PRESSURE SENSING DEVICE

• US 3,831,588 A
• Filed: 10/16/1972
• Issued: 08/27/1974
• Est. Priority Date: 10/16/1972
• Status: Expired due to Term

• Current Assignee: Wilhelm Rindner
• Original Assignee: Wilhelm Rindner
• Inventors: Rindner, Wilhelm
• Primary Examiner(s): Medbery, Aldrich F.
• Application Number:
  US05/297,778
• Time in Patent Office: 680 Days
• Field of Search: 128/2R,2.5E,2H,2.5D,348,349,2.5N 73/71.5U,406,389
• US Class Current: 600/488
• CPC Class Codes: A61B 5/02156 Calibration means
• CPC Class Codes: G01L 27/005 Apparatus for calibrating pressure sensors
• CPC Class Codes: G01L 9/0098 using semiconductor body comprising at least one PN junction as detecting element

Abstract

A pressure sensor which produces an electric output proportional to pressure on it is housed in a chamber having a flexible membrane for transmitting external pressure to the sensor. Means are provided for varying the pressure in the chamber by known amounts thus enabling calibration of the pressure sensing system while the sensor is at the site.

Claims

1. A pressure sensing device for insertion into the human body, means for measuring variable fluid pressures within the human body which includes a pressure sensor which provides an electric output proportional to fluid pressure exerted thereon, chamber means for housing said sensor including a flexible membrane arranged in a wall of said chamber opposite said sensor to exert on said sensor fluid pressure changes external to said housing and the outer side of said membrane to which said membrane is exposed, means for transmitting said sensor output to equipment responsive thereto, tube means connected to said chamber and in hermetically sealed communIcation with the inner side of said membrane, and calibration means for said sensor including means for applying fluid pressure changes of known magnitude to the interior of said tube means and to the inner side of said membrane and to said sensor, and means for indicating the response of said sensor to said fluid pressure changes interior and exterior of said chamber as a function of the electric output of said sensor proportional to said changes.

2. A pressure sensing device according to claim 1 wherein said tube means comprises a tube in hermetically sealed communication with said chamber.

3. A pressure sensing device according to claim 1 which includes a mechanical connection between said membrane and said sensor for transmitting to said sensor pressure applied to said membrane.

4. A pressure sensing device according to claim 2 suitable for intravenous use wherein said tube is a catheter.

5. A pressure sensing device according to claim 1 wherein said sensor is a junction transducer.

6. A pressure sensing device according to claim 1 which includes a temperature sensor in proximity to said pressure sensor which provides an electric output proportional to its temperature, and means for transmitting said temperature sensor output to equipment responsive thereto.

7. A pressure sensing device according to claim 1 wherein said pressure changes include atmospheric, subatmospheric and above-atmospheric pressures.

8. A pressure sensing device according to claim 1 wherein said calibration means includes a gas pump, means for optionally connecting said tube means to the suction or pressure sides of said pump for applying said pressure changes thereto, and means for indicating the pressures so applied.