High-speed transmission of blood stream gases

• US 4,187,856 A
• Filed: 04/03/1978
• Issued: 02/12/1980
• Est. Priority Date: 04/03/1978
• Status: Expired due to Term

• Current Assignee: Marquette Gas Analysis Corporation
• Original Assignee: Perkinelmer Incorporated
• Inventors: Whistler, Wayne J., Hall, Lawrence G.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/893,032
• Time in Patent Office: 680 Days
• Field of Search: 128/2 E, 128/2.1 E, 23/232 R, 250/281, 250/489, 422/83, 73/40.7, 73/421.5 R
• US Class Current: 600/562
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: G01N 33/4925 measuring blood gas content, e.g. O2, CO2 , HCO3
• CPC Class Codes: H01J 49/0427 using a membrane permeable to gases

Abstract

The various gases in the blood stream are analyzed by a mass spectrometer coupled to the catheter having on its distal end a membrane that passes the gases but not the blood. A "carrier" gas, such as helium, introduced under a small pressure through a small tube within the catheter lumen and into the area behind the membrane will produce a viscous flow that greatly speeds the gases to the mass spectrometer. The carrier gas is extracted prior to its arrival at the mass spectrometer.

Claims

1. A system for providing blood gas specimens from blood vessels to a gas analyzer comprising:

a catheter having an outside diameter of approximately three millimeters comprising a distal end and a proximal end, said distal end being sufficiently sharp to enter a human blood vessel, said distal end having an opening sealed with a membrane impervious to blood,

a first conduit interconnecting the proximal end of said catheter and the gas analyser,

a capillary tube extending through the lumen of said catheter,

a carrier gas source containing a carrier gas substantially lighter than said blood gas,

one end of said capillary tube terminating at the distal end of said catheter,

a second conduit connecting said carrier gas source to the other end of said capillary for admitting a carrier gas into said capillary tube extracting means connecting to said first conduit for causing said carrier gas to expand substantially more than said blood gas,

said extracting means including a vacuum pump for carrying away said carrier gas.