U.S. patent application number 12/712952 was filed with the patent office on 2010-07-22 for dome and screw valves for remotely adjustable gastric banding systems.
This patent application is currently assigned to ALLERGAN, INC.. Invention is credited to Janel BIRK, Robert E. HOYT, JR., Sean SNOW.
Application Number | 20100185049 12/712952 |
Document ID | / |
Family ID | 43920851 |
Filed Date | 2010-07-22 |
United States Patent
Application |
20100185049 |
Kind Code |
A1 |
BIRK; Janel ; et
al. |
July 22, 2010 |
DOME AND SCREW VALVES FOR REMOTELY ADJUSTABLE GASTRIC BANDING
SYSTEMS
Abstract
An implantable device controls the movement of fluid to an
inflatable portion of a gastric band. The implantable device
includes a body. The body has an inlet, an outlet and a valve seat
positioned between the inlet and the outlet. The body defines a
fluid passage from the inlet to the outlet. The implantable device
also includes a diaphragm. The diaphragm has one or more edges
coupled to the body. The diaphragm is made of an elastomeric
material and capable of being moved between a closed position that
blocks the valve seat and does not allow the fluid to move from the
inlet to the outlet and an open position that does not block the
valve seat and allows the fluid to move from the inlet to the
outlet.
Inventors: |
BIRK; Janel; (Oxnard,
CA) ; HOYT, JR.; Robert E.; (Santa Barbara, CA)
; SNOW; Sean; (Carpinteria, CA) |
Correspondence
Address: |
ALLERGAN, INC.
2525 DUPONT DRIVE, T2-7H
IRVINE
CA
92612-1599
US
|
Assignee: |
ALLERGAN, INC.
Irvine
CA
|
Family ID: |
43920851 |
Appl. No.: |
12/712952 |
Filed: |
February 25, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12603058 |
Oct 21, 2009 |
|
|
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12712952 |
|
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61107576 |
Oct 22, 2008 |
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Current U.S.
Class: |
600/37 |
Current CPC
Class: |
A61F 5/003 20130101;
A61F 5/0056 20130101; Y10T 137/87716 20150401; A61F 5/0059
20130101; A61F 5/0066 20130101; Y10T 137/7374 20150401 |
Class at
Publication: |
600/37 |
International
Class: |
A61F 2/00 20060101
A61F002/00 |
Claims
1. An implantable device for controlling movement of a fluid to an
inflatable portion of a gastric band, the implantable device
comprising: a body having an inlet, an outlet and a valve seat
positioned between the inlet and the outlet, the body defining a
fluid passage from the inlet to the outlet; a diaphragm having one
or more edges coupled to the body, the diaphragm being made of an
elastomeric material and capable of being moved from a closed
position that blocks the valve seat and does not allow the fluid to
move from the inlet to the outlet to an open position that does not
block the valve seat and allows the fluid to move from the inlet to
the outlet; an actuator configured to apply a force on the
diaphragm causing the diaphragm to move from the closed position to
the open position; and a microcontroller coupled to the actuator,
the microcontroller configured to receive a telemetric signal from
a remote transmitter and control the actuator based on the
telemetric signal.
2. The implantable device of claim 1 further comprising a cap,
coupled between the diaphragm and the actuator, for directing the
force from the actuator to the diaphragm.
3. The implantable device of claim 1 wherein the force is applied
on the one or more edges of the diaphragm.
4. The implantable device of claim 1 wherein the diaphragm moves in
a direction substantially opposite to a direction of the force.
5. The implantable device of claim 1 wherein the diaphragm prevents
the fluid from coming into direct contact with the actuator.
6. The implantable device of claim 1 wherein the diaphragm is made
of a flexible material.
7. The implantable device of claim 1 wherein the diaphragm is in
the open position when the actuator is in an energized state.
8. The implantable device of claim 1 wherein the diaphragm is in
the closed position when the actuator is in an unenergized
state.
9. The implantable device of claim 1 wherein the actuator is
selected from a group consisting of a solenoid, a stepper motor, a
piezoelectric actuator, an electroactive polymer, and combinations
thereof.
10. The implantable device of claim 1 wherein the remote
transmitter transmits the telemetric signal to the
microcontroller.
11. An implantable device that controls the movement of fluid to an
inflatable portion of a gastric band, the implantable device
comprising: a body having an inlet, an outlet and a valve seat, the
body defining a fluid passage from the inlet to the outlet; a valve
seal having one or more edges coupled to the body, the valve seal
being made of an elastomeric material and capable of being moved
from an open position that does not block the valve seat and allows
the fluid to move from the inlet to the outlet to a closed position
that blocks the valve seat and does not allow the fluid to move
from the inlet to the outlet; and an actuator having an actuator
body defining a threaded screw hole and positioned within the body
and a screw positioned within the threaded screw hole, the screw
configured to apply a force on the valve seal causing the valve
seal to move from the open position to the closed position when the
actuator receives a telemetric signal from a remote
transmitter.
12. The implantable device of claim 11 further comprising a motor,
positioned within the actuator body, for moving the screw within
the threaded screw hole.
13. The implantable device of claim 12 wherein the motor is
selected from a group consisting of a DC motor, an AC motor, a
solenoid, a stepper motor, a piezoelectric actuator, a
piezoelectric driver, an electroactive polymer, and combinations
thereof.
14. The implantable device of claim 13 wherein the motor is
configured to move the screw to a first screw position so that the
valve seal can be moved to a first valve seal position depending on
the telemetric signal received from the remote transmitter.
15. The implantable device of claim 14 wherein the first valve seal
position is selected from a group consisting of the closed
position, the open position, and a partially-open position which is
between the closed position and the open position.
16. The implantable device of claim 11 further comprising a
coupling mechanism, positioned between the valve seal and the
screw, for decoupling a rotational motion of the screw but allowing
for a translational motion of the screw.
17. The implantable device of claim 16 wherein the coupling
mechanism is selected from a group consisting of a tappet, a ball
bearing, a bellows unit, and combinations thereof.
18. The implantable device of claim 11 further comprising a flow
sensor, coupled to the valve seat, for determining and adjusting an
amount of the fluid flowing between the inlet and the outlet.
19. The implantable device of claim 11 further comprising a
pressure sensor, coupled to the valve seat, for determining and
adjusting a pressure of the fluid flowing between the inlet and the
outlet.
20. The implantable device of claim 11 wherein the remote
transmitter transmits the telemetric signal to the actuator.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 12/603,058, filed Oct. 21, 2009, which claims
the benefit of U.S. provisional patent application No. 61/107,576,
filed Oct. 22, 2008, the entire disclosure of each of these
applications are incorporated herein by reference.
FIELD
[0002] The present invention generally relates to medical systems
and apparatus and uses thereof for treating obesity and/or
obesity-related diseases, and more specifically, relates to dome
and screw valves for remotely adjustable gastric banding
systems.
BACKGROUND
[0003] Adjustable, gastric banding systems provide an effective and
substantially less invasive alternative to gastric bypass surgery
and other conventional surgical weight loss procedures. Despite the
sustained weight loss of invasive weight loss procedures, such as
gastric bypass surgery, it has been recognized that sustained
weight loss can also be achieved through a laparoscopically-placed
gastric band, for example, the LAP-BAND.RTM. (Allergan, Inc.,
Irvine, Calif.) gastric band or the LAP-BAND AP.RTM. (Allergan,
Inc., Irvine, Calif.) gastric band. Generally, gastric bands are
placed about the cardia, or upper portion, of a patient's stomach
forming a stoma that restricts the food's passage into a lower
portion of the stomach. When the stoma is of an appropriate size
that is restricted by a gastric band, food held in the upper
portion of the stomach provides a feeling of satiety or fullness
that discourages overeating. Unlike gastric bypass surgery
procedures, adjustable gastric banding systems are reversible and
require no permanent modification to the gastrointestinal
tract.
[0004] Over time, a stoma created by the gastric band may need an
adjustment in order to maintain an appropriate size, which is
neither too restrictive nor too passive. Prior art gastric banding
systems provide a subcutaneous fluid access port connected to an
expandable or inflatable portion of the gastric band. By adding
fluid to or removing fluid from the inflatable portion by means of
a hypodermic needle inserted into the fluid access port, the
effective size of the gastric band can be adjusted to provide a
tighter or looser constriction.
[0005] It would be desirable to allow for non-invasive adjustment
of gastric band constriction, for example, without the use of the
hypodermic needle. Thus, remotely adjustable gastric banding
systems capable of non-invasive adjustment are desired and
described herein.
SUMMARY
[0006] In one example embodiment of the present invention, there is
an implantable device that controls the movement of fluid to an
inflatable portion of a gastric band. The implantable device
includes a body. The body has an inlet, an outlet and a valve seat
positioned between the inlet and the outlet. The body defines a
fluid passage from the inlet to the outlet.
[0007] The implantable device also includes a diaphragm. The
diaphragm has one or more edges coupled to the body. The diaphragm
is made of an elastomeric material and capable of being moved
between a closed position that blocks the valve seat and does not
allow the fluid to move from the inlet to the outlet and an open
position that does not block the valve seat and allows the fluid to
move from the inlet to the outlet.
[0008] The implantable device also includes an actuator. The
actuator is configured to apply a force on the diaphragm causing
the diaphragm to move from the closed position to the open
position. The implantable device also includes a microcontroller
coupled to the actuator, the microcontroller configured to receive
a telemetric signal from a remote transmitter and control the
actuator based on the telemetric signal.
[0009] In another example embodiment of the present invention,
there is an implantable device that controls the movement of fluid
to an inflatable portion of a gastric band. The implantable device
includes a body. The body has an inlet, an outlet and a valve seat.
The body defines a fluid passage from the inlet to the outlet.
[0010] The implantable device also includes a valve seal. The valve
seal has one or more edges coupled to the body. The valve seal is
made of an elastomeric material and is capable of being moved
between an open position that does not block the valve seat and
allows the fluid to move from the inlet to the outlet and a closed
position that blocks the valve seat and does not allow the fluid to
move from the inlet to the outlet.
[0011] The implantable device also includes an actuator. The
actuator is positioned within the body. The actuator has an
actuator body defining a threaded screw hole and a screw positioned
within the threaded screw hole. The screw is configured to apply a
force on the valve seal causing the valve seal to move from the
open position to the closed position when the actuator receives a
telemetric signal from an implantable microcontroller. A first
telemetric signal may be used to move the valve seal from the open
position to the closed position and a second telemetric signal may
be used to move the valve seal from the closed position to the open
position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a perspective view of a remotely
adjustable gastric banding system according to an embodiment of the
present invention.
[0013] FIG. 2 illustrates an example configuration of the internal
components of the high precision pump unit illustrated in FIG. 1
according to an embodiment of the present invention.
[0014] FIGS. 3A and 3B illustrate the filling and draining,
respectively, of a gastric band using the systems described herein
according to an embodiment of the present invention.
[0015] FIGS. 4A and 4B illustrate cross-sectional views of an
exemplary valve in a closed position and an open position according
to an embodiment of the present invention.
[0016] FIGS. 5A and 5B illustrate cross-sectional views of an
exemplary dome valve in a closed position and an open position
according to an embodiment of the present invention.
[0017] FIGS. 6A and 6B illustrate cross-sectional views of an
exemplary screw valve in a closed position and an open position
according to an embodiment of the present invention.
[0018] FIGS. 7A, 7B and 7C illustrate side views of examples of the
coupling mechanism illustrated in FIGS. 6A and 6B according to
various embodiments of the present invention.
[0019] FIG. 8 is a flow chart of a method of controlling a dome
valve according to an embodiment of the present invention.
[0020] FIG. 9 is a flow chart of a method of controlling a screw
valve according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0021] The present invention generally provides remotely adjustable
gastric banding systems, for example, for treatment of obesity and
obesity related conditions, as well as systems for controlling
inflation of a gastric banding system.
[0022] Remotely adjustable gastric banding systems, otherwise
referred to as a remotely adjustable band (RAB), include one or
more medical devices, or a system, which allows a healthcare worker
to adjust a gastric band without requiring a hypodermic needle to
be inserted into an implanted access port. The RAB may use a remote
transmitter to send radiofrequency signals or telemetric signals
for powering and communicating with an implanted device of the RAB.
The implanted device can fill or drain a gastric band of the RAB as
requested by the healthcare worker via the remote transmitter. In
between filling and draining adjustments to the gastric band, the
volume of fluid contained in the gastric band ideally remains
unchanged.
[0023] In one embodiment, a dome valve is used to pass and block
fluid. The dome valve has an actuator that can adjust an
elastomeric diaphragm (e.g., a valve seal) to an open or closed
position. The dome valve can be used safely during magnetic
resonance imaging (MRI) since the dome valve does not have a
significant amount of ferromagnetic material. The elastomeric
diaphragm is also inexpensive and robust.
[0024] In another embodiment, a screw valve is used to pass and
block fluid. The screw valve has a screw that can adjust a valve
seal to multiple precise positions, not just fully open or fully
closed. The screw valve can be used in a high pressure environment
since no force is required to maintain a position and because the
screw can be driven to create a tight seal.
[0025] FIG. 1 illustrates a perspective view of a remotely
adjustable gastric banding system 100 according to an embodiment of
the present invention. The gastric banding system 100 includes a
gastric band 102, a reservoir 104, a high precision pump unit 106,
a remote transmitter 108 and tubing 110. The skin 122 of a human
illustrates a separation between implantable components and
non-implantable components. As illustrated, the remote transmitter
108 (e.g., a remote controller unit) is non-implantable, whereas
the gastric band 102, the reservoir 104, the high precision pump
unit 106, and the tubing 110 are implantable (e.g., an implantable
device), and can be implanted in the human using conventional
surgical techniques. The high precision pump unit 106 can be used
to replace or complement a conventional access port for adjusting
inflation or deflation of the gastric band 102. In some
embodiments, the system includes an override port 212 which can be
used, for example, with a hypodermic needle 112, to fill and drain
the gastric band 102.
[0026] The high precision pump unit 106 is connected to the
reservoir 104 and the gastric band 102 via the tubing 110, and can
move precisely metered volumes of fluid (e.g., saline) in or out of
the gastric band 102. Moving the fluid into the gastric band 102
causes inflation of at least one bladder, or an inflatable portion
114 (e.g., inflatable member) and constricts around the cardia, or
upper portion of the stomach, forming a stoma that restricts the
passage of food into a lower portion of the stomach. This stoma can
provide a patient with a sensation of satiety or fullness that
discourages overeating. In contrast, moving the fluid out of the
inflatable portion 114 of the gastric band 102 reduces the pressure
around the cardia and allows the stoma to be at least partially
released and allows the human to regain a hunger sensation.
[0027] The high precision pump unit 106 is implanted within a
patient, and therefore, is non-biodegradable. The encasement or
housing of the high precision pump unit 106 may be non-hermetically
sealed or hermetically sealed from the in situ environment (e.g.,
undisturbed environment) in the patient and formed at least
partially of any rugged plastic material including, polypropylene,
cyclicolephin co-polymer, nylon, and other compatible polymers and
the like or at least partially formed of a non-radioopaque metal.
The housing has a smooth exterior shape, with no jagged edges, to
minimize foreign body response and tissue irritation. The high
precision pump unit 106 is also sterilizable, in one embodiment,
dry heat sterilizable before implantation.
[0028] The reservoir 104 may be a soft, collapsible balloon made of
a biocompatible polymer material, for example, silicone, which
holds a reserve of a biocompatible fluid, for example, saline, to
allow for adjustments in the size of the gastric band 102. In one
embodiment, the reservoir 104 is fully collapsible and can contain
the extra fluid required to increase the volume of the gastric band
102 to therapeutic levels. Further, the reservoir 104 also may have
excess capacity so the gastric band 102 may be fully drained into
it without the reservoir 104 being filled beyond its maximum
capacity.
[0029] The reservoir 104 may represent one or both of a source
reservoir and a drain reservoir, where the source reservoir
provides fluid to the gastric band 102, and the drain reservoir
receives fluid from the gastric band 102.
[0030] The fluids used within the systems of the present invention
may include any fluid that is biocompatible. The fluid has no
adverse effect on the patient in the unlikely event that a leak
emanates from the system. The fluid can simply be water or any
biocompatible polymer oil such as caster oil. In an example
embodiment, the fluid is, saline.
[0031] The tubing 110 is any biocompatible flexible tubing that
does not degrade in vivo (e.g., within the human). The tubing 110
is configured to withstand hydraulic pressure up to about 30 psi
(about 206 kPa) without leakage. This hydraulic pressure tolerance
is true of the entire fluid path of the systems described herein.
Although the systems described herein do not generally leak, if
they do, fluid is not lost at a rate greater than about 0.2 cc/yr,
or about 0.1 cc/yr.
[0032] Other biocompatible and biostable polymers which are useful
for forming the reservoir 104 and the tubing 110 include:
polyolefins, polyisobutylene and ethylene-alphaolefin copolymers;
acrylic polymers and copolymers, ethylene-co-vinylacetate,
polybutylmethacrylate, vinyl halide polymers and copolymers, such
as polyvinyl chloride; polyvinyl ethers, such as polyvinyl methyl
ether; polyvinylidene halides, such as polyvinylidene fluoride and
polyvinylidene chloride; polyacrylonitrile, polyvinyl ketones;
polyvinyl aromatics, such as polystyrene, polyvinyl esters, such as
polyvinyl acetate; copolymers of vinyl monomers with each other and
olefins, such as ethylene-methyl methacrylate copolymers,
acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl
acetate copolymers; polyamides, such as Nylon 66 and
polycaprolactam; alkyd resins; polycarbonates; polyoxymethylenes;
polyimides; polyethers; epoxy resins, polyurethanes; rayon;
rayon-triacetate; cellulose, cellulose acetate, cellulose butyrate;
cellulose acetate butyrate; cellophane; cellulose nitrate;
cellulose propionate; cellulose ethers; and carboxymethyl
cellulose.
[0033] The systems and apparatus described herein further include
the remote transmitter 108 (e.g., a remote controller unit), which
provides access to system data and functions, and can be an
external, handheld, reusable battery-powered device. The remote
transmitter 108 can be made of any rugged plastic material
including polypropylene, cyclicolephin co-polymer, nylon, and other
compatible polymers and the like. The remote transmitter 108 is not
implanted within the patient so hermetic sealing of the unit is not
required. However, in one embodiment, the remote transmitter 108 is
at least water resistant, if not waterproof, and can be cleaned
using standard hospital disinfectants without damage to the
unit.
[0034] Further, the remote transmitter 108 has a user interface
including at least one display 116 and at least one user input 118.
In some example embodiments, the display 116 and the user input 118
are combined in the form of a touch screen with a color display. In
other embodiments, the display is grayscale. The remote transmitter
108 permits a clinician or a medical technician to navigate through
menu driven screens used for data entry, data collection, and
controlling the high precision pump unit 106.
[0035] The remote transmitter 108 is capable of communicating with
the high precision pump unit 106. "Capable of communicating" as
used herein refers to the remote controller's ability to establish
communications with the high precision pump unit 106 yet still have
the ability to break communication and the systems described herein
still function. To establish communication, in one example
embodiment, once the remote transmitter 108 is initialized, the
display 116 shows a searching query for a nearby high precision
pump unit 106. As the remote transmitter 108 is brought into range
of the high precision pump unit 106, a symbol displays the strength
of the communication link. Once stable communications have been
acquired, the display 116 shows the serial number of the system so
a clinician can verify they have the appropriate patient records in
hand. If the patient requires a tightening of the gastric band 102,
the clinician can enter the amount of the desired volume increase.
The remote transmitter 108 can also display the current volume
within the gastric band 102 and indicate the new volume as the
gastric band 102 fills. The display 116 can also indicate desired
and actual volumes during draining of the gastric band 102.
[0036] To verify the appropriate adjustment has been made to the
system, the clinician can set the remote transmitter 108 into a
pressure monitor mode and request that the patient drink water. The
display 116 shows a real time graph of the pressure measured within
the gastric band 102. This diagnostic tool may show higher
pressures and warning messages if the gastric band 102 has been
over-tightened.
[0037] The remote transmitter 108 can synchronize and charge when
coupled with a charging cradle or docking station. This docking
station provides the ability to recharge a rechargeable battery of
the remote transmitter 108 and provides a link to download
information to a personal computer such as the adjustment history
of a patient. Other data that can be stored on the remote
transmitter 108 and downloaded from the high precision pump unit
106 includes, but is not limited to serial number, gastric band
size, patient information, firmware version and patient adjustment
history. This data can be downloaded directly to a patient tracking
database for easy tracking.
[0038] Any data stored on the remote transmitter 108 or within the
high precision pump unit 106 can be electronically secured. In
other words, security measures can be put in place to keep the data
confidential, including communication between the high precision
pump unit 106 and the remote transmitter 108. Security measures can
include computer generated algorithms that prevent intrusion by
outside parties.
[0039] The high precision pump unit 106 can contain a micro-fluidic
pump with active valves. In such an embodiment, the high precision
pump unit 106 is a passive device that can only be powered by the
remote transmitter 108 when it is in close proximity. For example,
in one example embodiment, the remote transmitter 108 may be
configured to power and communicate with the high precision pump
unit 106 at any distance less than about 8 inches, in one
embodiment less than about 4 inches (about 10.2 cm) of tissue plus
about 4 inches of air, and in another embodiment about 2 inches
(about 5.1 cm) of air. Power and communications can be tailored to
transmit over longer distances or can be tailored to have the
remote transmitter 108 placed on the skin adjacent to the high
precision pump unit 106.
[0040] Further, the remote transmitter 108 can provide an inductive
power and telemetric control through a transmission 124 to the high
precision pump unit 106. The remote transmitter 108 may be
configured to provide continuous power to the high precision pump
unit 106. A dedicated microcontroller within the remote transmitter
108 monitors the amount of power that is transmitted. Further
still, a power management system may be implemented to optimize
energy transmission between the remote transmitter 108 and the high
precision pump unit 106 relative to their separation distance. For
example, the power transmission may automatically decrease as the
remote transmitter 108 is closer to the high precision pump unit
106, and may be increased as the distance is increased. This
minimizes wasted energy, and energy exposure to the patient.
[0041] The systems and apparatus described herein use common
surgical techniques to place the components in their respective
positions within a patient. The surgical techniques may be
identical or similar to those used in the placement of conventional
gastric banding systems. For example, the gastric band 102 may be
placed around the stomach using laparoscopic techniques, as known
to those of skill in the art. Like a conventional access port, the
high precision pump unit 106 may be sutured onto the rectus muscle
sheath or any other conveniently accessible muscle. In order to
achieve a secure attachment of the high precision pump unit 106,
the unit shall be sutured to the rectus muscle and remain securely
attached for forces below about 6 lbf, in one embodiment below
about 3 lbf (13.3 N). The tubing 110 from the high precision pump
unit 106 passes through the rectus muscle into the peritoneal
cavity in the same manner as the tubing of a conventional access
port.
[0042] The systems and apparatus of the present invention further
allow for a remotely controlled adjustment without needles,
non-invasively, by using the remote transmitter 108. Also, should
the remote transmitter 108 be unavailable, damaged, out of power,
or in the even of an emergency, an adjustment of the gastric band
102 can be performed invasively using a needle. By using the
override port 212, a clinician can choose to use the hypodermic
needle 112, a standard needle, or a syringe for adjustments. If any
of the electronics associated with the systems and apparatus
described herein become inoperable, the override port 212 can be
used to add or remove fluid from the gastric band 102. The override
port 212 and the hypodermic needle 112 can always be used to adjust
the gastric band 102.
[0043] FIG. 2 illustrates an example configuration of the internal
components of the high precision pump unit 106 illustrated in FIG.
1 according to an embodiment of the present invention. The housing
of the high precision pump unit 106 has an internal volume of
between about 0.75 in.sup.3 to about 1.6 in.sup.3. Exemplary
internal features of the high precision pump unit 106 that fit
within the housing include a first valve 202, a second valve 204, a
pump 206, a pressure/flow sensor 208, an electronics board 210
including an antenna 211, and the override port 212. The internal
components of the high precision pump unit 106 can be arranged in
any fashion appropriate for delivering and removing precise amounts
of fluid from the gastric band 102 and the reservoir 104.
[0044] The pump 206 can be actively or passively driven. If the
pump 206 is actively driven, a local power source such as a battery
(not illustrated) is provided to drive the pump 206. If the pump
206 is passively driven, it may be inductively powered by a device
external to the high precision pump unit 106. In an exemplary
configuration, the pump 206 is passively driven through inductive
power from the remote transmitter 108.
[0045] In one example embodiment, the pump 206 is an inductively
powered, electrically driven, positive displacement piezoelectric
pump. The pump 206 provides a means to move fluid into the gastric
band 102.
[0046] The pump 206 can move fluid from the reservoir 104 to the
gastric band 102 at rates higher than about 0.5 cc/min, for
example, higher than about 1 cc/min for band pressures less than
about 20 psi (about 138 kPa) relative to the reservoir pressure.
Alternatively, fluid can be drained from the gastric band 102 to
the reservoir 104 at rates higher than about 0.5 cc/min, for
example, higher than about 1 cc/min for band pressures above about
0.2 psi (about 1.38 kPa).
[0047] The first valve 202 and the second valve 204, illustrated in
FIG. 2, can be any valve known in the art to allow precise delivery
of fluid and precise flow rates therethrough. In one embodiment,
the first valve 202 and the second valve 204 only allow fluid to
move in one direction, therefore, the two valves are situated in
parallel with the high precision pump unit 106 allowing fluid to
drain back from the gastric band 102. Further, the first valve 202
and the second valve 204 should have a precision orifice that
restricts the flow rate to a well-characterized, precise
amount.
[0048] The gastric banding system 100 may further comprise at least
one flow or pressure sensor 208 disposed, for example, within or
adjacent to the high precision pump unit 106. In an exemplary
embodiment, two pressure sensors are situated within the fluid
pathway between the first valve 202 and the second valve 204 and
the gastric band 102. During a no-flow condition, both of the
pressure sensors may be used to measure pressure thereby providing
the benefits of redundancy and averaging.
[0049] For example, sensing or measuring the pressure within the
fluid pathway of the gastric banding system 100 provides diagnostic
uses. A clinician can measure pressure while a patient drinks
water, recording and analyzing resulting pressure fluctuations
which can help determine if the gastric band 102 is too
restrictive. Whether the gastric band 102 is too restrictive can
also be confirmed by the patient's response (generally discomfort)
upon drinking the water, and can then be appropriately adjusted.
Further, sensing or measuring pressure in the gastric banding
system 100 can be useful in diagnosing system leaks or
obstructions. For example, if the pressure consistently drops over
an extended period of time, the clinician can diagnose a leak
within the system and plan for an appropriate treatment to fix the
problem. In contrast, if there is an obstruction within the system
with a sustained pressure rise over time, the clinician can
diagnose an obstruction within the system and plan for an
appropriate treatment to fix the problem.
[0050] The override port 212, as illustrated in FIGS. 1 and 2, is
an optional feature of some of the embodiments of the present
invention. The override port 212 can be manufactured from a metal
or a non-radioopaque material and is accessible by insertion of the
hypodermic needle 112 (in FIG. 1) through a self-sealing septum 214
(in FIG. 2). The override port 212 allows a clinician to use the
hypodermic needle 112 or a standard syringe to fill or drain the
gastric band 102. Further, the override port 212 may be located on
the distal end 216 of the high precision pump unit 106, for
example, at a position substantially opposite from the proximal end
218 where the tubing 220 extends from the high precision pump unit
106. This placement of the override port 212 thereby reduces
possible occurrences of a needle damaging the tubing 220. An
extension body 222 emanating from the high precision pump unit 106
further protects the tubing 220 from accidental needle sticks.
[0051] The high precision pump unit 106 can be a passive device
which may be entirely controlled and powered by the remote
transmitter 108. The antenna 211 on the electronics board 210 is
housed within the high precision pump unit 106 and the remote
transmitter 108 is coupled to allow the transmission 124 of signals
and power through the skin 122 (as illustrated in FIG. 1). The
power issued from the remote transmitter 108 is continually
monitored by a dedicated microprocessor to ensure that power
transmission is minimized to the lowest level required for
operation. To minimize the transmission 124 of power and to
optimize the transmission 124 of command communication, the high
precision pump unit 106 and the remote transmitter 108 have a
channel frequency dedicated to command communication and a separate
channel frequency dedicated to power transmission. The command
communication can be configured, for example, to take place at
about 402-406 MHz while the power transmission, for example, takes
place at about 400 kHz. This command communication adheres to the
frequency and power standards set by the Medical Implant
Communications Service. To ensure accuracy, communication and
control commands are verified by error check algorithms prior to
data reporting or command implementation.
[0052] A portion of the electronics board 210 within the high
precision pump unit 106 is devoted to conditioning and managing the
power received at the antenna 211 or from a local battery.
Communication electronics manage the bidirectional transmissions
with timing verification and error checking. Controller circuits of
the electronics board 210 send commands to the first valve 202, the
second valve 204, the pump 206, and the pressure/flow sensor 208
and receive data back from the pressure/flow sensor 208. The
electronics board 210 can be encased in a biocompatible sealant if
further protection, or redundant protection, is necessary.
[0053] In one example embodiment, the systems and apparatus
described herein are configured and structured to be compatible
with MRI, or MRI safe, at, for example 1.5 T. In the exemplary
embodiment shown, the high precision pump unit 106 is entirely
inductively powered. The systems utilize no permanent magnets, no
long metallic wires or leads, and a minimal or negligible amount of
ferrous or ferromagnetic material. The systems are substantially
free or contain substantially no ferromagnetic materials.
Substantially no ferromagnetic materials refers to materials
containing less than about 5%, in one embodiment, less than about
1% or 0.1% (w/w) of ferromagnetic material. The resulting systems
are thus MRI safe given standard specifications regulating
translational and rotational attraction, MRI heating, and imaging
artifacts. In one embodiment, all materials selected for the
systems are selected to be compatible and safe in an MRI
environment.
[0054] Further, the inductive powering of the high precision pump
unit 106 requires that energy be passed through body tissue. Since
the body tissue absorbs a small amount of the energy passing
through it, the heating of the tissue can be proportional to the
total energy transferred. To ensure that the systems meet standards
to minimize tissue heating (below 2.degree. C. above body
temperature per ISO 45652), the systems described herein have been
designed to use very little power to move the fluid within the
system and do not cause excessive heating of the patient's
tissue.
[0055] The pressure/flow sensor 208 can monitor pressure inside the
gastric band 102 as needed. Using the remote transmitter 108 to
communicate with the high precision pump unit 106, a clinician can
monitor pressure inside the gastric band 102, for example, in "real
time" during an adjustment of the constriction within the gastric
band 102. This will allow the clinician to observe the response of
the gastric band 102 to a patient's adjustment. This may permit a
new modality for the gastric band 102 adjustment management to
monitor pressure as well as volume during an adjustment. With these
new pressure sensing capabilities, the clinician can make a
determination of whether there is a leak within the system (e.g.,
zero pressure reading) or whether there is an obstruction in the
system (e.g., prolonged pressure rise).
[0056] In an example embodiment, the high precision pump unit 106
includes a first fluid line including a first pump for passing
fluid in a first direction and a second fluid line in parallel with
the first fluid line including a first valve and a second pump for
passing fluid in an opposing direction. In another example
embodiment, the second pump is not needed because the gastric band
102 provides enough pressure the move the fluid to the reservoir
104. The parallel line configuration allows for filling and
draining of the gastric band 102 with a minimal number of
components and minimal complexity.
[0057] The systems and apparatus described herein can achieve at
least one of the following features. The total time required to
complete a fill or drain of the gastric band 102 does not exceed
about 10 minutes, and in one embodiment, about 5 minutes. The
systems are able to adjust the volume in the gastric band 102
accurately to within about 0.1 cc or about 10%, whichever is
greater. The pressure/flow sensor 208 has a resolution between
about 0.010 psi to about 0.025 psi, and in one embodiment, about
0.019 psi (about 130 Pa).
[0058] In one example embodiment of the present invention,
components of the systems can be replaced without replacing the
entire system and subjecting patients to overly invasive surgeries
to replace entire systems when a single component is defective or
damaged. For example, if the high precision pump unit 106 becomes
damaged, it can be replaced independently of other components.
Alternatively, if the gastric band 102 becomes damaged, it can be
replaced independently of other components. The same is true of the
tubing 110 and the reservoir 104. Although components can be
disconnected for single part replacement, components shall not
become dislodged from the tubing 110 for tubing pull-off forces
less than about 10 lbf, and in one embodiment, less than about 5
lbf (22.2 N).
[0059] The systems described herein meet at least one safety
specification. For example, in the event of any failure of the
systems, either no change in the gastric band 102 tightness or a
loosening of the gastric band 102 results. Further, the high
precision pump unit 106 is biocompatible for long term implantation
and the remote transmitter 108 is biocompatible for transient use
both per ISO 10993. The systems are designed to have no significant
interaction or interference with other electronics in any of the
following modalities: implantable energy sources such as
defibrillators and pacemakers; internal energy sources such as
electrosurgical instruments; external energy sources such as
ultrasound, x-rays and defibrillators; and radiofrequency signals
such as pacemaker programmers and neurostimulators.
Example 1
Implantation of a Gastric Band System
[0060] A 40 year old female is diagnosed by her clinician as obese,
weighing 510 lbs. The clinician suggests to the patient that she
consider the gastric banding system 100 according to the present
invention. She agrees and undergoes the implantation procedure. The
gastric band 102 is implanted around her cardia thereby creating a
stoma. The high precision pump unit 106 is sutured onto the rectus
muscle sheath and the tubing 110 and the reservoir 104 passes
through the rectus muscle into the peritoneal cavity and connects
to the gastric band 102. The gastric banding system 100 comes
pre-filled, so there is no need for the clinician to fill the
gastric banding system 100 during the surgical procedure. The
patient is sutured and sent to recovery.
Example 2
Adjustment of a Gastric Band System
[0061] The female patient of Example 1, after the completion of the
surgical implantation, has her gastric band system 100 properly
adjusted by her clinician. The clinician holds the remote
transmitter 108 to the skin 122 adjacent to the rectus muscle where
the high precision pump unit 106 is located and initiates
communication between the devices. An initial pressure of zero is
displayed for the gastric band 102 as no fluid has been added to
the gastric band 102. The clinician begins to fill the gastric band
102 using saline housed within the reservoir 104 at a rate of about
1 cc/min and the entire filling takes less than about 5
minutes.
[0062] After filling, to about 10 psi, the patient is instructed to
drink a glass of water in order to properly assess the proper
inflation pressure of the gastric band 102 to ensure it has not
been over inflated. Upon confirmation that the gastric band 102 is
properly inflated, the procedure is completed and the patient
returns to her normal life.
[0063] The patient instantly notices that she is much less hungry
than she previously had been and is consistently consuming less
food as her appetite has been decreased. She returns to her
clinician's office for a follow-up visit three months after her
implantation and initial gastric band filling and she has lost 20
pounds. A year later, she has lost nearly 60 lbs.
[0064] The gastric banding system 100 generally functions as
follows. When a clinician uses the remote transmitter 108 to adjust
the gastric band 102, the high precision pump unit 106 initiates a
sequence of events to move a precise amount of fluid in the desired
direction, where the filling is discussed in FIG. 3A and the
draining is discussed in FIG. 3B.
[0065] FIG. 3A illustrates the filling of the gastric band 102
according to an embodiment of the present invention. Just before
pumping is initiated, the second valve 204, in line with the pump
206, is opened. The pump 206 creates a differential pressure to
draw fluid out of the reservoir 104 and into the gastric band 102.
The first valve 202 and the pressure/flow sensor 208 are closed or
not engaged. The reservoir 104 is collapsible and does not impede
the outward flow of fluid. Further, the reservoir 104 is sized such
that when filled to the maximum recommended fill volume, there is a
slight vacuum therein. Once the proper amount of fluid has been
transferred from the reservoir 104 to the gastric band 102, the
electronics board 210 (or circuitry thereon) shuts off the pump 206
and closes the second valve 204. The gastric band 102 now assumes
the new higher pressure and fluid.
[0066] Referring to FIG. 3B, if the clinician decides to there is a
need to loosen the gastric band 102, fluid is released from the
gastric band 102 and returned to the reservoir 104. Once the high
precision pump unit 106 receives a drain command from the remote
transmitter 108, the first valve 202 behind the pressure/flow
sensor 208 opens. The fluid is transferred from the gastric band
102 through the pressure/flow sensor 208 and the first valve 202
and into the reservoir 104. The amount of fluid released from the
gastric band 102 can be monitored and determined by the
pressure/flow sensor 208. Once the correct volume of fluid has been
transferred, the first valve 202 is closed. With both the first
valve 202 and the second valve 204 closed, the volume in the
gastric band 102 is maintained and the pressure in the gastric band
102 can be measured accurately using the pressure/flow sensor
208.
[0067] When compared to conventional gastric banding systems having
standard access ports which exclusively require syringe access (as
oppose to being optional), the presently described systems and
apparatus offer several benefits. First, the conventional access
ports are located under a thick layer of fatty tissue, which is
generally the case as the devices are generally used to treat
obesity, and the access port can be difficult to locate. The
present systems reduce or eliminate the need for (or to locate) the
access port, as the use of the remote transmitter 108 removes the
need for adjustment using the hypodermic needle 112.
[0068] Secondly, when accessing the access port in conventional
systems, the ambiguity on its location may lead to damage by
accidentally puncturing the tubing 110 which connects the access
port 212 to the gastric band 102. This can require a revision
surgery in order to repair the punctured tubing 110. Further, when
a conventional access port cannot be located by palpation, x-ray
imaging may be required to guide a needle into the access port.
Such imaging practices put a patient at risk for x-ray radiation
exposure. The present systems and apparatus remove the need for
these unnecessary procedures and save the patient from x-ray
radiation exposure. The present systems and apparatus are
compatible with magnetic resonance imaging (MRI), which is much
safer for a patient.
[0069] In the unlikely event that the override port 212 of the
present invention needs to be used, the override port 212 may be
located away from the tubing connection to the gastric band 102 to
reduce the potential for tubing needle sticks. The high precision
pump unit 106 has geometry and a rigid case that can be structured
to facilitate the user in locating the override port 212 when
needed.
[0070] FIGS. 4A and 4B illustrate cross-sectional views of an
exemplary valve 400 in a closed position (FIG. 4A) and an open
position (FIG. 4B) according to an embodiment of the present
invention. The valve 400 may be used in place of one or both of the
first valve 202 and the second valve 204.
[0071] Referring to FIG. 4A, the valve 400 is biased in a closed
position, for example, by a spring preload force 402 acting on a
seal 404, for example, a flexible silicone seal 404. For example,
the spring preload force 402 pushes the flexible silicone seal 404
into sealing engagement with a valve seat 406. When the valve 400
is sealed as shown in FIG. 4A, fluid cannot pass from a valve inlet
408 to a valve outlet 410.
[0072] Now referring to FIG. 4B, when fluid flow is desired, a
signal is sent to a valve actuator (not shown), which removes the
spring preload force 402 and permits the flexible silicone seal 404
to relax or move upward into an open position, out of sealing
engagement with the valve seat 406. The fluid is then free to flow
from the valve inlet 408 to the valve outlet 410 until the valve
400 is closed, for example, by reapplication of the spring preload
force 402.
[0073] FIGS. 5A and 5B illustrate cross-sectional views of an
exemplary dome valve 500 in a closed position (FIG. 5A) and an open
position (FIG. 5B) according to an embodiment of the invention. In
one embodiment, the dome valve 500 is an implantable device that
controls the movement of fluid to the inflatable portion 114 of the
gastric band 102. The dome valve 500 may be used in place of one or
both of first valve 202 and the second valve 204.
[0074] The dome valve 500 is designed to be implanted into a
patient, and thus may be referred to as a micro valve. In an
embodiment, the dome valve 500 has a length of about 15 mm (e.g.,
10-25 mm range) and an about 10 mm outer, diameter (e.g., 7-15 mm
range). In one embodiment, the dome valve 500 is a radially
symmetric shape (e.g., disk, tube, rod, etc.). However, the dome
valve 500 can be any shape (e.g., circular, square, rectangular,
etc). The dome valve 500 can include a body 560, an actuator 505, a
cap 510, and a diaphragm 520.
[0075] The body 560 has an inlet component 530, an outlet component
535, and a bottom component 550. The inlet component 530, the
outlet component 535, and the bottom component 550 have been
identified for illustrative purposes and may not be separate
components from the body 560. An inlet 540, which is a fluid
entrance into the body 560, is defined between the inlet component
530 and the bottom component 550. An outlet 545, which is a fluid
exit from the body 560, is defined between the outlet component 535
and the bottom component 550.
[0076] The inlet component 530 and the bottom component 550 form a
valve seat 570. The valve seat 570 can be the surfaces (e.g., the
tips) of the inlet component 530 and the bottom component 550 which
provide sealing when the diaphragm 520 is placed against and in
contact with the inlet component 530 and the bottom component 550.
In one embodiment, the vertical column of the inlet component 530
and the bottom component 550 define the valve seat 570. The
vertical columns may be short segments (e.g., 1.5 mm) of plastic or
metal tubing (e.g., stainless steel).
[0077] The actuator 505 is configured to apply a force (e.g.,
stress) on the cap 510 causing the diagraph 520 to move from the
closed position (FIG. 5A) to the open position (FIG. 5B) when the
actuator 505 receives a telemetric signal 124 (e.g., electrical
energy) from the remote transmitter 108. The force includes a
smaller downward force 555 to keep the valve 500 in a closed
position (FIG. 5A) and a larger downward force 565 to keep the
valve 500 in an open position (FIG. 5B). In an embodiment, the
smaller force 555 is less than 10 newtons. In an embodiment, the
larger force 565 is between 10-100 newtons. In another embodiment,
the larger force 565 is between 15-45 newtons.
[0078] FIG. 5A illustrates the actuator 505 applying the smaller
force 555 (e.g., 0 newtons, little or no downward force, a reduced
in force, a de-energized state), which is low enough to keep the
valve 500 in the closed position. In particular, when the actuator
505 applies the smaller force 555, the cap 510 receives little or
no downward force on cap edges 515. Since the cap edges 515 are
adjacent to the diaphragm edges 525, the diaphragm edges 525 also
receive little or no downward force. As such, the diaphragm center
527 of the diaphragm 520 remains sitting on (or relaxed onto) the
valve seat 570, blocking fluid from flowing from the inlet 540 to
the outlet 545.
[0079] FIG. 5B illustrates the actuator 505 applying a large force
565 (e.g., an energized state) that compresses (e.g., squeezes) the
diaphragm edges 525 between the cap 510 and the body 560. The large
force 565 is great enough that the material on the diaphragm edges
525 is compressed, with the cap 510 blocking diaphragm edges 525
from expanding outward, the diaphragm is expanded inward such that
the diaphragm center 527 is moved up off the valve seat 570 due to
a build up of material. This opens a passage from the inlet 540 to
the outlet 545 and permitting fluid flow in the valve 500 as shown
by fluid flow indicators 575. When a downward force is applied, the
diaphragm center 527 moves in a substantially opposite direction to
the downward force.
[0080] The actuator 505 can take many forms (e.g., solenoids,
stepper motors, piezoelectric actuator, electroactive polymer,
etc.) as dictated by the specific application. In one embodiment of
the RAB, the actuator 505 is a piezoelectric actuator. In another
embodiment, the actuator 505 is an electroactive polymer.
[0081] The cap 510 may be positioned between the diaphragm 520 and
the actuator 505. The cap 510 has one or more cap edges 515 (e.g.,
cap ends). The cap edges 515 direct the small force 555 and the
large force 565 from the actuator 505 to the diaphragm 520. In one
embodiment, the cap 510 is part of the actuator 505.
[0082] The diaphragm 520, which may be referred to as a valve seal,
is positioned between the cap 510 and the body 560. The diaphragm
520 has a diaphragm center 527 (e.g., a body) and one or more
diaphragm edges 525 (e.g., ends of the diaphragm 520) coupled to
the body 560.
[0083] The diaphragm 520 (e.g., valve seal) has an open position
(FIG. 5B) and a closed position (FIG. 5A). When the diaphragm 520
is in the open position, the diaphragm 520 does not block the valve
seat 570 and therefore allows the fluid to move from the inlet 540
to the outlet 545. Conversely, when the diaphragm 520 is in a
closed position, the diaphragm 520 blocks the valve seat 570 and
does not allow the fluid to move from the inlet 540 to the outlet
545.
[0084] In one embodiment, the diaphragm 520 is made of an
elastomeric material. The elastomeric material includes silicon and
any other material that is stretchy like a rubber band. For
example, the elastomeric material includes flexible materials,
naturally occurring elastic substances (e.g., natural rubber), and
synthetically produced substances (e.g., silicon, butyl rubber,
neoprene).
[0085] The elastomeric material can be stretched across the valve
seat 570 to provide a seal and can buckle to create a gap 526 above
the valve seat 570. In an embodiment, the gap 526 below the
diaphragm 520 is substantially less than 1 mm off the valve seat
570. In one embodiment, the gap 526 is about 0.03 mm. In one
embodiment, the range for the gap 526 is between about 0.01 mm to
about 0.25 mm. In another embodiment, the range for the gap 526 is
between about 0.01 mm to about 0.10 mm.
[0086] In one embodiment, the diaphragm 520 is circular, although
any shape is possible (e.g., a thin strip, rectangular, etc).
[0087] The dome valve 500 has numerous advantages over conventional
valves. The dome valve 500 contains no ferromagnetic material as is
commonly used in conventional valves (e.g., solenoid valves). As a
result, the dome valve 500 advantageously can be safely used in
conjunction with magnetic resonance imaging (MRI) scanning.
[0088] Additionally, the dome valve 500 advantageously is not
concentric with the diaphragm, unlike conventional valves which
have a concentric shaped seal which results in high susceptibility
to leakage and contamination to the moving parts of the valve.
[0089] Advantageously, both the diaphragm 520 and the cap 510
restrict fluid from contacting the moving valve components, such as
the actuator 505. This allows the dome valve 500 to be used in a
system where the fluid is highly corrosive to the moving parts and
can be used where the moving parts rub and create contaminants that
must be keep free from the fluid, because the dome valve 500
protects the moving valve components from contamination.
[0090] Dome valve 500 advantageously can be inexpensively
manufactured, due partly to the mechanical linkage, while still
being robust and efficient. Opening the valve 500 requires very
little stroke or travel from the actuator 505 to produce a suitably
large upward deflection in the diaphragm 520. In contrast,
conventional valves use energy inefficient methods such as forming
a seal for a valve by heating a membrane comprised of two materials
with different coefficients of linear thermal expansion.
[0091] Also, the dome valve 500 achieves a low leak/leakage rate
when in the closed position (e.g., closed/sealed tightly) compared
to conventional valves and achieves a high flow rate when in the
open position. Further, the dome valve 500 minimizes the space
required for the implanted device because the dome valve 500 can be
smaller than other implantable devices.
[0092] FIGS. 6A and 6B illustrate cross-sectional views of an
exemplary screw valve 600 in a closed position (FIG. 6A) and an
open position (FIG. 6B) according to an embodiment of the present
invention. The screw valve 600 is part of the RAB and may be used
in place of one or both of the first valve 202 and the second valve
204. The screw valve 600 is designed small enough to be implanted
into a patient, and thus may be referred to as a micro valve. In an
embodiment, the screw valve 600 has a length of approximately 30-50
mm and an about 10 mm outer diameter (e.g., 7-15 mm range). In
comparison to the dome valve 500 embodiment discussed above (10-25
mm length, 10 mm outer diameter), the screw valve 600 is almost
twice as long, but has the same outer diameter.
[0093] The screw valve 600 in accordance with one embodiment of the
present invention generally includes a body 660, a screw 615, a
screw actuator 605, a coupling mechanism 610, a valve seal 620, and
a valve seat 670.
[0094] The body 660 houses the components of the screw valve 600.
The body 660 also has an inlet 640 and an outlet 645. The inlet 640
may be in communication with the reservoir 104 and the outlet 645
may be in communication with the inflatable portion 114 of the
gastric band 102, or vice-versa, using suitable fluid port
connectors, not shown.
[0095] The screw 615 includes a lead screw (where lead means a type
of screw, and does not mean the material lead as used in a graphite
pencil), power screw, translation screw. The screw 615 can be
designed to translate radial (e.g., circular) motion/movement into
linear (e.g., translational) motion/movement. The screw 615 is
configured to apply a force on the valve seal 620 to cause the
valve seal 620 to move from an open position (FIG. 6B) to a closed
position (FIG. 6A) when the screw actuator 605 receives a
telemetric signal 124 from the remote transmitter 108.
[0096] The screw actuator 605, positioned within the body 660 of
the screw valve 600, has an actuator body defining a threaded screw
hole 606. The screw 615 is positioned within the threaded screw
hole 606.
[0097] In one embodiment, the screw actuator 605 is a motor. In
another embodiment, the motor may be positioned within the screw
actuator 605. In another embodiment, the motor is external to the
body 660 for moving the screw 615.
[0098] The motor (not shown) may also be included in the screw
valve 600 and coupled to the screw 615 for moving the screw 615
within the threaded screw hole 606. The motor can be a DC motor, an
AC motor, a solenoid, a stepper motor, a piezoelectric actuator, a
piezoelectric driver, and an electroactive polymer. In one
embodiment, the motor is selected to be the same type of motor used
elsewhere in the implantable system. The motor can be configured to
move the screw 615 to at least two positions so that the valve seal
620 can be moved to at least two positions depending on the
telemetric signal 124 sent from the remote transmitter 108 to the
actuator 605.
[0099] The coupling mechanism 610, positioned between the valve
seal 620 and the screw 615, decouples a rotational motion of the
screw 615. In one embodiment, the coupling mechanism 610 may be
securely fastened or fixed to the valve seal 620 so that the
coupling mechanism 610 does not rotate with the rotation of the
screw 615. The screw 615 moves forward and backward (or upward and
downward) through both rotational and translational motion.
However, to prevent damage to the valve seal 620, the valve seal
620 should only receive translational motion (not rotational
motion). The coupling mechanism 610 decouples the rotational motion
of the screw 615 but transmits the translational motion. The
coupling mechanism 610 is illustrated as being a tappet, but can
also include a ball bearing, a bellows unit, etc., as illustrated
in FIGS. 7A-7C.
[0100] The valve seal 620 has one or more edges 621 coupled to the
body 660. The valve seal 620 is capable of being moved from an open
position that is spaced apart from the valve seat 670 and does not
block a fluid (e.g., saline) from flowing from the inlet 640 to the
outlet 645 to a closed position that blocks or contacts the valve
seat 670 and does not allow the fluid to move from the inlet 640 to
the outlet 645. The valve seal 620 can be in the closed position,
the open position, and a partially-open position, which is between
the closed position and the open position.
[0101] The valve seal 620, like the diaphragm 520, is made of an
elastomeric material. In one embodiment, the elastomeric material
is silicon. However, any material that is stretchy like a rubber
band can be used. For example, the elastomeric materials include
flexible materials, naturally occurring elastic substances (e.g.,
natural rubber), and synthetically produced substances (e.g.,
silicon, butyl rubber, neoprene).
[0102] The valve seat 670 provides an opening for the valve seal
620 to close or open. To close the screw valve 600, a command
signal (e.g., a telemetric signal) is sent to the screw actuator
605 which drives the screw 615 (and the coupling device or
mechanism 610) into the valve seal 620 to press the valve seal 620
onto the valve seat 670. To open the screw valve 600, a command
signal is sent to the screw actuator 605 which drives the screw 615
(and the coupling device or mechanism 610) away from the valve seal
620 to decompress or move the valve seal 620 away from the valve
seat 670.
[0103] The pressure/flow sensor 208 may also be included in or
coupled to the screw valve 600. For example, one or both of the
flow sensor and/or the pressure sensor can be coupled to the valve
seat 670 for determining and adjusting an amount of the fluid
flowing between the inlet 640 and the outlet 645.
[0104] FIG. 6A illustrates the screw 615 displacing the valve seal
620 onto the valve seat 670 to block the fluid from flowing from
the inlet 640 to the outlet 645.
[0105] FIG. 6B illustrates the screw 615 moved upward such that the
valve seal 620 is not touching the valve seat 670 to allow the
fluid to flow from the inlet 640 to the outlet 645 as shown by
fluid flow indicators 675. The fluid can also flow in the opposite
direction as shown by the fluid flow indicators 675.
[0106] The lead screw valve 600 provides many advantages when used
for the gastric banding system 100. For example, the screw valve
600 achieves a low leak/leakage rate when closed (e.g.,
closed/sealed tightly) compared to conventional valves and a high
flow rate during adjustment. The screw valve 600 is also easier to
manufacture than other implantable devices (such as the dome valve
500).
[0107] An additional advantage, is that the screw valve 600 can
remain in position (e.g., fully open, partially open, tightly
closed) in the presence of very high constant and intermittent
pressures present from the inlet 640 and the outlet 645. For
example, the screw valve 600 can handle high pressures, such as 30
psi. The screw valve 600 can resist high pressures by being
overdriven and by being a normally-still valve.
[0108] If the screw 615 is intentionally overdriven, the screw 615
presses tightly against the coupling mechanism 610, which presses
tightly against the valve seal 620, which presses tightly against
the valve seat 670. The term overdriven means that the screw 615 is
driven just beyond the point where the valve seal 620 contacts the
valve seat 670. The phrase "just beyond" means a point where force
is generated. Even though it's not possible (without damage) to
move the valve seal 620 beyond the point that it touches the valve
seat 670, it is possible to generate force. For example, forces
develop in the motor and forces develop loading up the motor. These
forces creating a force balance between the valve seal 620 and the
valve seat 670. In one embodiment, "just beyond" is a point where
an additional force is required from the motor.
[0109] Even though the screw 615 drives the valve seal 620 hard
into the valve seat 670, in one embodiment, the valve seal 620 is
made of a soft material (e.g., silicon) and the valve seat 670 is
made of a hard material (e.g., polished stainless steel) such that
the two materials can be pressed together without resulting in
substantial damage or marring. This tight seal blocks fluid,
including fluid under high pressure. The screw 615 can optionally
be reversed to relieve any unwanted excess pressure on the screw
615, the coupling mechanism 610, the valve seal 620, and the valve
seat 670.
[0110] Another advantage of the screw valve 600 is that the screw
615 can resist the opening and closing in the presence of steady or
high pressure, without requiring an additional energy, because the
screw valve 600 is a normally still valve (as oppose to normally
open or normally closed). Thus, in the absence of a drive command,
the screw actuated valve will remain in whichever state it was
left, whether that was fully open, partially open, or fully
closed.
[0111] An additional advantage of the screw valve 600 is the amount
of positions available to regulate fluid flow. The screw valve 600
can be fully open, fully closed, or anywhere in between, providing
significant flexibility in designing actuation drive
characteristics. The fluid flow rate can be adjusted by partially
opening the screw valve 600. The screw seal 620 can occupy any
position by making precise and incremental adjustments to the screw
615. In one embodiment, the screw valve 600 is used in a closed
loop system, where a sensor (e.g., flow sensor, a pressure sensor,
etc.) is used to adjust the position of the screw 615 to regulate
the fluid flow from the inlet 640 to the outlet 645.
[0112] FIGS. 7A, 7B and 7C illustrate side views of examples of the
coupling mechanism 610 illustrated in FIG. 6 according to various
embodiments of the present invention. FIG. 7A illustrates a tappet
705 as the coupling mechanism 610. The tappet 705 can be a sliding
rod for moving a valve. The tappet 705 touches the screw 615, and
connects or rides on the screw 615. The tappet 705 allows an
intentional rotational slippage between the tappet 705 and the
screw 615 to decouple the rotational motion.
[0113] FIG. 7B illustrates a ball 710 along with the tappet 705 as
the coupling mechanism 610. The ball 710 is located between the
screw 615 and the tappet 705. The ball 710 provides two surfaces
designed to allow an intentional rotational slippage between the
screw 615 and the valve seal 620. Having two surfaces for slippage
is advantageous because one surface may bind up due to particulate
contamination (e.g., particles from the screw 615 or the tappet
705) or manufacturing imperfection (e.g., molding flash, burrs,
etc.). The ball 710 can be a ball bearing.
[0114] FIG. 7C illustrates a bellows unit 715 as the coupling
mechanism 610 used with the screw 615. The bellows unit 715 can
isolate the screw 615 from the valve seal 620. Without the bellows
unit 715, the screw 615 would rotate and rub against a surface of
the valve seal 620 generating particulates which are further rubbed
against the valve seal 620. Since the valve seal 620 can be
sensitive and not designed to be rubbed with particulates, the
bellows unit 715 advantageously keeps all the possible generated
particulates enclosed and sealed away from the valve seal 620.
[0115] FIG. 8 is a flow chart of a method of using the dome valve
500 to control the movement of fluid between the reservoir 104 and
the inflatable portion 114 of the gastric band 102.
[0116] The process starts at step 800. At step 805, the dome valve
500 receives a telemetric signal from the remote transmitter 108.
Alternatively, the dome valve 500 can receive a signal from an
implanted microcontroller. The implanted microcontroller may be
part of, coupled to or located within the actuator 505. The
implanted microcontroller can receive a telemetric signal from the
remote transmitter 108. Next, the actuator 505 applies a downward
force on the diaphragm 520 to open the dome valve 500 at step 810.
The downward force is applied onto the diaphragm edges 525 of the
diaphragm 520 in the dome valve 500, lifting up the diaphragm
center 527, and allowing fluid to flow through the dome valve
500.
[0117] At step 815, the actuator 505 reduces the downward force on
the diaphragm 520 to close the dome valve 500. The downward force
is reduced on the diaphragm edges 525 of the diaphragm 520 in the
dome valve 500, lowering the diaphragm center 527, and blocking
fluid from flowing through the dome valve 500. The process ends at
step 820.
[0118] FIG. 9 is a flow chart of a method of using the screw valve
600 to control the movement of fluid between the reservoir 104 and
the inflatable portion 114 of the gastric band 102.
[0119] The process starts at step 900. At step 905, the screw valve
600 receives a telemetric signal from the remote transmitter 108.
Alternatively, the dome valve 600 can receive a signal from an
implanted microcontroller. The implanted microcontroller may be
part of, coupled to or located within the screw actuator 605. The
implanted microcontroller can receive a telemetric signal from the
remote transmitter 108. At step 910, the screw actuator 605 turns
the screw 615 in one direction to increase a force on the valve
seal 620 to close the screw valve 600.
[0120] Then, the screw actuator 605 turns the screw 615 in the
opposite direction to decrease the force on the valve seal 620 to
open the screw valve 600. The process ends at step 920.
[0121] Unless otherwise indicated, all numbers expressing
quantities of ingredients, properties such as molecular weight,
reaction conditions, and so forth used in the specification and
claims are to be understood as being modified in all instances by
the term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the specification and
attached claims are approximations that may vary depending upon the
desired properties sought to be obtained by the present invention.
At the very least, and not as an attempt to limit the application
of the doctrine of equivalents to the scope of the claims, each
numerical parameter should at least be construed in light of the
number of reported significant digits and by applying ordinary
rounding techniques.
[0122] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard deviation found in their respective testing
measurements.
[0123] The terms "a," "an," "the" and similar referents used in the
context of describing the invention (especially in the context of
the following claims) are to be construed to cover both the
singular and the plural, unless otherwise indicated herein or
clearly contradicted by context. Recitation of ranges of values
herein is merely intended to serve as a shorthand method of
referring individually to each separate value falling within the
range. Unless otherwise indicated herein, each individual value is
incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein is intended
merely to better illuminate the invention and does not pose a
limitation on the scope of the invention otherwise claimed. No
language in the specification should be construed as indicating any
non-claimed element essential to the practice of the present
invention.
[0124] Groupings of alternative elements or embodiments of the
invention disclosed herein are not to be construed as limitations.
Each group member may be referred to and claimed individually or in
any combination with other members of the group or other elements
found herein. It is anticipated that one or more members of a group
may be included in, or deleted from, a group for reasons of
convenience and/or patentability. When any such inclusion or
deletion occurs, the specification is deemed to contain the group
as modified thus fulfilling the written description of all Markush
groups used in the appended claims.
[0125] Certain embodiments of the present invention are described
herein, including the best mode known to the inventors for carrying
out the present invention. Of course, variations on these described
embodiments will become apparent to those of ordinary skill in the
art upon reading the foregoing description. The inventor expects
skilled artisans to employ such variations as appropriate, and the
inventors intend for the present invention to be practiced
otherwise than specifically described herein. Accordingly, the
present invention includes all modifications and equivalents of the
subject matter recited in the claims appended hereto as permitted
by applicable law. Moreover, any combination of the above-described
elements in all possible variations thereof is encompassed by the
present invention unless otherwise indicated herein or otherwise
clearly contradicted by context.
[0126] Furthermore, references may have been made to patents and
printed publications in this specification. Each of the above-cited
references and printed publications are individually incorporated
herein by reference in their entirety.
[0127] Specific embodiments disclosed herein may be further limited
in the claims using consisting of or and consisting essentially of
language. When used in the claims, whether as filed or added per
amendment, the transition term "consisting of" excludes any
element, step, or ingredient not specified in the claims. The
transition term "consisting essentially of" limits the scope of a
claim to the specified materials or steps and those that do not
materially affect the basic and novel characteristic(s).
Embodiments of the present invention so claimed are inherently or
expressly described and enabled herein.
[0128] In closing, it is to be understood that the embodiments of
the present invention disclosed herein are illustrative of the
principles of the present invention. Other modifications that may
be employed are within the scope of the present invention. Thus, by
way of example, but not of limitation, alternative configurations
of the present invention may be utilized in accordance with the
teachings herein. Accordingly, the present invention is not limited
to that precisely as shown and described.
* * * * *