Miniaturized pressure sensor having means for protection of diaphragm

• US 5,085,223 A
• Filed: 03/28/1990
• Issued: 02/04/1992
• Est. Priority Date: 07/29/1988
• Status: Expired due to Term

• Current Assignee: Radi Medical Systems AB (Abbott Laboratories Incorporated)
• Original Assignee: Radi Medical Systems AB (Abbott Laboratories Incorporated)
• Inventors: Ola, Hammarstrom, Lars, Tenerz, Bertil, Hok, Tomas, Engstrom, Roman, Lonc
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Longo, Robin R.
• Application Number:
  US07/469,555
• Time in Patent Office: 678 Days
• Field of Search: 128/637, 128/672, 128/673, 128/675, 128/748, 73/715, 73/861.47, 73/705, 73/706, 73/714, 73/726, 73/727, 73/756
• US Class Current: 600/488
• CPC Class Codes: A61B 5/02154 by optical transmission
• CPC Class Codes: G01L 9/0077 for measuring reflected light

Abstract

A miniaturized transducer for in vivo measurements of physiological pressure has a transducer unit and an inner tube with a wall opening. A diaphragm covers the wall opening. Distinguishing for the invention is that the diaphragm is protected by an outer tube arranged outside the inner tube, and having a wall opening situated radially opposite the wall opening of the inner tube. An end closure closes off the distal end of the tube and a seal seals the outer tube against the inner tube. The lumen of the inner tube is in communication with the atmospheric pressure.

Claims

1. A miniaturized pressure transducer assembly, comprising:

an outer tube;

an inner tube disposed coaxially therein, thereby defining an annular space therebetween, said inner tube being in communication with atmospheric pressure;

an annular joint located between a proximal end of said outer tube and an exterior wall of said inner tube;

said inner and outer tubes each having a cooperating aperture defined near distal ends thereof;

a diaphragm filling said aperture, said diaphragm being disposed in said annular space;

a pressure transducer unit disposed within said inner tube, said pressure transducer unit moved by a movement of said diaphragm; and

a distal end cap attached to said inner and outer tubes.

2. Transducer as claimed in claim 1, comprising a helix ribbon which is wound around the outer tube.

3. A transducer as claimed in claim 1, wherein said inner tube has first and second tubular portions, said first portion having an inner diameter greater than an outer diameter of said second portion.

4. Transducer as claimed in claim 3, wherein said inner tube has a joint between said first and second portions, said portions located inside the outer tube.

5. Transducer as claimed in claim 3, comprising a helix ribbon which is wound around said inner tube.

6. Transducer as claimed in claim 1, comprising a glue joint between said transducer unit is glued and an inner wall of said inner tube, said exterior wall of said inner tube connected to an inner wall of said outer tube.

7. Transducer as claimed in claim 1, wherein said inner tube has an additional wall aperture.

8. Transducer as claimed in claim 1, comprising a helix arranged at the distal end cap, said helix projecting forwards in the longitudinal direction of said tubes;

a safety thread anchored at one end in a distal end part of the helix and at another end in the end cap;

a tapered core filament arranged inside the helix, a larger end of said filament anchored in the distal end cap with a tip cantilevering out from the end cap.

9. Transducer as claimed in claim 1, wherein the end cap has a facet-ground tip.

10. Transducer as claimed in claim 1, comprising a helix ribbon which is wound around said inner tube.