Patent Description:
Medical devices, which included external or implantable medical devices (IMDs), may be used to treat a variety of medical conditions. Some medical devices may be attached to medical leads for sensing and/or delivery of electrical stimulation therapy to a patient via implanted electrodes. For example, an implantable electrical stimulation device may include an electrical stimulation generator and be attached to one or more implantable leads carrying one or more electrodes. In some cases, implantable electrodes may be coupled to an external medical device including an electrical stimulation generator via one or more percutaneous leads or fully implanted leads.

Example IMDs may be configured to function as neurostimulators, cardiac monitors, cardiac defibrillators, cardiac pacemakers and others. Electrical stimulation therapy may include stimulation of nerve, muscle, or brain tissue or other tissue within a patient. An electrical stimulation device may be fully implanted within the patient. Medical electrical stimulators have been proposed for use to relieve a variety of symptoms or conditions such as heart disease, chronic pain, tremor, Parkinson's disease, depression, epilepsy, migraines, urinary or fecal incontinence, pelvic pain, sexual dysfunction, obesity, and gastro paresis. An electrical stimulator may be configured to deliver electrical stimulation therapy via medical leads carrying electrodes implantable proximate to the heart, spinal cord, pelvic nerves, gastrointestinal organs, peripheral nerves, or within the brain of a patient. Stimulation proximate the spinal cord, within the brain, and proximate peripheral nerves are often referred to as spinal cord stimulation (SCS) deep brain stimulation (DBS), and peripheral nerve stimulation (PNS), respectively. <CIT> discloses a known system for securing the proximal end of a medical lead to a IMD.

This disclosure includes devices, systems, and techniques for securing the proximal end of a medical lead to an IMD with a fastener device incorporating a rotating member having a cam lobe. The cam lobe may be formed to have a substantially planar surface configured to contact the medical lead. For example, rotation of the rotating member can cause the substantially planar surface of the cam lobe to be disposed against the medical lead and provide a bias force resisting linear movement of the medical lead. In some examples, the rotating member and cam lobe can be used to impart a linear motion to a slider, intermediary impinger, or spring, which in turn is disposed against the medical lead providing a bias force resisting linear movement.

In one example, a medical device includes a housing having a channel configured to receive an electrical lead. The medical device can further have a rotatable member having a longitudinal axis about which the rotatable member is configured to rotate. The rotatable member can have an outer surface having a first radius from the longitudinal axis. The rotatable member can also have a cam lobe extending farther from the longitudinal axis than the first radius of the outer surface. The cam lobe can have a substantially planar surface parallel to the longitudinal axis. The substantially planar surface of the cam lobe can be configured to retain the electrical lead within the channel. The rotatable member can further have a lever extending from the rotatable member perpendicular to the longitudinal axis. The medical device can further have a slider having a central portion substantially parallel with the cam lobe. The central portion can terminate in a first end and a second end where both the first end and the second end extend away from the channel. The slider can further have a slider protrusion on the central portion of the slider. The slider protrusion can have a substantially planar surface parallel to the channel. The slider protrusion can be configured to engage the electrical lead as the rotatable member is rotated toward the center portion. The slider can further have a cam stop operably coupled to the first end and extending inward toward the rotatable member, substantially parallel with the first end. The cam stop can be configured to contact and restrict rotation of the rotatable member when the cam lobe engages the cam stop. The slider can further have a retraction member operably coupled to the second end and extending toward the rotatable member substantially parallel to the channel. The retraction member can be configured to contact the cam lobe during rotation of the cam lobe in a retraction direction. The cam lobe can be configured to engage the retraction member as the slider is pulled away from the channel.

In another example, a medical system having a medical device including a housing with a first channel configured to receive a first electrical lead. The medical device further can have a first rotatable member with a longitudinal axis about which the first rotatable member is configured to rotate. The first rotatable member can have an outer surface having a first radius. Further, the rotatable member can have a cam lobe extending farther from the longitudinal axis than the first radius of the outer surface. The cam lobe can have a substantially planar surface parallel to the longitudinal axis. The substantially planar surface of the cam lobe can be configured to retain the first electrical lead within the first channel. The medical device housing can further have a second channel defined by the housing configured to receive a second electrical lead and have a second rotatable member having a longitudinal axis about which the second rotatable member is configured to rotate. The second rotatable member can also have an outer surface having a first radius. The second rotatable member can also have a cam lobe extending farther from the longitudinal axis than the first radius of the outer surface. The cam lobe can have a substantially planar surface parallel to the longitudinal axis. The substantially planar surface of the cam lobe is configured to retain the second electrical lead within the second channel. The medical device can further have a first slider substantially encompassing the first rotatable member. The first slider is slidably mounted and configured to slide toward the first channel as the rotatable member rotates the cam lobe towards a central portion of the first slider. The central portion can be substantially parallel with the first channel. The first slider can have a retraction member located opposite of the central portion across from the rotatable member and substantially parallel to the central portion. The cam lobe can be configured to engage the retraction member as the cam lobe is rotated away from the central portion to move the slider away from the first channel. The medical device can further have a stimulation generator configured to generate electrical stimulation deliverable via one or more electrodes of the electrical lead.

In another example, a medical device having a housing with a channel configured to receive an electrical lead and a chamber adjacent to the channel. The medical device can further have a rotatable member located within the chamber. The rotatable member can have an outer surface having a first radius and a cam lobe extending farther from the first radius of the outer surface. The cam lobe can have a substantially planar surface parallel to the longitudinal axis. The medical device can further have a slider having a central portion substantially parallel with the cam lobe. The central portion can terminate in a first end and a second end where both the first end and the second end extend away from the channel. The slider can be configured to slide into contact with the electrical lead and secure the electrical lead within the channel. The cam lobe can be configured so as the rotatable member is rotated and the cam lobe engages the central portion of the slider, it pushes on the central portion to move the slider toward the channel. The slider can further have a slider protrusion on the central portion of the slider. The slider protrusion can have a substantially planar surface parallel to the channel. The slider protrusion can be configured to engage the electrical lead as the rotatable member is rotated toward the center portion. The slider can further have a cam stop operably coupled to the first end and extending inward toward the rotatable member, substantially parallel with the first end. The cam stop can be configured to contact and restrict rotation of the rotatable member when the cam lobe engages the cam stop. The slider may further have a retraction member operably coupled to the second end and extending toward the rotatable member substantially parallel to the channel. The retraction member can be configured to contact the cam lobe during rotation of the cam lobe in a retraction direction. The cam lobe can be configured to engage the retraction member as the slider is moved away from the channel.

The details of one or more examples of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of this disclosure will be apparent from the description and drawings.

This disclosure includes devices, systems, and techniques for securing the proximal end of a medical lead to a medical device, such as an IMD, with a cam based rotating fastener device. To retain a lead (or drug catheter in other examples) in an IMD, the IMD may utilize a set screw, which when advanced toward the lead, applies a force directly to the side of the lead housing or metal band around the housing of the lead. Friction forces and/or deformation caused by the set screw may prevent the lead from being pulled out from the IMD. The depth and force of the set screw is determined by the physician manually rotating the screw. However, if the physician over rotates the set screw, the force applied to the lead from the set screw may deform the lead and cause damage to the lead housing and/or elements within the lead, such as one or more electrical conductors. A damaged lead may need to be replaced or, if not replaced, prevent full operation of the medical device and/or lead.

As described herein, a cam lobe on the side of a rotatable member of a fastener may be configured to applying a force directly to the side of a lead with a limited distance the cam lobe can travel towards the side of the lead. The cam lobe may also define a substantially planar surface contacting the side of the lead to secure the lead and resist movement of the cam lobe due to axial force from the lead. This cam lobe thus avoids potential deformation of the lead. The cam fastener can also provide a very low-profile height compared to a set screw since it operates on the side of the cable rather than the top. Further, a portion of the set screw height is the additional needed height for movement (e.g., the extra rotational movement needed) and a retaining feature above the screw threads). A rotatable member's height of examples described below can be anywhere from <NUM> inches (<NUM>) to <NUM> inches (<NUM>) smaller than a set screw. Further, the rotatable member does not stick out away from the implantable device, thus creating a smooth profile for a flush profile surface. In one example, the volume occupied by rotatable member is, <NUM> cubic inches (<NUM> cubic cm), which may be comparable to or less than set screws, which may be used to retain a lead in other examples. Even when the rotatable member is used in combination with an intermediate member the volume occupied may be between <NUM> and <NUM> cubic inches (<NUM> and <NUM> cubic cm) in some examples.

The cam lobe shape provides a positive engagement feel for the implanting physician, has a low assembly height and provides permanent fastener retention. The substantially planar surface helps prevent any deformation from over rotation of a set screw. The force applied by the cam lobe is not dependent on the implanting physician, but instead is dependent upon whether the cam lobe is engaged with the lead or not. The substantially planar surface provides a "locking", "anti-rotation", or "resting position" action provided by the lobe's "substantially planar surface". The medical lead elastically deforms and provides a spring back return force to the lobe's planar surface. The elastic deformation force would need to be overcome for the cam to be turned out of its resting (locked) position.

Further, the cam shape cannot crush the implantable lead because the cam lobe has a fixed distance it extends toward the lead. Furthermore, an intermediate member can be added between the cam member and the lead to control the contact area and secure leads without axial force or movement. The intermediate member can be used to prevent abrasion to the lead as the intermediate member does not move or rotate as the rotatable member does. A rotatable cam provides simple operation, can be configured for standard tools (e.g., an Allen wrench, slotted screwdriver, hand operated lever, etc.) and can provide visual cues for the physician installing the IMD.

As described herein, a connector block may be referred to as a header of the IMD in some examples. Structures for retaining a medical lead may include actuatable cam mechanisms configured to mechanically connect a medical lead to an IMD. Such a flexible clamping mechanism may be located adjacent, near or next to channels configured to receive the proximal end of a medical lead. Actuating the rotatable cam mechanism may apply a compressive force to a medical lead in the proximal end of the medical lead, thereby mechanically connecting the medical lead to the rotating cam member.

For purposes of this disclosure the term "substantially" when used in relation to describing elements, shall be defined as being largely and or wholly the item specified. When used in relation to quantities, it can mean considerable in quantity; significantly great.

<FIG> illustrates an example medical system <NUM> including an IMD <NUM> with a medical lead(s) 26A, 26B (hereinafter referred to collectively as leads <NUM> or leads 26A, 26B, 26C, 26D) configured to deliver therapy. IMD <NUM> is configured to deliver therapy to patient <NUM> through medical leads <NUM>. Medical lead(s) <NUM> are connected to IMD <NUM> by connector block <NUM>. In some references, a connector block, such as connector block <NUM>, is instead referred to as a header of the IMD. In any event, connector block <NUM> provides the means for forming an electrical connection between electrical contacts of medical lead <NUM> and feedthrough pins of feedthroughs passing through the housing of IMD <NUM>, which forms a hermetically sealed enclosure for the electronic components of IMD <NUM>. In other examples, a portion of IMD <NUM> may accept a lead and provide electrical contact with a hermetic seal without being arranged as a separate header or connector block.

IMD <NUM> may include a power source as well as processing circuitry, microprocessors, internal memory, and other electronic circuitry for executing software or firmware to provide the functionality described herein. The software executing thereon may perform a variety of sensing, diagnostic, and/or therapy-related operations, one such therapy operation may be stimulation of spinal cord <NUM> through medical lead <NUM> operatively (i.e. electrically and/or mechanically) connected to IMD <NUM> by connector block <NUM>.

Connector block <NUM>. is configured to receive the proximal end of medical lead <NUM>. Connector block <NUM> includes one or more fasteners with actuatable clamps, such as fastener device <NUM> (shown in <FIG>), which are configured to secure the proximal end of one or more medical leads <NUM> to IMD <NUM>.

Medical system <NUM> further includes external programmer <NUM>. In different examples, external programmer <NUM> may include an external medical device, a programming device, a remote telemetry station, a physician-activated device, a patient-activated device, a display device or any other type of device capable of sending and receiving signals to and from IMD <NUM>. In some implementations, IMD <NUM> generates content to display on external programmer <NUM>. In other implementations, external programmer <NUM> communicates instructions to IMD <NUM> based on the content received from a cloud server, a computer system, and/or a mobile device.

As described herein, IMD <NUM>, and the software executing thereon, provides a platform for providing therapy to spinal cord <NUM> through medical lead(s) <NUM>. For example, IMD <NUM> may be configured to receive and process electrical signals produced by the body of patient <NUM> using medical lead(s) <NUM>. IMD <NUM> may also use medical lead(s) <NUM> to deliver therapy, such as SCS therapy, to spinal cord <NUM> of patient <NUM>. In other examples, one or more medical leads <NUM> may be dedicated by IMD <NUM> to receive electrical signals, and one or more other medical leads <NUM> may be dedicated to delivering therapy to spinal cord <NUM> of patient <NUM>.

In some examples, IMD <NUM> may implement techniques for automated receiving and processing of electrical signals indicating a need for therapy. For example, IMD <NUM> may allow a user, by communicating with external programmer <NUM>, control over one or more therapy techniques used by IMD <NUM> in response to IMD <NUM> receiving and processing electrical signals from medical lead <NUM> indicating a need for treatment. In another example, a user may use external programmer <NUM> to provide pre-determined responses for therapy through medical lead <NUM> to respond to IMD <NUM> receiving and processing electrical signals from medical lead <NUM> indicating a need for treatment.

In the example of <FIG>, IMD <NUM> is illustrated as an IMD for providing therapy to a spinal cord. However, in other examples, IMD <NUM> may be configured to function as a neurostimulator, cardiac monitor, cardiac defibrillator, cardiac pacemakers, or any other type of simulation and/or sensing device utilizing one or more medical leads.

As described herein, IMDs deliver therapy through one or more medical leads 26A, 26B based on external programmer <NUM> and/or internal programming for software which, as described, can efficiently deliver therapy to targeted areas. In this example, connector block <NUM> may be the result of multiple components.

Medical leads 26A, 26B may include one or more electrodes. In the example illustrated, medical leads 26A, 26B may each include a respective tip electrode and ring electrode located near a distal end of their respective medical leads 26A, 26B. When implanted, the tip electrodes and/or the ring electrodes are placed relative to or in a selected tissue, muscle, nerve or other location within the patient.

Medical leads 26A, 26B are connected at a proximal end to IMD <NUM> by connector block <NUM>. Connector block <NUM> may include one or more fasteners, such as fastener device <NUM> (see <FIG>) interconnecting with one or more contact rings located on the proximal end of medical leads 26A, 26B. Medical leads 26A, 26B are operatively connected to one or more of the electrical components within housing <NUM>. One or more conductors (not shown) extend within medical leads 26A, 26B from the contact rings along the length of the medical lead to engage the ring electrode and the tip electrode respectively. In some examples, medical leads 26A, 26B may each include a plurality of ring electrodes, such as four or eight electrodes. For example, DBS therapy may utilize medical leads including four ring electrodes, whereas SCS therapy may utilize medical leads including eight ring electrodes. In other examples, leads 26A, 26B may include a complex electrode array which may include electrodes at the same axial position on the lead but at different respective circumferential positions around the lead. These electrodes at different circumferential positions may be provided alone, or in combination with one or more ring electrodes, a tip electrode, or other types of electrodes on each lead. In any case, each of the tip electrodes (if present) and the ring electrodes are operatively coupled to a respective conductor within its associated medical lead bodies. For example, a first electrical conductor can extend along the length of the body of medical lead 26A from connector block <NUM> and operatively couple to the tip electrode and a second electrical conductor can extend along the length of the body of medical lead 26A from connector block <NUM> and operatively couple to the ring electrode. The respective conductors may be operatively coupled to circuitry, such as a stimulation generator <NUM> as described in <FIG>, of IMD <NUM> via connections in connector block <NUM>.

In different examples, stimulation <NUM> may instead include peripheral nerve stimulation (PNS) or peripheral nerve field stimulation (PNFS) therapy, and/or any other stimulation provided by a neurostimulator, a cardiac monitor, a cardiac defibrillator, a cardiac pacemaker, or any other type of mobile or non-mobile computing device suitable for performing the techniques described herein.

IMD <NUM> may also provide sensing functions in addition to or alternatively to stimulation functions. For example, IMD <NUM> may be configured to receive and process electrical signals produced by the body of patient <NUM> using medical leads 26A, 26B to indicate a need for therapy. After a need for therapy is detected by IMD <NUM>, IMD <NUM> may respond by using medical leads 26A, 26B to deliver therapy, such as stimulation <NUM>, to the body of patient <NUM>. In other examples, one or more medical leads 26A, 26B may be dedicated by IMD <NUM> to receiving electrical signals and/or delivering therapy, such as stimulation <NUM> to the body of patient <NUM>.

IMD <NUM> is illustrated as an IMD for providing therapy to the torso of patient <NUM>. However, in other examples, IMD <NUM> may be a neurostimulator, cardiac monitor, cardiac defibrillator, cardiac pacemaker or any other type of mobile or non-mobile computing device suitable for performing the techniques described herein.

Housing <NUM> of IMD <NUM> can be constructed of conductive materials, nonconductive materials or a combination thereof. As described herein, housing <NUM> of IMD <NUM> may provide a substantially sealed environment for processing circuitry, memories, transmitters, receivers, transceivers, sensors, sensing circuitry, therapy circuitry, antennas, power sources, and other components of IMD <NUM>. In the example of <FIG>, IMD <NUM> delivers therapy through one or more medical leads 26A, 26B connected operatively to IMD <NUM> by connector block <NUM> utilizing one or more fasteners, such as fastener device <NUM> as described in <FIG>.

<FIG> is a functional block diagram illustrating various components of an example IMD <NUM>. As shown in <FIG>, IMD <NUM> includes processing circuitry <NUM>, memory <NUM>, stimulation generator <NUM>, telemetry circuitry <NUM>, power source <NUM> and other various hardware components providing functionality for operation of the device. For example, IMD <NUM> includes programmable processing circuitry <NUM> to be configured to operate according to executable instructions, typically stored in a computer-readable medium or memory <NUM> such as static, random-access memory (SRAM) device or Flash memory device. IMD <NUM> may include additional discrete digital logic or analog circuitry not shown in <FIG>.

Stimulation generator <NUM> may connect to one or more medical leads 26A-26D. IMD <NUM> may utilize stimulation generator <NUM> connected to one or more medical leads 26A-26D to detect and recognize irregularities with the patient requiring treatment and/or therapy based on instructions from processing circuitry <NUM>. In some examples, IMD <NUM> may utilize stimulation generator <NUM> connected to one or more medical leads 26A-26D to provide treatment and/or therapy based on instructions from processing circuitry <NUM>.

Telemetry circuitry <NUM> may comprise any unit capable of facilitating wireless data transfer between IMD <NUM> and an external programmer <NUM>, where external programmer <NUM> may comprise an external medical device, a programming device, a remote telemetry station, a physician-activated device, a patient-activated device, a display device or any other type of device capable of sending and receiving signals to and from IMD <NUM>. Telemetry circuitry <NUM> and external programmer <NUM> are respectively coupled to one or more antennas for facilitating the wireless data transfer. Telemetry circuitry <NUM> may be configured to perform any type of wireless communication. For example, telemetry circuitry <NUM> may send and receive radio frequency (RF) signals, infrared (IR) frequency signals, or other electromagnetic signals. Any of a variety of modulation techniques may be used to modulate data on a respective electromagnetic carrier wave. Alternatively, telemetry circuitry <NUM> may use sound waves for communicating data or may use the patient's tissue as the transmission medium for communicating with a programmer positioned on the skin of a patient. In any event, telemetry circuitry <NUM> facilitates wireless data transfer between IMD <NUM> and external programmer <NUM>.

Power source <NUM> may be a rechargeable battery, such as a lithium ion or nickel metal hydride battery. Other rechargeable or conventional batteries may also be used. In some examples, external programmer <NUM> may be configured to recharge IMD <NUM> in addition to programming IMD <NUM>.

<FIG> is a functional block diagram illustrating various components of an external programmer <NUM> for use with IMD <NUM>. As shown in <FIG>, external programmer <NUM> includes user interface <NUM>, processing circuitry <NUM>, memory <NUM>, telemetry circuitry <NUM>, and power source <NUM>. A clinician or patient interacts with user interface <NUM> in order to manually change the parameters of a therapy program, change therapy programs within a therapy of programs, view therapy information, view historical therapy regimens, establish new therapy regimens, or otherwise communicate with IMD, such as IMD <NUM> in <FIG>, or view or edit programming information.

User interface <NUM> may include a screen and one or more input buttons, allowing external programmer <NUM> to receive input from a user. Alternatively, or additionally, user interface <NUM> may additionally, or only, utilize a touch screen display. The screen may be a liquid crystal display (LCD), dot matrix display, organic light-emitting diode (OLED) display, touch screen, or any other device capable of delivering and/or accepting information.

Input buttons for user interface <NUM> may include a touch pad, increase and decrease buttons, emergency shut off button, and other buttons needed to control the therapy, as described above regarding patient programmer <NUM>. Processing circuitry <NUM> controls user interface <NUM>, retrieves data from memory <NUM> and stores data within memory <NUM>. Processing circuitry <NUM> also controls the wireless transmission of data through telemetry circuitry <NUM> to an IMD, such as IMD <NUM> in <FIG>, by transmitting data to telemetry circuitry <NUM> as described in <FIG>. The transmitted data may include therapy program information specifying various drug delivery program parameters. Memory <NUM> may include operational instructions for processing circuitry <NUM> and data related to therapy for the patient.

Power source <NUM> may be a rechargeable battery, such as a lithium ion or nickel metal hydride battery. Other rechargeable or conventional batteries may also be used. In some cases, external programmer <NUM> may be used when coupled to an alternating current (AC) outlet, i.e., AC line power, either directly or via an AC/DC adapter. In some examples, external programmer <NUM> may be configured to recharge IMD <NUM> in addition to programming IMD <NUM>.

<FIG> illustrates an elevated view of the components of fastener device <NUM> within a medical device <NUM> having a housing <NUM> which defines a channel <NUM> configured to receive an electrical lead <NUM> or leads 26A and 26B. A rotatable member <NUM> defines a longitudinal axis <NUM> about which the rotatable member <NUM> is configured to rotate in a clockwise and/or counterclockwise manner. The rotatable member <NUM> can be constructed out of metal alloys or polymers. Conductive materials can be utilized if rotatable member <NUM> is desired to be electrically conductive. The rotatable member <NUM>. defines an outer surface <NUM> having a first radius <NUM> from the longitudinal axis <NUM>. A cam lobe <NUM> extends out from the outer surface <NUM> farther from the longitudinal axis <NUM> than the first radius <NUM> of the outer surface <NUM>. The cam lobe <NUM> defines a substantially planar surface <NUM> (also shown in <FIG>) parallel to the longitudinal axis <NUM>. The substantially planar surface <NUM> of the cam lobe <NUM> can be configured to retain the electrical lead <NUM> within the channel <NUM>. As discussed above, the substantially planar surface can be flat, near flat or almost flat, but is not required to be absolutely flat.

Substantially planar surface <NUM> may define a midsection 111A between edges 111B and 111C. By being substantially planar, both of edges 111B and 111C have a larger radius <NUM> from longitudinal axis <NUM> than the radius <NUM> from longitudinal axis <NUM> to midsection 111A. From the Pythagorean theorem: c=(a<NUM>+b<NUM>)<NUM>/<NUM>, we know if "a" (e.g., the radius <NUM>) remains constant and "b" (e.g., the length of the substantially planar surface <NUM>) increases, then "c" (the radius <NUM>) will increase as well. More succinctly expressed, if "a" remains constant and "b" increases, then "c" will increase as well. Thus, in one example, if the flat surface <NUM> of the cam <NUM> is <NUM> inches (<NUM>) and the substantially planar surface <NUM> is <NUM> inches (<NUM>), then radius <NUM> is <NUM> inches (<NUM>). In this manner, a larger rotational force is needed to rotate rotatable member <NUM> and overcome the larger radius and force applied by either of edges 111B and 111C against the lead during rotation than the smaller radius <NUM> to midsection 111A will require. The dimensional difference between the radius <NUM> and the radius <NUM> is <NUM> - <NUM> = <NUM> inches (<NUM> - <NUM> = <NUM>). The <NUM> inch (<NUM>) is the amount of over-compression the lead has to temporarily endure for the cam lobe to rotate to the substantially planar surface. This configuration of midsection 111A between 111B and 111C may resist undesired rotation of rotatable member <NUM><NUM> when the lead is retained by cam lobe <NUM> of rotatable member <NUM>. Further, to minimize the pressure applied to the lead when rotating the cam lobe <NUM> the curvature could be increased from zero, which would indicate a shape corner, to say RO. O <NUM><NUM> indicating a soft corner as shown by edges 111B and 111C in <FIG>.

While the longitudinal axis <NUM> is shown as perpendicular to channel <NUM>, the longitudinal axis <NUM> could also be parallel to or oblique to channel <NUM> so long as rotation of rotatable member <NUM> causes cam lobe <NUM> to extend into channel <NUM> and against electrical lead <NUM> within channel <NUM>.

Further shown in <FIG>, slider <NUM> defines a central portion <NUM> substantially parallel with the channel <NUM>. Slider <NUM> may be made of a metal alloy if it is desirable for slider <NUM> to be conductive or from a polymer if it is desired for slider <NUM> to be nonconductive. Central portion <NUM> of slider <NUM> terminates into a first end <NUM> and a second end <NUM> which both extend away from the channel <NUM> and can be perpendicular to the longitudinal axis <NUM>. In some examples, first end <NUM> and second end <NUM> extend in a direction substantially orthogonal from central portion <NUM>. The slider <NUM> can be configured to slide into contact with the electrical lead <NUM> and secure the electrical lead <NUM> within the channel <NUM>. When the rotatable member <NUM> is rotated (e.g., in a clockwise direction as shown in <FIG>, (but a counter-clockwise direction may be used in other examples) cam lobe <NUM> engages the central portion <NUM> of the slider <NUM> to apply a force to the central portion <NUM> which pushes the slider <NUM> (to the right in <FIG>) toward the channel <NUM>. This action of a slider is discussed in greater detail below with reference to <FIG>).

A slider protrusion <NUM> can be located on the central portion <NUM> of the slider <NUM> facing the channel <NUM>. The slider protrusion <NUM> defines a substantially planar surface <NUM> parallel to the channel <NUM> and the cam lobe <NUM>. The slider protrusion <NUM> can engage the electrical lead <NUM> as the rotatable member <NUM> is rotated toward the center portion <NUM>.

A cam stop <NUM> can be operably coupled to the first end <NUM> and can extend inward toward the rotatable member <NUM> and can run along first end <NUM>. The cam stop can be configured to contact and restrict rotation of the rotatable member <NUM> when the cam lobe <NUM> engages the cam stop <NUM> during rotation.

A retraction member <NUM> can be operably coupled to the second end <NUM> and extend toward the rotatable member <NUM> substantially parallel to the channel <NUM>. The retraction member <NUM> is configured to contact the cam lobe <NUM> during rotation of the rotatable member <NUM> in a retraction direction (a counterclockwise direction as shown in <FIG>). As the cam lobe <NUM> engages the retraction member <NUM>, force from the cam lobe <NUM> pushes the slider <NUM> away from the channel along line of motion arrow 132A.

Slider <NUM>, along with rotatable member <NUM>, are housed within chamber <NUM>. Slider <NUM> has a range of motion along motion arrow 132A and arrow 132B. As rotatable member <NUM> is configured to move in a clockwise or counterclockwise direction, cam lobe <NUM> will either engage center portion <NUM>, cam stop <NUM> or retraction member <NUM> at respective circumferential positions of rotatable member <NUM>. In response to cam lobe <NUM> engaging center portion <NUM>, force from cam lobe <NUM> will cause slider <NUM> to slide toward the channel <NUM> along motion arrow 132B. When the cam lobe <NUM> contacts cam stop <NUM>, cam stop <NUM> prevents rotatable member <NUM> from further rotation in the counterclockwise direction.

As shown in <FIG>, when substantially planar portion <NUM> of cam lobe <NUM> is substantially parallel with slider center portion <NUM>, this is a "locked position" and the force applied by cam lobe <NUM> to slider protrusion <NUM> to lead <NUM> will hold electrical lead <NUM> in place. As rotatable member <NUM> is rotated clockwise, cam lobe <NUM> disengages the center portion <NUM> and moves until it contacts retraction member <NUM>. As cam lobe <NUM> presses against retraction member <NUM>, slider <NUM> begins to slide away from channel <NUM> along motion arrow 132A until slider <NUM> is pushed away from channel <NUM>. If a user keeps rotating rotatable member <NUM> past retraction member <NUM>, cam lobe <NUM> will once again contact cam stop <NUM> which prevents further rotation. Although fastener device <NUM> may include slider <NUM>, rotatable member <NUM> may function without slider <NUM> in other examples.

<FIG> illustrate rotatable member <NUM>. As shown, a lever <NUM> can extend from the rotatable member <NUM> perpendicular to the longitudinal axis <NUM>. The lever <NUM> is configured to rotate the rotatable member <NUM> about the longitudinal axis <NUM>. As shown in the example of <FIG>, an intermediary spring member <NUM> can be optional as a structure (like slider <NUM>) positioned between the cam lobe <NUM> and electrical lead <NUM>, when the cam lobe <NUM> is parallel to the channel <NUM>. As shown in <FIG>, lever <NUM> is in an extended or released position in which a lead <NUM> can be inserted into, or removed from, channel <NUM>. Like <FIG>, when rotatable member <NUM> is turned clockwise by extending lever <NUM> in an upward fashion away from connector block <NUM>, cam lobe <NUM>+<NUM> is positioned out and away from channel <NUM>. Lever <NUM> is limited in rotation. Lever <NUM> can only move in an upward direction, or clockwise, until it hits edge <NUM> of connector block <NUM>.

In operation, the user would move lever <NUM> upward as shown in <FIG>. An electrical lead <NUM> can be inserted into channel <NUM> in this configuration. After insertion of the electrical lead <NUM> into channel <NUM>, the user could begin moving the lever <NUM> towards connector block <NUM> and thus begin to turn rotatable member <NUM> in a counterclockwise direction to rotate cam lobe <NUM> toward channel <NUM> as shown in <FIG>. In a locked position, as shown in <FIG>, lever <NUM> has been fully rotated to position cam lobe <NUM> as resting against spring <NUM> which in turn rests against the electrical lead <NUM> to hold lead <NUM> in place. It is noted spring <NUM> may not be used in other examples, so cam lobe <NUM> contacts the lead. As can be seen in <FIG>, lever <NUM> can rest in a lever channel <NUM> within connector block <NUM> to make lever <NUM> both flush with the connector block <NUM> and retain stop lever <NUM> at a position where the cam lobe <NUM> is in the locked position. The intermediary spring <NUM> can include a protrusion or structure configured to impinge or otherwise provide the forces of the cam lobe <NUM> onto the electrical lead <NUM>. In this manner, spring <NUM> may prevent the sliding and/or rotation from cam lobe <NUM> from moving or abrading the electrical lead <NUM>.

<FIG> illustrates an exploded view of examples of a hex head rotatable member <NUM> and a lever rotatable member <NUM> of <FIG>. Hex head rotatable member <NUM> may be like rotatable member <NUM> of <FIG>. Lever <NUM> and intermediary spring <NUM> are shown in exploded view above a right chamber <NUM> and hex head rotatable member <NUM> is shown in exploded view above a left chamber <NUM>. Chambers <NUM> are adjacent to respective channels 100A and 100B for electrical leads <NUM>.

Hex head rotatable member <NUM> has a six-sided hexagonal indentation <NUM> defined in surface <NUM>. Hexagonal indentation <NUM> is shaped to receive an Allen wrench. The Allen wrench (not shown) is used by placing one end of an Allen wrench within the hexagonal indentation <NUM>. The other end of the Allen wrench is then held by a hand of a user to rotate rotatable member <NUM>. Hex head rotatable member <NUM> is also shown having a cam lobe <NUM> which would also rotate as rotatable member <NUM> is rotated.

Both rotatable member <NUM> and <NUM> are placed within chambers <NUM> and flush mounted covers <NUM> are placed over chambers <NUM> to make connector block <NUM> flush on the surface and smooth for implantation. Covers <NUM> may be glued, welded, or otherwise fixed in place to connector block <NUM>. Although connector block <NUM> is shown, rotatable members <NUM> and <NUM> may be placed directly within a housing of the medical device in other examples.

<FIG> illustrate rotatable members <NUM> and <NUM> in a fully assembled configuration. As shown, hexagonal rotatable member <NUM> and slotted rotatable member <NUM> are shown being inserted into chambers 534A and 534B of connector block <NUM>. With reference to <FIG>, hexagonal rotator member <NUM> and slotted member <NUM> are being inserted into chambers <NUM> A and 534B respectively. It is of note, hexagonal rotator member <NUM> and slotted member <NUM> could be swapped into either chambers 534B and 534A as the same parts fit both chambers 534A and 534B. A ledge <NUM> (shown in chamber 534A) can traverse around a midsection surface of chambers 534A and 534B and at corresponding locations of respective covers <NUM>. The ledge <NUM> can engage rotatable member slot <NUM> and provide support to hold rotatable member <NUM> and <NUM> securely within chambers 534A and 534B. Ledge <NUM> assures rotatable members <NUM> and <NUM> are held within chambers 534A and 534B. Ledge <NUM> rests within channel <NUM>, which retains rotatable member <NUM> and <NUM> within chambers 534A and 534B respectively. Ledge <NUM> allows rotatable member <NUM> and <NUM> to also rotate freely within chamber 534A and 534B respectively while also retaining rotatable member <NUM> and <NUM> within chambers 534A and 524B. This ensures rotatable members cannot become lose within chambers 534A and/or 534B and possibly become lost or disassociated from IMD <NUM>.

Slotted rotatable member <NUM> defines a slot <NUM> bisecting surface <NUM>. Slot <NUM> is configured to receive a standard screwdriver which can rotate slotted rotatable member <NUM>. The standard screwdriver can be used similarly to an Allen wrench to rotate the rotatable member <NUM>. It is of note, both rotatable member <NUM> and rotatable member <NUM> could be a hex head rotatable member like rotatable member <NUM> or both could be a slotted rotatable member like rotatable member <NUM>.

With reference to <FIG>, a cross-section of the connector block <NUM> is shown with hexagonal rotatable member <NUM> and slotted rotatable member <NUM> installed. As shown both rotatable members <NUM> and <NUM> have their cam lobes 510A and 510B respectively in a "locked position" where electrical leads 226A and 226B are held in frictional position by the cam lobes 510A and 510B. It's of note neither rotatable member <NUM> nor <NUM> utilizes an intermediary spring <NUM>. Further, almost any type of standardized aperture for use with a Phillips screwdriver, an Allen wrench, torx wrench, a bristol wrench, or any other shape to facilitate rotation of rotatable member <NUM>, <NUM> or <NUM> can be used with a standard or proprietary tool.

With reference to <FIG>, a slotted hexagonal rotatable member <NUM> is shown. As shown rotatable members <NUM> has cam lobe <NUM> and hex-slotted recess <NUM>. Rotatable member <NUM> could be used with most any type of implant tool, such as a standard screwdriver or an Allen wrench. The hex-slotted recess <NUM> allows for an implanting physician to utilize either a standard screwdriver or an Allen wrench for coupling of the electrical lead to the IMD.

<FIG> are a conceptual diagram of a rotating member <NUM> within a chamber <NUM> which provides hard stops to prevent rotation of rotating member <NUM> beyond certain circumferential positions for the rotating member <NUM>. Chamber <NUM> can provide built in hard stops for rotating member <NUM>. Hard stops can assist an implantation physician with determining when the rotating member <NUM> is in the "locked position" and the "unlocked position. " Without hard stops <NUM> and <NUM>, rotating member <NUM> would continue to rotate in response to rotational force from the implantation physician. Thus, the physician may have difficulty identifying the fully "locked position" or an "unlocked position" by feel alone. Therefore, hard stops <NUM> and <NUM> may facilitate correct positioning of the rotatable member with respect to the lead <NUM>.

When rotatable member <NUM> is rotated in a clockwise direction, cam lobe <NUM> will eventually contact hard stop <NUM>, as shown in <FIG>, and stop rotating. In this position, rotatable member is in a substantially "locked position" at which cam lobe <NUM> has engaged electrical lead <NUM> within channel <NUM>. The implanting physician could simply turn the rotatable member <NUM> counterclockwise a short distance to fully engage the substantially planar surface <NUM> against electrical lead <NUM> thus providing a more secure electrical lead retaining position. The implanting physician should be able to feel the rotating member <NUM> substantially planar surface <NUM> engaging electrical lead <NUM> and being slightly harder to turn in a counterclockwise motion as the electrical lead <NUM> would provide resistance force to the rotating movement. The hard stop <NUM> could be set so the cam lobe <NUM> is in the "locked position" when the cam lobe <NUM> is engaged with hard stop <NUM>. Another alternative is to provide for the forces against cam lobe edge 212A of planar surface <NUM> to cause the cam lobe <NUM> to settle with the planar surface <NUM> against the lead <NUM>.

If the implanting physician needs to release the electrical lead <NUM> from channel <NUM>, the implanting physician would turn the rotatable member <NUM> in a counterclockwise direction. The implanting physician could rotate the rotatable member <NUM> until the cam lobe <NUM> engaged hard stop <NUM> indicating the rotatable member <NUM> is in an "unlocked position" at which the lead <NUM> may be removed from the channel <NUM>.

<FIG> are conceptual diagrams illustrating an example of an intermediary impinger <NUM> configured to mechanically connect a medical lead to an IMD. Intermediary impinger <NUM> can behave like spring <NUM> of <FIG>. Intermediary impinger <NUM> can function to convert the rotational motion of rotational member <NUM> into linear movement from cam lobe <NUM> forces against intermediary impinger <NUM> to electrical lead <NUM> within channel <NUM>. Utilizing an intermediary impinger <NUM> can reduce or prevent movement of the electrical lead <NUM> from causing rotation of the rotatable member <NUM>. As an example, if the lead <NUM> moves for whatever reason (e.g., patient movement), impinger <NUM> prevents this movement from being transferred to rotatable member <NUM>, as impinger <NUM> cannot move in a direction parallel with the channel <NUM>. If the impinger <NUM> were not present, the parallel force could pull the cam lobe <NUM> and cause rotation of rotatable member <NUM> until the cam lobe <NUM> no longer locked the lead <NUM> in place.

In another variation of spring <NUM>, intermediary impinger <NUM> has an "X"-shaped protrusion <NUM>, which when cam lobe <NUM> engages contact surface <NUM>, protrusion <NUM> extends toward channel <NUM> and engages electrical lead <NUM>. Protrusion <NUM> may be configured to have any type of structure or include a plurality of discontinuous projections.

<FIG> illustrate a process of insertion and retention of an electrical lead within an IMD utilizing a slider and rotatable member. Electrical lead <NUM> is shown being inserted within channel <NUM> in the example <FIG> (see state <NUM> <FIG>).

With reference to <FIG>, lead <NUM> is fully inserted within channel <NUM>. With reference to <FIG> in which the lead is fully inserted into channel <NUM>, an implanting physician can engage an Allen wrench in hexagonal indentation <NUM> and begin turning hex head rotatable member <NUM> clockwise (see state <NUM><NUM> <FIG>). Rotation of rotatable member <NUM> causes cam lobe <NUM> to contact and push slider <NUM> towards the lead <NUM> in channel <NUM> in. Slider <NUM> moves toward lead <NUM> in chamber <NUM>, which is shown by cam lobe <NUM> moving away from retraction member <NUM>.

With reference to <FIG>, hex head rotatable member <NUM> continues to move in a clockwise direction and now cam lobe corner <NUM> engages slider center portion <NUM> and applies a force to slider <NUM> in the direction of channel <NUM> to push slider <NUM> towards channel <NUM> and the lead <NUM> so slider protrusion <NUM> begins to engage the electrical lead <NUM> (see state <NUM> at <FIG>).

With reference to <FIG>, hex head rotatable member <NUM> continues to move in a clockwise direction and in <FIG> is in a "locked position", where the substantially planar surface <NUM> of cam lobe <NUM> is substantially parallel with the substantially planar surface <NUM> of slider protrusion <NUM> (see state <NUM> <FIG>). With reference to <FIG>, if the implanting physician keeps rotating the hex head rotatable member <NUM> past the "locked position," cam lobe <NUM> will engage cam stop <NUM>. Slider <NUM> is still holding the electrical lead <NUM> even though the implanting physician has rotated past the "locked position. " The lead <NUM> will likely push back against the slider <NUM>, which would center the cam lobe <NUM> again on the slider <NUM> to the equilibrium of the "locked position" of <FIG> which has a predetermined amount of force and pressure against the lead <NUM> for retention.

In some examples, a lead may need to be removed from a medical device. As shown in <FIG>, the implanting physician may release the electrical lead <NUM> from channel <NUM> by using an Allen wrench again to rotate hex head rotatable member <NUM> in a counterclockwise direction. As shown in <FIG>, cam lobe <NUM> is rotated away from lead <NUM> and is now facing slider second end <NUM> (see state <NUM> in <FIG>). In <FIG> as the implanting physician keeps rotating hex head rotatable member <NUM>, cam lobe corner <NUM> engages retraction member <NUM>. As the implanting physician keeps rotating the rotatable member <NUM>, cam lobe corner <NUM> pushes against the retraction member <NUM> to slide the slider <NUM> in a direction away from channel <NUM> and electrical lead <NUM> (see state <NUM> in <FIG>). Therefore, pulling slider <NUM> away from the lead <NUM> may overcome tissue ingress or other frictional forces otherwise holding the electrical lead <NUM> within the channel <NUM>. Once the slider <NUM> is pulled away from electrical lead <NUM>, then the implanting physician can remove electrical lead <NUM> from channel <NUM> (see state <NUM> of <FIG>).

<FIG> are conceptual diagrams illustrating an example slider device for securing a medical lead to an IMD with a rotatable member. Sliders <NUM>, <NUM>, <NUM> and <NUM> all represent various examples of sliders which could be used to retain an implantable lead within a medical device in use with a rotatable member. Each of the slider protrusions for each of sliders <NUM>, <NUM>, <NUM> and <NUM> all provide unique differences all depending on the desired hold on the implantable lead or for the application the implantable lead is being used.

Slider protrusion <NUM> shows an elongated concave structure. Slider protrusion <NUM> allows the slider <NUM><NUM> to better accept the implantable lead as the elongated concave structure is almost the same shape as out outer shell of an implantable lead. Thus, less force to placed upon an implantable lead and less risk of deformation of the implantable lead is realized as there are no pointed protruding surfaces in contact with the implantable lead.

Slide protrusion <NUM> shows a dual ripple structure. Slider <NUM> can localize the force applied to an implantable lead to two spots. Thus, the force exerted on the implantable lead would be localized to two spots. This is a variation on slide protrusions <NUM> and <NUM> which provide a distribution of the forces along the protrusions <NUM> and <NUM>. For example, slider protrusion <NUM> has a rounded edge and thus the force would be distributed along the slider protrusion with most of the force coming from the largest extending radius, which is in the middle of the slider protrusion. For the slider protrusion <NUM>, the protrusion <NUM> is substantially flat, as discussed above, so the force is distributed equally along protrusion <NUM>.

For example, various aspects of the described techniques may be implemented within one or more processors or processing circuitry, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term "processing circuitry" or "processing circuitry" may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of this disclosure.

In addition, any of the described units, circuits or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as circuits or units is intended to highlight different functional aspects and does not necessarily imply such circuits or units must be realized by separate hardware or software components. Rather, functionality associated with one or more circuits or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components.

The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions described as non-transitory media. Instructions embedded or encoded in a computer-readable storage medium may cause a programmable processing circuitry, or other processing circuitry, to perform the method, e.g., when the instructions are executed. Computer readable storage media may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.

Claim 1:
A medical device comprising:
a housing defining a channel configured to receive an electrical lead; and
a rotatable member (<NUM>, <NUM>) defining a longitudinal axis (<NUM>) about which the rotatable member (<NUM>, <NUM>) is configured to rotate,
characterized in that the rotatable member (<NUM>, <NUM>) defines:
an outer surface having a first radius from the longitudinal axis (<NUM>); and
a cam lobe (<NUM>) extending farther from the longitudinal axis (<NUM>) than the first radius of the outer surface, the cam lobe (<NUM>) defining a substantially planar surface (<NUM>) parallel to the longitudinal axis (<NUM>), wherein the substantially planar surface (<NUM>) of the cam lobe (<NUM>) is configured to retain the electrical lead within the channel.