DEVICE FOR STERILE MEASUREMENT OF LIQUID OR GAS PRESSURES

• US 3,818,765 A
• Filed: 02/16/1972
• Issued: 06/25/1974
• Est. Priority Date: 02/17/1971
• Status: Expired due to Term

• Current Assignee: Odd Eriksen
• Original Assignee: Odd Eriksen
• Inventors: Eriksen, Odd
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Yasich, Daniel M.
• Application Number:
  US05/226,802
• Time in Patent Office: 860 Days
• Field of Search: 73/406,395,398AR,431 128/25D,25E
• US Class Current: 73/706
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: G01L 19/0023 for flowthrough systems having a flexible pressure transmitting element
• CPC Class Codes: G01L 19/003 using a detachable interface or adapter between the process medium and the pressure gauge
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection
• CPC Class Codes: G01L 9/006 of metallic strain gauges fixed to an element other than the pressure transmitting diaphragm

Abstract

The present invention relates to a pressure measuring device, particularly for sterile medical pressure measurements, and which comprises a pressure sensor with a pressure sensitive membrane and a pressure chamber connectable to the liquid and gas circuit in which the pressure is to be measured, and operative to transfer said liquid and gas pressure to the pressure sensitive membrane. The improvement according to the invention comprises the feature that an impervious isolation membrane of significantly less rigidity than the pressure sensitive membrane is disposed between the latter membrane and the pressure chamber, in order to isolate the sensor from the medium in which the pressure measurements is to be performed. This feature according to the invention substantially facilitates the sterilization procedure for such pressure measuring device without disturbing the measurements, and in addition preferably provides electric insulation between said liquid or gas circuit and the pressure sensor.

Claims

1. An improved device for measurement of physiological fluid pressure comprising:

a pressure sensor provided with a pressure sensitive membrane for sensing the pressure of a fluid within a fluid circuit;

a housing presenting a hollow pressure chamber, said housing including an integral external wall segment presenting a fluid impervious membrane disposed in fluid sealing relationship with respect to a peripheral area of said hollow chamber;

means for connecting said housing to said circuit with said chamber in fluid communication with the interior of the circuit; and

means for detachably securing said sensor to said housing with said membranes disposed in facing relationship and in intimate pressure transmitting surface contact with one another, said fluid impervious membrane being of substantially less rigidity than said pressure sensitive membrane to thereby isolate the pressure sensor from the chamber without substantially effecting the measurement of pressure thereby, whereby the sensor may be detached from the housing while the latter remains connected to the circuit and without affecting the pressure in the circuit, and whereby the housing and its fluid impervious membrane may be presterilized prior to the attachment thereof to the sensor.