Respiratory gas sensors in folw path

• US 20020026937A1
• Filed: 08/28/2001
• Published: 03/07/2002
• Est. Priority Date: 08/28/2000
• Status: Abandoned Application

• Current Assignee: HealtheTech, Inc.
• Original Assignee: HealtheTech, Inc.
• Inventors: Mault, James R.
• Application Number:
  US09/940,750
• Publication Number:
  US 20020026937A1
• Time in Patent Office: Days
• US Class Current: 128/200.24
• CPC Class Codes: A61B 2560/0295 adapted for recording user messages or annotations
• CPC Class Codes: A61B 2560/0456 Apparatus provided with a docking unit
• CPC Class Codes: A61B 2560/0462 Apparatus with built-in sensors
• CPC Class Codes: A61B 2560/0468 Built-in electrodes
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/0833 Measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/4872 : Body fat
• CPC Class Codes: A61B 5/6817 : Ear canal
• CPC Class Codes: A61B 5/6826 : Finger
• CPC Class Codes: A61B 5/6838 : Clamps or clips
• CPC Class Codes: A61B 5/6896 : Toys
• CPC Class Codes: A61B 5/742 : using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 7/00 : Instruments for auscultation
• CPC Class Codes: G01N 33/0037 : for NOx
• CPC Class Codes: G01N 33/497 : of gaseous biological material, e.g. breath
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

A respiratory gas meter is useful in detecting a gas component of a respiratory gas flowing along a flow path in the meter as a user breathes. The meter includes a respiratory gas sensor disposed in the flow path of the meter. One example of a respiratory gas sensor includes a fluorescence gas sensor having a radiation emitter for directing radiation along the flow path and a radiation detector for detecting fluorescence from the respiratory gas induced by the radiation. The respiratory gas sensor also includes a narrow band filter disposed between the detector and the gas, to pass fluorescence to the radiation detector, so as to instantaneously detect components of the respiratory gas passing through the flow path. Another example of a respiratory gas sensor includes a micromachined sensor that detect nitric oxide through the change in resonance frequency of the micromechanical structure due to absorption of nitric oxide on the surface of the structure.

Claims

1. A respiratory gas meter for detecting a gas component of a respiratory gas flowing in a flow path of the meter as a user breathes, with a respiratory gas sensor disposed in the flow path, said respiratory gas sensor comprising:

a fluorescence gas sensor having a radiation emitter for directing radiation along the flow path and a radiation detector for detecting fluorescence from the respiratory gas induced by the radiation; and

a narrow band filter disposed between the detector and the gas, to pass fluorescence to the radiation detector, to instantaneously detect components of the respiratory gas passing through the flow path.

2. A respiratory gas meter as set forth in claim 1, wherein said fluorescence gas sensor further comprises:

a fluorescent material that changes in fluorescence in response to changes in the level of nitric oxide;

a radiation source means that induces fluorescence in the fluorescent material;

a nitric oxide permeable membrane disposed between the fluorescent material and the gas flow, so that nitric oxide from the gas flow interacts with the fluorescent material;

a detector means for detecting fluorescence from the fluorescent material; and

signal processing circuitry for detecting changes in the fluorescence due to the presence of nitric oxide in the respiratory gas of the user.

3. The respiratory gas meter as set forth in claim 2, wherein the fluorescent material is a transition metal complex.

4. The respiratory gas meter as set forth in claim 1 wherein a signal representing the sensed respiratory gas component is transmitted to a remote computing device.

5. The respiratory gas meter as set forth in claim 4 wherein said remote computing device is a personal digital assistant.

6. A respiratory gas meter for detecting a gas component of a respiratory gas flowing in a flow path of the meter as a user breathes, with a respiratory gas sensor disposed in the flow path, said respiratory gas sensor comprising:

a fluorescence quenching gas sensing means having a radiation emitter for directing radiation along the flow path and a radiation detector for detecting fluorescence from the respiratory nitric oxide gas induced by the radiation;

a fluorescent material that changes in fluorescence in response to changes in the level of nitric oxide;

a radiation source means that induces fluorescence in the fluorescent material;

a nitric oxide permeable membrane disposed between the fluorescent material and the gas flow, so that nitric oxide from the gas flow interacts with the fluorescent material;

a detector means for detecting fluorescence from the fluorescent material; and

signal processing circuitry for detecting changes in the fluorescence due to the presence of nitric oxide in the respiratory gas of the user.

7. The respiratory gas meter as set forth in claim 6, wherein the fluorescent material is a transition metal complex.

8. The respiratory gas meter as set forth in claim 6 wherein a signal representing the sensed respiratory gas component is transmitted to a remote computing device.

9. The respiratory gas meter as set forth in claim 8 wherein said remote computing device is a personal digital assistant.

10. A respiratory gas meter for detecting a gas component of a respiratory gas flowing in a flow path of the meter as a user breathes, with a respiratory gas sensor disposed in the flow path, said respiratory gas sensor comprising:

a micromachined gas sensor disposed in the flow path to instantaneously detect components of the respiratory gas passing through the flow path by a change in resonance frequency of a micromechanical structure due to gas absorption on the surface of the structure.

11. A respiratory gas meter as set forth in claim 10, wherein said micromachined sensor detects nitric oxide in the respiratory gas.

12. The respiratory gas meter as set forth in claim 11 wherein a signal representing the sensed respiratory gas component is transmitted to a remote computing device.

13. The respiratory gas meter as set forth in claim 12 wherein said remote computing device is a personal digital assistant.