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example, blood or plasma may be allowed to clot within the device and serum (the unclotted portion of the blood) may be withdrawn from the device.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 actuator;   an inlet for receiving blood from the subject into the device;   a pressure regulator able to create a pressure differential within the device to facilitate receiving the blood into the device, the pressure regulator comprising a flexible concave member moveable between a first configuration and a second configuration upon actuation of the actuator;   a separation membrane in fluid communication with the inlet, the separation membrane sized such that the blood received into the device and passing through the separation membrane is separated to form plasma or serum; and   a storage chamber for receiving the plasma or serum.   
     
     
         179 . 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. 
     
     
         180 . The device of  claim 178 , wherein the pressure regulator comprises a vacuum chamber separate from the storage chamber. 
     
     
         181 . The device of  claim 180 , wherein the vacuum chamber has a pressure less than ambient pressure before the device is applied to the subject. 
     
     
         182 . The device of  claim 178 , further comprising a cutter positioned to cause release of blood from the subject into the inlet. 
     
     
         183 . The device of  claim 182 , wherein the cutter comprises a needle. 
     
     
         184 . The device of  claim 182 , wherein the cutter comprises a microneedle. 
     
     
         185 . The device of  claim 182 , wherein the cutter comprises a blade. 
     
     
         186 . The device of  claim 178 , wherein the separation membrane comprises a polymer. 
     
     
         187 . The device of  claim 178 , wherein the separation membrane has an average pore diameter of less than about 20 micrometers. 
     
     
         188 . A device for receiving blood from a subject and processing the blood to form plasma or serum, the device comprising:
 an actuator;   an inlet for receiving blood from the subject into the device;   a pressure regulator able to mechanically create a vacuum to facilitate receiving the blood into the device, the pressure regulator comprising a flexible concave member moveable between a first configuration and a second configuration upon actuation of the actuator;   a separation membrane in fluid communication with the inlet, the separation membrane sized such that the blood received into the device and passing through the separation membrane is separated to form plasma or serum; and   a storage chamber for receiving the plasma or serum.   
     
     
         189 . The device of  claim 188 , 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. 
     
     
         190 . The device of  claim 188 , wherein the pressure regulator comprises a vacuum chamber separate from the storage chamber. 
     
     
         191 . The device of  claim 190 , wherein the vacuum chamber has a pressure less than ambient pressure before the device is applied to the subject. 
     
     
         192 . The device of  claim 188 , further comprising a cutter positioned to cause release of blood from the subject into the inlet. 
     
     
         193 . The device of  claim 192 , wherein the cutter comprises a needle. 
     
     
         194 . The device of  claim 192 , wherein the cutter comprises a microneedle. 
     
     
         195 . The device of  claim 192 , wherein the cutter comprises a blade. 
     
     
         196 . The device of  claim 188 , wherein the separation membrane comprises a polymer. 
     
     
         197 . The device of  claim 188 , wherein the separation membrane has an average pore diameter of less than about 20 micrometers.