FIELD

The present application generally relates to the field of dialysis, and more specifically to manifolds for use in a portable dialysis system.

BACKGROUND

Hemodialysis is used for removing toxic wastes from the human body in cases of renal failure, and involves using an artificial kidney in conjunction with an associated machine. The patient's blood is temporarily brought outside of the body with the help of tubes and passed through at least one semipermeable membrane, which may be a group of hollow fibers, in an artificial kidney, also called a dialyzer. The semi permeable membrane separates the blood from dialysate solution. The impurities from the blood pass through the membrane and into the dialysate solutions primarily by osmotic pressures. The cleansed blood is then returned to the body. During this procedure it is also necessary to remove excess fluids from the body. This is accomplished by a process known as ultrafiltration. In this process, fluid is removed from the patient by taking the fluid off through the dialyzer via convection and discarding it. The amount of ultrafiltrate which is removed from the body is normally controlled by the pressure across the semipermeable membrane. This transmembrane pressure is the result of the differential between the blood pressure and the pressure which exists on the dialysate side of the membrane.

In an alternate procedure to hemodialysis, known as hemofiltration, convection is used to withdraw massive amounts of fluid from the body, via the dialyzer and most of that volume is replaced by ultrapure, infusate grade, fluid pumped directly into the blood stream. In this process the ultrafiltrate removal volume is the difference between the amount of fluid removed and the amount of ultrapure infusate injected. Hemofiltration is better at removing large molecular toxins than hemodialysis but is not required in most cases.

The standard dialysis treatment, using an installed apparatus in hospitals, comprises two phases, namely, (a) true dialysis, in which toxic substances and scoriae (normally small molecules) pass through the semipermeable membrane from the blood to the dialysis liquid, and (b) ultrafiltration, in which a pressure difference between the blood circuit and the circuit for the dialysis liquid, more precisely a reduced pressure in the latter circuit, causes the blood content of water to be reduced by a predetermined amount.

Dialysis procedures using standard equipment tend to be cumbersome as well as costly, besides requiring the patient to be bound to a dialysis center for long durations. Conventional systems are also less reliable because of the necessity of using a myriad of tubes comprising the fluid circuits of the purification systems, thus increasing the risks of leakage and breakage. Accordingly there is need in the art for an extracorporeal blood processing system that can be operated in hemodialysis as well as hemofiltration modes, while at the same time offering reasonable portability to the patient. Such a portable dialysis system should also be conducive to using disposable components. Further, there is also a need for novel manifolds for dialysis systems with integrated blood purification system components, such as sensors, pumps and disposables, as well as molded blood and dialysate flow paths to avoid a complicated mesh of tubing and to enhance the robustness of the system.

SUMMARY

According to a first object of the present application, an extracorporeal blood processing system comprises a plastic molded compact manifold that supports a plurality of molded blood and dialysate fluidic pathways along with a plurality of relevant sensors, valves and pumps. A disposable dialyzer is connected to the molded manifold to complete the blood circuit of the system. The compact manifold is also disposable in one embodiment and can be installed by simply inserting into a recess provided in the dialysis unit.

It is an object of the present application to use the aforementioned extracorporeal blood processing system either in hemodialysis or hemofiltration protocol.

Accordingly in one embodiment, hemodialysis, a dialysate regeneration system, comprising sorbent cartridge(s), is connected to the molded manifold to complete the dialysate circuit of the system. The disposable dialyzer is already connected to complete the blood circuit. Spent dialysate is directed to flow through the sorbent cartridge(s) thereby allowing the system to operate as a multiple-pass closed loop portable artificial kidney in hemodialysis protocol. In this embodiment toxic and uremic wastes from the blood are predominantly removed into the dialysate by virtue of diffusion resulting from osmotic pressure differential at the semi-permeable membrane of the dialyzer.

In an alternate embodiment a reservoir(s) containing fresh ultra pure infusion grade dialysate is connected to the blood return circuit of the molded manifold whereas the spent dialysate outlet from the dialyzer is drained directly to waste. The disposable dialyzer is already connected to the complete the blood circuit. Thus the system operates as a single-pass open loop artificial kidney in hemofiltration protocol. In this embodiment toxic and uremic wastes from the blood are predominantly removed into the dialysate solution by virtue of convection resulting from transmembrane pressure differential between the blood and dialysate sides of the dialyzer.

It is another object of the present application to use two-way valves to direct the dialysate flow either through dialyzer in hemodialysis mode of operation or bypass the dialyzer to direct the dialysate flow directly to the patient in hemofiltration mode of operation. One or more two-way valve(s) is used to determine the mode of operation of the system of the present invention.

In one embodiment, the present application is a manifold for a blood purification system, the manifold comprising a plastic substrate comprising a first layer and a second layer, a first flow path defined by a first surface of the first layer and a first surface of the second layer, a second flow path defined by a first surface of the first layer and a first surface of the second layer, a third flow path defined by a first surface of the first layer and a first surface of the second layer, wherein each of the first, second, and third flow paths are isolated from each other, i.e. the fluid flowing in each of the first, second, and third flow paths is not free to flow in between each of the flow paths ever or unless a valve is actuated to permit such flow. Optionally, the manifold comprises at least one valve component fixedly attached to the first layer or second layer for directing fluid flow through at least one of said first, second, or third flow paths; and at least one sensor component fixedly attached to the first layer or second layer for measuring a fluid characteristic in at least one of said first, second, or third flow paths.

Optionally, the manifold is disposable. The manifold further comprises a pump tube segment integrated with at least one of said flow paths. The fluid characteristic is at least one of temperature or pressure. The activation of the valve component directs fluid flow through one of two separate fluid paths. The activation of the valve component is dependent upon a mode of operation of the blood purification system. The mode of operation is selected from the class comprising hemodialysis and hemofiltration. The activation of the valve component directs a dialysate fluid flow to a dialyzer in a hemodialysis mode of operation and directs infusion grade dialysate fluid flow to a patient in hemofiltration mode of operation. The term valve component or sensor component is used to denote the fact that not all of components which make up the valve components or sensor need to be included in the manifold.

In another embodiment, the manifold comprises a first fluid conducting segment, a second fluid conducting segment parallel to said first fluid conducting segment, a connecting fluid conducting segment that is perpendicular to the first and second fluid conducting segments, wherein said first fluid conducting segment, second fluid conducting segment, and connecting fluid conducting segments contain a first flow path, a second flow path, and a third flow path, each of said flow paths being isolated from each other and wherein said connecting fluid conducting segment connects the fluid flow paths in the first fluid conducting segment and with the fluid flow paths in the second fluid conducing segment.

Optionally, each of said first fluid conducting segment, second fluid conducting segment, and connecting fluid conducting segments comprise external edges that define a boundary bounding a space. The space comprises a first port, a pump tube segment, and a second port, through which fluid flows from said first fluid conducting segment to said second fluid conducting segment without flowing through said connecting fluid conducting segment. The manifold further comprises at least one valve component fixedly attached to at least one of said first fluid conducting segment, second fluid conducting segment, or connecting fluid conducting segments for directing fluid flow through at least one of said first, second, or third flow paths.

Optionally, the manifold further comprises at least one sensor component fixedly attached to at least one of said first fluid conducting segment, second fluid conducting segment, or connecting fluid conducting segments for measuring a fluid characteristic in at least one of said first, second, or third flow paths. The fluid characteristic is at least one of temperature or pressure. The activation of the valve component directs fluid flow through one of two separate fluid paths. The activation of the valve component is dependent upon a mode of operation of the blood purification system, such as hemodialysis or hemofiltration.

In another embodiment, the present application is directed to a dialysis machine comprising a door with a pressure plate positioned on an interior face of the door, a housing with a panel wherein said housing and panel define a recessed region configured to receive said interior face of said door, and an alignment mechanism fixedly attached to said panel, wherein said alignment mechanism detachably receives a manifold on said panel and positions said manifold against said pressure plate when the door is placed in said recessed region. Optionally, the alignment mechanism is at least one of contoured guides, pins, or latch.

