BR-122025016281-B1 - Fluid Handling Cassettes

BR122025016281B1BR 122025016281 B1BR122025016281 B1BR 122025016281B1BR-122025016281-B1

Abstract

FLUID HANDLING CASSETTES. A fluid handling cassette (80) comprises at least one fluidically actuated diaphragm valve (82) and one fluidically actuated diaphragm pump (84), wherein the actuating fluid is supplied to the cassette (80) through actuating orifices (96) located along a thin or narrow edge of the cassette (80). Actuating channels (110) within the cassette lead from the actuating orifices (96) to the actuating chambers of the valves and pumps in a space between the plates (86, 90, 88) comprising the cassette (80). The individual plates (86, 90, 88) have a nominal thickness that is sufficient to provide a rigid roof for the actuating channels (110), but sufficiently thin to minimize the overall thickness of the cassette. A plurality of these cassettes (80) can be stacked together or separated from each other to form a cassette assembly, providing a convenient way to install and remove the cassette assembly from its actuation receptacle. The arrangement allows an improved way of connecting a complex cassette assembly to its associated pressure distribution manifold without the use of a plurality of flexible connecting tubes between the two.

Inventors

KEVIN L. GRANT
BENJAMIN E. COLBURN
JOSEPH M. RAUSEO
BENJAMIN J. DOUCETTE
MARC J. GORAYEB

Assignees

DEKA PRODUCTS LIMITED PARTNERSHIP

Dates

Publication Date: 20260310
Application Date: 20190329
Priority Date: 20180330

Claims (4)

1. Fluid handling cassette (80) CHARACTERIZED in that it comprises: an intermediate plate (90) positioned between a first plate (86) and a second plate (88), the intermediate plate comprising: a first side with a first plurality of channel walls projecting from the first side, at least two channel walls of the first plurality of channel walls defining a first fluid channel (170a); and a second side with a second plurality of channel walls projecting from the second side and a tubular projection (158) from the second side forming an extension conduit, at least two channel walls of the second plurality of channel walls defining a second fluid channel (170b); a hole in the intermediate plate fluidically connecting the first fluid channel to the extension conduit; wherein the first plate contacts the channel walls on the first side of the intermediate plate, the second plate contacts the channel walls on the second side of the intermediate plate, and the tubular projection extends through the second plate; a plurality of edges, each of which is perpendicular and coincident with an outer edge of the intermediate plate; and an actuation orifice positioned on a first edge of the plurality of edges, located between the intermediate plate and the first plate and fluidically connected to the extension conduit.
2. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that the extension conduit (160) provides a mechanical connection to a capsule pump (210) and a fluid connection to the actuation chamber of the capsule pump.
3. Fluid handling cassette (80) CHARACTERIZED in that it comprises: an intermediate plate (90) positioned between a first plate (86) and a second plate (88), the intermediate plate comprising: a first side with a first plurality of channel walls projecting from the first side, and a tubular projection (158, 168) from the first side forming a conduit, at least two channel walls of the first plurality of channel walls defining a first fluid channel (172); and a second side with a second plurality of channel walls projecting from the second side, at least two channel walls of the second plurality of channel walls defining a liquid channel (128, 130); a hole (24b) in the intermediate plate fluidically connecting the liquid channel to the conduit; wherein the first plate contacts the channel walls on the first side of the intermediate plate, the second plate contacts the channel walls on the second side of the intermediate plate and the tubular projection extends through the first plate; a plurality of edges, each of which being perpendicular and coincident with an outer edge of the intermediate plate; and an actuating hole positioned on a first edge of the plurality of edges, located between the intermediate plate and the first plate and fluidically connected to the first fluid channel.
4. Fluid handling cassette (80), according to claim 3, CHARACTERIZED in that the conduit (168) provides a mechanical connection with a capsule pump (210) and a liquid connection with the pumping chamber of the capsule pump.

Description

FIELD OF THE INVENTION [001] The present disclosure relates, in general, to improvements in the design and construction of pumping or mixing cassettes for fluids, cassette assemblies, their constituent parts and associated devices. FUNDAMENTALS [002] Liquid handling cassettes comprising pumps and/or diaphragm valves may be fluidically (either hydraulically or pneumatically) actuated. In some examples, a cassette is designed to be fluidically connected to a pneumatically actuated manifold having electromechanical valves that selectively distribute positively or negatively pressurized gas or air to the cassette. A programmable electronic controller may be used to control the electromechanical valves to selectively deliver positive or negative pneumatic pressure to various pumps or valves in the cassette in a predetermined manner. [003] Some fluid handling cassettes may be substantially planar in shape, having a wide side flanked by a thin or narrow side having a thickness relatively smaller than the overall wide-side dimensions of the cassettes. Liquid inlet and outlet orifices may be incorporated into the edge or thin side of the cassette. However, in many of these devices, the actuation orifices for the cassette have been located on the face or wide side of the cassette directly above the actuation chambers of the pumps or valves being controlled. In general, the shortest route to an actuation channel in the cassette is provided from a cassette actuation orifice external to the actuation chamber and diaphragm of a pump or valve in the cassette. Additionally, in many cases, the pump or valve stations or regions of the cassette – comprising the actuation chamber on one side of the liquid-carrying chamber on the opposite side – may be defined by spheroidal or hemi-spheroidal chamber walls that extend above the plane of the cassette face, which makes the overall cassette thicker than desirable in some applications. In other cases, a pump module may comprise an assembly of blocks sandwiched or laminated together, with the pneumatic actuation channels or fluid channels embedded in one or more of the blocks. This arrangement may also result in an overall device thickness greater than desirable for certain applications. Some applications may require a plurality of fluid handling cassettes to be mounted close to each other in tight spaces. In these cases, it may be desirable to position a number of cassettes adjacent to each other, stack them against each other, or at least their broad sides face to face in close proximity. Reducing or minimizing the thickness of the individual cassettes that make up these assemblies may be particularly desirable. [004] It may be advantageous to have a pump cassette that plugs directly into its associated pressure distribution manifold (e.g., a manifold that selectively delivers pneumatic pressure to the pump cassette under the control of an electronic controller). In previously disclosed embodiments of a hemodialysis system using pneumatically actuated stand-alone pump cassettes, the pump cassettes were connected to a corresponding pneumatic manifold via flexible tubing, which led to significant challenges during assembly and operation. If a pump cassette can be located close to its associated manifold, a direct plug-in connection between the two would have substantial advantages. Under these circumstances, it would be particularly advantageous to have a compact manifold that allows a direct interface to a pump cassette, arranged so as to allow the cassette or cassette assembly to be plugged and unplugged from the manifold actuation ports with minimal effort. [005] In the design and operation of a pneumatic distribution manifold, the ability to use binary pressure control valves instead of continuously variable orifice valves would also provide significant advantages in both cost and reliability. However, in this case, controlling pressure delivery to individual pumps or cassette valves by binary pressure control valves poses additional challenges that must be overcome. A sufficiently robust electronic controller can be programmed to use control to manage the frequency and duration of binary valve actuation to achieve precise control of associated pneumatically actuated pumps or valves. SUMMARY [006] In one embodiment, a pump and/or valve cassette has a relatively flat shape, with one wide side flanked by a narrower, thinner side or edge. It comprises an intermediate plate positioned between two outer plates: a first outer plate facing one side of the intermediate plate, and a second outer plate facing the opposite side of the intermediate plate. The first outer plate is separated from the intermediate plate to form a first interplate space. The second outer plate is separated from the intermediate plate to form a second interplate space. The thickness of the first and second outer plates is limited to a thickness sufficient to provide rigidity to the plate and to provide a sealing