COUPLINGS FOR IMPLANTED LEADS AND EXTERNAL STIMULATORS, AND ASSOCIATED SYSTEMS AND METHODS
Couplings for implanted leads and external stimulators, and associated systems and methods are disclosed. A system in accordance with a particular embodiment includes a cable assembly that in turn includes an electrical cable having a proximal end and a distal end. A first connector is attached to the cable toward the proximal end and has a plurality of first connector contacts positioned to releasably connect to an external patient device. A second connector is attached by the cable toward the distal end, and includes a first portion and a second portion pivotably connected to the first portion. The first portion has a slot elongated along a slot axis and positioned to receive an implantable patient signal delivery element axially along the slot axis. The second portion has a plurality of second connector contacts positioned to releasably, electrically contact the signal delivery element when the signal delivery element is positioned within the slot and the first and second portions are placed in a secured position. At least one of the first and second portions is pivotable relative to the other between the secured position and an unsecured position.
Latest Nevro Corporation Patents:
- MRI compatible medical devices
- Systems and methods for selecting low-power, effective signal delivery parameters for an implanted pulse generator
- Selective high frequency spinal cord modulation for inhibiting pain with reduced side effects, and associated systems and methods
- Implanted pulse generators with reduced power consumption via signal strength/duration characteristics, and associated systems and methods
- Linked area parameter adjustment for spinal cord stimulation and associated systems and methods
The present disclosure is directed generally to couplings for implanted leads and external stimulators, 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 by 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.
One problem associated with existing stimulation systems and methods is that the practitioner may not initially implant the SCS lead in the optimal position. Accordingly, practitioners typically make small adjustments to the position of the implanted lead while the patient is in the operating room. The practitioner then applies stimulation to the lead via an external stimulator, which is temporarily attached to the lead while the lead still extends out of the patient's body. This process is repeated until the practitioner determines the position of the lead that is expected to produce the best patient result. The patient and practitioner can also use the external stimulator during a post-operative trial period, to optimize the characteristics of the applied signal before an implantable pulse generator is connected to the lead and implanted beneath the patient's skin.
To facilitate the foregoing process of alternately providing stimulation to the patient and moving the implanted portion of the lead, manufacturers have developed cables with releasable connectors. Accordingly, the practitioner can connect the cable to the external stimulator and the lead, apply the stimulation, then disconnect the cable, move the lead, and reconnect the cable with the lead in the new position. As noted above, this process can be repeated, as needed, until the desired lead location is obtained.
One drawback with the foregoing approach is that it may be difficult for the practitioner to repeatedly manipulate the connector that attaches the cable to the lead, while still maintaining control over the position of the lead. Another drawback is that the connectors, which are outside the patient's body, may be awkward and/or cumbersome for the patient during the post-operative trial period. Accordingly, there remains a need for improved techniques and systems for releasably connecting implanted patient leads to external stimulation devices.
Overview
Aspects of the present disclosure are directed generally to couplings that may be used to connect implanted leads or other implanted signal delivery elements, with external stimulators and/or other devices positioned external to a patient. Several aspects of the disclosure are described in the context of a spinal cord stimulation (SCS) system for purposes of illustration. In other embodiments, the disclosed systems and methods may be used in the context of other patient treatment and/or patient diagnostic systems. Several embodiments of representative systems and methods are described below with reference to
A patient treatment system in accordance with a particular embodiment includes a cable assembly that in turn includes an electrical cable having a proximal end and a distal end, with a first connector attached to the cable toward the proximal end, and a second connector attached to the cable toward the distal end. The first connector can include a plurality of first connector contacts positioned to releasably connect to an external patient device, for example, an external stimulator. The second connector can include a first portion and a second portion pivotably connected to the first portion. The first portion can have a slot elongated along a slot axis and positioned to receive an implantable patient signal delivery element axially along the slot axis. The second portion can have a plurality of second connector contacts positioned to releasably, electrically contact the signal delivery element when the signal delivery element is positioned within the slot and the first and second portions are placed in a secured position. The first and second portions are pivotable relative to each other between the secured position and an unsecured position.
A representative method for operating a patient treatment system can include implanting an implantable signal delivery element in a patient, and positioning a cable proximate to connection contacts of the implantable signal delivery device. The cable can include a proximal end with a first connector having first connector contacts, and a distal end with a second connector having first and second portions. The method can further include sliding the connection contacts of the signal delivery element axially into a slot carried by the second portion of the second connector. The method can still further include pivoting at least one of the first and second portions relative to the other to electrically connect the connection contacts of the signal delivery device with second connector contacts carried by the second portion of the second connector. The first connector can be releasably connected to an external patient device, for example, an external patient stimulator. As will be described further below, aspects of the foregoing systems and associated methods can allow the practitioner to manipulate the cable assembly connectors with only one hand, and/or can improve patient comfort while the cable assembly is connected to an implanted lead or other signal delivery element.
Representative Systems and Methods
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 “stimulate” and “stimulation” 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 stimulation 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
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 many cases, an external programmer 105 (e.g., a trial stimulator) is 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 stimulation 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. 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 stimulation. 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. In either embodiment, the practitioner will connect and disconnect the cable assembly 120 at least once during the process. Further details of features that facilitate this process are described below with reference to
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 a one-week trial period. 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 stimulation amplitude.
The first housing portion 130 can include a lead stop 139 within the slot 131 to stop the axial progress of the lead and to align the lead with electrical contacts in the second housing portion. In a particular embodiment, the lead stop 139 is a surface facing toward the first opening 133a, and located at a point where the cross-sectional shape of the slot 131 changes from one that accommodates both the lead 111 and the stylet shaft, to one that accommodates the stylet shaft only. An alignment indicator 138 provides the practitioner with visual confirmation that the lead is properly aligned. The first housing portion 130 can include a first tab 134 and the second housing portion 150 can include a second tab 154, both of which facilitate pivoting the two housing portions relative to each other. For example, the two tabs 134, 154 can be offset from each other in a direction generally parallel to the slot axis 132 to operate in a manner similar to that of a change purse. A latch 170 can hold the housing portions 130, 150 in a secured position when the lead or other signal delivery element is positioned in the slot 131.
In one embodiment, the pivot stop slot 175 alone prevents the housing portions 130, 150 from over-rotating relative to each other. In another embodiment, shown in
As is also shown in
One feature of at least some of the foregoing embodiments described above with reference to
Another feature of at least some of the foregoing embodiments is that the angle between the two housing portions 130, 150 is relatively small when the second connector 122 is in the unsecured configuration. For example, the angle can be less than 90° , less than 45° or less than 5° . An advantage of this arrangement is that it facilitates the practitioner's ability to secure and unsecure the second connector 122 with one hand. For example, when the angle has a value less than 90° , the practitioner can avoid placing forces on the housing portions 130, 150 that have a vector component which tends to unsecure the second connector 122 when the practitioner is attempting to secure the second connector 122. In addition, the amount of hand movement required to secure and/or unsecure the second connector 122 is relatively small, which decreases the likelihood that the practitioner will fumble with the second connector 122.
Still another feature of at least some of the foregoing embodiments is that the second connector 122 has a relatively small footprint (e.g., projected area, generally normal to the major surfaces of the first or second housing portions 130, 150). An expected advantage of this feature is that the small size makes the second connector 122 easier to manipulate. Another expected advantage of this feature is that the second connector will be less bulky and therefore more comfortable for the patient to wear during the trial period.
From the foregoing, it will be appreciated that specific embodiments of the disclosure have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. For example, in other embodiments, the second connector can include other arrangements that limit or prohibit over-rotating one housing portion relative to the other. In still further embodiments, the second connector can include other arrangements for securing one housing portion relative to the other, and/or for halting the axial movement of the lead or other signal delivery element positioned in the second connector. In yet further embodiments, the practitioner can leave the second connector attached to the implanted signal delivery element while the signal delivery element is repositioned, rather than disconnecting and reconnecting the connector with each new signal delivery element position.
Certain aspects of the disclosure described in the context of particular embodiments may be combined or eliminated in other embodiments. For example, in certain embodiments, the signal delivery element can have features different than those shown in
Claims
1. A patient treatment system, comprising:
- a cable assembly that includes: an electrical cable having a proximal end and a distal end; a first connector attached to the cable toward the proximal end, the first connector having a plurality of first connector contacts positioned to releasably connect to an external patient device; and a second connector attached to the cable toward the distal end, the second connector including: a first portion having a slot elongated along a slot axis and positioned to receive an implantable patient signal delivery element axially along the slot axis; a second portion pivotably connected to the first portion, at least one of the first and second portions being pivotable relative to the other between an unsecured position and a secured position, the second portion having a plurality of second connector contacts positioned to releasably, electrically contact the signal delivery element when the signal delivery element is positioned within the slot and the first and second portions are placed in the secured position.
2. The system of claim 1, further comprising the signal delivery element.
3. The system of claim 2 wherein the signal delivery element includes a lead having a terminal portion and an extension portion releasably connected to the terminal portion, and wherein the second connector contacts are positioned to releasably, electrically contact the extension portion.
4. The system of claim 1 wherein the second portion includes eight second connector contacts positioned to releasably contact the signal delivery element when the signal delivery element is positioned within the slot and the first and second portions are in the secured position, and wherein the second connector has a footprint of about 7.2 cm2 or less.
5. The system of claim 1 wherein the second connector includes a pivot stop positioned to allow a maximum opening between the first and second housing portions in the unsecured position is less than about 90°.
6. The system of claim 1 wherein the second connector includes a pivot stop positioned to allow a maximum opening between the first and second housing portions in the unsecured position is less than about 45°.
7. The system of claim 1 wherein the second connector includes a pivot stop positioned to allow a maximum opening between the first and second housing portions in the unsecured position is less than about 5°.
8. The system of claim 1, further comprising a lead stop positioned along the slot axis to prevent axial motion of the signal delivery element beyond the lead stop.
9. The system of claim 1 wherein the slot has first, second and third openings, the first opening being toward a first end of the slot axis and having first width, the second opening being toward a second end of the axis and having a second width, and the third opening extending along the slot axis from the first opening to the second opening and having a third width, the first width being greater than the third width, the first portion further having an alignment indicator that is visually accessible from outside the first portion, and wherein the system further comprises:
- a support member carried by the first portion, the support member carrying the second connector contacts in position to releasably contact the signal delivery element when the signal delivery element is positioned within the slot and the first and second portions are placed in the secured position; and
- a latch having a first element carried by the first portion and a second element carried by the second portion, the first and second elements being releasably engaged with each other when the first and second portions are placed in the secured position.
10. A patient treatment system, comprising:
- a cable assembly that includes: a cable having a proximal end and a distal end, the cable carrying a plurality of conductors; a first connector attached to the cable at the proximal end, the first connector having a plurality of first connector contacts, with individual first connector contacts electrically connected to corresponding individual conductors and positioned to releasably connect to an external patient stimulator; and a second connector attached to the cable at the distal end, the second connector including: a first housing portion having a slot elongated along a slot axis, the slot having first, second and third openings, the first opening being positioned toward a first end of the slot axis and having first width, the second opening being positioned toward a second end of the axis and having a second width, and the third opening extending along the slot axis from the first opening to the second opening and having a third width, the first width being greater than the third width, the first housing portion further having an alignment indicator that is visually accessible from outside the first housing portion; a second housing portion pivotably connected to the first housing portion, at least one of the first and second housing portions being pivotable relative to the other between an unsecured position and a secured position; a support member carried by the second housing portion, the support member having a plurality of second connector contacts positioned to releasably contact an implantable patient lead when the implantable patient lead is positioned within the slot and the first and second housing portions are placed in the secured position, with individual second connector contacts electrically connected to corresponding individual conductors; and a latch having a first element carried by the first housing portion and a second element carried by the second housing portion, the first and second elements being releasably engaged with each other when the second housing portion is placed in the secured position.
11. The treatment system of claim 10, further comprising the external patient stimulator, and wherein the first connector is releasably connected to the external patient stimulator.
12. The treatment system of claim 10, further comprising the implantable patient lead, and wherein the second connector is releasably connected to the implantable patient lead.
13. The treatment system of claim 12 wherein the implantable patient lead includes a row of connection contacts, and wherein a first connection contact in the row is positioned directly adjacent to the alignment indicator, with both the first connection contact and the alignment indicator visually accessible from outside the first housing portion.
14. The treatment system of claim 12, further comprising a stylet slidably positioned within the implantable patient lead, the implantable patient lead having a lead width, the stylet having a stylet width, and wherein the first width of the first opening is greater than the lead width, and wherein the third width of the third opening is greater than the stylet width and less than the lead width.
15. The treatment device of claim 10 wherein the first opening has a funnel shape.
16. The treatment device of claim 10 wherein the second opening is positioned adjacent to a ramped surface of the first housing portion.
17. The treatment device of claim 10 wherein the first housing portion includes a first outwardly extending closure tab, and wherein the second housing portion includes a second outwardly extending closure tab, the first and second closure tabs being offset from each other in a direction generally parallel to a pivot axis about which the second housing portion pivots relative to the first housing portion.
18. The system of claim 10 wherein the first element of the latch includes a recess and wherein the second element of the latch includes a flexible projection, and wherein an inner surface of the recess is covered by the projection when the second housing portion is in the secured position to provide a visual indication that the second housing portion is secured, and wherein the inner surface of the recess is exposed when the second housing portion is in the unsecured position to provide a visual indication that the second housing portion is unsecured.
19. The system of claim 18 wherein the recess is a first recess, and wherein the latch includes a second recess, the second recess receiving the projection when the first and second housing portions are in the unsecured position to at least resist further pivoting of the first and second housing portions away from each other.
20. The system of claim 10, further comprising a lead stop positioned along the slot axis to prevent axial motion of the lead beyond the lead stop.
21. A method for operating a patient treatment system, comprising:
- implanting an implantable signal delivery element in a patient;
- positioning a cable assembly proximate to connector contacts of the implantable signal delivery element, the cable assembly having a proximal end with a first connector having first connector contacts, and a distal end with a second connector having first and second portions;
- sliding the connector contacts of the signal delivery element axially into a slot carried by the second portion of the second connector, the slot being elongated axially along a slot axis;
- pivoting at least one of the first and second portions relative to the other to electrically connect the connection contacts of the signal delivery element with second connector contacts carried by the second portion of the second connector; and
- releasably connecting the first connector to an external patient device.
22. The method of claim 21, further comprising halting axial motion of the signal delivery element by sliding the signal delivery element into contact with a stop carried by the second connector.
23. The method of claim 21 wherein pivoting at least one of the first and second portions includes pivoting at least one of the first and second portions with only a single hand.
24. The method of claim 23, further comprising both applying a pivoting force to the at least one of the first and second portions, and reacting the pivoting force, with the single hand.
25. The method of claim 21, further comprising pivoting at least one of the first and second portions away from the other with a only single hand to electrically disconnect the connector contacts of the signal delivery element from the second connector contacts.
26. The method of claim 21, further comprising:
- pivoting at least one of the first and second portions away from the other to electrically disconnect the connector contacts of the signal delivery element from the second connector contacts; and
- at least restricting relative pivoting between the first and second portions beyond about 90°.
27. The method of claim 21, further comprising:
- pivoting at least one of the first and second portions away from the other to electrically disconnect the connector contacts of the signal delivery element from the second connector contacts; and
- at least restricting relative pivoting between the first and second portions beyond about 45°.
28. The method of claim 21, further comprising:
- pivoting at least one of the first and second portions away from the other to electrically disconnect the connector contacts of the signal delivery element from the second connector contacts; and
- at least restricting relative pivoting between the first and second portions beyond about 5°.
29. The method of claim 21, further comprising latching the first and second portions to each other with the connection contacts of the signal delivery element in electrical contact with the second connector contacts.
30. The method of claim 21 wherein sliding the connection contacts of the signal delivery element axially into a slot includes sliding the connection contacts fully into the slot without electrically connecting the connection contacts of the signal delivery element with the second connector contacts.
31. A method for operating a patient treatment system, comprising:
- implanting an implantable patient lead in a patient by inserting a stylet into the implantable patient lead and inserting the lead and the stylet together into the patient, the implantable patient lead having distal contacts and proximal contacts, the distal contacts being positioned within the patient, the proximal contacts being positioned outside the patient;
- positioning a cable assembly proximate to the proximal contacts of the implantable patient lead, the cable assembly having a proximal end with a first connector and a distal end with a second connector, the second connector having a first housing portion and a second housing portion pivotably connected to the first housing portion, the first housing portion having a slot elongated along a slot axis, the slot having a first slot opening toward a first end of the slot axis, a second slot opening toward a second end of the slot axis, and a third slot opening extending along the slot axis from the first slot opening to the second slot opening;
- sliding the proximal contacts of the patient implantable lead into the first slot opening;
- passing the stylet into the slot through the third slot opening so that the stylet extends outwardly from the slot through the second slot opening;
- visually confirming alignment of at least one of the proximal contacts of the implantable patient lead with an alignment indicator of the first housing portion;
- releasably securing the patient lead to the second connector using only a single hand by: pivoting the at least one of the first and second housing portions toward the other with only the single hand; clamping the proximal contacts of the implantable patient lead against corresponding second contacts carried by the second housing portion with only the single hand; and releasably latching the first and second housing portions together with only the single hand; wherein the method further comprises: releasably connecting the first connector to an external patient stimulator.
32. The method of claim 31 wherein implanting the patient lead includes implanting the patient lead proximate to the patient's spine, and wherein the method further comprises activating the external patient stimulator to address the patient's pain.
33. The method of claim 31 wherein pivoting at least one of the first and second housing portions relative to the other includes:
- engaging a first tab carried by the first housing portion with a first part of the hand;
- engaging a second tab carried by the second housing portion with a second part of the hand, the second tab being offset from the first tab in a direction generally parallel to a pivot axis about which the second housing portion pivots relative to the first housing portion; and
- moving at least one of the first and second parts of the hand toward the other.
34. The method of claim 31 wherein latching includes engaging a flexible projection carried by one of the first and second housing members with a recess carried by the other of the first and second housing members.
35. The method of claim 31, further comprising unclamping the proximal contacts from the second contacts by pivoting at least one of the first and second housing portions away from the other with only a single hand.
Type: Application
Filed: Sep 18, 2009
Publication Date: Mar 24, 2011
Applicant: Nevro Corporation (Palo Alto, CA)
Inventors: Jon Parker (San Jose, CA), Andre B. Walker (Monte Sereno, CA)
Application Number: 12/562,892
International Classification: A61N 1/34 (20060101); A61N 1/375 (20060101);