Plasma or serum production and removal of fluids under reduced pressure

Abstract

In some embodiments, the present invention generally relates to the separation of blood within a device to form plasma or serum. In some embodiments, the present invention generally relates to the removal of fluids, such as blood, contained within a device. In one aspect, the present invention is generally directed to systems and methods for receiving blood from a subject and processing the blood to form plasma or serum. For example, a device may be applied to the skin of a subject to receive blood from the subject and pass the blood through a separation membrane, which separates the blood into plasma and a portion concentrated in blood cells. As another example, blood or plasma may be allowed to clot within the device and serum (the unclotted portion of the blood) may be withdrawn from the device. The device may contain, in some cases, a vacuum source such as a pre-packaged vacuum to facilitate receiving of blood and/or passage of the blood through the separation membrane to produce plasma or serum. In certain embodiments, plasma, serum, or other fluids may be removed from the device by inserting a needle into a portion of the device that has reduced pressure, expelling gas into the device through the needle, then receiving plasma, serum, or other fluids through the needle.

What is claimed is: 
     
         1 - 177 . (canceled) 
     
     
         178 . A device for receiving blood from a subject and processing the blood to form plasma or serum, the device comprising:
 an inlet for introduction of blood from the subject into the device;   a microfluidic channel for receiving fluid in fluid communication with the inlet;   a storage chamber for receiving plasma or serum; and   a membrane that is substantially impermeable to cells, wherein the membrane separates the microfluidic channel from the storage chamber and is capable of separating blood passing through to produce a portion enriched in plasma or serum.   
     
     
         179 . The device of  claim 178 , wherein the storage chamber has a pressure less than ambient pressure. 
     
     
         180 . The device of  claim 179 , wherein the pressure is less than about 50 mmHg below ambient pressure. 
     
     
         181 . The device of  claim 179 , wherein the pressure is less than about 100 mmHg below ambient pressure. 
     
     
         182 . The device of  claim 178 , wherein the microfluidic channel has a cross-sectional diameter of less than 1 mm. 
     
     
         183 . The device of  claim 178 , wherein the microfluidic channel is sized to cause fluid flow using capillary action. 
     
     
         184 . The device of  claim 178 , further comprising a vacuum chamber, separate from the storage chamber. 
     
     
         185 . The device of  claim 178 , wherein the device comprises a dissolvable interface at the storage chamber. 
     
     
         186 . The device of  claim 185 , wherein the dissolvable interface comprises a salt. 
     
     
         187 . The device of  claim 178 , wherein the device further comprises a first module and a second module removable from the first module, wherein the second module comprises the storage chamber. 
     
     
         188 . The device of  claim 178 , wherein the storage chamber has a volume of less than 5 ml. 
     
     
         189 . The device of  claim 178 , wherein the storage chamber has a volume of less than 1 ml. 
     
     
         190 . The device of  claim 178 , wherein the device separates less than 1 ml of blood to produce a portion enriched in plasma or serum. 
     
     
         191 . The device of  claim 178 , wherein the device separates less than 100 microliters of blood to produce a portion enriched in plasma or serum. 
     
     
         192 . The device of  claim 178 , wherein at least a portion of the storage chamber is coated with a material that promotes thrombolysis. 
     
     
         193 . The device of  claim 178 , wherein at least a portion of the storage chamber is coated with a polyester. 
     
     
         194 . The device of  claim 178 , wherein the device further contains an anticoagulant. 
     
     
         195 . The device of  claim 194 , wherein the anticoagulant comprises heparin. 
     
     
         196 . The device of  claim 178 , wherein the membrane is a separation membrane. 
     
     
         197 . The device of  claim 178 , wherein the membrane comprises a copolymer. 
     
     
         198 . The device of  claim 178 , wherein the membrane has an average pore diameter of less than about 20 micrometers. 
     
     
         199 . The device of  claim 178 , further comprising a septum in fluid communication with the storage chamber.