BR-122025016279-B1 - Fluid Handling Cassettes

BR122025016279B1BR 122025016279 B1BR122025016279 B1BR 122025016279B1BR-122025016279-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 (8)

1. Fluid handling cassette (80) CHARACTERIZED in that it comprises an intermediate plate (90) comprising: an actuation orifice (96) fixed to a first edge of the intermediate plate (90) and extending beyond the first edge; a perimeter wall (112) around a pump station (84) or valve station (116) with a break (120) in the wall, the perimeter wall (112) projecting from a first side of the intermediate plate (90); an actuation channel (110) formed from two channel walls projecting from the first side of the intermediate plate (90), the actuation channel (110) extending from the break (120) in the perimeter wall (112) to the actuation orifice (96); a diaphragm (122, 124) located in the intermediate plate (90) within the perimeter wall (112), the diaphragm (122, 124) including a microsphere on an outer edge of the diaphragm (122, 124); a first plate (86) with a first side facing the intermediate plate (90) and comprising: a first side contacting the perimeter wall (112) and channel walls; a retaining wall (108) projecting from the first side to a sufficient distance to compress the microsphere against the intermediate plate (90), the retaining wall (108) being located and dimensioned to fit within the perimeter wall (112); wherein the first plate (86) and diaphragm (122, 124) define an actuation chamber.
2. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that the retaining wall (108) fits within the perimeter wall (122), creating an annular space, the annular space being in fluid communication with the actuation channel (110), the retaining wall (108) including one or more fenestrations (104) to provide a fluid path between the actuation chamber and the annular space.
3. Fluid handling cassette (80), according to claim 2, CHARACTERIZED in that the retaining wall (108) additionally comprises a curved surface within the wall, which is shaped to support the diaphragm (122, 124).
4. Fluid handling cassette (80), according to claim 3, CHARACTERIZED in that the retaining wall (108) further comprises a groove (106) extending from a fenestration through the diaphragm (122, 124) to an opposite side of the retaining wall (108).
5. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that the intermediate plate (90) is formed of an opaque material and the first plate (86) is transparent or translucent.
6. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that the first plate (86) allows the transmission of laser wavelengths and the intermediate plate (90) is opaque.
7. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that the first plate (86) is laser welded to the perimeter wall (112) or to the channel walls.
8. Fluid handling cassette (80), according to claim 1, CHARACTERIZED in that it further comprises a second plate (88); and wherein the intermediate plate (90) further comprises: two fluid orifices (24a, 24b), each defined by an opening through the intermediate plate (90) within the perimeter wall (112); and two fluid channels, each defined by channel walls projecting from a second side of the intermediate plate (90), wherein each fluid channel is in fluidic communication with one of the fluid orifices (24a, 24b); and wherein the second plate (88) transmits laser wavelengths and is laser welded to the fluid channels.

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