Portable spirometer with improved accuracy
First Claim
1. In a spirometer including a passageway, a flow sensor means for generating electric flow signals representing a rate of gas flow from a proximal end to a distal end of said passageway, said gas flow defining a downstream direction, and sampling means for sampling the flow signals, said flow sensor means situated between sad proximal and distal ends of said passageway, the improvement comprising:
- temperature sensing means for sensing a temperature of said flow sensor means, anddynamic correction means responsive to said temperature sensing means for determining a time-varying, dynamic, body-temperature-pressure-saturated (BTPS) correction factor, to compensate for temperature related volume changes in the gas in accordance with a time-variation in the temperature of said flow sensor means sensed by said temperature sensing means.
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Accused Products
Abstract
A spirometric measurement device includes an arrangement for computation of a dynamic correction factor to compensate for temperature-related volume changes in time varying raw forced expiratory volume (FEV) data due to cooling of expired gas. The correction factor, which compensates for body-temperature-pressure-saturated (BTPS) changes, varies in time according to variation of temperature of a flow sensor. The temperature of the flow sensor is accurately established by positioning a temperature sensor downstream of the flow sensor.
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Citations
20 Claims
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1. In a spirometer including a passageway, a flow sensor means for generating electric flow signals representing a rate of gas flow from a proximal end to a distal end of said passageway, said gas flow defining a downstream direction, and sampling means for sampling the flow signals, said flow sensor means situated between sad proximal and distal ends of said passageway, the improvement comprising:
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temperature sensing means for sensing a temperature of said flow sensor means, and dynamic correction means responsive to said temperature sensing means for determining a time-varying, dynamic, body-temperature-pressure-saturated (BTPS) correction factor, to compensate for temperature related volume changes in the gas in accordance with a time-variation in the temperature of said flow sensor means sensed by said temperature sensing means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. In a spirometer including a passageway, a flow sensor means for generating electric flow signals representing a rate of gas flow from a proximal end to a distal end of said passageway, said gas flow defining a downstream direction, and sampling means for sampling the flow signals to provide time varying forced expiratory volume (FEV) data, said flow sensor means situated between said proximal and distal ends of said passageway, the improvement comprising:
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temperature sensing means for sensing a temperature of said flow sensor means, said temperature sensing means situated in said passageway downstream of said flow sensor means, and programmed processing means programmed to compute a body-temperature-pressure-saturated (BTPS) correction factor, to compensate for temperature related volume changes in the gas in accordance with the temperature of said flow sensor means sensed by said temperature sensing means. - View Dependent Claims (19, 20)
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Specification