Methods and systems for determining the concentration of one or more analytes from a sample such as blood or plasma are described. The systems described herein can be configured to withdraw a certain volume of sample from a source of bodily fluid, direct a first portion of the withdrawn sample to an analyte monitoring system and return a second portion of the sample to the patient. The analyte monitoring system can include an automated blood withdrawal system that is configured to withdraw blood from the patient's vasculature at low pressure and/or withdrawal rates so as to reduce or prevent contamination of the withdrawn fluid from the infusion fluids.

A sampling apparatus can have an elongate tube and a liquid partitioning unit, first port can receive an incoming flow of test liquid and a second port may be coupled to the elongate tube. The liquid partitioning unit can combine the flow of test liquid with a plurality of partitioning elements to define a plurality of discrete liquid samples for movement along and storage in the elongate tube.

A medical valve can include a housing that includes a sidewall and defines a chamber. The medical valve can include a septum coupled to the housing. The septum can include a proximal surface and a selectively openable closure positioned within the chamber. The medical valve can further include a plurality of projections that extend away from the sidewall and are configured to contact the proximal surface of the septum to oppose movement of a restricted portion of the septum in a proximal direction such that an aspiration cracking pressure required to open the closure to permit fluid flow through the septum in the proximal direction exceeds an infusion cracking pressure required to open the closure to permit fluid flow through the septum in the distal direction.

Embodiments of a syringe-based device for delivering fluid include a housing, a port, the port being positioned at about the distal end of the housing, a plunger assembly, the plunger assembly including, a plunger seal, a valve, and a cannula, a first fluid reservoir, where the first fluid reservoir retains a first type of fluid, a syringe including a syringe body, a syringe port, a plunger, and a second fluid reservoir, the second fluid retaining a second type of fluid, and where the syringe transitions from a first configuration in which a first portion of the first fluid type is delivered through the port, to a second configuration in which the second type of fluid in the second fluid reservoir is delivered through the port, to a third configuration in which a second portion of the first fluid type is delivered through the port.

A fluid control device includes an inlet configured to be placed in fluid communication with a bodily fluid source and an outlet configured to be placed in fluid communication with a fluid collection device. The fluid control device has sequestration portion that can be vented or evacuated. The fluid control device has a first state in which an initial volume of bodily fluid can flow from the inlet to the sequestration portion and a second state in which (1) the initial volume is sequestered in the sequestration portion, and (2) a subsequent volume of bodily fluid, being substantially free of contaminants, can flow through at least a portion of the fluid control device and into the fluid collection device. The fluid control device can transition automatically or in response to an actuation of a portion of the fluid control device after the sequestration portion receives the initial volume.

The invention is directed to methods and devices for efficient separation of plasma irons whole blood which are suitable for point of care use in resource poor environments, in some embodiments, elements of such devices comprise (a) a sample collection receptacle (SCR) with at least one port, the sample collection receptacle capable of holding a predetermined volume of a sample of undiluted whole blood drawn through a port; (b) a filter chamber having an inlet and an outlet, and containing at least one filter capable of separating plasma from blood cells as sample passes from an inlet side to an outlet side of the at least one filter whenever the filter chamber is placed in Quid communication with a port of the sample collection receptacle; and (c) a manually driven pump operationally associated with the SCR and filter chamber for (i) drawing a predetermined volume of sample into ore SCR by a first user action and (ii) driving the predetermined volume at a substantially constant linear flow under a pressure not exceeding 2 psi from the SCR through the filter chamber and the outlet of the filter chamber by a second user action.

Medical device assemblies capable of aspirating liquid into a syringe barrel or other medical devices while evacuating any air from the syringe are described. An exemplary medical device includes a syringe barrel, plunger rod and stopper assembly having an air permeable and liquid impermeable porous portion and structure for forming a vacuum within either the stopper or the plunger rod. Described is a medical device including a syringe barrel, plunger rod and stopper assembly having an air permeable and liquid impermeable porous portion and structure for forming a vacuum within chamber between the stopper and plunger rod wherein the plunger rod includes a sealing edge and is moveable relative to the stopper. Exemplary medical devices may include a vent for allowing air that permeates through the porous portion to escape to atmosphere. Methods for aspirating a syringe barrel with a liquid are also provided.

The disclosed apparatus, systems and methods relate to devices, systems and methods for the collection of bodily fluids involving a single-use actuation and retraction mechanism disposed within a collector.

An apparatus includes a pre-sample reservoir, a diversion mechanism, and a flow metering mechanism. The diversion mechanism has an inlet port couplable to a lumen-defining device to receive bodily-fluids from a patient, a first outlet port fluidically couplable to the pre-sample reservoir, and a second outlet port fluidically couplable to a sample reservoir. The diversion mechanism defines a first fluid flow path and a second flow path that are configured to place the first outlet port and the second outlet port, respectively, in fluid communication with the inlet port. The flow metering mechanism is configured to meter a flow of a predetermined volume of bodily-fluid through the first fluid flow path into the pre-sample reservoir, to meter a flow of a second volume of bodily-fluid through the second fluid flow path into the sample reservoir, and to display a volumetric indicator associated with the predetermined volume and the second volume.

A fluid control device includes an inlet configured to be placed directly or indirectly in fluid communication with a bodily fluid source and an outlet configured to be placed in fluid communication with a fluid collection device. The fluid control device has a first state in which a negative pressure differential produced from an external source such as the fluid collection device is applied to the fluid control device to draw an initial volume of bodily fluid from the bodily fluid source, through the inlet, and into a sequestration portion of the fluid control device. The fluid control device has a second state in which (1) the sequestration portion sequesters the initial volume, and (2) the negative pressure differential draws a subsequent volume of bodily fluid, being substantially free of contaminants, from the bodily fluid source, through the fluid control device, and into the fluid collection device.