Method and apparatus for non-invasively measuring hemodynamic parameters using parametrics

A method of measuring the pressure in the blood vessel of a living subject, comprising:

• providing at least one transducer adapted for determining the pressure applied to at least one surface thereof;
• disposing said at least one surface of said at least one transducer proximate to said blood vessel;
• varying the level of compression applied to said blood vessel by said at least one transducer over time;
• determining the level of compression where a desired condition of the pulse pressure associated with said blood vessel exists based on the pressure determined by said at least one transducer;
• maintaining said at least one transducer at or near said level of compression where said desired condition exists;
• and
• measuring at least one pressure value using said transducer during at least a portion of said act of maintaining.

A method scaling an unscaled blood pressure measurement derived from a living subject, comprising:

• determining a first physiologic parameter of said subject;
• determining a second physiologic parameter of said subject;
• forming a relationship between said first and second parameters;
• and
• using said relationship to scale said unscaled blood pressure measurement.

A method scaling an unscaled blood pressure measurement derived from a living subject, comprising:

• determining a first physiologic parameter of said subject, said first parameter being related to the body mass of said subject;
• determining a second physiologic parameter of said subject, said second parameter being related to the location on said subject where said unscaled blood pressure measurement is obtained;
• functionally relating said first and second parameters to produce a third parameter;
• correlating said third parameter to a fourth parameter;
• and
• scaling said unscaled blood pressure measurement using at least said fourth parameter.

An apparatus for measuring the pressure within the blood vessel of a living subject comprising:

• a pressure transducer adapted to detect the pressure associated with said blood vessel and generate a signal relating thereto;
• at least one storage device associated with said pressure transducer, said at least one storage device having scaling data stored therein;
• at least one applanation assembly adapted to bias a portion of tissue proximate to said blood vessel;
• a controller operatively coupled to said at least one applanation assembly and adapted to control the position thereof;
• and
• a processor operatively connected to said transducer, at least one storage device, and said controller, said processor configured to generate an estimate of said blood pressure within said vessel based at least in part on said signal and said scaling data.

An information storage device, comprising;

• a data storage medium;
• a plurality of data stored on said medium, said plurality of data comprising a computer program adapted to run on a data processor, said data processor being operatively coupled to a controller which controls the position of a pressure transducer, said computer program, processor and controller being configured for determining the blood pressure of a living subject using the method comprising:
• varying the level of compression applied to said blood vessel by at least one pressure transducer over time;
• determining the level of compression where a desired condition of the pulse pressure associated with said blood vessel exists based on the pressure determined by said at least one transducer;
• maintaining said at least one transducer at or near said level of compression where said desired condition exists;
• and
• measuring at least one pressure value using said transducer during at least a portion of said act of maintaining.

A method of positioning a pressure sensor with respect to a blood vessel, comprising:

• disposing said sensor proximate to said blood vessel such that at least some degree of pressure coupling between said blood vessel and said sensor exists;
• moving said sensor in at least a first direction with respect to said blood vessel while obtaining a first pressure signal from said sensor;
• moving said sensor in at least a second direction with respect to said blood vessel while obtaining at least a second pressure signal;
• and
• analyzing said first and second signals to identify at least one relationship therebetween.

A method of qualifying physiologic pressure data, comprising:

• obtaining a plurality of pressure data from a subject;
• obtaining a plurality of second data relating to at least one physiologic event within said subject;
• and
• qualifying at least a portion of said pressure data based at least in part on said second data.