U.S. patent application number 17/407768 was filed with the patent office on 2021-12-09 for patient remote and associated methods of use with a nerve stimulation system.
The applicant listed for this patent is Axonics, Inc.. Invention is credited to Guangqiang JIANG, Eric SCHMID, Dennis SCHROEDER, John WOOCK.
Application Number | 20210379391 17/407768 |
Document ID | / |
Family ID | 1000005794832 |
Filed Date | 2021-12-09 |
United States Patent
Application |
20210379391 |
Kind Code |
A1 |
JIANG; Guangqiang ; et
al. |
December 9, 2021 |
PATIENT REMOTE AND ASSOCIATED METHODS OF USE WITH A NERVE
STIMULATION SYSTEM
Abstract
A neurostimulation system having an external or an implantable
pulse generator programmed to innervate a specific nerve or group
of nerves in a patient through an electrode as a mode of treatment,
having a patient remote that wirelessly communicates with the pulse
generator to increase stimulation, decrease stimulation, and
provide indications to a patient regarding the status of the
neurostimulation system. The patient remote can allow for
adjustment of stimulation power within a clinically effective range
and for turning on and turning off the pulse generator. The patient
remote and neurostimulation system can also store a stimulation
level when the pulse generator is turned off and automatically
restore the pulse generator to the stored stimulation level when
the pulse generator is turned on.
Inventors: |
JIANG; Guangqiang; (Irvine,
CA) ; WOOCK; John; (Costa Mesa, CA) ;
SCHROEDER; Dennis; (Los Angeles, CA) ; SCHMID;
Eric; (Los Angeles, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Axonics, Inc. |
Irvine |
CA |
US |
|
|
Family ID: |
1000005794832 |
Appl. No.: |
17/407768 |
Filed: |
August 20, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16457411 |
Jun 28, 2019 |
11123569 |
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17407768 |
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15969706 |
May 2, 2018 |
10384067 |
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16457411 |
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15861580 |
Jan 3, 2018 |
10105542 |
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15969706 |
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14992777 |
Jan 11, 2016 |
9895546 |
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15861580 |
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62101666 |
Jan 9, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 1/37211 20130101;
A61N 1/37241 20130101; A61N 1/36132 20130101; A61N 1/36057
20130101; A61N 1/36128 20130101; A61N 1/36146 20130101; A61N
1/37235 20130101; A61N 1/36142 20130101; A61N 1/37247 20130101 |
International
Class: |
A61N 1/372 20060101
A61N001/372; A61N 1/36 20060101 A61N001/36 |
Claims
1. A method of adjusting a nerve stimulation level of a
nerve-stimulating pulse generator with a patient remote, the method
comprising: receiving, at the nerve-stimulating pulse generator, a
command from the patient remote to adjust a stimulation level
within an adjustment range, the adjustment range stored in a memory
of the nerve-stimulating pulse generator and comprising: an upper
stimulation range that extends from a nominal stimulation setting
to a maximum stimulation setting, and a lower stimulation range
that extends from the nominal stimulation setting to a minimum
stimulation setting, wherein the nominal stimulation setting is a
stimulation setting configured to provide optimal clinical efficacy
of treatment; and determining with the nerve-stimulating pulse
generator a step-size by which the stimulation level is to be
adjusted, wherein the step-size is determined based on a difference
between the nominal stimulation setting of the nerve-stimulating
pulse generator and the maximum stimulation setting of the
nerve-stimulating pulse generator.
2. The method of claim 1, wherein the step-size is proportional to
the difference.
3. The method of claim 1, wherein the step-size is 1/3 of the
difference.
4. The method of claim 1, wherein the upper stimulation range and
the lower stimulation range have a same magnitude of difference
from the nominal stimulation setting, and wherein incremental
adjustment of the stimulation level with the patient remote is
limited to within the upper and lower stimulation ranges.
5. The method of claim 1, further comprising maintaining a first
stimulation level until the patient remote is operated to terminate
or change stimulation.
6. The method of claim 1, further comprising: receiving an
indication from the nerve-stimulating pulse generator indicating
that the nerve-stimulating pulse generator is in a fault condition,
and operating an automatic fault condition indicator, the automatic
fault condition indicator being configured to provide an alert in
response to receiving the indication.
7. The method of claim 1, further comprising: receiving a
confirmation from the nerve-stimulating pulse generator indicating
that an instruction from the patient remote has been executed by
the nerve-stimulating pulse generator; and operating a haptic
indicator, the haptic indicator being configured to vibrate in
response to receiving the confirmation.
8. The method of claim 1, further comprising: receiving a
battery-status information from the nerve-stimulating pulse
generator specifying at least a charge of voltage remaining in a
battery; and operating a therapy-remaining display configured to
indicate therapy remaining based on at least the charge of voltage
remaining in the battery of the nerve-stimulating pulse
generator.
9. The method of claim 8, wherein the therapy-remaining display
comprises a light emitting diode having at least two contrasting
colors or flashing and non-flashing modes or both to indicate if
the nerve-stimulating pulse generator needs re-charging, is
charging, or has sufficient charge for at least four days of
nominal stimulation.
10. The method of claim 9, wherein the patient remote is further
configured to illuminate the light emitting diode of the
therapy-remaining display with a non-flashing green color to
indicate at least 4 days of therapy remaining, with a non-flashing
amber color to indicate 2 to 4 days of therapy remaining, and with
a flashing amber color to indicate less than 2 days of therapy
remaining.
11. The method of claim 1, further comprising wirelessly
communicating with the nerve-stimulating pulse generator with a
patient-remote circuitry of the patient remote.
12. The method of claim 11, further comprising receiving a current
stimulation level from the nerve-stimulating pulse generator, and
wherein the patient-remote circuitry is further configured to
operate illumination of a plurality of light emitting diodes,
wherein a number of illuminated light emitting diodes indicates a
current stimulation level of the nerve-stimulating pulse
generator.
13. The method of claim 11, wherein receiving at the
nerve-stimulating pulse generator a command from the patient remote
comprises wirelessly increasing a stimulation level of the
nerve-stimulating pulse generator in response to operation of a
stimulation-increase button.
14. The method of claim 11, wherein receiving at the
nerve-stimulating pulse generator a command from the patient remote
comprises wirelessly decreasing a stimulation level of the
nerve-stimulating pulse generator in response to operation of a
stimulation-decrease button.
15. The method of claim 1, wherein the memory of the
nerve-stimulation pulse generator stores one or more pulse
programs, plans, or patterns.
16. A patient remote configured to wirelessly control a
nerve-stimulating pulse generator coupled to an implantable lead,
the patient remote comprising: a portable housing dimensioned to
fit within a single hand of an operator; circuitry at least
partially disposed within the housing; an activation switch
disposed within a recessed area of the portable housing and coupled
to the circuitry so as to reconfigure the patient remote between an
awake mode and an asleep mode; a stimulation-increase switch
disposed on an exterior surface of the portable housing and coupled
to the circuitry so as to wirelessly increase a stimulation level
of the pulse generator; and a stimulation-decrease switch disposed
on the exterior surface of the portable housing and coupled to the
circuitry so as to wirelessly decrease a stimulation level of the
pulse generator; wherein the circuitry is configured such that
wherein when the patient remote is in the asleep mode, the
stimulation-increase switch and the stimulation-decrease switch are
inactivated, wherein when the patient remote is in the awake mode,
the circuitry of the patient remote is configured to wirelessly
communicate with the pulse generator, and the stimulation level is
incrementally adjustable by actuation of the stimulation-increase
switch or the stimulation-decrease switch by a predetermined
percentage of a maximum stimulation level, a nominal stimulation
level, or a current stimulation level.
17. The patient remote of claim 16, wherein the
stimulation-increase switch and the stimulation-decrease switch are
each disposed on a raised region of the exterior surface of the
portable housing, and wherein a tactile surface of the
stimulation-increase switch is larger than a tactile surface of the
stimulation-decrease switch.
18. The patient remote of claim 16, wherein actuation of the
stimulation-increase switch incrementally increases the stimulation
level up to four stimulation levels above a nominal stimulation
level and actuation of the stimulation-decrease switch
incrementally decreases the stimulation level down respectively up
to three stimulation levels below the nominal stimulation
level.
19. The patient remote of claim 16, wherein each stimulation level
increase or stimulation level decrease of the pulse generator
comprises more than 5 percent of a nominal stimulation level or a
current stimulation level.
20. The patient remote of claim 16, further comprising a
stimulation-level display along on the exterior surface of the
portable housing, the patient remote configured to wirelessly
communicate with the pulse generator and the stimulation-level
display configured to indicate a current stimulation level of the
pulse generator after the activation switch of the patient remote
is switched from the asleep mode to the awake mode.
21. The patient remote of claim 20, wherein the stimulation-level
display comprises a plurality of light emitting diodes, wherein a
number of illuminated light emitting diodes indicates the current
stimulation level of the pulse generator.
22. The patient remote of claim 20, wherein the stimulation-level
display comprises at least seven light emitting diodes of at least
three or four differing sizes, wherein a nominal stimulation level
corresponds with illumination of the first three or four light
emitting diodes.
23. The patient remote of claim 16, further comprising a
therapy-remaining display along the exterior surface of the
portable housing configured to indicate therapy remaining based on
at least a charge of voltage remaining in a batter of the pulse
generator a stimulation use parameters by the patient.
24. The patient remote of claim 23, wherein the therapy-remaining
display comprises a light emitting diode having at least two
contrasting colors or flashing and non-flashing modes or both to
indicate if the pulse generator needs re-charging, is charging, or
has sufficient charge for at least four days of nominal
stimulation.
25. The patient remote of claim 23, wherein the therapy-remaining
display light emitting diode illuminates with a non-flashing green
color to indicate at least 4 days of therapy remaining, illuminates
with a non-flashing amber color to indicate 2-4 days of therapy
remaining, and illuminates with a flashing amber color to indicate
less than 2 days of therapy remaining.
26. The patient remote of claim 16, further comprising an automatic
fault condition indicator disposed on the exterior surface of the
portable housing configured to provide an alert if the pulse
generator is in a fault condition.
27. The patient remote of claim 16, further comprising a haptic
indicator coupled to the portable housing configured to vibrate
when a command from the patient remote has been executed by the
pulse generator.
28. The patient remote of claim 16, wherein the circuitry is
configured such that after the stimulation level of the pulse
generator is set, the patient remote maintains the stimulation
level until the patient remote is operated to terminate or change
stimulation by the pulse generator.
29. The patient remote of claim 16, wherein the patient remote to
pair with and communicate only and/or directly with the pulse
generator.
30. The patient remote of claim 16, wherein the maximum stimulation
level is set according to a comfort level of a patient.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 16/457,411, filed on Jun. 28, 2019, entitled
"Patient Remote and Associated Methods of Use With A Nerve
Stimulation System," which is a divisional of U.S. patent
application Ser. No. 15/969,706, filed on May 2, 2018, entitled
"Patient Remote And Associated Methods of Use With A Nerve
Stimulation System," and issued as U.S. Pat. No. 10,384,067 on Aug.
20, 2019, which is a divisional of U.S. patent application Ser. No.
15/861,580, filed on Jan. 3, 2018, entitled "Patient Remote And
Associated Methods of Use With A Nerve Stimulation System," and
issued as U.S. Pat. No. 10,105,542 on Oct. 23, 2018, which is a
divisional of U.S. patent application Ser. No. 14/992,777, filed on
Jan. 11, 2016, entitled "Patient Remote And Associated Methods Of
Use With A Nerve Stimulation System," and issued as U.S. Pat. No.
9,895,546 on Feb. 20, 2018, which claims the benefit of priority to
U.S. Provisional Patent Application No. 62/101,666, filed on Jan.
9, 2015, entitled "Patient Remote And Associated Methods Of Use
With A Nerve Stimulation System," the entirety of each which are
hereby incorporated by reference herein.
[0002] The present application is related to U.S. Provisional
Patent Application Nos. 62/038,122 filed on Aug. 15, 2014 and
entitled "Devices and Methods for Anchoring of Neurostimulation
Leads"; 62/038,131 filed on Aug. 15, 2014 and entitled "External
Pulse Generator Device and Associated Methods for Trial Nerve
Stimulation"; 62/041,611 filed on Aug. 25, 2014 and entitled
"Electromyographic Lead Positioning and Stimulation Titration in a
Nerve Stimulation System for Treatment of Overactive Bladder, Pain
and Other Indicators"; and concurrently filed U.S. Provisional
Patent Application Nos. 62/101,888 entitled "Electromyographic Lead
Positioning and Stimulation Titration in a Nerve Stimulation System
for Treatment of Overactive Bladder" 62/101,899 entitled
"Integrated Electromyographic Clinician Programmer For Use With an
Implantable Neurostimulator;" 62/101,897 entitled "Systems and
Methods for Neurostimulation Electrode Configurations Based on
Neural Localization," 62/101,884 entitled "Attachment Devices and
Associated Methods of Use With a Nerve Stimulation Charging Device;
and 62/101,782 entitled "Improved Antenna and Methods of Use For an
Implantable Nerve Stimulator;" each of which is assigned to the
same assignee and incorporated herein by reference in its entirety
for all purposes.
FIELD OF THE INVENTION
[0003] The present invention relates to neurostimulation treatment
systems and associated devices, as well as methods of treatment,
implantation and configuration of such treatment systems.
BACKGROUND OF THE INVENTION
[0004] Treatments with implantable neurostimulation systems have
become increasingly common in recent years. While such systems have
shown promise in treating a number of conditions, effectiveness of
treatment may vary considerably between patients. A number of
factors may lead to the very different outcomes that patients
experience, and viability of treatment can be difficult to
determine before implantation. For example, stimulation systems
often make use of an array of electrodes to treat one or more
target nerve structures. The electrodes are often mounted together
on a multi-electrode lead, and the lead implanted in tissue of the
patient at a position that is intended to result in electrical
coupling of the electrode to the target nerve structure, typically
with at least a portion of the coupling being provided via
intermediate tissues. Other approaches may also be employed, for
example, with one or more electrodes attached to the skin overlying
the target nerve structures, implanted in cuffs around a target
nerve, or the like. Regardless, the physician will typically seek
to establish an appropriate treatment protocol by varying the
electrical stimulation that is applied to the electrodes.
[0005] Current stimulation electrode placement/implantation
techniques and known treatment setting techniques suffer from
significant disadvantages. The nerve tissue structures of different
patients can be quite different, with the locations and branching
of nerves that perform specific functions and/or enervate specific
organs being challenging to accurately predict or identify. The
electrical properties of the tissue structures surrounding a target
nerve structure may also be quite different among different
patients, and the neural response to stimulation may be markedly
dissimilar, with an electrical stimulation pulse pattern,
frequency, and/or voltage that is effective to affect a body
function for one patent potentially may impose significant pain on,
or have limited effect for, another patient. Even in patients where
implantation of a neurostimulation system provides effective
treatment, frequent adjustments and changes to the stimulation
protocol are often required before a suitable treatment program can
be determined, often involving repeated office visits and
significant discomfort for the patient before efficacy is achieved.
While a number of complex and sophisticated lead structures and
stimulation setting protocols have been implemented to seek to
overcome these challenges, the variability in lead placement
results, the clinician time to establish suitable stimulation
signals, and the discomfort (and in cases the significant pain)
that is imposed on the patient remain less than ideal. In addition,
the lifetime and battery life of such devices is relatively short,
such that implanted systems are routinely replaced every few years,
which requires additional surgeries, patient discomfort, and
significant costs to healthcare systems.
[0006] Furthermore, not all adjustments to neural stimulation
systems have been implemented by clinicians. Patient devices can
adjust stimulation or to turn off the neurostimulation system.
Unfortunately, the wide variety of adjustments that can be made
have the potential to confuse patients and/or eventually result in
a significant reduction in long-term efficacy of these systems.
[0007] The tremendous benefits of these neural stimulation
therapies have not yet been realized. Therefore, it is desirable to
provide improved neurostimulation methods, systems and devices, as
well as methods for implanting and configuring such
neurostimulation systems for a particular patient or condition
being treated. It would be particularly helpful to provide such
systems and methods so as to improve ease of use by the physician
in implanting and configuring the system, as well as to improve
patient comfort and alleviation of symptoms for the patient. It
would also be helpful to provide systems and methods to allow the
patient to adjust the stimulation level delivered by such
neurostimulation systems, where such adjustment is simple,
unambiguous, and sufficiently limited to ensure the stimulation can
remain within a clinically effective range.
BRIEF SUMMARY OF THE INVENTION
[0008] A patient remote is provided to allow a patient to adjust
the stimulation level of a neurostimulation system, which can
include an electrical pulse generator coupled to an implanted
electrical lead. The degree of adjustment permitted to the patient
through the patient remote can be limited, such that while the
patient can incrementally increase or decrease the therapy
delivered by the neurostimulation system, so that the level of
stimulation therapy by the neurostimulation system is maintained
within a clinically effective range. By providing a controlled and
limited range of adjustment to a patient through the patient
remote, the patient is given a straightforward and simple tool for
operation of the neurostimulation system, without presenting a
selection of therapy or operational programs that may unnecessarily
confuse a patient or take the neurostimulation system outside of
the clinically effective range. The clinically effective range of
the neurostimulation system can be determined by a physician or the
clinician programmer when setting the parameters of the
neurostimulation system. The patient remote can also allow a
patient to turn off the neurostimulation system, which may be
desirable for the patient when performing activities that may
inadvertently interfere with, or be inadvertently interfered by,
the neurostimulation system and the nerves stimulated by the
neurostimulation system.
[0009] In some embodiments a patient remote according to the
present disclosure is configured to wirelessly control a
nerve-stimulating pulse generator coupled to an implantable lead in
a patient, where the patient remote includes: a portable housing
configured to be operable in a single hand of an operator.
Circuitry may be at least partially disposed within the portable
housing, and an activation switch can be on an exterior surface of
the portable housing and coupled with the circuitry to reconfigure
or transition the patient remote between an awake mode and an
asleep mode. A stimulation-increase switch can be disposed on the
exterior surface of the portable housing and coupled to the
circuitry so as to wirelessly increase a stimulation level of the
pulse generator when the patient remote is in the awake mode.
Actuation of the stimulation-increase switch for a first period of
time may increase the stimulation level (including by turn
stimulation on stimulation if the pulse generator was previously
off). Actuation of the stimulation-increase switch for a second
period of time may restore the stimulation level of the pulse
generator to a previously stored or last stored stimulation level
(and may also turn stimulation on). The first period of time and
the second period of time can be demarked by a threshold time. In
some aspects, actuation of the stimulation-increase switch for the
second period of time ramps the stimulation level to the previously
stored or last stored stimulation level. As described in any of the
embodiments herein, previously stored stimulation level can refer
to a last stored stimulation level.
[0010] In other aspects, the patient remote can further include a
stimulation-decrease switch disposed on the exterior surface of the
portable housing configured to wirelessly decrease the stimulation
level of the pulse generator, where when the activation switch of
the patient remote is in the awake mode, actuation of the
stimulation-decrease switch for the first period of time decreases
the stimulation level or turns off stimulation of the pulse
generator, and where actuation of the stimulation-decrease switch
for the second period of time stores the stimulation level in a
memory element and turns off the stimulation by the pulse
generator. In further aspects, actuation of the
stimulation-increase switch incrementally increases the stimulation
level up to three or four stimulation levels above a baseline or
nominal stimulation level and actuation of the stimulation-decrease
switch incrementally decreases the stimulation level down
respectively to three or two stimulation levels below the baseline
stimulation level. As described herein, a baseline or nominal
stimulation level can be the optimum stimulation level, which can
be determined by the CP or can be set by the clinician. In some
aspects, this nominal stimulation level can be determined based on
sensory or motor responses, qualitative sensory feedback or various
combinations thereof. In some embodiments, determination of the
nominal stimulation level can be based in part on a threshold level
of the selected electrodes and a maximum stimulation level based on
patient comfort. In some embodiments, the nominal stimulation can
be determined so that incremental adjustment of stimulation levels
by the patient in either direction remains within a clinically
effective range. In some aspects, each stimulation level increase
or stimulation level decrease of the pulse generator comprises more
than five percent (5%), optionally at least ten percent (10%) of a
nominal stimulation level or a current stimulation level.
[0011] In many embodiments, the patient remote can further include
a stimulation-level display disposed on the exterior surface of the
portable housing. The patient remote may be configured to
wirelessly communicate with the pulse generator and the
stimulation-level display may be configured to indicate a current
stimulation level of the pulse generator when the activation switch
of the patient remote is switched from the asleep mode to the awake
mode. In some aspects, the stimulation-level display can include a
plurality of light emitting diodes, where a number of illuminated
light emitting diodes indicates the current stimulation level of
the pulse generator. In other aspects, the stimulation-level
display can include at least seven light emitting diodes of at
least two, three or four sizes, where a baseline stimulation level
can be indicated by illumination of (for example) the first three
or four light emitting diodes.
[0012] In further aspects, the patient remote can also include a
therapy-remaining display disposed on the exterior surface of the
portable housing, and can be configured to indicate therapy
remaining status based on at least a charge or voltage remaining in
a battery of the pulse generator and stimulation use parameters by
the patient. In such aspects, the therapy-remaining display can
include a light emitting diode having at least two contrasting
colors or a single color with flashing and non-flashing modes or
both to indicate if the pulse generator needs re-charging, is
charging, or has sufficient charge for at least four days of
nominal stimulation. In particular aspects, the therapy-remaining
display light emitting diode can illuminate with a non-flashing
green color to indicate at least four (4) days of therapy
remaining, can illuminate with a non-flashing amber color to
indicate two to four (2-4) days of therapy remaining, and can
illuminate with a flashing amber color to indicate less than two
(2) days of therapy remaining. In some aspects, the patient remote
can further include an automatic fault condition indicator disposed
on the exterior surface of the portable housing that is configured
to provide an alert if the pulse generator is in a fault condition.
In other aspects, the patient remote can further include a haptic
indicator coupled to the portable housing that is configured to
vibrate when a command from the patient remote has been executed by
the pulse generator. In further aspects, the nerve-stimulating
pulse generator can include an external or implantable pulse
generator, and the implantable lead comprises at least one
electrode configured for insertion into a foramen of a sacrum near
a sacral nerve.
[0013] In other embodiments, a patient remote is configured to
wirelessly control a nerve-stimulating pulse generator coupled to
an implantable lead, the patient remote having: a portable housing
configured to be operable in a single hand of an operator and
circuitry at least partially disposed within the housing; an
activation switch disposed within a recessed area of the portable
housing so as to allow reconfiguration or transition between an
awake mode and an asleep mode; a stimulation-increase switch
disposed on an exterior surface of the portable housing, configured
to wirelessly increase a stimulation level of the pulse generator;
and a stimulation-decrease switch disposed on the exterior surface
of the portable housing, configured to wirelessly decrease a
stimulation level of the pulse generator; where when the recessed
activation switch of the patient remote is in the asleep mode, the
stimulation-increase switch and the stimulation-decrease switch are
inactivated, and where when the recessed activation switch of the
patient remote is in the awake mode, the patient remote is
configured to wirelessly communicate with the pulse generator. In
some aspects, the stimulation-increase switch and the
stimulation-decrease switch are each disposed on a raised region of
the exterior surface of the portable housing, where the
stimulation-increase switch can further have a tactile feature that
is larger in size than that of the stimulation-decrease switch. In
other aspects, actuation of the stimulation-increase switch can
incrementally increase the stimulation level up to three or four
stimulation levels above a baseline stimulation level, and
actuation of the stimulation-decrease switch can incrementally
decrease the stimulation level down respectively to three or two
stimulation levels below the baseline stimulation level. In further
aspects, each stimulation level increase or stimulation level
decrease of the pulse generator can be at least ten percent of a
baseline stimulation level or a current stimulation level.
[0014] In some embodiments, the patient remote can further include
a stimulation-level display disposed on the exterior surface of the
portable housing, where the patient remote is configured to
wirelessly communicate with the pulse generator and the
stimulation-level display is configured to indicate a current
stimulation level of the pulse generator, when the activation
switch of the patient remote is switched from the asleep mode to
the awake mode. In some aspects, the stimulation-level display can
include a plurality of light emitting diodes, where a number of
illuminated light emitting diodes indicates the current stimulation
level of the pulse generator. In particular aspects, the
stimulation-level display can include at least seven light emitting
diodes of at least three or four sizes, where a baseline
stimulation level can be indicated illumination of the first three
or four light emitting diodes. In other aspects, the patient remote
can further include a therapy-remaining display disposed on the
exterior surface of the portable housing configured to indicate
therapy remaining based on at least a charge of voltage remaining
in a batter of the pulse generator a stimulation use parameters by
the patient. In further aspects, the therapy-remaining display can
include a light emitting diode having at least two contrasting
colors or a single color with flashing and non-flashing modes to
indicate if the pulse generator needs re-charging, is charging, or
has sufficient charge for at least four days of nominal
stimulation. In such aspects, the therapy-remaining display light
emitting diode can illuminate with a non-flashing green color to
indicate at least four (4) days of therapy remaining, can
illuminate with a non-flashing amber color to indicate two to four
(2-4) days of therapy remaining, and can illuminate with a flashing
amber color to indicate less than two (2) days of therapy
remaining. In some aspects, the patient remote can further have an
automatic fault condition indicator disposed on the exterior
surface of the portable housing configured to provide an alert if
the pulse generator is in a fault condition. In other aspects, the
patient remote can further have a haptic indicator coupled to the
portable housing configured to vibrate when a command from the
patient remote has been executed by the pulse generator.
[0015] In further embodiments, the present disclosure is directed
to a method for controlling a nerve-stimulating pulse generator
coupled to an implantable lead within a patient with a patient
remote, the method including: wirelessly communicating with the
pulse generator after an activation switch of the patient remote
reconfigures or transitions the patient remote from an asleep mode
to an awake mode; displaying a current stimulation setting of the
pulse generator on a stimulation-level display of the patient
remote; and wirelessly increasing a stimulation level or turning on
stimulation of the pulse generator when a stimulation-increase
switch of the patient remote is actuated for a first period of time
or turning on and restoring stimulation of the pulse generator to a
previously stored stimulation level when the stimulation-increase
switch of the patient remote is actuated for a second period of
time. In some aspects, the method can include wirelessly decreasing
the stimulation level or turning off stimulation of the pulse
generator when a stimulation-decrease switch of the patient remote
is actuated for the first period of time or storing the stimulation
level and turning off stimulation of the pulse generator when the
stimulation-decrease switch of the patient remote is actuated for
the second period of time. In other aspects, the method can further
include automatically switching the patient remote from the awake
mode to the asleep mode after a period of patient remote
inactivity, wherein the period of inactivity comprises at least ten
(10) seconds. In further aspects, the method can also include
deactivating the stimulation-increase switch and
stimulation-decrease switch of the patient remote when the
activation switch of the patient remote is in the asleep mode. In
yet further aspects, the method can include displaying a status of
therapy remaining in the pulse generator on the patient remote,
where the therapy remaining status is based on at least a charge or
voltage remaining in a battery of the pulse generator and
stimulation use parameters by the patient.
[0016] In some embodiments, the present disclosure is directed to a
method for controlling a nerve-stimulating pulse generator coupled
to an implantable lead within a patient with a patient remote, the
method at least including actuating an activation switch to switch
a patient remote between an awake mode and an asleep mode, where
when the patient remote in the awake mode: actuating a
stimulation-increase switch for a first period of time to turn on
or incrementally increase the stimulation level of the pulse
generator or actuating the stimulation-increase switch for a second
period of time to turning on and restoring stimulation of the pulse
generator to a previously stored stimulation level; and actuating a
stimulation-decrease switch for the first period of time to turn
off or incrementally decrease the stimulation level of the pulse
generator or actuating the stimulation-decrease switch for the
second period of time to store the current stimulation level and
turn off stimulation of the pulse generator.
[0017] In other embodiments, the present disclosure is directed to
an implantable nerve stimulation system having an implantable
neurostimulator and a portable patient remote configured to
wirelessly control the implantable neurostimulator, where the
portable patient remote can include: an external housing having an
oblong or rectangular shape; a stimulation-increase switch disposed
on an exterior surface of the portable housing configured to
wirelessly increase a stimulation level of the implantable
neurostimulator; a stimulation-decrease switch disposed on the
exterior surface of the portable housing configured to wirelessly
decrease a stimulation level of the implantable neurostimulator;
and a recessed activation switch disposed on the external housing
and having an awake mode and an asleep mode, where when the
recessed activation switch of the patient remote is in the asleep
mode, the stimulation-increase switch and the stimulation-decrease
switch are inactivated, and where when the recessed activation
switch of the patient remote is in the awake mode, the patient
remote is configured to wirelessly communicate with the implantable
neurostimulator and actuation of the stimulation-increase switch
for a first period of time increases the stimulation level or turns
on stimulation of the implantable neurostimulator while actuation
of the stimulation-increase switch for a second period of time
turns on stimulation of the implantable neurostimulator and
restores the stimulation level of the implantable neurostimulator
to a previously stored stimulation level.
[0018] In further embodiments, the present disclosure is directed
to a system for treating a patient with a disorder associated with
a nerve, where the system includes a nerve-stimulating pulse
generator having wireless communication circuitry and a plurality
of stimulation levels; an implantable lead configured to be coupled
with the pulse generator and implanted in the patient in operative
communication with the nerve; and a patient remote. In such
embodiments, the patent remote can include: a portable housing
configured to be carried daily by the patient; circuitry disposed
within the portable housing, the circuitry configured to wirelessly
communicate with the wireless communication circuitry of the pulse
generator; and a stimulation level varying switch disposed on the
portable housing, the stimulation level switch coupled to the
circuitry so as to wirelessly alter an applied stimulation level of
the pulse generator when the switch is actuated, the applied
stimulation level being selected from among the plurality of
stimulation levels of the pulse generator so that actuation of the
stimulation level switch allows the patient to select a level of
stimulation being applied by the pulse generator to the lead; where
the patient remote and pulse generator are configured so that the
plurality of stimulation levels selectable by the patient using the
patient remote define a monovariant range of stimulation levels
extending from a least selectable stimulation level to a greatest
selectable stimulation level.
[0019] Further areas of applicability of the present disclosure
will become apparent from the detailed description provided
hereinafter. It should be understood that the detailed description
and specific examples, while indicating various embodiments, are
intended for purposes of illustration only and are not intended to
necessarily limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 schematically illustrates a nerve stimulation system,
which includes a clinician programmer and a patient remote used in
positioning and/or programming of both a trial neurostimulation
system and a permanently implanted neurostimulation system, in
accordance with aspects of the invention.
[0021] FIGS. 2A-2C show diagrams of the nerve structures along the
spine, the lower back and sacrum region, which may be stimulated in
accordance with aspects of the invention.
[0022] FIG. 3A shows an example of a fully implanted
neurostimulation system in accordance with aspects of the
invention.
[0023] FIG. 3B shows an example of a neurostimulation system having
a partly implanted stimulation lead and an external pulse generator
adhered to the skin of the patient for use in a trial stimulation,
in accordance with aspects of the invention.
[0024] FIG. 4 shows an example of a neurostimulation system having
an implantable stimulation lead, an implantable pulse generator,
and an external charging device, in accordance with aspects of the
invention.
[0025] FIG. 5A-5C show detail views of an implantable pulse
generator and associated components for use in a neurostimulation
system, in accordance with aspects of the invention.
[0026] FIG. 6 schematically illustrates a nerve stimulation system
utilizing a control unit with a stimulation clip, a ground patch,
two electromyography sensors, and ground patch sets connected
during the operation of placing a trial or permanent
neurostimulation system, in accordance with aspects of the
invention.
[0027] FIGS. 7-8 show signal characteristics of a neurostimulation
program, in accordance with aspects of the invention.
[0028] FIG. 9 is a schematic illustration of a patient remote, in
accordance with aspects of the invention.
[0029] FIGS. 9-1 to 9-7 are schematic illustrations of a patient
remote showing a progression of stimulation levels, in accordance
with aspects of the invention.
[0030] FIGS. 9-8 and 9-9 are schematic illustrations of a patient
remote with a therapy-remaining display showing levels of therapy
remaining for a neurostimulation system, in accordance with aspects
of the invention.
[0031] FIG. 9-10 is a schematic illustration of a patient remote
with an illuminated fault condition indicator, in accordance with
aspects of the invention.
[0032] FIG. 10 is a functional block diagram of components of a
patient remote, in accordance with aspects of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The present invention relates to neurostimulation treatment
systems and associated devices, as well as methods of treatment,
implantation/placement and configuration of such treatment systems.
In one particular embodiment, the invention relates to sacral nerve
stimulation treatment systems configured to treat overactive
bladder ("OAB") and relieve symptoms of bladder related
dysfunction. In addition, the descriptions herein may also be used
to treat other forms of urinary dysfunction and to treat fecal
dysfunction, therefore, throughout the description it should be
understood that what is described for OAB applies equally to other
forms of urinary dysfunction and fecal dysfunction. It will be
appreciated however that the present invention may also be utilized
for the treatment of pain or other indications, such as movement or
affective disorders, as will be appreciated by one of skill in the
art.
I. Neurostimulation Indications
[0034] Neurostimulation (or neuromodulation as may be used
interchangeably hereunder) treatment systems, such as any of those
described herein, can be used to treat a variety of ailments and
associated symptoms, such as acute pain disorders, movement
disorders, affective disorders, as well as bladder related
dysfunction. Examples of pain disorders that may be treated by
neurostimulation include failed back surgery syndrome, reflex
sympathetic dystrophy or complex regional pain syndrome, causalgia,
arachnoiditis, and peripheral neuropathy. Movement orders include
muscle paralysis, tremor, dystonia and Parkinson's disease.
Affective disorders include depressions, obsessive-compulsive
disorder, cluster headache, Tourette syndrome and certain types of
chronic pain. Bladder related dysfunctions include but are not
limited to OAB, urge incontinence, urgency-frequency, and urinary
retention. OAB can include urge incontinence and urgency-frequency
alone or in combination. Urge incontinence is the involuntary loss
or urine associated with a sudden, strong desire to void (urgency).
Urgency-frequency is the frequent, often uncontrollable urges to
urinate (urgency) that often result in voiding in very small
amounts (frequency). Urinary retention is the inability to empty
the bladder. Neurostimulation treatments can be configured to
address a particular condition by effecting neurostimulation of
targeted nerve tissues relating to the sensory and/or motor control
associated with that condition or associated symptom.
[0035] In one aspect, the methods and systems described herein are
particularly suited for treatment of urinary and fecal
dysfunctions. These conditions have been historically
under-recognized and significantly underserved by the medical
community. OAB is one of the most common urinary dysfunctions. It
is a complex condition characterized by the presence of bothersome
urinary symptoms, including urgency, frequency, nocturia and urge
incontinence. It is estimated that about 33 million Americans
suffer from OAB. Of the adult population, about 30% of all men and
40% of all women live with OAB symptoms.
[0036] OAB symptoms can have a significant negative impact on the
psychosocial functioning and the quality of life of patients.
People with OAB often restrict activities and/or develop coping
strategies. Furthermore, OAB imposes a significant financial burden
on individuals, their families, and healthcare organizations. The
prevalence of co-morbid conditions is also significantly higher for
patients with OAB than in the general population. Co-morbidities
may include falls and fractures, urinary tract infections, skin
infections, vulvovaginitis, cardiovascular, and central nervous
system pathologies. Chronic constipation, fecal incontinence, and
overlapping chronic constipation occur more frequently in patients
with OAB.
[0037] Conventional treatments of OAB generally include lifestyle
modifications as a first course of action. Lifestyle modifications
include eliminating bladder irritants (such as caffeine) from the
diet, managing fluid intake, reducing weight, stopping smoking, and
managing bowel regularity. Behavioral modifications include
changing voiding habits (such as bladder training and delayed
voiding), training pelvic floor muscles to improve strength and
control of urethral sphincter, biofeedback and techniques for urge
suppression. Medications are considered a second-line treatment for
OAB. These include anti-cholinergic medications (oral, transdermal
patch, and gel) and oral beta-3 adrenergic agonists. However,
anti-cholinergics are frequently associated with bothersome,
systemic side effects including dry mouth, constipation, urinary
retention, blurred vision, somnolence, and confusion. Studies have
found that more than 50% of patients stop using anti-cholinergic
medications within 90 days due to a lack of benefit, adverse
events, or cost.
[0038] When these approaches are unsuccessful, third-line treatment
options suggested by the American Urological Association include
intradetrusor (bladder smooth muscle) injections of Botulinum Toxin
(BoNT-A), Percutaneous Tibial Nerve Stimulation (PTNS) and Sacral
Nerve Stimulation (SNM). BoNT-A (Botox.RTM.) is administered via a
series of intradetrusor injections under cystoscopic guidance, but
repeat injections of Botox are generally required every 4 to 12
months to maintain effect and Botox may undesirably result in
urinary retention. A number or randomized controlled studies have
shown some efficacy of BoNT-A in OAB patients, but long-term safety
and effectiveness of BoNT-A for OAB is largely unknown.
[0039] Alternative treatment methods, typically considered when the
above approaches prove ineffective, is neurostimulation of nerves
relating to the urinary system. Such neurostimulation methods
include PTNS and SNM. PTNS therapy consists of weekly, 30-minute
sessions over a period of 12 weeks, each session using electrical
stimulation that is delivered from a hand-held stimulator to the
sacral plexus via the tibial nerve. For patients who respond well
and continue treatment, ongoing sessions, typically every 3-4
weeks, are needed to maintain symptom reduction. There is potential
for declining efficacy if patients fail to adhere to the treatment
schedule. Efficacy of PTNS has been demonstrated in a few
randomized-controlled studies, however, long-term safety and
effectiveness of PTNS is relatively unknown at this time.
II. Sacral Neuromodulation
[0040] SNM is an established therapy that provides a safe,
effective, reversible, and long-lasting treatment option for the
management of urge incontinence, urgency-frequency, and
non-obstructive urinary retention. SNM therapy involves the use of
mild electrical pulses to stimulate the sacral nerves located in
the lower back. Electrodes are placed next to a sacral nerve,
usually at the S3 level, by inserting the electrode leads into the
corresponding foramen of the sacrum. The electrodes are inserted
subcutaneously and are subsequently attached to an implantable
pulse generator (IPG). The safety and effectiveness of SNM for the
treatment of OAB, including durability at five years for both urge
incontinence and urgency-frequency patients, is supported by
multiple studies and is well-documented. SNM has also been approved
to treat chronic fecal incontinence in patients who have failed or
are not candidates for more conservative treatments.
A. Implantation of Sacral Neuromodulation System
[0041] Currently, SNM qualification has a trial phase, and is
followed if successful by a permanent implant. The trial phase is a
test stimulation period where the patient is allowed to evaluate
whether the therapy is effective. Typically, there are two
techniques that are utilized to perform the test stimulation. The
first is an office-based procedure termed the Percutaneous Nerve
Evaluation (PNE) and the other is a staged trial.
[0042] In the PNE, a foramen needle is typically used first to
identify the optimal stimulation location, usually at the S3 level,
and to evaluate the integrity of the sacral nerves. Motor and
sensory responses are used to verify correct needle placement, as
described in Table 1 below. A temporary stimulation lead (a
unipolar electrode) is then placed near the sacral nerve under
local anesthesia. This procedure can be performed in an office
setting without fluoroscopy. The temporary lead is then connected
to an external pulse generator (EPG) taped onto the skin of the
patient during the trial phase. The stimulation level can be
adjusted to provide an optimal comfort level for the particular
patient. The patient will monitor his or her voiding for 3 to 7
days to see if there is any symptom improvement. The advantage of
the PNE is that it is an incision free procedure that can be
performed in the physician's office using local anesthesia. The
disadvantage is that the temporary lead is not securely anchored in
place and has the propensity to migrate away from the nerve with
physical activity and thereby cause failure of the therapy. If a
patient fails this trial test, the physician may still recommend
the staged trial as described below. If the PNE trial is positive,
the temporary trial lead is removed and a permanent quadri-polar
tined lead is implanted along with an IPG under general anesthesia.
Other neuromodulation applications may have any number of
electrodes and more than one lead as the therapy may require.
[0043] A staged trial involves the implantation of the permanent
quadri-polar tined stimulation lead into the patient from the
start. It also requires the use of a foramen needle to identify the
nerve and optimal stimulation location. The lead is implanted near
the S3 sacral nerve and is connected to an EPG via a lead
extension. This procedure is performed under fluoroscopic guidance
in an operating room and under local or general anesthesia. The EPG
is adjusted to provide an optimal comfort level for the patient and
the patient monitors his or her voiding for up to two weeks. If the
patient obtains meaningful symptom improvement, he or she is
considered a suitable candidate for permanent implantation of the
IPG under general anesthesia, typically in the upper buttock area,
as shown in FIGS. 1 and 3A.
TABLE-US-00001 TABLE 1 Motor and Sensory Responses of SNM at
Different Sacral Nerve Roots Response Nerve Innervation Pelvic
Floor Foot/calf/leg Sensation S2-Primary somatic "Clamp" * of anal
Leg/hip rotation, Contraction of base contributor of pudendal
sphincter plantar flexion of entire of penis, vagina nerve for
external foot, contraction of calf sphincter, leg, foot
S3-Virtually all pelvic "bellows" ** of Plantar flexion of great
Pulling in rectum, autonomic functions and perineum toe,
occasionally other extending forward striated mucle (levetor toes
to scrotum or labia ani) S4-Pelvic autonomic "bellows" ** No lower
extremity Pulling in rectum and somatic; No leg pr motor
stimulation only foot
[0044] In regard to measuring outcomes for SNM treatment of voiding
dysfunction, the voiding dysfunction indications (e.g., urge
incontinence, urgency-frequency, and non-obstructive urinary
retention) are evaluated by unique primary voiding diary variables.
The therapy outcomes are measured using these same variables. SNM
therapy is considered successful if a minimum of 50% improvement
occurs in any of primary voiding diary variables compared with the
baseline. For urge incontinence patients, these voiding diary
variables may include: number of leaking episodes per day, number
of heavy leaking episodes per day, and number of pads used per day.
For patients with urgency-frequency, primary voiding diary
variables may include: number of voids per day, volume voided per
void and degree of urgency experienced before each void. For
patients with retention, primary voiding diary variables may
include: catheterized volume per catheterization and number of
catheterizations per day.
[0045] The mechanism of action of SNM is multifactorial and impacts
the neuro-axis at several different levels. In patients with OAB,
it is believed that pudendal afferents can activate the inhibitory
reflexes that promote bladder storage by inhibiting the afferent
limb of an abnormal voiding reflex. This blocks input to the
pontine micturition center, thereby restricting involuntary
detrusor contractions without interfering with normal voiding
patterns. For patients with urinary retention, SNM is believed to
activate the pudendal nerve afferents originating from the pelvic
organs into the spinal cord. At the level of the spinal cord,
pudendal afferents may turn on voiding reflexes by suppressing
exaggerated guarding reflexes, thus relieving symptoms of patients
with urinary retention so normal voiding can be facilitated. In
patients with fecal incontinence, it is hypothesized that SNM
stimulates pudendal afferent somatic fibers that inhibit colonic
propulsive activity and activates the internal anal sphincter,
which in turn improves the symptoms of fecal incontinence patients.
The present invention relates to a system adapted to deliver
neurostimulation to targeted nerve tissues in a manner that
disrupt, inhibit, or prevent neural activity in the targeted nerve
tissues so as to provide therapeutic effect in treatment of OAB or
bladder related dysfunction. In one aspect, the system is adapted
to provide therapeutic effect by neurostimulation without inducing
motor control of the muscles associated with OAB or bladder related
dysfunction by the delivered neurostimulation. In another aspect,
the system is adapted to provide such therapeutic effect by
delivery of sub-threshold neurostimulation below a threshold that
induces paresthesia and/or neuromuscular response or to allow
adjustment of neurostimulation to delivery therapy at sub-threshold
levels.
B. Positioning Neurostimulation Leads with EMG
[0046] While conventional approaches have shown efficacy in
treatment of bladder related dysfunction, there exists a need to
improve positioning of the neurostimulation leads and consistency
between the trial and permanent implantation positions of the lead.
Neurostimulation relies on consistently delivering therapeutic
stimulation from a pulse generator, via one or more
neurostimulation electrodes, to particular nerves or targeted
regions. The neurostimulation electrodes are provided on a distal
end of an implantable lead that can be advanced through a tunnel
formed in patient tissue. Implantable neurostimulation systems
provide patients with great freedom and mobility, but it may be
easier to adjust the neurostimulation electrodes of such systems
before they are surgically implanted. It is desirable for the
physician to confirm that the patient has desired motor and/or
sensory responses before implanting an IPG. For at least some
treatments (including treatments of at least some forms of urinary
and/or fecal dysfunction), demonstrating appropriate motor
responses may be highly beneficial for accurate and objective lead
placement while the sensory response may not be required or not
available (e.g., patient is under general anesthesia).
[0047] Placement and calibration of the neurostimulation electrodes
and implantable leads sufficiently close to specific nerves can be
beneficial for the efficacy of treatment. Accordingly, aspects and
embodiments of the present disclosure are directed to aiding and
refining the accuracy and precision of neurostimulation electrode
placement. Further, aspects and embodiments of the present
disclosure are directed to aiding and refining protocols for
setting therapeutic treatment signal parameters for a stimulation
program implemented through implanted neurostimulation
electrodes.
[0048] Prior to implantation of the permanent device, patients may
undergo an initial testing phase to estimate potential response to
treatment. As discussed above, PNE may be done under local
anesthesia, using a test needle to identify the appropriate sacral
nerve(s) according to a subjective sensory response by the patient.
Other testing procedures can involve a two-stage surgical
procedure, where a quadri-polar tined lead is implanted for a
testing phase to determine if patients show a sufficient reduction
in symptom frequency, and if appropriate, proceeding to the
permanent surgical implantation of a neuromodulation device. For
testing phases and permanent implantation, determining the location
of lead placement can be dependent on subjective qualitative
analysis by either or both of a patient or a physician.
[0049] In exemplary embodiments, determination of whether or not an
implantable lead and neurostimulation electrode is located in a
desired or correct location can be accomplished through use of
electromyography ("EMG"), also known as surface electromyography.
EMG, is a technique that uses an EMG system or module to evaluate
and record electrical activity produced by muscles, producing a
record called an electromyogram. EMG detects the electrical
potential generated by muscle cells when those cells are
electrically or neurologically activated. The signals can be
analyzed to detect activation level or recruitment order. EMG can
be performed through the skin surface of a patient, intramuscularly
or through electrodes disposed within a patient near target
muscles, or using a combination of external and internal
structures. When a muscle or nerve is stimulated by an electrode,
EMG can be used to determine if the related muscle is activated,
(i.e. whether the muscle fully contracts, partially contracts, or
does not contract) in response to the stimulus. Accordingly, the
degree of activation of a muscle can indicate whether an
implantable lead or neurostimulation electrode is located in the
desired or correct location on a patient. Further, the degree of
activation of a muscle can indicate whether a neurostimulation
electrode is providing a stimulus of sufficient strength,
amplitude, frequency, or duration to affect a treatment regimen on
a patient. Thus, use of EMG provides an objective and quantitative
means by which to standardize placement of implantable leads and
neurostimulation electrodes, reducing the subjective assessment of
patient sensory responses.
[0050] In some approaches, positional titration procedures may
optionally be based in part on a paresthesia or pain-based
subjective response from a patient. In contrast, EMG triggers a
measureable and discrete muscular reaction. As the efficacy of
treatment often relies on precise placement of the neurostimulation
electrodes at target tissue locations and the consistent,
repeatable delivery of neurostimulation therapy, using an objective
EMG measurement can substantially improve the utility and success
of SNM treatment. The measureable muscular reaction can be a
partial or a complete muscular contraction, including a response
below the triggering of an observable motor response, such as those
shown in Table 1, depending on the stimulation of the target
muscle. In addition, by utilizing a trial system that allows the
neurostimulation lead to remain implanted for use in the
permanently implanted system, the efficacy and outcome of the
permanently implanted system is more consistent with the results of
the trial period, which moreover leads to improved patient
outcomes.
C. Example Embodiments
[0051] FIG. 1 schematically illustrates an exemplary nerve
stimulation system, which includes both a trial neurostimulation
system 200 and a permanently implanted neurostimulation system 100,
in accordance with aspects of the invention. The EPG 80 and IPG 10
are each compatible with and wirelessly communicate with a
clinician programmer 60 and a patient remote 70, which are used in
positioning and/or programming the trial neurostimulation system
200 and/or permanently implanted system 100 after a successful
trial. As discussed above, the clinician programmer can include
specialized software, specialized hardware, and/or both, to aid in
lead placement, programming, re-programming, stimulation control,
and/or parameter setting. In addition, each of the IPG and the EPG
allows the patient at least some control over stimulation (e.g.,
initiating a pre-set program, increasing or decreasing
stimulation), and/or to monitor battery status with the patient
remote. This approach also allows for an almost seamless transition
between the trial system and the permanent system.
[0052] In one aspect, the clinician programmer 60 is used by a
physician to adjust the settings of the EPG and/or IPG while the
lead is implanted within the patient. The clinician programmer can
be a tablet computer used by the clinician to program the IPG, or
to control the EPG during the trial period. The clinician
programmer can also include capability to record
stimulation-induced electromyograms to facilitate lead placement
and programming. The patient remote 70 can allow the patient to
turn the stimulation on or off, or to vary stimulation from the IPG
while implanted, or from the EPG during the trial phase.
[0053] In another aspect, the clinician programmer 60 has a control
unit which can include a microprocessor and specialized
computer-code instructions for implementing methods and systems for
use by a physician in deploying the treatment system and setting up
treatment parameters. The clinician programmer generally includes a
user interface which can be a graphical user interface, an EMG
module, electrical contacts such as an EMG input that can couple to
an EMG output stimulation cable, an EMG stimulation signal
generator, and a stimulation power source. The stimulation cable
can further be configured to couple to any or all of an access
device (e.g., a foramen needle), a treatment lead of the system, or
the like. The EMG input may be configured to be coupled with one or
more sensory patch electrode(s) for attachment to the skin of the
patient adjacent a muscle (e.g., a muscle enervated by a target
nerve). Other connectors of the clinician programmer may be
configured for coupling with an electrical ground or ground patch,
an electrical pulse generator (e.g., an EPG or an IPG), or the
like. As noted above, the clinician programmer can include a module
with hardware and computer-code to execute EMG analysis, where the
module can be a component of the control unit microprocessor, a
pre-processing unit coupled to or in-line with the stimulation
and/or sensory cables, or the like.
[0054] In some aspects, the clinician programmer is configured to
operate in combination with an EPG when placing leads in a patient
body. The clinician programmer can be electronically coupled to the
EPG during test simulation through a specialized cable set. The
test simulation cable set can connect the clinician programmer
device to the EPG and allow the clinician programmer to configure,
modify, or otherwise program the electrodes on the leads connected
to the EPG.
[0055] The electrical pulses generated by the EPG and IPG are
delivered to one or more targeted nerves via one or more
neurostimulation electrodes at or near a distal end of each of one
or more leads. The leads can have a variety of shapes, can be a
variety of sizes, and can be made from a variety of materials,
which size, shape, and materials can be tailored to the specific
treatment application. While in this embodiment, the lead is of a
suitable size and length to extend from the IPG and through one of
the foramen of the sacrum to a targeted sacral nerve, in various
other applications, the leads may be, for example, implanted in a
peripheral portion of the patient's body, such as in the arms or
legs, and can be configured to deliver electrical pulses to the
peripheral nerve such as may be used to relieve chronic pain. It is
appreciated that the leads and/or the stimulation programs may vary
according to the nerves being targeted.
[0056] FIGS. 2A-2C show diagrams of various nerve structures of a
patient, which may be used in neurostimulation treatments, in
accordance with aspects of the invention. FIG. 2A shows the
different sections of the spinal cord and the corresponding nerves
within each section. The spinal cord is a long, thin bundle of
nerves and support cells that extend from the brainstem along the
cervical cord, through the thoracic cord and to the space between
the first and second lumbar vertebra in the lumbar cord. Upon
exiting the spinal cord, the nerve fibers split into multiple
branches that innervate various muscles and organs transmitting
impulses of sensation and control between the brain and the organs
and muscles. Since certain nerves may include branches that
innervate certain organs, such as the bladder, and branches that
innervate certain muscles of the leg and foot, stimulation of the
nerve at or near the nerve root near the spinal cord can stimulate
the nerve branch that innervate the targeted organ, which may also
result in muscle responses associated with the stimulation of the
other nerve branch. Thus, by monitoring for certain muscle
responses, such as those in Table 1, either visually, through the
use of EMG as described herein or both, the physician can determine
whether the targeted nerve is being stimulated. While stimulation
at a certain threshold may trigger the noted muscle responses,
stimulation at a sub-threshold level may still provide stimulation
to the nerve associated with the targeted organ without causing the
corresponding muscle response, and in some embodiments, without
causing any paresthesia. This is advantageous as it allows for
treatment of the condition by neurostimulation without otherwise
causing patient discomfort, pain or undesired muscle responses.
[0057] FIG. 2B shows the nerves associated with the lower back
section, in the lower lumbar cord region where the nerve bundles
exit the spinal cord and travel through the sacral foramens of the
sacrum. In some embodiments, the neurostimulation lead is advanced
through the foramen until the neurostimulation electrodes are
positioned at the anterior sacral nerve root, while the anchoring
portion of the lead proximal of the stimulation electrodes are
generally disposed dorsal of the sacral foramen through which the
lead passes, so as to anchor the lead in position. FIG. 2C shows
detail views of the nerves of the lumbosacral trunk and the sacral
plexus, in particular, the S1-S5 nerves of the lower sacrum. The S3
sacral nerve is of particular interest for treatment of bladder
related dysfunction, and in particular OAB.
[0058] FIG. 3A schematically illustrates an example of a fully
implanted neurostimulation system 100 adapted for sacral nerve
stimulation. Neurostimulation system 100 includes an IPG implanted
in a lower back region and connected to a neurostimulation lead
extending through the S3 foramen for stimulation of the S3 sacral
nerve. The lead is anchored by a tined anchor portion 30 that
maintains a position of a set of neurostimulation electrodes 40
along the targeted nerve, which in this example, is the anterior
sacral nerve root S3 which enervates the bladder so as to provide
therapy for various bladder related dysfunctions. While this
embodiment is adapted for sacral nerve stimulation, it is
appreciated that similar systems can be used in treating patients
with, for example, chronic, severe, refractory neuropathic pain
originating from peripheral nerves or various urinary dysfunctions
or still further other indications. Implantable neurostimulation
systems can be used to either stimulate a target peripheral nerve
or the posterior epidural space of the spine.
[0059] Properties of the electrical pulses can be controlled via a
controller of the implanted pulse generator. In some embodiments,
these properties can include, for example, the frequency, strength,
pattern, duration, or other aspects of the electrical pulses. These
properties can include, for example, a voltage, a current, or the
like. This control of the electrical pulses can include the
creation of one or more electrical pulse programs, plans, or
patterns, and in some embodiments, this can include the selection
of one or more pre-existing electrical pulse programs, plans, or
patterns. In the embodiment depicted in FIG. 3A, the implantable
neurostimulation system 100 includes a controller in the IPG having
one or more pulse programs, plans, or patterns that may be
pre-programmed or created as discussed above. In some embodiments,
these same properties associated with the IPG may be used in an EPG
of a partly implanted trial system used before implantation of the
permanent neurostimulation system 100.
[0060] FIG. 3B shows a schematic illustration of a trial
neurostimulation system 200 utilizing an EPG patch 81 adhered to
the skin of a patient, particularly to the abdomen of a patient,
the EPG 80 being encased within the patch. In one aspect, the lead
is hardwired to the EPG, while in another the lead is removably
coupled to the EPG through a port or aperture in the top surface of
the flexible patch 81. Excess lead can be secured by an additional
adherent patch. In one aspect, the EPG patch is disposable such
that the lead can be disconnected and used in a permanently
implanted system without removing the distal end of the lead from
the target location. Alternatively, the entire system can be
disposable and replaced with a permanent lead and IPG. When the
lead of the trial system is implanted, an EMG obtained via the
clinician programmer using one or more sensor patches can be used
to ensure that the leads are placed at a location proximate to the
target nerve or muscle, as discussed previously.
[0061] In some embodiments, the trial neurostimulation system
utilizes an EPG 80 within an EPG patch 81 that is adhered to the
skin of a patient and is coupled to the implanted neurostimulation
lead 20 through a lead extension 22, which is coupled with the lead
20 through a connector 21. This extension and connector structure
allows the lead to be extended so that the EPG patch can be placed
on the abdomen and allows use of a lead having a length suitable
for permanent implantation should the trial prove successful. This
approach may utilize two percutaneous incisions, the connector
provided in the first incision and the lead extensions extending
through the second percutaneous incision, there being a short
tunneling distance (e.g., about 10 cm) there between. This
technique may also minimize movement of an implanted lead during
conversion of the trial system to a permanently implanted
system.
[0062] In one aspect, the EPG unit is wirelessly controlled by a
patient remote and/or the clinician programmer in a similar or
identical manner as the IPG of a permanently implanted system. The
physician or patient may alter treatment provided by the EPG
through use of such portable remotes or programmers and the
treatments delivered are recorded on a memory of the programmer for
use in determining a treatment suitable for use in a permanently
implanted system. The clinician programmer can be used in lead
placement, programming and/or stimulation control in each of the
trial and permanent nerve stimulation systems. In addition, each
nerve stimulation system allows the patient to control stimulation
or monitor battery status with the patient remote. This
configuration is advantageous as it allows for an almost seamless
transition between the trial system and the permanent system. From
the patient's viewpoint, the systems will operate in the same
manner and be controlled in the same manner, such that the
patient's subjective experience in using the trial system more
closely matches what would be experienced in using the permanently
implanted system. Thus, this configuration reduces any
uncertainties the patient may have as to how the system will
operate and be controlled such that the patient will be more likely
to convert a trial system to a permanent system.
[0063] As shown in the detailed view of FIG. 3B, the EPG 80 is
encased within a flexible laminated patch 81, which include an
aperture or port through which the EPG 80 is connected to the lead
extension 22. The patch may further an "on/off" button 83 with a
molded tactile detail to allow the patient to turn the EPG on
and/or off through the outside surface of the adherent patch 81.
The underside of the patch 81 is covered with a skin-compatible
adhesive 82 for continuous adhesion to a patient for the duration
of the trial period. For example, a breathable strip having
skin-compatible adhesive 82 would allow the EPG 80 to remain
attached to the patient continuously during the trial, which may
last over a week, typically two weeks to four weeks, or even
longer.
[0064] FIG. 4 illustrates an example neurostimulation system 100
that is fully implantable and adapted for sacral nerve stimulation
treatment. The implantable system 100 includes an IPG 10 that is
coupled to a neurostimulation lead 20 that includes a group of
neurostimulation electrodes 40 at a distal end of the lead. The
lead includes a lead anchor portion 30 with a series of tines
extending radially outward so as to anchor the lead and maintain a
position of the neurostimulation lead 20 after implantation. The
lead 20 may further include one or more radiopaque markers 25 to
assist in locating and positioning the lead using visualization
techniques such as fluoroscopy. In some embodiments, the IPG
provides monopolar or bipolar electrical pulses that are delivered
to the targeted nerves through one or more neurostimulation
electrodes, typically four electrodes. In sacral nerve stimulation,
the lead is typically implanted through the S3 foramen as described
herein.
[0065] In one aspect, the IPG is rechargeable wirelessly through
conductive coupling by use of a charging device 50 (CD), which is a
portable device powered by a rechargeable battery to allow patient
mobility while charging. The CD is used for transcutaneous charging
of the IPG through RF induction. The CD can either be either
patched to the patient's skin using an adhesive or can be held in
place using a belt 53 or by an adhesive patch 52, such as shown in
the schematic of FIG. 6. The CD may be charged by plugging the CD
directly into an outlet or by placing the CD in a charging dock or
station 51 that connects to an AC wall outlet or other power
source.
[0066] The system may further include a patient remote 70 and
clinician programmer 60, each configured to wirelessly communicate
with the implanted IPG, or with the EPG during a trial, as shown in
the schematic of the nerve stimulation system in FIG. 6. The
clinician programmer 60 may be a tablet computer used by the
clinician to program the IPG and the EPG. The device also has the
capability to record stimulation-induced electromyograms (EMGs) to
facilitate lead placement, programming, and/or re-programming. The
patient remote may be a battery-operated, portable device that
utilizes radio-frequency (RF) signals to communicate with the EPG
and IPG and allows the patient to adjust the stimulation levels,
check the status of the IPG battery level, and/or to turn the
stimulation on or off.
[0067] FIG. 5A-5C show detail views of the IPG and its internal
components. In some embodiments, the pulse generator can generate
one or more non-ablative electrical pulses that are delivered to a
nerve to control pain or cause some other desired effect, for
example to inhibit, prevent, or disrupt neural activity for the
treatment of OAB or bladder related dysfunction. In some
applications, the pulses having a pulse amplitude in a range
between 0 mA to 1,000 mA, 0 mA to 100 mA, 0 mA to 50 mA, 0 mA to 25
mA, and/or any other or intermediate range of amplitudes may be
used. One or more of the pulse generators can include a processor
and/or memory adapted to provide instructions to and receive
information from the other components of the implantable
neurostimulation system. The processor can include a
microprocessor, such as a commercially available microprocessor
from Intel.RTM. or Advanced Micro Devices, Inc..RTM., or the like.
An IPG may include an energy storage feature, such as one or more
capacitors, and typically includes a wireless charging unit.
[0068] One or more properties of the electrical pulses can be
controlled via a controller of the IPG or EPG. In some embodiments,
these properties can include, for example, the frequency, strength,
pattern, duration, or other aspects of the timing and magnitude of
the electrical pulses. These properties can further include, for
example, a voltage, a current, or the like. This control of the
electrical pulses can include the creation of one or more
electrical pulse programs, plans, or patterns, and in some
embodiments, this can include the selection of one or more
pre-existing electrical pulse programs, plans, or patterns. In one
aspect, the IPG 10 includes a controller having one or more pulse
programs, plans, or patterns that may be created and/or
pre-programmed. In some embodiments, the IPG can be programmed to
vary stimulation parameters including pulse amplitude in a range
from 0 mA to 10 mA, pulse width in a range from 50 .mu.s to 500
.mu.s, pulse frequency in a range from 5 Hz to 250 Hz, stimulation
modes (e.g., continuous or cycling), and electrode configuration
(e.g., anode, cathode, or off), to achieve the optimal therapeutic
outcome specific to the patient. In particular, this allows for an
optimal setting to be determined for each patient even though each
parameter may vary from person to person.
[0069] As shown in FIGS. 5A-5B, the IPG may include a header
portion 11 at one end and a ceramic portion 14 at the opposite end.
The header portion 11 houses a feed through assembly 12 and
connector stack 13, while the ceramic case portion 14 houses an
antenna assembly 16 to facilitate wireless communication with the
clinician program, the patient remote, and/or a charging coil to
facilitate wireless charging with the CD. The remainder of the IPG
is covered with a titanium case portion 17, which encases the
printed circuit board, memory and controller components that
facilitate the electrical pulse programs described above. In the
example shown in FIG. 5C, the header portion of the IPG includes a
four-pin feed-through assembly 12 that couples with the connector
stack 13 in which the proximal end of the lead is coupled. The four
pins correspond to the four electrodes of the neurostimulation
lead. In some embodiments, a Balseal.RTM. connector block is
electrically connected to four platinum/iridium alloy feed-through
pins which are brazed to an alumina ceramic insulator plate along
with a titanium alloy flange. This feed-through assembly is laser
seam welded to a titanium-ceramic brazed case to form a complete
hermetic housing for the electronics. The number of header
electrical contacts is a function of the number of electrodes and
leads used for any particular system configuration.
[0070] In some embodiment, such as that shown in FIG. 5A, the
ceramic and titanium brazed case is utilized on one end of the IPG
where the ferrite coil and PCB antenna assemblies are positioned. A
reliable hermetic seal is provided via a ceramic-to-metal brazing
technique. The zirconia ceramic may comprise a 3Y-TZP (3 mol
percent Yttria-stabilized tetragonal Zirconia Polycrystals)
ceramic, which has a high flexural strength and impact resistance
and has been commercially utilized in a number of implantable
medical technologies. It will be appreciated, however, that other
ceramics or other suitable materials may be used for construction
of the IPG.
[0071] In one aspect, utilization of ceramic material provides an
efficient, radio-frequency-transparent window for wireless
communication with the external patient remote and clinician's
programmer as the communication antenna is housed inside the
hermetic ceramic case. This ceramic window has further facilitated
miniaturization of the implant while maintaining an efficient,
radio-frequency-transparent window for long term and reliable
wireless communication between the IPG and external controllers,
such as the patient remote and clinician programmer. The IPG's
wireless communication is generally stable over the lifetime of the
device, unlike prior art products where the communication antenna
is placed in the header outside the hermetic case. The
communication reliability of such prior art devices tends to
degrade due to the change in dielectric constant of the header
material in the human body over time.
[0072] In another aspect, the ferrite core is part of the charging
coil assembly 15, shown in FIG. 5B, which is positioned inside the
ceramic case 14. The ferrite core concentrates the magnetic field
flux through the ceramic case as opposed to the metallic case
portion 17. This configuration maximizes coupling efficiency, which
reduces the required magnetic field and in turn reduces device
heating during charging. In particular, because the magnetic field
flux is oriented in a direction perpendicular to the smallest
metallic cross section area, heating during charging is minimized.
This configuration also allows the IPG to be effectively charged at
depth of 3 cm with the CD, when positioned on a skin surface of the
patient near the IPG and reduces re-charging time.
[0073] FIG. 6 shows a setup for a test stimulation and EMG sensing
using a clinician programmer 60. As discussed above, the clinician
programmer 60 is a tablet computer with software that runs on a
standard operating system. The clinician programmer 60 includes a
communication module, a stimulation module and an EMG sensing
module. The communication module communicates with the IPG and/or
EPG in the medical implant communication service frequency band for
programming the IPG and/or EPG.
[0074] In order to confirm correct lead placement, it is desirable
for the physician to confirm that the patient has both adequate
motor and sensory responses before transitioning the patient into
the staged trial phase or implanting the permanent IPG. However,
sensory response is a subjective evaluation and may not always be
available, such as when the patient is under general anesthesia.
Experiments have shown that demonstrating appropriate motor
responses is advantageous for accurate placement, even if sensory
responses are available. As discussed above, EMG is a tool which
records electrical activity of skeletal muscles. This sensing
feature provides an objective criterion for the clinician to
determine if the sacral nerve stimulation results in adequate motor
response rather than relying solely on subjective sensory criteria.
EMG can be used not only to verify optimal lead position during
lead placement, but also to provide a standardized and more
accurate approach to determine electrode thresholds, which in turn
provides quantitative information supporting electrode selection
for programming. Using EMG to verify activation of motor responses
can further improve the lead placement performance of less
experienced operators and allow such physicians to perform lead
placement with confidence and greater accuracy.
[0075] In one aspect, the system is configured to have EMG sensing
capability during re-programming, which can be particularly
valuable. Stimulation levels during re-programming are typically
low to avoid patient discomfort which often results in difficult
generation of motor responses. Involuntary muscle movement while
the patient is awake may also cause noise that is difficult for the
physician to differentiate. In contrast to conventional approaches,
EMG allows the clinician to detect motor responses at very low
stimulation levels (e.g., sub-threshold), and help them distinguish
a motor response originated by sacral nerve stimulation from
involuntary muscle movement.
[0076] Referring to FIG. 6, several cable sets are connected to the
CP. The stimulation cable set consists of one stimulation mini-clip
3 and one ground patch 5. It is used with a foramen needle 1 to
locate the sacral nerve and verify the integrity of the nerve via
test stimulation. Another stimulation cable set with four
stimulation channels 2 is used to verify the lead position with a
tined stimulation lead 20 during the staged trial. Both cable sets
are sterilizable as they will be in the sterile field. A total of
five over-the-shelf sensing electrode patches 4 (e.g., two sensing
electrode pairs for each sensing spot and one common ground patch)
are provided for EMG sensing at two different muscle groups (e.g.,
perineal musculature and big toe) simultaneously during the lead
placement procedure. This provides the clinician with a convenient
all-in-one setup via the EMG integrated clinician programmer.
Typically, only one electrode set (e.g., two sensing electrodes and
one ground patch) is needed for detecting an EMG signal on the big
toe during an initial electrode configuration and/or re-programming
session. Typically, these over-the-shelf EMG electrodes are also
provided sterile though not all cables are required to be connected
to the sterile field. The clinician programmer 60 allows the
clinician to read the impedance of each electrode contact whenever
the lead is connected to an EPG, an IPG or a clinician programmer
to ensure reliable connection is made and the lead is intact. In
some embodiments, any electrode with unacceptable impedance can be
locked out from being assigned as an anode or cathode. Unacceptable
impedance can be impedance less than 50 or greater than 3,000 Ohms,
or alternatively less than 500 or greater than 5,000 Ohms. The
clinician programmer 60 is also able to save and display previous
(e.g., up to the last four) programs that were used by a patient to
help facilitate re-programming. In some embodiments, the clinician
programmer 60 further includes a USB port for saving reports to a
USB drive and a charging port. The clinician programmer may also
include physical on/off buttons to turn the clinician programmer on
and off and/or to turn stimulation on and off.
[0077] In some embodiments, the IPG, as well as the EPG, may be
configured with two stimulation modes: continuous mode and cycling
mode, such as shown in FIG. 7. The cycling mode saves energy in
comparison to the continuous mode, thereby extending the recharge
interval of the battery and lifetime of the device. The cycling
mode may also help reduce the risk of neural adaptation for some
patients. Neural adaptation is a change over time in the
responsiveness of the neural system to a constant stimulus. Thus,
cycling mode may also mitigate neural adaptation so to provide
longer-term therapeutic benefit. FIG. 7 shows an example of
stimulation in a cycling mode, in which the duty cycle is the
stimulation on time over the stimulation-on time plus the
stimulation-off time.
[0078] In some embodiments, the IPG/EPG is configured with a
ramping feature, such as shown in the example of FIG. 8. In these
embodiments, the stimulation signal is ramped up and/or down
between the stimulation-on and stimulation-off levels. This feature
helps reduce the sudden "jolting" or "shocking" sensation that some
patients might experience when the stimulation is initially turned
on or at the cycle-on phase during the cycling mode. This feature
is particularly of benefit for patients who need relative high
stimulation settings and/or for patients who are sensitive to
electrical stimulation.
D. Patient Remote Control
[0079] The patient remote (e.g. FIG. 1, element 70) is provided to
allow a patient to adjust the stimulation level of the electrical
pulse generator. The patient remote can be used to wirelessly
communicate with and control either an EPG (e.g., during a trial
phase) or an IPG (e.g., for a permanent neurostimulation system).
In some implementations, different patient remotes can be provided
to control the EPG and the IPG, whereas in other implementations, a
single patient remote can be programmed or reprogrammed to control
either an EPG or an IPG. A particular patient remote can be
configured to link with and wirelessly communicate with only a
single EPG or IPG so as to avoid patients altering the stimulation
of others.
[0080] The degree of adjustment permitted to the patient through
the patient remote can be limited, such that while the patient can
incrementally increase or decrease the therapy delivered by the
pulse generator, and can turn stimulation on or off, the level of
stimulation therapy by the pulse generator whenever the pulse
generator is applying stimulation is maintained within a clinically
effective combination of settings. By providing a limited range of
adjustment to a patient through the patient remote, the patient is
given a straightforward and simple tool for situational control of
the pulse generator and overall neurostimulation system, allowing
for the use of different stimulation levels (including no
stimulation when appropriate) while the patient is awake, while the
patient is asleep, while the patient is engaged in specific
activities, or in other situations. However, the patient may not be
presented with a selection of alternative therapies or multivariate
operational programs via the patient remote that may confuse the
patient or take the pulse generator outside of a clinically
effective range. In some aspects, the patient remote can be
configured to provide monovariant control to the patient. For
example, the patient remote can be limited to varying a stimulation
level of the stimulation program, while the other attributes of the
stimulation program (e.g. duration, electrode configuration, pulse
width, etc.) are maintained. The clinically effective range of the
pulse generator can be determined by a physician or the clinician
programmer when setting the parameters of the pulse generator and
neurostimulation system.
[0081] The patient remote can allow a patient to turn on and turn
off the pulse generator, where turning off the pulse generator may
be desirable for the patient when performing activities that may
inadvertently interfere with, or be inadvertently interfered by, an
active pulse generator and the nerves stimulated by the pulse
generator. For example, as noted in Table 1 above, innervation of
the S3 sacral nerve can cause a response in the plantar flexion of
the great toe or other toes. Thus, it may be desirable to provide a
patient the option to turn off the pulse generator while driving,
carrying heavy objects, or performing other activities that can
strain the foot or toes and may thereby inadvertently trigger a
pulling sensation in the rectum. Moreover, it may be desirable to
provide a patient the option to automatically restore the pulse
generator to a previous level of stimulation when the pulse
generator is turned on after a period of being turned off. In many
cases, the previous level of stimulation can be the last stored
stimulation level of the patient remote. In further
implementations, the patient remote can provide the patient with an
indication of battery status and/or therapy remaining for the
neurostimulation system and pulse generator.
[0082] Structurally, the patient remote can include a portable
housing, with one or more switches and one or more displays on or
embedded within the exterior surface of the portable housing. The
patient remote can have an activation switch and a
stimulation-increase switch disposed on an exterior surface of the
patient remote, allowing the patient (or other operator) to
activate the patient remote and then to instruct the
neurostimulation system to increase the stimulation level of the
pulse generator. The patent remote can also include any combination
of a stimulation-decrease switch (allowing the patient to decrease
the stimulation level), a stimulation-level display, a
therapy-remaining display, and/or a fault condition display
disposed on the exterior surface of the patient remote.
[0083] In other words, the portable housing of the patient remote
can be sized or dimensioned so as to fit within a single hand of a
patient. The patient remote can accordingly be operable within a
single hand of a patient, or another operator. Further, in the
context of the present disclosure, the switches of the patient
remote can instead be buttons, formed as part of the body of the
patient remote, or formed to pass through shaped holes in the
surface of the patient remote. In implementations of the patient
remote having buttons, the buttons can be spring biased or
otherwise supported so as to provide a degree of resistance to
actuation and/or to restore a button to a default status after
actuation is completed and the button is released. Any given switch
or button on the patient remote can be located within a depression
of the external surface of the patient remote, on a flat surface of
the external surface of the patient remote, or on a convex surface
of the external surface of the patient remote. Moreover, any given
switch or button on the patient remote can have a profile that is
flush with the external surface of the patient remote, elevated
from the external surface of the patient remote, or inset/depressed
within the external surface of the patient remote.
[0084] While the terms "switches" and "buttons" are used in the
described embodiments to illustrate various concepts, it is
appreciated that such terms can encompass any actuation feature
that is operable by a user to effect a change in state associated
with the patient remote. A change in state can include a change in
an activation state of the patient remote, or a mode of the pulse
generator and a stimulation level of the IPG or EPG that is
controlled by the patient remote. For example, the actuation
feature can be a button, lever, knob, or an optical or touch sensor
or any suitable feature that allows a user to effect the change in
state by interaction with the feature. In some embodiments, the
actuation features can include portions of a touch screen displayed
to a user.
[0085] FIG. 9 is a schematic illustration of a patient remote 900
showing the structure of a portable housing 902. The portable
housing 902 has an exterior surface, and in many embodiments the
patient remote 900 can have a control surface 903 on a top side of
the exterior surface where operational switches and display
elements can be disposed. In various aspects, the control surface
903 can be constructed of a material that is the same or different
as the rest of the portable housing 902. In other embodiments, the
portable housing 902 can have operational switches or display
elements on a bottom side or lateral sides of the portable housing
902. The portable housing 902 can be constructed from plastics,
lightweight metals (e.g., aluminum), or a combination thereof, and
can be designed and constructed to be of a size such that the
patient remote 900 can be held and operated in a single hand of a
patient. The patient remote 900 can have an oblong, elongated,
rectangular, spherical, square, ellipsoid, or irregular shape, or a
combination thereof. The patient remote 900 can be constructed to
be waterproof, where any structural seams of the portable housing
902 can have an airtight interface or sealed with an additional
polymer or chemical compound. The portable housing 902 can further
be designed to attach as a fob device, configured to be carried
daily, having a mechanical coupling structure 916 to attach the
patient remote 900 with a key ring, karabiner, or other such
mounting element.
[0086] The patient remote 900 can include within the interior of
the portable housing 902 transmission circuitry configured to
interface with the pulse generator, a battery that functions as a
power source for the patient remote, and control electronics.
Control electronics in the interior of the portable housing 902 can
be operatively coupled to relay signals to the transmission
circuitry for controlling control the pulse generator corresponding
to actuation of the one or more switches disposed on the exterior
surface of the portable housing 902. In alternative aspects, the
patient remote 900 can include circuitry to communicate with the
clinician programmer (CP).
[0087] The transmission circuitry can include a radio frequency
(RF) transmitter that communicates with other system elements on
the Medical Implant Communication Service (MICS) frequency band
(MedRadio 402-405 MHz). The wireless communication between the
patient remote 900 and the pulse generator to which the patient
remote 900 sends instructions can have an operational range of up
to three feet, in addition to transmission through the tissue of a
patient, in embodiments where the pulse generator is an IPG
implanted in the patient. A patient remote 900 having any or all of
an activation switch 904, stimulation-increase switch 906, or
stimulation-decrease switch 908 (where any or all of activation
switch 904, stimulation-increase switch 906, or
stimulation-decrease switch 908 can be buttons) disposed on the
exterior surface of the portable housing 902 can be configured such
that actuation of such switches and/or buttons (where actuation can
be depressing, triggering, toggling, or otherwise operating the
switch or button) causes the control electronics and/or
transmission circuitry of the patient remote 900 to relay a signal
to a neurostimulation system and/or to execute a function of the
patient remote 900 itself. In some aspects, the battery that powers
the patient remote 900 can be a permanent battery having an
operational life of three or more years. In alternative aspects,
the battery that powers the patient remote 900 can be a replaceable
or a rechargeable battery.
[0088] In some embodiments, the activation switch 904
(alternatively referred to as a "link switch") can be disposed on
the control surface 903, and in particular embodiments the
activation switch 904 can be disposed in a recessed region of the
control surface 903. In embodiments where the activation switch 904
is disposed in a recess of the control surface 903, activation
switch 904 is designed to be actuation due to deliberate effort. In
other words, where the structure of the activation switch 904 is
disposed within the recess, accidental or inadvertent actuation of
the activation switch 904 due to incidental physical contact with
the exterior surface of the portable housing 902 or contact with
other sections of the control surface 903 can be avoided by
providing sufficient physical resistance to a throw of the switch.
More succinctly, in various embodiments, the activation switch 904
is recessed so as to avoid accidental depression by the user when
the patient remote 900 is stored in a pocket or purse of the
patient. In these embodiments, the recess can have a sufficient
depth relative to the size of the activation switch 904 such that
the height of the activation switch 904 is shorter than the depth
of the recess, and thus the activation switch 904 does not extend
out of the recess.
[0089] The activation switch 904 operates to switch the patient
remote 900 between an asleep mode and an awake mode. When the
patient remote 900 is in an asleep mode, actuation of the
activation switch 904 causes the patient remote to switch to the
awake mode and to interrogate the neurostimulator to wirelessly
retrieve data regarding the status of the neurostimulation system
and/or pulse generator. The data retrieved from the
neurostimulation system can include the current stimulation level
of the pulse generator, which can be stored in a processor and/or
memory of the pulse generator. When the patient remote 900 is in
the awake mode, actuation of the activation switch 904 causes the
patient remote 900 to switch to the asleep mode. When the patient
remote 900 is in the asleep mode, the stimulation-increase switch
906 and the stimulation-decrease switch 908 (both also disposed on
the control surface 903) are inactivated, such that actuation of
either the stimulation-increase switch 906 or the
stimulation-decrease switch 908 does not cause the patient remote
900 to send any signal with transmission circuitry within the
portable housing 902. When the patient remote 900 is in the awake
mode, the stimulation-increase switch 906 and the
stimulation-decrease switch 908 are active, such that actuation of
either the stimulation-increase switch 906 or the
stimulation-decrease switch 908 causes the patient remote 900 to
send a corresponding instruction signal with transmission circuitry
within the portable housing 902. When in the awake mode, if the
patient remote 900 is inactive for a set period of time (e.g. none
of the activation switch 904, stimulation-increase switch 906, or
stimulation-decrease switch 908 are actuated for the set period of
time), the patient remote can automatically switch to the asleep
mode. In some aspects, the set period of time after which the
patient remote 900 will automatically switch to the asleep mode can
be five (5) to sixty (60) seconds, or any increment or gradient of
time within that range. In specific aspects, the set period of time
after which the patient remote 900 will automatically switch to the
asleep mode can be ten (10) seconds.
[0090] The control surface 903 can include a stimulation-increase
switch 906 coupled to control electronics and transmission
circuitry disposed within the portable housing 902. Actuation of
the stimulation-increase switch 906 can relay an instruction signal
to the pulse generator (i.e., through the control electronics and
transmission circuitry of the patient remote 900), where the
instruction signal can be selected based on duration of time that
the stimulation-increase switch 906 is actuated. When the
stimulation-increase switch 906 is actuated for a first period of
time, the patient remote 902 can send an instruction signal to the
pulse generator to incrementally increase the stimulation level of
the pulse generator. The first period of time will generally be a
period of time that is shorter than a threshold. The threshold may
generally be between 0.25 and 5 seconds, with the time period for a
longer switch actuation threshold time being sufficient to assure
that the longer duration switch actuation is clearly intentional,
typically being three seconds or more. Increasing the stimulation
level of the pulse generator can be limited to a maximum selectable
level of therapy. When the stimulation-increase switch 906 is
actuated for a second, longer period of time, the patient remote
902 can send an instruction signal to the pulse generator to
restore the stimulation level of the pulse generator to a
previously stored stimulation level. The second period of time can
be three seconds or more. In some aspects, when the pulse generator
is instructed to restore the previously stored stimulation level,
the pulse generator can gradually ramp up (as shown in FIG. 8) to
help reduce any sudden "jolting" or "shocking" sensation that some
patients might experience when the stimulation is turned on.
[0091] In situations where a patient has turned off the pulse
generator, providing a method to automatically return the
stimulation of the pulse generator to a previously stored
stimulation level allows a patient to efficiently and automatically
restore the neurostimulation system to a desired function or
status, avoiding the need for repetitive adjustment of the
stimulation level. In many embodiments, the previously stored
stimulation level can be the last stimulation level the pulse
generator was set to before turning off the neurostimulation
system. In some aspects, the data indicating the last stimulation
level can be stored in a memory of the pulse generator which is
retrieved by the patent remote 900 when the patient remote 900
switches from the asleep mode to the awake mode. In other aspects,
the stimulation level can be stored in a memory of the circuitry
within the patient remote 900 portable housing 902.
[0092] The stimulation-increase switch 906 can further have a
visible and/or tactile surface or feature shaped to indicate to an
operator that the stimulation-increase switch 906 is configured to
increase or restore the stimulation level of the pulse generator
(e.g., as an upward arrow, as a plus sign, etc.). In some aspects,
the stimulation-increase switch 906 can be relatively larger than
any stimulation-decrease switch 908 also disposed on the exterior
of the portable housing 902.
[0093] The control surface 903 can also include a
stimulation-decrease switch 908 coupled to control electronics and
transmission circuitry disposed within the portable housing 902.
Actuation of the stimulation-decrease switch 908 can relay an
instruction signal to the pulse generator, where the instruction
signal can be selected based on duration of time that the
stimulation-decrease switch 908 is actuated. When the
stimulation-decrease switch 908 is actuated for the first period of
time, the patient remote 902 can send a signal to the pulse
generator incrementally decrease the stimulation level of the pulse
generator, with the time period for a longer switch actuation
threshold time being sufficient to assure that the longer duration
switch actuation is clearly intentional, typically being three
seconds or more. If the stimulation level of the pulse generator is
at the minimum selectable level of therapy, actuation of the
stimulation-decrease switch 908 for the first period of time can
turn off stimulation by the pulse generator. When the
stimulation-decrease switch 908 is actuated for a second period of
time, the patient remote 902 can send a signal to the pulse
generator to store the status of the current stimulation level in a
memory and turn off stimulation by the pulse generator. The second
period of time can be three seconds or more. In some aspects, when
the pulse generator is instructed to turn off stimulation, the
pulse generator can gradually ramp down (as shown in FIG. 8) to a
zero stimulation status.
[0094] The stimulation-decrease switch 908 can further have a
visible and/or tactile surface or feature shaped to indicate to an
operator that the stimulation-decrease switch 908 is configured to
decrease the stimulation level of the pulse generator or turn off
stimulation by the pulse generator (e.g., as a downward arrow, as a
minus sign, etc.). In some aspects, the memory in which the
stimulation level is stored in the patient remote, or alternately
the memory may be stored in the pulse generator. In alternative
aspects, the stimulation-increase switch 906 and the
stimulation-decrease switch 908 can be relatively equal in
size.
[0095] The incremental increase or decrease of pulse generator
stimulation level by the patient remote 900 can be proportional to
an existing or current stimulation level. In many aspects, the
incremental increase or decrease of pulse generator stimulation
level can be a change of a predetermined degree. The predetermined
degree can be a percentage of a stimulation level, a fraction of a
stimulation level, a specific or static increment of stimulation
level, a proportional increment of stimulation level, a
range-dependent increment of stimulation level, a variable
increment of stimulation level, or the like. In some embodiments,
each incremental change can be five percent (5%), more than five
percent (5%), or ten percent (10%) of the existing stimulation
level, a maximum stimulation level, or a baseline stimulation
level. For example, if a pulse generator is delivering treatment at
a stimulation level of 2.0 mA, a single step up increasing the
stimulation level can be 0.2 mA (10% of 2.0 mA), thereby increasing
stimulation to 2.2 mA. A subsequent step up increasing the
stimulation level can be 0.22 mA (10% of 2.2 mA), thereby
increasing stimulation to 2.42 mA. Similarly, if a pulse generator
is delivering treatment at a stimulation level of 4.0 mA, a single
step down decreasing the stimulation level can be 0.4 mA (10% of
4.0 mA), thereby decreasing stimulation to 3.6 mA. In various
embodiments, the step size by which the pulse generator stimulation
level is changed can be 1% to 25% of the existing stimulation
level, or any increment or gradient of a percentage within that
range. The number of available treatment levels may be between 3
and 15, typically being between 4 and 10, and often being between 5
and 8.
[0096] In some alternative embodiments, for example, if a pulse
generator is delivering treatment at a baseline or nominal
stimulation level of 3.0 mA, a single step up increasing the
stimulation level can be ten percent of the baseline stimulation,
0.3 mA (10% of 3.0 mA), thereby increasing stimulation to 3.3 mA. A
subsequent step up increasing the stimulation level can also be
based on the baseline stimulation level, that step again being 0.3
mA, thereby increasing stimulation to 3.6 mA. Further within this
exemplary embodiment, a single step down decreasing stimulation
from a baseline level of 3.0 mA can lower the current stimulation
level to 2.7 mA, and a subsequent step down can decrease the
current stimulation level to 2.4 mA.
[0097] In further alternative embodiments, each step of stimulation
level can be based on a percentage of a maximum stimulation level.
For example, if a pulse generator has a maximum treatment
stimulation level of 4.0 mA, each step of stimulation level change
can be ten percent of the maximum stimulation level, 0.4 mA (10% of
4.0 mA). Thus, relative to the maximum stimulation level, a single
step down decreasing the stimulation level can be at 3.6 mA, a
subsequent step down decreasing the stimulation level can be at 3.2
mA, and so forth.
[0098] In other alternative embodiments, the patient remote 900 can
operate having an automated proportional stimulation step level
increments. For example, when the available stimulation range is
within a lower amplitude range, the incremental steps can be
smaller than those associated with a higher amplitude range. For
example, under conditions where the amplitude range of stimulation
level for the patient remote 900 is less than 1.0 milliamp (<1.0
mA), the default increment for a step of simulation level can be
0.05 mA. However, under conditions where the amplitude range of
stimulation level for the patient remote 900 is from 1.0 to 3.0
milliamps (1.0-3.0 mA), the default increment for a step of
simulation level can be 0.10 mA. Further, under conditions where
the amplitude range of stimulation level for the patient remote 900
is greater than 3.0 milliamps (>3.0 mA), the default increment
for a step of simulation level can be 0.20 mA. The proportional
change in stimulation level step can be varied depending on the
amount of treatment required, the number of amplitude ranges, the
breadth of amplitude ranges, and/or according to other factors
controlling the operation of the patient remote 900. The above
described incremental steps can also be applied when determining
electrode thresholds during electrode characterization and/or
programming.
[0099] In some embodiments, the patient remote 900 can be set to
incrementally adjust stimulation by a step-size defined by a
relationship between a maximum stimulation level (I.sub.max) and a
baseline, also referred to as a nominal or normal stimulation level
(I.sub.n). For example, the I.sub.max and the I.sub.n can be
determined and set-up by a physician programming the patient remote
900 via the clinician programmer. The amplitude of I.sub.max can be
set according to the comfort level of a patient (e.g. stimulation
level just below where any pain or discomfort is reported by the
patient). Where a difference between I.sub.max and I.sub.n is
.DELTA.I, the increment step size can be a set proportion or
percentage of .DELTA.I, for example steps sizes of 1/2.DELTA.I,
1/3.DELTA.I, or 1/4.DELTA.I. In some embodiments, the CP
automatically sets such an incremental step size (e.g. 1/3.DELTA.I)
with the IPG or EPG, for example during electrode characterization
and/or programming. Likewise, patient remote 900 can be programmed
with a step-size that corresponds to the step-size used by the CP
in programming the IPG or EPG. The amount by which the stimulation
levels can be adjusted below the nominal stimulation level (e.g.
lower range) can be defined to mirror the incremental range between
I.sub.max and I.sub.n (e.g. upper range). For example, where the
increment step size is defined as 1/3 .DELTA.I, the range over
which the stimulation level can be incrementally adjusted by the
patient remote includes seven stimulation levels, where the nominal
or normal stimulation level I.sub.n is in the middle of those seven
stimulation levels, incrementing up or down at 1/3 .DELTA.I per
step allows for a range of stimulation levels that reaches the
maximum stimulation level I.sub.max on one end of the available
treatment range, and a minimum stimulation level that mirrors
I.sub.max on the other end of the available treatment range, as
shown below:
TABLE-US-00002 -.DELTA.I -2/3.DELTA.I -1/3.DELTA.I I.sub.n
+1/3.DELTA.I +2/3.DELTA.I +.DELTA.I (where +.DELTA.I above I.sub.n
is I.sub.max and -.DELTA.I is I.sub.min).
[0100] By programming the patient remote 900 to increment
stimulation of a coupled pulse generator by a predetermined degree
such as 1/3 .DELTA.I, a full range of stimulation levels can be
achieved relative to a relationship between I.sub.max that matches
the comfort level of a patient and the nominal stimulation level
corresponding to optimized clinically effective therapy. It is
understood that the selection of a stimulation level increment step
size by programming the patient remote can allow for setting of a
stimulation level increment step to be a specific percentage of a
maximum stimulation level, or proportional to a range between the
maximum stimulation level and the nominal stimulation level. In
some embodiments, the pulse generator is configured to adjust
stimulation incrementally according to a step-size, such as
described in any of the embodiments described herein, in response
to an increase or decrease command received from the patient
remote. In one aspect, the command can include the step-size by
which the stimulation level is adjusted or the command can invoke
an incremental adjustment based on a step-size increment stored on
a memory of the pulse generator.
[0101] In various embodiments, the patient remote 900 can increase
and/or decrease the stimulation level by a predetermined
percentage. In some embodiments, the predetermined percentage is a
set percentage within a range between 5% and 20%, such as about 10%
(+/-2%). In some embodiments, the predetermined percentage is the
same for incremental increases and decreases, while in other
embodiments, the increase increment differs from that of the
decrease increment.
[0102] The control surface 903 can include a stimulation-level
display 910 embedded in the portable housing 902, and
electronically coupled to control electronics and transmission
circuitry disposed within the portable housing 902 such that the
stimulation-level display 910 can indicate the stimulation level
being delivered by the pulse generator to a patient. In some
embodiments, the stimulation-level display 910 can include a
plurality of lights or light emitting diodes (LEDs) arranged on the
control surface, where an illuminated subset of the total number of
the plurality of lights or LEDs can indicate the current
stimulation level of the pulse generator. In some aspects, the
stimulation-level display 910 can include seven (7) white-light
LEDs. The stimulation-level display 910 can have the plurality of
LEDs arranged in a pattern to reflect increases and decreases to
the stimulation level of the pulse generator. In arrangements of
the stimulation-level display 910 with seven LEDs as illustrated in
FIG. 9, a first LED 910-1 can indicate that the pulse generator is
set to deliver a stimulation level at the minimum power selectable
via the patient remote 900. In such arrangements of the
stimulation-level display 910 with seven LEDs, a second LED 910-2,
a third LED 910-3, a fourth LED 910-4, a fifth LED 910-5, and a
sixth LED 910-6, can indicate (as read from left to right,
optionally with all of the lower-level LEDs remaining illuminated
as stimulation level increases) progressively increasing power of
stimulation levels selectable via the patient remote 900 that the
pulse generator is set to deliver. Also in such arrangements,
illumination of a seventh LED 910-7 can indicate (optionally with
all other stimulation-level LEDs also being illuminated) that the
pulse generator is set to deliver a stimulation level at the
maximum power selectable via the patient remote 900. In other
aspects the stimulation-level display 910 can include green-light,
amber-light, or other colored-light LEDs, which can also provide a
relative qualitative indication of the power of each stimulation
level of the pulse generator. The LEDs used for the
stimulation-level display 910 can be of at least three (3) or four
(4) varying sizes to provide a relative qualitative indication of
the power of each stimulation level of the pulse generator. In
other words, relatively smaller LEDs can be used for the
stimulation levels closer or trending toward the minimum power
selectable via the patient remote 900 and relatively larger LEDs
can be used for the stimulation levels closer or trending toward
the maximum power selectable via the patient remote 900.
[0103] As noted above, a patient remote 900 can be configured to be
used with any appropriate respective pulse generator, such that the
patient remote 900 can link with and wirelessly communicate with
only a single EPG or IPG, so as to avoid inadvertent and
unintentional activation, alteration, or triggering of stimulation
of other pulse generators. Accordingly, in implementations of the
system, a specific patient remote 900 can be paired with a specific
pulse generator (e.g., an IPG, an EPG, or the like) such that the
patient remote 900 will only, or at least primarily, operate to
interact with the paired pulse generator. The pairing of a patient
remote 900 and a specific pulse generator can be established by
setting the patient remote 900 and the specific pulse generator to
transmit and receive data at the same predetermined wireless or
radio frequency. While the clinician programmer can be used to set
up or configure a patient remote 900, or establish the paring
between a patient remote 900 and a pulse generator, in operation
for managing stimulation levels, the patient remote 900 only and/or
directly communicates with the pulse generator.
[0104] FIGS. 9-1 to 9-7 are schematic illustrations of a patient
remote showing an increasing progression of stimulation levels by
the stimulation-level display 910 LEDs. As noted above, when a
patient remote 900 is turned on by actuation of the activation
switch 904, the patient remote can wirelessly interrogate and
retrieve the current stimulation level of a pulse generator from
the neurostimulation system. The patient remote 900 can indicate to
a patient that the patient remote 900 is transitioning from the
asleep mode to the awake mode by cycling illumination of the
stimulation-level display 910 LEDs. Once the current stimulation
level of the pulse generator is retrieved by the patient remote,
the stimulation-level display 910 can illuminate a corresponding
number of LEDs to indicate to a patient the current stimulation
level of the pulse generator. At any given stimulation level, the
LED indicating that stimulation level can be illuminated along with
all of the LEDs representative of lower stimulation levels. In
other aspects, at any given stimulation level, the patient remote
900 can illuminate only the LED indicating that specific
stimulation level.
[0105] The available stimulation levels of the pulse generator can
be programmed relative to a baseline stimulation level, and the
patient remote 900 can be configured provide a limited range of
selectable stimulation levels either greater than and/or less than
the baseline stimulation level, and ideally both. The baseline
stimulation level can be selected to correspond to illuminate any
one of a plurality of LEDs for the stimulation-level display 910,
which can further indicate the number of selectable stimulation
levels greater than and less than the baseline stimulation level.
In some embodiments, the pulse generator can be programmed to have
three selectable stimulation levels greater than the baseline
stimulation level and three selectable stimulation levels less than
the baseline stimulation level. In such embodiments, when the pulse
generator is set to the baseline stimulation level, the fourth LED
910-4 on the patient remote 900 is illuminated (optionally along
with first, second, and third LEDs). In other embodiments, the
pulse generator can be programmed to have four selectable
stimulation levels greater than the baseline stimulation level and
two selectable stimulation levels less than the baseline
stimulation level. In such embodiments, when the pulse generator is
set to the baseline stimulation level, the third LED 910-3 of the
patient remote 900 is illuminated (optionally along with first and
second LEDs). In alternative aspects, the pulse generator can be
programmed such that at the baseline stimulation level, one of the
second LED 910-2, the fifth LED 910-5, or the sixth LED 910-6 on
the patient remote 900 is illuminated, with corresponding
selectable stimulation levels greater than and less than the
baseline stimulation level.
[0106] Moreover, the baseline stimulation level can be selected to
ensure that any adjustment to the therapy via the patient remote
remains within a clinically effective range whenever stimulation is
applied. In some aspects the clinically effective range of
stimulation by the pulse generator can be from about 0.5 mA to
about 4 mA. In other aspects, the clinically effective range of
stimulation by the pulse generator can be from about 1 mA to about
3 mA. In alternative aspects, the ideal clinically effective range
of stimulation by the pulse generator can be from about 0.3 mA to
about 2.5 mA, while further for such aspects, stimulation by the
pulse generator that is less than 0.3 mA and between from about 2.5
mA to about 4 mA can also be clinically effective at providing
treatment. In some embodiments, stimulation is limited to below 4
mA. It is appreciated that the above ranges can be utilized in
characterizing and/or programming the neurostimulation device as
well. For example, electrodes with stimulation thresholds that
provide a desired parameter (e.g. sensory or motor response) an can
be categorized as to their suitability for delivering
neurostimulation based on which range the threshold lies. For
example, in some embodiments, electrodes with a threshold between
0.3-2.5 mA can be considered preferred electrodes for use in
neurostimulation therapy delivery, electrodes with thresholds less
than 0.3 mA and between 2.5-4 mA can be considered acceptable, and
electrodes with thresholds greater than 4 mA can be considered
unacceptable for delivering neurostimulation. It is understood that
these ranges are an example that is applicable to certain
embodiments and certain therapies (e.g. sacral neuromodulation for
treatment of OAB and fecal incontinence) and that various other
ranges can apply to various other neurostimulation systems and/or
therapies.
[0107] Accordingly, the baseline stimulation level can be selected
to have (1) a pulse amplitude or power within the clinically
effective range and (2) a proportional incremental change for
increasing or decreasing stimulation relative to the baseline
stimulation level such that, at either the maximum or minimum
stimulation level selectable via the patient remote, the therapy
delivered by the pulse generator remains within the clinically
effective range. In further embodiments, the clinically effective
range of the pulse generator can include pulses having a pulse
amplitude in a range between 0 mA to 1,000 mA, 0 mA to 100 mA, 0 mA
to 50 mA, or 0 mA to 25 mA.
[0108] In an exemplary embodiment, the pulse generator can be
programmed to have a baseline stimulation of 2.0 mA with three
selectable stimulation levels greater than the baseline stimulation
level and three selectable stimulation levels less than the
baseline stimulation level, where each step of adjustment can be
ten percent (10%) of the existing or current stimulation level. In
such an embodiment, the baseline stimulation level of 2.0 mA is
represented in the stimulation-level display 910 by the fourth LED
910-4 being illuminated, the minimum stimulation level selectable
by the patient remote 900 is 1.458 mA (represented by the first LED
910-1 being illuminated), and the maximum stimulation level
selectable by the patient remote 900 is 2.662 mA (represented by
the seventh LED 910-7 being illuminated).
[0109] In an alternative exemplary embodiment, the pulse generator
can be programmed to have a baseline stimulation of 2.0 mA with
four selectable stimulation levels greater than the baseline
stimulation level and two selectable stimulation levels less than
the baseline stimulation level, where each step of adjustment can
be ten percent (10%) of the existing or current stimulation level.
In such an embodiment, the baseline stimulation level of 2.0 mA is
represented in the stimulation-level display 910 by the third LED
910-3 being illuminated, the minimum stimulation level selectable
by the patient remote 900 is 1.62 mA (represented by the first LED
910-1 being illuminated), and the maximum stimulation level
selectable by the patient remote 900 is 2.9282 mA (represented by
the seventh LED 910-7 being illuminated).
[0110] Table 2 set forth below summarizes the functionality
resulting from actuation of each of the activation switch 904, the
stimulation-increase switch 906, and the stimulation-decrease
switch 908, which in some embodiments are in part dependent on the
status mode (i.e., awake or asleep) of the patient remote 900. As
noted above, when the patient remote 900 is in the asleep mode,
both of the stimulation-increase switch 906 and the
stimulation-decrease switch 908 are inactive.
TABLE-US-00003 TABLE 2 Patient Remote Control Elements and
Functionality Control Element Patient Remote Mode Action Function
Activation Asleep Short actuation Place Patient Remote in Awake
Switch Mode; Communicate with Neurostimulation System; Display
Current Stimulation Settings of Neurostimulation System. Awake
Short actuation Place Patient Remote in Asleep Mode. Stimulation-
Awake Short actuation Increase Stimulation Level UP by Increase One
Level; If Neurostimulation Switch System was OFF, Turn
Neurostimulation System ON at Stimulation Level 1. Long actuation
Turn Neurostimulation System ON and Ramp UP to Stored Previous
Stimulation Level . Stimulation- Awake Short actuation Decrease
Stimulation Level DOWN Decrease by One Level; If Stimulation Level
Switch is Decreased Below Stimulation Level 1, Turn
Neurostimulation System OFF. Long actuation Turn Neurostimulation
System OFF and Store Previous Stimulation Level.
[0111] FIGS. 9-8 and 9-9 are schematic illustrations of a patient
remote 900 with a therapy-remaining display 912 showing levels of
therapy remaining for a neurostimulation system. The
therapy-remaining display 912 can be an LED indicator capable of
emitting one or more colors of light. In FIG. 9-8, the
therapy-remaining display 912 is shown emitting a green light 913g
(as represented by the solid-line wavefront illustration). In FIG.
9-9, the therapy-remaining display 912 is shown emitting an amber
light 913a (as represented by the broken-line wavefront
illustration). In some embodiments, the therapy-remaining display
912 can disposed on the exterior surface of the portable housing
902, such as on the control surface 903. Further, the
therapy-remaining display 912 can illuminate with a constant
(non-flashing) emission of light, or can illuminate in a flashing
or intermittent mode. In implementations of the patient remote 900
where the therapy-remaining display 912 is a bi-color LED, the
color of light emitted by the therapy-remaining display 912 and
whether the light is emitted as constant or flashing can provide an
observer with a qualitative indication of how much therapy and/or
battery life is remaining in a neurostimulation system pulse
generator.
[0112] In an exemplary implementation, the therapy-remaining
display 912 can emit a green light 913g when the pulse generator
rechargeable battery has at least thirty percent (>30%) of its
charge capacity remaining, which can corresponds to at least four
(>4) days of nominal stimulation remaining in the
neurostimulation system. Further in this implementation, the
therapy-remaining display 912 can emit a constant amber light 913a
when the pulse generator battery has more than fifteen percent
(>15%) but less than thirty percent (<30%) of its charge
capacity remaining, which can corresponds to about two to four
(2-4) days of nominal stimulation remaining in the neurostimulation
system. The therapy-remaining display 912 emitting a constant amber
light 913a can be an indication to the patient that the pulse
generator battery is relatively low on charge and requires
recharging within the subsequent 2-4 days. Further in this
implementation, the therapy-remaining display 912 can emit a
flashing amber light 913a when the pulse generator battery has less
than fifteen percent (<15%) its charge capacity remaining. The
therapy-remaining display 912 emitting flashing amber light 913a
can be an indication to the patient that the pulse generator
battery is critically low on charge, requires immediate recharging,
and that the neurostimulation system may automatically turn off.
The therapy-remaining display 912 can further indicate that the
pulse generator battery is recharging, where in some aspects the
therapy-remaining display 912 can emit a flashing green light 913g
as the pulse generator battery recharges.
[0113] The amount of charge capacity will vary from battery to
battery for any pulse generator or neurostimulation system. In some
embodiments, the rechargeable battery can have a charge capacity
such that 30% of the charge capacity is about 3.55 Volts and 15% of
the charge capacity is about 3.45 Volts, where the
therapy-remaining display 912 can emit a constant or flashing green
light 913g or a constant or flashing amber light 913a as
appropriate relative to such voltages.
[0114] The amount of therapy remaining for a neurostimulation
system and pulse generator is dependent at least on the duration of
usage of the neurostimulation system and the level of stimulation
the neurostimulation system is instructed to deliver. Accordingly,
a processor coupled to the pulse generator can calculate the amount
of therapy remaining in a pulse generator based on factors
including, but not limited to, the overall capacity of the pulse
generator rechargeable battery, the amount of time elapsed since
the pulse generator rechargeable battery was last recharged, the
average stimulation level at which the pulse generator is operated,
the median stimulation level at which the pulse generator is
operated, the current voltage of the battery, and the like. In some
aspects, the therapy remaining and/or charge capacity of the pulse
generator rechargeable battery can be calculated according to one
or more of stimulation amplitude, stimulation frequency,
stimulation pulse width, stimulation cycling mode (e.g. duty
cycle), and impedance. Based on this calculation, when the patient
remote 900 interrogates the neurostimulator and retrieves the
status of the pulse generator, the therapy-remaining display 912
can illuminate to provide feedback to the patient indicative of the
current amount of therapy remaining in the pulse generator.
[0115] The visual indicators of the patient remote 900 can be
augmented with a haptic or vibratory feedback that punctuates
adjustments to stimulation level, where a vibrating element (e.g.,
a motor, a piezoelectric, etc.) is disposed within the interior of
the portable housing 902. The vibrating element can be configured
to activate when the pulse generator confirms that an instruction
from the patient remote 900 has been received and executed. Such
commands from the patient remote can include, but are not limited
to, turning on the pulse generator, turning off the pulse generator
increasing the stimulation level of the pulse generator, or
decreasing the stimulation level of the pulse generator. The
vibration element can also be configured to activate for situations
including, but not limited to, the patient remote 900 switching
from the asleep mode to the awake mode or providing a warning that
the rechargeable pulse generator battery has a low charge.
[0116] Table 3 set forth below summarizes the feedback indicators
provided in embodiments of the patient remote 900, such as the
stimulation-level display 910, the therapy-remaining display 912,
and the vibration element, and interpretations of the feedback from
the indicators.
TABLE-US-00004 TABLE 3 Patient Remote Indicators and Feedback
Patient Remote Indicators Structure Status Feedback Stimulation- 7
LED array Remote The LED array displays a "scanning" Level Display
transition from sequence. asleep mode to awake mode. Remote in
awake A number of LEDs are Illuminated mode. Corresponding to the
Current Stimulation Level. Therapy- Bi-Color LED Remote in awake
Therapy-Remaining Display Remaining mode. Indicates
Neurostimulation System Display Battery Status (e.g., good charge,
low charge, very low charge, charging) Haptic Vibration Motor
Remote in awake Vibration when the Neurostimulation mode. System
Confirms that a Command from the Patient Remote has been Received
and Executed.
[0117] The patient remote 900 can further include a fault condition
indicator 914, which can illuminate when either or both of the
patient remote and the pulse generator are in a fault condition.
The fault condition indicator 914 can be an LED, such as a
white-light, red-light, or other colored-light LED which can emit a
constant or flashing light when either or both of the patient
remote and the pulse generator are in a fault condition. Problems
with the neurostimulation system that can cause the fault condition
indicator 914 to illuminate include, but are not limited to,
failure of the pulse generator to respond to commands from the
patient remote 900, a low charge for the battery operating the
patient remote 900, where fault conditions are of the type common
to active implantable devices, which for example may be one or more
of low patient remote battery, patient remote software or hardware
fault, pulse generator hardware or software fault, and impedance
out of range.
[0118] In order to make the patient remote 900 a convenient fob
device for a patient to carry and used, the portable housing 902
can have a mechanical coupling structure 916 to attach the patient
remote 900 with a key ring, karabiner, or other such mounting
element. In various aspects, the mechanical coupling structure 916
can be embedded in the structure of the portable housing 902 or
looped around a portion of the portable housing 902.
[0119] FIG. 10 is a functional block diagram of components of a
patient remote 1000. In the embodiment as illustrated, the patient
remote 1000 encloses a battery 1002, control electronics 1004,
transmission circuitry 1006, and a bus structure 1008 to allow for
communication and transmission of power between the components of
the patient remote 1000. The patient remote also optionally
includes a memory 1010 for storing of data, such as the stimulation
status of a linked neurostimulation system. The control electronics
1004 also includes locations where the control electronics 1004 can
couple with an activation switch 1012, a stimulation-increase
switch 1014, and a stimulation-decrease switch 1016. The bus 1008
can further communicate with a stimulation level display 1018, a
therapy-remaining-display 1020, a vibration motor 1022, and a fault
condition indicator 1024.
[0120] The optional memory 1010 of the patient remote 1000 can
store a previous or last stimulation level at which a pulse
generator (e.g., an IPG or EPG) paired to the patient remote 1000
was operating. In implementations of the patient remote without an
optional memory 1010, the previous or last stimulation level at
which a pulse generator paired to the patient remote 1000 was
operating can be stored within data memory of the pulse generator,
respectively. The status or condition of the pulse generator can be
transmitted to the transmission circuitry 1006 of the patient
remote 1000 upon interrogation of the pulse generator when the
patient remote 1000 is triggered into an awake mode. The status or
condition of the pulse generator, particularly the information of
the previous or last stimulation level, can be conveyed to the
control electronic 1004 of the patient remote to allow for control
of the pulse generator via the patient remote based upon the
relevant stimulation level of the pulse generator. In many
implementations, the transmission of data between a pulse generator
and the patient remote can be wireless, and can further be set at a
predetermined radio frequency (RF) for a paired set of a patient
remote and pulse generator.
[0121] In the foregoing specification, the invention is described
with reference to specific embodiments thereof, but those skilled
in the art will recognize that the invention is not limited
thereto. Various features and aspects of the above-described
invention can be used individually or jointly. Further, the
invention can be utilized in any number of environments and
applications beyond those described herein without departing from
the broader spirit and scope of the specification. The
specification and drawings are, accordingly, to be regarded as
illustrative rather than restrictive. It will be recognized that
the terms "comprising," "including," and "having," as used herein,
are specifically intended to be read as open-ended terms of
art.
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