Flow sensor
First Claim
1. A bi-directional flow sensor for sensing pressure of a flow passing therethrough, the flow sensor comprising:
- a hollow tubular member having a ventilator end and a patient end and defining a bore with a central axis, the bore including a throat section disposed between the ventilator end and the patient end;
a flow restrictor bisecting the throat section and including a pair of pressure taps, the pair of pressure taps configured to be fluidly connected to a pressure conversion device of the sensor for conversion of a pressure differential to a flow rate;
a baffle disposed within the bore at the ventilator end and comprising a plurality of vanes, the baffle being sized and configured to limit non-axial flow at the pressure taps, wherein each of the plurality of vanes is radially oriented and includes a notch on a radially inward side proximal to the central axis such that the notches collectively define a pressure relief area within the bore; and
a flow obstruction disposed at the patient end and being configured to promote uniform velocity across the bore at the pressure taps.
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0 Petitions
Accused Products
Abstract
A bi-directional flow sensor may be adapted for reducing pneumatic noise during pressure sensing with a flow passing through the flow sensor. The flow sensor may include a hollow, tubular member having a throat section disposed between a ventilator end and a patient end. A flow restrictor may be disposed in the throat section and may be adapted to measure differential pressure in the flow. A baffle may be mounted at the ventilator end and may be adapted to minimize non-axial flow at pressure taps located on opposing ends of the flow restrictor. The patient end may include a flow obstruction configured to promote uniform velocity across the flow at the pressure taps during exhalation flow from the patient end to the ventilator end. The flow sensor can minimize pneumatic noise to less than 0.1 LPM to allow accurate patient flow measurement and triggering of inhalation and exhalation phases at flow rates of 0.2 LPM.
221 Citations
20 Claims
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1. A bi-directional flow sensor for sensing pressure of a flow passing therethrough, the flow sensor comprising:
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a hollow tubular member having a ventilator end and a patient end and defining a bore with a central axis, the bore including a throat section disposed between the ventilator end and the patient end; a flow restrictor bisecting the throat section and including a pair of pressure taps, the pair of pressure taps configured to be fluidly connected to a pressure conversion device of the sensor for conversion of a pressure differential to a flow rate; a baffle disposed within the bore at the ventilator end and comprising a plurality of vanes, the baffle being sized and configured to limit non-axial flow at the pressure taps, wherein each of the plurality of vanes is radially oriented and includes a notch on a radially inward side proximal to the central axis such that the notches collectively define a pressure relief area within the bore; and a flow obstruction disposed at the patient end and being configured to promote uniform velocity across the bore at the pressure taps. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A flow sensor, comprising:
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a hollow tubular member having a ventilator end and a patient end and defining a bore with a central axis, the bore including a throat section disposed between the ventilator end and the patient end; a flow restrictor within the throat section and including a pair of pressure taps, the pair of pressure taps configured to be fluidly connected to a pressure conversion device of the sensor; and a baffle disposed within the bore at the ventilator end and comprising a plurality of vanes, the baffle being sized and configured to restrict non-axial flow at the pressure taps, wherein each of the plurality of vanes is radially oriented and includes a notch on a radially inward side proximal to the central axis such that the notches collectively definite a pressure relief area within the bore. - View Dependent Claims (16)
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17. An apparatus comprising:
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a hollow tubular member having a first end and a second end and defining a bore with a central axis, the bore including a throat section disposed between the first end and the second end; a flow restrictor bisecting the throat section and including a pair of pressure taps, the pair of pressure taps configured to be fluidly connected to a pressure conversion device for conversion of a pressure differential to a flow rate; a flow obstruction disposed at the second end and being configured to promote uniform velocity across the bore at the pressure taps; a baffle disposed within the bore at the first end and comprising a plurality of vanes, the baffle being sized and configured to limit non-axial flow at the pressure taps, wherein each of the plurality of vanes is radially oriented and includes a notch on a radially inward side proximal to the central axis such that the notches collectively define a pressure relief area within the bore. - View Dependent Claims (18, 19, 20)
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Specification