U.S. patent application number 14/097568 was filed with the patent office on 2014-06-12 for method and apparatus for magnetic induction therapy.
This patent application is currently assigned to EMKINETICS, INC.. The applicant listed for this patent is EMKINETICS, INC.. Invention is credited to Daniel R. BURNETT, Christopher HERMANSON.
Application Number | 20140163304 14/097568 |
Document ID | / |
Family ID | 39269164 |
Filed Date | 2014-06-12 |
United States Patent
Application |
20140163304 |
Kind Code |
A1 |
BURNETT; Daniel R. ; et
al. |
June 12, 2014 |
METHOD AND APPARATUS FOR MAGNETIC INDUCTION THERAPY
Abstract
An energy emitting apparatus for providing a medical therapy
includes one or more energy generators, a logic controller
electrically connected to the one or more energy generators, and
one or more sensors for detecting electric conduction in a target
nerve that are connected to the logic controller. The one or more
energy generators produce energy focused on the target nerve upon
receiving a signal from the logic controller, and the energy is
varied by the logic controller according to an input provided by
the one or more sensors. In one embodiment, the energy emitting
apparatus is an apparatus for magnetic induction therapy that
includes one or more conductive coils disposed in an ergonomic
housing that produce a magnetic field focused on the target nerve
upon receiving an electric current from the logic controller based
on an input provided by the one or more sensors.
Inventors: |
BURNETT; Daniel R.; (San
Francisco, CA) ; HERMANSON; Christopher; (Santa Cruz,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EMKINETICS, INC. |
San Francisco |
CA |
US |
|
|
Assignee: |
EMKINETICS, INC.
San Francisco
CA
|
Family ID: |
39269164 |
Appl. No.: |
14/097568 |
Filed: |
December 5, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11866329 |
Oct 2, 2007 |
|
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14097568 |
|
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60848720 |
Oct 2, 2006 |
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Current U.S.
Class: |
600/13 |
Current CPC
Class: |
A61N 2/006 20130101;
A61N 1/3603 20170801; A61N 2/02 20130101 |
Class at
Publication: |
600/13 |
International
Class: |
A61N 2/00 20060101
A61N002/00; A61N 2/02 20060101 A61N002/02 |
Claims
1. A method of treating a condition within a patient body,
comprising: positioning an energy emitting element at a first
location along at least one foot of the patient body and into
proximity to a nerve which passes beneath the first location,
wherein the energy emitting element is in electrical communication
with a controller; positioning a conductive element at a second
location along the at least one foot, wherein the conductive
element is in communication with the controller; and transmitting
energy from the energy emitting element and into the nerve such
that the energy is conducted from the first location, through the
foot, and into the second location.
2. The method of claim 1 further comprising monitoring the energy
transmitted through the nerve via one or more sensors in electrical
communication with the controller.
3. The method of claim 2 further comprising modulating the energy
transmitted from the energy emitting element via the controller
based on feedback received from the one or more sensors such that
the condition is mitigated.
4. The method of claim 1 wherein the condition to be treated
comprises overactive bladder, urinary incontinence, fecal
incontinence, obesity, depression, hypertension, pain, back pain,
restless leg syndrome, Guillain Bane syndrome, quadriplegia,
paraplegia, neuralgia, irritable bowel syndrome, migraine,
vulvodynia, incompetence or pelvic pain.
5. The method of claim 1 wherein positioning an energy emitting
element comprises placing the energy emitting element against a
surface of the foot at the first location.
6. The method of claim 1 wherein transmitting energy from the
energy emitting element comprises transmitting electromagnetic
energy into the foot at the first location.
7. The method of claim 1 further comprising adjusting a position of
the energy emitting element relative to the foot.
8. The method of claim 1 wherein transmitting energy from the
energy emitting element comprises transmitting the energy in a
pulsed manner.
9. The method of claim 1 wherein transmitting energy from the
energy emitting element comprises transmitting the energy at a
frequency of 10-30 Hz.
10. The method of claim 1 wherein transmitting energy from the
energy emitting element comprises transmitting the energy for up to
30 minutes.
11. The method of claim 1 further comprising varying the energy
according to a muscular response in the patient.
12. The method of claim 1 wherein the controller comprises a logic
controller.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 11/866,329 filed Oct. 2, 2007, which claims
priority to U.S. Prov. Pat. App. 60/848,720 filed Oct. 2, 2006,
each of which is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to energy emitting apparatus
and methods for providing a medical therapy. In one embodiment, the
energy emitting apparatus is an ergonomic wrap or cradle that
contains conductive coils generating a magnetic field directed to a
target nerve.
BACKGROUND OF THE INVENTION
[0003] Overactive bladder ("OAB") and urinary incontinence ("UI")
affect over 16% of the American population each year, or
approximately 34 million men and women. Outside of the United
States, OAB and UI affects over 46 million Europeans. The economic
cost of OAB and UI is estimated to be in excess of $12 billion a
year in the United States alone.
[0004] Due to the social stigmas attached to OAB and UI and to
misunderstandings related to the symptoms associated with OAB and
UI, only 40% of the affected individuals in the United States seek
medical treatment. Of those 13.6 million Americans seeking medical
treatment, nearly 30% or 4 million individuals are reportedly
unsatisfied with their current therapy.
[0005] Known treatments for OAB and UI include exercise and
behavioral modifications, pharmacological therapies, surgical
intervention and neuromodulation, but each of these treatments
exhibits severe limitations.
[0006] Exercise and behavioral modifications often require patients
to adhere to stringent routines, including scheduled voiding,
maintenance of a bladder diary, and intense exercise regimens.
While this type of treatment may be a viable option for a small
group of highly dedicated individuals, its daily impact on a
person's life makes it unattractive for most patients.
[0007] Pharmacological intervention is the most widely prescribed
therapy for OAB and UI. Unfortunately, patients often suffer from
side effects related to their drug therapies. Such side effects are
sometimes serious and are particularly pronounced in elderly
patient populations that tend to use a plurality of medications. In
addition, approximately 30% of all patients subjected to
pharmacological therapies appear to be dissatisfied with the
efficacy of their prescribed treatments.
[0008] Surgical intervention IS extremely invasive and often
results in a long-term requirement for catheterization that may
become permanent in some instances. The negative impact of these
procedures on the patient's quality of life and their high expense
make surgical intervention a recommended option only when all other
treatment options have been exhausted.
[0009] Neuromodulation is another available therapy for OAB and UI.
In general, pulsed electromagnetic stimulation ("PES") has proven
to have beneficial effects in a variety of medical applications.
The related scientific principle is that an electric current
passing through a coil generates an electromagnetic field, which
induces a current within a conductive material placed inside the
electromagnetic field.
[0010] More particularly, PES has been shown to be an effective
method of stimulating a nerve positioned within the electromagnetic
field, thereby affecting a muscle controlled by that nerve. For
example, in the paper titled "Contactless Nerve Stimulation and
Signal Detection by Inductive Transducer" presented at the 1969
Symposium on Application of Magnetism in Bioengineering, Maass et
al. disclosed that a nerve threading the lumen of a toroid could be
stimulated by a magnetic field of 0.7 Volt peak amplitude and a 50
.mu.s duration in a monitor wire, and that such stimulation could
generate a contraction of major leg muscles in anesthetized
mammals.
[0011] Various attempts were made in the prior art to use PES for
treating a variety of ailments. For example, U.S. Pat. No.
4,548,208 to Niemi discloses an apparatus for inducing bone growth
by generating an electric current in the body through the external
application of an electromagnetic field. Such apparatus includes
opposing clamps disposed on a limb and may optionally include
feedback coils and a microprocessor for sensing the magnetic field,
so to avoid an overcurrent mode. Therefore, this apparatus
optimizes the magnetic field on the basis of measurements of the
generated magnetic field.
[0012] U.S. Pat. No. 4,940,453 to Cadwell discloses a method and
apparatus for magnetically stimulating the neural pathways of a
higher level organism. In this invention, a sinusoidally
fluctuating current flow is created through a coil that overlies
neurons to be stimulated, and frequency of the current flow and
frequency of the magnetic field produced by the coil predetermined
to correspond to the time constant of the neurons to be stimulated.
Sensors for sensing coil conditions, such as coil temperature, may
also be included.
[0013] U.S. Pat. No. 5,000,178 to Griffith discloses an electrical
to electromagnetic transducer for applying electromagnetic energy
to damaged parts of a living body by directing electromagnetic
radiation to a certain damaged body part. Electromagnetic radiation
is initially generated by a dipole consisting of a bar of high
permeability material wrapped with an electrically conductive coil.
Magnetic fields, which are generated away from the damaged body
part, intersect a conductive shield and establish eddy currents,
which in turn generate magnetic fields opposite and nearly equal to
the magnetic fields generated by the electromagnetic source. The
resultant electromagnetic fields reinforce the electromagnetic
field directed towards the damaged body part and diminish the
electromagnetic field directed away from the damaged body part.
[0014] U.S. Pat. No. 5,014,699 to Pollack et al. discloses a
non-invasive, portable electromagnetic therapeutic method and
apparatus for promoting the healing of damaged or diseased living
tissue, including fractured bone. These method and apparatus
involve generating a signal that has a series of substantially
symmetric voltage cycles of bursted pulses with narrow pulse widths
of 0.5 to 20 microseconds, and further involve converting the
signal into an electromagnetic field extending into an area that
contains tissue to be healed. This invention provides for no
feedback on the efficiency of the applied stimulation.
[0015] In a paper titled "Selective Stimulation and Blocking of
Sacral Nerves: Research Setup and Preliminary Results," published
in Annual International Conference of the IEEE Engineering in
Medicine and Biology Society, Vol. 13, No. 2, 1991, Wijkstrda et
al. used an external pulsed magnetic coil to stimulate a peripheral
nerve for the treatment of urinary incontinence. The authors used a
large magnetic field produced by a single coil to ensure that the
nerve was fired and the resulting nerve conduction was frequently
painful or intolerable. In addition, coil alignment was problematic
because an internally implanted coil was utilized, which had to be
aligned with the fully external magnetic field to stimulate the
nerve. Due to the difficulty in positioning the device, the
practical application of this therapy does not permit home
healthcare usage without a preset alignment and monitoring of the
nerve, and no provision was made to insure that the nerve was
actually being stimulated or to adjust the device in response to
commonly occurring physiologic and anatomic variations in nerve
locations.
[0016] U.S. Pat. No. 5,181,902 Erickson et al. and U.S. Pat. No.
5,314,401 to Tepper disclose pulsed electromagnetic field ("PEMF")
transducer systems usable to perform PEMF therapies (such as after
spinal fusion) by generating flux-aided electromagnetic fields. The
drive electronics includes a PEMF processor that executes a PEMF
program for controlling the activation of the electromagnetic
fields (field strength and cycle).
[0017] In a paper titled: "Magnetic Stimulation of the Bladder in
Dogs" presented at the 1993 AAEM Annual Meeting, the abstract of
which was published in the Muscle & Nerve issue of October
1993, Lin et al. disclosed that magnetic stimulation could be
employed to stimulate the cortex, spinal nerves and peripheral
nerves of dogs through direct trans-abdominal stimulation of the
detrusor muscles or through stimulation of the lumbosacral
roots.
[0018] As shown, the prior art makes no provision to measure the
efficacy of PES treatment, causing patients to be treated
improperly, either by an insufficient or excessive exposure to PES.
Other attempts to monitor PES dosage in the prior art exhibit
serious drawbacks. For example, U.S. Pat. No. 5,518,495 to Kot
discloses an apparatus for the treatment of arthritis utilizing a
magnetic field therapy, which includes an adjustable voltage source
that is connected to a source of line voltage and a coil connected
to the adjustable voltage source. This apparatus has no feedback
system to advise a healthcare provider of the efficiency of the
treatment.
[0019] U.S. Pat. No. 5,984,854 to Ishikawa et al. discloses a
method for treating urinary incontinence based on delivering a
train of current pulses through one or more magnetic stimulation
coils so to induce a train of magnetic flux pulses, which then
induce an eddy current within the body and stimulates a group of
pelvic floor muscles, the pudendal nerve, the external urethral
sphincter, or the tibial nerve. While this method includes the use
of pulsed electromagnetic for treating urinary incontinence, no
specific components are envisioned to facilitate the placement of
the magnetic coils over a targeted region of the body or a system
for monitoring the efficiency of the therapy being applied.
[0020] U.S. Pat. No. 6,086,525 to Davey et al. discloses a magnetic
nerve stimulator that includes a core constructed from a material
having a high field saturation having a coil winding disposed
thereon. A thyrister capacitive discharge circuit pulses the
device, and a rapidly changing magnetic field is guided by the
core, preferably made from vanadium permendur.
[0021] U.S. Pat. No. 6,701,185 to Burnett et al. also discloses an
electromagnetic stimulation device that includes a plurality of
overlapping coils, which can be independently energized in a
predetermined sequence such that each coil will generate its own
independent electromagnetic field and significantly increase the
adjacent field. Unfortunately, none of these patents provides a
system for monitoring the efficiency of the therapy in progress,
either with respect to the proper positioning of the winding over
the area to be treated or of the intensity of the magnetic field to
be applied.
[0022] Other PES therapies require the implantation of devices into
the patient, with the consequent discomfort, risk and cost to the
patient. For example, U.S. Pat. No. 6,735,474 to Loeb et al.
discloses a method and system for treating UI and/or pelvic pain by
injecting or laparoscopically implanting one or more battery- or
radio frequency-powered microstimulators that include electrodes
placed beneath the skin of the perineum and/or adjacent the tibial
nerve.
[0023] U.S. Pat. No. 6,941,171 to Mann et al. describes a method
and a system for treating incontinence, urgency, frequency, and/or
pelvic pain that includes implantation of electrodes on a lead or a
discharge portion of a catheter adjacent the perineal nerve(s) or
tissue(s) to be stimulated. Stimulation pulses, either electrical
or drug infusion pulses, are supplied by a stimulator implanted
remotely through the lead or catheter, which is tunneled
subcutaneously between the stimulator and stimulation site.
[0024] Other PES therapies in the prior art involve the use of
electrodes placed on or beneath the skin of a patient. Recent data
on invasive, needle-based PES of the posterior tibial nerve in
individuals with OAB and UI indicates that PES can modulate bladder
dysfunction through its action on the pudendal nerve and the sacral
plexus, which provide the major excitatory input to the
bladder.
[0025] In a paper titled "Percutaneous Tibial Nerve Stimulation via
Urgent.RTM. PC Neuromodulation System--An Emerging Technology for
managing Overactive Bladder," which was published in Business
Briefing: Global Surgery 2004, CystoMedix, Inc. disclosed that
peripheral tibial nerve stimulation ("PTNS") had been found
effective in treating OAB. The disclosed procedure involved the use
of electrode and generator components, including a small 34-gauge
needle electrode, lead wires and a hand-held electrical generator.
However, the procedure requires the permanent implantation of an
electrical stimulation device in the patient. One estimate put the
cost of treatment at nearly $14,000 with additional routine care
costs of $593 per patient per year. Additionally, risks of battery
failure, implant infection, and electrode migration led to a high
re-operation rate and made this procedure unattractive.
[0026] U.S. Pat. No. 7,117,034 to Kronberg discloses a method for
generating an electrical signal for use in biomedical applications
that includes two timing-interval generators. In this invention,
skin-contact electrodes may be placed over an area of interest and
a microprocessor may direct timing and sequencing functions,
although such timing and sequencing functions are not related to
the actual efficacy of the treatment while treatment is being
performed.
[0027] U.S. Patent Application Publication No. 2005/0171576 to
Williams et al. discloses an electro-nerve stimulation apparatus
that includes a pulse generator, a first electrically conductive,
insulated lead wire, a second electrically conductive, insulated
lead wire, an electrically conductive transcutaneous electrode and
an electrically conductive percutaneous needle electrode. Connected
to one end of the first and second lead wires is a connector for
electrically coupling with the pulse generator. In this invention,
a percutaneous needle electrode is inserted through the skin in
proximity to the desired internal stimulation site and electric
stimulation is employed, rather than pulsed electromagnetic
stimulation. Moreover, the Williams invention does not contemplate
mechanisms for facilitating use of the device by an untrained user,
nor a monitoring of the applied therapy.
[0028] A neuromodulation alternative is a posterior tibial nerve
stimulator, often referred to as SANS, but as is the case with
other forms of neuromodulation, this procedure is invasive in
nature and requires the insertion of a needle five centimeters into
the patient's ankle region to stimulate the posterior tibial nerve.
This procedure also requires a minimum of twelve sessions for
initial treatment, possibly with additional sessions required for
maintenance.
SUMMARY OF THE INVENTION
[0029] It is an object of the present invention to provide
apparatus and methods for magnetic induction therapy, in which
dosage of magnetic energy can be regulated according conduction in
a target nerve exposed to the magnetic field.
[0030] It is another object of the present invention to provide
apparatus and methods for magnetic induction therapy, in which the
flow of magnetic energy can be adjusted directionally by the
patient or a healthcare provider without altering the position of a
housing containing conductive coils that produce the magnetic
field.
[0031] It is a further object of the present invention to provide
apparatus and methods for treating a variety of ailments by
providing energy to a target nerve, for example magnetic energy,
electrical energy or ultrasound energy, at a location and in an
amount optimized by detecting conduction in the target nerve.
[0032] These and other objects of the present invention are
achieved by providing an energy emitting apparatus for delivering a
medical therapy that includes one or more energy generators, a
logic controller electrically connected to the one or more energy
generators, and one or more sensors for detecting electric
conduction in a target nerve, which are connected to the logic
controller. The one or more energy generators produce energy
focused on the target nerve upon receiving a signal from the logic
controller, and the applied energy is varied by the logic
controller according to an input provided by the one or more
sensors based on electric conduction in the target nerve. The
feedback provided by the sensors to the logic controller about the
efficacy of the applied treatment causes the logic controller to
modulate the current transmitted to the coils.
[0033] The applied energy may be a magnetic field, an electrical
field, an ultrasound, a visible light, or an infrared or an
ultraviolet energy. When a magnetic field is applied, the
energy-emitting device is an apparatus that provides a magnetic
induction therapy and that includes one or more conductive coils
disposed in an ergonomic housing. A logic controller is
electrically connected to the one or more coils, and one or more
sensors detect electric conduction in the target nerve and are
connected to the logic controller so to provide a feedback to the
logic controller. The conductive coils receive an electric current
from the logic controller and produce a magnetic field focused on a
target nerve, and the electric current fed by the logic controller
is varied by the logic controller according to an input provided by
the sensors, thereby causing amplitude, frequency or direction of
the magnetic field, or the firing sequence of the one or more
coils, to be varied according to the efficiency of the treatment
provided to the target nerve. In different embodiments of the
invention, the housing containing the conductive coils may be a
flexible wrap, a cradle or a garment, and the coils may be
overlapping and/or be disposed in different positions within the
housing, so to generate a magnetic field on different body parts
with the desired direction and amplitude.
[0034] The one or more coils may be stationary or movable within
the housing, making it possible to optimize the direction of
magnetic flow to the target nerve by disposing the coils in the
most effective direction. In different embodiments, the coils may
be movable manually by acting on a knob, lever, or similar type of
actuator, or may be translated automatically by the logic
controller in response to the input provided by the sensors. When a
preferred position for the coils has been established, the coils
may be locked in position and maintain that position during
successive therapy sessions. In other embodiments, the sensors may
be incorporated within the housing, or instead may be disposed on a
body part of interest independently of the housing.
[0035] In still other embodiments of the invention, the inductive
coils are disposed in a housing that is situated externally to a
patient's body, and additional inductive coils are implanted into
the body of the patient and are magnetically coupled to the
external inductive coils. With this coil arrangement, energy may be
transmitted from the external coils to the internal coils either to
recharge or to activate an implantable device. In yet other
embodiments of the invention, the electric current may varied by
the logic controller both on the basis of an input provided by the
one or more sensors and also an input provided by the patient
according to a muscular response she has perceived, for example,
the twitching of a toe after application of the magnetic field.
[0036] In yet other embodiments of the invention, the source of
energy for nerve stimulation may be electrical energy and nerve
conduction may be detected at a site sufficiently distant from the
site of stimulation, so to enable detection of nerve conduction
despite the confounding interference from the direct electrical
stimuli. In these embodiments, direct electrical stimulation of
nerve and muscle may be tailored to provide optimal therapy and, in
the case of electrode migration or other electrode malfunction, to
report lack of stimulation of the bodily tissues. Furthermore,
these embodiments enable a reduction in power requirement, because
control of the signal is provided by the sensor to the signal
generator loop.
[0037] Methods of use of the above apparatus are also described
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The drawings constitute a part of this specification and
include exemplary embodiments of the invention, which may be
embodied in various forms. It is to be understood that in some
instances various aspects of the invention may be shown exaggerated
or enlarged to facilitate an understanding of the invention.
[0039] FIG. 1 is a schematic view of an apparatus for magnetic
induction therapy according to a first embodiment of the
invention.
[0040] FIG. 2 is a schematic view of an apparatus for magnetic
induction therapy according to a second embodiment of the
invention.
[0041] FIG. 3 is a schematic view of an apparatus for magnetic
induction therapy according to a third embodiment of the
invention.
[0042] FIG. 4 is a schematic view of an apparatus for magnetic
induction therapy according to a fourth embodiment of the
invention.
[0043] FIG. 5 is a schematic view of an apparatus for magnetic
induction therapy according to a fifth embodiment of the
invention.
[0044] FIGS. 6A-6D are schematic illustrations depicting a first
method of use of an apparatus for magnetic induction therapy. This
method is based on adjusting the position of the conductive coils
so to optimize a magnetic flow applied to a target nerve.
[0045] FIGS. 7A-7D are schematic illustrations of a second method
of use of an apparatus for magnetic induction therapy. This method
is based on locking the conductive coils in position once
electrical conduction in a target nerve has been detected.
[0046] FIG. 8 is a schematic view of an embodiment of the invention
that includes a plurality of sensors.
[0047] FIGS. 9A-9D are schematic representations of different
garments adapted to operate as apparatus for magnetic induction
therapy according to the principles of the present invention.
[0048] FIG. 10 is a schematic view of an apparatus for providing
electrical stimulation.
[0049] FIG. 11 is a schematic view of another embodiment of an
apparatus for providing electrical stimulation.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0050] Detailed descriptions of embodiments of the invention are
provided herein. It is to be understood, however, that the present
invention may be embodied in various forms. Therefore, the specific
details disclosed herein are not to be interpreted as limiting, but
rather as a representative basis for teaching one skilled in the
art how to employ the present invention in virtually any detailed
system, structure, or manner.
[0051] Referring first to FIG. 1, a first embodiment of the
invention includes a coil wrap 20, which is depicted as disposed
over ankle 22 circumferentially to surround a portion of tibial
nerve 24. Because tibial nerve 24 is targeted, this embodiment is
particularly suited for the treatment of OAB and VI. In other
embodiments of the invention, coil wrap 20 may be configured to
surround other body parts that contain a portion of tibial nerve 24
or of other nerves branching from or connected to tibial nerve 24,
still making these embodiments suitable for treating OAB and VI. In
still other embodiments of the invention, coil wrap 20 may be
configured for surrounding body parts that contain other nerves
when treatments of other ailments are intended.
[0052] Coil wrap 20 may be manufactured from a variety of materials
suitable for wearing over ankle 22. Preferably, coil wrap is
produced from a soft, body-compatible material, natural or
synthetic, for example, cotton, wool, polyester, rayon,
Gore-Tex.RTM., or other fibers or materials known to a person
skilled in the art as non-irritating and preferably breathable when
tailored into a garment. Coil wrap 22 may even be manufactured from
a molded or cast synthetic material, such as a urethane gel, to add
extra comfort to the patient by providing a soft and drapable feel.
Additionally, coil wrap 20 may be produced from a single layer of
material or from multiple material layers and may include padding
or other filling between the layers.
[0053] Coil wrap 20 contains one or more conductive coils 26
arranged to produce a pulsed magnetic field that will flow across
tibial nerve 24 and generate a current that will flow along tibial
nerve 24 and spread along the length of tibial nerve 24 all the way
to its sacral or pudendal nerve root origins. Coils 26 may be a
single coil shaped in a simple helical pattern or as a figure eight
coil, a four leaf clover coil, a Helmholtz coil, a modified
Helmholtz coil, or may be shaped as a combination of the
aforementioned coils patterns. Additionally, other coil designs
beyond those mentioned hereinabove might be utilized as long as a
magnetic field is developed that will encompass tibial nerve 24 or
any other target nerve. When a plurality of coils is utilized, such
coils may be disposed on a single side of ankle 22, or may be
disposed on more than one side, for example, on opposing sides,
strengthening and directionalizing the flow of the magnetic field
through tibial nerve 24 or other peripheral nerves of interest.
[0054] Coil wrap 20 is preferably configured as an ergonomic wrap,
for example, as an essentially cylindrical band that can be pulled
over ankle 22, or as an open band that can be wrapped around ankle
22 and have its ends connected with a buckle, a hoop and loop
system, or any other closing system known to a person skilled in
the art. By properly adjusting the position of coil wrap 20 over
ankle 22, a patient or a health care provider may optimize the flow
of the magnetic field through tibial nerve 24, based on system
feedback or on sensory perceptions of the patient, as described in
greater detail below.
[0055] The electric current that produces the magnetic field by
flowing through coils 26 is supplied by a programmable logic
controller 28, which is connected to coils 26, for example, with a
power cord 32. A sensor 30 that feeds information to logic
controller 28 is also provided, in order to tailor the strength of
the magnetic field and control activation of coils 26 based on
nerve conduction. The purpose of sensor 30 is to detect and record
the firing of the target nerve and to provide related information
to logic controller 28, so to render the intended therapy most
effective. For example, sensor input may cause logic controller 28
to alter the strength or pulse amplitude of the magnetic field
based on sensor input, or fire the coils in a certain sequence.
[0056] In this embodiment, as well as in the other embodiments
described hereinafter, sensor 30 may include one or more sensor
patches and may be placed at different distances from the region of
direct exposure to the magnetic field. For example, sensor 30 may
be configured as a voltage or current detector in the form of an
EKG patch and may be placed anywhere in the vicinity of the target
nerve to detect its activation. For ease of description, the term
"coils" will be used hereinafter to indicate "one or more coils"
and "sensor" to indicate "one or more sensors," unless specified
otherwise.
[0057] By virtue of the above described arrangement, coil wrap 20
provides a reproducibly correct level of stimulation during an
initial therapy session and during successive therapy sessions,
because the presence or absence of nerve conduction is detected
and, in some embodiments, measured when coil wrap 20 is first
fitted and fine-tuned on the patient. In addition to properly
modulating the applied magnetic field, the positioning of coils 26
over ankle 22 may also be tailored according to the input provided
by sensor 30, so to fine-tune the direction of the magnetic field.
Such an adjustment of the direction, amplitude, and level of the
stimulation provided to the target nerve through the above
described automated feedback loop, to ensure that peripheral nerve
conduction is being achieved, is one of the key features in the
present invention.
[0058] If the magnetic pulse does not substantially interfere with
sensor 30, sensor 30 may be placed directly within the field of
stimulation, so that power supplied to the system may be conserved.
This is particularly important for battery-powered systems.
Alternatively, sensor 30 may also be placed at a distance from the
magnetic field and still properly detect neural stimulation.
[0059] In a method of use of coil wrap 20, the amplitude and/or
firing sequence of coils 26 may be ramped up progressively, so that
the magnetic field is increased in strength and/or breadth until
nerve conduction is detected, after which the applied stimulus is
adjusted or maintained at its current level for the remainder of
the therapy. The level of stimulation may be also controlled
through a combination of feedback from sensor 30 and feedback based
on perceptions of the patient. For example, the patient may
activate a switch once she perceives an excessive stimulation, in
particular, an excessive level of muscular stimulation. In one
instance, the patient may be asked to push a button or turn a knob
when she feels her toe twitching or when she experiences
paresthesia over the sole of her foot. The patient will then
continue pressing the button or keep the knob in the rotated
position until she can no longer feel her toe twitching or
paresthesia in her foot, indicating that that level of applied
stimulation corresponds to an optimal therapy level. From that
point on, the patient may be instructed to simply retain her foot,
knee, or other limb within coil wrap 20 until therapy has been
terminated while the system is kept at the optimal level. Adding
patient input enables control of coil wrap 20 during outpatient
treatments, because the patient is now able to adjust the intensity
of the magnetic field herself beyond the signals provided to logic
controller 28 by sensor 30.
[0060] Detecting and, if the case, measuring conduction in one or
more nerves along the conduction pathways of the stimulated nerve
confirms that the target nerve has been stimulated, providing an
accurate assessment of the efficiency of the applied therapy on the
patient. A concomitant detection of muscle contraction may also
confirm that the target nerve is being stimulated and provide an
indication to the patient or to a healthcare provider as to whether
stimulation has been applied at an excessive level in view of the
anatomical and physiological characteristics of the patient.
[0061] Based on the foregoing, coil wrap 20 allows for a
consistent, user-friendly targeting and modulation of the
peripheral nerves via the posterior tibial nerve on an outpatient
basis, in particular, the targeting and modulation of the pudendal
nerve and of the sacral plexus. When multiple coils 26 are present,
coils 26 may be activated simultaneously or differentially to
generate the desired magnetic field. The direction and location of
each of coils 26 may be reversibly or irreversibly adjusted by the
healthcare provider or by the patient, customizing the location of
the applied stimulation to the anatomy and therapy needs of each
patient. After a healthcare provider has optimized position and
firing sequence for each of coils 26, the patient may be sent home
with coil wrap 20 adjusted to consistently target the desired
nerve. In one variant of the present embodiment, an automatic
feedback system adjusts one or more of firing sequence, firing
strength or position of coils 26 within coil wrap 20 during the
initial setup and also during successive therapy sessions.
[0062] In summary, the teachings of the present invention include
the creation of a loop consisting of feeding information on nerve
conduction to logic controller 28 and on logic controller 28
tailoring the electrical current sent to coil wrap 20 according to
the information received from sensor 26 based on whether or not the
nerve is receiving the desired stimulation and, in some
embodiments, the desired amount of stimulation. This arrangement
offers an unparalleled level of therapy control and flexibility
within a home care setting, because a consistent, repeatable
stimulation of the target nerve can be attained. Aside from
adjusting the position of coils 26 in accordance with the patient's
anatomy and physiological variations, controlling pulse amplitude
is also of great importance even during different therapy sessions
with the same patient. For example, a patient with leg edema will
encounter difficulties in properly adjusting coil wrap 20 based on
whether her legs and ankles are swollen or not swollen, and the
power required to penetrate to posterior tibial nerve 24 (in the
case of a VI therapy) will vary greatly due to the variable depth
of the nerve. Thus, having feedback provided by sensor 26 becomes a
necessity for achieving an accurate dosage of the treatment rather
than an option. Benchtop testing has demonstrated that a system
constructed according to the present invention is capable of
non-invasively generating electrical currents similar to those
found in therapeutic electro-stimulation and to do so in different
settings.
[0063] Referring now to FIG. 2, a second embodiment of the
invention will be described with reference to a coil wrap 34
disposed over ankle 36 for the purpose of treating VI by targeting
tibial nerve 38. In this second embodiment, one or more Helmholtz
coils 40 are disposed within coil wrap 34 to create a more narrowly
directed magnetic field over tibial nerve 38. Like in the all other
embodiments described herein, more than one coil (in the present
embodiment, more than one Helmholtz coil 40) may be placed within
coil wrap 34 and be disposed in different positions within coil
wrap 34, in order to optimize magnetic flux over tibial nerve. For
example, two Helmholtz coils may be disposed one opposite to the
other within coil wrap 34.
[0064] Having coil windings arranged along a common longitudinal
axis, as required in a Helmholtz coil configuration, generates a
more focused magnetic field and a more accurate targeting of tibial
nerve 38 or of any other nerve. Like in the previous embodiment,
the operation of coils 40 is controlled by a logic controller 42,
which is in turn connected to sensor 44 that monitors conduction in
tibial nerve 44 and that generates a feedback to logic controller
42 about the efficiency of the therapy in progress. Therefore, like
in the previous embodiment, the coupling of sensor 44 with logic
controller 42 optimizes operation of coil wrap 34 according to
results measured at the level of tibial nerve 38. Also like in the
previous embodiment, manual adjustments to the parameters of
electric current provided by logic controller 42 to Helmholtz coil
40 may also be made manually by the patient or by a healthcare
provider, and coil wrap 34 may be structured so that the position
of Helmholtz coil 40 within coil wrap 34 is adjusted as desired
either manually by the patient or by a healthcare provider, or
automatically by logic controller 42.
[0065] Referring now to FIG. 3, a third embodiment of the invention
includes a coil wrap 46 configured for wrapping over the popliteal
fossa of a patient, in the region of the knee, to stimulate the
posterior tibial nerve (not shown). The configuration and structure
of coil wrap 46 reflect the body portion covered by coil wrap 46,
but the key system components of coil wrap 46, such as the type,
number and disposition of the coils (for example, the use of
overlapping coils); the connections of the coils with a logic
controller; and the use of one or more sensors (also not shown) to
detect nerve conduction are all comparable to those in the
previously described embodiments.
[0066] Referring now to FIG. 4, a fourth embodiment of the
invention includes a footrest or foot cradle 48, which is
structured to contain at least a portion of a foot 50. One or more
coils 52 are enclosed within cradle 48, and a sensor 54 is disposed
along the pathway of tibial nerve 55, sensing conduction in tibial
nerve 55, and is also connected to a logic controller 56. Coils 52,
sensor 54 and logic controller 56 may be arranged in different
configurations, in the same manner as in the preceding
embodiments.
[0067] Cradle 48 may be made from a variety of materials and may be
monolithic, or have a hollow or semi-hollow structure to enable the
movement of coils 52 within cradle 48, as described in greater
detail below. Preferably, cradle 48 has an ergonomically design
allowing the ankle and heel of the patient to be retained within
cradle 48, in a position that matches the positions of stimulating
coils 52 to the area of stimulation. The design of cradle 48
provides for a particularly comfortable delivery of therapy to
patients that prefer to remain seated during their therapy, and
enables the patient to perform the required therapy within a health
care facility, or to take cradle 48 home, typically after an
initial session and appropriate training in a health care facility.
In that event, the patient will be trained to apply sensor 54
autonomously and to adjust stimulation to a comfortable level.
[0068] FIG. 4 shows coils 52 disposed as overlapping and the use of
a single sensor patch 54 positioned proximally to the stimulation
site. However, coil 52 may be configured as a single coil, a figure
eight coil, a four leaf clover coil, a Helmholtz coil, a modified
Helmholtz coil or a any combination of the aforementioned coils, or
as any other coil design providing an effective stimulation to the
target nerve. In addition, coils 52 may be fired individually,
sequentially or simultaneously according to the feedback provided
by sensor 54.
[0069] In one variant of this embodiment, sensor 54 may include a
conductive electrode patch that provides a feedback to logic
controller 56 for adjusting, if necessary, the stimulation
parameters of coils 52. Alternatively, sensor 54 may be a sensor
patch that is either applied to the skin of the patient or is
incorporated within the structure of cradle 48.
[0070] Referring now to FIG. 5, a fifth embodiment of the invention
includes a knee rest or knee cradle 58 that contains one or more
conductive coils 60, one or more sensors 62 and a logic controller
64. The components of this embodiment are similar to those
described with reference to the preceding embodiments, as regards
the structure and materials of cradle 58, the nature and
disposition of coils 60, the type and operation of sensor 62, and
the function and operation of logic controller 64. Cradle 58 is
configured to target the popliteal fossa of the patient, thus to
target tibial nerve 66. In that respect, the present embodiment is
similar to the embodiment illustrated in FIG. 3, but while the
embodiment of FIG. 3 is configured as a wrap that may be worn while
the patient is standing, the present embodiment is configured as a
cradle that is more suited for treatment while the patient is
sitting or laying down.
[0071] A method of use of the foot cradle depicted in FIG. 4 is
described with reference to FIGS. 6A-6D. During a first step
illustrated in FIG. 6A, foot 68 is disposed in cradle 70 that
contains one or more conductive coils 72, which are connected to a
logic controller (not shown) that manages the flow of electric
power to coils 72.
[0072] During a second step illustrated in FIG. 6B, a sensor 74 is
disposed on foot 68 or on ankle 76 or on another appropriate
portion of the patient's body, in order to detect conductivity in
tibial nerve 78 or in another target nerve.
[0073] During a third step illustrated in FIG. 6C, a healthcare
provider analyzes conductivity measurements provided by sensor 74
(for example, by reading gauge 77) and first adjusts the
positioning of coils 72 until conduction in nerve 78 is detected.
For example, the healthcare provider may rotate a knob 80, slide a
lever or actuate any other displacement system for coils 72 that is
known in the art, so that coils 72 are translated until a magnetic
field of the proper amplitude and intensity is applied to cause
conduction in nerve 78. The position of coils 72 is then fine-tuned
manually until an optimal level of conduction in nerve 78 is
attained, and the therapy is continued for a length of time as
prescribed by the attending healthcare provider.
[0074] During a fourth, optional step illustrated in FIG. 6D,
settings for successive therapy sessions are set, for example by
locking knob 80 (in one embodiment, with a pin 81) so that the
healthcare provider or the patient repeat the therapy using the
predetermined settings. Alternatively, the patient may be trained
to adjust the amplitude and/or strength of the applied magnetic
field, as each therapy session requires.
[0075] While the present method has been described with regard to
foot cradle 70, the same method steps may be envisioned for coil
wraps or cradles of different configurations, for example, for the
coil wraps and cradles described with reference to the previous
figures.
[0076] In an alternative embodiment, the logic controller (not
shown) may automatically adjust coil positioning to optimize
therapy during the initial and successive sessions. While this
set-up may be more difficult to implement, it also provides for an
accurate targeting of the target nerve during each therapy session,
regardless of alterations in patient positioning or changes to the
anatomy of the patient (for example, when a foot is swollen). In
this embodiment, the device simply varies the orientation of coils
84 until stimulation has been sensed.
[0077] Further, coils 84 may be translated along a single direction
(for example, horizontally) or along a plurality of directions, to
provide for the most accurate positioning of coils 84 with respect
to the target nerve.
[0078] A second method of use of the foot cradle depicted in FIG. 4
is described now with reference to FIG. 7. While this second method
is also described with reference to a foot cradle 82 employing one
or more coils 84 that have a reversibly lockable, adjustable
orientation, the present method may be equally implemented with a
body-worn coil wrap, such as those described with reference to the
previous figures, or to other embodiments of the invention. In this
method, the patient or the healthcare provider adjusts the
positioning of coils 84 to detect conductivity in target nerve
89.
[0079] The position of coils 84 may be translated in different
directions (in the illustrated embodiment, may be translated
horizontally) and may be locked in an initial position once
conduction in nerve 89 is detected by a sensor (for example,
sensing patch 86)
[0080] More particularly, FIG. 7A illustrates the initial
positioning of foot 88 into cradle 82 and of sensor patch 86 on
ankle 90 or other appropriate body part of the patient. After
proper positioning of foot 88 is attained, a knob 92 (or other
equivalent device) may be employed to adjust the position of coils
84, based on the signals (for example, nerve conduction signals)
provided by sensor patch 86, as shown in FIG. 7B.
[0081] With reference to FIG. 7C, after neural conduction is
detected, coils 84 are locked in place, and, with further reference
to FIG. 7D, foot cradle 82 retains coils 84 locked in position for
further use in a home or healthcare office environment. Therefore,
in the present method, the patient or a healthcare provider simply
adjusts coil position by sliding coils 84 back and along one axis
until electric conduction in the target nerve is detected, although
adjustments along all three axes may be possible in different
variants of the present embodiment.
[0082] Referring now to FIG. 8, a sixth embodiment of the invention
relates to the use of multiple sensors. While FIG. 8 depicts an
embodiment shaped as a foot cradle 98, it should be understood that
the following description also relates to any other design, whether
shaped as a cradle or a wrap or otherwise. The plurality of sensors
94 described herein may detect a variety of physiologic changes,
including neural impulses, muscular contraction, twitching, etc.
that may occur with neural or muscular stimulation.
[0083] One or more of the illustrated sensors 94 may be employed
over body regions being stimulated (for example, back, leg, arm,
neck, head, torso, etc.) and may be either incorporated within an
actual cradle or wrap or, otherwise, be applied separately from the
cradle or the wrap.
[0084] Sensors 94 may be structured as disposable, single-use,
EKG-type patches that are attached to the body outside of cradle 98
along the nerve conduction pathway and are then connected to the
logic controller (not shown) before beginning therapy. This
arrangement provides for an intimate body contact of sensors 94
without the risk of infection or other detrimental side effects
that may be present with transcutaneous devices. Sensors 94 may be
employed both for beginning and for monitoring the stimulation
therapy; more specifically, sensors 94 may be employed during the
beginning of the therapy to optimize the strength of the magnetic
field and/or to adjust the positioning of coils 96 within the
cradle 98. Once therapy has begun, sensors 94 continue to monitor
nerve conduction to ensure that the correct level of stimulation is
being provided. In the event that for some reason nerve conduction
decays during therapy, the logic controller can automatically
adjust the magnetic field, ensuring that the appropriate therapy is
delivered for the appropriate amount of time.
[0085] One or more of sensors 94 in this embodiment, or any of the
embodiments described herein, may take the form of an inductive
coil designed to receive impulses from the underlying nerves, so
that inductive technologies may be used to both stimulate the nerve
or tissues as well as to record the effect of the stimulation on
nerves or tissues. Any of sensors 94 may be connected to the logic
controller through one or more connection modes, including, but not
limited to, wireless signals, wired signals, radio frequencies,
Bluetooth, infrared, ultrasound, direct switching of the current
circuit, etc., so long as communication between the sensor and the
device is effective.
[0086] During implementation of the present method, a healthcare
provider may simply elect to use sensors 94 to adjust the device,
for example, to lock coils 96 into position, during the first
therapy session and not require the use of sensors 94 during each
successive therapy session.
[0087] Referring now to FIGS. 9A-9D, there are shown different,
non-limiting embodiments of the invention shaped as body worn
ergonomic applicator garments. Each of these embodiments is shown
with overlapping coils, although coils of any configurations may be
used. Each of the wraps of FIGS. 9A-9D corresponds to a coil wrap,
into which a body part may be placed. These garments contain one or
more sensors (not shown) that provide feedback to a logic
controller (also not shown), or sensors may be applied separately
from those garments. Systems may also be included for reversibly or
irreversibly locking the coils within the applicator.
[0088] More particularly, FIG. 9A illustrates an embodiment, in
which coils 100 are embedded in a knee wrap 102 and are connected
to a logic controller (not shown) by a connector 104. FIG. 9B
instead illustrates an embodiment, in which coils 106 are disposed
within an abdominal garment, for example shorts 108 and in which
coils 106 are also connected to a logic controller (not shown) by a
connector 110. A marking 112 may be added on one side of shorts 108
to indicate wrap orientation. FIG. 9C illustrates a coil wrap
shaped like a band 114, in which coils 116 are connected to a logic
controller (not shown) by a connector 118. When this embodiment is
employed, band 114 may be wrapped around a body portion (for
example, an arm) and be retained in place by a system known in the
art, for example, a hook and loop system, a strap and buckle
system, or simply a hook disposed at one end of band 114 for
engaging fabric or other material in another portion of band 114.
FIG. 9D illustrates an embodiment shaped as a shoulder strap 120,
the length of which may be adjusted by a buckle 122 and which has
coils 124 disposed in one or more points, for example, at the joint
between an arm and a shoulder as shown. Each of these embodiments
includes one or ore sensors (not shown) that may coupled to the
garment, or that may applied separately from the garment.
[0089] Other embodiments that are not illustrated include, bur are
not limited to: a head worn garment, such as a cap; a neck worn
garment, such as a neck brace; and a lower-back garment. Each
garment and applicator may also utilize the locking, targeting coil
feature described previously, without requiring the use of the any
sensing components after a proper positioning of the coils in
relation to the target nerve or nerves has been established.
[0090] Still other embodiments of the invention are depicted in
FIGS. 10 and 11. In these embodiments, the source of energy for
nerve stimulation is electrical energy that is dispensed through a
percutaneous stimulator, such as a percutaneous needle 124, or a
transcutaneous stimulator, such as an electrode 126. As shown in
FIG. 10, an electrical pulse controller 128 is electrically
connected both to percutaneous needle 124 and to sensor 134, to
provide the desired feedback and modulate the power to percutaneous
needle 134. In the embodiment of FIG. 11, electrical pulse
controller 130 is connected both to electrode 126 and to sensor
136, and performs a function similar to that of electrical pulse
controller 128. With these embodiments, nerve conduction may be
detected at a site sufficiently distant from the site of
stimulation, so to enable detection of nerve conduction despite the
confounding interference from the direct electrical stimuli.
Further, direct electrical stimulation of nerve and muscle may be
tailored to provide optimal therapy and, in the case of electrode
migration or other electrode malfunction, to report lack of
stimulation of the bodily tissues. Still further, these embodiments
enable a reduction in power requirement, because control of the
signal is provided by the sensor to the signal generator loop.
[0091] As shown, a device constructed according to the principles
of the present invention provides a targeted and precise
stimulation of the posterior tibial nerve, or of other peripheral
nerves, in a non-invasive manner by employing an ergonomic wrap or
cradle that specifically targets the posterior tibial nerve in a
consistent and repeatable manner. For example, in patients with OAB
or VI, the novel, reversibly lockable movement of the coils and the
use of a logic controller-sensor loop enables the application of a
magnetic field that can be varied in location, amplitude and
strength according to the amount of stimulation actually induced in
one or more target nerves and of the response of the patient to the
therapy. An apparatus according to the present invention may
deliver any frequency of stimulation, including low frequencies,
high frequencies, mid frequencies and ultrahigh frequencies, and
overlapping and non-overlapping coils may be used to generate the
desired field, although overlapping or Helmholtz coils are
preferred due to their ability to target a broader region and
achieve more thorough stimulation.
[0092] Ailments that may be treated through the use of apparatus
and methods of the present invention include not only OAB and VI,
but also obesity, depression, urinary incontinence, fecal
incontinence, hypertension, pain, back pain, restless leg syndrome,
Guillain Barre syndrome, quadriplegia, paraplegia, diabetic
polyneuropthy, dyskinesias, paresthesias, dental procedure pain,
knee osteoarthritis, anesthesia (pain relief during surgery),
Alzheimer's disease, angina (chest pain from heart disease),
ankylosing spondylitis, back pain, burn pain, cancer pain, chronic
pain, dysmenorrhea (painful menstruation), headache, hemiplegia,
hemiparesis (paralysis on one side of the body), labor pain, local
anesthesia during gallstone lithotripsy, facial pain, trigeminal
neuralgia, bruxism (tooth grinding) pain, myofascial pain,
pregnancy-related nausea or vomiting, neck and shoulder pain, pain
from broken bones, rib fracture or acute trauma, diabetic
peripheral neuropathy, phantom limb pain, post-herpetic neuralgia
(pain after shingles), postoperative ileus (bowel obstruction),
irritable bowel syndrome, postoperative nausea or vomiting,
postoperative pain, post-stroke rehabilitation, rheumatoid
arthritis, skin ulcers, spinal cord injury, temporomandibular joint
pain, detrusor instability, spinal muscular atrophy (in children),
pain during hysteroscopy, gastroparesis, chronic obstructive
pulmonary disease rehabilitation, carpal tunnel syndrome, soft
tissue injury, multiple sclerosis, intermittent claudication,
attention-deficit hyperactivity disorder (ADHD), cognitive
impairment, knee replacement pain, achalasia, atopic eczema,
bursitis, carpal tunnel syndrome, dementia, depression, dry mouth,
dystonia, enhanced blood flow in the brain, enhanced blood
perfusion of the uterus and placenta, esophageal spasm,
fibromyalgia, fracture pain, Guillain-Barre syndrome, hemophilia,
herpes, hip pain, interstitial cystitis, irritable bowel syndrome,
pruritis, joint pain, labor induction, local anesthesia, menstrual
cramps, muscle cramps, muscle spasticity, muscle strain or pain,
musculoskeletal trauma, myofascial pain dysfunction syndrome, nerve
damage, osteoarthritis, pain medication adjunct, pancreatitis,
Raynaud's phenomenon, repetitive strain injuries, sacral pain,
schizophrenia, shingles, shoulder subluxation, sickle cell anemia
pain, Skin flap ischemia (during plastic surgery), sphincter of
Oddi disorders, sports injuries, thrombophlebitis, tinnitus
(ringing in the ear), restless legs, tremor, whiplash and
neuralgias. In contrast to implantable nerve stimulators, this
therapy is completely non-invasive and does not require a major
surgery to implant a permanent nerve stimulation device. Moreover,
this therapy can be controlled to optimize the level of therapy
delivered according to power consumption and nerve stimulation
requirements and need not be delivered by a professional healthcare
provider.
[0093] In other embodiments of the invention, neural stimulation
may be applied as electrical transcutaneous stimulation, for
example, by inserting an invasive electrical needle into a target
body part and by modulating stimulation is modulated on the basis
of information sent back to the logic controller from the one or
more sensors that are used to detect and/or maintain the correct
level of stimulation. The transcutaneous electrical stimulation
sensor may be placed in the body independently or be incorporated
within the wrap and may provide, among other things, feedback as to
the quality of the electrical connection to the skin, which is
directly related to the burn risk inherently associated with this
type of therapy. In fact, these methods of stimulation may not be
optimal due to the resulting skin irritation and risk of potential
burns, a very serious issue in the large percentage of patients
that have neuropathies. Even when patches are applied to monitor
transcutaneous stimulation very closely, the patches may still
become displaced and allow a burn to occur. Moreover, potentially
interfering electrical impulses may develop at the treatment site,
creating a noisy environment for the detection of nerve
conduction.
[0094] In still other embodiments of the invention, an external
coil or coils may be inductively connected to an implanted coil or
coils may be utilized. In these embodiments, an ergonomic
applicator may be adjusted by the user or by a healthcare provider
such to optimize inductive power transmission between the external
and implanted coils. One or more sensors may be utilized to provide
a feedback that the relative coil positions have been optimized,
and the external coil may then be reversibly locked into position
within the ergonomic applicator. Two applications of this
embodiment relate to the transfer of power to recharge an
implantable device, and to the transfer of power to activate an
implantable device.
[0095] In the first application, when an implantable rechargeable
device is utilized, the external coils may be used for recharging
the implanted device by means of inductive fields generated by the
external coils. The external coils may include circuitry that
determines the amount of resistance encountered by the magnetic
field or other electrical properties related to the quality and
degree of the magnetic coupling that is being established. Based on
this feedback, the position of the external coils may be adjusted
manually or automatically to optimize the coupling achieved with
during each recharging session. Alternatively, a sensor may be
incorporated into the implantable device and may communicate the
degree and quality of the magnetic coupling to the external coils
and/or the connected circuitry via wireless communication,
providing a feedback for the automatic or manual adjustment of the
external recharging coils.
[0096] The coils within the ergonomic applicator may be reversibly
locked into place for the duration of the recharge session, and the
implantable device may also communicate to the external recharging
unit that the implantable device has been fully recharged,
terminating the recharging session has been completed. By providing
for an intermittent recharging of an implanted device, an apparatus
according to the present invention enables the implantable device
to devote more power to performing its intended function optimally
and with a lesser concern about protecting or extending battery
life.
[0097] In the second application, the powering coils may contain
circuitry to determine the amount of resistance encountered by the
applied magnetic field, or other electrical properties that may
reflect the quality and degree of the magnetic coupling that is
being achieved. Based on this feedback, the powering coils in the
applicator may be adjusted manually or automatically to activate
and optimize the coil coupling at the beginning of each therapy
session. Alternatively, a sensor may be incorporated into the
implantable device and communicate the degree and quality of the
magnetic coupling externally via wireless communication, which may
in turn provide feedback for the automatic or manual adjustment of
the powering coil. In one variant of the present embodiment, the
inductive coils may be magnetically coupled to a needle targeting
the posterior tibial nerve.
[0098] An exemplary method of use of an apparatus according to the
present invention on a patient suffering from VI and/or OAB
includes the following steps:
[0099] The patient places a conductive wrap contained within a
flexible material over a region of the ankle (or alternatively over
the knee) to provide the required pulsed magnetic field.
Alternatively, the patient may use an ergonomic foot/leg rest or
cradle having embedded coils.
[0100] A sensor (for example, a sensor patch) is placed on the
patient's body along the path of the nerve, ideally proximal to the
stimulation site to ensure afferent nerve stimulation, and is
connected to a logic controller.
[0101] A physician or healthcare provider adjusts the coils in the
wrap or cradle until nerve conduction is achieved based on patient
and sensor feedback. An optimal position is sought, and the coils
may be reversibly locked into position within the conductive wrap
or ergonomic cradle and remain in this position during subsequent
use.
[0102] During the therapy session, the logic controller provides an
electric current to the coils, generating an inductive magnetic
field. In one embodiment, this field begins at low amplitude and
slowly ramps up until nerve conduction exceeds a threshold level,
as signaled by the sensor and possibly by the patient, who may feel
motory conduction. Alternatively, one or more coils may also be
activated to increase the covered area of stimulation in the event
that stimulation does not occur with the initial coil configuration
or is inadequate
[0103] The optimal stimulation may be determined in a variety of
manners, for example, by measuring exposure to electromagnetic
fields capable of generating a square wave electric signal at a
frequency of 10-30 Hz at the targeted tissue depth. The square wave
configuration of the signal may be generated via Fourier
transformation or may be a ramped current generated in any
manner.
[0104] The inductive magnetic pulses continue for an appropriate
duration of use, for example, for 15-30 minutes. The sensor may
remain in place during the entire therapy session to ensure that
stimulation occurs consistently and to provide for appropriate
corrections if nerve conduction deteriorated. The logic controller
may be powered either by a portable power source such as a battery,
or by or a fixed power source such as a traditional wall
outlet.
[0105] The conductive wrap and/or ergonomic cradle is removed from
the body when therapeutic stimulation is not being delivered,
typically at the end of the therapy session.
[0106] The conductive wrap and/or ergonomic cradle is reapplied
along with the sensor patch (ideally disposable) from time to time
as indicated, for example, on a daily basis, and steps 4-8 are
repeated.
[0107] The invention described herein may be applied to any body
tissues, including nerve, muscle, skin, vasculature, or any other
organ or tissue within the human body. Further, the devices and
methods described herein may be used to treat any conditions suited
for neuromodulation regardless of whether the stimulation source is
an electromagnetic field, a direct electric current, a RF field,
infrared energy, visible light, ultraviolet light, ultrasound, or
other energy dispensing device.
[0108] While the invention has been described in connection with
the above described embodiments, it is not intended to limit the
scope of the invention to the particular forms set forth, but on
the contrary, it is intended to cover such alternatives,
modifications, and equivalents as may be included within the scope
of the invention. Further, the scope of the present invention fully
encompasses other embodiments that may become obvious to those
skilled in the art and the scope of the present invention is
limited only by the appended claims.
* * * * *