U.S. patent application number 13/885273 was filed with the patent office on 2014-10-16 for dialysis device and method of dialysis.
This patent application is currently assigned to Temasek Polytechnic. The applicant listed for this patent is Christian Gert Bluchel, Liutong Lin. Invention is credited to Christian Gert Bluchel, Liutong Lin.
Application Number | 20140309584 13/885273 |
Document ID | / |
Family ID | 43431412 |
Filed Date | 2014-10-16 |
United States Patent
Application |
20140309584 |
Kind Code |
A1 |
Bluchel; Christian Gert ; et
al. |
October 16, 2014 |
DIALYSIS DEVICE AND METHOD OF DIALYSIS
Abstract
A dialysis device is provided comprising a disposable housing
having a dialysate flow path along which dialysate received from a
patient is subjected to contaminant removal when in operation,
wherein said disposable housing comprises a storage chamber in
fluid communication with the dialysate flow path for storing the
dialysate therein; a controller for controlling the operation of
said disposable housing; an interface means capable of operably
coupling the controller and the disposable housing to enable the
contaminant removal from the dialysate, and a fluid displacement
means configured to move the dialysate along the dialysate flow
path, wherein said fluid displacement means comprises a deformable
diaphragm integrally formed with at least one wall of said storage
chamber, wherein the flow path is fluidly sealed from the
controller and interface means. A method of dialysis, a dialysis
system and kits are also provided.
Inventors: |
Bluchel; Christian Gert;
(Singapore, SG) ; Lin; Liutong; (Singapore,
SG) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bluchel; Christian Gert
Lin; Liutong |
Singapore
Singapore |
|
SG
SG |
|
|
Assignee: |
Temasek Polytechnic
Singapore
SG
|
Family ID: |
43431412 |
Appl. No.: |
13/885273 |
Filed: |
November 8, 2011 |
PCT Filed: |
November 8, 2011 |
PCT NO: |
PCT/SG11/00395 |
371 Date: |
March 21, 2014 |
Current U.S.
Class: |
604/28 |
Current CPC
Class: |
A61M 1/1658 20130101;
A61M 2209/088 20130101; A61M 2205/121 20130101; A61M 2205/7518
20130101; A61M 1/1696 20130101; A61M 2205/126 20130101; A61M
2205/33 20130101; A61M 2205/128 20130101; A61M 1/28 20130101; A61M
2205/123 20130101 |
Class at
Publication: |
604/28 |
International
Class: |
A61M 1/28 20060101
A61M001/28 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 15, 2010 |
GB |
1019228.4 |
Claims
1.-61. (canceled)
62. A dialysis device comprising: a disposable housing having a
dialysate flow path along which dialysate received from a patient
is subjected to contaminant removal when in operation, wherein said
disposable housing comprises a storage chamber in fluid
communication with the dialysate flow path for storing the
dialysate therein; a controller for controlling the operation of
said disposable housing; an interface means capable of operably
coupling the controller and the disposable housing to enable the
contaminant removal from the dialysate, and a fluid displacement
means configured to move the dialysate along the dialysate flow
path, wherein said fluid displacement means comprises a deformable
diaphragm integrally formed with at least one wall of said storage
chamber, wherein the flow path is fluidly sealed from the
controller and interface means.
63. The dialysis device as claimed in claim 62, wherein said
disposable housing comprises a sorbent zone in fluid communication
with the dialysate flow path for removing contaminants in the
dialysate.
64. The dialysis device as claimed in claim 62, wherein said
disposable housing further comprises valve means disposed along the
dialysate flow path configured to control the direction of movement
of the dialysate relative to the sorbent zone and storage
chamber.
65. The dialysis device as claimed in claim 64, wherein said valve
means is operative by the flow direction of dialysate along said
flow path.
66. The dialysis device as claimed in claim 64, the controller
further comprising actuation means for actuating said fluid
displacement means and said valve means when said controller is
connected to the disposable housing by said interface means.
67. The dialysis device as claimed in claim 62, wherein said
deformable diaphragm is in fluid contact on one side with the
dialysate flow path and, on another opposite side, in contact with
a pressure chamber that is capable of receiving fluid therein.
68. The dialysis device as claimed in claim 67, wherein the
deformable diaphragm is disposed and fluidly sealed from the
pressure chamber and a rigid member.
69. The dialysis device as claimed in claim 67, wherein the
actuation means comprises a pump capable of fluid communication
with the pressure chamber when said interface means operably
couples said disposable housing to said controller.
70. The dialysis device as claimed in claim 69, wherein said
interface means comprises a conduit connector that fluidly couples
the pump of the controller to the pressure chamber of the
disposable housing.
71. The dialysis device as claimed in claim 70, wherein the conduit
connector comprises a first mating part disposed on the controller
and a second mating part adapted disposed on the disposable
housing, and wherein the first and second mating parts are
configured to lockingly engage with each other.
72. The dialysis device as claimed in claim 70, wherein the
disposable housing comprises an additive dispensing means for
dispensing a desired additive into the dialysate.
73. The dialysis device as claimed in claim 72, wherein the
additive dispensing means is activated by fluid pressure changes
that occur in the conduit connector that is in fluid communication
with the pump.
74. The dialysis device as claimed in claim 72, wherein the
additive dispensing means is discrete from the disposable
housing.
75. The dialysis device as claimed in claim 74, wherein the
additive dispensing means comprises an interface means.
76. The dialysis device as claimed in claim 75, wherein the
interface means comprises a connector that fluidly couples the
additive dispensing means to the flow path disposed in the
disposable housing.
77. The dialysis device as claimed in claim 76, wherein the
connector comprises a first mating part disposed on the additive
dispensing means and a second mating part disposed on the
disposable housing, and wherein the first and second mating parts
are configured to lockingly engage with each other.
78. The dialysis device as claimed in claim 77, wherein the first
mating part disposed on the additive dispensing means and/or second
mating part disposed on the disposable housing are sealed to
maintain the sterility of the additive solution in the additive
dispensing means.
79. The dialysis device as claimed in claim 78, wherein the first
mating part disposed on the additive dispensing means and/or second
mating part disposed on the disposable housing are sealed by means
of a plug or frangible seal.
80. The dialysis device as claimed in claim 79, wherein the first
mating part disposed on the additive dispensing means mates with
the second mating part disposed on the disposable housing by
breaking or puncturing or dislodging the plug or seal of the mating
part.
81. The dialysis device as claimed in claim 70, wherein said
disposable housing further comprises a gas vent in fluid
communication with the flow path for venting gas from said
dialysate.
82. The dialysis device as claimed in claim 81, wherein the gas
vent is activated by fluid pressure changes that occur in the
conduit connector that is in fluid communication with the pump.
83. The dialysis device as claimed in claim 82, wherein the gas
vent is coupled to a hydrophilic bacteria filter in the dialysate
flow path.
84. The dialysis device as claimed in claim 62, wherein said
storage chamber is upstream of said sorbent zone.
85. The dialysis device as claimed in claim 69, wherein said
controller comprises a computer configured to act on instructions
for operation of the pump.
86. The dialysis device as claimed in claim 70, wherein the
interface means comprises a pressure sensor configured to determine
the pressure of said dialysate when in the disposable housing.
87. The dialysis device as claimed in claim 86, wherein the
pressure sensor is disposed in the controller and is in fluid
communication with the conduit connector.
88. The dialysis device as claimed in claim 62, comprising an
ammonia sensor configured to detect ammonia present in said
dialysate.
89. The dialysis device as claimed in claim 88, wherein the ammonia
sensor is disposed in the disposable housing.
90. The dialysis device as claimed in claim 89, wherein the ammonia
sensor is configured to detect ammonia or ammonium ions.
91. The dialysis device as claimed in claim 89, wherein the ammonia
sensor comprises a material which changes color in the presence of
ammonia.
92. The dialysis device as claimed in claim 89, wherein the ammonia
sensor comprises an ammonia-sensitive membrane.
93. The dialysis device as claimed in claim 88, wherein the ammonia
sensor is disposed in the controller.
94. The dialysis device as claimed in claim 93, wherein the ammonia
sensor is configured to detect ammonia or ammonium ions.
95. The dialysis device as claimed in claim 93, wherein the ammonia
sensor comprises a material which changes color in the presence of
ammonia.
96. The dialysis device as claimed in claim 93, wherein the ammonia
sensor comprises an ammonia-sensitive membrane.
97. The dialysis device as claimed in claim 89, wherein the ammonia
sensor comprises an ammonia-selective potentiometric or
amperometric electrode.
98. The dialysis device as claimed in claim 93, wherein the ammonia
sensor is configured to detect ammonia in gas extracted from a
dialysate flow by a degasser.
99. The dialysis device as claimed in claim 98, wherein the
degasser is disposed in the disposable housing.
100. The dialysis device as claimed in claim 62, wherein the device
is powered by a battery.
101. The dialysis device as claimed in claim 100, wherein the
battery is a rechargeable battery.
102. The dialysis device as claimed in claim 101, wherein the
rechargeable battery is a lithium polymer battery.
103. The dialysis device as claimed in claim 62, wherein the flow
path comprises a fibrin trap located upstream of the sorbent
zone.
104. A kit comprising the dialysis device of claim 62, together
with instructions for use.
Description
TECHNICAL FIELD
[0001] The present invention relates to a dialysis device and in
particular to a portable or wearable dialysis device. The invention
also relates to a method of conducting dialysis.
BACKGROUND
[0002] Kidneys are vital organs of the human homeostasis system.
Kidneys act as a natural filter in the body which remove toxic
metabolic wastes such as urea from the blood. Kidney failure or
malfunction may lead to an accumulation of toxins and to an
imbalanced electrolyte level in the blood, which may result in
undesirable repercussions that are hazardous to an individual's
health.
[0003] Renal dysfunction and/or failure and, in particular,
end-stage renal disease, may cause the body to lose the ability to
adequately remove toxic waste in the blood and restore the optimal
level of electrolytes in the blood, within physiological ranges.
Dialysis is commonly used to replace inadequate kidney function by
removing toxic waste.
[0004] For the past few years, the predominant form of dialysis
used for patients with end-stage renal disease (ESRD) is
hemodialysis. Hemodialysis involves the use of an extracorporeal
system for the removal of toxins directly from the patient's blood
by passing a large amount of the patient's blood through a
filtering unit or dialyzer. Hemodialysis treatment typically lasts
several hours and must be performed under medical supervision three
to four times a week, which significantly decrease a patient's
mobility and quality of life. Furthermore, as hemodialysis is
performed periodically rather than on a continuous basis, patient
health deteriorates as soon as a "treatment cycle" in which
contaminants are removed has been completed.
[0005] The other form of dialysis used for patients with kidney
failure is peritoneal dialysis, most commonly applied in the
following two techniques: "continuous ambulatory peritoneal
dialysis" (CAPD) and "automated peritoneal dialysis" (APD). In
CAPD, fresh dialysate is infused into the patient's abdominal
(peritoneal) cavity where, by means of diffusion, metabolic waste
and electrolytes in the blood are exchanged with the dialysate
across the peritoneal membrane. To allow sufficient diffusion of
the electrolytes and metabolic waste to occur, the dialysate is
retained in the abdominal (peritoneal) cavity for a couple of hours
before removal and replacement (of the spent dialysate) with fresh
dialysate. Major drawbacks of continuous ambulatory peritoneal
dialysis are a low level of toxin clearance, and the need to
continuously replace the spent dialysate, which can be arduous for
the patient and disruptive to his/her daily activities.
[0006] To address this problem, devices have been designed that
reconstitute used/spent dialysate from hemodialysis and/or
peritoneal dialysis as opposed to discarding it. However, current
devices that reconstitute used/spent dialysate have several
associated disadvantages including complex set up procedures and
difficulties in maintaining the sterility of components. A further
disadvantage is that current devices often require a plurality of
fluid connections, which increases the risk of introducing
biological contamination and reduces sterility of the device. In
addition several components must be disposed of either daily,
weekly or monthly adding another layer of complexity to the
operation of such devices. In addition, the flow system of known
regenerating dialysis devices requires a plurality of pumps, which
in turn undesirably increases the overall size, weight and power
consumption of the device.
[0007] Accordingly, there is a need to provide a dialysis device
that overcomes or at least ameliorates one or more of the
disadvantages described above. There is also a need to provide a
dialysis device without compromising on the size, weight and power
consumption of the device.
SUMMARY
[0008] According to a first aspect, there is provided a dialysis
device comprising:
[0009] a disposable housing having a flow path along which
dialysate received from a patient is subjected to contaminant
removal when in operation;
[0010] a controller for controlling the operation of said
disposable housing; and
[0011] an interface means capable of operably coupling the
controller and the disposable housing to enable the removal of
contaminant from the dialysate;
[0012] wherein the flow path is fluidly sealed from the controller
and interface means.
[0013] Advantageously, the disposable housing may be disposed of on
a daily basis or after each dialysis cycle. This is advantageous as
this improves the sterility of the disposable housing and reduces
the chances of patient infection. It is a further advantage of the
device that as the flow path is fluidly sealed from the controller,
the sterility of the device can be maintained by daily disposal of
disposable housing and therefore the disclosed device does not
suffer, or is at least not as readily prone to, biological
contamination compared to known dialysis devices.
[0014] It is a further advantage of the dialysis device that a
single connector between the disposable housing and controller is
required, thus reducing the complexity of setting the device up for
operation.
[0015] It is a further advantage that the connector between the
disposable housing and the controller is fluidly sealed to prevent
biological or chemical contamination of the device.
[0016] It is a further advantage that the size of the dialysis
device according to the disclosure can be significantly reduced
relative to other dialysis devices.
[0017] It is a further advantage that the dialysis device according
to the disclosure operates at a low system pressure resulting which
in turn improves energy utilisation.
[0018] It is a further advantage that the device according to the
disclosure is energy efficient.
[0019] According to a second aspect, there is provided a dialysis
controller operable with a disposable housing having fluid
displacement means configured to move dialysate along a flow path
disposed within said housing, the controller comprising:
[0020] actuation means for actuating said fluid displacement means
and an interface means for connecting said controller to said
disposable housing, wherein said controller and said interface
means are fluidly sealed from said flow path during operation of
the disposable housing.
[0021] According to a third aspect, there is provided a disposable
dialysis housing that is configured to be operated by a controller,
the disposable housing comprising:
[0022] a flow path disposed therein along which dialysate received
from a patient is subjected to contaminant removal when in
operation; and
[0023] an interface means for connecting said housing to a
corresponding interface means of said controller,
[0024] wherein in use, the flow path is fluidly sealed from said
controller and said interface means.
[0025] According to a fourth aspect, there is provided a dialysis
system comprising:
[0026] a disposable housing having a flow path containing dialysate
received from a patient, the dialysate undergoing contaminant
removal while disposed in the flow path;
[0027] a controller operably connected to said disposable housing
by an interface means to control the operations of the disposable
housing;
[0028] wherein said flow path is fluidly sealed from the controller
and interface means.
[0029] According to a fifth aspect, there is provided use of a
dialysis device in accordance with the present disclosure, to treat
a patient suffering from kidney malfunction.
[0030] According to a sixth aspect, there is provided a dialysis
method implemented in a dialysis system comprising a disposable
housing having a flow path extending therethrough and a sorbent
zone for contaminant removal, an interface means operably coupling
said disposable housing to a controller for controlling the passage
of dialysate along the flow path of said disposable housing, the
method comprising the step of:
[0031] passing a dialysate along the flow path of said disposable
housing while ensuring that the flow path and dialysate therein is
fluidly sealed from the interface means and the controller.
[0032] According to a seventh aspect, there is provided a dialysis
system comprising:
[0033] a disposable housing having a flow path containing dialysate
received from a patient, the dialysate undergoing contaminant
removal while disposed in the flow path;
[0034] a pressure sensor configured to determine fluid pressure
changes in the flow path.
[0035] a controller operably connected to said disposable housing
by an interface means to control the operations of the disposable
housing and wherein the controller is configured to determine the
flow rate of dialysate in the flow path based on the pressure
changes output by the pressure sensor.
[0036] According to a eighth aspect, there is provided a kit
comprising the dialysis device according to the first aspect,
together with instructions for use.
[0037] According to a ninth aspect, there is provided a kit
comprising the controller according to the second aspect, together
with instructions for use.
[0038] According to a tenth aspect, there is provided a kit
comprising the disposable housing according to the third aspect,
together with instructions for use.
DEFINITIONS
[0039] The following words and terms used herein shall have the
meaning indicated:
[0040] The term "sorbent" as used herein broadly refers to a class
of materials characterized by their ability to adsorb and/or absorb
the desired matter of interest.
[0041] The term "non-toxic" as used herein refers to a substance
that causes little to no adverse reactions when present in the
human body.
[0042] The term "contaminants" in the context of this
specification, means any constituents, typically toxic
constituents, within a dialysate that are generally harmful to
human health and which are desirable to be removed in a dialysate
detoxification process. Typical contaminants include, but are not
limited to ammonium, phosphates, urea, creatinine and uric
acid.
[0043] The term "biocompatible" as used herein refers to the
property of a material that does not cause adverse biological
reactions to the human or animal body.
[0044] The term "upstream" as used herein refers to a localization
within the flow path, relative to a point of reference, and in
direction opposite to that of the dialysate flow. The term
"downstream" as used herein refers to a localization within the
flow path, relative to a point of reference, and in direction of
the dialysate flow.
[0045] The term "crack-pressure" as used herein refers to the point
at which the internal pressure of a pneumatic system triggers the
opening of a valve.
[0046] The term "regenerate" as used herein refers to the action of
detoxifying dialysate by removal of uremic toxins.
[0047] The term "reconstitute" as used herein refers to the action
of converting regenerated dialysate to essentially the same state
and chemical composition as fresh peritoneal dialysate prior to
dialysis.
[0048] The term "outflow mode" as used herein refers to the flow of
dialysate from the patient's body through a sorbent. The flow is
referenced from the patient's body.
[0049] The term "inflow mode" as used herein refers to the flow of
the dialysate from a sorbent to the patient's body. The flow is
referenced to the patient's body.
[0050] The term "fluid" as used herein refers to a liquid or a
gas.
[0051] Throughout this disclosure, certain embodiments may be
disclosed in a range format. It should be understood that the
description in range format is merely for convenience and brevity
and should not be construed as an inflexible limitation on the
scope of the disclosed ranges. Accordingly, the description of a
range should be considered to have specifically disclosed all the
possible sub-ranges as well as individual numerical values within
that range. For example, description of a range such as from 1 to 6
should be considered to have specifically disclosed sub-ranges such
as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6,
from 3 to 6 etc., as well as individual numbers within that range,
for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the
breadth of the range
[0052] The word "substantially" does not exclude "completely" e.g.
a composition which is "substantially free" from Y may be
completely free from Y. Where necessary, the word "substantially"
may be omitted from the definition of the invention.
[0053] Unless specified otherwise, the terms "comprising" and
"comprise", and grammatical variants thereof, are intended to
represent "open" or "inclusive" language such that they include
recited elements but also permit inclusion of additional, unrecited
elements.
[0054] As used herein, the term "about", in the context of
concentrations of components of the formulations, typically means
+/-5% of the stated value, more typically +/-4% of the stated
value, more typically +/-3% of the stated value, more typically,
+/-2% of the stated value, even more typically +/-1% of the stated
value, and even more typically +/-0.5% of the stated value.
[0055] Certain embodiments may also be described broadly and
generically herein. Each of the narrower species and subgeneric
groupings falling within the generic disclosure also form part of
the disclosure. This includes the generic description of the
embodiments with a proviso or negative limitation removing any
subject matter from the genus, regardless of whether or not the
excised material is specifically recited herein.
DISCLOSURE OF OPTIONAL EMBODIMENTS
[0056] Exemplary, non-limiting embodiments of a flow system of
dialysis device will now be disclosed.
[0057] The flow system of a dialysis device comprises: a disposable
housing having a flow path along which dialysate received from a
patient is subjected to contaminant removal;
[0058] a controller for controlling the operation of said
disposable housing; and
[0059] an interface means capable of connecting the controller and
the disposable housing to enable contaminant removal from the
dialysate;
[0060] wherein the flow path is fluidly sealed from the controller
and interface means.
[0061] In one embodiment, the disposable housing further comprises
a sorbent zone in fluid communication with the dialysate flow path
for removing contaminants in the dialysate.
[0062] In one embodiment, the disposable housing further comprises
a storage chamber in fluid communication with the dialysate flow
path for storing the dialysate therein.
[0063] In one embodiment, the disposable housing further comprises
a fluid displacement means configured to move the dialysate along
the dialysate flow path.
[0064] In one embodiment, the disposable housing further comprises
valve means disposed along the dialysate flow path configured to
control the direction of movement of the dialysate relative to the
sorbent zone and storage chamber. In one embodiment the valve means
are operative by the flow direction of dialysate along said flow
path. In a preferred embodiment, the valve means are check valves.
In another embodiment the valves are pressure actuated or
mechanically actuated. In one embodiment, the controller further
comprises actuation means for actuating said fluid displacement
means and said valve means when said controller is connected to the
disposable housing by said interface means.
[0065] In a preferred embodiment, all check-valves along the
dialysate flow path to the sorbent zone are resistant to clogging
by fibrin.
[0066] In a preferred embodiment, the fluid displacement means
comprises a deformable diaphragm.
[0067] In one embodiment the deformable diaphragm is in fluid
contact on one side with the dialysate flow path, and on another
opposite side, in contact with a pressure chamber that is capable
of receiving fluid therein. Pressure changes within the pressure
chamber deform said deformable diaphragm which thereby moves
dialysate within said dialysate flow path.
[0068] In one embodiment, the deformable diaphragm is disposed and
fluidly sealed from the pressure chamber and a rigid member.
[0069] In one embodiment, the actuation means comprises a pump
capable of fluid communication with the pressure chamber when said
interface means operably couples said disposable housing to said
controller.
[0070] In another embodiment, the actuation means is a motor which
drives a piston wherein said piston actuates the deformable
diaphragm.
[0071] In one embodiment the pump is selected from the group
consisting of gear pumps, diaphragm pumps, piston pumps, hydraulic
pumps, pneumatic pumps and mechanical pumps. In a preferred
embodiment the pump is a pneumatic pump. In one embodiment, the
pump is capable of achieving a dialysate flow rate of from 0.1 l/hr
to 20 l/hr.
[0072] In one embodiment, the interface means comprises a conduit
connector that fluidly couples the pump of the controller to the
pressure chamber of the disposable housing.
[0073] In one embodiment, the conduit connector comprises a first
mating part disposed on the controller and a second mating part
disposed on the disposable housing, and wherein the first and
second mating parts are configured to lockingly engage with each
other.
[0074] In one embodiment, the fluid displacement means is
integrally formed with a wall of the storage chamber.
[0075] This is advantageous as it permits the pumping mechanism of
the dialysis device to be shared by the storage chamber thereby
permitting a reduction in the size of the disposable housing. This
is further advantageous as it permits the construction of a more
portable and unobtrusive device to be used by a patient.
[0076] In one embodiment, the disposable housing comprises an
additive dispensing means for dispensing a desired additive into
the dialysate. In one embodiment, the additive dispensing means is
activated by fluid pressure changes that occur in the conduit
connector that is in fluid communication with the pump.
[0077] This is advantageous, as only one pump, and only one
interface connector is required to activate both the storage
chamber comprising a deformable diaphragm to move dialysate along
the flow path and the additive dispensing means. This reduces the
requirement for additional pumps and connections and thus results
in a significant reduction in the size of the dialysis device
relative to known dialysis devices.
[0078] In one embodiment, the disposable housing further comprises
a gas vent in fluid communication with the flow path for venting
gas from said dialysate. In one embodiment the gas vent is
activated by fluid pressure changes that occur in the conduit
connector that is in fluid communication with the pump.
[0079] Again, this is advantageous, as only one pump is required to
activate the storage chamber comprising a deformable diaphragm to
move dialysate along the flow path, the additive dispensing means
and the gas vent means. As all of these elements of the device can
be activated by a single pump and a single connection this further
permits miniaturization of the device and enhances portability and
energy efficiency. Furthermore, with only one pump to activate
these elements there is also a significant reduction in the
complexity of the device which results in a decrease in
manufacturing costs relative to known dialysis devices.
[0080] In one embodiment, the conduit connector is insulated such
that there is no electrical contact between the disposable housing
and the controller.
[0081] It is an advantage of the device according to the disclosure
that the conduit connector results in no electric or electronic
contact between the disposable housing and controller.
[0082] In an alternative embodiment, the interface means provides
electric or electronic contact between the disposable housing and
controller.
[0083] In one embodiment the storage chamber is located upstream of
said sorbent zone.
[0084] In one embodiment the controller comprises a computer
configured to act on instructions for operation of the pump.
[0085] In one embodiment, the interface means comprises a pressure
sensor configured to determine the pressure of said dialysate when
in the disposable housing. In one embodiment, the pressure sensor
is disposed in the controller. In one embodiment, the pressure
sensor is disposed in the controller and is in fluid communication
with the conduit connector. In a preferred embodiment, the pressure
sensor is disposed in the interface means.
[0086] Advantageously, the pressure sensor can, by determining the
pressure of the dialysate in the flow path, also determine the
pressure in the peritoneal cavity of a patient. This is further
advantageous as it permits the use of one sensor to the pressure of
the dialysate in the flow path and in the peritoneal cavity of a
patient. It is a further advantage that the use of one sensor
permits the device to be reduced in size to fewer components being
required in the device.
[0087] In another embodiment, the disposable housing further
comprises a fibrin filter means disposed along the flow path to
remove fibrin from dialysate before said dialysate enters said flow
path. In one embodiment, the fibrin filter means is disposed
immediately adjacent to the patient's body, for example at the exit
of the patient's peritoneal cavity. In one embodiment, the filter
for removing the fibrin is made of poly(vinyl)chloride (PVC). In
one embodiment, the filter for removing the fibrin is made of
polypropylene. The filter may also be capable of withstanding the
pressure within the flow system without any appreciable change in
its desired properties. Advantageously, the fibrin filter means is
capable of removing fibrin, mucus or forms of coagulation arising
from the peritoneal cavity before the dialysate enters the flow
system. This advantageously reduces the risk of clogging of the
flow system. More advantageously, filtering off fibrin containing
material prolongs the lifespan of the flow system. The fibrin
filter means may be a filtration device, a filter paper or any
means suitable for filtering away fibrin containing material in the
dialysate.
[0088] In one embodiment, the flow path may comprise a trap located
upstream of the sorbent zone. In one embodiment the trap comprises
an inlet valve and a filter located opposite the inlet valve. The
inlet valve is preferably a resiliantly deformable disk valve. In
use the dialysate enters the trap in an inflow mode through the
disk valve. During an outflow mode the disk valve is closed
preventing the flow of dialysate from the sorbent zone to the
patient. The dialysate that enters the sorbent zone may comprise
fibrin. The fibrin is prevented from entering the sorbent zone by
the filter and is therefore retained in the trap. Advantageously,
the trap is capable of removing fibrin, mucus or forms of
coagulation arising from the peritoneal cavity before the dialysate
enters the sorbent zone of the dialysis device. This advantageously
reduces the risk of clogging of the flow path. More advantageously,
filtering off fibrin containing material prolongs the lifespan of
the flow system. The filter means may be a filtration device, a
filter paper or any means suitable for filtering away fibrin
containing material in the dialysate.
[0089] In one embodiment, the flow system may further comprise a
micro-organism filter means being disposed along said flow path,
said micro-organism filter means being configured to remove
microorganisms from the dialysate when transmitted along the flow
path. In one embodiment, the micro-organism filter means may be a
micro-organism filter capable of inactivating bacteria from the
dialysate by having bactericidal properties. The filter means also
serves to remove any microorganisms that have inadvertently entered
the flow system.
[0090] As the dialysis device works to regenerate and reconstitute
spent dialysate, the presence of a microorganism filter means for
filtering microorganisms from the dialysate ensures the sterility
of the dialysate returning to the patient's body. In one embodiment
the micro-organism filter means may be a filtration device, a
filter membrane or any means suitable for filtering away
micro-organisms containing material in the dialysate. In one
embodiment, the bacteria filter for removing microorganisms has
pore sizes of no more than about 0.20 microns. In another
embodiment, the micro-organism filter has a surface area of from
about 0.05 m.sup.2 to about 0.60 m.sup.2. The surface area of the
micro-organism filter may be about 0.185 m.sup.2. The bacteria
filter may also be capable of withstanding the pressure within the
flow system without any appreciable change in its desired
properties.
[0091] In another embodiment, the disposable housing further
comprises a gas vent means in fluid communication with said flow
path for removing gas from the dialysate. In one embodiment, the
gas vent means comprises a sorbent gas vent downstream of the
sorbent zone for removing gas from the dialysate that has been
generated by contact with the sorbent zone. In a preferred
embodiment the sorbent gas vent is in fluid communication with said
flow path.
[0092] In one embodiment, the gas vent means comprises a degasser,
downstream of the sorbent zone, for removing gas from the
dialysate. In a preferred embodiment, the degasser is in fluid
communication with said flow path.
[0093] In one embodiment, the sorbent gas vent is a hydrophobic
membrane. The hydrophobic membrane may be selected from
polytetrafluoroethylene (Teflon.RTM.), polypropylene or other
hydrophobic polymeric materials. In a preferred embodiment, gas is
vented by the hydrophobic membrane by applying a positive internal
pressure in the flow path or alternatively by establishing a
negative pressure on the external side of the membrane. In one
embodiment, positive internal pressure for degassing is provided by
a suitable flow resistor, for example an orifice or filter membrane
or a backpressure regulator, for example a check valve having a
preselected crack pressure.
[0094] In another embodiment, the degasser comprises a vacuum
degasser comprising a vacuum pump to create a negative external
pressure on the external side of the hydrophobic membrane. In one
embodiment the vacuum pump is disposed in the controller. In a
preferred embodiment the interface means comprises a vacuum pump
connector to fluidly couple the vacuum pump of the controller with
the external side of the hydrophobic membrane when said controller
is connected to the disposable housing by the interface means.
[0095] In a preferred embodiment, the degasser comprises a vacuum
degasser comprising a pump, for example a diaphragm pump, to create
a negative external pressure on the hydrophobic membrane. In a
preferred embodiment, the negative pressure is controlled by a
pressure sensor. The pump and pressure sensor may be disposed
within the controller.
[0096] Advantageously, when the sorbent gas vent is disposed
downstream of the sorbent zone, the large amount of gases that are
released from the sorbent zone when the dialysate reacts with
sorbent contained therein, can be quickly and effectively released
from the dialysis device. More advantageously, this prevents the
build up of pent up gases which may undesirably increase the
pressure within the flow system. More advantageously, this also
prevents dialysate from returning to a patient that contains gases
which can impede dialysis treatment and may be harmful to the
patient. The sorbent gas vent may be disposed within said
disposable housing and is in fluid communication with the flow path
therein. In one embodiment, the sorbent gas vent is disposed
immediately adjacent to the sorbent zone, along said flow path for
removing gas from the dialysate.
[0097] In one embodiment, the controller further comprises a
control means for controlling said actuation means. Preferably, the
control means is electrically coupled to a power source located in
said controller. In a preferred embodiment the control means is a
pressure sensor.
[0098] In a preferred embodiment, the pressure sensor senses
pressure of the dialysate flow into the flow path and the pressure
of the dialysate flow in the flow path before entering the sorbent
zone. The pressure sensor may also provide feedback input to a
pressure regulator to regulate the pressure of the dialysate
flowing to and from the dialysis device.
[0099] The pressure sensor may also provide feedback to trigger an
alarm in case the detected pressure is outside an acceptable
range.
[0100] In one embodiment, the disposable housing further comprises
an additive dispensing means ("enrichment module") for dispensing
an "additive solution" or "enrichment solution" into the
dialysate.
[0101] The additive solution or enrichment solution may comprise
essential substances for normal functioning of the human body,
selected from the group consisting of potassium, calcium and
magnesium. The substances may also include osmotic agents essential
for the efficacy of dialysis, such as glucose, oligosaccharides or
amino acids. In one embodiment, the additive solution comprises
substances such as supplements, nutrients, vitamins and co-factors
that generally promote human health. The additive solution may also
include therapeutic substances such as medications and
hormones.
[0102] In one embodiment, the dispenser comprises a diaphragm
integrally formed with a wall of said dispenser. In one embodiment
the diaphragm is in fluid contact on one side with the additive or
enrichment solution and, on another opposite side, in contact with
a pressure chamber that is capable of receiving fluid therein.
Pressure changes within the pressure chamber deform said diaphragm
which thereby dispenses additive solution into the dialysate. In
another embodiment, the dispenser may be actuated by a syringe
pump. In one embodiment the syringe pump is disposed in the
controller.
[0103] In one embodiment, the additive dispensing means may be
discrete from the disposable housing. This is advantageous as the
enrichment module and its contents can be subjected to different
sterilization techniques. For example, when the additive dispensing
means contains an additive solution containing glucose heat
treatment is the preferred sterilisation method. However, gamma
radiation is the preferred sterilization technique for the
disposable housing.
[0104] In one embodiment, the additive dispensing means comprises
an interface means. In one embodiment, the interface means
comprises a connector that fluidly couples the additive dispensing
means to the flow path disposed in the disposable housing. In one
embodiment, the connector comprises a first mating part disposed on
the additive dispensing means and a second mating part disposed on
the disposable housing, and wherein the first and second mating
parts are configured to lockingly engage with each other. In one
embodiment, the first mating part disposed on the additive
dispensing means and/or second mating part disposed on the
disposable housing may be sealed to maintain the sterility of the
additive solution in the additive dispensing means. In one
embodiment, the first mating part disposed on the additive
dispensing means and/or second mating part disposed on the
disposable housing are sealed by means of a plug or frangible
seal.
[0105] In one embodiment, the first mating part disposed on the
additive dispensing means mates with the second mating part
disposed on the disposable housing by breaking or puncturing or
dislodging the plug or seal of the mating part. This is
advantageous as it precludes the inadvertent reuse of a spent
additive dispensing means in a new disposable housing.
[0106] In one embodiment, the additive dispensing means comprises a
container for holding the additive solution. In one embodiment, the
container may be a bag located in a rigid housing. In one
embodiment, the additive dispensing means is a rigid container
comprising a sponge located at an end of the container in
communication with a connector. In this embodiment, the sponge
facilitates delivery of the additive solution from the additive
dispensing means to the dialysate flow path. In another embodiment,
the container may be resiliently deformable. In one embodiment the
container is manufactured from a biocompatible plastics material.
Advantageously, all these embodiments allow air-free withdrawal of
the enrichment solution in the container thus enabling orientation
independent use of the dialysis device.
[0107] In one embodiment, the dialysis device has an automatic
dispensing system comprising a fixed displacement pump to dispense
a fixed volume of additive solution to the dialysate flow path. The
fixed displacement pump comprises a rigid casing defining a hollow
interior. The volume of the interior may be selected from the group
consisting of about 0.1 to about 10 ml; about 0.1 to about 9 ml
about 0.1 to about 8 ml about 0.1 to about 7 ml about 0.1 to about
6 ml about 0.1 to about 5 ml about 0.1 to about 4 ml about 0.1 to
about 3 ml about 0.1 to about 2 ml about 0.1 to about 1 ml and
about 0.1 to about 0.5 ml.
[0108] In one embodiment, the fixed displacement pump comprises two
chambers separated by a deformable impermeable membrane or
diaphragm. In one embodiment, one of the chambers (chamber 1) is
located in fluid communication with a pump, for example an air
pump. The other chamber (chamber 2) is in fluid communication with
the enrichment module. In one embodiment, the air pump actuates the
deformable diaphragm to induce negative pressure in chamber 2 and
thereby withdraws additive solution from the enrichment module. In
one embodiment the negative pressure is selected from about 30,
about 40, about 50, about 60 and about 70 mmHg. In another
embodiment, the air pump actuates the deformable diaphragm to apply
positive pressure in chamber 2 to dispense additive solution into
the dialysate in the dialysate flow path. This is advantageous as
it permits a predetermined amount of additive solution to be
dispensed into the dialysate flow path consistently. The volume
dispensed is entirely dependent on the pump volume and is
independent of dialysate pressure or flow rate.
[0109] In one embodiment, the air pump is used to actuate the
storage chamber comprising a deformable diaphragm to move dialysate
along the flow path, the additive dispensing means and the gas vent
means. As only one pump is required for the operation of the
device, the device is very energy efficient. As such the device may
be powered by a battery. In one embodiment, the device comprises a
rechargeable battery, such as a rechargeable lithium polymer
battery.
[0110] It is a further advantage that the same controller may be
used for an entire range of dialysis devices such as wearable
devices, portable devices and desktop devices. Advantageously, a
patient can use a wearable device for mobility during the day and a
heavy duty device during sleep at home, with the same
controller.
[0111] Rechargeable batteries are advantageous as the device does
not have to be connected to an AC power source. As such, there is
no danger of inadvertent interruption of the power supply.
[0112] In one embodiment the rechargeable battery can be detached
from the device and recharged on a separate charging unit. In
another embodiment the rechargeable battery can be recharged in
situ in the dialysis device.
[0113] It is a further advantage then when the device is powered
using rechargeable batteries, a patient can be moved easily while
continuing the dialysis procedure, for example during an emergency
or in a natural disaster scenario where no power (and water) may be
available.
[0114] A battery in accordance with the disclosure may have the
following exemplary characteristics:
Charging:
[0115] Maximum Charge Current: about 1200 mA Charge Limited
Voltage: about 12.6V End-of Current: about 24 mA
Discharging:
[0116] Maximum Discharge Current: about 2400 mA End Voltage: about
8.25V
Operation:
[0117] Temperature Charge: about 0-45 Temperature Discharge: about
-20.about.+60
[0118] The battery may have a lifetime of greater than 100 cycles;
preferably greater than 200 cycles and more preferably greater than
300 cycles of recharging.
[0119] In one embodiment that dialysis device is only activated
when the controller and disposable housing are coupled together. In
one embodiment, the disposable housing is provided with a pin
adapted to activate a switch located on the controller. In one
embodiment, the switch may be a limit switch. When the controller
and disposable housing are coupled together the pin on the
disposable housing actuates the switch in the controller to connect
the battery to the controller power lines. In one embodiment, the
pin is deformable or breakable. This is advantageous as the broken
or deformed pin cannot actuate the switch once the controller is
removed from the disposable housing, thus preventing the
inadvertent or intentional re-use of a used disposable unit.
[0120] In one embodiment, the disposable housing further comprises
an ammonia sensor configured to detect ammonia present in said
dialysate. Advantageously, the sensor for detecting ammonia present
in the dialysate maximizes the utilization of the sorbent before
the sorbent has to be replaced. Due to the presence of the sensor,
the patient will be able to accurately identify when the sorbent of
the flow system has to be replaced.
[0121] In one embodiment, the ammonia sensor is capable of
detecting the concentration of ammonia present in the dialysate in
the form of free ammonia or ammonium ions. The ammonia sensor may
also provide a feedback input to the control system of the dialysis
device so that if the ammonia concentration exceeds an undesired
upper limit range, the control system may activate an alarm and/or
deactivate the pump.
[0122] In one embodiment, the ammonia sensor is positioned in any
part of the dialysate flow path downstream of the sorbent. In
another embodiment, the ammonia sensor is located in the vacuum
degasser. In particular, the ammonia sensor may be located upstream
of the vacuum pump as described herein to detect ammonia in the gas
emitted from the hydrophobic membrane. Alternatively, the ammonia
sensor may be located to detect ammonia in an exhaust of the vacuum
pump. In this embodiment, the ammonia sensor is disposed in the
controller.
[0123] In one embodiment, the ammonia sensor may comprise a
material or indicator strips, which change colour on exposure to or
in the presence of ammonia or ammonium ions. In one embodiment, the
ammonia sensor is an optochemical sensor. In another embodiment,
the ammonia sensor comprises an ammonia-sensitive membrane. In
another embodiment, the ammonia sensor may comprise a conductivity
sensor to monitor for ammonia. In one embodiment, the ammonia
sensor is an ammonia-selective potentiometric or amperometric
electrode. In one embodiment, the ammonia sensor is configured to
detect ammonia in gas extracted from a dialysate flow by a
degasser.
[0124] In one embodiment, the ammonia sensor is disposed in the
controller.
[0125] In one embodiment, the device comprises a gas vent means
comprising a degasser, downstream of the sorbent zone, for removing
gas from the dialysate. In one embodiment, the gas vent means is a
hydrophobic membrane. In a preferred embodiment, the gas vent means
comprises two hydrophobic membranes arranged in parallel. Each
hydrophobic membrane is located adjacent to an air vent. In one
embodiment a hydrophilic membrane is located between the
hydrophobic membranes. In one embodiment, the hydrophilic membrane
is curved to facilitate the flow of gas in the dialysate to the
hydrophobic membranes.
[0126] In another embodiment, the degasser is in fluid
communication with an air pump to create a negative external
pressure on the external side of the hydrophobic membrane. In one
embodiment the air pump is disposed in the controller. In a
preferred embodiment the interface means comprises an air pump
connector to fluidly couple the air pump of the controller with the
external side of the hydrophobic membrane when said controller is
connected to the disposable housing by the interface means.
[0127] In a preferred embodiment, the degasser comprises a pump,
for example an air pump, to create a negative external pressure on
the hydrophobic membrane. In a preferred embodiment, the negative
pressure is controlled by a pressure sensor. The pump and pressure
sensor may be disposed within controller.
[0128] In one embodiment, the air vent is in fluid communication at
one end with a pump, for example an air pump, located in the
controller and at another end with an ammonia sensor and exhaust.
In one embodiment gas is vented by the hydrophobic membrane by
applying a positive internal pressure in the dialysate flow path or
alternatively by establishing a negative pressure on the external
side of the membrane. In one embodiment, positive internal pressure
for degassing is provided by a suitable flow resistor, for example
an orifice or filter membrane or a backpressure regulator, for
example a check valve having a preselected crack pressure. In one
embodiment, the disposable housing comprises an outflow conduit for
transmission of dialysate from said patient's body and an inflow
conduit for transmission of dialysate to said patient's body.
[0129] In one embodiment, the degasser is disposed in the
disposable housing.
[0130] In one embodiment, the disposable housing may be disposed of
on a daily basis or after each dialysis cycle. It is an advantage
of the device that as the flow path is fluidly sealed from the
controller the sterility of the device can be maintained, or at
least ameliorated, by daily disposal of the disposable housing. It
is a further advantage of the device that as only one connection is
required between the disposable housing and the patient, the risk
of biological contamination of the device is significantly reduced.
It is a further advantage that the connector between the disposable
housing and the controller is fluidly sealed to prevent biological
or chemical contamination of the device. It is an advantage of the
device that, as the flow path is fluidly sealed from the
controller, the risk of biological and/or chemical contamination of
the dialysate by the controller is significantly reduced.
[0131] In one embodiment, the flow path through which the dialysate
flows may be made of resilient, chemically and biologically inert
materials. In one embodiment, the flow path may also be able to
withstand the pressure within the dialysis device without leakage.
In one embodiment, the flow path is manufactured from medical grade
polymer such as polycarbonate, nylon, silicone or polyurethane.
Other components of the flow system may also be connected using a
connector made of resilient material such as of medical grade
polymer as nylon or polycarbonate or polysulphone.
[0132] In one embodiment, the flow system further comprises a
conductivity sensor. In another embodiment, the flow system further
comprises a urea sensor. In another embodiment, the flow system
further comprises a creatinine sensor. In a further embodiment, the
flow system comprises a glucose sensor. In one embodiment, these
further sensors may be located downstream of the sorbent in the
flow path. In one embodiment, these sensors may be disposed along
the dialysate flow path adjacent to or within the degasser.
[0133] It is an advantage of the device of the disclosure that due
to the requirement for only one pump and a deformable diaphragm
integrally formed with a wall of the storage chamber that the
overall size of the device can be significantly reduced relative to
other dialysis devices.
[0134] In one embodiment the disposable housing may be provided
with a tamper proof seal. In another embodiment, the controller may
be provided with a tamper proof seal. The tamper proof seal may be
located on the conduit connector disposed on the controller or
disposable housing. This is advantageous as the tamper proof seal
will ensure that the controller or disposable housing are sterile
before use. The tamper proof seal will also prevent a controller of
disposable housing that has been tampered with from being used in a
dialysis cycle. This is further advantageous as biological or
chemical contamination of the device, and the risk of patient
infection is further reduced.
[0135] There is also provided a dialysis controller operable with a
disposable housing having fluid displacement means configured to
move dialysate along a flow path disposed within said housing, the
controller comprising actuation means for actuating said fluid
displacement means and an interface means for connecting said
controller to said disposable housing, wherein said controller and
said interface means are fluidly sealed from said flow path during
operation of the disposable housing.
[0136] There is also provided a disposable dialysis housing that is
configured to be operated by a controller, the disposable housing
comprising:
a flow path disposed therein along which dialysate received from a
patient is subjected to contaminant removal when in operation; and
an interface means for connecting said housing to a corresponding
interface means of said controller, wherein in use, said flow path
is fluidly sealed from said controller and said interface
means.
[0137] There is also provided a dialysis system comprising:
[0138] a disposable housing having a flow path containing dialysate
received from a patient, the dialysate undergoing contaminant
removal while disposed in the flow path;
[0139] a controller operably connected to said disposable housing
by an interface means to control the operations of the disposable
housing;
[0140] wherein said flow path is fluidly sealed from the controller
and interface means.
[0141] In one embodiment, the system comprises a pressure sensor
configured to determine fluid pressure changes in the flow path. In
another embodiment the controller is configured to determine the
flow rate of dialysate in the flow path based on the pressure
changes output by the pressure sensor.
[0142] In one embodiment, the controller comprises a computer
program encoded in at least one computer readable medium, the
computer program comprising a set of instructions, encoded in at
least one computer readable medium, operable to implement, when
executed by a processor, calculating the flow rate of dialysate in
the flow path based on said pressure changes output by said
pressure sensor.
[0143] In one embodiment, the controller comprises a computer
program encoded in at least one computer readable medium, the
computer program comprising a set of instructions, encoded in at
least one computer readable medium, operable to implement, when
executed by a processor, calculating the use time of the sorbent
cartridge based on the start time of dialysis using a new
disposable housing comprising a sorbent zone. In one embodiment the
start time is correlated with a predetermined lifetime of the
sorbent zone in the disposable housing. In one embodiment the use
time of the sorbent zone is monitored in real time. In one
embodiment, when the processor detects that the use time is equal
to the predetermined lifetime of the sorbent zone, dialysis is
stopped. This is advantageous, as dialysis will be stopped thus
preventing overuse of the sorbent zone and reducing any untreated
dialysate being sent back to the patient.
[0144] There is also provided a dialysis method implemented in a
dialysis system comprising a disposable housing having a flow path
extending therethrough and a sorbent zone for contaminant removal,
an interface means operably coupling said disposable housing to a
controller for controlling the passage of dialysate along the flow
path of said disposable housing, the method comprising the steps
of:
[0145] passing a dialysate along the flow path of said disposable
housing while ensuring that the flow path and dialysate therein is
fluidly sealed from the interface means and the controller.
[0146] In one embodiment the method comprises the step of:
[0147] measuring pressure changes in the dialysate flow path during
said passing step; and
[0148] determining the flow rate of dialysate along said dialysate
flow path according to changes in said measured pressure.
[0149] In one embodiment, the method further comprises the step of
adjusting the determined flow rate to a target flow rate.
[0150] There is also provided a dialysis system comprising:
[0151] a disposable housing having a flow path containing dialysate
received from a patient, the dialysate undergoing contaminant
removal while disposed in the flow path;
[0152] a pressure sensor configured to determine fluid pressure
changes in the flow path.
[0153] a controller operably connected to said disposable housing
by an interface means to control the operations of the disposable
housing and wherein the controller is configured to determine the
flow rate of dialysate in the flow path based on the pressure
changes output by the pressure sensor.
[0154] In one embodiment the controller comprises a computer
program encoded in at least one computer readable medium, the
computer program comprising a set of instructions, encoded in at
least one computer readable medium, operable to implement, when
executed by a processor, a calculation of the flow rate of
dialysate in the flow path based on the pressure changes output by
the pressure sensor.
[0155] In one embodiment said determining step comprises the steps
of:
a). applying a first preselected pressure to a flow path to permit
a volume of dialysate to enter or exit said flow path; b).
detecting a second preselected pressure in said storage chamber as
a result of the entry or exit of dialysate to or from said flow
path; c). determining the volume of dialysate that has entered or
exited the flow path, and d). correlating the time required to
reach said second preselected pressure with the volume of dialysate
that has entered or exited said flow path to determine the flow
rate of the dialysate in the dialysis device.
[0156] In one embodiment, the controller comprises a further
computer program encoded in at least one computer readable medium,
the further computer program comprising a set of instructions,
encoded in at least one computer readable medium, operable to
implement, when executed by a processor, an iterative optimisation
of said preselected pressure based on said determined flow rate of
dialysate in the flow path.
[0157] There is also provided the use of a dialysis device
according the disclosure, to treat a patient suffering from kidney
malfunction.
[0158] There is also provided a kit comprising the dialysis device
according to the disclosure, together with instructions for
use.
[0159] There is also provided a kit comprising the controller
according to the disclosure, together with instructions for
use.
[0160] There is also provided a kit comprising the disposable
housing according to the disclosure, together with instructions for
use.
BRIEF DESCRIPTION OF DRAWINGS
[0161] The accompanying drawings illustrate a disclosed embodiment
and serve to explain the principles of the disclosed embodiment. It
is to be understood, however, that the drawings are designed for
purposes of illustration only, and not as a definition of the
limits of the invention.
[0162] FIG. 1a is a schematic diagram of one embodiment of the
disclosed dialysis device.
[0163] FIG. 1b is a schematic diagram of one embodiment of the
disclosed dialysis device, wherein the flow of the dialysate is
toward the storage chamber from the peritoneal cavity.
[0164] FIG. 1c is a schematic diagram of one embodiment of the
disclosed dialysis device, wherein the flow of the dialysate is
from the storage chamber to the peritoneal cavity.
[0165] FIG. 1d is a schematic diagram of one embodiment of the
disclosed dialysis device.
[0166] FIG. 1e is a schematic diagram of one embodiment of the
disclosed dialysis device.
[0167] FIG. 1f is a schematic diagram of one embodiment of the
disclosed dialysis device.
[0168] FIG. 2a is a schematic diagram of an alternative embodiment
of the disclosed dialysis device, wherein the flow of the dialysate
is toward the storage chamber from the peritoneal cavity.
[0169] FIG. 2b is a schematic diagram of the embodiment of FIG. 2a,
wherein the flow of the dialysate is from the storage chamber
toward the peritoneal cavity.
[0170] FIG. 3 is a graphic representation of the flow control of
the dialysate according to an embodiment of the present
disclosure.
[0171] FIGS. 4a-d are a cross sectional views of a prototype of a
disposable housing in accordance with an embodiment of the present
disclosure.
[0172] FIG. 5 is a perspective view of a prototype of one
embodiment of the dialysis device disclosed herein.
[0173] FIG. 6 is a schematic diagram of one embodiment of the
disclosed disposable housing comprising a discrete additive
dispensing means.
[0174] FIG. 7 is a schematic diagram of one embodiment of the
disclosed dialysis device comprising a discrete additive dispensing
means in locking engagement with a disposable housing in accordance
with the disclosure.
[0175] FIG. 8 is a cross sectional view of a sealed connector of
the additive dispensing means in accordance with the
disclosure.
[0176] FIG. 9 is a cross sectional view of a sealed connector of
the additive dispensing means in accordance with the
disclosure.
[0177] FIG. 10 is a cross sectional view of an embodiment of an
additive dispensing means in accordance with the disclosure.
[0178] FIG. 31 is a cross sectional view of an embodiment of an
additive dispensing means in accordance with the disclosure.
[0179] FIG. 12a-c is a cross sectional view of an embodiment of an
automatic dispensing system in accordance with the disclosure.
[0180] FIG. 13 is a graphic representation of the voltage drop of a
rechargeable battery versus dialysis time in a dialysis device in
accordance with the disclosure.
[0181] FIG. 14 is a graphic representation of the voltage drop of a
rechargeable battery versus dialysis time with constant pumping in
a device in accordance with the disclosure.
[0182] FIG. 15 is an embodiment of a degasser in a device in
accordance with the disclosure.
[0183] FIG. 16 is an embodiment of a fibrin trap in a device in
accordance with the disclosure.
[0184] FIG. 17 is an embodiment of a power-connecting switch in
accordance with the disclosure.
[0185] In the figures, like numerals denote like parts.
DETAILED DESCRIPTION OF DRAWINGS
[0186] Referring to FIG. 1a, there is shown one embodiment of the
disclosed dialysis device (200).
[0187] The dialysis device comprises a disposable housing (10)
having a flow path in the form of conduit (20), a controller in the
form of a control housing (30) for controlling the operation of the
disposable housing (10). In this figure the disposable housing (10)
and control housing (30) are not operably connected to each other.
The disposable housing (10) and control housing (30) comprise
interface means in the form of a conduit connector (40a) disposed
on said control housing (30) and (40b) disposed on the disposable
housing (10) capable of connecting the control housing and the
disposable housing. The disposable housing (10) and control housing
(30) are brought into operative engagement when the conduit
connector (40a) is brought into locking engagement with conduit
connector (40b) The conduit (20) of the disposable housing (10) is
fluidly sealed from the control housing (30) and conduit connector
(40a,40b).
[0188] The dialysis device comprises a flexible dialysate tube (50)
which is capable of being in fluid communication with the
peritoneal cavity (60) and a conduit (20). The dialysis device
further comprises a storage chamber (70) located in a rigid
compartment (180). The storage chamber (70) comprises a deformable
diaphragm (71) integrally formed in one of the walls of the storage
chamber (70). The deformable diaphragm (71) is in fluid
communication on one side with the dialysate conduit (20) and, on
another opposite side, in fluid communication with a pressure
chamber (80). When the disposable housing (10) and control housing
(30) are operably coupled to each other, the conduit connector
(40a,40b) fluidly couples the pressure chamber (80) of the
disposable housing (10) to a pump (90) located in the control
housing (30).
[0189] The pump (90) is configured to actuate the deformable
diaphragm (71), by inducing a pressure change in the pressure
chamber (80) which deforms the deformable diaphragm (71) and
thereby moves dialysate within said dialysate conduit (20).
[0190] Check valves (100,101,102,103) are disposed along the
conduit (20) and are configured to, in the outflow mode, allow the
dialysate to flow from the peritoneal cavity (60) to the storage
chamber (70), and in the inflow mode allow the dialysate to flow
from the storage chamber (70) to said sorbent zone (110) for
removal of contaminants therein, and further permit the dialysate
substantially free of said contaminants to flow back to the
peritoneal cavity (60).
[0191] The disposable housing is also provided with an enrichment
module (120), for dispensing a preselected amount of an enrichment
solution into the dialysate, in fluid communication with the
conduit (20) via a conduit (130). The enrichment module is also in
fluid communication with an enrichment solution reservoir (121).
The pump (90) is in fluid communication with a deformable membrane
(72) of the enrichment module 120 via conduit connector (40a,40b),
when the disposable housing (10) and control housing (30) are in
operable engagement.
[0192] An ammonia sensor (140) is also provided downstream of the
sorbent zone (110) to detect any ammonia in the dialysate. Ammonia
is detected by the ammonia detector (141) when the disposable
housing (10) and control housing (30) are operably coupled to each
other.
[0193] A degasser in the form of a hydrophobic membrane (150) is
also located downstream of the sorbent zone. The external side of
the hydrophobic membrane (150) is in fluid communication with a
vacuum pump (151) via the conduit connector (40a,40b) when the
control housing and disposable housing are operably coupled.
[0194] Referring now to FIG. 1b, there is the embodiment of FIG. 1a
showing the disposable housing (10) and control housing (30)
operably coupled with each other, operating in an outflow mode,
wherein the flow of the dialysate is toward the storage chamber
(70) from the peritoneal cavity (60) of a patient. The pump (90)
actuates the deformable diaphragm (71), by inducing negative
pressure in the pressure chamber (80). The negative pressure in the
pressure chamber (80) deforms the deformable diaphragm (71) by
biasing the deformable diaphragm (71) in the direction of arrow A
and thereby moves dialysate from said peritoneal cavity (60) of the
patient into the dialysate conduit (20) via bubble trap (51). The
dialysate flows to the storage chamber (70) through check valve
(100). A pressure sensor (170) is located in operable communication
with the pump (90) to establish a preselected negative pressure
within the pressure chamber (80) and to determine if the pressure
of the dialysate being withdrawn from the peritoneal cavity (60) is
within a safe limit.
[0195] The pump (90) operates intermittently under the control of
the pressure sensor (170) to maintain the negative pressure in the
pressure chamber (80) within a preselected range. Once the storage
chamber (70) is full of dialysate, this is detected by the pressure
sensor (170), triggering the inversion of the pump direction and
thus converting the system to an inflow mode.
[0196] The pump 90 is also in fluid communication with a diaphragm
(72) integrally formed in a wall of said enrichment module (120).
At the same time as the storage chamber (70) is actuated under
negative pressure, the enrichment module (120) is also actuated
under negative pressure by the pump (90), such that a predetermined
amount of an enrichment solution is withdrawn from an enrichment
solution reservoir (121) though check valve (103) into the
enrichment module (120). Check valve (102) ensures that no
dialysate is withdrawn into the enrichment module (120) from the
conduit (20).
[0197] Referring to FIG. 1c, the flow system of FIG. 1b is shown in
the inflow mode, wherein the flow of the dialysate is from the
storage chamber (70) to the peritoneal cavity (60). Once the
storage chamber (70) is full, the pump (90) actuates the deformable
diaphragm (71), by inducing positive pressure in the pressure
chamber (80).
[0198] The positive pressure in the pressure chamber (80) deforms
the deformable diaphragm (71) by biasing the deformable diaphragm
(71) in the direction of arrow B and thereby moves dialysate from
the storage chamber (70) and check valve (100) closes preventing
dialysate from returning to the peritoneal cavity (60) before being
treated to remove contaminants.
[0199] The pressure sensor (170) monitors the pressure in the
pressure chamber (80) to ensure that the pressure of the dialysate
being returned to the peritoneal cavity (60) in the inflow mode is
within a safe limit.
[0200] The dialysate flows from the storage chamber (70) into the
sorbent zone (110) through check valve (101). The regenerated
dialysate from the sorbent zone (110) then flows past a degasser in
the form of a hydrophobic membrane (150). The external side of the
membrane is subjected to negative pressure by a vacuum pump (151)
to aid the removal of gas generated during the dialysis procedure.
The dialysate then flows through an ammonia sensor (140) which
monitors the level of ammonia in the regenerated dialysate, to
ensure that the ammonia level does not exceed a safe limit, prior
to returning to the peritoneal cavity (60) of a patient. Ammonia is
detected by the ammonia detector (141).
[0201] The regenerated dialysate then flows past an enrichment
module (120). In the inflow mode, the pump (90) actuates the
diaphragm (72) of the enrichment module (120), which has previously
been primed with a volume of enrichment solution from the
enrichment solution reservoir (121), under positive pressure. As
the enrichment module (120) is actuated, check valve (103) closes
to ensure that the enrichment solution does not flow back into the
enrichment solution reservoir (121). The enrichment module (120)
then dispenses a preselected amount of enrichment solution
containing desired substances, such as electrolytes, osmotic
agents, nutrients, medication and the like, into the dialysate
conduit (20) through check valve (102) and conduit (130).
[0202] The regenerated dialysate then flows back to the peritoneal
cavity (60) through the bubble trap (51) and flexible dialysate
conduit (50).
[0203] As in the outflow mode, the pump (90) is operated
intermittently under the control of the pressure sensor (170) to
maintain the positive pressure in the pressure chamber (80) within
a preselected range. Once the storage chamber is empty of
dialysate, the pressure sensor (170) detects this and inverts the
pump direction and converts the system to the outflow mode to
repeat the dialysis cycle.
[0204] Referring to FIG. 1d, there is presented an alternative
embodiment of the dialysis device according to the disclosure. The
dialysis device (200) works in essentially the same way as the
device described in FIGS. 1a-c. The regenerated dialysate from the
sorbent zone (110) flows past a degasser in the form of a
hydrophobic membrane (150). The external side of the membrane is
subjected to negative pressure by a vacuum pump (151) in fluid
communication with the hydrophobic membrane to aid the removal of
gas generated during the dialysis procedure. Differing from 1a-c,
the gas vented from the dialysate is then passed through an ammonia
sensor (140) located in the control housing (30). The ammonia
sensor monitors the level of ammonia in the gas vented from the
dialysate to ensure that the ammonia level does not exceed a safe
limit, prior to returning the dialysate to the peritoneal cavity
(60) of a patient.
[0205] Referring to FIG. 1e, there is shown an alternative
embodiment of the dialysis device according to the disclosure. The
dialysis device (200) works in essentially the same way as the
device described in FIGS. 1a-c. However, the pump (90) also
subjects the hydrophobic membrane (150) via the conduit connector
(not shown) and valve (104) to negative pressure during an outflow
mode (where dialysate is received from a patient's peritoneal
cavity (60) via a flexible dialysate tube (50)). Valve (104)
ensures that no gas is introduced into the dialysate path via the
hydrophobic membrane (150) during an inflow mode, when the pump
(90) subjects the pressure chamber (80) to positive pressure.
Ammonia gas released from the dialysate is then detected by the
ammonia sensor (140).
[0206] Referring to FIG. 1f, there is shown an alternative
embodiment of the dialysis device according to the disclosure. The
dialysis device (200) works in essentially the same way as the
device described in FIGS. 1a-c. However, the pump (90) is in fluid
communication with both the pressure chamber (80) and the
enrichment module (120) via a single connection (41) in the
disposable housing (10). The pump (90) also subjects the degasser
in the form of a hydrophobic membrane (150) to negative pressure
during an outflow mode (where dialysate is received from a
patient's peritoneal cavity (60) via a flexible dialysate tube
(50)). During an inflow mode the pump (90) subjects the pressure
chamber (80) to positive pressure. Valve (104) ensures that no gas
is introduced into the dialysate path via the hydrophobic membrane
(150) during an inflow mode, when the pump (90) subjects the
pressure chamber (80) to positive pressure. Ammonia gas released
from the dialysate is then detected by the ammonia sensor
(140).
[0207] Referring to FIG. 2a, there is presented an alternative
embodiment of the flow system (201) in accordance with the present
disclosure wherein the flow of the dialysate is toward the storage
chamber (70) from the peritoneal cavity (60), i.e. outflow mode.
The pump (90) actuates the deformable diaphragm (71), by inducing
negative pressure in the pressure chamber (80). The negative
pressure in the pressure chamber (80) deforms the deformable
diaphragm (71) by biasing the deformable diaphragm (71) in the
direction of arrow A and thereby moves dialysate from said
peritoneal cavity (60) of the patient into the dialysate conduit
(20) via bubble trap (51). The dialysate flows to the storage
chamber (70) located in a rigid compartment (180) through check
valve (100). A pressure sensor (170) is located in operable
communication with the pump (90) to establish a preselected
negative pressure within the pressure chamber (80) and to determine
if the pressure of the dialysate being withdrawn from the
peritoneal cavity (60) is within a safe limit.
[0208] The pump (90) operates intermittently under the control of
the pressure sensor (170) to maintain the negative pressure in the
pressure chamber (80) within a preselected range. Once the storage
chamber (70) is full of dialysate, this is detected by the pressure
sensor (170) which inverts the pump direction and converts the
system to an inflow mode.
[0209] An enrichment module (120) is provided in fluid
communication with the conduit (20) via a conduit (130). The
enrichment module (120) is configured to be actuated by a syringe
pump (91) in the inflow mode.
[0210] Referring to FIG. 2b, the flow system of FIG. 2a is shown in
the inflow mode, wherein the flow of the dialysate is from the
storage chamber (70) to the peritoneal cavity (60). Once the
storage chamber (70) is full, the pump (90) actuates the deformable
diaphragm (71), by inducing positive pressure in the pressure
chamber (80). The positive pressure in the pressure chamber (80)
deforms the deformable diaphragm (71) by biasing the deformable
diaphragm (71) in the direction of arrow B and thereby moves
dialysate from the storage chamber (70) and check valve (100)
closes preventing dialysate from returning to the peritoneal cavity
(60) before being treated to remove contaminants.
[0211] The pressure sensor (170) monitors the pressure in the
pressure chamber (80) to ensure that the pressure of the dialysate
being returned to the peritoneal cavity (60) in the inflow mode is
within a safe limit.
[0212] The dialysate flows from the storage chamber (70) into the
sorbent zone (110) through check valve (101). The regenerated
dialysate from the sorbent zone (110) flows past a degasser in the
form of a hydrophobic membrane (150) located upstream of a check
valve (105). The presence of check valve (105) results in a
positive pressure gradient across the hydrophobic membrane which
permits the removal of any unwanted gas emitted during the dialysis
operation. The dialysate then flows through an ammonia sensor (140)
which monitors the level of ammonia in the regenerated dialysate,
to ensure that the ammonia level does not exceed a safe limit,
prior to returning to the peritoneal cavity (60) of a patient.
[0213] The regenerated dialysate then flows past an enrichment
module (120). In the inflow mode, the syringe pump (91) actuates
the enrichment module (120), which contains a volume of enrichment
solution under positive pressure. The enrichment module (120) then
dispenses a preselected amount of enrichment solution containing
desired substances, such as electrolytes, osmotic agents,
nutrients, medication and the like, into the dialysate conduit (20)
via conduit (130). The syringe pump (91) only operates in the
inflow mode.
[0214] The regenerated dialysate then flows back to the peritoneal
cavity (60) through the bubble trap (51) and flexible dialysate
conduit (50).
[0215] As in the outflow mode, the pump (90) is operated
intermittently under the control of the pressure sensor (170) to
maintain the positive pressure in the pressure chamber (80) within
a preselected range. Once the storage chamber is empty of
dialysate, the pressure sensor (170) detects this and inverts the
pump direction and converts the system to the outflow mode to
repeat the dialysis cycle.
[0216] FIG. 3, shows a graphic representation of the flow control
of dialysate in an embodiment of the dialysis device according to
the present disclosure. The phases of the flow control in FIG. 3
are separated into "outflow, "inflow" and "dwell".
[0217] In an outflow mode, a negative actuating pressure is
produced by a pump, which is operated intermittently under the
control of a pressure sensor. As can be seen in FIG. 3, the
negative pressure in the pressure chamber is maintained within the
limits of a preselected upper and lower pressure. Unobstructed flow
of dialysate is indicated by continuous (rapid) relief of
(negative) pressure during the off-times of the pump. The
measurement of the time which passes during the pressure relief
(t.sub.R--relaxation time) may be used to estimate the effected
fluid flow speed. When the storage chamber is full of dialysate,
the pressure cannot be relieved anymore and the pressure becomes
static for a period of time (t.sub.S--static time). This is
detected by a pressure sensor, which triggers the reversal of the
pump to an inflow mode. The average "outflow" flow rate is equal to
the volume of the storage chamber ("tidal volume") divided by the
time required to fill the storage chamber completely. This rate is
dependent on the choice of preselected pressure limits and can be
modified accordingly.
[0218] During the inflow mode a positive actuating pressure is
produced by the pump. The dialysate contained in the storage
chamber is subsequently forced through the sorbent zone of the
device and is then returned to the patient. The pump is operated
intermittently, such that the positive pressure is regulated
between preselected upper and lower pressure limits. The fluid in
the storage chamber is forced through the sorbent cartridge,
thereby relieving the (positive) pressure. The duration of this
relief can be used to estimate the flow rate (t.sub.R--relaxation
time). When the pump chamber is empty, the pressure cannot be
relieved anymore and the pressure becomes static for a period of
time (t.sub.S--static time), indicating completion of the "inflow"
phase. The average "inflow" flow rate equals the volume of the
storage chamber divided by the time required to complete
"inflow".
[0219] FIG. 3 also shows a wait time or "dwell" time (t.sub.W).
This period is used to control the overall fluid exchange rate:
overall flow rate equals storage chamber volume (tidal volume)
divided by the total cycle time (t.sub.C=outflow+inflow+dwell). For
example, if a specific overall exchange rate is desired, then the
system can use the dwell time as a flexible wait time until the
desired total cycle time has passed.
[0220] FIG. 4a shows a prototype disposable housing (400) in
accordance with an embodiment of the present disclosure. FIG. 4b
shows a cross sectional view of the disposable housing taken along
axis A-A of FIG. 4a. The disposable housing comprises an enclosure
(401) defining an interior (402) for receiving a control housing
(not shown) via a conduit connector (403). The disposable housing
comprises a rigid compartment (404) defining a pressure chamber
(405) in which a storage chamber (406) is disposed. The storage
chamber has a deformable diaphragm (420) integrally formed in a
wall thereof. The storage chamber (406) is in fluid communication
with a sorbent zone (407), via a fluid channel (416).
[0221] The sorbent zone (407) comprises a check valve (409, see
FIGS. 4c and 4d) in fluid communication with a degasser in the form
of a hydrophobic membrane (410).
[0222] FIG. 4c provides a cross-sectional view of the sorbent
module along axis C-C of FIG. 4a. An enrichment module (411) is in
fluid communication with an enrichment solution reservoir (412) via
a check valve (413). The enrichment module (411) is also in fluid
communication with the conduit of dialysate via check valve
(414).
[0223] FIG. 4d provides a cross-sectional view of the sorbent
module along axis D-D of FIG. 4a. The regenerated dialysate exits
the disposable housing via check valve (409) and outlet (415).
[0224] In use during an outflow mode, the control housing (not
shown) is located in the interior (402) of the disposable housing
(400, see FIGS. 4a and 4b). The pump in the control housing
actuates the deformable diaphragm (420) located in the wall of the
storage chamber (406), via the conduit connector (403, see FIG. 4b)
by transmitting pump fluid from the conduit connector (403) thereby
inducing negative pressure in the pressure chamber (405). The
negative pressure in the pressure chamber (405) moves dialysate
from the peritoneal cavity of the patient into the storage chamber
(406) through check valve (408). At the same time as the storage
chamber (406) is actuated under negative pressure, the enrichment
module (411, see FIG. 4c) is also actuated under negative pressure
by the pump such that a predetermined amount of an enrichment
solution is withdrawn from an enrichment solution reservoir (412)
though check valve (413) into the enrichment module (411).
[0225] In use during the inflow mode once the storage chamber (406)
is full, the pump actuates the deformable diaphragm (420) located
in the wall of the storage chamber (406) via the conduit connector
(403) by transmitting fluid to the conduit connector (403) and
thereby inducing positive pressure in the pressure chamber (405).
The positive pressure in the pressure chamber (405) moves dialysate
from the storage chamber (406) and check valve (408) closes
preventing dialysate from returning to the peritoneal cavity before
being treated to remove contaminants. Dialysate flows from the
storage chamber (406) into the sorbent zone (407) through channel
(416). The regenerated dialysate exiting from the sorbent zone
(407) flows past a hydrophobic membrane (410) to remove any
unwanted gas emitted during the dialysis operation. The degassed
dialysate then flows past an enrichment module (411), a check valve
(409) and exits the disposable housing via tube connector
(415).
[0226] In the inflow mode, the pump also actuates the enrichment
module (411) under positive pressure and check valve (413) closes.
The enrichment module (411) dispenses a preselected amount of
enrichment solution containing desired substances, such as
electrolytes, osmotic agents, nutrients, medication and the like,
into the dialysate through check valve (414). The dialysate is then
returned to the peritoneal cavity via a check valve (409) and a
tube connector (415).
[0227] Referring now to FIG. 5, there is shown a picture of a
prototype of one embodiment of the entire flow system disclosed
herein, with a disposable housing (500) and the control housing
(510).
[0228] Referring to FIG. 6, there is shown one embodiment of a
disposable housing (601) having a flow path in the form of conduit
(20). The disposable housing (601) comprises a flexible dialysate
tube (50) which is capable of being in fluid communication with the
peritoneal cavity (60) and a conduit (20). The dialysis device
further comprises a storage chamber (70) located in a rigid
compartment (180). The storage chamber (70) comprises a deformable
diaphragm (71) integrally formed in one of the walls of the storage
chamber (70). The deformable diaphragm (71) is in fluid
communication on one side with the dialysate conduit (20) and, on
another opposite side, in fluid communication with a pressure
chamber (80).
[0229] The pump (670) is configured to actuate the deformable
diaphragm (71), by inducing a pressure change in the pressure
chamber (80) which deforms the deformable diaphragm (71) and
thereby moves dialysate within said dialysate conduit (20).
[0230] Check valves (100,102,103,105) are disposed along the
conduit (20) and are configured to, in the outflow mode, allow the
dialysate to flow from the peritoneal cavity (60) to the storage
chamber (70), and in the inflow mode allow the dialysate to flow
from the storage chamber (70) to said sorbent zone (110) for
removal of contaminants therein, and further permit the dialysate
substantially free of said contaminants to flow back to the
peritoneal cavity (60).
[0231] The disposable housing is also provided with a discrete
enrichment module (620), for dispensing a preselected amount of an
enrichment solution into the dialysate. The enrichment module is
not in fluid communication with the dialysate flow path in this
figure. The enrichment module comprises an enrichment solution
reservoir (621), a container in the form of a bag manufactured from
a biocompatible material for holding the enrichment solution (not
shown). The enrichment module (620) is provided with a connector
(622) adapted for fluid communication with the dialysate conduit
(20) of the disposable housing (601). The connector (622) is sealed
prior to insertion into the disposable housing to maintain the
sterility of the enrichment solution in the enrichment module
(620). The disposable housing is provided with a male connector
(623) of complementary configuration to the connector (622) located
on the enrichment module (620). When in mating engagement (see FIG.
7) the male connector (623) serves to break the seal of the
connector (622) to form a fluid connection between the enrichment
reservoir (621) in the enrichment module (620) and the dialysate
conduit (20) of the disposable housing (601).
[0232] The disposable housing (601) also comprises an enrichment
pump (660) for adding a predetermined amount of enrichment solution
to the dialysate conduit (20).
[0233] A degasser in the form of a hydrophobic membrane (150) is
also located downstream of the sorbent zone (110). The external
side of the hydrophobic membrane (150) is in fluid communication
with air conduits (630 and 631).
[0234] A hydrophilic membrane (610) is disposed in the degasser
compartment, in the dialysate flow path and directly downstream of
the hydrophobic degasser membrane (150). The hydrophilic membrane
(610) serves as a barrier to prevent gas, particles and bacteria
contained in the dialysate exiting the sorbent zone (110) from
reaching the peritoneal cavity (60). The membrane also produces a
backpressure facilitating the venting of gas through the degasser
membrane (150).
[0235] Referring to FIG. 7, there is shown an embodiment of the
disclosed dialysis device (700). The dialysis device comprises a
disposable housing (601) having a flow path in the form of conduit
(20), a controller in the form of a control housing (690) for
controlling the operation of the disposable housing (601). The
disposable housing (601) and control housing (690) comprise
interface means in the form of conduit connectors (691a, 691b,
691c) that connect the control housing (690) and the disposable
housing (601). The disposable housing (601) and control housing
(690) are brought into operative engagement when the conduit
connectors are brought into locking engagement. The conduit (20) of
the disposable housing (601) is fluidly sealed from the control
housing (690) and conduit connectors (691a, 691b, 691c).
[0236] The dialysis device (700) comprises a flexible dialysate
tube (50) which is capable of being in fluid communication with the
peritoneal cavity (60) and a conduit (20). The dialysis device
further comprises a storage chamber (70) located in a rigid
compartment (180). The storage chamber (70) comprises a deformable
diaphragm (71) integrally formed in one of the walls of the storage
chamber (70). The deformable diaphragm (71) is in fluid
communication on one side with the dialysate conduit (20) and, on
another opposite side, in fluid communication with a pressure
chamber (80). When the disposable housing (601) and control housing
(690) are operably coupled to each other, the conduit connector
(691a, 691b, 691c) fluidly couples the pressure chamber (80) of the
disposable housing (601) to an air pump (670) located in the
control housing (690).
[0237] The air pump (670) is configured to actuate the deformable
diaphragm (71), by inducing a pressure change in the pressure
chamber (80) which deforms the deformable diaphragm (71) and
thereby moves dialysate within said dialysate conduit (20).
[0238] Check valves (100,102,103,105) are disposed along the
conduit (20) and are configured to, in the outflow mode, allow the
dialysate to flow from the peritoneal cavity (60) to the storage
chamber (70), and in the inflow mode allow the dialysate to flow
from the storage chamber (70) to said sorbent zone (110) for
removal of contaminants therein, and further permit the dialysate
substantially free of said contaminants to flow back to the
peritoneal cavity (60).
[0239] In this figure the discrete enrichment module (620), is
located in the disposable housing (601). The connector (622) of the
enrichment module (620) is in mating engagement with the male
connector (623) of the disposable housing to form a fluid
connection between the enrichment reservoir (621) in the enrichment
module (620) and the dialysate conduit (20) of the disposable
housing (601).
[0240] The disposable housing (601) also comprises an enrichment
pump (660) for adding a predetermined amount of enrichment solution
to the dialysate conduit (20). The enrichment pump (660) is a fixed
displacement pump comprising a diaphragm (661) in fluid
communication with the air pump (670). The air pump (670) exerts a
positive or a negative air pressure to the diaphragm (661) of the
enrichment pump (660) and the deformable diaphragm (71) of the
storage chamber (70), functioning as pneumatic pump for cycling
dialysate through the dialysate conduit (20) at the same time. On
one side of the diaphragm (661) in the enrichment pump (660) is an
air compartment which fluidly connects to the air pump (670), and
the other side is the enrichment solution compartment connecting to
the enrichment reservoir (621) reservoir via the mated connectors
(622,623). When the enrichment solution compartment is subjected to
negative pressure enrichment solution is drawn from the enrichment
reservoir (621). When a positive pressure is applied to the air
compartment, the enrichment solution is forced out of the
enrichment pump (660) into the dialysate conduit (20).
[0241] A degasser in the form of a hydrophobic membrane (150) is
also located downstream of the sorbent zone (110). The external
side of the hydrophobic membrane (150) is in fluid communication
with air conduits (630 and 631). In a normal dialysis operation,
air conduit (630) is an outlet to the ammonia sensor (140) and air
conduit (630) is in fluid communication with the air pump (670).
During degassing, the air pump (670) in the control housing (690)
exerts a negative pressure to remove any gas from the dialysate in
the dialysate conduit (20). A check valve (680) prevents external
air from entering air conduit (630).
[0242] A hydrophilic membrane filter (610) downstream of the
hydrophobic membrane (150), prevents gas, particles and bacteria
contained in the dialysate from reaching the peritoneal cavity
(60). The membrane (610) also produces a backpressure facilitating
the venting of gas through the hydrophobic membrane (150).
[0243] FIGS. 8a and 8b show an embodiment of a sealed connector
(622) in accordance with the present invention. The connector (622)
on the enrichment module (620) is provided with a plug (800) that
can be dislodged by the connector (623) located on the disposable
housing (601). In FIG. 8b the connector (622) on the enrichment
module is brought into mating engagement with the connector (623)
on the disposable housing (601) to dislodge the plug (800).
[0244] FIGS. 9a and 9b show an embodiment of a sealed connector
(622) in accordance with the present invention. The connector (622)
on the enrichment module (620) is provided with a plug (800) that
can be pierced by the connector (623) located on the disposable
housing (601). In FIG. 8b the connector (622) on the enrichment
module is brought into mating engagement with the connector (623)
on the disposable housing (601) to pierce the plug (800).
[0245] FIGS. 10a and 10b show the embodiment of a sealed connector
of FIGS. 9a and 9b. The connector (622) on the enrichment module
(620) is provided with a plug (800) that can be pierced by the
connector (623) located on the disposable housing (601). In FIG.
10b the connector (622) on the enrichment module is brought into
mating engagement with the connector (623) on the disposable
housing (601) to pierce the plug (800). The enrichment module is a
rigid container for holding the additive solution, comprising a
sponge (1001) located at an end of the container in communication
with a connector (622). The sponge facilitates delivery of the
enrichment solution from the enrichment reservoir (621) to the
dialysate conduit (20).
[0246] FIG. 11 shows another embodiment of a container in the
enrichment module (620). In this figure the container is in the
form of a resiliently deformable bottle (1101). The bottle on the
left hand side is full of enrichment solution. The bottle on the
right hand side of the figure is depleted.
[0247] FIG. 12a shows a cross-sectional view of the enrichment pump
(660). The enrichment module (620) comprises an enrichment
reservoir (621) in fluid communication with the enrichment pump
(660) via the mated connectors (622 and 623). The enrichment pump
(660) is provided with a diaphragm (661) which defines an air
chamber (662) in fluid communication with the air pump (not shown)
and an enrichment solution chamber (663) in fluid communication
with the enrichment reservoir (621).
[0248] FIG. 12b shows a close up view of FIG. 12a in an outflow
cycle. When the air pump exerts a negative pressure beyond 50 mmHg,
in the dialysate outflow cycle, enrichment solution is drawn from
the enrichment reservoir (621) into the enrichment solution chamber
(663) of the enrichment pump (660).
[0249] FIG. 12c shows the enrichment pump (660) in an inflow cycle.
In the inflow cycle when a positive pressure greater than 200 mmHg
is exerted in the air chamber (662), the enrichment solution
chamber (663) will be emptied and a fixed volume of enrichment
solution, VEP, will flow to and merge with the dialysate in the
dialysate conduit via outlet (1201).
[0250] FIGS. 13 and 14 show the results of battery tests on a
dialysis device in accordance with the disclosure. The purpose of
the experiment was to determine the minimum capacity of the battery
that is needed to support the operation of a high capacity dialysis
cartridge for at least 12 hours. Based on an average power
consumption of 153 mA of the system, for a 12 hour operation, the
minimum battery capacity needed would be at least 1836 mAh. Thus,
to retain at least 80% of the battery capacity over a year, the
minimum battery needed will be 2203 mAH. This is according to the
retentive specifications of the battery, where the battery capacity
will drop to 80% of its overall capacity when its operation cycle
is more than 300 cycles (1836 mAh.times.120%). To determine the
actual usage duration for the system, 2 tests were performed using
an 11.1V, 2250 mAH, Lithium Polymer battery.
Test #1:
[0251] Taking a representative operation scenario for a normal flow
control, where the pump is being turned ON and OFF to maintain at
either 400 mmHg (Inflow) or -100 mmHg (Outflow), without a
relaxation of the pressure, the result showed that a 2250 mAh
capacity battery was able to support the mentioned operation for 18
Hrs before it was shut down by the firmware at 10.5V. FIG. 13 shows
the graph showing the voltage drop of the battery versus the
operation time in this experiment.
Test #2:
[0252] In the second test, assuming the worst case scenario that
the pump is constantly ON for the whole inflow and outflow cycle
operation, the results show that the battery can last for 14.5 Hrs
before it was shut down by the firmware at 10.5V. Below is the
graph showing the voltage drop of the battery versus the operation
time in this experiment.
[0253] FIG. 15a shows an exploded view of a degasser (1501) in
accordance with the disclosure. The degasser comprises a gas vent
means in the form of two hydrophobic membranes (1502) and (1503).
The hydrophobic membranes are arranged in parallel on either side
of a hydrophilic membrane (1504). Each hydrophobic membrane (1502
and 1503) is located adjacent to air vents (1505 and 1506). The
degasser is also provided with air inlets/outlets (1507 and 1508)
and a dialysate outlet (1509). The hydrophilic membrane is curved
to facilitate the flow of gas in the dialysate to the hydrophobic
membranes and subsequently the air vents to remove gas from the
dialysate in the dialysate conduit of the dialysis device. In use a
4 micro paper filter seals the top of the sorbent zone in the
dialysis device and is covered by the degasser. The hydrophilic
membrane is located adjacent to the paper filter by a spacer (not
shown). The hydrophilic membrane reduces sorbent powder leakage
from the sorbent zone and paper filter and also acts as a bacterial
filter.
[0254] Referring to FIG. 15b, in a normal dialysis operation, a
first air outlet (1507) is in fluid communication with an ammonia
sensor and a second air outlet (1508) is in fluid communication
with a degassing exhaust via another connecting air-port (not
shown). When detecting for ammonia gas presence in the case of
sorbent cartridge exhaustion, atmospheric air flows through a
throttle valve, or any stable flow constrained valves, in the
controller, allowing a controlled amount of air to flow through the
first air outlet (1507), to an air conduit above the hydrophobic
membranes, and flow out from the other end of the air conduit to
the second air outlet (1508), and circulate to an ammonia sensor in
the controller. During degassing, the air pump in the controller
exerts a negative pressure to remove any gas, in particular CO2, in
the air conduit via the first air outlet (1507) back to an exhaust
in the controller.
[0255] Referring to FIG. 16, an exploded view of a fibrin trap
(1601) is shown. During dialysis, it is possible that dialysate
will contain some small amount of fibrin. The trap comprises an
inlet valve (1602) and a filter (not shown) located opposite the
inlet valve (1602). The inlet valve is in the form of a resiliently
deformable disk hinged on a stud (1605) such that the hinge is
located away from the dialysate flow into the trap and thus will
not catch on any fibrin present in the dialysate. In use the
dialysate enters the trap through an inlet (1604) and passes
through the disk valve (1602). The disk valve is located on a stud
(1605). During an outflow mode, the disk valve (1602) is closed
against the inlet (1604) preventing the flow of dialysate from the
sorbent zone to the patient. The dialysate that enters the sorbent
zone may comprise fibrin. The fibrin is prevented from entering the
sorbent zone by the filter (1603) and is therefore retained in the
trap (1601).
[0256] FIG. 17A shows a power-connecting switch in accordance with
an embodiment of an invention. The switch (1701) is located in the
controller (1702). The switch is in an open condition when the
controller (1702) is not coupled to a disposable housing. A
resiliently deformable material, in the form of a rubber tube
(1703), is located in a channel (1704), immediately adjacent to the
switch (1701).
[0257] A pin (1705) is located on a breakable frame (1706) on the
disposable housing (1707), which is of complementary configuration
to the channel (1704) located on the controller (1702). When the
disposable housing and controller are coupled together, the pin
(1705) is received in the channel (1704) and the frame is deformed
and broken (1708) by the controller (1702) (FIG. 17B).
[0258] The pin (1705) when located in the channel (1704) exerts a
positive compressing force on the rubber tube (1703) which closes
the switch (1701). The frame continues to urge the pin toward the
rubber tubing to actuate the switch (1701) into a closed condition
(FIG. 17B). The switch (1701) now electrically connects the battery
(not shown) to the controller to permit the dialysis device to be
used by a patient. The fractured frame (1706) can no longer hold
the pin (1705) rigidly upright for the pin (1705) to get inserted
into the channel (1704) on the controller (1702) again.
Applications
[0259] It is an advantage of the device that as the flow path is
fluidly sealed from the controller the sterility of the device can
be maintained by daily disposal of disposable housing.
[0260] It is a further advantage of the dialysis device that a
single connector between the disposable housing and controller is
required, thus reducing the complexity of setting the device up for
operation.
[0261] It is a further advantage that the size of the dialysis
device according to the disclosure can be significantly reduced
relative to other dialysis devices.
[0262] It is a further advantage that the device according to the
disclosure is energy efficient.
[0263] It is an advantage of the device according to the disclosure
that as the fluid displacement means is integrally formed with a
wall of the storage chamber this permits the pumping mechanism of
the dialysis device to be shared by the storage chamber thereby
permitting a reduction in the size of the disposable housing. This
is further advantageous as it permits the construction of a more
portable and unobtrusive device to be used by a patient.
[0264] It is a further advantage that the connector between the
disposable housing and the controller is fluidly sealed to prevent
biological or chemical contamination of the device. It is an
advantage of the device that, as the flow path is fluidly sealed
from the controller, the risk of biological and/or chemical
contamination of the dialysate by the controller is significantly
reduced.
[0265] It is a further advantage of the device that as only one
pump and only one interface connector is required this reduces the
requirement for additional pumps and connections and thus results
in a significant reduction in the size of the dialysis device
relative to known dialysis devices.
[0266] It is a further advantage of the device of the disclosure
that as only one pump is required to activate a storage chamber, an
additive dispensing means and a gas vent means, this further
permits miniaturization of the device and enhances portability and
energy efficiency.
[0267] It is a further advantage that as only one pump is required
to activate the storage chamber, the additive dispensing means and
the gas vent means, there is a significant reduction in the
complexity of the device which results in a decrease in
manufacturing costs relative to known dialysis devices.
[0268] It is a further advantage of the device that the pressure
sensor can also be used to measure a patient's intraperitoneal
pressure, without additional pressure sensors.
[0269] It will be apparent that various other modifications and
adaptations of the invention will be apparent to the person skilled
in the art after reading the foregoing disclosure without departing
from the spirit and scope of the invention and it is intended that
all such modifications and adaptations come within the scope of the
appended claims.
* * * * *