Non-invasive pressure sensor

• US 5,716,342 A
• Filed: 10/10/1995
• Issued: 02/10/1998
• Est. Priority Date: 10/10/1995
• Status: Expired due to Term

• Current Assignee: Circuit Tree Medical, Inc. (STAAR Surgical Company)
• Original Assignee: Circuit Tree Medical, Inc. (STAAR Surgical Company)
• Inventors: Dumbraveanu, Gheorghe, Urich, Alex, Curtis, Michael
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US08/540,501
• Time in Patent Office: 854 Days
• Field of Search: 604/31, 604/67, 604/DIG. 13, 604/118, 73/715-718, 73/719-731, 128/672-686, 222/105
• US Class Current: 604/118
• CPC Class Codes: A61F 9/00736 Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments A61F9/008 takes precedence
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 Pressure isolators

Abstract

An adapter assembly for a pressure sensor. The adapter includes a sensor housing that has a first port and a second port that are both in fluid communication with an inner chamber of the housing. The assembly further includes a membrane housing that is pressed into the first port of the sensor housing and connected to a fluid line. Extending from the membrane housing is a membrane which separates the sensor housing inner chamber into a first subchamber and a second subchamber. The first subchamber is in fluid communication with the fluid line. The second subchamber is in fluid communication with a pressure transducer which is pressed into the second port of the sensor housing. Any variation of pressure within the fluid line will cause a change in the volume of the first subchamber. The change in the first subchamber volume will deflect the membrane and vary the volume of the second subchamber. In accordance with the ideal gas equation, the change of the second subchamber volume will vary the pressure of the second subchamber. The pressure transducer senses the change in the second subchamber pressure. The change in the second subchamber pressure corresponds to the variation in the line pressure. The membrane can be removed so that the pressure transducer can be reused even in contaminated environments.

Claims

1. A pressure transducer assembly for a fluid line which has a line pressure, comprising:

a sensor housing that has a first port and a second port that are in fluid communication with an inner chamber of said sensor housing;

a membrane housing that is detachably connected to said first port and the fluid line;

a tubular shaped membrane that has a diameter and a longitudinal axis, said tubular shaped membrane has a first end coupled to said sensor housing and an opposite unsupported second end, said tubular shaped membrane having a length that extends from said first end to said second end, said length being greater than said diameter of said tubular shaped membrane, said membrane is attached to membrane housing and extends into said inner chamber, said membrane separates said inner chamber into a first subchamber that has a first volume and a second subchamber that has a second volume, said first subchamber is adapted to be in fluid communication with the fluid line, wherein a variation in the line pressure will vary said first volume of said first subchamber and deflect said membrane in a direction essentially perpendicular to the longitudinal axis of said membrane to vary the diameter of said membrane, wherein said membrane deflection varies said second volume of said second subchamber and varies a corresponding pressure within said second subchamber; and

,

a pressure transducer that is attached to said second port of and disposed outside of said sensor housing and is in fluid communication with said second subchamber, said pressure transducer senses the variation in said second subchamber pressure.

2. The assembly as recited in claim 1, wherein said first volume of said first subchamber is greater than said second volume of said second subchamber.

3. The assembly as recited in claim 2, wherein said membrane is constructed from a silicone rubber material.

4. A pressure transducer assembly for a fluid line which has a line pressure, comprising:

a sensor housing that has a first port and a second port that are in fluid communication with an inner chamber of said sensor housing, said first port being connected to the fluid line;

a membrane housing that is detachably connected to said second port;

a tubular shaped membrane that has a diameter and a longitudinal axis, said tubular shaped membrane has a first end coupled to said sensor housing and an opposite unsupported second end, said tubular shaped membrane having a length that extends from said first end to said second end, said length being greater than said diameter of said tubular shaped membrane, said membrane is attached to membrane housing and extends into said inner chamber, said membrane separates said inner chamber into a first subchamber that has a first volume and a second subchamber that has a second volume, said second subchamber is adapted to be in fluid communication with the fluid line, wherein a variation in the line pressure will vary said second volume of said second subchamber and deflect said membrane in a direction essentially perpendicular to the longitudinal axis of said membrane to vary the diameter of said membrane, wherein said membrane deflection varies said first volume of said first subchamber and varies a corresponding pressure within said first subchamber; and

,

a pressure transducer that is attached to and disposed outside of said membrane housing and is in fluid communication with said first subchamber, said pressure transducer senses the variation in said first subchamber pressure.

5. The assembly as recited in claim 4, wherein said first volume of said first subchamber is greater than said second volume of said second subchamber.

6. The assembly as recited in claim 5, wherein said membrane is constructed from a silicone rubber material.