Method and apparatus for noninvasive determination of peripheral arterial lumenal area
First Claim
1. A method for collecting data concerning a patient comprising the steps of:
- providing a cuff around a portion of a patient;
pumping a fluid into said cuff;
measuring the pressure variation in said cuff, a first portion of said pressure variation being a function of said fluid being pumped into said cuff, a second portion of said pressure variation being a function of the expansion and contraction of said portion of said patient caused by blood flowing through said portion of said patient;
determining the volume of fluid pumped into said cuff per pump stroke;
determining the relation between cuff volume and cuff pressure based on said determination of said volume of fluid pumped into said cuff per pump stroke; and
determining the change in volume of said portion of said patient caused by blood flowing through said portion of said patient by monitoring said second portion of said pressure variation.
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Accused Products
Abstract
An occlusive cuff is placed around a limb (e.g. an arm) of a patient. A fluid, such as air, is pumped into the cuff, and the pressure in the cuff is measured. The pressure variation in the cuff with respect to time is caused by the pump and expansion/contraction of the arm caused by blood being pumped therethrough by the patient'"'"'s heart. This variation in pressure is used to calculate systolic and diastolic pressure, artery lumen area compliance and artery volume compliance, artery lumen area, and the blood flow rate through the patient'"'"'s arteries (e.g. the brachial artery for the case of the patient'"'"'s arm, or the femoral artery or the case of the patient'"'"'s leg).
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Citations
14 Claims
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1. A method for collecting data concerning a patient comprising the steps of:
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providing a cuff around a portion of a patient;
pumping a fluid into said cuff;
measuring the pressure variation in said cuff, a first portion of said pressure variation being a function of said fluid being pumped into said cuff, a second portion of said pressure variation being a function of the expansion and contraction of said portion of said patient caused by blood flowing through said portion of said patient;
determining the volume of fluid pumped into said cuff per pump stroke;
determining the relation between cuff volume and cuff pressure based on said determination of said volume of fluid pumped into said cuff per pump stroke; and
determining the change in volume of said portion of said patient caused by blood flowing through said portion of said patient by monitoring said second portion of said pressure variation. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus comprising:
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a cuff for surrounding a portion of a patient;
a pump for pumping a fluid into and out of said cuff;
a flow meter coupled to said pump for measuring the volume of said fluid being pumped into and out of said cuff and determining a pump stroke volume for said pump;
a transducer for measuring the pressure of the fluid in the cuff;
filter circuitry for providing a measure of the change in cuff pressure caused by said pump and the change in cuff pressure caused by said patient'"'"'s pulse; and
circuitry for calculating a cuff compliance based on said pump stroke volume and said chance in cuff pressure caused by said pump and for calculating the change in the size of said portion of said patient caused by said patient'"'"'s pulse based on said change in cuff pressure caused by said patient'"'"'s pulse. - View Dependent Claims (9)
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10. An apparatus comprising:
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a cuff for surrounding a portion of a patient;
a pump for pumping a fluid into and out of said cuff;
a flow meter coupled to said pump for measuring the volume of said fluid being pumped into and out of said cuff and determining a pump stroke volume for said pump;
a transducer for measuring the pressure of the fluid in the cuff;
means for measuring the change in cuff pressure caused by said pump and the change in cuff pressure caused by said patient'"'"'s pulse; and
means for calculating a cuff compliance based on said pump stroke volume and said change in cuff pressure caused by said pump, and for calculating the change in the size of said portion of said patient caused by said patient'"'"'s pulse based on said change in cuff pressure caused by said patient'"'"'s pulse.
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11. A method comprising the steps of
providing a cuff including a plurality of bladders around a portion of a patient; -
inflating said bladders one at a time so that one of said bladders are in an inflated state;
pumping a fluid in and out of each of said bladders when said bladders are inflated;
measuring the pressure in said bladders when said bladders are inflated; and
using said pressure to determine the area of the lumen of an artery extending through each bladder. - View Dependent Claims (12)
measuring the volume of said fluid pumped in and out of said bladders;
determining the bladder compliance based on said measure of the volume of said fluid and the measure of said pressure; and
generating a measure of the change in cuff volume caused by a patient'"'"'s pulse.
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13. An apparatus comprising:
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a cuff comprising a plurality of bladders therein;
a manifold for selectively connecting a selected one of said bladders to a pump, said pump pumping fluid in and out of said bladder; and
a transducer for measuring the pressure at said selected bladder, said transducer being used to calculate lumen area of an artery.
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14. An apparatus comprising:
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a cuff comprising a plurality of bladders therein;
first means for selectively connecting a selected one of said bladders to a pump, said pump pumping fluid in and out of said bladder; and
second means for measuring the pressure at said selected bladder, said second means calculating the lumen area of an artery.
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Specification