Heater for optical gas sensor

• US 7,301,125 B2
• Filed: 03/01/2005
• Issued: 11/27/2007
• Est. Priority Date: 05/31/2001
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Inventors: Davis, Raymond G.
• Primary Examiner(s): Hoang; Tu Ba
• Assistant Examiner(s): PATEL, VINOD D
• Application Number:
  US11/069,114
• Publication Number:
  US 20050145796A1
• Time in Patent Office: 1,001 Days
• Field of Search: 219/201, 219/522, 219/543, 219/203, 359/512, 2503381-342, 250/504.R, 250/352, 600/529, 600/537, 600/532, 73 232- 233, 73/250.5, 733/350.1, 73/310.5, 128/200.24, 128/201.15
• US Class Current: 219/201
• 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 21/0332 with temperature control control of temperature G05D23/00; cryostats F17C3/08
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

A heater for a window of an optical gas sensor is provided. The heater may be positioned over a portion of the window or may form at least a portion of the window. Alternatively, the heater may be separate from the optical gas sensor and positionable over the window either in contact therewith or in close proximity thereto. In one embodiment, the heater is substantially transparent to the relevant wavelengths of electromagnetic radiation that are used in optical monitoring of respiratory gases, anesthetic agents, or the like. Alternatively, the heater may be configured so as to provide a substantially unobstructed optical pathway through the window. Optical gas sensors and complementary transducers that include the heater are also disclosed.

Claims

1. An optical gas sensor, comprising:

a support housing;

an optical window coupled to the support housing, wherein the optical window includes a first portion having a first diameter, and a second portion having a second diameter that is less than the first diameter such that a step is defined along a periphery of the optical window, and wherein the first portion includes a first region in which the first portion and the second portion overlap defining a first thickness, and a second region outside the first region in which the first portion and the second portion do not overlap defining a second thickness that is less than the first thickness; and

a heating assembly operatively coupled to the first portion of the optical window such that the heating assembly is disposed over only the second region of the first portion of the optical window.

2. The optical gas sensor of claim 1, wherein the optical window is formed from sapphire.

3. The optical gas sensor of claim 1, wherein the first portion includes a substantially planar surface, and wherein the heating assembly is coupled to the substantially planar surface.

4. The optical gas sensor of claim 1, wherein the second portion includes a substantially convex surface.

5. The optical gas sensor of claim 1, wherein the heating assembly includes an opening providing an optical path to the optical window.

6. The optical gas sensor of claim 1, wherein the heating assembly comprises a flexible circuit and a heating generating element coupled to the flexible circuit.

7. The optical gas sensor of claim 1, further comprising a temperature-sensing component in communication with the heating assembly.

8. The optical gas sensor of claim 1, wherein an opening is defined in the support housing, and wherein at least a portion of the second portion of the optical window is disposed in the opening.

9. The optical gas sensor of claim 8, further comprising a receiving cavity defined proximate to the opening, and wherein at least a portion of the first portion of the optical window is disposed in the receiving cavity.

10. The optical gas sensor of claim 1, wherein the first portion and the second portion of the optical window are substantially circular.