Apparatus for promoting waste-free primary flow in a patient monitoring device

• US 5,231,991 A
• Filed: 12/21/1990
• Issued: 08/03/1993
• Est. Priority Date: 12/21/1990
• Status: Expired due to Fees

• Current Assignee: Protocol Systems Inc
• Original Assignee: Protocol Systems Inc
• Inventors: Nelson, Craig H.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/633,244
• Time in Patent Office: 956 Days
• Field of Search: 128/716, 128/718, 128/719, 128/204.14, 128/205.27, 55/158, 55/159, 55/164, 73/19, 210/435
• US Class Current: 600/529
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: G01N 1/34 Purifying; Cleaning processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003
• CPC Class Codes: G01N 2001/4066 using difference of solubility between liquid and gas, e.g. bubbling, scrubbing or sparging
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

Apparatus for promoting waste-free primary flow in a patient monitoring device is disclosed and includes a waste trap with a body defining a waste chamber with the body including an entry port for communication with a primary channel of the device, and an exit port for communication with a secondary channel of the device. The exit port has a first cross-sectional area. The exit port is defined by a porous, gas-permeable, waste-blocking member that extends into the chamber to promote waste-free primary flow in any orientation of the trap. The member has a total-pore area exceeding the first cross-sectional area. Operatively connected between the ports is means for monitoring the differential pressure therebetween and for sending signals representative of such pressure to associated control circuitry of the device for determining the volume of waste in said body based on signals received from the monitoring means.

Claims

1. Apparatus for promoting waste-free primary flow in a patient monitoring device during a measurement cycle, such device including a gas-sensing channel for conducting primary flow and a secondary channel for conducting secondary flow, with each such channel having a negative pressure existing therein, said apparatus comprising:

a waste trap with a body defining a waste chamber, said body including an entry port for communication with the gas-sensing channel and an exit port for communication with the secondary channel, and structure for directing said secondary flow through said body from the entry port to the exit port where it continues through the secondary channel; and

said exit port comprising a porous, gas-permeable, waste-blocking member that extends into the chamber, for providing waste-free primary flow independent of the orientation of said body.

2. The apparatus of claim 1 wherein said exit port has a first cross-sectional area, and said member has a total-pore area exceeding said first cross-sectional area.

3. The apparatus of claim 2 wherein said waste-blocking member extends from said exit port substantially across the chamber.