U.S. patent application number 12/913028 was filed with the patent office on 2011-04-28 for systems and methods for delivering drugs.
Invention is credited to Glenn R. Booma, Yet-Ming Chiang, Michael J. Cima, J. Richard Gyory.
Application Number | 20110098676 12/913028 |
Document ID | / |
Family ID | 40090246 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110098676 |
Kind Code |
A1 |
Chiang; Yet-Ming ; et
al. |
April 28, 2011 |
SYSTEMS AND METHODS FOR DELIVERING DRUGS
Abstract
A patch pump device generally includes at least one fluid
source, a fluid communicator, and an electrochemical actuator. The
fluid communicator is in fluid communication with the fluid source.
The electrochemical actuator is operative to cause fluid to be
delivered from the fluid source into the fluid communicator.
Inventors: |
Chiang; Yet-Ming;
(Framingham, MA) ; Cima; Michael J.; (Winchester,
MA) ; Gyory; J. Richard; (Sudbury, MA) ;
Booma; Glenn R.; (Natick, MA) |
Family ID: |
40090246 |
Appl. No.: |
12/913028 |
Filed: |
October 27, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12181085 |
Jul 28, 2008 |
7828771 |
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12913028 |
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60952217 |
Jul 26, 2007 |
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60989605 |
Nov 21, 2007 |
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Current U.S.
Class: |
604/512 ;
604/151; 604/506 |
Current CPC
Class: |
A61M 5/1723 20130101;
A61M 5/1452 20130101; A61M 2005/14252 20130101; A61M 2205/8231
20130101; A61P 25/24 20180101; A61M 2005/14513 20130101; A61M
2005/14268 20130101; A61M 2005/1726 20130101; A61P 1/16 20180101;
A61M 2005/14204 20130101; A61P 25/16 20180101; A61P 31/14 20180101;
A61P 43/00 20180101; A61M 5/148 20130101; A61M 5/14248
20130101 |
Class at
Publication: |
604/512 ;
604/151; 604/506 |
International
Class: |
A61M 5/142 20060101
A61M005/142; A61M 19/00 20060101 A61M019/00 |
Claims
1-53. (canceled)
54. A device for delivering a therapeutic to a patient comprising:
an electrochemical actuator including a negative electrode, a
positive electrode, and a species formulated to intercalate,
de-intercalate, alloy with, oxidize, reduce, or plate with a first
portion of the electrochemical actuator to an extent different than
with a second portion of the electrochemical actuator, thereby
imparting a differential strain between the first and second
portions and causing a displacement of at least a portion of the
electrochemical actuator; and an electrical circuit electrically
coupled to the electrochemical actuator so as to allow the
electrochemical actuator to discharge therethrough, the electrical
circuit including only fixed resistive elements, the electrical
circuit configured to allow the electrochemical actuator to
discharge such that the therapeutic is delivered to the patient
with linear flow.
55. The device of claim 54, further comprising: a housing being
movable between an unassembled configuration in which the
electrochemical actuator is in a deactivated state, and an
assembled configuration in which the electrochemical actuator is in
an activated state such that the electrical circuit is closed
causing the electrochemical actuator to discharge, thereby
delivering the therapeutic to the patient.
56. The device of claim 55, wherein the housing includes a first
portion and a second portion, the first portion and the second
portion configured to form a cooperative fit when the housing is in
the assembled position to activate the electrochemical
actuator.
57. The device of claim 56, wherein when the housing is in the
assembled position, the first portion of the housing and the second
portion of the housing releasably lock together.
58. The device of claim 56, wherein the first portion of the
housing includes a first electrical contact and the second portion
of the housing includes a second electrical contact, the first and
second electrical contacts are positioned to contact each other
when the housing is in the assembled position but not when the
housing is in the unassembled position.
59. The device of claim 54, wherein one of the negative electrode
and the positive electrode is a bimorph electrode.
60. The device of claim 54, wherein the first portion of the
electrochemical actuator and the second portion of the
electrochemical actuator are formed of different materials.
61. The device of claim 54, wherein one of the first portion of the
electrochemical actuator and the second portion of the
electrochemical actuator comprises a dimensionally-active
material.
62. The device of claim 54, wherein the first portion of the
electrochemical actuator is configured to allow intercalation of a
species to a different extent than to the second portion of the
electrochemical actuator, thereby imparting differential strain
between the first portion and the second portion to cause
deflection of the electrode.
63. The device of claim 54, wherein the displacement of the
electrochemical actuator is approximately proportional to a current
though the electrical circuit, and the therapeutic is delivered to
the patient at a rate approximately proportional to the
displacement rate of the electrochemical actuator.
64. A device for delivering a flowable material a patient
comprising: a delivery system including a source, a cannula, and an
electrochemical actuator including an electrode configured to
deflect as the electrochemical actuator undergoes a change in
electrical potential, the deflection of the electrode being
operative to cause the flowable material to be delivered from the
source; and a housing configured for removably associating the
delivery system with the body of the patient, the housing being
movable between an unassembled configuration in which the delivery
system is in a deactivated state, and an assembled configuration in
which a first portion forms a cooperative fit with a second portion
and activates the electrochemical actuator, thereby delivering the
flowable material from the source through the cannula.
65. The device of claim 64, wherein the cannula is in fluidically
isolated from the source in the unassembled configuration.
66. The device of claim 64, wherein the cannula is movable from a
retracted position in which the cannula is disposed inside the
housing when the housing is in the unassembled configuration and a
deployed position in which the cannula protrudes outside the
housing when the housing is in the assembled configuration.
67. The device of claim 64, further comprising: an insertion
mechanism, the insertion mechanism configured to insert the cannula
into the body of the patient when the housing is moved between an
unassembled configuration and the assembled configuration.
68. The device of claim 64, further comprising: an insertion
mechanism, the insertion mechanism including a needle slidably
disposed within the cannula, the insertion mechanism configured to
insert the cannula into the body of the patient when the housing is
moved between an unassembled configuration and the assembled
configuration.
69. The device of claim 68, wherein the insertion mechanism
includes a spring coupled to the needle to urge the needle in a
direction to insert the cannula into the body of the patient, and a
latch configured to restrain the spring in a compressed state.
70. The device of claim 64, wherein the first portion of the
housing includes a first electrical contact and the second portion
of the housing includes a second electrical contact, the first and
second electrical contacts positioned to contact each other when
the housing is in the assembled position to activate the
electrochemical actuator thereby delivering the flowable material
from the source through the cannula.
71. A method for administering a drug to a patient, the method
comprising: securing a disposable infusion pump to the patient's
skin, wherein the disposable infusion pump comprises (i) a
reservoir storing a fluid which includes at least one drug; (ii) an
electrochemical actuator including an electrode configured to
deflect as the electrochemical actuator discharges; and (iii) at
least one fluid communicator positionable to penetrate the
patient's skin; and activating the electrochemical actuator causing
the electrode to deflect, thereby delivering fluid from the
reservoir, through the fluid communicator, and into the
patient.
72. The method of claim 71, further comprising: discharging the
electrochemical actuator through an electrical circuit having only
fixed resistive elements, the discharging of the electrochemical
actuator causing the electrochemical actuator to deflect at a rate
approximately proportional to a current though the electrical
circuit, thereby delivering fluid from the reservoir, through the
fluid communicator, and into the patient at a substantially linear
flow rate.
73. The method of claim 71, wherein the drug includes at least one
of an opioid narcotic, a NonSteroidal AntiInflamatory, a local
anesthetic, a dopamine antagonist, an antihistamine, an
antileukotriene, an anticholinergic, an immunotherapeutic agent, an
antispastic, a vitamin, a selegiline and a rasagiline.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 60/952,217, filed Jul. 26, 2007. This
application also claims the benefit of U.S. Provisional Application
Ser. No. 60/989,605, filed Nov. 21, 2007. Both of these
applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention is generally in the field of medical devices,
and more particularly in the field of drug delivery devices.
[0003] Drug delivery involves delivering a drug or other
therapeutic compound into the body. Typically, the drug is
delivered via a technology that is carefully selected based on a
number of factors. These factors include but are not limited to the
characteristics of the drug, such as drug dose, pharmacokinetics,
complexity, cost, and absorption, the characteristics of the
desired drug delivery profile (such as uniform, non-uniform, or
patient-controlled), the characteristics of the administration mode
(such as the ease, cost, complexity, and effectiveness of the
administration mode for the patient, physician, nurse, or other
caregiver), or other factors or combinations of these factors.
[0004] Conventional drug delivery technologies present various
challenges. Oral administration of a dosage form is a relatively
simple delivery mode, but some drugs may not achieve the desired
bioavailability and/or may cause undesirable side effects if
administered orally. Further, the delay from time of administration
to time of efficacy associated with oral delivery may be
undesirable depending on the therapeutic need. While parenteral
administration by injection may avoid some of the problems
associated with oral administration, such as providing relatively
quick delivery of the drug to the desired location, conventional
injections may be inconvenient, difficult to self-administer, and
painful or unpleasant for the patient. Furthermore, injection may
not be suitable for achieving certain delivery/release profiles,
particularly over a sustained period of time.
[0005] Passive transdermal technology, such as a conventional
transdermal patch, may be relatively convenient for the user and
may permit relatively uniform drug release over time. However, some
drugs, such as highly charged or polar drugs, peptides, proteins
and other large molecule active agents, may not penetrate the
stratum corneum for effective delivery. Furthermore, a relatively
long start-up time may be required before the drug takes effect.
Thereafter, the drug release may be relatively continuous, which
may be undesirable in some cases. Also, a substantial portion of
the drug payload may be undeliverable and may remain in the patch
once the patch is removed.
[0006] Active transdermal systems, including iontophoresis,
sonophoresis, and poration technology, may be expensive and may
yield unpredictable results. Only some drug formulations, such as
aqueous stable compounds, are suited for active transdermal
delivery. Further, modulating or controlling the delivery of drugs
using such systems may not be possible without using complex
systems.
[0007] Infusion pump systems may be large and may require tubing
between the pump and the infusion set, impacting quality of life.
Further, infusion pumps may be expensive and may not be disposable.
From the above, it would be desirable to provide new and improved
drug delivery systems and methods that overcome some or all of
these and other drawbacks.
SUMMARY OF THE INVENTION
[0008] A patch pump device generally includes at least one fluid
source, a fluid communicator, and at least one electrochemical
actuator. The fluid communicator is in fluid communication with the
fluid source. The electrochemical actuator is operative to cause
fluid to be delivered from the fluid source into the fluid
communicator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic block diagram illustrating an
embodiment of a fluid delivery system.
[0010] FIG. 2 is a schematic view of an embodiment of an
electrochemical actuator, wherein FIG. 2(a) illustrates the
electrochemical actuator in a charged state and FIG. 2(b)
illustrates the electrochemical actuator as it discharges.
[0011] FIG. 3 is a schematic view of another embodiment of an
electrochemical actuator, wherein FIG. 3(a) illustrates the
electrochemical actuator in a charged state and FIG. 3(b)
illustrates the electrochemical actuator as it discharges.
[0012] FIG. 4 is a side cross-sectional view of an embodiment of a
pump device, wherein FIG. 4(a) illustrates the pump device in an
unassembled position; FIG. 4(b) illustrates the pump device in an
assembled position; and FIG. 4(c) illustrates the pump device
pumping fluid therefrom.
[0013] FIG. 5 illustrates another embodiment of a pump device,
wherein FIG. 5(a) is a top plan view of the pump device in an
unassembled position; FIG. 5(b) is a side cross-sectional view of
the pump device in the unassembled position; FIG. 5(c) is a top
plan view of the pump device in an assembled position; and FIG.
5(d) is a side cross-sectional view of the pump device in the
assembled position.
[0014] FIG. 6 is a side cross-sectional view of another embodiment
of a pump device, wherein FIG. 6(a) illustrates a needle insertion
mechanism being attached to a base portion of the pump device; FIG.
6(b) illustrates the needle insertion mechanism inserting a needle
and cannula through the base portion of the pump device; FIG. 6(c)
illustrates the pump device in an unassembled position; and FIG.
6(d) illustrates the pump device in an assembled position.
[0015] FIG. 7 is a side cross-sectional view of another embodiment
of a pump device, wherein FIG. 7(a) illustrates the pump device in
an unassembled position and FIG. 7(b) illustrates the pump device
in an assembled position.
[0016] FIG. 8 is a side cross-sectional view of another embodiment
of a pump device, wherein FIG. 8(a) illustrates the pump device in
an unassembled position and FIG. 8(b) illustrates the pump device
in an assembled position.
[0017] FIG. 9 is a schematic illustrating an embodiment of an
electrical circuit that may be used in an embodiment of a pump
device.
[0018] FIG. 10 is a graph illustrating one exemplary, non-limiting
embodiment of a displacement curve, indicating the displacement
behavior as a function of time for an electrochemical actuator
positioned in the electrical circuit of FIG. 9.
[0019] FIG. 11 is a graph illustrating one exemplary, non-limiting
embodiment of a fluid flow curve, indicating the fluid flow
behavior as a function of time for a fluid source associated with
the electrical circuit of FIG. 9.
[0020] FIG. 12 is a schematic illustrating an embodiment of an
electrical circuit that includes electrical contacts.
[0021] FIG. 13 is a schematic illustrating an embodiment of an
electrical circuit that includes a variable resistor.
[0022] FIG. 14 is a schematic illustrating an embodiment of an
electrical circuit that includes a switch.
[0023] FIG. 15 is a graph illustrating a displacement curve,
indicating the displacement behavior as a function of time for a
fluid source associated with the electrical circuit of FIG. 14.
[0024] FIG. 16 is a schematic view of an embodiment of a device
that includes an embodiment of a control system.
[0025] FIG. 17 is a side cross-sectional view of an embodiment of a
pump device that includes multiple fluid sources operated by
different electrochemical actuators.
[0026] FIG. 18 is a side cross-sectional view of an embodiment of a
pump device that includes multiple fluid sources operated by the
same electrochemical actuator.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Described below are embodiments of systems and methods of
delivering a fluid, which may include a drug, into a patient in
need thereof. The patient may be a human or other mammal for
example. In embodiments, the systems and methods may embody a pump
device suited for subcutaneous or intravenous delivery of a fluid,
which may or may not include one or more drugs. The pump device may
employ an electrochemical actuator, which may have characteristics
of both a battery and a pump. Specifically, the electrochemical
actuator may include an electrochemical cell that produces a
pumping force as the cell discharges. Thus, the pump device may
have relatively fewer parts than a conventional drug pump, such
that the pump device is relatively more compact, disposable, and
reliable than conventional drug pumps. These attributes of the pump
device may permit reducing the cost and the discomfort associated
with infusion drug therapy. Further, such a pump device may have a
control means, such as a controller and/or other circuitry,
operative to regulate drug or fluid flow from the pump device. Such
control means may permit implementing one or more release profiles
using the pump device, including release profiles that require
uniform flow, non-uniform flow, continuous flow, discontinuous
flow, programmed flow, scheduled flow, user-initiated flow, or
feedback responsive flow, among others. Thus, the pump device may
effectively deliver a wider variety of drug therapies than other
pump devices.
[0028] FIG. 1 is a schematic block diagram illustrating an
embodiment of a fluid delivery system 100. The fluid delivery
system 100 generally includes an electrochemical actuator 102
associated with a fluid source 104 and a fluid communicator 106.
The fluid source 104 may contain a fluid to be delivered into a
target 108 via the fluid communicator 106. The electrochemical
actuator 102 may actuate or otherwise create a pumping force to
deliver the fluid from the fluid source 104 into the fluid
communicator 106. Specifically, the electrochemical actuator 102
may be any device that experiences a change in volume or position
in response to an electrochemical reaction that occurs therein. For
example, the electrochemical actuator 102 may include a charged
electrochemical cell, and at least a portion of the electrochemical
cell may actuate as the electrochemical cell discharges. Thus, the
electrochemical actuator 102 may be considered a self-powered
actuator or a combination battery and actuator.
[0029] In use, the fluid communicator 106 may be associated with
the target 108, and the electrochemical actuator 102 may be
operated. Specifically, the electrochemical actuator 102 may
discharge and actuate. The resulting mechanical work may act on the
fluid source 104 or may be transferred through intervening
mechanics to the fluid source 104, causing the fluid to be
delivered through the fluid communicator 106 into the target
108.
[0030] In embodiments, the fluid delivery system 100 may be a
system for delivering a drug into a human body. In such
embodiments, the fluid source 104 may be a reservoir, pouch, or
bladder, or other known fluid source containing a drug in fluid
form, and the target 108 may be a human in need of a drug therapy
or prophylaxis. The fluid communicator 106 may be a needle,
catheter, cannula, infusion set, or other known delivery device
that is inserted into or otherwise associated with the human body
for drug delivery. When the electrochemical reaction is occurring
in the electrochemical actuator 102, the electrochemical actuator
102 may cause the drug to be communicated from the fluid source 104
into the human body. Such drug delivery may be subcutaneous,
intravenous, intraarterial, intramuscular, intracardiac,
intraosseous, intradermal, intrathecal, intraperitoneal,
intratumoral, epidural, and/or peri-neural depending on, for
example, the location of the fluid communicator 106 and/or the
entry location of the drug.
[0031] In embodiments, the fluid delivery system 100 may be used to
deliver a drug formulation which comprises a drug, meaning a
therapeutic or prophylactic agent including an active
pharmaceutical ingredient. In other embodiments, the fluid delivery
system 100 may deliver a fluid that does not contain a drug. For
instance, the fluid may be a saline solution or a diagnostic agent,
such as a contrast agent.
[0032] The drug may be in a pure form or formulated in a solution,
a suspension, or an emulsion, among others, using one or more
pharmaceutically acceptable excipients known in the art. For
example, a pharmaceutically acceptable vehicle for the drug may be
provided, which may be essentially any aqueous or non-aqueous
vehicle known in the art. Examples of aqueous vehicles include
physiological saline solutions, solutions of sugars such as
dextrose or mannitol, and pharmaceutically acceptable buffered
solutions, and examples of non-aqueous vehicles include fixed
vegetable oils, glycerin, polyethylene glycols, alcohols, and ethyl
oleate. The vehicle may further include antibacterial
preservatives, antioxidants, tonicity agents, buffers, stabilizers,
or other components.
[0033] Representative examples of drugs that may be delivered with
embodiments of the present device include, but are not limited to,
opioid narcotics such as fentanyl, remifentanyl, sufentanil,
morphine, hydromorphone, oxycodiene and salts thereof; NonSteroidal
Antilnflamatories (NSAIDs) such as diclofenac, naproxen, ibuprofen,
and celecoxib; local anesthetics such as lidocaine, tetracaine, and
bupivicaine; dopamine antagonists such as apomorphine, rotigotine,
and ropinerole; drugs used for the treatment and/or prevention of
allergies such as antihistamines, antileukotrienes,
anticholinergics, and immunotherapeutic agents; antispastics such
as tizanidine and baclofin; vitamins such as niacin; Selegiline;
and rasagiline. Essentially any peptide, protein, biologic, or
oligonucleotide, among others, that is normally delivered by
subcutaneous, intramuscular, or intravenous injection or other
parenteral routes, may be delivered using embodiments of the
devices described herein. In embodiments, the device may be used to
administer a drug combination of two or more different drugs using
a single or multiple delivery port and being able to deliver the
agents at a fixed ratio or by means enabling the delivery of each
agent to be independently modulated. For example, two or more drugs
can be administered simultaneously or serially, or a combination
(e.g. overlapping) thereof.
[0034] Although the fluid delivery system 100 and other systems and
methods described herein are generally described as communicating
drugs into a human body, such systems and methods may be employed
to deliver any fluid of any suitable biocompatibility or viscosity
into any object, living or inanimate. For example, the systems and
methods may be employed to deliver other biocompatible fluids into
living beings, including human beings and other animals. Further,
the systems and methods may deliver drugs or other fluids into
living beings other than human beings, such as animals and plant
life. Also, the systems and methods may deliver any fluids into any
target, living or inanimate. The systems and methods described
herein are generally systems and methods of delivering fluids using
an electrochemical actuator, including a self-powered actuator
and/or combined battery and actuator.
[0035] Embodiments of such electrochemical actuators are generally
described in U.S. patent application Ser. No. 11/150,477 entitled
"Electrochemical Methods, Devices, and Structures" by Chiang et
al., U.S. patent application Ser. No. 11/881,830 entitled
"Electrochemical Actuator" by Chiang et al., and U.S. patent
application Ser. No. 12/035,406 entitled "Electrochemical Actuator"
by Chiang et al., each of which is herein incorporated by
reference. Such electrochemical actuators may include at least one
component that responds to the application of a voltage or current
by experiencing a change in volume or position. The change in
volume or position may produce mechanical work that may act on a
fluid source or may be transferred to a fluid source, such that a
fluid can be delivered out of the fluid source.
[0036] In embodiments, the electrochemical actuator may include a
positive electrode and a negative electrode, at least one of which
is an actuating electrode. These and other components of the
electrochemical actuator may form an electrochemical cell, which
may initially be charged. The electrochemical cell may begin
discharging when a circuit between the electrodes is closed,
causing the actuating electrode to actuate. The actuating electrode
may thereby perform work upon another structure, such as the fluid
source or transfer structure associated with the fluid source. The
work may cause fluid to be pumped or otherwise dispensed from the
fluid source into the target.
[0037] More specifically, the actuating electrode may experience a
change in volume or position when the closed circuit is formed, and
this change in volume of position may perform work upon the fluid
source or transferring structure. For example, the actuating
electrode may expand, bend, buckle, fold, cup, elongate, contract,
or otherwise experience a change in volume, size, shape,
orientation, arrangement, or location, such that at least a portion
of the actuating electrode experiences a change in volume or
position. In embodiments, the change in volume or position may be
experienced by a portion of the actuating electrode, while the
actuating electrode as a whole may experience a contrary change or
no change whatsoever. It is noted that the electrochemical actuator
may actually include a number of electrochemical actuators arranged
in series, parallel, or some combination thereof. For example, a
number of such electrochemical actuators may be stacked together.
As another example, concurrent or sequenced delivery of multiple
agents may be achieved by including one or more electrochemical
actuators acting on two or more fluid sources.
[0038] FIG. 2 is a schematic of an embodiment of an electrochemical
actuator 202. As shown, the electrochemical actuator 202 may
include a positive electrode 210, a negative electrode 212, and an
electrolyte 214. These components may form an electrochemical cell
that is initially discharged and is then charged before use, or is
initially charged, as shown in FIG. 2(a). The positive electrode
210 may be configured to expand in the presence of the electrolyte
214. When a circuit between the electrodes 210, 212 is closed,
current may travel from the positive electrode 210 to the negative
electrode 212. The positive electrode 210 may experience a change
in volume, resulting in longitudinal displacement of at least a
portion of the positive electrode 210, as shown in FIG. 2(b).
Thereby, the positive electrode 210 may exert a pumping force or
pressure on a fluid reservoir 204 or associated transfer structure
216, such as the illustrated plate. The pumping force or pressure
may cause fluid to be pumped from the fluid reservoir 204. Thus,
the electrochemical actuator 202 may be considered a self-powered
electrochemical pump. In the illustrated embodiment, the
electrochemical cell has a positive electrode 210 selected to have
a lower chemical potential for the working ion when the cell is
charged, and is thereby able to spontaneously accept working ions
from the negative electrode 212 as the cell is discharged. In
embodiments the working ion includes but is not limited to the
proton or lithium ion. When the working ion is lithium, the
positive electrode 210 may comprise one or more lithium metal
oxides including LiCoO.sub.2, LiFePO.sub.4, LiNiO.sub.2,
LiMn.sub.2O.sub.4, LiMnO.sub.2, LiMnPO.sub.4,
Li.sub.4Ti.sub.5O.sub.12, and their modified compositions and solid
solutions; oxide compound comprising one or more of titanium oxide,
manganese oxide, vanadium oxide, tin oxide, antimony oxide, cobalt
oxide, nickel oxide or iron oxide; metal sulfides comprising one or
more of TiSi.sub.2, MoSi.sub.2, WSi.sub.2, and their modified
compositions and solid solutions; a metal, metal alloy, or
intermetallic compound comprising one or more of aluminum, silver,
gold, boron, bismuth, gallium, germanium, indium, lead, antimony,
silicon, tin, or zinc; a lithium-metal alloy; or carbon comprising
one or more of graphite, a carbon fiber structure, a glassy carbon
structure, a highly oriented pyrolytic graphite, or a disordered
carbon structure. The negative electrode 212 may comprise lithium
metal, a lithium metal alloy, or any of the preceding compounds
listed as positive electrode compounds, provided that such
compounds when used as a negative electrode are paired with a
positive electrode that is able to spontaneously accept lithium
from the negative electrode when the cell is charged. Other
configurations are also possible.
[0039] In embodiments, the electrochemical actuator may include an
anode, a cathode, and a species, such as a lithium ion. At least
one of the electrodes may be an actuating electrode that includes a
first portion and a second portion. The portions may have at least
one differing characteristic, such that in the presence of a
voltage or current, the first portion responds to the species in a
different manner than the second portion. For example, the portions
may be formed from different materials, or the portions may differ
in thickness, dimension, porosity, density, or surface structure,
among others. The electrodes may be charged, and when the circuit
is closed, current may travel. The species may, intercalate,
de-intercalate, alloy with, oxide, reduce, or plate with the first
portion to a different extent than the second portion. Due to the
first portion responding differently to the species than the second
portion, the actuating electrode may experience the change in
volume or position.
[0040] An example of such an embodiment is shown in FIG. 3, which
is a schematic view of another embodiment of an electrochemical
actuator 302. The electrochemical actuator 302 may include a
positive electrode 310, a negative electrode 312, and a species
314. The species 314 may be an electrolyte that includes, for
example, a lithium ion. The positive electrode 310 may include a
first portion and a second portion. The first portion may include a
material that is dimensionally active when in the presence of
species. For example, aluminum expands upon alloying with or being
intercalated by lithium. The second portion may include a material
that is not dimensionally active when in the presence of the
species, or is relatively less dimensionally active than the
material of the first portion. For example, copper does not
substantially intercalate or alloy with lithium. Thus, the positive
electrode 310 may be considered a bimorph structure, with one of
the portions serving as a positive current collector.
[0041] The negative electrode 312 may serve as a negative current
collector. For example, the negative electrode 312 may include a
layer of lithium metal bonded to or deposited on a layer of copper.
Initially, the electrodes may be charged but may not form a closed
circuit, as shown in FIG. 3(a). The positive electrode 310 may have
a lower chemical potential for lithium than the negative electrode
312. When the circuit between the two electrodes is closed, as
shown in FIG. 3(b), current may flow toward the negative electrode
312. The first portion of the positive electrode 310 may alloy or
intercalate with the lithium, causing an expansion in volume, while
the second portion may act as a mechanical constraint. Thereby, the
positive electrode 310 may bend or otherwise displace. The
displacement of the positive electrode 310 may be transferred to a
fluid reservoir 304, causing the fluid reservoir 304 to expel
fluid.
[0042] As mentioned above, such an electrochemical actuator may
power a fluid delivery device suited delivering of a
drug-containing or non-drug containing fluid into a human patient
or other target. Such a fluid delivery system may be embodied in a
relatively small, self-contained, and disposable device, such as a
patch device that can be removably attached to the skin of the
human body. The patch device may be relatively small and
self-contained because the electrochemical actuator serves as both
the battery and a pump. The small and self-contained nature of the
device advantageously may permit concealing the device beneath
clothing and may allow the patient to continue normal activity as
the drug is delivered. External tubing may not be required to
communicate fluid from the fluid reservoir into the body, unlike
conventional drug pumps. Instead, any tubing may be contained
within the device, and a needle or other fluid communicator may
extend from the device into the body. The electrochemical actuator
may initially be charged, and may begin discharging once the patch
device is activated to pump or otherwise deliver the drug or other
fluid into the body. Once the electrochemical actuator has
completely discharged or the fluid reservoir is empty, the patch
device may be removed and discarded. The small and inexpensive
nature of the electrochemical actuator and other components of the
device may permit disposing of the entire device, unlike
conventional pump devices having a pump that is retained. Thus, the
device may permit drug delivery, such as subcutaneous or
intravenous drug delivery, over a time period that may vary from
several minutes to several days. Subsequently, the device may be
removed from the body and discarded.
[0043] For the purposes of this disclosure, the term "disposable"
generally means a single use device, or a component thereof, that
is intended to be discarded. Because the electrochemical actuator
may serve as a battery, the electrochemical actuator may discharge
with use, and thereafter may be discarded. Because the
electrochemical actuator also serves as the pumping mechanism,
however, discarding the electrochemical actuator also discards the
pumping mechanism. Such a configuration differs from a conventional
infusion pump, which includes a pumping mechanism that is retained
for subsequent reuse. Unlike a conventional infusion pump, a patch
pump device comprising the electrochemical actuator may be
completely disposable.
[0044] Such a device may generally include a drug or fluid delivery
system associated with a housing. As generally described above, the
drug delivery system may include an electrochemical actuator suited
to drive a drug from a fluid reservoir through a needle or other
fluid communicator. The housing may at least partially contain the
fluid delivery system and may be suit for removably associating the
fluid delivery system with human skin.
[0045] So that the device can be worn on the skin, a releasable
adhesive may at least partially coat an underside of the housing.
The adhesive may be non-toxic, biocompatible, and releasable from
human skin. To protect the adhesive until the device is ready for
use, a removable protective covering may cover the adhesive, in
which case the covering may be removed before the device is applied
to the skin. Alternatively, the adhesive may be heat or pressure
sensitive, in which case the adhesive may be activated once the
device is applied to the skin. Example adhesives include but are
not limited to acrylate based medical adhesives of the type
commonly used to affix medical devices such as bandages to skin.
However, the adhesive is not necessary and may be omitted, in which
case the housing may be associated with the skin, or generally with
the body, in any other manner.
[0046] The size, shape, and weight of the device may be selected so
that the device may be comfortably worn on the skin after the
device is applied via the adhesive. For example, the device may
have a size in the range of about one inch by about one inch by
about 0.1 inches to about five inches by about five inches by about
one inch, and in some embodiments in a range of about two inches by
about two inches by about 0.25 inches to about four inches by about
four inches by about 0.67 inches. The weight of the device may be
in the range of about five grams to about two hundred grams, and in
some embodiments in a range of about fifteen grams to about one
hundred grams. The device may be able to dispense a volume in the
range of about 0.1 milliliters to about one thousand milliliters,
and in some cases in the range of about 0.3 milliliters to about
one hundred milliliters, such as between about 0.5 milliliters and
about five milliliters. The shape of the device may be selected so
that the device may be relatively imperceptible under clothing. For
example, the housing may be relatively smooth and free from sharp
edges. However, any size, shape, or weight is possible.
[0047] The housing may be formed from a material that is relatively
lightweight and flexible, yet sturdy. The housing also be may
formed from a combination of materials such as to provide specific
portions that are rigid and specific portions that are flexible.
The material may also be relatively low-cost, so that the device
may be disposable. Example materials include plastic and rubber
materials, such as polystyrene, polybutene, carbonate, urethane
rubbers, butene rubbers, silicone, and other comparable materials
and mixtures thereof, although a combination of these materials or
any other material may be used.
[0048] In embodiments, the housing may include two portions: a base
portion and a movable portion. The base portion may be suited for
attaching to the skin. For example, the base portion may be
relatively flexible. An adhesive may be deposited on an underside
of the base portion, which may be relatively flat or shaped to mate
with a particular body area. The movable portion may be sized and
shaped for association with the base portion. In embodiments, the
two portions may be designed to lock together, such as via a
locking mechanism. In some cases, the two portions may releasably
lock together, such as via a releasable locking mechanism, so that
the movable portion may be removably associated with the base
portion. To assemble the device, the movable portion may be movable
with reference to the base portion between an unassembled position
and an assembled position. In the assembled position, the two
portions may form a device having an outer shape suited for
concealing the device under clothing. Embodiments of such a device
are generally described below with reference to FIGS. 4-10,
although a range of configurations are possible.
[0049] FIG. 4 is a side cross-sectional view of an embodiment of a
patch device 400. The device 400 generally includes a fluid
delivery system associated with a housing 418, which may include a
base portion 422 and a movable portion 424. An adhesive 420 may be
positioned on an underside of the base portion 422. The movable
portion 424 may house one or more components of the fluid delivery
system, such as an electrochemical actuator 402, a fluid reservoir
404, and fluid communicator 406. The movable portion 424 may be
sized and shaped for insertion into the base portion 422. More
specifically, the movable portion 424 may be movable with reference
to the base portion 422 between an unassembled position shown in
FIG. 4(a), and an assembled position shown in FIGS. 4(b-c). In the
assembled position, the two portions 422, 424 may mate and lock
together. When assembled, the outer surface of the device 400 may
be relatively smooth and easy to conceal under clothing.
[0050] In the embodiment illustrated in FIG. 4, a releasable
locking mechanism is formed by detents 426 located on an exterior
surface of the movable portion 424 and a grooved flange 428 located
on an interior surface of the base portion 422. In the unassembled
position, the detents 426 rest in the grooved flange 428 to support
the movable portion 424 above the base portion 422. To assemble the
device 400, a force F is applied to the movable portion 424 to push
it downward. The force F causes the grooved flange 428 to flex
outward and the detent 426 to travel past the grooved flange 428.
Thus, the movable portion 424 travels further into the base portion
422 and becomes firmly seated therein. The grooved flange 428
returns to prevent the detent 426 from moving upward, releasably
locking the device 400 together. When so assembled, the device 400
takes on a bulbous shape that is relatively free from sharp edges.
It is noted that, in some embodiments, the locking mechanism may
not be releasable.
[0051] In the embodiment shown in FIG. 5, the device 500 generally
includes a housing formed from a base portion 522 and a movable
portion 524. Like the device 400, the base portion 522 may have an
adhesive on an underside for associating the device 500 with the
skin (not shown for clarity). A fluid delivery system may generally
be contained in the movable portion 524 (not shown for
clarity).
[0052] More specifically, the base portion 522 may have a
relatively oval exterior and an interior that is sized and shaped
to receive the movable portion 524. For example, the movable
portion 524 may have a body 530 and a projection 532, and the base
portion 522 may have an interior slot 534 and an opening 536. The
interior slot 534 may be sized and shaped for receiving the
projection 532, and the opening 536 may be sized and shaped for
receiving the body 530. To assemble the device 500, the projection
532 may be inserted through the opening 536 along the slot 534, as
shown in FIG. 5(b). The body 530 may be pressed into the opening
536 so that the movable portion 524 becomes firmly seated in the
base portion 522, as shown in FIG. 5(d). When so assembled, the
shape of the movable portion 524 may naturally limit its upward and
rearward movement, releasably locking the two portions 522, 524
together. The assembled device 500 may take on a smooth oval shape
that is relatively free from sharp edges and has a relatively low
profile, so that the device 500 may be concealed under
clothing.
[0053] In the embodiment shown in FIG. 6, specifically FIG. 6(c)
and FIG. 6(d), the device 600 may include a movable portion 624
that snaps onto an exterior of a base portion 622 instead of being
inserted therein. Specifically, the base portion 622 may include a
base 638 and a guide 640 that projects upward from the base 638.
The base 638 may be a layer of adhesive, such as a flexible,
double-sided layer of adhesive. Alternatively, the base 638 may
comprise a plate having an adhesive on an underside. The movable
portion 624 may have a cavity that houses components of the fluid
delivery system, such as an electrochemical actuator 602, a fluid
source 604, and associated electronics 672 (embodiments of which
are described below with reference to FIG. 10). A recess 642 may be
formed in the movable portion 624 for receiving the guide 640. To
assemble the base portion 622 and the movable portion 624, the
movable portion 624 may be positioned over the base portion 622 as
shown in FIG. 6(e). The guide 640 may locate the recess 642, so
that the portions 622, 624 are properly aligned. A force may be
applied to press the movable portion 624 onto the base portion 622,
as shown in FIG. 6(d). The guide 640 and the recess 642 may form a
snap fitting, such that the device 600 becomes releasably locked
together. Alternatively, the movable portion 624 may adhere to the
base portion 622, such as in embodiments in which the base 638 is a
double-side layer of adhesive. When assembled, the device 600 has a
relatively smooth and low profile exterior that may permit
concealing the device beneath clothing.
[0054] It should be noted that different embodiments of the device
may be assembled using different hand motions. For example, the
device 400 shown in FIG. 4 may be assembled by exerting a force on
the movable portion 424 in a direction generally perpendicular to
the surface of the skin, as shown in FIG. 4(b), while the device
500 shown in FIG. 5 may be assembled by exerting a force on the
movable portion 524 in a direction that forms an angle with the
surface of the skin, as shown in FIG. 5(b). Thus, different
embodiments of the device may be better suited for assembly on
different parts of the body or with fluid communicators inserted at
different angles, as further described below. It also should be
noted that some embodiments of the device, such as the device 400,
the device 500, and the device 600 may be assembled using one hand.
Assembling the device with one hand may facilitate attaching the
device to a portion of the body that cannot be accessed easily. For
example, some drugs or other fluids may be infused through the
backside of the body, which may be difficult to access with both
hands. Assembling the device on the backside of the body, for
example, may be relatively easy with embodiments of the device that
can be assembled using one hand.
[0055] In embodiments, the device may be designed such that
assembling the device simultaneously inserts the fluid communicator
into the body. Specifically, the fluid communicator may initially
be retracted inside the housing and may be transferred from the
housing into the body during assembly of the device. More
specifically, the force that causes the housing to move from the
unassembled position to the assembled position may also be
effective to cause the needle to enter the body.
[0056] In the embodiment of the device 400 shown in FIG. 4, for
example, the fluid communicator 406 may be a needle extending
downward from the movable portion 424. When the device 400 is in
the unassembled position, as shown in FIG. 4(a), the needle may be
protected inside the base portion 422. A septum 444 or other
penetrable member may be positioned in the base portion 422
adjacent to the needle, enclosing the base portion 422 so that the
needle is not exposed to contaminants. When the force F is applied
to move the movable portion 424 to the assembled position, as shown
in FIG. 4(b), the needle penetrates the septum 444 and enters the
skin. Because the force F is applied relatively perpendicular to
the surface of the skin, the needle may enter the body at an angle
that is relatively perpendicular to the surface of the skin. Such a
configuration may be suited for patients that prefer inserting the
needle in a perpendicular orientation, or for drugs or other fluids
that are suited for being delivered via a needle in a perpendicular
orientation. However, in other embodiments, other configurations
are possible.
[0057] For example, in the embodiment of the device 500 shown in
FIG. 5, the fluid communicator 506 may be a needle positioned at an
end of the projection 532. The slot 534 may extend downward through
the base portion 522, forming an angle with an underside of the
base portion 522. The slot 534 may terminate in an aperture 546
formed through the underside of the base portion 522. The
projection 532 may be sized such when the projection 532 is
positioned in the slot 534, the needle passes through the aperture
546 into the skin. To assemble the device 500, the projection 532
is inserted through the slot 534. The force F is applied at an
angle with reference to the surface of the skin to push the
projection 532 along the slot 534, such that continued application
of the force F inserts the needle into the body at an angle with
reference to the surface of the skin. Inserting the needle at an
angle may be preferred by some users and/or for some types of drug
or fluid delivery.
[0058] In the embodiments described above with reference to FIG. 4
and FIG. 5, the force that causes the device to move into the
assembled position is the same force that acts on the needle to
insert the needle into the body. In such embodiments, the needle
travels into the body in the same direction that the movable
portion travels into the base portion. In other embodiments, the
device may include mechanics that alter the direction of the force
before the force acts on the needle. In such embodiments, the force
may act on the movable portion in one direction and may act on the
needle in another direction. For example, the mechanics may alter
the direction of a perpendicular force before the force acts on the
needle, so that the force can insert the needle into the body at an
angle. Example mechanics may include a spring and a latch, wherein
associating the movable portion with the base portion releases the
latch to cause the spring to insert the needle into the body. In
such embodiments, the mechanics may permit selecting the insertion
angle of the needle, such as by rotating a dial or sliding a
slider, so that the user can adjust the insertion angle based on
his personal preference. A person of skill may be able to design
such mechanics based on the disclosure above.
[0059] In still other embodiments, the force that causes the needle
to enter the body may be applied completely separately from the
force that places the device in the assembled position. For
example, the needle may be manually inserted into the body before
the device is associated with the needle. As another example, the
electrochemical actuator may apply a force to the needle to insert
the needle into the body. Further, a separate insertion mechanism
may be provided for inserting the needle into the body.
[0060] Such an embodiment is shown in FIG. 6, specifically with
reference to FIG. 6(a) and FIG. 6(b). Specifically, the device 600
may be suited for use with a separate needle insertion mechanism
648. The needle insertion mechanism 648 may be adapted for
inserting a fluid communicator 606, such as a needle or cannula,
through the base portion 622 of the device 600 and into the body.
For example, the base portion 622 may include an opening 650 for
receiving the fluid communicator 606, the opening 650 being formed
through the guide 640 and the base plate 638. To permit aligning
the needle insertion mechanism 648 with the base portion 622, and
more specifically, to permit aligning the fluid communicator 606
with the opening 650, the needle insertion mechanism 648 may
include a recess 652 sized and shaped to mate with the guide
640.
[0061] To insert the fluid communicator 606, the needle insertion
mechanism 648 may be placed on the base portion 622, as shown in
FIG. 6(b). A spring 654, which is generally retained within the
needle insertion mechanism 648 in a compressed state, may be
released via a releasable latch 656. The spring 654 may be in
communication with the fluid communicator 606 and may expel the
fluid communicator 606 out of the needle insertion mechanism 648
when the latch 656 is released. The fluid communicator 606 may
travel through the opening 650, as shown in FIG. 6(b), and into the
body, as shown in FIG. 6(c). Thereafter, the needle insertion
mechanism 648 may be removed from the base portion 622, as shown in
FIG. 6(c), so that the movable portion 624 may be positioned
thereon as shown in FIG. 6(d). The needle insertion mechanism 648
may subsequently be discarded, or may be saved for re-use depending
on the embodiment.
[0062] In embodiments, the fluid communicator 606 may be a soft
cannula 658. A needle 660 may be fixedly associated with the spring
654 to initially pierce the skin and assist in inserting the soft
cannula 658 into the body, as shown in FIG. 6(b). The needle 660
may subsequently be retracted or removed from the body, leaving the
soft cannula 658 in place, as shown in FIG. 6(c). An aligning guide
662 may further guide the soft cannula 658 into the body, although
the aligning guide 662 is not necessary and may be omitted.
[0063] In embodiments, the needle insertion mechanism may be
designed for one handed operation to facilitate inserting the
catheter in hard to reach places. Further, the needle insertion
mechanism may be designed to insert the needle at a variety of
different angles, including a user-selected angle. Fluid
communicators other than needles or soft cannulas may be inserted
by the needle insertion mechanism, depending on the embodiment. The
needle inserting force may be supplied by the spring or in other
manners, such as by the user, manually, in which case the spring
may be omitted. Although the illustrated needle insertion mechanism
is separate from the device, which permits reducing the size and/or
weight of the device, the needle insertion mechanism may be an
integral part of the device that is retained within the device
after the needle is inserted. It also should be noted that the
configuration described above, in which a piercing needle that
assists with inserting a soft cannula is subsequently removed from
the body, may be employed with reference to other embodiments.
[0064] By way of example, the fluid communicator is described above
as being a needle or a cannula. In embodiments, the needle or a
soft cannula may be relatively small for comfort. In other
embodiments, the fluid communicator can be any catheter or other
device for delivering fluids into the body, or combinations
thereof. In embodiments, the fluid communicator may be relatively
sterile. Further, the device may be used in association with a
conventional infusion set, in which case the fluid communicator may
be one or more parts of the infusion set, such as a standard Luer
lock or other connector that is adapted to connect the device to
the infusion set, or the fluid communicator may be omitted
completely. In another embodiment, the pump patch is not limited to
subcutaneous delivery. For example, the device may be connected to
an indwelling infusion port, such as a central venous access port
known in the art, in which case the fluid communicator may be a
suitable adaptor for associating the device with the port. In still
another embodiment, the fluid communicator may comprise a
microneedle array suitable for transdermal delivery of fluid drugs,
as known in the art.
[0065] Although embodiments of the device are described above as
comprising two separate portions that can be assembled together, or
two separate portions and a needle insertion mechanism, in other
embodiments the device may be a single portion or the device may
have more than two separate portions.
[0066] Further, in the embodiments described above, the fluid
delivery system is generally housed in one portion of the device,
namely, the movable portion. In other embodiments, the fluid
delivery system may be housed in other portions of the device, such
as the base portion, or in a combination of a number of portions of
the device, such as a combination of the base portion and the
movable portion. Examples are shown in FIGS. 7 and 8. FIG. 7, for
example, illustrates an embodiment of a device 700 that is
generally similar to the device 500. However, the fluid delivery
system of the device 700 may be split between a base portion 722
and a movable portion 724. In an unassembled position, shown in
FIG. 7(a), the base portion 722 may house an electrochemical
actuator 702 while the movable portion 724 may house a fluid source
704 and a fluid communicator 706. In an assembled position, shown
in FIG. 7(b), the electrochemical actuator 702 may be brought into
direct or indirect communication with the fluid source 704.
[0067] FIG. 8 illustrates an embodiment of a device 800 that is
generally similar to the device 600. However, the fluid delivery
system of the device 800 may be split among a base portion 822 and
a movable portion 824. In an unassembled position, shown in FIG.
8(a), the base portion 822 may house an electrochemical actuator
802 and a control system 872. The fluid communicator 806 may also
be positioned in the base portion 822, after having been inserted
via a needle insertion mechanism. The movable portion 824 may house
a fluid source 804. In an assembled position, shown in FIG. 8(b),
the electrochemical actuator 802 may be brought into direct or
indirect communication with the fluid source 804.
[0068] Depending on the embodiment, the components of the fluid
delivery system, including the electrochemical actuator, the fluid
source, and the fluid communicator, may be positioned among various
portions of the device, such as the base portion, the movable
portion, and the needle insertion mechanism (if present). The
components may be separated until the device is assembled to
achieve selected design criteria, such as increased safety,
decreased cost, or improved quality of life. For example, the wet
and sterile components, such as the fluid source and fluid
communicator, may be separated from the dry and non-sterile
components, such as the electrochemical actuator and any associated
electronics, for safety purposes. Examples of such embodiments
include the device 700 and the device 800.
[0069] Some components may be separated to permit reusing one or
more components while discarding one or more other components. Such
embodiments may permit disposing of certain spent or damaged
portions while reusing other fresh and functioning portions. For
example, a fluid source that contains a relatively expensive drug
may be separated from the electrochemical actuator and/or
associated electronics to permit reusing the fluid source if the
electrochemical actuator or electronics are defective.
Alternatively, a fluid source that contains a drug delivered in
relatively high volumes may be separated from the electrochemical
actuator and associated electronics to permit reusing the
electrochemical actuator and electronics with multiple fluid
sources. As another example, electronics may be separated from the
fluid source and/or electrochemical actuator to permit reusing the
electronics even after the fluid source is empty and/or the
electrochemical actuator has completely discharged. Further, the
fluid communicator may be separated from one or more other
components to permit reusing the other components in the event that
needle insertion fails or the needle needs to be changed. An
example of such an embodiment is the device 600, which includes the
associated needle insertion mechanism. Further, some components may
be separated to permit un-assembling and reassembling the device
without reinserting the fluid communicator. Such an embodiment may
permit certain activities, such as shopping and bathing. An example
of such an embodiment is the device 600. Based on the above
disclosure, a range of other configurations are possible. For
example, the device may include a fluid communicator portion, an
electrochemical actuator portion, a fluid source portion, and an
electronics portions. These portions may be assembled to form a
device of the type described herein, yet may be unassembled and
reassembled to substitute and discard portions as necessary.
[0070] After the device is assembled, the electrochemical actuator
may be activated so that the electrochemical actuator begins
discharging, as further described below. The electrochemical
actuator may actuate as it discharges, directly or indirectly
acting on the fluid source to drive the fluid into the body. For
example, the electrochemical actuator may be positioned in direct
contact with the fluid source, such that actuation of the
electrochemical actuator directly acts on the fluid source to
deliver fluid out of the fluid source. Alternatively, a
transferring structure or other appropriate mechanics may be
positioned between the electrochemical actuator and the fluid
source, such that actuation of the electrochemical actuator is
transferred through the transferring structure to the fluid source.
In embodiments, the transfer structure may amplify the change in
volume or displacement experienced by the electrochemical actuator,
such that a relatively small change in volume or displacement may
produce the desired effect upon the fluid source.
[0071] For example, in the embodiment shown in FIG. 4, the
electrochemical actuator 402 may directly act on the fluid source
404. As shown in FIG. 4(a), the fluid source 404 may be a
deformable bladder or pouch positioned in direct contact with the
electrochemical actuator 402. When the electrochemical actuator 402
actuates, a force or pressure may be applied to the fluid source
404, causing the fluid source 404 to deform, as shown in FIG. 4(b).
The pressure within the fluid source 404 may increase, driving the
fluid through the fluid communicator 406, as shown in FIG.
4(c).
[0072] In the embodiment shown in FIG. 6, the electrochemical
actuator 602 may indirectly act on the fluid source 604 via, for
example, a transfer structure 668. As shown in FIG. 6(c), the fluid
source 604 may be a chamber, and the transfer structure 668 may be
a piston in communication with the chamber. When the
electrochemical actuator 602 actuates, a force may be applied to
the transfer structure 668. In turn, the transfer structure 668 may
apply a force to the fluid source 604 to drive fluid through the
fluid communicator 606.
[0073] The transfer structure is described as a piston by way of
example, although the transfer structure may have any other
configuration envisioned by a person of ordinary skill based on the
present disclosure. Such a transfer structure may comprise one or
more known mechanical or electrical components arranged in any
combination and/or location in the device that permits transferring
work from the electrochemical actuator to the fluid source.
Including a transfer structure may permit the device to have a
range of different shapes, sizes and dimensions, as the
electrochemical actuator need not be in direct physical contact
with the fluid source.
[0074] By way of example, the fluid source is described above as
being a bladder, reservoir, pouch, chamber or barrel. In other
embodiments, the fluid source may be any component capable of
retaining a fluid or drug in fluid form. In the illustrated
embodiments, the fluid source may not be refillable, permitting
disposal of the device. In other embodiments, the fluid source may
be refilled, which may permit reusing at least a portion of the
device and/or varying the drug or fluid delivered by the
device.
[0075] In embodiments, the fluid source may be sized to correlate
with the electrochemical potential of the electrochemical actuator.
For example, the size and/or volume of the fluid source may be
selected so that the fluid source becomes about substantially empty
at about the same time that the electrochemical actuator becomes
about substantially discharged. Such a configuration may permit
reducing the size and/or cost of the device, as the fluid source
may not be too large or contain too much drug in relation to the
driving potential of the electrochemical actuator, and similarly,
the electrochemical may not be too large or contain too much power
in relation to the amount of drug in the fluid source. In other
embodiments, the electrochemical actuator may be oversized with
reference to the fluid source. Such a configuration may be used
with relatively expensive drugs to ensure the fluid source is about
substantially empty before the electrochemical actuator completely
discharges, so that waste of the drug is reduced.
[0076] Further, the device may include more than one fluid source
in some embodiments. Such a configuration may permit using a single
device to deliver two or more drugs or fluids. The two or more
drugs or fluids may be delivered discretely, simultaneously,
alternating, according to a program or schedule, or in any other
manner as further described below. In such embodiments, the fluid
sources may be associated with the same or different
electrochemical actuators, the same or different fluid
communicators, the same or different operational electronics, or
the same or different portions of the housing.
[0077] One example embodiment is shown in FIG. 17, which is a side
cross-sectional view of an embodiment of a pump device 1700 that
includes multiple fluid sources 1704a and 1704b. The fluid sources
1704a and 1704b are operated by different electrochemical actuators
1702a and 1702b, respectively. The device 1700 may be suited for
delivering two or more drugs or fluids in any configuration. For
example, the device 1700 may be used in embodiments in which a drug
is to be delivered at infrequent intervals over an extended period,
such as a period of several days. In such an embodiment, one fluid
source 1704a may comprise the drug and the other fluid source 1704b
may comprise a fluid such as saline. The saline may be periodically
administered between doses of the drug to impede clogs from forming
in the fluid communicator 1706.
[0078] Another example embodiment is shown in FIG. 18, which is a
side cross-sectional view of an embodiment of a pump device 1800
that includes multiple fluid sources 1802a and 1804b operated by
the same electrochemical actuator 1802. The device 1800 may be
suited for delivering two or more drugs or fluids in a range of
configurations. For example, the device 1800 may be used in
embodiments in which the drug or fluid has constituent components
that are segregated prior to delivery into the body. For example,
the drug may be stored in a dry powder form (e.g., lyophilized) in
one compartment and then shortly or immediately prior to
administration, it may be reconstituted into a solution or
suspension with a suitable fluid vehicle known in the art, e.g.,
saline solution, for delivery. This may be particularly
advantageous for certain drugs, such as biologics or protein drugs,
that may preferably be in a lyophilized or other dry powder form in
order to provide drug stability during storage, i.e., shelf
stability. In these and in other embodiments, the fluid source 1802
may comprise a drug storage reservoir suited to store a drug or
other non-fluid that can be reconstituted. In embodiments,
intervening mechanics may transfer and/or amplify the displacement
of the electrochemical actuator 1802 to each of the fluid sources
1804a and 1804b in different manners, permitting different fluid
flow rates from the fluid sources 1804b and 1804b. Although devices
having two fluid sources are illustrated, one of skill would
understand that more than two fluid sources may be provided in
other embodiments.
[0079] Devices having two or more fluid sources may have a number
of different configurations within the scope and spirit of the
present disclosure. For example, the fluid sources may be separated
into different portions of the housing, which may permit replacing
one of the fluid sources at a relatively higher frequency than the
other fluid source. Further, the electrochemical actuator may be
substituted with any other pump device, in which case one or more
separate batteries may also be provided. The fluid sources may also
have different sizes, shapes, and configurations depending on the
use of the device.
[0080] It should be noted that the electrochemical actuator may be
relatively small. For example, the electrochemical cell may have a
volume in the range of about five cubic millimeters to about ten
cubic centimeters, and more specifically in a range of about 0.1
cubic centimeters to about one cubic centimeter. The small size of
the electrochemical actuator may permit reducing the size of the
device. Further, the electrochemical actuator may include
relatively few parts, reducing the size and cost of the device and
increasing its reliability. The electrochemical actuator may power
other components of the device. For example, the electrochemical
actuator may power a display, a needle insertion mechanism, or
other components of the device. Also, the electrochemical actuator
may be relatively scalable, in a manner analogous to conventional
batteries. For example, two or more electrochemical actuators may
be provided, and in embodiments, the electrochemical actuator may
be rechargeable. By way of example, the electrochemical actuator is
described as driving, pumping, or expelling fluid from the fluid
source. However, a person of skill would understand that the
present disclosure encompasses other manners of delivering fluid
from the fluid source. For example, the electrochemical actuator
may pull fluid from the fluid source, such as by creating a vacuum
within the fluid source, among other potential configurations.
Further, the electrochemical actuator may be substituted with any
known pump or other device suited to cause fluid flow from the
fluid source, in which case a separate power source may also be
provided.
[0081] The electrochemical actuator may be positioned in an
electrical circuit within the device. The electrochemical actuator
may comprise an electrochemical cell that is initially charged and
actuates as it discharges. When the electrical circuit is open, the
electrochemical actuator may be prevented from discharging, which
may simultaneously prevent the electrochemical actuator from
actuating. Thereby, fluid may be prevented from flowing out of the
fluid source. When the electrical circuit is closed, the
electrochemical actuator may begin discharging, simultaneously
causing the electrochemical actuator to actuate. Thereby, fluid may
be permitted to flow out of the fluid source. Thus, fluid may be
expelled from the fluid source when the electrical circuit is
closed but not otherwise.
[0082] In embodiments, the electrochemical actuator may discharge
and actuate at rates that are dependent upon properties of the
electrical circuit. When a property of the electrical circuit is
varied, the discharge rate of the electrochemical actuator may be
varied, which may simultaneously vary the actuation of the
electrochemical actuator. Thereby, the fluid flow rate out of the
fluid source may be varied. In embodiments, the device may include
means for controlling or regulating fluid flow from the device. The
flow control means may be operative to vary properties associated
with the electrical circuit, such as to start fluid flow from the
device, stop fluid flow from the device, and/or vary a rate of
fluid flow from the device. Embodiments of flow control means are
described in detail below and can be implemented in any combination
to permit delivering drugs according to one or more releases
profiles. Release profiles that may be implemented may include
release profiles having linear flow, non-linear flow,
user-initiated flow, feedback responsive flow, or combinations of
these flows, among others. For purposes of this disclosure, the
term linear flow generally means flow that has a relatively
constant flow rate. The term non-linear flow generally means flow
that does not necessarily have a relatively constant flow rate,
including modulated flow, pulsatile flow, discontinuous flow,
and/or flow that correlates to a program or schedule that may not
necessarily require a relatively constant flow rate. The term
user-initiated flow generally means flow that is initiated in
response to an input into the device. The term feedback-responsive
flow generally means flow that adjusts in response to one or more
sensed conditions, described below. Thus, the pump device may be
effective to deliver a wider variety of drug therapies than other
pump devices.
[0083] FIG. 9 is a schematic illustrating an embodiment of an
electrical circuit 900 that may be used to power embodiments of a
pump device. As shown, the electrical circuit 900 may include an
electrochemical actuator 902 positioned in electrical communication
with a resistor 980. The electrochemical actuator 902 may comprise
an electrochemical cell that is initially charged at a relatively
constant voltage, and displaces as it discharges. The resistor 980
may have a relatively constant electrical resistance. When the
electrical circuit 900 is closed, as shown, a current 982 may be
induced in the electrical circuit 900. The electrochemical actuator
902 may begin discharging across the resistor 980, simultaneously
causing the electrochemical actuator 902 to actuate. Thereby, fluid
may be permitted to flow out of the fluid source.
[0084] More specifically, the discharge of the electrochemical
actuator 902 may be relatively proportional to the current 982
traveling through the electrical circuit 900, or stated
alternatively, the electrical resistance of the resistor 980.
Because the electrical resistance of the resistor 980 may be
relatively constant, the electrochemical actuator 902 may discharge
at a relatively constant rate. Thus, the discharge of the
electrochemical actuator 902 may be relatively linear with the
passage of time, meaning the displacement of the electrochemical
actuator 902 may be relatively linear with the passage of time.
[0085] FIG. 10 is a graph illustrating an embodiment of a
displacement curve 1000, indicating the displacement behavior as a
function of time for the electrochemical actuator 902 positioned in
the electrical circuit 900 of FIG. 9. As shown, the displacement of
the electrochemical actuator 902 is relatively linear with the
passage of time under the conditions described above. In
embodiments, the electrochemical actuator 902 may linearly displace
for a time period that ranges from several minutes to several days.
For example, the electrochemical actuator 902 may linearly displace
for a time period in the range of about five minutes to about five
weeks, and more specifically in a range of about five hours to
about five days. Thereafter, the linear displacement may taper off
and become non-linear, as the electrochemical cell reaches a
completely discharged state and the electrochemical actuator 902
stops actuating.
[0086] FIG. 11 is a graph illustrating an embodiment of a fluid
flow curve 1100, indicating the fluid flow behavior as a function
of time for a fluid source associated with the electrical circuit
900 of FIG. 9. Because the displacement rate of the electrochemical
actuator 902 is relatively constant as shown in FIG. 10, the fluid
flow rate from the device also may be relatively constant, as shown
in FIG. 11. Thus, a device comprising the electrical circuit 900
may deliver fluid according to a relatively continuous release
profile, meaning the fluid may flow at a relatively constant rate
until the fluid source becomes empty or the electrochemical
actuator becomes completely discharged.
[0087] In embodiments, the device may experience a brief priming
period at start-up during which the fluid flow rate may not be
relatively constant. For example, the displacement curve 1000
demonstrates that the electrochemical actuator 902 may experience a
brief priming period when the electrochemical actuator 902 is first
discharged. During the priming period, reaction products may not
have accumulated on the electrochemical actuator 902, preventing
the electrochemical actuator 902 from displacing linearly. To
compensate for such a priming period, the electrochemical actuator
902 may be briefly discharged prior to use, so that when the device
is in use, the electrochemical actuator 902 may experience
relatively linear displacement almost immediately. Further, the
fluid flow curve 1100 indicates the fluid source may experience a
brief priming period when the electrochemical actuator 902 first
displaces. During the priming period, the fluid source may be
pressurized and fluid may begin traveling toward the fluid
communicator. To compensate for such a priming period, the fluid
source may initially be pressurized, and a check valve may be
provided adjacent to the fluid communicator, such that fluid begins
flowing through the fluid communicator almost immediately after the
electrochemical actuator begins displacing. For example, the fluid
source 604 is not pressurized in the device 600 shown in FIG. 6(d),
and therefore fluid may not initially flow from the device 600 at a
relatively constant rate, but such issue may be addressed by
pressurizing the fluid source 604 and providing the check valve
adjacent to the fluid communicator 606.
[0088] Because the displacement of the electrochemical actuator may
be relatively proportional to the current passing through the
electrical circuit, the electrochemical actuator may be relatively
easy to control. For example, the displacement of the
electrochemical actuator may be varied by one or more flow control
means positioned in the electrical circuit. Examples of such flow
control means include one or more electrical contacts, switches,
controllers, circuitry components, or combinations thereof, as
further described below. The flow control means may be operative to
control the electrical circuit. For example, the flow control means
may be operative to open or close the electrical circuit. When the
flow control means open the electrical circuit, the electrochemical
actuator may stop discharging and actuating, such that the fluid is
not expelled from the fluid source. When the flow control means
closes the electrical circuit, the electrochemical actuator may
begin discharging and actuating, such that fluid is expelled from
the fluid source. The flow control means also may be operative to
vary the current through the electrical circuit, such as by varying
the resistance of the electrical circuit. When the flow control
means varies the current or the resistance, the electrochemical
actuator may discharge at a varied rate, such that the
electrochemical actuator displaces at a varied rate to expel from
the fluid source at a varied flow rate.
[0089] FIG. 12 is a schematic illustrating an embodiment of an
electrical circuit 1200 that includes electrical contacts 1264. The
electrical contacts 1264 may permit the electrochemical actuator
1202 to displace when the electrical contacts 1264 are in
electrical communication with each other, but not otherwise. As
shown, the electrical contacts 1264 are not in electrical
communication with each other. Therefore, the electrical circuit
1200 is broken. The electrochemical actuator 1202 is not
discharging or displacing, and therefore fluid is not flowing. In
embodiments, such electrical contacts 1264 may preserve the
electrochemical actuator 1202 in the charged state until the device
is assembled, so that the electrochemical cell may not lose charge
until the device is to be used. Such electrical contacts 1264 may
also prevent fluid flow until the device is assembled.
[0090] Such an embodiment is shown and described with reference
back to FIG. 4. Specifically, electrical contacts 464 may be
positioned in the base portion 422 and the movable portion 424. The
electrical contacts 464 are shown as (+) and (-) for illustrative
purposes, although the configuration may be reversed in other
embodiments. When the device 400 is in the unassembled position
shown in FIG. 4(a), the electrical contacts 464 may not contact
each other, breaking the electrical circuit to prevent the
electrochemical actuator 402 from discharging and actuating. When
the device 400 is moved into the assembled position shown in FIG.
4(b), the electrical contacts 464 may contact each other to close
the electrical circuit, permitting the electrochemical actuator 402
to begin discharging and actuating, provided the electrical circuit
is not broken in some other place. Subsequently, the
electrochemical actuator 402 may act on the fluid reservoir 404 to
deliver fluid out of the fluid communicator 406, as shown in FIG.
4(c). It should be noted that assembling the device 400 may not
cause the electrical contacts 464 to directly contact each other,
but instead may place the electrical contacts 464 in electrical
communication with each other so that the electrical circuit can be
closed. Alternatively, the electrical contacts may be omitted
completely, in which case the electrochemical actuator may or may
not be prevented from discharging when the device is
unassembled.
[0091] With reference back to FIG. 12, when the electrical contacts
1264 are positioned in the electrical circuit 1200 with an
electrochemical actuator 1202 having a relatively constant voltage
and a resistor 1280 having a relatively constant electrical
resistance, fluid may not be delivered until the device is
assembled, and thereafter fluid may be delivered according to a
relatively continuous release profile. Specifically, fluid may
begin flowing once the device is assembled and may continue flowing
at a relatively constant rate until the electrochemical actuator
becomes completely discharged or the fluid source becomes empty.
Alternatively, the release profile may be varied by implementing
one or more additional flow control means as further described
below.
[0092] FIG. 13 is a schematic illustrating an embodiment of an
electrical circuit 1300 that includes a variable resistor 1380. The
variable resistor 1380 may be any electrical component having an
electrical resistance that may be altered or controlled. More
specifically, varying the variable resistor 1380 may vary the
current 1382 induced in the circuit 1300, which in turn may vary
the discharge rate of the electrochemical actuator 1302. Similarly,
varying the discharge rate of the electrochemical actuator 1302 may
vary the displacement rate of the electrochemical actuator 1302,
which in turn may vary the fluid flow rate from the fluid source.
Thus, the electrical resistance of the variable resistor 1380 may
be adjusted to control the fluid flow from the fluid source. The
adjustment in the fluid flow may be proportional to the adjustment
in the electrical resistance, due to the principles described
above.
[0093] FIG. 14 is a schematic illustrating an embodiment of an
electrical circuit 1400 that includes a switch 1484. The switch
1484 may be operative to open or close the electrical circuit 1400.
When the switch 1484 is closed, the electrochemical actuator 1402
may discharge. For example, the electrochemical actuator 1402 may
discharge at a relatively constant rate in embodiments in which the
resistor 1480 has a relatively constant electrical resistance. When
the switch 1484 is opened, the electrochemical actuator 1402 may be
prevented from discharging, which prevents the electrochemical
actuator 1402 from displacing. Thus, the switch 1484 may be
adjusted to control the fluid flow from the fluid source.
[0094] FIG. 15 is a graph illustrating a displacement curve 1500,
indicating the displacement behavior as a function of time for a
fluid source associated with the electrical circuit 1400 of FIG.
14. The switch 1484 may be intermittently opened and closed to vary
the duty cycle of the electrochemical actuator 1402, thereby
varying the displacement of the electrochemical actuator 1402. For
example, during a full on cycle, the switch 1484 may be closed so
that the electrochemical actuator 1402 may displace at a relatively
constant rate. During a duty cycle, the switch 1484 may be
intermittently opened and closed so that the effective displacement
rate of the electrochemical actuator 1402 is relatively lower than
the displacement rate during the full on cycle. Specifically, the
effective displacement rate may depend upon the amount of time the
switch 1484 spends in the opened and closed positions. The
displacement curve 1500 illustrates the displacement for the
electrochemical actuator 1402 when the switch 1484 is closed during
the duty cycle for 16% of the time, 33% of the time, and 66% of the
time, respectively, although any configuration is possible. As
shown, closing the switch 1484 for 66% of the time results in a
relatively higher effective displacement rate, and therefore a
relatively higher fluid flow rate, than closing the switch 1484 for
33% of the time or 16% of the time.
[0095] FIG. 16 is a schematic view of an embodiment of a device
1600 that includes an embodiment of a control system 1672. The
control system 1672 may be adapted to control an electrochemical
actuator 1602. Specifically, the control system 1672 may vary the
displacement of the electrochemical actuator 1602 to vary the fluid
flow rate from a fluid source 1604, through a fluid communicator
1606, and into a user 1608. For example, the control system 1672
may vary the displacement of the electrochemical actuator 1602 by
opening the circuit, closing the circuit, or varying the current or
resistance of the circuit. Thereby, the control system 1672 may
permit administering a selected release profile or altering a
release profile. For example, the control system 1672 may
administer a constant fluid flow rate, a varied fluid flow rate, a
continuous fluid flow, a discontinuous fluid flow, a modulated
fluid flow, a pulsed fluid flow, a programmed fluid flow , a
scheduled fluid flow, a feedback responsive fluid flow, a
user-controlled fluid flow, or a fluid flow that is varied at a
rate responsive to a biological or mechanical measure. Therefore,
the control system 1672 may permit safe delivery of the drug
therapy in a manner that benefits the user 1608.
[0096] The control system 1672 may comprise one or more flow
control means, such as one or more of the electrical contacts,
resistor, variable resistor, and switch described above, or other
known circuitry components or combinations thereof. In embodiments,
the control system 1672 may also comprise a controller and a
memory, such as a microcontroller or a state machine. The memory
may include a program of operation comprising a set of instructions
executable by the controller. The controller may execute the
program of operation to vary the current or resistance of the
electrical circuit according to the set of instructions. For
example, the controller may be operative to control the one or more
flow control means to open the circuit, close the circuit, or vary
the current or resistance of the circuit. Thereby, the controller
may be operative to vary the fluid flow from the device to achieve
a selected release profile. For example, the release profile may be
a programmed release profile, a scheduled release profile, or a
release profile that is response to one more inputs received from,
for example, a feedback system 1676 or a user interface 1678. In
embodiments, the control system 1672 may be powered by an external
power source 1674. The power source 1674 may be another
electrochemical actuator of suitable voltage, although the power
source 1674 may have any other configuration or may be omitted.
[0097] In other embodiments, the flow control means may be arranged
within the electrical circuit to control the circuit in a
particular manner as a function of time, in which case control
system 1672 may not include the controller and in which case a
pre-defined release profile may be "hard-coded" into the electrical
circuit.
[0098] In embodiments, the control system 1672 may control the
electrical circuit according to the time of day. For example, a
schedule may be set by the user. Such an embodiment may permitting
controlling the flow according to the circadian rhythm of the
body.
[0099] In embodiments, the control system 1672 may permit
controlling the electrical circuit in response to inputs received
from one or both of the feedback system 1676 and the user interface
1678. For example, the control system 1672 may open the circuit,
close the circuit, or vary the current or resistance of the circuit
in response to the inputs.
[0100] The feedback system 1676 may be adapted to measure or
otherwise sense one or more conditions associated with the device
and/or the user. For example, the feedback system 1676 may sense an
actual current through the electrical circuit, an actual voltage
across the electrical circuit, an actual discharge of the
electrochemical actuator 1602, an actual displacement of the
electrochemical actuator 1602, an actual fluid flow out of the
fluid source 1604, an actual fluid flow through the fluid
communicator 1606, an actual current rate through the electrical
circuit, an actual voltage rate across the electrical circuit, an
actual discharge rate of the electrochemical actuator 1602, an
actual displacement rate of the electrochemical actuator 1602, an
actual fluid flow rate out of the fluid source 1604, an actual
fluid flow rate through the fluid communicator 1606, proxies for
these conditions, other conditions, or combinations thereof. For
example, the feedback system 1676 may comprise one or more sensors
known in the art and appropriately positioned within the device
1600, such as a strain gauge, a capacitive sensor, a variable
resistance sensor, a flow sensor, or a vision sensor, among others.
The feedback system 1676 may provide the sensed conditions to the
control system 1676, which may be operative to change the discharge
rate of the electrochemical actuator 1602 in response to the sensed
conditions, such as by opening the circuit, closing the circuit, or
varying the current or resistance of the circuit. Thereby, the
control system 1676 may maintain the desired release profile.
[0101] In embodiments, the feedback system 1676 may be in
communication with the user and may sense one or more conditions
associated with the user. For example, the feedback system 1676 may
remove a bodily fluid from the user 1608, and in response the
control system 1672 may adjust the release profile. The feedback
system 1676 may also be in communication with a power source, such
as the power source 1674, which may be another electrochemical
actuator. In another variation, the feedback system 1676 may
include a biosensor, e.g., to assess the concentration of one or
more analytes in a physiological fluid of the patient.
[0102] As mentioned above, the control system 1672 may be in
communication with a user interface 1608. The user interface 1678
may accept one or more inputs from the user, and the control system
1672 may adjust the release profile in response to the input. The
user inputs may comprise one or more of the following: a request to
initiate fluid flow, a request to discontinue fluid flow, a request
to cause temporarily fluid flow, and a request to vary the fluid
flow rate. For example, the device may include one or more
user-responsive controls such as a switch, a button, or a slider.
The switch may permit the user to turn the fluid flow on or off,
such as by opening or closing the circuit. The button may permit
the user to initiate a temporary fluid flow, such as by temporarily
closing the circuit. The slider may permit the user to vary the
flow rate of the fluid flow, such as by varying the current through
the electrical circuit. The user interface 1608 may also include a
display, which may display information delivered by the control
system 1672, such as the number of doses dispensed and/or a number
of doses remaining. Such information may be provided to the control
system 1672 by, for example, the feedback system 1676.
[0103] Thus, the control system 1672 may permit delivering drugs
continuously, on-demand, or in a modulated manner. The device may
be used, for example, for continuous delivery of normally injected
compounds, for the delivery of compounds requiring titration and
precise control, or for on-demand patient controlled analgesia.
[0104] The device 1600 is shown and described by way of example,
and other configurations are included within the scope of the
present disclosure. For example, the displacement of the
electrochemical actuator 1602 may be transferred to the fluid
source 1604 through a transfer mechanism 1668 as shown, although
the transfer mechanism 1668 may be omitted. Further, the feedback
system 1676 and/or the user interface 1678 may be omitted, in which
case the control system 1676 may not be responsive to feedback or
inputs received from the user 1608, respectively.
[0105] By way of example, the flow control means are described
above as controlling the fluid flow from the device by controlling
the discharge of the electrochemical actuator. Such embodiments may
preserve the potential of the electrochemical actuator, such that
discharge of the electrochemical actuator results in correlated
fluid flow. In other embodiments, the electrochemical actuator may
actuate as it charges, in which case charging the electrochemical
actuator results in correlated fluid flow. In still other
embodiments, the flow control means may control the fluid flow by
controlling the transfer structure or other intervening mechanics
between the electrochemical actuator and the fluid source. In such
embodiments, the electrochemical actuator may continuously
discharge, but transfer of the correlated displacement may be
interrupted or reduced in amplification by the transfer mechanism.
A person of skill may be able to implement such a configuration
based on the above disclosure.
[0106] Upon reading the present disclosure, a person of skill would
appreciate that the described embodiments of the device are merely
illustrative examples that convey the scope and breadth of the
present disclosure. Other embodiments of the device that combine
portions of the embodiments described above are included within the
scope of the present disclosure.
[0107] Embodiments of the present device may be used to deliver a
variety of drugs according to one or more release profiles. For
example, the drug may be delivered according to a relatively
uniform flow rate, a varied flow rate, a preprogrammed flow rate, a
modulated flow rate, in response to conditions sensed by the
device, in response to a request or other input from a user or
other external source, or combinations thereof. Thus, embodiments
of the present device may be used to deliver drugs having a short
half-life, drugs having a narrow therapeutic window, drugs
delivered via on-demand dosing, normally-injected compounds for
which other delivery modes such as continuous delivery are desired,
drugs requiring titration and precise control, and drugs whose
therapeutic effectiveness is improved through modulation delivery
or delivery at a non-uniform flow rate. These drugs may already
have appropriate existing injectable formulations.
[0108] For example, the present devices may be useful in a wide
variety of therapies. Representative examples include, but are not
limited to, insulin delivery for Type 1 or Type 2 diabetes;
leutenizing hormone releasing hormone (LHRH) or follicle
stimulating hormone (FSH) for infertility; immunoglobulin for
autoimmune diseases; apomorphine for Parkinson's disease;
interferon A for chronic hepatitis B, chronic hepatitis C, solid or
hematologic malignancies; antibodies for the treatment of cancer;
octreotide for acromegaly; ketamine for pain, refractory
depression, or neuropathic pain; heparin for post-surgical blood
thinning; corticosteroid (e.g., prednisone, hydrocortisone,
dexamethasone) for treatment of MS; morphine, hydromorphone,
fentanyl or other opioids or non-opioids for post-operative pain or
for chronic and breakthrough pain; and tizanidine for spasticity
(e.g., MS, SCI, etc.).
[0109] In a particular embodiment, the device may be used to
administer ketamine for the treatment of refractory depression or
other mood disorders. In embodiments, ketamine may include either
the racemate, single enantiomer (R/S), or the metabolite (wherein
S-norketamine may be active).
[0110] In another particular embodiment, an embodiment of the
device herein may be used for administration of Interferon A for
the treatment of hepatitis C. In one embodiment, a several hour
infusion patch is worn during the day or overnight three times per
week, or a continuous delivery system is worn 24 hours per day.
Such a device may advantageously may replace bolus injection with a
slow infusion, reducing side effects and allowing the patient to
tolerate higher doses. In other Interferon A therapies, the device
may also be used in the treatment of malignant melanoma, renal cell
carcinoma, hairy cell leukemia, chronic hepatitis B, condylomata
acuminata, follicular (non-Hodgkin's lymphoma, and AIDS-related
Kaposi's sarcoma.
[0111] In still another particular embodiment, an embodiment of the
device described herein may be used for administration of
apomorphine or other dopamine agonists in the treatment of
Parkinson's Disease ("PD"). Currently, a bolus subcutaneous
injection of apomorphine may be used to quickly jolt a PD patient
out of an "off" state. However, apomorphine has a relatively short
half-life and relatively severe side effects, limiting its use. The
device described herein may provide continuous delivery and may
dramatically reduce side effects associated with both apomorphine
and dopamine fluctuation. In one particular embodiment, the device
provides continuous delivery of apomorphine or other dopamine
agonist, with, optionally, an adjustable baseline and/or a bolus
button for treating an "off" state in the patient. Advantageously,
this method of treatment may provide improved dopaminergic levels
in the body, such as fewer dyskinetic events, fewer "off" states,
less total time in "off" states, less cycling between "on" and
"off" states, and reduced need for levodopa; quick recovery from
"off" state if it occurs; and reduced or eliminated nausea/vomiting
side effect of apomorphine, resulting from slow steady infusion
rather than bolus dosing.
[0112] In yet another embodiment, an embodiment of the device may
be used for administration of an analgesic, such as morphine,
hydromorphone, fentanyl or other opioids, in the treatment of pain.
Advantageously, the device may provide improved comfort in a less
cumbersome and/or less invasive technique, such as for
post-operative pain management. Particularly, the device may be
configured for patient-controlled analgesia.
[0113] Publications cited herein and the materials for which they
are cited are specifically incorporated by reference. Modifications
and variations of the methods and devices described herein will be
obvious to those skilled in the art from the foregoing detailed
description. Such modifications and variations are intended to come
within the scope of the appended claims.
* * * * *