MEASURING HEAD FOR DIAGNOSTIC INSTRUMENTS AND METHOD

• US 20070084466A1
• Filed: 10/09/2006
• Published: 04/19/2007
• Est. Priority Date: 10/10/2005
• Status: Active Grant

• Current Assignee: Vyaire Medical GmbH
• Original Assignee: CareFusion Germany 234 GmbH (Becton, Dickinson & Co)
• Inventors: Reinstadtler, Jurgen
• Granted Patent: US 9,320,456 B2
• Time in Patent Office: Days
• US Class Current: 128/204.260
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 2016/102 Measuring a parameter of the content of the delivered gas
• CPC Class Codes: A61M 2016/1025 the O2 concentration
• CPC Class Codes: A61M 2016/103 the CO2 concentration

Abstract

This invention relates to a measuring head which comprises an intake, an outlet, a mouthpiece and an electrically controlled proportional valve. The intake may be connected to a pressurized gas reservoir. The outlet releases exhaled gas and excess gas into the ambient. A mouthpiece provides gas to a subject and accepts exhaled gas from the subject. The electrically controlled, proportional valve is pneumatically connected between said intake and said mouthpiece for controlling the gas flow from said intake to said mouthpiece and said outlet. The invention urther relates to a method for controlling a gas flow from the intake to the outlet.

Claims

1. A measuring head comprising:

an intake for being connected to a pressurized gas reservoir;

an outlet for releasing exhaled gas and excess gas into the ambient;

a mouthpiece for providing gas to a subject and accepting exhaled gas from said subject;

said mouthpiece being pneumatically connected to said outlet;

an electrically controlled, proportional valve;

which is pneumatically connected between said intake and said mouthpiece for controlling the gas flow from said intake to said mouthpiece and said outlet.

2. The measuring head of claim 1, wherein said mouthpiece comprises a flow sensor for measuring the flow of said inhaled gas by and exhaled gas from said subject.

3. The measuring head of claim 1, wherein said measuring head further comprises a pressure sensor for measuring the pressure of said inhaled gas by and exhaled gas from said subject.

4. The measuring head of claim 1, wherein said electrically controlled, proportional valve comprises two on/off solenoid valves.

5. The measuring head of claim 4, wherein the ratio of the flows through two open solenoid valves at a predetermined pressure difference between said intake and said ambient is approximately a power of two.

6. The measuring head of claim 1, wherein said measuring head comprises a pressure sensor which is pneumatically connected to a connection tube between said intake and said proportional valve.

7. A method for controlling a gas flow from an intake to an outlet and a mouthpiece by measuring head, the method comprising:

generating an electrical signal having a monotonic dependence from the gas flow caused by inhaling of a subject; and

controlling an opening of a proportional valve between said intake and said outlet and said mouthpiece by said signal for compensating the gas flow caused by inhaling.

8. The method of claim 7, wherein said electrical signal is generated by a flow sensor and said flow sensor measures the gas flow through said mouthpiece.

9. The method of claims 7, wherein the pressure at said intake is measured.

10. The method of claim 9, further comprising:

closing said outlet; and

obtaining a two-dimensional gas flow array while said outlet is closed by;

applying several different pressure values at said intake;

performing the following at each pressure value;

adjusting several different openings at said proportional valve; and

measuring of the gas flow through said mouthpiece.

11. The method of claim 9, further comprising:

obtaining an estimated gas flow through said intake based on a two-dimensional gas flow array, the pressure at said intake and the opening of said proportional valve; and

adjusting the opening of said proportional valve such that said estimated gas flow exceeds said gas flow caused by inhaling.