MULTI-DYNAMIC-RANGE SENSOR

• US 20100305465A1
• Filed: 05/27/2009
• Published: 12/02/2010
• Est. Priority Date: 05/27/2009
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Bentley, Ian, Ricks, Lamar Floyd, Bey, Paul Prehn
• Granted Patent: US 10,330,513 B2
• Time in Patent Office: Days
• US Class Current: 600/538
• CPC Class Codes: A61B 5/0878 using temperature sensing means
• CPC Class Codes: G01F 1/696 Circuits therefor, e.g. constant-current flow meters
• CPC Class Codes: G01F 7/00 Volume-flow measuring devices with two or more measuring ranges; Compound meters

Abstract

A sensing system that produces a multi-dynamic range output is provided. In an illustrative embodiment, a first channel and a second channel receive an analog output signal from a sensing element. The first channel provides a first digital output signal that has a first dynamic range, and the second channel provides a second digital output signal that has a second narrower dynamic range. In some cases, the second narrower dynamic range falls within the first dynamic range, and the first digital output signal may provide a first resolution and the second digital output signal may provide a second greater resolution. The dynamic range and/or resolution of one or more of the first channel and second channel may be dynamically reconfigurable, if desired.

Claims

1. A respiration sensing system for sensing respiration of a patient, the respiration sensing system comprising:

a sensing element configured to sense a respiration flow rate, the sensing element providing an analog output signal that is related to the sensed respiration flow rate;

a first channel receiving the analog output signal from the sensing element, the first channel including a first Analog-to-Digital Converter (ADC) and providing a first digital output signal that has a first dynamic range and a first resolution;

a second channel receiving the analog output signal from the sensing element, the second channel including a second Analog-to-Digital Converter (ADC) and providing a second digital output signal that has a second dynamic range and a second resolution, wherein the second dynamic range is narrower than the first dynamic range, and the second resolution is higher than the first resolution; and

an output selector that outputs the second digital output signal if the analog output signal is within the dynamic range of the second ADC and outputs the first digital output signal if the analog output signal is outside the dynamic range of the second ADC.

2. The respiration sensing system of claim 1 wherein the second dynamic range is a subset of the first dynamic range.

3. The respiration sensing system of claim 1 wherein the first ADC has a common number of bits as the second ADC.

4. The respiration sensing system of claim 1 wherein the sensing element includes a heat source and a number of temperature sensors.

5. The respiration sensing system of claim 1 further comprising a third channel receiving the analog output signal from the sensing element, the third channel including a first Analog-to-Digital Converter (ADC) and providing a third digital output signal that has a third dynamic range different than the first and second dynamic ranges.

6. The respiration sensing system of claim 1 wherein the first dynamic range and/or the second dynamic range is dynamically reconfigurable.

7. A flow sensing system for sensing a fluid flow in a fluid stream, the flow sensing system comprising:

a sensing element configured to sense a fluid flow in a fluid stream, the sensing element providing an analog output signal that is related to the sensed fluid flow;

a first channel receiving the analog output signal from the sensing element, the first channel including a first Analog-to-Digital Converter (ADC) and providing a first digital output signal that has a first dynamic range; and

a second channel receiving the analog output signal from the sensing element, the second channel including a second Analog-to-Digital Converter (ADC) and providing a second digital output signal that has a second dynamic range;

wherein the second dynamic range is narrower than the first dynamic range, and the second dynamic range falls within or substantially falls within the first dynamic range.

8. The flow sensing system of claim 7 wherein the second dynamic range is a subset of the first dynamic range.

9. The flow sensing system of claim 7 wherein the first digital output signal has a first resolution and the second digital output signal has a second resolution, wherein the second resolution is greater than the first resolution.

10. The flow sensing system of claim 7 wherein the first ADC and the second ADC have a common number of bits.

11. The flow sensing system of claim 7 wherein the sensing element includes a heat source and a number of temperature sensors.

12. The flow sensing system of claim 11 wherein at least one of the temperature sensors is positioned upstream of the heat source and at least one of the temperature sensors is positioned downstream of the heat source.

13. The flow sensing system of claim 12 wherein a flow rate of the fluid flow in a fluid stream creates a temperature differential between the at least one of the temperature sensors that is positioned upstream of the heat source and the at least one of the temperature sensors that is positioned downstream of the heat source.

14. The flow sensing system of claim 7 further comprising an output selector that provides the second digital output signal if the analog output signal is within the dynamic range of the second ADC and provides the first digital output signal if the analog output signal is outside the dynamic range of the second ADC.

15. The flow sensing system of claim 7 wherein the second dynamic range is dynamically reconfigurable.

16. A method for sensing a fluid flow in a fluid stream, the method comprising:

sensing a fluid flow in a fluid stream with a sensing element and providing an analog signal that is related to the sensed fluid flow;

converting the sensed analog signal to a first digital signal with a first Analog-to-Digital Converter (ADC) to provide a first digital signal that has a first dynamic range;

converting the sensed analog signal to a second digital signal with a second Analog-to-Digital Converter (ADC) to provide a second digital output signal that has a second dynamic range, wherein the second dynamic range is narrower than the first dynamic range, and the second dynamic range falls within or substantially falls within the first dynamic range;

selecting the second digital signal with an output selector if the analog signal is within the dynamic range of the second ADC; and

selecting the first digital signal with the output selector if the analog signal is outside the dynamic range of the second ADC.

17. The method of claim 16 wherein the first digital signal has a first resolution and the second digital signal has a second resolution, wherein the second resolution is greater than the first resolution.

18. The method of claim 16 wherein the first ADC and the second ADC have a common number of bits.

19. The method of claim 16 wherein the step of sensing the fluid flow in the fluid stream with a sensing element includes heating the fluid flow with a heat source and sensing a temperature of the fluid flow with one or more temperature sensors.

20. The method of claim 16 further comprising reconfiguring the second dynamic range.