U.S. patent application number 14/997254 was filed with the patent office on 2016-07-21 for low profile actuator and improved method of caregiver controlled administration of therapeutics.
The applicant listed for this patent is MEDIPACS, INC. Invention is credited to Mark P. Banister, William G. Bloom, Yordan M. Geronov, Mark D. McWilliams, David Swenson, Mark A. Van Veen.
Application Number | 20160206817 14/997254 |
Document ID | / |
Family ID | 43732822 |
Filed Date | 2016-07-21 |
United States Patent
Application |
20160206817 |
Kind Code |
A1 |
Banister; Mark P. ; et
al. |
July 21, 2016 |
LOW PROFILE ACTUATOR AND IMPROVED METHOD OF CAREGIVER CONTROLLED
ADMINISTRATION OF THERAPEUTICS
Abstract
A polymer actuator, power supply and method of using the
activation are described.
Inventors: |
Banister; Mark P.; (Tucson,
AZ) ; Bloom; William G.; (Tucson, AZ) ;
Geronov; Yordan M.; (Tucson, AZ) ; McWilliams; Mark
D.; (Tucson, AZ) ; Swenson; David; (Tucson,
AZ) ; Van Veen; Mark A.; (Tucson, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MEDIPACS, INC |
San Diego |
CA |
US |
|
|
Family ID: |
43732822 |
Appl. No.: |
14/997254 |
Filed: |
January 15, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13395627 |
Mar 12, 2012 |
9238102 |
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PCT/US10/48489 |
Sep 10, 2010 |
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14997254 |
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61241375 |
Sep 10, 2009 |
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61244884 |
Sep 23, 2009 |
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61267334 |
Dec 7, 2009 |
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61295247 |
Jan 15, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 5/1723 20130101;
A61M 2230/30 20130101; A61M 2205/18 20130101; A61M 2230/201
20130101; A61M 5/148 20130101; A61M 2205/502 20130101; A61M 2230/42
20130101; A61M 2230/202 20130101; A61M 2205/0272 20130101; A61M
2230/205 20130101; A61M 5/14244 20130101; A61M 2205/0277
20130101 |
International
Class: |
A61M 5/172 20060101
A61M005/172; A61M 5/148 20060101 A61M005/148; A61M 5/142 20060101
A61M005/142 |
Goverment Interests
GOVERNMENT SUPPORT
[0002] This invention in part was made with U.S. government support
under (IIP 0848528) awarded by the National Science Foundation. The
U.S. Government may have certain rights in the invention.
Claims
1-102. (canceled)
103: A polymeric actuator assembly comprising: a housing; a carrier
having an upper surface within the housing; a plurality of discrete
polymeric actuators disposed across the upper surface; an
electrolyte contained in the housing and in contact with the
plurality of discrete polymeric actuators; and an apparatus for
changing the pH in the electrolyte; wherein, each discrete
polymeric actuator has a volume that expands in response to the
change in pH, and each discrete polymeric actuator is physically
constrained to cause the expansion to be predominantly in a
direction that is directed away from the upper surface.
104: The polymeric actuator assembly of claim 103, characterized by
one or more of the following features: (a) wherein the carrier has
a plurality of wells with openings across the upper surface, and
each discrete polymer actuator is disposed within one of the wells
that provides physical constraint, and wherein each well preferably
has a volume defined by the upper surface and a surface of the well
below the carrier surface, and wherein most of the volume of each
discrete polymeric actuator is contained within the volume to
provide said physical constraint; (b) wherein the carrier is formed
from a porous polymer that facilitates contact between the
electrolyte and each discrete polymeric actuator; (c) wherein the
carrier has a lower surface opposing the upper surface, and further
comprising a second plurality of discrete polymeric actuators
defining a second area arrangement across the lower surface; (d)
wherein the upper surface is substantially planar, and each
polymeric actuator is constrained to exert a force that is normal
to the upper surface; (e) wherein each polymeric actuator has a
long axis that is substantially normal to the upper surface; (f)
wherein the apparatus is an electrode set; (g) wherein the
electrode set includes an individual electrode that passes into
each of the discrete polymeric actuators; and, optionally, wherein
(i) each of the individual electrodes are individually addressable;
(ii) wherein the electrode set includes an electrode that is
commonly coupled to multiple individual electrodes; (iii) wherein
the electrode set includes a rigid electrode that functions as a
platen for exerting a force, and wherein the rigid electrode
receives a normal force from the plurality of discrete polymers in
response to the change in pH; and (iv) wherein the electrode set
includes an electrode that is formed upon one of a housing surface,
a polymeric actuator surface, the carrier surface; and (h) wherein
the apparatus is a container within the housing containing a
solution configured to modify the pH of the electrolyte when the
solution is released from the container.
105: A polymeric actuator assembly of claim 103, wherein the
carrier has an upper surface and a plurality of wells formed in the
carrier, each well opening onto the surface; and wherein said
plurality of polymeric actuators each has a volume that is
partially contained in a corresponding one of the wells.
106: The polymeric actuator assembly of claim 105, characterized by
one or more of the following features: (a) wherein the polymeric
actuator is configured to expand in response to modifying the pH,
and each well corresponding to a polymeric actuator constrains the
polymeric actuator to predominantly expand in a direction that is
normal to the upper surface; (b) wherein the means for changing the
pH includes an electrode set; and, optionally, wherein (i) the
electrode set includes: an upper electrode in contact with an upper
portion of the electrolyte solution; a lower electrode in contact
with a lower portion of the electrolyte solution; and a porous
separator that separates the lower portion from the upper portion;
(ii) wherein the carrier is the porous separator; and/or (iii)
wherein one or more of the upper and lower electrodes is in direct
contact with one or more of the polymeric actuators; and (c)
wherein the means for changing the pH within the electrolyte
solution includes a container with pH modifying solution within the
housing.
107: A polymeric actuator system comprising: a housing; a polymeric
actuator within the housing; a first electrode in contact with the
electrolyte; a first electrolyte in contact with the polymeric
actuator and the first electrode; a second electrode; a second
electrolyte in contact with the second electrode; and a porous
separator configured to separate the first electrolyte from the
second electrolyte; wherein the first electrolyte is configured to
change in pH in response to current passing between the first
electrode to the second electrode and, the polymeric actuator is
configured to change volume in response to the change in pH.
108: The polymeric actuator system of claim 107, characterized by
one or more of the following features: (a) wherein at least one of
the electrodes is in direct contact with the polymeric actuator;
(b) further comprising an electrode coupled to the first electrode
that passes into the polymeric actuator; (c) wherein the polymeric
actuator comprises a plurality of discrete polymeric actuators;
and, optionally, wherein the separator isolates a polymeric
actuator and a corresponding electrode from another polymeric
actuator and corresponding electrode; (d) further comprising a
porous carrier and wherein the polymeric actuator comprises a
plurality of discrete polymeric actuators supported on the carrier
in an area arrangement; (e) wherein each carrier is the porous
separator; and, optionally, wherein the porous carrier includes a
surface with a plurality of wells formed therein, and each of the
discrete polymeric actuators is at least partially contained by one
of the wells; and wherein the surface preferably includes an upper
surface, and each discrete polymeric actuator is a polymeric pillar
having a long axis that is normal to the upper surface.
109: An actuator system comprising: a housing; a polymeric actuator
having a volume disposed within the housing; an electrolyte within
the housing and in contact with the polymeric actuator; an
electrode set within the housing and configured to modulate an ion
concentration or pH of the electrolyte in response to charge being
passed through the electrode set; and a power supply configured to:
(A) deliver a first positive bias charge through the electrode set
during a first time period, the volume being configured to change
from a first volume to a second volume in response to the delivery
of the first positive bias charge; and deliver a negative bias
charge through the electrode set having a magnitude that is less
than the first positive bias charge, a rate of change of the volume
is configured to be reduced in response to the delivery of the
negative bias charge; (B) deliver a first positive bias charge
through the electrode set during a first time period, the volume
being configured to change from a first volume to a second volume
in response to the delivery of the first positive bias charge;
pause for a second time period that is longer than the first time
period; and deliver a second positive bias charge during a third
time period, the second positive bias charge having a greater
magnitude than the first positive bias charge; or (C) a power
supply configured to programmably pass charge through the electrode
such that the polymeric actuator alternates between relatively
short periods of rapid expansion each followed by a relatively
longer period with reduced expansion.
110: The actuator system of claim 109, characterized by one or more
of the following features: (A)(1) wherein the power supply is
further configured to deliver a second positive bias charge through
the electrode set after having delivered the first negative bias
charge; and wherein the second positive bias charge preferably has
a greater magnitude than the first positive bias charge; (A)(2)
wherein the polymeric actuator is configured to expand in response
to the delivery of the first bias charge, and, optionally wherein
(i) the polymeric actuator expansion substantially ceases in
response to the delivery of the negative bias charge; or (ii)
wherein the rate of change of the volume is reduced in magnitude by
at least 70% in response to the delivery of the negative bias
charge; (A)(3) wherein the polymeric actuator includes a plurality
of discrete polymeric actuators; and, optionally, further
comprising a carrier having a plurality of wells formed therein,
each of the plurality of discrete polymeric actuators being
partially contained within one of the wells; (A)(4) further
comprising: a controller for controlling the power supply; and a
sensor configured to provide information to the controller based
upon a sensed characteristic of the actuator system, the controller
being configured to modify operation of the power supply in
response to the provided information, and, optionally, wherein (i)
the controller is configured to modify the magnitude of the first
positive bias charge in response to the provided information so as
to more accurately control the change in volume; or (ii) wherein
the controller is configured to modify the magnitude of the
negative bias charge in response to the provided information in
order to minimize the rate of change in volume, and (A)(5) wherein
the power supply is configured to repeatedly deliver a positive
bias charge followed by a negative bias charge, the negative bias
charge having a magnitude that is less than the positive bias
charge; or (B)(1) the housing is configured to expand along a
single axis in response to the change in volume of the actuator,
and/or (B)(2) wherein the power supply is configured to repeatedly
execute a cycle of delivering a positive bias charge during
relatively short periods of more rapid expansion that are each
followed by relatively long periods of reduced or no expansion. a
polymeric actuator having a volume; an electrolyte in contact with
the polymeric actuator; an electrode set configured to modulate an
ion concentration or pH of the electrolyte in response to charge
being passed through the electrode set; and (B)(3) the power supply
is configured (i) to pass a positive bias charge through the
electrode set to cause each relatively short period of rapid
expansion; or (ii) to pass a negative bias charge having a smaller
magnitude than the positive bias charge through the electrode set
to initiate each relatively longer period with reduced expansion;
and, optionally, (B)(4) further comprising a housing containing the
polymeric actuator, the electrolyte, and the electrode set, the
housing having a linear dimension configured to increase in
response to the expansion.
111: A method of controlling an expansion of a polymeric actuator
comprising: providing a housing containing a polymeric actuator, an
electrolyte in contact with the polymeric actuator, and an
electrode set configured to modulate ion concentration or pH within
the electrolyte in response to current being passed through the
electrode set, the polymeric actuator having a volume that is
responsive to the change in ion concentration or pH; passing a
first forward bias charge through the electrode set that is
sufficient to change the volume from a first volume to a second
volume; and passing a reverse bias charge through the electrode set
that is of smaller magnitude than the forward bias charge and that
is sufficient to reduce a rate of change of the volume.
112: The method of claim 111, characterized by comprising one or
more of the following features: (a) wherein the second volume is
larger than the first volume, and, optionally, further comprising
passing a second forward bias charge through the electrode set that
is sufficient to change the volume to a third volume that is larger
than the second volume; (b) further comprising repeatedly repeating
the steps of (1) passing a forward bias charge through the
electrode set sufficient to increase the volume of the polymeric
actuator and (2) passing a negative bias charge through the
electrode set that is sufficient to reduce a rate of change of the
volume; and (c) further comprising sensing an impedance between two
electrodes of the electrode set, and optionally, wherein (i) the
magnitude of the first forward bias charge is modified based upon
the sensed impedance in order to more accurately control the change
in volume, and/or (ii) wherein the reverse bias charge is modified
based upon the sensed impedance in order to minimize the rate of
change of the volume.
113: A method of providing a therapeutic liquid comprising:
providing a liquid delivery device comprising: a housing configured
to be mounted to a patient body; a reservoir within the housing; a
fluid delivery device coupled to the reservoir and configured to
deliver fluid to the patient; and a controller having a memory
device; selecting a medication type and concentration based upon a
particular class of patient conditions; filling the reservoir with
the type and concentration of the medication; and storing
information on the memory device that defines parameters that
govern operation of the fluid delivery device pursuant to safety
and efficacy of administration specific to the medication type and
concentration.
114: The method of claim 113, characterized by one or more of the
following features: (a) further comprising placing the liquid
delivery device into a health care facility inventory after filling
the reservoir and storing the information, and, optionally, further
comprising: retrieving the liquid delivery device from inventory;
placing the liquid delivery device upon the patient's body; and
coupling the liquid delivery device to the patient's body; (b)
wherein filling the reservoir occurs prior to storing information
on the memory device that defines the parameters; (c) wherein
storing information on the memory device that defines the
parameters occurs before filling the reservoir; and (d) including
the step of loading an operating system on the controller; (e)
including the step of providing the liquid delivery device to a
health care facility inventory, wherein the liquid delivery device
includes: the reservoir within the housing containing a medication
having a type and concentration; the controller having a memory
device storing information defining parameters that govern
operation of the fluid delivery device according to safety and
efficacy of administration of the medication type and
concentration; a user interface; and the controller configured to:
read the information defining the parameters; receive inputs from
the user interface; and operate the fluid delivery device to
administer the medication to the patient pursuant to the
parameters; based on a physician order, a caregiver retrieving the
liquid delivery device from inventory; the caregiver placing the
housing onto the patient body; the caregiver coupling the fluid
delivery device to the patient body; and the caregiver activating
the liquid delivery device to deliver the medication to the
patient; and optionally further characterized by one or more of the
following features: (i) further comprising activating the liquid
delivery device while in a pharmacy prior to retrieval by the
caregiver; (ii) wherein the fluid delivery device is in locked
state when the fluid delivery device is in inventory and further
comprising receiving a security input from the caregiver to unlock
the device in order to enable the activation; and wherein the
security input optionally is one of (1) a wireless input, (2) an
input from a keypad, and (3) an input from a touch screen; and
(iii) further comprising the device issuing a warning to the
caregiver if the caregiver operates the device outside of
guidelines for the medication type and concentration.
115: A therapeutic liquid delivery device comprising: a housing
configured to be mounted to a patient body; a reservoir within the
housing containing a medication; a fluid delivery device coupled to
the reservoir and configured to deliver fluid to the patient; a
controller having a memory device storing information including:
(1) an operating system that is factory loaded that enables
operation of the device; and (2) parameters received from a filling
and programming facility that are specific to the medication type
and concentration; a user interface; the controller configured to:
Read information defining the parameters; Receive inputs from the
user interface; and Operate the fluid delivery device to administer
the medication to the patient pursuant to the parameters.
116: The device of claim 115, characterized by one or more of the
following features: (a) wherein the memory device includes write
once memory storing the information to prevent modification of the
parameters; (b) Wherein the parameters define selectable bolus
dosages wherein a caregiver can select a bolus dosage by utilizing
the user interface; and (c) Wherein the parameters define a range
of bolus dosages.
117: An article of manufacture for providing a therapeutic liquid
comprising: a liquid delivery device comprising: a housing
configured to be mounted to a patient body; a reservoir within the
housing, and optionally containing a medication; a fluid delivery
device coupled to the reservoir and configured to deliver fluid to
the patient; a user interface; and a controller having a computer
readable storage medium having computer readable code disposed
thereon for: (a) storing information on the memory device that
defines parameters that govern operation of the fluid delivery
device pursuant to safety and efficacy of administration specific
to the medication type and concentration; (b) reading information
defining parameters received from a filling and programming
facility that are specific to the medication type and
concentration; receive inputs from the user interface; and operate
the fluid delivery device to administer the medication to the
patient pursuant to the parameters; or (c) storing information
defining parameters that govern operation of the fluid delivery
device according to safety and efficacy of administration of the
medication type and concentration; the controller configured to:
read the information defining the parameters; receive inputs from
the user interface; and operate the fluid delivery device to
administer the medication to the patient pursuant to the
parameters; based on a physician order, a caregiver retrieving the
liquid delivery device from inventory.
118: The article of manufacture of claim 117, characterized by one
or more of the following features: (a) wherein the memory device
includes write once memory storing the information to prevent
modification of the parameters; (b) wherein the parameters define
selectable bolus dosages wherein a caregiver can select a bolus
dosage by utilizing the user interface; (c) wherein the parameters
define a range of bolus dosages. (d) wherein the computer readable
program code further includes a computer readable program step of
activating the liquid delivery device while in a pharmacy prior to
retrieval by the caregiver; (e) wherein the fluid delivery device
is in locked state when the fluid delivery device is in inventory,
and the computer readable program code further includes a computer
program step, upon receiving a security input from the caregiver,
to unlock the device in order to enable the activation; and (f)
wherein the computer readable program code further includes a
computer readable program step of causing the device to issue a
warning to the caregiver if the caregiver operates the device
outside of guidelines for the medication type and
concentration.
119: A medication delivery system comprising a computer controlled
liquid delivery device, including a pump, and a patient monitoring
device, wherein the patient monitoring device provides feedback to
the computer controlled liquid delivery device for adjusting or
stopping the pump, or for signaling an alarm, if the patient
monitoring device detects signs of over-or-under-medication of the
patient, wherein the patient monitoring device preferably is
selected from the group consisting of a pulse oximeter, a blood
CO.sub.2 sensor, a respiration rate monitor, a blood pressure
monitor, and a glucose monitor.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Ser. Nos. 61/241,375, 61/244,884, 61/267,334 and
61/295,247, filed respectively on Sep. 10, 2009, Sep. 23, 2009,
Dec. 7, 2009 and Jan. 15, 2010, the contents of which are
incorporated herein in their entireties.
FIELD OF THE INVENTION
[0003] The present invention in one aspect concerns a low profile
actuator assembly. More particularly the actuator of the present
invention utilizes a polymeric actuator configured to generate a
large linear displacement over an area in response to a change in
an ionic concentration of pH of an electrolyte that is in contact
with the polymeric actuator, and the use of a porous electrode
separator material in such a device. The invention has particular
utility in connection with administration of therapeutic liquids
and will be described in connection with such utility, although
other utilities are contemplated.
[0004] In another aspect the invention concerns a low profile
actuator assembly of the above type and a power supply that powers
the actuator to displace in one or more linear steps over a time
period.
[0005] In yet another embodiment the present invention concerns a
low profile and volumetrically efficient medication delivery device
configured to be placed on the body of a patient during fluid
delivery to the patient. More particularly the present invention
incorporates a low profile area actuator assembly that causes fluid
delivery by displacing a collapsible reservoir in response to
receiving a current or charge input from a power supply.
[0006] In still another aspect, the invention concerns a method for
improving the efficiency of caregiver-controlled administration of
low or high potency therapeutic liquids and potentially dangerous
medications to a patient in a healthcare facility.
BACKGROUND OF THE INVENTION
[0007] Actuators are devices that generate displacements or force
for various applications. These can take on many forms such as
motors, air cylinders, hydraulic cylinders, and electromagnetic
solenoids to name a few. These actuators are utilized for many
different applications and have been in use for decades.
[0008] More recently there have been attempts at developing
applications for actuators that require small size and "low
profile". By low profile, we mean that the actuator must operate
over an area but be spatially constrained in thickness and/or
length. This can be quite challenging in the actuator art. An
example of such an application is an IV pump that is to be worn by
a patient. To avoid discomfort and embarrassment the patient would
prefer that such a pump be very thin so as to not be particularly
noticeable under clothing or even swim suits.
[0009] Conventional actuators do not meet the full need for such an
application. There is a need for thinner and lower profile
actuators that still meet high performance actuation requirements
such as a generation of high forces and displacements. Furthermore
the state of the art polymer actuators do not include a separator
material to isolate and create distinct ionic or pH boundaries of
the electrolyte at the anode or cathode side of the electrodes.
This eliminates comingling of the ionic or pH regions, the addition
of the separator material substantially increases the response,
accuracy, time and volume changes of the actuator material as well
as improving the range of electrode materials and configurations of
the cathode and anode electrodes within the device.
[0010] Patients have need of pumped medication in a variety of
settings. Most pumps such as IV pumps are relatively bulky and
usually only suitable at a bedside in a managed care environment
such as a hospital. More recently medications have been delivered
by more portable pumps that may be fastened to the body. Such pumps
are more convenient than the larger IV pumps but still suffer from
tradeoffs such as limitations on the amount of medication that may
be delivered. Moreover, wearing a pump on the body can be quite
uncomfortable. There is a need to improve upon these pumps in terms
of their comfort and their ability to deliver larger volumes of
medication.
[0011] Also, critical high potency medications such as Schedule II
pain therapeutics are often administered to patients at healthcare
facilities. Schedule II pain medications are particularly important
for patients having undergone surgeries or having conditions
involving acute pain. In such a situation a doctor writes an order
or prescription for treatment of the patient. The order is filled
or verified by the facility pharmacy and may need to be renewed
every 48 to 96 hours. The order can then be dispensed by an
automated cabinet system to a caregiver (e.g., a nurse) as required
by the patient.
[0012] Insufficient or delayed pain therapy may impair a patient's
ability to heal and leave the healthcare facility. What is needed
is a new process that addresses these issues while simplifying the
process of administering the medication.
SUMMARY OF THE INVENTION
[0013] The present invention, in one aspect, provides a polymeric
actuator assembly comprising: a housing; a carrier having an upper
surface within the housing; a plurality of discrete polymeric
actuators disposed in an area arrangement across the upper surface;
an electrolyte contained in the housing and in contact with the
plurality of discrete polymeric actuators; and an apparatus for
changing the pH in the electrolyte, wherein each discrete polymeric
actuator has a volume that expands in response to the change in pH,
and each discrete polymeric actuator is geometrically constrained
to cause the expansion to be predominantly in a direction that is
directed away from the upper surface.
[0014] The present invention also provides, in another aspect, a
polymeric actuator assembly comprising: a housing; a carrier having
an upper surface and a plurality of wells formed in the carrier,
each well opening onto the upper surface; a plurality of polymeric
actuators each having a volume that is partially contained in a
corresponding one of the wells; an electrolyte solution contained
within the housing and in contact with the plurality of polymeric
actuators; and an apparatus for modifying the pH within the
electrolyte solution.
[0015] In yet another aspect, the present invention provides a
polymeric actuator assembly comprising: a housing; a polymeric
actuator within the housing; a first electrode in contact with the
electrolyte; a first electrolyte in contact with the polymeric
actuator and the first electrode; a second electrode; a second
electrode in contact with the second electrode; and a porous
separator configured to separate the first electrolyte from the
second electrolyte, wherein the first electrolyte is configured to
change in pH in response to current passing between the first
electrode to the second electrode, and the polymeric actuator is
configured to change volume in response to the change in pH.
[0016] The present invention, in another aspect also provides an
actuator system comprising: a housing; a polymeric actuator having
a volume disposed within the housing; an electrolyte within the
housing and in contact with the polymeric actuator; an electrode
set within the housing and configured to modulate an ion
concentration or pH of the electrolyte in response to charge being
passed through the electrode set; and a power supply configured to:
[0017] (1) deliver a first positive bias charge through the
electrode set during a first time period, the volume is configured
to change from a first volume to a second volume in response to the
delivery of the first positive bias charge; and [0018] (2) deliver
a negative bias charge through the electrode set having a magnitude
that is less than the first positive bias charge, a rate of change
of the volume is configured to be reduced in response to the
delivery of the negative bias charge.
[0019] Also provided by the present invention is a actuator system
comprising: a housing; a polymeric actuator having a volume
disposed within the housing; an electrolyte within the housing and
in contact with the polymeric actuator; an electrode set within the
housing and configured to modulate an ion concentration or pH of
the electrolyte in response to charge being passed through the
electrode set; and a power supply configured to: [0020] (1) deliver
a first positive bias charge through the electrode set during the
first time period, the volume is configured to change from a first
volume to a second volume in response to the delivery of the first
positive bias charge; [0021] (2) pause for a second time period
that is longer than the first time period; and [0022] (3) deliver a
second positive bias charge during a third time period, the second
positive bias charge having a greater magnitude than the first
positive bias charge.
[0023] The present invention further provides an actuator system
comprising: a polymeric actuator having a volume; an electrolyte in
contact with a polymeric actuator, an electrode set configured to
modulate an ion concentration or pH of the electrolyte in response
to charge being passed through the electrode set; and a power
supply configured to programmably pass charge through the electrode
such that the polymeric actuator alternates between relatively
short periods of rapid expansion each followed by a relatively
longer period with reduced expansion.
[0024] Additionally, the present invention provides a method of
controlling an expansion of a polymeric actuator comprising:
providing a housing containing a polymeric actuator, an electrolyte
in contact with polymeric actuator, and an electrode set configured
to modulate ion concentration or pH within the electrolyte in
response to current being passed through the electrode set, the
polymeric actuator having a volume that is responsive to the change
in ion concentration or pH; passing a first forward bias charge
through the electrode set that is sufficient to change the volume
to a second volume; and passing a reverse bias charge through the
electrode set that is of smaller magnitude than the forward bias
charge and that is sufficient to reduce a rate of change of the
volume.
[0025] The invention also provides a low profile medication
delivery device comprising: a chassis having a first pocket and a
second pocket; an actuator assembly overlaying a collapsible
reservoir disposed within the first pocket; and electronics
disposed within the second pocket and coupled to the actuator
assembly, the actuator assembly configured to expand and compress
the collapsible reservoir in response to current being passed
through the actuator assembly.
[0026] In yet another aspect, the present invention provides a
method of providing therapeutic liquid device comprising: providing
a liquid delivery device comprising: a housing configured to be
mounted to a patient body; a reservoir within the housing; a fluid
delivery device coupled to the reservoir and configured to deliver
fluid to the patient; and a controller having a memory device;
selecting a medication type and concentration based upon a
particular class of patient conditions; filling the reservoir with
the type and concentration of the medication; and storing
information on the memory device that defines parameters that
govern operation of the fluid delivery device pursuant to safety
and efficacy of administration specific to the medication type and
concentration.
[0027] The invention also provides a therapeutic liquid delivery
device comprising: a housing configured to be mounted to a patient
body; a reservoir within the housing containing a type of
medication having a concentration; a fluid delivery device coupled
to the reservoir and configured to delivery fluid to the patient; a
controller having a memory device storing information including:
[0028] (1) an operating system that is factory loaded that enables
all operation of the device; and [0029] (2) parameters received
from a filling and programming facility that are specific to the
medication type and concentration; and a user interface; the
controller configured to: [0030] (i) read the information defining
the parameters; [0031] (ii) receive inputs from the user interface;
and [0032] (iii) operate the fluid delivery device to administer
the medication to the patient pursuant to the parameters.
[0033] The present invention also provides a method of
administering a therapeutic fluid comprising: providing a liquid
delivery device to a health care facility inventory, the liquid
delivery device including: [0034] (1) a housing configured to be
mounted to a patient body; [0035] (2) a reservoir within the
housing containing a medication having a type and concentration;
[0036] (3) a fluid delivery device coupled to the reservoir and
configured to deliver fluid to the patient; [0037] (4) a controller
having a memory device storing information defining parameters that
govern operation of the fluid delivery device according to safety
and efficacy of administration of the medication type and
concentration; and [0038] (5) a user interface; [0039] wherein the
controller is configured to: [0040] (i) read the information
defining the parameters; [0041] (ii) receive inputs from the user
interface; and [0042] (iii) operate the fluid delivery device to
administer the medication to the patient pursuant to the
parameters; based on a physician order, a caregiver retrieving the
liquid delivery device from inventory; the caregiver placing the
housing onto the patient body; the caregiver coupling the fluid
delivery device to the patient body; and the caregiver activating
the liquid delivery device to deliver the medication to the
patient.
[0043] The invention also provides an article of manufacture for
providing a therapeutic liquid comprising a liquid device
comprising: a housing configured to be mounted to a patient body; a
reservoir within the housing; a fluid delivery device coupled to
the reservoir and configured to delivery fluid to the patient; a
user interface; and a controller having a computer readable storage
medium having computer readable program code disposed therein for
storing information on the memory device that defines parameters
that govern operation of the fluid delivery device pursuant to
safety and efficacy of administration specific to the medication
type and concentration.
[0044] In addition, the invention provides an article of
manufacture for delivering a therapeutic liquid comprising: a
housing configured to be mounted to a patient body; a reservoir
within the housing containing a medication; a fluid delivery device
coupled to the reservoir and configured to delivery fluid to the
patient; a controller having a computer readable storage medium
having computer readable program code disposed therein for reading
information defining parameters received from a filling and
programming facility that are specific to the medication type and
concentration; receive inputs from the user interface; and operate
the fluid delivery device to administer the medication to the
patient pursuant to the parameters.
[0045] In yet another embodiment, the invention provides an article
of manufacture for administering a therapeutic fluid comprising: a
liquid delivery device, the liquid delivery device including: a
housing configured to be mounted to a patient body; a reservoir
within the housing containing a medication having a type and
concentration; a fluid delivery device coupled to the reservoir and
configured to deliver fluid to the patient; a user interface; and a
controller having computer readable storage medium having computer
readable program code for storing information defining parameters
that govern operation of the fluid delivery device according to
safety and efficacy of administration of the medication type and
concentration; the controller configured to: read the information
defining the parameters; receive inputs from the user interface;
and operate the fluid delivery device to administer the medication
to the patient pursuant to the parameters; based on a physician
order, a caregiver retrieving the liquid delivery device from
inventory.
[0046] In still yet another embodiment of the invention, the
therapeutic liquid delivery device of the present invention is
paired with a patient monitoring device such as, for example, a
pulse oximeter, a blood CO.sub.2 sensor, a respiration rate sensor;
a blood pressure monitor, or a glucose monitor, or the like, with
feedback to the liquid delivery device controller to adjust, alarm
or stop the pump if the patient is showing signs of overmedication.
The feedback also could be used to adjust the pump if the patient
is showing signs of undermedication.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Further features and advantages of the present invention
will be seen from the following detailed description, taken into
conjunction with the attached drawings, in which like numerals
depict like parts, and wherein,
[0048] FIG. 1A depicts an exemplary system 100 according to the one
aspect of the present invention;
[0049] FIG. 1B depicts an exemplary actuator assembly 120;
[0050] FIG. 1C depicts an exemplary actuator assembly 140;
[0051] FIG. 2A depicts a plan or area view of an actuator 2 of the
present invention with various details missing;
[0052] FIG. 2B depicts a cross section taken through actuator 2
along AA depicted in FIG. 2A;
[0053] FIG. 3 depicts a detailed view of a single discrete
polymeric actuator 6 from FIG. 2B having an individual electrode
passing into the volume of actuator 6;
[0054] FIG. 4A depicts a plurality of discrete polymeric actuators
6 joined by a strip or web of polymeric material 30;
[0055] FIG. 4B depicts alternative shapes for discrete polymeric
actuators;
[0056] FIG. 5 depicts an actuator assembly using a plurality of
carriers 36 rather than one single carrier 4 for supporting
discrete polymeric actuators 6;
[0057] FIG. 6A depicts an alternative actuator assembly 38
including a carrier 40 having a plurality of individually
addressable electrodes 42 that each correspond to a polymeric
actuator 44;
[0058] FIG. 6B depicts a cross section taken through actuator
assembly 38 along AA of FIG. 6A;
[0059] FIG. 7A depicts an alternative actuator assembly 50
including an electrode 60 formed on an upper surface of a polymeric
web 56 that joins a plurality of discrete polymeric actuators
54;
[0060] FIG. 7B depicts a cross section taken through assembly 50
along AA of FIG. 7A;
[0061] FIG. 8A depicts an alternative actuator assembly 64
including a "double sided" carrier 66 supporting active reactive
discrete polymeric actuators 72 on a first side and base reactive
polymeric actuators 74 on a second side;
[0062] FIG. 8B depicts a cross section taken through assembly 64
along AA of FIG. 8A;
[0063] FIG. 9 depicts a polymeric actuator system in accordance
with another aspect of the present invention;
[0064] FIG. 10 depicts a method of the present invention in flow
chart form;
[0065] FIG. 11 depicts a current versus time curve of the present
invention;
[0066] FIG. 12A depicts a plan or actuator view of an exemplary
actuator assembly that can be utilized with the present
invention;
[0067] FIG. 12B depicts a cross section taken through the actuator
along AA depicted in FIG. 12A;
[0068] FIG. 12C depicts a detailed view of a single discrete
polymeric actuator from FIG. 12B having an individual electrode
passing into the volume of the actuator;
[0069] FIG. 13 depicts a method of the present invention in flow
chart form;
[0070] FIG. 14A depicts an overall system utilizing a further
aspect of the present invention;
[0071] FIG. 14B depicts a simplified block diagram of a device
according to the further aspect of the present invention;
[0072] FIG. 15 depicts an electrical block diagram of a device
according to the further aspect of the present invention;
[0073] FIG. 16 depicts a simplified diagram of a device according
to the further aspect of the present invention;
[0074] FIG. 17 depicts a method of manufacturing, configuring, and
delivering a device such as one depicted according to FIGS. 14B, 15
and 16;
[0075] FIG. 18 depicts a method of use of a device provided
according to the method FIG. 17;
[0076] FIG. 19A depicts a prior art method of delivering
medication;
[0077] FIG. 19B depicts a new simplified method of delivering
medication according to the present invention;
[0078] FIG. 20A depicts an exemplary medication delivery device of
the present invention in block diagram form;
[0079] FIG. 20B depicts an exemplary medication delivery device of
the present invention in schematic form;
[0080] FIG. 21 depicts an actuator assembly utilized in the
medication delivery device of the present invention;
[0081] FIG. 22A depicts a plan view of a medication delivery device
of the present invention;
[0082] FIG. 22B depicts a cutaway plan view of a medication
delivery device of the present invention to illustrate pockets for
holding device components;
[0083] FIG. 22C depicts a cross-sectional view of a medication
delivery device of the present invention;
[0084] FIG. 23A depicts a plan view of a medication delivery device
of the present invention;
[0085] FIG. 23B depicts a cross-sectional view of a preferred
embodiment of a portion of a medication delivery device of the
present invention;
[0086] FIG. 23C depicts a cross-sectional view of an alternative
embodiment of a portion of a medication delivery device of the
present invention;
[0087] FIG. 24A depicts a cross-sectional view of a medication
delivery device of the present invention;
[0088] FIG. 24B depicts a cross sectional view of a preferred
embodiment of an actuator/reservoir pocket;
[0089] FIG. 24C depicts a cross-sectional view of an alternative
embodiment of an actuator/reservoir pocket;
[0090] FIG. 25 depicts an alternative embodiment of a medication
delivery device having more than one actuator/reservoir pocket;
[0091] FIG. 26 depicts an alternative embodiment of a medication
delivery device having more than one collapsible reservoir in an
actuator/reservoir pocket; and
[0092] FIG. 27 is a block diagram depicting yet another alternative
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0093] In the following description directional or geometric terms
such as "upper", "lower", and "side" are used solely with reference
to the orientation of the Figures depicted in the drawings. These
are not to imply or be limited to a direction with respect to a
gravitational reference frame but are utilized to distinguish
directions relative to each other. Because components of the
present invention can be positioned in a number of different
orientations, the directional terminology is used for purposes of
illustration and is in no way limiting. It is to be understood that
other embodiments may be utilized and structural or logical changes
may be made without departing from the scope of the present
invention.
[0094] Details in the various embodiments such as how current or
wiring is routed to electrodes from power supplies are left out for
illustrative simplicity since various methods of such routing is
known in the art. The term "electrolyte" refers to and includes all
aqueous, non-aqueous, polymer and solid electrolytes, including
those that are generally well known in the art. The term
"electrodes" refer to anodes and cathodes commonly used in
electrochemical systems that are made of materials well known in
the art such as metals, carbons, graphenes, oxides or conducting
polymers or combinations of these. The term "separator" refers to
any nano, micro or macro porous material that allows targeted ions
to move through or across it faster than surrounding ion containing
media. The term "ion" refers to ions and ion species as well as
anion, cation, electrons and protons, and concentration values of
these. The term "housing" refers to the exterior portion of the
device which may be fabricated from flexible material, rigid
material, elastic materials, non elastic materials or a combination
of these such as rubbers, silicone, polyurethane, metalized polymer
films and other plastics or polymers known in the art. The housing
is configured to allow movement and expansion of the internal parts
as well as allowing for filling device with electrolyte, acting as
a container and barrier to stop any electrolyte leakage or
evaporation, allowing electrodes to make electrical contact with
power source as well as to enter and exit the housing, if needed,
and also the ability to vent any unwanted gas generation, if
needed.
[0095] The foregoing refers to polymeric actuators. In an exemplary
embodiment these polymer actuators are formed from ion or pH
responsive epoxy polymer Hydrogel based polymers. Examples of such
polymers are described in commonly owned WIPO patent application WO
2008079440A2, Entitled `SUPER ELASTIC EPOXY HYDROGEL", filed on
Jul. 10, 2007 and published on Jul. 3, 2008. Other polymer actuator
examples may contain polymers which have ionic functional groups,
such as carboxylic acid, phosphoric acid, sulfonic acid, primary
amine, secondary amine, tertiary amine, and ammonium, acrylic acid,
methacrylic acid, vinylacetic acid maleic acid, meta kurir yl oxy
ethylphosphoric acid, vinylsulfonic acid, styrene sulfonic acid,
vinylpyridine, vinylaniline, vinylimidazole, aminoethyl acrylate,
methylamino ethyl acrylate, dimethylamino ethyl acrylate,
ethylamino ethyl acrylate, ethyl methylamino ethyl acrylate,
diethylamino ethyl acrylate, aminoethyl methacrylate, methylamino
ethyl methacrylate, dimethylaminoethyl methacrylate, ethylamino
ethyl methacrylate, ethyl methylamino ethyl methacrylate,
diethylamino ethyl methacrylate, aminoproply acrylate,
methylaminopropyl acrylate, dimethylamino propylacrylate,
ethylaminopropyl acrylate, ethyl methylaminopropyl acrylate,
diethylamino propylacrylate, aminopropyl methacrylate,
methylaminopropyl methacrylate, dimethylaminopropyl methacrylate,
ethylaminopropyl methacrylate, ethyl methylaminopropyl
methacrylate, polymers, such as diethylamino propyl methacrylate,
dimethylaminoethyl acrylamide, dimethylaminopropylacrylamide, and
alpha kurir yl oxy ethyl trimethylammonium salts, are reported to
be of use but these examples are for reference and not intended to
limit the scope or use of the invention.
[0096] An exemplary embodiment of a system 100 according to the
present invention is schematically depicted with respect to FIG.
1A. System 100 includes power supply 101 coupled to controller 103
and an electrode set 104 within actuator assembly 105. Power supply
101 is configured to deliver current or pass charge between the
electrodes set 104 under control of controller 103.
[0097] Actuator assembly 105 includes a polymeric actuator 102 and
an associated electrode set 104 including top electrode 106 and
bottom electrode 108. The electrode set 104 and the polymeric
actuator 102 are contained within housing 110. Contained within
housing 110 is an electrolyte solution 112U and 112L that immerses
the electrode set 104 and actuator 102. Separating electrode 108
from electrode 106 is a porous separator membrane 114. The
electrolyte includes an upper electrolyte portion 112U that is in
fluidic and electrical contact with upper electrode 106 and
polymeric actuator 102. The electrolyte also includes a lower
electrolyte portion 112L that is in contact with the lower
electrode 108. When power supply 101 passes current through
electrode set 104, this results in a pH difference between upper
electrolyte portion 112U and lower electrolyte portion 112L and
more importantly modulates the pH of upper electrolyte portion 112U
that is in contact with polymeric actuator 102. In one embodiment
of FIG. 1A the upper electrode 106 is not in contact with polymeric
actuator 102 and is responsive to power supply 101 to modulate the
pH of upper electrolyte portion 112U. In a second embodiment of
FIG. 1A upper electrode 106 is in direct contact with polymeric
actuator 102. In a third embodiment, upper electrode 106 has a
portion that extends into the polymeric actuator 106. This may be
similar to an electrode discussed with respect to FIG. 3.
[0098] Polymeric actuator 102 is pH responsive and expands or
contracts in response to a pH change in the upper electrolyte
portion 112U. There are two types of polymeric actuators 102 that
may be used including an "acid-responsive" polymeric actuator and a
"base-responsive" polymeric actuator. An "acid responsive"
polymeric actuator will expand in response to a decreased pH in
upper electrolyte portion 112U surrounding polymeric actuator 102.
This can be accomplished by providing a positive bias of electrode
106 relative to electrode 108. Applying the positive bias causes
current to flow from electrode 106 to electrode 108 and causes a
positive ion concentration in the upper electrolyte portion 112U
surrounding actuator 102 to increase. Thus the upper electrolyte
portion 112U surrounding actuator 102 becomes acidic (lower pH) and
causes actuator 102 to expand. If the bias is reversed the upper
electrolyte portion 112U surrounding actuator 102 becomes more
basic which causes an opposite effect on actuator 102.
[0099] A "base responsive" polymeric actuator 102 also may be used.
In that case, applying a negative bias to electrode 106 relative to
electrode 108 will cause the pH in the upper electrolyte portion
112U surrounding polymeric actuator to increase which will in turn
cause the base responsive polymeric actuator 102 to expand. When
polymeric actuator 102 expands, it causes the entire actuator
assembly 105 to expand.
[0100] An alternative design of an actuator assembly 120 utilizing
both acid responsive and base responsive actuators is depicted in
FIG. 1B in schematic form. Actuator assembly 120 includes an acid
responsive polymeric actuator 122, a base responsive polymeric
actuator 124, a top electrode 126, and a bottom electrode 128 all
within housing 130. A top electrolyte 132 surrounds top electrode
126 and acid responsive actuator 122; a bottom electrolyte
surrounds bottom electrode 128 and base responsive actuator 124. A
porous separator membrane 136 separates the top electrolyte 132
from the bottom electrolyte 134.
[0101] When a positive bias current is applied between top
electrode 126 and bottom electrode 128 and pH of the top
electrolyte 132 decreases while the pH of the bottom electrolyte
134 increases. The decreased pH (acidity increase) of the top
electrolyte 132 causes acid responsive polymeric actuator 122 to
expand while the increased pH (more basic) of bottom electrolyte
143 causes base responsive polymeric actuator 124 to expand. Having
two layers of actuators may double the total displacement
obtainable for the actuator assembly 120. It is anticipated that
additional layers of polymeric actuators with alternating layers of
acid responsive and base responsive polymeric actuators can be used
to further increase the maximum expansion of actuator assembly
120.
[0102] An alternative embodiment of an actuator assembly 140 is
depicted with respect to FIG. 1C and includes a pH responsive
polymeric actuator 142, a container of pH modifying solution 144,
and an electrolyte 146 all inside housing 148. When the container
144 is pierced or otherwise opened, it spills into electrolyte 146,
modifying the pH of electrolyte 146. The changing pH within
electrolyte 146 cause actuator 142 to expand or contract which in
turn causes actuator assembly 140 to expand or contract.
[0103] In one embodiment actuator 142 is an acid responsive
polymeric actuator and container 144 is a breakable container that
contains an acidic solution. Upon breaking open container 144 the
acidic solution lowers the pH of electrolyte 146 causing actuator
142 to expand. When actuator 142 expands, it in turn causes housing
148 to expand.
[0104] In another embodiment actuator 142 is a basic responsive
polymeric actuator and container 144 is a breakable container that
contains a basic solution. Upon breaking open container 144, the
basic solution raises the pH of electrolyte 146 causing actuator
142 to expand. When actuator 142 expands, it in turn causes housing
248 to expand.
[0105] Another actuator 2 of the present invention with various
details left out is depicted in plan view with respect to FIG. 2A.
Actuator 2 includes a carrier 4 and a plurality of discrete
polymeric actuators 6. The polymeric actuators 6 are disposed in an
area arrangement (or a two-dimensional arrangement) across an upper
surface of carrier 4. In an exemplary embodiment upper surface 8 is
a planar surface 8 disposed along mutually perpendicular axes 10A
and 10B.
[0106] The actuator 2 is further depicted with respect to FIG. 2B
which is a cross section taken along AA of FIG. 2A. Each of the
polymeric actuators 6 may be referred to as a polymeric pillar 6
that has a long axis extending along an axis 10C. In an exemplary
embodiment axis 10C is mutually perpendicular to axes 10A and
10B.
[0107] Carrier 2 has a plurality of wells or holes 12 formed
therein that define openings 14 along surface 8 of carrier 2. Each
of the wells 12 supports one of the discrete polymeric actuators 6.
In the illustrated embodiment each discrete polymeric actuator 6
has a volume that is primarily contained within a well 12. A small
portion 16 of the volume of each polymeric actuator 6 may extend
above the well 12.
[0108] Each of the discrete polymeric actuators 6 is formed from a
material that is volumetrically responsive to a change in pH within
an electrolyte 22 that is in contact with discrete polymeric
actuators 6. Stated another way, when the electrolyte 22 changes
pH, the volume of each discrete polymeric actuator 6 also changes.
To cause this change in pH, actuator 2 includes an apparatus for
changing the pH of the electreolyte 22.
[0109] In the depicted embodiment, the apparatus for changing the
pH includes an electrode set which includes an upper electrode 18,
a lower electrode 20, and a porous separator membrane 24 that
separates electrode 20 from the electrolyte solution 22 in contact
with polymeric actuators 6. Applying a current between upper
electrode 18 and lower electrode 20 causes an ionic concentration
change in electrolyte 22 which is logarithmically related to the pH
of electrolyte 22.
[0110] In one embodiment, the discrete polymer actuators 6 are
formed from an "acid responsive" polymer that expands in response
to a decrease in pH of the surrounding electrolyte 22. By providing
a positive bias at electrode 18 relative to electrode 20, the pH in
surrounding electrolyte 22 decreases causing discrete polymeric
actuators 6 to expand. To improve contact between polymeric
actuators 6 and electrolyte solution 22, carrier 22 is formed from
a "micro porous polymeric material" such as porous
polyethylene.
[0111] The polymeric actuators are constrained such that when they
expand, they tend to generate a net force and displacement
primarily along axis 10C. Because most of the volume of each
actuator 6 is contained within a well 12, the net expansion must be
in an upward direction within each well 12. Further, the actuators
6 are packed together closely enough to constrain a "mushrooming"
effect of the actuators 6 above the surface 8 to further enhance
the net upward motion and force generated by actuators 6 during
expansion.
[0112] The actuator assembly 2 includes a housing 26 that includes
an upper portion 26A, lower portion 26B, and a compliant portion
26C. When the actuators 6 push upward they have the effect of
expanding housing 26 along the axis 10C in response to the change
in pH. In one embodiment actuator electrode 18 is rigid and
functions as a rigid platen. Actuators 6 may push against electrode
18 that in turn pushes up against top portion 26A.
[0113] FIG. 3 depicts a preferred embodiment of the present
invention wherein the electrode 18 contacts an individual electrode
28 that extends into the volume of polymeric actuator 6. This has
an advantage of increasing the rate of expansion of the actuator
material 6 by reducing a diffusion time of charge into polymeric
actuators 6.
[0114] FIG. 4A depicts an alternative embodiment for discrete
polymeric actuators 6. FIGS. 2A and 2B depict polymeric actuators 6
as being completely separate. In an alternative embodiment,
discrete polymeric actuators 6 are coupled together via a web of
material 30. This has a the advantage of allowing the actuators to
be molded or formed together as one part 32 that can be more easily
or quickly assembled onto a carrier 4.
[0115] FIG. 4B depicts alternative shapes for polymeric actuators.
FIGS. 2A, 2B, 3 and 4A depict polymeric actuators as having a
cylindrical shape with a rounded lower end. In contrast, discrete
polymeric actuator 6B has a cone shaped lower end and discrete
polymeric actuator 6C is a cylindrical shape that is flat on both
ends.
[0116] FIG. 2A depicts actuator assembly 2 as having a single
carrier 4 holding discrete polymeric actuators 6. FIG. 5 depicts an
alternative actuator assembly design 34 having multiple carriers
36.
[0117] FIGS. 6A and 6B depict an alternative actuator assembly 38
including a carrier 40 having individually addressable electrodes
42. FIG. 6B depicts a cross section taken through AA of FIG. 6A.
Each electrode 42 is positioned to modulate the pH in an
electrolyte 45 that is in the vicinity of each discrete polymeric
actuator 44. The expansion of each polymeric actuator 44 is
somewhat separately controllable via a corresponding contact 42 on
carrier 40.
[0118] Actuator assembly 38 also includes an outer housing 46 upon
which is formed a lower electrode 48. A portion 41 of carrier 40
abuts and seals against the housing 46 such that carrier 40
functions as a porous separator to separate lower electrode 48 from
electrolyte 45 that surrounds polymeric actuators 44. A positive
bias of an electrode 42 with respect to lower electrode 48 will
tend to lower the pH within the electrolyte 45 that is adjacent to
the lower electrode 48. In the case of acid responsive polymeric
actuators 44 the volume of each discrete polymeric actuator 44 will
tend to increase with the application of a positive bias to its
corresponding or adjacent electrode 42. Except for the formation of
electrode 48, the outer housing 46 is similar in construction to
housing 26 described with respect to FIGS. 2A and 2B.
[0119] FIGS. 7A and 7B depict an alternative actuator assembly 50
including a carrier 52 and discrete polymeric actuators 54. FIG. 7B
depicts a cross section taken through AA of FIG. 7A. Discrete
polymeric actuators 54 are joined by a web 56 of polymeric material
that defines an upper surface 58 common to a plurality of the
discrete polymeric actuators 54. Disposed upon the upper surface 58
is an upper electrode 60. Applying a bias between upper electrode
60 and lower electrode 62 enables a modulation of the volume of the
discrete polymeric actuators 54. Surrounding the carrier 52 and
discrete polymeric actuators 54 is an outer housing 64 that is of
similar construction to outer housing 26 described with respect to
FIGS. 2A and 2B.
[0120] FIGS. 8A and 8B depict an alternative actuator assembly 64.
FIG. 8B depicts a cross section taken through AA of FIG. 8A.
Actuator assembly 64 includes a carrier 66 having an upper surface
68 and an opposing lower surface 70. A plurality of acid reactive
discrete polymeric actuators 72 are disposed in an area arrangement
along upper surface 68. A plurality of base reactive discrete
polymeric actuators 74 are disposed in an area arrangement along
lower surface 70. A porous separator 75 separates an upper
electrolyte 77 from a lower electrolyte 79.
[0121] When a positive bias is applied to upper electrode 76
relative to lower electrode 78 this has the effect of reducing pH
in the vicinity of actuators 72 and increasing the pH in the
vicinity of actuators 74. Therefore all of the actuators 72 and 74
will expand under this bias wherein electrode 76 has a positive
bias with respect to electrode 78. This design has the advantage of
increasing maximum displacement of actuator 64 relative to an axis
of 80. Actuator assembly 64 includes an outer housing 82 that is
similar to the outer housing 26 described with respect to FIGS. 2A
and 2B.
[0122] An exemplary embodiment of a system 202 according to another
aspect of the present invention is schematically depicted with
respect to FIG. 9. System 202 includes power supply 204 couple to
controller 206 and to electrode set 208 within actuator assembly
210. Power supply 204 is configured to deliver current or pass
charge through the electrode set 208 under the control of
controller 204. Controller 206 is configured to apply a current
versus time profile to electrode set 208 by controlling power
supply 204.
[0123] In other preferred embodiments controller 206 may be in
communication with remote or wireless devices to allow for remote
activation, deactivation and programming changes when needed. This
may be done through IR (infrared), WIFI, RF (radio frequency),
Magnetic or other types of wireless communication and would also
allow for remote monitoring of an environment around system 202,
and feedback from sensors monitoring performance and results of the
activity of actuator 210.
[0124] In a preferred embodiment system 202 also includes a sensor
212 configured to sense characteristics within actuator 210 such as
an electrical impedance within actuator 210. In an exemplary
embodiment sensor 212 is integrated within power supply 204 and is
configured to sense the electrical impedance between two electrodes
of electrode set 208. In alternative embodiments sensor 212 may be
separate from power supply 204. In additional alternative
embodiments sensor 212 may sense parameters such as ion
concentration, pH, complex impedance, resistance, resistivity,
inductance, capacitance, and/or other measured parameters within
actuator 210. Sensor 212 is configured to provide information to
controller 206 that is indicative of the measured parameters.
Controller 206 is configured to modify a current versus time
profile to be applied to electrode set 208 in response to
information received from sensor 212.
[0125] In a preferred embodiment actuator assembly 210 is
configured to expand linearly along an axis A in response to charge
that is passed between electrodes 216 and 218 of electrode set 208.
Controller 208 receives information from sensor 212 that is
indicative of the linear expansion of actuator assembly 210 that
includes an impedance measured between electrodes 216 and 218.
Controller 208 is configured to modify an amount of charge being
passed between electrodes 216 and 218 in order to control the
linear expansion of actuator assembly 210 to a predetermined
value.
[0126] Actuator assembly 210 includes a polymeric actuator 214 and
associated electrode set 208 including upper electrode 216 and
lower electrode 218. The electrode set 208 and the polymeric
actuator 214 are contained within housing 220. Contained within
housing 220 is an electrolyte solution 222 that immerses actuator
214 and electrode set 208. Separating upper electrode 216 from
lower electrode 218 is a porous separator membrane 226. The
electrolyte includes an upper electrolyte portion 222U that is in
fluidic and electrical contact with upper electrode 216 and
polymeric actuator 214. The electrolyte 222 also includes a lower
electrolyte portion 222L that is in fluidic and electrical contact
with the lower electrode 218.
[0127] When power supply 204 passes current through electrode set
208, this results in an ionic concentration or pH difference
between upper electrolyte portion 222U and lower electrolyte
portion 222L and more importantly modulates the ionic concentration
or pH of upper electrolyte portion 222U that is in contact with
polymeric actuator 214. In one embodiment of FIG. 9 the upper
electrode 216 is not in contact with polymeric actuator 214 and is
responsive to power supply 204 to modulate the ionic concentration
or pH of upper electrolyte portion 222U. In a second embodiment of
FIG. 9 upper electrode 116 is in direct contact with polymeric
actuator 214. In a third embodiment, upper electrode 216 has a
portion that extends into or through the polymeric actuator 214.
This may be similar to an electrode 288 discussed with respect to
FIG. 12C.
[0128] Polymeric actuator 214 is pH responsive and will expand or
contract in response to a pH change in the upper electrolyte
portion 222U. Two types of polymeric actuators 214 that may be used
include an "acid-responsive" polymeric actuator and a
"base-responsive" polymeric actuator. An "acid-responsive"
polymeric actuator will expand in response to a decreased pH in
upper electrolyte portion 222U surrounding polymeric actuator 214.
This can be accomplished by providing a positive bias of electrode
216 relative to electrode 218. Applying the positive bias causes
current to flow from electrode 216 to electrode 218 and causes a
positive ion concentration in the upper electrolyte portion 222U
surrounding actuator 214 to increase. Thus the upper electrolyte
portion 222U surrounding actuator 214 becomes acidic (lower pH) and
causes actuator 214 to expand. If the bias is reversed the upper
electrolyte portion 222U surrounding actuator 214 becomes more
basic which causes an opposite effect on actuator 214.
[0129] A "base responsive" polymeric actuator 214 may also be used.
In that case, applying a negative bias to electrode 216 relative to
electrode 218 will cause the pH in the upper electrolyte portion
222U surrounding polymeric actuator to increase which will in turn
cause the base responsive polymeric actuator 214 to expand. When
the polymeric actuator 214 expands, it causes the entire actuator
assembly 210 to expand.
[0130] An exemplary operation of actuator system 202 is depicted in
flow chart form with respect to FIG. 10, Steps 230-238 represent
steps of charge being transferred across electrode set 108 and/or
of suspended operation by power supply 240 under the control of
controller 206. While steps 230-238 are being performed, sensor 212
is providing information to controller 206 indicative of a linear
expansive state of actuator assembly 210 along axis A. Controller
206 is responsive to the information and modifies the amount of
charge being transferred between electrodes 216 and 218 in response
to the information in order to provide a predetermined linear
expanse state for actuator assembly 210 for each step of steps
230-238. At the beginning of the process of FIG. 10, polymeric
actuator 214 has a first volume.
[0131] In step 230, power supply 204 deliveries a first forward
bias charge between electrodes 216 and 218 during a first time
period. This modifies the pH of the upper electrolyte 222U.
Polymeric actuator 214 expands (or contracts) in response to the pH
change from a first volume to a second volume. At the end of the
first time period, the volume of polymeric actuator 214 is
expanding (or contracting) at a first expansion (or contraction)
rate. In a preferred embodiment, the power supply 204 adjusts a
forward bias charge magnitude in response to information received
from sensor 212 in order to achieve a predetermined second volume
for polymeric actuator 214.
[0132] In step 232, power supply 204 delivers a first negative bias
charge between electrodes 216 and 218 during a second time period.
This oppositely changes the pH of upper electrolyte portion 222U
relative to step 230 and primarily moves the pH toward a relatively
neutral state. The polymeric actuator rate of expansion (or
contraction) slows in response. In a preferred embodiment power
supply 204 adjusts the negative bias charge magnitude in response
to information from sensor 212 to reduce the magnitude of the rate
of expansion to a magnitude that approaches zero as closely as
possible. In one embodiment the rate of expansion is reduced to
less than 50% of the first expansion rate. In other embodiments
magnitude of the rate of expansion is reduced to less than 40%,
less than 30%, less than 20%, less than 10%, less than 5%, or less
than 1% of the first expansion rate. The magnitude of the first
negative bias charge is less than the magnitude of the first
positive bias charge since the negative bias charge is being used
only to stop the volume change of actuator 214, whereas the first
positive bias charge is being used to change the volume from a
first volume to a predetermined second volume.
[0133] In step 234 power supply 204 suspends operation for a third
time period during which the volume of actuator assembly 210 does
not change significantly. In step 236 power supply 204 delivers a
second forward bias charge between electrodes 216 and 218 during a
fourth time period. Polymeric actuator expands (or contracts) from
a third volume to a fourth volume in response to the delivery of
the second forward bias charge. In a preferred embodiment, the
third volume is equal to the second volume. Step 236 is similar to
step 230 except that in an exemplary embodiment the amount of
charge transferred in step 236 may be different than in step 230.
This will be discussed in infra.
[0134] Step 238 is similar to step 232. During step 238, power
supply 238 delivers a second reverse bias charge to electrode set
208 during a fifth time period to slow a magnitude of a rate of
expansion (or contraction) of actuator 214. In step 240, operation
of power supply power supply 204 is suspended during a sixth time
period.
[0135] After step 240, the steps of applying forward bias charge
(similar to steps 230 and 236) for expansion (or contraction),
applying negative bias charge to slow or stop expansion (similar to
steps 232 and 238), and suspending operation (similar to 234 and
240) may continue until actuator 214 reaches a maximum (or minimum)
volume.
[0136] In an exemplary embodiment system 202 is configured to
linearly expand actuator assembly 210 along an axis A in
approximately equal sized steps. In this exemplary embodiment an
apparatus similar to that depicted with respect to FIGS. 12A-12C
(to be discussed infra) is utilized. In order to maintain equal
size steps it is required that the forward bias charge transferred
in step 236 be greater than that transferred in step 230.
Subsequent steps will require yet larger amounts of charge transfer
to achieve the same linear volume increase.
[0137] An exemplary graph of current versus time 242 delivered by
power supply 204 to electrode set 208 is depicted with respect to
FIG. 11. It is to be understood that current versus time 242 is
delivered by power supply 204 under the control of controller 206.
Controller 206 may be receiving inputs from a sensor 212 such as
information indicative of an impedance between electrodes 216 and
218 (the impedance may also be measured from an additional third
electrode if needed) and controller 206 may adjust a current level
and or a current duration in response.
[0138] At an initial time 244 actuator 214 has an initial volume V.
During a first time period 246 power supply 204 delivers a positive
current level 248. This corresponds to step 230 of FIG. 10.
[0139] During a second time period 250, power supply 204 delivers a
negative current level 252. Second time period 250 is of lesser
magnitude than first time period 246. Second time period 250 may
correspond to step 232 of FIG. 10. During a third time period 254,
power supply 204 suspends operation. In some embodiments it may be
desirable in the third time period to apply a positive current of
smaller magnitude than level 248 instead of suspending operation
entirely. Third time period 254 may correspond to step 234 of FIG.
10.
[0140] During a fourth time period 256 power supply 204 delivers a
positive current level 258. Fourth time period 256 may be of longer
duration than first time period 246. Fourth time period 256 may
correspond to step 236 of FIG. 10.
[0141] While FIG. 11 depicts essentially a steady state DC current
being applied to electrode set during time periods 246, 250, and
256, this does not have to be the case. In one embodiment the
current is pulsed during each time period 246, 250, and 256. In a
second embodiment the current is ramped up and down during each
time period 246, 250, and 256. In a third embodiment the current
applied is in a curve such as an exponential curve during portions
or all of time periods 246, 250, and 256. Other examples of current
versus time are possible while achieving the claimed invention.
[0142] Another embodiment of the invention is similar to that
depicted in FIGS. 10 and 11 except that steps 232 and 238 are
eliminated. Thus, the power supply 204 alternates between supplying
forward bias charge similar to step 230 and in suspending operation
similar to step 234. In such an embodiment the expansion rate of
polymeric actuator 214 will slowly continue to expand (or contract)
at an exponentially decreasing rate during time periods of
suspended operation of power supply 204.
[0143] While polymeric actuator 214 is depicted in FIG. 9 as being
a single unitary polymeric actuator 214, it is to be understood
that polymeric actuator 214 may include a plurality of discrete or
separate polymeric actuators 214. An exemplary embodiment of an
actuator assembly 262 utilizing a plurality of discrete polymeric
actuators 266 is depicted with respect to FIGS. 12A-12C.
[0144] An actuator 262 of the present invention with various
details left out is depicted in plan view with respect to FIG. 12A.
Actuator 262 includes a carrier 264 and a plurality of discrete
polymeric actuators 266. The polymeric actuators 266 are disposed
in an area arrangement (or a two-dimensional arrangement) across an
upper surface 268 of carrier 264. In an exemplary embodiment upper
surface 268 is a planar surface 268 disposed along mutually
perpendicular axes 270A and 270B.
[0145] The actuator 262 is further depicted with respect to FIG.
12B which is a cross section taken along AA of FIG. 12A. Each of
the polymeric actuators 266 may be referred to as a polymeric
pillar 266 that has a long axis extending along an axis 270C. In an
exemplary embodiment axis 270C is mutually perpendicular to axes
270A and 270B.
[0146] Carrier 262 has a plurality of wells or holes 272 formed
therein that define openings 274 along surface 268 of carrier 262.
Each of the wells 272 supports one of the discrete polymeric
actuators 266. In the illustrated embodiment each discrete
polymeric actuator 266 has a volume that is primarily contained
within a well 272. A small portion 276 of the volume of each
polymeric actuator 266 may extend above the well 272.
[0147] Each of the discrete polymeric actuators 266 is formed form
a material that is volumetrically responsive to a change in pH
within an electrolyte 282 that is in contact with discrete
polymeric actuators 206. Stated another way, when the electrolyte
282 changes pH, the volume of the each discrete polymeric actuator
266 also changes. To cause this change in pH, actuator 262 includes
an electrode set 208 coupled to a power supply 204 (not shown in
FIGS. 12A-12C) that is similar to that depicted with respect to
FIG. 9.
[0148] The electrode set 208 includes an upper electrode 278 and a
lower electrode 280. Actuator assembly 262 also includes a porous
separator membrane 224 that separates electrode 280 from the
electrolyte solution 282 in contact with polymeric actuators 266.
Applying a current between upper electrode 278 and lower electrode
280 causes an ionic concentration change in electrolyte 282 which
is logarithmically related to the pH of electrolyte 282.
[0149] In one embodiment, the discrete polymer actuators 266 are
formed from an "acid responsive" polymer that expands in response
to a decrease in pH of the surrounding electrolyte 282. By
providing a positive bias at electrode 278 relative to electrode
280, the pH in surrounding electrolyte 282 decreases causing
discrete polymeric actuators 266 to expand. To improve contact
between polymeric actuators 266 and electrolyte solution 282,
carrier 282 is formed from a "micro porous polymeric material" such
as porous polyethylene.
[0150] The polymeric actuators are constrained such that when they
expand, they tend to generate a net force and displacement
primarily along axis 270C. Because most of the volume of each
actuator 266 is contained within a well 272, the net expansion must
be in an upward direction within each well 272. Further, the
actuators 266 are packed together closely enough to constrain a
"mushrooming" effect of the actuators 266 above the surface 268 to
further enhance the net upward motion and force generated by
actuators 266 during expansion.
[0151] The actuator assembly 262 includes a housing 286 that
includes an upper portion 286A, lower portion 286B, and a compliant
portion 286C. When the actuators 266 push upward they have the
effect of expanding housing 286 along the axis 270C in response to
the change in pH. In one embodiment actuator electrode 278 is rigid
and functions as a rigid platen. Actuators 266 may push against
electrode 278 that in turn pushes up against top portion 286A.
[0152] FIG. 12C depicts a preferred embodiment of the present
invention wherein the electrode 278 contacts an individual
electrode 288 that extends into the volume of polymeric actuator
266. This has an advantage of increasing the rate of expansion of
the actuator material 266 by reducing a diffusion time of charge
into polymeric actuators 266.
[0153] Other preferred embodiments may include multiple actuators
210 attached to a single controller 206 and power supply 204 with
the electrodes 208 entering and exiting the exterior to continue on
from first actuator package to the next actuator package to enable
stacking or linear lines of actuators all in electrical
connection.
[0154] FIG. 13 depicts an exemplary method of the current invention
in flow chart form. This method may be used when actuator system
202 forms part of an IV pump for delivering medication to a
patient. For example, actuator 210 may be utilized to compress an
IV bag in a portable IV pump.
[0155] During the steps 292-298, power supply 204 is transferring
charge between electrodes 216 and 218 under control of controller
206. Therefore controller 206 is executing the steps 292-298
utilizing power supply 204.
[0156] The pH of electrolyte 222U is modulated when current is
passed between electrodes 216 and 218. For the purposes of FIG. 13
discussion we define a forward bias current as one which a pH
change that results in an expansion of polymeric actuator 214.
Therefore controller 206 modulates and determines the expansion of
polymeric actuator according to a current versus time profile that
is defined by steps 292-298.
[0157] Sensor 212 monitors the state of actuator assembly 210.
Sensor 212 provides information to controller 206 that is
indicative of an expansive state of polymeric actuator 214 and
actuator assembly 210. Controller 206 is configured to modify
operation in response to the information in order to control the
expansion of actuator 210 to within a predetermined range.
[0158] The step 290, power supply 204 transfers a first forward
bias charge Q1 between electrodes 216 and 218 during a time T1 and
at an average rate I1. In response to the transfer of charge Q1,
actuator 210 expands from a first volume to a second volume at a
rapid rate due to a relatively high current level I1. During this
expansion, a medication pump utilizing actuator system 202 may
deliver a medication bolus roughly during time T1.
[0159] According to optional step 292, power supply 104 transfers a
reverse bias charge during a time T2. During time T2, the rate of
expansion is either reduced to a lower rate or is substantially
halted.
[0160] According to step 294, power supply 204 transfers a second
forward bias charge Q3 over a time T3 and at a current level I3.
Current level I3 is lower than current level I1. Current level I3
may be less than 50% than current level I1. Time T3 is considerably
longer than time T1. Time T3 may be more than ten times as long as
time T1. In the case of a portable IV pump, the pump would be
delivering a basal rate during time T3.
[0161] In step 296, steps of 290-294 are repeated (possibly
including optional step 292) in which the parameters used may
change. For example charge Q1 (the forward bias charge) may be
increased in order to get the same size of bolus in the case of a
portable IV pump. Step 298 is again a repeat of steps 290-294 in
which parameters may change. Steps 298 can then be repeated again
and again. In the embodiment in which system 202 is a portable IV
pump this may continue until the pump has discharged all available
fluid. Alternatively the actuator 214 may be returned to an initial
state and then the method of FIG. 13 may be repeated.
[0162] Another aspect of the present invention is described below,
with reference to FIGS. 14-19.
[0163] Critical high potency medications such as Schedule II pain
therapeutics are often administered to patients at healthcare
facilities. Schedule II pain medications are particularly important
for patients having undergone surgeries or having conditions
involving acute pain. In such a situation a doctor writes an order
or prescription for treatment of the patient. The order is filled
or verified by the facility pharmacy and may need to be renewed,
e.g., every 48 to 96 hours. The order can then be dispensed by an
automated cabinet system to a caregiver (e.g., a nurse) as required
by the patient. The process flow for receiving and administering
pain therapies according to a current process is depicted in FIG.
19A.
[0164] The situation according to FIG. 19A involves a patient that
is experiencing severe pain and has been prescribed a Schedule II
controlled substance pain medication such as morphine. In a first
step 302, the caregiver assesses the patient's pain by computing a
"pain score". Seeing that the patient needs pain therapy, the
caregiver needs to obtain assistance from another caregiver in
order to sign in to an automated dispensing cabinet system in a
second step 304.
[0165] The caregiver must perform the steps according to steps
304-308 with a second caregiver as witness in order to assure
proper handling and documentation for a Schedule II pain therapy
medication. This is partly because such medications have been
subject to substance abuse and theft.
[0166] In step 306, a glass cylinder of the medication is removed
from the dispenser system. In the event that the full cylinder is
not required in step 308, the caregiver loads a syringe and
discards extra medication while the second caregiver observes and
documents wastage medication. At this stage a computation of the
correct dosage must often be calculated by the caregiver according
to the concentration of the medication. Given the urgency of the
situation and other distractions, errors can easily be made at this
step that may result in a hazard to the patient and/or an
insufficient dosage to eliminate the pain.
[0167] After the syringe is loaded the caregiver injects the
medication into the patient at a step 310 and documents the dose
given along with the pain score computation at a step 312.
Disadvantages of this methodology include delays in administering
the medication, potential errors, and issues with narcotic
diversion. Additionally manual and time consuming patient-specific
record keeping has to be completed and entered into the healthcare
facility's information system on an ongoing basis further consuming
the caregivers time.
[0168] Insufficient or delayed pain therapy may impair a patient's
ability to heal and leave the healthcare facility. What is needed
is a new process that addresses these issues while simplifying the
process of administering the medication.
[0169] A process flow and device of the present invention is
depicted in FIGS. 14A and 14B respectively in block diagram form.
The process starts at a device manufacturer or factory 314 at which
medication delivery device 316 is manufactured. After manufacture,
the device is delivered to a filling and programming facility 318
where it is filled with a high potency medication. After being
filled the device is delivered to a pharmacy 320 that is part of a
healthcare facility 322. Healthcare facility 322 is typically a
hospital but it may also be a clinic, hospice, doctor's office,
nursing center, ambulance, or other fixed or mobile healthcare
facility where healthcare is provided to a patient.
[0170] At the healthcare facility 322 a doctor 324 may place an
order for device 316. The pharmacy then makes the device available
to a caregiver 326 via an automated dispensing system 328. The
caregiver can then administer medication from device 316 to patient
330.
[0171] Device 316 is small and configured to be mounted to the body
of patient 330. Device 316 includes therapeutic liquid 332
configured for delivery to patient 330. Device 316 includes a pump
or actuator 334 under control of electronics 336 that controllably
displaces the liquid 332 to the patient's body. The electronics 336
include programming instructions and parameters that govern the
proper displacement of the liquid 332 to the patient 330.
[0172] The electronics 336 are configured to receive data or code
inputs at different times during the process flow depicted in FIG.
14A. These inputs include an operating system 338 received at
factory 314, medication and patient class-specific parameters 340
received at filling facility 318, and caregiver usage related
inputs 342 during use in facility 322.
[0173] The electronics 336 are described in greater detail in block
diagram form in FIG. 15. A controller 344 which includes a
processor, program memory, and data memory controls operation of
actuator 334 via actuator driver 346. Controller 344 receives
inputs from programming interface 348, user interface 350, sensor
352 and energy monitor 354.
[0174] Programming interface 348 is configured to receive inputs at
factory 314 and filling facility 318. Programming interface 348 may
include a wireless portion for receiving wireless inputs and/or a
data connector. In one embodiment programming interface 348 is
configured to receive portions or all of an operating system during
the manufacture of device 316. Programming interface 348 is
configured to receive parameters governing the operation of device
316 while device 336 is in filling and programming facility
318.
[0175] User interface 350 may include various features such as a
display, buttons, LED indicator lights, audio indicators, as well
as a wireless interface by which a caregiver can remotely make
inputs. User interface 350 is configured to be utilized by
caregiver 326. User interface 350 is generally not configured to
alter the parameters received through programming interface 348 but
generally only allows operation of device 316 within bounds
provided by the parameters.
[0176] In an exemplary embodiment, electronics 336 include an
energy monitor 354 that is configured to monitor current delivered
by actuator driver 346 to actuator 334. In this embodiment actuator
334 includes a polymeric actuator that is configured to change
volume and displace fluid from a liquid container or bag 332 in
response to an amount of charge received from actuator driver 346.
Information from energy monitor 354 is fed back to controller 344
to assure that a specified amount of charge is passed from actuator
driver 346 to actuator 334. Other embodiments of device 316 can
also be contemplated for moving fluid such as a pump that may
require other forms of energy monitors.
[0177] Sensor 352 may be a pressure sensor configured to sense a
pressure exerted on the therapeutic liquid by actuator 334. The
sensed pressure may be used to control operation of actuator driver
346. The sensor can also be utilized as a secondary feedback path
to provide redundant monitoring of the actuator for safety
purposes. Other types of sensors 352 are contemplated to be used in
device 316 such as displacement sensors, capacitive sensing,
inductive sensing, to name a few.
[0178] Device 316 also includes a self contained power source or
battery 356 that provides power to a voltage regulator 358. Voltage
regulator 358 provides appropriate logic voltages to electronics
336.
[0179] Device 316 is depicted in simplified schematic form in FIG.
16. Device 316 includes an outer housing 360 that is configured to
be mounted to the body of patient 330. Once housing 360 is mounted
on patient 330, a conduit 362 is coupled to the patient so that
therapeutic liquid reservoir 332 is now coupled to patient 330. In
a preferred embodiment the fluid coupling to the patient is
subcutaneous. Alternatively, embodiments may have alternative modes
of medication administration such as intravenous, intramuscular,
trans-dermal, or other methods to enable a fluid to cross the skin
barrier.
[0180] Device 316 includes a user interface 350 that may include
any or all of keys 364, display 366, and an LED indicator 368. The
user interface 350 may also include an external wireless device
(not shown) that is configured to communicate with controller 336
using a wireless link such as RFID, IR, Bluetooth or other forms of
wireless communication. The user interface may provide status and
historical therapeutic and event information to the operator via
wired or wireless methods.
[0181] Device 316 may also include a security measure or device
configured to limit access to use of device 316. Various security
measures may include physical keys or user interfaces requiring the
caregiver 326 to enter a code to unlock or enable the device
316.
[0182] An example of a security measure includes a removable label
369 having a code that is utilized to unlock device 316 once the
label is removed. This code may be entered by the pharmacist or
caregiver for the purpose of activating device 316 and enabling
medication to be administered by device 316. The label may be kept
in a secured location such as upon a patient chart. Other examples
of security measures include wireless devices that interface with
device 316 and utilize a security code mechanism, proximity sensing
mechanism or combination thereof.
[0183] A method of providing device 316 to healthcare facility 322
caregivers is described with respect to FIG. 17 in flow chart form.
In a first step 370, device 316 is manufactured in factory 314. As
part of the manufacturing process, an operating system is installed
onto controller 344. Device 316 is then transferred to filling and
programming facility 314 in an unfilled state before or after step
372. At this point, device 316 may be used for a wide range of
potential therapies.
[0184] According to 372, a medication type and concentration is
selected based on a particular class of patient conditions from
among a plurality of different classes of patient conditions. Based
upon the particular class, device 316 is filled with the medication
type and concentration in step 374. In step 376, parameters are
stored on controller 344 that are specific to the (1) class of
patient conditions, (2) the type of medication, and (3) the
concentration of the medication. The parameters govern the
operation of the device 316 according to safety and efficacy
requirements of the particular type and concentration of the
medication. Some examples of these parameters follow:
[0185] Bolus Dosage Selection: A selection or range of possible
bolus dosages are provided consistent with the class of patient
conditions, the medication type, and concentration. In one
exemplary embodiment there is no limits on the dosages but there
are "soft guardrails" wherein the device 316 is configured to issue
warnings when a bolus dosage or sequence of dosages have values
that are outside of a recommended range. The warning may be a
visual and/or audible warning issued from user interface 350. The
warning may include warning information that is transmitted
wirelessly to another device such as a cellular phone or network, a
computer network, a PDA, or any other device that can provide a
warning to a caregiver.
[0186] Maximum Dosage Over Specified Time Periods: For example,
there may be an upper limit on the total dosage that should be
administered over 24 hours. In one embodiment the device 316 may be
configured to issue a warning to the caregiver if the dosage over a
specified time period is above a threshold.
[0187] Minimum Dosage: Since the patient is of a certain patient
class there may be a lower limit dosage below which is insufficient
to reduce patient suffering and/or facilitate recovery. If a
caregiver operates the device below the minimum, then a warning may
be generated.
[0188] In one embodiment of the invention, step 374 is performed
before step 372. In another embodiment, step 374 is performed after
step 376. In yet another embodiment steps 374 and 376 are performed
concurrently.
[0189] Once the device 316 has been filled and programmed according
to steps 374 and 376, the device is placed in inventory of
healthcare facility 322 in a step 378. According to steps 374 and
376, device 316 has been filled and programmed for a specific class
of patient conditions. The parameters that are inputted according
to step 376 cannot be overridden by a caregiver and are preferably
stored in a write once or write protected memory in controller 336
to prevent any change to them.
[0190] A method of use of device 316 is depicted according to FIG.
18 in flow chart form. The discussion that follows will refer to a
situation requiring pain medication but it is to be understood that
a similar procedure may be used for other types of medications.
Prior to step 380 the device 316 is in inventory in pharmacy 320. A
doctor 324 may have a patient 313 (FIG. 14A) who is or will be
experiencing considerable pain following an acute illness, surgical
procedure, or bodily malfunction.
[0191] According to step 380, the doctor 324 produces a
prescription for the pain medication which is transferred to
pharmacy 320. A pharmacist reviews the prescription, selects device
316, and verifies the order according to step 382. The pharmacist
will select a device 316 having that is pre-configured with
parameters, medication type, and concentration that are consistent
with the prescription.
[0192] Once the pharmacist has verified the proper device according
to the order, the pharmacist activates the device 316 according to
step 384. According to step 386 the pharmacist then utilizes an
automated dispensing system to transfer the device to caregiver
326. The caregiver 326 then places upon the patient and couples the
device via an administration route (conduit and coupling means) 362
to the patient 330 according to step 388. In an exemplary
embodiment, administration route is subcutaneous. In step 390, the
caregiver 326 enters a code into device 316 that unlocks the device
and enables administration of medication to patient 330. In step
392 the caregiver manipulates the user interface 350 to administer
the medication to patient 330.
[0193] The method of this invention has substantial benefits over
the current methods of administration using syringes. This is
illustrated by comparing FIGS. 19A and 19B that contrast the
current prior art method (FIG. 19A) to the new process according to
the present invention. As discussed before in the background, the
current processes involving syringes includes steps 302-312 as
illustrated in FIG. 19A. The new process is depicted in steps 402,
404, and 406. As before, the caregiver does assess patient pain and
compute a pain score. According to the new method, the caregiver
can then utilize user interface 350 to quickly unlock the device
316 and administer medication immediately as needed without help
from another caregiver and without all the steps 302-312 of the
prior art. Because device 316 has an internal memory, an automatic
record is generated of the medication administration according to
step 406 that can then be downloaded or accessed via wireless
transmission and update the patient specific electronic records at
the healthcare facility.
[0194] At this point several examples of pre-configured devices 316
will be disclosed. Each of these devices are initially the same
design produced in factory 314 but become configured for a
particular class of patients within filling within facility
318.
Example 1
[0195] Morphine: According to this example of step 374 of FIG. 17,
the device 316 is filled with morphine having a 50 mg/ml
(milligrams of Morphine per milliliter) concentration. The device
receives bolus dose parameters according to step 376 to enable a
caregiver to provide boluses of 0.5 mg (0.01 ml), 1.0 mg (0.02 ml),
2.0 mg (0.04 ml), and 5.0 mg (0.1 ml).
Example 2
[0196] Hydromorphone: According to this example of step 374 the
device 316 is filled with hydromorphone having a 10 mg/ml
concentration. In step 376 the device receives bolus dose
parameters enabling the caregiver to provide doses of 0.2 mg (0.02
ml), 0.25 mg (0.025 ml), 0.5 mg (0.05 ml), 1 mg (0.1 ml), and 2 mg
(0.02 ml).
Example 3
[0197] fentanyl: According to this example of step 374 the device
316 is filled with fentanyl having a concentration of 0.05 ml/mg.
The device receives bolus dose parameters to enable the caregiver
to inject boluses of 0.015 mg (0.3 ml), 0.025 mg (0.05 ml), 0.05 mg
(0.1 ml), 0.075 mg (0.15 ml), and 0.1 mg (0.2 ml).
[0198] The present invention has been described as delivering
Schedule II controlled substances for pain relief. However the
present invention may deliver other fluids such as pharmaceutical
drugs, other controlled substances, vitamins, hormones, hydration
liquids, biologics, liquids with site specific identification or
therapy molecular tags, insulin, immune system therapeutics such as
Enbrel & Humira, and gene therapeutics. In addition other
non-opioid medications may be used to supplement analgesia,
including non-steroidal anti-inflammatory medications and low-dose
anti-depressants.
[0199] Referring now to FIGS. 20A-26, an exemplary embodiment of a
medication delivery apparatus 502 according to the present
invention is depicted in block diagram form with respect to FIG.
20A and schematic form with respect to FIG. 20B. Medication
delivery apparatus 502 includes an outer housing 504 configured to
be attached or mounted to a patient body. Within housing 504 is a
collapsible reservoir 506 adjacent to an area actuator assembly 508
that is electrically coupled to control and memory electronics
510.
[0200] Area actuator assembly 508 is responsive to electrical
signals received from control electronics 510. Area actuator
assembly 508 is configured to expand and press upon collapsible
reservoir 506 in response to charge or current received from
electronics 510. Area actuator 510 will be described in more detail
with respect to FIG. 21 and later figures.
[0201] When area actuator assembly 508 expands and compresses
collapsible reservoir 506, fluid within collapsible reservoir 506
is displaced under pressure from reservoir 506, through conduit
512, and to patient 514. In a preferred embodiment a subcutaneous
fluid interface exists between conduit 512 and patient 514.
[0202] Disposed upon outer housing 504 is a user interface 516.
User interface 516 may includes any or all of input keys or buttons
518, display 520, and LED indicator lights 522. User interface 516
may also include a wireless device (not shown) utilized to control
medication delivery device 502, and facilitate access to electronic
medical records stored in the device memory. The user interface is
also configured to facilitate secure access to the device when
necessary.
[0203] FIG. 21 depicts a preferred embodiment of actuator assembly
508 coupled to electronics 510. Actuator assembly 508 is a sealed
device including an outer housing 524 that may include a flexible
film material to allow for expansion of housing 524. Outer housing
524 is sealed and encases a sealed region 525 that includes inner
contents of actuator assembly 508.
[0204] Inner contents of actuator assembly 508 include a responsive
material 526 disposed between electrodes 528 including upper
electrode 528U and lower electrode 528L. A porous separator
membrane 530 separates upper electrode 528U from sealed region 525.
Also within sealed housing 524 is an electrolyte solution 532
including an upper electrolyte solution 532U that is between
separator membrane 530 and upper electrode 528U and a lower
electrolyte solution 532L that is between membrane 530 and housing
524.
[0205] In a preferred embodiment responsive material 526 is
polymeric actuator 526 that is responsive to pH changes within
lower electrolyte solution 532L. Electronics 510 are configured to
pass charge between electrodes 528 and, in doing so, modulate the
pH within the lower electrolyte 532L by changing the charge
distribution within housing 524. There are two types of polymeric
actuators 526 that may be used within actuator assembly 508
including an "acid-responsive" polymeric actuator and a
"base-responsive" polymeric actuator. An "acid-responsive"
polymeric actuator will expand in response to a decreased pH in
electrolyte 532L surrounding polymeric actuator 526. This can be
accomplished by providing a positive bias of electrode 528U
relative to electrode 528L. Applying the positive bias causes
current to flow from electrode 528U to electrode 528L and causes a
positive ion concentration in the electrolyte 532L surrounding
actuator 526 to increase. Thus the electrolyte 532L surrounding
actuator 526 becomes acidic (lower pH) and causes actuator 526 to
expand. (If the bias is reversed the electrolyte 532L surrounding
actuator 526 becomes more basic which causes an opposite effect on
actuator 526.)
[0206] A "base responsive" polymeric actuator may also be used. In
that case, applying a negative bias to electrode 528L relative to
electrode 528U will cause the pH in the electrolyte 532L
surrounding polymeric actuator to increase which will in turn cause
the base responsive polymeric actuator 526 to expand. When
polymeric actuator 526 expands, it causes the entire actuator
assembly 508 to expand.
[0207] Other designs of actuator assemblies 508 can be envisioned
using multiple polymeric actuators 526 and more than two electrodes
528. These alternative designs may be of various geometric shapes
and sizes and be substituted into the medication delivery device of
the present invention without departing from the broad scope of the
invention.
[0208] A resulting medication delivery device 502 is in top plan
view in FIG. 22A, cutaway view in FIG. 22B, and in cross section
view in FIG. 22C. In FIG. 22A and in figures that follow certain
details of device 502 are left out for illustrative simplicity.
FIG. 22A depicts a top view of medication delivery device 502
illustrating outer housing 504, user interface 516, and fluid
conduit 512. Device 502 has its longest dimension along a primary
lateral axis X, a second longest dimension along secondary lateral
axis Y, and the minimum dimension along depth axis Z (FIG. 22C).
Axes X, Y, and Z are mutually orthogonal. Arranged along primary
axis X are an actuator/reservoir pocket 534 and an electronics
pocket 536. This arrangement minimizes a depth dimension of device
502. This is important for patient comfort, since patients are more
sensitive to the thickness of a body carried device than to the
lateral dimensions.
[0209] Pockets 534 and 536 are better illustrated in FIG. 22B which
is a cutaway view of device 502. Between pockets 534 and 536 is a
liquid seal 538 to protect electronics 510 from fluid that may leak
from conduit 512 or in the event that reservoir 506 or actuator
assembly 508 becomes ruptured. Also included are electrical leads
540 that couple electronics in pocket 536 to the actuator assembly
508 in pocket 534 and pass through seal 538.
[0210] Device 502 may also include a fluid fill port 513 for
filling reservoir 506 with fluid. Alternatively reservoir 506 may
be filled via fluid conduit 512. In a preferred embodiment, fluid
fill port 513 or fluid conduit 512 are configured to enable
reservoir 506 to be filled in a facility that is separate from the
factory within which device 502 is manufactured.
[0211] FIG. 22C depicts a cross section of device 502 taken through
section AA' of FIG. 22A. Arranged along depth axis Z from top to
bottom are top or upper support 542, actuator assembly 508,
collapsible reservoir 506, and lower support 544. Upper support 542
and lower support 544 are rigidly or fixedly positioned with
respect to each other such that expansion of actuator assembly 508
is constrained to squeeze collapsible reservoir 506. In one
embodiment, upper support 542 and lower support 544 are formed
integrally with outer housing 504. In a second embodiment upper
support 542 and lower support 544 are formed a second integral part
that is mounted within housing 504. As a third embodiment upper
support 542 and lower support 544 are formed as separate parts that
are mounted to housing 504. In all embodiments upper support 542
and lower support 544 are configured to be in a fixed relationship
to facilitate a proper interaction of actuator assembly 508 and
collapsible reservoir 506 to assure reliable dispensing of fluid
from collapsible reservoir 506 in response to dimensional expansion
of actuator assembly 508 along thickness axis Z.
[0212] FIGS. 23A, 23B, and 23C provide a more detailed view of
actuator assembly 508. FIG. 23A is a plan view of device 502 that
is similar to FIG. 22A except that a cross section BB' is indicated
taken through pocket 534. FIGS. 23B and 23C are cross sectional
views taken through section BB' of FIG. 23C focusing on actuator
assembly 508 and leaving out further details for simplicity.
[0213] FIG. 23B depicts a preferred embodiment of actuator assembly
508 having a film envelope or housing 524, upper electrode 528U,
polymeric actuator 526, and lower electrode 528L. Upper electrode
528U is adjacent to upper support 542 and lower electrode 528L is
adjacent to collapsible reservoir 506. In order to reduce a number
of parts, the lower electrode 528L is configured to function as a
piston plate to transfer an expansive force of polymeric actuator
526 to collapsible reservoir 506. In order to assure that
collapsible reservoir can be fully compressed, the piston plate
area is made to correspond to that of the fluid bag 506 and is
relative thick and rigid. In order to maximize spatial efficiency
in pocket 534 (to not make pocket 534 overly large relative to the
size of reservoir 506) and to allow for expansion of film bag 524,
the upper electrode 528U is sized smaller in area relative to
piston plate/lower electrode 528L.
[0214] FIG. 23C depicts an alternative embodiment of actuator
assembly 508 wherein piston plate 546 is a separate part rather
than being the lower electrode 528L. In this alternative embodiment
piston plate 546 is relatively rigid and sized with an area larger
relative to upper electrode 528U. Piston plate 546 is sized to
correspond to the size of collapsible reservoir 506 to maximize
volumetric fluid delivery from device 502. Piston plate 546 is
disposed between actuator assembly 508 and collapsible fluid
reservoir 506.
[0215] In the embodiments depicted in FIGS. 23A-C the actuator
assembly 508 overlays the fluid bag 506 and each have lateral
dimensions along primary lateral axis X and secondary lateral axis
Y that correspond closely to the lateral dimensions of pocket 534
in order to maximize the a total fluid volume output of device 502
relative to the size of device 502. The actuator 508 and the bag
506 have relatively thin dimensions along depth axis Z in order to
minimize overall depth of device 502 to maximize patient
comfort.
[0216] In both illustrated embodiments, upper electrode 528U is
adjacent to upper support 542. Lower electrode/piston plate 528L or
piston plate 546 is adjacent to collapsible reservoir 506.
Collapsible reservoir 506 is adjacent to lower support 544.
[0217] FIGS. 24A-C depict an exemplary embodiment of device 502
with emphasis on pockets 534 and 536. FIG. 24A is a cross sectional
view taken through AA' of FIG. 22A illustrating pocket 534 and
pocket 536. Pocket 534 contains actuator assembly 508 overlaying
collapsible reservoir 506. Pocket 536 contains electronics 510 that
are coupled to actuator 506 via leads 540. As can be seen,
disposing actuator/reservoir pocket 534 and electronics pocket 536
along primary or major lateral axis X minimizes the dimension of
device 502 along depth axis Z. The depth axis of a patient-worn
device is the largest dimensionally-based source of discomfort for
wearing such a device. The device of the present invention breaks
new ground in terms of patient comfort relative to volume of
medication delivered.
[0218] The reservoir/actuator pocket 534 is approximately square
looking upon the lateral axes X and Y. This maximizes volumetric
efficiency of the reservoir actuator pocket 534 in terms of volume
of fluid delivered relative to size of device 502. Leading to the
patient is a conduit 512 that, in an exemplary embodiment, exits
pocket 543 on a side that opposes the electronics 510 relative to
axis X. In addition, the electrical lead through 540 is on an
opposing side of actuator pocket 534 relative to conduit 512 and
relative to axis X.
[0219] FIG. 24B depicts a cross section of a preferred embodiment
of pocket 534 taken through section BB' of FIG. 24A. In this
preferred embodiment, lower electrode 528L is also a piston plate
and has an area corresponding to that of collapsible reservoir 506.
Upper electrode 528U has a smaller area relative to lower electrode
528L. Pocket 534 includes a tapered chamfered upper wall 548 that
corresponds to the asymmetry between upper electrode 528U and lower
electrode/piston plate 528L. An upper portion of pocket 534
provides upper support 542 and is adjacent to the upper electrode
528U of actuator assembly 508. A lower portion of pocket 534
provides lower support 544 and is adjacent to collapsible fluid
reservoir 506.
[0220] FIG. 24C depicts an alternative embodiment of pocket 534
taken through section BB' of FIG. 23A. In this alternative
embodiment electrodes 528U and 528L may be approximately the same
size. A separate piston plate 546 is disposed between and adjacent
to collapsible fluid reservoir 506 and actuator assembly 508.
Piston plate 546 has an area that corresponds to that of
collapsible fluid reservoir 506 to maximize delivery of fluid from
reservoir 506. The area of piston plate 546 is relatively larger
than the area of upper electrode 528U.
[0221] FIG. 25 depicts an alternative embodiment of device 502 in
plan cutaway view. FIG. 25 depicts a device 502 deploying two
reservoir/actuator pockets 534A and 534B for dispensing two
different fluids to a patient. Pocket 534A contains an actuator
508A overlaying a collapsible reservoir 506A containing a first
fluid. Pocket 534B contains an actuator (not shown) overlaying a
collapsible reservoir 506B containing a second fluid that is
different than the first fluid. Fluids from bags 506A and 506B exit
to the patient through fluid conduits 512A and 512B respectively.
Fluid conduits 512A and 512B may combine to mix fluids prior to
dispensing to the patient, or they may remain unmixed in individual
conduits. Structures of the actuators, collapsible bags, and other
features therein may be similar to those discussed with respect to
FIGS. 21, 22C, 23B or 23C, and 24A or 24C.
[0222] FIG. 26 depicts an alternative embodiment of device 502 in
cross section form taken through AA' of FIG. 22A. This alternative
embodiment of device 502 deploys two fluid bags including a first
fluid bag 550U overlaying a second fluid bag 550L. As actuator 526
expands, it compresses both fluid bags 550U and 550L
simultaneously. Other elements such as housing 504, upper support
542, and lower support 544 are similar to those discussed with
respect to FIG. 22C.
[0223] FIG. 27 illustrates yet another embodiment of the present
invention. In this alternative embodiment, a liquid delivery device
602 as described above is paired with a patient monitoring device
604, such as a pulse oximeter, a blood CO.sub.2 sensor, a
respiration rate sensor, a blood pressure monitor, a glucose
monitor, or the like, with feedback to the liquid delivery device
controller, to adjust or stop the pump, or signal an alarm if the
patient is showing signs of overmedication. The feedback also could
be used to adjust the pump to deliver additional medication if the
patient is showing signs of undermedication.
[0224] Other embodiments can be envisioned with other arrangements
and configurations of fluid bags and actuators. The scope of the
present invention is not intended to be limited except as recited
in the claims.
* * * * *