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BR-122022025397-B1 - Fluid Handling Cassettes, Fluid Handling Cassette Assembly, Manifold Adapter, Seating Apparatus, Method for Controlling a Diaphragm Pump, and Method for Controlling a Fluid Flow Rate of a Diaphragm Pump

BR122022025397B1BR 122022025397 B1BR122022025397 B1BR 122022025397B1BR-122022025397-B1

Abstract

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 such cassettes (80) may be stacked together or separated from each other to form a cassette assembly, providing a convenient means of installing and removing the cassette assembly from its actuating receptacle. This arrangement allows for an improved way of connecting a complex cassette assembly to its associated pressure distribution manifold without the use of multiple 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 (20)

  1. 1. Manifold adapter (266, 268) configured to connect a pressure distribution manifold (260) to a liquid handling cassette assembly (226) CHARACTERIZED in that it comprises: a housing having a first side comprising a first set of transfer holes configured to connect to the actuation outlet holes of the manifold, and having a second opposite side comprising a second set of transfer holes (261) configured to connect to actuation inlet holes of the cassette assembly (226); the first set of transfer holes (288) comprising a first spatial arrangement configured to correspond to a spatial arrangement of the actuation outlet holes of the manifold; the second set of transfer holes (271) comprising a second spatial arrangement configured to correspond to a spatial arrangement of the actuation inlet holes of the cassette assembly; wherein the first spatial arrangement of transfer holes is different from the second spatial arrangement of transfer holes.
  2. 2. Collector adapter, according to claim 1, CHARACTERIZED in that the first spatial arrangement covers an area of the first side of the adapter housing (266) having a first length and a first width, and the second spatial arrangement covers an area of the second side of the adapter housing having a second length and a second width, wherein the second length is greater than the first length so that the collector adapter housing (266) suspends one side of the collector.
  3. 3. Collector adapter, according to claim 1, CHARACTERIZED in that the second side of the housing includes an elastomeric wiper gasket (282) comprising a plurality of wiper seals (283), each of said plurality of wiper seals being associated with a transfer orifice on the second side of the adapter housing, wherein the wiper gasket is embedded under an upper plate of the adapter housing.
  4. 4. A seating apparatus (292) for a cassette assembly (226) having a fitting side and an opposite mounting side, the seating apparatus (292) CHARACTERIZED in that it comprises: a stationary frame member (294) connected to a movable cassette assembly (298) by a plurality of links (332a, 332b) on a first side of the cassette assembly and on a second opposite side of the cassette assembly, the links on the first side of the cassette assembly connected to a first stationary flange of the stationary frame member, and the links on the second side of the cassette assembly connected to a second stationary flange of the stationary frame member; the links, each comprising a swing arm having a first end pivotally coupled to the stationary flange and a second end coupled to an elongated slot (320) in the cassette assembly; the second end of the swing arm configured to move in an arced trajectory to move the cassette assembly, wherein the elongated slot restricts the movement of the cassette assembly by the swing arm to a linear motion toward or away from the stationary frame member.
  5. 5. Settling apparatus (292), according to claim 4, CHARACTERIZED in that the cassette assembly (298) comprises a first movable flange (300a) and a first rail (302a) on the first side of the cassette assembly, and a second movable flange (300b) and a second rail (302b) on the second side of the cassette assembly, each said movable flange having a surface generally parallel to the direction of movement of the cassette assembly, the elongated slot is formed in the movable flange and oriented perpendicular to the direction of movement of the cassette assembly, and wherein the first and second rails are configured to retain the mounting side of the cassette.
  6. 6. Settling apparatus (292), according to claim 5, CHARACTERIZED in that it comprises a handle assembly (308) pivotally connected to the cassette assembly (298), such that movement of a handle of the handle assembly in a direction away from the stationary frame member (294) moves the cassette assembly away from the stationary frame member (294), and movement of the handle in a direction towards the stationary frame member moves the cassette assembly towards the stationary frame member.
  7. 7. Settling apparatus (292), according to claim 6, CHARACTERIZED in that the pivotal connection of the handle assembly (308) comprises a first pivotal connection from a first handle arm to the first stationary flange (296a), a second pivotal connection from a second handle arm to the second stationary flange (296b), a third pivotal connection from the first handle arm to a swinging handle arm (306a) connected to the first movable flange (302a) of the cassette assembly, a fourth pivotal connection from the second handle arm (306b) to a swinging handle arm connected to the second movable flange (302b) of the cassette assembly, wherein the first and third pivotal connections and the second and fourth pivotal connections are separated from each other in the first and second handle arms.
  8. 8. Settling apparatus (292), according to claim 6, CHARACTERIZED in that it comprises a third stationary flange (340) of the stationary frame member, said third stationary flange facing the handle assembly and generally perpendicular to the first and second stationary flanges (302a, 302b), wherein the handle assembly (308) includes a spring-loaded plunger configured to engage a hole or recess in the third stationary flange, such that the cassette assembly (298) can be locked in a retracted position when the handle of the handle assembly is moved towards the stationary frame member (294).
  9. 9. Method for controlling a pneumatically actuated diaphragm pump (23a) CHARACTERIZED in that it comprises: opening a valve (N1, LP1) that fluidically connects a pneumatic pressure source to an actuation chamber (14020) of the diaphragm pump; monitoring one or more gas pressures in the actuation chamber (14020) of the diaphragm pump; closing the valve when the pressure in the actuation chamber is equal to or greater than a target pressure (14050); and opening the valve when an average magnitude of the monitored pressures is less than the target pressure (14050).
  10. 10. Method, according to claim 9, CHARACTERIZED in that it further comprises the act of calculating the average of the monitored pressures after the valve (N1, LP1) closes.
  11. 11. Method according to claim 10, CHARACTERIZED in that it further comprises the act of adjusting the average pressure to zero before the valve (N1, LP1) closes.
  12. 12. Method according to claim 9, CHARACTERIZED in that the valve (N1, LP1) is a binary valve.
  13. 13. Method according to claim 9, CHARACTERIZED in that the pressure is monitored by a controller (14035) with a pressure sensor (196) fluidically connected to the actuation chamber (14020).
  14. 14. Method according to claim 13, CHARACTERIZED in that the controller (14035) receives pressure information from the pressure sensor (196) and uses said pressure information to control the valve (N1, LP1).
  15. 15. Method for controlling a fluid flow rate of a pneumatically actuated diaphragm pump (23a) CHARACTERIZED in that it comprises: opening a valve (N1, LP1) for the first time, the valve fluidically connecting a pneumatic pressure source to an actuation chamber (14020) of the diaphragm pump; monitoring one or more pressures of a gas in the actuation chamber of the diaphragm pump; timing the first valve opening; closing the valve when the pressure in the actuation chamber is equal to or greater than a target pressure (14050); opening the valve when an average magnitude of the monitored pressures falls below the target pressure; detecting the end of a pump stroke based on the monitored pressures; timing the end of the pump stroke; and changing the target pressure based on a difference between a stroke duration and a predetermined target stroke duration, wherein the stroke duration is the time difference between the end of the pump stroke and the first valve opening.
  16. 16. Method, according to claim 15, CHARACTERIZED in that it further comprises the step of calculating the average of the monitored pressures after the valve (N1, LP1) closes.
  17. 17. Method according to claim 16, CHARACTERIZED in that it further comprises the step of adjusting the average pressure to zero before the valve (N1, LP1) closes.
  18. 18. Method according to claim 17, CHARACTERIZED in that the valve (N1, LP1) is a binary valve.
  19. 19. Method according to claim 15, CHARACTERIZED in that the pressure is monitored by a controller (14035) using a pressure sensor fluidically connected to the actuation chamber.
  20. 20. Method according to claim 19, CHARACTERIZED in that the controller (14035) controls the valve (N1, LP1) using information from the pressure sensor.

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