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`US008092414B2
`
`c12) United States Patent
`Schnell et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,092,414 B2
`Jan.10,2012
`
`(54) DIAPHRAGM PRESSURE POD FOR
`MEDICAL FLUIDS
`
`(75)
`
`Inventors: William J. Schnell, Libertyville, IL
`(US); David Bell, Grayslake, IL (US);
`Karen Wilson, Seattle, WA (US); David
`S. Utterberg, Seattle, WA (US)
`
`(73) Assignee: NxStage Medical, Inc., Lawrence, MA
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 1494 days.
`
`(21) Appl. No.: 11/270,080
`
`(22) Filed:
`
`Nov. 9, 2005
`
`(65)
`
`Prior Publication Data
`
`US 2007/0179422Al
`
`Aug. 2, 2007
`
`(51)
`
`Int. Cl.
`A61M 37100
`(2006.01)
`C02F 1144
`(2006.01)
`(52) U.S. Cl. ....................... 604/6.11; 604/4.01; 210/741
`(58) Field of Classification Search ................. 604/4.01,
`60416.09, 6.11, 6.16, 65-67; 210/645, 739,
`210/741
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`3,713,341 A
`111973 Madsen et al.
`3,863,504 A
`2/1975 Borsanyi
`4,077,882 A
`3/1978 Gangemi
`2/1980 Ellis
`4,189,936 A
`4,398,542 A
`8/1983 Cunningham et al.
`4,457,749 A
`7/1984 Bellotti et al.
`3/1986 Wisman eta!.
`4,573,997 A
`4,610,256 A
`9/1986 Wallace
`4,666,598 A
`5/1987 Heath et al.
`4,770,787 A
`9/1988 Heath et al.
`111989 Young et al.
`4,795,440 A
`
`111989 Heath et al.
`4,798,090 A
`9/1991 Giesler et al.
`5,044,401 A
`2/1993 Tamari
`5,186,431 A
`1111994 Utterberg
`5,360,395 A
`5/1995 Gordon
`5,417,673 A
`10/1995 Wolbring et al.
`5,456,675 A
`7/1997 Utterberg
`5,643,205 A
`5,693,008 A * 12/1997 Brugger et al . .............. 604/4.01
`5,980,741 A
`1111999 Schnell et al.
`6,280,406 Bl
`8/2001 Dolecek et al.
`6,409,696 Bl
`612002 Toavs et al.
`6,517,508 Bl
`212003 Utterberg
`6,526,357 Bl *
`212003 Soussan et al . ................. 702/45
`2002/0049412 Al
`412002 Madrid et al.
`200210177786 Al
`1112002 Balbo
`2004/0068239 Al
`412004 U tterberg et al.
`2005/0147525 Al
`712005 Bousquet
`2005/0159710 Al
`712005 Utterberg
`2005/0209563 Al
`912005 Hopping et al.
`2005/0224405 Al
`10/2005 Neri et al.
`2008/0175719 Al*
`712008 Tracey et al.
`
`................... 417/38
`
`OTHER PUBLICATIONS
`
`International Search Report dated Jan. 24, 2008, 4 pages.
`* cited by examiner
`
`Primary Examiner - Leslie Deak
`(74) Attorney, Agent, or Firm -Miles & Stockbridge P.C.;
`Mark A. Catan
`
`ABSTRACT
`(57)
`A tubular medical fluid flow set comprises a pressure sensing
`chamber connected in flow-through relation to fluid flow
`tubing of the set. The pressure sensing chamber defines a
`movable, flexible, impermeable diaphragm dividing the
`chamber into two separate compartments. The fluid flow tub(cid:173)
`ing communicates with one of the compartments and is iso(cid:173)
`lated from the other of the compartments. A port is carried on
`the chamber, the port having a seal therein, and communicat(cid:173)
`ing with the other of the compartments. Thus, the other of the
`compartments is hermetically sealed until the port is opened
`for connection with a pressure measuring device, to keep the
`flexible diaphragm in a desired, initial position prior to open(cid:173)
`ing of the seal.
`
`28 Claims, 7 Drawing Sheets
`
`32
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`12
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`16/f
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`\
`\.---35
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`I I
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`U.S. Patent
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`Jan. 10, 2012
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`Sheet 1of7
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`US 8,092,414 B2
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`10
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`FIG. 1
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`52y/
`42 !I
`\
`-1~
`~* 44 41
`
`I
`11
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`18
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`I
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`k20
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`FIG. 2
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`40
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`34
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`35
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`I
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`r--
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`32
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`12
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`U.S. Patent
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`Jan.10,2012
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`Sheet 2of7
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`US 8,092,414 B2
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`FIG. 3
`4
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`32
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`FIG. 4
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`32
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`5
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`FIG. 6
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`40
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`FIG. S
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`40
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`U.S. Patent
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`Jan.10,2012
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`Sheet 3of7
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`US 8,092,414 B2
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`84
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`87
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`86
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`88
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`FIG. 7
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`78
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`77
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`70
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`74
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`69
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`60
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`64
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`62
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`U.S. Patent
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`Jan.10,2012
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`Sheet 4of7
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`US 8,092,414 B2
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`FIG. 8
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`22a
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`FIG. 9
`98
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`116
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`98
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`94
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`100
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`U.S. Patent
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`Jan.10,2012
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`Sheet 5of7
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`US 8,092,414 B2
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`FIG. 10
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`84
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`42a
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`44a
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`102
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`FIG. 11
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`42a
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`U.S. Patent
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`Jan.10,2012
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`Sheet 6of7
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`US 8,092,414 B2
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`FIG. 13
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`116a
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`120a
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`FIG. 12
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`FIG. 14
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`FIG. 17
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`aoa
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`132
`\
`\
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`130
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`I
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`136
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`FIG. 15
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`120a
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`I
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`FIG. 16
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`132
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`134
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`134
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`U.S. Patent
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`Jan.10,2012
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`Sheet 7of7
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`US 8,092,414 B2
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`FIG. 18
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`19~
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`FIG. 19
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`150
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`166
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`158
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`US 8,092,414 B2
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`1
`DIAPHRAGM PRESSURE POD FOR
`MEDICAL FLUIDS
`
`BACKGROUND OF THE INVENTION
`
`Sets for extracorporeal blood handling, and also parenteral
`solution sets, generally require flow-through chambers, often
`called drip chambers, which, in use, utilize an upper liquid
`level of the medical liquid passing through it, with an air
`space on top. Such chambers generally have a permanently
`connected, branching, hollow-bore, flexible, branch line
`communicating with said air space for an air pressure line
`which connects via a reversible connector at its remote end to
`an equipment pressure port on the permanent equipment,
`which in turn communicates with a pressure monitor trans(cid:173)
`ducer for measuring air-pressure in the chamber as a surro(cid:173)
`gate for blood-pressure. A pressure-transmitting sterility bar(cid:173)
`rier or diaphragm separates the sterile, disposable set and the
`unsterile permanent equipment.
`These sets generally need to be initially primed with saline
`or another parenteral solution, where the proper upper liquid
`level is provided in each drip chamber present. Then, in the
`field of extracorporeal blood handling such as in hemodialy(cid:173)
`sis, connection may be made with a fistula set or other means
`of access to the patient's bloodstream, and the saline in the
`primed set is replaced by blood, which is transferred to and
`from an extracorporeal blood processing device. These
`devices may comprise hemodialyzers, hemofilters and other
`devices for extracting components in the blood and returning
`the balance to the donor.
`Alternately, it is also known for a flow-through chamber to
`incorporate a diaphragm as the pressure-transmitting sterile
`barrier which may be in direct contact with blood or another
`parenteral solution, or may only be in contact with air above
`the upper liquid level. For example, see Madsen et al. U.S.
`Pat. No. 3,713,341, Borsanyi U.S. Pat. No. 3,863,504, and
`Gangemi U.S. Pat. No. 4,077,882.
`As taught in Brugger et al. U.S. Pat. No. 5,693,008, a
`flow-through chamber or "pod" is provided, having a dia- 40
`phragm that transmits pressure but prevents passage of blood
`across said diaphragm. The pod comprises a rigid chamber in
`which said diaphragm is mounted and which further com(cid:173)
`prises a reversible connector which communicates with an
`airspace between said connector and the non-sterile side of
`said diaphragm. Said reversible connector, air space and non(cid:173)
`sterile diaphragm side are open to atmosphere prior to medi-
`cal treatment. To prepare for treatment, the reversible connec-
`tor is connected directly to the pressure port on the face of the
`dialysis machine. Thus, a pressure tight system is attained and
`the machine's pressure transducer can measure pressure in
`the sterile set's flow-through blood pathway. Flow-through
`blood tubing must convey blood to and from that pod
`mounted on the face of the machine.
`As a disadvantage of these diaphragmatic systems, the
`great majority of over 100,000+ dialysis machines which are
`clinically used at the present time have their pre-pump arte(cid:173)
`rial, post pump arterial and/or venous pressure ports for mea(cid:173)
`suring blood pressure positioned on the face of the machine
`remote from other sites to which the blood tubing must be
`routed, such as the to the blood pump, the dialyzer (in the case
`ofhemodialysis), the safety shut-off clamp, etc. Thus there is
`a disadvantage in the use of this system. It is always desirable
`to minimize the length of the extracorporeal blood flow path,
`both for reasons of simple economy, to minimize extracorpo(cid:173)
`real pressure drop and clottable surface area, as well as to
`minimize the total extracorporeal blood volume.
`
`2
`It is a further disadvantage of the current diaphragmatic
`system that the non-sterile side of the diaphragm is open to
`atmosphere prior to being brought into sealing relation with
`the equipment's pressure port, and therefore may be dis(cid:173)
`placed prior to use. Such displacement results in pressure
`measurement errors and/or limited pressure measurements.
`It is a disadvantage of sets which fit the great majority of the
`world's dialysis machines that they have drip chambers and
`permanently attached branch lines. Such branch lines com-
`10 plicate the sets' construction, packaging and use and are
`expensive.
`By this invention, a generally airless pressure chamber
`(called a "pod") which contains a diaphragm may be used as
`a substitute for a pressure monitoring drip chamber regardless
`15 of the front panel placement of necessary equipment. By this
`invention the pod is not connected to the pressure port on the
`face of a dialysis machine, but is spaced therefrom, and the
`important function of pressure monitoring still takes place.
`This achieves numerous advantages when compared with the
`20 prior drip chamber. Specifically, in the pod of this invention,
`it becomes unnecessary to set a liquid level as in many prior
`art chambers, and a blood-air interface can be completely
`avoided. At the same time, the chamber of this invention may
`be significantly smaller than the drip chambers of the prior
`25 art, and thus may have a reduced priming volume. Also, the
`volume of the chamber can be temporarily further reduced by
`manipulation of the diaphragm, for example during the rinse
`back step in extracorporeal blood handling procedures such
`as dialysis, to reduce the amount of solution needed in the
`30 rinse back process.
`Also by this invention there are achieved important advan(cid:173)
`tages when compared with the pods of the prior art. Com(cid:173)
`pared with the priming volume and tubing costs of extracor(cid:173)
`poreal circuits using pods of the prior art, this invention saves
`35 cost because less large-bore blood tubing, but more small
`bore air pressure monitoring tubing, is used, the latter not
`containing blood. Thus it can be of a much finer, and cheaper,
`gauge than blood tubing, resulting in a net savings of plastic
`and cost, with less blood volume.
`Sets utilizing the pod of this invention are easier to prime
`and operate, because there is no liquid level needed to be set
`in a chamber, as in the prior art. The pod ofthis invention may
`have branch connections for access to parenteral solutions
`such as saline or heparin solution, and it also may carry a
`45 connected, blood-free pressure monitor line (pressure tubing)
`for connection to a remote pressure port, forthe monitoring of
`particularly blood pressure in the tubular set which carries the
`chamber. Cost may be saved in the manufacture and assembly
`of the set of this invention, since the blood tubing may be
`50 shortened, as it does not have to extend to the face of the
`dialysis machine, while also reducing extracorporeal blood
`volume (priming volume), as a clinical advantage.
`The pod of this invention may be positioned precisely
`where pressure needs to be determined. For example, to
`55 detect line kinks or leaks, the pressure measuring chamber or
`pod should be upstream of the tubing which may leak or
`become kinked. Where a dialyzer is remotely monitored from
`a machine (as is generally the case) the placing of a pressure
`measuring chamber or pod immediately downstream from it
`60 is impossible in the case of drip chambers or prior art pods. As
`a further advantage, the pressure chamber of this invention
`does not require a permanently connected pressure monitor
`line. Rather, it can connect with a reusable pressure monitor
`line. Thus the set utilizing the chamber is less expensive, and
`65 there is an overall saving of cash because many disposable
`sets may be sequentially used with a single pressure monitor
`line, if desired.
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`US 8,092,414 B2
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`3
`DESCRIPTION OF THE INVENTION
`
`In accordance with this invention, a tubular blood flow set
`is provided which comprises a pressure sensing pod con(cid:173)
`nected in flow-through relation to fluid flow tubing of said set,
`typically blood tubing. The pressure sensing pod defines a
`movable, flexible, impermeable diaphragm dividing the pod
`into two separate compartments. The fluid flow tubing com(cid:173)
`municates with one of the compartments for fluid flow
`through the compartment. The fluid flow tubing is isolated
`from the other of the compartments by the diaphragm. A pod
`connector carried on the pod communicates with the other of
`the compartments. In one embodiment of this invention a
`hollow-bore branch line is permanently attached to and com(cid:173)
`municates with the pod connector. The branch line is long
`enough, and terminates in a releasable connector such that it
`mates with the machine's pressure port. In another embodi(cid:173)
`ment, the pod connector is releasable, and may be temporarily
`attached to a separate branch line bearing an appropriate
`mating connector for the pod connector. As before, the branch
`line is long enough, and terminates in a releasable or non(cid:173)
`releasable connector to the pressure sensing machines pres(cid:173)
`sure port. Preferably, the pod connector is sealed prior to
`attachment to either the machine port directly, or preferably to
`said separate branch line. Such sealing may be permanently
`breached, as in a frangible barrier, or it may be reversibly
`opened such as attained by a slit disc of U.S. Patent Publica(cid:173)
`tion No. US 2005/0159710 Al, the disclosures of which are
`incorporated by reference.
`Thus, the one compartment of the pod is part of a fluid flow
`path, typically blood, through the fluid flow set and the pres(cid:173)
`sure sensing chamber. The other of the compartments is pref(cid:173)
`erably hermetically sealed by a sealed port, until opened for
`connection with a pressure measuring device. The effect of
`this is to keep the movable, flexible diaphragm in a desired,
`initial position prior to said opening. The diaphragm, when
`the hermetic seal is broken, is capable of moving between a
`first position and a second, opposed position in which the
`diaphragm in the first position can bow outwardly from the
`blood pathway, to maximize blood volume in the chamber,
`while the diaphragm in the second position can bow inwardly
`to minimize, but typically not eliminate, blood volume in the
`chamber. In some embodiments, the diaphragm has a central,
`domed portion which can flip between the two positions.
`In an arterial, pre-pump pod embodiment where the pod is
`generally subjected to negative pressure [but sometimes posi(cid:173)
`tive pressure when priming], the diaphragm may be moveable
`between the first and second positions when the hermetic seal
`is broken, but not before. The same holds for the post pump,
`positive pressure situation.
`In some embodiments, the sealed port is opened by engage(cid:173)
`ment with a connector which is carried on an end of a length
`of separate pressure tubing. This connector may be, for
`example, a male luer lock connector or any other desired
`connector that is compatible for connection with the sealed
`port carried on the pod. Also, the pressure tubing connects at
`an opposed end thereof with the pressure measuring device,
`either permanently or separably, as may be desired.
`Specifically, in some embodiments the sealed port of the
`pod may be so sealed by a partition having a peripheral
`connection with a lumen wall of the sealed port. A major
`portion of the peripheral connection is relatively thin, capable
`of being easily broken open, while a minor portion of the
`peripheral connection is thicker than the major portion of the
`peripheral connection, so that the minor portion functions as
`a hinge. Thus the partition can pivot, but it cannot separate
`
`30
`
`4
`from the rest of the sealed port as it is tom open by an
`advancing connector such as a male luer.
`In some embodiments, the sealed port partition is relatively
`thin in a line of tearing weakness extending across the parti(cid:173)
`tion, as well as around most of the periphery so that, when
`broken, there are two hinges and half partitions which distend
`a lesser distance inwardly than the previous embodiment.
`Further, by this invention in some embodiments, a first
`section of the partition adjacent to the major portion (but
`10 radially inwardly therefrom) is thicker than the correspond(cid:173)
`ing, opposite section of the partition adjacent to the periphery
`thereof. The effect ofthis is to focus rupturing force provided
`by pressure from a male luer or other tubular connector to the
`periphery of the partition at the first section. Thus, when a
`15 normal, flat-ended tubular connector is inserted into the
`sealed port and pressed inwardly, it encounters the first sec(cid:173)
`tion and presses against it, without contact with the opposite
`section. Accordingly, the rupturing force is focused against
`only a portion of the periphery of the partition, that portion
`20 being at least part of the major portion of the peripheral
`connection, thin enough to be easily broken open. This force
`is focused because the tubular connector is engaging only the
`first section of the partition because ofits increased thickness,
`and not the corresponding, opposite section. Thus the total
`25 force required for frangibility of the partition is less. The
`partition easily opens and pivots about the minor portion of
`the peripheral connection, to open the sealed port.
`Typically the first section of the partition is at least twice as
`thick as the corresponding, opposite section.
`Thus, a blunt tube such as a male luer can easily open the
`partition.
`Further in accordance with this invention, a pressure sens(cid:173)
`ing chamber or pod for a tubular medical flow set described
`above may be directly and permanently attached to an inlet or
`35 outlet connector, for direct, typically releasable, connection
`with an extracorporeal blood processing device. The set that
`carries the chamber is for handling extracorporeal blood flow,
`with the pressure sensing chamber being directly attached,
`preferably to the downstream end of, the extracorporeal blood
`40 processing device such as a hemodialyser. The pressure
`monitor system that utilizes the pressure sensing pod is thus
`capable of monitoring pressure of the entire length of the
`blood flow tubing extending downstream from the extracor(cid:173)
`poreal blood processing device, typically a dialyzer. This is a
`45 significant area for pressure monitoring, because it is typi(cid:173)
`cally the majority of the extracorporeal blood flow circuit that
`operates under positive pressure. A serious blood leak or kink
`anywhere along the line downstream of the dialyser can thus
`be detected by a pressure fluctuation, if there is constant
`50 monitoring through the pressure sensing chamber.
`Generally, the diaphragm of the pod occupies substantially
`a first position when the interior of the flow set is filled with a
`blood at close to atmospheric pressure, as when the pump is
`stopped or during priming, and the diaphragm is urged
`55 towards the second position whenever the blood side pressure
`on the diaphragm is less than the air side pressure on the
`diaphragm. Such greater air side pressure may be intention(cid:173)
`ally applied through said pressure tubing, which may be
`flexible, by a machine system having an air pump communi-
`60 eating with said tubing, or the pressure tubing may be discon(cid:173)
`nected from the machine's port and reconnected to a device
`such as a syringe. In either case, positive pressure may inten(cid:173)
`tionally be applied to the chamber to drive the diaphragm
`towards the second position, which may be desirable during a
`65 blood rinse back procedure, involving rinsing blood from the
`tubular set, back to the patient, since the internal volume of
`the chamber is minimized by such intentional pressurization,
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`5
`thus reducing the hydration that must be provided to the
`patient. The tubing may carry a clamp or valve to retain the
`positive pressure at the diaphragm.
`Alternately, the pod of this invention may comprise an
`arterial post-pump and/or venous pod embodiment where the
`pod is generally subjected to positive pressure. The dia(cid:173)
`phragm may substantially initially occupy the second posi(cid:173)
`tion when the interior of the flow set is filled with with blood
`at close to atmospheric pressure; and the diaphragm is urged
`towards the first position whenever the blood side pressure is
`greater than the air side pressure on the diaphragm, so that the
`greater the blood pressure, the more the diaphragm is driven
`from the second position toward the first position.
`Movement of the diaphragm between the first and second
`positions is restricted by the fact that, in the pressure sensing
`process, a sealed, fixed volume of air exists between the
`diaphragm and a pressure sensing transducer, with the branch
`line pressure tubing extending therebetween. Thus, move(cid:173)
`ment of the diaphragm toward one position or another posi(cid:173)
`tion will reflect a change of the level of compression of the air 20
`or other compressible fluid in the fluid flow path between the
`diaphragm and the pressure sensing transducer, thus trans(cid:173)
`mitting the pressure of the blood to the transducer. Thus, in
`this circumstance, the diaphragm does not flip back and forth
`with ease between the first and second positions because of
`the sealed volume of air or other compressible fluid in the flow
`path between the diaphragm and the pressure transducer.
`Further in accordance with a preferred embodiment of this
`invention, the sealed port communicating with the otherofthe
`compartments of the pressure sensing chamber facilitates the
`priming of the medical fluid flow set, since it provides the
`sealed, fixed volume of air discussed above that holds the
`diaphragm in the desired position. This desired position may
`vary, depending on whether the pod is to be exposed to
`reduced pressure or elevated pressure during normal opera(cid:173)
`tion.
`One can see that ifthe other of the compartments separated
`from fluid flow by the diaphragm is not sealed, the diaphragm
`will flip from one position to the other in accordance with
`pressures that are encountered in the fluid (blood) flow path
`during shipping, installation or priming. If the diaphragm
`winds up in the wrong position at the end of priming, incon(cid:173)
`venient steps will have to be taken, while maintaining steril(cid:173)
`ity, to remedy it.
`Thus, the sealed port holds the diaphragm in its desired
`position, which position depends upon its contemplated use,
`until priming or other desired step(s) has been completed.
`Then, one can open the seal of the pressure sensing pod port
`as a sealed connection is made with a pressure line, so that
`now the pod is again sealed with the pressure line communi(cid:173)
`cating between the chamber and the pressure monitor.
`Specifically, when the blood flow set of this invention is
`being used as an arterial set for hemodialysis, upstream from
`the roller pump tubing so as to encounter negatively pressur(cid:173)
`ized blood (i.e., blood under suction pressure from the roller
`pump), it may be preferred for the pod diaphragm at ambient
`pressure to initially occupy a position substantially close to
`the first, volume maximizing position. Thus, as negative (sub(cid:173)
`atmospheric) bloodline pressure increases, the diaphragm
`moves incrementally toward the second position, with that
`movement being resisted by the sealed, fixed volume of air,
`which is being expanded in response to the negative (subat(cid:173)
`mospheric) pressure of the blood acting upon the diaphragm.
`Thus, the negative pressure is duplicated in the fixed volume
`of air or other compressible fluid, and may be sensed by the
`pressure transducer, which is positioned remotely from the
`pressure sensing chamber and diaphragm used in this inven-
`
`6
`tion. Under positive pressure blood line conditions, the dia(cid:173)
`phragm starts generally at the opposite, first position. How(cid:173)
`ever, when there is open or ambient pressure on both sides of
`the diaphragm, the diaphragm may flip back and forth
`between its first and second positions relatively easily.
`The above-described chamber or pod may have a bottom
`wall, which further defines a channel having a wall of U or
`V-shaped cross section. Accordingly, when the diaphragm is
`forced into its extreme, second position, fluid flow is not
`10 blocked through the channel, so that flow is provided in all
`circumstances through the medical fluid flow set. Specifi(cid:173)
`cally, the channel wall may be U-shaped and substantially
`contiguous with the internal diameter wall of the flow tubing
`of the set, preferably being substantially aligned with, and of
`15 a size similar to, the inner diameter wall of the flow tubing of
`the set where it connects with the chamber. This can promote
`efficient fluid flow through the entire set, even when the
`diaphragm is held in its second, blood volume minimizing
`position.
`Also, one or more access ports may be provided to the
`pod's inlet or outlet connection or the pressure chamber com(cid:173)
`municating with its blood pathway. These ports may be used
`to provide parenteral solution, heparin, or other medicaments
`to the blood or for withdrawing blood or air or saline from the
`25 flowpath.
`The pod may be connected at one end via a flowthrough
`port with the pump tubing of the set, which comprises typi(cid:173)
`cally roller pump tubing, which is carried on many extracor(cid:173)
`poreal blood transport sets. Alternately, the flowthrough port
`30 may connect with another pump apparatus, or it may connect
`to a venous air-trapping chamber, or any other flowthrough
`component of an extracorporeal set. The pressure chamber
`(pod) then has another end with another flowthrough port
`which may fit tubing of same or different diameter from pump
`35 tubing or to another flowthrough component. Thus, this pod
`may serve the additional function of a pump segment connec(cid:173)
`tor, a tube connector, or a device connector, as well as pro(cid:173)
`viding other function as described herein.
`Further by this invention, blood may be rinsed from the
`40 extracorporeal blood flow tubing and returned to the patient,
`after an extracorporeal blood flow procedure such as hemo(cid:173)
`dialysis. The blood flow tubing is connected to the pod having
`the flexible diaphragm, which defines a blood holding vol(cid:173)
`ume. The diaphragm is sealingly mounted within the cham-
`45 ber. This method comprises the steps of pressurizing the
`chamber to move the diaphragm, to cause the blood holding
`volume of the chamber to be substantially minimized, with(cid:173)
`out blocking blood flow through the blood flow tubing and
`chamber. Then, parenteral solution such as saline is caused to
`50 pass into the tube and chamber to replace the blood, while the
`blood is returned to the patient. The substantially minimized
`blood holding volume of the chamber reduces the fluid vol(cid:173)
`ume of the extracorporeal blood flow tube, which provides
`clinical advantage, and requires the use of less solution to
`55 provide the desired rinseback.
`Typically, this method is practiced after the step of using
`the pod to sense blood pressure in the blood flow tube during
`extracorporeal blood processing, with the diaphragm being
`positioned to enlarge the blood-holding volume in the cham-
`60 ber above the minimum volume, a length of pressure tubing
`extending from the chamber to a pressure monitor device.
`Further by this invention, a pressure transmitting pod
`defines a chamber, the pod being for connection and flow(cid:173)
`through relation to fluid flow tubing of the fluid flow set. The
`65 pod has a flexible fluid impermeable diaphragm dividing the
`pod into separate compartments. The first of the compart(cid:173)
`ments communicates with flow connectors for the fluid flow
`
`000011
`
`Nipro Ex. 1001
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`

`
`7
`tubing. A second of the compartments communicates with a
`pressure connection port for connection with the length of
`pressure tubing at one end thereof. The tubing is for sealed
`connection at its other end to a remote pressure connector of
`a pressure sensing machine, to transmit pressure from the
`second of the compartments through the pressure tubing to
`the pressure sensing machine for pressure monitoring. The
`diaphragm has a dome shape, and is sufficiently flexible to
`easily distort in a manner reflective of pressure changes, to
`vary the volumes of the two compartments. In some embodi- 10
`ments, the diaphragm of dome shape can vary the volume of
`the respective compartments at a pressure variation of 500
`mm. mercury by at least 3 cc.
`The pressure tubing may be permanently connected to the 15
`connection port, the pod, or releasably connected as previ(cid:173)
`ously described. The pressure tubing at its other end can
`connect to a remote tubing connector for connection to the
`machine remote pressure port during medical treatments, or
`permanently, if desired. As previously described, the pod 20
`connection port is sealed from the atmosphere by an internal
`partition, the seal being openable by sealing attachment with
`a connector of the pressure tubing.
`
`DESCRIPTION OF THE DRAWINGS
`
`In the drawings, FIG. 1 is a partially diagrammatic, sec(cid:173)
`tional view of a portion of a first embodiment of a tubular
`blood flow set using the pressure sensing pod and flexible
`diaphragm disclosed.
`FIG. 2 is an exploded, perspective view of the pressure
`sensing pod of FIG. 1.
`FIG. 3 is a plan view of the pressure sensing pod of FIG. 1.
`FIG. 4 is a longitudinal sectional view taken along line 4-4
`of FIG. 3.
`FIG. 5 is a transverse, sectional view taken along line 5-5 of
`FIG. 3.
`FIG. 6 is an end elevational view of the chamber of FIG. 3.
`FIG. 7 is a plan view of a hemodialysis set, making use of 40
`another embodiment of this invention.
`FIG. 8 is an exploded, longitudinal sectional view of a
`pressure sensing pod of the set of FIG. 7.
`FIG. 9 is a sectional view taken along line 9-9 of FIG. 8.
`FIG. 10 is a fragmentary, enlarged plan view of a portion of
`FIG. 7, showing the connection of the pressure sensing pod of
`FIG. 8.
`FIG. 11 is a detailed view of FIG. 8, showing how a con(cid:173)
`nector such as a male luer lock connector can rupture the
`partition for access to the pressure sensing pod.
`FIG. 12 is a view similar to FIG. 9 of another embodiment
`of the sealed port partition.
`FIG. 13 is a sectional view taken along line 13-13 of FIG.
`12.
`FIG. 14 is a fragmentary view of the sealed port of FIG. 13,
`carried on a pod as in previous embodiments, about to be
`connected with a pressure tube as in previous embodiments.
`FIG. 15 is a sectional view showing an initial connection
`(ofluer lock type) of the components of FIG. 14.
`FIG. 16 shows a fully advanced, sealed connection of the
`components of FIG. 14, with the partition of FIG. 12 being
`opened by advancement of the male luer lock connector.
`FIG. 17 is a perspective view of the connector of FIG. 14,
`showing internal parts.
`FIG. 18 is a plan view ofanother embodiment of the pod of
`this invention.
`
`US 8,092,414 B2
`
`8
`FIG. 19 is a sectional view taken along line 18-18 of FIG.
`A.
`
`DESCRIPTION OF SPECIFIC EMBODIMENTS
`
`Referring to the drawings, FIG. 1 shows a portion of a
`venous set 10 for hemodialysis, conventional except as oth(cid:173)
`erwise shown. Set 10 is shown to comprise a length of roller
`pump tubing 11, which is conventionally attached to one end
`of pressure sensing pod chamber 12 of this invention. The
`opposed end 14 of pod 12 may connect to a length of set
`tubing 16, which may connect to other set components, which
`may be of conventional design for an extracorporeal blood
`conveying set. Particularly, tubing 16 may fit within the inner
`diameter of end portion 14 so that such tubing is of a different
`inner diameter from that of pump tubing 11, if desired. Thus,
`pressure pod 12 also includes the function of a connector for
`joining together tubing of differing diameters in the blood set.
`Similarly, t