response to a temperature increase commensurate with the flow of bodily fluid into the cannula bore.
Claim 2
Independent Claim
79 words
A method of detecting the penetration of liquid into the bore of a cannula comprising the steps of: establishing a heat transfer relationship between the cannula and a thermochromic crystalline material, the thermochromic crystalline material undergoing a change in color in response to an increase in its temperature; and visually observing the crystalline material to determine if the material has changed color in response to a temperature increase commensurate with the flow of bodily fluid into the cannula bore.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein the step of establishing a heat transfer relationship comprises: placing the thermochromic crystalline material in intimate contact with a portion of the exterior surface of the cannula.
Claim 4
Dependent Claim
151 words
In apparatus for sampling bodily fluid, said apparatus comprising a cannula having a distal end for penetrating a body and a proximal end, said cannula being comprised of a thermally conductive material and defining a bore, the improvement comprising: an element comprising a thermochromic crystalline material disposed in intimate heat transfer relationship with the exterior of the cannula at a position displaced from a distal end thereof, the thermochromic crystalline material having a color which is temperature dependent, and a hub member for supporting the cannula, the element comprising the thermochromic crystalline material being in abutting relationship with said hub member and encircling said cannula, the penetration into the bore of the cannula of a fluid having a temperature which differs from the initial temperature of the cannula resulting in the transfer of thermal energy between the fluid and the crystalline material whereby the crystalline material will undergo a color change.
Claim 5
Dependent Claim
151 words
In apparatus for sampling bodily fluid, said apparatus comprising a cannula having a distal end for penetrating a body and a proximal end, said cannula being comprised of a thermally conductive material and defining a bore, the improvement comprising: an element comprising a thermochromic crystalline material disposed in intimate heat transfer relationship with the exterior of the cannula at a position displaced from a distal end thereof, the thermochromic crystalline material having a color which is temperature dependent, and a hub member for supporting the cannula, the element comprising the thermochromic crystalline material being in abutting relationship with said hub member and encircling said cannula, the penetration into the bore of the cannula of a fluid having a temperature which differs from the initial temperature of the cannula resulting in the transfer of thermal energy between the fluid and the crystalline material whereby the crystalline material will undergo a color change.
Claim 6
Dependent Claim
12 words
The apparatus of claim 3 wherein the cannula is comprised of steel.
References Cited (Backward Citations)
US3434968A
Cited
US3633425A
Cited
US3651695A
Cited
US3886930A
Cited
US3889658A
Cited
US3942514A
Cited
US3955420A
Cited
US3998210A
Cited
US3926368A
Cited
US4281543A
Cited
US4079729A
Cited
US4108163A
Cited
US4015591A
Cited
US4175543A
Cited
US4108175A
Cited
US4215699A
Cited
US4186750A
Cited
US4245652A
Cited
US4280508A
Cited
US4448204A
Cited
US4312362A
Cited
US4436098A
Cited
US4413633A
Cited
US4447164A
Cited
US4509532A
Cited
US4476877A
Cited
US4416290A
Cited
US4679571A
Cited
US4728547A
Cited
US4665927A
Cited
US4846005A
Cited
US4827944A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-19 | 1994-05-21 | 1994-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-19 | 1998-05-21 | 1998-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-19 | 2002-05-21 | 2002-11-20 | $7700.00 | Window Closed / Lapsed |