Detecting vascular stenosis in chronic hemodialysis patients
OwnerCharles L. Feldman, Kenneth Kleinman +1inventors
InventorsCharles L. Feldman, Kenneth Kleinman, Thomas Shook
Life of this patent
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Abstract
Stenotic regions in the vasculature of chronic hemodialysis patients are detected and monitored by blood velocity measuring.
Claims45
A method of detecting an occlusion in a blood conduit of a hemodialysis patient comprising:
- inserting a velocity detector into an examined blood conduit at a selected site;
- measuring velocity of the blood flow in a first region of the examined blood conduit;
- moving said velocity detector to a second region of the examined blood conduit;
- measuring velocity of the blood flow in at least a second region of the examined blood conduit;
- and comparing the velocities measured in the different regions to obtain an indication of an occlusion in said blood conduit.
A system for detecting a partial occlusion in a blood conduit of a hemodialysis patient comprising:
- a velocity detector insertable into different regions of an examined blood conduit at a selected site used for hemodialysis access, said velocity detector constructed to provide velocity signals representative of velocity of the blood flow at said different regions;
- and
- a processor constructed to receive said velocity signals from said detector and arranged to compare said velocity signals measured at different regions of the examined blood conduit to create a velocity profile.
A method of detecting an occlusion in a blood conduit of a hemodialysis patient including,
- inserting a velocity sensing device into said conduit to provide a velocity signal representative of the velocity of blood flow in said conduit at the location of said device in said conduit and a position signal representative of said location,
- moving said velocity sensing device through said conduit,
- and sensing a significant change in said velocity signal and the position signal when said significant change occurs to provide an indication of the location of an occlusion in said blood conduit.
Apparatus for detecting an occlusion in a blood conduit of a hemodialysis patient comprising,
- a velocity sensing device in said conduit constructed and arranged to provide a velocity signal representative of the velocity of blood flow in said conduit at the location of said device in said conduit and a position signal representative of said location,
- said velocity sensing device being movable through said conduit,
- and a detector constructed and arranged to sense a significant change in said velocity signal and the position signal when said significant change occurs to provide an indication of the location of an occlusion in said blood conduit.
A method of detecting an occlusion in a blood conduit of a hemodialysis patient comprising the steps of:
- locating a section of blood flow conduit having a zone of a known cross-sectional area;
- substantially all blood passing through said zone also flowing in the examined blood conduit;
- measuring a velocity of the blood flow in said zone;
- measuring a velocity of the blood flow in a region of the examined blood conduit;
- and
- determining a cross-sectional area of said region based on said velocities.
A system for detecting a stenosis in a blood conduit of a hemodialysis patient comprising:
- a detector constructed and arranged to provide velocity signals representative of velocity of the blood flow;
- a blood flow conduit having a zone of a known cross-sectional area that intercepts substantially all blood flowing in said blood conduit;
- and
- a processor constructed and arranged to receive velocity signals from said detector and provide an area signal representative of a cross-sectional area of a region of said blood conduit.
Dependencies are inferred from the claim text.