CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claim priority to U.S. Patent Application No. 61/828,149, titled "ELECTROKINETIC PUMPS," and filed May 28, 2013, the entirety of which is incorporated by referenced herein. This application also claims priority to U.S. Patent Application No.

61/917,848, titled "ELECTROKINETIC PUMPS," and filed December 18, 2013, the entirety of which is incorporated by reference herein. INCORPORATION BY REFERENCE

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. BACKGROUND

[0003] Referring to FIG. 1 A, a traditional reciprocating dual action electrokinetic pump assembly 100 includes an electrokinetic engine 103 having a first chamber 102 and a second chamber 104 separated by a porous dielectric material (not shown), which provides a fluidic path between the first chamber 102 and the second chamber 104. Capacitive electrodes are disposed within the first chamber 102 and the second chamber 104. In use, the dual action electrokinetic pump assembly 100 works by producing electrokinetic or osmotic flow of a pump fluid through the dielectric material from one chamber 102, 104 to the other chamber 102, 104 as a voltage is applied across the electrodes. The flow of the pump fluid from one chamber to the next causes a movable member 1 12, 1 14 connected to the respective filing chamber 102, 104 to move, thereby providing pumping of a fluid from a fluid reservoir into a delivery chamber.

[0004] Electrokinetic pump systems generally are able to pump or deliver approximately the same amount of delivery fluid as the amount of pump fluid transferred from one chamber to the other. In a traditional non-reciprocating EK system, one pump chamber is larger and overfilled with pump fluid relative to the desired delivered amount to ensure that there is always enough pump fluid to completely fill the opposite chamber and thus delivered the desired volume. For example, for a desired delivery volume of 25uL per stroke, the rear chamber can be designed to hold, and then filled with, 40uL of fluid while the front chamber can be designed to hold 25uL. Thus, there will always be enough pump fluid from the rear chamber to fill the front chamber and deliver 25uL of fluid. [0005] In contrast, in a traditional reciprocating EK pump assembly 100, it is ideal to have the pump chambers 102, 104 be filled such that one side of the pump chamber is at a maximum stroke volume while the other side is at a minimum stroke volume so that the maximum stroke volume can be achieved. For example, in a system designed to delivery 25uL of fluid, it is ideal to have one pump chamber 102 is filled with 25 uL of pump fluid while the other pump chamber is filled with 0 mL of pump fluid and vice versa. Thus, each chamber should be designed to hold

25uL, and 25uL of pump fluid total should be placed in the chambers 102, 104. In practice, however, it is nearly impossible to fill or maintain the chambers 102, 104 with the exact amount of desired fluid (due, for example, to errors in manually or mechanically filling the chambers and/or evaporation of the pump fluid during use).

[0006] If too little pump fluid is placed in the chambers 102, 104 (e.g., less than 25uL for a 25uL delivery stroke), then the stroke volume will be limited to that amount of fluid. On the other hand, referring to FIG. IB, if too much pump fluid is placed in the chambers 102, 104, then the system will also pump less than the desired amount of fluid. For example, if each chamber is designed to hold 25ul, but one side is filled with 12.5ml to begin while the other side is filed with 22.5ml to begin, then each stroke volume will be only 15uL (as the extra l OuL will remain in the overfilled chamber, prohibiting lOuL of fluid from moving into and out of that chamber, and thus pumping lOuL less than desired). Thus, not filling or maintaining the chambers precisely for a reciprocating EK pump system can disrupt the precision and efficiency of the system. Accordingly, a reciprocating EK pump system with a finely tuned amount of buffer solution is desired.

[0007] Furthermore, during wound treatment, it is advantageous to incorporate the concept of Negative Pressure Wound Therapy (NPWT), which has been proven particularly useful in healing large wounds, such as surgical wounds. However, such traditional NPWT systems are costly and require the patient to remain still in bed during treatment. Further, it can be difficult to accurately measure and maintain the negative pressure at the treatment site to ensure proper treatment.

[0008] Finally, none of the commercially available would treatment systems incorporate fluid delivery to either treat or cleanse the wound automatically. It is desirable to have a small, portable pumping system that can provide both fluid delivery and evacuation to treat the wound.

SUMMARY OF THE DISCLOSURE

[0009] Described herein is a dual action reciprocating electrokinetic pump system with a buffer reservoir. Also described herein is a wound treatment system that can include the reciprocating EK pump system and/or that can provide accurately monitored negative pressure wound therapy, such as with a pressure sensor attached directly to the wound patch.

[00010] In general, in one embodiment, an electrokinetic pump system includes a

reciprocating electrokinetic engine configured to pass electrokinetic pump fluid therethrough, a pair of pump chambers surrounding the electrokinetic engine, a pump fluid reservoir containing an electrokinetic pump fluid and in fluid communication with the pair of pump chambers, and a check valve. Each pump chamber is configured to deliver a delivery fluid when pump fluid is transferred thereto. The check valve is configured to allow electrokinetic pump fluid from the pump fluid reservoir into at least one of the chambers.

[00011] This and other embodiments can include one or more of the following features. The check valve can be configured to open and permit flow of fluid from the pump fluid reservoir when the pump fluid level in the system is below a threshold amount. The fluid pump reservoir can be a closed-ended tube. The fluid pump reservoir can be wrapped at least partially around a housing of the reciprocating electrokinetic engine and the pair of pump chambers. The electrokinetic pump system can further include a wound patch and a controller containing electronic instructions for operation of the electrokinetic engine to deliver or evacuate fluid from the wound patch. The pump fluid reservoir can be a tube capped with a moisture barrier grease. The system can further include first and second inlet check valves configured to allow the delivery fluid to be pulled in or out of the pair of pump chambers, and the reservoir check valve can be set to a higher cracking pressure than the first and second inlet check valves. The pump fluid reservoir can be a flexible tube.

[00012] In general, in one embodiment, a wound treatment system includes a wound patch, a first electrokinetic pump configured to deliver fluid to the wound patch, a second electrokinetic pump configured to evacuate the wound patch and hold a pressure under the wound patch at a set negative pressure, and a pressure sensor connected to the wound patch and configured to measure the pressure under the wound patch.

[00013] This and other embodiments can include one or more of the following features. The wound treatment system can further include a pressure sensing line having air therein. The pressure sensing line can extend between the pressure sensor and the wound patch. The pressure sensing line between the pressure sensor and the wound patch can be adapted to function as a noise dampener of the pressure signal from the wound patch. The pressure sensing line can be a straight tube, a tube with a single loop between the pressure sensor and the wound pump or a tube formed into a coil. The pressure sensor can include a filter configured to filter vibrational noise. [00014] in general, in one embodiment, a method of restoring a volume of an electrokinetic pumping fluid to an electrokinetic pump system includes: (1) monitoring an operation of an electrokinetic pump system; (2) determining an amount of pumping fluid lost when a desired pump stoke volume of pumping fluid is decreased; and (3) replenishing the pumping fluid according to the determining step while the electrokinetic pump system remains in operation.

[00015] This and other embodiments can include one or more of the following features. The replenishing step can further include drawing a volume of pumping fluid from a pumping fluid reservoir disposed adjacent to a housing containing the electrokinetic pump system. The replenishing step can further include drawing a volume of pumping fluid from a tube containing pumping fluid.

[00016] In general, in one embodiment, a method of providing a pressure based wound therapy includes: (1) applying a wound patch to a wound site; (2) operating an electrokinetic pump to deliver a wound therapy fluid from a reservoir to the wound site; (3) monitoring the pressure within the wound site; and (4) operating the electrokinetic pump to maintain a pressure therapy profile within the wound site.

[00017] This and other embodiments can include one or more of the following features. The pressure therapy profile can include maintaining a negative pressure at the wound site. The pressure therapy profile can include delivering a preset volume of a therapeutic agent to the wound site, allowing a preselected dwell time to elapse, and evacuating the wound side by operation of the electrokinetic pump. Before or during the preselected dwell time, the electrokinetic pump can operate to provide or maintain a negative pressure therapy profile in the wound site. The method can further include operating the electrokinetic pump to remove fluid from the wound site. The method can further include a controller in communication with the electrokinetic pump system and can contain computer readable instructions for performing the operating and monitoring steps. The overall volume can be within 8 inches x 3.25 inches x 1.25 inches. The electrokinetic pump system can have a weight of less than 300 grams, less than 350 grams, less than 400 grams, less than 450 grams or less than 500 grams. The electrokinetic pump system can further include a wound patch.

[00018] In general, in one embodiment, an EK wound treatment system includes a first electrokinetic pump configured to deliver fluid to a wound patch. A second electrokinetic pump is configured to evacuate the wound patch and hold a pressure under the wound patch at a set negative pressure. A controller contains electronic instructions for operation of the first and the second electrokinetic pumps to deliver fluid to or evacuate fluid from the wound patch. A manifold base is configured to support the first and second electrokinetic pumps and the controller. A reservoir is supported by the base and adapted and configured for fluid communication with the first and the second electrokinetic pumps.

[00019] This and other embodiments can include one or more of the following features. The EK wound treatment system can further include a pressure sensor connected to the wound patch and configured to measure the pressure under the wound patch in communication with the controller. The manifold can further include a first surface configured to receive the reservoir and a second surface configured to receive the EK pumps or the controller. The first surface can be on one side of the base and the second side can be on an opposite side of the base. The manifold can further include a recess adapted and configured to receive all or a portion of the reservoir. The reservoir can further include a first bag having a first connection port and a second bag having a second connection port. The electrokinetic pump system can further include a clamp configured to join the first bag and the second bag. The clamp can be formed on one or both of the first bag and the second bag. The reservoir can be configured to hold the delivery fluid and/or the waste fluid. The manifold can further include one or more of integral fluid conduits, fluid connection ports for one or more pumps or reservoir connectors, electronic component connections, electrical connectors, pump electronic connectors, pump fluid connections, housing connections, battery housings, power connections, sensor lines, sensor attachment points, surface shaped to engage with a reservoir, surface shaped to engage with or conform to a patient, or mounting surface on a patient or a mounting strap. The reservoir can further include one or more attachment points, one or more single bag containers, one or more double bag container, a fluid barrier that when the reservoir is coupled to the manifold can be between the manifold and the reservoir, one or more surfaces shaped to engage with a manifold, one or more surfaces shaped to engage with or conform to a patient or mounting surfaces on a patient, or mounting straps. The electrokinetic pump system can further include a reservoir frame having one or more attachment points to coupling to the manifold, surfaces shaped to engage with a manifold, surfaces shaped to engage with or conform to a patient or mounting surfaces on a patient or mounting straps, or other device for maintaining the EK pumping manifold in a therapy position on the user. BRIEF DESCRIPTION OF THE DRAWINGS

[00020] FIG. 1 A is a traditional reciprocating EK pump assembly.

[00021] FIG. IB shows a traditional reciprocating EK pump assembly with one pump chamber overfilled with pump fluid, resulting in a lower stroke volume.

[00022] FIG. 2 is a reciprocating EK pump assembly with a buffer reservoir to automatically fill the pump chambers. [00023] FIG. 3 shows the initial fill, forward, and reverse strokes in a reciprocating EK pump assembly with a buffer reservoir.

[00024] FIG. 4 shows a pump system including a flexible tube for the buffer reservoir.

[00025] FIG. 5 shows an exemplary wound pump manifold incorporating a reciprocating EK pump assembly.

[00026] FIG. 6 shows an exemplary wound pump system including reciprocating EK pump assemblies for delivery and evacuation as well as pressure sensors in the fluid lines to determine total fluid flow in and out of the wound patch.

[00027] FIG. 7 shows an exemplary wound pump system including reciprocating EK pump assemblies for delivery and evacuation as well as dual pressure sensors in the fluid lines to determine total fluid flow in and out of the wound patch.

[00028] FIG. 8 shows an exemplary wound pump system including reciprocating EK pump assemblies for delivery and evacuation as well as a pressure sensor connected directly to the wound patch via a tube of air to monitor the pressure under the patch.

[00029] FIG. 9 shows an exemplary wound pump system including reciprocating EK pump assemblies for delivery and evacuation as well as a filtered pressure sensor connected directly to the wound patch to monitor the pressure under the patch.

[00030] FIGs. 10 and 1 1 show use of a wound treatment system for fluid delivery and negative pressure wound therapy.

[00031] FIG. 12A shows another exemplary wound pump manifold embodiment incorporating a reciprocating EK pump assembly.

[00032] FIG. 12B is a side view an exemplary wound pump manifold embodiment having pump ports in the support base.

[00033] FIG. 13 is a side view of an alternative configuration of a wound pump manifold having a stacked component configuration and an optional housing.

[00034] FIG. 14A is a side view of an exemplary single walled reservoir or fluid container configuration shown in position below the manifold base.

[00035] FIGs. 14B and 14C illustrate side views of exemplary double walled and single walled reservoir or fluid container configurations shown in position below the manifold base.

[00036] FIG. 14D is a side view of an exemplary fluid barrier between a double walled reservoir or fluid container and the manifold base.

[00037] FIG. 15 is a side view of an exemplary single walled reservoir or fluid container with a top supply configuration shown in position below the manifold base.

[00038] FIG. 16 is a side view of an exemplary single walled reservoir or fluid container with a top drain configuration shown in position below the manifold base. [00039] FIG. 17 is a schematic view of a multiple delivery fluid reservoir and selector valve for custom fluid delivery profiles.

[00040] FIG. 18 is a pressure versus time signal trace from a wound patch pressure sensor during operation of a wound pump manifold.

[00041] FIG. 19A is a side view of a base having a tray or attachment configured to receive a framed or frameless reservoir.

[00042] FIG. 19B is a side view of a base having complementary mating connection points to receive a similarly configured frameless reservoir.

[00043] FIG. 19C is a side view of a base having a plurality of magnetic connection points to receive a similarly configured frameless reservoir.

[00044] FIG. 20 is side view of a framed reservoir having connection points for attachment to the manifold base member.

[00045] FIG. 21 is an isometric view of a framed reservoir having corner mounting locations and illustrating five optional connection port locations I, II, III, IV and V for coupling to one or more manifold pumps.

[00046] FIG. 22A is an isometric view of a two notched bag reservoir held together by a clamp.

[00047] FIG. 22B is an isometric view of the top bag of FIG. 22A.

[00048] FIG. 22C is an isometric view of the bottom bag of FIG. 22A.

[00049] FIG. 23 is an isometric view of another two notched bag reservoir embodiment having different shaped bag coupling ports.

[00050] FIGs. 24A and 24B illustrate isometric and bottom up views, respectively, of an integrated wound pump manifold.

[00051] FIG. 24C is an isometric view of an EK pump component configured for a plug -n- pump use with the manifold of FIGs. 24A and 24B.

DETAILED DESCRIPTION

Reciprocating Electrokinetic Pump with Buffer Reservoir

[00052] Referring to FIG. 2, a reciprocating electrokinetic pump assembly 200 includes an electrokinetic engine 203 connected to a first chamber 202 and a second chamber 204. The electrokinetic engine 203 includes a porous dielectric material surrounded or sandwiched by porous capacitive electrodes. Electrokinetic engines and reciprocating electrokinetic engines are described in U.S. Patent Application No. 1 1/1 12,867, filed April 21, 2005, titled

"ELECTROKINETIC DELIVERY SYSTEMS, DEVICES AND METHODS," Patent No. 7,517,440, the entire content of which is incorporated by reference herein. The pump chamber 202 includes a movable member 212, and the pump chamber 204 includes a movable member

214. The capacitive electrodes are in communication with an external voltage source to provide a voltage thereacross to drive the electrokinetic engine.

[00053] The electrokinetic engine 203 and chambers 202, 204 are connected through fluid lines to a delivery fluid reservoir 226 and a delivery chamber 228. One-way check valves 244a, b, c, d are configured to allow delivery fluid to be pulled in and out of pump chambers 102, 104 for delivery. Further, an external buffer reservoir 222 is connected through a high pressure check valve 254 to both of the pump chambers 202, 204. The high pressure check valve 254 can be set to a higher cracking pressure than the one-way check valves 244a,b,c,d.

[00054] In use, as a voltage is applied across the electrodes of the electrokinetic engine 203, pump fluid will flow through the engine 203, such as from pump chamber 204 to pump chamber 202. As pump chamber 202 is filled with pump fluid, the movable member 212 will move, thereby pushing delivery fluid out of the chamber 202 into the delivery chamber 228 through one-way check valve 244b (the delivery fluid from chamber 202 is prevented from exiting the inlet port via the one-way check valve 244a). Simultaneously, pump fluid is removed from pump chamber 204, causing the movable element 214 to move and draw delivery fluid from the fluid reservoir 226 into the chamber 204 through check valve 244d (again, the delivery fluid is prevented from being drawn into the pump chamber 204 through the one-way check valve 244c). When all of the pump fluid has been transferred from the chamber 204 to the chamber 202 so as to create a full delivery stroke (described further below), the voltage direction can be reversed and the flow of pump fluid reversed (i.e., such that pump fluid travels from pump chamber 202 to 204, allowing delivery fluid to be delivered to the delivery chamber 228 from pump chamber 204 and filled into pump chamber 202 from the reservoir 226).

[00055] The external buffer reservoir 222 and high pressure check valve 254 can be designed to allow the pump fluid to be automatically filled to the desired amount during usage of the pump (e.g., to compensate for the fluid levels decreasing from evaporation or not being filled high enough during manufacturing). If the level of the pump fluid has gotten too low to deliver the desired stroke when pumping from chamber 202 to chamber 204, then the movable element 212 will hit the edge of the pump chamber 202 before chamber 204 is filled all of the way. Once this occurs, the EK engine 203 will continue to generate pressure - positive pressure on chamber 204 side and negative pressure on the chamber 202 side. The high pressure check valve 254 to the external buffer reservoir 222 will be opened when the negative pressure on chamber 202 is lower than the check valve cracking pressure. As a result, the external buffer reservoir 222 can thus deliver fluid to the system. The stroke can then continue until the chamber 204 is filled with the appropriate amount of pump fluid. Once the chamber 204 is filled, the EK engine 203 will not be able to generate negative pressure to activate the buffer check valve 254, thereby closing the valve 254 and ensuring that the correct amount of buffer fluid is filled into the chambers.

Normal reciprocating operation of the system 200 can then be resumed.

[00056] In some embodiments, the system 200 can be designed to only fill only when the engine 203 runs in one direction, e.g., as the engine 203 runs to pump the pump fluid from pump chamber 202 to pump chamber 204. Such a system advantageously requires only a single fluid connection to the lines of the pump chamber (as shown in FIG. 2). Because the engine 203 continuously reverses direction, such automatic refilling in only one direction still allows for quick and efficient refilling of the buffer reservoir when necessary. In other embodiments, the buffer reservoir 222 can be used to fill either chamber 202, 204 during operation in any direction

(for example, by having a second fluid line from the buffer reservoir connected directly to the line into pump chamber 204).

[00057] Advantageously, because the high pressure check valve 254 is set to a higher cracking pressure than the one-way check valves 244a,b,c,d, the check valve 254 will not open during normal operation (i.e., unless the pressure is high enough to as to indicate a low level of pump fluid in the system 200).

[00058] The system 200 can thus automatically fills the pump chambers to the desired pump fluid level, thereby maintaining the precision and efficiency of the pump. The system 200 is advantageously twice as efficient as a non-reciprocating pump, as strokes in both the forward and the reverse direction result in delivering fluid.

[00059] In some embodiments, it is sufficient to have a slight difference, such as up to 5ul, up to 3ul, or up to 2ul, between the desired pumping volume and the actual amount of pump volume. For example, chamber 204 can have a stroke volume of 24 ul, and chamber 202 can have a stroke volume of 26 ul. Both can be at an initial volume of 10 ul. When pumping fluid from chamber 202 to chamber 204, chamber 204 is filled completely via the buffer reservoir and be able to pump 24 ul. On the reverse stroke, pumping from 204 to 202, the chamber cannot draw from the buffer reservoir and only be able to deliver 24 ul. The 2 ul of inefficiency can be ignore or accepted. If ignored or accepted, the system will always perform to the smallest of the two chambers (in this case, pumping 24 ul).

[00060] Referring to FIG. 3, in some embodiments, the pump fluid in the system 200 can be deliberately underfilled during filling or manufacturing of the system. When pumping starts by running the electrokinetic engine 203, the pumping fluid from one chamber (e.g. chamber 202) will be transferred to the other chamber (e.g. pumping chamber 204). After all of the pumping fluid has been pulled from one chamber to the other, the pressure differential will crack the check valve 254 and draw fluid from the external buffer reservoir 222 as described above. Deliberately underfilling the system 200 allows the system to be optimized and/or calibrated after the initial stroke while avoiding overfilling the chambers.

[00061] Referring to FIG. 4, in some embodiments, the buffer reservoir 222 can be a flexible tube that can be configured to be wrapped around the electrokinetic engine and pump chambers (which can be, for example, stacked in a cylindrical coin shape as shown in FIG. 4). For example, the buffer reservoir 222 can be made of a tubing of thick polyethylene that is made of 3/8" tubing with 1/16" wall, and capped with a dose of grease or silicone oil. In other examples, the buffer reservoir 222 can be a bag fluidly connected to the check valve or an aluminum or stainless steel tubing that has a plastic coated inner diameter and capped with a heavy dose of grease, silicone oil, or viscous paraffin oil. The buffer reservoir 222 can be made of a material with very low water vapor transmission rates, such as aluminize plastic bag.

Electrokinetic Pump for Wound Treatment

[00062] Because the reciprocating EK system 200 is approximately twice as efficient as non- reciprocating pumps, it can advantageously be much more compact than traditional electrokinetic pump systems. For example, a reciprocating EK pump can be used as part of a portable wound treatment system. Electrokinetic pump systems for use with wound treatment systems are described in U.S. Patent Application No. 13/632,884, filed October 1, 2012, titled

"ELECTROKINETIC PUMP BASED WOUND TREATMENT SYSTEM AND METHODS," Publication No. US-2013-0085462-A1, the entire content of which is incorporated by reference herein.

[00063] Referring to FIG. 5, a portable wound treatment system can be configured to deliver fluid to a wound treatment site and evacuate the wound treatment site. The wound treatment system can include a manifold 500 having manifold base 564 with a delivery pump 520a and an evacuation pump 520b. A fluid container 525 can be positioned next to, and substantially parallel with, the pumps 521,b (i.e., on the same side of the base 564), as shown in Figure 5 to hold the delivery and/or waste fluids. Other placements of the container 525 are possible, as descried further below. The container 525 can be a dual lumen container (e.g. with a flexible or stretchable membrane between the lumens) to hold both supply and waste fluids or there can be two separate containers 525 to hold the supply and waste fluids. In some embodiments, if a dual lumen container 525 is used, the container 525 can be designed to hold more fluid than is initially present in the container 525. For example, the container 525 can be designed to hold 150ml, but be filled with only 100ml of deliver fluid. Such additional space provides for the removal of extra waste from the wound site (such as exudates, etc.) that can accumulate during wound treatment. The manifold 500 can also hold a battery 552, a controller 554, and pressure sensors for evacuation 556 and delivery 558.

[00064] Because the delivery and evacuation pumps 520a,b can be reciprocating pumps with a buffer reservoir as described above, they can be compact and lightweight, allowing the entire manifold to be compact and lightweight. For example, the manifold 500 can be less than 30 cubic inches, such as less than 20 cubic inches. In one embodiment, the manifold 500 is 2.75 inches by 7 inches by 1 inch with a 150ml reservoir. The manifold can be less than 300g, such as approximately 23 Og without fluid in the delivery and/or waste reservoir. Further, each pump (including an engine, two chambers, and a fluid reservoir) can be less than 50g, such as approximately 3 Og.

[00065] Another embodiment of a portable wound treatment system 1200 is shown in Figures 12A-12B. The manifold 1200 of the wound treatment system can include a manifold base 1264 two reciprocating EK pumps - one configured to deliver fluid to a wound treatment site (supply pump 1220a) and the other configured to evacuate the environment of the wound treatment site (evacuation pump 1220b). A controller 1254 can be configured to control the deliver and/or evacuation using the 1220a,b. The controller 1254 and pumps 1220 can all be flushly mounted onto the base 1264. Further, a container 1225 can be located on the underside of the manifold base 1264 (i.e., opposite to the pumps 1220a,b and controller 1254) to hold the delivery and/or waste fluids. Advantageously, by including the container 1225 on the opposite side of the manifold base 1264 as the pumps 1220a,b and controller 1254, leakage of fluid from the container 1225 can be prevented from reaching the pumps 1220a,b, controller 12554, and other electronics. Thus, in the event of a leaking reservoir or container 1225, the fluid leak would be isolated from the electronics or power supply, thereby ensuring ongoing pump operation while also protecting the electronics and power supply from fluid damage. Having the container 1225 in the cut-out on the underside of the manifold base 1264 can also advantageously reduce the footprint of the manifold 1200. The manifold base 1264 and the fluid container 1225 may be coupled in a number of different ways, as described further below.

[00066] Fluid lines can connect the patch, the pumps 1220a,b, and the reservoir 1225 to one another. For example, line 1231 can extend from the wound patch to the evacuation pump 1220b to allow flow therebetween. Fluid line 1232 can connect the evacuation pump 1220b to the reservoir 1225. Fluid line 1234 can connect the reservoir 1225 to the supply pump 1220a, and supply line 1233 can connect the supply pump 1220a to the wound patch. In addition, the pumps 1220a,b may each include a buffer reservoir 1222 (only buffer reservoir 1222 for supply pump 1220a can be seen in FIG. 12A) to automatically fill the respective pump 1256, 1258 with buffer fluid, as described above. [00067] In some embodiments, rather than including separate lines that must be connected together (i.e. from the reservoir to the pumps and the pumps to the patch), through-base pump ports 1288 (see FIG. 12B) can be included. The through-base pump ports 1288 can provide a simple snap mechanism, for example, for the supply and return lines. Other fluid pathways or pump vias may be provided within, on, or in the base depending upon configuration.

[00068] Another embodiment of a wound pump manifold 1300 is shown in FIG. 13. The manifold 1300 is similar to manifold 1200 except that the controller 1354, battery 1352, and pumps 1320a,b are located in a housing to further separate the container 1325 from the electronics. Further, the controller 1354 and battery 1352 are stacked over the pumps 1320a,b.

[00069] Because the delivery and evacuation pumps can be reciprocating pumps with a buffer reservoir as described above, they can be compact and lightweight, allowing the entire manifold to be compact and lightweight. For example, the manifold 1200 can be less than 30 cubic inches, such as less than 20 cubic inches. In one embodiment, the manifold is 8 inches by 3.25 inches by 1.25 inches with a 150ml reservoir. Other reservoir sizes and configurations are possible such as, for example, 100 ml, 200 ml, 250 ml, 300 ml or other size depending upon the specific wound treatment therapy being provided. Still further, the manifold can be less than 300g, such as approximately 230g without fluid in the delivery and/or waste reservoir. In still another further aspect, each pump (including an engine, two chambers, and a fluid reservoir) can be less than 50g, such as approximately 30g.

[00070] Given the pumping efficiency and configurations of the reciprocal EK pumping systems, the manifolds 500, 1200, 1300 can advantageously deliver large amounts of fluid at low voltages. For example, a wound pump manifold may operate to delivery 1 liter of fluid using only 1.5 volts. In another configuration, an EK wound pump manifold may deliver 4 liters of fluid using only 3 volts. In one specific configuration, an EK pump wound manifold can deliver 70 ul of fluid with 0.225 mJ energy. In an illustrative embodiment, 0.025A at 3 volts can be provided to an EK pump for 6 sec. As a result, 0.225 milijoules applied to the pump can move 70 nl of fluid. Put another way, one exemplary EK pump manifold configuration can deliver about 1 liter of fluid with a single alkaline battery AA battery. Still further, another exemplary EK pump manifold configuration can deliver about 4 liters of fluid using 2 AA alkaline batteries.

[00071] The containers for drainage and supply for any of the embodiments described herein can be configured in a number of different ways. For example, FIG. 14A is a side view of an exemplary fluid container 1425 underneath a base 1464. The container 1425 has a drainage lumen 1427a and a supply lumen 1427b separated by a single wall 1488, such as a movable or flexible membrane. Figures 14B -14D show that a separate liner 1490 can be placed around one or both of the lumens 1427a,b to protect from leakage. Further, in some embodiments, a fluid barrier 1489 can be placed between the reservoir 1425 and the base 1464 to further prevent fluid from reaching the pumps, controller, or other electronics.

[00072] In some embodiments, rather than being located side-by-side and flush with the base, the lumens of the reservoir can be stacked upon one another. For example, Figure 16 shows a base 1564 with a supply 1527b located flush therewith and a drain 1527a located therebelow. Figure 17 shows the drain 1627a,b sandwiched between the supply 1627b and the base 1664. The embodiments illustrated in FIGs. 15 and 16 may also be modified to be configured as illustrated in the variations of FIGs. 14A-14D.

[00073] In some embodiments, the fluid container can be configured to include multiple sub- containers for delivery of multiple fluids. FIG. 17 is a schematic view of a multiple delivery fluid reservoir and selector valve for custom fluid delivery profiles. FIG. 17 illustrates a reservoir or container 1725 having multiple delivery fluid reservoirs 1791a,b,c and a selector valve 1781 configured to select which fluid is delivered. Each reservoir 1791a,b,c contains a delivery fluid Dl, D2 and D3. The delivery fluid in each reservoir may be the same or different and may be selected based on the particular wound therapy being delivered or the particular needs of a patient receiving wound therapy treatment using an EK pump manifold embodiment. The delivery fluids may include, for example, saline, a pharmacologically active agent, a drug, a growth promoting compound or agent, an antibiotic agent, an antimicrobial agent, a pain relieving agent or other compound as specified by the particular wound therapy protocol being delivered. The selector valve 1787 is connected to each of the reservoirs 1791a,b,c and as needed to the wound patch, depending upon the specific configuration being employed. The selector valve 1781 may be set manually or be under the control of the pump manifold controller, depending upon the specific requirements of the wound therapy regime being implemented.

[00074] The fluid containers for delivery fluid and/or waste described herein may be coupled to the manifold base using any of a wide variety of different coupling techniques or mechanisms. For purposes of illustration, the containers are described in general terms herein as being frameless or framed. Any of the attachment techniques described in FIGs. 19A-21 may be used in any of the others with appropriate modification.

[00075] FIG. 19A is a side view of a manifold 1900A having a base 1964 with a tray 1987 or attachment configured to receive a framed or frameless reservoir 1925 therein. For example, the reservoir 1925 can be configured to snap or slide into the tray 1987. The reservoir 1925 may have edge or surface features provided to ensure secure mating to the base 1964 or fluid connection thereto. In addition, edge or surface features or components may be included to ensure that the reservoir 1925 is properly aligned and received into the base 1964 (i.e., that the delivery connection port for the reservoir is coupled to the appropriate port in the base and similarly for the evacuation port connection).

[00076] FIG. 19B is a side view of a manifold 1900B having a base 1964 having mating connection points 1977a,b (e.g., female connection points) to receive a frameless reservoir 1925 including complementary mating connection points 1978a,b (e.g., male connection points). The mating connections are illustrated as hemispherical and other configurations such as shaped notches, tongue and groove or pin and socket may also be employed in other configurations. It is to be appreciated that any male - female connector type may be employed to join the reservoir 1925 to the base frame 1964.

[00077] FIG. 19C is a side view of a manifold 1900C having a base 1964 with magnetic mating features 1968a,b,c,d,e configured to receive magnetic mating features 1969a,b,c,d,e on a frameless reservoir 1925. Magnets may be placed on one or both of the base and the reservoir. Alternatively, magnets may be placed on one and a suitable magnetically attractive plate positioned on the other component. In still another configuration, the magnet orientation may be used to ensure proper mating of the reservoir to the base.

[00078] FIG. 20 is side view of a manifold 2000 where the reservoir 2025 includes a support frame 2027. The support frame 2027 can be configured to attach to the base 2064, such as through bolts or screws. Corner mounts can be used to secure the frame to the receiving surface of the manifold base. In this embodiment, the receiving surface is the bottom surface. Other surfaces of the manifold base may be utilized as the connecting surface depending upon the specific design considerations of the EK pumping manifold configuration.

[00079] FIG. 21 is an isometric view of a framed reservoir 2025 having a solid frame 2055 and corner mounting locations 2063a,b,c,d configured to secure the frame 2055 to a manifold. The mounting locations 2063a,b,c,d are shown in the support frame corners for purposes of illustration. The mounts 2063a,b,c,d may be located in any suitable location, and there may be more or fewer than the illustrated four mounting points. The reservoir 2025 also includes optional connection port locations I, II, III, IV and V for coupling to one or more manifold pumps. As illustrates in FIG. 21, the connection port locations may be placed in any number of different positions depending upon the specific design criteria for an EK wound pump manifold system.

[00080] FIGS. 22A-22C show a two-bag reservoir 2225 including a top bag 2223a and a bottom bag 2223b that are held together by a clamp 2275. Each bag 2223a,b can be a notched bag (i.e., be shaped similar to a boot). The clamp 2275, when closed, holds the bags 2223a,b in position and provides a base for coupling connection ports 2266a,b to the manifold base fluid connection ports. In one embodiment, the connection ports 2266a,b can be configured to extend through the clamp 2275 (as shown in Figure 22A). In addition to or in place of the clamp 2275, a clip or other joining element can be used to hold the bags 2223a,b together. In an alternative configuration, only one of the top bag or bottom bag is provided with a clip, clamp or other joining element to hold the bags in position for use with the EK pumping manifold.

[00081] FIG. 23 shows a two-bag reservoir 2325 where each connection port 2366a,b is a different shape. Having ports 2366a,b of different shapes can advantageously ensure that fluid connections are properly made to the manifold. In this way, there is only a single proper orientation and connection mode for the reservoir to the manifold base.

[00082] In still further embodiments, the manifold base may be configured to include pumping conduits, fluid connections between components, electronic connections, sensor connections, or built-in sensor ports. FIGs. 24A and 24B illustrate isometric and bottom up views, respectively, of one integrated manifold base 2464. As best seen in FIG. 24A, the integrated manifold base 2464 includes a battery connection 2424, electronic socket 2426 to receive one or more controllers, and pump connections 2428a,b. As shown in FIG. 24B, two fluid connection ports 2430a,b are provided on the bottom of the base 2464 for coupling to a reservoir. An appropriately sized and shaped recessed portion 2442 is provided to receive the reservoir. The reservoir may be configured as described elsewhere and also may be coupled to the base 2464 using any suitable method. The reservoir connection ports 2430a,b can be in fluid communication with fluid conduits within the integrated manifold (not shown).

[00083] Returning to FIG. 24A, pump connections 2428, 2429 are shown, each with two fluid connection ports 2438a,b and 2439a,b, respectively, to be attached to appropriate pump ports. An exemplary EK pump component 2420 for use in an integrated manifold is seen in FIG. 24C. The illustrated EK pump component 2420 has a pair of pump connections 2440a,b with fittings adapted and configured to couple to the connections 2438a,b or 2439a,b provided on the manifold base. The EK pump component 2420 also includes one or more electronic connection points 2442a,b for connection to the corresponding connection point on the manifold. The illustrated EK pump component 2420 may be configured as a plug-n-pump component. The EK pump component 2420 can be snapped onto the integrated base 2464 of FIG. 24A, thereby forming both fluid and electrical/electronic connections to the fluid, electrical (i.e., power) and control systems or components provided by the manifold. In some embodiments, all connectivity - both fluid and electronic - can be provided by the manifold base. In such a configuration, snap on designs of electronics, pump components, and reservoirs may be provided that mate onto various appropriate connection points on the manifold as illustrated by FIG. 24C and the recess of FIG. 24B. Not shown in these various views would be the one or more internal conduits and connections used to configure the manifold for the desired operation. Advantageously, such an integrated multi-function manifold base may simplify construction, set up, or operation since all fluid and electronic connections are provided.

[00084] Connections through the manifold support base may also include one or more valves, pressure sensors, or other components used in pump operation. The manifold support base may also be integrated into a connection base for power or battery, controller, sensors, and pumps to provide a multipurpose electronic fluid control backplane. The manifold support base may be configured to have all connection points for the pumps and components. The reservoir may be coupled to the base using snaps, velcro, straps, buckles, magnets, or other suitable coupling techniques. The manner of coupling the reservoir may permit changing of a reservoir in use or configured for single use. In a single use configuration, the manifold connections may have a failure mode or tamper mode that renders the system inoperable after the single use or if tampered with for multiple use.

[00085] An exemplary wound pump system 600 using the reciprocating EK pump assembly with buffer reservoir is shown in FIG. 6. The system includes two electrokinetic engines 603a,b each configured to provide pumping in both directions (i.e., powering two "pumps" via respective chambers 602a, 604a, 602b, 604b) and to be refilled by a buffer reservoir, as described above with respect to FIG. 2. The first electrokinetic engine 603a can be configured to deliver fluid from a drug reservoir to the wound site, which can be covered by a wound patch 666. The second electrokinetic engine 603b can be configured to evacuate fluid from the patch 666 to a waste collection 628. A pressure sensor 662 in the fluid lines can be used to evaluate the amount of fluid entering the patch 666 while a second pressure sensor 664 in the fluid lines can be used to evaluate the amount of fluid exiting the patch 666. By having the pressure sensors 662 and 666 between the reservoirs and the pump systems (rather than between the pump systems and the patch), a clearer pressure signal, and thus more precise flow volume or rate, can be obtained.

[00086] A similar system 700 is shown in FIG. 7, where dual pressure sensors 762a,b and 764a,b in the fluid lines can be used to measure the total flow volume into the wound patch and out of the wound patch using pressure differentials between the dual sensors. Mechanisms for controlling the delivery and removal of fluid through pressure sensors and pressure differentials are described in U.S. Patent Application No. 13/465,902, filed May 7, 2012, titled "SYSTEM AND METHOD OF DIFFERENTIAL PRESSURE CONTROL OF A RECIPROCATING ELECTROKINETIC PUMP, Publication No. US-2012-02821 1 1-Al , the entire content of which is incorporated herein by reference. Although FIG. 7 does not show the buffer reservoirs and associated check valves, it is understood that these can be present. [00087] FIG. 18 is a pressure versus time signal trace from a wound patch pressure sensor during operation of a wound pump manifold. The trace illustrates how the pressure within the wound treatment patch is controllable using an EK pump manifold as described herein. The controllable change in pressure is attributed to the cyclic operation of the EK pumps to deliver fluid to the patch. Operation of the delivery EK pump produces an increasing pressure reading.

Operation of the evacuation EK pump for removal or evacuation of fluid from the patch produces a decreasing pressure reading.

Negative Pressure Electrokinetic Wound Pump

[00088] In some embodiments, the wound pump systems described herein can be used for negative pressure wound therapy. That is, the evacuation pump can be used to pull fluid from the wound site and then maintain the wound site a predetermined negative pressure. When performing negative pressure wound therapy, it is important to monitor and control the pressure under the wound site precisely.

[00089] In order to compensate for vibrations that can occur during normal wear of the wound pump system (which can then cause errors in pressure readings when measured in the fluid flow lines), a separate pressure sensor can be used to directly measure the pressure under the patch, thereby allowing for precise control over the pressure under the patch for negative pressure wound therapy.

[00090] For example, referring to FIG. 8, a system 800 can include a pressure sensor 888 configured to directly measure the pressure under the patch 866. A tube or column of air 890 can be located between the patch 866 and the pressure sensor 888. The air 890 between the pressure sensor and the patch can advantageously dampen out high frequency noise due to movement of the wound site or other disturbances in the system. The tube can be connected to the wound patch and run parallel to the evacuation tubing. The tube can be straight, spiral, coiled, or otherwise shaped so as to hold air therein.

[00091] In another example, referring to FIG. 9, a system 900 can include a pressure sensor

999 configured to directly measure the pressure under the patch 966. The pressure sensor 999 can be in the fluid lines directly next the patch 966 (as opposed to on the opposite side of the engine 903b). The signal from the pressure sensor 999 can be filtered to remove noise from the fluid lines either by: (1) a passive filter, such as a resistance-capacitance (RC) filter; (2) an active filter, such as an RC with an amplifier; or (3) numerical filtering, such as a moving average, exponential filter, or infinite response filter. In some embodiments, a filter such as described herein can be used with the air sensor described above with respect to FIG. 8, thereby further compensating for any vibrations in the system. [00092] Although FIGs. 8 and 9 do not show the buffer reservoirs and associated check valves, it is understood that these can be present.

[00093] Referring to FIGs. 10 and 1 1, negative pressure wound therapy systems that directly measure the pressure under the patch can be used to precisely maintain the desired pressure under the patch. That is, during evacuation of the pump, it can be determined through the direct pressure measurement whether the desired pressure has been achieved (i.e., if the pressure is low enough). If not, the evacuation pump can be run again. If so, then the negative pressure can be set to dwell for a short time interval, such as 1, 5, or 10 seconds. The pressure can then be checked. If the pressure has gotten too high (e.g., as a result of exudate seeping into the wound site), then the evacuation pump can be run again. The process can be repeated until the total negative pressure wait time has been achieved. Once the negative pressure dwell time has been delivered, the cleansing or medication fluid can be delivered to the wound site. It can then be determined whether the total desired volume has been delivered. If not, the pump can be turned on to deliver more fluid. If so, then the delivered fluid can dwell on the wound site for the desired dwell time. The process of evacuating fluid and holding a negative pressure can then be repeated.

[00094] The systems described herein can thus be used to maintain the wound site at a negative pressure of at least -80mmHg, such as at least -lOOmmHg, -200mmHg, or -300mmHg.

[00095] When a feature or element is herein referred to as being "on" another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being "connected", "attached" or "coupled" to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being "directly connected", "directly attached" or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.

[00096] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as "/".

[00097] Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly", "downwardly", "vertical", "horizontal" and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[00098] Although the terms "first" and "second" may be used herein to describe various features/elements, these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.

[00099] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word "about" or "approximately," even if the term does not expressly appear. The phrase "about" or

"approximately" may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/- 0.1% of the stated value (or range of values), +/- 1% of the stated value (or range of values), +/- 2% of the stated value (or range of values), +/- 5% of the stated value (or range of values), +/- 10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[000100] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others.

Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[000101] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure.

Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.