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US 5,301,686 AGranted
Fluid sampling method
AssigneeCobe Laboratories, Inc.
InventorDavid P. Newman
Life of this patent
Estimating the term…
Abstract
A fluid sampling method in which a variable volume chamber between a needle site and a syringe creates a negative pressure at the tip on its removal from the needle site to reduce the exposure to liquid at the time of removal.
Claims10
A method for withdrawing a sample of a fluid from a sample site on a fluid container, said method being adapted to reducing the amount of excess fluid at the sample site, said method comprising:
- engaging a sampling device with the sampling site, said sampling device defining a variable volume passage with a relatively larger volume position and a relatively smaller volume position and having a tip at one end of the variable volume passage and a valve at another end of the variable volume passage opposite the one end;
- sealing the tip of the sampling device to the sampling site;
- decreasing the volume of the variable volume passage by moving the variable volume passage to a relatively smaller volume position;
- releasing air from the variable volume passage through the valve;
- withdrawing the sample of fluid from the sample site through the variable volume passage in the sampling device;
- increasing the volume of the variable volume passage by moving the variable volume passage to a relatively larger volume position to create a negative pressure in the variable volume passage;
- closing the valve to prevent entry of air into the variable volume passage through the valve;
- drawing the excess fluid into the variable volume passage by action of the negative pressure;
- and
- disengaging the sampling device from the sampling site.
7 more elements
A method for withdrawing a sample of a fluid from a sample site on a fluid container, said method being adapted to reducing the amount of excess fluid at the sample site, said method comprising:
- engaging a sampling device with the sampling site, said sampling device defining a variable volume passage having a relatively larger volume position and a relatively smaller volume position and having a tip at one end of the variable volume passage and a check valve at another, opposite, end of the variable volume passage and further having a resilient member for biasing the variable volume passage toward the relatively larger volume position;
- sealing the tip of the sampling device to the sampling site;
- compressing the resilient member of the sampling device;
- decreasing the volume of the variable volume passage by moving the variable volume passage to the relatively smaller volume position against biasing action of the resilient member;
- releasing air from the variable volume passage through the check valve;
- withdrawing the sample of fluid from the sample site through the variable volume passage in the sampling device;
- decompressing the resilient member of the sampling device;
- increasing the volume of the variable volume passage by moving the variable volume position to the relatively larger volume position by the biasing action of the resilient member to create a negative pressure in the variable volume passage;
- closing the check valve by action of the negative pressure to prevent entry of air into the variable volume passage through the check valve;
- drawing the excess fluid into the variable volume passage by action of the negative pressure;
- and
- disengaging the sampling device from the sampling site.
9 more elements
Dependencies are inferred from the claim text.