U.S. patent application number 11/049044 was filed with the patent office on 2005-06-16 for apparatus and method for peritoneal dialysis.
Invention is credited to Haight, LeVoy G., McNeil, Frank, Smith, Gloria, Sorenson, James LeVoy, Winterton, Reed F..
Application Number | 20050131340 11/049044 |
Document ID | / |
Family ID | 26928197 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050131340 |
Kind Code |
A1 |
Sorenson, James LeVoy ; et
al. |
June 16, 2005 |
Apparatus and method for peritoneal dialysis
Abstract
An apparatus and method for treatment of end stage renal decline
and failure through peritoneal dialysis enabling ambulatory
transfer of dialysate to and from the peritoneum of a renal
patient, this in synthesis and coordination with normal
physiological rhythms of the patient. The system remains
unobtrusive and less restrictive of patient ambulation and
orientation. The present invention includes expendables
disposability of which facilitates safe reuse of more expensive
portions and is sufficiently simple for use in a home care
environment. It may be designed to incorporate real-time,
interactive or remote monitoring and regulation and visual or
audible indication of system pressures, chemical balances and other
important variables.
Inventors: |
Sorenson, James LeVoy; (Salt
Lake City, UT) ; Haight, LeVoy G.; (West Jordan,
UT) ; McNeil, Frank; (Sandy, UT) ; Smith,
Gloria; (Salt Lake City, UT) ; Winterton, Reed
F.; (Salt Lake City, UT) |
Correspondence
Address: |
TRASK BRITT
P.O. BOX 2550
SALT LAKE CITY
UT
84110
US
|
Family ID: |
26928197 |
Appl. No.: |
11/049044 |
Filed: |
February 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11049044 |
Feb 1, 2005 |
|
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09962027 |
Sep 24, 2001 |
|
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60234681 |
Sep 22, 2000 |
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Current U.S.
Class: |
604/29 |
Current CPC
Class: |
A61M 2209/088 20130101;
A61M 1/285 20130101; A61M 1/28 20130101; A61M 1/1696 20130101; A61M
1/284 20140204 |
Class at
Publication: |
604/029 |
International
Class: |
A61M 001/00 |
Claims
What is claimed is:
1. A method of performing peritoneal dialysis, comprising:
selection of a device system for treatment of renal decline or
failure, wherein said device system comprises: a portable pump
including a disposable cartridge interface; a receptacle system
comprising exhausted dialysate storage capacity and unused or
recycled dialysate storage capacity designed selectively to be worn
by a renal patient, wherein said receptacle may comprise a polymer
bag with at least one opening in fluid communication with said
conduit; a delivery conduit structured and arranged to support
passage of exhausted dialysate from and unused dialysate to the
peritoneum of the patient; a filter assembly associated with the
delivery conduit and structured and arranged to permit filtering of
both air and contaminants from unused or recycled dialysate; and an
indicator wherein at least one, but potentially any, of a plurality
of therapeutic variables may be monitored and regulated to achieve
a desired therapeutic balance; association of said device system
with an indwelling dialysis catheter such that substantially all of
an amount of exhausted dialysate within a peritoneum of the patient
may be removed; and infusion of a therapeutic volume of unused or
recycled dialysate optimal for treatment of the patient.
2. The method according to claim 1, wherein a selected volume of
unused or recycled dialysate, which is in excess of the therapeutic
volume and is sufficient to accomplish dialysis through an extended
period of time during which the patient may be in a sleeping
condition, may be selectively introduced to the peritoneum of the
patient.
3. The method according to claim 1, wherein said bag further
includes structure attached to one inner side of the bag and to the
opposing inner side of the bag to retain the cross-sectional
dimension of the bag at a limited degree of distention without
limiting flow of a dialysate within or through the bag.
4. The method according to claim 1, wherein the exhausted dialysate
may be removed and said unused or recycled dialysate may be infused
simultaneously.
5. The method according to claim 1, wherein the exhausted dialysate
undergoes a process that extends its useful life.
6. The method according to claim 5, wherein said process comprises
subjection to a pulsating flow pattern.
7. The method according to claim 5, wherein said process comprises,
alone or in combination, filtration or chemical modification.
8. The method according to claim 1, wherein said delivery conduit
is structured and arranged to permit said passage or reciprocal
circulation of exhausted dialysate from and unused or recycled
dialysate to the peritoneum selectively either simultaneously or
sequentially.
9. The method according to claim 1, wherein said delivery conduit
includes a plurality of lumens, a first of which lumens comprises a
corresponding first distal orifice and is structured and arranged
to permit passage of exhausted dialysate from the peritoneum and a
second of which lumens, comprises a corresponding second distal
orifice and permits passage of unused or recycled dialysate to the
peritoneum.
10. The method according to claim 9, wherein said first distal
orifice may be located within the peritoneum at a site remote from
said second distal orifice.
11. The method according to claim 1, wherein said therapeutic
variables may comprise, alone or in combination, body temperature
or blood content of the patient or dialysate temperature or
dialysate flow volume or dialysate flow direction or dialysate flow
timing or dialysate chemistry balance including albumen, urea, uric
acid, creatinine, creatine, pH, ions or electrolytes.
12. The method according to claim 1, wherein said therapeutic
variables may be monitored or regulated selectively, automatically,
or by direct intervention.
13. The method according to claim 1, wherein said operating
conditions may be monitored or regulated from a source remote from
the patient.
14. The method according to claim 1, wherein said device system
further comprises a patient vest structured and arranged to support
the receptacle system proximal to and with minimal cross-sectional
extension from the patient.
15. The method according to claim 1, wherein said method may be
performed irrespective of the location, orientation or movement of
the patient.
16. The method according to claim 9, further comprising a third
lumen that carries circuitry to deliver data from at least one
probe that measures therapeutic or physiologic or diagnostic
parameters of the fluid adjacent the peritoneum.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of Ser. No. 09/962,027,
filed Sep. 24, 2001, now U.S. Pat. No. ______, which application
claims the priority benefit of Provisional Patent Application Ser.
No. 60/234,681, filed Sep. 22, 2000, for "APPARATUS AND METHOD FOR
PERITONEAL DIALYSIS", the content of both of which are incorporated
by this reference.
TECHNICAL FIELD
[0002] This invention relates to means for treatment of renal
decline and failure. It is particularly directed to an improved
system for ambulatory transfer of dialysate to and from the
peritoneum.
BACKGROUND
[0003] State of the Art
[0004] Medical practice has numerous applications for treatment of
impaired renal function and ultimate decline and failure with
peritoneal dialysis. The application of peritoneal dialysis,
involves introduction of a dialysate solution to the peritoneal
cavity outside the omentum, through an indwelling single lumen
catheter entering the peritoneum through the abdominal wall near
the pelvis. The dialysate remains within the peritoneum for
approximately four hours until osmotic diffusion of bodily wastes
from a renal patient through the semipermeable epithelial tissues
approaches an equilibrium of saturation in the dialysate. At some
point within this terminal range of approach the dialysate is
functionally exhausted and is transferred out of the peritoneum and
exchanged for a new infusion of unused dialysate.
[0005] Existing peritoneal dialysis systems suffer from any of a
number of disadvantages. Most devices require the patient to be
tethered and confined and to be situated at a fixed location with a
dialyzing bag hanging from an IV stand for gravity feed throughout
the transfer of dialysate to and from the peritoneum of the patient
and do not permit ambulation during transfer of dialysate. Some
systems utilize pumps that have the disadvantages of substantial
cost, size and weight that are prohibitive of significant
ambulation during dialysate transfer.
[0006] Irrespective of which paradigm has been used, heretofore,
peritoneal dialysis procedures presuppose introduction and
maintenance of a total of approximately three liters or twelve
pounds of dialysate solution to and within the peritoneum for an
extended period of time for the patient, with the epithelial
tissues of the peritoneum acting essentially as an artificial
kidney; the process uncomfortably expands and distends the abdomen
of the patient and results in discomfort, disfigurement, flatulence
and inconvenience. These disadvantages are virtually continuous
from the inception of each dialysis treatment.
[0007] Prior art devices for containment of dialysate bags for
gravity flow have heretofore been available exclusively for
attachment to IV stands adjacent to the patient's person,
precluding comfort in movement such as standing, walking or other
ambulation and other positions and activities and, further also,
detracting from the aesthetic appeal to the patient and
diminishment of the patient's body balance and self-image.
[0008] Previous peritoneal dialysis processes only crudely infer
the terminal range within which dialysate has approached
equilibrium, is exhausted and to be exchanged for unused dialysate.
The inference is drawn from historic norms of a broad population
despite potentially substantial variances from one individual to
another.
[0009] A related disadvantage of prior art peritoneal dialysis is
the deleterious effect on surrounding epithelial tissues from
extended exposure to dialysate that is saturated with caustic
bodily toxins. Upon diagnosis of end stage renal failure, the
present prognosis is between two and three years life expectancy,
due in large measure to the continuous unnaturally high exposure of
these sensitive tissues to noxious bodily wastes within exhausted
dialysate.
[0010] Heretofore, inefficiencies have resulted from infusion of
excessive or insufficient amounts of dialysate relative to the
needs of the particular patient during a particular time frame.
Similarly, dialysate infused in ideal amounts but incorrectly
presumed to be exhausted is occasionally discarded prematurely.
[0011] A need exists for a dialysis system providing ambulatory,
unobtrusive, light weight, symmetric, orientation-neutral and
convenient storage and containment of new or exhausted dialysate
and associated systems.
[0012] A further need exists for such a renal treatment system with
single patient components that are inexpensive, disposable and
sufficiently simple for use in a home care or ambulatory
environment.
[0013] A need also remains for an improved peritoneal dialysis
system wherein electronic circuitry and associated indicators
enable monitoring of the solute and regulation of flow rates,
including system pressures, temperature, system timing, chemical
balances and other therapeutic variables to more closely mimic and
optimize normal physiological patterns and to enhance the patient's
and physician's ability to determine optimal dosage, regime and
protocol to obtain such goals.
[0014] There exists a need for such monitoring and regulation
optionally from locations remote from the patient. Whether remote
or not there is a continuing need for the foregoing features that
may be actuated automatically or by direct intervention based on
real time interaction.
[0015] Further yet, a need exists for a peritoneal dialysis system
closely customized to the circumstances of a particular patient
enabling a more accurate determination of the terminal point at
which exhausted dialysate is to be reconditioned or transferred
from the patient and exchanged for unused dialysate or, if
practicable, reconditioned dialysate.
SUMMARY OF THE INVENTION
[0016] The present invention provides an improved apparatus and
method for ambulatory patient dialysis including transfer of
peritoneal dialysate and comprising monitoring, regulation and
indication of therapeutic variables to more closely parallel the
natural, pre-symptomatic kidney function and excretion patterns of
the renal system and to achieve correspondent acceptable
physiological function.
[0017] This novel system enables coordination of fluid transfers
and dialysis processes with ambient physiological activity of the
patient. Balance in physiological dynamics is enhanced with a more
effective delivery and monitoring system that follows natural
rhythms. A system of indicators may communicate various therapeutic
variables and physiological measurements, for example, urea,
presence of air, temperatures and electrolytes in the dialysate.
Accordingly, the indicator system results in reduction of incidence
of peritonitis, potentially resulting in cost savings and because
it is more efficient in determining the parameters of the dialysate
thereby improving timing and fluid exchange. Such fine tuning of
physiological balances enhances the physician's and patient's
ability to determine optimal dynamic dosage, regime and protocol
for the benefit of the patient, irrespective of physical
orientation of the patient or of the treatment system or of both.
The system entails a small portable pump, filter system,
receptacle, with improvements comprising a dialyzing fluid bag
designed to be worn, which may alternatively simply be hung from an
IV stand for gravity flow where preferably, a novel vest for low
profile, aesthetically appealing, symmetric and unobtrusive system
containment and placement, and indicators whereby fluid flow rates,
volume, timing, direction, pulsating patterns and dialysate and
bodily electrolytes, urea, protein, acid-base balances as examples
may be monitored and regulated. The system comprising these
improvements is inexpensive, disposable and sufficiently simple for
use in a home care environment and may be equipped with a real-time
monitor and indicator of various system conditions, dialysate
parameters and other important therapeutic variables.
[0018] The invention in one embodiment is a device system for
treatment of and support during renal decline or failure. It
comprises a portable pump including a disposable cartridge
interface; a receptacle system, which may be bladder-like,
comprising exhausted dialysate storage capacity and unused or
recycled dialysate storage capacity, designed selectively to be
worn by a patient; a conduit which may be structured and arranged
to support passage of unused or recycled dialysate to and exhausted
dialysate from a peritoneum of the patient and a filter assembly
associated with the conduit and structured and arranged to permit
filtering of both air and contaminants from the unused or recycled
dialysate.
[0019] The receptacle system may include a polymer bag with a first
wall and an opposing second wall, and include at least one opening
in fluid communication with the conduit. It further may include
structure attached to an inner side of the first wall and to an
opposing inner side of the second wall to retain the
cross-sectional dimension of the bag within a limited range of
distention of the bag when a dialysate is in the bag without
limiting flow of the dialysate in or through the bag.
Alternatively, for the same purpose, the receptacle system may
include either a dimensionally stable or a semi-rigid encasement
structured and arranged to abut the bag against at least one of the
walls. The encasement may comprise a single plate in combination
with a vest or a pocket.
[0020] The patient vest of the present invention, where utilized,
may be structured and arranged to support the receptacle system
proximal to and with minimal cross-sectional extension from the
patient. The vest may be configured to support the receptacle
system irrespective of location, orientation or movement of the
patient. It comprises any of at least two sides which may include a
front side, back side, left side and right side. It further
comprises means of affixing the vest in close proximity to the body
of said patient such as, alone or in combination, any of either
Velcro.RTM. or buckles or straps or button structure with
corresponding eye structure or ties or zipper or belt or at least
one hole through which an arm of a patient may be placed. A pocket
or pouch is associated with at least one of the sides whereby at
least a portion of the receptacle system may be enveloped within
the pocket or pouch.
[0021] Indicator means may also be included whereby at least one
therapeutic variable, but potentially any of a plurality of
therapeutic or diagnostic variables, may be monitored or regulated
to determine and establish optimal dynamic dosage or optimal
dynamic regime or optimal dynamic protocol, or any or all of the
foregoing. Such optimal dynamics enable achievement of a desired
therapeutic balance. The indicator means may further enable
detection of achievement of the desired therapeutic balance. Such
therapeutic variables may be monitored or regulated selectively
automatically or by direct intervention and may be monitored or
regulated from a source remote from the patient. These therapeutic
variables may comprise, alone or in combination, dialysate
temperature or dialysate flow volume or dialysate flow direction or
dialysate flow timing or dialysate chemistry including, for
example, albumen, urea, uric acid, creatinine, creatine, pH, ions
or electrolytes. The therapeutic variables may be monitored or
regulated with detection structure positioned in any of a variety
of locations including without limitation associated with the
conduit or the pump or the receptacle system or any combination of
the foregoing. The detection structure may be located proximal to
or within the body of the patient and thus may further monitor and
regulate the variables of body temperature or residual pressure or
blood content of the patient.
[0022] In another embodiment, the conduit of the present invention
may comprise a plurality of lumens, a first of which lumens is
structured and arranged to support passage of exhausted dialysate
from a peritoneum of the patient, and a second of which lumens is
structured and arranged to support passage of unused or recycled
dialysate to the peritoneum. A third lumen may be structured and
arranged to measure directly or by inference parameters such as
temperature, pH and electrolytes in the peritoneum, including
probes for the measurement of appropriate chemistry, pH and
temperature. The system thereby enables exhausted dialysate to be
admitted and unused or recycled dialysate to be delivered in
alternating sequence or simultaneously in reciprocating
circulation. In this embodiment the first lumen includes a
corresponding first distal orifice, and the second lumen includes a
corresponding second distal orifice. The first and second distal
orifices may be located within the peritoneum at respective sites
remote from each other. Subject to determination by an attending
physician, the point of entry of the conduit may generally
preferably be through the abdomen, near the pelvis or
alternatively, particularly in cases involving reciprocal
circulation or recycling of dialysate, at a point near but below
the diaphragm. The passage of dialysate may be in the form of any
of a variety of pulsating flow patterns, and may be coordinated to
increase rate, frequency and magnitude of dialysate circulation
along, against and among epithelial and other tissues of and within
the peritoneum. Thus, exhausted dialysate may be admitted and
unused or recycled dialysate may be delivered simultaneously.
[0023] Accordingly, the present invention contemplates a method of
performing peritoneal dialysis, comprising selection of the above
characterized device system for treatment of renal decline or
failure; association of said device system with an indwelling
dialysis catheter such that substantially all of an amount of
exhausted dialysate within a peritoneum of a patient may be removed
to be disposed of or processed for recycling; and infusion of a
therapeutic volume of unused or recycled dialysate optimal for
treatment of the patient.
[0024] In accordance with this method a selected volume of unused
dialysate, which is in excess of the therapeutic volume and is
sufficient to accomplish dialysis through an extended period of
time during which the patient may be in a sleeping condition, may
selectively be introduced to the peritoneum of the patient. This
method may incorporate the distention-limiting structure within or
around the receptacle system, may accommodate simultaneous or
sequential passage or reciprocal circulation of exhausted and
unused or recycled dialysate, either of which may be in a pulsating
flow pattern, and may involve having the exhausted dialysate
undergo a process that extends its useful life such as, alone or in
combination, filtration or chemical, electrical, thermal or light
modification.
[0025] Likewise, the conduit of this method may include a plurality
of lumens, the first of which comprises a corresponding first
distal orifice and is structured and arranged to permit passage of
exhausted dialysate from the peritoneum and a second of which
comprises a corresponding second distal orifice and permits passage
of unused or recycled dialysate to the peritoneum. In this method,
the first distal orifice may be located within the peritoneum at a
site remote from the second distal orifice.
[0026] The therapeutic variables of this method may likewise
comprise, alone or in combination, body temperature or blood
content of the patient or dialysate temperature or dialysate flow
volume or dialysate flow direction or dialysate flow timing or
dialysate chemistry balance including albumen, urea, uric acid,
creatinine, creatine, pH, ions or electrolytes and may be monitored
or regulated selectively automatically or by direct intervention,
which may be from a source remote from the patient.
[0027] The device system of this method may further comprise the
aforementioned patient vest structured and arranged to support the
receptacle system proximal to and with minimal cross-sectional
extension from the patient, which method may be performed
irrespective of the location, physical orientation or movement of
the patient.
[0028] This device system and method may utilize any of a variety
of indicators and associated structures, alone or in combination,
such as chemical, electrical or light based technologies, including
chemiluminescent, biofluorescent, electrochemical and chemical
color indicators.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0029] In the drawings, which illustrate what is currently regarded
as the best mode for carrying out the invention:
[0030] FIG. 1 is a perspective view of the preferred embodiment of
the device system;
[0031] FIG. 2 is a partially exploded view of the filter;
[0032] FIG. 3a is a perspective view of a first embodiment of the
receptacle;
[0033] FIG. 3b is a perspective view of a partially cut away second
embodiment of the receptacle;
[0034] FIG. 3c is a perspective view of a partially cut away third
embodiment of the receptacle;
[0035] FIG. 4a depicts a perspective view of a first embodiment of
the vest of the system relative to the patient;
[0036] FIG. 4b depicts a perspective view of a second embodiment of
the vest of the system;
[0037] FIG. 4c depicts a perspective view of a third embodiment of
the vest of the system;
[0038] FIG. 4d depicts a perspective view of a fourth embodiment of
the vest of the system;
[0039] FIG. 5a illustrates an adjacent dual lumen structure
comprising remote distal tips; and
[0040] FIG. 5b similarly portrays a concentric dual lumen structure
including remote distal tips.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0041] The structural elements of one configuration of the present
novel device system 5 for peritoneal dialysis are shown in FIG. 1.
A pump 10 is detachably associated with a flexible conduit 15,
preferably having cross-sectional patency, along a disposable
cartridge interface 20 between a filter 25 and a receptacle system
30.
[0042] The illustrated pump 10 operates on the basis of peristaltic
action but other pump mechanisms not illustrated could be utilized
for portable, high-volume operation. The cartridge 20 comprises
collapsible, resilient tubing 35 and is in fluid communication with
the conduit 15 by means of couplings 40, 45. The conduit 15 may be
releasably associated in fluid communication with the receptacle
system 30 at a junction 50 and with the filter 25 at a joint 55.
The filter 25 is releasably coupled to, and in fluid communication
with, an indwelling catheter 60 at a patient disconnect 65. An
indicator means 70 may be placed at any of a variety of locations,
alone or in combination, depending upon the nature of the indicator
means and its function or functions, as further elaborated below,
but is depicted as being located between the catheter 60 and the
filter 25.
[0043] More particularly set forth in FIG. 2a, the filter 25
comprises a hydrophobic filter 75, a hydrophilic screen 80 and a
hydrophilic filter 85 all sequenced between a base 90 and a convex
capture lid 95. The base 90 includes internal ribs 100 which abut
and support the hydrophilic filter 85 while accommodating exposure
of maximum surface area of the hydrophilic filter 85 to dialysate
throughput. The hydrophilic screen 80 provides counter support for
the hydrophilic filter 85 and support for the hydrophobic filter
75. The convex curvature of the capture lid 95 accommodates the
hydrophobic filter 75 and passage of air therethrough. The lid 95
includes an air outlet 105 for air screened from passing dialysate
by the hydrophobic filter 75. The base 90 and lid 95 are sealed
together along their respective periphery 110,115 by any
commercially feasible means such as, for example, a press-fit,
sonic weld or adhesive.
[0044] Dialysate passage toward the peritoneum through the filter
25 is accommodated through an upstream port 120 that admits
dialysate to the filter 25 between the hydrophobic filter 75 and
hydrophilic filter 85. The hydrophobic filter 75 allows passage of
air through to the air outlet 105 while preventing leakage of
dialysate out of or penetration of contaminants into the dialysate.
The hydrophilic filter 85 permits passage of the dialysate while
filtering out microbial and other contaminants from the dialysate
prior to its passage through a downstream port 125 and eventual
entrance into the peritoneum.
[0045] As illustrated in FIG. 2b, exhausted dialysate passing out
of the peritoneum can, depending on the configuration of the filter
25, either pass back through the downstream port 125 and bypass the
hydrophilic filter through an up stream check valve 127 associated
with the upstream port 120 or entirely circumvent the filter 25
through a combination of alternate conduit and associated check
valves (not shown).
[0046] Various configurations of the receptacle system 30 are
illustrated in FIGS. 3a-3c. FIG. 3a depicts a dual bag system 30
including a disposal reservoir 135, a supply reservoir 140 and
respective disposal tubing 145 and supply tubing 150 each
associated with a common tubing 155 through a generally indicated
check valve 160. The reservoirs 135,140 may in one configuration be
connected in fluid communication with each other by a processing
stage 165.
[0047] The processing stage 165 may have the capacity, alone or in
combination, to filter, chemically neutralize, electronically alter
or modify the condition of dialysate by other means such as, for
example, with light, or heat (not shown) in a reconditioning
manner. Accordingly, unused dialysate or reconditioned dialysate or
a combination of both may be reintroduced to the peritoneum for
additional dialysis until an appropriate level of exhaustion of the
dialysate is reached.
[0048] Indicator means 70 may be associated with the device system
5 to enable regulation or monitoring or both regulation and
monitoring of at least one therapeutic variable but potentially any
of a plurality of therapeutic variables of the patient. Thus the
present invention dramatically enhances the ability to monitor and
affect key variables, e.g., to recognize decline in the condition
of the peritoneal lining and its ability to participate adequately
in the dialyzing process; to identify shifts in the optimal amount
of residual dialysate; to ascertain changes to be made in the
composition of the dialysate to be used; and to queue alterations
to the frequency of transfers and exchanges.
[0049] As illustrated in FIGS. 3a and 3b, the indicator means 70
may be embodied as an electrochemical device interposed along the
disposal tubing 145 or disposal lumen 170 or otherwise may comprise
an indwelling electrode 175 in fluid communication with the
dialysate. The electrode 175 may be structured and arranged to
provide on-line, real-time, objective, quantitative information
about the status of the dialysate. The electrode 175 may further be
associated with transmission means or receiver means or transceiver
means or regulator means or monitor means (none of which is shown)
enabling communication to or from a monitor or regulator or both a
monitor and regulator (not shown) which monitor or regulator may be
remote from the device system 5. Examples of such probes include pH
probes available from Omega Engineering, Inc. of Stamford, Conn.
and pH conductivity probes from The Hach Company of Loveland, Colo.
Non-electrical, chemical pH probes may similarly be utilized.
Examples of such electrochemical probes include the ammonia
NH.sub.4 probe of Omega Engineering, Inc., or seven-analyte-capable
probes of Yellow Springs Instruments, Yellow Springs, Ohio.
[0050] Illustrative of various applications of pH probes, the
filter or tubing may include a pH strip in contact with used
dialysate that responds to the alkaline nature of the urine content
of used dialysate. The pH level is directly proportional to the
concentration of alkaline waste (comprised mostly of urea); a
higher pH level would indicate that the used dialysate comprises a
higher concentration of waste products. To preclude leaching from
the indicator to the new or reconditioned dialysate to be infused
into the peritoneum, the probe may be positioned between the
upstream check valve 127 and downstream check valve 128 within the
filter 25. An example of one group of compounds that could be used
as an indicator is anthrocyanins or quinones. A slight modification
of this configuration involves use of the pH indicator material on
the surface of the material molded as a system component that is in
fluid communication with the used dialysate. Similarly, the pH
material may be integral with such molding material. Thus the used
dialysate causes pH indicator material exposed on the component
surface and in fluid communication with the used dialysate to
change color. This change may be detected by a sensor (not shown)
to determine waste product concentration. Indicators for other
waste products may also be used. As an alternative to the pH
indicator, material that changes color in response to exposure to
other waste products could be utilized.
[0051] Alternatively, indicator means 70 may be embodied as a
chemical test involving a color strip indicator (not shown) exposed
to a sample of dialysate removed from the peritoneum, preferably
from the upstream side 180 of the filter 25 so as to limit the
potential for peritonitis. The color strip changes color in direct
relation to the extent to which the dialysate approaches the
osmotic diffusion equilibrium. For example, a new color strip
colored red may become colored mauve when exposed to slightly used
dialysate or purple with moderately used dialysate, but become
colored blue when fully exhausted. Accordingly a patient or care
giver is enabled to recognize more accurately when dialysate has
arrived at the optimal dynamic terminal point, and thus is informed
that an infusion of new or reconditioned dialysate is needed. For
example, QuantiMetrix Corp. of Redondo Beach, Calif. or Diagnostic
Chemicals, Ltd. of Prince Edward Island, Canada with its U.S.
subsidiary supplies impregnated paper indicator materials used with
colorimetry dipsticks or other impregnated materials capable of
such colormetrics functions.
[0052] Yet another embodiment of the indicator means 70 is in the
nature of modified electrochemical or chemiluminescence tests
wherein a sensor is associated with a selected site of the skin of
a renal patient (not shown) and an electronic current is introduced
to stimulate dilation of pores and thereby enable access to the
subcutaneous interstitial tissues with selected light waves. The
reflective and refractive interaction between the light wave
lengths and the liquids of which the interstitial tissues are
comprised enables a determination of constituents of the liquids.
Comparison of the constituents with the known relationship between
waste products in blood and interstitial liquids enables an
inference of the proximity to the terminal point on the dialysis
rate curve. Materials supportive of such an embodiment are
available through Diagnostic Chemicals, Ltd. U.S.A. of Oxford,
Conn.
[0053] Another embodiment of an indicator may utilize a wavelength
of light that is absorbed or otherwise affected by a certain waste
chemical. An LED (not shown) may be structured and arranged to
shine a light though the tubing as well as the used dialysate as it
flows through the tubing. An associated sensor (not shown) detects
the amount or nature of light that passes through the fluid. The
amount or nature of light reflected or attenuated by the used
dialysate is relative to the concentration of waste chemical in the
used dialysate and accordingly provides an indication of the
condition of the used dialysate.
[0054] Additional indicator means may be embodied as a probe 185
associated with remote tip 190 of the indwelling catheter 60, for
measuring temperature, pressure, blood characteristics or the
like.
[0055] FIG. 3b illustrates one configuration of the receptacle
system 30 involving a dual lumen alternative, including the
disposal lumen 170 and a supply lumen 195. A supply check valve 200
may be interposed on the supply lumen 195 in configurations
involving a single bag reservoir 205 where both lumens 170, 195
pass through the cartridge interface 20 of the pump 10 instead of
parting to allow the disposal lumen to circumvent the pump.
[0056] Retaining structure 210 may be attached to opposing inner
sides 215, 220 of a bag 135, 140, 205 to retain the cross-sectional
dimension of the bag 135, 140, 205 within a limited range of
distention, and thus to enhance the comfort, mobility and
appearance of the patient when the device system 5 is being carried
or worn, during either dialysis or ambulatory transfer.
[0057] Alternative retention structure illustrated in FIG. 3c
involves a dimensionally stable or a semi-rigid encasement 225 that
compresses the dialysate bag 205 or bags 135, 140 between a first
side 230 and second side 235 connected to each other by at least
one connecting member 240.
[0058] Yet another retention structure illustrated in FIG. 4c is a
dimensionally stable or a semi-rigid plate 245 within a pocket 250
of a vest 255 in a manner that limits the distention of the bag 205
or bags 135, 140 and thereby retains the cross-sectional dimension
of the receptacle system 30 at a minimum.
[0059] The nature, location and function of the indicator means 70
and receptacle system 30 to be selected for use with the device
system 5 is influenced at least by the particular function to be
accomplished or variable or variables sought to be indicated. It
will be appreciated that a wide variety of potential permutations
of the features of the receptacle system 30 or indicator means 70
may be adapted to a preferred embodiment in accordance with the
preferences or needs of a given patient or service provider or
circumstance. Accordingly, specific illustration of the nature,
location or function of indicator means 70 or receptacle system 30
in the present disclosure should not be understood to limit the
intended scope of the appended claims.
[0060] For containment of the portable device system 5, any of a
variety of vest configurations is contemplated in the present
invention as partially set forth generally in FIGS. 4a-4d. FIG. 4c
illustrates one preferred embodiment of the vest 255 that is
structured and arranged in a configuration to contain the device
system 5 within the pocket 250. The pocket 250 is located on the
inside 260 of the back side 265 of the vest 255. In this
configuration the vest 255 opens up from the front side 270.
[0061] The vest 255 may be configured to position the pocket 250 on
the front side 270 as well, as set forth in FIGS. 4a and 4b, or on
a left side or right side (not shown). Similarly, the vest 255
depicted in FIG. 4d resembles a daypack; accordingly, the pocket
250 comprises a substantial portion of the vest and may be worn on
the front side 270 or back side 265 of the patient.
[0062] Similar versatility may be embodied in the means of
attaching the vest 255 to the patient. Belts 275, laces 280
including ties 285, zippers 290, Velcro.RTM. 295, sewn seams 300,
buttons 305 with eyes 310, straps 315, buckles 320 and any other
such means of connecting may be utilized.
[0063] In FIGS. 5a and 5b, one advantageous aspect of a multi-lumen
feature is illustrated. Whether the plurality of lumens is in a
side by side configuration as illustrated in FIG. 5a or concentric
as illustrated in FIG. 5b, and irrespective of the location of the
insertion site of the catheter 60, the remote tip 190 of the supply
lumen 195 can be located within the peritoneal cavity 325 at an
infusion site 330 that enhances the washing action of the unused or
reconditioned dialysate across the omentum within the peritoneal
cavity. For an ambulatory patient, for example, such a site 330
would be just below the diaphragm. In such an application, the tip
190 is preferably remote from the terminal end 335 of the disposal
lumen 170; for example, the terminal end 335 would be located in
the lower abdominal area near the pelvis.
[0064] The device system and method of the present invention
provide distinct advantages over prior peritoneal dialysis systems
and methods. Thus, reference herein to specific details of the
illustrated or other preferred embodiments is by way of example and
not intended to limit the scope of the appended claims. It will be
apparent to those skilled in the art that many modifications of the
basic illustrated embodiments may be made without departing from
the spirit and scope of the invention as recited by the claims.
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