Sensor with optical pressure transducer and method of manufacturing a sensor component

• US 7,554,666 B2
• Filed: 05/22/2007
• Issued: 06/30/2009
• Est. Priority Date: 05/25/2006
• Status: Active Grant

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Inventors: Russell, James T.
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): Hansen; Jonathan M
• Application Number:
  US11/805,074
• Publication Number:
  US 20070273887A1
• Time in Patent Office: 770 Days
• Field of Search: 356/480, 356/481, 356/517, 356/519, 356/450, 385/13, 600/532, 737/00
• US Class Current: 356/450
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/0866 Passive resistors therefor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/102 Measuring a parameter of the content of the delivered gas
• CPC Class Codes: G01B 2290/25 Fabry-Perot in interferometer, e.g. etalon, cavity
• CPC Class Codes: G01B 9/02023 Indirect probing of object, e.g. via influence on cavity or fibre
• CPC Class Codes: G01F 1/38 the pressure or differential pressure being measured by means of a movable element, e.g. diaphragm, piston, Bourdon tube or flexible capsule
• CPC Class Codes: G01F 1/383 with electrical or electro-mechanical indication
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices
• CPC Class Codes: G01L 9/0077 for measuring reflected light

Abstract

An airway adapter that comprises a housing and a pressure transducer. The housing comprises a flow path having a first end and a second end, a first pressure port that communicates with the flow path, and a second pressure port that communicates with the flow path. The first pressure port is spaced apart from the second pressure port. The flow restriction is disposed in the flow path between the first and second pressure ports that creates a pressure differential therebetween. The pressure transducer generates a signal that reflects the differential pressure created by the flow restriction between the first and second pressure ports, wherein the pressure transducer comprises an optical interferometer.

Claims

1. A sensor assembly comprising:

(a) a housing comprising;

(i) a flow path,

(ii) a first pressure port that communicates with the flow path, and

(iii) a second pressure port that communicates with the flow path, wherein the first pressure port is spaced apart from the second pressure port;

(iv) a channel that runs from the first pressure port to the second pressure port,

(b) a flow restriction disposed in the flow path between the first and second pressure ports and that creates a pressure differential therebetween; and

(c) a pressure transducer comprising a diaphragm disposed in the channel to substantially seal the first pressure port from the second pressure port such that the pressure differential between the first pressure port and the second pressure port causes a deformation of the diaphragm, wherein the pressure transducer generates a signal that reflects the differential pressure created by the flow restriction between the first and second pressure ports, and wherein the pressure transducer also comprises an optical interferometer.

2. The sensor assembly of claim 1, further comprising:

a detection chamber disposed within the flow path, the detection chamber having a pair of transmissive windows comprising a material at least partially transmissive for a selected wavelength, such that, during operation, a beam of radiation of the selected wavelength passes through the windows and traverses the detection chamber to be detected by a photodetector, the detected radiation being useable for measuring a constituent of a gas flowing through the detection chamber.

3. The sensor assembly of claim 2, wherein the flow restriction includes differences in cross sectional area between the detection chamber and one or more other portions of the flow path.

4. The sensor assembly of claim 1, wherein at least a portion of the pressure transducer is disposed within the channel.

5. The sensor assembly of claim 4, wherein the signal generated by the pressure transducer that reflects the pressure differential created by the flow restriction between the first and second pressure ports comprises a signal generated by the optical interferometer that reflects the deformation of the diaphragm.

6. The sensor assembly of claim 5, further comprising a transmissive window formed in a wall of the channel, wherein the optical interferometer comprises:

(i) a source that emits electromagnetic radiation through the transmissive window formed in the wall of the channel toward the diaphragm, and

(ii) a photodetector photodeeter that receives electromagnetic radiation from the diaphragm through the transmissive window formed in the wall of the channel, and wherein the signal generated by the optical interferometer that reflects the deformation of the diaphragm comprises a signal generated by the photodetector that reflects one or more characteristics of the electromagnetic radiation received by the photodetector.

7. The sensor assembly of claim 6, wherein one or more characteristics of the electromagnetic radiation comprise an intensity of the electromagnetic radiation and/or a phase of the electromagnetic radiation.

8. The sensor assembly of claim 1, wherein the flow path is structured to conduct a respiratory gas flow and wherein the first pressure port comprises a member structured to reduce ingress of moisture from the flow path into the channel.

9. The sensor assembly of claim 5, wherein the diaphragm is disposed at the first pressure port or the second pressure port.