U.S. patent application number 11/707104 was filed with the patent office on 2007-10-04 for rfid-based apparatus, system, and method for therapeutic treatment of a patient.
Invention is credited to Stanley R. JR. Craig, Marcelo G. Lima.
Application Number | 20070233204 11/707104 |
Document ID | / |
Family ID | 38437975 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070233204 |
Kind Code |
A1 |
Lima; Marcelo G. ; et
al. |
October 4, 2007 |
RFID-based apparatus, system, and method for therapeutic treatment
of a patient
Abstract
Provided is an implantable RFID-enabled micro-electronic
neurostimulator system comprising a) an internal subsystem having
(i) an array of electrodes, where at least one electrode pair
contacts a nerve; (ii) a multiplexer; (iii) digital to analog
signal converter; and (iv) a RFID based control and stimulation
chip; and (b) an external subsystem having (i) a controller; and
(ii) an RF interface.
Inventors: |
Lima; Marcelo G.; (San
Diego, CA) ; Craig; Stanley R. JR.; (Westport,
MA) |
Correspondence
Address: |
MORGAN LEWIS & BOCKIUS LLP
1111 PENNSYLVANIA AVENUE NW
WASHINGTON
DC
20004
US
|
Family ID: |
38437975 |
Appl. No.: |
11/707104 |
Filed: |
February 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60774039 |
Feb 16, 2006 |
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60774040 |
Feb 16, 2006 |
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60774041 |
Feb 16, 2006 |
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Current U.S.
Class: |
607/46 |
Current CPC
Class: |
A61N 1/37247 20130101;
A61N 1/0551 20130101; A61N 1/0534 20130101; A61N 1/37223 20130101;
A61N 1/37288 20130101; A61N 1/3787 20130101; A61N 1/0541 20130101;
A61N 1/321 20130101; A61N 1/3601 20130101; A61N 1/37205 20130101;
A61N 1/0556 20130101; A61N 1/0531 20130101 |
Class at
Publication: |
607/046 |
International
Class: |
A61N 1/05 20060101
A61N001/05 |
Claims
1. An implantable RFID-enabled micro-electronic neurostimulator
system comprising: (a) an internal subsystem implant having (i) an
array of electrodes, where at least one electrode pair contacts a
nerve; (ii) a multiplexer; (iii) digital to analog signal
converter; and (iv) a RFID based control and stimulation chip; and
b) an external subsystem having (i) a controller; and (ii) an RF
interface.
2. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is configured to be programmable
and to supply power to the internal subsystem.
3. The RFID-enabled micro-electronic neurostimulator system of
claim 2, wherein the supplied power includes RF energy emitted by
the controller.
4. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the internal subsystem is encased in a casing, the
casing being a material selected from the group consisting of one
or more titanium alloys, ceramic, and polyetheretherketone
(PEEK).
5. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller includes an interface for
interfacing with a computer.
6. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is configured to stimulate patient
specific nerve physiology and stimulation parameters.
7. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is shaped for placement around a
patient's ear.
8. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is shaped in the form of a
patch.
9. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is included in a watch-like
device.
10. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the external subsystem is flexible.
11. The RFID-enabled micro-electronic neurostimulator system of
claim 7, wherein the controller and RF interface are woven into
clothing and remotely powered.
12. The RFID-enabled micro-electronic neurostimulator system of
claim 1, further comprising a transponder located in the internal
subsystem, wherein the external subsystem controller is configured
to: identify a unique ID tag corresponding to the implant;
communicate with the implant having the unique ID tag; and send a
signal to the internal subsystem transponder.
13. The RFID-enabled micro-electronic neurostimulator system of
claim 12, wherein the transponder is a passive RFID
transponder.
14. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller further includes a programming
device and wherein the controller is configured to: provide an RF
signal to the implant; sense and record data; and interface with
the programming device.
15. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the controller is configured to communicate with
the implant at preprogrammed intervals.
16. The RFID-enabled micro-electronic neurostimulator system of
claim 1, further comprising a core subsystem within the internal
subsystem, wherein the controller is configured to initiate a
stimulation cycle by making a request to the core subsystem, the
request being in the form of an encoded RF waveform including
control data.
17. The RFID-enabled micro-electronic neurostimulator system of
claim 16, wherein the request is encrypted.
18. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the implant is hermetically sealed.
19. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the implant is configured to provide continuous
open loop electrical stimulation to a nerve during sleep hours.
20. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the implant is configured to provide constant
stimulation to a nerve during sleep hours.
21. The RFID-enabled micro-electronic neurostimulator system of
claim 20, wherein the implant is configured to provide bi-phasic
stimulation to a nerve.
22. The RFID-enabled micro-electronic neurostimulator system of
claim 20, wherein the stimulation pulse width is about 200
microseconds at a stimulation frequency of about 10-40 hertz.
23. The RFID-enabled micro-electronic neurostimulator system of
claim 1, wherein the implant is configured to provide stimulation
to a nerve at preprogrammed conditions.
24. The RFID-enabled micro-electronic neurostimulator system of
claim 23, wherein the implant is configured to provide bi-phasic
stimulation to a nerve.
25. The RFID-enabled micro-electronic neurostimulator system of
claim 23, wherein the implant stimulation pulse width is about 200
microseconds at a stimulation frequency of about 10-40 hertz.
26. The implantable RFID-enabled micro-electronic neurostimulator
system of claim 1, further comprising an antenna, a micrologic CPU,
and a memory configured to store protocols which are selective to a
patient in need of neurostimulation.
27. The implantable RFID-enabled micro-electronic neurostimulator
system of claim 1, wherein the nerve is selected from the group
consisting of one or more peripheral nerves, deep brain/cortical
nerves, sacral nerve, vagus nerve, spinal cord, cochlear nerve,
pulmonary nerve, gastric nerve and occipital nerve.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Applications 60/774,039, 60/774,040, and 60/774,041 filed on Feb.
16, 2006, all of which are expressly incorporated herein by
reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus, system, and
method for implantable therapeutic treatment of a patient.
BACKGROUND OF THE INVENTION
[0003] Acute and chronic conditions such as pain, arthritis, sleep
apnea, seizure, incontinence, and migraine are physiological
conditions affecting millions of people worldwide. For example,
sleep apnea is described as an iterated failure to respire properly
during sleep. Those affected by sleep apnea stop breathing during
sleep numerous times during the night. There are two types of sleep
apnea, generally described in medical literature as central and
obstructive sleep apnea. Central sleep apnea is a failure of the
nervous system to produce proper signals for excitation of the
muscles involved with respiration. Obstructive sleep apnea (OSA) is
cause by physical obstruction of the upper airway channel
(UAW).
[0004] Current treatment options range from drug intervention,
non-invasive approaches, to more invasive surgical procedures. In
many of these instances, patient acceptance and therapy compliance
is well below desired levels, rendering the current solutions
ineffective as a long term solution.
[0005] Implants are a promising alternative to these forms of
treatment. For example, pharyngeal dilation via hypoglossal nerve
(XII) stimulation has been shown to be an effective treatment
method for OSA. The nerves are stimulated using an implanted
electrode. In particular, the medial XII nerve branch (i.e., in.
genioglossus), has demonstrated significant reductions in UAW
airflow resistance (i.e., increased pharyngeal caliber).
Stimulation of the vagus nerve is thought to affect some of its
connections to areas in the brain prone to seizure activity. Sacral
nerve stimulation is an FDA-approved electronic stimulation therapy
for reducing urge incontinence. Stimulation of peripheral nerves
may help treat arthritis pain.
[0006] While electrical stimulation of nerves has been
experimentally shown to remove ameliorate certain conditions, e.g.,
obstructions in the UAW, current implementation methods typically
require accurate detection of an condition (e.g., a muscular
obstruction of an airway), selective stimulation of a muscle or
nerve, and a coupling of the detection and stimulation components.
Additionally, attempts at selective stimulation have to date
required multiple implants with multiple power sources, and the
scope of therapeutic efficacy has been limited. A need therefore
exists for an apparatus and method for programmable and/or
selective neural stimulation of multiple implants or contact
excitation combinations using a single controller power source.
SUMMARY OF THE INVENTION
[0007] The present invention relates to an apparatus, system, and
method for selective and programmable implants for the therapeutic
treatment of obstructive sleep apnea.
[0008] In one embodiment, an implantable RFID-enabled
micro-electronic neurostimulator includes an implantable
RFID-enabled micro-electronic neurostimulator system having an
implant subsystem including one or more of a) an array of
electrodes, where at least one electrode pair contacts a nerve, b)
a multiplexer digital to analog signal converter, and c) a RFID
based control and stimulation chip. The system also includes an
external subsystem having one or more of a controller, an RF
interface and an optional power source.
[0009] In certain embodiments, the present invention is suitable
for the stimulation of certain nerves to treat conditions which may
be ameliorated by stimulation of a nerve. Such nerves and
conditions include, but are note limited to multiple small
peripheral nerves for treatment of arthritis pain; deep
brain/cortical stimulation for treatment of one or more of
essential tremor, Parkinson's disease, dystonia, depression,
tinnitus, epilepsy, stroke pain, and obsessive compulsive disorder;
sacral nerve stimulation for the treatment of incontinence, pelvic
pain and sexual dysfunction; vagus nerve stimulation for treatment
of epilepsy and/or depression; peripheral nerve stimulation for
treatment of chronic pain; spinal cord stimulation for treatment of
one or more of chronic pain, angina pain, and peripheral vascular
disease pain; cochlear nerve stimulation for treatment of profound
deafness; pulmonary nerve stimulation for treatment of respiratory
support; gastric nerve stimulation for treatment of one or more of
obesity, gastroparesis, and irritable bowel syndrome; and occipital
nerve stimulation for treatment of headaches/migraine and/or
traumatic brain injury.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention, and together with the description serve to explain
the principles of the invention. In the drawings:
[0011] FIG. 1 shows an embodiment of an internal subsystem.
[0012] FIG. 2 shows an embodiment of an internal subsystem with the
core subsystem and internal RF interface in a silicon package.
[0013] FIG. 3 shows a hypoglossal nerve an implant.
[0014] FIG. 4 shows multiple embodiments of neural interface
electrode arrays.
[0015] FIG. 5 shows an embodiment of an internal subsystem
implant.
[0016] FIG. 5A is a breakout view of FIG. 1.
[0017] FIG. 6A shows an embodiment of an internal subsystem with
the neural interface electrodes on the bottom layer of the
implant.
[0018] FIG. 6B shows an embodiment of an internal subsystem with
the neural interface electrodes on the top and bottom layers of the
implant.
[0019] FIG. 7 shows an embodiment of an external subsystem with a
controller.
[0020] FIG. 8 shows two embodiments of the external controller.
[0021] FIG. 9 shows an embodiment of a controller and implant used
to treat incontinence.
[0022] FIG. 10 shows an embodiment of a controller and implant used
to treat seizures.
[0023] FIG. 11 shows a controller and network of implants used to
treat arthritis pain.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
[0025] One embodiment the present invention includes an external
subsystem and an internal subsystem. In certain embodiments, the
external subsystem can include one or more of (1) a controller, (2)
an external RF interface, and (3) an optional power source. The
internal subsystem may include an implant. In certain embodiments,
the implant can include one or more of (1) a neural interface which
can include an array of electrodes where at least one electrode
contacts a nerve, is placed in close proximity to a nerve, or wraps
around a nerve, (2) a core subsystem, and (3) an internal RF
interface. In some embodiments, the neural interface may further
include a digital to analog signal converter and a multiplexer. In
some embodiments the core subsystem may include a microprocessor.
The microprocessor may have a micrologic CPU and memory to store
protocols selective to a patient. The microprocessor may be part of
an integrated silicon package. In still further embodiments, the
internal RF interface includes one or more of a transponder,
internal antenna, modulator, demodulator, clock, and rectifier. The
transponder can be passive or active. In some embodiments, one or
more of a controller, external RF interface, and optional power
source are positioned on the skin of a user/patient, typically
directly over or in close proximity to, an implant.
[0026] In certain embodiments, the external subsystem controller is
in the form of an earpiece or patch including any one or more of a
controller, external RF interface, and optional power source, e.g.,
a battery, AC to DC converter, or other power source known to those
skilled in the art. Still further embodiments include incorporation
of the external subsystem 200 into a watch-like device for, e.g.,
the treatment of arthritic pain, or in a belt. In certain
embodiments, the external subsystem sends and receives control
logic and power using an external RF interface. In such
embodiments, the external subsystem can further include one or more
of a crypto block, data storage, memory, recording unit,
microprocessor, and data port. In some embodiments the
microprocessor may have a micrologic CPU and memory to store
protocols selective to a patient. The microprocessor may be part of
an integrated silicon package.
[0027] The system of the present invention can be used to treat a
number of conditions by stimulating nerves which are associated
with treating a condition. Stimulation can be such that the
stimulus is transmitted by a nerve, or stimulation can be such that
nerve transmission in a nerve is blocked by nerve depolarization.
Some non-limiting examples of treatment by nerve stimulation
include multiple small peripheral nerves for treatment of arthritis
pain; deep brain/cortical stimulation for treatment of one or more
of essential tremor, Parkinson's disease, dystonia, depression,
tinnitus, epilepsy, stroke pain, and obsessive compulsive disorder;
sacral nerve stimulation for the treatment of incontinence, pelvic
pain and sexual dysfunction; vagus nerve stimulation for treatment
of epilepsy and/or depression; peripheral nerve stimulation for
treatment of chronic pain; spinal cord stimulation for treatment of
one or more of chronic pain, angina pain, and peripheral vascular
disease pain; cochlear nerve stimulation for treatment of profound
deafness; pulmonary nerve stimulation for treatment of respiratory
support; gastric nerve stimulation for treatment of one or more of
obesity, gastroparesis, and irritable bowel syndrome; and occipital
nerve stimulation for treatment of headaches/migraine and/or
traumatic brain injury.
[0028] Each of the components of various embodiments of the claimed
invention is described hereafter. In certain embodiments, the
present invention is an open loop system. In other embodiments the
present invention is a closed loop system. The components of the
embodiments can be rearranged or combined with other embodiments
without departing from the scope of the present invention.
[0029] The Internal Subsystem
[0030] In certain embodiments, the internal subsystem includes an
implant, which includes one or more of (1) a core subsystem, (2) a
neural interface, and (3) an internal RF interface. Certain
embodiments of the implant components and component arrangements
are described below.
[0031] Implant Components
[0032] The following paragraphs describe embodiments of the implant
of the present invention, which includes one or more of a core
subsystem, neural interface, and internal RF interface
components.
[0033] The Core Subsystem
[0034] FIG. 1 shows an embodiment of the internal subsystem 100. In
certain embodiments the internal subsystem 100 includes an implant
105 (non-limiting representative embodiments of implant 105 are
shown in FIGS. 3, 5, 5A, 6A, 6B, and 8-11) which may have a core
subsystem 140. The middle portion of FIG. 1 shows a detailed view
of an embodiment of the core subsystem 140. The core subsystem 140
may include one or more of a power module 144, microprocessor 141,
crypto block 142, and input output buffer 143. In certain
embodiments, the microprocessor 141 may have a micrologic CPU, and
may have memory to store protocols selective to a patient. In the
embodiment shown, the core subsystem includes a power module 144, a
core subsystem microprocessor 141 for managing communication with
an external RF interface 203, at least one I/O buffer 143 for
storing inbound and outbound signal data, and a core subsystem
crypto block 142. In some embodiments, the core subsystem
microprocessor 141 communicates with the external RF interface 203
in full duplex. The core subsystem microprocessor 141 may generate
signals for controlling stimulation delivered by the neural
interface 160, and it may process signals received from the neural
interface 160. In certain embodiments, the core subsystem
microprocessor logic includes an anti-collision protocol for
managing in-range multiple transponders and readers, a management
protocol for reset, initialization, and tuning of the implant 105,
and a protocol to facilitate the exchange of data with the neural
interface 160. The core subsystem microprocessor 141 is
programmable and may further include an attached non-volatile
memory. The microprocessor 141 may be a single chip 145 or part of
an integrated silicon package 170.
[0035] FIG. 2 shows an embodiment of an internal subsystem 100 with
the core subsystem 140 and internal RF interface 150 in an
integrated silicon package 170. For size comparison, FIG. 2 shows
the core subsystem 140, internal RF interface 150, and core
subsystem microprocessor 141 next to the silicon package 170.
[0036] The Neural Interface
[0037] The right portion of FIG. 1 shows an embodiment of a neural
interface 160. The neural interface 160 can include an array of
electrodes 161 where at least one electrode 161 contacts a nerve.
In one embodiment, the neural interface 160 includes an array of 10
to 16 electrodes 161. This arrangement is exemplary only however,
and not limited to the quantity or arrangement shown. The core
subsystem 140 connects to the neural interface 160, and controls
neural interface stimulation. In the embodiment shown, the neural
interface 160 is attached to the printed circuit board 130. In some
embodiments, the neural interface 160 may further include a digital
to analog signal converter 164 and a multiplexer 166. In certain
embodiments the multiplexer 166 is included on the printed circuit
board 130. In other embodiments, the multiplexer 166 is included on
a thin layer film or flexible membrane around the surface of the
chip.
[0038] In the embodiment shown, the neural interface 160 receives
power from RF waves received by the implant 105. In one embodiment,
the digital to analog signal converter 164 uses the RF waves to
power one or more capacitors 165, which may be located in the
converter 164. In certain embodiments, the capacitors 165 are
arranged in an array on a microfilm. These capacitors 165 store
charges, which are used to generate analog burst pulses for
delivery by the neural interface 160. In embodiments including a
multiplexer 166, the multiplexer 166 may be used to deliver power
to multiple capacitors 165, and can be used to deliver power to
multiple electrodes 161 in the neural interface 160. In still
further embodiments, the multiplexer 166 is programmable.
[0039] In certain embodiments, the neural interface 160 is
physically located on the opposite side of the printed circuit
board 130 to which the core subsystem 140 is attached. In other
embodiments, the one or more electrodes 161 are physically
separated from the core subsystem 140 by the printed circuit board
130. Each electrode 161 connects to the core subsystem 140 through
wires 133 (e.g., traced wires ) on the printed circuit board 130.
This layered approach to separating the core subsystem 140 from the
electrodes 161 has significant benefits in the bio-compatible
coating and manufacturing of the implant. By minimizing the area
exposed to the HGN, the bio-compatible coating is only required in
the area surrounding the exposed parts of the electrodes 161.
[0040] In certain embodiments, the electrodes 161 may be
manufactured with a biocompatible material coating. In other
embodiments, the electrodes may include embedded platinum contacts
spot-welded to a printed circuit board 130 on the implant 105. The
electrodes 161 may be arrayed in a matrix, with the bottoms of the
electrodes 161 exposed for contact to the HGN. Since the electrodes
161 attach to the top portion of the core subsystem 140 through
leads on the printed circuit board, there is no need for wire-based
leads attached to the contact points, allowing for miniaturization
of the electrodes 161.
[0041] FIG. 3 shows a hypoglossal nerve implanted with a neural
interface 160. In one embodiment, exposed portions of the neural
interface 160 deliver selective stimulation to fascicles of the
HGN. Selective stimulation allows co-activation of both the lateral
HGN branches, which innervate the hypoglossus (HG) and styloglossus
(SG), and the medial branch. This selective stimulation of HG
(tongue retraction and depression) and the SG (retraction and
elevation of lateral aspect of tongue) results in an increased
maximum rate of airflow and mechanical stability of the upper
airway (UAW). Selective stimulation is a unique approach to nerve
stimulation when implanted on the hypoglossal nerve (HGN). The
neural interface 160 may also sense the neural activity of the
nerve it interfaces with and may transmit that sensed activity to
the core subsystem microprocessor 141.
[0042] FIG. 4 shows embodiments of neural interface electrode
arrays. These embodiments are exemplary only, and the arrays are
not limited to the quantity or arrangement of the electrodes shown
in the figure. In one embodiment, at least one electrode 161 is in
contact with a nerve. In certain embodiments, the electrodes 161
may be in the shape of a linear, regular, or irregular array. In
certain embodiments, the electrode 161 array may be in a form
suitable for wrapping around a nerve (e.g., a helical shape or
spring-like shape as shown in FIG. 3). The electrodes 161 may also
be arranged in a planar form to help reshape the nerve and move the
axons closer to the electrodes 161. This facilitates access to
multiple nerve axons, which enables multiple modes of stimulation
for enhanced UAW dilation and stability. With a planar form factor,
stimulation can also be delivered in two dimensions, enabling
optimal excitation of the functional branches of the nerve.
Excitation happens through bi-phasic electrical stimulation of
individual electrodes 161.
[0043] The upper number of electrodes is determined by the space
available for the implant, which varies by indication (e.g.,
arthritis). In one embodiment, the present invention includes one
or more electrodes in contact with a nerve. As shown in FIG. 3, in
certain embodiments, the electrodes which may contact with a nerve
(e.g., a hypoglossal nerve) or be placed in close proximity to a
nerve, and may have any regular or irregular arrangement. In the
embodiments shown in FIGS. 4 and 6A/6B, the electrodes 161 are
arranged in a matrix of pairs, with the pairs serving as anode and
cathode complementary elements 162/163. The matrix arrangement of
electrodes 161 provides multiple nerve stimulating points, and has
several advantages. The matrix arrangement allows a web of nerve
fascicles of a nerve, e.g., the hypoglossal nerve to be accessed,
enabling selective stimulation of particular areas of the nerve.
Stimulation by the neural interface electrodes is controlled by the
core subsystem microprocessor 141. This facilitates access to
multiple nerve axons, which enables multiple modes of
stimulation.
[0044] The Internal RF Interface
[0045] The left portion of FIG. 1 shows a detailed view of an
embodiment of the internal RF interface. The internal RF interface
may include one or more of a transponder, internal antenna,
modulator, demodulator, clock, and rectifier. The transponder can
be passive or active. In certain embodiments, the internal RF
interface can send and/or receive one or more of control logic and
power. In still further embodiments, the internal RF interface 150
delivers one or more of power, clock, and data to the implant core
subsystem 140. In certain embodiments the data is delivered via a
full duplex data connection. In some embodiments, the internal RF
interface 150 sends data (e.g., function status) of one or more
electrodes 161 to a controller 205, described below, for review by
a technician or physician.
[0046] The internal RF interface 150 operates according to the
principle of inductive coupling. In an embodiment, the present
invention exploits the near-field characteristics of short wave
carrier frequencies of approximately 13.56 MHz. This carrier
frequency is further divided into at least one sub-carrier
frequency. In certain embodiments, the present invention can use
between 10 and 15 MHz. The internal RF interface 150 uses a sub
carrier for communication with an external RF interface 203, which
may be located in the controller 205. The sub-carrier frequency is
obtained by the binary division of the external RF interface 203
carrier frequency. In the embodiment shown, the internal RF
interface 150 is realized as part of a single silicon package 170.
The package 170 may further include a chip 145 which is a
programmable receive/transmit RF chip.
[0047] In certain embodiments, the internal RF interface 150 also
includes a passive RFID transponder 156 with a demodulator 158 and
a modulator 157. The transponder 156 uses the sub carrier to
modulate a signal back to the external RF interface 203. The
transponder 156 may further have two channels, Channel A and
Channel B. Channel A is for power delivery and Channel B is for
data and control. In certain embodiments, the transponder 156 may
employ a secure full-duplex data protocol.
[0048] The internal RF interface 150 further includes an inductive
coupler 152, an RF to DC converter 155, and an internal antenna
151. In certain embodiments, the internal antenna 151 includes a
magnetic component. In such embodiments, silicon traces may be used
as magnetic antennas. In other embodiments, the antenna may be a
high Q coil electroplated onto a silicon substrate, and can vary in
size according to the amount of power required in treating an
indication and the required distance from the controller. A
parallel resonant circuit 153 may be attached to the internal
antenna 151 to improve the efficiency of the inductive coupling.
The internal antenna 151 may be realized as a set of PCB traces 133
on the implant 105. Size of the antenna traces is chosen on the
basis of power requirements, operating frequency, and distance to
the controller 205. Both the internal RF interface 150 and the core
subsystem microprocessor 141 are powered from an RF signal received
by the internal antenna 151. A shunt regulator 154 in the resonant
circuit 153 keeps the derived voltage at a proper level.
[0049] Internal Subsystem Design
[0050] In the present invention it is important to note that the
size of the internal subsystem can vary, and can have any shape.
For example, for the treatment of arthritic pain, the internal
subsystem 100 can be designed such that multiple implants 105
respond to the same secured RF signal from a single external
subsystem 200. Similarly, the implant 105 can be small enough and
properly shaped to facilitate placement at or near or on a nerve by
injecting the implant 105.
[0051] Implant Subsystem Arrangement
[0052] The implant 105 may be located on any suitable substrate and
may be a single layer or multi-layer form. FIG. 5 shows an implant
105 constructed as a single integrated unit, with a top layer 110
and a bottom layer 110 which may be implanted in proximity to, in
contact with, or circumferentially around a nerve, e.g., the
hypoglossal nerve. FIG. 5A is a breakout view of FIG. 5.
[0053] In certain embodiments, implant components are layered on a
nerve. This alleviates the need for complex wiring and leads. In
FIGS. 5 and 5A, the top layer 110 includes a core subsystem 140, an
internal RF interface 150, and a neural interface 160. The top
layer 110 serves as the attachment mechanism, with the implant
components on the bottom layer 110. The neural interface 160 may be
surface bonded to contacts on a printed circuit board 130. The
bottom layer 110 is the complementary portion to the top layer 110,
and serves as an attachment mechanism so that the implant 105
encompasses the HGN. Although conductive parts in contact with the
HGN may be located at any suitable position on the implant 105, in
the embodiment shown in FIGS. 5 and 5A, the bottom layer 110 has no
conductive parts.
[0054] In the embodiment shown in FIGS. 5 and 5A, and as described
above, the core subsystem 140 is included in a silicon package 170
(FIG. 2) attached to a printed circuit board (PCB) 130 on the top
layer 110. The PCB 130 has a first side 131 and a second side 132.
The silicon package 170 is placed on a first side 131 of the
printed circuit board 130. In certain embodiments the PCB 130 may
be replaced with a flexible membrane substrate. In the embodiment
shown, the silicon package 170 further includes the internal RF
interface 150. The neural interface 160 attaches to the second side
132 of the PCB 130. In this embodiment, the neural interface 160
(FIG. 6B) further includes a plurality of neural interface
electrodes 161 (FIG. 4) arranged into anode and cathode pairs
162/163, shown in this embodiment as an array of 10 to 16 elements.
The number and arrangement of anode and cathode pairs 162/163 is
exemplary only, and not limited to the embodiment shown. The
silicon package 170 (FIG. 2) connects to the anode and cathode
pairs 162/163 via traced wires 133 printed on the PCB 130.
[0055] In other embodiments, such as the one shown in FIG. 6A, the
neural interface electrode anode and cathode pairs 162/163 are
located on the bottom layer 110 of the implant 105. In still other
embodiments, such as the one shown in FIG. 6B, the neural interface
electrode anode and cathode pairs 162/163 are located on both the
top and the bottom layers 110/120. The matrix arrangement of
electrodes 161 provides multiple nerve stimulating points, and has
several advantages. The matrix arrangement allows a web of nerve
fascicles of the hypoglossal nerve to be accessed, enabling
selective stimulation of particular areas of the nerve. In some
embodiments, power is delivered to the matrix of electrodes 161
from the D/A converter 164 to capacitors 165 via a multiplexer
166.
[0056] The implant 105 may further include an isolation layer 112
(FIG. 6A). In certain embodiments a protective coating 114 (FIGS.
6A and 6B) may be applied to the top and bottom layers 110/120 of
the implant 105. The implant 105 may further be coated with a
protective coating 114 for biological implantation. Further, in
certain embodiments all or a portion of the device may be encased
in a biocompatible casing. In such embodiments, the casing may be a
material selected from the group consisting of one or more titanium
alloys, ceramic, and polyetheretherketone (PEEK).
[0057] External Subsystem
[0058] In certain embodiments, the external subsystem 200 may
include one or more of (1) a controller, (2) an external RF
interface and (3) an optional power source. An embodiment of an
external subsystem 200 including these elements is shown in FIG. 7.
Typically the external subsystem 200 is located externally on or
near the skin of a patient.
[0059] The Controller
[0060] FIG. 7 shows an embodiment of an external subsystem 200 with
a controller 205. The controller 205 controls and initiates implant
functions. In other embodiments, the controller 205 may be part of
the internal subsystem 100 instead of external subsystem 200, and
in still further embodiments, portions of the controller 205 may be
in both the external and internal subsystems 200/100. In certain
embodiments, the controller 205 may further have one or more of a
controller crypto block 201, data storage 206, a recording unit
207, and a controller microprocessor 204. In some embodiments the
controller microprocessor 204 may have a micrologic CPU and memory
to store protocols selective to a patient. The controller
microprocessor 204 is programmable and may further include an
attached non-volatile memory. The microprocessor 204 may be a
single chip or part of an integrated silicon package.
[0061] In certain embodiments, the controller may further include
one or more of an external RF interface 203 having RF transmit and
receive logic, a data storage 206 that may be used to store patient
protocols, an interface 202 (e.g., a USB port), a microprocessor
203, an external antenna (not shown), a functionality to permit the
controller 205 to interface with a particular implant 105, and an
optional power source 215. In certain embodiments, the controller
electronics can be either physically or electromagnetically coupled
to an antenna. The distance between the external RF interface
antenna and the implant 105 may vary with indication. In certain
embodiments, distance is minimized to reduce the possibility of
interference from other RF waves or frequencies. Minimizing the
distance between the external antenna and the implant 105 provides
a better RF coupling between the external and internal subsystems
200/100, further reducing the possibility of implant activation by
a foreign RF source. An encrypted link between the external and
internal subsystems 200/100 further reduces the possibility of
implant activation by foreign RF. In other embodiments, one or more
of the internal antenna 151 and external antenna are maintained in
a fixed position. Potential design complexity associated with
internal RF interface antenna 151 orientation is minimized through
the ability to position the external RF interface antenna in a
specific location (e.g., near the patient's ear). Even if the
patient moves, the internal RF interface antenna 151 and controller
205 remain coupled.
[0062] In certain other embodiments, the controller 205 also serves
as (1) a data gathering and/or (2) programming interface to the
implant 105. The controller 205 has full control over the operation
of the implant 105. It can turn the implant 105 on/off,. and may be
paired to the implant 105 via a device specific ID, as described
herein below with respect to use of the implant 105 and controller
205 of the present invention. In still further embodiments, the
controller microprocessor 204 calculates stimulus information. The
stimulus information is then communicated to the implant 105. The
implant 105 then provides a calculated stimulus to a nerve. In
another embodiment, the controller 205 preloads the implant 105
with an algorithmic protocol for neural stimulation and then
provides power to the implant 105.
[0063] External RF Interface
[0064] In the embodiment shown in FIG. 7, the external subsystem
200 includes an external RF interface 203 that provides an RF
signal for powering and controlling the implant 105. The external
RF interface 203 can be realized as a single chip, a plurality of
chips, a printed circuit board, or even a plurality of printed
circuit boards. In other embodiments, the printed circuit board can
be replaced with a flexible membrane. The external RF interface 203
may include one or more of a transponder 208 (not shown), external
antenna (not shown), modulator 210 (not shown), and demodulator
211, clock 212 (not shown), and rectifier 213 (not shown). The
external RF interface transponder 208 can be passive or active. In
certain embodiments, the external RF interface 203 can send and/or
receive one or more of control logic and power. In still further
embodiments, the external RF interface 203 delivers one or more of
power, clock, and data to one or more of the external subsystem
controller 205 and the internal subsystem 100 via the internal RF
interface 150. In certain embodiments the data is delivered via a
full duplex data connection.
[0065] In an embodiment, the external RF interface 203 operates at
a carrier frequency of about 13.56 MHz. In certain embodiments, the
external RF interface 203 can operate between 10 and 15 MHz. This
carrier frequency is further divided into at least one sub-carrier
frequency. The sub-carrier frequency is obtained by the binary
division of the external RF interface 203 carrier frequency. The
external RF interface 203 uses the sub carrier for communication
with the internal RF interface 150. The external RF interface
transponder 208 (not shown) uses the sub carrier to modulate a
signal to the internal RF interface 150. The transponder 208 (not
shown) may further have two channels, Channel A and Channel B.
Channel A is for power delivery and Channel B is for data and
control. The transponder 208 (not shown) may employ a secure
full-duplex data protocol.
[0066] In certain embodiments, the external RF interface 203 may
further include a demodulator 211 (not shown) and a modulator 210
(not shown). In still further embodiments, the external RF
interface 203 further includes an external antenna. In certain
embodiments, the external antenna includes a magnetic component. In
such embodiments, silicon traces may be used as magnetic antennas.
The external antenna may be realized as a set of PCB traces. In
other embodiments, the antenna may be a high Q coil electroplated
onto a silicon substrate. Size of the antenna traces is chosen on
the basis of power requirements, operating frequency, and distance
to the internal subsystem 100. Antenna size may also be chosen
according to the indication to be treated. In certain embodiments,
the external antenna may transmit the power received by internal
subsystem 100. In certain other embodiments, the external antenna
may be larger, and have a higher power handling capacity than the
internal antenna 151, and can be realized using other antenna
embodiments known by those skilled in the art.
[0067] In certain embodiments, the external subsystem 200 is
loosely coupled to an optional power source 215. In one embodiment,
the controller power source 215 is not co-located with the external
RF interface antenna. The external power source 215 may be in one
location, and the external RF interface 203 and optionally the
controller 205 are in a second location and/or third location. For
example, each of the power source 215, controller 205 and external
RF interface 203 can be located in difference areas. In one
embodiment, the power source 215 and the controller 205 and the
external RF interface 203 are each connected by one or more
conductive members, e.g. a flexible cable or wire. Additionally, in
certain embodiments, the controller 205 and optional power source
215 may be co-located, and the external RF interface 203 may be
located elsewhere (i.e., loosely coupled to the controller 205). In
such embodiments, the external RF interface 203 is connected to the
controller 205 by a flexible cable or wire.
[0068] Since the power source 215 may be separately located from
the controller 205 and/or external RF interface antenna, a larger
power source 215 can be externally located but positioned away from
the nerve that requires stimulation. Further, to reduce wasted
power, a larger external RF interface antenna can be used. This
provides the advantage of less discomfort to a user and therefore
enhances patient compliance.
[0069] Such embodiments can also provide power to 2, 3, 4, 5 or
more loosely coupled external RF interfaces 203. Thus, each
external RF interface 203 can be positioned at or near the site of
an implant 105 without the need for a co-located power source 215.
In certain embodiments, each external RF interface 203 draws power
from a single power source 215, and thus a single power source 215
powers a plurality of implants 105. Of course, the amount of power
provided to each implant 105 will vary by indication and distance
between the external RF interface 203 and the implant 105. The
greater the distance between the external RF interface 203 and the
implant 105, the greater the power level required. For example, a
lower power is generally required to stimulate peripheral nerves,
which are closer to the surface of the skin. As apparent to one of
skill in the art, the power received at the implant 105 must be
high enough to produce the desired nerve stimulus, but low enough
to avoid damaging the nerve or surrounding tissue.
[0070] The external RF interface 203 may further include a
programmable receive/transmit RF chip, and may interface with the
controller crypto unit 201 for secure and one-to-one communication
with its associated implant 105. The external RF interface 203
includes a parameterized control algorithm, wherein the
parameterized control algorithm compares the sensed information to
a reference data set in real time. The algorithm may be included in
the controller microprocessor 204. Depending upon the patient's
size and severity of disease state, the algorithm will vary a
number of parameters which include frequency, amplitude of the
signal, number of electrodes involved, etc.
[0071] Interaction With Outside Information Sources
[0072] The external subsystem controller 205 may also interface
with a computer. In some embodiments, the controller interface 202
is a built-in data port (e.g., a USB port). The built-in micro USB
port serves as the interface to a physician's PC. The purpose of
the PC interface is to tune (and re-tune) the implant system and
transfer recorded data. Via the controller interface 202 a computer
also transfer historical data recorded by the implant 105. The
controller 205 may obtain and update its software from the
computer, and may upload and download neural interface data to and
from the computer. The software may be included in the controller
microprocessor 204 and associated memory. The software allows a
user to interface with the controller 205, and stores the patient's
protocol program.
[0073] External Subsystem Design
[0074] The external subsystem 200 can be of regular or irregular
shape. FIG. 8 shows two embodiments of an external subsystem
controller 205, one with the controller 205 included with an
earpiece much like a Bluetooth earpiece, and one with the
controller 205 included with a patch. In the embodiments shown,
potential design complexity associated with internal RF antenna 151
orientation is minimized through the single and fixed position of
the controller 205. The patient may move and turn without
disrupting the coupling between the controller 205 and the internal
antenna 151. In the embodiment with the controller 205 in an
earpiece, a flexible receive/transmit tip in the earpiece aligns
the controller external RF interface antenna with the implant 105.
In the embodiment with the controller 205 in a patch, the patch is
aligned with the implant 105 and placed skin. The patch may include
one or more of the controller 205, a replaceable adhesive layer,
power and RFID coupling indication LED, and a thin layer
rechargeable battery. Still further embodiments include
incorporation of the external subsystem 200 into a watch-like
device for, e.g., the treatment of arthritic pain, or in a belt.
Yet another range of variations are flexible antennas and the
controller RF chip woven into clothing or an elastic cuff, attached
to controller electronics and remotely powered. Controller 205
designs may be indication specific, and can vary widely. The
controller 205 embodiments in FIG. 8 are exemplary only, and not
limited to those shown.
[0075] Communication With the Implant as a Function of Design
[0076] The distance between the external RF interface antenna and
the implant 105 may vary with indication. In certain embodiments,
e.g., in an embodiment for treating sleep apnea, the distance
between this contact area and the actual implant 105 on a nerve is
1 to 10 cm, typically 3 cm, through human flesh. This distance,
along with the controller crypto unit 201 and the core subsystem
crypto unit 142 in the implant 105, reduces potential interference
from other RF signals. Minimizing the distance between the external
antenna and the implant 105 provides a better RF coupling between
the external and internal subsystems 200/100, further reducing the
possibility of implant activation by a foreign RF source. An
encrypted link between the external and internal subsystems 200/100
further reduces the possibility of implant activation by foreign
RF. In other embodiments, one or more of the internal antenna 151
and external antenna are maintained in a fixed position. Potential
design complexity associated with internal RF interface antenna 151
orientation is minimized through the ability to position the
external RF interface antenna in a specific location (e.g., near
the patient's ear). Even if the patient moves, the internal RF
interface antenna 151 and controller 205 remain coupled.
[0077] Implant Power
[0078] In certain embodiments, the implant 105 is externally
powered by near field RF waves, the RF waves are inductively
converted to DC power, which powers the implant 105 and delivers
electrical signals to selected elements of the neural interface
160. In one embodiment, the implant 100 uses between 0.1 to about 1
milliamps, preferably averaging about 0.5 milliamps of current and
about 10 to 30 microwatts of power. In some embodiments, the near
field RF waves are emitted from the controller 205. In certain
embodiments, controller 205 can be powered by an optional power
source 215, e.g., a battery. In certain embodiments, the battery
can be rechargeable battery. In other embodiments, the optional
power source 215 is AC to DC converter, or other power sources
known to those skilled in the art.
[0079] Implant and Controller Security
[0080] In certain embodiments, the controller 205 identifies the
patient's unique ID tag, communicates with and sends signals to the
implant 105. In certain embodiments, a controller crypto unit 201
may be installed to ensure that communication between the
controller 205 and the implant 105 is secure and one-to-one. The
controller crypto unit 201 may include the implant's unique ID
tag.
[0081] In particular, the implant 105 may have a unique ID tag,
which the controller 205 can be programmed to recognize. A
controller microprocessor 204 confirms the identity of the implant
105 associated with the controller 205, thereby allowing setting of
the patient's specific protocol. The setting may be accomplished
using a computer interfaced with the controller 205 through an
interface 202 on the controller 205.
[0082] More particularly, once the controller crypto unit 201
establishes a link with the core subsystem crypto unit 142, the
controller 205 communicates a stimulation scenario to the core
subsystem microprocessor 141. The controller 205 initiates a
stimulation cycle by making a request to the core subsystem 140 by
sending an encoded RF waveform including control data via the
external RF interface 203. The core subsystem 140 selects a trained
waveform from memory and transmits the stimulation waveform to the
core subsystem microprocessor 141. Once the core subsystem
microprocessor 141 receives the waveform, the core subsystem 140
generates a stimulating signal for distribution to the neural
interface 160.
[0083] In certain embodiments, the controller 205 prevents
self-activation or autonomous operation by the implant 105 by
handshaking. Handshaking occurs during each communications cycle
and ensures that security is maintained. This prevents other
devices operating in the same frequency range from compromising
operation of the implant 105. Implant stimulus will not commence
unless an encrypted connection is established between the external
RF interface 203 and the implant 105. This serves as an
anti-tampering mechanism by providing the implant 105 with a unique
ID tag. The external controller 205 is matched, either at the point
manufacture or by a physician, to a particular ID tag of the
implant 105, typically located in an EPROM of the implant 105. In
certain embodiments, the EPROM may be included in the core
subsystem microprocessor 141. In other embodiments, the EPROM may
be included in the controller microprocessor 204. This prevents
alien RF interference from `triggering` activation of the implant
105. While arbitrary RF sources may provide power to the implant
105, the uniquely matched controller 205 establishes an encrypted
connection before directing the implant 105 to commence stimulus,
thereby serving as a security mechanism.
[0084] Implant and Controller Positioning
[0085] Prior to implantation of the present invention for the
treatment of a condition, the patient is first diagnosed as being a
suitable candidate for such treatment. For example, with respect to
sleep apnea, patients are diagnosed in a sleep lab and an implant
105 is prescribed for their specifically diagnosed condition. Once
diagnosis is complete, the implant 105 is implanted in the
patient's body, typically on or in the vicinity of a nerve. In
certain embodiments, the implant 105 is implanted on the HGN. In
such embodiments, the implant 105 may be implanted below the ear
unilaterally at the sub-mandibular triangle, encasing the
hypoglossal nerve. In treatment of incontinence the implant 105 is
placed on or near the sacral nerve, and in treatment of arthritis,
implants 105 are placed near the peripheral nerves transmitting
pain.
[0086] Once implanted, the implant 105 is used to stimulate the
nerve. Stimulation of a fascicle or axon can act to maintain nerve
activity. Hence in certain embodiments, the present invention can
maintain muscular tone (e.g., in the tongue, thereby preventing
apnea). Therefore, in certain embodiments, controller 205,
described in more detail above, activates implant 105 to stimulate
neural activity to ameliorate the negative physiological impact
associated an indication.
[0087] In embodiments where the device is implanted in a manner to
stimulate the HGN, the implant 105 delivers tone to the tongue.
Maintaining tongue muscle tone stops the tongue from falling back
and obstructing the upper airway. In embodiments where the device
is implanted to stimulate the sacral nerve, the controller 205
sends small electrical impulses to the sacral nerve, acting as a
bladder toner, reducing or eliminating the patient's urge
incontinence. In other embodiments, the implant subsystem is
implanted in a manner so as to provide analgesia to a patient by
using stimulation to suppress transmission of nerve impulses from a
nerve by depolarizing the nerve using bi-phasic stimulation. The
stimulation may be provided continuously during sleep hours, or
upon preprogrammed customer-specific intervals. The implant 105 may
also sense and record neural activity.
[0088] Implant and Controller Treatments
[0089] The desired treatment is determined by assessing a patient's
needs and measuring a patient's needs against predetermined
stimulation protocols. The neural interface 160 stimulation
protocols are measured until a desired response is achieved. Once a
desired stimulation level is achieved, those protocols may be
programmed into a controller 205. Stimulation may be programmed for
delivery in an open loop or closed loop. After the controller 205
is programmed, the patient activates the controller 205 at bed time
or at desired intervals. In the case of arthritic pain or other
pain, the patient can activate the controller on an "as needed"
basis. This electrical stimulation provides a signal to the
targeted nerve and starts the treatment. Upon completion of one
treatment cycle, the duration of which is determined in the tuning
phase of the implantation procedure, described above, the core
subsystem 140 can report completion back to the controller 205 via
RF communication, and optionally goes to an idle state until
receiving another set of instructions.
[0090] Typically, the controller is programmed post-implantation at
the time of customization. The patient's muscle activity or sensed
pain level is measured against the stimulation parameters.
Multi-contact design of the electrodes 161 (FIG. 4) allows a
technician to measure effectiveness of stimulating each of the
electrode points individually and in combination. This is
accomplished by a PC software application that takes into account
patient history and response, thus eliminating redundant
combinations as the calibration proceeds. Once a desired
stimulation level is achieved, those parameters are programmed in
the controller.
[0091] In certain embodiments, controller 205 can also determine
when treatment is required, and stimulate a targeted nerve based on
that determination. In order to make such a determination,
controller 205 can include one or more sensors that generate
signals as a function of the activity and/or posture of the
patient. In other embodiments the patient may enter an input into
the controller 205 telling it to commence treatment. However, as
noted above, controller 205 can be activated by a user and then
function in a manner such that the implant is continuously active
until the patient manually deactivates the controller by pressing a
button on the controller 205, or by moving the controller 205 out
of range of the implant. In other embodiments, the controller 205
can be programmed to activate and deactivate an implant 105 at
programmed intervals.
[0092] This electrical stimulation provides a signal to the nerve
or nerves of interest and starts the treatment of the patient's
condition. Upon completion of one cycle, the duration of which is
determined in the tuning phase of the implantation procedure,
described above, the core subsystem 140 can report completion back
to the controller 205 via RF communication, and optionally goes to
an idle state until receiving another set of instructions.
Non-limiting examples of treatment programs are provided below.
[0093] Sleep Apnea
[0094] FIG. 3 shows an embodiment of an implant 105 and controller
205 that may be used to treat obstructive sleep apnea. In certain
embodiments, such as the one shown in FIG. 3, the implant 105 is
implanted on or in the vicinity of the HGN. In such embodiments,
the implant 105 may be implanted below the ear unilaterally at the
sub-mandibular triangle, encasing the hypoglossal nerve. In certain
embodiments, a stimulation frequency of about 10-40 Hz can be used.
Stimulation may also be delivered in pulses, with pulse widths
about 100 to 300 microseconds, more typically 200 microseconds.
Although any suitable pulse width can be used, preferred pulses are
at a width that simultaneously prevent nerve damage and reduce or
eliminate corrosion of neural interface electrodes. The embodiment
in FIG. 3 is exemplary only, and not limited to what is shown.
[0095] Incontinence
[0096] FIG. 9 shows an embodiment of a controller 205 and implant
105 used to treat incontinence. The system treats incontinence by
stimulating the sacral nerve, which controls voiding function.
Sacral nerve stimulation is an FDA-approved electronic stimulation
therapy for reducing urge incontinence. The implant is surgically
placed on the sacral nerve in the lower spine. An external
subsystem controller 205 then sends small electrical impulses
continuously to the sacral nerve, acting as a bladder toner,
reducing or eliminating the patient's urge incontinence.
[0097] Stimulation may be programmed for delivery in an open loop
or closed loop at a suitable frequency. In certain embodiments, a
stimulation frequency of about 5 to 25 Hz is used, preferably 15
Hz. Stimulation may also be delivered in pulses of 0.5 to 3 mA,
with pulse widths of about 100 to 300 microseconds, more typically
210 microseconds. Although any suitable pulse width can be used,
preferred pulses are at a width that simultaneously prevent nerve
damage and reduce or eliminate corrosion of neural interface
electrodes. After the controller 205 is programmed, the patient
activates the controller 205 when the urge to void is felt, at bed
time, or at desired intervals. The embodiment in FIG. 9 is
exemplary only, and not limited to what is shown.
[0098] Seizures
[0099] FIG. 10 shows an embodiment of an controller 205 and implant
105 used to treat seizures. The embodiment in FIG. 10 is exemplary
only, and not limited to what is shown. In the embodiment shown,
the implant is attached to, or in the vicinity of, the vagus nerve.
Stimulation of the vagus nerve is thought to affect some of its
connections to areas in the brain prone to seizure activity.
Patients who suffer from complex partial seizures or generalized
seizures where consciousness is lost, and who do not respond to
anticonvulsant medication, and patients who cannot undergo brain
surgery are candidates for vagus nerve stimulation therapy. Vagus
nerve stimulation may also be used to treat photosensitive epilepsy
and epilepsy resulting from head injury.
[0100] Vagus nerve stimulation may be programmed for delivery in an
open or closed loop. In certain embodiments, a stimulation
frequency of about 100 to 300 Hz is used, preferably 200 Hz.
Stimulation is delivered in pulses of 3 to 10 mA, typically 7 mA.
In certain embodiments, pulses are applied in bursts of 10 to 30,
preferably 20 pulse bursts, with burst durations of 150 to 350
microseconds, typically 95 microseconds.
[0101] Although any suitable pulse width can be used, preferred
pulses are at a width that simultaneously prevents nerve damage and
reduces or eliminates corrosion of neural interface electrodes. The
controller 205 may be programmed to provide stimulation constantly,
or at predetermined intervals. In other embodiments, the patient
activates the controller 205 to provide stimulation prior to the
onset of a seizure.
[0102] Arthritis
[0103] FIG. 11 shows a controller 205 and network of implants 105
for treating arthritis pain. In the embodiment shown, the implants
105 reduce or eliminate arthritis pain by bi-phasic stimulation and
depolarization of nerve pain signals. In certain embodiments the
implant 105 is surgically implanted on or in the vicinity of a
nerve that transmits arthritis pain. In other embodiments, the
implant 105 is injected. In certain embodiments, an implant 105 is
less than 1 square centimeter in size, and includes only a single
pair of electrodes 161 (not shown).
[0104] The controller 205 is multiplexed and/or networked to the
internal RF interface antennas 151 of multiple implants 105. In the
embodiment shown, a network of multiple implants 105 is controlled
and powered by a single external controller 205. In other
embodiments, multiple controllers 205 power and control multiple
implants 105. The number and location of controllers 205 and
implants 105 is exemplary only, and not limited to what is shown in
the figure.
[0105] In certain embodiments the controller 205 is in a patch
(FIG. 8). In other embodiments, the controller is in a wrist band
(not shown), and in still further embodiments, the controller may
be in a belt (not shown), or an earpiece (FIG. 8). In still further
embodiments, a single controller 205 may control and power a single
implant 105. The shape of the controller 205 and number of implants
105 shown in FIG. 11 is exemplary only, and not limited to what is
shown.
[0106] Other embodiments of the apparatus and methods described can
be used in the present invention. Various alternatives,
substitutions and modifications for each of the embodiments and
methods of the invention may be made without departing from the
scope thereof, which is defined by the following claims. All
references, patents and patent applications cited in this
application are herein incorporated by reference in their
entirety.
* * * * *