SYSTEMS AND METHODS FOR AUTOMATICALLY AND/OR INCREMENTALLY ADJUSTING ONE OR MORE SIGNAL DELIVERY PARAMETERS FOR SACRAL NEUROMODULATION
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present application claims priority to U.S. Provisional Patent Application No. 63/612,695, filed December 20, 2023, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present technology is directed toward electrically modulating nervous tissue to treat a patient condition.
BACKGROUND
[0003] Inflammatory Bowel Disease (IBD) is a digestive disorder characterized by chronic inflammation of the gastrointestinal tract. IBD includes both Crohn's disease, which causes intermittent inflammation of the gastrointestinal tract, and ulcerative colitis, which causes continuous inflammation of the colon. Both Crohn's disease and ulcerative colitis cause similar patient symptoms, including patient discomfort (e.g., abdominal pain), abnormal gastrointestinal tract function (e.g., diarrhea), and other complications (e.g., fever, weight loss, etc.). IBD is typically treated using pharmaceutical therapies including anti-inflammatory drugs and immune system suppressors. In extreme cases, patients may even undergo surgery to remove inflamed or damaged portions of the colon or other portions of the digestive tract. However, neither pharmaceuticals nor surgery cure IBD, and symptoms often persist or recur during or after treatment. Moreover, in certain patients, pharmaceuticals and surgery have minimal efficacy and/or induce unwanted side effects. Accordingly, a need exists for improved treatments for IBD.
[0004] Neurological stimulation systems generally have a signal generator that generates electrical pulses, and one or more signal delivery devices such as leads that deliver the electrical pulses to neurological tissue or muscle tissue. The delivered electrical pulses modulate neural activity to treat an underlying patient condition. For example, neurostimulation has been used to treat various disorders such as pain, movement disorders, cardiac disorders, and various other medical conditions. Sacral neuromodulation (SNM) is a type of neuromodulation in which electrical stimulation is applied to one or more sacral nerves to treat a patient condition. SNM has been used to treat various urological disorders, including urinary retention, urinatory incontinence, and fecal incontinence.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figure 1 is a partially schematic illustration of an implantable sacral neuromodulation system positioned at a patient's sacral region to deliver electrical signals in accordance with some embodiments of the present technology.
[0006] Figure 1 B illustrates sacral nerve anatomy of a patient, along with a portion of a signal delivery device of the system of Figure 1A shown as implanted at a representative location in accordance with some embodiments of the present technology.
[0007] Figure 2A is a partially schematic illustration of an electrical signal generated in accordance with some embodiments of the present technology.
[0008] Figure 2B is a partially schematic illustration of another electrical signal generated in accordance with some embodiments of the present technology.
[0009] Figure 3 is a flowchart of a method of treating a patient using sacral nerve stimulation in accordance with embodiments of the present technology.
[0010] Figure 4 is a flowchart of another method of treating a patient using sacral nerve stimulation in accordance with embodiments of the present technology.
[0011] Figure 5 is a flowchart of a method for determining one or more signal delivery parameters of a sacral nerve stimulation electrical signal in accordance with embodiments of the present technology.
[0012] Figure 6 is a flowchart of a method of monitoring a patient receiving sacral nerve stimulation in accordance with embodiments of the present technology. DETAILED DESCRIPTION
A. Introduction
[0013] The present technology is directed to treating Inflammatory Bowel Disease (IBD) and other similar conditions using neuromodulation. For example, many of the embodiments described herein include electrically stimulating one or more sacral nerves of a patient to treat the patient's IBD. As described in detail throughout this Detailed Description, the electrical signal can be delivered via an implanted signal delivery device positioned proximate one or more of the patient's sacral nerves. In some embodiments, the present technology includes automatically and/or incrementally adjusting an amplitude or other signal delivery parameter of the electrical signal. This can be done according to a predefined schedule, in response to detecting changes in electrical impedance, in response to patient input, or in response to other events or inputs. Without intending to be bound by theory, automatically and/or incrementally adjusting an amplitude or other signal delivery parameter may offset potential reductions in efficacy that a patient may experience over time.
[0014] Unless otherwise stated, the terms "generally," "about," and "approximately" refer to values within 10% of a stated value. For example, the use of the term "about 100" refers to a range of 90 to 110, inclusive. In instances in which relative terminology is used in reference to something that does not include a numerical value, the terms are given their ordinary meaning to one skilled in the art.
[0015] As used herein, and unless otherwise noted, the terms "modulate," "modulation," "stimulate," and "stimulation" refer generally to electrical signals that have an inhibitory, excitatory, and/or other effect on a target neural population. Accordingly, a sacral nerve "stimulator" can have an inhibitory effect and/or an excitatory effect on certain neural populations.
[0016] As used herein, the terms "electrical therapy signal," "electrical signal," "therapy signal," "signal," and other associated terms are used interchangeably and generally refer to an electrical signal that can be characterized by one or more parameters, such as frequency, pulse width, and/or amplitude.
[0017] As used herein, the term "amplitude" includes both voltage-controlled amplitude ("voltage amplitude") and current-controlled amplitude ("current amplitude"), unless the context clearly dictates otherwise. Thus, the systems and methods described herein can include automatically and/or incrementally adjusting a current amplitude of an electrical signal and/or automatically and/or incrementally adjusting a voltage amplitude of an electrical signal, depending on the device. In voltage amplitude, a device controls voltage but the current may vary. In current amplitude, a device controls current but the voltage may vary.
[0018] As used herein, "proximate a target neural population" refers to the placement of a signal delivery element such that it can deliver electrical stimulation to the target neural population. For example, if the target population includes the third sacral spinal nerve, "proximate the target neural population" includes, but is not limited to, the relative lead positions described and shown in Figure 1 B, as well as other positions not expressly described herein.
[0019] Specific details of certain embodiments of the disclosure are described below with reference to methods for modulating one or more target neural populations (e.g., nerves) or sites of a patient, and associated implantable structures for providing the modulation. Although selected embodiments are described below with reference to modulating the sacral nerves, the modulation may in some instances be directed to other neurological structures and/or target neural populations and/or other neurological tissues throughout the body. For example, some embodiments may include modulating the vagus nerve, the splenic nerve, the splanchnic nerve, and/or other peripheral nerves. Some embodiments can have configurations, components, and/or procedures different than those described herein, and other embodiments may eliminate particular components and/or procedures. A person of ordinary skill in the relevant art, therefore, will understand that the present disclosure may include other embodiments with additional elements, and/or may include other embodiments without several of the features shown and described below with reference to Figures 1 A-6.
B. Representative Embodiments of Sacral Neuromodulation Systems and Associated Stimulation Waveforms
[0020] Figure 1A schematically illustrates a sacral neuromodulation system 100 ("the system 100") implanted to stimulate a patient's sacral nerves and configured in accordance with embodiments of the present technology. The system 100 includes a signal generator 1 10 and a signal delivery device 120. The signal generator 110 can be implanted and/or implantable subcutaneously within the patient P. For example, in the illustrated embodiment the signal generator 110 is implanted subcutaneously at the lower back/upper buttock area of the patient P (e.g., adjacent but posterior to the iliac crest IC and/or iliac fossa IF).
[0021] The signal delivery device 120 extends from the signal generator 1 10 and can be implanted within the patient P proximate a target neural population. In some embodiments, the target neural population includes one or more of the sacral spinal nerves (e.g., the S1 sacral nerve, the S2 sacral nerve, the S3 sacral nerve and/or the S4 sacral nerve). Accordingly, in some embodiments the signal delivery device 120 can extend through one of the sacral foramen S1 -S4 (the illustrated embodiment depicts the signal delivery device 120 extending through the sacral foramen S1 ) and adjacent one or more sacral spinal nerves when implanted. More specifically, the signal delivery device 120 can be implanted proximate the S1 sacral nerve, the S2 sacral nerve, the S3 sacral nerve, and/or the S4 sacral nerve. The signal delivery device 120 can carry features configured to administer therapy to the target neural population. For example, the signal delivery device 120 can include one or more lead(s) or lead bodies 122 extending from the signal generator 110 toward the target neural population (e.g., toward the S3 sacral nerve). As described in greater detail with reference to Figure 1 B, the lead 122 can include or carry one or more electrical contacts or electrodes (e.g., ring electrodes, cuff electrodes, and/or other suitable electrical contacts) that deliver electrical signals to the target neural population.
[0022] In operation, the signal generator 1 10 can generate and transmit signals (e.g., electrical signals) to the signal delivery device 120. In turn, the signal delivery device 120 can deliver the electrical signals to the target neural population, e.g., to electrically modulate neurons within the target neural population to induce a therapeutic effect in the patient. Representative electrical signals that can be generated by the signal generator 1 10 and delivered to the patient P via the signal delivery device 120 are described in greater detail below with reference to Figures 2A and 2B.
[0023] The signal generator 110 can include a machine-readable (e.g., computer- readable) medium containing instructions for generating and transmitting electrical signals. Accordingly, generating electrical signals in accordance with the methods described herein can include executing computer-executable instructions contained by, on, or in computer-readable media located within the signal generator 1 10. The signal generator 110 can also include one or more processors for executing the machine- readable instructions (e.g., to perform any of the methods disclosed herein), memory unit(s), batteries (rechargeable and/or non-rechargeable), communication devices (e.g., an antenna), and/or other software or hardware-based components. As shown in Figure 1 A, the signal generator 1 10 can include a single housing for storing some or all of the foregoing components, although in other embodiments some or all of the foregoing components can be stored in separate housings.
[0024] In some embodiments, the signal generator 1 10 can be configured to communicate with one or more external controllers. For example, the signal generator 110 can wirelessly communicate with a physician controller (not shown) that is external to the patient P. A physician or other healthcare provider can use the physician controller to program the signal generator 1 10, e.g., to select parameters for the electrical signal to be generated by the signal generator 110. In some embodiments, the signal generator 1 10 can also communicate with a patient controller that is external to the patient P. The patient P can use the patient controller to control various aspects of the therapy provided by the signal generator 1 10. For example, the patient may be able to start and stop electrical stimulation therapy using the patient controller, and/or control certain parameters (e.g., amplitude) of the electrical stimulation using the patient controller. In some embodiments, the signal generator 1 10 can transmit data to the physician controller and/or the patient controller for user review. For example, the signal generator 110 may periodically (or on demand) transmit data associated with one or more of electrode impedance, battery power, program settings (e.g., current signal parameters), historical program settings (e.g., historical signal parameters), program/parameter changes, usage data (e.g., stimulation start and stop times), or the like. The physician controller and the patient controller can include a dedicated controller device, or be implemented as an application on a smartphone, tablet, etc. As described below in Section C of this Detailed Description, in some embodiments the physician controller and/or the patient controller can also perform one or more operations of methods for automatically and/or incrementally adjusting signal delivery parameters. The physician controller and/or the patient controller can therefore also include one or more processors for executing machine-readable instructions, e.g., to perform any of the methods described herein. [0025] In some embodiments, the system 100 can be implanted in the patient P to treat IBD or an associated condition, including Crohn's disease or ulcerative colitis. For example, the system 100 can deliver electrical signals to one or more sacral nerves of the patient to modulate the one or more sacral nerves. As described in detail throughout this Detailed Description, the electrical signal can treat, reduce, and/or ameliorate the IBD. For example, the electrical signal may reduce one or more IBD-related symptoms (e.g., diarrhea, abdominal pain, weight loss, etc.), and/or reduce inflammation causing the one or more symptoms. In some embodiments, the system 100 can be implanted in the patient P to treat another disorder, such as a disorder characterized by urinary control issues (e.g., urinary retention, overactive bladder, urinary urge incontinence, urgency-frequency, etc.), fecal incontinence, or other disorders. Moreover, although shown as providing unilateral stimulation, in some embodiments the system 100 can be configured to provide bilateral sacral nerve stimulation to treat the patient's IBD. Additional details of electrical signals and stimulation regimes for treating IBD are described below with reference to Figures 2A and 2B.
[0026] In some embodiments, prior to receiving the signal generator 110, the patient P undergoes a trial period during which the patient P receives electrical stimulation to determine whether the patient P responds favorably to stimulation therapy. During the trial period, the patient P may use a temporary, external trial stimulator that generates and transmits electrical signals to the target neural population via the signal delivery device 120 or another implanted signal delivery element. If the patient responds favorably during the trial period, the patient may elect to have the signal generator 1 10 implanted to facilitate chronic stimulation therapy. In some embodiments, the trial period can be omitted, and the signal generator 1 10 can be implanted without the patient previously receiving stimulation from a temporary external signal generator.
[0027] Figure 1 B is an illustration of a sacral plexus SP of a patient, along with a distal portion of the lead 122 shown as implanted at a representative location. The sacral plexus SP includes four sacral spinal nerves: the first sacral nerve S1 , the second sacral nerve S2, the third sacral nerve S3, and the fourth sacral nerve S4. The lead 122 is shown as extending along (e.g., proximate to) the third sacral nerve S3 such that it can electrically stimulate the third sacral nerve S3. In other embodiments, however, the lead 122 can be positioned proximate other sacral spinal nerves, and/or proximate other nerve fibers of the sacral plexus SP, to electrically stimulate other target tissue. In yet other embodiments, the lead 122 can be positioned proximate other neural structures of the sacral plexus SP.
[0028] Figure 1 B also shows a plurality of electrodes or electrical contacts 124a-d carried by the lead 122, as described previously. Electrical signals generated by the signal generator 1 10 and transmitted through the lead 122 can be delivered to the target neural population via the electrodes 124a-d. Although shown as having four electrodes, the lead 122 can have more or fewer electrodes, such as one, two, three, four, five, six, seven, eight, or more.
[0029] In some embodiments, test stimulation may be administered to a patient during a procedure to implant the signal delivery device 120. This can be done to ensure adequate placement of the lead 122, e.g., to ensure that the electrical signals delivered via the lead 122 are applied to the target neural population. In some embodiments, test stimulation is administered at or above a sensory threshold during an implant procedure such that the patient can give intraoperative feedback about the location of the sensation, and thus the location of the lead 122. In some embodiments, test stimulation is administered at or above a motor threshold during the implant procedure, and a motor response to the test stimulation is observed to determine the location of the lead 122. In other embodiments, however, placement of the lead 122 can be confirmed using other techniques (e.g., imaging), such that intraoperative test stimulation is not required.
[0030] Figure 2A is a partially schematic illustration of a representative electrical signal waveform 200 ("the signal 200") generated in accordance with embodiments of the present technology. The signal 200 can be generated by the system 100 (e.g., by the signal generator 110) described above with respect to Figures 1A and 1 B, or by another sacral neuromodulation system. As described throughout this Detailed Description, the signal 200 can be delivered to a patient's sacral region to treat a patient condition such as IBD.
[0031] The signal 200 includes repeating pulse periods 201 , with each pulse period 201 having a biphasic pulse 202 followed by an interpulse interval 212. Each pulse 202 includes a first pulse phase 203 having a first polarity followed by a second pulse phase 204 having a second polarity that is opposite the first polarity. For example, in the illustrated embodiment the first pulse phase 203 is an anodic pulse phase and the second pulse phase 204 is a cathodic pulse phase, although in other embodiments the anodic pulse phase and the cathodic pulse phase can be reversed, such that the cathodic pulse phase is the first pulse phase and the anodic pulse phase is the second pulse phase. In other embodiments, the signal 200 includes monophasic pulses. In such embodiments, the signal 200 includes repeating pulses of the same polarity.
[0032] In some embodiments, the first pulse phase 203 is separated from the second pulse phase 204 by an interphase interval 208. During the interphase interval 208, the amplitude of the signal 200 can return to baseline (e.g., zero or about zero), although in other embodiments the amplitude of the signal 200 during the interphase interval 214 can be a non-zero value. In some embodiments, the interphase interval 208 is omitted, and the signal 200 transitions directly from the first pulse phase 203 to the second pulse phase 204.
[0033] The first pulse phase 203 can have a pulse width 206 within a pulse width range of from about 100 microseconds to about 2 milliseconds. For example, the first pulse phase 203 can have a pulse width 206 within a pulse width range of from about 100 microseconds to about 1 .5 milliseconds, or from about 100 microseconds to about 1 millisecond, or from about 100 microseconds to about 800 microseconds, or from about 200 microseconds to about 700 microseconds, or from about 200 microseconds to about 600 microseconds, or from about 300 microseconds to about 700 microseconds, or from about 300 microseconds to about 600 microseconds, or from about 300 microseconds to about 500 microseconds, or from about 400 microseconds to about 600 microseconds, or from about 400 microseconds to about 500 microseconds. For example, in some embodiments the pulse width 206 can be about 100 microseconds, about 150 microseconds, about 200 microseconds, about 250 microseconds, about 300 microseconds, about 350 microseconds, about 400 microseconds, about 450 microseconds, about 500 microseconds, about 550 microseconds, about 600 microseconds, about 650 microseconds, or about 700 microseconds. The foregoing pulse width ranges and values are provided by way of example only — in some embodiments, the electrical signals described herein may have pulse width values outside the foregoing ranges.
[0034] In some embodiments, the second pulse phase 204 has the same or about the same pulse width as the first pulse phase 203. Accordingly, the second pulse phase 204 can have any of the pulse widths recited above with respect to the first pulse phase 203. In other embodiments, however, the second pulse phase 204 can have a different pulse width than the first pulse phase 203. For example, if the first pulse phase 203 has a pulse width of 400 microseconds or less, the second pulse phase 204 may have a pulse width of 600 microseconds or more. Likewise, if the first pulse phase 203 has a pulse width of 600 microseconds or more, the second pulse phase 204 may have a pulse width of 400 microseconds or less. In general, when the second pulse phase 204 has a different pulse width than the first pulse phase 203, the pulse width of the second pulse phase 204 can be 50%, 60%, 70%, 80%, 90%, 1 10%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190% or 200% of the pulse width of the first pulse phase 203.
[0035] Regardless of whether the first pulse phase 203 and the second pulse phase 204 have the same pulse width, a total charge delivered during the second pulse phase 204 can be equal or approximately equal in magnitude and opposite in polarity from the total charge delivered during the first pulse phase 203. In this way, the second pulse phase 204 is a charge balancing pulse that prevents or at least reduces charge buildup at the electrode used to deliver the signal 200. Accordingly, in embodiments for which the first pulse phase 203 and the second pulse phase 204 have an equal or approximately equal pulse width, the first pulse phase 203 and the second pulse phase 204 can have an equal or approximately equal and opposite amplitude. In embodiments in which the first pulse phase 203 and the second pulse phase 204 have different pulse widths, the first pulse phase 203 and the second pulse phase 204 can have different amplitudes such that the total charge delivered during the first pulse phase 203 and the second pulse phase 204 remains approximately the same. In other embodiments, the pulse 202 can be charge imbalanced, such that the first pulse phase 203 and the second pulse phase 204 do not deliver charges of the same magnitude. In such embodiments, charge buildup at the electrode may passively dissipate.
[0036] The interpulse interval 212 is a quiescent period between sequential pulses 202. During the interpulse interval 212, the signal 200 can return to a baseline amplitude (e.g., zero or about zero) such that little to no charge is administered to the patient. In some embodiments, the interpulse interval can be within an interpulse interval range of from about 1 millisecond to about 1 second, such as from about 5 milliseconds to about 500 milliseconds, or from about 50 milliseconds to about 500 milliseconds, or from about 100 milliseconds to about 300 milliseconds. The foregoing interpulse interval ranges and values are provided by way of example only — in some embodiments, the electrical signals described herein may have interpulse interval values outside the foregoing ranges. In some embodiments, the duration of the interpulse interval 212 can be set independently from the duration of the pulses 202. In other embodiments, the duration of the interpulse interval 212 is set based on a selected pulse 202 duration and desired signal frequency.
[0037] The duration of the pulse period 201 determines the frequency of the signal 200. For example, if the duration of the pulse period 201 is 200 milliseconds, then the frequency of the signal is 5 Hz (i.e., five pulse periods 201 are delivered per second). The signal 200 can have a frequency between about 0.5 Hz and about 50 Hz. For example, the signal 200 can have a frequency within a frequency range of from about 1 Hz to about 40 Hz, or from about 1 Hz to about 30 Hz, or from about 1 Hz to about 25 Hz, or from about 1 Hz to about 20 Hz, or from about 1 Hz to about 15 Hz, or from about 5 Hz to about 15 Hz, or from about 1 Hz to about 12 Hz, or from about 1 Hz to about 10 Hz, or from about 2 Hz to about 8 Hz, or from about 3 Hz to about 7 Hz, or from about 4 Hz to about 6 Hz, or from about 4.5 Hz to about 5.5 Hz, or from about 4.8 Hz to about 5.2 Hz. In other embodiments, the signal 200 can have a frequency of about 0.5 Hz, about 1 Hz, about 2 Hz, about 3 Hz, about 4 Hz, about 5 Hz, about 6 Hz, about 7 Hz, or about 8 Hz. In some embodiments, the signal 200 can have a frequency of about 4.2 Hz, about 4.4 Hz, about 4.6 Hz, about 4.8 Hz, about 5.0 Hz, about 5.2 Hz, about 5.4 Hz, about 5.6 Hz, or about 5.8 Hz. The foregoing frequency ranges and values are provided by way of example only — in some embodiments, the electrical signals described herein may have frequency values outside the foregoing ranges.
[0038] The pulses 202 can have a current amplitude between about 0.1 mA and about 20 mA. For example, in some embodiments the pulses 202 have a current amplitude within a current amplitude range of from about 0.1 mA to about 10 mA, or from about 0.1 mA to about 7 mA, or from about 0.2 mA to about 6 mA, or from about 0.3 mA to about 5 mA, or from about 0.3 mA to about 4 mA, or from about 0.4 mA to about 3 mA, or from about 0.5 mA to about 3 mA, or from about 0.8 mA to about 2 mA, or from about 1 mA to about 1 .5 mA. The pulses 202 can also have a voltage amplitude between about 0.1 V and 15 V. For example, in some embodiments the pulses 202 have a voltage amplitude within a voltage amplitude range of from about 0.1 V to about 10 V, or from about 0.2 V to about 8 V, or from about 0.2 V to about 6 V, or from about 0.3 V to about 5 V, or from about 0.3 V to about 4 V, or from about 0.4 V to about 3 V. In some embodiments, the amplitude (e.g., the current amplitude and/or the voltage amplitude) of the signal 200 is set based on an individual patient's sensory threshold and/or motor threshold. For example, in some embodiments the pulses 202 have a peak amplitude that is below the sensory or perception threshold of the patient. In such embodiments, the patient generally cannot actively feel the signal 200 as it is being administered. For example, the pulses 202 may have an amplitude that is 50% of sensory threshold, 60% of sensory threshold, 70% of sensory threshold, 80% of sensory threshold, 90% of sensory threshold, or 95% of sensory threshold. In other embodiments, the pulses 202 have an amplitude that is at or above the sensory threshold, such that the patient can perceive the signal 200 being delivered. In yet other embodiments, the pulses 202 have an amplitude that is below the motor threshold of the patient. In such embodiments, the signal 200 does not induce clinically discernable movement (e.g., muscle twitching) in the patient while being administered. For example, the pulses 202 may have an amplitude that is 50% of motor threshold, 60% of motor threshold, 70% of motor threshold, 80% of motor threshold, 90% of motor threshold, or 95% of motor threshold.
[0039] In some embodiments, electrical signals generated in accordance with the present technology can have one more ramped parameters. For example, Figure 2B illustrates an electrical signal 250 ("the signal 250") with a ramped amplitude in accordance with some embodiments of the present technology. The signal 250 can be generally similar to the signal 200, and can have any of the parameters and parameter values described above in connection with the signal 200. However, relative to the signal 200, an amplitude of the of the signal 250 can be ramped such that a peak amplitude of the signal 250 changes over time. In the illustrated embodiment, for example, the signal 250 includes a plurality of pulses 252 (five pulses 252a-252e are shown), with each sequential pulse 252 having a different amplitude than the preceding pulse 252. More specifically, the amplitude of the signal 250 increases from pulse 252a to pulse 252c, and then decreases from pulse 252c to pulse 252e. This pattern can then be repeated. In some embodiments, the signal 250 includes multiple pulses 252 at a common amplitude before being ramped up or down to a different amplitude (e.g., multiple pulses are delivered with an amplitude equal to the pulse 252a before the signal 250 is ramped to delivering pulses with an amplitude equal to the pulse 252b). Although shown as being ramped in two directions, in other embodiments the signal 250 is ramped only in a single direction (e.g., the amplitude is either increased or decreased, but not both), until a maximum or minimum amplitude is reached.
[0040] In some embodiments, other parameters of the signal 250 (e.g., pulse width, interpulse interval, frequency, etc.) can remain constant (e.g., unchanged) as the amplitude of the pulses 252 is ramped. In other embodiments, one or more other parameters can be ramped, in addition to the amplitude being ramped. For example, in some embodiments both a pulse width and an amplitude of the pulses 252 is ramped. In such embodiments, the pulse width of the pulses 252 may be inversely ramped with the amplitude, such that as the amplitude increases, the pulse width decreases, and vice versa. Moreover, in some embodiments the pulse width, frequency, or other parameter is ramped instead of the amplitude.
[0041] The electrical signals described herein (e.g., the signal 200 of Figure 2A and the signal 250 of Figure 2B) can be administered intermittently or continuously. Continuous stimulation refers to delivering the electrical signals without interruption. Intermittent stimulation refers to cycling between "on" times during which the signal is being administered, and "off" times during which the signal is not being administered. In some embodiments, the "on" time can be between about 1 second and about 10 minutes, and the "off" time can be between about 1 second and about 30 minutes. Representative examples of suitable intermittent stimulation schedules include 10 seconds on, 10 seconds off; 10 seconds on, 30 seconds off; 10 seconds on, 60 seconds off; 10 seconds on, 90 seconds off; 30 seconds on, 30 seconds off; 30 seconds on, 60 seconds off; 30 seconds on, 90 seconds off; 1 minute on, 1 minute off; 10 minutes on, 10 minutes off, etc. The on times and off times are provided by way of example only — in some embodiments, the electrical signals described herein may be applied according to different on times and off times.
[0042] Regardless of whether the signal is administered intermittently or continuously, the signal can be administered according to a duty cycle of between about 0.1 % and about 100%. As used herein, and referring again to Figure 2A, the term duty cycle refers to the fraction of a single pulse period 201 (which consists of a single pulse 202 and a single interpulse interval 212) in which the pulse 202 is being actively delivered. That is, for a single pulse period, the duty cycle can be expressed as: (pulse width/duration of pulse period) x 100. For example, if a pulse period comprises (1 ) a biphasic pulse with no interphase interval and with each phase of the pulse having a pulse width of 500 microseconds, followed by (2) an interpulse interval having a duration of 99 milliseconds (e.g., before the following pulse period begins), the duty cycle is 1 % (1 millisecond combined pulse width/100 millisecond pulse period duration, x 100). In this way, the term duty cycle is different than the term intermittent, which generally refers to delivering sequential pulse periods in a row for a first duration (e.g., 10 seconds), followed by a quiescent period during which no pulse periods are delivered for a second duration (e.g., for 90 seconds).
[0043] In some embodiments, the electrical signals described herein (e.g., the signal 200 of Figure 2A and the signal 250 of Figure 2B) are administered during discrete stimulation sessions or periods that have a duration less than 24 hours. For example, the stimulation sessions may have a duration of between about 5 minutes and about 12 hours, such as between about 15 minutes and about 6 hours, or between about 15 minutes and about 4 hours, or between about 15 minutes and about 3 hours, or between about 15 minutes and about 2 hours, or between about 30 minutes and about 3 hours, or between about 30 minutes and about 2 hours, or between about 30 minutes and about 1 .5 hours, or between about 45 minutes and about 1 .5 hours. In some embodiments, the stimulation sessions can have a duration of about 5 minutes, about 15 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1 .5 hours, about 2 hours, about 2.5 hours, about 3 hours, about 3.5 hours, or about 4 hours. The patient can receive one or more stimulation sessions per day. For example, in some embodiments the patient receives a single stimulation session per day. In other embodiments, the patient receives multiple (e.g., two, three, four, etc.) discrete stimulation sessions per day. During periods between stimulation sessions, the patient generally does not receive any stimulation, or at least any clinically meaningful stimulation. The foregoing representative stimulation period durations are provided by way of example only — in some embodiments, the electrical signals described herein may be applied during stimulation sessions having different durations. One expected advantage of delivering stimulation during discrete stimulation sessions having a relatively short duration is that doing so may reduce the frequency with which the patient must recharge the power source in the signal generator. Another expected advantage is that it may reduce the likelihood the patient becomes desensitized (e.g., habituates) to the stimulation. In some embodiments, however, electrical stimulation is applied for 24 hours per day.
[0044] The number and/or duration of stimulation sessions can be associated with various patient events or activities. In a first representative example, the stimulation sessions may occur while the patient is prandial. For example, the patient may receive one, two, three, or four 30-minute stimulation sessions per day, timed to occur while the patient is eating. In a second representative example, the electrical stimulation may be delivered during a single, one to six hour stimulation session per day, timed to (a) precede sleep (b) occur during sleep, or (c) both (a) and (b). In a third representative example, the electrical stimulation may be delivered during one or two one-hour stimulation sessions per day, timed to occur before, during, and/or after bowel movements. In yet another representative example, the electrical stimulation may be delivered during short (e.g., 5-minute) stimulation sessions that occur each hour the patient is awake and/or active. For any of the foregoing examples, the signals can be applied using any of the signal parameters described for the signal 200 with reference to Figure 2A and the signal 250 with reference to Figure 2B. The foregoing examples are also provided by way of example only — the stimulation sessions can be applied at other times throughout the day, tied to other patient events, and/or according to other intervals beyond those described above.
[0045] In some embodiments, the patient can control when they receive the stimulation session. For example, the patient may have access to a patient controller that can control operation of the signal generator (e.g., the signal generator 110 shown in Figure 1 A) to initiate a stimulation session. Providing the patient with control over the timing of the stimulation sessions may be beneficial because the patient can initiate stimulation during a convenient time and/or when the patient experiences IBD symptoms (or an increase in the severity of IBD symptoms). In a representative example, the patient may select to initiate the stimulation session during the day (e.g., as opposed to at night), while avoiding certain activities (e.g., driving, periods of concentration, etc.), and/or during or after periods or activities that may lead to an increase in symptoms (e.g., during or after consuming food). In other embodiments, a signal generator can be programmed to automatically administer the stimulation session during predetermined intervals. For example, the signal generator can be programmed to automatically deliver a stimulation session every day at 1 PM or another selected time. As another example, the signal generator can be programmed to automatically deliver a stimulation session timed with certain patient activities. For example, the signal generator can be programmed to automatically deliver a stimulation session at a time the patient typically eats a meal (e.g., 8AM, 12PM, and/or 6PM). Additionally or alternatively, the signal generator can be programmed to automatically deliver a stimulation session at a time that the patient's symptoms are typically the worst, which can be determined using patient feedback such as questionnaires, symptoms logs, etc. As yet another example, the signal generator can be programmed to automatically deliver a stimulation session based on a time the patient takes other medication (e.g., concurrent with taking medication, a specified duration before taking medication, or a specified duration after taking medication). Programming the signal generator to automatically administer the stimulation session may be advantageous because it eliminates the possibility of a patient forgetting to initiate therapy, and therefore may provide a more consistent therapy.
C. Automatically and/or Incrementally Adjusting one or more Signal Delivery Parameters
[0046] Certain patients may experience a decrease in the efficacy of sacral nerve stimulation over a period of time due to a number of different factors. For example, the target neural population may accommodate or habituate to the electrical signal, and thereby respond less to the same stimulus. As another example, the effective charge being delivered to the target neural population may change (e.g., decrease) as a result of a change in electrode impedance and/or a change in the relative position of the electrode (e.g., caused by lead migration, changes in spine position, etc.). This decrease in efficacy can often be restored by changing one or more signal delivery parameters associated with the electrical signal, such as the amplitude, pulse width, frequency, etc. However, most sacral nerve stimulation systems provide limited recourse for patients suffering from a decrease in efficacy due to the foregoing reasons. While some patient controllers permit a patient to manually increase the amplitude of the electrical signal within prescribed limits, such manual increases rely on patient interaction and may amount to a mere guess as to what new amplitude may restore the lost efficacy. Patients have a range of technical competence and reliability to complete complicated device adjustments without assistance Accordingly, it is typically advised defor a patient to wait until their next scheduled healthcare visit to the have the signal parameters adjusted to restore the lost efficacy.
[0047] The present technology provides systems and methods for automatically addressing the decrease in efficacy due to nerve accommodation, changes in electrode impedance, changes in electrode position, and other factors. For example, Figure 3 is a flowchart of a method 300 for treating a patient using sacral nerve stimulation. The method 300 can begin at block 302 by delivering an electrical signal to one or more sacral nerves, e.g., to treat a condition such as IBD. The electrical signal can be any of the electrical signals described above in Section B of this Detailed Description.
[0048] The method 300 can continue at block 304 by automatically increasing an amplitude of the electrical signal by a predetermined amount after a predetermined duration. The predetermined amount can be defined as a numerical value or a percent value. Potential numerical values may range between about 0.1 mA and about 5 mA, and may include, but are not limited to, 0.1 mA, 0.2 mA, 0.3 mA, 0.4 mA, 0.5 mA, 0.6 mA, 0.7 mA, 0.8 mA, 0.9 mA, 1 .0 mA, 1 .2 mA, 1 .4 mA, 1 .6 mA, 1 .8 mA, 2 mA, 2.5 mA, 3 mA, 4 mA, 5 mA, etc. Although the foregoing values are defined in terms of current amplitude, the numerical value can alternatively be defined in terms of voltage amplitude (e.g., mV) for any of the foregoing values. Potential percent values may range between about 0.5% and about 20%, and may include, but are not limited to, 0.5%, 1 %, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, etc. The predetermined duration may range between about 1 day and about 90 days, or between about 1 day and about 60 days, or between about 1 day and about 30 days, and may include particular periods such as about 1 day, about 5 days, about 10 days, 20 days, 30 days, 40 days, 50 days, 60 days, etc.
[0049] In some embodiments, the predetermined amount and/or the predetermined duration can be set by the physician. This can be done during an initial office visit during which the physician programs the sacral neuromodulation system, during one or more follow-up visits, and/or remotely. As a first example, the physician may program the system to automatically increase the stimulation amplitude by 0.1 mA every 30 days. As a second example, the physician may program the system to automatically increase the stimulation amplitude by 5% every 20 days. The foregoing schedules are provided by way of example only — the present technology can include other predetermined amounts and predetermined durations, as set forth above.
[0050] In other embodiments, the predetermined amount and/or the predetermined time can be based at least in part on one or more reference patient data sets. For example, a computing system and/or the physician can review the timing and degree of efficacy reduction for similarly situated patients (e.g., with the same or similar condition, same or similar symptoms, same or similar age, etc.), and use such data to predict when and to what degree the reduction in efficacy for a particular patient may occur. The physician can then program the system to automatically increase the stimulation amplitude at intervals that coincide with the anticipated reduction in efficacy.
[0051 ] The operations at block 302 and 304 can be iteratively repeated indefinitely.
In other embodiments, the operations at block 302 and 304 can be iteratively repeated for a prescribed number of amplitude increases and/or for a prescribed duration. For example, in some embodiments the amplitude could be increased by 1 % every day for a period of 30 days, and then cease to further increase absent patient or physician input. In other embodiments, the amplitude could be increased by 0.1 mA every 30 days for a period of 3 months. Regardless of whether the operations at blocks 302 and 304 are repeated indefinitely or for a set duration, the systems and methods described herein can include a limit on the amplitude increase, e.g., to reduce the likelihood of overstimulating the patient. Moreover, although the method 300 includes automatically increasing the stimulation amplitude, the patient and the physician may still retain control over the amplitude (e.g., via a patient controller and a physician controller, respectively) to permit them to make elective, on-demand adjustments to the stimulation amplitude, as desired.
[0052] In some embodiments, the systems and methods described herein track one or more metrics associated with the patient therapy to determine when to adjust the amplitude of the electrical signal, instead of predefining when the adjustment will occur as described with reference to the method 300 of Figure 3. For example, Figure 4 is a flowchart of another method 400 for treating a patient using sacral nerve stimulation. Similar to the method 300 of Figure 3, the method 400 can begin at block 402 by delivering an electrical signal to one or more sacral nerves via one or more implanted electrodes, e.g., to treat a condition such as IBD. The electrical signal can be any of the electrical signals described above in Section B of this Detailed Description.
[0053] The method 400 can continue at block 404 by measuring an electrical impedance associated with the electrical signal. Changes in electrical impedance can be caused by, among other things, lead migration, changes in spine position (e.g., lumbo-thoracic extension), tissue fibrosis, or other factors. Generally, an increase in impedance will result in a decrease in the effective charge that reaches the target neural population, while a decrease in impedance will result in an increase in the effective charge that reaches the target neural population. Accordingly, the electrical impedance can be monitored at block 404 to provide an estimate of the effective charge being delivered to the target neural population. In some embodiments, the electrical impedance can be continuously monitored. In other embodiments, the electrical impedance can be measured at discrete intervals (e.g., twice per hour, once per hour, once per day, once every 10 days, etc.). The discrete intervals can be selected based on expected changes in impedance over time. In yet other embodiments, the electrical impedance can be "on-demand" and triggered by the physician (e.g., during a periodic checkup) or by the patient.
[0054] The method 400 can continue at block 406 by, in response to measuring a change in the electrical impedance that is greater than a threshold value, changing an amplitude of the electrical signal to counter the change in impedance. For example, if the electrical impedance increases by the threshold value, the amplitude could be increased to offset the reduction in charge reaching the target neural population. Similarly, if the electrical impedance decreases by the threshold value, the amplitude could be decreased proportionally to the decrease in impedance. In some embodiments, the threshold value represents a change in impedance relative to an average impedance (such as a 24-hour average) of a specific magnitude. In some embodiments, the threshold value can be between about 1 Ohm and about 100 Ohms, such as a change relative to average of at least 1 Ohm, 2 Ohms, 3 Ohms, 4 Ohms, 5 Ohms, 6 Ohms, 7 Ohms, 8 Ohms, 9 Ohms, 10 Ohms, 15 Ohms, 20 Ohms, 25 Ohms, 30 Ohms, 40 Ohms, 50 Ohms, 60 Ohms, 75 Ohms, 100 Ohms, or other values. The adjustment can be proportional to the detected change in impedance, and can be between about 0.1 mA and about 5 mA or other increments described herein. In some embodiments, the system delivering the electrical signal can be programmed to automatically adjust the amplitude in response to detecting the change in electrical impedance.
[0055] After the amplitude is adjusted at block 406, the method 400 can return the operation at block 402 and deliver the electrical signal to the one or more sacral nerves at the adjusted amplitude. Accordingly, the operations at block 402, 404, and 406 can be iteratively repeated such that the amplitude is continuously adjusted to account for changes in impedance. Moreover, the operations at block 404 and 406 can be performed without interrupting or otherwise stopping delivery of the electrical signal. Without being bound by theory, this is expected to reduce the patient's perception of any changes in therapy.
[0056] Instead of or in addition to adjusting amplitude based on impedance measurements, in some embodiments the present technology utilizes patient feedback to adjust amplitude. For example, Figure 5 is another flowchart of a method 500 for determining a therapeutic amplitude for sacral nerve stimulation for a patient in need of treatment. The method 500 can begin at block 502 by delivering an electrical signal to one or more sacral nerves at a first test amplitude. The first test amplitude can include any of the values described herein, and can generally range between about 0.1 mA and about 20 mA, or between about 0.1 mA and about 10 mA, or any of the other current amplitude ranges described herein (for current-controlled stimulation) or between about 0.1 V and about 15 V, or between about 0.1 V and about 10 V, or any of the other voltage amplitude ranges described herein (for voltage-controlled stimulation).
[0057] The method 500 can continue at block 504 by receiving an input from the patient indicating the perceived intensity of sensation caused by the electrical signal at the first test amplitude. For example, in embodiments in which the first test amplitude is above the patient's sensation threshold, the patient can indicate the strength of the sensation induced by the electrical signal. This can be done using a subjective numerical rating scale (e.g., with 1 being low intensity and 5 being high intensity) or other suitable scales. In embodiments in which the method 500 is performed in a healthcare clinic, the healthcare provider can input the patient's rating into a computing system, e.g., via the physician controller. In embodiments in which the method 500 is not performed at a healthcare clinic (e.g., at the patient's home), the patient can input the patient's rating into the patient controller. Accordingly, the patient rating can be received by a computing system that is operably coupled to the patient's stimulator.
[0058] Additional test amplitudes can be delivered to receive additional ratings. Indeed, the method 500 can continue at block 506 by determining whether there are additional stimulation amplitudes to test. If there are, the method 500 can continue at block 508 by changing the test amplitude, e.g., to a second test amplitude. The change can be an increase or a decrease relative to the first test amplitude. The change can be defined as a numerical value (e.g., between about 0.1 mA and 5 mA) or a percent value (e.g., between about 0.5% and about 20%). The method 500 can then repeat the operations at block 502 and 504, but at the second test amplitude. Indeed, the method 500 can iteratively repeat the operations at blocks 502, 504, 506, and 508 for any number of test amplitudes. In some embodiments, the number of test amplitudes is two, three, four, five, six, seven, eight, nine, ten, or more. After ratings have been received for each of the test amplitudes, the method 500 can determine at block 506 that there are no more amplitudes to test. This can be after a number of predetermined test amplitudes have been tested, or in response to patient feedback (e.g., reaching a 5 out of 5 on the numerical rating scale).
[0059] The method 500 can then continue at block 510 by selecting a therapeutic amplitude based at least in part on the patient's rating of the test amplitudes. In some embodiments, the computing system receiving the patient ratings can include a software module for analyzing the patient ratings to determine the therapeutic amplitude. For example, in embodiments in which the computing system is the physician controller, the physician controller can include non-transitory memory storing a software module containing one or more algorithms for calculating a therapeutic amplitude based on patient ratings of the test amplitudes. In this way, the therapeutic amplitude can be selected based at least in part on the patient's perception of the test amplitudes.
[0060] In some embodiments, the method 500 can be performed in a healthcare setting, e.g., via a physician controller that is a part of the sacral nerve stimulation system. This can be done during the initial patient visit to program the system, and/or during one or more follow-up visits. In other embodiments, the method 500 can be performed at the patient's home or without the direct supervision of a healthcare provider. In such embodiments, the patient controller can have a software program that directs the patient through the method 500 and determines, based on the patient ratings, the appropriate therapeutic amplitude. Regardless of whether the method 500 is performed in a healthcare setting or at the patient's home, the method 500 can be scheduled based on expected changes in impedance over time, such that the amplitude can be periodically adjusted to account for changes in impedance.
[0061] Although each of the methods 300-500 of Figures 3-5 describe adjusting an amplitude of the electrical signal, in other embodiments the same methods can be used to adjust other parameters of the electrical signal, in addition to or in lieu of adjusting the amplitude. For example, similar methods can be used to adjust a pulse width, frequency, and/or duty cycle of the electrical signal. In some embodiments, multiple signal delivery parameters can be adjusted simultaneously using the methods described herein.
[0062] Moreover, some or all of the operations described with reference to the methods 300-500 of Figures 3-5 can be performed (e.g., automatically performed) by one or more devices of a programmed neuromodulation system, such as the system 100 described with reference to FIGS. 1 A and 1 B. Accordingly, the present technology further includes programming a system to perform the operations of the methods 300- 500 of Figures 3-5, as well as systems programmed to perform the operations of the methods 300-500 of Figures 3-5.
D. Patient and/or Healthcare Provider Notifications
[0063] As set forth above, patients typically can turn their implanted stimulation system on and off. For example, if the patient is receiving continuous stimulation, the patient may elect to turn stimulation off during periods in which they want a break from stimulus induced sensations. As another example, if the patient is receiving one or more discrete stimulation sessions per day, the patient may elect to turn the stimulator off during periods of non-use, e.g., to reduce the frequency with which the patient must recharge the battery. Other example situations in which a patient may wish to turn the implanted system off include MRI scans, surgeries, other medical procedures, driving, becoming pregnant, or other situations. One downside of enabling a patient to turn the system off is that the patient may forget to turn the system back on. This is particularly problematic if the stimulation is being delivered below the sensation threshold, meaning that the patient cannot feel whether stimulation is being actively delivered. Forgetting to turn the system back on may contribute to a loss of treatment efficacy over time.
[0064] The present technology provides systems and methods expected to reduce the likelihood that a patient forgets to turn their stimulator on after turning it off. For example, the systems described herein can automatically generate an alert if the signal generator has been turned off for defined duration, which can be set by a physician and be between about 1 hour and about 5 days (e.g., off for at least one hour, off for at least one day, etc.). The alert can be sent to the patient, e.g., via the patient controller or via the patient's mobile phone. Similarly, the systems described herein can automatically generate an alert if the patient has not initiated a stimulation session as prescribed. As described above in Section B, in some embodiments the sacral nerve stimulation described herein is delivered during one or more discrete stimulation sessions per day. For example, a patient may be prescribed two one-hour stimulation sessions per day. If fewer than two stimulation session are administered on a given day, the systems described herein can generate an alert and display it to the patient via the patient controller. If the triggering condition responsible for the alert is not addressed within a certain time frame (e.g., within one hour, within one day, etc.), then an alert can be sent to the patient's healthcare provider.
[0065] For example, Figure 6 is a flowchart of a method 600 for monitoring a patient being treated using sacral nerve stimulation. The method 600 can begin at block 602 by determining that (a) the patient has missed a stimulation session, and/or (b) the patient's stimulator has been turned off for a defined duration. In some embodiments, the operation at block 602 can be performed by the patient controller (which can be a dedicated hardware device or implemented as an application on the patient's mobile phone or tablet). For example, the patient controller can be programmed to assume that the implanted stimulator is not active and/or is turned off unless it receives a notification from the implanted stimulator indicating otherwise. In such embodiments, the patient controller can determine that the stimulator is off or is not active if it does not receive a notification from the implanted stimulator. In other embodiments, the operation at block 602 can be performed by another device, including by the implanted stimulator itself.
[0066] The method 600 can continue at block 604 by providing a first alert to the patient indicating that the patient has missed a stimulation session and/or that the patient's stimulator has been off for the defined duration. The alert can be generated by a device operably coupled to the implanted stimulator such as the patient controller. In other embodiments, the alert can be generated by another device (e.g., the implanted stimulator) and transmitted to the patient controller for review by the patient. If the device is not within range of the patient controller, the device can store the first alert until the device is within range of the patient controller, at which point it can transmit the first alert to the patient controller.
[0067] In some embodiments, the patient can silence or clear the first alert using the patient controller. The patient may optionally be able to confirm they intentionally skipped the stimulation session or turned the stimulator off. In other embodiments, the first alert is only cleared once the condition that caused the first alert to be generated is cured (e.g., after the missing stimulation session is administered and/or after the stimulator is turned back on). Regardless, if a suitable response is received from the patient at block 606, then the method can continue at block 610 by turning the first alert off. If the alert was silenced by the patient, the system may regenerate the first alert after a predefined duration, such as after 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 12 hours, or 24 hours. If the alert was cleared by the patient (either by fulfilling the triggering condition or indicating that the triggering condition was intentional), the method can return to monitoring the status of the stimulator as if the triggering condition did not occur.
[0068] If, however, a response to the first alert is not received from the patient, the method 600 can continue at block 608 by providing a second alert to the patient's healthcare provider indicating that the patient has missed a stimulation session and/or that the patient's stimulator is off. The healthcare provider can then follow up with the patient as needed. In some embodiments, the operation at block 608 is performed regardless of whether the patient responds to the first alert. That is, the second alert is sent to the healthcare provider at the same time that the first alert is sent to the patient.
[0069] Without intending to be bound by theory, the method 600 is expected to improve patient adherence to prescribed stimulation regimens and reduce the likelihood the patient inadvertently is not receiving stimulation therapy as intended. In this way, the method 600 may help improve patient outcomes. [0070] Some or all of the operations described with reference to the method 600 of Figure 6 can be performed (e.g., automatically performed) by one or more devices of a programmed neuromodulation system, such as the system 100 described with reference to FIGS. 1 A and 1 B. Accordingly, the present technology further includes programming a system to perform the operations of the method 600 of Figure 6, as well as systems programmed to perform the operations of the method 600 of Figure 6.
E. Representative Examples
[0071] The following examples are provided to further illustrate embodiments of the present technology and are not to be interpreted as limiting the scope of the present technology. To the extent that certain embodiments or features thereof are mentioned, it is merely for purposes of illustration and, unless otherwise specified, is not intended to limit the present technology. It will be understood that many variations can be made in the procedures described herein while still remaining within the bounds of the present technology. Such variations are intended to be included within the scope of the presently disclosed technology.
1 . A method of treating a patient using sacral nerve stimulation, the method comprising: delivering an electrical signal to one or more sacral nerves of the patient via one or more implanted signal delivery elements, wherein the electrical signal has an amplitude in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V; and automatically increasing the amplitude of the electrical signal by a predetermined amount after a predetermined duration.
2. The method of example 1 wherein the predetermined amount is a numerical value between about 0.1 mA and about 5 mA or between about 0.1 V and about 5 V.
3. The method of example 1 wherein the predetermined amount is a percent value between about 0.5% and 20%. 4. The method of any of examples 1 -3 wherein the predetermined duration is between about 1 day and about 30 days.
5. The method of any of examples 1 -4 wherein the predetermined amount and/or the predetermined duration are based at least in part on one or more reference patient data sets.
6. The method of any of examples 1 -5 wherein the operations of delivering and automatically increasing are iteratively repeated until (a) a prescribed number of increases occurs, (b) a prescribed duration occurs, and/or (c) a maximum amplitude is reached.
7. The method of any of examples 1 -6 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the electrical signal at least partially addresses the patient’s IBD.
8. A system for treating a patient, the system comprising: an implantable signal delivery element positionable proximate a sacral nerve of the patient; and a signal generator programmed with instructions that, when executed, cause the signal generator to: deliver an electrical signal to the sacral nerve of the patient via the implantable signal delivery element, wherein the electrical signal has an amplitude in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V; and automatically increase the amplitude of the electrical signal by a predetermined amount after a predetermined duration.
9. The system of example 8 wherein the predetermined amount is a numerical value between about 0.1 mA and about 5 mA or between about 0.1 V and about 5 V. 10. The system of example 8 wherein the predetermined amount is a percent value between about 0.5% and 20%.
1 1 . The system of any of examples 8-10 wherein the predetermined duration is between about 1 day and about 30 days.
12. The system of any of examples 8-11 wherein the predetermined amount and/or the predetermined duration are based at least in part on one or more reference patient data sets.
13. The system of any of examples 8-12 wherein the operations of delivering and automatically increasing are iteratively repeated until (a) a prescribed number of increases occurs, (b) a prescribed duration occurs, and/or (c) a maximum amplitude is reached.
14. The system of any of examples 8-13 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the electrical signal, when administered, at least partially addresses the patient’s IBD.
15. A method of treating a patient using sacral nerve stimulation, the method comprising: delivering an electrical signal to one or more sacral nerves of the patient via one or more implanted signal delivery elements, wherein the electrical signal has an amplitude in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V; measuring an electrical impedance associated with the electrical signal; and in response to measuring a change in the electrical impedance that is greater than a threshold value, changing an amplitude of the electrical signal.
16. The method of example 15 wherein the amplitude is increased in response to measuring an increase in the electrical impedance that is greater than the threshold value. 17. The method of example 15 or example 16 wherein the amplitude is decreased in response to measuring a decrease in the electrical impedance that is greater than the threshold value.
18. The method of any of examples 15-17 wherein the threshold value is between about 1 Ohm and about 100 Ohms.
19. The method of any of examples 15-18 wherein measuring the electrical impedance includes measuring the electrical impedance at predefined intervals.
20. The method of any of examples 15-19 wherein measuring the electrical impedance includes continuously measuring the electrical impedance.
21. The method of any of examples 15-20, further comprising iteratively repeating the operations of delivering, measuring, and changing.
22. The method of any of examples 15-21 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the electrical signal at least partially addresses the patient’s IBD.
23. A system for treating a patient, the system comprising: an implantable signal delivery element positionable proximate a sacral nerve of the patient; and a signal generator programmed with instructions that, when executed, cause the signal generator to deliver an electrical signal to the sacral nerve of the patient via the implantable signal delivery element, wherein the electrical signal has an amplitude in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V, wherein the system is further configured to: measure an electrical impedance associated with the electrical signal; and in response to measuring a change in the electrical impedance that is greater than a threshold value, change an amplitude of the electrical signal
24. The system of example 23 wherein the amplitude is increased in response to measuring an increase in the electrical impedance that is greater than the threshold value.
25. The system of example 23 or example 24 wherein the amplitude is decreased in response to measuring a decrease in the electrical impedance that is greater than the threshold value.
26. The system of any of examples 23-25 wherein the threshold value is between about 1 Ohm and about 100 Ohms.
27. The system of any of examples 23-26 wherein measuring the electrical impedance includes measuring the electrical impedance at predefined intervals.
28. The system of any of examples 23-27 wherein measuring the electrical impedance includes continuously measuring the electrical impedance.
29. The system of any of examples 23-28, further comprising iteratively repeating the operations of delivering, measuring, and changing.
30. The system of any of examples 23-29 wherein the patient has Inflammatory Bowel Disease (IEBD), and wherein the electrical signal, when administered, at least partially addresses the patient’s IBD.
31. A method of determining a therapeutic amplitude of sacral nerve stimulation for a patient, the method comprising: delivering an electrical signal to one or more sacral nerves of the patient, wherein the electrical signal has a first test amplitude in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V; receiving a rating from the patient indicating a perceived intensity of sensation caused by the electrical signal at the first test amplitude; repeating the operations of delivering and receiving for a second test amplitude, wherein the second test amplitude is in a current amplitude range of from about 0.1 mA to about 10 mA or in a voltage amplitude range of from about 0.1 V to about 10 V and wherein the second test amplitude has a different value than the first test amplitude; and selecting a therapeutic amplitude based at least in part on the patient's rating of the first and second test amplitudes.
32. The method of example 31 wherein the operations of delivering and receiving are repeated for at least three different test amplitudes.
33. The method of example 31 or example 32 wherein the second test amplitude is greater than the first test amplitude by between about 0.1 mA and about 5 mA or between about 0.1 V and about 5 V.
34. The method of any of examples 31 -33 wherein selecting the therapeutic amplitude includes analyzing the patient ratings for each test amplitude using one or more algorithms.
35. The method of any of examples 31 -34 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the method further comprises delivering the electrical signal at the therapeutic amplitude to at least partially address the patient’s IBD.
36. A method of monitoring a patient receiving sacral nerve stimulation, the method comprising: automatically determining a patient has missed a stimulation session and/or that the patient's stimulator has been turned off for a defined duration; providing a first alert to the patient via a patient controller, wherein the first alert indicates that the patient has missed a stimulation session and/or that the patient's stimulator has been turned off for the defined duration; if a response to the first alert is received from the patient, turning off the first alert; and if a response to the first alert is not received from the patient within a predefined period, providing a second alert to the patient's healthcare provider indicating that the patient has missed a stimulation session and/or that the stimulator has been turned off for the defined duration.
37. The method of example 36 wherein the defined duration is between about 1 hour and about 5 days.
38. The method of example 36 or example 37 wherein determining that the patient has missed a stimulation session and/or that the patient's stimulator has been turned off for the defined duration is performed by the patient controller.
39. The method of any of examples 36-36 wherein providing the first alert includes: generating the first alert at a signal generator implanted within the patient; and transmitting the first alert from the signal generator to the patient controller.
40. The method of example 39, further comprising: determining that the signal generator is not in range of the patient controller before transmitting the first alert to the patient controller; and storing the first alert on the signal generator until the signal generator is in range of the patient controller.
41. The method of any of examples 36-40 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the stimulation sessions are prescribed for treating the patient’s IBD. 42. A sacral nerve stimulation system, comprising: a signal generator; a patient controller; a processor; and a memory storing instructions that, when executed by the processer, cause the sacral nerve stimulation system to: determine a patient has missed a stimulation session and/or that the signal generator has been turned off for a defined duration; provide a first alert to the patient via the patient controller, wherein the first alert indicates that the patient has missed a stimulation session and/or that the signal generator has been turned off for the defined duration; if a response to the first alert is received from the patient, turn off the first alert; and if a response to the first alert is not received from the patient within a predefined period, transmit a second alert to the patient's healthcare provider indicating that the patient has missed a stimulation session and/or that the stimulator has been turned off for the defined duration.
43. The system of example 42 wherein the patient controller includes the processor and the memory.
44. The system of example 42 wherein the signal generator includes the processor and the memory.
45. The system of any of examples 42-44 wherein the defined duration is between about 1 hour and about 5 days.
46. The system of any of examples 42-45 wherein the patient has Inflammatory Bowel Disease (IBD), and wherein the signal generator is programmed with instructions for generating an electrical signal during the stimulation session having parameters selected to address the patient’s IBD. F. Conclusion
[0072] From the foregoing, it will be appreciated that specific embodiments of the disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. For example, electrical signals described herein can be delivered at combinations of parameter values within the foregoing ranges at values that are not expressly disclosed herein. Certain aspects of the technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Further, while advantages associated with certain embodiments of the disclosed technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.
[0073] The use of "and/or," as in "A and/or B" refers to A alone, B alone, and both A and B. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.
[0074] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, to between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.