US5205828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epidural needle location indicator assembly
Assignee: DU-KEDEM TECHNOLOGIES Ltd
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Filing: 1991-10-24
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Granted: 1993-04-27
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Expires: 2011-10-24
Abstract
Abstract An epidural needle location indicator device for semiautomatically indicating when an epidural needle has entered into the epidural space in preparation of the delivery of epidural anesthesia. The device can be used with conjunction with a conventional Tuohy needle and takes advantage on the reduction in pressure experienced upon entry into the epidural space causes a visible controlled forward movement of the stilette.
Inventors
- 👤 Dan Kedem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:04
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/34; A61B17/3401; A61B5/00; A61B5/48; A61B5/4887; A61B5/4896
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
168 words
An epidural needle location indicator assembly capable of indicating when a needle traveling through hard tissue first penetrates soft tissue, comprising: (a) a housing; (b) a hollow needle secured near its posterior end to the anterior end of said housing and having an anterior end which is directed laterally; (c) a displaceable piston located in said housing, capable of traveling between a fixed forward displaceable piston position and a fixed back displaceable piston position, said piston positions being a preselected distance apart; (d) a flexible blind end catheter located in said needle, passing through said displaceable piston, said blind end catheter preventing coring of tissues during the forward travel of said needle and serving to transmit tissue pressure to said displaceable piston; (e) a grasping means connected to said displaceable piston for alternately grasping or releasing said catheter; (f) means for releasably locking said displaceable piston to said housing at said back displaceable piston position; and (g) means for biasing said displaceable piston toward said front piston position.
Claim 2
Dependent Claim
168 words
An epidural needle location indicator assembly capable of indicating when a needle traveling through hard tissue first penetrates soft tissue, comprising: (a) a housing; (b) a hollow needle secured near its posterior end to the anterior end of said housing and having an anterior end which is directed laterally; (c) a displaceable piston located in said housing, capable of traveling between a fixed forward displaceable piston position and a fixed back displaceable piston position, said piston positions being a preselected distance apart; (d) a flexible blind end catheter located in said needle, passing through said displaceable piston, said blind end catheter preventing coring of tissues during the forward travel of said needle and serving to transmit tissue pressure to said displaceable piston; (e) a grasping means connected to said displaceable piston for alternately grasping or releasing said catheter; (f) means for releasably locking said displaceable piston to said housing at said back displaceable piston position; and (g) means for biasing said displaceable piston toward said front piston position.
Claim 3
Dependent Claim
26 words
An assembly as in claim 1 wherein said means for releasably locking includes a removable pin capable of penetrating both said housing and said displaceable piston.
Claim 4
Dependent Claim
29 words
An assembly as in claim 1 wherein said means for releasably locking said displaceable piston to said housing at said back displaceable piston position is a bayonet safety latch.
Claim 5
Dependent Claim
14 words
An assembly as in claim 1 wherein said means for biasing is a spring.
Claim 6
Dependent Claim
17 words
An assembly as in claim 1 wherein said spring is in the form of a coil spring.
Claim 7
Dependent Claim
20 words
An assembly as in claim 1 wherein said biasing means includes a biasing piston located posteriorly from said displaceable piston.
Claim 8
Dependent Claim
24 words
An assembly as in claim 6 wherein said biasing means further includes a compressible fluid hydraulically connecting said displaceable piston and said biasing piston.
Claim 9
Dependent Claim
24 words
An assembly as in claim 6 wherein said biasing means further includes a mechanical element mechanically connecting said biasing piston and said displaceable piston.
Claim 10
Dependent Claim
13 words
An assembly as in claim 8 wherein said mechanical element is a spring.
Claim 11
Dependent Claim
38 words
A device as in claim 1 wherein said grasping means includes a cylindrical member made of a compressible solid surrounding said catheter, said cylindrical member located in a cylindrical cavity, which cavity is located in said displaceable piston.
Claim 12
Dependent Claim
26 words
A device as in claim 10 wherein said cylindrical member is capable of being compressed sufficiently to grasp said catheter and prevent said catheter from moving.
Claim 13
Dependent Claim
34 words
A device as in claim 1 wherein said grasping means includes two opposing annular members surrounding said catheter, said annular members located in an elliptical cavity, which cavity is located in said displaceable piston.
Claim 14
Dependent Claim
52 words
A device as in claim 12 wherein said annular members are capable of being rotated so as to alternately come into sufficiently close proximity of each other so as to grasp said catheter and prevent said catheter from moving, or to separate sufficiently so as to allow said catheter to move freely.
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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) | 1996-04-26 | 1996-10-26 | 1997-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-26 | 2000-10-26 | 2001-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-26 | 2004-10-26 | 2005-04-27 | $7700.00 | Window Closed / Lapsed |