SPINAL CORD MODULATION FOR INDUCING PARESTHETIC AND ANESTHETIC EFFECTS, AND ASSOCIATED SYSTEMS AND METHODS
Spinal cord modulation for inducing paresthetic and anesthetic effects, and associated systems and methods are disclosed. A representative method in accordance with an embodiment of the disclosure includes creating a therapeutic effect and a sensation in a patient by delivering to the patient first pulses having a first set of first signal delivery parameters and second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set, and wherein the first pulses, the second pulses or both the first and second pulses are delivered to the patient's spinal cord.
The present application claims priority to U.S. Provisional Application 61/171,790, filed on Apr. 22, 2009 and incorporated herein by reference.
TECHNICAL FIELDThe present disclosure is directed generally to spinal cord modulation for inducing paresthetic and anesthetic effects, and associated systems and methods.
BACKGROUNDNeurological stimulators have been developed to treat pain, movement disorders, functional disorders, spasticity, cancer, cardiac disorders, and various other medical conditions. Implantable neurological stimulation systems generally have an implantable pulse generator and one or more leads that deliver electrical pulses to neurological tissue or muscle tissue. For example, several neurological stimulation systems for spinal cord stimulation (SCS) have cylindrical leads that include a lead body with a circular cross-sectional shape and one or more conductive rings spaced apart from each other at the distal end of the lead body. The conductive rings operate as individual electrodes and, in many cases, the SCS leads are implanted percutaneously through a large needle inserted into the epidural space, with or without the assistance of a stylet.
Once implanted, the pulse generator applies electrical pulses to the electrodes, which in turn modify the function of the patient's nervous system, such as altering the patient's responsiveness to sensory stimuli and/or altering the patient's motor-circuit output. In pain treatment, the pulse generator applies electrical pulses to the electrodes, which in turn can generate sensations that mask or otherwise alter the patient's sensation of pain. For example, in many cases, patients report a tingling or paresthesia that is perceived as more pleasant and/or less uncomfortable than the underlying pain sensation. While this may be the case for many patients, many other patients may report less beneficial effects and/or results. Accordingly, there remains a need for improved techniques and systems for addressing patient pain.
The present disclosure is directed generally to spinal cord modulation and associated systems and methods that induce, produce, generate, or otherwise cause paresthetic and anesthetic effects in a patient. Such systems and methods can be used to treat patient pain. Specific details of certain embodiments of the disclosure are described below with reference to methods for modulating one or more target neural populations or sites of a patient, and associated implantable structures for providing the modulation. Although selected embodiments are described below with reference to modulating the dorsal root and/or other particular regions of the spinal column to control pain, the leads may be in some instances be used to modulate other neurological structures of the spinal cord. Some embodiments can have configurations, components or procedures different than those described in this section, and other embodiments may eliminate particular components or procedures. A person of ordinary skill in the relevant art, therefore, will understand that the invention may have other embodiments with additional elements, and/or may have other embodiments without several of the features shown and described below with reference to
In general terms, aspects of many of the following embodiments are directed to producing a sensation (e.g., paresthesia or a paresthetic effect) in the patient, in addition to producing a therapeutic effect (e.g., anesthesia or an anesthetic effect) in the patient. The therapeutic effect can be produced by inhibiting, suppressing, downregulating, blocking, preventing, or otherwise modulating the activity of the affected neural population (e.g., nerve cells). Such embodiments may be useful in cases for which the patient benefits from an anesthetic effect, but, because the anesthetic effect typically creates an absence of pain and/or other sensations, the patient may require the assurance or comfort of a detectable sensation. By supplementing the anesthetic effect with a paresthetic effect, which is detected by the patient, the patient and/or the associated practitioner can better monitor the manner in which the anesthesia-producing signals are provided. In other embodiments, the patient and/or the practitioner may have other bases for supplementing anesthesia-producing signals with paresthesia-producing signals. Further details are described below with reference to
The pulse generator 101 can transmit signals to the signal delivery element 110 that up-regulate (e.g., stimulate or excite) and/or down-regulate (e.g., block or suppress) target nerves. As used herein, and unless otherwise noted, the terms “modulate” and “modulation” refer generally to signals that have either type of effect on the target nerves. The pulse generator 101 can include a machine-readable (e.g., computer-readable) medium containing instructions for generating and transmitting suitable therapy signals. The pulse generator 101 and/or other elements of the system 100 can include one or more processors 107, memories 108 and/or input/output devices. Accordingly, the process of providing modulation signals (e.g., electrical signals) and executing other associated functions can be performed by computer-executable instructions contained on computer-readable media, e.g., at the processor(s) 107 and/or memory(s) 108. The pulse generator 101 can include multiple portions, elements, and/or subsystems (e.g., for directing signals in accordance with multiple signal delivery parameters), housed in a single housing, as shown in
The pulse generator 101 can also receive and respond to an input signal received from one or more sources. The input signals can direct or influence the manner in which the therapy instructions are selected, executed, updated and/or otherwise performed. The input signal can be received from one or more sensors 112 (one is shown schematically in
In some embodiments, the pulse generator 101 can obtain power to generate the therapy signals from an external power source 103. The external power source 103 can transmit power to the implanted pulse generator 101 using electromagnetic induction (e.g., RF signals). For example, the external power source 103 can include an external coil 104 that communicates with a corresponding internal coil (not shown) within the implantable pulse generator 101. The external power source 103 can be portable for ease of use.
In another embodiment, the pulse generator 101 can obtain the power to generate therapy signals from an internal power source, in addition to or in lieu of the external power source 103. For example, the implanted pulse generator 101 can include a non-rechargeable battery or a rechargeable battery to provide such power. When the internal power source includes a rechargeable battery, the external power source 103 can be used to recharge the battery. The external power source 103 can in turn be recharged from a suitable power source (e.g., conventional wall power).
In some cases, an external programmer 105 (e.g., a trial modulator) can be coupled to the signal delivery element 110 during an initial implant procedure, prior to implanting the pulse generator 101. For example, a practitioner (e.g., a physician and/or a company representative) can use the external programmer 105 to vary the signal delivery parameters provided to the signal delivery element 110 in real time, and select optimal or particularly efficacious parameters. These parameters can include the position of the signal delivery element 110, as well as the characteristics of the electrical signals provided to the signal delivery element 110. In a typical process, the practitioner uses a cable assembly 120 to temporarily connect the external programmer 105 to the signal delivery device 110. The cable assembly 120 can accordingly include a first connector 121 that is releasably connected to the external programmer 105, and a second connector 122 that is releasably connected to the signal delivery element 110. Accordingly, the signal delivery element 110 can include a connection element that allows it to be connected to a signal generator either directly (if it is long enough) or indirectly (if it is not). The practitioner can test the efficacy of the signal delivery element 110 in an initial position. The practitioner can then disconnect the cable assembly 120, reposition the signal delivery element 110, and reapply the electrical modulation. This process can be performed iteratively until the practitioner obtains the desired position for the signal delivery device 110. Optionally, the practitioner may move the partially implanted signal delivery element 110 without disconnecting the cable assembly 120. Further details of suitable cable assembly methods and associated techniques are described in co-pending U.S. application Ser. No. 12/562,892, filed on Sep. 18, 2009, and incorporated herein by reference.
During this process, the practitioner can also vary the position of the signal delivery element 110. After the position of the signal delivery element 110 and appropriate signal delivery parameters are established using the external programmer 105, the patient 190 can receive therapy via signals generated by the external programmer 105, generally for a limited period of time. In a representative application, the patient 190 receives such therapy for one week. During this time, the patient wears the cable assembly 120 and the external programmer 105 outside the body. Assuming the trial therapy is effective or shows the promise of being effective, the practitioner then replaces the external programmer 105 with the implanted pulse generator 101, and programs the pulse generator 101 with parameters selected based on the experience gained during the trial period. Optionally, the practitioner can also replace the signal delivery element 110. Once the implantable pulse generator 101 has been positioned within the patient 190, the signal delivery parameters provided by the pulse generator 101 can still be updated remotely via a wireless physician's programmer (e.g., a physician's remote) 111 and/or a wireless patient programmer 106 (e.g., a patient remote). Generally, the patient 190 has control over fewer parameters than does the practitioner. For example, the capability of the patient programmer 106 may be limited to starting and/or stopping the pulse generator 101, and/or adjusting signal amplitude.
In any of these foregoing embodiments, the parameters in accordance with which the pulse generator 101 provides signals can be modulated during portions of the therapy regimen. For example, the frequency, amplitude, pulse width and/or signal delivery location can be modulated in accordance with a preset program, patient and/or physician inputs, and/or in a random or pseudorandom manner. Such parameter variations can be used to address a number of potential clinical situations, including changes in the patient's perception of pain, changes in the preferred target neural population, and/or patient accommodation or habituation.
In process portion 252, a paresthetic effect is created in the patient by applying second pulses to the spinal cord in accordance with second signal delivery parameters. In general terms, an aspect of at least one of the second signal delivery parameters is different than an aspect of the corresponding first signal delivery parameter, so as to produce a paresthetic effect rather than an anesthetic, non-paresthetic effect. In particular embodiments, the paresthetic effect creates a tingling and/or other patient-detectable sensation. In process portion 253, information obtained from the patient's feedback to the paresthetic effect is used. For example, the patient and/or practitioner may use this information to understand that the system is in an “on” state rather than an “off” state, and/or to determine whether the lead is properly or improperly placed, and/or to obtain an indication of the amplitude or signal strength provided by the system. In other embodiments, the process can include obtaining different information and/or taking different actions. Further details of representative methods employing variations of some or all of the foregoing steps are described below with reference to
In some cases, the pain experienced by the patient (and addressed with the methods and systems of the present disclosure) may not be experienced by the patient on a continual basis. For example, in some instances, the patient may experience pain while standing or walking, but not while lying down. In such instances, it can be difficult to accurately conduct the pre-implant procedure described above with reference to
As noted above, some patients may experience pain while standing or walking, but not while lying down. Because the patient is typically lying down while the practitioner adjusts the signal delivery parameters, it may not be immediately evident that the parameters are creating the desired effect in the patient. Accordingly, the practitioner can position the signal delivery device at a site expected to produce the desired anesthetic, non-paresthetic effect in the patient, and can accompany the signals intended to produce that effect with signals that deliberately produce a patient-detectable paresthetic effect. When the patient begins to report a paresthetic effect, the practitioner can have an enhanced degree of confidence that the signal delivery parameters that are common to both the first pulses (which produce the anesthetic effect) and the second pulses (which produce the paresthetic effect) are properly selected. These signal delivery parameters can include the location at which the signal is delivered, the strength (e.g., amplitude) of the signal, and/or other parameters. If, based on patient feedback to the second pulses, the parameter values can be improved, the practitioner can change the first signal delivery parameters, e.g., by moving the lead, applying signals to different contacts on the lead, changing signal strength and/or making other adjustments. In a particular example, this arrangement can reduce the likelihood that the practitioner will inadvertently increase the amplitude of the anesthesia-producing first pulses to a level that will produce discomfort and/or muscle activation when the patient changes position. In other embodiments, other signal delivery parameters may be adjusted, as described further below with reference to
In addition to or in lieu of providing feedback that may be used to adjust signal delivery parameters associated with the first pulses (e.g., the anesthesia-producing pulses), aspects of the foregoing process may be used to identify faults (e.g., defects, abnormalities and/or unexpected states) associated with the system at an early stage. For example,
Process portion 364 includes identifying a fault with the delivery of the first pulses based at least in part on the presence or absence of a patient response to the changing amplitude of the second pulses. For example, while the patient may be unable to detect whether or not the first pulses are being delivered, the practitioner can increase the amplitude of both the first and second pulses to a point at which the practitioner would expect the patient to report a paresthetic effect created by the second pulses. If the patient fails to report such an effect, the practitioner may be alerted to a fault in the signal delivery system that applies to both delivery of the first pulses and the second pulses. Accordingly, the practitioner can rectify the fault and continue the process of establishing suitable signal delivery parameters for the first pulses, and optionally, the second pulses as well. The fault may be that the system is not on, that there is an electrical discontinuity between the signal generator and the lead contacts, that an element of the signal generator or lead has failed, and/or that the system has another abnormality or unexpected characteristic. In other embodiments, the fault can be identified by the presence of a patient response, rather than the absence of a patient response. For example, if the patient reports a sensation when no sensation is expected (e.g., if the patient reports muscle cramping, sensation and/or stimulation), this may indicate a system fault. In other cases, this may indicate a misplaced lead, or a patient with a lower than expected activation threshold.
In at least some instances, it may be desirable to the physician or other practitioner to control the amplitude or strength of the anesthesia-producing first pulses, and the patient control the amplitude or strength of the paresthesia-producing second pulses. Accordingly, the system 100 (
The first pulses 541a can be provided at a duty cycle that is less than 100%. For example, as shown in
In general, the pulse width of the second pulses 542a can be greater than that of the first pulses 541a (as shown in
The pulses shown in
In one aspect of the embodiment shown in
In any of the foregoing embodiments, the signal delivery parameters selected for any of the first pulses 541a-e (referred to collectively as first pulses 541) and the second pulses 542a-e (referred to collectively as second pulses 542) can be selected to produce an anesthetic, non-paresthetic effect, and a paresthetic effect, respectively. As discussed above, in at least some embodiments, the first pulses 541 will be provided at a higher frequency than the second pulses 542. For example, the first pulses 541 can be provided at a frequency of from about 1.5 kHz to about 50 kHz, while the second pulses 542 can be provided in a range of from about 2 Hz to about 1.2 kHz. In other embodiments, the pulses can have different relationships. For example, the second pulses 542 can be within a 3 kHz to 10 kHz range, but at a frequency less than the first pulses 541.
The lead body is generally positioned to preferentially modulate tactile fibers (e.g., to produce the paresthetic effect described above) and to avoid modulating fibers associated with nociceptive pain transmission. In a particular embodiment, a lead body 110a can be positioned centrally in a lateral direction (e.g., aligned with the spinal cord midline 189) to provide signals directly to the spinal cord 191. In other embodiments, the lead body can be located laterally from the midline 189. For example, the lead body can be positioned just off the spinal cord midline 189 (as indicated by lead body 110b), and/or proximate to the dorsal root 193 or dorsal root entry zone 188 (e.g., 1-4 millimeters from the spinal cord midline 189, as indicated generally by lead body 110c), and/or proximate to the dorsal root ganglion 194 (as indicated by lead body 110d). Other suitable locations for the lead body 110 include the “gutter,” also located laterally from the midline 189. In still further embodiments, the lead bodies may have other locations proximate to the spinal cord 191 and/or proximate to other target neural populations, e.g., laterally from the midline 189 and medially from the dorsal root ganglion 194. In any of the foregoing embodiments, electrical pulses may be applied to the lead body 110 to provide both a paresthetic and an anesthetic effect, as described above. As discussed above, the patient can be implanted with a single lead body (e.g., one of the lead bodies 110a-110d) or multiple lead bodies (e.g., combinations of the lead bodies 110a-110d).
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the invention. For example, the signal delivery parameters may have values other than those specifically described above, but which are also selected to produce anesthetic or paresthetic effects in the manner described above. Particular embodiments were described above in the context of signals applied to the patient's spinal cord, but in other embodiments, signals (e.g., signals creating an anesthetic, non-paresthetic effect, and/or signals creating a paresthetic effect) can be applied to other neural populations, including, but limited to, peripheral nerves. For example, such methods can include applying first pulses to the patient's spinal cord to create an anesthetic, non-paresthetic effect, and applying second pulses to a peripheral nerve to create a paresthetic effect. Systems suitable for carrying out embodiments of the foregoing techniques are included in co-pending U.S. application Ser. No. ______, filed concurrently herewith, titled “Devices for Controlling High Frequency Spinal Cord Stimulation for Inhibiting Pain, and Associated Systems and Methods” (Attorney Docket No. 66245.8024US), and incorporated herein by reference.
Certain aspects of the invention described in the context of particular embodiments may be combined or eliminated in other embodiments. For example, the wave forms described above with reference to
Claims
1. A method for treating a patient, comprising:
- creating a therapeutic effect and a sensation in a patient by delivering to the patient first pulses having a first set of first signal delivery parameters and second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set, and wherein the first pulses, the second pulses or both the first and second pulses are delivered to the patient's spinal cord.
2. The method of claim 1 wherein delivering the first pulses includes delivering bursts of first pulses, and wherein delivering the second pulses includes delivering a single second pulse during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
3. The method of claim 1 wherein delivering the first and second pulses includes delivering the first and second pulses to the same electrode implanted in electrical communication with a target neural population at the patient's spinal cord, and wherein delivering the first pulses includes delivering intermittent bursts of first pulses, and wherein delivering the second pulses includes delivering a single second pulse during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
4. The method of claim 1 wherein delivering the first pulses includes delivering bursts of first pulses, and wherein delivering the second pulses includes delivering a burst of second pulses during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
5. The method of claim 1 wherein the first parameter is a first signal frequency and the second parameter is a second signal frequency and wherein the first signal frequency is higher than the second signal frequency.
6. The method of claim 1 wherein the first parameter is a first signal frequency and the second parameter is a second signal frequency and wherein the first signal frequency is in the range of from about 1.5 kHz to about 50 kHz, and the second signal frequency is in the range of from about 2 Hz to about 1.2 kHz.
7. The method of claim 1 wherein creating a therapeutic effect includes creating an anesthetic, non-paresthetic effect, and wherein creating a sensation includes creating a paresthetic effect.
8. A method for treating a patient, comprising:
- creating a therapeutic, non-paresthetic effect in a patient by delivering, to a target neural population at the patient's spinal cord, first pulses having a first set of first signal delivery parameters; and
- creating a sensation in the patient by delivering, to the spinal cord, second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set.
9. The method of claim 8 wherein creating a therapeutic effect includes creating an anesthetic effect.
10. The method of claim 8 wherein creating a sensation includes creating a paresthetic effect.
11. The method of claim 8 wherein delivering the second pulses includes delivering the second pulses to the target neural population.
12. The method of claim 8 wherein delivering the first pulses includes delivering bursts of first pulses, and wherein delivering the second pulses includes delivering a single second pulse during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
13. The method of claim 8 wherein delivering the first and second pulses includes delivering the first and second pulses to the same electrode implanted in electrical communication with the target neural population, and wherein delivering the first pulses includes delivering intermittent bursts of first pulses, and wherein delivering the second pulses includes delivering a single second pulse during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
14. The method of claim 8 wherein delivering the first pulses includes delivering bursts of first pulses, and wherein delivering the second pulses includes delivering a burst of second pulses during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, wherein the first pulses have a first pulse width and the second pulses have a second pulse width greater than the first pulse width.
15. The method of claim 8 wherein the first parameter is a first signal frequency and the second parameter is a second signal frequency and wherein the first signal frequency is higher than the second signal frequency.
16. The method of claim 8 wherein the first parameter is a first signal frequency and the second parameter is a second signal frequency and wherein the first signal frequency is in the range of from about 1.5 kHz to about 50 kHz, and the second signal frequency is in the range of from about 2 Hz to about 1.2 kHz.
17. The method of claim 8 wherein the first parameter is a first pulse width and the second parameter is a second pulse width and wherein the first pulse width is less than the second pulse width.
18. The method of claim 8, further comprising:
- fixing an amplitude of the first pulses and preventing the patient from changing the amplitude of the first pulses; and
- allowing the patient to change an amplitude of the second pulses.
19. The method of claim 8, further comprising:
- increasing an amplitude of the first pulses without creating a patient-detectable sensation;
- creating a patient sensation by increasing an amplitude of the second pulses as the amplitude of the first pulses is increased; and
- based on patient feedback to the second pulses, changing the first signal delivery parameters.
20. A method for treating a patient, comprising:
- creating an anesthetic, non-paresthetic effect in a patient by delivering, to a target neural population at the patient's spinal cord, first pulses having a first set of first signal delivery parameters, wherein the anesthetic effect of the first pulses is undetected by the patient and/or produces a reduction or elimination of pain in the patient;
- creating a patient-detectable paresthetic effect in the patient concurrent with the anesthetic, non-paresthetic effect by delivering, to the patient's spinal cord, second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set; and
- based on patient feedback to the second pulses, changing the first signal delivery parameters.
21. The method of claim 20 wherein creating a patient-detectable paresthetic effect includes creating a patient-detectable paresthetic effect with an external trial modulator placed external to the patient, and wherein the method further comprises:
- implanting a modulator in the patient; and
- programming the implanted modulator to create an anesthetic, non-paresthetic effect in the patient by delivering the first pulses in accordance with the changed first signal delivery parameters.
22. The method of claim 20 wherein delivering the second pulses includes delivering the second pulses to the same target neural population as receives the first pulses.
23. The method of claim 20 wherein the target neural population is a first target neural population and wherein delivering the second pulses includes delivering the second pulses to a second target neural population different than the first target neural population.
24. The method of claim 20 wherein changing the first signal delivery parameters includes changing an amplitude of the first pulses.
25. The method of claim 20 wherein changing the first signal delivery parameters includes changing a position of an electrode delivering the first pulses.
26. The method of claim 20 wherein delivering first pulses includes delivering first pulses from a first electrode of an implanted electrode device, and wherein changing the first signal delivery parameters includes delivering the first pulses from a second electrode spaced apart from the first electrode.
27. The method of claim 20, further comprising identifying the patient as one who receives the anesthetic, non-paresthetic effect when in at least one body position, but not when in at least another body position.
28. The method of claim 20, further comprising obtaining patient feedback as a result of changing strengths of the first and second pulses in a parallel manner.
29. A method for treating a patient, comprising:
- creating an anesthetic, non-paresthetic effect in a patient by delivering, to a target neural population at the patient's spinal cord, first pulses having a first set of first signal delivery parameters, wherein the anesthetic effect of the first pulses is undetected by the patient and/or produces a reduction or elimination of pain in the patient;
- providing an indication of a strength of the first pulses by creating a patient-detectable paresthetic effect in the patient, wherein creating the paresthetic effect includes delivering, to the patient's spinal cord, second pulses having a second set of second signal delivery parameters, and wherein a strength of the second pulses is correlated with a strength of the first pulses, and wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set; and
- changing the strengths of the first and second pulses in a parallel manner.
30. The method of claim 29 wherein changing the strengths of the pulses includes changing the amplitudes of the pulses.
31. The method of claim 29 wherein changing the strengths of the first and second pulses in a parallel manner includes (a) increasing the strengths concurrently, (b) decreasing the strengths concurrently, or both (a) and (b).
32. The method of claim 29 wherein changing the strengths of the pulses includes changing the strengths of the first and second pulses by the same amount.
33. The method of claim 29 wherein the strengths of the pulses are offset, and wherein changing the strengths of the pulses includes changing the strengths of the pulses by different amounts.
34. The method of claim 29 wherein delivering the first and second pulses includes delivering the first and second pulses to the same target neural population.
35. The method of claim 29 wherein changing the strengths of the first and second pulses includes increasing the strength of the second signal as the strength of the first signal increases, in a concurrent or sequential manner.
36. The method of claim 29 wherein changing the strengths of the pulses includes changing the strengths of the pulses in response to a patient request.
37. A method for treating a patient, comprising:
- creating an anesthetic, non-paresthetic effect in a patient by delivering, to a target neural population at the patient's spinal cord, first pulses having a first set of first signal delivery parameters, wherein the anesthetic effect of the first pulses is undetected by the patient and/or produces a reduction or elimination of pain in the patient;
- creating a patient-detectable paresthetic effect in the patient by delivering, to the patient's spinal cord, second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set;
- changing amplitudes of the first and second pulses in parallel; and
- identifying a fault with the delivery of the first pulses based in least in part on the presence or absence of patient response to the changing amplitude of the second pulses.
38. The method of claim 37 wherein changing the amplitudes of the first and second signals includes changing the amplitudes concurrently.
39. The method of claim 37 wherein identifying a fault is based at least in part on an absence of a patient response.
40. The method of claim 37 wherein identifying a fault is based at least in part on the presence of a patient response.
41. The method of claim 37 wherein changing amplitudes includes increasing amplitudes.
42. The method of claim 37 wherein changing amplitudes includes decreasing amplitudes.
43. The method of claim 37 wherein identifying a fault includes identifying an electrical discontinuity in an electrical path between a pulse generator and a signal delivery electrode.
44. The method of claim 37 wherein identifying a fault includes identifying a signal delivery system as being in an off state.
45. A method for treating a patient, comprising:
- creating an anesthetic, non-paresthetic effect in a patient by delivering, to a target neural population at the patient's spinal cord, first pulses having a first set of first signal delivery parameters; and
- based on a request from the patient, supplementing the anesthetic, non-paresthetic effect in the patient with a patient-detectable paresthetic effect by delivering, to the patient's spinal cord, second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set.
46. The method of claim 45 wherein the patient previously received paresthesia-inducing pulses from a first implanted spinal cord modulator, and wherein delivering the first pulses includes delivering the first pulses from a second implanted spinal cord modulator, and wherein supplementing the anesthetic, non-paresthetic effect in the patient with a patient-detectable paresthetic effect includes emulating an effect of the paresthesia-inducing pulses by delivering the second pulses from the second implanted spinal cord modulator.
47. The method of claim 45, further comprising:
- fixing an amplitude of the first pulses and preventing the patient from changing the amplitude of the first pulses; and
- allowing the patient to change an amplitude of the second pulses.
48. The method of claim 45 wherein providing the first and second pulses includes providing the first and second pulses to the same target neural population.
49. The method of claim 45 wherein providing the first and second pulses includes providing the first and second pulses to different target neural populations.
50. A method for treating a patient, comprising:
- in a patient who previously received paresthesia-inducing pulses from a first implanted spinal cord modulator, implanting a second spinal cord modulator; and
- using the second spinal cord modulator to: create an anesthetic, non-paresthetic effect in the patient by delivering first pulses having a first set of first signal delivery parameters to a target neural population at the patient's spinal cord; and create a patient-detectable paresthetic effect in the patient by delivering, to the patient's spinal cord, second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set, and wherein the paresthetic effect emulates the paresthesia-inducing pulses from the first implanted spinal cord modulator.
51. The method of claim 50, further comprising removing the first implanted spinal cord modulator from the patient and replacing the first implanted spinal cord modulator with the second spinal cord modulator.
52. The method of claim 50, further comprising:
- fixing an amplitude of the first pulses and preventing the patient from changing the amplitude of the first pulses; and
- allowing the patient to change an amplitude of the second pulses.
53. A patient treatment system, comprising:
- a signal delivery device having a plurality of electrodes configured to be implanted within a patient, proximate to one or more target neural populations at the patient's spinal cord;
- an implantable pulse generator having a controller programmed with instructions for: directing first pulses to the signal delivery device to create an anesthetic, non-paresthetic effect in the patient, the first pulses having a first set of first signal delivery parameters; and directing second pulses to the signal delivery device to create a paresthetic effect in the patient, the second pulses having a second set of second signal delivery parameters, wherein a first value of at least one first parameter of the first set is different than a second value of a corresponding second parameter of the second set.
54. The system of claim 53, further comprising:
- an external physician programmer programmed with instructions for adjusting an amplitude of the first pulses; and
- an external patient controller programmed with instructions for adjusting an amplitude of the second pulses, and programmed with instructions preventing adjustment of the amplitude of the first pulses.
55. The system of claim 53 wherein the implantable pulse generator further includes instructions for receiving updates to the first signal delivery parameters, independent of updates to the second signal delivery parameters.
56. The system of claim 53 wherein the implantable pulse generator includes instruction for interleaving one or more second pulses between sequential bursts of the first pulses.
57. The system of claim 53 wherein the implantable pulse generator includes instructions for directing the first pulses to a first electrode of the signal delivery device and directing the second pulses to a second electrode of the signal delivery device different that the first electrode.
58. The system of claim 53 wherein the first pulses have a frequency of from about 3 kHz to about 10 kHz, and the second pulses have a frequency of from about 20 Hz to about 1.2 kHz.
59. The system of claim 53 wherein the implantable pulse generator is programmed with instructions for directing the first and second pulses sequentially to the same electrode of the signal delivery device.
60. The system of claim 53 wherein the implantable pulse generator is programmed with instructions for directing the first and second pulses to the same electrode of the signal delivery device, with a single second pulse directed during an interval between sequential bursts of the first pulses, without the first pulses overlapping temporally with the second pulses, and with the first pulses having a first pulse width and the second pulses having a second pulse width less than the first pulse width, the first pulses being directed at a first frequency, the second pulses being directed at a second frequency less than the first frequency.
Type: Application
Filed: Apr 22, 2010
Publication Date: Oct 28, 2010
Inventors: Konstantinos Alataris (Belmont, CA), Andre B. Walker (Monte Sereno, CA), Jon Parker (San Jose, CA)
Application Number: 12/765,685
International Classification: A61N 1/34 (20060101); A61N 1/36 (20060101);