AU2018202370A1 - Dialysis system including heparin injection - Google Patents

Abstract

A renal therapy machine includes a blood filter including a plurality of porous fibers, a blood circuit in communication with the blood filter, a dialysate circuit in communication with the blood filter, and at least one pump or valve positioned and arranged to purge air from the blood filter into the dialysate circuit, as a physiologically compatible solution, other than dialysate, is moved across the porous fibers of the blood filter. The machine is configured to perform a priming sequence in which (i) the physiologically compatible solution primes the blood circuit and is flowed within the fibers and through pores in the fibers of the blood filter, and (ii) the at least one pump or valve purges air, via the dialysate circuit, from the blood filter into the dialysate circuit. flAl9fll S Sheet 28 of 48 co :9 a.e B < D 0 'D r- a a dess 00 u .cni

Description

AUSTRALIA Patents Act, 1990 ORIGINAL

COMPLETE SPECIFICATION APPLICANTS: Baxter International Inc. (a Delaware Corporation)

Baxter Healthcare SA

INVENTORS: CHILDERS, RobertW KELLY, Thomas D ROGER, Rodolfo ADDRESS FOR SERVICE : Peter Maxwell and Associates

Level 6 60 Pitt Street SYDNEY NSW 2000

INVENTION TITLE; DIALYSIS SYSTEM INCLUDING HEPARIN

ÍNJECTION DIVISIONAL OF AU - 2015 202 293-1 May 2015

The following statement is a full description of this invention including the best method of performing it known to us:-

BACKGROUND

[0001] The presentdisclosure relates generally to medical treatments. More specifically, the present disclosure relates to medical fluid treatments, such as the treatment of renal failure and fluid remova! for congestive heart failure.

[0002] Hemodialysis ("HD") in general uses diffusion to remove waste producís from a patient's blood. A diffusive gradient that occurs across the semi-permeable dialyzer between the blood and an electrolyte solution called diaiysate causes diffusion. Hemofiltration ("HF") is an alternative renal replacement therapy that relies on a convective transport of toxins from the patient's blood. This therapy is accomplished by adding substitution or replacement fluid to the extracorporeal Circuit during treatment (typically ten to ninety liters of such fluid). That substitution fluid and the fluid accumulated by the patient in between treatments is ultrafiltered over the course of the HF treatment, providing a convective transport mechanism that is particularly beneficia! in removing middle and large molecules (in hemodialysis there is a small amount of waste removed along with the fluid gained between dialysis sessions, however, the solute drag from the removal of that ultrafiltrate is not enough to provide convective clearance).

[0003] Flemodiafiltration ("FIDF") is a treatment modality that combines convective and diffusive clearances. HDF uses diaiysate to flow through a dialyzer, similar to standard hemodialysis, providing diffusive clearance. In addition, substitution solution is provided directly to the extracorporeal Circuit, providing convective clearance.

[0004] Fióme hemodialysis ("HFID") is performed in the patient's home. One drawback of home hemodialysis has been the need for a dedicated water treatment, which ineludes equipment, water connection and drainage. Installing and using those components is a difficult and cumbersome task that can require a patient's home to be modified. Nevertheless, there are benefits to daily hemodialysis treatments versus bi- or tri-weekly visits to a treatment center. In particular, a patient receiving more frequent treatments removes more toxins and waste producís than a patient receiving ¡ess frequent but perhaps longer treatments. Accordingly, there is a need for an ¡mproved HMD system. ' - — “y

SUMMARY

[0005] The present disclosure provides a home hemodialysis (“HHD”) system. In one embodiment, the home system ineludes a mobile cart and integral bag manager. A latch is pulled out to unlock door of the system instrument. The door can be opened to expose a latch hook and peristaltic pump heads.

[0006] The instrument accepts a disposable unit which in one embodiment is loaded from above and slid to the right. The disposable unit pivots towards the machine interface, which allows peristaltic tube loops of the disposable unit to fit over peristaltic pump heads of the instrument. Also, supply lines of the disposable unit are passed over individual pinch valve plungers.

[0007] The pinch valve plungers pinch the supply tubes against a pinch valve sírike píate. The valve assembly is in one embodiment a motor-driven cam operated pinch valve subassembly. The motor in one embodiment is a stepper motor.

[0008] The system in one embodiment ineludes a bellows or bladder that compresses a cassette against the instrument door using a pressure píate and gasket. These apparatuses are structured to accommodate an inline inductive heater provided with the disposable cassette. The bellows is air actuated in one embodiment. The instrument ineludes a primary coil that inductively heats conductive heating disks located within the cassette, which in turn heat fluid flowing through the cassette.

[0009] A muiti-peristaltic pump race retracte and extends in onc embodiment íüustrates to facilítate loading of the peristaltic tubes of the cassette onto the peristaltic pump heads. The race is then moved towards the tubes for operation.

[0010] The system in one embodiment ineludes a manual blood pump operator, which allows the patíent or caregiver to move the blood pump head manually, [0011] The system ineludes a bag management system having shelves that fold up, out of the way, and down, sequentiaily for placement of supply bags. The system in one embodiment supports up to five, six liter solution bags. The bags can be dual chambcr bags. The shelves in an embodiment are provided with sensors that allow detection of whether the bags have been (i) loaded or not and (ii) opened or not for therapy. The sensors in one embodiment are capacitive sensors placed on opposite ends of the shelves.

[0012] The disposable cassette in one embodiment connects fluidly to a heparin syringe for the injection of heparin into the blood circuit. The syringe fits into a !uer connector assembly, which in turn is loaded into a syringe pump. The assembly is tumed in the syringe pump to lock the syringe in the syringe pump for treatment. The assembly accommodaíes large syringes, such as fifty to sixty mílliliter syringes, which can lock directly into the syringe pump. In one embodiment, the heparin line passes through the side of the cassette. Here, heparin can enter at the blood pump outlet just prior to the dialyzer inlet.

[0013] The system also ineludes a retractable saline bag support rod The saline in one embodiment connects to the cassette near the heparin line. A saline valve is located on each side of the blood pump to control the flow of saline to same.

[0014] A dialyzer inlet pressure sensor interface in one embodiment doubles as a flow control valve. The cassette can also form an integral venus air separation chamber.

[0015] Priming is performed in one embodiment via gravity. Gravity primes the venous line, the arterial line and the air trap (drip chamber).

[0016] ín another embodiment, priming is preformed via a combination of pumping dialysate and a physiologically safe fluid, such as saline. In particular, a hemodíalysis machine can inelude a blood circuit, a dialysate Circuit, a dialyzer placed in communiation with the blood Circuit and the dialysate circuit; and a priming sequence in which dialysate is used to prime a fírst portion of the dialysate circuit and a physiologically compatible solutíon, other than dialysate, is used to prime a second portion of the dialysate circuit, the dialyzer and the blood circuit. The fírst portion of the dialysate circuit ineludes a recirculation loop primed by a dialysate supply pump in one embodiment. The second portion of the dialysate circuit can then be located at least substantially between the recirculation loop and the dialyzer, and which is primed by at least one of a blood pump and a downstream dialysate pump. In one embodiment, a volumetric balancing unit separates the fírst and second portions of the dialysate circuit.

[0017] The cassette in one embodiment uses balance tubes to balance fresh and spend dialysate flow. The balance tubes have outlets at the top of the tubes when mouníed for operation to allow air to leave the tubes. The cassette also employs diaphragm valves that opérate with a compliance chamber that seáis against backpressure.

[0018] For instancc, a hemodíalysis machine can inelude a dialysis instrument having at least one peristaltic pump actuator and fírst and second pneumatic valve actuators. The instrument operates with a disposable cassette, the disposable cassette incíuding a rigid portion, with at least one peristaltic pump tube extending from the rigid portion for operation with the at least one pump actuator. The rigid portion defines fírst and second valve chambers in operable connection with the fírst and second valve actuators, respectively, the fírst and second valve chambers communicating fluidly with each other, at least the fírst valve chamber communicating fluidly with a compliance chamber, the compliance chamber absorbing energy from a pneumatic closing pressure applicd to cióse the first valve chamber, so as to tend to prevent the pneumatic closing pressure from opening an existing closure of the second valve chamber.

[0019] The machine in one embodiment ineludes a vacuum applied to the compliance chamber to absorb the energy from the pneumatic closing pressure applied to cióse the first valve chamber.

[0020] In the above example, a flexible membrane can be sealed to the rigid portion, the pneumatic closing pressure applied to the membrane to cióse the first valve chamber. Here, the compliance chamber is formed in part via a portion of the flexible membrane, wherein the flexible membrane portion is configured to absorb the energy from the pneumatic closing pressure. The cassette can altematively inelude a flexible diaphragm located on an opposing side of the rigid portion from the flexible membrane, the compliance chamber formed in part via the flexible diaphragm, the flexible diaphragm configured to absorb the energy from the pneumatic closing pressure.

[0021] The disposable cassette can have múltiple compliance chambers operating with different sets of valve chambers. The compliance chamber aids both upstream and downstream valves. The compliance chamber overcomes a backpressure applied by the closing of the second valve chamber to the first vaive chamber, to aliow the first valve chamber to cióse properly.

[0022] In another compliance chamber embodiment, the dialysis instrument has a pump actuator and ñrst and second valve actuators. A disposable cassette is operable with the dialysis instrument, the disposable cassette including a pump portion operable with the pump actuator, the first and second valve chambers communicating fluidly with each other, at least the first valve chamber communicating fluidly with a compliance chamber, the compliance chamber negating a first backpressure due to a pneumatic closing pressure used to cióse the first valve chamber to help to ensure the pneumatic pressure applied to the first valve chamber will elose the first valve chamber against a second backpressure from an existing closure of the second valve chamber. Here, a pneumatic pressure applied to the second valve chamber can be the same as the pneumatic pressure applied to the first valve chamber. The first backpressure would exist around an outside of a port of the first valve chamber if not for the compliance chamber, the second backpressure existing inside the port.

As before, the compliance chamber is further configured to tend to prevent the pneumatic pressure applied to the first valve chamber from opening the closed second valve chamber.

And, the machine in one embodiment inchides a vacuum appíied to the compiiance chamber to ensure the pneumatic pressure applied to the fírst valve chamber will cióse the first valve chamber.

[0023] In a further compiiance chamber embodiment, the dialysis instrument has a pump actuator and first and second valve actuators. The disposable cassette is operable with the dialysis instrument, the disposable cassette including a pump portion operable with the pump actuator, and first and second valve chambers operable with the first and second valve actuators, respectively, the cassette further ineludes a compiiance chamber in fluid communication with the first and second valve chambers, the compiiance chamber defíned at least in part by a rigid wall of the cassette and a diaphragm located on an opposing side of the rigid wall from the fírst and second valve chambers. The rigid wall in one embodiment defines fírst and second apertures that allow the fírst and second valve chambers to communicate fluidly, respectively, with the compiiance chamber. The cassette can include a flexible membrane located on an opposing side of the cassette from the diaphragm, the membrane for closing the first and second valve chambers. Again, the compiiance chamber can aid at least one of: (i) maintenance of an existing closure of the second valve chamber when the fírst valve chamber is closed; and (ii) a proper closure of the fírst valve chamber at a time when the second valve chamber is already closed. In one embodiment, the aiding is provided via a vacuum applied to the compiiance chamber.

[0024] In still a further compiiance chamber embodiment, a dialysis instrument has a pump actuator and first and second valve actuator. A disposable cassette is operable with the dialysis instrument, the disposable cassette including a pump portion operable with the pump actuator, and first and second valve chambers operable with the first and second valve actuators, respectively. A compiiance chamber is placed in fluid communication with the first and second valve chambers, the compiiance chamber defíned by in part by a flexible membrane used to cióse at least one of the first and second valve chambers, the valve chambers each defining an aperture for fluid communication with the compiiance chamber. The disposable cassette can inelude a rigid wall, the fírst and second valvcs chambers extending from the rigid wall towards the flexible membrane, wherein the apertures of the fírst and second valve chambers are formed in the rigid wall, and wherein the rigid wall also forms a third, larger aperture to allow fluid flowing through the valve chamber apertures to communicate fluidly with the flexible membrane of the compiiance chamber, Again, the compiiance chamber aiding at least one of: (i) maintenance of an existing closure of the second valve chamber when the first valve chamber is closed; and (ii) a proper closure of the fírst valve chamber at a time when the second valve chamber is already closed. Again, the aíding can be provided vía a vacuutn applied to the compliance chamber.

[0025] It is therefore an advantage of the present disclosure to properly seal valves in fluid communication with one another.

[0026] It is another advantage of the present disclosure to provide an efficient priming technique that combines the ase of dialysate and another physiologicaíly safe fluid, such as saline.

[0027] Additional features and advantages are described hereirt, and will be apparent from, the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

[0028] Fig. 1 is a perspective view of one embodiment of a personal home hemodiaíysis (“HHD”) system having a mobile cart and integral bag manager.

[0029] Fig. 2 illustrates the system of the present disclosure, in which a latch is pulled out to unlock a door.

[0030] Fig. 3 illustrates the system of the present disclosure, in which a door is opened exposing a latch hook and peristaltíc pump heads.

[0031] Fig. 4 illustrates one embodiment of the system of the present disclosure, in which the door is hidden to more clearly show the door latch.

[0032] Fig. 5 illustrates one embodiment of the system of the present disclosure, in which a disposable unit is loaded from above and slid to the right.

[0033] Fig. 6 illustrates one embodiment of the system of the present disclosure, in which the disposable unit ís pivoted forward towards the interface.

[0034] Fig. 7 illustrates one embodiment of the system of the present disclosure, in which the disposable unit pivots forward and the tube loops fit over the peristaltíc pump heads.

[0035] Fig. 8 illustrates one embodiment of the system of the present disclosure, ín which íhc supply lincs are placed in operable communication with individual pinch valve plungers.

[0036] Fig. 9 illustrates one embodiment of the system of the present disclosure, in which the supply lines are hidden to show pinch valve plungers.

[0037] Fig. 10 is rear view of one embodiment of the system of the present disclosure showing a pinch valve strike píate.

[0038] FÍG. 11 is a perspective view of one embodiment of a cam operated pinch valve subassembly operable with the system of the present disclosure.

[0039] FIG. 12 ¡s another perspective view of the pinch valve 5 subassembly of FIG. 11.

[0040] FIG. 13 is a perspective view of the pinch valve subassembly of FIG. 11 with its housing and motor hidden.

[0041] FIG. 14 ¡llustrates a stepper motor operating with the pinch valve subassembly of FIG. 11. 1 [0042] FIG. 15 illustrates blood lines operable with the system of FIG, 1.

[0043] FIG. 16 illustrates blood line clamps closed on the blood lines of FIG. 15.

[0044] FIG. 17 illustrates one embodiment of a blood line clamp subassembly operable with the system of the present disclosure.

[0045] FIG. 18 illustrates one embodiment of a blood line clamp manual override.

[0046] FIG. 19 illustrates a user access to a manual override of the blood line clamps.

[0047] FIG. 20 is a perspective expioded view of one embodiment of a door showing a pressure píate, gasket and bellows operable with the system of the present disclosure.

[0048] FIG. 21 illustrates the system with a door cover removed exposing tubes for bellows.

[0049] FIG. 22 illustrates the system with the door hidden to better show an iníine heating system.

[0050] FIG. 23 illustrates the system with the door and cassette hidden to better show a heater coil and wave heater disks.

[0051] FIG. 24 illustrates a front view of a retracted peristaltic pump race of the system of the present disclosure.

[0052] FiG. 25 ¡llustrates a rear view of a retracted peristaitic pump race.

[0053] FIG. 26 illustrates a rear view of the peristaitic pump race extended.

[0054] FIG. 27 illustrates that an instrument housing supports the front of the pump race actuator shafts.

[0055] FIG. 28 illustrates one embodiment of a manual blood pump operation of the system of the present disclosure.

[0056] FIG. 29 illustrates a manual blood pump operation with the instrument door ciosed and latched.

[0057] FIG. 30 illustrates one embodiment of a bag management system operable with the HHD system having shelves folded up and ready for placement of a first supply bag.

[0058] Fig. 31 illustrates a supply bag placed on a botíom sheíf of the bag management system.

[0059] Fig. 32 illustrates one embodiment in which the bag management system can hold up to five solution bags.

[0060] Fig. 33 illustrates the bag management system with all solution bags connected and bag peel seáis broken.

[0061] Fig. 34 illustrates the bag management system with capacitive sensors placed on opposite ends of the shelves.

[0062] Fig. 35 illustrates one embodiment of a connection of disposable set to a heparin syringe, [0063] Fig. 36 illustrates the syringe and luer connector assembly loaded into a syringe pump.

[0064] Fig. 37 illustrates the connector of Fig. 36 rotated 45° to lock the syringe into the syringe pump.

[0065] Fig. 38 illustrates that a large, e.g., 50/60 mi, syringe can lock directly into the syringe pump.

[0066] Fig. 39 illustrates one embodiment of a syringe pump mechanism operable with the HHD system of the present disclosure.

[0067] Fig. 40 illustrates one embodiment of a viewing window for viewing heparin delivery.

[0068] Fig. 41 illustrates the heparin line passing through the side of the cassette and attaching to the backside of the instrument.

[0069] Fig. 42 illustrates that heparin entere at the blood pump outlet just before the dialyzer inlet.

[0070] Fig. 43 illustrates one embodiment of a saline bag support rod operable with the HHD system of the present disclosure.

[0071] Fig. 44 illustrates the saline line connected to the cassette near the heparin linc.

[0072] Fig. 45 illustrates a saline valve located on each side of the blood pump.

[0073] Fig. 46 illustrates that the saline valve porís feed into each side of the blood pump.

[0074] Fig. 47 illustrates that a dialyzer inlet pressure sensor interface can serve additionally as a flow control valve.

[0075] Fig. 48 i Ilústrales the venous and arterial lines are connected togeiher to form a priming loop.

[0076] Fig. 49 iilustraíes one embodiment of a venous air separation chamber operable with the system of the present disclosure.

[0077] Figs. 50 and 51 illustrate one embodiment of a venous air separation chamber valve operable with the system of the present disclosure.

[0078] Fig. 52 is a fluid schematic illustrating one possible fluid flow regime for the HHD system of the present disclosure.

[0079] Figs. 53A and 53B illustrate one embodiment of a disposable set operable with the system of the present disclosure.

[0080] Fig. 54 is a fluid schematic illustrating one embodiment for gravity priming of the venous line, the arterial line and the air trap (drip chamber).

[0081] Fig. 55 is a fluid schematic illustrating one embodiment for pressurized priming of the díalyzer and purging of air from blood side Circuit.

[0082] Figs. 56 and 57 are fluid schematics illustrating one embodiment for priming the dialysate Circuit.

[0083] Fig. 58 is a section view of one embodiment for balance tubes having outlets at the tops of the tubes, the tubes operable with the HHD system of the present disclosure.

[0084] Fig. 59 is a fluid schematic illustrating the HHD system of the present disclosure performing hemodialysis.

[0085] Fig. 60 is a fluid schematic illustrating the HHD system of the present disclosure performing pre-dilution hemofíltration.

[0086] Fig. 61 is a fluid schematic illustrating the HHD system of the present disclosure performing post-dilution hemofíltration.

[0087] Fig. 62 is a fluid schematic illustrating the HHD system of the present disclosure performing post-dilution hemodíafíltration.

[0088] Fig. 63 is a fluid schematic illustrating one embodiment for closing an arterial line clamp, opening a salinc valve and infusing salinc bolus during thcrapy.

[0089] Fig. 64 is a fluid schematic illustrating one embodiment for recirculating ffesh dialysate in heater circuit and balance tubes to remove ultrafiltration (“UF”).

[0090] Fig. 65 is a fluid schematic illustrating one embodiment for closing a venous line clamp, opening a satine valve and rinsing back blood from the arterial line.

[0091] Fig. 66 is a fluid schematic illustrating one embodiment for closing an arterial line clamp, opening a saline valve and rinsing back blood from the venous line.

[0092] Fíg. 67A is a perspective view of one embodiment of a disposable interface subassembly operable with the HHD system of the present disclosure.

[0093] Fig. 67B is another view of the disposable interface subassembly of Fig. 67A.

[0094] Fig. 67C is an expioded view of an intemal module operable with the subassembly of Figs. 67A and 67B, [0095] Fig. 68 is a perspective view illustrating springs at the four comers of the subassembly of Figs. 67A and 67B that retract the intemal module of Fig. 67C.

[0096] Fig. 69 is a perspective view illustrating the backside of one embodiment of a cassette interface faceplate operable with the HHD system ofthe present disclosure.

[0097] Fig, 70 is a perspective view illustrating the backside of one embodiment of a membrane gasket operable with the HHD system of the present disclosure, [0098] Fig. 71 is a perspective view of the intemal instrument componente ffom the backside of the hemodialysis system, showing that there is room for additional, e.g., electrical, components.

[0099] Fig. 72 is a perspective view of one embodiment of the HHD system operating in conjunction with an online dialysaíe generation system.

[00100] Fig. 73A illustrates one embodiment of a diaphragm valve assembly having a compliance chamber seal against backpressure, which is operable with the HHD system of the present disclosure.

[00101] Fig. 73B illustrates one embodiment of a valve assembly having compliance chambers.

[00102] Fig. 74 is a perspective view of a disposable cassette having the valve assembly of Figs. 73A and 73B.

[00103] Fig. 75 illustrates one embodiment of a peristaltic pump head sized to opérate with múltiple supply lines for mixing different fluids of the HHD system of the present disclosure.

DETAILED DESCRIPTION

[00104] Rcfcrring now to the drawings, Fig. 1 illustrates onc embodiment of a system 10 sitting idie with its dust cover (not illustrated) removed. A handle 12 for a cart 14 is located in a iowered position to minimize the space that system 10 consumes. Sheives 16 for the supply bags (shown below) are also shown in a Iowered or “down” position, which minimizes the height of system 10.

[00105] System 10 is programmed in an introductory State to instruct the user to open a door 18 shown in Fig. 2. Fig. 2 illustrates a close-up view of system 10 with a latch 34 pulled out ίο unlock door 18, Once door 18 is unlocked as seen in Fig. 3, ít swings open, e.g., about forty-fíve degrees, and is held in the open position by a stop (not seen), so that a disposable set (shown below) can be loaded or unloaded.

[00106] Fig. 3 illustrates instrument 20 of system 10 with door 18 held in the open position, exposing múltiple peristaltic pump heads 22, a latch hook 24, inductive heater coil 26 and a slotted area 28 for the blood lines (not iliustrated) to run to and from the patient. Ultrasonic air bubble detectors and optical blood/saline/air detectors are integrated into the molded slotted area 28 just above a cutout in the slot for the venous and arterial line clamps. The cutout located in slotted area 28 accommodates the venous and the arterial line cfamps. Figure 16 shows the venous and arterial line clamps 76 in the closed position, in which the clamps extend through a respective cutout. In an altemative embodiment, the inductive heater coi 1 26 is retracted into the system to facilítate loading.

[00107] In Fig. 4, door 18 is not shown for clarity to illustrate latch 34 and latch hook 24, wherein latch 34 mechanically engages latch hook 24 to hold door 18 closed against the main portion of instrument 20. One suitable latch assembly is shown and described in Figs. 11 and 13 of U.S. Pat. No. 6,261,065, “System and Methods for Control of Pumps Employing Electrícal Field Sensing”, the pertinent portions of which are incorporated herein expressly by reference.

[00108] As seen in Fig. 5, once door 18 has been opened, system 10 prompts the user to load the disposable set, A cassette 40 of the disposable set is lowered into the bag of instrument 20 and moved to the right (with respect to the orientation of instrument 20 in Fig, 4). Cassette 40 is loaded starting at the upper left side of open door 18, so that the patient’s blood lines extending downwardly from cassette 40 do not interfere with the loading procedure. The patient’s left hand can grasp a dialyzer 36 connected to cassette 40, whiíe the patient’s right hand can grasp a tubing bundle 38 formed by the supply and drain lines. Single handed loading is also possible, e.g., using right hand only grasp bundle 38 to move both cassette 40 and dialyzer 36.

[0100] As sccn in Figs. 6 and 7, door 18 pivots cassette 40 forward towards a cassette interface 50 of instrument 20 when an opening 42 in cassette 40 is located directly over the inductivo heater transformer coil 26. In an altemative embodiment, transformer coil 26 is retracted to facilítate loading of cassette 40. In such case, coi! 26 is then extended into operating position after cassette 40 is loaded against interface 50. A bezel (not shown) provides locating stops for stopping cassette 40 in the vertical and horizontal directions.

[0103] As cassette 40 mates with the cassette interface 50, the peristaltic pump tubing loops 44 of cassette 40 slip over the vertically aügned pximping heads 22. A pump race 46 is retracted automatically upwardly when door 18 is opened to provide clearance between the pump heads 22 and pump race 26 to facilítate the ioading of pump tubing 44 and cassette 40.

[0102] Fíg. 8 illustrates the supply Unes 38a to 38e of bundle 38 (number of supply lines 38 can vary) passing over retracted pinch valves 48. System 10 also retracts pinch valves 48 automatically when door 18 is opened to facilítate the Ioading of bundle 38 and cassette 40 against interface 50 of instrument 20. System 10 opens and closes pinch valves 48 in a controlled manner, eliminating the need for manual clamps on supply lines 38a to 38e. Fig. 9 is shown with supply lines 38 removed to more clearly illustrate pinch valve plungers 48.

[0103] Fig. 10 further illustrates pinch valve 48/supply line 38 interactíon, Pinch valves 48 pinch supply lines 38 closed against a strike píate 52. In Fig. 10, four pinch valves 48 for supply lines 38b to 38e are pinching a respective supply Une closed against strike píate 52, while a fífth pinch valve 48 is retracted, allowing supply line 38a to be open.

[0104] Figs. 11 and 12 illustrate a pinch valve subassembly 60, in which three of the five plungers 48 are extended (closed State). Clamp heads 54 are connected to a pinch valve body 62 of subassembly 60. Fig. 13 is shown with body 62 removed to illustrate springs 56 that spring load pinch valve plungers 48, e.g., so as to be normally closed. Springs 56 preload pinch valve plungers 48, allowing for variations in the wall thickness of supply tubes 38. Fig. 13 also illustrates that clamp heads 54 are formed with cam followers 58, which ride on associated cara lobes 62 coupled to a camshafi 64 (Figs. 11 and 14). A motor 66, e.g,, a stepper motor, is coupled to a drive camshaft 64. Fig. 14 illustrates that in one embodiment, the individual cam lobes 62 each define aperturas configured fít onto a keyed portion 68 of shaft 64. Fíg. 14 further illustrates the interactíon of cam followers 58 and cam lobes 62, [0105] Fig. 15 illustrates that when cassette 40 is loaded into instrument 20 of System 10, biood lines 72 and 74 exit to the lower lefi of door assembly 90 with venous and arterial iinc clamps 76 (Fig. 16) open initxally. Fig. 16 illustrates that venous and arterial Une clamps 76 pinch bioodlines 72 and 74 against housing portion 78 of instrument 20 to cióse bloodliaes 72 and 74, During normal operation, systera 10 operates clamps 76 independently as needed. Fig. 17 is shown with housing portion 78 and door assembly 90 removed to more fully illustrate venous and arterial line clamp subassembly 70. A strike parí of housing portion 78 seen in Fig. 16 is located between the venous and arterial Unes 72 and 74 and pinches the lines together with the clamping levers 76 when closed.

[0106] Fig. 18 iilustrates the venous and arterial line clamp subassembly 70 less a housing 77 shown in Fig. 17, in which clarnps 76 are in the open positíon. Subassembly 70 ineludes bellows 80 that hold clamps 76 open during normal operation. Subassembly 70 also allows for an Alien wreneh 82 with a T-handle 84 to be used to opérale a worm gear 86 that is coupled operably to a cam 88, which cooperate to manually open both the venous and arterial line clamps 76 if need be. In an altemative embodiment, subassembly 70 ineludes dual worm gears and a split cam, so that the venous and arterial line clamps 76 can be manually operated independently. Fig. 19 iilustrates the placement of the T-handíe Alien wreneh 82 with respect to instrument 20 when the venous and arterial line clamps 76 are operated manually. In one embodiment, system 10 causes an, e.g., red, flag (not iliustrated) to protrude when the clamps 76 have been opened manually. The flag retracte when the manual override is not engaged.

[0107] Fig. 20 iilustrates an exploded view of the door assembly 90 taken from inside instrument 20. A pair of bellows or bladders 92a and 92b pushes a píate 94 having a gasket 96 to press the cassette 40 (not seen here) against the disposable interface 50 (not seen here). A space between bladders 92a and 92b is provided to accommodate the inductive heater coil 26 extending from disposable interface 50. Alteraatively, instrument 20 provides a single bellows (bladder) to press cassette 40 against the disposable interface 50, which has an intemal opening to accommodate heater coil 26 extending from disposable interface 50.

[0108] In an altérnate faiísafe embodiment (not iliustrated), the bellows 92a and 92b are replaced by a cavity with a diaphragm that is connected sealably to front pressure píate 18. Springs are located between front pressure píate 18 and the back wall of the cavity and press cassette 40 against disposable interface 50, except when a vacuum is present within the cavity. In the altemative embodiment, system 10 can also introduce posítive pressure into the cavity to increase the sealing forcé.

[0109] Fig. 21 iilustrates system 10 with the door cover 98 (Fig, 20) removed. Pneumatic lines 102a and 102b to bellows 92a and 92b, respectively, are shown teed together before the exiting door 18 through a hollow hínge 104. A vertical metal bar 106 completes a Circuit for the inductive heater transformer primary coil 26 when the door 18 is closed against interface 50 of instrument 20. Fig. 22 is also shown with door 18 removed to illustrate the inductive heating system including transformer coil 26 and a wave-shaped disk or disks 108 located in disposable cassette 40, which fomi a secondary coil that heats dialysis fluid due to i R losses. Fig. 23 removes cassette 40 to show inductive heater 100 more clearly. Heater 100 transfers energy from the inductive coil of the transformer 26 into wave washers 108a and 108b íhat are iocated within cassette 40. Washers 108a and 108b in tum heat dialysate as it flows through cassette 40.

[0110] Fig, 24 illustrates the front of the instrument 20 with door assembly 90 and device housing hidden to expose a mechanism 110 that extends and retracte triple peristaitic pump race 46. Mechanism 110 ineludes four idler gears 112 that tie geared triple cams 114 together to move race 46 to extend (towards tubing 44) and retract (from tubing 44) smoothly. Mechanism 110 is configured such that race 46 extends towards tubing 44 only after door 18 is closed and latched to preelude the operator from being exposed to any moving componente. The centers of pump heads 22 are aligned to provide clearance between the pump heads and triple race 46 when the race is retracted.

[0111] Fig. 25 illustrates the backside of the retractable triple peristaitic pump race 46 and mechanism 110 for moving race 46. Cams 114 are Iocated at each end of race mechanism 110 and race 46. A middle eam 114 is also provided. Each idler gear 112 (Fig. 12) includes a shafi 113 that transmite roíational motion from the idler gears to all three cams 114 simultaneously. Cams 114 each include lobes 116 that rotate simultaneously and in concert within large rounded end slots 118 to simultaneously and evenly extend and retract race 46. Shafts 113 of idler gears 112 (Fig. 24) maintaín the horizontal orientation of the peristaitic pump race 46 as the race moves up and down.

[0112] Fig. 25 illustrates the cam lobes 116 rotated simultaneously and in concert upwardly, pushing the pump race 46 away from gear motors 120 that are coupled to pump heads 22. The open parts of the horizontaliy stabilizing idler guide slots are above the shafts 113 of idler gears. Fig. 26 illustrates the cam lobes 116 rotated simultaneously and in concert downwardly, pushing pump race 46 towards the pump gear motors 120 coupled to pump heads 22. The open parts of the horizontaliy stabilizing idler guide slots 122 are now below the shafts 113 of idler gears 112.

[0113] Fig. 27 illustrates molded support bosses 124 secured to instrument 20 that support shafts 113 of the idler gears 112 and support the shafts 115 of cams 114 on one end. A bar (not shown here but shown in Fig. 71), which mounts to bosses 124, supports the shafts 113 of gears 112 and shafts 115 of cams 114 on their other ends. A motor (not iliustrated) that drives cams 114, which opérate the retractable pump race 46, is attached to any of the shafts 115 of any of cams 114. Attaching the motor to the shaft of center cam 114 may be preferred so that clearance in the gear train is symmetric with respect to outer cams 114.

[0114] Figs. 28 and 29 illustrate that system 10 includes a crank 130 that is connected to the blood pump head 22 to opérate the head manually. Manual retum of the blood contained within íhe extracorporeal Circuit is necessary in the event of a faiiure of system 10 or after an extended power faiiure. It is typically necessary to manually opérate the vcnous and arterial line clamps 76 (from a failed closed State) before being able to retum the blood in extracoiporeal Circuit to the patient. Fig. 29 also illustrates that door 18 in one embodiment defines an opening or aperture 132 through which manual crank 130 for the blood pump 22 can be inserted with the door closed. Crank 130 ineludes a large gripping handle 134 and crankshaft 136, which is sufficíently long to allow the user to easiíy turo, blood pump head 22. In an altérnate embodiment, manual crank 130 is built into the door assembly 90 and is accessible to engage pump head 22 when door 18 is opened and hinged away from machine interface 50.

[0115] As seen in Fig. 30, in one bag management embodiment, system 10 prompts the user initially to fold up all of bag shelves 16 except for the bottom shelf 16. The user is then able to break a peel seal of a dual chamber bag (if used), place the fírst solution bag 140 on bottom shelf 16 and connect the bag to the bottom supply line 38e extending from disposable cassette 40, as shown in Fig. 31. When shelf sensors 138 detect that the bag has been placed onto first shelf 16 and that the peel seal 142 has been broken, system 10 prompts the user to place a second bag 140 on the second lowest shelf 16, and so on. System 10 continúes to prompt the user to place Solutions bags 140 onto shelves 16 and connect the bags to supply fines 38 until all of shelves 16 are filled, as shown in Fig. 32.

[0116] As shown in Fig. 32, a peel seal 142 of dual chamber bag 140 present on the top shelf 16 is not broken, a condition which sensors 138 can sense, causing system 10 to instruct the user to break peel seal 142 before continuing with treatment. One such sensor arrangemení and peel seal open check is described in U.S. Patent Application No. 11/773,742, entitled “Mobile Dialysis System Having Supply Container Detection”, filed Juiy 5, 2007, assigned to the assignee of the present disclosure, the pertinent portions of which are incorporated herein expressly by reference. Fig. 33 illustrates all solution bags 140 with peel seáis 142 broken, such that treatment can continué.

[0117] Fig. 34 illustrates onc embodiment for the placcmcnt of the capacitivc sensors 138 that detect the presence of the solution bags, whether peel seal is broken, and perhaps even whether the same solution is present in each bag 140. Other sensors or combinations of sensors can be used altematively, including optical sensors, inductive sensors, bar code readers, radio frequeney Identification (“RFÍD”) tags and cameras, [0118] Fig. 35 illustrates a luer connection assembly 144, which is located on an end of a heparin line 146, which in tum is connected to disposable cassette 40. A heparin syringe 148 ranging in size from ten miüiliters to sixty miililíters, can be connected to luer connection assembly 144 of the disposable set and is inserted with the plunger 150 pointing down into a syringe pump 152 as shown in as shown in Fig. 36, The luer connection assembly 144 is then rotated to lock the syringe in place as shown in Fig. 37. Syringe 148, for sizes larger than 30 milliliters, is inserted with the plunger 150 pointing down into a syringe pump 152 as shown in as shown in Fig. 38. The integral grip 149 on the larger heparín syringes is rotated forty-five degrees to lock the syringe 148 into the syringe pump 152 as shown in Figs. 37 and 38 versus grip 149 shown in Fig. 36.

[0119] Syringe pump 152 is shown in more detai] in Fig. 39. Pump 152 includes a stepper motor 154, gears 156, guide rails 158 and a concave push píate 160 that self-centers on the end of the syringe plunger 150. Air exits syringe 148 above the heparín and is purged during the priming of the extracorporeal Circuit because syringe 148 is inverted for use. Stepper motor 154 incremente 0.9 degrees per step in one implementation. Pump 152 and assembly 144 are sized to accept nearly any size of syringe 148. The user inputs the syringe stroke length and syringe stroke volume into System 10. System 10 can thereañer determine the volume of heparín to be delivered.

[0120] Smaller syringes 148 are visible through a window 162 in the side of the pump as shown in Fig. 40. Larger syringes housings are visible since they are not inserted into syringe pump 152 and remain outside of instrument 20 as illustrated in Fig. 38. Should a saline or dialysate bag leak, or be spilled, onto instrument 20, the liquid could flow into the heparín pump and out the opening in side window 162 but would not flow inside the instrument, where the fluid could damage instrument 20.

[0121] Figs. 41 and 42 Alústrate that heparín line 146 passes through an air bubble detector 164 to cassette 40. System 10 introduces heparín into thepatient’s blood stream at the outlet 166 of the blood pump just before the blood passes into the diaíyzer. The intemal volume of the heparín iine is essentially that of a very small diameter tube of mininmm length. A diaphragm actuated pinch val ve 165 (plunger only shown in Fig. 41), which does not add to the interaal volume of the heparín line, can be provided to block the flow of heparín to cassette 40.

[0122] Fig. 43 illustrates a support rod 168 that collapses into instrument 20 when not in use. Support rod 168 supports a saline bag 170 that is used for priming system 10 and rinsing blood back to the patient ai the end of the therapy. Aitematively, rod 168 is detachable from instrument 20 when not in use.

[0123] Figs. 43 and 44 illustrate that saline Une 172 enters insírument 20 adjacent to the entry ofheparin line 164 (see also Fig. 41). Fig, 45 illustrates thattwo saline flow control val ves 174 a and 174b are located on each side of blood pump tubing loop 44. The center port from each of the valves feeds directly into blood flow into, or Corning from, the blood pump as shown in Fig. 46. The third saline valve 174c is located on the backside of cassette 40 as seen in Figs. 45 and 46 and is positioned to put saline directly into a venous air separation (drip) chamber 176. The saline valve 174a on the blood pump outlet, and the saline valve 174b leading to dialyzer 36, are opened sequentiaily to gravity prime the arterial blood line and the venous drip chamber 176 as illustrated later in Fig. 54.

[0124] As seen in Fig. 47, a normally evacuated dialyzer inlet line pressure transducer interface 178 is pressurized so that it operates as a flow control valve, preventing saline from backflowing into the dialyzer or filter 36. The gravity head from the saline bag causes saline to flow into the blood Circuit and into the reversed rotating pump inlet 180 (the outlet under normal operating flow) when saline valve 174a is opened. The reversed flow blood pump head 22 draws saline from the saline bag and pumps it through reversed flow outlet 182 (the inlet under normal operating conditions) and down the arterial line 186.

[0125] As seen in Fig. 48, the venous line 184 and arterial line 186 are connected in series during priming so that air is purged from both lines vía venous line drip chamber 176 shown in Fig. 49. Standard connections 188 (Fig. 48) can be used to connect the venous line 184 and arterial line 186 in a closed loop. Gravity prevenís air from being drawn from the saline bag as long as the bag contains saline. Saline flows slowly into the venous air separation chamber 176 in a “reverse” direction (from normal blood flow) during priming.

[0126] In Fig. 49, the inverted-U shaped venous air separation chamber 176 has a vent port 190 located at its top, so that air can gather there and be vented to the drain. Fig. 50 shows a valve 196 located on the opposite side of the cassette 40 from vent port 190, which is opened whenever air needs to be vented from the chamber. A second vent valve 192 also shown in Fig. 50 can be placed optionally in series with first vent valve 196 and operated sequentiaily so that prcdctcmiincd voíumctric incrementa of air can be vented from systcm 10 to a controlled vent volume 194 shown in Fig. 51. As seen in Fig. 51, port 190 connected to the center of the cassette-based diaphragm valve 196 communicates with air separation chamber 176 so that the “dead” volume needed for these apparatuses is mínímized. Valve 196 seáis well against the pressure present in the venous air separation chamber. Saline bags can be replaced during a therapy since they can be primed directly into the drip chamber 176 using the third saline valve 174c (Fig. 49).

[0127] FIG. 52 is a schematic of one embodiment of a fluid management System associated with the disposable set. In general, the fluid management system ineludes a bíood Circuit 210 and a dialysate Circuit 220. System 10 operates the disposable set to provide the hemodialysís therapy. Set 200 of FIGS. 53A and 53B ¡Ilústrales an embodiment of a disposable set 200 operable with system 10. Disposable set 200 ineludes cassette 40, filter 36, pump tubes 44, supply tubes 38, balance tubes 202, arterial line 184 and venous line 186, etc., discussed herein.

[0128] Once disposable set 200 has been loaded into the hemodialysís system 10, dialysate bags 140 have been connected, the saline bag 170 (FIG. 43) has been connected and the heparin syringe 148 has been loaded, system 10 primes itself automaticaüy starting with the blood side Circuit. The heparin pump plunger 150 ís moved forward until heparin is detected by heparin line air detector AD-HL shown in FIG. 52. Heparin valve V-H is then elosed. Next, saline is flowed from the saline bag 170 into the blood side Circuit 210 as illustrated in FIG. 54, first through valve V-SA and then through valve V-SDC. A ievel sensor L-ATB in the AIR TRAP drip chamber deteets saline flow into the drip chamber 176 and determines when to cióse valves V-SA and V-SDC.

[0129] As shown in FIG. 55, the post pump blood valve V-PPB is then elosed, V-SV is opened and PUMP-Blood pumps saline in a reverse flow direction. Pressure sensor P-VL and Ievel sensor L-ATB are used to determine when to open air vent valves V-AVB-P and V-AVB-S. The blood pump pushes the saline backwards down the arterial line and into the venous line. When saline reaches the venous air separator (drip chamber 176), the air will be separated from the fluid and will be discharged into a drain line 206 through vent valves V-AVB-P and V-AVB-S until the air separation chamber 176 is flooded with saline.

[0130] Next, as seen in FIG. 55, saline is flowed up into the bottom of dialyzer 36 and up through its hollow fibers. Valve V-PPB is controllably opened so that the air that exits the top of the dialyzer 36 flows into the priming loop, becomes separated in air írap 176 and discharged to drain 206. Saiine is aiso flowed through pours of the fibers of dialyzer 36 to fill the housing of dialyzer 36. System 10 monitors the pressure in the venous line using pressure sensor P-VL to maintain the blood side Circuit 210 at a controlled pressure during priming.

[0031] As seen in FIG. 56, spent dialysate pump, PUMP-DS and valves V-DS, V-B1-SI, V-B1-SO and V-DD vent air from the dialyzer housing to drain 206. Valves V-D1-VEN, CK-VEN, V-DI-FIL, V-Di-PRE and CK-PRE are opened controilably to allow a predetermined volume of saiine to be pushed into the dialysate Circuit 220, purging air from- associated dialysate lines. A second satine bag 170 can be replaced during a therapy by selecting “replace satine bag”, causing the saline line to be primed automatícally into the air trap 176.

[0132] As shown in Fig. 56, dialysate valve V-DB1 that is associated with the dialysate bag on the top shelf is opened so that dialysate can flow into the inlet of dialysate PUMP-DF. PUMP-DF ptLshes the dialysate through the inline fluid heater and into a dialysate side air trap 208. Dialysate flows out the bottom of the air trap 208, through valve V-FI and into balance tube B2, through valve V-B2-FI, pushing fluid out the other side of balance tube B2. The fluid exiting the other side of balance tube B2 flows through valve V-B2-SO and into the dialysate recirculating Circuit 203 through valve V-DR. The recirculating círcuit 223 tees into the supply line circuit 205 at the inlet to PUMP-DF. Pump-DS is operating at the same time drawing air, dialysate and/or saline from the blood side of the dialyzer, though the dialysate side of the díalyzer, into the remainder of the dialysate circuit. PUMP-DS pushes the fluid through valve V-B1-SI and into balance tube Bl, pushing fluid out the other side of balance tube Bl. The fluid exiting the other side of balance tube Bl flows through valve V-B1-FO and valve V-DI-FIL into the dialysate side of the dialyzer 36.

[0133] Fig. 57 is similar to Fig. 56 except the roles of balance tubes 202 Bl and B2 are reversed. As fluid enters the dialysate circuit 220, the pressure in the circuit increases, forcing air to be discharged under pressure to drain line 206 through open vent valves V-AVD-P and V-AVD-S.

[0134] Fig. 58 illustrates balance tubes 202. Instrument 20 ineludes pairs of optical sensors (not shown) operable with balance tubes 202 to determine an end of travel of a separator 212 located within each balance tube 202. The optical sensors in one embodiment are reflective, so that an emitter and receiver of each sensor can be on the same (e.g., non-door) side of balance tube 202. The sensors altematively inelude emitiere and receivers located on opposite sides of balance tubes 202. Outlets 214 on both ends of both balance tubes 202 are at the balance tube tops when mounted for operation as shown if Fig. 58, so that air will pass through the balance tubes and not bccomc trapped in the tubes as long as systcm 10 is level. Mechanicaí stops 216 limit the movement of separators 212 to that visible to the optical sensors.

[0135] Fig. 59 illustrates HHD system 10 performing hemodialysis. Here, fresh dialysate is pushed from balance tubes 202 to dialyzer 36 vía valve V-DI-FÍL, while spent dialysate is removed from dialyzer 36 via valve V-DS to balance tubes 202.

[0136] FIG. 60 ¡líustrates HHD system 10 performing pre-dilution hemofiltration. Here, fresh diaiysate is pushed from balance tubes 202 to blood circuií 210 directly via valve V-Di-PRE, while spent diaiysate is removed from dialyzer 36 via valve V-DS to balance tubes 202.

[0137] FIG. 61 illustrates HHD system 10 performing post-diiution hemofiltration. Here, fresh diaiysate is pushed from balance tubes 202 to blood Circuit 210 directly via valve V-DI-VEN, while spent diaiysate is removed from dialyzer 36 via valve V-DS to balance tubes 202, [0138] FIG. 62 illustrates HHD system 10 performing post-dilution hemo-diafiltration. Here, fresh diaiysate is pushed from balance tubes 202 to (i) dialyzer 36 via valve V-DI-FIL and (¡i) blood Circuit 210 directly via valve V-DI-VEN, while spent diaiysate is removed from dialyzer 36 via valve V-DS to balance tubes 202.

[0139] FIG. 63 illustrates one embodiment for closing arterial line clamp V-ALC, opening a saline valve V-SA and infusing a saline bolus into blood Circuit 210 during therapy.

[0140] FIG. 64 illustrates one embodiment for recirculating fresh diaiysate through Fluid Heater and recirculating Circuit 223 and balance tubes B1 and B2 to remove UF, In FIG. 64, pump-DF pumps fluid in a loop that ineludes Fluid Heater since valve V-DBY is open. Valve V-FI is closed so no fresh diaiysate is delivered to balance chambers 202. Pump-DS pulís spent fluid from the dialyzer 36 through valve V-DS and pushes the spent fluid through valve V-B1-SI and into the right side of balance tube B1. Fresh fluid then flows from the left side of balance tube B1 through valves V-B2-FI and V-B2-FI and into the left side of balance tube B2. Spent fluid then flows out the right side of balance tube B2 through valves V-B2-SO and V-DD and into the drain line. In this manner, a volume of spent fluid is sent to drain 206 without a corresponding volume of fresh fluid delivered from supply bags 140 to either balance chamber B1 or B2.

[0141] FIG. 65 iilustrates one embodiment for closing venous ¡ine clamp V-VLC, opening a salíne valve V-SA and rinsing back the arterial line 184.

[0142] FIG, 66 iilustrates one embodiment for closing arteriai line clamp V-ALC, opening a saline valve V-SA and rinsing back the venous line 186.

[0143] FIGS. 67A to 67C ¡Ilústrate a cassette ínterface assembly 250, which houses, among other ítems, cassette interface 50, door íatch 24, heater 26, a bellows bladder 252 and an internal module 260. Internal module 260 is bounded by Ínterface píate 50 and a back--—---7 píate 254. Interna! module 260 houses a plurality of gaskets 256, a pneumatic vaive assembly 258, a pinch vaive assembly 262, and a plurality of manifold plates 264.

[0144] All or most all of the valves, pressure sensors, level sensors, etc., can be removed without disassembly of subassembly 250. The inductive heater mechanism 26 and bellows bladder 252 (different from bladder 92 above) require removal of intemal module 260. To this end, four screws 266, each with a spring 268, fix a housing 270 of subassembly 250 to intemal module 260. Intemal module 260 can be unbolted from screws 266, so that springs 268 push intemal module 260 forward and out of the housing 270. Power and control connections (not shown) to subassembly 250 are also disconnected to remove intemal module 260 completely.

[0145] As seen additionally in Figs. 68 to 70, four springs 268 on the backside of subassembly 250 retract the intemal interface module 260 when bellows bladder 252 is not pressurized by pushing screens away from housing 270 and pulling interface module 260 along with the screws. When the bellows bladder 252 is pressurized, intemal module 260 is pushed forward and applies pressure to cassette 40, pushing the cassette against a door gasket, which seáis fluid pathways on both the front side and the rear side of the cassette 40. The membrane gaskets 256 on the intemal module 260 mate up against the faceplate 50 of the interface module 250. The faceplate 50 is configured so that it can support a vacuum between the cassette sheeting and pressure sensors, liquid level sensors, etc., bringing the sensors into intímate contad with the cassette sheeting and the fluid on the other side of the sheeting. System 10 is also configured to port a vacuum between the cassette sheeting and the thin sections of the membrane gasket 256 above the valves. This vacuum can be used to detect holes, tears or slits in the cassette sheeting before, and during a therapy.

[0146] Fig. 71 is a view of the backside of system 10 with the cover removed. The open space houses interface assembly 250, hinged shelves 16, peristaltic pump motors 120 a pneumatic pump, a power supply, battery and electronics that opérate the system.

[0147] Fig. 72 Alústrales system 10 operating altematively with an online dialysate gcncration system 300. System 300 gcncratcs dialysate online or on-demand, climinating bags 140, shelves 16 and múltiple supply tubes 38. A single supply tube 38 feeds from generation system 300 to instrument 20. Water iniet fine 302 and drain lines 304 iead to and from generation system 300, respectively.

[0148] Figs. 73A, 73B and 74 Alústrate a cassette 40 diaphragm vaive chamber configuration 280, which so Ivés an inherent problem with diaphragm valves have when attemptíng to seal against downstream pressure because the pressure that is trying to sea! off the valve is actíng on an area that is just slightly íarger than an area upon which the downstream pressure is actíng. The difference between the two areas is the area defined by the top of the “volcano”. Also, if the downstream fluid vohime is completely fíxed when the diaphragm valve cioses, further raovement of the diaphragm is prevented añer the initiation of the seal because of the incompressibility of the trapped fluid. The result is that the downstream pressure equals the valve sealing pressure. Diaphragm valve configuration 280 provides a diaphragm valve that can seal against both upstream and downstream pressure via a connection of two diaphragm valve chambers 282 and 284 placed in series. Diaphragm valve chambers 282 and 284 are connected fluidly via a comph'ance chamber 286, which allows sheeting seáis 288 of the cassette sheeting to cióse around respective volcano ports 290 of both valve chambers 282 and 284.

[0149] Chamber configuration 280 in both Figs. 73A and 73B ineludes a rigid middle or base wall 281 from which valve ports 290 and the valve chamber walls extend upwardly. Wall 281 defines an aperture 283 for each valve chamber 282 and 284. Fluid communicates between valve chambers 282 and 284 and compliance chamber 286 via apertures 283.

[0150] Fig. 73A shows a cross-section of two diaphragm valve chambers 282 and 284 with an integral compliance chamber 286, wherein the diaphragms can readily cióse seáis 288 to ports 290. Here, a vacuum is applied to a lower diaphragm 289 at the compliance chamber 286. Diaphragm 289 is flexible and has a relativeiy large cross-sectional area to absorb íhe kinetic energy created by a pneumatic valve actuator applying a posiíive pressure Pa, such that the posiíive sealing pressure applied to one valve chamber 282 or 284 is much íess Hkely to harm an existing seal of a fluidly connected upstream or downstream valve chambers. The negative pressure pulís sheeting 288 down around ports 290 and allows valve chamber 282 or 284 to be sealed against the backpressure applied by its own sealing pressure (around the outside of port 290) plus backpressure from a fluidly connected upstream or downstream valve chamber residing up through the center of port 290.

[0151] Compliance chamber 286 as seen in Fig. 73B is configured a little bit diffcrcntíy and uses a portion of the membrane or sheeting seáis 288 of valve chambers 282 and 284 to provide a compliant material covering a relativeiy large cross-sectional area 292 of chamber 286. Here, a vacuum applied to sheeting 288 at chamber 286 negates the posiíive pressure Pe applied around the outside of ports 290 and expands the relativeiy large area 292 of the valve seal sheeting, pulling sheeting 288 down around the outside of port 290. The configuration of Fig. 73B is advantageous in one respect because posxtive and negative pressures are applied to the same side of the cassette at chamber confíguration 280, such that associated pneumatics can be located on a single side of the cassette..

[0152] By changing the pressure seen at compliance chamber 286 from a positive pressure when the valve chambers 282 and 284 are open to a negative valué afier the vaíve chambers results in that only the liquid side center of the volcano port 290 is exposed to high positive pressure. The liquid annular area of valve chambers 282 and 284 on the outsíde of volcano ports 290 sees the applied vacuum, which allows the air sealing pressure on the outside of the cassette to seal against backpressures that would have oíherwise forced it open. This allows valve chambers 282 and 284 to seáis well in both upstream and downstream confígurations.

[0153] In one example, suppose the total seal area of valve chambers 282 and 284 is one square ínch and that the sealing area at the top of volcano port 290 is 0.1 square inch over the volcano. A positive ten psig air pressure would then apply an extcmal forcé of 10 lbs to the entire valve chamber 282 or 284. A backpressure on the annular fluid side of the associated port 290 from the applied ten psig pressure plus a backpressure the backpressure up through the center of port 290 from a downstream sealed valve would exert almost the same opposite “unsealing” forcé of ten pound (only difference would be the small annular area of port 290 at the top, which is a function of the port wall thickness and the diameter of the tube), resulting in a potentially leaky valve chamber 282 or 284. A higher positive pressure, e.g., íwenty psig, could be applied to valve chamber 282 or 284 forcing sheeting 288 to seal to port 290 against the 10 psig backpressure, however, the noise generated to create the twenty psig air pressure could objectionabie to the user. There would also be no redundancy in the different valve pressures.

[0154] Back to back valve chambers 282 and 284 of Figs. 73A and 73B, on the other hand, separated by an applied negative pressure, e.g., 5 psig vacuum, both seal independently well. The ten psig air pressure would still apply 10 lbs extemal forcé to seal both valves 282 and 284, however, the 10 psig pressure at the center of the volcano port 290 and the -5 psig pressure on the annular arca around the volcano would apply a total pressure of ten psig * 0.1 sq in + (- 5 psig) * 0.9 sq in = -3.5 lbs. The net forcé to cióse the valve would be 13.5 lbs so that valve would seal very well.

[0155] It may be possible to not use a sepárate vacuum and instead rely on the expansión of the flexible part of the compliance chamber 286 to absorb energy from the backpressure from one valve chamber 282 or 284 applied to the other valve chamber 282 or 284. Here, apertures 283 allow the pressurized fluid inside chambers 282 and 284 and around ports 290 to communicate with fluid inside compliance chamber 286 and expand diaphragm 289 or sheeting area 292, allowing the backpressure around ports 290 to dissipate.

[0156] Valves V-DI-PRE, CK-PRE, V-DI-VEN and CK-VEN in Fig. 52 (and other flow schematics) and valve chambers 282 and 284 of valve configuration 280 of cassette 40 shown in Fig. 74 are constructed as shown schematically in Figs. 73A and 73B and can seal against higher pressiire in either directíon. That is, not only does compliance chamber 286 serve to not disrupt an existing upstream or downstream first valve chamber closure when a second valve chamber in fluid communication with the fírst valve chamber is opened, compliance chamber 286 also aids in the closure of a fírst valve chamber when a second valve chamber in communication with the fírst valve chamber (upstream or downstream) has been closed previously, which could otherwise create posítive fluid pressure against which the closure of the fírst valve chamber would have to fight [0157] Fig. 75 illustrates that system 10 in one embodiment ineludes a wide pump head 22 that drives two dialysate pump segmente 44 to mix two Solutions in a ratio that is approximately equal to the ratio of the tube inside diameters squared (mix ratio = (IDi/ID2)2), assuming the wall thicknesses of tubes 44 is the same. For a 1:1 mix ratio, consecutive segments of tubing from the same roll of tubing can be taken to províde segmente of the same wall thickness and good mixing accuracy. Mixing accuracy is optimized because the inlet pressure on the supply lines is controlled within about four inches of water column by the bag manager, the tubing inner diameter is controlled during the manufacture of the disposable set, the pump race diameters are the same and the pump actuator rotational speed is the same for the parallel tubing segments. System 10 also ensures that an initial supply fluid temperature of each of the different dialysis fluids in tubes 44 is within a few degrees of each other.

[0158] It shoutd be understood that various changes and modifications to the presentiy preferred embodiments described herein wiil be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without díminishing its intended advantages. It is íherefore intended that such changes and modifications be covcrcd by the appcndcd claims.

Claims (20)

1. THE CLAIMS DEFINING THE INVENTIQN ARE AS FOLLOWS:-

   1. A renal therapy machine comprising: a blood filter including a plurality of porous fibers; a blood Circuit in communication with the blood filter; a dialysate Circuit in communication with the blood filter; and at least one pump or valve positioned and arranged to purge airfrom the blood filter into the dialysate Circuit, as a physiologically compatible solution, other than dialysate, is moved across the porous fibers of the blood filter, wherein the renal therapy machine is configured to perform a priming sequence in which (i) the physiologically compatible solution, other than dialysate, primes the blood Circuit and is flowed within the fibers and through pores in the fibers of the blood filter, and (ii) the at least one pump or valve purges air, via the dialysate Circuit, from the blood filter into the dialysate Circuit.
2. 2. The renal therapy machine of Claim 1, wherein the at least one pump or valve is a spent dialysate pump or valve.
3. 3. The renal therapy machine of Claim 1, which ineludes a blood pump operable with the blood Circuit, wherein the blood filter ineludes a housing holding the porous fibers, and wherein the physiologically compatible solution, other than dialysate, is pumped by the blood pump through pores in the fibers of the blood filter and filis the housing of the blood filter.
4. 4. The renal therapy machine of Claim 1, which ineludes a blood pump operable with the blood Circuit, and wherein the physiologically compatible solution, other than dialysate, is pumped by the blood pump through the pores in the fibers of the blood filter and into the dialysate Circuit.
5. 5. The renal therapy machine of Claim 4, wherein the physiologically compatible solution, otherthan dialysate, flowed into the dialysate Circuit purges airfrom the dialysate Circuit.
6. 6. The renal therapy machine of Claim 5, which ineludes a fresh dialysate pump operable with the dialysate Circuit, and wherein the dialysate Circuit is additionally primed using dialysate pumped by the fresh dialysate pump.
7. 7. The renal therapy machine of Claim 1, which ineludes a fresh dialysate pump operable with the dialysate Circuit, and wherein the dialysate Circuit is primed using dialysate pumped by the fresh dialysate pump.
8. 8. The renal therapy machine of Claim 1, which ineludes a blood pump and at least one blood Circuit valve operable with the blood Circuit, and wherein the blood Circuit is primed using the blood pump and the at least one blood Circuit valve.
9. 9. The renal therapy machine of Claim 1, wherein the physiologically compatible solution, otherthan dialysate, ineludes saline.
10. 10. A renal therapy machine comprising: a blood filter including a housing holding a plurality of porous fibers; a blood Circuit in communication with the blood filter and operable with a blood pump; a dialysate Circuit in communication with the blood filter; and at least one pump or valve positioned and arranged to purge airfrom the blood filter into the dialysate Circuit, as a physiologically compatible solution, other than dialysate, is moved across the porous fibers of the blood filter, wherein the renal therapy machine is configured to perform a priming sequence in which (i) the physiologically compatible solution, other than dialysate, is pumped by the blood pump to prime the blood Circuit and to flow within the fibers and through pores in the fibers of the blood filter, (ii) wherein the at least one pump or valve vents air, via the dialysate Circuit, from the blood filter into the dialysate Circuit and (iii) wherein the physiologically compatible solution, other than dialysate, enters a portion of the housing of the blood filter outside of the fibers.
11. 11. The renal therapy machine of Claim 10, wherein the physiologically compatible solution, other than dialysate, is pumped by the blood pump through the pores in the fibers of the blood filter and into the dialysate Circuit.
12. 12. The renal therapy machine of Claim 10, wherein the at least one pump or valve enables the physiologically compatible solution, other than dialysate, to flow through the pores in the fibers of the blood filter and into the dialysate Circuit.
13. 13. The renal therapy machine of Claim 10, wherein the at least one pump or valve is a spent dialysate pump or valve.
14. 14. The renal therapy machine of Claim 10, wherein the blood pump pumps in múltiple directions to prime the blood Circuit.
15. 15. A renal therapy machine comprising: a blood filter; a blood Circuit in communication with the blood filter; a blood pump operable with the blood Circuit; a dialysate Circuit in communication with the blood filter and including a balancing structure forming a fresh dialysate Circuit side between a fresh dialysate source and a fresh fluid inlet to the blood filter and a spent dialysate Circuit side between a dialysate outlet of the blood filter and a drain; and at least one pump or valve positioned and arranged to vent airfrom the blood filter into the dialysate Circuit, as a physiologically compatible solution, other than dialysate, is moved across porous fibers of the blood filter, wherein the renal therapy machine is configured to perform a priming sequence in which (i) the physiologically compatible solution, other than dialysate, is pumped by the blood pump to prime the blood Circuit and at least a portion of the spent dialysate Circuit side of the dialysate Circuit formed by the balancing structure, (ii) dialysate is pumped by a fresh dialysate pump to prime the fresh dialysate Circuit side of the dialysate Circuit formed by the balancing structure, and (iii) the at least one pump or valve vents air, via the dialysate Circuit, from the blood filter into the dialysate Circuit.
16. 16. The renal therapy machine of Claim 15, wherein the dialysate used to prime the fresh dialysate Circuit side of the dialysate Circuit formed by the balancing structure is fresh dialysate from the fresh dialysate source.
17. 17. The renal therapy machine of Claim 15, wherein the at least one pump or valve is a spent dialysate pump operable with the spent dialysate Circuit side to pulí the physiologically compatible solution, other than dialysate, from the blood filter and into the spent dialysate Circuit side.
18. 18. The renal therapy machine of Claim 17, wherein the spent dialysate pump operable with the spent dialysate Circuit side also pushes the physiologically compatible solution, other than dialysate, to the balancing structure, causing fresh dialysate to flow along the fresh dialysate Circuit side from the balancing structure to the blood filter.
19. 19. The renal therapy machine of Claim 15, wherein the fresh dialysate pump operable with the fresh dialysate Circuit side pulís fresh dialysate from the fresh dialysate source into the fresh dialysate Circuit side formed by the balancing structure.
20. 20. The renal therapy machine of Claim 19, wherein the fresh dialysate pump also pushes the fresh dialysate to the balancing structure, causing the physiologically compatible solution, other than dialysate, to flow along the spent dialysate Circuit side, from the balancing structure to the drain. Dated this 4th day of April 2018 Baxter International Inc. and Baxter Healthcare SA Patent Attorneys for the Applicant PETER MAXWELL AND ASSOCIATES