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US 7,142,901 B2Granted
Parameter compensated physiological monitor
AssigneeMasimo Corporation
InventorsMassi E. Kiani, Mohamed Diab, Ammar Al-Ali, Walter M. Weber
Life of this patent
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Abstract
A monitor has a primary input from which a spectral characteristic of a tissue site can be derived. The monitor also has a secondary input from which at least one parameter can be determined. A compensation relationship of the spectral characteristic, the parameter and a compensated physiological measurement is determined. A processor is configured to output the compensated physiological measurement in response to the primary input and the secondary input utilizing the compensation relationship.
Claims13
A monitor comprising:
- a primary input from which a spectral characteristic of a tissue site is derivable;
- a secondary input from which at least one parameter is determinable;
- and
- a processor configured to output a compensated physiological measurement in response to said primary input and said secondary input utilizing a compensation relationship between said spectral characteristic and said at least one parameter and said compensated physiological measurement;
- wherein said compensation relationship comprises:
- baseline calibration data relating said spectral characteristic to an uncompensated physiological measurement;
- modified calibration data generated from a modification of said baseline calibration data in response to said at least one parameter;
- and
- a look-up table having sold spectral characteristic as an input and providing said compensated physiological measurement as an output according to said calibration data;
- wherein said at least one parameter is a blood gas measurement and said compensation relationship further comprises:
- a comparison of said uncompensated physiological measurement with said blood gas measurement;
- a sensitivity control;
- and
- modification rules responsive to said comparison and said sensitivity control, said modification rules determining said modification.
11 more elements
A monitor comprising:
- a primary input from which a spectral characteristic of a tissue site is derivable;
- a secondary input from which at least one parameter is determinable wherein said spectral characteristic has a dependence on said parameter;
- and
- a processor configured to output a compensated physiological measurement in response to a primary input and said secondary input utilizing a relationship between said spectral characteristic and said at least one parameter and said compensated physiological measurement;
- wherein said compensation relationship comprises:
- calibration data relating said spectral characteristic to an uncompensated physiological measurement;
- a look-up table having at least said spectral characteristic and said at least one parameter as an input and providing said compensated measurement as an output according to said calibration data;
- and
- wherein said at least one parameter is a carboxyhemoglobin concentration and said look up table distinguishes carboxyhemoglobin from oxyhemoglobin.
6 more elements
A monitor comprising:
- a primary input from which a spectral characteristic of a tissue site is derivable;
- a secondary input from which at least one parameter is determinable wherein said spectral characteristic has a dependence on said parameter;
- and
- a processor configured to output a compensated physiological measurement in response to said primary input and said secondary input utilizing a relationship between said spectral characteristic and said at least one parameter and said compensated physiological measurement;
- wherein said compensation relationship comprises:
- calibration data representing a plurality of wavelength-dependent compensation calibration curves, each of said compensation calibration curves relating said spectral characteristic to said compensated physiological measurement;
- a look-up table having said spectral characteristic as an input and providing as an output said compensated physiological measurement according to said compensation calibration curves;
- and
- a wavelength determination in response to said at least one parameter so as to select a sensor wavelength and a corresponding one of said compensation calibration curves.
6 more elements
A monitoring method comprising the steps of:
- inputting a sensor signal responsive to a spectral characteristic of a tissue site;
- deriving a physiological measurement from said characteristic;
- obtaining a parameter, wherein said physiological measurement has a dependency on said parameter;
- determining a relationship between said spectral characteristic and said parameter that accounts for said dependency;
- compensating said physiological measurement for said parameter utilizing said relationship;
- and
- displaying said physiological measurement;
- wherein said compensating step comprises the substeps of:
- storing baseline calibration data;
- modifying said baseline calibration data according to said parameter so as to provide modified calibration data;
- and
- looking-up said physiological measurement from said modified calibration data according to said spectral characteristic;
- and
- wherein said physiological measurement provides an SpO2 value and said parameter is a manually input SaO2 value, said modifying substep comprising the further steps of:
- comparing said SpO2 value to said SaO2 value so as to determine a difference;
- and
- determining said modified calibration data so as to reduce said difference.
14 more elements
A monitoring method comprising the steps of:
- inputting a sensor signal responsive to a spectral characteristic of a tissue site;
- deriving a physiological measurement from said characteristic;
- obtaining a parameter, wherein said physiological measurement has a dependency on said parameter;
- determining a relationship between said spectral characteristic and said parameter that accounts for said dependency;
- compensating said physiological measurement for said parameter utilizing said relationship;
- and
- displaying said physiological measurement;
- wherein said compensating step comprises the substeps of:
- storing baseline calibration data;
- looking-up said compensated physiological measurement from said calibration data according to said spectral characteristic and said parameter;
- and
- wherein said parameter is a hemoglobin constituent measurement and said looking-up comprises the substeps of:
- distinguishing said hemoglobin constituent from oxyhemoglobin and reduced hemoglobin;
- and
- providing an adjusted oxygen saturation measurement according to said distinguishing substep.
12 more elements
A monitoring method comprising the steps of;
- inputting a sensor signal responsive to a spectral characteristic of a tissue site;
- deriving a physiological measurement from said characteristic;
- obtaining a parameter, wherein said physiological measurement has a dependency on said parameter;
- determining a relationship between said spectral characteristic and said parameter that accounts for said dependency;
- compensating said physiological measurement for said parameter utilizing said relationship;
- wherein said compensating step comprises the substeps of:
- storing wavelength-dependent calibration data;
- determining a wavelength according to at least one of said parameter and said physiological measurement;
- selecting an active portion of said calibration data according to said wavelength;
- adjusting a sensor so that said spectral characteristic corresponds to said wavelength;
- looking-up said physiological measurement from said active portion of said calibration data according to said spectral characteristic;
- and
- displaying said physiological measurement.
10 more elements
A monitor comprising:
- a primary input means for determining a spectral characteristic associated with a tissue site;
- a secondary input means for determining a parameter that is relevant to measuring oxygen saturation at said tissue site;
- and
- a compensation relationship means for relating said spectral characteristic, said parameter and an oxygen saturation measurement;
- wherein said compensation relationship comprises a means for modifying a sensor wavelength and for selecting corresponding wavelength dependent calibration data.
2 more elements
A monitor comprising:
- a primary input from which a spectral characteristic of a tissue site is derivable;
- a secondary input from which at least one parameter is determinable;
- and
- a processor configured to output a compensated physiological measurement in response to said primary input and said secondary input utilizing a relationship between said spectral characteristic and said at least one parameter and said compensated physiological measurement;
- wherein said compensation relationship comprises a sensitivity control.
2 more elements
A monitoring method comprising the steps of;
- receiving a sensor signal responsive to a physiological parameter of a tissue site;
- deriving a physiological indication of said physiological parameter;
- obtaining a parameter indication, wherein said physiological indication has a dependency on said parameter indication;
- determining a relationship between said physiological indication and said parameter indication that accounts for said dependency;
- determining a measurement of said physiological parameter utilizing said relationship;
- wherein said relationship comprises a sensitivity control;
- and
- displaying said measurements.
5 more elements
Dependencies are inferred from the claim text.