U.S. patent application number 15/959439 was filed with the patent office on 2018-10-18 for device including multilayer membrane to control fluid drainage and methods of use thereof.
The applicant listed for this patent is Elwha LLC. Invention is credited to Ralph G. Dacey, JR., Roderick A. Hyde, Muriel Y. Ishikawa, Jordin T. Kare, Eric C. Leuthardt, Nathan P. Myhrvold, Dennis J. Rivet, Michael A. Smith, Clarence T. Tegreene, Lowell L. Wood, JR., Victoria Y.H. Wood.
Application Number | 20180296983 15/959439 |
Document ID | / |
Family ID | 56366774 |
Filed Date | 2018-10-18 |
United States Patent
Application |
20180296983 |
Kind Code |
A1 |
Dacey, JR.; Ralph G. ; et
al. |
October 18, 2018 |
DEVICE INCLUDING MULTILAYER MEMBRANE TO CONTROL FLUID DRAINAGE AND
METHODS OF USE THEREOF
Abstract
A device and methods are disclosed herein for fluid removal
during wound treatment or for removal or dialysis of components
from blood or tissue. A device is disclosed that includes a
multilayer membrane including a plurality of layers; an
electroactive polymer within each layer; and a controller operably
connected to sequentially activate the electroactive polymer to
alter one or more sizes of the plurality of the variably-sized
pores within one or more layers of the multilayer membrane. A
device is disclosed that includes a multilayer membrane including a
plurality of layers; an actuator operably attached to the plurality
of layers of the multilayer membrane; and a controller operably
activating the actuator to alter a relative lateral position of the
two or more layers of the multilayer membrane to align two or more
of the plurality of pores within the plurality of layers of the
multilayer membrane.
Inventors: |
Dacey, JR.; Ralph G.; (St.
Louis, MO) ; Hyde; Roderick A.; (Redmond, WA)
; Ishikawa; Muriel Y.; (Livermore, CA) ; Kare;
Jordin T.; (San Jose, CA) ; Leuthardt; Eric C.;
(St. Louis, MO) ; Myhrvold; Nathan P.; (Medina,
WA) ; Rivet; Dennis J.; (Richmond, VA) ;
Smith; Michael A.; (Phoenix, AZ) ; Tegreene; Clarence
T.; (Mercer Island, WA) ; Wood, JR.; Lowell L.;
(Bellevue, WA) ; Wood; Victoria Y.H.; (Livermore,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Elwha LLC |
Bellevue |
WA |
US |
|
|
Family ID: |
56366774 |
Appl. No.: |
15/959439 |
Filed: |
April 23, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14593110 |
Jan 9, 2015 |
9956531 |
|
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15959439 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 1/0088 20130101;
B01D 69/12 20130101; A61M 1/1631 20140204; A61M 1/1623 20140204;
A61M 2205/3334 20130101; B01D 2325/26 20130101; B01D 67/0088
20130101 |
International
Class: |
B01D 67/00 20060101
B01D067/00; B01D 69/12 20060101 B01D069/12; A61M 1/16 20060101
A61M001/16; A61M 1/00 20060101 A61M001/00 |
Claims
1.-72. (canceled)
73. A method comprising providing a multilayer membrane including a
plurality of layers, each layer of the plurality of layers having
an electroactive polymer, wherein the electroactive polymer
surrounds each of a plurality of variably-sized pores in the
plurality of layers of the multilayer membrane; sequentially
activating the electroactive polymer by a controller operably
connected to activate the electroactive polymer and to alter one or
more sizes of the plurality of variably-sized pores within a first
layer of the multilayer membrane and altering one or more sizes of
the variably-sized pores sequentially within a second layer and one
or more subsequent layers of the multilayer membrane; and aligning
at least one of the plurality of the variably-sized pores in the
first layer with at least one of the plurality of variably-sized
pores in one or more subsequent layers of the multi layer
membrane.
74. The method of claim 73, wherein providing the multilayer
membrane includes applying the multilayer membrane to a wound.
75. The method of claim 73, wherein providing the multilayer
membrane includes providing a hemodialysis multilayer membrane
device to a patient.
76. The method of claim 73, including applying pressure or suction
to the multilayer membrane with a pump.
77. The method of claim 73, including sending a control signal from
the controller to control fluid flow through each layer of the
plurality of layers of the multilayer membrane by altering the
electroactive polymer to provide pulsed transport to control entry
rate and exit rate of fluid through the multilayered membrane.
78. The method of claim 73, including sending a control signal from
the controller to control fluid flow through each layer of the
plurality of layers of the multilayer membrane by altering the
electroactive polymer to provide continuous transport to control
entry rate and exit rate of fluid through the multilayered
membrane.
79. The method of claim 73, including sending a control signal from
the controller to alter the electroactive polymer in one or more
nanoporous layers of the plurality of layers of the multilayer
membrane to control flow through the one or more nanoporous
layers.
80. The method of claim 73, including sending a control signal from
the controller to a UV illumination source to activate
self-sterilization of the device.
81. A system for controlling wound drainage, comprising: a
multilayer membrane configured for application to a wound site, the
multilayer membrane including at least three membrane layers, each
of the at least three membrane layers including a plurality of
variably-sized pores and an electroactive polymer surrounding the
plurality of variably-sized pores, wherein the electroactive
polymer is electrically activatable by an electrical potential
applied across the membrane layer to control the sizes of the
plurality of variably-sized pores; and a controller configured to
receive at least one signal from a moisture sensor located in the
wound site, the controller operably connected to activate the
electroactive polymer to alter one or more sizes of the plurality
of the variably-sized pores of each membrane layer in sequence to
control fluid transport through the multilayer membrane responsive
to the at least one signal from the moisture sensor.
82. The system of claim 81, including the moisture sensor.
83. The system of claim 81, including a sealant located at the
periphery of the multilayer membrane and adapted to prevent leakage
of air or fluids into or out of the wound site.
84. The system of claim 81, including a cover encompassing the
multilayer membrane and adapted for connecting the membrane with a
peristaltic pump and fluid waste reservoir.
85. The system of claim 81, including a fluid waste reservoir.
86. The system of claim 81, including a battery configured to
supply the electrical potential across each membrane layer.
87. The system of claim 81, wherein the controller is responsive to
a conditional stimulus.
88. The system of claim 81, wherein the controller is operably
connected to activate the electroactive polymer in the plurality of
layers of the multi layer membrane to produce peristaltic pumping
activity by aligned variably-sized pores in three or more layers of
the multilayer membrane.
89. The system of claim 81, including a pump configured to apply
pressure or suction to the multilayer membrane.
90. The system of claim 81, including a UV illumination source to
provide self-sterilization of the device.
91. The system of claim 81, wherein the controller is external to
the device.
92. The system of claim 81, wherein the controller includes
operational programs for self-cleaning the device.
93. A hemodialysis system comprising: a multilayer membrane adapted
to contact a blood of a patient on a first side and a dialysis
solution on a second side, the multilayer membrane including a
plurality of membrane layers containing an electroactive polymer,
each layer of the plurality of membrane layers including a
plurality of variably-sized pores, the electroactive polymer
responsive to an applied electrical potential to vary a size of the
variably-sized pores; at least one sensor for detecting a level of
a metabolite or a toxin in the blood of the patient; and a
controller operably connected to sequentially apply an electrical
potential to activate the electroactive polymer within the
plurality of membrane layers to alter one or more sizes of the
plurality of the variably-sized pores to control a passage of fluid
containing the metabolite or toxin through the multilayer membrane
from the first side to the second side, the controller responsive
to one or more signals from the at least one sensor; wherein at
least one of the plurality of the variably-sized pores in a first
membrane layer is aligned with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
94. The hemodialysis system of claim 93, wherein the multilayer
membrane has a surface area of approximately 1 square meter.
95. The hemodialysis system of claim 93, wherein at least one of
the plurality of variable-sized pores has a diameter of
approximately 0.1 to 5.0 .mu.m.
96. The hemodialysis system of claim 93, wherein the at least one
sensor includes at least one of an amperometric sensor, a
conductivity sensor, and a conductometric sensor.
97. The hemodialysis system of claim 93, wherein the at least one
sensor includes at least one of a glucose sensor; a urea sensor; a
uric acid sensor, a sucrose sensor, and a trypsin sensor.
98. The hemodialysis system of claim 93, wherein the multilayer
membrane is configured for counter-current flow with the blood on
the first side of the multilayer membrane flowing in a direction
opposite a direction of flow of dialysis solution on the second
side the membrane.
99. The hemodialysis system of claim 93, wherein the controller is
operably connected to activate the electroactive polymer to push
fluid flow or pull fluid flow through each layer of the two or more
layers of the multilayer membrane.
100. The hemodialysis system of claim 93, wherein the controller is
operably connected to activate the electroactive polymer to provide
pulsed transport of fluid to control entry rate and exit rate of
fluid through the multi layered membrane.
101. The hemodialysis system of claim 93, wherein the controller is
operably connected to activate the electroactive polymer to provide
continuous transport to control entry rate and exit rate of fluid
through the multilayered membrane.
102. The hemodialysis system of claim 93, comprising an ultraviolet
illumination source to provide self-sterilization of the device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the earliest
available effective filing date(s) from the following listed
application(s) (the "Priority Applications"), if any, listed below
(e.g., claims earliest available priority dates for other than
provisional patent applications or claims benefits under 35 USC
.sctn. 119(e) for provisional patent applications, for any and all
parent, grandparent, great-grandparent, etc. applications of the
Priority Application(s)).
PRIORITY APPLICATIONS
[0002] The present application constitutes a continuation of U.S.
patent application Ser. No. 14/593,110, entitled DEVICE INCLUDING
MULTILAYER MEMBRANE TO CONTROL FLUID DRAINAGE AND METHODS OF USE
THEREOF, naming RALPH G. DACEY, JR., RODERICK A. HYDE, MURIEL Y.
ISHIKAWA, JORDIN T. KARE, ERIC C. LEUTHARDT, NATHAN P. MYHRVOLD,
DENNIS J. RIVET, MICHAEL A. SMITH, CLARENCE T. TEGREENE, LOWELL L.
WOOD, JR., AND VICTORIA Y. H. WOOD as inventors, filed 9 Jan. 2015
with attorney docket no. 0307-002-018-000000, which is currently
co-pending or is an application of which a currently co-pending
application is entitled to the benefit of the filing date.
[0003] If an Application Data Sheet (ADS) has been filed on the
filing date of this application, it is incorporated by reference
herein. Any applications claimed on the ADS for priority under 35
U.S.C. .sctn..sctn. 119, 120, 121, or 365(c), and any and all
parent, grandparent, great-grandparent, etc. applications of such
applications, are also incorporated by reference, including any
priority claims made in those applications and any material
incorporated by reference, to the extent such subject matter is not
inconsistent herewith.
[0004] If the listings of applications provided above are
inconsistent with the listings provided via an ADS, it is the
intent of the Applicant to claim priority to each application that
appears in the Domestic Benefit/National Stage Information section
of the ADS and to each application that appears in the Priority
Applications section of this application.
[0005] All subject matter of the Priority Applications and of any
and all applications related to the Priority Applications by
priority claims (directly or indirectly), including any priority
claims made and subject matter incorporated by reference therein as
of the filing date of the instant application, is incorporated
herein by reference to the extent such subject matter is not
inconsistent herewith.
SUMMARY
[0006] A device and methods of use thereof are disclosed herein for
fluid removal during wound treatment or for removal or dialysis of
components from blood or tissue. A device is disclosed that
includes: a multilayer membrane including a plurality of layers,
each layer of the plurality of layers having a plurality of
variably-sized pores; an electroactive polymer within the each
layer and surrounding each of the plurality of variably-sized
pores; and a controller operably connected to sequentially activate
the electroactive polymer to alter one or more sizes of the
plurality of the variably-sized pores within a first layer of the
multilayer membrane and to sequentially alter one or more sizes of
the variably-sized pores sequentially within a second layer and one
or more subsequent layers of the multilayer membrane; wherein at
least one of the plurality of the variably-sized pores in the first
layer is aligned with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
[0007] In some aspects, the controller sequentially activates the
electroactive polymer to vary aperture of one or more of the
plurality of the variably-sized pores and to vary accessibility to
the one or more of the plurality of the variably-sized pores within
the multilayer membrane. The controller may be responsive to a
conditional stimulus. In some aspects of the device, the at least
one of the plurality of the variably-sized pores in the first layer
aligned with the at least one of the plurality of variably-sized
pores in one or more subsequent layers of the multilayer membrane
are accessible to fluid flow through a plurality of layers of the
multilayer membrane in response to the conditional stimulus. The
conditional stimulus may include one or more of pH stimulus,
chemical stimulus, analyte stimulus, fluid presence stimulus,
electrical stimulus, magnetic stimulus, or pressure stimulus. The
conditional stimulus may include one or more of programmed
stimulus, scheduled stimulus, open loop pulsed stimulus, or
stimulus provided by an external command.
[0008] In some aspects, the controller may be operably connected to
activate the electroactive polymer in the plurality of layers of
the multilayer membrane to produce peristaltic pumping activity by
aligned variably-sized pores in three or more layers of the
multilayer membrane. The controller may be operably connected to
activate the electroactive polymer to alter the size of one or more
aligned variably-sized pores sequentially for each layer of two or
more layers of the multilayer membrane to generate pressure or
suction through the multilayer membrane. The controller may be
operably connected to activate the electroactive polymer in to
provide variable fluid flow rates by separately controlling the
size of one or more aligned variably-sized pores of each layer of
two or more layers of the multilayer membrane. The device of claim
1, wherein the controller may be operably connected to activate the
electroactive polymer to separately control movement of each layer
of two or more layers to provide variable fluid flow rates. In some
aspects of the device, a pump may be configured to apply pressure
or suction to the multilayer membrane. The controller may be
operably connected to alter the relative position of the two or
more layers of the multilayered membranes to expose one or more of
the plurality of variably-sized pores in each of the two or more
layers to pressure or suction from the pump.
[0009] In some aspects, the controller may be operably connected to
activate the electroactive polymer to push fluid flow or pull fluid
flow through each layer of the two or more layers of the multilayer
membrane. The controller may be operably connected to activate the
electroactive polymer to provide pulsed transport of fluid to
control entry rate and exit rate of fluid through the multilayered
membrane. The controller may be operably connected to activate the
electroactive polymer to provide continuous transport to control
entry rate and exit rate of fluid through the multilayered
membrane. In some aspects, the device may include one or more
nanoporous layers in the multilayer membrane, wherein the
controller is operably connected to activate the electroactive
polymer in the one or more nanoporous layers to provide controlled
transport of fluid through the one or more nanoporous layers. The
device may include one or more of a surgical drainage device, CSF
shunt, or an artificial kidney. The device may include a UV
illumination source to provide self-sterilization of the device.
The controller may be external to the device. The controller may
include operational programs for self-cleaning the device.
[0010] A method of varying a fluid flow rate through a multilayer
membrane is disclosed that includes: sending a control signal from
a controller operably connected to activate an electroactive
polymer within each layer of a plurality of layers of a multilayer
membrane, wherein the electroactive polymer surrounds each of a
plurality of variably-sized pores in the plurality of layers of the
multilayer membrane; altering the electroactive polymer surrounding
one or more sizes of the plurality of variably-sized pores within a
first layer of the multilayer membrane and altering the one or more
sizes of the variably-sized pores sequentially within a second
layer and one or more subsequent layers of the multilayer membrane;
and aligning at least one of the plurality of the variably-sized
pores in the first layer with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
[0011] The method may include: controlling accessibility to the one
or more sizes of the plurality of the variably-sized pores within
the multilayer membrane by altering the electroactive polymer in
response to a conditional stimulus. The method may include:
receiving a conditional stimulus at the controller. The method may
further include: aligning the at least one of the plurality of the
variably-sized pores in the first layer with the at least one of
the plurality of variably-sized pores in one or more subsequent
layers of the multilayer membrane to provide access to fluid flow
through a plurality of layers of the multilayer membrane in
response to the conditional stimulus. The method may include:
sending a control signal from the controller operably connected to
activate the electroactive polymer in the plurality of layers of
the multilayer membrane to produce peristaltic pumping activity by
aligned variably-sized pores in three or more layers of the
multilayer membrane. The method may further include: sending a
control signal from the controller operably connected to activate
the electroactive polymer to alter the size of one or more aligned
variably-sized pores sequentially for each layer of two or more
layers of the multilayer membrane to generate pressure or suction
through the multilayer membrane.
[0012] The method may include: sending a control signal from the
controller operably connected to activate the electroactive polymer
to provide variable fluid flow rates by separately controlling the
size of one or more aligned variably-sized pores of each layer of
two or more layers of the multilayer membrane. The method may
include: sending a control signal from the controller operably
connected to activate the electroactive polymer to separately
control movement of each layer of two or more layers to provide
variable fluid flow rates. The method may include: applying
pressure or suction to the multilayer membrane through a pump. The
method may further include: sending a control signal from the
controller to alter the relative position of two or more layers of
the multilayered membranes to expose the one or more of the
plurality of variably-sized pores in each of the two or more layers
to pressure or suction from the pump. The method may include:
sending a control signal from the controller to control fluid flow
through each layer of the plurality of layers of the multilayer
membrane by altering the electroactive polymer to push fluid flow
or pull fluid flow through the multilayer membrane. The method may
include: sending a control signal from the controller to control
fluid flow through each layer of the plurality of layers of the
multilayer membrane by altering the electroactive polymer to
provide pulsed transport to control entry rate and exit rate of
fluid through the multilayered membrane. The method may include:
sending a control signal from the controller to control fluid flow
through each layer of the plurality of layers of the multilayer
membrane by altering the electroactive polymer to provide
continuous transport to control entry rate and exit rate of fluid
through the multilayered membrane. The method may include: sending
a control signal from the controller to alter the electroactive
polymer in one or more nanoporous layers of the plurality of layers
of the multilayer membrane to control flow through the one or more
nanoporous layers. The method may include: sending a control signal
from the controller to a UV illumination source to activate
self-sterilization of the device.
[0013] A method is disclosed that includes: providing a multilayer
membrane including a plurality of layers, each layer of the
plurality of layers having an electroactive polymer, wherein the
electroactive polymer surrounds each of a plurality of
variably-sized pores in the plurality of layers of the multilayer
membrane; sequentially activating the electroactive polymer by a
controller operably connected to activate the electroactive polymer
and to alter one or more sizes of the plurality of variably-sized
pores within a first layer of the multilayer membrane and altering
one or more sizes of the variably-sized pores sequentially within a
second layer and one or more subsequent layers of the multilayer
membrane; and aligning at least one of the plurality of the
variably-sized pores in the first layer with at least one of the
plurality of variably-sized pores in one or more subsequent layers
of the multilayer membrane.
[0014] A device is disclosed that includes: a multilayer membrane
including a plurality of layers, each layer of the plurality of
layers having a plurality of pores on the plurality of layers of
the multilayer membrane; an actuator operably attached to the
plurality of layers of the multilayer membrane; and a controller
operably activating the actuator to alter a relative lateral
position of two or more layers of the plurality of layers to align
two or more of the plurality of pores within the two or more layers
of the plurality of layers of the multilayer membrane; wherein the
two or more pores are aligned and accessible through the two or
more layers of the plurality of layers of the multilayer membrane.
In some aspects, two or more pores of the each layer of the
plurality of layers have a substantially identical size. The two or
more pores of the substantially identically-sized pores may be
aligned and accessible through the plurality layers of the
multilayer membrane. In some aspects of the device, at least one
pore of the each layer of the plurality of layers have a variable
size. The controller may be operably connected to alter the size of
the variably-sized pores.
[0015] In some aspects, the controller may be operably connected to
the plurality of layers of the multilayer membrane to produce
peristaltic pumping activity by aligned variably-sized pores in
three or more layers of the multilayer membrane. The controller may
be operably connected to alter the size of at least one aligned
variably-sized pores of each layer of the two or more layers to
generate pressure or suction. The controller may be operably
connected to provide variable flow rates by separately controlling
the size of the aligned variably-sized pores of the each layer of
the two or more layers. The controller may be operably connected to
sequentially activate the actuator to vary accessibility to the two
or more of the plurality of pores. The controller may be responsive
to a conditional stimulus. In some aspects, the conditional
stimulus may include one or more of pH stimulus, chemical stimulus,
analyte stimulus, fluid presence stimulus, electrical stimulus,
magnetic stimulus, or pressure stimulus. In some aspects, the
conditional stimulus may include one or more of programmed
stimulus, scheduled stimulus, open loop pulsed stimulus, or
stimulus provided by an external command. The plurality of pores
may include pores of variable size and pores of fixed size. The
device may further include a pump configured to apply pressure or
suction to the multilayer membrane.
[0016] In some aspects of the device, the controller operably may
activate the actuator to alter the relative position of the two or
more layers of the multilayered membranes to expose one or more of
the plurality of pores to pressure or suction from the pump. In
some aspects, the controller may operably activate the actuator to
provide variable fluid flow rates by separately controlling lateral
movement of each layer of the two or more layers. The controller
may operably activate the actuator to alter the relative lateral
position of the two or more layers of the plurality of layers to
push fluid flow or pull fluid flow through each layer of the two or
more layers of the plurality of layers. The controller may provide
pulsed signals to the actuator to control entry rate and exit rate
of fluid through the multilayered membrane. The controller operably
may activate the actuator to initiate continuous transport to
control entry rate and exit rate of fluid through the multilayered
membrane. In some aspects, the device may include one or more
nanoporous layers in the multilayer membrane, wherein the
controller operably activates the actuator to open and close pores
to provide controlled transport of fluid through the nanoporous
layer. In some aspects, the device may include one or more of a
surgical drainage device, CSF shunt, or an artificial kidney. The
device may further include a UV illumination source to provide
self-sterilization of the device. In some aspects, the controller
is external to the device. In some aspects, the controller includes
operational programs for self-cleaning the device.
[0017] A method of varying a fluid flow rate through a multilayer
membrane is disclosed that includes: sending a control signal from
a controller operably connected to activate an actuator operably
attached to a plurality of layers of the multilayer membrane to
alter a relative lateral position of two or more layers of the
plurality of layers, wherein each layer of the plurality of layers
has a plurality of pores on the plurality of layers; and aligning
by the actuator two or more pores of the plurality of pores in the
two or more layers of the multilayer membrane.
[0018] The method may include: controlling accessibility to the two
or more pores within the multilayer membrane by activating the
actuator to align the two or more pores of the plurality of pores.
The method may include: receiving a conditional stimulus at the
controller. The method may include: sending a control signal from
the controller to activate the actuator to alter the relative
lateral position of three or more layers of the multilayer membrane
to produce peristaltic pumping activity by aligned pores in the
three or more layers. The method may further include: applying
pressure or suction to the multilayer membrane through a pump. The
method may include: sending a control signal from the controller to
alter the relative position of two or more layers of the
multilayered membranes to expose the two or more pores to pressure
or suction from the pump.
[0019] The method may include: sending a control signal from the
controller to control fluid flow through each layer of the two or
more layers of the multilayer membrane by activating the actuator
to push flow or pull flow through the multilayer membrane. The
method may include: sending a control signal from the controller to
control fluid flow through each layer of the two or more layers of
the multilayer membrane by activating the actuator to provide
pulsed transport to control entry rate and exit rate of fluid
through the multilayered membrane. The method may include: sending
a control signal from the controller to control fluid flow through
each layer of the two or more layers of the multilayer membrane by
activating the actuator to control continuous transport to control
entry rate and exit rate of fluid through the multilayered
membrane. The method may include: sending a control signal from the
controller to control fluid flow through each layer of the two or
more layers of the multilayer membrane by activating the actuator
to control flow through one or more nanoporous layers in the
multilayer membrane. The method may include: sending a control
signal from the controller to a UV illumination source to activate
self-sterilization of the device.
[0020] A method is disclosed that includes: providing a multilayer
membrane including a plurality of layers, each layer of the
plurality of layers having a plurality of pores on the plurality of
layers of the multilayer membrane; operably activating an actuator
by a controller to alter a relative lateral position of two or more
layers of the plurality of layers; and aligning by the actuator two
or more pores of the plurality of pores in the two or more layers
of the multilayer membrane.
[0021] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 depicts a diagrammatic view of an aspect of a
device.
[0023] FIG. 2 depicts a diagrammatic view of an aspect of a
device.
[0024] FIGS. 3A, 3B, and 3C depict a diagrammatic view of an aspect
of a device.
[0025] FIG. 4 depicts a diagrammatic view of an aspect of a
device.
[0026] FIGS. 5A, 5B, and 5C depict a diagrammatic view of an aspect
of a device.
[0027] FIGS. 6A, 6B, 6C, 6D, and 6E depict a diagrammatic view of
an aspect of a device.
[0028] FIG. 7 depicts a diagrammatic view of an aspect of a
method.
[0029] FIG. 8 depicts a diagrammatic view of an aspect of a
method.
DETAILED DESCRIPTION
[0030] In the following detailed description, reference is made to
the accompanying drawings, which form a part hereof. In the
drawings, similar symbols typically identify similar components,
unless context dictates otherwise. The illustrative embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented here.
[0031] A device and methods of use thereof are disclosed herein for
fluid removal during wound treatment or for removal or dialysis of
components from blood or tissue. A device is disclosed that
includes: a multilayer membrane including a plurality of layers,
each layer of the plurality of layers having a plurality of
variably-sized pores; an electroactive polymer within the each
layer and surrounding each of the plurality of variably-sized
pores; and a controller operably connected to sequentially activate
the electroactive polymer to alter one or more sizes of the
plurality of the variably-sized pores within a first layer of the
multilayer membrane and to sequentially alter one or more sizes of
the variably-sized pores sequentially within a second layer and one
or more subsequent layers of the multilayer membrane; wherein at
least one of the plurality of the variably-sized pores in the first
layer is aligned with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
[0032] In some aspects, the controller may sequentially activate
the electroactive polymer to vary aperture of one or more of the
plurality of the variably-sized pores and to vary accessibility to
the one or more of the plurality of the variably-sized pores within
the multilayer membrane. The controller may be responsive to a
conditional stimulus. In some aspects of the device, the at least
one of the plurality of the variably-sized pores in the first layer
aligned with the at least one of the plurality of variably-sized
pores in one or more subsequent layers of the multilayer membrane
are accessible to fluid flow through a plurality of layers of the
multilayer membrane in response to the conditional stimulus. In
some aspects of the device, the controller may be operably
connected to activate the electroactive polymer in the plurality of
layers of the multilayer membrane to produce peristaltic pumping
activity by aligned variably-sized pores in three or more layers of
the multilayer membrane. The controller may be operably connected
to activate the electroactive polymer to alter the size of one or
more aligned variably-sized pores sequentially for each layer of
two or more layers of the multilayer membrane to generate pressure
or suction through the multilayer membrane.
[0033] A method of varying a fluid flow rate through a multilayer
membrane is disclosed that includes: sending a control signal from
a controller operably connected to activate an electroactive
polymer within each layer of a plurality of layers of a multilayer
membrane, wherein the electroactive polymer surrounds each of a
plurality of variably-sized pores in the plurality of layers of the
multilayer membrane; altering the electroactive polymer surrounding
one or more sizes of the plurality of variably-sized pores within a
first layer of the multilayer membrane and altering the one or more
sizes of the variably-sized pores sequentially within a second
layer and one or more subsequent layers of the multilayer membrane;
and aligning at least one of the plurality of the variably-sized
pores in the first layer with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
[0034] A method is disclosed that includes: providing a multilayer
membrane including a plurality of layers, each layer of the
plurality of layers having an electroactive polymer, wherein the
electroactive polymer surrounds each of a plurality of
variably-sized pores in the plurality of layers of the multilayer
membrane; sequentially activating the electroactive polymer by a
controller operably connected to activate the electroactive polymer
and to alter one or more sizes of the plurality of variably-sized
pores within a first layer of the multilayer membrane and altering
one or more sizes of the variably-sized pores sequentially within a
second layer and one or more subsequent layers of the multilayer
membrane; and aligning at least one of the plurality of the
variably-sized pores in the first layer with at least one of the
plurality of variably-sized pores in one or more subsequent layers
of the multilayer membrane.
[0035] A device is disclosed that includes: a multilayer membrane
including a plurality of layers, each layer of the plurality of
layers having a plurality of pores on the plurality of layers of
the multilayer membrane; an actuator operably attached to the
plurality of layers of the multilayer membrane; and a controller
operably activating the actuator to alter a relative lateral
position of two or more layers of the plurality of layers to align
two or more of the plurality of pores within the two or more layers
of the plurality of layers of the multilayer membrane; wherein the
two or more pores are aligned and accessible through the two or
more layers of the plurality of layers of the multilayer membrane.
In some aspects, two or more pores of the each layer of the
plurality of layers have a substantially identical size. The two or
more pores of the substantially identically-sized pores may be
aligned and accessible through the plurality layers of the
multilayer membrane. In some aspects of the device, at least one
pore of the each layer of the plurality of layers have a variable
size. The controller may be operably connected to alter the size of
the variably-sized pores.
[0036] In some aspects, the controller may be operably connected to
the plurality of layers of the multilayer membrane to produce
peristaltic pumping activity by aligned variably-sized pores in
three or more layers of the multilayer membrane. The controller may
be operably connected to alter the size of at least one aligned
variably-sized pores of each layer of the two or more layers to
generate pressure or suction. The controller may be operably
connected to provide variable flow rates by separately controlling
the size of the aligned variably-sized pores of the each layer of
the two or more layers.
[0037] A method of varying a fluid flow rate through a multilayer
membrane is disclosed that includes: sending a control signal from
a controller operably connected to activate an actuator operably
attached to a plurality of layers of the multilayer membrane to
alter a relative lateral position of two or more layers of the
plurality of layers, wherein each layer of the plurality of layers
has a plurality of pores on the plurality of layers; and aligning
by the actuator two or more pores of the plurality of pores in the
two or more layers of the multilayer membrane.
[0038] A method is disclosed that includes: providing a multilayer
membrane including a plurality of layers, each layer of the
plurality of layers having a plurality of pores on the plurality of
layers of the multilayer membrane; operably activating an actuator
by a controller to alter a relative lateral position of two or more
layers of the plurality of layers; and aligning by the actuator two
or more pores of the plurality of pores in the two or more layers
of the multilayer membrane.
[0039] FIG. 1 depicts a diagrammatic view of an aspect of a device.
A device 100 may be placed upon a wound 150 of a mammalian subject
to draw liquid from the wound 150 and through a plurality of
variably-sized pores 120 of the device 100. The device 100 includes
a sealant 160 to seal the device including a shell 170 around the
device to surround the wound 150 of the mammalian subject. A device
100 comprising: a multilayer membrane 110 including a plurality of
layers 115, 118, each layer of the plurality of layers having a
plurality of variably-sized pores 120; an electroactive polymer
124, 128 within the each layer 115, 118 and surrounding each of the
plurality of variably-sized pores 120; and a controller 130
operably connected to sequentially activate the electroactive
polymer 124, 128 to alter one or more sizes of the plurality of the
variably-sized pores 120 within a first layer 115 of the multilayer
membrane and to sequentially alter one or more sizes of the
variably-sized pores 120 sequentially within a second layer 118 and
one or more subsequent layers 118 of the multilayer membrane 110;
wherein at least one of the plurality of the variably-sized pores
120 in the first layer 115 is aligned with at least one of the
plurality of variably-sized pores in one or more subsequent layers
118 of the multilayer membrane 110. The variably-sized pores 120
may be opened 124 or closed 128 in response to the conditional
stimulus. The controller 130 may be configured to respond to the
conditional stimulus by varying accessibility to the one or more of
the plurality of the variably-sized pores 120 within the multilayer
membrane 110. The device 100 includes the controller 130 and
circuitry including a battery 140 is used to draw an electrical
potential across each membrane layer 110.
[0040] A pump 180 (e.g., a peristaltic pump, a MEMS pump, a
micro-vibrating flow pump, or a micropump) is operably attached to
the device through compartmental outlets 185 into a holding
reservoir 190. The pump 180 is configured to apply pressure or
suction to the device including the multilayer membrane 110 to draw
liquid out of the wound and through the pores 120 of the device. In
some aspects in addition to or instead of the pump attached to the
device, the controller may sequentially activate the electroactive
polymer to vary aperture of one or more of the plurality of the
variably-sized pores and to vary accessibility to the one or more
of the plurality of the variably-sized pores within the multilayer
membrane in response to the conditional stimulus. The controller
may be operably connected to activate the electroactive polymer in
the plurality of layers of the multilayer membrane to produce
peristaltic pumping activity by aligned variably-sized pores in
three or more layers of the multilayer membrane.
[0041] FIG. 2 depicts a diagrammatic view of an aspect of a device
200 comprising: a multilayer membrane 210 including a plurality of
layers 218, each layer of the plurality of layers having a
plurality of variably-sized pores 220; an electroactive polymer
224, 228 within the each layer 218 and surrounding each of the
plurality of variably-sized pores 220; and a controller 230
operably connected to sequentially activate the electroactive
polymer to alter one or more sizes of the plurality of the
variably-sized pores 220 within a first layer 215 of the multilayer
membrane and to sequentially alter one or more sizes of the
variably-sized pores 220 sequentially within a second layer 218 and
one or more subsequent layers 218 of the multilayer membrane 210;
wherein at least one of the plurality of the variably-sized pores
220 in the first layer is aligned with at least one of the
plurality of variably-sized pores in one or more subsequent layers
210 of the multilayer membrane.
[0042] The device 200 includes the controller 230 and circuitry
including a battery 250 is used to draw an electrical potential
across each membrane layer 210. Electronic activation 255 of the
membranes controls the passage of fluid through the multilayer
membrane 210. For example, multilayer membranes 210 comprised of
electroactive polymers 224, 228 can act as valves with pores
approximately 0.1-5.0 .mu.m in diameter that open 224 or close 228
depending on the oxidation state of the polymers.
[0043] FIGS. 3A, 3B, and 3C depict a diagrammatic view of an aspect
of a device 300 comprising: a multilayer membrane 310 including a
plurality of layers, each layer of the plurality of layers having a
plurality of variably-sized pores 320; an electroactive polymer
324, 328 within the each layer 315, 318 and surrounding each of the
plurality of variably-sized pores 320; and a controller 330
operably connected to sequentially activate the electroactive
polymer 324, 328 to alter one or more sizes of the plurality of the
variably-sized pores within a first layer 315 of the multilayer
membrane and to sequentially alter one or more sizes of the
variably-sized pores 320 sequentially within a second layer 318 and
one or more subsequent layers of the multilayer membrane 310,
wherein at least one of the plurality of the variably-sized pores
320 in the first layer 315 is aligned with at least one of the
plurality of variably-sized pores 320 in one or more subsequent
layers 318 of the multilayer membrane 310.
[0044] The device 300 includes the controller 330 and circuitry
including a battery 350 is used to draw an electrical potential
across each membrane layer 310. Electronic activation 355 of the
membranes controls the passage of fluid through the multilayer
membrane 310. For example, multilayer membranes 310 comprised of
electroactive polymers 324, 328 can act as valves with pores
approximately 0.1-5.0 .mu.m in diameter that open 324 or close 328
depending on the oxidation state of the polymers.
[0045] The controller 330 controls a battery 350 to delivery an
electrical potential 355 of the electroactive polymers 324, 328 in
the plurality of membranes 310 so that pores within the membranes
are in an open 324 or closed 328 state within each layer of the
multilayer membrane. In step 1 (FIG. 3A), a first layer 313 of the
multilayer membrane is comprised of electroactive polymers that are
in an open state 324. The second 315 and third layers 318 of the
multilayer membrane 310 are comprised of electroactive polymers
that are in a closed state 328.
[0046] In step 2 (FIG. 3B), a second 315 layer of the multilayer
membrane is comprised of electroactive polymers that are in an open
state 324. The first 313 and third 318 layers of the multilayer
membrane 310 are comprised of electroactive polymers that are in a
closed state 328.
[0047] In step 3 (FIG. 3C), a third 318 layer of the multilayer
membrane is comprised of electroactive polymers that are in an open
state 324. The first 313 and second 315 layers of the multilayer
membrane 310 are comprised of electroactive polymers that are in a
closed state 328. The sequential opening 324 and closing 328 of
pores in each layer of the multilayer membrane 310 in steps 1, 2,
and 3 may act to draw fluid out of a wound of the mammalian
subject. The sequential opening and closing of pores draw fluid
through each layer of the multilayer membrane 310. A peristaltic
pump may be used to enhance fluid flow out of the multilayer
membrane 310 and into a fluid collection reservoir. Active pumping
from each membrane compartment 310 is coordinated by the controller
330 to coincide with opening 324 and closing 328 of the membrane
pores as described above.
[0048] FIG. 4 depicts a diagrammatic view of an aspect of a device
400 including a multilayer membrane 410 comprising a plurality of
pores 420 of variable size is used to control the flow 430 of
cerebral spinal fluid (CSF) in a patient with hydrocephalus. A
cerebral shunt composed of a ventricular catheter 480, a distal
catheter 490 and a membrane device 400 with a pressure sensor 440
is implanted to control intracranial pressure in the patient. The
flow 430 of CSF fluid from the lateral ventricle 480 of the brain
to the peritoneal cavity is controlled by a controller 450 in the
multilayer membrane device which monitors intracranial pressure and
responsively adjusts the fluid flow rate.
[0049] A device 400 includes a multilayer membrane 410 including a
plurality of layers 410, each layer of the plurality of layers
having a plurality of pores 420 on the plurality of layers of the
multilayer membrane; an actuator 460, 470 operably attached to the
plurality of layers 410 of the multilayer membrane; and a
controller 450 operably activating the actuator 460, 470 to alter a
relative lateral position of two or more layers 410 of the
plurality of layers to align two or more of the plurality of pores
420 within the two or more layers 410 of the plurality of layers of
the multilayer membrane; wherein the two or more pores 420 are
aligned and accessible through the two or more layers 410 of the
plurality of layers of the multilayer membrane.
[0050] FIGS. 5A, 5B, and 5C depict a diagrammatic view of an aspect
of a device 500 including a multilayer membrane 510 including a
plurality of layers 510, each layer of the plurality of layers
having a plurality of pores 520 on the plurality of layers of the
multilayer membrane; an actuator 560 operably attached to the
plurality of layers 510 of the multilayer membrane; and a
controller 550 operably activating the actuator 560 to alter a
relative lateral position of two or more layers 510 of the
plurality of layers to align two or more of the plurality of pores
520 within the two or more layers 510 of the plurality of layers of
the multilayer membrane; wherein the two or more pores 520 are
aligned and accessible through the two or more layers 510 of the
plurality of layers of the multilayer membrane; a multilayer
membrane 510 comprising a plurality of pores 520 of variable size;
a controller 550 responsive to a conditional stimulus configured to
alter a relative position 560 of two or more layers of the
multilayer membrane 410 to align 560 one or more identical sizes
520 of the pores within a plurality of layers of the multilayer
membrane; wherein the one or more identical sizes 520 of the pores
are aligned and accessible through the plurality layers of the
multilayer membrane in response to the conditional stimulus.
[0051] FIG. 5A depicts a diagrammatic view of an aspect of a device
500 comprising: a multilayer membrane 510 comprising a plurality of
pores 520 of variable size, e.g., 5.0 .mu.m. A controller 550
responsive to a conditional stimulus configured to activate an
actuator 560 to alter a relative position of two or more layers of
the multilayer membrane 510 to align by the actuator 560 one or
more identical sizes 520 of the 5.0 .mu.m pores to allow flow
through a plurality of layers of the multilayer membrane. The one
or more 5.0 .mu.m sizes 520 of the pores are aligned and accessible
through the plurality layers of the multilayer membrane in response
to the conditional stimulus.
[0052] FIG. 5B depicts a diagrammatic view of an aspect of a device
500 comprising: a multilayer membrane 510 comprising a plurality of
pores 520 of variable size, e.g., 5.0 .mu.m. A controller 550
responsive to a conditional stimulus is configured to actuate an
actuator 560 to alter a relative position of two or more layers of
the multilayer membrane 510 and to alter alignment 560 of one or
more identical sizes 520 of the 5.0 .mu.m pores in order to block
flow through a plurality of layers of the multilayer membrane. The
one or more 5.0 .mu.m sizes 520 of the pores are not aligned and
flow through the plurality layers of the multilayer membrane is not
accessible in response to the conditional stimulus.
[0053] FIG. 5C depicts a diagrammatic view of an aspect of a device
500 comprising: a multilayer membrane 510 comprising a plurality of
pores 520 of variable size, e.g., 5.0 .mu.m or 0.1 .mu.m. A
controller 550 responsive to a conditional stimulus is configured
to activate an actuator 560 to alter a relative position of two or
more layers of the multilayer membrane 510 and to align 560 one or
more identical sizes 520 of the 5.0 .mu.m pores to allow flow
through a plurality of layers of the multilayer membrane and to
block flow through 0.1 .mu.m pores of the multilayer membrane. The
one or more 5.0 .mu.m sizes 520 of the pores are aligned and
accessible through the plurality layers of the multilayer membrane
in response to the conditional stimulus.
[0054] FIGS. 6A, 6B, 6C, 6D, and 6E depict a diagrammatic view of
an aspect of a device 600 comprising: a multilayer membrane
including a plurality of layers 610, each layer of the plurality of
layers 610 having a plurality of variably-sized pores 620; an
electroactive polymer 624, 628 within the each layer 615, 618 and
surrounding each of the plurality of variably-sized pores 620; and
a controller 630 operably connected to sequentially activate the
electroactive polymer 624, 628 to alter one or more sizes of the
plurality of the variably-sized pores within a first layer 615 of
the multilayer membrane and to sequentially alter one or more sizes
of the variably-sized pores 620 sequentially within a second layer
618 and one or more subsequent layers of the multilayer membrane
610, wherein at least one of the plurality of the variably-sized
pores 620 in the first layer 615 is aligned with at least one of
the plurality of variably-sized pores 620 in one or more subsequent
layers 618 of the multilayer membrane.
[0055] The at least one of the plurality of the variably-sized
pores 620 in the first layer 615 aligned with the at least one of
the plurality of variably-sized pores in one or more subsequent
layers 618 of the multilayer membrane are accessible to fluid flow
640 through a plurality of layers 610 of the multilayer membrane in
response to the conditional stimulus.
[0056] In FIGS. 6A, 6B, 6C, 6D, and 6E, the controller 630 is
operably connected to activate the electroactive polymer 624, 628
in the plurality of layers 610 of the multilayer membrane to
produce peristaltic pumping activity (FIG. 6A through FIG. 6E) by
aligned variably-sized pores 620 in three or more layers 615, 618
of the multilayer membrane 610. The peristaltic pumping activity of
the multilayer membrane 610 produces sequential fluid flow 640
through the variably-sized pores 620 surrounded by the
electroactive polymer 624, 628 in the three or more layers 618 of
the multilayer membrane 610.
[0057] FIG. 7 depicts a diagrammatic view of an aspect of a method.
A method 700 of varying a fluid flow rate through a multilayer
membrane includes: sending 710 a control signal from a controller
operably connected to activate an electroactive polymer within each
layer of a plurality of layers of a multilayer membrane, wherein
the electroactive polymer surrounds each of a plurality of
variably-sized pores in the plurality of layers of the multilayer
membrane; altering 720 the electroactive polymer surrounding one or
more sizes of the plurality of variably-sized pores within a first
layer of the multilayer membrane and altering the one or more sizes
of the variably-sized pores sequentially within a second layer and
one or more subsequent layers of the multilayer membrane; and
aligning 730 at least one of the plurality of the variably-sized
pores in the first layer with at least one of the plurality of
variably-sized pores in one or more subsequent layers of the
multilayer membrane.
[0058] FIG. 8 depicts a diagrammatic view of an aspect of a method.
A method 800 of varying a fluid flow rate through a multilayer
membrane includes: sending 810 a control signal from a controller
operably connected to activate an actuator operably attached to a
plurality of layers of the multilayer membrane to alter a relative
lateral position of two or more layers of the plurality of layers,
wherein each layer of the plurality of layers has a plurality of
pores on the plurality of layers; and aligning 820 by the actuator
two or more pores of the plurality of pores in the two or more
layers of the multilayer membrane.
[0059] The device may include an ultraviolet (UV) illumination
source to provide self-sterilization of the device. A controller
may send a control signal to a UV illumination source to activate
self-sterilization of the device. The controller may include
operational programs for self-cleaning the device. Self-cleaning of
the device may occur by washing the membranes with an aqueous
solution such as normal saline at prescribed intervals to ensure
that the pores maintain a clear flow. If the device is located on
or within the subject's body, additional fluids could be absorbed
by the subject's body via natural means.
[0060] A device includes a multilayer membrane having a plurality
of layers, each layer of the plurality of layers having a plurality
of variably-sized pores. The plurality of layers may be constructed
of an electroactive polymer to form the variably sized pores.
Alternatively, the pores may be formed from short DNA subunits to
form the pores. Computer design will fit the DNA subunits together
to form the pores. The pores constructed from DNA subunits may be
of dimensions 14 nm in length and 5.5 nm in diameter. This formed
the main part of their artificial nanopore.
[0061] To overcome hydrophilicity of the DNA subunits to embed in a
hydrophobic membrane, the scientists chemically attached to the DNA
subunits to Porphyrin molecules that will anchor the DNA subunits
within a lipid membrane. These structures were then able to embed
the DNA subunit tubes within the membrane. See, e.g., Burns et al.,
Angewandte Chemie International Edition, Volume 52, Issue 46, page
11943, Nov. 11, 2013, which is incorporated herein by reference. A
device may include a multilayer membrane having a plurality of
layers, each layer of the plurality of layers having a plurality of
variably-sized pores may be used to detect the presence of bacteria
or other contaminants in situ with the device. For example, the
device may detect red blood cells (6-8 .mu.m) in the urine;
bacteria (0.2 to 30 .mu.m) in a wound; yeast (0.3 to 8 .mu.m),
viruses (0.005 to 0.1+.mu.m), poliovirus (2.37 .mu.m). The in situ
data from analysis of cells passing through the multilayer membrane
dependent upon pore size is useful diagnostic data during on-going
treatment. See, e.g., "Relative Pore Size Chart for filtration",
Spectrumlabs.com, which is incorporated herein by reference.
Fabrication of a Multilayer Membrane Comprising a Plurality of
Variably-Sized Pores
[0062] The device includes a multilayer membrane including each
layer of the multilayer membrane comprising a plurality of
variably-sized pores. The multilayer membrane may be made a wide
range of conducting polymer membranes to suit particular target
applications. These include free standing membrane based on both
polypyrrole and polyaniline with a variety of counterions,
composite films, and co-polymers. The counterions used have varied
from simple ones such as pTS to large polyelectrolytes such as
heparin. Examples of the types of membrane that have been produced
may depend upon the conductivity and tensile strength desired in
the membrane. Examples of the composition of the membrane include,
but are not limited to, polypyrrole-benzenesulfonate;
polypyrrole-1,3-benzenedisulfonate; polypyrrole-dodecyl sulfate;
polypyrrole-4-ethylbenzene sulfonate;
polypyrrole-2-mesitylenesulfonate; polypyrrole-1,5-naphthalene
disulfonate; polypyrrole-paratoluenesulfonate;
polypyrrole-paratoluenesulfonate/dodecylsulfate;
polypyrrole-poly(vinylsulfonate) composite; polypyrrole-nafion
composite; poly(3-carboxy-4-methylpyrrole)-paratoluenesulfonate;
copolymer of pyrrole with 3-carboxy-4-methylpyrrole; poly
aniline.
[0063] In addition, to the free standing and composite membranes,
techniques may be developed for fabricating thin CEP films onto
conventional substrates. A thin selective layer is formed with
superior flux characteristics. Conventional substrates such as
polysulfone (PS) or poly vinylidene fluoride (PVDF) are sputtered
with a thin film of platinum. The platinum layer does not unduly
block the pores of the substrate and does not affect the bulk
permeability. The platinised substrate is then used as a working
electrode and a thin layer of conducting polymer is
electrochemically deposited. The film acts as a selective barrier
for transport.
[0064] Two different types of application of the coated platinised
films may be considered. In the first example, the redox properties
of the CEP film may be used to induce transport. In the second one,
a membrane may have a platinum coating on both sides. In this
example the polymer acts as a thin selective layer.
[0065] Separation of Mineral Ions.
[0066] Polypyrrole -pTS may be electrochemically deposited onto a
PVDF substrate by a galvanostatic method (2 mA cm.sup.-2) and grown
for 3 minutes from a solution containing 0.2 M pyrrole monomer and
0.05 M pTS to give a coating of about 4 .mu.m. The coated membrane
was then used to separate copper (II) ions from iron (III) in
solution. The transport may be carried out with a feed solution
containing 0.1 M Copper (II) and 0.1 M iron (III) in 0.01 M H2S04.
The receiving solution contains 0.01 M H2S04. The electrical pulse
potential used may be -0.4V-+0.6V with a pulse width of 20
seconds.
[0067] When an electrical pulse potential is applied, copper is
preferentially transported across the membrane, with a separation
factor of 5. In this example, the application of potential to the
film may induce not only redox changes in the polymer but also
reduced copper(II) to copper metal onto the surface of the polymer
and subsequently re-oxidized it. Because of the kinetics the
copper(II) are thus pre-concentrated in the vicinity of the
polymer-solution interface and are insert into the reduced
polypyrrole. Another point of interest is that the transport of
copper (U) continues for a long time after the applied potential is
switched off. During application of potential, the membrane becomes
loaded with copper metal. This metal slowly reoxidises after the
potential waveform is stopped.
[0068] Transport of Proteins.
[0069] Conducting polymer coated platinised substrates may also be
used to separate proteins. The PVDF substrate is platinised on both
sides and coated with Ppy/pTS on one side. Instead of applying a
squarewave potential in a three electrode system, there is now a
two electrode system, namely the two sides of the membrane. The
separation of the electrodes is thus controlled and small, only 110
.mu.m. If a constant current is applied between the electrodes, the
system acts as an electrophoretic system with a high electric
field. The results of a test separation experiment of human serum
albumin (HSA) and myoglobin, two proteins of similar molecular
weight using a double-sided platinum coated PVDF membrane, has been
shown. The feed solution was a mixture of HSA (670 ppm or 10 .mu.M)
and Myoglobin (175 ppm or 10 .mu.M) in Milli-Q water whilst the
permeate solution was Milli-Q water. A current density of 1.28 mA
cm.sup.-2 is applied with the cathode facing the feed solution.
PPy/pTS was deposited on one side of the Pt/PVDF at 1 mA cm.sup.-2
for 60 s. Significant HSA transport occurs across the film.
[0070] Nearly one third of the HAS may be transferred in six hours.
No myoglobin is detected (<0.2 ppm) in the permeate side. This
very effective separation is due partly to the pI of the two
proteins. At pH 6.5 HSA (pI=4.8) is negatively charged whilst
Myoglobin (pI=7.5) has a positive charge. The CEP coating allows
different selectivities by incorporating particular selective
functional groups into the polymer and changing the hydrophobicity
of the surface layer. In this case the polymer layer effectively
eliminates the Myoglobin transport, increasing the selectivity
markedly (by a factor of over 6). See, e.g., W. E. Price et al.
Synthetic Metals 102: 1338-1341, 1999, which is incorporated herein
by reference.
Etching Process Using Ion-Beam Technology
[0071] The device including a multilayer membrane includes pores
that may be created with an etching process using ion-beam
technology. For nitrate treatment, the membrane pores are about 10
nanometers in diameter. Membrane samples may contain about 1
billion holes per square centimeter. See, e.g., U.S. Pat. No.
7,632,406, which is incorporated herein by reference.
Electrically-Driven Fluidic Valve Comprising a Microporous
Membrane
[0072] The device including a multilayer membrane includes a
plurality of variably-sized pores. One or more types of
electroactive polymer surround the plurality of variably-sized
pores. The electroactive polymer may be a conjugated polymer
including, but not limited to, polyaniline, polypyrrole,
polythiophene, polyparaphenylvinylene, poly(p-pyridylvinylene) and
derivatives thereof.
[0073] The multilayer membrane may be a microporous membrane having
pores varying in size between 0.1 and 5 .mu.m.
[0074] To cover the multilayer membrane as the microporous membrane
with an electroactive polymer, it is necessary to make the membrane
conductive. The microporous membrane may be rendered conductive by
a metalization process.
[0075] The device includes a multilayer membrane may include each
layer of the multilayer membrane comprising a plurality of
variably-sized pores. The operation of the multilayer membrane as a
microporous membrane including the variably-sized pores is based
upon changing the oxidation-reduction state of the electroactive
polymer covering the pores of the membrane. When the variably-sized
pores are closed, that is to say when the polymer covers the pores
of the membrane, the polymer is in the oxidized state. In this
state, the anion of the electrolytic salt is inserted into the
polymer, resulting in an increase in the diameter of the polymeric
fibers.
[0076] The multilayer membrane including variably-sized pores is
opened by changing the oxidation-reduction state of the polymer,
namely by changing it from the oxidized state to the reduced state.
To change the oxidation-reduction state of the polymer, the
multilayer membrane is exposed in the presence of an electrolytic
solution containing a solvent, such as acetonitrile, and an
electrolyte salt is used to functionalize the microporous membrane,
but in the absence of monomers. This electrolyte salt is identical
to the one used in the method of functionalizing the variably-sized
pores by polymerization. However, in alternative aspects, it is
possible to use other electrolytic solutions such as an aqueous
solution of NaCl. The electrolytic salt is contained in the
solution with a concentration lying in the range from 10.sup.-1 to
5.times.10.sup.-1 mol/l.
[0077] To change the oxidation-reduction state of the electroactive
polymer that form variably-sized pores in the multilayer
microporous membrane, a voltage may be applied to the terminals of
the cell holding the multilayer membrane. This voltage varies on
either side of the oxidation-reduction potential of the polymer
used. Preferably, the voltage applied varies between -5 and +5
volts, depending on whether it is desired to oxidize or reduce the
polymer.
[0078] The variably-sized pores of the multilayer membrane may have
an opening and closing time lying between 1 and 100 milliseconds,
depending on the pore diameter of the microporous multilayer
membrane, which may vary between 0.2 and 1 .mu.m. See, e.g., U.S.
2006/0138371, which is incorporated herein by reference.
Device Including a Self-Priming Pump
[0079] The device includes a multilayer membrane wherein each layer
of the multilayer membrane comprises a plurality of variably-sized
pores that may utilize a self-priming peristaltic pump actuated
with a single linear actuator. The pump is tolerant of bubbles and
particles and can pump liquids, foams, and gases. The pump may be
actuated by a motor and/or a shape memory alloy (SMA) wire; or may
be manually actuated. The pump may include a Delrin acetal plastic
body with two integrated valves, a flexible silicone tube, and an
actuator. Pumping is achieved as the forward motion of the actuator
first closes the upstream valve, and then compresses a section of
the tube. The increased internal pressure opens a downstream burst
valve to expel the fluid. Reduced pressure in the pump tube allows
the downstream valve to close, and removal of actuator force allows
the upstream valve and pump tube to open, refilling the pump. The
motor actuated design offers a linear dependence of flow rate on
voltage in the range of 1.75-3 V. Flow rate may decrease from a
value of 780 .mu.l/min (with an increase in back pressure) to a
maximum back pressure of 48 kPa. At 3V and minimum back pressure,
the pump consumes 90 mW. The shape memory alloy actuated design
offers a 5-fold size and 4-fold weight reduction over the motor
design, higher maximum back pressure, and substantial insensitivity
of flow rate to back pressure at the cost of lower power efficiency
and flow rate. The manually actuated version is simpler and
appropriate for applications unconstrained by actuation
distance.
[0080] The device includes a multilayer membrane wherein each layer
of the multilayer membrane comprises a plurality of variably-sized
pores that may utilize miniature fluid pumps. For many
applications, a miniature pump would supply sufficient flow rate
and pressure, while having a low voltage requirement, low power
consumption, a simple control system, and low cost. Peristaltic
pumps move fluid by exerting forces on the outside of a pumping
chamber, which often consists of a flexible tube containing the
fluid. Many peristaltic pumps have the advantage that the pump
actuator components do not touch the fluid and that the pumping
chamber can be made disposable to ensure sterility and prevent
cross-contamination. Miniature peristaltic pumps have been
microfabricated using polydimethylsiloxane (PDMS), PDMS bonded to
glass, or glass bonded to silicon. In most of these, a series of
two or more actuators compress regions of a channel (the pumping
chamber) to produce a peristaltic wave. In other miniature
peristaltic designs, the pump chamber is created from a section of
flexible tubing and the pumping action is created by motor-driven
rollers, magnetic balls, or drops of magnetic liquid which compress
the tube.
[0081] A miniature peristaltic pump may use a single reciprocating
actuator motion to produce pumping. This pump may use off-the-shelf
tubing and may be manufactured using conventional materials and
methods including injection molding, stereolithography, or CNC
machining. The pump consumes 90 mW of electrical power at 3V, and
allows control of flow rate by controlling voltage. Although here
we present only one size of the pump, we have created smaller and
larger versions which achieve 0.1.times.to 5.times.the nominal flow
rate and/or higher back pressures (up to 69 kPa).
[0082] In some aspects, the pump may be driven by a gear motor
shown in various phases of the pumping cycle. The pumping chamber
and inlet and outlet connections are a single piece of commercially
available silicone tubing. In some aspects, the pump with motor is
8 mm.times.22 mm.times.35 mm, weighs 3.6 g, and consists of four
parts: motor, cam, pump body, and tube. The pumping cycle may be
described in three phases. Phase 1: Cam rotation pushes down on the
plunger arm, pinching the tubing and creating the upstream valve.
Phase 2: Further motion of the plunger arm rotates the plunger
clockwise (about the protrusion of the upstream valve), compressing
the pumping chamber. Increased pressure in the pumping chamber
causes the downstream burst valve to open, expelling fluid from the
pumping chamber. Phase 3: The downstream valve closes as pressure
is reduced in the pumping chamber. As the cam rotates further, it
allows the plunger arm to spring upward, and the elasticity of the
tubing and line pressure open the upstream valve. The pumping
chamber draws liquid through the now-open upstream valve into the
pumping chamber.
[0083] A miniature peristaltic pump design may use a single
(linear) actuator motion to effect both valving and pumping
actions. A pump may utilize a motor, SMA, and/or manually actuated
versions of the design. The pump is self-priming, tolerant of
bubbles and particles, can pump liquids, foams, and gases, and can
be manufactured using conventional materials and methods such as
injection molding or CNC machining. All designs may be fabricated
from Delrin acetal plastic and a flexible silicone tube acts as the
pump chamber.
[0084] The motor actuated pump's flow rate is linearly dependent on
driving voltage in the range of 1.75-3V against a constant back
pressure, allowing for easy regulation of flow rate. Pump flow rate
decreases from 780 .mu.l/min to the maximum back pressure of 48
kPa. The pump consumes-90 mW of power when pumping against minimal
back pressure at 3V. However, we estimate only 6% of this power is
used to drive the liquid while over 60% of the power is consumed by
the motor and gearbox, motivating improvement in the choice of the
actuator. This pump system measures 8 mm.times.22 mm.times.35 mm
and weighs 3.6 g.
[0085] The SMA actuated pump offers lower flow rates (a maximum of
60 Umin) and lower flow rate per power (0.14 .mu.l min.sup.-1
mW.sup.-1). However, it offers a 5-fold package volume reduction
and 4-fold weight reduction over the motor actuated pump, and
allows for further downscaling. The manually actuated design is
simpler and intended for situations where travel distance of
actuator is not a design constraint. See, e.g., V. Shkolnikov et
al., Sensors and Actuators A 160: 141-146, 2010, which is
incorporated herein by reference.
[0086] Device Including a Peristaltic Polydimethylsiloxane (PDMS)
Micropump
[0087] The device utilizing a peristaltic PDMS micropump may be
actuated by the thermopneumatic force. The peristaltic PDMS
micropump includes the three peristaltic-type actuator chambers
with microheaters on the glass substrate and a microchannel
connecting the chambers and the inlet/outlet port. The micropump
may be fabricated by the spin-coating process, the two-step curing
process, the molding process using negative photoresist. The
diameter and the thickness of the actuator diaphragm are 2.5 mm and
30 m, respectively. The maximum flow rate of the micropump is about
0.36 L/s at 2 Hz for the zero hydraulic pressure difference, when
the three-phase input voltage is 20V.
[0088] A PDMS micropump with a mechanical actuator fabricated by
using multi-stacked PDMS-molding technique may be utilized with the
device including a multilayer membrane wherein each layer of the
multilayer membrane comprises a plurality of variably-sized pores.
The membrane-type micropumps with various actuators have advantages
and disadvantages from the viewpoint of power consumption,
integration method, response time, operation frequency and voltage,
fabrication process, and actuation efficiency. For the simple
fabrication process and the large volume stroke of the micropump,
the thermopneumatic actuation method may be used.
[0089] The micropump requires a microvalve unit for the one-way
flow rate of the working fluid. Microvalves are classified into the
passive and active valves. The active valve is useful to control
the flow rate under the some pressure difference, but its
fabrication process is complicated. The passive check valve opens
only to the forward pressure and have simple structures compared to
the active valve. However, with the passive check valve, the
control of reverse flow rate under the pressure difference is
impossible.
[0090] In alternative aspects, the peristaltic micropump using the
thermopneumatic actuation may be used. The peristaltic-type
actuators can be operated as the dynamic valves and controlled
easily by the applied electric input power without any additional
process for the fabrication of the microvalves unit.
[0091] See, e.g., O. C. Jeong et al., Sensors and Actuators A
123-124: 453-458, 2005, which is incorporated herein by
reference.
[0092] Method of Operation of Sensors for Detection of Moisture
[0093] A moisture sensor may be attached to the device including a
multilayer membrane to serve as a wound dressing or bandage on a
wound. Before applying the dressing the clinician may cleanse the
wound as per best practice guidelines and place the device
including a multilayer membrane and the sensor onto the wound,
ensuring that a porous, non-adhesive coating of the sensor is
placed downwards. The porous non-adhesive cover is bonded to the
sensor pair but can be cut to a smaller size if the device and
dressing chosen for use with the sensor is smaller than the area of
the non-adhesive cover. Sensor tags, found at the end of the paired
sensor electrodes, are taped down at the edge of the dressing (if
an adhesive dressing is used). The longer sensor, as used in this
study for leg ulcers, can have the tags tucked into the patient's
bandage.
[0094] The device including a multilayer membrane and a moisture
sensor may be attached to a wound dressing or bandage on a wound.
To read the moisture level, the tags on the moisture sensor are
freed from the edge of the dressing or bandage and the portable
meter is clipped onto them. The meter applies a low, alternating
current to the sensor. The sensor is made up of a pair of small,
silver chloride electrodes. The low current applied through the
paired sensor electrodes does not interfere with local tissue or
patient comfort and after ten to thirty seconds a reading of
moisture level is obtained, based on the value of electrical
impedance across the sensor electrodes. As ions and other charged
molecules move in the wound exudate under the influence of electric
current, it is possible to relate electrical impedance readings to
five useful clinical bands of moisture level at the wound
interface. Dry environments do not allow charges to move around and
cause high electrical impedance readings, wet environments lead to
easy charge movement and low impedance readings. The desired
"moist" condition is a range of impedance located between the high
and low values.
[0095] The five moisture bands discernable from the sensor readings
are:
[0096] Dry: electrically high impedance
[0097] Dry to moist: impedance falling from high levels to
mid-range
[0098] Moist: mid-range impedance
[0099] Moist to wet: impedance tending to low
[0100] Wet: low impedance.
[0101] The device may include a controller in communication with
the moisture sensor to determine the moisture band reading and to
use that reading to signal the device to adjust pumping action of
the device. For example, a "wet" reading should trigger increased
moisture removal by the device. A "moist to wet" reading might not
trigger activation of the device and result in reduced pumping
activity by the device. See, e.g., McColl et al., Wounds UK, 5:
94-99, 2009, which is incorporated herein by reference.
Device for Wound Treatment, Wound Healing, and Exudate
Management
[0102] The device may measure the rate of exudate fluid
accumulation in a reservoir attached to the device. The moisture
levels in the wound are recorded by the controller and analyzed by
the control circuitry to use that reading to signal the device to
adjust pumping action of the device. Methods may be utilized to
evaluate wound healing based on exudate fluids and wound moisture
level. Wound exudate must be effectively managed if the optimal
moist environment necessary for wound healing is to be created, and
the surrounding skin protected from the risks of maceration. The
production of wound exudate occurs as a result of vasodilation
during the early inflammatory stage of healing under the influence
of inflammatory mediators such as histamine and bradykinin. It
presents as serous fluid in the wound bed and is part of normal
wound healing in acute wounds. However, when the wound becomes
chronic and non-healing with persistent, abnormal inflammation or
when infection becomes established, exudate takes on a different
guise and generates clinical challenges. In the chronic wound,
exudate contains proteolytic enzymes and other components not seen
in acute wounds. This type of exudate has justifiably been termed a
wounding agent in its own right because it has the capacity to
degrade growth factors and peri-wound skin and predispose to
inflammation. In order to develop an effective management approach,
the clinician must be able to accurately assess and understand the
implications of the composition and quantity of exudate present in
the wound.
[0103] Exudate Composition.
[0104] Wound exudate is derived from serum through the
inflammatory/extravasation process. Acute wound exudate contains
molecules and cells that are vital to support the healing process.
It has a high protein content (although lower than that found in
serum), with a specific gravity greater than 1.020. Its composition
includes electrolytes, glucose, cytokines, leukocytes,
metalloproteinases, macrophages and micro-organisms. In the first
48 to 72 hours after wounding, platelets and fibrin may be present,
but this reduces as bleeding diminishes.
TABLE-US-00001 TABLE 1 Some constituents of exudate and their
functions. Component/Function Fibrin/Clotting. Platelets/Clotting.
Polymorphonuclearcytes (PMNs)/Immune defense, production of growth
factors. Lymphocytes/Immune defense. Macrophages/Immune defense,
production of growth factors. Micro-organisms/Exogenous factor.
Plasma proteins, albumin, globulin, fibrinogen/Maintain osmotic
pressure, immunity, transport of macromolecules. Lactic
acid/Product of cellular metabolism and indicates biochemical
hypoxia. Glucose Cellular energy source. Inorganic salts/Buffering,
pH hydrogen ion concentration in a solution. Growth
factors/Proteins controlling factor-specific healing activities.
Wound debris/dead cells No function. Proteolytic enzymes/Enzymes
that degrade protein, including serine, cysteine, aspartic
proteases and matrix metalloproteinases (MMPs) Tissue inhibitors of
metalloproteinases (TIMPS)/Controlled inhibition of
metalloproteinases.
[0105] As fluid passes through the inflamed vessel walls
(extravasation), the wound exudate consists of modified serum and
will therefore contain similar solutes. As it arrives at the wound
surface, this fluid may be contaminated with tissue debris and
microorganisms. Healing acute wounds produce exudate containing
active growth factors. These are not present in chronic wounds.
[0106] See, e.g., White and Cutting, Modern exudate management: a
review of wound treatments, 2006, which is incorporated herein by
reference.
Device Including Electrostrictive Actuators to Control Pore
Diameter within the Multilayer Membrane
[0107] The device may include a supporting frame that supports the
multilayer membrane. A supporting base may be connected to a strut
assembly. The strut assembly may be connected to additional
structure within the overall structural system. The supporting
base/strut assembly structure is indicative of usual support and
overall system interface for membrane structures. A controller may
activate actuators affixed to supporting base adjacent to the
supporting base periphery to initiate fluid flow through the
multilayer membrane. Upon initiation of fluid flow, actuators bend
upon electrical activation. Electrostrictive actuators may be used
having high mechanical modulus and strain combination. In some
embodiments an actuator may be incorporated into a polymer-polymer
actuator bed. See, e.g., U.S. Pat. No. 6,724,130; U.S. Pat. No.
6,545,391; and U.S. Pat. No. 7,015,624, which are incorporated
herein by reference.
Device Having a Multilayer Membrane and Including a Pressure
Sensor
[0108] The device including a multilayer membrane may include a
pressure sensor to monitor intracranial pressure, e.g., resulting
from flow of cerebral spinal fluid, wherein the pressure sensor may
signal to control circuitry on the device. For example, a passive
resonant sensor may be used to monitor intracranial pressure and to
wirelessly signal to control circuitry. A wireless, real-time
pressure monitoring system with passive, flexible, millimeter-scale
sensors may be scaled down to dimensions of 1.times.1.times.0.1
cubic millimeters. This level of dimensional scaling is enabled by
sensor design and detection schemes, which overcome the operating
frequency limits of traditional strategies and exhibit
insensitivity to lossy tissue environments. The system may be used
to capture human pulse waveforms wirelessly in real time as well as
to monitor in vivo intracranial pressure continuously using sensors
down to 2.5.times.2.5.times.0.1 cubic millimeters. Printable
wireless sensor arrays may be used in real-time spatial pressure
mapping.
[0109] Passive Resonant Sensors.
[0110] A pressure-sensitive capacitive element sensor may be
integrated with an inductive antenna to form a resonant circuit,
which has a unique resonant frequency under zero pressure. To
achieve size scalability, a distributed resonant tank may be
created by stacking a deformable dielectric layer between the two
inductive spirals in a sandwich structure. Under applied pressure,
the separation distance between the spiral layers is reduced,
increasing the effective coupling capacitance and shifting the
resonant frequency down to lower frequencies. The spiral layers are
printed or lithographically patterned on flexible polyimide
substrates, while the pressure sensitive dielectric layer is
implemented with a microstructured styrene-butadiene-styrene (SBS)
elastomer. The microstructured elastomer dielectric sensor has been
shown to be more sensitive than its unstructured counterpart. The
improved sensitivity is due to reduced viscoelastic behavior of
thin films and the change in effective permittivity of the region
between the plates under compression, in addition to the change in
separation distance. The pyramidal elastomer microstructures deform
to fill in the air gaps between them with applied pressure, thus
increasing the effective permittivity. This sandwich form enables a
simple low-cost method of wax printing process by eliminating the
need for vias to connect discrete inductive and capacitive
structures in parallel. SBS elastomer may be used instead of other
commonly known elastomers, such as poly(dimethyl siloxane) (PDMS)
or polyurethane, due its low loss in the high frequency range.
However, one drawback when using SBS is the drift in capacitance
values during cycling measurements.
[0111] Wireless real-time monitoring may be demonstrated in the
device having a multilayer membrane with a system of passive,
flexible millimeter-scale sensors as small as 1.times.1.times.0.1
mm.sup.3. The sensor devices are more than an order of magnitude
smaller in volume than recent research devices for pressure
sensing, e.g., intraocular pressure or intracranial pressure (ICP),
and more than two orders smaller than commercial solutions. The
level of scaling may be achieved by leveraging the presented GDD
detection scheme, which overcomes the operating frequency limits of
traditional strategies and exhibits insensitivity to lossy tissue
environments. This system may be used to capture human pulse
waveforms in real time as well as to continuously monitor in vivo
ICPs with sensors down to 2.5.times.2.5.times.0.1 mm.sup.3.
Furthermore, printable wireless sensor arrays may be used in
concurrent spatial pressure mapping. The pressure sensor design
allows ultra-thin and ultra-small flexible sensors, as well as a
readout scheme.
[0112] The sensor design and detection scheme allow for a highly
size-scalable system of pressure sensors with a wireless detection
platform. Systematic design and tuning of these sensors by
inductive spiral length may be determined with an analytical model,
which is shown to agree with simulated and measured results. The
greatest deviation between analytical calculations, electromagnetic
simulations and measured resonant frequencies is observed with the
smallest sensor. This is probably due to an overestimation of
inductances at high spiral fill ratio by analytical models.
Effective spiral length is desirable for improved mutual coupling
to the readout antenna in the near field. This relationship is
analogous to that of the number of inductor turns to mutual
inductance in a transformer. However, the benefit of increasing
effective spiral length is diminishing as thinner and more tightly
spaced spirals are fit into a given area because parasitic
resistances and capacitances become considerable. The 0.1 mm.sup.3
device is designed with five turns, which is the maximum achievable
in a 1-mm.sup.2 area with a minimum feature size and pitch of 25
mm. The square design is later modified to remove edges and create
a more rounded form factor for comfort and ease of implantation in
human pulse waveform and in vivo mouse ICP studies.
[0113] The sensor system may operate with 44 mm.sup.2 sensors over
a distance of 15 mm in air from the readout antenna, while the
smallest 11 mm.sup.2 sensors operate over about 3 mm. The use of a
microstructured elastomer as the dielectric layer enhances pressure
sensitivity in the low pressure range due to an increase in
effective permittivity on top of the reduction in separation
distance between the spiral layers under compression. The 5-turn 11
mm.sup.2 design with 50 mm metal traces and spacing outperforms the
most sensitive passive wireless pressure. At pressures above 100 mm
Hg, the microstructures are fully deformed and, hence, only the
separation distance reductions act to increase the variable
capacitance under applied pressure, resulting in a lower
sensitivity. High Pearson correlation coefficient of 0.99 for the
relationship between applied pressure and measured sensor resonant
frequency indicates excellent linearity within the 0-100 mm Hg
range. This is sufficient for the purposes of critical care and
health monitoring, as physiological pressures fall within this
range.
[0114] A further embodiment of active wireless sensing includes a
battery-powered intraocular pressure monitor that is able to
integrate into 1 cubic millimeter volume. The compact form has been
achieved by vertically assembling two IC chips, a solar cell,
battery and microelectromechanical system capacitive sensor. The
wireless sensor has been shown to capture pressures every 15 min
with a pressure resolution of 0.5 mmHg in bench top testing,
through 5 mm of saline. The device memory can store pressure
measurements up to 3 days before requiring an external wireless
download. The device battery has a 28-day lifetime without
recharging by the integrated solar cell.
[0115] Flexible sensor arrays perform additional application of
wireless spatial pressure mapping for intracranial pressure. ICP
mapping may be useful in assessing local pressure buildups.
Moreover, multiple pressure sensors would allow flow rates to be
determined from measured pressure differentials. Determining flow
rate is important for cerebrospinal fluid shunt applications in
patients with hydrocephalus. The flow rate can be used in a
feedback loop to control the shunt valve opening and closing. Each
22 mm.sup.2 pressure sensor in the prototype planar array is tuned
with our analytical models to possess an individually addressable
resonant frequency band spaced 350 MHz apart. For a typical
pressure sensor with 1 MHz per mm Hg sensitivity, each sensor only
needs to occupy a bandwidth of 100 MHz to cover the physiological
pressure range of 0-100 mm Hg. This allows all sensors to be
concurrently monitored with a single readout antenna. Unique
resonant peaks corresponding to individual sensors in the array can
be best distinguished in the GDD spectrum. Resonant peaks in the
GDD spectrum are sharper than in the PRD spectrum for a sensor of
the same quality factor, resulting in less overlap between
frequency adjacent sensors. Non-uniform spacing of resonant
frequencies and inconsistent pressure sensitivity of the fabricated
sensor array can be primarily attributed to process variation. See,
e.g., Chen et al., Nature Communications, 5: 5028, 2014; DOI:
10.1038/ncomms6028, which is incorporated herein by reference.
Optimizing Dialysate Flow Rate Through the Device Including a
Multilayer Membrane
[0116] The device including a multilayer membrane may have a
diffusive clearance dependent upon blood and dialysate flow rates
and the overall mass transfer area coefficient (K.sub.oA) of the
dialyzer. Although K.sub.oA should be constant for a given
dialyzer, urea K.sub.oA has been reported to vary with dialysate
flow rate possibly because of improvements in flow distribution.
One may determine the dependence of K.sub.oA for urea, phosphate
and .beta.2-microglobulin on dialysate flow rate in dialyzers
containing undulating fibers to promote flow distribution and two
different fiber packing densities.
[0117] Clearances of urea and phosphate, but not
.beta.2-microglobulin, increased significantly with increasing
dialysate flow rate. However, increasing dialysate flow rate had no
significant effect on K.sub.oA or K.sub.o for any of the three
solutes examined, although K.sub.o for urea and phosphate increased
significantly as the average flow velocity in the dialysate
compartment increased.
[0118] For dialyzers with features that promote good dialysate flow
distribution, increasing dialysate flow rate beyond 600 mL/min at a
blood flow rate of 400 mL/min is likely to have only a modest
impact on dialyzer performance, limited to the theoretical increase
predicted for a constant K.sub.oA. See, e.g., Bhimani et al.,
Nephrol Dial Transplant 25: 3990-3995, 2010, which is incorporated
herein by reference.
Device Including a Biosensor to Monitor Urea Levels in a Tissue of
the Subject
[0119] The device including a multilayer membrane may include a
biosensor to monitor urea levels in a tissue of the subject. The
amperometric biosensor for urea determination measures a
decomposition product of urea produced by urease which is an
electrochemically oxidized. The carbon black (CB) paste electrode
is covered by a semipermeable membrane containing immobilized
urease. The urea biosensor action is based upon a cation-radical of
the carbamic acid that undergoes dimerization to hydrazine. In
addition, higher potential (>0.6 V), electro-oxidation of
ammonia and amination of the electrode surface are observed. The
working potential of 0.35 V may be selected for optimal urease-CB
electrode operation, and the response properties of the electrode
may be characterized. The biosensor possesses a linear range of
response up to 5 mM of urea, a coefficient of variation equaling
3.7%, and a response time of 1.5 min. See, e.g., Laurinavicius, et
al., IEEE Sensors Journal, 13: 2208-2213, 2013, which is
incorporated herein by reference.
Device Including a Biosensor to Monitor Creatinine Levels in a
Tissue of the Subject
[0120] The device including a multilayer membrane may include a
highly sensitive and stable conductometric biosensor for creatinine
determination. Creatinine can be used for the diagnosis of renal,
thyroid and muscle function. The biosensor is based on solid-state
contact ammonium-sensitive sensor. Creatininase is chemically
immobilized on the surface of the solid-state contact
ammonium-sensitive membrane via glutaraldehyde covalent attachment
method. The conductometric creatinine biosensors demonstrate high
sensitivity and short response time toward creatinine. The
detection limit of the biosensor was about 2.times.10.sup.-6M and
the response time was shorter than 10 seconds in phophate buffer
solution at pH 7.20. The linear dynamic range of the biosensor was
between 1.times.10.sup.-1 and 9.times.10.sup.-6M creatinine
concentration in phosphate buffer solution at pH 7.2. The biosensor
exhibited good operational and storage stability for at least 4
weeks kept in dry at 4-6.degree. C. It had a reproducible and
stable response during continuous work at least for 10 h with the
relative standard deviation of 0.5% (n=48) for creatinine of
1.times.10.sup.-3M in phosphate buffer solution.
[0121] Creatinine is the end product of creatinine metabolism in
mammalian cells. Therefore, it is an important diagnostic substance
in biological fluid. Creatinine can be used for the diagnosis of
renal, thyroid and muscle function. The creatinine level in blood
serum and urine is clinically used as a parameter of muscle damage.
The physiological concentration of creatinine ranges between 40 and
150 .mu.mol/L in serum, but pathological values due to muscle
disorder or kidney dysfunction may rise to concentration higher
than 1000 .mu.mol/L.
[0122] For routine creatinine determinations in clinical
laboratory, the most frequently used methods are the HPLC and
spectrophotometric one based on the Jaffe reaction. Several
enzymatic methods have been reported to increase specificity. For
this reason, the methods based on a combination of enzyme with
specific sensor, such as ion-selective electrodes or other probes
have been shown to be rapid, simple and promising for reduction of
time and cost for the creatinine analysis. Various potentiometric
and amperometric enzyme electrodes for creatinine determination
have been reported. In these studies, a creatinine biosensor in a
flow injection analysis system, and the application of a creatinine
sensitive ion-selective field-effect transistor (ISFET) were
described.
[0123] A device including conductometric sensors for biosensing
devices consists of a planar glass support with interdigitated gold
electrode pairs on one surface in a planar configuration. The
operation of the biosensor device is based on measurement of the
bulk conductance of the sensitive membrane due to biochemical
reaction in solution. Conductometric sensor transducers are
considerably beneficial since construction in a single way, high
compatibility, rugged and relatively inexpensive, and no need of
any reference electrode. Conductometric biosensors have also been
described in the detection of glucose, urea, uric acid, sucrose,
and trypsin.
[0124] An alternative conductometric creatinine biosensor may be
based on solid-state contact ammonium-sensitive sensor chip
membrane. The main analytical characteristics of the biosensor,
such as pH behavior, time of immobilization and the enzyme loading
have been investigated with respect to the influence on
sensitivity, limit of detection, dynamic range, response time,
operation and storage stability. See, e.g., Isildak et al.,
Biochemical Engineering Journal 62: 34-38, 2012, which is
incorporated herein by reference.
Prophetic Example 1
Device Including a Multilayer Membrane to Control Wound
Drainage
[0125] A device to control the transport and disposal of fluids
from surgical wounds, and chronic wounds (e.g., diabetic, bedsores,
etc.) includes a multilayer membrane, a membrane cleaner, a
moisture sensor, a controller, a peristaltic pump, an ultraviolet
sterilization light and a filtrate receptacle. In this example the
device is applied to the leg wound of a diabetic patient to control
the moisture level of the wound and to avoid microbial infection.
The device is attached externally to cover the wound, maintain
sterility and control moisture by removing wound exudate fluids.
The controller activates the pump and the multilayer membrane to
remove exudate fluids in response to signals from the moisture
sensor.
[0126] A device including a multilayer membrane to control wound
drainage is shown in FIG. 1. A semi-rigid plastic cover encompasses
the multilayer membrane and forms a manifold connecting the
membrane compartments with the peristaltic pump and a fluid waste
reservoir. A multilayer membrane with three membrane layers
comprised of electroactive polymers covers the wound and is sealed
on its periphery by a sealant which prevents leakage of air or
fluids into or out of the wound site. The sealant is a
polymerizable adhesive composition (see e.g., U.S. Patent Appl.
2008/0243082 by Goodman published Oct. 2, 2008 which is
incorporated herein by reference). A device including a multilayer
membrane with three layers is made from electroactive polymers
which are responsive to the controller. For example, an
electroactive membrane may be constructed by electrochemically
depositing polypyrrole-para-toluenesulfonate onto a PVDF substrate
to create a membrane that selectively transports cations when a
pulsed, square wave potential is applied to the membrane (see e.g.,
Price et al., Synthetic Metals 102: 1338-1341, 1999 which is
incorporated herein by reference). Electroactive membranes with
pores of preselected sizes in predetermined locations may be
created with an etching process using ion beam technology (see
e.g., U.S. Pat. No. 7,632,406 issued to Wilson et al. on Dec. 15,
2009 which is incorporated herein by reference). For example,
polycarbonate membranes coated in gold, containing pores
approximately 0.1 .mu.m in diameter may be constructed with the
pores aligned on adjacent membrane layers (see FIG. 2). Device
circuitry including a battery is used to draw an electrical
potential across each membrane layer (See FIG. 2). Electronic
activation of the membranes controls the passage of fluid through
the membranes. For example, membranes comprised of electroactive
polymers can act as valves with pores approximately 0.1-5.0 .mu.m
in diameter that open or close depending on the oxidation state of
the polymers (see e.g., U.S. Patent Pub. No. 2006/0138371 by Gamier
published on Jun. 29, 2006 which is incorporated herein by
reference). Each membrane layer is activated or deactivated in
sequence to control the flow of fluid (e.g., wound exudate) through
the membranes. For example, sequential opening and closing of
membrane pores to prevent backflow of wound exudate and wound
infections may be as follows (See FIG. 3):
[0127] 1) membrane 1 is open; membrane 2 is closed; membrane 3 is
closed;
[0128] 2) membrane 1 is closed; membrane 2 is open; membrane 3 is
closed;
[0129] 3) membrane 1 is closed; membrane 2 is closed; membrane 3 is
open;
In concert with opening and closing of the membranes a pump may be
activated to actively draw wound exudate fluids through the
membranes and into a collection reservoir.
[0130] A peristaltic pump is connected to the compartments adjacent
to each membrane layer (see FIG. 1). Multiphase peristaltic pumps
are described (see e.g., Jeong et al., Sensors and Actuators A
123-124: 453-458, 2005 and Shkolnikov et al., Sensors and Actuators
A 160: 141-146, 2010 which are incorporated herein by reference).
Fluid flow through the multilayer membranes may be passive or
active (i.e., peristaltic pumping). Active pumping from each
membrane compartment is coordinated by the controller to coincide
with opening and closing of the membrane pores as described above
(see FIG. 3). The controller receives signals from a moisture
sensor located in the wound site, and when excessive fluid
accumulates the controller responds by initiating fluid transport
through the multilayer membrane. A flexible sterile moisture sensor
is incorporated in the device including a multilayer membrane to
detect the level of exudate in the wound and to signal the
controller. See e.g., McColl et al., Wounds UK 5: 94-99, 2009 which
is incorporated herein by reference. Fluids are transported through
the multilayer membrane and collected in a reservoir (see FIG. 1).
The rate of exudate fluid accumulation in the reservoir and the
moisture level in the wound are recorded by the controller and
analyzed by the device circuitry. Methods to evaluate wound healing
based on exudate fluids and wound moisture level are described. See
e.g., White and Cutting, Modern Exudate Management: A Review of
Wound Treatments, 2006; available online at:
http://www.worldwidewounds.com/2006/september/White/Modern-Exudate-Mgt.ht-
ml and McColl et al., Ibid. which are incorporated herein by
reference.
[0131] The device including a multilayer membrane includes an
ultraviolet (UV) light source to sterilize the multilayer membrane.
For example, light emitting diodes (LED) that emit UV-C wavelength
light are used for disinfection. An LED that emits approximately
254 nm wavelength light is available from Crystal IS, Inc., Green
Island, N.Y. (e.g., see the Crystal IS-Technical Sheet which is
incorporated herein by reference). Periodic exposure of the
multilayer membranes to approximately 2000 to 8000 microwatt
seconds per square centimeter of 254 nm light kills 90% of bacteria
and viruses.
Prophetic Example 2
Device Including a Multilayer Membrane to Control Drainage of
Cerebral Spinal Fluid
[0132] A device including a multilayer membrane is used to control
the flow of cerebral spinal fluid (CSF) in a patient with
hydrocephalus. A cerebral shunt composed of a ventricular catheter,
a distal catheter and the device including a multilayer membrane
with a pressure sensor is implanted to control intracranial
pressure in the patient. See FIG. 4. The flow of CSF fluid from the
lateral ventricle of the brain to the peritoneal cavity is
controlled by the multilayer membrane in the device which monitors
intracranial pressure and responsively adjusts the fluid flow
rate.
[0133] A device including a multilayer membrane is constructed with
multilayer membranes, a pressure sensor and circuitry to control
the flow of CSF in a ventricular-peritoneal shunt. The device
including a multilayer membrane contains a three layer membrane
with moveable membrane layers to control the flow of CSF. Membranes
with pores of preselected sizes in predetermined locations may be
created with an etching process using ion beam technology (see
e.g., U.S. Pat. No. 7,632,406 issued to Wilson et al. on Dec. 15,
2009 which is incorporated herein by reference). For example,
polycarbonate membranes, containing pores approximately 5.0 .mu.m
in diameter may be aligned to allow fluid to flow (see FIG. 5A) and
misaligned to decrease fluid flow (see FIG. 5B). Membranes with
pores approximately 0.1-5.0 .mu.m in diameter which control fluid
flow are described (see e.g., U.S. Patent Pub. No. 2006/0138371 by
Gamier published on Jun. 29, 2006 which is incorporated herein by
reference). The multilayer membranes may include different sized
pores which can be selectively aligned to control fluid flow. For
example, lateral movement of the membranes can align membrane pores
that are 5.0 .mu.m in diameter and misalign 0.1 .mu.m pores to
increase flow through the membrane (see FIG. 5C). Movement of the
membrane layers is accomplished by piezo linear actuators. Piezo
linear actuators with a maximum displacement of 2.2 .mu.m and
resolution to less than 1.0 nm are available from PI Ceramic GmbH,
Lederhose, Germany (see e.g., Piezo Technical Sheet from PI
Ceramics). Moreover, systems for membrane position control have
been described (see e.g., U.S. Pat. No. 6,724,130 issued to Su et
al. on Apr. 20, 2004 which is incorporated herein by
reference).
[0134] A pressure sensor on the device including a multilayer
membrane monitors intracranial pressure and signals to control
circuitry on the device. For example, a passive resonant sensor to
monitor intracranial pressure and signal wirelessly to control
circuitry is described (see e.g., Chen et al., Nature
Communications 5: 5028, 2014; DOI: 10.1038/ncomms6028 which is
incorporated herein by reference). Control circuitry on the device
including a multilayer membrane analyzes intracranial pressure
readings and responds by moving multilayer membranes laterally to
align or misalign different membrane pores (see FIG. 5C). Alignment
of membrane pores may increase or decrease the flow rate of CSF
through the cerebral shunt and decrease or increase intracranial
pressure. Pressures ranging from 0-100 mm Hg are detected by the
sensor and analyzed by the device controller. For example, if
abnormally high intracranial pressure, e.g., approximately 30 mm
Hg, is detected by the pressure sensor the control circuitry will
move the membranes to align large pores (e.g. 5 .mu.m pores) and
relieve the pressure by allowing increased flow of CSF out of the
lateral ventricle and into the peritoneal cavity. When normal
intracranial pressure (e.g., approximately 7-15 mm Hg) is restored
the controller may move the membranes to align smaller pores and
reduce the flow rate of CSF from the brain to the peritoneal
cavity. Continuous monitoring of intracranial pressure and
adjustment of CSF flow rate is automated by programming the device
including a multilayer membrane. The device may be implanted for
days, weeks or longer to control intracranial pressure. The device
is periodically sterilized by UV irradiation to prevent infection
of the membranes, catheters and pressure sensor.
[0135] The device including a multilayer membrane includes an
ultraviolet (UV) light source to sterilize the multilayer membranes
and catheters. For example, light emitting diodes (LEDs) that emit
UV-C wavelength light are used for disinfection. An LED that emits
approximately 254 nm wavelength light is available from Crystal IS,
Inc., Green Island, N.Y. (e.g., see the Crystal IS-Technical Sheet
which is incorporated herein by reference). Periodic exposure of
the multilayer membranes and attached catheters to approximately
2000 to 8000 microwatt seconds per square centimeter of 254 nm
light kills 90% of bacteria and viruses. Irradiation down the lumen
of catheters and on the faces of the multilayer membrane on a
weekly schedule may prevent infection by microbes.
Prophetic Example 3
Device Including a Multilayer Membrane for Hemodialysis
[0136] A device including a multilayer membrane is used to remove
waste products and excess water from the blood of a patient with
kidney failure. A hemodialysis multilayer membrane device has
multiple membrane layers composed of electroactive polymers which
control metabolite diffusion and free water flow from the blood to
the dialysate fluid. The device including a multilayer membrane
contains sensors to detect the level of toxic metabolites in the
blood of the patient, and control circuitry in the device responds
to signals from the sensors by activating and deactivating the
multilayer membranes in sequence. The device including a multilayer
membrane has a sterilization unit to allow repeated hemodialysis
with the same device.
[0137] A device including a multilayer membrane for hemodialysis is
constructed with multilayer membranes that are responsive to
electrical signals from the control circuitry of the device. A
multilayer membrane with three membrane layers comprised of
electroactive polymers is constructed with pores that allow passage
of metabolites (e.g., urea, creatinine, phosphate and potassium
ions), small proteins (e.g., .beta..sub.2-microglobulin,
cystostatin C, and myoglobin) and free water from the blood into a
buffer solution (e.g., bicarbonate buffer). A multilayer membrane
with a surface area of approximately 1.0 square meter is contacted
on one side by arterial blood and on the opposite side by a
dialysis solution (e.g., a sodium bicarbonate buffer solution which
contains sodium and chloride at concentrations equivalent to those
in normal plasma, and a normal blood pH (e.g., approximately pH
7.4). Counter-current flow, with blood flowing one direction on one
side of the membrane and dialysis buffer flowing the opposite
direction on the other side of the membrane promotes dialysis of
the blood. A multilayer membrane with three layers is made from
electroactive polymers which are responsive to the controller. For
example, an electroactive membrane may be constructed by
electrochemically depositing polypyrrole-para-toluenesulfonate onto
a PVDF substrate to create a membrane that selectively transports
cations when a pulsed, square wave potential is applied to the
membrane (see e.g., Price et al., Synthetic Metals 102: 1338-1341,
1999 which is incorporated herein by reference). Electroactive
membranes with pores of preselected sizes may be created with an
etching process using ion beam technology (see e.g., U.S. Pat. No.
7,632,406 issued to Wilson et al. on Dec. 15, 2009 which is
incorporated herein by reference). For example, polycarbonate
membranes coated in gold, containing pores approximately 0.1 .mu.m
in diameter may be constructed with the pores aligned on adjacent
membrane layers (see FIG. 2). Device circuitry including a battery
is used to draw an electrical potential across each membrane layer
(See FIG. 2). Electronic activation of the membranes controls the
passage of fluid and metabolites through the membranes. For
example, membranes comprised of electroactive polymers can act as
valves with pores approximately 0.1-5.0 .mu.m in diameter that open
or close depending on the oxidation state of the polymers (see
e.g., U.S. Patent Pub. No. 2006/0138371 by Gamier published on Jun.
29, 2006 which is incorporated herein by reference). Each membrane
layer is activated or deactivated in sequence to control the flow
of fluid (e.g., H.sub.20) through the membranes and to facilitate
diffusion. For example, sequential opening and closing of membrane
pores to promote diffusion and to prevent backflow of metabolites,
toxins and water may be as follows (See FIG. 3):
[0138] 1) membrane 1 is open; membrane 2 is closed; membrane 3 is
closed;
[0139] 2) membrane 1 is closed; membrane 2 is open; membrane 3 is
closed;
[0140] 3) membrane 1 is closed; membrane 2 is closed; membrane 3 is
open;
[0141] Opening and closing of the membranes occurs as pumps
continuously draw blood and dialysate past the multilayer
membranes. For example the arterial blood flow rate may be
approximately 400 mL/minute and the dialysate flow rate may be
approximately 600 mL/minute to achieve optimal clearance of urea
and phosphate from the blood (see e.g., Bhimani et al., Nephrol.
Dial. Transplant 25: 3990-3995, 2010 which is incorporated herein
by reference).
[0142] To monitor hemodialysis, sensors measure metabolites in the
patient's blood and report the data to control circuitry on the
device. For example an amperometric biosensor for urea samples the
arterial blood entering the device including a multilayer membrane
and reports the concentration of urea before, during and after
hemodialysis. An amperometric biosensor for urea is described (see
e.g., Laurinavicius et al., IEEE Sensors Journal 13: 2208-2213,
2013 which is incorporated herein by reference). Flow-through
conductivity sensors monitor the ionic strength (e.g., Na+, K+,
Cl--, HPO4-concentrations) of the dialysis fluid and the arterial
blood entering the device including a multilayer membrane.
Conductivity sensors that report to control microcircuitry are
available from GE Healthcare Bio-Sciences AB, Uppsala, Sweden (see
e.g., GE Conductivity Sensor Spec available online at:
http://www.gelifesciences.com corn which is incorporated herein by
reference). Also a creatinine biosensor is incorporated to monitor
creatinine concentrations in the blood and dialysate. A
conductometric creatinine biosensor which signals to microcircuitry
is described (see e.g., Isildak et al., Biochemical Engineering
Journal 62: 34-38, 2012 which is incorporated herein by reference).
Metabolite concentration data and conductivity data are analyzed by
microcircuitry in the device including a multilayer membrane which
responds by opening or closing membrane pores and coordinated
pumping of blood and dialysis fluid. The device including a
multilayer membrane may also signal the patient or caregiver when
dialysis is complete, for example, when urea and creatinine levels
are within the normal range.
[0143] Each recited range includes all combinations and
sub-combinations of ranges, as well as specific numerals contained
therein.
[0144] All publications and patent applications cited in this
specification are herein incorporated by reference to the extent
not inconsistent with the description herein and for all purposes
as if each individual publication or patent application were
specifically and individually indicated to be incorporated by
reference for all purposes.
[0145] Those having ordinary skill in the art will recognize that
the state of the art has progressed to the point where there is
little distinction left between hardware and software
implementations of aspects of systems; the use of hardware or
software is generally (but not always, in that in certain contexts
the choice between hardware and software can become significant) a
design choice representing cost vs. efficiency tradeoffs. Those
having ordinary skill in the art will recognize that there are
various vehicles by which processes and/or systems and/or other
technologies disclosed herein can be effected (e.g., hardware,
software, and/or firmware), and that the preferred vehicle will
vary with the context in which the processes and/or systems and/or
other technologies are deployed. For example, if a surgeon
determines that speed and accuracy are paramount, the surgeon may
opt for a mainly hardware and/or firmware vehicle; alternatively,
if flexibility is paramount, the implementer may opt for a mainly
software implementation; or, yet again alternatively, the
implementer may opt for some combination of hardware, software,
and/or firmware. Hence, there are several possible vehicles by
which the processes and/or devices and/or other technologies
disclosed herein may be effected, none of which is inherently
superior to the other in that any vehicle to be utilized is a
choice dependent upon the context in which the vehicle will be
deployed and the specific concerns (e.g., speed, flexibility, or
predictability) of the implementer, any of which may vary. Those
having ordinary skill in the art will recognize that optical
aspects of implementations will typically employ optically-oriented
hardware, software, and or firmware.
[0146] In a general sense the various aspects disclosed herein
which can be implemented, individually and/or collectively, by a
wide range of hardware, software, firmware, or any combination
thereof can be viewed as being composed of various types of
"electrical circuitry." Consequently, as used herein "electrical
circuitry" includes, but is not limited to, electrical circuitry
having at least one discrete electrical circuit, electrical
circuitry having at least one integrated circuit, electrical
circuitry having at least one application specific integrated
circuit, electrical circuitry forming a general purpose computing
device configured by a computer program (e.g., a general purpose
computer configured by a computer program which at least partially
carries out processes and/or devices disclosed herein, or a
microdigital processing unit configured by a computer program which
at least partially carries out processes and/or devices disclosed
herein), electrical circuitry forming a memory device (e.g., forms
of random access memory), and/or electrical circuitry forming a
communications device (e.g., a modem, communications switch, or
optical-electrical equipment). The subject matter disclosed herein
may be implemented in an analog or digital fashion or some
combination thereof.
[0147] At least a portion of the devices and/or processes described
herein can be integrated into a data processing system. A data
processing system generally includes one or more of a system unit
housing, a video display device, memory such as volatile or
non-volatile memory, processors such as microprocessors or digital
signal processors, computational entities such as operating
systems, drivers, graphical user interfaces, and applications
programs, one or more interaction devices (e.g., a touch pad, a
touch screen, an antenna, etc.), and/or control systems including
feedback loops and control motors (e.g., feedback for sensing
position and/or velocity; control motors for moving and/or
adjusting components and/or quantities). A data processing system
may be implemented utilizing suitable commercially available
components, such as those typically found in data
computing/communication and/or network computing/communication
systems.
[0148] The foregoing detailed description has set forth various
embodiments of the devices and/or processes via the use of block
diagrams, flowcharts, and/or examples. Insofar as such block
diagrams, flowcharts, and/or examples contain one or more functions
and/or operations, it will be understood by those within the art
that each function and/or operation within such block diagrams,
flowcharts, or examples can be implemented, individually and/or
collectively, by a wide range of hardware, software, firmware, or
virtually any combination thereof. In one embodiment, several
portions of the subject matter described herein may be implemented
via Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs), digital signal processors (DSPs),
or other integrated formats. However, some aspects of the
embodiments disclosed herein, in whole or in part, can be
equivalently implemented in integrated circuits, as one or more
computer programs running on one or more computers (e.g., as one or
more programs running on one or more computer systems), as one or
more programs running on one or more processors (e.g., as one or
more programs running on one or more microprocessors), as firmware,
or as virtually any combination thereof, and that designing the
circuitry and/or writing the code for the software and or firmware
would be well within the skill of one of skill in the art in light
of this disclosure. In addition, the mechanisms of the subject
matter described herein are capable of being distributed as a
program product in a variety of forms, and that an illustrative
embodiment of the subject matter described herein applies
regardless of the particular type of signal bearing medium used to
actually carry out the distribution. Examples of a signal bearing
medium include, but are not limited to, the following: a recordable
type medium such as a floppy disk, a hard disk drive, a Compact
Disc (CD), a Digital Video Disk (DVD), a digital tape, a computer
memory, etc.; and a transmission type medium such as a digital
and/or an analog communication medium (e.g., a fiber optic cable, a
waveguide, a wired communications link, a wireless communication
link (e.g., transmitter, receiver, transmission logic, reception
logic, etc.), etc.).
[0149] The herein described components (e.g., steps), devices, and
objects and the description accompanying them are used as examples
for the sake of conceptual clarity and that various configuration
modifications using the disclosure provided herein are within the
skill of those in the art. Consequently, as used herein, the
specific examples set forth and the accompanying description are
intended to be representative of their more general classes. In
general, use of any specific example herein is also intended to be
representative of its class, and the non-inclusion of such specific
components (e.g., steps), devices, and objects herein should not be
taken as indicating that limitation is desired.
[0150] With respect to the use of substantially any plural or
singular terms herein, the reader can translate from the plural to
the singular or from the singular to the plural as is appropriate
to the context or application. The various singular/plural
permutations are not expressly set forth herein for sake of
clarity.
[0151] The herein described subject matter sometimes illustrates
different components contained within, or connected with, different
other components. It is to be understood that such depicted
architectures are merely examples, and that in fact many other
architectures can be implemented which achieve the same
functionality. In a conceptual sense, any arrangement of components
to achieve the same functionality is effectively "associated" such
that the desired functionality is achieved. Hence, any two
components herein combined to achieve a particular functionality
can be seen as "associated with" each other such that the desired
functionality is achieved, irrespective of architectures or
intermedial components. Likewise, any two components so associated
can also be viewed as being "operably connected," or "operably
coupled," to each other to achieve the desired functionality, and
any two components capable of being so associated can also be
viewed as being "operably couplable," to each other to achieve the
desired functionality. Specific examples of operably couplable
include but are not limited to physically mateable or physically
interacting components or wirelessly interactable or wirelessly
interacting components or logically interacting or logically
interactable components.
[0152] While particular aspects of the present subject matter
described herein have been shown and described, changes and
modifications may be made without departing from the subject matter
described herein and its broader aspects and, therefore, the
appended claims are to encompass within their scope all such
changes and modifications as are within the true spirit and scope
of the subject matter described herein. Furthermore, it is to be
understood that the invention is defined by the appended claims. It
will be understood that, in general, terms used herein, and
especially in the appended claims (e.g., bodies of the appended
claims) are generally intended as "open" terms (e.g., the term
"including" should be interpreted as "including but not limited
to," the term "having" should be interpreted as "having at least,"
the term "includes" should be interpreted as "includes but is not
limited to," etc.). It will be further understood that if a
specific number of an introduced claim recitation is intended, such
an intent will be explicitly recited in the claim, and in the
absence of such recitation no such intent is present. For example,
as an aid to understanding, the following appended claims may
contain usage of the introductory phrases "at least one" and "one
or more" to introduce claim recitations. However, the use of such
phrases should not be construed to imply that the introduction of a
claim recitation by the indefinite articles "a" or "an" limits any
particular claim containing such introduced claim recitation to
inventions containing only one such recitation, even when the same
claim includes the introductory phrases "one or more" or "at least
one" and indefinite articles such as "a" or "an"; the same holds
true for the use of definite articles used to introduce claim
recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, such recitation
should typically be interpreted to mean at least the recited number
(e.g., the bare recitation of "two recitations," without other
modifiers, typically means at least two recitations, or two or more
recitations). Furthermore, in those instances where a convention
analogous to "at least one of A, B, and C, etc." is used, in
general such a construction is intended in the sense one having
skill in the art would understand the convention (e.g., "a system
having at least one of A, B, and C" would include but not be
limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, or A, B, and C
together, etc.). In those instances where a convention analogous to
"at least one of A, B, or C, etc." is used, in general such a
construction is intended in the sense one having skill in the art
would understand the convention (e.g., "a system having at least
one of A, B, or C" would include but not be limited to systems that
have A alone, B alone, C alone, A and B together, A and C together,
B and C together, or A, B, and C together, etc.). Virtually any
disjunctive word and/or phrase presenting two or more alternative
terms, whether in the description, claims, or drawings, should be
understood to contemplate the possibilities of including one of the
terms, either of the terms, or both terms. For example, the phrase
"A or B" will be understood to include the possibilities of "A" or
"B" or "A and B."
[0153] While various aspects and embodiments have been disclosed
herein, other aspects and embodiments will be apparent to those
skilled in the art. The various aspects and embodiments disclosed
herein are for purposes of illustration and are not intended to be
limiting, with the true scope and spirit being indicated by the
following claims.
* * * * *
References