Neural stimulation device providing sub-perception stimulation

Abstract

A method and external device for providing sub-perception stimulation to a patient via an implanted stimulator device is disclosed. A stimulation parameter is determined for the patient that provides sub-perception stimulation to address a symptom of the patient. A schedule is determined to provide scheduled bolus stimulation, where each bolus includes a duration during which stimulation is applied to the patient according to the stimulation parameter, and where the scheduled boluses are separated by an off time when no stimulation is provided to the patient. Preferably, a first duration of each scheduled bolus is (3) minutes or more, and a second duration of each off time is (30) minutes or more. By selecting an option on the external device, additional boluses can be provided as needed in addition to the scheduled boluses, although providing such additional boluses is subject to a lockout period.

Description

Technical Field

[0001] This application relates to implantable medical devices (IMDs), generally to spinal cord stimulators, and more specifically to methods for controlling such devices. Background Technology

[0002] Implantable neurostimulator devices are devices that generate and deliver electrical stimulation to the body's nerves and tissues for the treatment of various biological disorders, such as pacemakers for treating arrhythmias, defibrillators for treating cardiac fibrillation, cochlear stimulators for treating deafness, retinal stimulators for treating blindness, muscle stimulators for generating coordinated limb movements, spinal cord stimulators for treating chronic pain, cortical and deep brain stimulators for treating motor and psychological disorders, and other neurostimulators for treating urinary incontinence, sleep apnea, shoulder subluxation, etc. The following description will primarily focus on the use of the invention within spinal cord stimulation (SCS) systems, such as those disclosed in U.S. Patent 6,516,227. However, the invention can be found to be applicable to any implantable neurostimulator device system.

[0003] An SCS system typically includes an implantable pulse generator (IPG) 10 as shown in Figure 1. The IPG 10 includes a biocompatible device housing 12 that houses the circuitry and battery 14 required for IPG operation. The IPG 10 is coupled to electrodes 16 via one or more electrode leads 15 forming an electrode array 17. The electrodes 16 are configured to contact the patient's tissue and are supported on a flexible body 18, which also houses an individual lead wire 20 coupled to each electrode 16. The lead wire 20 is also coupled to a proximal contact 22, which can be inserted into a lead connector 24 fixed in a head on the IPG 10, the head of which may include, for example, epoxy resin. Once inserted, the proximal contact 22 connects to head contacts within the lead connector 24, which are then fed through the housing via feedthrough pins to the circuitry within the housing 12, although these details are not shown.

[0004] In the illustrated IPG 10, there are sixteen lead electrodes (E1 to E16) split between two leads 15, with the head 23 containing a 2×1 array of lead connectors 24. However, the number of leads and electrodes in the IPG is application-specific and can therefore vary. The conductive housing 12 may also include electrodes (Ec). In SCS applications, the electrode leads 15 are typically implanted near the dura mater in the patient's spine on either side of the midline of the spinal cord. Proximal electrodes 22 tunnel through the patient's tissue to a distal location, such as the buttock where the IPG housing 12 is implanted, where they are coupled to the lead connectors 24. In other IPG examples designed for direct implantation at sites requiring stimulation, the IPG may be leadless, with its electrodes 16 instead appearing on the body of the IPG 10 for contact with patient tissue. In other IPG solutions, the IPG leads 15 may be integrated with and permanently attached to the housing 12. The goal of SCS treatment is to provide electrical stimulation from electrode 16 to relieve the patient’s symptoms, most notably chronic back pain.

[0005] The IPG 10 may include an antenna 26a that allows it to communicate bidirectionally with multiple external devices, as shown in FIG. 4. The antenna 26a depicted in FIG. 1 is shown as a conductive coil within the housing 12, although the coil 26a may also be present in the head 23. When the antenna 26a is configured as a coil, communication with external devices preferably occurs using near-field magnetic induction. The IPG may also include a radio frequency (RF) antenna 26b. In FIG. 1, the RF antenna 26b is shown within the head 23, but it may also be within the housing 12. The RF antenna 26b may include a patch, slot, or wire, and may operate as a monopole or dipole. The RF antenna 26b preferably uses far-field electromagnetic waves for communication. The RF antenna 26b can operate according to any number of known RF communication standards, such as Bluetooth, Zigbee, WiFi, MICS, etc.

[0006] Stimulation in the IPG 10 is typically provided by pulses, as shown in Figure 2. Stimulation parameters typically include: the amplitude of the pulse (A; whether current or voltage V); the frequency (F) and pulse width (PW); the electrode 16 (E) activated to provide stimulation; and the polarity (P) of these activated electrodes, i.e., whether the activated electrode acts as an anode (source current to the tissue) or a cathode (sink current from the tissue). These stimulation parameters, taken together, constitute the stimulation program that the IPG 10 can perform to provide therapeutic stimulation to the patient.

[0007] In the example of Figure 2, electrode E5 has been selected as the anode, thus providing a pulse of positive current with an amplitude of +A to the tissue. Electrode E4 has been selected as the cathode, thus providing a corresponding pulse of negative current with an amplitude of -A to the tissue. This is an example of bipolar stimulation, where only two lead-based electrodes (one anode and one cathode) are used to provide stimulation to the tissue. However, more than one electrode can act as an anode for a given time, and more than one electrode can act as a cathode for a given time (e.g., tripolar stimulation, quadrupole stimulation, etc.).

[0008] The pulse shown in Figure 2 is biphasic, comprising a first phase 30a followed by a second phase 30b of opposite polarity. The use of biphasic pulses is known to be useful in active charge recovery. For example, the current path to each electrode of the tissue may include a series-connected DC blocking capacitor, see, for example, U.S. Patent Application Publication 2016 / 0144183, which will be charged during the first phase 30a and discharged (recovered) during the second phase 30b. In the example shown, the first phase 30a and the second phase 30b have the same duration and amplitude (although opposite polarities), ensuring the same amount of charge during both phases. However, it is known that the second phase 30b can also be charged in balance with the first phase 30a if the integrals of the amplitude and duration of the two phases are equal in magnitude. The width PW of each pulse is defined here as the duration of the first pulse phase 30a, although the pulse width can also refer to the total duration of the first pulse phase 30a and the second pulse phase 30b. Note that an interphase period (IP) during which no stimulation is provided can be set between the two phases 30a and 30b.

[0009] The IPG 10 includes stimulation circuitry 28, which can be programmed, as defined by a stimulation program, to generate stimulation pulses at the electrodes. Thus, the IPG 10 acts as a power source to deliver electricity to the electrodes for stimulation of the patient. Stimulation circuitry 28 may include, for example, the circuitry described in U.S. Patent Application Publications 2018 / 0071513 and 2018 / 0071520 or in USP 8,606,362 and 8,620,436.

[0010] Figure 3 illustrates the external test stimulation environment that can be used before IPG 10 is implanted into a patient. During external test stimulation, stimulation can be attempted on the intended implantation patient without actually implanting IPG 10. In contrast, one or more test leads 15' are implanted in the patient's tissue 32 at a target location 34, such as within the spine as previously described. The proximal ends of one or more test leads 15' exit from the incision 36 and are connected to an external test stimulator (ETS) 40. The ETS 40 typically mimics the operation of the IPG 10 and can therefore deliver stimulation pulses to the patient's tissues as described above. See, for example, 9,259,574, which discloses a design for an ETS. The ETS 40 is typically worn externally by the patient for a short period (e.g., two weeks), which allows the patient and their clinician to experiment with different stimulation parameters to try and find stimulation procedures that relieve the patient's symptoms (e.g., pain). If the external test stimulus proves successful, one or more test leads 15' are removed, and a complete IPG 10 and one or more leads 15 are implanted as described above; if unsuccessful, only one or more test leads 15' are removed.

[0011] Similar to IPG 10, ETS 40 may include one or more antennas enabling bidirectional communication with external devices, as further illustrated with reference to FIG4. Such antennas may include a near-field magnetic induction coil antenna 42a and / or a far-field RF antenna 42b, as previously described. ETS 40 may also include stimulation circuitry 44 capable of generating stimulation pulses according to a stimulation program; this circuitry may be similar to or include the same stimulation circuitry 28 present in IPG 10. ETS 40 may also include a battery (not shown) for operating power.

[0012] Figure 4 illustrates various external devices that can wirelessly transmit data with IPG 10 and ETS 40, including a patient-held external controller 45 and a clinician programmer 50. Devices 45 and 50 can both be used to send stimulation programs to IPG 10 or ETS 40—that is, to program their stimulation circuits 28 and 44 to generate the previously described pulses with the desired shape and timing. Devices 45 and 50 can also both be used to adjust one or more stimulation parameters of the stimulation program currently being executed by IPG 10 or ETS 40. Devices 45 and 50 can also receive information from IPG 10 or ETS 40, such as various status information.

[0013] External controller 45 may be as described, for example, in U.S. Patent Application Publication 2015 / 0080982, and may include any dedicated controller configured to work with IPG 10. External controller 45 may also include general-purpose mobile electronic devices such as mobile phones that have been programmed to allow them to function as wireless controllers for IPG 10 or ETS 40 in medical device applications (MDAs), as described in U.S. Patent Application Publication 2015 / 0231402. External controller 45 includes a user interface comprising means for inputting commands (e.g., buttons or icons) and a display 46. The user interface of external controller 45 enables the patient to adjust stimulation parameters, although it may have limited functionality compared to the more powerful clinician programmer 50, as described later.

[0014] The external controller 45 may have one or more antennas capable of communicating with IPG 10 and ETS 40. For example, the external controller 45 may have a near-field magnetic induction coil antenna 47a, which is capable of wireless communication with coil antennas 26a or 42a in IPG 10 or ETS 40. The external controller 45 may also have a far-field RF antenna 47b, which is capable of wireless communication with RF antennas 26b or 42b in IPG 10 or ETS 40.

[0015] The external controller 45 may also have control circuitry 48, which may include a microprocessor, microcomputer, FPGA, other digital logic structures, application-specific integrated circuit (ASIC), etc., capable of executing instructions from electronic devices. Control circuitry 48 may, for example, receive patient adjustments to stimulation parameters and create stimulation programs that will be wirelessly transmitted to IPG 10 or ETS 40.

[0016] The clinician programmer 50 is further described in U.S. Patent Application Publication 2015 / 0360038, and is only briefly described here. The clinician programmer 50 may include a computing device 51, such as a desktop computer, laptop computer, tablet computer, mobile smartphone, personal digital assistant (PDA) type mobile computing device, etc. In Figure 4, the computing device 51 is shown as a portable computer, which includes typical computer user interface devices such as a screen 52, mouse, keyboard, speaker, stylus, printer, etc., not all of which are shown for convenience. Figure 4 also shows auxiliary devices for the clinician programmer 50, typically dedicated to its operation as a stimulus controller, such as a communication "stick" 54 and a joystick 58, which can be coupled to appropriate ports on the computing device 51, such as, for example, a USB port 59.

[0017] The antenna used in the clinician programmer 50 for communication with the IPG 10 or ETS 40 may depend on the type of antenna included in those devices. If the patient's IPG 10 or ETS 40 includes a coil antenna 26a or 42a, the rod 54 may similarly include a coil antenna 56a for establishing near-field magnetic induction communication at close range. In this example, the rod 54 may be secured close to the patient, for example, by placing it in a strap or sleeve that can be worn by the patient and is near the patient's IPG 10 or ETS 40.

[0018] If IPG 10 or ETS 40 includes RF antenna 26b or 42b, then rod 54, computing device 41, or both may similarly include RF antenna 56b to establish communication with IPG 10 or ETS 40 over greater distances. (In this case, rod 54 may not be necessary). Clinician programmer 50 may also communicate wirelessly or via a wired link provided at an Ethernet or network port with other devices and networks, such as the Internet.

[0019] To program the stimulation procedures or parameters of IPG 10 or ETS 40, the clinician interfaces with a clinician programmer graphical user interface (GUI) 64 provided on a display 52 of computing device 51. As will be understood by those skilled in the art, the GUI 64 can be presented by executing clinician programmer software 66 on computing device 51, which can be stored on the device's non-volatile memory 68. Those skilled in the art will further appreciate that the execution of the clinician programmer software 66 on computing device 51 can be facilitated by control circuitry 70 (such as a microprocessor, microcomputer, FPGA, other digital logic structures capable of executing programs in the computing device, etc.). In addition to executing the clinician programmer software 66 and presenting the GUI 64, such control circuitry 70 can also enable communication via antennas 56a or 56b to transmit selected stimulation parameters to the patient's IPG 10 through the GUI 64.

[0020] A portion of GUI 64 is shown as an example in Figure 5. Those skilled in the art will understand that the details of GUI 64 will depend on the position of the clinician programmer software 66 in its execution, and will depend on the GUI selections made by the clinician. Figure 5 shows a point in GUI 64 to allow setting stimulation parameters for a patient and storing them as a stimulation program. On the left is a program interface 72, which, as further described in '038 disclosure, allows naming, loading, and saving stimulation programs for a patient. On the right is a stimulation parameter interface 82, in which specified stimulation parameters (A, D, F, E, P) can be defined for the stimulation program. Values ​​of the stimulation parameters related to waveform shape (A; in this example, current), pulse width (PW), and frequency (F) are shown in the waveform parameter interface 84, which includes buttons that the clinician can use to increase or decrease these values.

[0021] The stimulation parameters associated with electrode 16 (the activated electrode E and its polarity P) can be adjusted in the electrode parameter interface 86. The electrode stimulation parameters are also visible and operable in the lead interface 92, which shows the lead 15 (or 15') approximately in its proper position relative to each other, for example, on the left or right side of the spine. A cursor 94 (or other selection device such as a mouse pointer) can be used to select a specific electrode in the lead interface 92. Buttons in the electrode parameter interface 86 allow the selected electrode (including the housing electrode Ec) to be designated as anode, cathode, or off. The electrode parameter interface 86 also allows specifying the relative intensity of the anodic or cathodic current of the selected electrode as a percentage X. This is particularly useful if, as described in the '038 disclosure, more than one electrode acts as anode or cathode at a given time. Based on the example waveform shown in Figure 2, as shown in the lead interface 92, electrode E5 has been selected as the sole anode for the pull current, and this electrode receives X = 100% of the specified anodic current + A. Similarly, electrode E4 has been selected as the sole cathode for sinking current, and this electrode receives X = 100% of the cathode current - A.

[0022] As shown, GUI 64 specifies the pulse width PW for only the first pulse phase 30a. Nevertheless, the clinician programmer software 66, which runs GUI 64 and receives input from it, ensures that IPG 10 and ETS 40 are programmed to present the stimulation program as biphasic pulses when biphasic pulses are used. For example, the clinician programming software 66 can automatically determine the duration and amplitude of both pulse phases 30a and 30b (e.g., each with a duration of PW and opposite polarities +A and -A). The advanced menu 88 can also be used (among other things) to define the relative duration and amplitude of pulse phases 30a and 30b, and allows for other more advanced modifications, such as setting the duty cycle (on / off time) of the stimulation pulses, and the rise time it takes for the stimulus to reach its programmed amplitude (A). The mode menu 90 allows the clinician to select different modes for determining the stimulation parameters. For example, as described in '038 disclosure, mode menu 90 can be used to enable electronic trolling, which includes an automatic programming mode that performs current guidance along the electrode array by moving the cathode in a bipolar manner.

[0023] Although GUI 64 is shown as operating in the clinician programmer 50, the user interface of the external controller 45 can also provide similar functionality.

[0024] Figure 6 illustrates an alternative embodiment of the implantable SCS system 600, which includes an implantable electrode lead 602 having electrodes 16 disposed thereon. The SCS system 600 does not use an implantable IPG to power the electrical stimulation. Instead, power is provided from an external power source (EPS) 604 via radio frequency (RF) transmission through patient tissue 32. The EPS has an RF antenna 606 configured to transmit RF power, and the implantable lead 602 includes an antenna 608 configured to receive RF power. The implantable lead 602 also has a simple circuit (not shown) configured to rectify the RF power and generate pulses. Similar to the IPG system described above, the RF-powered system 600 can use an external controller 45 to control and transmit stimulation parameters. However, in system 600, the external controller 45 provides stimulation parameters to the EPS 604 instead of the implantable IPG. Although the EPS 604 and the external controller 45 are shown as separate units in Figure 6, the EPS 604 and the external controller 45 can be combined into a single unit. The SCS system 600 shown is superior to the system shown in Figure 1 in that it does not require surgical implantation of the IPG (10, Figure 1) and the tunnel lead wire (20, Figure 1) between the IPG and the electrode leads. However, a disadvantage of system 600 (Figure 6) is that the patient must position the EPS 604 near their tissues whenever they wish to receive stimulation. For example, the EPS 604 can be carried in a strap, bag, or other carrier device. As shown in Figure 6, systems that rely on the RF energy provided by the EPS are referred to herein as "RF systems". Summary of the Invention

[0025] An external device configured to communicate with an implantable stimulator device implanted in a patient is disclosed, comprising: control circuitry configured to: provide stimulation parameters for the patient to address the patient's symptoms; provide a schedule for the supply of scheduled stimulation boluses for the patient, wherein each scheduled bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, wherein the scheduled bolus is separated by off-times when no stimulation is provided to the patient, wherein the first duration of each scheduled bolus is 3 minutes or longer, and wherein a second duration of each off-time is 30 minutes or longer; and transmit instructions to cause the implantable stimulator device to deliver the scheduled bolus to the patient's neural tissue according to the schedule.

[0026] In the example, stimulation parameters are set to provide subsensory stimulation to address the patient's symptoms. In the example, the implantable stimulator device includes a spinal cord stimulator. In the example, the stimulation provided during each scheduled bolus includes a periodic pulse sequence. In the example, stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the first duration of the scheduled bolus is variable. In the example, the second duration of the off-time is variable. In the example, the control circuitry is also configured to: determine the patient's activity or receive information indicating the patient's activity. In the example, the control circuitry is also configured to: adjust either or both of the first duration of the scheduled bolus or the second duration of the off-time based on the determined activity or information indicating that activity. In the example, the stimulation parameters are determined based on the determined activity or information indicating that activity. In the example, the external device includes a graphical user interface. In the example, the control circuitry is also configured to: receive input at the graphical user interface at a first time to immediately provide an additional stimulation bolus. In the example, the control circuitry is also configured to transmit a command such that the implantable stimulator device immediately provides additional bolus stimulation to the patient's neural tissue in addition to the scheduled bolus. In the example, the control circuitry is programmed with a lockout period, wherein the control circuitry is further configured to transmit a command such that the implantable stimulator device immediately provides additional bolus stimulation to the neural tissue only if a third duration between the first time and the preceding scheduled bolus is equal to or longer than the lockout period. In the example, the control circuitry is also configured to rearrange at least one of the scheduled boluses after the additional bolus, according to the lockout period.

[0027] A method for delivering stimulation to a patient using an implantable stimulator device is disclosed, comprising: determining stimulation parameters for the patient to address the patient's symptoms; determining a schedule for the delivery of scheduled stimulation boluses to the patient, wherein each bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, wherein the scheduled bolus is separated by off-times when no stimulation is provided to the patient, wherein the first duration of each scheduled bolus is 3 minutes or longer, and wherein a second duration of each off-time is 30 minutes or longer; and delivering the scheduled bolus to the patient's neural tissue according to the schedule using the implantable stimulator device.

[0028] In the example, stimulation parameters provide subsensory stimulation to address the patient's symptoms. In the example, the neural tissue includes the patient's spinal cord. In the example, the stimulation provided during each scheduled bolus includes a periodic pulse sequence. In the example, stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the first duration of the scheduled bolus is variable. In the example, the second duration of the off-time is variable. In the example, the method further includes: determining the patient's activity. In the example, either or both of the first duration of the scheduled bolus or the second duration of the off-time are adjusted based on the determined activity or information indicating the activity. In the example, stimulation parameters are determined based on the determined activity or information indicating the activity. In the example, the patient's activity is determined using an activity sensor. In the example, the activity sensor is within the implantable stimulator device. In the example, stimulation parameters are determined in an external device communicating with the implantable stimulator device, and the timing is determined in the external device. In the example, information regarding the injection is transmitted from an external device communicating with the implantable stimulator device to the implantable stimulator device, and wherein the external device includes a graphical user interface. In the example, the method further includes: immediately providing an additional injection to the neural tissue in addition to providing the scheduled injection. In the example, the graphical user interface is programmed with a locked time period and further includes: immediately providing an additional stimulation injection to the neural tissue only if a third duration between the first time period and the preceding scheduled injection is equal to or longer than the locked time period. In the example, the method further includes: rescheduling at least one of the scheduled injections after the additional injection, according to the locked time period.

[0029] An external device configured to communicate with an implantable stimulator device implanted in a patient is disclosed, comprising: control circuitry configured to: provide stimulation parameters for the patient to address the patient's symptoms; provide a schedule for the supply of scheduled stimulation boluses to the patient, wherein each scheduled bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, wherein the scheduled boluses are separated by off-times of a second duration when no stimulation is provided to the patient; receive input at a graphical user interface of the external device at a first time to immediately provide additional stimulation boluses; and transmit instructions to cause the implantable stimulator device to provide at least the scheduled boluses to the patient's neural tissue according to the schedule.

[0030] In the example, stimulation parameters are set to provide subsensory stimulation to address the patient's symptoms. In the example, the implantable stimulator device includes a spinal cord stimulator. In the example, the first duration of each scheduled injection is 3 minutes or longer, and the second duration of each off-time is 30 minutes or longer. In the example, the stimulation provided during each scheduled injection includes a periodic pulse sequence. In the example, stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the first duration of the scheduled injection is variable. In the example, the second duration of the off-time is variable. In the example, the control circuitry is also configured to: determine the patient's activity or receive information indicating the patient's activity. In the example, the control circuitry is also configured to: adjust either or both of the first duration of the scheduled injection or the second duration of the off-time based on the determined activity or information indicating that activity. In the example, the stimulation parameters are determined based on the determined activity or information indicating that activity. In the example, the control circuitry is configured to transmit a command such that the implantable stimulator device immediately provides additional bolus stimulation to the patient's neural tissue in addition to the scheduled bolus. In the example, the control circuitry is programmed with a locked time period, wherein the control circuitry is further configured to transmit a command such that the implantable stimulator device immediately provides additional bolus stimulation to the neural tissue only if a third duration between the first time and the preceding scheduled bolus is equal to or longer than the locked time period. In the example, the control circuitry is also configured to reschedule at least one of the scheduled boluses after the additional bolus, according to the locked time period.

[0031] A method for delivering stimulation to a patient using an implantable stimulator device and an external device communicating with the implantable stimulator device is disclosed, comprising: determining stimulation parameters for the patient to address the patient's symptoms; determining a schedule of scheduled stimulation boluses for the patient, wherein each bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, wherein the scheduled boluses are separated by off-times when no stimulation is provided to the patient; receiving input from the patient at a graphical user interface of the external device at a first moment to immediately provide additional stimulation boluses; and using the implantable stimulator device to deliver the scheduled boluses to the patient's neural tissue according to the schedule.

[0032] In the example, stimulation parameters provide subsensory stimulation to address the patient's symptoms. In the example, the neural tissue includes the patient's spinal cord. In the example, the stimulation provided during each scheduled bolus includes a periodic pulse sequence. In the example, stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the first duration of the scheduled bolus is variable. In the example, the second duration of the off-time is variable. In the example, the method further includes determining the patient's activity. In the example, either or both of the first duration of the scheduled bolus or the second duration of the off-time are adjusted based on the determined activity or information indicating that activity. In the example, stimulation parameters are determined based on the determined activity or information indicating that activity. In the example, the patient's activity is determined using an activity sensor. In the example, the activity sensor is within the implantable stimulator device. In the example, stimulation parameters are determined in an external device communicating with the implantable stimulator device, and the timing is determined in the external device. In the example, information regarding the injection is transmitted from an external device communicating with the implantable stimulator device to the implantable stimulator device, and wherein the external device includes a graphical user interface. In the example, the method further includes: immediately providing an additional injection to the neural tissue in addition to providing the scheduled injection. In the example, the graphical user interface is programmed with a locked period, and further includes: immediately providing an additional stimulatory injection to the neural tissue only if a third duration between the first time and the preceding scheduled injection is equal to or longer than the locked period. In the example, the method further includes: rescheduling at least one of the scheduled injections after the additional injection, according to the locked period.

[0033] An external device configured to communicate with an implantable stimulator device implanted in a patient is disclosed, comprising: control circuitry configured to: provide stimulation parameters for the patient to address the patient's symptoms; wherein the stimulation parameters provide subsensory stimulation pulses to address the patient's symptoms; receive a first input to program a first duration; receive a second input at a graphical user interface of the external device at a first time to immediately provide a single injection stimulation, and transmit instructions to cause the implantable stimulator device to provide a single injection to the patient's neural tissue during the first duration, wherein the single injection comprises a plurality of periodic subsensory stimulation pulses formed according to the stimulation parameters.

[0034] In the example, the implantable stimulator device includes a spinal cord stimulator. In the example, the first duration of a single injection is 3 minutes or longer. In the example, stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the control circuitry is also configured to: determine patient activity or receive information indicating patient activity. In the example, the control circuitry is also configured to: adjust the first duration of the single injection based on the determined activity or information indicating that activity. In the example, stimulation parameters are determined based on the determined activity or information indicating that activity. In the example, the control circuitry is programmed with a lockout period, wherein the control circuitry is also configured to: transmit a command such that the implantable stimulator device immediately provides a single injection stimulation to the neural tissue only if a second duration between the first time and the previous injection is equal to or longer than the lockout period. In the example, the control circuitry is also configured to: schedule at least one additional injection after the single injection based on the lockout period.

[0035] A method for delivering stimulation to a patient using an implantable stimulator device and an external device communicating with the implantable stimulator device is disclosed, comprising: determining stimulation parameters for the patient to address the patient's symptoms, wherein the stimulation parameters provide subsensory stimulation pulses to address the patient's symptoms; receiving a first input at the external device to program a first duration; receiving a second input from the patient at a graphical user interface of the external device to immediately deliver a single injection stimulation; and using the implantable stimulator device to deliver a single injection to the patient's neural tissue during the first duration, wherein the single injection comprises a plurality of periodic subsensory stimulation pulses formed according to the stimulation parameters.

[0036] In the example, the neural tissue includes the patient's spinal cord. In the example, the first duration of a single injection is 3 minutes or longer. In the example, the stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency. In the example, the frequency is 10 kHz or lower. In the example, the frequency is 1 kHz or lower. In the example, the amplitude includes a constant current amplitude. In the example, the method further includes: determining the patient's activity. In the example, adjusting the first duration of the single injection based on the determined activity. In the example, determining the stimulation parameters based on the determined activity. In the example, the patient's activity is determined using an activity sensor. In the example, the activity sensor is located within the implantable stimulator device. In the example, information about the injection is transmitted from an external device to the implantable stimulator device. In the example, the graphical user interface is programmed with a locked time period and further includes: immediately delivering a single stimulation injection to the neural tissue only when a third duration between the first time period and the preceding scheduled injection is equal to or longer than the locked time period. In the example, the method further includes: rescheduling at least one of other injections after the single injection based on the locked time period. Attached Figure Description

[0037] Figure 1 illustrates an implantable pulse generator (IPG) that can be used for spinal cord stimulation (SCS) according to the prior art.

[0038] Figure 2 shows an example of stimulation pulses that can be generated by IPG according to the prior art.

[0039] Figure 3 illustrates the use of an external experimental stimulator (ETS) according to existing technology that can be used to provide stimulation prior to IPG implantation.

[0040] Figure 4 illustrates various external devices, based on existing technologies, capable of communicating with and programming stimuli in the IPG and ETS.

[0041] Figure 5 shows a graphical user interface (GUI) of a clinician programmer external device for setting or adjusting stimulation parameters according to the prior art.

[0042] Figure 6 shows alternative configurations of the SCS system using an external power supply.

[0043] Figure 7 A system for providing the prescribed amount of stimulation is shown.

[0044] Figure 8 An algorithm for determining the dosage of stimulation is shown.

[0045] Figure 9 A user interface for tracking the prescribed stimuli is shown.

[0046] Figure 10 An algorithm for identifying and monitoring bolus-mode stimuli is shown.

[0047] Figure 11 An algorithm for preemptive stimulus injection is shown.

[0048] Figures 12A-12C The algorithm used for preemptive stimulus injection is shown.

[0049] Figure 13A and Figure 13B The use of stimulation injection in providing subsensory stimulation therapy is illustrated.

[0050] Figure 14 A graphical user interface that can be operated on an external device is shown, which can be used to schedule subsensory therapy.

[0051] Figure 15 This demonstrates how to use the IPG system to detect various patient activities and perform injection procedures associated with specific detected activities.

[0052] Figure 16A and Figure 16B An algorithm that can operate on an external device is shown for determining an optimized injection procedure for a patient. Detailed Implementation

[0053] Typically, once a patient has been identified as a candidate for neuromodulation therapy (such as spinal cord stimulation (SCS)), the patient receives one or more surgically implantable electrode leads (such as lead 15, Figure 1). These leads can then be connected to an external experimental stimulator (ETS 40, Figure 4), which allows the patient and their clinician to experiment with different stimulation parameters to try and find a stimulation program that relieves the patient's symptoms (e.g., pain). If the experimental stimulation proves successful, the patient can receive a fully implantable IPG (10, Figure 1). The patient will also typically receive an external controller (45, Figure 4) that can be programmed with one or more stimulation programs that include parameters determined to be most effective. The external controller allows the patient to select the stimulation program and also allows them to control various parameters of their treatment (such as stimulation intensity, duration, etc.). In the current paradigm, patients are simply discharged, and they can freely self-administer the treatment without needing to return to their physician for effectiveness or follow-up review.

[0054] The inventors have recognized the shortcomings of this treatment paradigm. On the one hand, simply discharging patients without further follow-up may miss opportunities for further evaluation and optimization of their treatment. This contrasts with typical pharmacological regimens, in which clinicians prescribe a limited number of drug doses and require follow-up visits to re-prescribe.

[0055] Another problem with the current SCS (Self-Suppressive Cognitive Surgery) paradigm, which allows patients unrestricted self-treatment, is that patients may overuse stimuli and develop tolerance to them. Even without other side effects, overstimulation can reduce therapeutic effectiveness. Patients may increase the frequency and / or intensity of their stimulation to compensate for this reduction. However, this increase in stimulation can actually negatively impact the patient's treatment because it accelerates the rate at which the patient develops tolerance. An ideal system would allow clinicians to manage the use of stimulation so that patients do not overuse it and thus reduce therapeutic effectiveness.

[0056] The systems and methods disclosed herein enable clinicians to prescribe a set amount of stimulation that a patient can receive before requesting a further prescription for additional stimulation. According to some embodiments, the prescribed amount of stimulation can be programmed into the patient's external controller or IPG. The system can track the amount of stimulation used. The user interface of the external controller can include an indication of the remaining prescribed amount of stimulation. When the patient has used all the prescribed stimulation, the patient can be directed to schedule a follow-up visit with their clinician to receive a "refill" of their stimulation prescription. According to some embodiments, the patient's external controller can be an internet-connected device, in which case the external controller can be configured to send a message to the clinician indicating that the patient has used all their prescribed stimulation, allowing the clinician to proactively contact the patient to schedule an appointment.

[0057] Figure 7 A system 700 for prescribing and monitoring stimulation therapy is illustrated. The system includes a clinician programmer 50, which includes the functions described above. Furthermore, the clinician programmer 50 includes one or more treatment prescription modules 702 configured to assist the clinician in prescribing a specific amount of stimulation therapy. The one or more treatment prescription modules 702 may be implemented as instructions contained within a non-transitory computer-readable medium associated with the clinician programmer 50 and executable by the processing resources of the clinician programmer (i.e., one or more microprocessors and / or control circuitry). Such execution configures the clinician programmer to perform the functions of the prescription modules 702, which will be described in more detail below.

[0058] The clinician programmer is configured to send stimulation prescriptions to the patient's external controller 45 or the patient's IPG 10. The patient's external controller 45 may have all the functions described above for controlling the patient's IPG 10 (Figures 1, 3, and 4), ETS (Figure 4), and / or EPS 604 (Figure 6). In the illustrated embodiment, the external controller is configured with a stimulation tracking and display module 704, which is configured to receive stimulation prescriptions from the clinician programmer 50, track the amount of stimulation used, and display the remaining amount of stimulation on the prescription to the patient. The stimulation tracking and display module 704 may be implemented as instructions contained within a non-transitory computer-readable medium associated with the external controller 45 and executable by the processing resources of the external controller (i.e., one or more microprocessors and / or control circuitry). This execution configures the external controller to perform the functions of the stimulation tracking and display module. According to other embodiments, the prescription and tracking of the stimulation used may be performed in the IPG, which may transmit prescription / usage information to the patient's external controller for display.

[0059] When the prescribed stimulus is exhausted, the patient can be prompted to schedule an appointment with their clinician to receive a further prescription for additional stimulus. As mentioned above, if the patient's external controller 45 is a networked device, it can be configured to send a notification to the clinician indicating that the patient's prescribed stimulus has been exhausted or is about to be exhausted, allowing the clinician to proactively contact the patient to schedule an appointment. In embodiments where the IPG tracks prescriptions, the IPG can be configured to send a notification (e.g., via Bluetooth connection) to the patient's personal phone or other computing device, informing them that the prescription has been exhausted or is nearing exhaustion. According to some embodiments, the clinician programmer 50 can be configured to refresh prescriptions via an Internet connection.

[0060] According to some embodiments, the prescribed stimulation amount can be set as the total amount of charge actively delivered. Figure 8 An example embodiment of algorithm 800 is shown, which a clinician can use to determine and prescribe the amount of total charge to prescribe treatment for a patient. Algorithm 800 can be implemented as a program in clinician programmer 50 (Figure 4), for example, as a prescription module 702 (…). Figure 7 The algorithm is a component of [the system / mechanism]. It assumes that clinicians and patients have identified one or more stimulation procedures that are expected to benefit the patient. The process of determining the appropriate stimulation procedure can be called the fitting process.

[0061] At step 802 of the algorithm, the algorithm receives stimulation parameters for one or more procedures determined during the fitting process. For example, suppose a clinician has determined that a patient experiences pain relief when stimulated with a simple biphasic stimulation waveform (such as the waveform shown in Figure 2). Assume the waveform has a frequency of 100 Hz, an amplitude of 3 mA, and a pulse width of 100 μs. All these parameters are provided to the algorithm in step 802. Of course, the stimulation procedures can be more complex, for example, involving complex pulse shapes, pulse patterns, and the like. Furthermore, multiple procedures can be determined during the fitting process. But for simplicity, a single simple biphasic waveform is considered here.

[0062] At step 804, the algorithm analyzes the stimulation waveform included in the defined stimulation program and calculates the rate at which charge is injected into the patient during the execution of the stimulation program (i.e., the amount of actively driven charge provided as a function of time). For example, the stimulation parameters listed above would nominally deliver 0.108 coulombs of charge per hour during the execution of the stimulation program.

[0063] At step 806, the algorithm receives input indicating the ideal amount of stimulation to be applied before the patient returns for a follow-up visit. For example, suppose the clinician believes the patient should typically receive 12 hours of stimulation daily, and the clinician wants the prescription to last for 6 months, after which the patient should return for a follow-up visit. The clinician inputs these time parameters into the user interface of the clinician programmer, for example, as in prescription module 702 (…). Figure 7 Part of ).

[0064] At step 808, the algorithm calculates the charge prescription. In this simple example, the calculation is relatively straightforward. The programmed stimulation parameter values—amplitude, frequency, and pulse width—provide an actively driven charge at a rate of 0.108 coulombs per hour. If the patient receives stimulation for 12 hours daily, this rate correlates with 1.3 coulombs per day, which further correlates with 232 coulombs over six months (180 days). Therefore, based on the parameters provided by the clinician, the prescription will be calculated as 232 coulombs. It should be understood that because the algorithm has access to the stimulation waveform program and associated stimulation parameters, it can be configured to calculate an actively driven charge typically used for any stimulation duration, even for complex waveforms.

[0065] At step 810, the calculated charge prescription can be sent from the clinician programmer to the patient's external controller. It should be noted that while the illustrated algorithm 800 calculates the stimulus prescription based on charge coulombs, clinicians and patients themselves may not be interested in the absolute value of the coulombs. Instead, clinicians can simply prescribe the stimulus based on specific stimulus parameters, the daily stimulus amount, and the ideal length of time before the follow-up appointment. Given these data points, algorithm 800 calculates the "charge prescription." It should also be noted that the prescription can be determined based on the total energy related to the stimulus amount or some other metric. For example, clinicians can prescribe the stimulus based on time, the time of day, or the stimulus push, which will be discussed in more detail below. The prescription module 702, executed on the clinician programmer, can be configured with various options to allow clinicians to prescribe stimuli.

[0066] Figure 9 An embodiment of an external controller 45 with a display 46 is shown. The external controller may include a stimulus tracking and display module 704. Figure 7 The system is configured to receive stimulation prescriptions from a physician controller and take into account the amount of charge used during stimulation. The remaining charge on the patient's prescription can be displayed on a display 46 of the patient's external controller. For example, in the illustrated embodiment, the external controller presents a meter 902 indicating the remaining amount of treatment on the prescription. When patients use their SCS system, their external controller can track the amount of charge used and can display the remaining charge on the prescription (as charge or some variable related to charge). When a patient's prescribed charge is depleted or nearly depleted, they may be prompted to schedule a follow-up appointment with a clinician. Patients may use their prescribed stimulation at a faster rate than expected, for example, by applying stimulation more frequently or by using a larger amplitude or pulse width. In this case, the patient will be prompted to schedule a follow-up earlier than expected, six months later. This allows the patient and clinician to explore why the patient needs more stimulation than expected.

[0067] According to some embodiments, the stimulation can be provided in discrete blocks of stimulation, referred to as a “bolus” of stimulation. A bolus of stimulation can be considered similar to a single dose of stimulation, analogous to a dose of medication. For example, a bolus may include stimulation over a first time period, such as 10 minutes (or 30 minutes, or 1 hour, etc.). After the bolus is administered, no further stimulation is provided until another bolus is administered. Typically, the time period between boluses (i.e., the second time period) is on the order of at least several minutes or hours. For example, according to some embodiments, the second time period may be from thirty minutes to twelve hours. However, according to some embodiments, the patient may administer another bolus immediately following the first bolus, just as the patient may take a second dose of medication immediately following the first dose. Preferably, the bolus comprises multiple pulses periodically administered at a set frequency.

[0068] Observations have shown that some patients respond well to bolus therapy. Patients can initiate a bolus when pain occurs. Some patients experience prolonged pain relief lasting for hours or longer after receiving a bolus. According to some embodiments, clinicians can prescribe bolus therapy based on the number of boluses. To draw an analogy with medication prescribing, clinicians might prescribe a given number of boluses daily for a specific duration. For example, a clinician might prescribe five 30-minute boluses daily for three months, after which the patient returns for follow-up evaluation.

[0069] Figure 10 An example of a method 1000 for determining and specifying a bolus injection pattern for treatment is shown. At step 1002, appropriate stimulation parameters are determined for the patient. As described above, this process is typically performed in a clinician programmer 50 (Figures 4, 5, and...). Figure 7This is accomplished during the fitting session with the help of an implantable IPG (or ETS or EPS) and its external controller 45. It is assumed that during the fitting process, the clinician has identified one or more stimulation procedures to alleviate the patient's pain, and that the clinician believes the patient is likely to respond well to the bolus treatment. After determining the optimal stimulation parameters, the patient can be released using the implantable IPG (or ETS or EPS) and its external controller 45 to determine the appropriate time period corresponding to the stimulation bolus. For example, the stimulation tracking and display module 704 in the patient's external controller can be programmed with a bolus algorithm configured to assist the patient and clinician in determining the appropriate stimulation bolus. The goal is to determine the stimulation time period that achieves long-term pain relief. When the patient experiences a pain attack, they can activate a trial bolus. For example, a trial bolus could include a 5-minute stimulation using the patient's optimal stimulation parameters. The patient will receive the bolus of stimulation, after which the stimulation will terminate. The patient can then be asked to periodically assess their pain relief using the interface of their external controller (e.g., hourly after the administration of the trial bolus). Different stimulation time periods can be tried over a period of days or weeks to determine the shortest time period that provides the longest sustained pain relief. Depending on the preferences of the patient and clinician, various optimization criteria can be used to determine the optimal bolus. Alternatively, at step 1004, the clinician can simply decide what time period of stimulation will constitute a stimulation push.

[0070] Once the appropriate stimulation duration corresponding to the stimulation injection has been determined, the patient can receive a prescription for the injection quantity (step 1006). According to some embodiments, the patient can return to their clinician after the injection determination step (step 1004), allowing the clinician to program the patient's external controller with the prescription for the given number of injections. According to some embodiments, if the patient's external controller is a networked device, the patient may not need to return to the clinician. Instead, the patient's external controller can send the injection duration to the clinician's programmer via an Internet connection, and the clinician's programmer can send the injection prescription to the patient's external controller via an Internet connection. Once the patient's external controller is programmed with the injection prescription, the external controller can monitor the number of injections used (step 1008). The remaining number of injections on the patient's prescription can be displayed on the external controller. Once the patient has used the prescribed number of injections, the patient can be prompted to schedule a follow-up visit with their clinician.

[0071] It should be noted that, according to some embodiments, clinicians can simply specify a stimulation duration as a bolus without using an algorithm such as Algorithm 1000. For example, a clinician can simply decide that a stimulation bolus will correspond to a ten-minute stimulation. Alternatively, according to some embodiments, the patient's external controller can be programmed with an algorithm that helps the patient determine the appropriate stimulation bolus without the clinician's approval. For example, the patient's external controller can be programmed to have a bolus calibration duration, such as two weeks, during which the patient is prompted to rate or rank the treatment using different bolus durations. After the calibration duration, the external controller uses the determined optimal stimulation duration as the stimulation bolus. The external controller can then begin tracking the number of remaining boluses prescribed by the patient. For example, the external controller's GUI can notify the patient that they have x boluses remaining out of y boluses.

[0072] According to some embodiments, a patient's external controller can be programmed with one or more algorithms that attempt to optimize when a stimulus push should be issued. When the algorithm determines that a push should be issued, the patient's external controller can alert the patient to administer the stimulus push themselves. Such embodiments may be particularly useful for patients using RF systems (i.e., systems without an implanted IPG). Patients using such systems can receive a notification or alert when it is time to receive a stimulus push, and then the patient can appropriately schedule their external power supply (EPS) to administer the push themselves. Alternatively, patients using systems with a conventional IPG can use their external controller to instruct the IPG to issue a stimulus push when they receive an alert that it is time to issue a push. According to some embodiments, the external controller can simply instruct the IPG to issue a push automatically without requiring the patient to instruct the external controller to do so. According to some embodiments, the patient can receive an alert on their personal computing device (such as a personal phone) when it is time to administer a push.

[0073] Figure 11An example of an algorithm 1100 for predicting when a push should be made is shown. Algorithm 1100 includes a “training period” during which the algorithm attempts to associate one or more “pain predictors” with instances where the patient himself makes a push. A pain predictor is a predictor that indicates the need for stimulation. Examples of pain predictors may include time of day, weather, the patient’s activity level, or one or more physiological parameters of the patient, such as heart rate, blood pressure, posture, or the like. For example, during the training period, the algorithm may determine that the patient tends to make a push at certain times of day. Therefore, the algorithm can determine those times of day when the patient is likely to experience pain. Similarly, the algorithm may determine that the patient tends to make a push when transitioning from a sitting to a standing position, or vice versa. Such postural changes can be detected using measured evoked compound action potentials (ECAPs) or other sensed neural responses, as described in PCT International Patent Serial No. PCT / US20 / 036667, filed June 8, 2020. Alternatively (or additionally), an accelerometer may be used to determine changes in posture and / or patient activity levels. One or more physiological sensors associated with the patient may be used to determine physiological parameters such as heart rate, blood pressure, and the like. According to some embodiments, pain predictors such as activity levels, weather, posture, and the like may be determined based on patient input (e.g., via an application running on their external controller or other external devices communicating with their external controller). Alternatively, to determine weather conditions, the patient's external controller (or other external devices communicating with the external controller) may be configured to obtain weather information via Internet weather data. For example, the training period may be several days or several weeks.

[0074] Once the training period ends, the algorithm can proceed to targeted or automated treatment protocols, whereby it monitors one or more pain predictors. When a pain predictor is detected, the algorithm can instruct the patient to preemptively administer a bolus, or it can automatically administer a bolus to the patient without patient input. As mentioned above, the embodiment instructing the patient to preemptively administer a bolus is particularly useful for patients with RF systems that do not use implanted IPGs.

[0075] According to some embodiments, patients can be prompted to rate the effectiveness of the attempted treatment procedure, for example, by selecting a rating on the user interface of their external controller. Based on patient feedback, the algorithm can attempt to optimize the algorithm.

[0076] Figures 12A-12C An example of algorithm 1100 for determining when to preemptively issue a stimulus push is shown. Figures 12A-12C The example algorithm 1100 shown uses the time of day as a pain predictor and also uses patient feedback to optimize the algorithm. Figure 12A The training period is shown, in which patients self-administer a bolus (by a lightning bolt) each time they perceive an attack of pain (represented by a lightning bolt). Figures 12A-12C (The capsule is represented in the image). According to some embodiments, the algorithm can track the timing of the patient's own injection and then attempt to preemptively inject before the patient experiences a pain attack. Note that in... Figure 12A In this study, patients' pain events were more heavily weighted in the earlier part of the day. It is assumed that Algorithm 1100 has already tracked... Figure 12A The three-day treatment is shown in the image. Figure 12B The algorithm attempts to be based on the patient's condition. Figure 12A The bolus injection administered is delivered preemptively over a three-day timeframe. For example, in... Figure 12A In this case, patients received an average of three bolus injections per day. Therefore, in Figure 12B In the middle, Algorithm 1100 is interacting with... Figure 12A The algorithm automatically delivers boluses during the most matching time periods. Patients can continue to self-administer boluses, and Algorithm 1100 can continue to optimize the timing of automatic bolus delivery. For example, on days 1 and 3, preemptive boluses may not be sufficient to fully relieve the patient's pain, and the patient must self-administer additional boluses on these days. Figure 12B In the study, patients rated two-fifths of their treatment responses. Figure 12C In this algorithm, the treatment is attempted to be improved by issuing a third bolus earlier in the day, corresponding to a self-administered bolus. The patient does not need to self-administer stimulation boluses over the three-day period and rates the treatment as four out of five. Algorithm 1100 can therefore determine... Figure 10 The timing determined in C can be used for ongoing treatments.

[0077] Compared to traditional continuous therapy, bolus therapy offers several advantages. For example, bolus therapy reduces the chance of patients overusing stimulation, thus preventing the development of tolerance to the treatment. Furthermore, bolus therapy is particularly suitable for RF stimulation systems, such as those described above with reference to Figure 6. Because bolus stimulation is applied for only a limited duration, patients using RF systems only need access to their external power source during the period they receive the bolus stimulation.

[0078] Various aspects of the disclosed technology include processes that can be implemented in an IPG or ETS, and / or in an external device (such as a clinician programmer or external controller), which can be expressed as formulas and stored as instructions in a computer-readable medium associated with such a device, such as being stored in magnetic storage, optical storage, or solid-state storage. The computer-readable medium having such stored instructions may also include devices readable by a clinician programmer or external controller, such as in a memory stick or removable disk, and may reside elsewhere. For example, the computer-readable medium may be associated with a server or any other computer device, thus allowing instructions to be downloaded to the clinician programmer system or external system, or to the IPG or ETS, via, for example, the Internet. The various algorithms described herein and stored in a non-transitory computer-readable medium can be executed by one or more microprocessors and / or control circuitry configured within the associated device, causing the device to perform the steps of one or more algorithms.

[0079] The disclosed techniques for delivering stimulation via injection have also demonstrated benefits in providing sub-perception stimulation therapy to patients. As discussed in other applications, such as PCT International Patent Application Serial No. PCT / US2020 / 040529 filed July 1, 2020, while spinal cord stimulation (SCS) therapy can be an effective means of relieving patient symptoms (such as pain), such stimulation can also cause sensory abnormalities. Sensory abnormalities—sometimes referred to as “supra-perception” therapy—are sensations such as tingling, itching, heat, cold, etc., which can accompany spinal cord stimulation therapy. Typically, the effects of sensory abnormalities are mild, or at least not of great concern to patients. Furthermore, for patients whose pain (neurogenic, nociceptive, and / or mechanical) is now controlled by stimulating nerve tissue through SCS therapy, experiencing sensory abnormalities may be a reasonable trade-off. Some patients even find sensory abnormalities comfortable and soothing.

[0080] Nevertheless, at least for some patients, SCS therapy will ideally provide complete pain relief without sensory abnormalities—often referred to as “subsensory” or subthreshold therapy, which the patient cannot perceive. The '529 application explains different examples of how effective subsensory therapy can be provided to patients. In the examples of the '529 application, subsensory stimulation is typically provided at frequencies such as 10 kHz or lower, or more preferably 1 kHz or lower. Providing subsensory stimulation at lower frequencies is preferred because it is generally less power-intensive, meaning the battery in the IMD will last longer or will not need to be charged as frequently as when using higher frequencies.

[0081] '529 application provides an example of the injection that provides subsensory stimuli, which is discussed in this paper.' Figure 13A and Figure 13B As shown in the image. Figure 13A As shown, and as in the previous example, injections are provided periodically and within set time periods (such as ten minutes, thirty minutes, one hour, two hours) or any other effective duration, with time intervals of no stimulation between injections. As discussed earlier, patients can initiate injections of stimulation when pain occurs, or these injections can be administered automatically. Providing subsensory stimulation via injection can be beneficial because some patients experience prolonged pain relief lasting for hours or longer after receiving injections of stimulation. Furthermore, providing injections of stimulation saves power in the IPG because the stimulation is not continuous and also helps prevent tissue overstimulation and habituation, where tissue becomes “accustomed” to the stimulation, making it less effective over time.

[0082] like Figure 13B As shown, the subsensory stimulation parameters used during each stimulation bolus can be adjusted. For example, the stimulation bolus shown is 100 minutes in length and consists of five different time intervals t1-t5, each lasting 20 minutes. In this example, one or more stimulation parameters (e.g., pulse width and frequency) are adjusted to conform to the subsensory stimulation parameters 420 identified as optimized in application '529'. In this example, these optimized stimulation parameters 420' include the relationship between the frequency and pulse width of the subsensory stimulation pulses. However, other stimulation parameters, such as pulse amplitude, can also be identified as part of the optimized stimulation parameters 420'. In this example, the subsensory stimulation parameters are changed during each bolus, conforming to the optimized stimulation parameters 420'. For example, during the first part of the bolus (t1, 20 minutes), a relatively high pulse width and a relatively low pulse frequency are used. During the next part of the bolus (t2, 20 minutes), the frequency is increased while the pulse width is decreased. Again, this is just one example. Furthermore, the subsensory stimulation parameters used during the injection do not need to be changed, but can instead remain constant throughout the entire duration of each injection.

[0083] Subsensory stimulation therapy is well-suited for prescriptions using bolus-based stimulation, as discussed in the '529 application. Subsensory stimulation is relatively quickly "washed in" and relatively slowly "washed out." "Washing in" refers to the period before the subsensory stimulation becomes effective for the patient's symptoms (such as pain), and can be as short as a few seconds or minutes. "Washing out" refers to the period after stimulation has ceased, during which the subsensory stimulation remains effective for the treated symptoms, and can be up to several hours. Accordingly, delivering subsensory stimulation by bolus can be effective and beneficial because each bolus provides rapid treatment for the patient and remains effective even after the bolus ends and the next bolus is applied. Delivering subsensory stimulation by bolus has additional benefits, as no stimulation is provided during the time intervals between boluses, saving power and being more considerate of the IPG's battery. Delivering subsensory stimulation by bolus also prevents overstimulation of the patient and again avoids tissue habituation.

[0084] Figure 14 An example of how subsensory bolus therapy can be administered to a patient is shown. Various options are shown that can be selected by the patient or clinician to set the duration of the bolus and the off-time between boluses. Various options are shown through which the patient or clinician can schedule the bolus stimulation. This example is illustrated in the context of a GUI that may appear on the patient's external controller 45 or the clinician's programmer 50, because any of these external devices, as previously described, can be used to adjust the patient's stimulation therapy. As previously mentioned, the GUI can be presented by executing software stored in the memory of the external device. Figure 14 The various options for injectable stimulation therapy shown in the document can also be used for extrasensory therapy involving sensory abnormalities, although the focus is on providing subsensory therapy.

[0085] Option 500 allows the patient or clinician to input relevant subsensory stimulation parameters to be used during each bolus, such as the amplitude (A) of the stimulation (e.g., in mA), the pulse width (PW) of the stimulation pulse, and the frequency (F) of such pulses. These stimulation parameters can be entered manually and preferably include optimized subsensory stimulation parameters 420 determined in various ways disclosed in '529 application'. Option 501 can be selected for using such optimized stimulation parameters 420'. Note that, as taught in '529 application', the selection of option 501 can cause the algorithm to run to determine optimized stimulation parameters 420 specifically for the patient. Because these details are described in '529 application', they will not be repeated here. Although not shown, the stimulation parameters can vary during each bolus, such as just relative to Figure 13B As described.

[0086] Option 502 allows the patient or clinician to specify bolus parameters, such as the duration of the bolus (e.g., 30 minutes) and the off-time between boluses when no stimulation occurs (e.g., 3.5 hours). Option 502 may include a graph to show a timeline of when boluses will occur during the course of the day. For example, Figure 14 The diagram illustrates that betting according to the schedule will occur every four hours, such as 3:30-4:00 AM, 7:30-8:00 AM, and 11:30 AM to noon. Betting durations can be 3 minutes or longer, 10 minutes or longer, 30 minutes or longer, 1 hour or longer, 2 hours or longer, 3 hours or longer, or even longer. Off-peak durations can be 30 minutes or longer, 1 hour or longer, 2 hours or longer, 5 hours or longer, or even longer.

[0087] Option 504 allows patients or clinicians to specify the administration of boluses on a daily schedule, and more specifically, allows boluses to be scheduled for different durations and at different times depending on the day of the week. Such an arrangement is sensible because a patient's stimulation needs may vary depending on his or her activities, which may vary throughout the week. In this example, for simplicity, the schedule for bolus stimulation is the same for weekdays (Monday through Friday) and weekends (Saturday and Sunday). This is, of course, just an example, and each day of the week can also be scheduled individually and uniquely.

[0088] In this example, the injections are scheduled during periods when the patient is expected to be engaged in significant activity. For instance, during a weekday, the injection is scheduled between 7:30 and 9:00 AM, when the patient is awake and preparing for work. At 9:00 AM, the injection stops because the patient is now at work and likely less active. Again, because stimulation can have a significant washout period, especially when using subsensory therapy, it can be assumed that the patient will continue to experience therapeutic benefits for some time (after 9:00 AM), even after the stimulation has stopped. At midday, when the patient is likely to become more active again (e.g., lunchtime), another injection can be administered, this time lasting until 1:30 PM. Even if the patient is inactive at this time, scheduling the injection is still possible because the washout period since the previous injection has now expired. The next injection is administered from 7:30 to 8:30 PM. Note that this injection may be shorter (one hour, compared to the earlier 1.5-hour injection) because the need for subsensory stimulation may be less at this time.

[0089] On weekends, the injections are administered at different times. For example, patients may sleep in on these days, so the first daily injection might be shifted later, such as from 8:30 a.m. to 10:00 a.m. The second injection is also scheduled for a later time, from 3:00 p.m. to 4:30 p.m., because patients may be shopping or engaged in other activities at this time. The third injection is administered later in the day and for a longer duration, from 8:30 p.m. to 10:30 p.m. This is sensible because patients may be out in the evening and therefore require more effective treatment at these times.

[0090] Option 506 allows patients to self-administer a bolus of stimulation by selecting option 508. This can be useful because predefined bolus schedules (e.g., options 502, 504) may not always be optimal, and patients may experience symptoms during the off-peak periods between boluses. Required boluses can be shorter than otherwise scheduled (e.g., 30 minutes).

[0091] Option 510 allows setting a lockout period, which is set to 2.5 hours in the example shown. The lockout period includes a time period during which a bolus cannot be specified, and such a period is preferably referenced relative to the previous bolus. In the example shown, the lockout period begins at the end of the previous bolus, although in other examples it may begin at the beginning of the previous bolus. The lockout period prevents patient overstimulation because another bolus is not permitted until the lockout period expires.

[0092] The lockout period option 510 can be accessible only to the clinician; for example, this option can be set only when a clinician's password is entered. For instance, a clinician might know from experience that the washout period after a bolus includes 3 hours, and therefore could set the lockout period accordingly, for example, to a slightly smaller value of 2.5 hours. Once established, the lockout period 510 can include global restrictions on programmable stimuli using the GUI and can affect the ability to schedule bolus stimuli. For example, if the lockout period is set to 2.5 hours, the GUI can prohibit the input of off-times shorter than that in option 502. Similarly, when scheduling a bolus using option 504, the GUI can prohibit setting a time interval between the end of a bolus and the start of the next bolus that is shorter than the lockout period. Finally, the lockout period can also affect a patient's ability to self-administer a bolus using option 506, as explained below.

[0093] Figure 14The bottom shows the operation of the locked period, assuming that a time slot for the bolus stimulus has been scheduled according to option 504. Specifically, it shows a schedule occurring on Saturday, with three bolus deliveries (a, b, and c) scheduled at different times of day. Two examples are shown where a patient attempts to self-administer an additional bolus using option 508. In the first example, bolus 'a' ends at 10:00 AM, and the patient attempts to self-administer a bolus at noon. Because only 2 hours have passed since bolus 'a' ended, and because this time slot is less than the 2.5-hour locked period, the GUI will not allow this self-administered bolus. Although not shown, the GUI will inform the patient that no bolus will be provided and the reason, and may even suggest that the patient not self-administer a bolus until the locked period expires at 12:30 PM.

[0094] Lockout periods can also affect subsequent scheduled boluses. In the next example, a patient attempts to self-administer an extra bolus at 1 p.m. Because 3 hours have passed since bolus 'a' ended, and because this period is longer than the 2.5-hour lockout period, the GUI will allow the self-administered bolus. However, this self-administered bolus will end at 1:30 p.m., and the next bolus 'b' is scheduled for 3 p.m. Because this cutoff period (1.5 hours) will be shorter than the lockout period (2.5 hours), the GUI can reschedule bolus 'b' at a later time to align with the lockout period. Therefore, bolus 'b' is rescheduled to begin at 4 p.m. instead of 3 p.m. Rescheduling bolus 'b' will also affect bolus 'c', which may also need to be rescheduled given the prescribed lockout period. However, this is not the case in the example shown. The rescheduled bolus 'b' will end at 5:30 p.m., while bolus 'c' is scheduled to begin at 8:30 p.m. This results in a cutoff period longer than the lockout period between bolus 'b' and 'c'. Therefore, there is no need to reschedule push 'c'. Although not shown, locking the time period will result in the cancellation of some previously scheduled pushes, rather than rescheduling them in a timely manner (e.g., pushing).

[0095] like Figure 15As shown, injection programming can also be dependent on patient activity. Patient activity can be detected by activity sensor 520. Activity sensor 520 can be associated with the patient's IPG or can include a wearable motion sensor capable of communicating with the IPG or the patient's external controller 45. Activity sensor 520 within the IPG can include an accelerometer or can include sensing circuitry associated with the IPG electrodes. For example, as mentioned above, other sensed responses to stimulation at the ECAP or electrodes can be used to determine the patient's activity or posture. See, for example, PCT International Patent Application Serial No. PCT / US20 / 036667, filed June 8, 2020. Activity sensor 520 can also be within the patient's external controller 45. As used herein, patient "activity" can include activities performed by the patient (e.g., running, swimming, walking, etc.) or specific patient postures (e.g., standing, prone, supine, sitting, etc.).

[0096] Activity sensor 520 can determine patient activity or take measurements indicating activity. These determinations or measurements can then be provided to control circuitry 530, which can determine the activity from the measurements if activity sensor 520 has not yet determined it. Control circuitry 530 can reside in the IPG or within an associated external device, and therefore data received from activity sensor 520 at control circuitry 520 can be received wirelessly or via a wired connection. For example, control circuitry 530 can include control circuitry 48 in external controller 45 or control circuitry 70 in clinician programmer 50. Control circuitry 530 can also be associated with stimulation circuitry 28 in the IPG. This is because both the control circuitry of the IPG and the control circuitry of the external device can be used to program the injection that the patient should receive based on the detected patient activity. For example, if control circuitry 530 is within the IPG, it will receive activity data from the activity sensor via a wired connection (if activity sensor 520 is within the IMD) or wirelessly (if activity sensor 520 is outside the IPG) and can adjust the injection programming accordingly. If the control circuitry 530 is located within an external device (such as a patient external controller 45), the control circuitry can again receive activity data from the activity sensor via a wired connection (if the activity sensor 520 is within the external device) or a wireless connection (if the activity sensor 520 is in the IPG or includes different wearable sensors), and the injection programming can be adjusted accordingly via wireless programming of the IPG. Figure 15 In the example shown, it is assumed that the relevant patient activities may include sleeping, sitting, standing, walking, or some other uncertain activities, although the list of these activities is just an example.

[0097] The control circuit 530 can be programmed to the IPG (its stimulation circuit 28, Figure 1) using an injection procedure suitable for detected patient activity in the various ways just described. Figure 15 In the example shown, there are five injection procedures (AEs), each associated with a patient's sleep, dressing, standing posture, walking, and other activities. Preferably, each injection procedure provides a schedule for applying the injection to the patient. In the example shown, this schedule is determined by the injection duration and the off-time, similar to the previous combination with option 502 (…). Figure 14 As described above. However, each betting program can be set with different betting start and stop times. For example, a betting program can be set to a daily / weekly betting schedule, similar to the previous combination of option 504 ( Figure 14 As described in ) Although in Figure 15 Not shown in the diagram, but in addition to scheduled boluses within each bolus procedure, patients are also able to self-administer boluses (508, Figure 14 Furthermore, the duration (506) and lockout period (510) of this self-administered bolus can be adapted to the activity in question. For example, more strenuous activities (e.g., walking) or patient movements involving greater heights may allow for a longer duration or a shorter lockout period for the self-administered bolus, and thus options 506 and 510 can be modified accordingly. In practice, bolus procedures associated with certain activities can have a lockout period of zero, meaning that the bolus can be administered at any time regardless of when the last bolus was provided. The bolus procedure can be predetermined and, as taught in application '529, can be predetermined based on a test for a specific patient.

[0098] Furthermore, each injection procedure may include or reference a stimulation procedure, i.e., stimulation parameters (such as amplitude, pulse width, and frequency) used to form pulses during each injection period in the injection procedure. For example, injection procedure A uses stimulation procedure A, which uses A1, F1, and PW1 during each injection period. Injection procedure B differs from injection procedure A because it sets a longer duration for each injection, but does not change the frequency of injection. However, injection procedure B also uses the same stimulation procedure A as injection procedure A. When compared to injection procedure A, injection procedure C does not change the duration or frequency of injections, but uses a different stimulation procedure B with different pulse frequencies (F2) and pulse widths (PW2). Injection procedure D uses the same stimulation procedure B, but causes injections to occur more frequently. Injection procedure E uses the same injection duration and frequency as injection procedure D, but uses a different stimulation procedure C. In short, each injection procedure can arrange and set the duration and timing of injections, and can provide the use of different stimulation parameters during each injection period. When the stimulus provided by the injection procedure is sub-sensory, the stimulation procedure AC can be determined according to the optimal stimulation parameters 420', as described in various ways in the '529 application cited above. The injection procedure can be executed by the control circuitry in the IPG by providing the relevant injection and stimulation parameters to the stimulation circuitry 28 of the IPG (Figure 1).

[0099] The control circuit 530 can also receive other types of information and thus determine and use the appropriate injection procedure for the patient. For example, the control circuit 530 can also receive information from other sensors or information sources 521. Other sensors or information sources 521 may, for example, sense certain conditions or vital signs of the patient (e.g., EEG, EKG, blood pressure, body temperature, etc.), and the control circuit 530 can select an injection procedure based on these sensed conditions or vital signs. Other sensors or information sources 521 may be located away from the patient but may provide information to the control circuit 530 via one or more communication links (such as the Internet). For example, sensor 521 may include information about the weather, such as information collected from one or more weather sensors. It is known that weather can affect the symptoms of patients undergoing neurostimulation, thus ensuring that the patient's injection procedure is changed according to different weather conditions. The control circuit 530 can also receive information 522 about the patient or their disease process and select an injection procedure accordingly. For example, patient information 522 may include the patient's gender, age, indicators of their specific disease process, duration of their disease process, duration since implantation, etc. In short, the control circuit 530 can select the injection procedure based on many different variables, although for simplicity... Figure 15 Focus on variables related to patient activity.

[0100] Figure 15The bottom of the diagram illustrates an example of managing bolus administration and bolus procedure supply when certain patient activities are detected. For instance, detection determines that the patient is sleeping from midnight to 7 a.m., and therefore bolus procedure A is run. From 7 a.m. to 9 a.m., the patient is standing, and therefore bolus procedure C is run; from 9 a.m. to 5 p.m., the patient is sitting, and therefore bolus procedure B is run. From 5 p.m. to 7 p.m. and from 8 p.m. to 10 p.m., control circuit 530 cannot discern the patient's activity, possibly because the patient is rapidly changing their activity. In this respect, control circuit 530 can change the bolus procedure on a slow timescale and not necessarily every time the patient's activity changes (e.g., for negligible periods). If the detected activity changes on a fast timescale, "Other" bolus procedure E can be selected by default; note that the frequency of bolus administration can be increased during these periods when patient activity cannot be accurately determined.

[0101] Figures 16A-16B A fitting algorithm 550 is illustrated that can be used to determine one or more bolus procedures for use by a patient. As will be discussed, algorithm 550 can vary bolus parameters (e.g., duration and off-time) and / or stimulation parameters (e.g., amplitude, pulse width, and frequency) when determining an optimal bolus procedure for the patient. It should be noted that algorithm 550 can also be used to determine optimal bolus procedures for various patient activities, as just mentioned. Figure 15 As described. In other words, for simplicity, patient activities were not referenced. Figure 16A The following description is provided. It is envisioned that algorithm 550 can be executed on an external device (such as an external controller 45 or a clinician programmer 50), although the external device can receive information for other components in the system.

[0102] Algorithm 550 preferably begins by determining a suitable stimulation program for the patient. This can be regarded as establishing a neural dose for the patient, i.e., the amount of charge per second that the patient will receive during each bolus. In one example, the neural dose can be understood or calculated as the product of amplitude, pulse width, and frequency, and algorithm 550 initially tries three such doses for the patient: medium, high, and low doses. These doses can be set by different stimulation programs. For example, the medium dose includes using a stimulation program (SP2) with an average of amplitude (A2), pulse width (PW2), and frequency (F2). The high dose can include using a stimulation program (SP3) that provides a higher neural dose, so it can have a higher amplitude (A3 > A2), pulse width (PW3 > PW2), and / or frequency (F3 > F2) than those used during the medium dose. Similarly, the low dose can include using a stimulation program (SP1) that provides a lower neural dose, so it can have a lower amplitude (A1 < A2), pulse width (PW1 < PW2), and / or frequency (F1 < F2) than those used during the medium dose. Each of these doses - i.e., each of the stimulation programs of SP2, SP3, and SP1 - can be tried on the patient within a time period t1, which can vary but can be about one day in length. At the end of each stimulation program, the patient can rate the extent to which the stimulation program resolves his symptoms, such as by entering rating information into his external controller 45 or clinician programmer 50. If necessary, and when algorithm 550 can operate, this rating can be telemetered to the clinician programmer 50.

[0103] Preferably, the stimulation programs tried on the patient in algorithm 550 include sub-perceptual programs and thus include a subset of the optimized stimulation parameters 420 previously discussed in the '529 application. That being said, algorithm 550 can also consider and evaluate supra-threshold programs.

[0104] Algorithm 550 can continue by determining the one or more stimulation programs (doses) that are best for the patient based on the patient ratings. In Figure 16A the example, assume that two optimal stimulation regimens (e.g., SP2 and SP3) are determined for the patient, although only one optimal stimulation regimen can also be determined.

[0105] At this point, Algorithm 550 can attempt to determine optimal injection parameters—such as injection duration and shutdown time—for use with the previously determined optimal stimulation procedure. Therefore, stimulation procedure SP2 is used during the injection, and a first injection duration (t2) and shutdown time (t3) are attempted. The times t2 and t3 are variable, but can initially be equal to 30 minutes and 90 minutes, respectively. Multiple injections are delivered to the patient within a time period t1 (e.g., one day), long enough to provide multiple injections and subsequent shutdown cycles. The patient can then use these parameters to rate their experience as before.

[0106] Afterward, maintain the same stimulation procedure (SP2) and change the injection parameters. For simplicity, Figure 16A Only the shut-off time (t3) was adjusted, increasing it from 90 minutes to 240 minutes. However, the bolus duration (t2) could also be changed. Patients were again rated for these new parameters.

[0107] If more than one stimulation procedure has previously been identified as the best candidate (e.g., SP3), Algorithm 550 can repeat the process, providing the stimulation procedure as a bolus, and varying the bolus parameters as previously described. The patient can again rate the bolus procedure for each outcome.

[0108] like Figure 16B As shown, at the end of Algorithm 550, various patient ratings can be considered to determine one of several bolus procedures that are best for the patient. Figure 16B Example patient ratings are shown when stimulation is not provided using bolus injections (when initially trying medium, high, and low neurological doses of SP2, SP3, and SP1), and when stimulation is subsequently provided using bolus injections (using two optimal stimulation procedures, SP2 and SP3). In the first example, SP2 and SP3 were rated the highest (4), and thus those stimulation procedures were tried while providing stimulation according to various bolus parameters (i.e., various bolus durations and off-times). Providing bolus injections using SP2 with a bolus duration of 30 minutes and an off-time of 90 minutes yielded the highest patient rating (5), indicating that this bolus procedure was best suited to the patient. Note that in this example, the patient preferred bolus stimulation. This may mean that continuous stimulation (using SP2) was actually overstimulating the patient without any useful results (and wasting electricity at the same time).

[0109] Note that Algorithm 550 can also determine that continuous stimulation without bolus injection may be most suitable for the patient. This is illustrated in the second example. Continuous SP3 without bolus injection provided the highest rating (5), even higher than the rating (4) when SP3 was provided with bolus injection. This may indicate that bolus stimulation is not suitable for this patient.

[0110] In the third example, note that SP3, when run continuously without bolus stimulation, gave the same high rating as when the same stimulation procedure was provided with bolus stimulation (duration = 30 minutes and off time = 90 minutes) (5). Considering these results, stimulation will preferably be provided in the form of bolus stimulation, as this is as effective as when stimulation is provided continuously. Furthermore, providing bolus stimulation reduces the risk of overstimulation of patients and saves power.

[0111] Booster stimulation can also be provided to patients using other types of implantable systems, including RF systems using an external power source (EPS) 604, as described above with respect to Figure 6. When using such a system, the boost is provided by simply wearing the EPS 604 when stimulation is desired (booster duration) and not wearing the EPS when stimulation is not desired (off time). In this respect, the timing of boost therapy using an external device (such as an external controller 45 or a clinician programmer 50) does not involve actual control of the IPG 10. Instead, such timing can alert the patient when the EPS 604 should be worn and removed, effectively causing the IPG 10 to provide stimulation by boost, as described herein.

[0112] The EPS 604 itself may include the disclosed GUI, or be controlled by a GUI available in a connected device (e.g., a clinician programmer or a telephone application), and can be programmed and stored using an injection schedule, meaning no external controller or clinician programmer is required. In this way, the EPS 604 can be programmed to start or stop injections according to a programmed schedule as discussed above, and can turn stimulation on or off regardless of whether the patient is wearing or has removed the EPS. The EPS 604 can notify the patient when it has started (or is about to start) a specific injection, allowing the patient to wear the EPS at that time, and can notify the patient when the injection has stopped, allowing the patient to remove the EPS. Furthermore, as discussed above, the patient can use the EPS 604 to self-administer injections, and the EPS 604 can be programmed with lockout periods to prevent overuse of injections while maintaining functionality as needed.

[0113] While particularly useful in providing stimulation to the spinal cord of patients, the disclosed technique is also applicable to the stimulation of other neural tissues, such as the brain, peripheral nerves, peripheral ganglia, and so on.

[0114] While specific embodiments of the invention have been shown and described, it should be understood that the foregoing discussion is not intended to limit the invention to these embodiments. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the invention is intended to cover substitutions, modifications, and equivalents that may fall within the spirit and scope of the invention as defined by the claims.

Claims

1. An external device configured to communicate with an implantable stimulator device implanted in a patient, comprising: The control circuit is configured as follows: Stimulation parameters tailored to the patient are provided to address the patient's symptoms, wherein the stimulation parameters are provided over multiple stimulation boluses, each bolus comprising a first duration. A schedule for the supply of the multiple stimulation boluses for the patient is provided, wherein each scheduled bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, and wherein the scheduled boluses are separated by off-times of a second duration during which no stimulation is provided to the patient. Input is received at the graphical user interface of the external device immediately to provide an additional injection of the multiple stimulations, wherein the additional injection includes: during which the stimulation is applied to the patient for the first duration according to the stimulation parameters, and The device transmits instructions to cause the implantable stimulator to deliver at least the scheduled bolus to the patient's nerve tissue according to a timetable.

2. The external device according to claim 1, wherein, The stimulation parameters provide subsensory stimulation to address the patient's symptoms.

3. The external device according to claim 1, wherein, The implantable stimulator device includes a spinal cord stimulator.

4. The external device according to claim 1, wherein, Each scheduled push lasts for a first duration of 3 minutes or longer, and each interruption lasts for a second duration of 30 minutes or longer.

5. The external device according to claim 1, wherein, The stimulation provided during each scheduled injection consists of a periodic pulse sequence.

6. The external device according to claim 5, wherein, The stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency.

7. The external device according to claim 6, wherein, The frequency is 10 kHz or lower or 1 kHz or lower, or the amplitude includes a constant current amplitude.

8. The external device according to claim 1, wherein, The first duration of the scheduled injection is variable.

9. The external device according to claim 1, wherein, The second duration of the shutdown time is variable.

10. The external device according to claim 1, wherein, The control circuit is also configured to: determine the patient's activities or receive information indicating the patient's activities.

11. The external device according to claim 10, wherein, The control circuit is further configured to adjust either or both of the first duration of the scheduled injection or the second duration of the shutdown time based on the determined activity or information indicating the activity.

12. The external device according to claim 10, wherein, The stimulus parameters are determined based on the identified activity or information indicating the activity.

13. The external device according to claim 1, wherein, The control circuitry is configured to transmit instructions such that the implantable stimulator device immediately delivers an additional stimulator injection to the patient's nerve tissue in addition to the scheduled injection.

14. The external device according to claim 1, wherein, The control circuit is programmed with a locked period, wherein the control circuit is configured to transmit instructions such that the implantable stimulator device immediately delivers an additional stimulator injection to the neural tissue only if a third duration between the first time and the preceding scheduled injection is equal to or longer than the locked period.

15. The external device according to claim 14, wherein, The control circuit is also configured to rearrange at least one of the scheduled pushes after an additional push, based on the locked period.

16. An external device configured to communicate with an implantable stimulator device implanted in a patient, comprising: The control circuit is configured as follows: Provide stimulation parameters tailored to the patient to address the patient's symptoms. A schedule for the supply of scheduled stimulation boluses to the patient is provided, wherein each scheduled bolus includes a first duration during which stimulation is applied to the patient according to the stimulation parameters, wherein the scheduled boluses are separated by off-times when no stimulation is provided to the patient, wherein the first duration of each scheduled bolus is 3 minutes or longer, and wherein the second duration of each off-time is 30 minutes or longer. The device transmits instructions to cause the implantable stimulator to deliver a scheduled injection to the patient's nerve tissue according to the timetable.

17. The external device according to claim 16, wherein, The stimulation parameters provide subsensory stimulation to address the patient's symptoms, and the implantable stimulator device includes a spinal cord stimulator.

18. The external device according to claim 16, wherein, The stimulation provided during each scheduled injection consists of a periodic pulse sequence.

19. The external device according to claim 16, wherein, The stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency.

20. The external device according to claim 19, wherein, The frequency is 10 kHz or lower, or 1 kHz or lower, and the amplitude includes a constant current amplitude.

21. The external device according to claim 16, wherein, The first duration of the scheduled injection is variable.

22. The external device according to claim 16, wherein, The second duration of the shutdown time is variable.

23. The external device according to claim 16, wherein, The control circuit is also configured to: determine the patient's activities or receive information indicating the patient's activities.

24. The external device according to claim 23, wherein, The control circuit is further configured to adjust either or both of the first duration of the scheduled injection or the second duration of the shutdown time based on the determined activity or information indicating the activity.

25. The external device according to claim 23, wherein, The stimulus parameters are determined based on the identified activity or information indicating the activity.

26. The external device according to claim 16, wherein, The external device includes a graphical user interface.

27. The external device according to claim 26, wherein, The control circuit is also configured to receive input at the graphical user interface at a first moment in order to immediately provide additional stimulation injection.

28. The external device according to claim 27, wherein, The control circuit is also configured to transmit instructions such that the implantable stimulator device immediately provides additional bolus stimulation to the patient's nerve tissue in addition to the scheduled bolus.

29. The external device according to claim 27, wherein, The control circuit is programmed with a locked time period, wherein the control circuit is further configured to transmit instructions such that the implantable stimulator device immediately provides an additional stimulation injection to the neural tissue only if a third duration between the first time and the preceding scheduled injection is equal to or longer than the locked time period.

30. The external device according to claim 29, wherein, The control circuit is also configured to rearrange at least one of the scheduled pushes after an additional push, based on the locked period.

31. An external device configured to communicate with an implantable stimulator device implanted in a patient, comprising: The control circuit is configured as follows: Stimulation parameters are provided for the patient, wherein the stimulation parameters provide subsensory stimulation pulses to address the patient's symptoms, wherein the stimulation parameters are provided in multiple stimulation boluses, each stimulation bolus including a first duration. Receive the first input used to program the first duration. Upon receiving a second input at the graphical user interface of the external device, an additional injection of stimulation is immediately provided in a series of stimulation injections, wherein the additional injection includes the first duration during which the stimulation is applied to the patient according to the stimulation parameters, and The device transmits instructions to provide the additional injection to the patient's neural tissue during the first duration, wherein the additional injection comprises a plurality of periodic subsensory stimulation pulses formed according to the stimulation parameters.

32. The external device according to claim 31, wherein, The implantable stimulator device includes a spinal cord stimulator.

33. The external device according to claim 31, wherein, The initial duration of the additional injection is 3 minutes or longer.

34. The external device according to claim 31, wherein, The stimulation parameters include one or more of the pulse amplitude, pulse width, or pulse frequency.

35. The external device according to claim 34, wherein, The frequency is 10 kHz or lower.

36. The external device according to claim 34, wherein, The frequency is 1 kHz or lower.

37. The external device according to claim 34, wherein, The amplitude includes the constant current amplitude.

38. The external device according to claim 31, wherein, The control circuit is also configured to: determine the patient's activities or receive information indicating the patient's activities.

39. The external device according to claim 38, wherein, The control circuit is also configured to adjust the first duration based on the determined activity or information indicating the activity.

40. The external device according to claim 38, wherein, The stimulus parameters are determined based on the identified activity or information indicating the activity.

41. The external device according to claim 31, wherein, The control circuit is programmed with a locked period, wherein the control circuit is further configured to transmit instructions such that the implantable stimulator device immediately provides the additional injection stimulation to the neural tissue only if the second duration between the first time and the previous injection is equal to or longer than the locked period.

42. The external device according to claim 41, wherein, The control circuit is also configured to schedule at least one additional push after the additional push, based on the locked time period.

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